Pulmonary and renal pressure-flow relationships: what should be taught?

This article is from a symposium presented at the annual meeting of the Human Anatomy and Physiology Society (HAPS) on June 11, 2000. The presentation was funded under the auspices of a National Science Foundation Course, Curriculum, and Laboratory Improvement Program entitled "Development of Active Learning Materials for Physiology and Functional Anatomy: A Cooperative HAPS-APS Initiative." This symposium was part of the first module to be developed on "gradients and conductances: what flows where and why?" This presentation was designed to model the usefulness of the general model of gradients and conductances in the physiology and pathophysiology of the respiratory and renal systems. Thirteen different examples of pressure-flow-resistance and concentration-flux relationships are introduced; several ideas for active-learning activities and simple figures appropriate for undergraduate physiology classes are included. The symposium assumes that undergraduate students have already learned about diffusion, osmosis, and the basic principles of cardiovascular physiology. The presentation was designed to follow a symposium entitled: "Cardiovascular pressure-flow relationships: what should be taught?"     

What makes physiology hard for students to learn? Results of a faculty survey

Teachers of physiology at all postsecondary levels were asked to participate in a survey about the possible sources of students' difficulty in learning physiology. Sixty-three physiology teachers responded to the 18-question survey; 35 of the respondents also responded to a request for written comments about this issue prior to taking the survey. Three categories of possible factors contributing to physiology being hard to learn were defined: 1) the nature of the discipline, 2) the way it is taught, and 3) what students bring to the task of learning physiology. Respondents thought that characteristics of the discipline (it requires causal reasoning, it uses graphs and mathematics, and it is highly integrative) and characteristics of students (they believe that learning and memorizing are the same thing, they cannot or will do attempt to integrate, and they compartmentalize) were significantly more important than any aspect of teaching in making physiology hard to learn. Recommendations are offered in this article to help students deal with the sources of difficulty that were identified.     

Differences between African-American and Caucasian students on enrollment influences and barriers in kinesiology-based allied health education programs

Kinesiology departments have recently started to offer allied health education programs to attract additional students to teacher education units (9). Although allied health professions offer increased work opportunities, insufficient enrollment and training of minority students in these academic fields contribute to underrepresentation in the workforce (3). To improve workforce diversity, kinesiology departments must understand how enrollment influences and barriers differ by race among prospective students. Therefore, the purpose of this study was to identify differences in allied health education enrollment influences and enrollment barriers between minority and Caucasian students. Participants (n = 601) consisted of students enrolled in kinesiology-based allied health education programs. Multivariate ANOVA was used to compare group differences in enrollment decision making. "Personal influence," "career opportunity," and "physical self-efficacy" were all significantly stronger enrollment influences among African-American students than among Caucasian students, and "social influence," "experiential opportunity," "academic preparation," and "physical self-efficacy" were all perceived as significantly greater barriers compared with Caucasian students. Findings support the need to recruit African-American students through sport and physical education settings and to market program-based experiential opportunities.     

Assessing formal teaching of ethics in physiology: an empirical survey, patterns, and recommendations

Ethics should be an important component of physiological education. In this report, we examined to what extent teaching of ethics is formally being incorporated into the physiology curriculum. We carried out an e-mail survey in which we asked the e-mail recipients whether their institution offered a course or lecture on ethics as part of the physiology teaching process at their institution, using the following query: "We are now doing an online survey in which we would like to know whether you offer a course or a lecture on ethics as part of your physiology teaching curriculum." The response rate was 53.3%: we received 104 responses of a total of 195 sent out. Our responses came from 45 countries. While all of our responders confirmed that there was a need for ethics during medical education and scientific training, the degree of inclusion of formal ethics in the physiology curriculum varied widely. Our survey showed that, in most cases (69%), including at our Medical University of Graz, ethics in physiology is not incorporated into the physiology curriculum. Given this result, we suggest specific topics related to ethics and ethical considerations that could be integrated into the physiology curriculum. We present here a template example of a lecture "Teaching Ethics in Physiology" (structure, content, examples, and references), which was based on guidelines and case reports provided by experts in this area (e.g., Benos DJ. Ethics revisited. Adv Physiol Educ 25: 189-190, 2001). This lecture, which we are presently using in Graz, could be used as a base that could lead to greater awareness of important ethical issues in students at an early point in the educational process.     

