D Scerner: Critical Appraisal of a Study Genetic Analysis Shows Gene Expression is Changed by Cocaine

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1 L3 D Scerner: Critical Appraisal of a Study Genetic Analysis Shows Gene Expression is Changed by Cocaine TEAChEr SECTion for PArTS i AnD ii objectives: Using instructional materials in the activity, students will be able to: Module 1 Thinking About the Study Find sources of potential bias in the study and describe how they might affect the results in Part I and/or Part II Identify the type of study design in Part I and/or Part II Indignify independent, dependent, and controlled variables in the study in Part I and/or Part II Module 2 The Results Create graphs from data presented in data tables Create data tables from graphs Use correct type of graph to represent data Use data presented in Venn Diagrams Use data to determine whether gene activity increases or decreases (Part I) Module 3 Analyzing the Results Use a written guide to systematically analyze the study results to determine their meaning (Part I and/or Part II) Module 4 Comparing and Contrasting Compare and contrast the journal report to the media report to determine accuracy of the media report in Part I and/or Part II Complete a Venn Diagram that compares the journal and media reports in Part I and/or Part II ACTiviTy DESCriPTion: How often do we hear Research Says To develop science literacy skills, students need to ask Does it Really. Using a peer-reviewed journal article that has been transformed for age appropriateness, students will analyze a peer-reviewed report of a scientific study. They will compare the results reported in the journal article to a media article that reported the results of the same study. Student analysis is carefully directed in a systematic way through the use of four student modules. The modules created for each critical appraisal lesson are very similar in structure to help students develop scientific habits of mind as they work through the lessons. This lesson is based on 2009 The University of Texas Health Science Center at San Antonio 1

2 a study done to analyze the epigenetic effects of cocaine. The study is divided into two parts to help students process the information. Each of the two parts can be done as a stand-alone lesson or they can be done together. The study was funded by the National Institute on Drug Abuse. MATEriAlS: 1 class set of the Journal Article Genetic Analysis Shows Gene Expression is Changed by Cocaine Part I and/or Part II 1 class set of the Media Article Cocaine Spurs Long-Term Change in Brain Chemistry 1 copy of the Student Modules per student (Note: If copy numbers are limited, you can make a class set of the modules and have students record their answers in a journal or on their own paper) MAnAGEMEnT SuGGESTionS: The lesson can be divided up into separate modules; each can be done at different times of the year to align with the scope and sequence. SuGGESTED MoDifiCATionS: Allow students to work in pairs and provide modules with some information prefilled for students in need of such assistance. SuGGESTED ExTEnSionS: Students can research other factors that cause epigenetic regulation of gene expression. references used: Hill, AB. (1965). The environment and disease: Association or causation Proceedings of the Royal Society of Medicine, 58, Last, JM. (2000). A Dictionary of Epidemiology. USA: Oxford University Press. Renthal, W., et al. (2009). Genome-wide Analysis of Chromatin Regulation by Cocaine Reveals a Role for Sirtuins. Neuron, 62, U.S. News and World Report. (2009). Cocaine Spurs Long-Term Change in Brain Chemistry. Available online at accessed on June 25, The University of Texas Health Science Center at San Antonio 2

