An investigative laboratory course in human physiology using computer technology and collaborative writing

Active investigative student-directed experiences in laboratory science are being encouraged by national science organizations. A growing body of evidence from classroom assessment supports their effectiveness. This study describes four years of implementation and assessment of an investigative laboratory course in human physiology for 65 second-year students in sports medicine and biology at a small private comprehensive college. The course builds on skills and abilities first introduced in an introductory investigations course and introduces additional higher-level skills and more complex human experimental models. In four multiweek experimental modules, involving neuromuscular, reflex, and cardiovascular physiology, by use of computerized hardware/software with a variety of transducers, students carry out self-designed experiments with human subjects and perform data collection and analysis, collaborative writing, and peer editing. In assessments, including standard course evaluations and the Salgains Web-based evaluation, student responses to this approach are enthusiastic, and gains in their skills and abilities are evident in their comments and in improved performance.     

Developing experimental design and troubleshooting skills in an advanced biochemistry lab

Two skills critically important to all scientists are the ability to design good experiments and to troubleshoot experiments that do not yield the expected results. In spite of their importance, however, these skills are rarely taught as a part of the undergraduate science curriculum. This deficiency was addressed by creating an advanced biochemistry laboratory course that focuses on the development of experimental design and troubleshooting skills. The course provides students with the opportunity to design and evaluate their own experiments through semester-long independent projects that have a common theme (in this case, protein purification, but any theme could be used). Students plan their projects and carry through the experiments by consulting the primary research literature. The instructor provides minimal input in troubleshooting situations, instead allowing the student to think through and implement alternative solutions. A 2-year survey of the course revealed that students were often frustrated but felt the course significantly improved their experimental laboratory skills as well as introducing them to “real-world” laboratory experience. They further indicated that they preferred the approach used in this course to directed “cook-book” laboratory experiences.     

Inquiry-based laboratory course improves students' ability to design experiments and interpret data

We redesigned our intermediate-level organismal physiology laboratory course to center on student-designed experiments in plant and human physiology. Our primary goals were to improve the ability of students to design experiments and analyze data. We assessed these abilities at the beginning and end of the semester by giving students an evaluation tool consisting of an experimental scenario, data, and four questions of increasing complexity. To control for nontreatment influences, the improvement scores (final minus initial score for each question) of students taking both the laboratory and the companion lecture course were compared with those of students taking the lecture course only. The laboratory + lecture group improved more than the lecture-only group for the most challenging question. This evidence suggests that our inquiry-based curriculum is achieving its primary goals. The evaluation tool that we developed may be useful to others interested in measuring experimental analysis abilities in their students.     

Multiweek cell culture project for use in upper-level biology laboratories

This article describes a laboratory protocol for a multiweek project piloted in a new upper-level biology laboratory (BIO 426) using cell culture techniques. Human embryonic kidney-293 cells were used, and several culture media and supplements were identified for students to design their own experiments. Treatments included amino acids, EGF, caffeine, epinephrine, heavy metals, and FBS. Students researched primary literature to determine their experimental variables, made their own solutions, and treated their cells over a period of 2 wk. Before this, a sterile technique laboratory was developed to teach students how to work with the cells and minimize contamination. Students designed their experiments, mixed their solutions, seeded their cells, and treated them with their control and experimental media. Students had the choice of manipulating a number of variables, including incubation times, exposure to treatment media, and temperature. At the end of the experiment, students observed the effects of their treatment, harvested and dyed their cells, counted relative cell numbers in control and treatment flasks, and determined the ratio of living to dead cells using a hemocytometer. At the conclusion of the experiment, students presented their findings in a poster presentation. This laboratory can be expanded or adapted to include additional cell lines and treatments. The ability to design and implement their own experiments has been shown to increase student engagement in the biology-related laboratory activities as well as develop the critical thinking skills needed for independent research.     

浅谈在生物化学实验中培养学生的数据处理与分析能力

在生物化学实验中,教师应该重视培养学生的数据处理与分析能力。教师可以通过课堂讲解、课堂设问和实验设计等结合的方式,培养学生建立数据与单位的概念,指导学生掌握有效数字的计算,同时引导学生使用基本的软件工具分析处理数据,最终运用统计学的定量与分析得到可靠合理的实验结果。     

Learning how scientists work: experiential research projects to promote cell biology learning and scientific process skills

