Tales from the front lines: the creative essay as a tool for teaching genetics.

In contrast to the more typical mock grant proposals or literature reviews, we describe the use of the creative essay as a novel tool for teaching human genetics at the college level. This method has worked well for both nonmajor and advanced courses for biology majors. The 10- to 15-page essay is written in storylike form and represents a student's response to the choice of 6-8 scenarios describing human beings coping with various genetic dilemmas. We have found this tool to be invaluable both in developing students' ability to express genetic concepts in lay terms and in promoting student awareness of genetic issues outside of the classroom. Examples from student essays are presented to illustrate these points, and guidelines are suggested regarding instructor expectations of student creativity and scientific accuracy. Methods of grading this assignment are also discussed.     

运动对细胞凋亡的影响

细胞凋亡是一种由基因控制的细胞自主性死亡过程,其性质为生理性细胞死亡。细胞凋亡的研究已成为生物医学领域中最热门的课题之一。运动可以诱导细胞凋亡,细胞凋亡发生的比率和程度与运动形式、运动强度和运动持续时间有关,其机制可能主要包括以下方面:影响凋亡相关基因、自由基的介导使氧化与抗氧化系统失衡,损伤线粒体的结构和功能以及机械损伤。为此就运动对细胞凋亡影响的一些新的研究进展进行了综述。     

The effects of mouthpiece use on cortisol levels during an intense bout of resistance exercise

Research has suggested mouthpiece use during exercise results in an increase in muscle strength and endurance. However, the research is difficult to replicate, and the methodology suggested measures that were too subjective to determine a mouthpiece effect. Thus, the purpose of this study was to use an objective measure to determine a possible physiological mechanism occurring during and after exercise with mouthpiece use. A within-subjects design was used in which 28 division I football players, aged 18-22 years, performed 2 identical bouts of a 1-hour intense resistance exercise, with each subject being randomly assigned the use of a custom-fit mouthpiece either during the first or second session. During both exercise sessions, saliva was analyzed for cortisol at the following time points: pre-exercise, 25, 45, and 60 minutes of exercise, and 10 minutes postexercise. The results revealed a significant difference in cortisol levels with the use of a mouthpiece vs. no mouthpiece (p = 0.019) at 10 minutes postexercise. Additionally, although the expected increase in cortisol levels from pre to 10 minutes postexercise was present in the no-mouthpiece group (p = 0.01), no such increase was observed in the mouthpiece group. These observations are most likely because of the decrease in cortisol from post to 10 minutes post (p = 0.04) in the mouthpiece group. These data demonstrate that although cortisol continued to increase in the no-mouthpiece session, there was a significant decrease in cortisol in the no-mouthpiece condition 10 minutes postexercise.     

An improved method for extraction and separation of photosynthetic pigments

The method for extracting and separating hydrophobic photosynthetic pigments proposed by Katayama et al. (Japanese Journal of Phycology, 42, 71-77, 1994) has been improved to introduce it to student laboratories at the senior high school level. Silica gel powder was used for removing water from fresh materials prior to extracting pigments by a mixture of organic solvents that was also used for chromatographic separation of the pigments. A small silica gel thin-layer plate or a paper strip was used for separating the pigments. The improved method may be applicable to all kinds of plant materials including algae, is easier than most other methods, and can lead to more successful results in separating these pigments by both thin-layer chromatography and paper chromatography. The method has been carried out in student laboratories in some senior high schools and universities in Japan. The results indicate that this laboratory exercise is effective for students to recognise the unity and diversity of plants. Therefore, this laboratory seems to be useful for teaching plant systematics as well as for teaching photosynthesis.     

Immunology's first priority dispute--an account of the 17th-century Rudbeck-Bartholin feud

Modern immunology has been notably free of public disputes over credit for major discoveries in this discipline. But the early recognition of the lymphatic system witnessed two examples of heated priority feuds. The first in the 17th-century concerned the greater anatomical organization of the system, while the second in the 18th-century concerned its function. This essay reviews the earlier of the two disputes, in which a Swedish medical student (Ole Rudbeck) charged a respected Danish Professor (T. Bartholin) with plagiarism and antedating his observations. Thus ethical issues in immunology predate modern times. How this discipline reached this point in its history is another focus of this essay and also an excuse to review briefly the anatomy of the lymphatic system. The influence of nationalistic pride on priority disputes is also discussed.     