3 Activity Administrivia Intended Grade Level: 6 8 key ConCEPTS: Critical appraisal skills, compare/contrast, analyzing results of a study, study design, variables, controlled variables, epigenetics, drug abuse ProCESS SkillS utilized in lesson: Communication, inference, prediction, analysis of data, graphing PrEviouS learning ASSuMED: Basic scientific process skills, graphing skills, sources of bias Relevant TEKS 6, 7, and 8 Grade Science 6, 7, 8.2 Scientific investigation and reasoning. The student uses scientific inquiry methods during laboratory and field investigations. The student is expected to: (D) construct tables and graphs, using repeated trials and means, to organize data and identify patterns; (E) analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and predict trends. 6, 7, 8.3 Scientific investigation and reasoning. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions and knows the contributions of relevant scientists. The student is expected to: (A) in all fields of science, analyze, evaluate, and critique scientific explanations by using empirical evidence, logical reasoning, and experimental and observational testing, including examining all sides of scientific evidence of those scientific explanations, so as to encourage critical thinking by the student; 6, 7, and 8 Grade Health 6.4 Health information. The student comprehends ways of researching, accessing, and analyzing health information. The student is expected to: (A) list ways to evaluate health products, practices, and services such as sunblocks, dietary aides, and over-the-counter medications; and (B) use critical thinking to research and evaluate health information. 6.5 Health behaviors. The student engages in behaviors that reduce health risks throughout the life span. The student is expected to: (C) describe chemical dependency and addiction to tobacco, alcohol, and other drugs and substances; 6.10 Personal/interpersonal skills. The student describes healthy ways to communicate consideration and respect for self, family, friends, and others. The student is expected to: (G) identify stressors and their impact on the health of the individual and family Health information. The student knows how to research, access, analyze, and use health information. The student is expected to: (A) use critical thinking to analyze and use health information such as interpreting media messages; (B) develop evaluation criteria for health information; Health behaviors. The student engages in behaviors that reduce health risks throughout the life span. The student is expected to: (H) explain the impact of chemical dependency and addiction to tobacco, alcohol, drugs and other substances; (I) relate medicine and other drug use to communicable disease, prenatal health, health problems in later life, and other adverse consequences; key Words for Web Page: Critical appraisal skills, compare/contrast, analyzing results of a study, study design, variables, controlled variables, graphing, epigenetics, cocaine, genes, chromosomes, gene regulation 2009 The University of Texas Health Science Center at San Antonio 3

4 JOURNAL ARTICLE Transformed into part of a plain language anthology Genetic Analysis Shows Gene Expression is Changed by Cocaine (Part II) Abstract/Summary: Changes in gene activity are responsible for long-lasting changes to the brain reward system (BRS) caused by drug addiction. As described in Part 1, ChIP is a test that allows researchers to study the activity of thousands of genes. This study used ChIP to compare BRS gene activity in mice given the illegal drug Cocaine to gene activity in mice given salt water. Many BRS genes were affected in mice given cocaine. A new family of genes, SIRT, was among the genes identified. Part of the SIRT mouse study showed that cocaine increases SIRT gene activity. A separate experiment using rats indicates that SIRT blockers reduce the amount of cocaine taken by rats. This study links SIRT to cocaine use and provides clues to possible new treatments for cocaine users. Background: A gene is the basic unit of instruction for a trait. Each gene is located in a specific place on a DNA (Deoxyribonucleic acid) molecule. DNA is a large molecule that contains thousands of genes. These genes, in turn, contain genetic instructions needed for functioning and development of all living things. Genetic instructions are read when DNA is activated to make smaller molecules called mrna (messenger Ribonucleic acid). Each mrna has a code to make one type of protein (See Figure 1). DNA can make many types of mrna and therefore can direct the production of many kinds of proteins. Genes in DNA can be turned on or off and their activity level can be turned up or down. In this way, the amount of each type of protein made can be controlled. DNA DNA Molecule mrna Figure 1 From DNA to Protein (Modified from original The University of Texas Health Science Center at San Antonio mrna C PROTEIN C Amino Acids link to Make Protein C A C G U A U C G U A C A Ribosome C C C trna TEI PLAIN LANGUAGE ANTHOLOGY This article was transformed for age level from the original article: William Renthal, et al., (2009). Genome-wide Analysis of Chromatin Regulation by Cocaine Reveals a Role for Sirtuins. Neuron, 62, AUTHORS of Original Article: William Renthal,1,6 Arvind Kumar,1,6 Guanghua Xiao,2,6 Matthew Wilkinson,4 Herbert E. Covington III,4 Ian Maze,4 Devanjan Sikder,3 Alfred J. Robison,4 Quincey LaPlant,1,4 David M. Dietz,4 Scott J. Russo,4 Vincent Vialou,4 Sumana Chakravarty,1 Thomas J. Kodadek,3 Ashley Stack,5 Mohamed Kabbaj,5 and Eric J. Nestler,1,4* 1 Departments of Psychiatry and Neuroscience 2 Department of Clinical Sciences 3 Department of Internal Medicine The University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA 4 Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA 5 Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA 6 These authors contributed equally to this work This transformed article is for K 12 educational use only and follows peer-reviewed format. * Corresponding author 1