Facilitating not only the mastery of sophisticated subject matter, but also the development of process skills is an ongoing challenge in teaching any introductory undergraduate course. To accomplish this goal in a sophomore-level introductory cell biology course, I require students to work in groups and complete several mock experiential research projects that imitate the professional activities of the scientific community. I designed these projects as a way to promote process skill development within content-rich pedagogy and to connect text-based and laboratory-based learning with the world of contemporary research. First, students become familiar with one primary article from a leading peer-reviewed journal, which they discuss by means of PowerPoint-based journal clubs and journalism reports highlighting public relevance. Second, relying mostly on primary articles, they investigate the molecular basis of a disease, compose reviews for an in-house journal, and present seminars in a public symposium. Last, students author primary articles detailing investigative experiments conducted in the lab. This curriculum has been successful in both quarter-based and semester-based institutions. Student attitudes toward their learning were assessed quantitatively with course surveys. Students consistently reported that these projects significantly lowered barriers to primary literature, improved research-associated skills, strengthened traditional pedagogy, and helped accomplish course objectives. Such approaches are widely suited for instructors seeking to integrate process with content in their courses.     

Leading Students to Investigate Diffusion as a Model of Brine Shrimp Movement

Integrating experimental biology laboratory exercises with mathematical modeling can be an effective tool to enhance mathematical relevance for biologists and to emphasize biological realism for mathematicians. This paper describes a lab project designed for and tested in an undergraduate biomathematics course. In the lab, students follow and track the paths of individual brine shrimp confined in shallow salt water in a Petri dish. Students investigate the question, “Is the movement well characterized as a 2-dimensional random walk?” Through open, but directed discussions, students derive the corresponding partial differential equation, gain an understanding of the solution behavior, and model brine shrimp dispersal under the experimental conditions developed in class. Students use data they collect to estimate a diffusion coefficient, and perform additional experiments of their own design tracking shrimp migration for model validation. We present our teaching philosophy, lecture notes, instructional and lab procedures, and the results of our class-tested experiments so that others can implement this exercise in their classes. Our own experience has led us to appreciate the pedagogical value of allowing students and faculty to grapple with open-ended questions, imperfect data, and the various issues of modeling biological phenomena.     

Selective use of the primary literature transforms the classroom into a virtual laboratory

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.     

Study of physiological responses to acute carbon monoxide exposure with a human patient simulator

Human patient simulators are widely used to train health professionals and students in a clinical setting, but they also can be used to enhance physiology education in a laboratory setting. Our course incorporates the human patient simulator for experiential learning in which undergraduate university juniors and seniors are instructed to design, conduct, and present (orally and in written form) their project testing physiological adaptation to an extreme environment. This article is a student report on the physiological response to acute carbon monoxide exposure in a simulated healthy adult male and a coal miner and represents how 1) human patient simulators can be used in a nonclinical way for experiential hypothesis testing; 2) students can transition from traditional textbook learning to practical application of their knowledge; and 3) student-initiated group investigation drives critical thought. While the course instructors remain available for consultation throughout the project, the relatively unstructured framework of the assignment drives the students to create an experiment independently, troubleshoot problems, and interpret the results. The only stipulation of the project is that the students must generate an experiment that is physiologically realistic and that requires them to search out and incorporate appropriate data from primary scientific literature. In this context, the human patient simulator is a viable educational tool for teaching integrative physiology in a laboratory environment by bridging textual information with experiential investigation.     

Flap models in the rat: a review and reappraisal.

The laboratory rat has long provided plastic surgical investigators a model to study many aspects of flap physiology. Clinical advances in reconstructive surgery have succeeded or preceded experimental work, setting the stage for further advances. We have critically reviewed all reports of flap models in the laboratory rat. This has begun with simple skin flaps designed on various areas of the body and continued with a review of free-tissue transfer models. Because of the multitude of as yet unanswered questions remaining, the laboratory rat will invariably continue to be widely used as an investigatory source in this area. This report should allow investigators to select more easily reliable, reproducible experimental models, and, one hopes, to streamline their investigative efforts.     

Teaching advanced genetics without lectures

In an effort to increase student engagement and therefore student learning, an advanced genetics course was developed in which traditional lectures were eliminated. Instead, students were required to complete reading assignments before each class meeting, and those readings were then the topic of group discussion. Assigned readings alternated between text assignments and articles from the primary literature. Students were made accountable for their own preparation by the administration of a quiz at the start of each class. Group discussion of the topics engaged students in the learning process and readministration of the quiz at the end of class allowed them to benefit from the group interaction and understanding. Interspersing text readings and primary literature led to student understanding of how genetic knowledge is acquired and interpreted and how experimental detail leads to the construction of general models.     