Exploring the influence of plant and animal item contexts on student response patterns to natural selection multiple choice items

Background

Research has shown that students have a variety of ideas about natural selection that may be context dependent. Prior analyses of student responses to open-ended evolution items have demonstrated that students apply more core ideas about natural selection when asked about animals, but respond with the same number of naive ideas for plant and animal items. Other research has shown that changing an item to ask about trait loss or gain shifted the types of naive ideas applied by students in their responses. In this paper, we take up both of these findings to determine if differences exist in the types of ideas students apply to similar items with either a plant or an animal in the item stem.

Results

In order to understand if students applied different ideas to plants or animals in distractor-driven multiple-choice questions, we analyzed high school biology students’ responses to matched-item pairs. Dichotomous scoring revealed that students chose the correct response more often for the animal items as compared to the plant items. Chi squared analyses revealed significant differences in the distribution of student responses to matched items. For example, more students chose responses that defined animal fitness as related to their strength and plants’ fitness related to its longevity.

Conclusions

These results suggest that varied context of plants or animals in item stems on diagnostic assessments can provide teachers with a more complete picture of their students’ ideas about natural selection prior to instruction. This is particularly important in assessments used prior to instruction; as teachers will gain greater insight into the variety of ways students think about natural selection across different types of plants and animals.

     

Teacher Competencies in Health Education: Results of a Delphi Study

Objective

The aim of this research study was to identify the core competencies for health education teachers in supporting the development of health literacy among their students.

Method/Results

A three round Delphi method was employed. Experts in health education were asked to identify core competencies for school health educators. Twenty six participants from the academic field were invited to participate in the study. Twenty participants completed the first round of the Delphi, while eighteen took part in round two and fifteen participated in the final round. Data were collected using an electronic questionnaire. The first round contained an open ended question in which participants were asked to name and define all the competencies they perceived were important. Thematic analysis was undertaken on these data. A list of 36 competencies was created from this round. This list was then returned to the same participants and they were asked to rate each competency on a 7 point semantic differential scale in terms of importance. The resulting data were then analysed. For the final round, participants were presented with a list of 33 competencies and were asked to rank them again, in order of importance.

Conclusion

Twelve core competencies emerged from the analysis and these competencies comprised of a mixture of knowledge, attitude and skills. The authors suggest that how these competencies are achieved and operationalised in the school context can be quite complex and multi-faceted. While the authors do not seek to generalise from the study they suggest that these competencies are an important input for all stakeholders, in order to question national and international teacher guidelines. In addition the competencies identified may provide a useful starting point for others to undertake deeper analysis of what it means to be an effective health educator in schools.     

Use of concept mapping in an undergraduate introductory exercise physiology course

Physiology is often considered a challenging course for students. It is up to teachers to structure courses and create learning opportunities that will increase the chance of student success. In an undergraduate exercise physiology course, concept maps are assigned to help students actively process and organize information into manageable and meaningful chunks and to teach them to recognize the patterns and regularities of physiology. Students are first introduced to concept mapping with a commonly relatable nonphysiology concept and are then assigned a series of maps that become more and more complex. Students map the acute response to a drop in blood pressure, the causes of the acute increase in stroke volume during cardiorespiratory exercise, and the factors contributing to an increase in maximal O(2) consumption with cardiorespiratory endurance training. In the process, students draw the integrative nature of physiology, identify causal relationships, and learn about general models and core principles of physiology.     

Lay understanding of low-frequency electric and magnetic fields

People do not start with a blank slate when they hear risk-communication messages. All such messages are processed through existing knowledge structures and understanding. Hence, to design effective and reliable risk-communication materials one must understand the state of people's knowledge--correct and incorrect--about an issue. We developed a simple "mental model" of what people minimally need to know to make informed decisions about field-related issues. Then we performed studies to explore how and to what extent respondents of various groups understood physical properties of 60-Hz electric and magnetic fields. Actual knowledge of respondents was then compared with the predicates of the model. Electrical engineering juniors and semi-technical employees of utilities displayed a good command of most of the concepts in the simple model, but little awareness of the limits to their knowledge. Lay respondents correctly knew only a few of the simplest elements of the model, but they displayed a much greater awareness of the limits to their knowledge. Both lay and semi-technical respondents were found to share several misconceptions. On average, they correctly rank-ordered some common field-exposure conditions by field strength, but they could not differentiate between electric and magnetic fields and could not differentiate among field strengths associated with different appliances. Most respondents dramatically underestimated the range of actual field strengths. Many respondents understood that field strength decreases with distance from a source, but they underestimated the rate of decrease. In contrast to X-rays and microwaves, which respondents appeared to think about in rather similar terms, 60-Hz fields were not thought of as being highly similar to any other agent, although the closest parallels were found with ultrasound. Changes in mood, thought, and behavior, and the existence of an "electrical aura," were all seen as plausible results of exposure to a 60-Hz field. Although lay respondents displayed a variety of incomplete and confusing ideas, most of these ideas probably do not pose significant obstacles to the learning of a correct, simple, mental model.     