5 TEI PLAIN LANGUAGE ANTHOLOGY Inside cells, DNA molecules are organized into chromosomes. In chromosomes, parts of the DNA molecule wrap around proteins (like thread around a spool) called histones (Figure 2). Histones are associated with individual genes. Histones help control which genes in a chromosome are turned on or off at a given time. They also help control how active the genes are once they are turned on. Just as the volume of a television set can be turned up or down, gene activity can be turned up or down (regulated). Adding or removing A (acetyl) Groups and M (methyl) Groups to or from histones can regulate gene activity. In general, A (acetyl) Groups added to histones turn up gene activity. When A Groups are removed from histones, gene activity is turned down. In general, M (methyl) Groups added to histones turn down gene activity. When M Groups are removed, gene activity increases. (See Figure 2). There are exceptions to this, however. Also, genes can be regulated in many other ways. DNA A AA M M M Histone Tails Histone Chromosome Gene Activity increases when decreases when A Groups Added M Groups Removed A Groups Removed M Groups Added Figure 2 Histones (Modified from original Many substances in our environment affect gene activity. This is of major importance and is called epigenetics. Epigenetics refers to changes in the phenotype of an organism but not to its genotype. This means there is a change in the way genes act, but no actual change to the genes themselves. These changes can be good if they help the organism function well, but they are bad when they disturb normal function. Scientists do not know how long epigenetic The University of Texas Health Science Center at San Antonio

6 changes can last, but some can be passed from one generation to another. Cocaine (and other addictive drugs) changes gene activity. Unfortunately, cocaine-related changes in gene activity cause long-lasting changes in the brain that can lead to full blown addiction. TEI PLAIN LANGUAGE ANTHOLOGY Drug addiction is a disease. As described above, cocaine and other addictive drugs cause biological changes in the body. The disease progresses when drug use acts as a stimulus. The stimulus activates the BRS and a reward is produced in response. The reward is a good feeling that results from higher levels of certain brain chemicals, such as dopamine. The reward causes a person to want to repeat the behavior that caused it, so the person seeks more drugs. Over time, the natural ability to respond to the reward decreases. An addicted person has cravings and becomes obsessed with getting the drug. Eventually, the addict must have more and more of the drug to feel its effects. Addiction is truly a devastating disease. Introduction: Past research has shown that the use of drugs, like cocaine, causes long-term changes in the BRS. A major goal for new research has been to learn how drugs act upon this area of the brain to cause addiction. Existing research has also shown that drug use can cause epigenetic changes in genes (Hyman, et al., 2006; Freeman, et al., 2001; McClung and Nestler, 2003). A powerful test called ChIP is able to examine thousands of genes at once and identify which are turned on and which are turned up or down. ChIP was used in this study to compare gene activity in the BRS between mice given cocaine and those given salt water. Thousands of genes in the BRS of mice were analyzed by ChIP. A new gene family, SIRT (Sirtuins), was linked to cocaine use. This part of the study was done with rats. Mice and rats were used because the research could not be done safely with human volunteers. To ensure that the animals were well cared for, the research was conducted according to guidelines set forth by the National Institutes of Health and the Animal Care and Use Committee of Florida State University. Procedure: From this study, researchers identified thousands of genes affected by cocaine use. One group, SIRT (sirtuin), was of special interest because it had not been identified in previous research on the epigenetic effects of cocaine. ChIP was performed on BRS samples from mice treated with cocaine or salt water. In order to link a change in SIRT activity to cocaine use (behavior), another experiment using rats was done. Rats were used because they are more easily trained to push a lever to give themselves shots of cocaine. Thirty rats were used. The rats all weighed between g at the beginning of the experiment. Temperatures in the rats environment were constant at 22 o C. Rats had access to as much food and water as they wanted. They were kept in a 12 hour light/dark cycle. The rats were connected to a device that would give them cocaine when they pushed a lever. The rats were monitored as they learned to use the lever. Of the 30 rats, 12 met all training requirements set by researchers. The results from these 12 rats were used in the analysis. Of these 12 rats, 7 were given a SIRT blocking chemical and 5 were given a SIRT boosting chemical. See Figure The University of Texas Health Science Center at San Antonio 3

