Backyard Toxicology

Transcription

Backyard Toxicology

Backyard Toxicology
Overview of the Course
Toxicology is all around us, it’s constantly in the news, and toxins affect us on a day to day
basis. In New York City, this is a particularly meaningful subject because one in four New
Yorkers lives within a mile of a state Superfund site. In some areas of the Bronx, twenty-five
percent of children suffer from asthma as a result of air toxins. These issues are on the minds of
high school students, and make toxicology an appealing subject.
Backyard Toxicology is a course designed to develop the critical thinking and scientific writing
skills necessary to bridge the gap between Regents-level science and college-level science
courses. The course was designed based on personal observations from a Regents Chemistry
course comprised of Einstein* students. The idea was to create a course that will prepare
students for any college-level science course, rather than focusing on a specific subject matter.
The course uses an interdisciplinary subject as a way of exposing students to the scientific
thought process. The course synthesizes the students’ existing knowledge of biology and
chemistry concepts and then integrates these basic concepts with critical reading of research
articles and authentic toxicology research.
Goals and Objectives
The curriculum for Backyard Toxicology is based on the CREATE method developed by Sally
Hoskins. The course is designed to make scientific writing and research accessible to students,
allowing them to think critically about research. During the course of reading scientific articles,
the students are pushed to understand core concepts in Toxicology and make connections
between new concepts and even other disciplines of science. Harnessing their new understanding
of toxicology research, students then design and conduct their own experiments.
Organization of the Course
In the first Unit of the course, students read a series of three articles from a single lab, following
the course of their experiments from one to the next. By breaking the articles down into
individual components, they become accessible to the students. The use of concept mapping and
cartooning allows students to form connections between key concepts in the paper and make the
complicated scientific methods more accessible. Students then analyze the data collected by the
researchers, figure-by-figure and table-by-table, empowering the students to think critically
about data and research. They develop their own hypotheses for the published figures and draw
their own conclusions about the data before comparing what they have concluded to the real
conclusions of the researchers. The students then propose the next experiment. Review panels
consisting of groups develop criteria for successful projects and select a project from the
proposals of their peers. The students then see the next experiment the researchers actually did
and the process repeats itself two more times. The timing of this unit is flexible, and the
progression should flow with the class. Articles can be added or removed to adjust for a fast or
slow moving class.
Unit two is the experimental unit of the course. The students are challenged with the task of
transforming their understanding of toxicology into authentic toxicology research. Students are
first introduced to the concept of serial dilutions, a topic generally regarded as challenging in
college Chemistry and Molecular Biology. Students utilize this new skill in a lab testing the
effects of commonly encountered chemicals (nicotine, caffeine and alcohol) on California
Blackworms. Finally, students prepare proposals for an experiment, and like the CREATE
method, student-comprised panels select the best proposal. Each group then acts as a research
team and conducts the experiment selected.
There are daily assignments in the course that will allow the instructor to gauge students’
progress. In addition, there are in depth group discussions, facilitated by instructors that
challenge the students push the boundaries of their knowledge and empower them to think
critically about science. Students are asked to express their ideas in different formats which help
build skills that are relevant in today’s scientific community.
Course Contents
Unit One – CREATE Toxicology
Unit Two – Independent Toxicology Research
Course Materials
Articles
• Bozic, J., DiCesare, J., Wells, H., Abramson, C.I. 2007. Ethanol levels in honeybee
hemolymph resulting from alcohol ingestion. Alcohol (41): 281-284.
• Bozic, J., Abramson, C.I., Bedencic, M. 2006. Reduced ability of ethanol drinkers for
social communication in honeybees (Apis mellifera carnica Poll.). Alcohol (38):179-183.
• Mixson, T.A., Abramson, C.I., Bozic, J. 2010. The behavior and social communication of
honey bees (Apis mellifera carnica Poll.) under the influence of alcohol. Psychological
Report 106(3):701-717.
Analysis Template
Toxicants and Worms Packet
Credits
Lauren Esposito was a fellow in the CASE GK-12 program from 2008-2010, is a current College
NOW fellow and doctoral candidate in Biology at CUNY. Her research, based out of the
American Museum of Natural History is on scorpions, an animal notorious for toxins. This
course was developed using lesson plans written by Susan Conklin and the Society of
Toxicology, and the CREATE methodology developed by Sally G. Hoskins, Leslie M. Stevens,
and Ross H. Nehm.
Unit One – CREATE Toxicology
This unit introduces students to the field of toxicology by exploring a series of three papers
investigating the effects of ethanol on honeybees. Teachers are strongly urged to read the article
““But if it’s in the newspaper, doesn’t that mean it’s true?” Developing critical reading and
analysis skills by analyzing newspaper science with C.R.E.A.T.E.” by Sally G. Hoskins
(American Biology Teacher 72(7): 415–420) before beginning this unit. The methodology
created by Dr. Hoskins is the cornerstone of this unit, and teachers should be familiar with it for
this course to be successful.
Total Time Allotment – 50 hours
Goals / Objectives – Students will:
• Become familiar with toxicology terminology
• Learn how to read scientific literature
• Learn how to interpret results and data from scientific studies
• Become objective participants in the scientific process
Materials –
1. Journal articles (3)
2. Vocabulary notebook
3. Analysis Template
4. Markers, poster paper, white paper
5. Toxicants and Worms Lab Packet, California blackworms, recovery containers for
blackworms (petri dishes), disposable Beral pipettes (with tips cut off) or eyedroppers, 4
chambers per group (petri dishes), distilled water, filter paper, toxicant solutions, waste
beaker, probes, black permanent marker
Activity #1 – Blackworm Lab 1
This is the first day and first lab of the course. It is intended to be an inquiry lab, where the
students are immediately immersed into the science of toxicology through an authentic
toxicology investigation. This lab looks at the effects of ethanol on California blackworms.
Activity #2 – Article 1 Concept Mapping
This activity begins as a post-lab exercise from Activity 1. It then transfers what the students
have learned about concept mapping to reading scientific articles.
Activity #3 – Read
This activity continues breaking down Article 1 into accessible components. This activity tackles
the results and methods sections in the form of cartoons and captions.
Activity #4 - Elucidate the Hypothesis
This activity continues breaking down Article 1 into accessible components. Here students use
all the interpretive work they have done on the article sections to figure out what the actual
hypothesis (or hypotheses) being tested is.
Activity #5 – Analyze and Interpret the Data
This activity continues to analyze Article 1. Here students look at the data and determine for
themselves what is it saying, forming their own conclusions about the research. This step is very
enabling. It transforms the article from something that is taken as scientific fact because it has
been published, to something that is simply one person’s (or a few people’s) point of view. The
students will realize that they can be participators in science rather than being passive observers.
Activity #6 – Think of the Next Experiment
This activity is a follow up to Article 1. Here students think about what the next step from this
research is. They design an experiment that they feel would build on the research from Article 1
to ask a new question or test a different hypothesis. They then form Review Panels and review
all of the proposals created by the students. This is similar to how funding agencies and journal
reviewers operate in the world science research. The students are tasked with forming criteria
and selecting the best proposal.
This activity is a follow up to Activity 1. Here students do the next step in the experiments to
determine of the effects of toxicants on blackworms. This time after the experiments are
concluded the students think of the next experiment and their peers review the proposals, like
they did in Activity 6. The concept mapping and research proposal skills are reinforced in an
authentic experiment.
Activity #8 – Article 2
This activity is a repeat of Activities 2-6 using the second in a series of articles on the effects of
ethanol on honeybees, written by a single research group. The goal is to scaffold the skills of
CREATE while allowing the students to see the actual progression of scientific research in a
laboratory.
This activity is a follow up to Activities 1 and 7. Here students go on to the next step in the
blackworm experiments, and determine of the effects of caffeine. As in Activity 7, after the
experiments are concluded the students think of the next experiment and their peers review the
proposals. The concept mapping and research proposal skills are again reinforced in an authentic
experiment.
Activity #10 – Article 3
This activity is a repeat of Activities 2-6 using the third in a series of articles on the effects of
ethanol on honeybees, written by a single research group. The goal is to scaffold the skills of
CREATE while allowing the students to see the actual progression of scientific research in a
laboratory.
Unit Two – Toxicology Research
In unit two, the students will take what they have already learned about Toxicology, add some
practical lab skills, and combine them to design and conduct an experiment of their own.
Total Time Allotment – 30 hours
Goals / Objectives – Students will:
• Learn to work as a research team
• Learn how to perform serial dilutions
• Learn how to design and conduct their own experiment
• Learn how to present scientific results to their peers
Materials
• Lab Notebooks
• CuSO4, H20, Scale, Graduated cylinder, Test tubes, Pipettes, Stirring rods, Volumetric
flask
• Materials as needed by students for Independent Projects
Activity #11 – CuSO4 Serial Dilutions
This activity is an essential skill for toxicological research. The activity is simply intended to
serve as a skill builder for the subsequent activity. Students should learn to successfully make
serial dilutions of a solution.
Activity #12 – Experiment Proposals
This activity begins the second phase of the course: CREATE research. Students will propose
their own research projects based on the articles they have read and experiments they have
performed in class. The class will then form Review Panels and each panel will develop criteria
and then select the best project from another group.
Activity #3 – Research Projects
This activity continues the second phase of the course: CREATE research. Students will conduct
the Panel selected experiments they proposed in Activity 12. Before beginning their research,
students must each summarize and present an article to their group. They must then write an
introduction section to be submitted to the instructor along with their supplies ‘order’ for their
experiment.
Activity #4 - Reporting Results
Students should draw from their knowledge of the articles they read during the CREATE process
to create appropriate tables and figures of their results. Conclusions should be drawn from the
results just as in the articles with the CREATE method. Each group will then present their
projects to the class.
Backyard Toxicology
Spring, 2008
Meister Hall, Room G03C
Mondays and Wednesdays: 4:30- 6:00 PM
Instructor: Lauren Esposito
E-mail: [email protected]
Office Hours: After Class or Scheduled by Appointment
Phone: (212) 769-5614
I. Rationale:
Toxins are all around us, in the air we breathe and the food we eat. Toxicology, the study of how toxins
interact with organisms, involves aspects of physics, biology, chemistry, and geology. During this course
you will be introduced to Toxicology through scientific literature. You will then use what you have learned
to conduct your own research project and design a scientific experiment. This course will show you how
to make the connections between learning about science, thinking about science and doing science.
II. Course Aims and Objectives:
Aims
This course will help you prepare for advanced courses in all disciplines of science by allowing you to
start thinking about science as a researcher rather than memorization of terms and concepts. By
“thinking like a toxicologist”, you will build skills to help you succeed in any college-level class.
Specific Learning Objectives:
The goal of this course is to read scientific literature, design a toxicology experiment, conduct the
experiment, analyze the results, and present the findings in a scientific format to your peers.
By the end of this course, students will:
Understand what toxicology is and how it is connected to other science disciplines, themselves and their
environment.
Learn how to actively read scientific articles and form conclusions from data presented.
Learn how to propose research projects based on previous experiments.
Learn how to perform serial dilutions of chemicals in a lab using beakers and graduated cylinders.
Understand why every step of the scientific process is critical to evaluating the success of scientific
experimentation.
Learn how to present scientific information so that it can be evaluated and replicated by other scientists.
III. Format and Procedures:
Group work: Most of the assignments for this class will be done in groups. ALL GROUP MEMBERS
MUST BE ABLE TO SHOW EVIDENCE THAT THEY PARTICIPATED IN ASSIGNEMENTS. The work is
expected to be evenly divided. In the event that one member of the group is not contributing, she or he
will receive a zero for that assignment.
Lectures: This course will not include any traditional lectures! Every class requires active participation by
every person.
Article readings: Three articles will be read during this course. Each requires that you read and analyze
each section. Some of this must be done at home, and it is critical that you come to class prepared or you
will negatively affect the grades of all your group members.
Labs: Labs will be performed in groups throughout this course. Lab Safety rules and procedures are to be
followed AT ALL TIMES! The lab will typically begin with a brief discussion of the lab activity by the
professor. The group will designate ONE “materials” person to collect the necessary materials. Everyone
must participate in every lab, and each person must record notes in their own lab notebook. The group is
responsible for cleaning their lab station when the experiment is complete, and the “materials” person
must return all the equipment.
Notebooks: Vocabulary notebooks should be kept with definitions of unknown terms from the articles.
They will be turned in at the end of the semester for a grade, so it is important to make sure they contain
entries.
Research: For the final experiment, each student must find, read and summarize at least 1 SCIENTIFIC
reference to contribute to their group. The experiments will require organization, cooperation and
participation of all group members to be successful. A successful project must have all components: a
summarized article for each member of the group, an introduction, a materials list, a cartooned methods
section, a hypothesis, data tables, results tables and figures, a conclusion, and a list of references.
Additionally, each group must design and carry out a scientific experiment.
Presentations: This course will end in a presentation of the results of your experiments. Each group will
make and present a research poster. Every group member must participate in both the poster and the
presentation. The format for the poster will be discussed in class.
IV. My Assumptions
“The important thing in science is not so much to obtain new facts as to discover new ways of thinking
about them.” ~William Lawrence Bragg
This class is intended to help you to succeed not only as a toxicologist, but in any field. By integrating
things that you learn in class with actual experiments, you apply the things that you learn rather than
simply memorizing them. Often, there is a disjunction between things taught in the classroom and their
actual uses in the real world. Understanding that the things we learn about are relevant to our lives is an
important lesson that brings greater meaning to our studies.
V. Course Requirements:
1. Class attendance and participation policy:
Every student must come to each class and be ON TIME. In the event you are absent, you must
bring a note from a doctor or health professional. Unexcused absences will NOT be tolerated, and you
will receive a zero for any assignments or quizzes that day. Please contact me in advance if you need to
be absent due to a conflict. Make-up tests must be scheduled IN ADVANCE. Every student is expected
to participate in every class. Come prepared, and ready to learn! You are allowed a maximum of three
(3) absences for the semester whether they are excused or unexcused. If you miss more than
three classes you will be removed from the class and receive a “WU” which is calculated as an
“F” in your college GPA.
2. Course readings:
Articles will be handed out in class.
3. Assignments: Many of the assignments for this course will be handed in as a group. Everyone is
expected to contribute to the group assignment. Each individual must be prepared to show proof of their
contribution. You must come to class with all of your assignments, either individual or group, completed
and ready to hand in.
VI. Grading Procedures: Grades will be based on:
1. Participation 33.3%
2. Major Assignments (Labs, Article assignments) 33.3%
3. Final Experiment and Presentation 33.3%
VII. Academic Integrity
Each student in this course is expected to abide by the Code of Academic Integrity. This means that any
work submitted by a student in this course for academic credit will be the student's own work, and cannot
be copied from any other work without the proper citation. Cheating will not be tolerated, any student
caught cheating will be referred to the Office of the Vice President for Student Affairs for disciplinary
action.
VIII. Tentative Course Schedule:
Date
Topics
Materials
Assignments
25-Feb
Toxicology
Concept Map
Syllabus
HW: Familiarize yourself with the class policies
27-Feb
Blackworm
Lab 1
Blackworm Lab Packet
HW: Finish answering lab questions
3- Mar
Concept
Mapping
Article 1 Introduction
HW: Look up term definitions
5-Mar
Concept
Mapping ctd.
10-Mar
Reading the
Results
Article 1 Methods &
Results sections
12-Mar
Reading the
Results ctd.
Article 1 Methods &
Results sections
HW: Look up term definitions, work on table and figure
annotations.
17-Mar
Elucidate the
Hypothesis
Article 1 Methods &
Results sections
HW: None!
19-Mar
Analyze and
Interpret Data
24-Mar
26-Mar
31-Mar
2-Apr
Analyze and
Interpret Data
ctd.
Think of the
next
Experiment
Blackworm
Lab 2
Blackworm
Lab 2 ctd.
Article 1, all sections;
CREATE analysis
template
Article 1, all sections;
CREATE analysis
template
Research Proposals
Blackworm Lab Packet,
Lab 1
Lab 1
HW: Complete analysis templates
HW: Cartoon the next experiment
HW: None!
HW: Read Article 2 Introduction
7-Apr
Concept
Mapping
HW: Read Article 2 Results and Methods
9, 14Apr
Reading the
Results
Article 2 Methods &
Results sections
HW: Look up term definitions, work on cartoons, table and
figure legends, table and figure annotations
16-Apr
Elucidate the
Hypothesis
Article 2 Methods and
Results Sections
HW: Complete CREATE analysis templates
21-Apr
Analyze and
Interpret Data
Article 2- all sections,
CREATE analysis
templates
HW: Read discussion section
23, 28
Apr
NO CLASS!!
30-Apr
Analyze and
Interpret Data
CREATE analysis
templates
5-May
Think of the
Next
Experiment
Research Proposals
HW: None!
7-May
Blackworm
Lab 3
Lab 1, Lab 2
9-May
Blackworm
Lab 3 ctd.
Lab 1, Lab 2
HW: Read Article 3 Introduction
12-May
Concept
Mapping
HW: Read Article 3 Results and Methods
14-May
Reading the
Results
Article 3 Methods &
Results sections
HW: Look up term definitions, work on cartoons, table and
figure legends, table and figure annotations
19-May
Elucidate the
Hypothesis
21-May
Analyze and
Interpret Data
Article 3 Methods and
Results Sections
CREATE analysis
templates
26-May
Think of the
Next
Experiment
Research Proposals
HW: None!
28-May
Serial Dilutions
Lab Materials
HW: Think about toxicants in your life
2-June
Proposals
Labs, Articles
HW: Cartoon a research proposal, write hypothesis
4-June
Review Panels
Research Proposals
HW: Find, read, summarize an article relevant to your project.
9-June
Research
Projects
Research Proposals,
Article summaries
HW: Complete Introduction, lab order, data sheets
11, 16,
18, 23
June
Research
Projects
Research projects
materials
HW: Make Tables, Figures, write Conclusion, make a list of
references, prepare presentation
Presentation
Research Presentations
25June
Spring Break
HW: Complete CREATE analysis templates, Read discussion
Adv Physiol Educ 33: 17–20, 2009;
doi:10.1152/advan.90184.2008.
A Personal View
Learning our L.I.M.I.T.S.: less is more in teaching science
Sally G. Hoskins1 and Leslie M. Stevens2
1
Department of Biology and the Graduate Center, City College of the City University of New York, New York, New York;
and 2Section of Molecular Cell and Developmental Biology, University of Texas, Austin, Texas
Submitted 3 September 2008; accepted in final form 21 November 2008
primary literature; undergraduate; nature of science
undergraduate cell biology some 25 years ago,
the 1-semester lecture course was packed with information.
Cell structure, gene expression, membrane proteins–all these
hot topics were covered in great detail. We finished the course
confident we had learned a lot, or at least committed a great
deal of cell biology to memory. But that was then. The past 3
decades have seen an explosion of biological discovery, with
methodological breakthroughs allowing the analysis of cellular
and genetic mechanisms in unprecedented detail. Twenty-first
century biologists have a rapidly deepening understanding of
the molecular basis of evolution, development, and disease,
and the recent emergence of the field of genomics has set the
stage for continued exponential progress in this century. Much
of what we teach now was discovered long after we received
our PhDs.
The semester, however, is still 14 wk long, and while some
of the new findings have replaced the content that we learned
in college, a fair amount of the “old” knowledge has held up.
If we try to cover that material while adding highlights of the
past few decades, we find ourselves packing some 40 wk worth
of information into a single semester. We hope our readers will
agree that teaching, and especially learning, that amount of
material is impossible in a single course. Furthermore, an
intense focus on transmitting content is completely at odds
with the recommendations of science education reform panels,
which encourage us to foster scientific thinking in the classroom (12–14, 16).
WHEN WE TOOK
Address for reprint requests and other correspondence: S. G. Hoskins, Dept.
of Biology, City College, City Univ. of New York, Marshak 607, Convent
Ave. at 138th St., New York, NY 10031 (e-mail: [email protected]).
This situation has serious consequences. Research published
a decade ago showed that undergraduates drop out of Biology
majors largely due to a sense of being “overwhelmed” by
detailed and “boring” content (15), an unfortunate situation
that persists today (6). Despite the growth in biomedical
research in the United States, the fraction of American undergraduate students who undertake graduate training in biology is
declining (10). College biology teaching clearly needs to
change (1, 7, 11, 17). But how? Most professors have much
more on their minds than science education. Tenure and
promotion are largely tied to “productivity”–a measure of grant
dollars and published research–while teaching expertise rarely
factors into the equation. However, only a tiny proportion of
first-time grant applications are funded, requiring time-consuming multiple submissions for virtually every grant awarded.
Under these circumstances, why would faculty members
change the way they teach, especially now that the Instructor’s
Version of the textbook comes with handy PowerPoint slides
and test banks?
We suggest that by adopting a “less is more” philosophy and
limiting the quantity of information they try to impart, physiology faculty members will improve both their own experience
in the classroom and their students’ understanding of physiology–the field, not just the facts. We used this philosophy in
designing and evaluating a new upper-level biology course for
undergraduates focused on journal articles rather than textbooks [see Ref. 8 for details of the approach and assessment
data and Ref. 9 for more on adapting the “CREATE” (for
Consider, Read, Elucidate the hypotheses, Analyze and interpret the data, and Think of the next Experiment) approach to
the classroom]. Primary literature brings the reader inside the
1043-4046/09 $8.00 Copyright © 2009 The American Physiological Society
17
Downloaded from ajpadvan.physiology.org on May 18, 2010
Hoskins SG, Stevens LM. Learning our L.I.M.I.T.S.: less is more in teaching
science. Adv Physiol Educ 33: 17–20, 2009; doi:10.1152/advan.90184.2008.—The
rapid and accelerating pace of change in physiology and cell biology, along with the
easy access to huge amounts of content, have altered the playing field for science
students, yet most students are still mainly taught from textbooks. Of necessity,
textbooks are usually broad in scope, cover topics much more superficially than do
journal articles, and present the scientific process as a linear string of successful
experiments, largely ignoring the reality of rejected hypotheses, unanticipated
discoveries, or surprising findings that may shift paradigms. We suggest that a more
narrow focus on scientific thinking, using a new method for reading a series of
journal articles that track the evolution of a single project over a period of years, can
more realistically convey the excitement and challenges of research science and
perhaps stimulate some students to consider research careers for themselves. Our
approach, termed “CREATE” (for Consider, Read, Elucidate hypotheses, Analyze
data, and Think of the next Experiment), has proven successful at both demystifying the scientific literature and humanizing science/scientists in undergraduate
biology courses (8), and we suggest that it could be profitably expanded to
physiology courses.