Aims of undergraduate physiology education: a view from the University of Chicago

Physiology may play an important, if not essential role, in a liberal arts education because it provides a context for integrating information and concepts from diverse biological and extra-biological disciplines. Instructors of physiology may aid in fulfilling this role by clarifying the core concepts that physiological details exemplify. As an example, presented here are the core principles that are the basis for an undergraduate physiology course taught at the University of Chicago. The first of these is: Evolution has resulted in organisms comprising mechanisms for maintenance, growth, and reproduction, despite perturbations of the internal and external environment. Such principles necessitate a coupling of physiology to diverse disciplines (i.e., "sciomics") and provide a basis for integrating discoveries in other disciplines.     

Electrokinetic membrane processes in relation to properties excitable tissues. II. Some theoretical considerations

A quantitative theory is presented for the behavior of a membrane-electrolyte system subject to an electric current flow (the "membrane oscillator"). If the membrane is porous, carries "fixed charges," and separates electrolyte solutions of different conductances, it can be the site of repetitive oscillatory changes in the membrane potential, the membrane resistance, and the hydrostatic pressure difference across the membrane. These events are accompanied by a pulsating transport of bulk solutions. The theory assumes the superposition of electrochemical and hydrostatic gradients and centers round the kinetics of resistance changes within the membrane, as caused by effects from diffusion and electro-osmotic fluid streaming. The results are laid down in a set of five simple, basic expressions, which can be transformed into a pair of non-linear differential equations yielding oscillatory solutions. A graphical integration method is also outlined (Appendix II). The agreement between the theory and previous experimental observations is satisfactory. The applied electrokinetic concepts may have importance in relation to analyses of the behavior of living excitable cells or tissues.     

Do Ask,Do Tell: High Levels of Acceptability by Patients of Routine Collection of Sexual Orientation and Gender Identity Data in Four Diverse American Community Health Centers

Background

The Institute of Medicine and The Joint Commission have recommended asking sexual orientation and gender identity (SOGI) questions in clinical settings and including such data in Electronic Health Records (EHRs). This is increasingly viewed as a critical step toward systematically documenting and addressing health disparities affecting lesbian, gay, bisexual, and transgender (LGBT) people. The U.S. government is currently considering whether to include SOGI data collection in the Stage 3 guidelines for the incentive program promoting meaningful use of EHR. However, some have questioned whether acceptable standard measures to collect SOGI data in clinical settings exist.

Methods

In order to better understand how a diverse group of patients would respond if SOGI questions were asked in primary care settings, 301 randomly selected patients receiving primary care at four health centers across the U.S. were asked SOGI questions and then asked follow-up questions. This sample was mainly heterosexual, racially diverse, and geographically and regionally broad.

Results

There was a strong consensus among patients surveyed about the importance of asking SOGI questions. Most of the LGBT respondents thought that the questions presented on the survey allowed them to accurately document their SOGI. Most respondents—heterosexual and LGBT—answered the questions, and said that they would answer such questions in the future. While there were some age-related differences, respondents of all ages overwhelmingly expressed support for asking SOGI questions and understood the importance of providers'' knowing their patients'' SOGI.

Conclusions

Given current deliberations within national health care regulatory bodies and the government''s increased attention to LGBT health disparities, the finding that patients can and will answer SOGI questions has important implications for public policy. This study provides evidence that integrating SOGI data collection into the meaningful use requirements is both acceptable to diverse samples of patients, including heterosexuals, and feasible.     

Identification of repeat sequence heterogeneity at the polymorphic short tandem repeat locus HUMTH01[AATG]n and reassignment of alleles in population analysis by using a locus-specific allelic ladder.

