Title Be specific, but keep the title simple, short, and to the point regarding what your experiment was about.

Transcription

1 A Guide to Writing Scientific Lab Reports Scientific writing is essential for the dissemination of research results, and the ability to clearly convey detailed information to someone else is essential in any career. The best way to prepare for writing your lab report is to be sure you understand the experiment you are writing about. If you are not clear on the purpose or procedure of the experiment, talk to your instructor or a classmate. Start by creating an outline for the report using the sections listed below. As you are working on your report, imagine you will be giving the report to your roommate or parents someone who was not present for the experiment. The reader should be able to understand the purpose, methods, results, and significance of the experiment just by reading the report. Do not plagiarize! Plagiarism is using any idea, text, or information that is not your own without proper citation, thus presenting the work as if it is your own. Inappropriate use of someone else s work is plagiarism, regardless of whether or not you intend to plagiarize. Furthermore, even if you work with a partner in lab you should not both submit the exact same lab report. This is also considered plagiarism. You must write your own lab report. You are responsible for and will be held accountable for your own work. Handing in a report that is full of quoted text and citations with very little of your own writing is also not appropriate. One strategy for preparing a report in your own words is to carefully read and take notes on the topic you re going to write about, then, without looking back at your books or notes, describe out loud the purpose of the experiment, what you did, what you observed, and what it means. Then go back and write down what you said. Where you described something that you had read elsewhere, cite the source. By explaining the report out loud without looking at notes, books, or the computer, you will be forced to put everything in your own words. Lab reports take time and revision. Don t wait until the night before it s due and expect to write a quality product! Lab Report Format Keep text between point fonts, and use standard fonts (ex. Ariel, New Times Roman, Calibri, etc ), and single or double space is fine. There is no set report length. Just say what you need to say. Some people are skilled at writing concisely while others are less so. I m not grading you based on length but quality of the report. Your report should include the following sections, and one section can directly follow the previous, without the need for separate pages per section. Spelling and grammar will count! Title Be specific, but keep the title simple, short, and to the point regarding what your experiment was about. Author and Affiliation Provide your name, affiliation (use FMU). Please see sample lab report for an example of what needs to be included here. Abstract This is a very brief summary of your goal in this experiment: what you did, and your results. DO NOT include actual data, tables, or references to literature in this part. Again, see sample lab report for an example of what needs to be included here. Introduction The introduction provides background information on the topic to be covered. In your lab report you MUST cite from the Fox textbook as a bare minimum reference for your background! For example, if the report was on how blood pressure changes with different body postures you would want to paraphrase background material on how the body regulates blood pressure. Relevant vocabulary and concepts should be described. You would glean this information from a source (like the textbook). After paraphrasing that material, you end the sentence with an in-text citation, giving credit to the source for that material. You must reference your source of information using numerical superscripts at the end of the appropriate sentence(s). [See example lab report provided online.] For example, take the following sentences and citation: Normally there are minor fluctuations in blood pressure throughout the day, depending on activity and changes in body posture. The brain stem detects blood pressure fluctuations, and stimulates modification as needed if that pressure deviates from normal range. 1 Changes in blood pressure, either above or below the normal range, stimulate 1