A Personal View
18
LESS IS MORE IN TEACHING SCIENCE
making use of their advanced training and reducing the amount
of preclass preparation required.
In the CREATE classroom, less is more. We initially withhold article titles, abstracts, and discussion sections and provide only the introduction, methods, and results pages for
article 1 of the four-article series, challenging students to
grapple directly with the data, analyzing and interpreting the
findings as if they had been generated in the students’ own
laboratories. This intensive encounter with primary literature is
the first time many students have been encouraged to delve
beyond textbook summaries to the nuts and bolts of scientific
discovery. After the first article has been fully analyzed in
class, and before seeing what experiments were in fact done
next by the team of researchers, each student designs two
possible “next experiments” to carry out in the system. The
class then compares the student-designed experiments and
debates possible research directions for the project in an
exercise that models the decision-making process typical of
bona fide scientific grant panels. The analysis process repeats
with each article in the series.
Many faculty members are reluctant to change what they do
in the classroom (typically lecture) for fear that taking time for
class discussion will result in less content being covered during
the semester. We find that in regard to coverage of content, less
is plenty in the CREATE classroom. To read and understand
Table 1. Summary of CREATE tools
CREATE Classroom Tool
Using the Tool Encourages Students to:
Concept mapping
●
●
●
Relate old and new knowledge
Define what they do and don’t know about a topic
Review to fill gaps in knowledge
Cartooning
●
●
●
●
Visualize the experiments by representing “what went on in the laboratory”
Link specific methods to specific data
Triangulate information in methods/figure or table legends/narratives
Construct a context for the data
Elucidating hypotheses
●
Define, in their own words, the question being asked or hypothesis being tested in
experiments related to each figure or table
Annotating figures
●
Actively engage with data
Determine the significance of each figure
Closely read figure legends and narratives
Prepare for in-class analysis of the data’s significance
●
●
●
Analyzing data using templates
●
●
●
●
Determine the logic of each experiment
Define controls and determine their role
Relate data presented to results derived
Debate the significance of the data, defend their own ideas, and intelligently
criticize the authors’ interpretations
Designing a followup experiment
●
●
●
Recognize research as a neverending process
Exercise creativity in experimental design
Consider that multiple options exist; science is not necessarily linear and predictable
Grant panel exercise
●
●
●
●
Consider how research funding decisions are made
Use critical analysis to rank student-designed experiments
Develop verbal communication abilities by pitching/defending particular
experiments
Learn to work in small groups and reach a consensus
●
●
●
●
See scientists as humans much like themselves, not stereotypes of pop culture
Make personal connections to research/researchers
Get their own questions answered
Recognize the diversity of personalities that can all be “scientists”
E-mail interviews of article authors
CREATE stands for for Consider, Read, Elucidate hypotheses, Analyze data, and Think of the next Experiment. See Refs. 8 and 9 for additional information
on how these tools are used in the CREATE classroom.
Advances in Physiology Education • VOL
33 • MARCH 2009
authors’ laboratory by presenting the actual methods used and
data generated. Making sense of these data is where much of
the excitement of scientific discovery resides. Our CREATE
approach brings this excitement to the classroom. We designed
CREATE to demystify scientific literature and humanize science, with the goals of improving students’ critical thinking
ability, content understanding, attitudes toward science/scientists, and personal interest in the research process. Rather than
relying on a textbook, CREATE uses guided analysis of a
series of four journal articles, produced sequentially from a
single laboratory, to highlight the evolution of a research
project over a number of years. Students prepare for the class
at home, using an assortment of pedagogical tools (Table 1),
first to orient themselves in the topic area and define background subjects for review and then to break down the mass of
information in the article, reassemble it into component experiments, and critically interpret the data illustrated. Applying the
CREATE pedagogical tools in preparation for the class frees
students to spend their classroom time on instructor-led in-depth
discussion of the experimental findings and their implications.
We find that CREATE students are empowered by rising to the
intellectual challenge of deciphering the logic of each article
and realizing, often for the first time, that they can “think like
scientists.” At the same time, CREATE instructors are able to
run the class more like a laboratory meeting than a lecture,
A Personal View
develop a facility with data-analysis skills rather than focusing
on memorizing or engaging only superficially with content that
will rapidly age.
We evaluate students based on 1) the concept maps, cartoons, figure annotations, and other homework assigned in
preparation for class and collected in student notebook/portfolios, 2) participation in class discussion and analysis of experiments, contributions to small-group work, and participation in
grant panel debates, and 3) performance on open-book/opennotes exams. As preclass homework, students construct concept maps and cartoon experiments to define for themselves
“what went on in the laboratory” (as opposed to “what was
found,” i.e., the results presented in the figure), define hypotheses in their own words, and annotate figures. Students also
draw conclusions from the data, summarizing their interpretations on template forms of our design. The templates prompt
students to take the final step of defining control and experimental cases, determining which panels of figures or lanes on
gels, for example, should be compared directly, and coming to
their own conclusions about what the data mean. We give two
open-book/open-notes exams and twice per semester collect
and examine the notebook/portfolios in which students compile
their data analyses, homework assignments, and experiments
they designed. An example of a typical homework assignment
would be asking students to take the data from a table in one
of the articles and represent it in graphical form and then
interpret the graph that they sketched. Exam grades, notebook
grades, and class participation factor equally into the final
grades.
Keeping up with the notebook/portfolios by applying the
CREATE tools to each article is the key to student success, as
these at-home activities prepare students to think on their feet
as they critically analyze the data in class. Working through the
sequential CREATE steps demystifies the process of reading
and analyzing an article, helping students achieve fluency in
the universal language of data analysis. At the same time,
well-prepared students free faculty members from the drudgery
of describing every experimental detail, allowing the instructor
to coach students in discussion of the significance of the
findings, contributing insights and sidebar stories from their
own research experiences.
Open-book tests reflect the reality that no working biologist
we know walks into their laboratory and carries out a series of
experiments based exclusively on memorized information
without looking at any written material, logging on to a
computer, or conversing with anyone. Research science is an
open-book activity. The exam questions, often short-essay
questions or requests for critical analysis of data, reflect issues
previously discussed in class. Successful answers are ones that
demonstrate that students have the data-decoding skills and
analytical ability that lead to genuine understanding of the
article’s findings.
A unique feature of the CREATE approach is that it goes
beyond data analysis to give students insight into the personalities and motivations of researchers. Late in the semester,
students generate an e-mail survey for the articles’ authors,
posing questions aimed at providing a behind-the-scenes look
at the people behind the papers. Students’ questions range from
personal (What made you decide to become a research scientist? How do you deal with rejection of a grant or paper?) to
broader issues (Do you have to be a straight-A student to
33 • MARCH 2009
virtually any cell biology article, students must review aspects
of gene expression, immunology, cell structure, and cell signaling. Thus, students assigned a series of four 20-page articles, rather than ten to fifteen 20-page chapters of a textbook,
still integrate a great deal of content as a basis for intelligent
discussion of the data. What is different about content coverage
in the CREATE class is that it is contextual, directly related to
a particular experimental situation. For example, understanding
of methodology is reinforced by brief content reviews. A basic
method like in situ hybridization with a digoxygenin-labeled
probe detected via alkaline phosphatase histochemistry, used in
many studies for mRNA localization, can trigger a quick
review of probe production and binding (plasmids, RNA synthesis, and nucleotide specificity), bonds (covalent linkage of
digoxygenin to a nucleotide and hydrogen bonding of probe
and target nucleotides), antibody/antigen recognition (amino
acid R groups, protein shape, and hydrogen/van der Waals/
ionic bonds), the basis of specific binding, and enzyme/substrate interactions. Brief, narrowly focused reviews of content
allow the instructor to rapidly determine students’ depth of
understanding of “the basics” (information they theoretically
mastered in prerequisite courses but often don’t fully understand), fill any conceptual gaps (e.g., what, exactly, makes
antibodies “specific?”), and then return to the problem at hand:
what do we learn from the patterns of gene expression revealed
by the experiment illustrated in Fig. X?
Some in-class figure analysis focuses on canonical experimental designs seen in many studies. These include timecourse experiments, dose-response curves, controls for antibody specificity, how “n” for a study is determined, and when
or how to use statistical methods. As an example, one of our
module articles contains a figure showing the characterization
of a new bioassay for axonal growth cone collapse in response
to a topical application of ephrin. In “old-style” teaching, we
might have spent a mere 90 s on the entire figure, simply telling
the students what dose was chosen, what time point was
selected, and what controls were performed. In the CREATE
classroom, in contrast, we challenge the students to dissect
each aspect of the experiment and figure out how each of these
parameters was determined. We consider why the collapse
assay needed to be characterized empirically (i.e., you can’t
buy a commercial kit for analysis of a phenomenon you
discovered yourself) and how, specifically, the authors designed, performed, and interpreted their dose response, time
course, and antibody specificity tests. Taking time over this
figure, which is merely a precursor to the bulk of the article’s
data, helps students see how novel phenomena are actually
approached in laboratory situations. We do not expect students
to remember the particulars of this experiment long term;
rather, the next time they see a dose-response figure in a
different article, we expect they will recognize and understand
it. In this way, the CREATE method is constructivist (5),
aiming at coaching students in building their own understanding of the approaches taken in a given series of experiments. In
the CREATE classroom, more time is spent on activities at
higher levels on the Bloom scale (analyzing, debating, and
designing) than on the less cognitively challenging lower levels
(naming, classifying, and defining) typical of many lectures (3,
4). With the ongoing explosion of information in 20th–21st
century biology, we feel it important that students learn approaches that can be adapted to new information as it arises and
19
A Personal View
20
“think like a biologist/physiologist/chemist/geologist.” They
have written and rewritten manuscripts, grants, and book chapters in response to criticism from colleagues, critically analyzed numerous articles, and given talks at conferences. Professors using CREATE spend class time posing challenging
questions, moderating discussion, and guiding students in clarifying their explanations and defending their ideas. By limiting
lecture in favor of active analysis, the CREATE instructor can
devote class time to modeling the scholarly thinking characteristic of their field–something all of us already know
how to do.
ACKNOWLEDGMENTS
We thank the National Science Foundation (Grant DUE 0618536) Course,
Curriculum, and Laboratory Improvement program for support. We also thank
students of the City College of New York Bio 31206 and 355 classes for
participation (this study was approved by the City College of New York
Institional Review Board).
REFERENCES
1. Alberts B. A wakeup call for science faculty. Cell 123: 739 –741, 2005.
2. American Association for the Advancement of Science. Science for all
Americans: a Project 2061 Report on Literacy Goals in Science, Mathematics, and Technology. Washington, DC: AAAS, 1989.
3. Anderson LW, Krathwohl DR. (editors). A Taxonomy for Learning,
Reaching and Assessing: a Revision of Bloom’s Taxonomy of Educational
Objectives (complete edition). New York: Longman, 2007.
4. Bloom BS, Krathwohl DR. Taxonomy of Educational Objectives: the
Classification of Educational Goals, by a Committee of College and
University Examiners. Handbook 1: Cognitive Domain. New York: Longman, 1956.
5. Brooks J, Brooks M. The Case for Constructivist Classrooms. Alexandria, VA: Association for Supervision and Curriculum Development,
1993.
6. Cech T, Kennedy D. Doing more for Kate. Science 310: 1741, 2005.
7. Handlesman J, Ebert-May D, Beichner R, Bruns P, Chang A, DeHaan
R, Gentile J, Lauffer S, Tighlman S, Wood W. Scientific teaching.
Science 304: 521–522, 2004.
8. Hoskins S, Stevens L, Nehm R. Selective use of primary literature
transforms the classroom into a virtual laboratory. Genetics 176: 1381–
1389, 2007.
9. Hoskins S. Using a paradigm shift to teach neurobiology and the nature of
science–a C.R.E.A.T.E.-based approach. J Undergrad Neurosci Educ 6:
A40 –A52, 2008.
10. Kennedy D. Science teaching roundup. Science 317: 17, 2007.
11. Knight J, Wood W. Teaching more by lecturing less. Cell Biol Educ 4:
298 –310, 2005.
12. National Research Council. National Science Education Standards.
Washington, DC: National Academies, 1996.
13. National Research Council. Inquiry and the National Science Education
Standards: a Guide for Teaching and Learning. Washington, DC: National Academies, 2000.
14. National Research Council. BIO 2010: Transforming Undergraduate
Education for Future Research Biologists. Washington, DC: National
Academies, 2003.
15. Seymour E, Hewett N. Talking about Leaving: Why Undergraduates
Leave the Sciences. Boulder, CO: Westview, 1997.
16. Siebert E, McIntosh S. College Pathways to the Science Education
Standards. Arlington, VA: National Science Teachers Association, 2001.
17. Steitz J. Commentary: Bio 2010 –new challenges for science educators.
Cell Biol Educ 2: 87–91, 2003.
33 • MARCH 2009
become a researcher? What would be your “dream discovery?”). The range of responses received from authors (including graduate students, postdocs, and professors) reveal “scientists” to be a varied group of individuals with diverse attitudes
and motivations, much like the students themselves. This
aspect of CREATE humanizes science, helping to dispel students’ preconceptions of scientists as antisocial geeks and of
research as an activity open only to geniuses. In addition, the
scientists who responded to our survey seemed to appreciate
this “outreach” opportunity to share their experiences with our
students.
Like the “use what you have” home decorating shows,
where the style maven, without spending a dime, reconfigures
your living room using furniture you already own, our approach allows Biology faculty members to capitalize on skills
they already have but may only rarely bring to the undergraduate classroom. Biology professors know how to design research studies, evaluate scientific findings, and run laboratory
meetings. The CREATE class takes advantage of these abilities, running as an active discussion in which methods are
deciphered, results presented, and interpretations debated. Because students prepare on their own for class, the CREATE
professor need not review every basic issue. Instead, the
professor is freed to model “thinking like a scientist”– using
sophisticated logic and data analysis skills developed over
years of study– during every class. Faculty members using
CREATE shift the challenge of learning to the students, who
construct their own understanding as they work through the
steps of the process.
Our approach aligns well with recommendations that students must take charge of their own learning (5, 16) as well as
with the call for science teaching to focus on the research
process (2, 7, 12–14, 16). CREATE faculty members do not
“describe biology” through lecture but instead establish a
classroom environment within which students discover biology
for themselves. Students decode the biological research process through their own efforts, as they work to critically
analyze, interpret, and understand data. Despite the relatively
narrow content focus, students reported that they reviewed “all
the biology and cell biology I ever learned” during the semester, said the CREATE approach helped them with scientific
reading in general, and developed more positive attitudes about
research/researchers (see Ref. 8 for student interview excerpts).
We suggest that the CREATE approach should be applicable
to all areas of biology and encourage physiology faculty
members to consider a parallel approach: limiting content,
reading related articles in sequence, withholding summaries in
favor of close analysis in class, and guiding students in getting
their own questions answered through e-mail interviews of
authors. Abandoning the lecture format may initially feel like
stepping off of a cliff, but there are practical as well as
cognitive advantages to emphasizing the analytical approaches
typical of one’s subject in the undergraduate classroom. Professors already know the logic of their discipline and how to
Copyright Ó 2007 by the Genetics Society of America
DOI: 10.1534/genetics.107.071183
Genetics Education
Innovations in Teaching and Learning Genetics
Edited by Patricia J. Pukkila
Selective Use of the Primary Literature Transforms the Classroom Into
a Virtual Laboratory
Sally G. Hoskins,*,1 Leslie M. Stevens† and Ross H. Nehm*,§
*Biology Department and The Graduate Center, The City College of the City University of New York, New York, New York 10031,
†
Section of Molecular Cell and Developmental Biology, University of Texas, Austin, Texas 78712 and §School of Education,
The City College of the City University of New York, New York, New York 10031
Manuscript received January 22, 2007
Accepted for publication April 25, 2007
ABSTRACT
CREATE (consider, read, elucidate hypotheses, analyze and interpret the data, and think of the next
experiment) is a new method for teaching science and the nature of science through primary literature.
CREATE uses a unique combination of novel pedagogical tools to guide undergraduates through analysis of
journal articles, highlighting the evolution of scientific ideas by focusing on a module of four articles from
the same laboratory. Students become fluent in the universal language of data analysis as they decipher the
figures, interpret the findings, and propose and defend further experiments to test their own hypotheses
about the system under study. At the end of the course students gain insight into the individual experiences
of article authors by reading authors’ responses to an e-mail questionnaire generated by CREATE students.
Assessment data indicate that CREATE students gain in ability to read and critically analyze scientific data, as
well as in their understanding of, and interest in, research and researchers. The CREATE approach
demystifies the process of reading a scientific article and at the same time humanizes scientists. The positive
response of students to this method suggests that it could make a significant contribution to retaining
undergraduates as science majors.
D
ESPITE the stunning success of research science
in the last half of the 20th century, there is a general consensus that the teaching of science to college
students has not made parallel gains (Chickering and
Gamson 1987; Felder 1987; American Association
for the Advancement of Science 1989; Seymour and
Hewett 1997; Glenn Commission 2000; McCray et al.
2003; National Research Council 2003; Handlesman
et al. 2004; Alberts 2005; Cech and Kennedy 2005).
Indeed, the vast increase in scientific knowledge has
potentially contributed to this problem, because instructors feel compelled to teach their students an evergrowing body of facts, and students spend more time
honing their memorization skills than they do learning
how to understand and evaluate scientific data. The
1
Corresponding author: Biology Department, The City College of New
York, Marshak Hall 607, 138th St. and Convent Ave., New York, NY 10031.
E-mail: [email protected]
Genetics 176: 1381–1389 ( July 2007)
sense of discovery felt by the scientists involved in generating this new information is unfortunately rarely communicated to undergraduates. Textbooks, for example,
typically present the growth of scientific knowledge as a
gradual increase of information over time, ignoring the
blind alleys, digressions, and unexpected findings that
in fact characterize research science. Although laboratory courses are often proposed as a complement to
lecture classes that rely on textbooks, students in lab
classes too often test hypotheses developed by others,
perform experiments for which the results are known,
and fail to become intellectually invested in their results. Many undergraduate science majors do not have
the opportunity to carry out individual laboratory research projects; even for those that do, the short-term
nature of most such projects makes it difficult for students to visualize how their work fits into the overall
scientific progress of the laboratory. As a consequence,
many undergraduates have little sense of how scientific
1382
S. G. Hoskins, L. M. Stevens and R. H. Nehm
knowledge is generated, how research projects progress
over time, or of how scientists think about and actually
do research. These factors often combine to induce
disappointed students to drop out of science majors
(Seymour and Hewett 1997; Alberts 2005; Cech and
Kennedy 2005), a problem that is exacerbated for minority students, who remain underrepresented at all levels
of academic science (National Science Foundation
2002; American Council on Education 2003; Bok
2003, Atwell 2004; total enrollment by gender/race/
ethnicity is at http://www.aamc.org/data/facts/2003/
2003school.html).
As one approach to addressing these problems, we
have developed CREATE (consider, read, elucidate hypotheses, analyze and interpret data, and think of the
next experiment), a teaching method that involves students in reading and analyzing the primary scientific
literature while simultaneously exposing them to the
intellectual excitement and challenges experienced by
the scientists who carried out the work under discussion.
In contrast to other approaches that use single or partial journal articles in the undergraduate classroom
( Janick-Buckner 1997; Herman 1999; Muench 2000;
Chowe and Drennan 2001; Klemm 2002; Herreid
2004), CREATE focuses on a sequence of articles that
reports a single line of research from one laboratory as it
developed over a period of years. In addition to promoting the development of skills that students need to
understand and analyze scientific information, the
CREATE approach introduces students to issues regarding the nature of science (Lederman 1992;
Schwartz et al. 2004) and to the creative roles played
by individuals in scientific research. CREATE is not
meant to substitute for standard lecture classes and
hands-on research projects, but rather to supplement
and complement such classes. Consistent with the recommendations of recent reform documents (American
Association for the Advancement of Science 1989;
Bransford et al. 1999; Glenn Commmission 2000;
National Research Council 1999, 2000, 2003), CREATE
involves in-depth study of a single line of scientific research, which takes advantage of the narrative nature of
science (Muench 2000; Kitchen et al. 2003). A CREATE
module consists of four articles, published in sequence
from the same lab, that are read and analyzed sequentially, providing insight into the evolution of ideas as a
project develops over time.
As outlined below, CREATE employs a unique combination of pedagogical tools and active classroom approaches that facilitate learning (Bransford et al. 1999;
Siebert and McIntosh 2001; Chin et al. 2002; Zohar
and Nemet 2002; Osborne et al. 2004). We had two
overall goals. The first was to develop each student’s
ability to think like a scientist in terms of designing experiments, analyzing and interpreting data, and critically evaluating results as well as proposed follow-up
experiments. Our second goal was to increase the stu-
dents’ interest in science and scientific research by
providing them with insights into the experiences, both
intellectual and personal, of working scientists. We
tested the ability of CREATE to meet these goals in an
elective course for juniors and seniors that required
Genetics and Cell Biology as prerequisites. The 3-credit
CREATE class met twice weekly for 75 min/class with a
single instructor (S. G. Hoskins), and the class size
ranged from 12 to 25 students in the three separate
classes (51 students overall) that are discussed in this report. We focused on a module of four articles from the
laboratory of Christine Holt (Cambridge, UK) (Nakagawa
et al. 2000; Mann et al. 2002, 2003; Williams et al. 2003)
that analyze the role of ephrin/eph-mediated signal
transduction in axon guidance during optic nerve
development. Our assessments indicate improvements
both in the ability of CREATE students to think
scientifically and in their confidence in their abilities.
Importantly, CREATE students also developed a new
appreciation for science and for scientists as individuals.
