A cogent technique to circumvent the use of (some) ratio measures in physiology.

Physiologists often express the change in the value of a measurement made on two occasions as a ratio of the initial value. This is usually motivated by an assumption that the absolute change fails to capture the true extent of the alteration that has occurred in attaining the final value - if there is initial variation among individual cases. While it may appear reasonable to use ratios to standardize the magnitude of change in this way, the perils of doing so have been widely documented. Ratios frequently have intractable statistical properties, both when taken in isolation and when analysed using techniques such as regression. A new method of computing a standardized metric of change, based on principal components analysis (PCA), is described. It exploits the collinearity within sets of initial, absolute change and final values. When these sets define variables subjected to PCA, the standardized measure of change is obtained as the product of the loading of absolute change onto the first principal component (PC1) and the eigenvalue of PC1. It is demonstrated that a sample drawn from a population of these standardized measures: approximates a normal distribution (unlike the corresponding ratios); lies within the same range; and preserves the rank order of the ratios. It is also shown that this method can be used to express the magnitude of a physiological response in an experimental condition relative to that obtained in a control condition. KEY POINTS: The intractable statistical properties of ratios and the perils of using ratios to standardize the magnitude of change are well known. A new method of computing a standardized metric, based on principal components analysis (PCA), is described, which exploits the collinearity within sets of initial, absolute change and final values. A sample drawn from a population of these PCA-derived measures: approximates a normal distribution (unlike the corresponding ratios); lies within the same range as the ratios; and preserves the rank order of the ratios. The method can also be applied to express the magnitude of a physiological response in an experimental condition relative to a control condition.

Myths and Methodologies: Standardisation in human physiology research-should we control the controllables?

The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.

When it's time for the sex talk, words matter.

In recent years, the traditional, unspoken assumption in published biomedical research studies that the young, healthy (usually white) male is the "default human" has received increasing scrutiny and criticism. The historical underrepresentation of female participants in biomedical research has been increasingly recognized and addressed, including with the current call for papers at the American Journal of Physiology-Heart and Circulatory Physiology. Our goal in the present Perspectives is to discuss the topic of terminology (man/woman vs. male/female) for human research participants when considering sex as a biological variable. This important consideration is consistent with the importance of gender identity and related topics to psychological, emotional, and physical health. Just as pronouns are important, so is appropriate terminology when referring to human research volunteers. Despite some disagreement regarding terminology between our two groups of authors, we provide consensus recommendations. Importantly, we all agree that the most vital aspect of the present discussion is the broader focus on sex as a biological variable and appropriate inclusion of biological sex in in vitro, preclinical, and human research studies.

A world beyond P: policies, strategies, tactics and advice.

A short review of the changing approach to statistics' contribution to the conduct of physiological experiments, with suggestions for further changes and better practice.

Predicting success in an undergraduate exercise science program using science-based admission courses.

Student success is an important focus within higher education as it relates to retention, progression, and graduation rates. Limited research exists examining the predictors of success within an undergraduate Exercise Science program. The purpose of this investigation was to examine the viability of an admission policy implemented within an undergraduate Exercise Science program as a method of predicting student success. Data from 652 students from 2012 through 2018 were collected from the University's Enterprise Information Management system. Regression analysis indicated ES 2100, an introductory Exercise Science course, was the best predictor of student performance in required major courses. Furthermore, the results indicated performance in general education courses, including English Composition II, Precalculus, General Chemistry II Laboratory, Human Anatomy and Physiology II, and General Psychology were also significantly related to performance in the required major courses, after controlling for performance in other courses. The results of the investigation provide insight regarding future success within required major courses in the program. This knowledge can be valuable when examining methods to improve retention of students, progression, minimizing repeat attempts at courses, and improving graduation rates. In conclusion, the identification of these courses, related to student success, may provide valuable insight for other Exercise Science-related programs that are considering implementing a program admission policy.

Statistical considerations in reporting cardiovascular research.