A fitness screening model for increasing fitness assessment and research experiences in undergraduate exercise science students

When students analyze and present original data they have collected, and hence have a cultivated sense of curiosity about the data, student learning is enhanced. It is often difficult to provide students an opportunity to practice their skills, use their knowledge, and gain research experiences during a typical course laboratory. This article describes a model of an out-of-classroom experience during which undergraduate exercise science students provide a free health and fitness screening to the campus community. Although some evidence of the effectiveness of this experience is presented, this is not a detailed evaluation of either the service or learning benefits of the fitness screening. Working in small learning groups in the classroom, students develop hypotheses about the health and fitness of the population to be screened. Then, as part of the health and fitness screening, participants are evaluated for muscular strength, aerobic fitness, body composition, blood pressure, physical activity, and blood cholesterol levels. Students then analyze the data collected during the screening, accept or reject their hypotheses based on statistical analyses of the data, and make in-class presentations of their findings. This learning experience has been used successfully to illustrate the levels of obesity, hypercholesterolemia, and lack of physical fitness in the campus community as well as provide an opportunity for students to use statistical procedures to analyze data. It has also provided students with an opportunity to practice fitness assessment and interpersonal skills that will enhance their future careers.     

Teaching cell biology in the large-enrollment classroom: methods to promote analytical thinking and assessment of their effectiveness

A large-enrollment, undergraduate cellular biology lecture course is described whose primary goal is to help students acquire skill in the interpretation of experimental data. The premise is that this kind of analytical reasoning is not intuitive for most people and, in the absence of hands-on laboratory experience, will not readily develop unless instructional methods and examinations specifically designed to foster it are employed. Promoting scientific thinking forces changes in the roles of both teacher and student. We describe didactic strategies that include directed practice of data analysis in a workshop format, active learning through verbal and written communication, visualization of abstractions diagrammatically, and the use of ancillary small-group mentoring sessions with faculty. The implications for a teacher in reducing the breadth and depth of coverage, becoming coach instead of lecturer, and helping students to diagnose cognitive weaknesses are discussed. In order to determine the efficacy of these strategies, we have carefully monitored student performance and have demonstrated a large gain in a pre- and posttest comparison of scores on identical problems, improved test scores on several successive midterm examinations when the statistical analysis accounts for the relative difficulty of the problems, and higher scores in comparison to students in a control course whose objective was information transfer, not acquisition of reasoning skills. A novel analytical index (student mobility profile) is described that demonstrates that this improvement was not random, but a systematic outcome of the teaching/learning strategies employed. An assessment of attitudes showed that, in spite of finding it difficult, students endorse this approach to learning, but also favor curricular changes that would introduce an analytical emphasis earlier in their training.     

Trial of integrated laboratory practice

In most laboratory practices for students in medical schools, a laboratory guidebook is given to the students, in which the procedures are precisely described. The students merely follow the guidebook without thinking deeply, which spoils the students and does not entice them to think creatively. Problem-based learning (PBL) could be one means for the students themselves to actively learn, find problems, and resolve them. Such a learning attitude nurtures medical students with lifelong learning as healthcare professionals. We merged PBL and laboratory practices to promote deep thinking habits and developed an integrated laboratory practice. We gave a case sheet to groups of students from several schools. The students raised hypotheses after vivid discussion, designed experimental protocols, and performed the experiments. If the results did not support or disproved the hypothesis, the students set up another hypothesis followed by experiments, lasting for 4 or 5 consecutive days. These procedures are quite similar to those of professional researchers. The main impact achieved was the fact that the students developed the experimental design by themselves, for the first time in their college lives. All students enjoyed the laboratory practice, which they had never experienced before. This is an antidote to the guidebook-navigated traditional laboratory practice, which disappoints many students. As educators in basic medical sciences stand on the edge in terms of educating the next generation, there is a need to provide a strong foundation for medical students to design and perform scientific experiments. The integrated laboratory practice may provide the solution.     

Comparing biology majors from large lecture classes with TA-facilitated laboratories to those from small lecture classes with faculty-facilitated laboratories

The teaching faculty for this course sought to address their own concerns about the quality of student learning in an impersonal large lecture biology class for majors, the difficulties in getting to know each student by name, and difficulties in soliciting answers and reactions from the students during the lecture. Questions addressed by this study were, Do active-learning activities in a small and personal lecture setting enhance student learning more than active-learning activities in large impersonal lectures? and Are students more satisfied with an educational experience in a small and personal lecture setting? Based on faculty perceptions of how they best relate to their students, the prediction was that the students in the experimental group with small lecture classes and increased direct contact with the teaching faculty would learn physiological principles better than the students in the control group in the large impersonal lecture portion of the course. One of the laboratory sections of this large enrollment biology course was randomly selected to be taught with separate small lectures by the teaching faculty. In addition, the teaching faculty participated in the laboratory with these students during their experiments correlated with the lecture material. The students in both groups were compared by pre- and posttests of physiological principles, final course grades, and class satisfaction surveys.     