THE CREATE METHOD
In our previous experience, when students were assigned to read research articles, they often read only the
abstract, introduction, and discussion, merely glanced at
the figures and tables, and accepted the authors’ conclusions without developing a thorough understanding
of the experimental results on which they were based. To
avoid this problem, we do not initially provide CREATE
students with the articles’ titles, abstracts, discussion/
conclusion sections, or the authors’ names. Using the
specific exercises outlined below, we challenge the students to understand the methods, explain the experimental designs, and interpret the data as if they had
made these findings themselves. Class discussion focuses
on figure-by-figure data analysis and interpretation, with
the professor acting as ‘‘lab head’’ and discussion leader,
guiding students through evaluation of experiments and
in synthesis and application of scientific concepts—
higher-level cognitive activities known to facilitate understanding (Bloom et al. 1956). Mini-lectures of 10–15
min are occasionally used to review essential background
material, but most class time is spent in whole-class or
small-group discussion. After analyzing each article, the
students generate their own proposals for what the next
experiment would be if they were carrying out the research themselves. They then discuss and debate their
ideas with other students in an exercise meant to model
the peer review that real science undergoes. As the
CREATE process repeats with each module article, students experience how an actual research project develops over time. To enhance the students’ understanding
of the personal experience of scientists carrying out
research, students communicate with some of the article
authors by e-mail, in which they pose their own questions
Genetics Education
about researchers’ motivations and experiences. Sequential steps of the CREATE process are summarized below:
Consider: We explain to the students that, as they
read each article, our goal is for them to work through
the data as if they had generated it themselves. To facilitate this, they are given each section (Introduction, Results and Methods, Discussion) sequentially and they are
not provided with the title and abstract of the article nor
with the names of the authors. Although some students
may try to circumvent this process by using the Internet
to obtain the complete article prematurely, we did not
find this to be a problem in our CREATE classes. Even if
students do ‘‘look ahead,’’ it does not significantly interfere with their learning experience because most of
the CREATE activities require the students to think for
themselves.
The students are introduced to the principles of
concept mapping (Good et al. 1990; Novak 1990, 2003;
Allen and Tanner 2003). They are then assigned to
read the Introduction section of the first article and
to construct a concept map of it by defining key terms
and creating appropriate diagrammatic linkages between them. Such maps highlight the range of issues
that the article addresses and alert students to concepts
that they need to review in preparation for reading and
analyzing the article. This exercise empowers the students to take charge of their own learning (Novak and
Gowin 1984; Brooks and Brooks 1993).
Read: Students read the Methods and Results sections of the article. Then they are instructed to go
through the Results section figure by figure and, using
the information in the Methods section, ‘‘work backwards’’ from the data presented in each figure (or table)
to determine how the results were obtained, that is,
what experiment was performed. Students (1) diagram
each experiment in a cartoon format that illustrates
the methods used, (2) annotate the figures by adding
clarifying labels, and (3) write their own descriptive
titles for each cartoon and each figure. We emphasize
that the cartoons are meant to depict what was physically
done in each experiment (see Figure 1 for an example
of a CREATE student’s cartoon), not to show what the
results were or to restate what the authors said about the
experiment. We require the students to draw a sketch
for this step, rather than a flow chart. We find that
creating a visual representation of what was done in
each experiment is critical for the students’ ability to
interpret the resulting data. In the annotation step, the
students use the information from the figure legend to
instructively label each panel in the figure. They note
which panels serve as controls and which are experimental and also categorize the type of experiment
depicted, e.g., ‘‘dose-response histogram.’’ To carry out
this step, students must look closely at the figures and
their legends to determine exactly what is represented
in each panel. Finally, writing their own titles for the
figures as well as their cartoons gives the students a sense
1383
Figure 1.—Sample student cartoon. To link the information given in the Methods sections with the data represented
in figures and tables of the Results, students make sketches to
illustrate the experiments that were performed. The student
cartoon above illustrates an experiment in which mouse L
cells were transfected with frog ephrinB2 and then frog retinal explants were challenged to extend axons on membrane
carpets made from the L cells. Creating these visual representations facilitates understanding of the hands-on lab work that
led to the results reported.
of ownership of the material and can help them to distill
the essential information. For example, one student
rewrote ‘‘Ephrin-B overexpression at the chiasm induces precocious ipsilateral projections in the early
tadpole’’ as ‘‘Early Ephrin-B drives axons ipsilaterally.’’
Each of these activities promotes the development
of conceptual linkages between what was actually done
in each experiment and the data that were obtained.
These methods encourage visualization and abstraction
as well as integrative and synthetic thinking, all of which
facilitate learning (Bloom et al. 1956; Kozma and
Russell 1997; Foertsch 2000, Zull 2002; Yuretich
2004). These steps—the cartooning, annotation, and
retitling—are done by students as homework in preparation for class. Thus, students arrive in class familiar
with the article and ready to participate actively in class
discussion.
Elucidate the hypotheses: Research articles typically
involve numerous individual experiments, each of which
plays a role in the final conclusions. Introductions to
articles, however, tend to emphasize one major finding,
and the Materials and Methods sections often describe
the methods without linking them to individual figures
or tables. The students triangulate between their cartoons, annotated figures, and rewritten figure/table
titles to dissect the ‘‘anatomy’’ of the study by identifying
each individual experiment and defining the specific
hypothesis that it tested or the question that it addressed.
The student-generated hypotheses or questions are
written above the figure or table to which they apply.
1384
Analyze and interpret the data: Students analyze each
figure using CREATE analysis templates (supplemental
Figure S1 at http://www.genetics.org/supplemental/),
which build on the work done in the previous steps
and guide them in determining which panels in a
figure (or numbers in a table) should be compared
directly. As they fill in the templates, students compare
the control and experimental panels that they identified during figure annotation, relate the results to the
hypothesis or question that the experiment addresses,
and begin to draw conclusions. Students also explicitly
relate the findings to the hypotheses previously elucidated, judge how convincing they find the data to be,
and note any questions that they would like to ask the
authors. Templates filled out as homework prepare
students for active discussion of the outcomes of experiments. Templates are always used for article 1 of
the module. Some students continue to use them for
subsequent articles while others are able to generate
their own analyses after their initial experience with
the templates.
Class discussion of the articles focuses on data analysis, and the instructor runs the discussion much like a
lab meeting. Some analysis is done in small groups, with
students charged to work together and then to report
their conclusions back to the class. When all of the figures have been analyzed and thoroughly discussed in
class, students record their overall interpretations and
conclusions as a list of bulleted points—points that they
think would be worth including in a Discussion section.
Only after completing their own lists are students provided with the actual Discussion section of the article.
After reading it, they make a similar list of points based
on the authors’ conclusions. Comparing the two lists
highlights the role of interpretation in science, showing that data may be interpreted from several different or even opposing viewpoints (Germann and Aram
1996). Finally, students make a summary concept map,
this time using the articles’ figures and tables as central
concepts and creating linkages between them that indicate the logical flow of ideas in the article. After the
intense and detailed analysis of individual experiments,
this is an opportunity for the students to step back and
weave the individual parts of the article into a ‘‘big
picture.’’
Think of the next experiment: Each student imagines that he or she is an author of the article just
analyzed and asks: What experiments should be done
next? The students diagram two of their proposed
experiments in cartoons that are discussed in class. To
model the scientific peer-review process, the class collaboratively devises criteria for judging proposals and then
divides into several three- or four-person ‘‘grant panels,’’
each of which selects one of the student experiments to
‘‘fund.’’ Often, different groups choose different ‘‘best’’
experiments. Such an outcome contrasts with some
students’ preexisting views of scientific research as a
linear path with one obvious step after another. Grant
panel discussions help students hone data interpretation and verbal logic skills (Vanzee and Minstrell
1997; Marbach-Ad and Sokolove 2000; Zohar and
Nemet 2002) and foster an understanding of how
science works by modeling the discussions and debates
that are characteristic of research laboratories (Steitz
2003) and actual grant panels.
Final steps and reiteration of the CREATE process:
After the CREATE methods are applied to the first
article, the process is repeated with each additional
module article, although in these cases there is the
added excitement of discovering whether the experiments reported in the subsequent articles match any of
the students’ proposed experiments. For students who
independently had the same idea as the authors, the
experience reinforces the idea that they are learning to
think like scientists. For students who have different
‘‘next experiments,’’ the experience underscores the
idea that real projects can move in many different
directions. This realization contrasts with some students’ previously held beliefs that science is very predictable and that scientists always know what their
results will be (Table 1 and supplemental Table S1 at
http://www.genetics.org/supplemental/). Analysis of
the subsequent articles generally proceeds more rapidly because the students are now familiar with the
experimental system as well as with the CREATE tools.
Interviews with scientist–authors: At the conclusion
of the module, our first class of CREATE students prepared a survey of 12 questions (supplemental Table
S2 at http://www.genetics.org/supplemental/) that was
e-mailed to each author of the four articles, a group that
included technicians, graduate students, postdoctoral
fellows, and principal investigators. One author visited
the class and was interviewed directly in a session that
was videotaped. Subsequent CREATE student cohorts
read the e-mail interviews and viewed the videotape
generated by the first class; thus, authors were contacted
only once. CREATE students’ questions ranged from
scientific (‘‘How did you choose your research area?’’)
and ethical concerns (‘‘Have you ever encountered any
ethical issues and how were they resolved?’’) to more
personal issues (‘‘Did you ever wake up and just want to
give up? How did you deal with it?’’). The range of
responses from 10 different authors (50% response
rate) to the same questions highlighted for students that
scientists are individuals with different motivations and
goals. Especially important for our students was the realization that their previous stereotypes of scientists as
‘‘antisocial’’ and as ‘‘geniuses’’ were inaccurate (Table 1
and supplemental Table S1 at http://www.genetics.org/
supplemental/), which evoked comments such as: ‘‘I
realized ½for the first time that scientists are people like
me. . . . if I wanted to, if I worked at it . . . I could become
a scientist’’ (supplemental Table S1 at http://www.genetics.
org/supplemental/).
Genetics Education
Assessment: Many studies that describe methods for
engaging undergraduate students with the primary scientific literature have been published (see, for example,
Janick-Buckner 1997; Herman 1999; Muench 2000;
Chowe and Drennan 2001; Mangurian et al. 2001;
Klemm 2002; Herreid 2004). We did not directly compare the CREATE approach with these other methods
because we did not design CREATE solely as a method
for reading the primary literature. Instead, the CREATE
approach uses a linked sequence of articles as a portal
into the research laboratory such that the students
experience many of the cognitive activities that scientists use in their daily work. CREATE students also had
the opportunity to learn about the personal experiences
of the scientists involved in the work. Our goal was to
achieve a synergy between the intellectual and personal
aspects of research science that would enhance students’ interest in science as well as their abilities to read
and understand scientific literature. For these reasons,
we chose to use pre- and post-course testing, an established approach in science education, to determine
whether the students made gains in these specific areas
(Edwards and Fraser 1983; McMillan 1987; RuizPrimo and Shavelson 1996; Stoddart et al. 2000;
Bissell and Lemons 2006; Bok 2006).
To determine whether there were improvements in
the students’ ability to critically read and interpret data,
we administered critical thinking tests (CTTs; adapted
from http://www.flaguide.org/) pre- and post-course.
CTT questions required the use of general data analysis
skills and were not specific to the CREATE module. To
determine whether the CREATE approach facilitated
the ability of students to understand and integrate
concepts related to the module content, we carried
out pre- and post-course assessments in which students
constructed concept maps based on seed terms (Novak
2003). (Note that these assessment maps were distinct
from previously described concept maps used as learning tools in the CREATE classroom.) Finally, to explore
students’ understanding of the nature of science and
their attitudes toward science and scientists, we used
oral interviews (Glaser and Strauss 1967; Novak
1998; Ary et al. 2002) and an online, anonymous SelfAssessed Learning Gains survey (http://www.wcer.wisc.
edu/salgains/instructor/). The latter two assessments
also provided information on the students’ own perceptions of how their critical thinking and data analysis
skills had changed and gave us feedback on students’
reactions to the course format.
CREATE, in all three implementations, was demonstrated to improve students’ critical thinking skills
(Figure 2) and their ability to read/analyze scientific
literature and understand complex content (Figure 2
and supplemental Figures S2 and S3 at http://www.
genetics.org/supplemental/). Students taught using the
CREATE method self-reported increased confidence in
their reading and analysis abilities, as well as enhanced
1385
Figure 2.—Summary of results on CTT. Students who
took CREATE classes demonstrated gains in their ability to
critically analyze data and draw logical conclusions. CTTs requiring data interpretation were administered pre- and postcourse. The CTT was a 30-min closed-book activity, designed
on the basis of the Field-tested Learning Assessment Guide
(http://www.flaguide.org/), in which students read and responded to six ‘‘story problems’’ requiring them to interpret
data presented in charts or tables and explain why they did or
did not agree with the conclusions stated in the problem. This
test was not based on material covered in the CREATE modules. Horizontal bars with asterisks indicate questions on
which significant increases in numbers of logical justifications
(statements) or decreases in numbers of illogical justifications
were seen post-course, compared to pre-course, in written responses to CTT questions (***P , 0.001; **P , 0.02; *P ,
0.05; paired t-test). These data suggest that students’ critical
thinking and data analysis abilities improved during the
CREATE semester. For each question, we included only data
for students who answered the same question in both pre- and
post-tests; thus, the N is smaller for questions 4, 5, and 6. Error
bars indicate standard error. Questions 1–3, N ¼ 48; question
4, N ¼ 42; question 5, N ¼ 34; question 6, N ¼ 24. Additional
information regarding the CTT appears in the supplemental
data at http://www.genetics.org/supplemental/.
skills that transferred from the CREATE class to other
science classes (supplemental Figure S4 at http://
www.genetics.org/supplemental/). They also exhibited
improved understanding of the nature of science,
increased interest in science participation, enhanced
personal engagement with science, and more positive
views of science and scientists (Table 1; supplemental
Figure S4 and supplemental Table S1 at http://www.
genetics.org/supplemental/). Thus, CREATE students
experienced gains in both their academic skills and
their perception of the scientific enterprise.
I expected: they had a theory, they proved that theory;
that’s it. ½Now I see it’s more like a blind person
placed in a room and trying to feel around as to
what they think a structure may be; and even
when they think a structure is ‘‘that’’ they’re still
not sure as to what it is, but they can kind of come
up with what it is, based on the shape, and
touching it, and comparing it to another structure
that’s next to it. . . .(S4)
I walked away with skills that are going to help me in
every single class I take again, and even in life, really.
I feel like I can take on my own taxes this year!
½laughs Just being able to sit down and focus and not
get bogged down. (S6)
Before ½the CREATE class I used to read the entire
paper and then go to the pictures. Now. . .it’s figures
first, then text. . . . I’m more of a detective now. I
could, like, pinpoint certain words and look it
up. . . . I could find the main part of the figure. And
I wasn’t able to do that before, I would just read, to
read. . . . I would only get it ½the overall point of the
experiment or article after I read the whole paper,
and probably went through it with like, a professor
or something, or in class? But now I think I’m good
on my own. I could decipher what the message is,
on my own. (S2)
Class 1
(continued )
As far as research, I learned that one answer can lead
to so many different things, and every person has
their own ideas about where the ideas will lead. And
I thought that was like the coolest thing—you know,
you could have, like six different groups doing the
same research, and get the same result; then go in
different directions. And I thought that was
interesting, because I ½had always thought
everybody would go in the same direction. (S3)
I thought ½before from lab to lab they had to buy each
others’ things; like if I needed a knockout mouse I
would have to buy it? But it actually turned out to be a
give and take, like ‘‘my stuff is your stuff’’—I didn’t
know that. Another thing is. . .a lot of revision goes into
these papers. . . . which shows you that it’s not all cut and dried;
it’s not all clear; and that even top grade scientists can make
mistakes. . . . It’s like a circle; if those papers weren’t passed
around and read from one person to another, from one
student to another, new ideas won’t come up. . . . It’s a
network. It’s a network of thoughts. (S10)
Understanding of how scientific research is carried out
I took microbiology—we read a paper then—if I read
it again it would probably be totally different now,
with this approach. . . . If I had to do it all over again,
I’d probably want to take this course after the first
two intro courses—because it allowed me to interpret
information differently; ‘‘think outside the box’’ so to
speak. . . . This pretty much required us to do all the
work ourselves. . . .It wasn’t just a bunch of facts that
we just had to accept. We had to actually question
it. (S8)
It’s the most effective way of teaching that I’ve ever
had, especially in a science course. Because in ½real
science you’re not really given exams, and you’re not
asked, like, to memorize things—you’re asked to
analyze and understand—and I think this class really
focused on analyzing and understanding, as opposed
to memorizing. (S3)
Class 3
I had a paper for one of one of my other classes—called
Muscle and Nerve—I had to do a review paper on a
presentation I did. And ½because of the CREATE class
I have never read through papers so quickly than I did
those five papers, and I could actually sit there and say,
‘‘Oh, this makes sense; OK. This is dose response to
creatine in embryonic umbilical cords. I’m like, oh,
that was so great! I didn’t think I would apply it so
quickly . . . (S7)
Transfer of the CREATE approach to other classes
I would recommend it to every student taking a science
major or nonscience major, and I think this class
should be a prerequisite in order to graduate with
a science degree. I think it’s a very strong class that
expands all the students’ minds. . . . And I think that
this course will definitely help anyone who wants to
pursue a career a science, whatever that might be,
because it helps you really really understand what
science is about. It’s not just a textbook that you
read and memorize things; you actually learn so
much. (S1)
Reaction to the CREATE approach
Class 2
Post-course interviews: student comments about CREATE and its effect on their views of science and their own abilities
TABLE 1
1386
I myself could be a scientist now. Before I was like ‘‘½Only
some kinds of people can be scientists’’ and it has to be like
these geniuses, who were, you know, like eight times
smarter—I learned that it can be anybody. Anyone can
be a scientist; it has to do with having a passion to do
research, and just a drive, and not to get bogged down by
failed experiments and things not going right, but just to
go through a process, because there’s a thinking process
you have to go through, of elimination, and trying, and
experimenting. (S5)
I feel like this course . . . has made me become less
intimidated. . . . because these people are just like you and
I—you can sit here and wonder why the sky is blue—and
you take your question and you put it to the test. . . . This
course has definitely helped me with knowing that scientists
are just people, just like you and I. Whatever work they’re
doing. . . . I can do it myself, you know? . . . I’m not a scientist,
½but I’m contemplating if I should be! . . . I’m starting to like
research. What I love about it is the creative part of it. And
I’m questioning. . . . can I still have that while being a
medical doctor? This class has kind of changed my life in
a way. (S3)
Increased interest in becoming a scientist
I got to see they’re like everyone else. . . . Growing up, you
think of scientists as geniuses like Einstein or
whatever—but they have a job just like anyone else, and
the concepts aren’t that difficult . . . anyone could think of
another experiment. You don’t have to have a super-high
IQ. It’s just thinking up the work and being truthful with
the data and not tweaking your results to match what you
want it to be, but just coming up with a hypothesis,
running the experiments, writing the data as you see it
and trying to analyze it as best as possible. (S4)
My scope of thinking has been widened. First, I have
more ideas pulled together and I’m using my
initiative much more. And I’m being innovative
and I’m being very active; right on my feet
thinking; and I have more interest in doing the
work. My interest has been boosted up. It’s very
easy; it’s made open for me to bring out the best
out of me and then to join with others. The other
thing too; in that class we learned to work together.
We had different types of people in the groups, so
we were learning something else. In addition to
our individual capacities we were learning how to
exchange ideas with others. (S2)
Class 3
I definitely have changed my perspective of scientists. Before
I thought being a scientist was a job where you were antisocial;
cooped up in a lab, and that’s it. And I always figured people
who become scientists are not ‘‘people people,’’ and I don’t
think that any more. (S11)
Personal connection to science and scientists
You need to be skeptical in science—not just take the data
for what they say it is. A lot of times ½before, we study papers,
we just look at the discussion and the title and take that
for granted, and this class has taught us to be skeptical—to
be scientists, and look at the data and try to analyze it for
ourselves and see if we get the same conclusion that they
got . . . from the data. (S6)
Thinking like a scientist
Class 2
Representative comments of CREATE students about the CREATE approach and its effect on their views of science and their own abilities. Interviews lasting 20 min were
conducted at the end of the semester and audiotaped. Interview questions examined students’ overall reaction to the CREATE approach, whether the course had affected their
ability to ‘‘think like a scientist,’’ whether their views of science or scientists had changed over the course of the semester, whether their scientific reading skills had been affected,
and whether their confidence in their ability to participate in science research had changed. We made transcripts of the interviews from the first class and used a constant comparison approach to categorize responses on the basis of broad themes that emerged in multiple interviews (Glaser and Strauss 1967; Novak 1998; Ary et al. 2002). We then
analyzed interviews of subsequent cohorts on the basis of the similarity to or difference from the initially defined emergent categories (centered headings). The number following
each quote corresponds to a distinct student (S) participant. Class 1: n ¼ 12; class 2: n ¼ 13; class 3: n ¼ 12.
I think I’m a little bit more confident that I could
do it if I really wanted to go in that direction. I
think the human aspect of it and the way that
research is carried out by individuals, that whole
experience has changed for me. I feel that if I
wanted to do it I could. Like, there’s somany
people that help you along the way and get you
started, and just the whole thought process, to
think of experiments and to do them, is
interesting to me. (S8)
I believe scientists are people; they are like everyday
people. Anyone can be a scientist. . . . Before I used
to think that scientists were rigid people who wore
lab coats and didn’t talk to anyone ½laughs but
from the class and from the responses we got from
the e-mails I see that scientists are ‘‘people persons,’’
everyday people; meaning they didn’t have to be
super-geniuses or really up in status to become
a scientist; with connections or anything like
that. (S1)
I think the biggest, kind of like enlightenment for me
½laughs is that you can have your own ideas . . . and
you can come up with your own interpretation of
things and not necessarily be ‘‘wrong.’’ I think there
is a lot more creativity behind science than most
people are aware of. . . . Through this course, the
creativity, for me it’s been like ‘‘Wow I can really
think about these things and not just take in this data
and say ‘‘OK this is it; I can’t question it.’’ For me that
was the biggest insight. It was like ‘‘I can question it
and maybe come up with an alternate explanation.