2 corrective responses by the medulla oblongata. If blood pressure decreases or increases above normal range the medulla responds by either a sympathetic or a parasympathetic stimulation. For example, a drop in blood pressure below the set point is detected by baroreceptors within the aortic arch and carotid sinus. This information is relayed to the medulla, which stimulates a sympathetic increase in heart rate and vasoconstriction of systemic arterioles, and these compensatory responses will increase blood pressure. 2a Make sure you paraphrase the information from the text by putting the information in your own words. Don t copy (word-for-word) what is written in the textbook because that is considered plagiarism. If you choose to make direct quotes that material must be within quotation marks, and then you site your source immediately after it. For example, take the following sentence and citation: The sensors for arterial blood pressure are called baroreceptors and are located in the aortic arch and carotid sinuses. 2b At the end of the introduction, explain the purpose of the experiment, and how it is important to physiological function. Then you must state a clear, testable hypothesis for the experiment(s) being covered. This includes what you would expect might happen as an outcome of the experiment. For example: I hypothesize that, based on what we know about blood pressure regulation, changing from a supine to an upright posture will cause an increase in blood pressure as a compensatory response by the body. Here would be the listed from my example in the paragraphs above: 1. Boundless. "Role of the Cardiovascular Center." Boundless Anatomy and Physiology, 23 Oct Retrieved 23 Aug from textbook/cardiovascular-system-blood-vessels-19/control-of-blood-pressure-184/role-of-the-cardiovascular-center / [In the above reference, the title of the webpage is Boundless. Role of the Cardiovascular Center. The website company is Boundless Anatomy and physiology, and it was accessed on Aug 23, 2017, and the web address is shown.] 2a. Fox, SI, Human Physiology Biol 236, 1 st ed. New York, NY, McGraw-Hill Co.; (Pg. 17). [In the above reference, there is one author, the title of the book is Human Physiology Biol 236, it is the first edition, the publisher is located in New York, NY, the publishing company is McGraw-Hill, the year of publication is 2015, and the page number where the paraphrased information can be found is 17.] 2b. Fox, SI, Human Physiology Biol 236, 1 st ed. New York, NY, McGraw-Hill Co.; (Pg. 271). [In the above reference, it is the SAME reference as #2, but reflects a direct quote from Pg. 271.] Methods Explain how you did the experiment and what materials you used. You are reporting on something that happened in the past, so write it in past tense. Explain what you did and how you did it. If the lab report is written based on class data (which is USUALLY the case) you can simply explain how the basic experiment was conducted, how many people participated (subjects), and what equipment was involved in the data collection. You should also explain how the data was summarized and analyzed (such as in an Excel spreadsheet). End the methods section with what analyses were performed to compare the data sets (T-test, ANOVA). Results The results section needs a written portion, in addition to any data tables and figures. In this written portion you should report any summary data (such as class averages of data sets for different conditions) and then, if the data was statistically analyzed, report the P-values and then report any significant differences found between the experimental groups. You DO NOT explain your data in the results section! You simply report averages, P-values, and differences among groups, and refer to any tables and figures. You will explain your data results in the discussion section. Discussion The discussion section should include the interpretation of your results. You do not need to repeat the numbers stated in the results section but need to explain the physiological basis for what you observed. If something changed WHY did the change occur? What is the physiological basis for what you observed in the results? It is important in this section to tie together what your experimental results mean within the broader context of the physiology of the topic 2

3 you were examining. To end the discussion, you can also mention possible sources of experimental error. Sometimes things go wrong. That s okay. You can explain that here. Provide the full citation for all in-text citations (numerical superscripts) provided earlier in the report. Below I ve given you several examples of how you would provide a literature citation properly. In general, for a Human Physiology lab report you MUST at least use the course textbook as one of your references within the report. Additionally, you can use scientific journal articles. Textbooks and journal articles are the preferred and most accurate sources for any biological report. If appropriate you can use a science-based web page or article (ex. Medline, WebMD, etc ). In general, Joe Blow s web page just doesn t cut it for a college lab report citation. Also, DO NOT use the lab handout as a literature source UNLESS that handout has a citation within it giving the source of its background material. In general, our lab handouts have no citations. Citing a journal article: 1. Olufsen, M.S., J.T. Ottesen, and H.T. Tran (2005). Blood pressure and blood flow variation during postural change from sitting to standing: model development and validation. Journal of Applied Physiology Vol. 99 No. 4, Example of citing a textbook: 1. Fox, SI, Human Physiology Biol 236, 1 st ed. New York, NY, McGraw-Hill Co Pg. 17. Example of citing a journal article: 1. Raven PB and Chapleau MW. Blood Pressure Regulation XI: Overview and Future Research Directions. European Journal of Applied Physiology. 2015; 114(3): Pgs [In the above reference, the authors names are given (last name and first initials), followed by article title, journal name, the volume of the journal and issue (in parentheses), followed by page number(s).] Example of citing a webpage: 1. Boundless. "Role of the Cardiovascular Center." Boundless Anatomy and Physiology. 23 Oct Retrieved 23 Aug from textbook/cardiovascular-system-blood-vessels-19/control-of-blood-pressure-184/role-of-the-cardiovascular-center / Sample Lab Report The Effect of Exercise Duration on Heart Rate Tamatha Barbeau Department of Biology, Francis Marion University, Florence SC Abstract In our experiment, we measured changes in heart rate, in 38 student athletes between the ages of 20 and 22 years old, in response to changes in exercise duration by manual palpation of radial pulse. We found that heart rate increased proportionally with exercise duration up until 15 minutes of exercise, where-after heart rate remained steady for the remainder of the 30 minutes. These results indicated that, in student athletes of similar age, cardiovascular performance in exercise-conditioned individuals resulted in an increase in mean target heart rate during the first 15 minutes of exercise followed by no additional increase in heart rate for the remaining time intervals. 3