The effect of aerobic exercise during the interset rest periods on kinematics, kinetics, and lactate clearance of two resistance loading schemes

It may be possible to enhance set and session kinematics and kinetics by engaging in low-intensity aerobic exercise during the interset rest period. The purpose of this study therefore was to quantify the change in session kinematics and kinetics of 35% 1RM and 70% 1RM loading schemes equated by volume, when aerobic exercise or passive rest was undertaken between sets. Twelve male student athletes were recruited for this study. Squat average force, peak force, average power, peak power, total work, and total impulse were quantified using a force plate and linear transducer. Blood lactate samples were taken before set 1, after set 1, after set 2, and after the last set performed. No significant (p < 0.05) differences (0.37-9.24%) were found in any of the kinematic and kinetic variables of interset after active or passive interset rest periods. Significant increases (64-76%) in blood lactate occurred from the inception of exercise to completion, for both the heavy and light loading schemes. However, no significant differences in lactate accumulation were noted, whether active or passive recovery was undertaken in the interest rest period. It was concluded that active recovery in the form of low-intensity cycling offered no additional benefits in terms of lactate clearance and enhancement of set and session kinematics and kinetics.     

运动对细胞凋亡的影响

细胞凋亡是一种由基因控制的细胞自主性死亡过程,其性质为生理性细胞死亡。细胞凋亡的研究已成为生物医学领域中最热门的课题之一。运动可以诱导细胞凋亡,细胞凋亡发生的比率和程度与运动形式、运动强度和运动持续时间有关,其机制可能主要包括以下方面：影响凋亡相关基因、自由基的介导使氧化与抗氧化系统失衡,损伤线粒体的结构和功能以及机械损伤。为此就运动对细胞凋亡影响的一些新的研究进展进行了综述。     

Immediate exercise hyperemia: contributions of the muscle pump vs. rapid vasodilation.

A striking characteristic of the blood flow adaptation at exercise onset is the immediate and substantial increase in the first few (0-5 s) seconds of exercise. The purpose of this mini-review is to put into context the present evidence regarding mechanisms responsible for this phase of exercise hyperemia. One potential mechanism that has received much attention is the mechanical effect of muscle contraction (the muscle pump). The rapid vasodilatory mechanism(s) is another possible mechanism that has recently been shown to exist. This review will provide the reader with 1) an understanding of the basic physics of blood flow and the theories of muscle pump function, 2) a critical examination of evidence both for and against the contribution of the muscle pump or rapid vasodilatory mechanisms, and 3) an awareness of the limitations and impact of experimental models and exercise modes on the contribution of each of these mechanisms to the immediate exercise hyperemia. The inability to measure microvenular pressure continues to limit investigators to indirect assessments of the muscle pump vs. vasodilatory mechanism contributions to immediate exercise hyperemia in vivo. Future research directions should include examination of muscle-contraction-induced resistance vessel distortion as a trigger for rapid smooth muscle relaxation and further investigation into the exercise mode dependency of muscle pump vs. rapid vasodilatory contributions to immediate exercise hyperemia.     

The use of a knowledge survey as an indicator of student learning in an introductory biology course

A knowledge survey (KS) is a series of content-based questions sequenced in order of presentation during a course. Students do not answer the questions; rather, they rank their confidence in their ability to answer each question. A 304-question KS was designed and implemented for a multisection, multi-instructor introductory biology course to determine whether this tool could be used to assess student learning. The KS was administered during the first 2 wk and the last 2 wk of the semester online via WebCT. Results were scored using one point for each "not confident" response (level 1), two points for each "possibly confident" response (level 2), and three points for each "confident" response (level 3). We found that scores increased significantly between the pre- and post-KS, indicating that student confidence in their knowledge of the course material increased over the semester. However, the correlation between student confidence and final grades was negligible or low, and chi-square tests show that KS scores and matched exam questions were not significantly related. We conclude that under the conditions implemented in our study, the KS does not reliably measure student learning as measured by final grades or exam questions.     

Emil du Bois-Reymond vs Ludimar Hermann

This essay recounts a controversy between a pioneer electrophysiologist, Emil du Bois-Reymond (1818-1896), and his student, Ludimar Hermann (1838-1914). Du Bois-Reymond proposed a molecular explanation for the slight electrical currents that he detected in frog muscles and nerves. Hermann argued that du Bois-Reymond's 'resting currents' were an artifact of injury to living tissue. He contested du Bois-Reymond's molecular model, explaining his teacher's observations as electricity produced by chemical decomposition. History has painted Hermann as the wrong party in this dispute. I seek to set the record straight.     

A teaching exercise for the identification of bacteria using an interactive computer program

An interactive computer program written in Fortran is described which provides an exercise in the identification of bacteria. The program, IDEN, provides a novel way of enhancing a student's approach to systematic bacteriology and numerical identification procedures. An unknown bacterium is assigned to a student who is provided with a list of possible species and a list of tests which may be carried out. The student's objective is the correct identification of the unknown in the most economical manner. An indication is given concerning the way in which this program can be used to enhance theoretical instruction and practical investigation.     