And it might be, it might not be, but at least I’m
‘allowed’ to do so; there’s no big law against that.’’ (S12)
Class 1
(Continued)
TABLE 1
Genetics Education
1387
1388
CONCLUSIONS
To our knowledge, CREATE is the only multiply
assessed educational method shown to increase both
understanding of and interest in scientific research
among undergraduate students. In this regard it is also
notable that 64% of our CREATE students were members of minority groups that are traditionally underrepresented among students progressing on to careers in
science. We anticipate that the CREATE method will
benefit students from a variety of backgrounds, however. Our data suggest that the CREATE approach could
significantly alleviate the well-documented disengagement of many college students from science (Seymour
and Hewett 1997; National Science Foundation
2002; Alberts 2005; Cech and Kennedy 2005). It is also
important to note that the CREATE approach does not
require any significant financial expenditure and therefore will be accessible to instructors at many different
types of institutions.
We believe that the CREATE curriculum, which encourages students to think of themselves as scientists, will
complement and enhance students’ experience of traditional lecture-based science teaching and inquiry lab
classes. Although CREATE was initially developed for use
in an upper division elective course with relatively few students, we believe that elements of the CREATE method
can be effectively adapted for use in lower division and
larger science classes. The approach is adaptable to
content in any area of science, and articles can be chosen
to be accessible to students at a variety of levels. Earlier
exposure to CREATE analytical approaches may help students to develop critical analysis skills early in their college
careers so that they can benefit from them throughout
their college coursework (Braxton et al. 2000). Correspondingly, the earlier that students develop an appreciation for the creative nature of scientific investigation
and, in particular, recognize that they, too, could make
an important contribution to science, the less likely it is
that they will drop out of science majors.
In contrast to K–12 teachers, most instructors at the
college level have not had formal training in how to
teach effectively. Many faculty members in the sciences
obtain academic positions and promotions on the basis
of their research accomplishments. In this respect, we
believe that the CREATE approach can benefit instructors as well as students because, rather than requiring
instructors to learn a completely new teaching method,
it encourages faculty members to use skills that many
employ in their laboratories every day. The CREATE
class is very similar to a lab meeting in which methods
are described, results reported and analyzed, interpretations discussed, and future directions debated. In
short, by using primary literature as a portal into the
activities of working scientists, and by guiding class
discussions rather than lecturing, instructors can create
a virtual laboratory in which every student is a scientist.
We thank David Eastzer, Shubha Govind, and David Stein for their
valuable discussions and advice during the development and implementation of this project. We thank Ruth Ellen Proudfoot for advice
on statistical analyses, Christina Nadar and Arturo de Lozanne for help
with graphics, and two anonymous reviewers for insightful comments
on a previous version of the article. We also are very grateful to Carol
Mason for her participation in a group interview, to Christine Holt for
her encouragement of the project, and to all of the article authors who
responded by e-mail to our students. Finally, we thank all of the City
College of New York students who participated in the CREATE classes.
This material is based upon work supported by the National Science
Foundation (NSF) under grant no. 0311117 to S.G.H. and L.M.S. (CoPrincipal Investigators). We thank the NSF for support and the NSF
Course, Curriculum and Laboratory Improvement program officers
for helpful discussions during the development and implementation
of the CREATE project.
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Backyard Toxicology: Activity 1- Blackworm Lab 1
Activity Description: This is the first day and first lab of the
course. It is intended to be an inquiry lab, where the students
are immediately immersed into the science of toxicology
through an authentic toxicology investigation. This lab looks
at the effects of ethanol on California blackworms.
Process Skills Goals: Concept mapping,
team work, safe animal handling, data
recording, critical thinking.
Knowledge Goals: Dose-response; the
definition of toxicology and its
connections to other sciences, real
world, their own lives; how to conduct a
toxicological assay.
Estimated Length of Activity:
2 class periods (2-3 hours)
Pre-activity: Concept map the
term ‘toxicology’ as a class
on the board.
Major Assignment: Conduct a toxicological assay
of ethanol on California blackworms, draw a doseresponse curve from the data points and write a
summary of the findings.
Assessment: Non-formative- participation with the
group and class discussion
Formative- Summary of findings and doseresponse curve
Materials: Blackworm lab packet, California blackworms (available at aquarium/ pet stores
where live fish food is sold), ethanol, graduated cylinders, 5 petri dishes per group, probes
Activity Instructions:
**The teacher should prepare the ethanol concentrations according to the instructions provided
in the blackworm lab packet prior to class. It will save time if the teacher assembles the probes as
well.
Begin the class by introducing concept mapping. Write the term ‘toxicology’ on the board and
encourage the class to make connections to themselves, their environment and what they know
about toxins and environments from other classes.
Follow the lab activity instructions in the packet.
Instructor Notes
Toxicants and California Blackworms
In this investigation, participants work in groups to determine the normal behavior of
California blackworms (Lumbriculus variegatus). They then determine how various
concentrations of assigned toxicants affect the worms’ behavior. This investigation introduces
testing of potential toxicants, an important component in environmental health science.
After testing different toxicants and concentrations, participants will investigate exposure
pathways, nature of effects, acute and chronic exposure, and reversible and irreversible
effects. The participants discuss and analyze their data, observe physiological effects, and
present their findings to the class. Through extensions, participants can develop new
investigations based on their findings.
£
The activity is written for workshop participants and may need modification for
classroom use.
Suggested Background Reading
•
An Introduction to Toxicology
National Science Education Standards for Grades 5–12
Science as Inquiry
• Abilities Necessary to Do Scientific Inquiry
Conduct scientific investigations. Students conduct an investigation that tests the
behavioral effects of various concentrations of alcohol, caffeine, and nicotine on California
blackworms.
Formulate and revise scientific explanations using logic and evidence. After considering
the data while answering a series of questions and participating in group discussions,
students formulate explanations for the worms’ behavior and suggest future experiments
based on scientific knowledge, logic, and investigational evidence.
Life Science
• The Behavior of Organisms
Organisms have behavioral responses to internal changes and external stimuli. Students
recognize how organisms respond to external stimuli through exposure to environmental
changes caused by the introduction of toxicants.
Science in Personal and Social Perspectives
• Personal and Community Health
Personal choice concerning health involves multiple factors. By observing, understanding,
and discussing biological consequences of products such as alcohol and tobacco,
students will be able to make more informed decisions about personal health practices.
Risks & Choices, Center for Chemistry Education, Miami University (Ohio)
www.terrificscience.org—Permission granted to copy for classroom use only.
1
Instructor Notes
Safety
As the instructor, you are expected to provide participants with the necessary safety
equipment (including personal protective equipment such as goggles, gloves, aprons, etc.)
and appropriate safety instruction to allow them to work safely in the laboratory. Always
follow local, state, and school policies. Read and follow all precautions on labels and MSDSs
provided by the manufacturer for all chemicals used.
Materials
For Getting Ready
Per class
• materials to make a probe
§ narrow rubber bands
§ electrical tape
§ applicator stick or bamboo skewer
• containers for preparing, measuring, and storing stock solutions
• Bunsen burner or hot plate
• glass stirring rod
• distilled water or untreated spring water
• toxicants
§ 80-proof vodka (for ethanol)
§ Vivarin® (for caffeine)
§ cigarettes of regular length and strength (for nicotine)
£
For the Procedure
Per class
• California blackworms
California blackworms may be ordered from Carolina Science & Math
(800/334-5551; #B3-L412). The worms may also be available at local tropical fish
stores.
•
£
recovery container for blackworms
Per group
• disposable Beral pipets (with tips cut off) or eyedroppers
• 4 chambers
Chambers can be small weighing dishes or petri dishes placed over a white sheet of
paper. Any small, clear container that will allow at least a 1-cm depth for the
solutions will work.
•
•
•
•
distilled water
filter paper
toxicant solutions (prepared in Getting Ready)
waste beaker
2
Instructor Notes
•
•
•
probes (prepared in Getting Ready)
stopwatch or other timer
black permanent marker
Getting Ready
Solution Preparation
In each case, make the stock solution first and then use it for dilutions. Use ONLY distilled
water or spring water for making all dilutions and holding the worms. Tap water may kill
the worms because they are very sensitive to chlorine.
Ethanol
Do not use denatured ethanol, methanol, or isopropyl alcohol. Vodka is recommended
because it is clear and nearly odorless. To prepare the stock solution of ethanol, to 100 mL
80-proof vodka (40% ethanol), add distilled water to bring to a final solution volume of
400 mL (10% ethanol). Use this stock solution to prepare the following solutions:
•
•
•
Solution #1: To 5 mL stock solution, add distilled water to bring to a final solution
volume of 200 mL (0.25% ethanol).
volume of 200 mL (2.5% ethanol).
Solution #3: Measure out 200 mL stock solution (10% ethanol).
Caffeine
Vivarin is recommended as the source for caffeine rather than NoDoz® tablets, which contain
a mint flavoring. To prepare the stock solution of caffeine, place two Vivarin tablets (total
400 mg caffeine) in an Erlenmeyer flask and add distilled water to bring to a final solution
volume of 400 mL. Heat while frequently stirring to dissolve the tablets. It helps to gently
break the tablets by tapping them with a glass rod while the solution is being heated. Do
not let the solution boil. Use this stock solution to prepare the following solutions:
•
•
•
volume of 200 mL.
volume of 200 mL.
Solution #3: Measure out 200 mL stock solution.
Nicotine
Use any generic or name-brand cigarette that is regular length and strength (do not use
menthol, 100’s, or ultralights). To prepare the stock solution of nicotine, stir the tobacco
from two cigarettes (total 2.2 mg nicotine) in 500 mL very warm distilled water for
15–20 minutes. Strain or filter the solution after soaking. (You will lose about 50 mL of
solution through straining). This process makes about 450 mL (0.011 mg/mL). Use this
stock solution to prepare the following solutions:
3
Instructor Notes
•
•
•
volume of 200 mL.
volume of 200 mL.
Solution #3: Measure out 200 mL stock solution.
The intent of this investigation is to determine what behavior changes occur at different
sublethal concentrations. However, as a demonstration you may wish to expose one worm
to a double-strength alcohol solution and one to a double-strength nicotine solution. Both
of these are usually fatal.
Probes
Make probes by cutting a 2.5-cm piece of a narrow rubber band and then tape it to the end
of an applicator stick or bamboo skewer. Use electrical tape to attach the rubber band.
About half of the rubber band should hang from the end of the stick (Drewes, 1997).
Procedure Notes and Outcomes
In this investigation, participants work in collaborative groups of three or four to observe
California blackworms and establish normal behavior. This baseline observation is used for
comparison when toxicants are tested. Participants then test their worms with their assigned
toxicant: alcohol, caffeine, or nicotine. Three concentrations are used and the participants
are assigned observation criteria for the worms during the exposure. After answering a
series of questions and participating in a group discussion, participants present their data,
proper explanations, and suggest future experiments to the class.
This investigation can range from structured to open-ended, depending on the intended
grade and ability level as well as on the length of the class period and the time devoted to
the study. For instance, participants can mix their own dilutions and calculate the
concentrations, or the solutions can already be prepared. Participants can use more
concentrated stock solutions to test concentrations that determine the range for lethal,
sublethal, or no effect. Participants can also investigate the physiological effects of these
concentrated solutions on organisms. The time of exposure can be changed.
First, participants must to learn to manipulate the worms and to observe normal behaviors.
They will soon develop their own “system” for handling the worms. They could be assigned
to read the article in Carolina Tips (see References) to complete their introduction to the
worms.
For all experiments, use full-length worms that are uniform in color. Worms that are dark
with lighter sections have recently undergone regeneration and should not be used. Use
care in handling the worms with the pipet so as not to fragment them. The worms should
be “probed” only with the special probes made for this activity, never the tip of the pipet or
forceps.
4
Instructor Notes
Participants should determine the anterior end from the posterior end. The anterior end is
blunter and more darkly pigmented than the posterior end. It is also the end that will move
first. If several worms are in the chamber, they will clump together in a ball, as they like to
“cling” to things. This in itself is a normal behavior that the participants will want to note.
Participants can separate the group by gently probing the worms or pipetting with water.
Once the anterior and posterior ends are established, participants should begin observing
the swimming behavior. Touch the probe to the posterior end. The worm will swim forward
in a corkscrew fashion, alternating clockwise and counterclockwise. When the worm is
probed on the anterior end, it will coil and reverse its position. Both these movements are
quite rapid, and it may take some time to note the differences.
Next, participants can observe crawling behavior. The worm can be placed in a petri dish or
weighing dish on moistened filter paper (remove all excess water). Again they should probe
both the posterior and anterior ends of the worm. In each case the worm will move by
peristaltic crawling (successive waves of muscle contractions) in the opposite direction.
Results that might be noted for the suggested toxicants are listed below. These sample
results represent some of the behavior changes that participants have observed using the
given concentrations. You may note different observations on different days, depending on
how participants observe and perceive the changes as well as on the size and health of the
worms used.
Sample Data
In ethanol, the worms will be less likely to clump and will become rather inactive as the
concentrations increase. In the highest concentration, they may straighten out in the middle
but have their ends curled. The anterior area will be more affected. The worms may need to
be probed several times to stimulate a response. They will have less skill in swimming,
although they will still be able to crawl. They should begin to recover in 15 minutes after
exposure to the first two solutions. Although the worms in the first two solutions will
recover completely within 24 hours, recovery may not be complete after 24 hours with the
third solution.
In caffeine, the worms become very active as the concentration increases, but they may try
to clump at the lower concentration. They will show a greater sensitivity to probing both in
swimming and crawling. At the higher concentration they may first curl in a ball and then
stretch out. Some recovery should be seen after 15 minutes in the lower concentrations,
and all should fully recover within 24 hours.
With nicotine, the worms may twitch in the solution. The tail may curl with loss of response.
In the highest concentration, paralysis will occur. With paralysis, the worm will stretch and
just seem to float in the water. There should be some recovery at the lower concentration
in 15 minutes, and all worms should recover within 24 hours.
5
Instructor Notes
Plausible Answers to Questions
1. Exposure occurs when an organism comes in contact with a toxicant. Exposure frequency
refers to how often, exposure duration refers to how long, and exposure concentration
refers to how much. Using this terminology, describe each for your investigation.
Answers will vary.
2. Two types of toxicity tests can be performed. Acute toxicity tests are a high single
exposure for a brief duration. Chronic toxicity tests are usually a persistent and longer
exposure (depending on the organism’s lifespan) at a lower concentration than the
acute test.
a. Based on this information, which type of test was done in this investigation?
This was an acute toxicity test.
b. What are the benefits of using an acute toxicity test?
It saves time, one can see immediate responses to the toxicant; and one can learn
the per dose limit of tolerance to a toxicant.
c. What are the benefits of using a chronic toxicity test?
One can learn the cumulative effects of the toxicant; it more closely approximates
normal exposure to toxicants.
3. Using the data from your assigned toxicant, design a chronic toxicity test that you
might perform on the blackworms. Predict what your results might be.
One might begin by exposing the worms to the lowest alcohol concentration used in
this experiment, as well as exposing them to even lower concentrations. Since the
exposure needs to be chronic, the experiment would last over a much longer period of
time (months or even years). The exposure could be constant or periodic. Periodic
exposures, meaning the worms are given some recovery time in between exposures,
would be more representative of “real life” exposures.
4. The exposure pathway is how a toxicant enters the body. What was the exposure
pathway for your toxicant?
The exposure pathway is through the surface membrane of the worm. It is unlikely that
for a water-soluble toxicant, such as alcohol, entry would be through the mouth. Ingestion
of a toxicant by these worms would probably have to be associated with food. (You can
demonstrate this to the participants by removing the head and the tail of a worm and
showing that the toxicant still has a dramatic systemic effect.)
5. Toxicity is affected by both intrinsic and extrinsic factors. Extrinsic factors, such as
temperature or barometric pressure, occur outside the body. Intrinsic factors, such as
age, metabolism, and genetic differences, are inherent to an individual organism. Using
the following factors, predict how you think each could affect the results with your
toxicant. Be specific!
6
Instructor Notes
a. temperature
b. age
c. metabolism
d. genetic difference
Answers will vary.
6. Your concentrations represent sublethal concentrations of the toxicant. Explain what
you think this means.
The concentration of the toxicant is not high enough to kill the worms during the
period of time they were exposed.
7. The potency of a toxicant is the measure of its strength. Paracelsus (1493–1541) is
quoted as saying “The dose makes the poison.” The more potent the toxicant, the less
it takes to evoke a response. Based on the concentrations listed above and your
observations, which toxicant do you think is the most potent and why?
Answers will vary.
8. Based on your toxicant, what body systems do you think were affected and why?
Answers will vary.
9. At the end of the 24-hour recovery, you can generally determine whether the effects of
your toxicant are reversible or irreversible. Based on the toxicant that you used, tell
whether the effects were reversible or irreversible at each concentration.
All of the worms recovered within 24 hours, so the effects of these toxicants are reversible.
The effects of the strongest ethanol solution is a possible exception.
10. Did all of your worms (at each concentration) demonstrate the same behavior? Assume
that one worm demonstrated normal behavior and the other four demonstrated
abnormal behavior. How would you explain this?
No, all of the worms at each concentration did not demonstrate the same behavior.
This can be explained by variability, or differences, between the worms. For example,
there may be genetic, age, health, or size differences between the worms.
11. The investigation that you did was a controlled experiment.
a. What was the control?
A set of blackworms whose behavior was observed but to which no toxicant was
applied; the blackworms in only distilled water.
b. Why is a control necessary in a scientific experiment?
To be able to determine what is “normal” so we can compare and determine
deviations from normality.
7
Instructor Notes
12. Risk assessment of a toxicant is the estimate of severity and the likelihood of harm to
human health or the environment that occurs from exposure to a risk agent (toxicant).
The toxicants that you tested are relevant to human health. Name some toxicants you
might test that would harm the environment and thus pose a threat to the worms.
Ammonia, chlorine, or other forms of alcohol that are commonly released into the
environment, such as antifreeze.
13. How do lifestyles play a part in risk assessment of human health toxicants?
Lifestyles affect an individual’s health, metabolism, and limits of exposure to toxicants.
For example, risk increases if a person is in poor health. Limits of exposure to toxicants
can be affected by actions such a frequency of exposure to alcohol or career choice.
Risk increases as the frequency of alcohol (ethanol) exposure increases. Also, a mechanic
will probably be exposed to more toxicants than a secretary; thus a mechanic’s risk for
exposure to certain chemicals would be higher. Remember, exposure does not necessarily
mean the toxicant has entered the person’s body. If the mechanic is very careful (which
is also a lifestyle choice), the dose of the toxicants would be zero.
14. Can the results of your tests be applied to humans or other vertebrates? Why or why
not?
Not directly. Effects can only be extrapolated from an experimental system to another
system if the two types of systems can be shown to be sufficiently similar in relevant
characteristics and behavior.
15. Based on what you have learned from your investigation and your answers to the
questions above, analyze your data and summarize any conclusions that can be drawn
from the results.
Answers will vary.
16. As a group, discuss your findings. Using reference material, look up any information
about your toxicant that will help in further analyzing your data. Suggest additional
investigations using your toxicant and make a group presentation of your findings to
the class.
Answers will vary.
Extensions
Participants may test other toxicants. They will need to determine the initial concentration
for their stock solution by trial and error. The goal of the experiment is to determine three
sublethal concentrations that produce the following results:
1. low concentration—evokes little or no response
2. middle concentration—evokes a near maximum response
3. high concentration—is sublethal and evokes a maximum response
8
Instructor Notes
The following are just some examples of toxicants that might be tested:
•
Aleve®, Nuprin®, aspirin, Tylenol®, Excedrin® PM
•
melatonin, Nytol®, Dexatrim®, vitamins
•
Benadryl®, Sudafed®
•
saccharin, Nutrasweet®
•
chlorinated water
•
pesticides, antifreeze, detergents
•
UV radiation
References
Drewes, C.D. “Those Wonderful Worms,” Carolina Tips. 59 (3). Carolina Biological Supply: Burlington, NC,
1996.
Drewes, C.D. “Screening for Sublethal Behavioral Effects in a Freshwater Oligochaete, Lumbriculus
variegatus.” Lab for Dr. Drewes’ toxicology class, 1995.
Lesiuk, N.M.; Drewes, C.D. “Blackworms, Blood Vessel Pulsations, and Drug Effects,” The American Biology
Teacher. 1999, 61 (1), 48–53.
9
Activity Instructions
This investigation represents a model for testing potential toxicants on organisms. You will
determine the behavioral changes that occur when blackworms are exposed to different
concentrations of an assigned toxicant through a controlled experiment. At the end of the
investigation, you will analyze your data, present your findings to the class, and suggest
other possible experiments.
Safety
In a laboratory setting, you are ultimately responsible for your own safety and for the safety
of those around you. It is your responsibility to specifically follow the standard operating
procedures (SOPs) which apply to you, including all local, state, and national guidelines on
safe handling, storage, and disposal of all chemicals and equipment you may use in the
labs. This includes determining and using the appropriate personal protective equipment
(e.g., goggles, gloves, apron). If you are at any time unsure about an SOP or other regulation,
check with the course instructor.
Procedure
You will work in groups and be assigned a toxicant to test.
1. Label four chambers as follows: “Control,” “#1,” “#2,” and “#3” along with the name of
the toxicant you’ve been assigned. Pour distilled water into each chamber to a depth of
1 cm.
2. Using a pipet, transfer 20 worms to your control chamber. Be sure to choose worms
that are full length and uniform in color. Do not select worms that have distinct lighter
patches.
3. Transfer five worms from the control chamber to each of the other chambers (#1, #2,
and #3). Observe the behavior of the worms in all four chambers based on your assigned
criterion from Table 1. Also look for physical changes such as bulging in the center,
bleeding, or fragments breaking off. If any worms die, record the mortality.
10
Table 1: Observation Criteria
Behavior
Procedure
Clumping behavior
Note whether the worms tend to clump together in a ball.
Swimming behavior
Use the probe to touch the anterior end (blunter and more darkly pigmented)
of the worm and observe the movement. Then touch the posterior end and
again observe the movement. Make note if all worms exhibit the same
behavior or if some remain normal while others exhibit a change.
Crawling behavior
Use the pipet to transfer the worm onto moistened filter paper in another
chamber and remove all excess water. Probe the worm first on the anterior end
and then on the posterior end to make your observations. Use a different
worm at each 3-minute interval.
Also make note of activity level (faster or slower than normal) and individual position in the water,
such as stretched out, curled in a ball, and ends curled, as well as anything else that might be
considered an unusual response.