An allelic ladder containing amplified sequences of seven alleles of the polymorphic human tyrosine hydroxylase locus, HUMTH01, was constructed and employed as a standard marker. Sequence analysis of each ladder component indicates that fragments differ by integral multiples of the AATG core repeat sequence characteristic of this locus. Individual alleles are designated "5" through "11," according to the number of complete reiterations of the core repeat contained within them. Comparison of the HUMTH01 allelic ladder with DNA samples amplified at this locus revealed core repeat length heterogeneity (i.e., deletions or insertions shorter than one core repeat) within the human population. In particular, a common allele was identified which migrates more quickly than allele 10, but more slowly than allele 9, on electrophoresis through a denaturing polyacrylamide gel. Sequence analysis of this allele, designated "10-1," reveals lack of a single adenine normally present in the seventh copy of the AATG. The allelic ladder was used to reevaluate previously published population data. Results of testing for Hardy-Weinberg equilibrium and population substructure were not altered significantly by these modifications.     

A laboratory exercise using a physical model for demonstrating countercurrent heat exchange

A physical model was used in a laboratory exercise to teach students about countercurrent exchange mechanisms. Countercurrent exchange is the transport of heat or chemicals between fluids moving in opposite directions separated by a permeable barrier (such as blood within adjacent blood vessels flowing in opposite directions). Greater exchange of heat or chemicals between the fluids occurs when the flows are in opposite directions (countercurrent) than in the same direction (concurrent). When a vessel loops back on itself, countercurrent exchange can occur between the two arms of the loop, minimizing loss or uptake at the bend of the loop. Comprehension of the physical principles underlying countercurrent exchange helps students to understand how kidneys work and how modifications of a circulatory system can influence the movement of heat or chemicals to promote or minimize exchange and reinforces the concept that heat and chemicals move down their temperature or concentration gradients, respectively. One example of a well-documented countercurrent exchanger is the close arrangement of veins and arteries inside bird legs; therefore, the setup was arranged to mimic blood vessels inside a bird leg, using water flowing inside tubing as a physical proxy for blood flow within blood vessels.     

Structural morphology of renal vasculature

An automatic segmentation technique has been developed and applied to two renal micro-computer tomography (CT) images. With the use of a 20-microm voxel resolution image, the arterial and venous trees were segmented for the rat renal vasculature, distinguishing resolving vessels down to 30 microm in radius. A higher resolution 4-microm voxel image of a renal vascular subtree, with vessel radial values down to 10 microm, was segmented. Strahler ordering was applied to each subtree using an iterative scheme developed to integrate information from the two segmented models to reconstruct the complete topology of the entire vascular tree. An error analysis of the assigned orders quantified the robustness of the ordering process for the full model. Radial, length, and connectivity data of the complete arterial and venous trees are reported by order. Substantial parallelism is observed between individual arteries and veins, and the ratio of parallel vessel radii is quantified via a power law. A strong correlation with Murray's Law was established, providing convincing evidence of the "minimum work" hypothesis. Results were compared with theoretical branch angle formulations, based on the principles of "minimum shear force," were inconclusive. Three-dimensional reconstructions of renal vascular trees collected are made freely available for further investigation into renal physiology and modeling studies.     

Sex and gender in medical education: a national student survey

Background

Gender- and sex-specific medicine is defined as the practice of medicine based on the understanding that biology (dictated by sex chromosomes) and social roles (gender) are important in and have implications for prevention, screening, diagnosis, and treatment in men and women. In light of the many ways that sex and gender influence disease presentation and patient management, there have been various initiatives to improve the integration of these topics into medical education curriculum. Although certain schools may include the topics, their impact on the student body’s knowledge has not been as fully studied. By studying the opinions of US allopathic and osteopathic-enrolled students on the extent to which their schools address these topics and their understanding of these topics, this study examined the role of gender specific medicine in the US medical school curriculum.

Methods

An email solicitation with link to an anonymous survey was sent to approximately 35,876 student members of five US medical student organizations. The survey instrument consisted of yes/no, multiple choice, and attitude awareness questions. Data was analyzed as a complete data set to evaluate national trends and via subset analysis using chi-square, paired t test, and one-way anova.

Results

A total of 1097 students responded. The majority of respondents strongly agreed that sex and gender medicine (SGBM) improves patient management (96.0 %) and should be included as a part of the medical school curriculum (94.4 %). Only 2.4 % of participants agreed that SGBM is the same as Women’s Health. When asked specifically about inclusion of an identified sex and gender-based medicine curriculum at their institution, students answered not sure at 40.8, 25.1, 19.1, and 20.3 % from first year to fourth year, respectively. Males reported a higher rate of exposure to SGBM content areas (in medical history taking, domestic violence) than women.