Essay contest reveals misconceptions of high school students in genetics content

National educational organizations have called upon scientists to become involved in K-12 education reform. From sporadic interaction with students to more sustained partnerships with teachers, the engagement of scientists takes many forms. In this case, scientists from the American Society of Human Genetics (ASHG), the Genetics Society of America (GSA), and the National Society of Genetic Counselors (NSGC) have partnered to organize an essay contest for high school students as part of the activities surrounding National DNA Day. We describe a systematic analysis of 500 of 2443 total essays submitted in response to this contest over 2 years. Our analysis reveals the nature of student misconceptions in genetics, the possible sources of these misconceptions, and potential ways to galvanize genetics education.     

Glucose transport in cultured animal cells: an exercise for the undergraduate cell biology laboratory

Membrane transport is a fundamental concept that undergraduate students of cell biology understand better with laboratory experience. Formal teaching exercises commonly used to illustrate this concept are unbiological, qualitative, or intricate and time consuming to prepare. We have developed an exercise that uses uptake of radiolabeled nutrient analogues by attachment-dependent animal cells cultured on multiwell trays. This system can readily be manipulated within a typical 3-h laboratory period to yield reproducible, biologically relevant, quantitative data regarding key aspects of membrane transport. Each 24-well tray of cultures allows a group of two to four students to compare eight conditions in triplicate. If different groups of students test different conditions or different types of cells, data can be shared for an even broader experience. The exercise is also readily adaptable for open-ended student projects. Here we illustrate the exercise measuring uptake of the nonmetabolizable glucose analogue [(3)H]-2-deoxy-D-glucose. Students successfully tested the effects of competing sugars, putative inhibitors of the GLUT1 transporter, and changes in cell physiology that might be expected to affect glucose transport in epithelial cells and fibroblasts. In this exercise students find the nutritional and medical implications of glucose transport and its regulation intriguing. They also learn to handle radioisotopes and cultured cells.     

Visfatin mRNA expression in human subcutaneous adipose tissue is regulated by exercise

Visfatin [pre-beta-cell colony-enhancing factor (PBEF)] is a novel adipokine that is produced by adipose tissue, skeletal muscle, and liver and has insulin-mimetic actions. Regular exercise enhances insulin sensitivity. In the present study, we therefore examined visfatin mRNA expression in abdominal subcutaneous adipose tissue and skeletal muscle biopsies obtained from healthy young men at time points 0, 3, 4.5, 6, 9, and 24 h in relation to either 3 h of ergometer cycle exercise at 60% of Vo(2 max) or rest. Adipose tissue visfatin mRNA expression increased threefold at the time points 3, 4.5, and 6 h in response to exercise (n = 8) compared with preexercise samples and compared with the resting control group (n = 7, P = 0.001). Visfatin mRNA expression in skeletal muscle was not influenced by exercise. The exercise-induced increase in adipose tissue visfatin was, however, not accompanied by elevated levels of plasma visfatin. Recombinant human IL-6 infusion to mimic the exercise-induced IL-6 response (n = 6) had no effect on visfatin mRNA expression in adipose tissue compared with the effect of placebo infusion (n = 6). The finding that exercise enhances subcutaneous adipose tissue visfatin mRNA expression suggests that visfatin has a local metabolic role in the recovery period following exercise.     

Validating concepts of mental disorder: precedents from the history of science

A fundamental issue in any branch of the natural sciences is validating the basic concepts for use in that branch. In psychiatry, this issue has not yet been resolved, and indeed, the proper nature of the problem has scarcely been recognised. As a result, psychiatry (or at least those parts of the discipline which aspire to scientific status) still cannot claim to be a part of scientific medicine, or to be incorporated within the common language of the natural sciences. While this creates difficulties within the discipline, and its standing in relation to other branches of medicine, it makes it an exciting place for “frontiersmen” (and women). This is one of the key growing points in the natural science tradition. In this essay, which moves from the early history of that tradition to today’s debates in scientific psychiatry, I give my views about how these fundamental issues can move towards resolution.     

Males Under-Estimate Academic Performance of Their Female Peers in Undergraduate Biology Classrooms

Women who start college in one of the natural or physical sciences leave in greater proportions than their male peers. The reasons for this difference are complex, and one possible contributing factor is the social environment women experience in the classroom. Using social network analysis, we explore how gender influences the confidence that college-level biology students have in each other’s mastery of biology. Results reveal that males are more likely than females to be named by peers as being knowledgeable about the course content. This effect increases as the term progresses, and persists even after controlling for class performance and outspokenness. The bias in nominations is specifically due to males over-nominating their male peers relative to their performance. The over-nomination of male peers is commensurate with an overestimation of male grades by 0.57 points on a 4 point grade scale, indicating a strong male bias among males when assessing their classmates. Females, in contrast, nominated equitably based on student performance rather than gender, suggesting they lacked gender biases in filling out these surveys. These trends persist across eleven surveys taken in three different iterations of the same Biology course. In every class, the most renowned students are always male. This favoring of males by peers could influence student self-confidence, and thus persistence in this STEM discipline.     