4. Gently draw your worms from each chamber (except the control) back into a pipet. (If
this is too difficult, get another chamber with some distilled water and put your worms
there temporarily.) Discard the distilled water and then add your assigned toxicant
solution in the corresponding chamber to a depth of 1 cm. Transfer your worms back
into the chamber. Expose the worms to the toxicant for at least 15 minutes. During the
exposure period, make your assigned observations every 3 minutes on all four chambers
and record them by 3-minute intervals on your data sheet.
5. After the exposure period has ended, allow the worms to recover. Draw your worms
into a pipet or transfer them to a clean chamber. Empty the toxicant into the waste
beaker and fill the chamber to a depth of 1 cm with distilled water. Add the worms. (Try
to expel as much toxicant as possible out of the pipet first if they have been held in the
pipet.) Again observe the worms at 3-minute intervals on all four chambers for at least
15 minutes during the recovery period and record your observations just as you did
before. Be sure to make notes about any recovery (a return to normal behavior) that
takes place.
6. Leave the worms in their chambers overnight and observe again the next day. Be sure
to record the number of mortalities that occurred overnight. Return fully recovered
worms to the original large container after 48 hours. Any worms that don’t appear to
be in good health or fully recovered after 48 hours should go in a separate container
marked “Recovery.”
11
Questions
Collaborate with your group to obtain data for all concentrations of your toxicant. Complete
your data table on the last page with the following information on toxicant concentrations
and then answer the questions.
Table 2: Toxicant Concentrations
Ethanol
Caffeine
Nicotine
Solution #1
0.25%
0.08 mg/mL
0.00055 mg/mL
Solution #2
2.5%
0.33 mg/mL
0.00275 mg/mL
Solution #3
10%
1.0 mg/mL
0.011 mg/mL
1. Exposure occurs when an organism comes in contact with a toxicant. Exposure
frequency refers to how often, exposure duration refers to how long, and exposure
concentration refers to how much. Using this terminology, describe each for your
investigation.
2. Two types of toxicity tests can be performed. Acute toxicity tests are a high single
exposure for a brief duration. Chronic toxicity tests are usually a persistent and longer
exposure (depending on the organism’s lifespan) at a lower concentration than the
acute test.
a. Based on this information, which type of test was done in this investigation?
b. What are the benefits of using an acute toxicity test?
c. What are the benefits of using a chronic toxicity test?
3. Using the data from your assigned toxicant, design a chronic toxicity test that you
might perform on the blackworms. Predict what your results might be.
4. The exposure pathway is how a toxicant enters the body. What was the exposure
pathway for your toxicant?
5. Toxicity is affected by both intrinsic and extrinsic factors. Extrinsic factors, such as
temperature or barometric pressure, occur outside the body. Intrinsic factors, such as
age, metabolism, and genetic differences, are inherent to an individual organism.
Using the following factors, predict how you think each could affect the results with
your toxicant. Be specific!
a. temperature
b. age
c. metabolism
d. genetic difference
6. Your concentrations represent sublethal concentrations of the toxicant. Explain what
you think this means.
12
7. The potency of a toxicant is the measure of its strength. Paracelsus (1493–1541) is
quoted as saying “The dose makes the poison.” The more potent the toxicant, the less
it takes to evoke a response. Based on the concentrations listed above and your
observations, which toxicant do you think is the most potent and why?
8. Based on your toxicant, what body systems do you think were affected and why?
9. At the end of the 24-hour recovery, you can generally determine whether the effects of
your toxicant are reversible or irreversible. Based on the toxicant that you used, tell
whether the effects were reversible or irreversible at each concentration.
10. Did all of your worms (at each concentration) demonstrate the same behavior? Assume
that one worm demonstrated normal behavior and the other four demonstrated
abnormal behavior. How would you explain this?
11. The investigation that you did was a controlled experiment.
a. What was the control?
b. Why is a control necessary in a scientific experiment?
12. Risk assessment of a toxicant is the estimate of severity and the likelihood of harm to
human health or the environment that occurs from exposure to a risk agent (toxicant).
The toxicants that you tested apply to human health. Name some toxicants you might
test that would harm the environment and thus pose a threat to the worms.
13. How do lifestyles play a part in risk assessment of human health toxicants?
14. Can the results of your tests be applied to humans or other vertebrates? Why or why
not?
15. Based on what you have learned from your investigation and your answers to the
questions above, analyze your data and summarize any conclusions that can be drawn
from the results.
16. As a group, discuss your findings. Using reference material, look up any information
about your toxicant that will help in further analyzing your data. Suggest additional
investigations using your toxicant and make a group presentation of your findings to
the class.
13
Conc:_____
Solution #3
Conc:_____
Solution #2
Conc:_____
Solution #1
Control
Observed behavior
b
__________ efore exposure
Toxicant:
12 min
15 min
3 min
6 min
9 min
12 min
15 min
3 min
6 min
9 min
12 min
15 min
3 min
6 min
9 min
12 min
15 min
12 min
15 min
3 min
6 min
9 min
12 min
15 min
3 min
6 min
9 min
12 min
15 min
3 min
6 min
9 min
12 min
15 min
6 min
6 min
9 min
3 min
3 min
9 min
Observed behavior during recovery
(total recovery time ____)
Observed behavior during exposure
(total exposure time ____)
Observed behavior
after 24 hours
recovery
Data Sheet
14
Backyard Toxicology: Activity 2- Concept Mapping
Activity Description: This activity begins as a pos-lab
exercise from Activity 1. It then transfers what the students
have learned about concept mapping to reading scientific
articles.
Process Skills Goals: Concept mapping,
teamwork, reading primary scientific
literature.
Knowledge Goals: How to read an
introduction from a scientific paper, how
to translate scientific research into a
concept map combining prior and new
knowledge of the topic, the importance
of understanding of the affect of toxins
on a model organism.
Pre-activity: Concept map the
term ‘toxicology’ as a class
on the board. Ask the
students to draw on their lab
to build on the concept map
from Activity 1.
Major Assignment: Individually read the
introduction of a scientific article and as a group
create a concept map about the topic of focus.
Search for definitions to unknown terms and
record them in a vocabulary notebook.
Assessment: Non-formative- participation with the
group and class discussion
Formative- Concept map, current vocabulary
notebook.
Materials: Article 1 introduction, large paper, markers, vocabulary notebook
The teacher should reintroduce the term toxicology and ask the class to help create a concept
map on the board, drawing from the first concept mapping exercise and student observations in
the blackworm lab.
Provide the class with the introduction (only!) of the article. Ask the students to read the article
in class and construct a concept map in groups from the introduction.
There should be a significant number of toxicology terms in their concept maps that need to be
defined. Encourage them to find these definitions for themselves, and record the terms and their
definitions in their vocabulary notebooks.
Have students share their concepts maps and definitions with the class in a teacher led class
discussion.
Alcohol 41 (2007) 281e284
Ethanol levels in honeybee hemolymph resulting from alcohol ingestion
Janko Bozica, John DiCesareb, Harrington Wellsc, Charles I. Abramsond,*
a
Department of Biology, University of Ljubljana, 1000 Ljubljana, Slovenia
Department of Chemistry and Biochemistry, University of Tulsa, Tulsa, OK 74104, USA
c
Department of Biology, University of Tulsa, Tulsa, OK 74104, USA
d
Department of Psychology, Oklahoma State University, 215 N. Murray, Stillwater, OK 74078, USA
Received 24 February 2007; received in revised form 4 April 2007; accepted 4 April 2007
b
Abstract
Our previous work on a social insect model of ethanol-induced behavior focused on behavioral studies of honeybees (Apis mellifera L.).
We now investigate the dependence of honeybee blood ethanol concentration on both the amount of ethanol consumed and time elapsed
since ingestion. Blood ethanol level was determined using gas chromatograph using hemolymph taken from harnessed bees. Significantly
increased levels of ethanol in honeybee hemolymph were detected within 15 min of feeding bees alcohol. Within 30 min, ethanol concentration increased 2.7 times. The concentration of ethanol ingested also had a significant effect on blood ethanol level. However, postfeeding
times greater than 30 min did not significantly increase ethanol concentration in bee hemolymph. This study integrates with our behavioral
data on the effect of ethanol on honeybees. Our laboratory and field experiments show a correlation between the time frame for behavioral
changes and significant increases of blood ethanol levels shown in this study. Ó 2007 Elsevier Inc. All rights reserved.
Keywords: Honeybee; Apis mellifera; Gas chromatograph; Ethanol; Hemolymph
Introduction
Investigations of social insect models of induced ethanol
behavior have concentrated on the behavioral effects of ethanol on honeybees (Apis mellifera L.). Previous results
from this laboratory have shown several effects that are
common among humans and bees. These include the ability
to self-administer ethanol and disruptions in both locomotion and Pavlovian conditioning (see Abramson et al.,
2007 for a review). Our most recent work has extended
the behavioral analysis to more complicated aspects of honeybee behavior. Drinking ethanol will disrupt, for example,
both complex decision processes in free-flying forager bees
and social communication within the hive (Abramson et al.,
2005; Bozic et al., 2006).
We now turn our attention to the physiology of ethanol
consumption in the honeybee. The present paper provides
some physiological background for the possible action of
ethanol through the blood on the central nervous system.
We investigate the dependence of blood ethanol concentration on postingestion time and on concentration of ethanol
consumed.
In the phylum Arthropoda, some data exist on how ethanol
is metabolized in insects. Alcohol dehydrogenize in the fruit
fly Drosophila is from the type II short-chain dehydrogenises
(Benach et al., 2005). It can bind both ethanol and acetaldehyde. Other studies using Drosophila suggest that there also
exists acetaldehyde dehydrogenize (Fry et al., 2004). However, it remains controversial whether this enzyme contributes to the metabolism of ingested ethanol in fruit flies.
The majority of data on blood ethanol levels and its
physiological influence is available from studies using
mammals and humans (Grant et al., 2000; Jones et al.,
1991; Norberg et al., 2000). Blood concentration of ethanol
depends on transport from the digestive track to the blood
and catabolism of ethanol in the body. Ethanol conversion
to acetaldehyde is catalyzed by alcohol dehydrogenize in
these organisms (Sherman et al., 1994; Umulis et al.,
2005). Acetaldehyde is then oxidized to acetate by acetaldehyde dehydrogenize.
Materials and methods
Bees preparation and hemolymph sampling
* Corresponding author. Tel.: þ1-405-744-7492; fax: þ1-405-7448067.
E-mail address: [email protected] (C.I. Abramson).
0741-8329/07/$ e see front matter Ó 2007 Elsevier Inc. All rights reserved.
doi: 10.1016/j.alcohol.2007.04.003
Honeybees (Apis mellifera L.) were collected at random
as they departed the hive 1 day before an experiment. Each
282
J. Bozic et al. / Alcohol 41 (2007) 281e284
bee was placed in a glass vial in an ice water bath. When
a bee became inactive, it was immediately removed from
the vial and placed into a restraining harness. After regaining consciousness, each subject was fed a 1.5 M sucrose solution (commercial sugar and distilled water) until it would
no longer extend its proboscis; the subjects were then left
until the following morning (for further details, see Abramson et al., 1997). Prefeeding ensured that all subjects had
the same motivation to eat and pass food along their digestive tracks. Different sets of subjects were used for each of
the experiments described.
On the following day (postfeeding day), bees were randomly assigned to treatment groups and fed with 10 ml of
a test solution. Test solutions were always 1.5 M sucrose
with different concentration of ethanol. Solutions were
made by diluting 95% ethanol (Pharmco, Brookfield, CT
ethyl alcohol, 190 proof) with distilled water to make the
final concentrations for feeding bees.
After feeding, a bee was set aside, still in the harness, for
the required postingestion period before its hemolymph was
sampled. A harnessed bee was briefly narcotized with CO2
immediately before blood sampling. The bee’s thorax cuticle was then punctured at the abdominal side of the wings’
base and the blood collected in a 1-ml disposable glass microcap (Drummond Scientific Co). This procedure was successfully used in previous honeybee blood studies (Bozic
and Woodring, 1997, 1998), and insures that neither the
honey stomach nor the intestine is punctured during hemolymph sampling. The 1.00 ml of hemolymph taken from
a bee was mixed with 9.00 ml of a 1-butanol stock solution
to afford 10 ml of 0.502 mM 1-butanol solution, which was
immediately frozen at 20 C until analyzed by gas
chromatography.
Gas chromatography analysis
Ethanol concentration in the honeybee hemolymph was
determined by gas chromatography analysis using 1-butanol
as an internal standard. A standard curve was prepared with
1.000 mM 1-butanol and 5.000, 1.000, 0.500, 0.100, and
0.050 mM aqueous ethanol solutions resulting in a Rsquared value of 0.999. The standards and honeybee blood
samples were analyzed on a Hewlett Packard 5890 GC
equipped with a Flame Ionization Detector (FID), Peak
Simple analysis software, and a 30-m J&W Scientific capillary column (0.25 mM DB-Wax). The analysis conditions
were isothermal at 80 C for 5 min with 1 ml/min of helium
carrier gas and a head pressure of 16 psi.
Experiments
Time dependence
First, we wanted to determine how concentration of ethanol in blood changes over time since consumption. We
used 10 ml of a test solution containing 5% ethanol,
1.5 M sucrose to feed bees (t 5 0 min). This concentration
was selected because it is known from our previous work
that a 5% ethanol solution will disrupt honeybee behavior
under both laboratory and field conditions. Bees were sampled at 15, 30, 60, 120, 240, and 480 min postethanol ingestion (treatments). A control group was fed 10 ml 1.5 M
sucrose with no ethanol and sampled 10 min after feeding.
For each test treatment, we used six to eight bees (n 5 48
total). Half the bees for each treatment were tested on
day 1 and the remaining tested on day 2.
Concentration dependence
We used a 30 min postethanol ingestion time to test the
effect of ingestion of different ethanol concentration on ethanol blood levels. Bees were fed 10 ml of 0, 1, 2.5, and 5%
ethanol in 1.5 M sucrose. These are the same concentrations that were used in our behavioral experiments (see review: Abramson et al., 2007). We assigned three to four
bees to each treatment on two separate experimental days.
Tests were run in parallel for all ethanol food concentrations (n 5 22 total).
Data analysis
Data were analyzed using a one-way ANOVA with Tukey comparison of mean values. In addition, linear regression was used to show dose dependence of blood ethanol
concentrations on concentration of ethanol in food. All
statistics were applied using SPSS.
Results
Ethanol was separable based on the gas chromatography
protocol used. A linear relation existed between ethanol
concentration in standards and levels detected in the gas
chromatography analysis (GC-mM 5 0.951 StandardmM þ 0.0440; significant of regression F 5 10,358.01,
df 5 1.3, P !.0001).
Time dependence
Onset of ethanol effects on the central nervous system of
the honeybee is related to the time taken for ethanol to enter
the blood. Our shortest experimental time was 15 min. At
that time, we find a significant amount of ethanol in the
honeybee’s blood (24.6 6 9.2 mM, Fig. 1, ANOVA:
F 5 6.11, df 5 4.21, P 5 .002; Tukey test). Average ethanol
concentration in the blood increased 2.7 times during the
next 15 min. Postingestion times greater than 30 min did
not significantly increase the ethanol concentration in the
blood (average ranged from 64 to 77 mM: Fig. 1). We observed a relatively steady state mean ethanol value for the
resting periods longer than 1 h. Based on the slope between
15 and 30 min (slope 5 2.75 mM/min) extrapolated to the
x-axis the estimated delay of onset of ethanol in the honeybee’s blood is 6.1 min.
100
Blood EtOH (mM)
Blood EtOH (mM)
100
50
0
283
0
2
4
6
8
Time (hours)
Fig. 1. Effect of resting time after feeding bees with 10 ml of 5% ethanol
sugar solution on ethanol blood concentration. Mean values and standard
error are plotted for each data point.
Concentration dependence
Ethanol concentrations in food had a significant effect
on ethanol concentration in the blood of honeybees
30 min after consumption of the ethanol solution
(F 5 7.58, df 5 3.18, P 5.0017). The largest differences
were observed at lower concentrations of ethanol in sugar
solution (Fig. 2). A positive correlation was found between
an increase in blood ethanol concentration and the amount
of ethanol consumed (F 5 24.56, df 5 1.20, P !.0001);
amount consumed was equal to the ethanol concentration 10 ml droplet.
Discussion
This study correlates well with our behavioral data on
the effect of ethanol on honeybees. Our laboratory and field
experiments were in the same time frame as the significant
increases of blood ethanol level observed in our sample.
Just 15 min postingestion there were elevated ethanol
levels. In foraging situations, the elevated levels are likely
to increase even faster due to the anatomy and physiology
of the honeybee. Nectar consumed by a forager is regurgitated from its honey stomach to be processed into honey by
hive mates and stored in wax cells for future use. Of course,
foragers must use some of the nectar collected for metabolic purposes to stay alive. This occurs by passing nectar
from the honey stomach into the intestines where sugar is
absorbed (Morse and Flottum, 1990). Nectar flow from
honey stomach to intestine is highly regulated in honeybees, and inversely related to hemolymph sugar levels (Rocess and Blatt, 1999). Activities that increase sugar
metabolism have been shown to increase the rate at which
nectar passes from the honey stomach to the intestine
50
0
0
2
4
6
% EtOH
Fig. 2. Effect of concentration of ethanol in sugar solution on blood ethanol concentration 30 min after feeding. Mean values and standard error
are plotted for each data point.
(Rocess and Blatt, 1999). So, higher energetic demands
of bees increase flow of nutrients from the honey stomach
to the intestine, and from the intestine to the hemolymph.
We suspect that ethanol absorption is correlated with that
of sugars and, like mammals, increased flow from the stomach to the intestine increases the rate of absorption of ethanol. The key to this flow in honeybees is metabolic
demand, which is elevated by flight activity.
In our foraging experiment (Abramson et al., 2005;
Bozic et al., 2006), we found dramatic effects of ethanol
consumption occurring within 15 min postingestion when
an artificial feeder contained ethanol at the foraging site.
The frequency of social behavior naturally occurring inside
of the hive also changed because of ethanol consumption.
Most prominent was disruption of waggle dance communication, which has been shown to correlate with the dopamine system in honeybees (Bozic and Woodring, 1998).
Dopaminergic, GABA, and neuropeptide neuron transmission and modulation have been recognized to control in animals centrally generated motor patterns (Marder and
Bucher, 2001). A fertile area for future research is the neurophysiologic background of ethanol effects on fixed motor
patterns generated by the central nervous system.
In comparison to vertebrate models, ethanol blood concentration was high and remained elevated for an extended
period of time (Matthews et al., 2001). These results were reflected in a study that complements the work presented here
(Maze et al., 2006). The Maze study used an enzyme assay to
estimate ethanol in bee blood. Its focus was higher concentrations of ethanol (5e50%), and looked at blood alcohol levels
starting 30 min after ingestion (then at 6, 12, 24, and 48 h).
Our study focus was on lower concentrations of ethanol
(1e5%) that are more likely to be encountered naturally by
honeybees. We also looked more closely at onset (15 min;
284
then at 30 min, 1, 2, 4 and 8 h), and considered chronic alcoholism in addition to a single meal. As expected, 50% ethanol
produces much higher blood alcohol levels (over 100 mM)
than does 1% ethanol (approximately 5 mM) in a bee’s diet.
However, the blood alcohol levels we report for 5% ethanol
consumption are consistent with those reported earlier based
on the variation among bees observed in both studies (SE bars
of the studies meet at about 50 mM). At the lower ethanol
concentrations we used, ethanol level in the blood can be seen
to be an accelerating function of ethanol amount ingested.
This is probability related to the maximum rate a bee can process ethanol (Fig. 2). The Maze study does not report a drop in
blood ethanol until 12 h postingestion. The correlation in results from both studies suggests that these results are either
artifacts of an analytical technique or artifacts of sampling
bees from a particular hive.
With respect to time, notably, both studies show that ethanol remains extremely elevated in the hemolymph for
a prolonged period. This is most likely due to the rate of
nectar passing from the honey stomach into intestine, which
is under control of blood glucose level (Rocess and Blatt,
1999). That is, unlike mammals that deal with excess glucose by sequestering it after it has entered the blood stream,
honeybees sequester the sugar by holding it in the honey
stomach so that it never reaches the hemolymph (Rocess
and Blatt, 1999). Honeybee metabolic rate in resting bees
is about 1/25 that of foragers in flight (Rothe and Nachtigall, 1989; Wood et al., 2005), Thus, the nectar flow from
the honey stomach during our experimental time would
be expected to be low since we used resting bees. Although
data do not exist on whether ethanol can be digested before
passing into the blood, it has been shown that alcohol dehydrogenase and acetaldehyde dehydrogenase are among the
proteins secreted by honeybee feeding glands (Santos
et al., 2005). Further, there are several different alleles of
alcohol dehydrogenize in honeybees (Martins et al.,
1977). The transport model from stomach to intestine links
ethanol with sucrose absorption and predicts differences in
both blood alcohol levels and duration of inebriation base
on metabolic rate and nectar sugar concentration. Obviously, much more work is required in this area and how
enzyme system relates to the ecology of honeybees.
Acknowledgments
Janko Bozic participation was supported by Fulbright
Scholarship at Oklahoma State University.
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ANALYSIS TEMPLATE—Fill one in for each figure or table
Figure or Table Number:
_____
1) “Official” title for this figure or table (from the caption):
2) My (simplified, decoded, in regular language) title for this figure or table:
3) The specific hypothesis being tested, or specific question being asked in the
experiment represented here is:
ANALYSIS: First, refer to your cartoon of what the experimenters did, and to
your annotated figure, and to the information you wrote in above. Then, answer
the following for each figure or table:
4a) For descriptive studies,
If we compare panel(s)__________ and __________, or columns __________
and
___________, we learn about________________________________________
and
___________, we learn about________________________________________
and
___________, we learn about________________________________________
4b) For experimental tests,
The controls in this experiment are:
They are represented (in which part of the chart or graph, or what figure panels?)