Conclusions

Medical students recognize the differentiation between SGBM principles and women’s health, and understand the translational value of sex and gender-specific principles in the clinical setting. However, current curricular offerings fall short of providing students with adequate coverage of specific evidence-based health differences.

     

Online Respondent-Driven Sampling for Studying Contact Patterns Relevant for the Spread of Close-Contact Pathogens: A Pilot Study in Thailand

Background

Information on social interactions is needed to understand the spread of airborne infections through a population. Previous studies mostly collected egocentric information of independent respondents with self-reported information about contacts. Respondent-driven sampling (RDS) is a sampling technique allowing respondents to recruit contacts from their social network. We explored the feasibility of webRDS for studying contact patterns relevant for the spread of respiratory pathogens.

Materials and Methods

We developed a webRDS system for facilitating and tracking recruitment by Facebook and email. One-day diary surveys were conducted by applying webRDS among a convenience sample of Thai students. Students were asked to record numbers of contacts at different settings and self-reported influenza-like-illness symptoms, and to recruit four contacts whom they had met in the previous week. Contacts were asked to do the same to create a network tree of socially connected individuals. Correlations between linked individuals were analysed to investigate assortativity within networks.

Results

We reached up to 6 waves of contacts of initial respondents, using only non-material incentives. Forty-four (23.0%) of the initially approached students recruited one or more contacts. In total 257 persons participated, of which 168 (65.4%) were recruited by others. Facebook was the most popular recruitment option (45.1%). Strong assortative mixing was seen by age, gender and education, indicating a tendency of respondents to connect to contacts with similar characteristics. Random mixing was seen by reported number of daily contacts.

Conclusions

Despite methodological challenges (e.g. clustering among respondents and their contacts), applying RDS provides new insights in mixing patterns relevant for close-contact infections in real-world networks. Such information increases our knowledge of the transmission of respiratory infections within populations and can be used to improve existing modelling approaches. It is worthwhile to further develop and explore webRDS for the detection of clusters of respiratory symptoms in social networks.     

Teaching the interrelationship between stress, emotions, and cardiovascular risk using a classic paper by Walter Cannon

Classroom discussion of the classic article by Walter B. Cannon in 1914, entitled "The emergency function of the adrenal medulla in pain and the major emotions," is an excellent tool to teach graduate students the interaction between stress, emotions, and cardiovascular function. Using this article, we are able to review important early research by Dr. Cannon, including discussion of his scientific methods and results and how they hold true today. This article outlines how this classic paper is used to allow students to explore basics principles of cardiovascular control during stress. The teaching points that are presented illustrate how students can be directed to understand the interrelationship between chronic stress and cardiovascular disease.     

Recognizing the Symptoms of Mental Illness following Concussions in the Sports Community: A Need for Improvement

Objective

To evaluate the awareness of concussion-related symptoms amongst members of the sports community in Canada.

Methods

A cross-sectional national electronic survey was conducted. Youth athletes, parents, coaches and medical professionals across Canada were recruited through mailing lists from sports-related opt-in marketing databases. Participants were asked to identify, from a list of options, the symptoms of a concussion. The proportion of identified symptoms (categorized as physical, cognitive, mental health-related and overall) as well as participant factors associated with symptom recognition were analyzed.

Results

The survey elicited 6,937 responses. Most of the respondents (92.1%) completed the English language survey, were male (57.7%), 35–54 years of age (61.7%), with post-secondary education (58.2%), or high reported yearly household income (>$80,000; 53.0%). There were respondents from all provinces and territories with the majority of respondents from Ontario (35.2%) or British Columbia (19.1%). While participants identified most of the physical (mean = 84.2% of symptoms) and cognitive (mean = 91.2% of symptoms), they on average only identified 53.5% of the mental health-related symptoms of concussions. Respondents who were older, with higher education and household income, or resided in the Northwest Territories or Alberta identified significantly more of the mental health-related symptoms listed.

Interpretation

While Canadian youth athletes, parents, coaches and medical professionals are able to identify most of the physical and cognitive symptoms associated with concussion, identification of mental health-related symptoms of concussion is still lagging.