4 Introduction Heart rate changes in response to many factors, including exercise, stress, fear, cardiovascular health, pharmacological agents, and changes in blood pressure, among many other reasons. 1 For example, if a person s activity levels increase, their muscles and brain will increase their demands for oxygen (O2) and glucose in the bloodstream in order to fuel the activity. As activity levels increase, the skeletal muscles and brain start using up available blood O2 faster, resulting in a momentary drop in blood O2 levels. In response to lower O2 levels in cerebral spinal fluid and blood, chemoreceptors for O2 in the medulla oblongata and in the aortic arch and carotid sinuses sense the change, and the medulla responds with a sympathetic stimulation of the heart, causing heart rate to increase. 1 The increased heart rate increases cardiac output so that more O2 is circulated to the lungs, and then more O2 is made available in the blood to skeletal muscles and the brain to sustain the exercise. 1 This elevated heart rate continues as long as the O2 demand, by muscles and the brain, remain high. 2 One of the most common ways to measure the body s demand for O2 during exercise is by determining the target heart rate. 3 In this study, I will examine the target heart rate of 40 student athletes, ranging in age from years old, in response to varying exercise durations. I propose that as exercise duration increases, target heart rate will increase proportionally. Methods 40 students athletes, from Francis Marion University, Florence, S.C., ranging in age from years old, participated in the experiment. This sample size consisted of 20 male and 20 female participants with no known health problems. Heart rate was measured through manual palpation of the radial artery pulse. For each subject, maximum heart rate was calculated by the standard formula of 220 bpm minus the subject s age. At various time intervals of exercise, target heart rate was calculated as 50% of the maximum heart rate. Following resting measurements (time 0), subjects exercised on a stationary bicycle for 5, 10, 15, 20, 25, and 30 minutes. Upon reaching each time interval their heart rate was measured, the target heart rate calculated, and data entered in an Excel spreadsheet. After all of the subject s data was collected for all time intervals, the data was analyzed using a one-way ANOVA followed by pair-wise contracts to find out where heart rate changed between the intervals. Results Mean target heart rate was 72, 90, 120, 180, 185, 186, and 182 bpm for exercise durations of 0, 5, 10, 15, 20, 25, and 30 min respectively. The One-Way ANOVA P-value was < , indicating that heart rate was different among the time intervals. Pair-wise contrasts showed that mean heart rate increased significantly from 0, 5, 10, to 15 minutes, but then remained consistent between minutes. Discussion My results indicate that, in athletic students between the ages of years old, showed an increase in mean heart rate during the first 15 minutes of exercise, followed by a plateau of heart rate for the remainder of the exercise duration. This shows that the target heart rate increased during the early stages of light exercise and then remains high, without significant further increase, for the remaining time. Physiologically, the body has met its overall demands for O2 within the first 15 min of light exercise. This indicates that, at this particular level of exercise intensity, mean target heart rate plateaus at approximately 180 bpm. Future studies could elaborate on these findings to show whether target heart rate increases above 180 bpm in response to greater exercise intensity over time. As with any experiment, there were 4

5 possible sources of error, which could include inaccurate measuring of heart rate, or variation in the intensity of how individual subjects exercised. For example, some subjects could have bicycled more slowly over the entire duration while others might have engaged in more strenuous bicycling. 1. Fox, SI, Human Physiology Biol 236, 1 st ed. New York, NY, McGraw-Hill Co (Pg ) 2. Science Buddies Sweaty Science: How Does Heart Rate Change with Exercise? Retrieved 23, Aug from 3. Exercise Intensity: How to Measure it. Mayo Clinic Retrieved 23, Aug from 5