The experimental groups are:
They are represented:
We need to compare the controls in _________ with the experimental groups in
____________to find out____________________________________________
We need to compare the controls in _________ with the experimental groups in
____________to find out____________________________________________
(Continue if there are more experiments in the figure):
We also need to compare ____________________ with _______________ to
find out ______________
When we do this, we learn that:
5) Overall, what we learn from this figure is:
6) The following issues are ones of concern to me: (these can be things you don’t
understand, criticisms of the method, questions for the authors, or anything else
that comes to mind)
Backyard Toxicology: Activity 3- Reading the Results
Activity Description: This activity continues breaking down
Article 1 into accessible components. This activity tackles
the results and methods sections in the form of cartoons and
captions.
Process Skills Goals: teamwork, reading
primary scientific literature, cartooning
Knowledge Goals: How to read the
results and methods sections of a
scientific paper, how to visualize
scientific research in the form of a
cartoon, how to rephrase scientific
jargon to get at the underlying
information presented.
Pre-activity: Read results
section and look for
definitions for unknown
terms.
Major Assignment: Individually read the results
and methods sections of a scientific article, and
search for definitions to unknown terms. Create a
cartoon of the experiments presented in the results
sections. Rewrite the captions of figures and tables
so they can be better understood, and add
informative labels.
Assessment: Non-formative- individual
participation and participation in class discussions
Formative- Cartoon, current vocabulary notebook,
captions.
Materials: Article 1 results, material and methods sections, white paper, markers, vocabulary
notebook
Provide the class with the Methods and Results sections of the first article.
Ask students to read the Results Section and, using the Methods section for more information, do
the following:
a) Make a cartoon diagram of each experiment from the results section. The idea is to draw
what the experiment may have actually looked like in cartoon form.
b) Annotate all of the figures and tables in the results section by adding clarifying labels.
The students will need to really study the figures and the legends in order to do this. They
should be sure to clearly identify the control group and each experimental group in each
figure and table. They should feel free to write on their copy of the sections when adding
labels or even to make notes.
Activity Instructions ctd:
c) Ask students to write their own descriptive titles for each cartoon and each figure. The
students should come up with new titles that are meaningful and informative to them.
d) This process may need a few iterations to get the students on board. Small group in-class
working sessions may help students through this process the initial time. They can get
ideas from one another, but should complete the assignment individually.
Backyard Toxicology: Activity 4- Elucidate the Hypothesis
Activity Description: This activity continues breaking down
Article 1 into accessible components. Here students use all
the interpretive work they have done on the article sections to
figure out what the actual hypothesis (or hypotheses) being
tested is.
primary scientific literature, analytical
thinking
1 class period (1-1.5 hours)
Pre-activity: Review concept
map, cartoons, figures and
tables.
Major Assignment: As a group, determine the
hypothesis tested for each table and figure in the
paper. Contribute justified arguments to the class
discussion.
participation and participation in class discussion
Knowledge Goals: Using scientific
information presented in a publication to
determine the hypothesis of the study
(which is not always clearly indicated in
scientific literature).
Formative- Hypotheses.
Materials: Article 1 introduction, results, material and methods sections, concept maps, cartoons,
table and figure legends and annotations, vocabulary notebook
In this activity the students need bring all their hard work together and look for clues to the
actual hypotheses being tested.
Students should look at every figure or table given and identify the hypothesis that was tested.
This should be done in class in small groups, followed up by a class discussion of each group’s
ideas.
Backyard Toxicology: Activity 5- Analyze and Interpret the Data
Activity Description: This activity continues to analyze
Article 1. Here students look at the data and determine for
themselves what is it saying, forming their own conclusions
about the research. This step is very enabling. It transforms
the article from something that is taken as scientific fact
because it has been published, to something that is simply
one person’s (or a few people’s) point of view. The students
will realize that they can be participators in science rather
than being passive observers.
primary scientific literature, critical
scientific thinking
Knowledge Goals: an understanding of
how to evaluate scientific literature and
use critical thinking to form conclusions
based on results and hypotheses, how to
engage in active scientific discussion
with peers
2-3 classes (2- 4.5 hours)
Pre-activity: Review
hypotheses created in groups.
Major Assignment: Using the hypotheses from
Activity 4 and the CREATE analysis templates
students will analyze the data results presented in
each table and figure and draw their own
conclusions. They will then be given the
discussion section of the article containing the
conclusions of the authors. They will make a list
of the author’s conclusions and compare their
conclusions to those of the authors
Formative- student conclusions, list of authors’
conclusions and completed analysis templates.
Materials: Article 1 introduction, results, material and methods, and discussion sections,
vocabulary notebook, CREATE analysis templates
Using the CREATE analysis templates, the students will go through every single figure and table
and analyze the results for themselves, drawing their own conclusions from the real data.
1. This activity should be done in small groups and the teacher should act as a facilitator of
the discussion within each group, circling around the room.
2. Have students individually fill out a CREATE analysis template for each table and figure.
3. Students will compare each figure to data tables and/or other figures. They should then
relate their findings to the hypothesis they had previously determined for each figure.
Their findings should be analyzed and discussed among the group.
4. The students should then be able to form their own conclusion from the data. They
should make a list of the conclusions drawn from each figure and table.
5. Once their lists have been completed, the students should be provided with the
Discussion section from the Journal article.
6. Ask the students to make a list of the conclusions made by the authors and compare it to
their own conclusions.
7. If time allows, have everyone briefly discuss their findings as a class. Did they differ
from the findings of the paper? Why or why not?
Backyard Toxicology: Activity 6- Think of the Next Experiment
Activity Description: This activity is a follow up to Article 1.
Here students think about what the next step from this
research is. They design an experiment that they feel would
build on the research from Article 1 to ask a new question or
test a different hypothesis. They then form Review Panels
and review all of the proposals created by the students. This
is similar to how funding agencies and journal reviewers
operate in the world science research. The students are tasked
with forming criteria and selecting the best proposal.
Process Skills Goals: teamwork, critical
scientific thinking
1-2 classes (2- 3 hours)
Pre-activity: If desired, assign
students the cartooning
activity for homework.
Otherwise this can be done
individually in class.
Major Assignment: Building on Article 1, the
students come up with a new research project
proposal.
how to formulate scientific research
projects, how to evaluate scientific
research, and how to engage in active
scientific discussion with peers
Formative- Student proposals, group proposal
criteria.
Materials: Article 1, vocabulary notebook, white paper, markers, poster paper
Direct students to take over the role as lead researcher and think of the next experiment they
would do as a follow up to the journal article.
1. Every student should individually (for homework or in class) design the next experiment
and draw a cartoon (with very minimal words) showing what the next experimental
design/methods would be.
2. In class have students assemble in groups. Each group is now a Proposal Review Panel
that will review the proposed experiments and decide which it will fund.
3. The first step of the review process is for each Panel to come up with a list of criteria for
funding a successful project. What things would a project proposal need to show for the
panel to approve of it?
5. Next the Panels should review all of the experiments and decide on one to fund based on
the criteria they established.
6. Each Panel should then share their criteria and their selection with the class.
Students should realize that not only can research take off in a wide range of directions, but what
makes a “good” experiments depends on how you look at it.
Backyard Toxicology: Activity 7- Effect of Nicotine on Blackworms
Activity Description: This activity is a follow up to Activity
1. Here students do the next step in the experiments to
determine of the effects of toxicants on blackworms. This
time after the experiments are concluded the students think
of the next experiment and their peers review the proposals,
like they did in Activity 6. The concept mapping and
research proposal skills are reinforced in an authentic
experiment.
scientific thinking
2 classes (2- 3 hours)
Pre-activity: As a class,
concept map ‘nicotine’
Major Assignment: Effects of nicotine on
California Blackworms, research proposals of a
follow-up experiment
participation in groups in class discussions
Formative- lab questions, student proposals
(homework), group proposal criteria
Materials: nicotine portion of Toxicants and Worms Lab Packet, results from Activity 1,
California blackworms, probes, petri dishes, graduated cylinders, nicotine solutions, white paper,
markers, poster paper
Introduce the term ‘nicotine’ and ask the class to help make a concept map on the board as in
Activity 1.
**The teacher should prepare the nicotine solutions in advance for the Blackworm Lab, as in
Activity 1 (see preparation instructions in the lab packet).
1. Ask the students to form groups and conduct the nicotine portion of the experiment from
the Toxicants and Worms Lab Packet, and answer the questions based on their
observations of the effects of nicotine and ethanol. They should compare and contrast the
effects.
5. For homework, ask the students to ‘think of the next experiment’ based on what they
have done in the activity and make a cartoon diagram (just as they did in Activity 6).
6. The next experiments should be reviewed in panel, just as the students have already done
(in Activity 6). Make sure the groups define their criteria for a successful project before
reviewing the next experiments.
7. Share the group project selections and criteria as a class.
Backyard Toxicology: Activity 8- CREATE Article 2
Activity Description: This activity is a repeat of Activities 26 using the second in a series of articles on the effects of
ethanol on honeybees, written by a single research group.
The goal is to scaffold the skills of CREATE while allowing
the students to see the actual progression of scientific
research in a laboratory.
Pre-activity:
Process Skills Goals: teamwork, concept
mapping, cartooning, critical thinking
Major Assignment: CREATE process using
Article 2
Knowledge Goals: how to read the
scientific paper, visualize scientific
research in the form of a cartoon,
rephrase scientific jargon to get at the
underlying information presented, use
scientific information presented in a
publication to determine the hypothesis
of the study formulate scientific research
projects, evaluate scientific research,
with peers, evaluate scientific literature
and use critical thinking to form
conclusions based on results and
hypotheses
Formative- concept maps of introductions,
cartooning results, table and figure captions and
annotations, hypotheses, CREATE analysis
templates, students conclusions, list of author
conclusions, student proposals, group proposal
criteria, vocabulary notebooks
Materials: Article 2, CREATE analysis templates, white paper, poster paper, markers,
vocabulary notebooks
The teacher should gauge the participation level and enthusiasm of the class and assign portions
of the CREATE process for homework accordingly. Refer to the Activities 2-6, and the Hoskins
articles for detailed instructions on each step.
C- Concept map the introduction
R- Read the results, cartooning experiments, captioning and annotating tables and figures
E- Elucidate the hypothesis (for each table and figure)
A- Analyze and Interpret the data (using the CREATE Analysis template)
TE- Think of the next Experiment- cartoon a proposal, Review Boards select the best one
Alcohol 38 (2006) 179e183
Reduced ability of ethanol drinkers for social communication
in honeybees (Apis mellifera carnica Poll.)
Janko Bozica,*, Charles I. Abramsonb, Mateja Bedencica
a
Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, 1000 Ljubljana, Slovenia
b
Department of Psychology, Oklahoma State University, Stillwater, OK 74078, USA
Received 30 April 2005; received in revised form 17 October 2005; accepted 27 January 2006
Abstract
Foraging behavior was evaluated in honeybees trained to fly to a feeder containing sucrose only, 1% ethanol, 5% ethanol, or 10% ethanol. The results indicated that exposure to ethanol disrupted several types of honeybee social behavior within the hive. Consumption of
ethanol at the feeding site reduced waggle dance activity in foraging bees and increased occurrence of tremble dance, food exchange, and
self-cleaning behavior. These ethanol-induced changes in behavior may reflect effects on the central nervous system similar to the previously observed effects of food poisoning with sublethal doses of insecticides. Ó 2006 Elsevier Inc. All rights reserved.
Keywords: Honeybee; Waggle dance; Tremble dance; Apis mellifera; Social behavior; Ethanol
1. Introduction
This is the sixth in a series of behavioral experiments
testing the suitability of honeybees (Apis mellifera L.) as
an animal model for the study of alcoholism. Previous results from this laboratory have shown several alcoholrelated effects in bees that share properties in common with
similar effects in humans. These include self-administration, disruption of learning, locomotion, and decision making, preferences for commercially available alcoholic
beverages, the ability of an emetic to limit consumption
of ethanol, and an increase in aggression (Abramson
et al., 2000, 2003, 2004a, 2004b, 2005).
This paper continues the search for common behavioral
effects of ethanol on human and honeybee behavior by asking the question whether ethanol consumption influences
the foraging honeybee behavior. It is known that consumption of ethanol in humans can cause cognitive dysfunction,
aggression, and other abnormal social behavior (see recent
papers Giancola, 2004; Herzog, 1999; Peirce et al., 2000).
In the interest of further developing our social insect model,
this study evaluated the influence of ethanol consumption
on behavior of the foraging bee inside of the hive. The effects of ethanol consumption on the waggle dance and other
* Corresponding author. Tel.: þ386-1-42-333-88; fax: þ386-1-25-73390.
E-mail address: [email protected] (J. Bozic).
0741-8329/06/$ e see front matter Ó 2006 Elsevier Inc. All rights reserved.
doi: 10.1016/j.alcohol.2006.01.005
behaviors of foraging bees were assessed after they returned
to the hive following a foraging trip.
After a foraging trip, a honeybee shares collected nectar among nestmates by mouth-to-mouth food exchange,
also called trophalaxis (Winston, 1987). Excited upon
finding a nectar source, the foraging bee performs a waggle dance on the comb inside of the hive. This dance contains information about the location of a food source (von
Frisch, 1965). Bees that follow the dancer are in the best
position to pick up dance information (Bozic & Abramson, 2003). It is also known that bees that are disrupted
at a feeding site will emit a tremble dance rather than
a waggle dance. The tremble dance consists of irregular
movements in all directions (Seeley, 1992). We expected
that ethanol will affect waggle dance behavior and other
related behavior inside of the hive during foraging
activity.
2. Materials and methods
2.1. Procedure
Honeybees (Apis mellifera carnica Poll.) were reared in
a two frame observation hives during spring 2003. For 2
days, we individually marked potential foragers at the hive
entrance using numbered tags. After tagging, we trained
bees to forage to a feeder located 250 m from the hive.
The feeders were custom made from six, 200 ml plastic
180
cups. This training took 1 day. The following morning we
started the first day of actual experimental trials.
In the morning of the first experimental day, bees were
offered a 1.5 M sucrose solution. After a minimum of 10
marked bees were consistently returning to the feeder for
90 min, we switched the 1.5 M solution to a solution containing 10% (v/v) ethanol. The 10% solution remained in
place until no marked bees appeared for 15 min. After this
15-min period, the 10% solution was removed and the
feeder remained empty for 4 h. The 10% solution reduced
the number of foraging visits so dramatically in a half an
hour (last recorded visit of the marked bee in 25th min) that
we were not able to continue with 10% test solution (no
marked bee in next 15 min). The rationale behind the 4-h
time period was to ensure that bees were not suffering aftereffects from the 10% solution when we switched to a new
ethanol solution. Following the 4-h period, we renewed the
feeder with 1.5 M sucrose and within 30 min the 10 marked
bees were returning. The sucrose-only feeder remained in
place for 60 min at which time we replaced the sucrose-only feeder with one containing 1% (v/v) ethanol. The 1%
ethanol feeder remained in place for 90 minduntil
30 min before sundown. The experiment was continued
the following day. On the second day of experiment, we
started with a 1% ethanol solution for 60 min, then
switched to a 5% (v/v) solution for 60 min, and finally returned to a sucrose-only solution.
At the feeding site, we tried to remove all unmarked
bees on the first day. On the second day, we could not do
this because of the large number of unmarked foragers.
The solution in the feeder was replaced as needed. At the
feeding site, we recorded the time of arrival of any marked
bee. Once inside the observation hive, we recorded the behavior of the marked bees with a Cannon MV600i miniDV
camcorder.
2.2. Data analysis
We calculated the number of visits, number of returns,
and duration of returns for each feeder solution. For all
marked bees, which were observed at the feeder and inside
of the hive, we counted the number of trophalaxis encounters, waggle dances, tremble dances, self-cleaning, attending and following of the waggle dancers, and walking or
resting on the comb inside of the hive in 30-min time periods. Return times between successive treatments at the
feeding station were tested with one-way analysis of variance with post hoc multiple Tukey comparison at 0.05 significance level. The number of visits at the feeder between
successive 30-min time periods was tested with c2 goodness-of-fit test. We compared counts of behavior inside of
the hive with the number of visits at the feeder during the
same time periods. Our hypothesis was that occurrence of
observed behaviors inside of the hive was under influence
of foraging visits. Possible independence of in-hive behavior counts was tested with two by two Fisher’s exact test,
because many observed frequencies were less than five.
The same test was used to evaluate independence of occurrence of waggle dance to other hive behavior. The waggle
dance behavior is the only behavior that can be clearly related to the foraging visits between observed behaviors inside of the hive, and therefore was chosen for comparison
with other behavior on the comb. All statistics were applied
using SPSS for Windows 12.0.
3. Results
3.1. Foraging activity
Foraging activity was significantly affected by the presence of ethanol in the feeding solution. Return time of the
foragers (Fig. 1) was significantly affected by exposure to
the ethanol solution in the feeder [F(6, 853) 5 7.33,
P !.001], even by the 1% ethanol solution (Tukey multiple
comparison test, P !.05). Ethanol exposure significantly
increased return time of foragers when exposed to 1% ethanol solution at the feeder compared to solution containing
no ethanol, and also when exposed to 5% ethanol solution
at the feeder compared to 1% ethanol solution or to the solution containing no ethanol (Fig. 1). We were not able to
show significantly longer time for 10% ethanol solution because only 10 bees returned for a total of 17 times to the
feeder. We also observed that when exposed to 10% ethanol
solution, some bees actually were not able to fly back into
the hive.
In contrast, foraging visits were affected only by 5% and
10% ethanol solution (Fig. 2). Significant decreases in number of visits were observed in 10% ethanol exposure on the
first day (goodness-of-fit test, c2 5 16.3, df 5 1, P !.001)
and 5% ethanol on the next day (goodness-of-fit test,
c2 5 23.4, df 5 1, P !.001). We observed 55 visits in
30 min of feeding on sugar solution containing no ethanol
before bees were exposed to 10% ethanol solution. We
counted only 20 visits during feeding on ethanol solution
in next 30 min. Actually, most visits (12 out of 20) occurred
in the first 10 min. Due to the low frequency of visits, we
stopped exposure to 10% ethanol after 30 min of data
collection.
When the feeder was removed for 4 h and subsequently
filled with sucrose only, we counted 36 visits in next 30 min
of data collection. This was significantly higher than that
when the animals were exposed to the 10% ethanol solution
(goodness-of-fit test, c2 5 4.57, df 5 1, P 5.033; Fig. 2). In
the next 30 min, we observed a significant increase of foraging activity, up to 72 visits (goodness-of-fit test,
c2 5 16.08, df 5 1, P !.001).
On the next day, we observed a significant drop in visitsdfrom 36 in the first 30 min of foraging on 5% ethanol
solution to only five visits in the next 30 min of feeding on
5% ethanol solution (goodness-of-fit test, c2 5 23.4, df 5 1,
P !.001). We were not able to observe any additional
181
Fig. 1. Effect of ethanol on return time of 135 marked foragers. Generally, longer return times to the feeder were observed at higher concentrations of ethanol. There were significant differences between successive trials: 0e1%, 1e5%, and 5e1%. Star indicates significant Tukey comparison at P ! .05 for
successive trials. At the top are indicated days, number of the bees, and number of returns to the feeder. The vertical line divides 2 observation days.
visits of marked bees in the last 10 min of exposure to 5%
ethanol solution. Bees regained normal foraging rate (25
visits) in the next 30 min after replacing 5% ethanol solution with sucrose only (goodness-of-fit test, c2 5 13.3,
df 5 1, P !.001).
3.2. Behavior of foraging bees inside of the hive
We observed quantitative and qualitative changes in behavior inside of the hive when bees foraged at different ethanol solutions. In general, ethanol reduced waggle dance
activity and increased tremble dance activity, but it also affected other observed behavior patterns (Fig. 2).
After exposure to the 10% ethanol solution, we observed
a significant increase in frequency of trophalaxis, tremble
dance, and self-cleaning when compared to the frequency
of feeder visits (Fisher’s exact test, P !.001, for all three
tests; Fig. 2). Frequency of tremble dance and self-cleaning
also significantly increased relative to the foraging visits after exposure to 1% ethanol when bees were exposed to 5%
ethanol solution on the second experimental day (Fisher’s
exact test, P !.001 tremble dance, P 5 .027 self-cleaning).
Frequency of tremble dance also significantly increased relative to the foraging visits between the 30-min periods during exposure to 5% ethanol solution (Fisher’s exact test,
P !.001). The number of waggle dances decreased after
application of ethanol. In the first exposure to 10% ethanol,
no waggle dances were observed. That drop in frequency
was correlated with the lower frequency of feeder visits
(Fig. 2). On one other occasion, when bees were exposed
to 5% ethanol after 1% ethanol solution, we observed a significant decrease in waggle dance frequency (Fisher’s exact
test, P !.001; Fig. 2).
When we replaced the ethanol solutions with a sucroseonly solution, the frequency of the tremble dance significantly decreased when compared to the number of visits
(Fisher’s exact test, P !.001). Frequency of trophalaxis
and self-cleaning significantly decreased only after exposure to 10% ethanol when compared to the number of visits
(Fisher’s exact test, P !.001, both comparisons; Fig. 2).
An increase of waggle dance activity compared to the number of feeder visits was observed after the 10% ethanol solution was replaced with sucrose only (Fisher’s exact test,
P !.001; Fig. 2). The frequency of waggle dances also significantly increased when compared to the feeder visits between 30-min periods of the exposure to the 1% ethanol
solution during the second experimental day (Fisher’s exact
test, P 5.023).
Diminishing waggle dance behavior after exposure to
10% and 5% ethanol solutions was always correlated with
a significant increase of frequency of trophalaxis, tremble
dance, self-cleaning, and walking-and-resting activities
(Fisher’s exact test, P !.015 walking-and-resting at 5%
ethanol, P !.001 all other cases; Fig. 2). When the 10%
ethanol solution was replaced with sucrose only, the frequencies of the same behaviors to the values was similar
to the frequencies observed before exposure to 10% ethanol
(Fig. 2). After replacing the 5% ethanol solution with sucrose only, only the frequency of tremble dance significantly decreased when compared to the waggle dances
(Fisher’s exact test, P 5 .038).
When bees were exposed to a 1% ethanol solution after
removal of the sucrose-only solution, the decrease in the
frequency of the waggle dance was significantly negatively
correlated with an increase of tremble dance frequency
(Fisher’s exact test, P 5.007). Increase in the frequency
of the waggle dance when exposed to 1% ethanol solution
on the second day was negatively correlated with trophalaxis (Fisher’s exact test, P 5 .009) and self-cleaning (Fisher’s exact test, P 5 .004).