7 TEI PLAIN LANGUAGE ANTHOLOGY 30 Rats Were Trained to Push a Lever to Give Themselves Cocaine 12 Met Training Requirements Set by Researchers 18 Did Not Meet Training Requirements and Were Dropped From Experiment 7 rats Were Given SIRTS Blocker 5 rats Were Given SIRTS Booster The University of Texas Health Science Center at San Antonio Figure 3 Rat Experiment Study Design Discussion: Part 1 of this study revealed that many BRS genes in mice were affected by cocaine use. Many of these BRS genes have been linked to cocaine use in previous studies (Freeman et al., 2001; McClung and Nestler, 2003; Yao et al., 2004). Cocaine caused increases in histone changes (A Groups and M Groups added or removed) at many more genes than it caused decreases. Some of these genes were greatly affected by cocaine. One group, the SIRT (sirtuins), was of special interest to the researchers. Before this study, no one knew SIRT was involved in cocaine addiction. Humans make seven forms of SIRT. They are involved in many processes in the body, like cell growth, and aging (Michan & Sinclair, 2007). SIRT genes were more active in cocaine-treated mice than in salt water-treated mice. Figure 4 shows the activity of both forms of SIRT identified in this study. Results: 3 G E 2.5 N E 2 A C 1.5 T I V I T Y (*fold change) Salt Water-Treated 0 Cocaine-Treated SIRT 1 SIRT 2 *fold change is the number of times greater than normal Figure 4 SIRT Gene Activity in BRS of Mice Treated with Cocaine and Salt Water

8 Rats trained to give themselves cocaine by pressing a lever received injections of either SIRT boosting or SIRT blocking chemicals. Chemicals that boost SIRT caused cocaine-using and seeking behavior. Chemicals that block SIRT decreased cocaine use at certain doses of cocaine (Figure 5). This is an exciting finding, because chemicals that lower SIRT activity might be important treatments for people addicted to cocaine. TEI PLAIN LANGUAGE ANTHOLOGY N U M B E R O F I N J E C T I O N S ( o f S I R T B o o s t e r o r B l o c k e r ) Amount of Cocaine Per Dose (μg) SIRT Blocker SIRT Booster Figure 5 Effect of SIRT on Cocaine Self-Administration in Rats Conclusion: The main findings of this study were: one group of SIRT genes, when active, increases cocaine use in rats and blocking SIRT activity may reduce cocaine use. Thus, this study provides more evidence that cocaine makes epigenetic changes to genes. These changes are related to behaviors linked to cocaine addiction. These cocaine-induced biological changes, in turn, result in long-lasting changes to the brain. References: Bowers, M.S., and Kalivas, P.W. (2003). Forebrain astroglial plasticity is induced following withdrawal from repeated cocaine administration. Eur. J. Neurosci. 17, Freeman, W.M., Nader, M.A., Nader, S.H., Robertson, D.J., Gioia, L., Mitchell, S.M., Daunais, J.B., Porrino, L.J., Friedman, D.P., and Vrana, K.E. (2001). Chronic cocaine-mediated changes in non-human primate nucleus accumbens gene expression. J. Neurochem. 77, The University of Texas Health Science Center at San Antonio 5

9 TEI PLAIN LANGUAGE ANTHOLOGY References continued: Hyman, S.E., Malenka, R.C., and Nestler, E.J. (2006). Neural mechanisms of addiction: the role of reward-related learning and memory. Annu. Rev. Neurosci. 29, McClung, C.A., and Nestler, E.J. (2003). Regulation of gene expression and cocaine reward by CREB and DeltaFosB. Nat. Neurosci. 6, Medline Plus Accessed August 27, 2009 Michan, S., and Sinclair, D. (2007). Sirtuins in mammals: insights into their biological function. Biochem. J. 404, Nestler, E.J. (2008). Transcriptional mechanisms of addiction: role of delta-fosb. Philos. Trans. R. Soc. Lond. B Biol. Sci. 363, Renthal, W. et al., (2009). Genome-wide Analysis of Chromatin Regulation by Cocaine Reveals a Role for Sirtuins. Neuron, 62, Yao, W.D., Gainetdinov, R.R., Arbuckle, M.I., Sotnikova, T.D., Cyr, M., Beaulieu, J.M., Torres, G.E., Grant, S.G., and Caron, M.G. (2004). Identification of PSD-95 as a regulator of dopamine-mediated synaptic and behavioral plasticity. Neuron 41, National Institutes of Health, The New Genetics Accessed August 26, 2009 Study Disclosure: Funding support for the study was from Grants supplied by NIDA (National Institute on Drug Abuse). No member of the research team disclosed a conflict of interest. Measures of Readability for this Translation (text only): Flesch-Kincaid Grade Level 8.1 Flesch Reading Ease The University of Texas Health Science Center at San Antonio