Practical application of fundamental concepts in exercise physiology

The collection of primary data in laboratory classes enhances undergraduate practical and critical thinking skills. The present article describes the use of a lecture program, running in parallel with a series of linked practical classes, that emphasizes classical or standard concepts in exercise physiology. The academic and practical program ran under the title of a particular year II module named Sports Performance: Physiology and Assessment, and results are presented over a 3-yr period (2004-2006), based on an undergraduate population of 31 men and 34 women. The module compared laboratory-based indexes of endurance (e.g., ventilatory threshold and exercise economy) and high-intensity exercise (e.g., anaerobic power), respectively, with measures of human performance (based on 20-m shuttle run tests). The specific experimental protocols reinforced the lecture content to improve student understanding of the physiological and metabolic responses (and later adaptations) to exercise. In the present study, the strongest relationship with endurance performance was the treadmill velocity at maximal aerobic power (r = +0.88, P < 0.01, n = 51); in contrast, the strongest relationship with high-intensity exercise performance was the mean power output (in W/kg) measured during a 30-s all-out cycle ergometer sprint (r = +0.80, P < 0.01, n = 48). In class student data analysis improved undergraduate indepth or critical thinking during seminars and enhanced computer and data presentation skills. The endurance-based laboratories are particularly useful for examining the underlying scientific principles that determine aerobic performance but could equally well be adapted to investigate other topics, e.g., differences in the exercise response between men and women.     

How to contend with paraphyly in the taxonomy of the delphinine cetaceans?

Molecular phylogenetic analyses conducted over the past 15 yr have consistently had difficulties resolving relationships among the cetacean species in the subfamily Delphininae. In addition, paraphyly of the genera Tursiops and Stenella in these molecular phylogenies has been a recurrent problem since the first appearance of such a phylogeny in 1999, suggesting that these genera do not accurately reflect the evolutionary relationships of the species they contain. Morphological analyses have not resolved the issues. The genera in Delphininae originated in the 19th Century on questionable morphological grounds. The species were nearly all originally described in the genus Delphinus of Linnaeus. Recent molecular phylogenies based on various mitochondrial and nuclear DNA markers have suggested a wide range of possible relationships among these taxa, and several authors have suggested synonymizing all the taxa (Lagenodelphis, Stenella, Sousa, and Tursiops) under Delphinus. Until molecular and/or morphological analyses adequately sort out relationships in this very recently radiated group, one possible solution indeed would be to merge all the delphinine genera with Delphinus. Implications of such a move and alternatives are discussed.

Editor's Note: Papers from past Norris Award winners have primarily been a revised or reduced version of the actual presentation given as a plenary talk at the biennial conference. Dr. Perrin requested being allowed to take a topic from his presentation and expand on it to present a set of ideas in the form of an essay that could pass the rigors of the peer‐review process. As a result, this Norris Award paper has undergone peer‐review and has taken longer than usual for a Norris Award paper to appear in the journal following its presentation at the biennial conference. It also has co‐authors, with varying opinions on the issues discussed in the essay, to cover appropriately and more thoroughly those components of the paper that required additional expertise. I believe this approach has produced an excellent, thought‐provoking essay and is an approach that should be available to future Norris Award winners if they so choose to take it. Since this essay is meant to elicit dialogue, comments are welcome and will be considered for publication in Letters to the Editor.

     

Hybrid lecture-online format increases student grades in an undergraduate exercise physiology course at a large urban university

Hybrid courses allow students additional exposure to course content that is not possible in a traditional classroom environment. This exposure may lead to an improvement in academic performance. In this report, I describe the transition of a large undergraduate exercise physiology course from a traditional lecture format to a hybrid lecture-online format. A total of 658 final grades (traditional = 346, hybrid = 312) was used to evaluate the effect of course format on academic performance. The hybrid online portion was delivered using WebCT Vista, enhanced with various instructional technologies. The hybrid lecture portion was enhanced with an in-class response system. PowerPoint files were used to distribute in-class lectures in both formats of the course. Final student grades were 9.9% higher (83% of the increase due to an increase in the exam grade) when the course was administered in a hybrid format (P = 0.01), which translated to a one letter grade increase on a standard grading scale. Transition from a traditional lecture format to a hybrid format significantly enhanced student learning; presumably, this increase is due to the fact that students were able to increase their exposure to course content via access to material on WebCT.