4. Discussion
The most striking change in behavior following consumption of ethanol was a reduction of waggle dance activity and a corresponding increase in tremble dance activity
(Fig. 2). Moreover, when bees reduced foraging activity,
182
Fig. 2. Frequencies of behaviors observed in 170 marked bees that were recorded at the feeder and in the hive. Increase of ethanol concentration in the
feeding solution decreased frequency of the feeder visits, and decrease of ethanol had opposite effect. Diamonds mark significant differences between successive feeder concentrations, c2 goodness-of-fit test, P !.05. There were also observed significant changes of hive behaviors of foragers when compared to
the foraging visits () or to the waggle dance activity of the foragers (stars), Fisher’s exact test, P !.05. At the top are indicated days and number of bees.
The vertical line divides 2 observation days. The experimental trials were divided into equal half an hour periods to enable proper comparison of behavior
counts.
the foraging bees that returned stayed inside the hive for
a longer time. This could explain our observed longer return times (Fig. 1) as well as the fact that our bees were
having difficulty flying when exposed to ethanol. This
was especially pronounced in bees that consumed a 10%
ethanol solution.
We also observed variations in tremble dance activity
following exposure to ethanol. Of particular interest, bees
were observed exchanging food during the tremble dance.
This is the first time that food exchange during trembling
has been reported in the literature. Bees are known to initiate the tremble dance in times of stress; for example, an
increase of tremble dance activity is induced in foraging
bees after visiting a poisoned food source (Biesmeijer,
2003; Schmuck, 1999) or a feeder crowded with bees
(Thom, 2003). Our study suggests that at least some levels
of ethanol exposure may increase tremble dance activity
due to increased stress conditions for the foraging bees,
in a manner like the poisoned food source.
As in our previous papers exploring the social insect
model, it is emphasized that only in the honeybee can such
a relatively large concentration of ethanol be tested in animals. Moreover, in our free flying experiment it is easy to
overlook the fact that they are wild animals that are actually
self-administering the ethanol solution. The wide repertoire
of social behavior, learning and orientation capabilities of
honeybees make them an excellent invertebrate model for
the study of ethanol effects. In addition to what is known
about honeybee physiology and behavior, a total genome library (http://www.hgsc.bcm.tmc.edu/projects/honeybee/) is
available, complemented by increasing knowledge of honeybee functional genetics (Rueppell et al., 2004). Such a database will provide new opportunities for studying the
molecular basis of ethanol-induced behavior of bees.
Acknowledgments
This research was funded by Slovenian Research
Agency by project L1-5213 and research program P1-0184.
References
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Meyers, J. E., & Benbassat, D. (2004a). The development of an ethanol
model using social insects III: Preferences to ethanol solutions. Psychol Rep 94, 227–239.
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Hanig, K. D., & Rice, J. (2000). The development of an ethanol model
using social insects I: Behavior studies of the honey bee (Apis mellifera
L.). Alcohol Clin Exp Res 24, 1153–1166.
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free-foraging honey bees (Apis mellifera). Behav Ecol Sociobiol 53,
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Bozic, J., & Abramson, C. I. (2003). Following and attendingdtwo distinct behavior patterns of honeybees in a position to collect the dance
information. Mellifera 3e6, 48–55.
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Peirce, R. S., Frone, M. R., Russell, M., Cooper, M. L., & Mudar, P.
(2000). A longitudinal model of social contact, social support, depression, and alcohol use. Health Psychol 19, 28–38.
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Backyard Toxicology: Activity 9- Effect of Caffeine on Blackworms
Activity Description: This activity is a follow up to Activities
1 and 7. Here students go on to the next step in the
blackworm experiments, and determine of the effects of
caffeine. As in Activity 7, after the experiments are
concluded the students think of the next experiment and their
peers review the proposals. The concept mapping and
research proposal skills are again reinforced in an authentic
experiment.
scientific thinking
Pre-activity: As a class,
concept map ‘caffeine’
Major Assignment: effects of caffeine on
California Blackworms, research proposals on a
follow-up experiment
Formative- lab questions, student proposals
(homework), group proposal criteria
Materials: caffeine portion of Toxicants and Worms Lab Packet, results from Activities 1 and 7,
California blackworms, probes, petri dishes, graduated cylinders, caffeine solutions, white paper,
markers, poster paper
Introduce the term ‘caffeine’ and ask the class to help make a concept map on the board as in
Activity 1.
**The teacher should prepare the caffeine solutions in advance for the Blackworm Lab, as in
Activity 1 (see preparation instructions in the lab packet).
1. Ask the students to form groups and conduct the caffeine portion of the experiment from
the Toxicants and Worms Lab Packet, and answer the questions based on their
observations of the effects of caffeine, nicotine and ethanol. They should compare and
contrast the effects.
5. For homework, ask the students to ‘think of the next experiment’ based on what they
have done in the activity and make a cartoon diagram.
6. The next experiments should be reviewed in panel. Make sure the groups define their
criteria for a successful project before reviewing the next experiments.
7. Share the group project selections and criteria as a class.
Backyard Toxicology: Activity 10- CREATE Article 3
Activity Description: This activity is a repeat of Activities 26 using the third in a series of articles on the effects of
ethanol on honeybees, written by a single research group.
The goal is to scaffold the skills of CREATE while allowing
the students to see the actual progression of scientific
research in a laboratory.
5 classes (5- 7.5 hours)
Pre-activity:
Process Skills Goals: teamwork, concept
mapping, cartooning, critical thinking
Major Assignment: CREATE process using
Article 3
Knowledge Goals: how to read the
scientific paper, visualize scientific
research in the form of a cartoon,
rephrase scientific jargon to get at the
underlying information presented, use
scientific information presented in a
publication to determine the hypothesis
of the study formulate scientific research
projects, evaluate scientific research,
with peers, evaluate scientific literature
and use critical thinking to form
conclusions based on results and
hypotheses
Formative- concept maps of introductions,
cartooning results, table and figure captions and
annotations, hypotheses, CREATE analysis
templates, students conclusions, list of author
conclusions, student proposals, group proposal
criteria, vocabulary notebooks
Materials: Article 3, CREATE analysis templates, white paper, poster paper, markers,
vocabulary notebooks
The teacher should gauge the participation level and enthusiasm of the class and assign portions
of the CREATE process for homework accordingly. Progressively more homework than Atricle
2. Refer to the Activities 2-6, and the Hoskins articles for detailed instructions on each step.
C- Concept map the introduction
R- Read the results, cartooning experiments, captioning and annotating tables and figures
E- Elucidate the hypothesis (for each table and figure)
A- Analyze and Interpret the data (using the CREATE Analysis template)
TE- Think of the next Experiment- cartoon a proposal, Review Boards select the best one
Psychological Reports, 2010, 106, 3, 1-17. © Psychological Reports 2010
THE BEHAVIOR AND SOCIAL COMMUNICATION OF
HONEY BEES (APIS MELLIFERA CARNICA POLL.)
UNDER THE INFLUENCE OF ALCOHOL1, 2
T. ANDREW MIXSON AND CHARLES I. ABRAMSON
Oklahoma State University
JANKO BOŽIČ
University of Ljubljana
Summary.—In this study, the effects of ethanol on honey bee social communication and behavior within the hive were studied to further investigate the usefulness
of honey bees as an ethanol-abuse model. Control (1.5 M sucrose) and experimental (1.5 M sucrose, 2.5% w/v ethanol) solutions were directly administered to individual forager bees via proboscis contact with glass capillary tubes. The duration,
frequency, and proportion of time spent performing social and nonsocial behaviors
were the dependent variables of interest. No differences in the relative frequency or
proportion of time spent performing the target behaviors were observed. However,
ethanol consumption significantly decreased bouts of walking, resting, and the
duration of trophallactic (i.e., food-exchange) encounters. The results of this study
suggest that a low dose of ethanol is sufficient to disrupt both social and nonsocial
behaviors in honey bees. In view of these results, future behavioral-genetic investigations of honey bee social behavior are encouraged.
Ethyl alcohol, or ethanol, is best known for its role as the intoxicating agent in alcoholic beverages. In humans, impairments of memory
and learning (Moulton, Petros, Apostal, Park, Ronning, King, et al., 2005;
Soderlund, Parker, Schwartz, & Tulving, 2005; Mintzer, 2007), visual acuity and depth perception (Watten & Lie, 1996; Nawrot, Nordenstrom, &
Olson, 2004; Souto, Bezerra, & Halsey, 2008), fine and gross motor skills
(McNaughton & Preece, 1986; Breckenridge & Berger, 1990; Marczinski,
Harrison, & Fillmore, 2008), and decision-making abilities (Field, Christiansen, Cole, & Goudie, 2007; Phillips & Ogeil, 2007; Stoner, George,
Peters, & Norris, 2007) are common short-term effects of acute ethanol
consumption. Long-term ethanol consumption places individuals at an
elevated risk of several chronic health problems including hepatic damage (Ekstedt, Franzén, Holmqvist, Bendsten, Mathiesen, Bodemar, et al.,
2009; Hatton, Burton, Nash, Munn, Burgoyne, & Sheron, 2009), pancreatiAddress correspondence to Dr. Charles I. Abramson, Laboratory of Comparative Psychology and Behavioral Biology, Departments of Psychology and Zoology, Oklahoma State 116
N. Murray, Stillwater, OK 74078 or e-mail ([email protected]).
2
Mr. Mixson was supported by a Lew Wentz Foundation Research Project Award. The authors thank Dr. James W. Grice for his suggestions and comments regarding the statistical
analyses.
1
DOI 10.2466/PR0.106.3.
ISSN 0033-2941
2
T. A. MIXSON, ET AL.
tis (Webster, 1975), and sexual dysfunction (Mandell & Miller, 1983; Cocores, Miller, Pottash, & Gold, 1988; Grinshpoon, Margolis, Weizman, &
Ponizovsky, 2007). Alcohol consumption during pregnancy can also damage the developing human fetus. The Centers for Disease Control (2005)
estimate that the fetal alcohol syndrome rate in the United States ranges
from 0.2 to 1.5 per 1,000 live births.
The effects of alcohol abuse on society are deep-reaching. Annually
claiming an estimated 79,000 lives, excessive alcohol use constitutes the
third leading lifestyle-related cause of death in the United States (Centers for Disease Control, 2008). According to the National Highway Traffic Safety Administration (2008), nearly one-third of all traffic fatalities in
2006 and 2007 were related to alcohol-impaired driving. Moreover, toxicology testing conducted by the Centers for Disease Control revealed that
one-third of those who committed suicide in 2003 tested positive for alcohol (Karch, Crosby, & Simon, 2006). Social pressures from friends and
peers play a key role in the prevalence of alcohol abuse and underage
drinking, which suggests that some individuals may be at risk of forming a dependence on alcohol at an early age (Graham, Marks, & Hansen,
1991). The above-mentioned problems represent only a small fraction of
the total number of public health issues that stem from alcohol misuse.
However, the experimental study of ethanol’s effects on human health and
behavior is limited by obvious ethical and moral constraints (Dolinsky
& Babor, 1997). This is problematic in the development of effective treatments and recovery programs for alcoholics.
As a result, researchers have extensively developed invertebrate
models to study the pharmacology of alcohol tolerance, dependence,
and abuse. Research has demonstrated that the molecular architecture
of invertebrate and vertebrate nervous systems share several similarities
(Abramson, Sanderson, Painter, Barnett, & Wells, 2005). For example, both
types of organisms have ligand- and voltage-gated ion channels, and Gprotein coupled receptors (Harris, 1999; Holmes, Barhoumi, Nachman,
& Pietrantonio, 2003). Studies focusing on the fruit fly, Drosophila melanogaster, and the roundworm, Caenorhabditis elegans, have made impressive strides in elucidating the metabolic pathways implicated in ethanolinduced intoxication. Results generated from research with these model
organisms have also demonstrated high symmetry with findings from
vertebrate studies (Lovinger & Crabbe, 2005). For example, Singh and Heberlein (2000) demonstrated that the concentrations of ethanol required
to induce locomotor behaviors in D. melanogaster are similar to those described in humans. On a molecular level, cAMP-associated signaling proteins have been implicated in effects related to acute and chronic ethanol exposure in both fruit flies and mice (Moore, DeZazzo, Luk, Tully,
HONEY BEES: ALCOHOL-CONSUMPTION MODEL
3
Singh, & Heberlein, 1998; Thiele, Willis, Stadler, Reynolds, Bernstein, &
McKnight, 2000).
Work with C. elegans has also improved understanding of the genetics
of alcohol-induced effects on behavior. Davies, Pierce-Shimomura, Kim,
VanHoven, Thiele, Bonci, et al. (2003) discovered that ethanol sensitivity
in C. elegans is dependent on neuronal expression of the slo-1 gene. This
gene derives its name from the slowpoke ortholog gene in D. melanogaster, which is known to encode a large conductance calcium-activated BK
potassium channel (Wang, Saifee, Nonet, & Salkoff, 2001; Davies, et al.,
2003). In C. elegans, slo-1 loss-of-function mutations result in ethanol resistance, while slo-1 gain-of-function mutations result in the depression
of locomotion and egg-laying behaviors (see Davies, et al., 2003). Several
studies have demonstrated that mammalian BK potassium channels are
also sensitive to ethanol (Dopico, Anantharam, & Treistman, 1998; Gruss,
Henrich, König, Hempelmann, Vogel, & Scholz, 2001). Interestingly, BK
potassium channels also mediate muscle contraction, neurotransmitter release, and hormonal secretion in mammals (Sah, 1996; Davies, et al., 2003).
It should be noted that the above-mentioned studies represent only a
small fraction of the massive amount of alcohol research conducted with
D. melanogaster and C. elegans. These studies highlight the usefulness of a
simple systems approach in elucidating the mechanisms that mediate ethanol’s various biochemical, genetic, and molecular-level modes of action.
Continued research with these organisms is sure to involve the discovery of many other parallels between mammalian and invertebrate nervous
systems. Nevertheless, research with these organisms is somewhat limited to fairly simple motor responses (Wolf & Heberlein, 2003). This shortcoming arguably reduces the comparative value of behavioral research
conducted with these organisms.
At first glance, the honey bee may seem an unlikely organism for
alcohol research. However, in contrast to the abovementioned invertebrate ethanol models, honey bees have a very expansive behavioral repertoire that can be analyzed following acute or chronic ethanol consumption (Wolf & Heberlein, 2003; Abramson, et al., 2005). Much is also known
about the natural history, physiology, genetics, and behavior of this species. Given the social structure and caste differentiation of honey bees, foraging workers rely heavily on social behaviors such as the waggle dance
to relay information about nearby food sources (von Frisch, 1965). This
complex social structure and division of labor exhibited by the honey bee
has also garnered much attention from behavioral geneticists (Ruppell,
Pankiw, & Page, 2004; Whitfield, Cziko, & Robinson, 2003). Indeed, considerable advances in the understanding of the genetic mechanisms which
underlie honey bee foraging and nest-defense behaviors have been made
4
recently (Giray & Robinson, 1996; Ruppell, et al., 2004; Hunt, Amdam,
Schlipalius, Emore, Sardesai, Williams, et al., 2007; Alaux, Sinha, Hasadsri,
Hunt, Guzman-Novoa, DeGrandi-Hoffman, et al., 2009).
Despite the novelty of eusocial insects, it should be emphasized that
the social structure of honey bees is markedly different from the social nature of humans. Cross-species comparisons regarding the social nature of
individual humans and honey bees indeed warrant cautious interpretation. This seemingly limits the value of studying ethanol’s effects on honey
bee behavior. However, it should be noted that an important facet of eusocial insect life is that the behavior of individuals is exceedingly simplified,
compared to the behavioral repertoire of solitary insects (Oster & Wilson,
1978). As a result, the experimenter is provided with added experimental
control that is not available when working with organisms that exhibit a
higher prevalence of idiosyncratic differences in behavior.
This should not imply, however, that similarities do not exist between
humans and honey bees, and that informative cross-species comparisons
cannot be made. For example, it has been demonstrated that ethanol induces aggression and the disruption of locomotive, learning, and decision-making abilities in both humans and honey bees (Abramson, Stone,
Ortez, Luccardi, Vann, Hanig, et al., 2000; Abramson, Place, Aquino, &
Fernandez, 2004; Abramson, et al., 2005; Božič, Abramson, & Bendencic,
2006). Like humans, honey bees also demonstrate self-administration of
ethanol and exhibit preferences for commercially available alcoholic beverages (Abramson, Kandolf, Sheridan, Donohue, Božič, Meyers, et al.,
2004). Moreover, Antabuse® (disulfarim) is also capable of limiting ethanol consumption in honey bees (Abramson, Fellows, Browne, Lawson, &
Ortiz, 2003). Despite these interesting findings, knowledge of ethanol’s effects on the relative frequency and duration of social and nonsocial behaviors within the colony is rudimentary.
Previous work has established that a 5% ethanol solution significantly
reduces the foraging activity of worker bees, with a 1% ethanol solution
causing an increase in the return time of foragers from the food source to
the hive (Božič, et al., 2006). Significant increases in the frequency of trophallaxis, tremble dancing, and self-cleaning within the hive occur relative
to foraging visits from artificial feeders containing increasing concentrations of ethanol. That is, the frequency of these behaviors increases with
increasing concentrations of ethanol up to 10%. The same study revealed
that the frequency of waggle dancing is negatively correlated with the
consumption of increasing concentrations of ethanol. The primary aim of
this study was to expand current knowledge of ethanol’s effects on honey
bee behavior by identifying its actions on the following three dependent
variables, i.e., the measures of individual honey bee behavior listed in Ta-
5
ble 1: (1) the relative frequency of occurrence of behaviors, (2) the overall
proportion of time spent performing each type of behavior, and (3) the
duration of individual behavior displays. Given the results of previous research, it was hypothesized that relative to sucrose-treated foragers, ethanol-treated foragers will undergo a decrease in the magnitude of each of
the abovementioned measures of those behaviors listed in Table 1.
Method
Subjects
Carniolan honey bees (Apis mellifera carnica) were reared in a twoframe observation hive during May 2008 at the University of Ljubljana, Slovenia. Forager bees (N = 400) were captured at the hive entrance,
marked with numbered identification tags, and reintroduced into the
hive. Application of the ID tags was accomplished by capturing individual bees at the hive entrance with a plastic vial as they flew out of the hive.
Each bee was then placed under a plastic mesh screen, a small amount of
adhesive was applied to the thorax using a toothpick, and a plastic identification tag measuring about 4 mm in diameter was immediately applied
to the adhesive. Identification tags of various colors with numbers ranging
from 1 to 99 were utilized in this study. A small amount of pressure was
applied to the tag with the toothpick for approximately 15 sec. to allow
the adhesive to cure. After applying the identification tag, the plastic mesh
screen was removed, and the bees were released. These tags can be easily
acquired from a company that sells beekeeping equipment, as beekeepers
typically use them to aid in visually identifying the queen.
Experiments did not begin until two days following the application
of all identification tags. The behaviors of 26 individual marked bees (control: n = 13; experimental: n = 13) bees observed. This small sample resulted
from the fact that individual bees were not included in the experiment unless they were observed to successfully follow a waggle dance. Typically,
bees located around a waggle dancer will exhibit attending or following
the dance. Following is distinguished from attending, in that the former
requires the bee to follow the dancer’s abdomen for two complete turns
of the figure-eight waggle dance (see Božič & Abramson, 2003). This stringent criterion was utilized to ensure that the bees included in the experiment were in fact forager bees, and not nurse bees. Both forager and nurse
bees are colloquially referred to as worker bees, but worker bees do not
typically leave the hive to forage for pollen and nectar until they are about
20+ days old (Seeley, 1982). Failure to control for age-related differences in
behavior would result in ambiguous results and make it nearly impossible
to attribute any experimental effects to the ethanol treatment.
6
Measures
The behaviors listed in Table 1 were recorded for 1 hr. with a Canon MV600i miniDV camcorder for each of the experimental and control
group subjects. The postfeeding videos were analyzed to document the
frequency and duration (in sec.) of the 14 target behaviors described in
Table 1.
Procedures
Following a waggle dance, marked foragers were fed either a control
(1.5 M sucrose) or experimental (2.5% w/v ethanol in 1.5 M sucrose) solution via direct proboscis contact with 100 mm glass capillary tubes containing the solutions. A 2.5% (w/v) ethanol concentration in 1.5 M sucrose
was utilized because it is known from previous work that a 5% ethanol solution will significantly disrupt honey bee behavior both under laboratory
and field conditions (Božič, et al., 2006). Furthermore, ethanol concentrations equal to or greater than 10% severely inhibit movement and foraging
activity (Božič, et al., 2006), while a 5% ethanol solution significantly impairs Pavlovian conditioning of the proboscis extension reflex (Abramson,
et al., 2000). In other words, the 2.5% w/v concentration was selected to
further specify the alcohol tolerance threshold on honey bee behavior and
to prevent a severe disruption of behavior that would otherwise occur
with a higher ethanol concentration.
This procedure took place for a 1-hr. period, and each bee was fed for
approximately 2 sec. or until it stopped consuming the solution as indicated by retraction of the proboscis, whichever occurred first. It should
be noted that this methodology did not allow measurement of the total
volume of liquid imbibed by each bee. However, each individual was allowed to imbibe the control or experimental solution ad libitum after it
was placed into contact with the proboscis. This is a unique aspect of the
experimental design, in that it minimizes experimenter interaction with
the hive and enhances the value of the experiment as a field study. In other words, by requiring individual bees to consume a fixed volume of the
control or experimental solution, excessive disruption of the naturally occurring behaviors of the subject would have occurred. The use of capillary
tubes to administer the solutions also allowed selective treatment of the
control and experimental group subjects with the proper solutions. Moreover, from a comparative perspective, it is critical to remember that humans also exhibit individual differences in the amount of alcohol they will
consume voluntarily in a given period of time (Weafer & Fillmore, 2008).