Transposing from the Laboratory to the Classroom to Generate Authentic Research Experiences for Undergraduates

Large lecture classes and standardized laboratory exercises are characteristic of introductory biology courses. Previous research has found that these courses do not adequately convey the process of scientific research and the excitement of discovery. Here we propose a model that provides beginning biology students with an inquiry-based, active learning laboratory experience. The Dynamic Genome course replicates a modern research laboratory focused on eukaryotic transposable elements where beginning undergraduates learn key genetics concepts, experimental design, and molecular biological skills. Here we report on two key features of the course, a didactic module and the capstone original research project. The module is a modified version of a published experiment where students experience how virtual transposable elements from rice (Oryza sativa) are assayed for function in transgenic Arabidopsis thaliana. As part of the module, students analyze the phenotypes and genotypes of transgenic plants to determine the requirements for transposition. After mastering the skills and concepts, students participate in an authentic research project where they use computational analysis and PCR to detect transposable element insertion site polymorphism in a panel of diverse maize strains. As a consequence of their engagement in this course, students report large gains in their ability to understand the nature of research and demonstrate that they can apply that knowledge to independent research projects.     

Using the two-hybrid screen in the classroom laboratory

The National Science Foundation and others have made compelling arguments that research be incorporated into the learning of undergraduates. In response to these arguments, a two-hybrid research project was incorporated into a molecular biology course that contained both a lecture section and a laboratory section. The course was designed around specific goals for educational outcomes, including introducing research to a wide range of students, teaching students experimental design and data analysis, and enhancing understanding of course material. Additional goals included teaching students to search genomic databases, to access scientific articles, and to write a paper in scientific format. Graded events tested these goals, and a student evaluation indicated student perception of the project. According to our analysis of the data, the yeast two-hybrid screen was a success: several novel clones were identified; students met expectations on graded lab reports, the poster session, and the final paper; and evaluations indicated that students had achieved the outlined goals. Students indicated on the evaluations that the research project increased their interest in research and greatly improved understanding of the course material. Finally, several students in the course intend to submit the findings of the research project to an undergraduate research journal.     

Adaptation to altitude as a vehicle for experiential learning of physiology by university undergraduates

In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation. Here, teams of three to four students measured the maximal rate of oxygen uptake, cognitive function, hand and foot volume changes, reticulocyte count and hematocrit, urinary pH and 24-h urine volume, athletic performance, and nocturnal blood oxygen saturation. Their data allowed the students to quantify the effect of altitude on the oxygen cascade and to demonstrate the following altitude-related changes: 1) impaired performance on selected cognitive function tests, 2) mild peripheral edema, 3) rapid reticulocytosis, 4) urinary alkalinization and diuresis, 5) impaired aerobic but not anaerobic exercise performance, 6) inverse relationship between blood oxygen saturation and resting heart rate, and 7) regular periodic nocturnal oxygen desaturation events accompanied by heart rate accelerations. The students learned and applied basic statistical techniques to analyze their data, and each team summarized its results in the format of a scientific paper. The students were uniformly enthusiastic about the use of self-directed experimentation to explore the physiology of altitude adaptation and felt that they learned more from this course format than a control group of students felt that they learned from a physiology course taught by the same instructor in the standard classroom/laboratory format.     

Modeling the temperature kinetics of aerobic solid-state biodegradation

This study evaluated three models of microbial temperature kinetics using CO2 respiration data from aerobic solid-state biodegradation experiments. The models included those of Andrews and Kambhu/Haug, Ratkowsky et al., and the Cardinal Temperature Model with Inflection (CTMI) of Rosso et al. A parameter estimation routine implemented the Complex-Box search method for each model on 48 data sets collected during the composting of synthetic food waste or sewage-sludge (biosolids) mixed with maple wood chips at different oxygen concentrations and extents of decomposition. Each of the three nonlinear temperature kinetic functions proved capable of modeling a wide range of experimental data sets. However, the models differed widely in the consistency of their parameters. Parameters in the CTMI model were more stable over the course of the degradation process, and that variability which did arise was directly related to changes in the microbial process. Additional benefits of the CTMI model include the ease of parameter determinations, which can be approximated directly from laboratory experiments or full-scale system analysis, and the direct value of its parameters in engineering design and process control under a wide range of biodegradation conditions.