10 TEI NewsReviews A PLAIN LANGUAGE ANTHOLOGY STUDY FINDS: Cocaine Spurs Long-Term Change in Brain Chemistry Study in mice finds drug alters gene activity, points to new methods for treatment Teacher Enrichment Initiatives Many remember those fried-egg this is your brain on drugs ads. They compared an egg cooking to your brain on drugs. Now, a new study reveals how addictive drugs like cocaine cook the brain. Nora Volkow is Director of NIDA (National Institute on Drug Abuse). NIDA paid for this new study. Dr. Volkow noted that the study revealed how cocaine changes gene activity in the brain reward system. Dr. Volkow stated: These genes represent promising new targets for medications to treat cocaine addiction. Dr. Eric Nestler of Mount Sinai School of Medicine led the study. The research team used a new test to observe changes in gene activity of cocaine-treated mice. The changes involve a shift in proteins called histones. Histones control how the genetic code in DNA is read to make RNA. Information in RNA is then used to make proteins. Using the new test, scientists mapped the effects of drug use in the brain s reward system. The process uncovered a new finding. A family of genes called the SIRT (sirtuins) are activated by cocaine use. These genes also control addiction-related behaviors in lab animals. The research was published May 14, 2009 in the journal Neuron. The study offers new findings about genes that are altered by cocaine in this brain region, Nestler said. Blocking the activity of the SIRT (sirtuins) reduced both cocaine's rewarding effects and the motivation to selfadminister the drug. In other words, scientists may be able to take away the desire for cocaine. They may also be able to take away the pleasure a person gets from using it. Transformed for age level and academic use from the original article: U.S. News and World Report. (2009). Cocaine Spurs Long-Term Change in Brain Chemistry. Available online at accessed on June 25, This transformed article has a Flesch-Kincaid Reading level of 7.5, Flesch Reading Ease of The University of Texas Health Science Center at San Antonio

11 MODULE 1 Thinking AbOUT ThE STUDy D Scerner and her L ete group must deal with this preliminary information to help clearly discern the facts of this case. gene ExprESSiOn ChAngED by COCAinE general information: D SCErnEr, ThE LifE-LOng LEArnEr: STUDEnT graphic OrgAnizEr Parts I and II Name of Study Genetic Analysis Shows Gene Expression is Changed by Cocaine Parts I and II First Author Funders Institution(s) Disclaimers/Disclosures Health Science Content Describe the test subjects of the study Purpose of study Design of Article Newspaper Magazine Peer-Reviewed Journal Web Article/Blog Interview Words to Define L The University of Texas Health Science Center at San Antonio 1

12 Parts I and II MODULE 1 Thinking AbOUT ThE STUDy EThiCAL TrEATMEnT Of TEST SUbJECTS STUDy DESign OBSERVATIONAL CHECK LIST Case Report Case Series Cross Sectional Case-Control Study Cohort Study gene ExprESSiOn ChAngED by COCAinE Why is it important to treat test animals with respect What type of information should laws guiding treatment of test animals include After reading your article, determine if the study was an observational or experimental study. Then decide which study design was used and check the appropriate box. Explain your choice in the space provided. EXPERIMENTAL CHECK LIST Intervention Study Randomized Controlled Trial D ziner is a master at identifying the basic design in any study. He hones in on clues and puts them together to reveal the true design of any study. Observational-Explain Your Choice Why is this important to know Experimental-Explain Your Choice Why is this important to know 2009 The University of Texas Health Science Center at San Antonio 2

13 Parts I and II MODULE 1 Thinking AbOUT ThE STUDy D riddler takes the lead in identifying the study variables, bringing the group one step closer to the heart of this study. gene ExprESSiOn ChAngED by COCAinE STUDy DESign identify Variables in the Study Identify Independent Variable of study Identify Dependent Variable of study Identify Controlled Variables of study D isabler uses her well-honed super sleuthing skills to detect and disable any sources of bias that might affect the results of this study. STUDy DESign Sources of bias Sponsors, Funders, Target Audience, Predetermined study goals How might each of these affect the results of the study How did the research team handle any possible impact on the study from factors such as conflict of interest 2009 The University of Texas Health Science Center at San Antonio 3