Previous work with harnessed honey bees revealed that ethanol concentrations in the hemolymph approached 23 mM approximately 30 min.
after bees consumed 10 μL of a 2.5% ethanol solution in 1.5 M sucrose
(Božič, et al., 2006); for resting periods longer than 1 hr., blood ethanol
Swarm chain
Trophallaxis
Trail follow
Tremble dance
Attending tremble dance
Waggle dancing
Attending a waggle dance
Following
SC
FE
TF
TD
ATD
D
A
F
RS
Resting
In cell
Self-cleaning
Walking
Walking after following a waggle
dance
Resting in swarm
Behavior
R
INC
CL
W
WF
Abbreviation
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Social
Description
Bee remains stationary.
Bee deposits nectar or pollen in a comb cell.
Bee removes pollen particles from its body.
Bee traverses the hive.
Walking activity that occurs after a bee follows a waggle dance; the interval of
time that elapses before the bee exits the hive after following a waggle dance.
Bee remains stationary but clings to other bees with its legs as they traverse
the hive.
Bee interlocks its legs with bees above and below it.
Bee shares nectar with another bee via proboscis contact.
Bee follows the walking path of another bee.
Irregular movements in all directions.
Bee attends a tremble dance.
Bee performs a waggle dance.
Bee attends a waggle dance.
Bee follows a waggle dance (bee must follow the dancer for two complete cycles
of the figure-eight movement).
TABLE 1
Behavior Descriptions and Abbreviation Key
7
8
concentrations remained relatively stable for at least 8 hr. following ethanol ingestion. Immediately following the 1-hr. feeding period, the hive
was filmed for 1 hr. with a Canon MV600i miniDV camcorder. A total of
seven feeding and postfeeding trials were conducted. To control for calendar variables, bees from both groups were included in each feeding trial.
No more than two feeding trials and observation periods were conducted
each day, in order to keep from compounding the honey bees’ blood ethanol concentrations. The postfeeding videos were analyzed to document
the frequency and duration of the 14 target behaviors described in Table 1.
Analysis
The above-mentioned measures of the behaviors identified in Table 1
were analyzed with the nonparametric, Mann-Whitney U statistical test to
identify significant differences between control (sucrose-treated) and experimental (ethanol-treated) group subjects. Data were analyzed with this
statistic, because an exploratory data analysis revealed that most of the
three measures of the behaviors listed in Table 1 violated assumptions of
normality and homogeneity of variance. Following the recommendations
of Field (2005, p. 532), effect size estimates for the Mann-Whitney U test
were calculated by converting the z-score reported by SPSS into an effect
size estimate, r. To make quantitative comparisons across the three measures of the behaviors listed in Table 1 possible, sample sizes, z-scores, and
effect size estimates are reported in addition to the U statistics and p values in Tables 2, 3, and 4. All statistical analyses were performed with SPSS
16.0 for Windows.
Results
The following measures of each social and nonsocial behavior listed
in Table 1 were analyzed for each individual bee: (1) the relative frequency
of occurrence of each behavior, (2) the proportion of total time spent performing each behavior, and (3) the duration of each individual behavioral display. Individual behavior displays (N = 994; control: n = 486; experimental: n = 508) were observed. The duration of each of these behavioral
displays was also recorded, yielding a total of 11.4 hr. of behavioral data.
Ethanol-treated foragers did not differ from sucrose-treated foragers
in terms of their relative frequency (see Table 2) or proportion of total time
(see Table 3) spent performing each of the target behaviors listed in Table
1. However, compared to sucrose-treated foragers (Mdn = 32.5 sec.), ethanol-treated foragers (Mdn = 14.5 sec.) had significantly shorter instances of
resting (U = 534.5, p < .001, r = .35, two-tailed test). Ethanol-treated foragers
also spent significantly less time per instance of walking (Mdn = 31.9 sec.)
than did sucrose-treated foragers (Mdn = 33.8 sec.; U = 23289.5, p = .037,
r = .10, two-tailed test). In other words, although sucrose- and ethanol-
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
C
E
R
0
0
.02
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.41
.42
0
0
0
0
0
0
Min.
0
0
.06
0
0
0
0
0
0
0
.03
.04
.08
0
0
0
0
0
0
0
.43
.47
0
0
0
.03
Q1
0
0
.04
0
.09
.10
0
0
0
0
0
0
.07
.06
.13
.09
0
0
0
0
.02
0
.45
.47
0
0
.05
.03
0
.03
Median
.13
.20
.04
.08
0
0
0
0
0
.08
.10
.17
.14
.01
0
0
0
0
.15
.07
.08
.11
.01
.01
.47
.52
.04
.05
Q3
.23
.25
.17
.12
0
.24
.20
.44
.16
.07
.05
.75
.75
.08
.07
.06
.03
.08
.04
.16
.14
.25
.20
.03
.21
.04
.16
.07
Max.
n
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
Z
r
.20
−1.00
−1.26
.25
.22
.01
−.06
−1.13
.03
.09
−.44
−.16
.11
.11
−.56
−.57
.03
.16
.37
.04
.26
.15
−.16
−.81
−1.90
−.19
−1.33
−.75
U
61.5
62.5
78.0
84.0
82.0
76.0
73.5
77.0
82.5
69.5
47.5
81.5
59.0
71.0
p
.207
.258
.317
.956
.870
.663
.567
.576
.870
.418
.058
.851
.184
.451
Note.—C = control group subjects (1.5 M sucrose); E = experimental group subjects [1.5 M sucrose, 2.5% (w/v) ethanol]; Min. = minimum;
Max. = maximum; Q1 = first quartile (25%), Q3 = third quartile (75%); n = number of bees: control = 13, experimental = 13; Z = z statistic reported by
SPSS; r = effect size estimate. Refer to Table 1 for behavior key. All minimum, median, maximum, and quartile values are reported as frequencies.
F
A
D
ATD
TD
TF
FE
SC
RS
WF
W
CL
INC
Group
Behavior
TABLE 2
Descriptive Statistics and Mann-Whitney U Results of the Relative Frequency of Occurrence of Each Behavior
9
Group
Min.
Q1
Median
Q3
Max.
n
Z
r
U
p
C
0
0
.01
.12
.33
13
−.70
.14
72.0
.485
E
0
0
0
.08
.27
13
INC
C
0
0
.02
.03
.26
13
−.81
.16
69.0
.420
E
0
0
.01
.03
.15
13
CL
C
0
0
0
0
.01
13
−.19
.04
81.5
.851
E
0
0
0
0
.02
13
W
C
.41
.55
.81
.84
.99
13
−1.00
.20
65.0
.317
E
.60
.73
.84
.93
.97
13
WF
C
0
0
0
0
.04
13
−.86
.17
68.5
.388
E
0
0
0
.02
.10
13
RS
C
0
0
0
0
.08
13
−.08
.02
83.5
.935
E
0
0
0
0
.06
13
SC
C
0
0
0
0
.26
13
−.63
.12
76.0
.526
E
0
0
0
0
.11
13
FE
C
0
0
0
.01
.03
13
−.39
.08
77.0
.696
E
0
0
.01
.01
.03
13
TF
C
0
0
.02
.03
.07
13
−.08
.02
83.0
.939
E
0
.01
.01
.02
.05
13
TD
C
0
0
0
0
.01
13
−.10
.02
83.0
.922
E
0
0
0
0
.03
13
ATD
C
0
0
0
0
.01
13
−.06
.01
84.0
.956
E
0
0
0
0
.04
13
D
C
0
0
0
0
.03
13
−1.00
.20
78.0
.317
E
0
0
0
0
0
13
A
C
0
.01
.02
.03
.06
13
−.39
.08
77.0
.700
E
0
.01
.02
.03
.06
13
F
C
0
0
0
.02
.08
13
−1.5
.30
57.5
.132
E
0
0
.02
.04
.06
13
Note.—C = control (1.5 M sucrose) group subjects; E = experimental [1.5 M sucrose, 2.5% (w/v) ethanol] group subjects; Q1 = first quartile (25%),
Q3 = third quartile (75%); n = number of bees: control = 13, experimental = 13; Z = z statistic reported by SPSS; r = effect size estimate. Refer to Table
1 for behavior key. All minimum, median, maximum, and quartile values are reported as proportions.
R
Behavior
TABLE 3
Descriptive Statistics and Mann-Whitney U Results of the Overall Proportion of Time Spent Performing Each Behavior
10
Behavior
Group
Min.
Q1
Median
Q3
Max.
n
Z
r
U
p
C
4.43
19.8
32.5
58.4
668
45
−3.22
.35
534.5
.001†
E
1.13
5.04
14.5
41.7
285
40
INC
C
.460
1.53
3.85
6.21
88.2
32
−.35
.04
455.0
.725
E
.900
1.89
3.19
13.3
53.6
30
CL
C
1.07
2.14
5.97
6.93
10.0
7
−1.43
.40
11.0
.153
E
3.23
6.02
8.17
16.0
20.0
6
W
C
.240
14.5
33.8
81.9
583
216
−2.08
.10
23,290
.037*
E
.533
7.18
31.9
70.9
1686
243
WF
C
1.77
6.07
7.78
10.5
31.9
8
−.62
.15
33.0
.534
E
1.27
6.12
10.4
22.3
138
10
RS
C
4.86
23.9
30.0
104
130
6
−.33
.12
5.00
.739
E
8.67
51.2
93.7
136
179
2
SC
C
27.8
89.3
128
273
522
7
−1.25
.40
5.00
.210
E
22.4
23.9
25.3
169
313
3
FE
C
.200
1.63
3.53
10.8
43.8
37
−1.94
.24
416.0
.052
E
.267
1.03
2.33
4.68
22.9
31
TF
C
.960
3.35
6.52
8.99
26.2
54
−.13
.01
1,170
.895
E
1.73
3.90
5.90
9.73
16.8
44
TD
C
.700
2.75
4.70
9.08
18.4
4
−1.43
.25
32.0
.151
E
1.07
1.50
1.92
2.23
7.0
29
ATD
C
10.7
10.7
10.7
10.7
10.7
1
−.66
.25
2.00
.513
E
2.13
2.48
4.10
9.72
17.2
7
D
C
37.3
37.3
37.3
37.3
37.3
1
na
na
na
na
E
0
0
0
0
0
0
A
C
1.50
5.27
8.12
12.3
45.6
50
−.12
.01
911.5
.908
E
2.40
4.73
7.57
10.7
27.7
37
F
C
6.36
13.8
17.8
23.6
39.2
10
−.44
.08
90.0
.660
E
5.10
10.9
18.1
24.8
108
20
Note.—C = control group subjects (1.5 M sucrose); E = experimental group subjects [1.5 M sucrose, 2.5% (w/v) ethanol]; Q1 = first quartile (25%),
Q3 = third quartile (75%); na = not available; n = behavior frequency (the total number of individual behavior displays produced by each of the
thirteen bees in each group); Z = z statistic reported by SPSS; r = effect size estimate. Number of bees included in experiment: control = 13, experimental = 13. Refer to Table 1 for behavior key. All minimum, median, maximum, and quartile values are reported in seconds. The U- and p-values of dance (D) behavior could not be computed because only a single instance of this behavior occurred. *p < .05. †p < .01.
R
TABLE 4
Descriptive Statistics and Mann-Whitney U Results of the Duration of Individual Behavior Displays
11
12
treated foragers did not differ in the total amount of time walking or resting, when the inebriated forager bees walked or rested, they did so for
relatively shorter periods of time. The mean duration of individual instances of trophallaxis between control and experimental group subjects
was not significant, but of substantial effect size; ethanol-treated subjects
displayed shorter bouts of food exchanges with hive mates (Mdn = 2.33
sec.) than did sucrose-treated subjects (Mdn = 3.53 sec.; U = 416, p = .052,
r = .24, two-tailed test). Additional Mann-Whitney U tests revealed that the
lengths of individual displays of the remaining behaviors did not differ
between control and experimental group bees (see Table 4).
Discussion
No significant effects of ethanol on the relative frequency or proportion of time spent performing each of the target behaviors were observed
(see Tables 2 and 3). This null effect may be attributable to insufficient
sample sizes for both the control and experimental groups. It should also
be noted that only a single instance of waggle dancing was observed by a
marked forager in the 11.4 hr. of behavioral data collected from the postfeeding video recordings. This low rate of waggle dancing is indicative of
depressed foraging activity that may have been induced by weather and
seasonality. Negative results are never appealing; however, the lack of any
effect on the relative frequency or proportion of time spent performing the
target behaviors minimally implies that ethanol treatment does not significantly disrupt the division of labor within the hive. That is, the forager
bees included in the experiment continued to perform similar activities
within the hive regardless of whether they consumed ethanol. However,
several significant effects were identified when considering the length of
individual behavior displays.
For example, the duration of bouts of walking and resting were significantly lower in the experimental group subjects (see Table 4). These
shorter resting and walking behavior events suggest a higher frequency
of behavior changes in ethanol-treated bees. These results also suggest
that a low dose of ethanol stimulates mobility and movement in honey
bees, as indicated by the decreased duration of resting and walking displays in the ethanol-treated subjects. Interestingly, lower doses of ethanol
stimulate walking speed in Drosophila, or fruit flies, while higher doses
reduce movement and mobility (Wolf & Heberlein, 2003). Previous work
has demonstrated that high doses of ethanol also reduce movement and
mobility in honey bees (Abramson, et al., 2000). The concentrations of ethanol required to stimulate locomotion and reduce coordination in Drosophila are remarkably similar to those required to cause the same effects
in humans (Singh & Heberlein, 2000).
13
In terms of social behavior, previous research demonstrated a significant overall increase in trophallactic activity when compared to feeder
visits in a colony that was allowed to forage freely from a 10% ethanol solution (Božič et al., 2006). In the present study, bees fed a 2.5% ethanol solution did not exhibit an increase in the frequency or proportion of time
spent engaged in trophallactic encounters. Nevertheless, experimentalgroup (i.e., ethanol-treated) subjects did perform shorter food exchanges
with surrounding bees relative to control subjects (see Table 4). Hence, it
appears that a low dose of ethanol is sufficient to also induce a higher frequency of change in the display of social behaviors. This result does warrant great caution in interpretation, as other social behaviors including
waggle dancing, attending, and following were not affected in the present
study following ethanol consumption. This finding does indicate, however, that the social behaviors of honey bees are differentially affected by
ethanol. This could be attributed to the likely explanation that different social behaviors in honey bees are controlled by the expression of different
sets of genes and gene products.
Much of what is known about the genetic bases of ethanol tolerance
and metabolism in invertebrates has been elucidated by research efforts
focusing on D. melanogaster and C. elegans as ethanol models. However,
the behavioral repertoire of these organisms is limited to simple motor responses (Wolf & Heberlein, 2003; Abramson, et al., 2005) and these species
lack a complex social structure and related social behaviors. In this respect,
the honey bee (Apis mellifera) has the potential to complement behavioralgenetic studies with Drosophila and C. elegans, especially in the study of
ethanol’s effects on the genetic underpinnings of socially-related behaviors. Several genes implicated in the actions of ethanol have been mostly
conserved between arthropods and vertebrates (Heberlein, Wolf, Rothenflush, & Guarnieri, 2004). Given the conservative nature of these genes, future investigations of the molecular-genetic and neural bases of the ethanol-induced behaviors observed in the present study are warranted.
A total genome library of the honey bee is available online at
http://www.hgsc.bcm.tmc.edu/projects/honeybee/. Coupled with increasing knowledge of the functional genetics of D. melanogaster and C. elegans,
such a database will provide new opportunities to elucidate the molecular
bases of ethanol-induced behaviors in the honey bee. This type of future
research is absolutely critical if cross-species comparisons of the effects of
acute ethanol intoxication on social behaviors are to be made between humans and honey bees. Behavioral-genetic studies with the honey bee have
the potential to substantiate its efficacy as a valid ethanol model for the
comparative purpose of better understanding alcohol’s various modes of
action in humans.
14
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Accepted April 21, 2010.
Backyard Toxicology: Activity 11- Serial Dilutions
Activity Description: This activity is an essential skill for
toxicological research. The activity is simply intended to
serve as a skill builder for the subsequent activity. Students
should learn to successfully make serial dilutions of a
solution.
1 class (1- 1.5 hours)
Pre-activity:
Process Skills Goals: teamwork,
following laboratory instructions
Major Assignment: In groups, make serial
dilutions of CuSO4
Knowledge Goals: how to measure using
a balance, how to measure using a
graduated cylinder and pipette, how to
make serial dilutions.
Formative- none
Materials: Lab Instructions, CuSO4, H2O, Balance, Graduated cylinder, Test tubes, Pipettes,
Stirring rods, Volumetric flask
Tell the class that CuSO4 (copper sulfate) makes a blue solution in water. As the concentration of
dissolved particles decreases, the value of the color becomes lighter because there are fewer
particles to reflect the light. This is similar to adding water to a glass of soda, the more water
you add, the more dilute the soda becomes because there the ratio of soda particles to water
particles increases.
Monitor group progress.
Serial Dilutions of CuSO4 In this exercise you will learn how to perform serial dilutions of chemicals. Background CuSO4 (copper sulfate) makes a blue solution in water. As the concentration of dissolved particles decreases, the value of the color becomes lighter because there are fewer particles to reflect the light. Materials CuSO4 H2O Balance Graduated cylinder Test tubes Pipettes Stirring rods Volumetric flask Procedure Start with the most concentrated solution. Decide what final volume you want for each solution, and begin with twice that. (In this example, we’ll use 10 mL for each treatment, so start with 20 mL of your most concentrated solution.) Take half this amount (10 mL) and add it to the same volume of water (10 mL). This is your first dilution, and its concentration is half that of the starting solution. Repeat by removing half the volume of this solution, and again, adding it to the same volume of water. Repeat until all the dilutions are made. You will have to discard half of the volume of your last dilution to make the final volumes all equal. (Try 5‐fold or 10‐fold serial dilutions to cover a broader range of doses.) 1. Make 100.0 mL of a 0.5 CuSO4 molar solution in a volumetric flask. 2. Using a pipette, transfer ________ this solution to a graduated cylinder and add distilled water up to 20.0 mL. Put into test tube. 3. Now take _______ of this second solution and transfer it to another 10.0 mL graduated cylinder and add water to make a 10.0 mL solution. 4. Continue transferring 1.0 mL of each solution and diluting it four more times or until the solution is colorless. This is called serial dilution. 5. Show calculations for making the original solution, and calculate the molarity of each of the other six solutions. Backyard Toxicology: Activity 12- Experiment Proposals
Activity Description: This activity begins the second phase
of the course: CREATE research. Students will propose their
own research projects based on the articles they have read
and experiments they have performed in class. The class will
then form Review Panels and each panel will develop criteria
and then select the best project from another group.
scientific thinking
Pre-activity:
Major Assignment: groups will concept map
‘toxicants in the environments’, for homework
students will cartoon a research proposal, groups
will evaluate proposals from other groups in a
Phase I Review Panel
research proposals, and how to engage in
active scientific discussion with peers
Formative- group concept maps, individually
cartooned research proposal, group review panel
criteria
Materials: previous activities, articles, white paper, markers, poster paper
1. In class, have the groups concept map toxicants in their environment.
2. For homework, each student is assigned the task of cartooning an experiment idea just as
they did for the CREATE articles. They can draw from any resource for ideas and are
NOT limited to the next blackworm experiment. The only rule is that the toxicant cannot
be hazardous for handling by the students and the organism must be either a plant or an
invertebrate.
a. In addition to the cartoon the students should clearly define the hypothesis being
tested, the control and experimental groups, and a list of the materials needed.
1. In class have groups exchange their cartooned experiments. Each group now becomes a
Phase I Panel reviewing the proposals from one other group. The Panel will select the
best proposal from the group and must also make recommendations to improve the
practicality or feasibility of the project. The group (that the proposal originated from) will
then conduct the experiment from the proposal selected taking the recommendations into
consideration.
** The teacher must review the selected proposal and make feasibility recommendations to
ensure the projects are actually possible for classroom research. This is phase II of the review
process.
Backyard Toxicology: Activity 13- Research Projects
Activity Description: This activity continues the second
phase of the course: CREATE research. Students will
conduct the Panel selected experiments they proposed in
Activity 12. Before beginning their research, students must
each summarize and present an article to their group. They
must then write an introduction section to be submitted to the
instructor along with their supplies ‘order’ for their
experiment.
scientific thinking
projects, how to synthesize a scientific
article, and how to engage in active
scientific discussion with peers, how to
write an introduction to a scientific
article, how to conduct (and modify) a
scientific experiment
Pre-activity: Find, read and
summarize an article on the
topic of your research
Major Assignment: Formulate and conduct a
research project in groups. First read, summarize
and present an article to the group. Then as a
group write an introduction section from the
summarized articles and prepare a supplies order
for your project. Then prepare appropriate data
tables for recording the data collected. Then
conduct the experiment, refine and repeat.
participation in groups
Formative- individual article summaries, group
introductions, group supply orders, group data
tables
Materials: lab supplies as requested in group supply orders
1. The groups should prepare an “order” of the materials needed for their selected project.
2. For the project selected, the students in the group should each find one related
background article in google scholar and present a summary of the article to their group
members. The group should then prepare a 1-2 page Introduction for their project.
**The teacher should obtain the materials needed by the class during this period.
3. Data collection tables should be prepared by groups for each part of the experiment. Once
the teacher approves them, the students can proceed with their experiment.
4. Groups should be encouraged to modify and repeat experiments as needed and as time
allows.
Backyard Toxicology: Activity 14- Reporting Results
Activity Description: Students should draw from their
knowledge of the articles they read during the CREATE
process to create appropriate tables and figures of their
results. Conclusions should be drawn from the results just as
in the articles with the CREATE method. Each group will
then present their projects to the class.
scientific thinking
2-5 classes (4- 7.5 hours)
Pre-activity: Clean up data
tables from experiment
Major Assignment: Formulate results and draw
conclusions from research. Present a research
project to peers in groups.
participation in groups
Formative- group tables and figures, group
conclusions, group presentations
projects, and how to engage in active
scientific discussion with peers, how to
write results and conclusion sections of a
scientific article, how to present the
results of a scientific experiment
Materials: data sheets, introductions, researched articles and summaries
1. Students should prepare data tables and figures for their results and make conclusions.
2. They should write a conclusion section and a prepare a list of references for the articles
that were summarized.
3. Each group should then prepare a presentation of their results, and present it to the class.
The format for presentations is at the discrepancy of the teacher: PPT or Scientific Poster.

Backyard Toxicology

Transcription

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