14 MODULE 2 ThE REsULTs GEnE ExpREssiOn ChanGED by COCainE Part II Data presentation Using Figure 4, determine fold, change (gene activities). SIRT 1 SIRT 2 Salt Water Cocaine How does gene activity compare between salt water and cocaine for SIRT 1 Why did scientists use rats to test the effect of SIRT on the amount of cocaine rats took In Figure 5, how did SIRT blockers compare to SIRT boosters Why is it important to know that SIRT blockers lower the amount of cocaine used D Cypher is the real master when it comes to the data. There s no one better to have on the team when it comes to sorting out the numbers. nature of Data Collection Self Reported Clinical Setting Interview in Person Phone Interview Questionnaires Lab Procedures Check all that apply and explain how each might affect the results Graphs Use data from the Figure 5 Graph to create a data table on the following page. Is the graph or data table better to display the data Explain The University of Texas Health Science Center at San Antonio 1

15 MODULE 2 ThE REsULTs GEnE ExpREssiOn ChanGED by COCainE Part II Use Figure 5 Effects of SIRT on Cocaine Self-Administration in Rats to create a data table below. Be sure to include a complete title and column headers The University of Texas Health Science Center at San Antonioº 2

16 D Finer takes the lead when it s time to analyze the results and define the cause of the results and the degree of certainty about the cause. MODULE 3 AnALyzing REsULts gene ExpREssiOn ChAngED by COCAinE 1. strength of Relationship: Study bias or factors negatively affecting the experiment make the results less reliable. List factors that affected the study results. Part II What Caused the Results Describe the results of the study in terms of each item listed below. Write your answers in the space provided. *Modified from Bradford-Hill considerations on causality Answers here: 2.Consistency: Were the results similar in repeated trials or in different studies Explain. If so, the results are more reliable. 3.Compare test group to Control: How did the test and control groups compare This helps establish the cause of any observed change. 4.strength of Effect: An increase in the treatment that results in an increase in observed change helps verify that the independent variable caused the results. Was this true in this study Explain. 5.plausibility: Is there a reasonable way to explain how the treatment might cause the observed changes Explain. 6.study Design: What kind of study design was used 7. Analogy: How could you find out if the results of this study are similar to those of other studies 2009 The University of Texas Health Science Center at San Antonio 1

17 MODULE 3 AnALyzing REsULts gene ExpREssiOn ChAngED by COCAinE think about your answers to the previous questions. What probably caused the results found in this study how did the use of cocaine affect gene activity in mice Why was it important to do the experiment to test sirt boosters and sirt blockers Why are the results of this study important for the general public to know Part II 2009 The University of Texas Health Science Center at San Antonio 2

18 MODULE 4 COMparing and COntrasting gene ExprEssiOn ChangED by COCainE Part II Planning Page style Title written to catch readers attention Results reported with little information about methods Length of article Length of paragraphs Number of details about the study Peer-Reviewed Research Report Media Article Tables, Charts and Graphs included Describe use of pictures and color Describe writing style and use of references 2009 The University of Texas Health Science Center at San Antonio 1

19 Part II MODULE 4 COMparing and COntrasting gene ExprEssiOn ChangED by COCainE study Description Researchers, Organizations and Universities described Peer-Reviewed Research Report Media Article Details about funders and researchers included Conflict of interest statement included Sources of possible bias reported Type of study design reported Study sample described Detailed description of procedures used in the study Reported effects of cocaine on gene activity What issue(s) is/are included in the media report but not the research article 2009 The University of Texas Health Science Center at San Antonio 2

20 MODULE 4 COMparing and COntrasting gene ExprEssiOn ChangED by COCainE Part II Data Analysis of data described Use of statistics described Information about gene activity Formulae included Peer-Reviewed Research Report Media Article Overall Comparison Conclusions of the researchers described Describe which is more reliable and why Describe which is more interesting and why Overall Accuracy Peer-Reviewed Research Report Media Article 2009 The University of Texas Health Science Center at San Antonio 3

21 MODULE 4 COMparing and COntrasting D Vennder takes the lead in putting it all together and comparing and contrasting the articles. gene ExprEssiOn ChangED by COCainE Compare and contrast the peer-reviewed article and the media literature article. Consider factors from your completed planning page. Venn DiagRaM Part II R E S E A R C H R E P O R T M E D I A A R T I C L E 2009 The University of Texas Health Science Center at San Antonio 4