The problem of inadequate statistical reporting is long standing and widespread in the biomedical literature, including in cardiovascular physiology. Although guidelines for reporting statistics have been available in clinical medicine for some time, there are currently no guidelines specific to cardiovascular physiology. To assess the need for guidelines, we determined the type and frequency of statistical tests and procedures currently used in the American Journal of Physiology-Heart and Circulatory Physiology. A PubMed search for articles published in the American Journal of Physiology-Heart and Circulatory Physiology between January 1, 2017, and October 6, 2017, provided a final sample of 146 articles evaluated for methods used and 38 articles for indepth analysis. The t-test and ANOVA accounted for 71% (212 of 300 articles) of the statistical tests performed. Of six categories of post hoc tests, Bonferroni and Tukey tests were used in 63% (62 of 98 articles). There was an overall lack in details provided by authors publishing in the American Journal of Physiology-Heart and Circulatory Physiology, and we compiled a list of recommended minimum reporting guidelines to aid authors in preparing manuscripts. Following these guidelines could substantially improve the quality of statistical reports and enhance data rigor and reproducibility.

Guidelines for authors and reviewers on antibody use in physiology studies.

Antibody use is a critical component of cardiovascular physiology research, and antibodies are used to monitor protein abundance (immunoblot analysis) and protein expression and localization (in tissue by immunohistochemistry and in cells by immunocytochemistry). With ongoing discussions on how to improve reproducibility and rigor, the goal of this review is to provide best practice guidelines regarding how to optimize antibody use for increased rigor and reproducibility in both immunoblot analysis and immunohistochemistry approaches. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/guidelines-on-antibody-use-in-physiology-studies/ .

Guidelines for measuring cardiac physiology in mice.

Cardiovascular disease is a leading cause of death, and translational research is needed to understand better mechanisms whereby the left ventricle responds to injury. Mouse models of heart disease have provided valuable insights into mechanisms that occur during cardiac aging and in response to a variety of pathologies. The assessment of cardiovascular physiological responses to injury or insult is an important and necessary component of this research. With increasing consideration for rigor and reproducibility, the goal of this guidelines review is to provide best-practice information regarding how to measure accurately cardiac physiology in animal models. In this article, we define guidelines for the measurement of cardiac physiology in mice, as the most commonly used animal model in cardiovascular research. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/guidelines-for-measuring-cardiac-physiology-in-mice/ .

Guidelines for experimental models of myocardial ischemia and infarction.

Myocardial infarction is a prevalent major cardiovascular event that arises from myocardial ischemia with or without reperfusion, and basic and translational research is needed to better understand its underlying mechanisms and consequences for cardiac structure and function. Ischemia underlies a broad range of clinical scenarios ranging from angina to hibernation to permanent occlusion, and while reperfusion is mandatory for salvage from ischemic injury, reperfusion also inflicts injury on its own. In this consensus statement, we present recommendations for animal models of myocardial ischemia and infarction. With increasing awareness of the need for rigor and reproducibility in designing and performing scientific research to ensure validation of results, the goal of this review is to provide best practice information regarding myocardial ischemia-reperfusion and infarction models. Listen to this article's corresponding podcast at ajpheart.podbean.com/e/guidelines-for-experimental-models-of-myocardial-ischemia-and-infarction/.

Item statistics derived from three-option versions of multiple-choice questions are usually as robust as four- or five-option versions: implications for exam design.

Different versions of multiple-choice exams were administered to an undergraduate class in human physiology as part of normal testing in the classroom. The goal was to evaluate whether the number of options (possible answers) per question influenced the effectiveness of this assessment. Three exams (each with three versions) were given to each of two sections during an academic quarter. All versions were equally long, with 30 questions: 10 questions with 3 options, 10 questions with 4, and 10 questions with 5 (always one correct answer plus distractors). Each question appeared in all three versions of an exam, with a different number of options in each version (three, four, or five). Discrimination (point biserial and upper-lower discrimination indexes) and difficulty were evaluated for each question. There was a small increase in difficulty (a lower average score on a question) when more options were provided. The upper-lower discrimination index indicated a small improvement in assessment of student learning with more options, although the point biserial did not. The total length of a question (number of words) was associated with a small increase in discrimination and difficulty, independent of the number of options. Quantitative questions were more likely to show an increase in discrimination with more options than nonquantitative questions, but this effect was very small. Therefore, for these testing conditions, there appears to be little advantage in providing more than three options per multiple-choice question, and there are disadvantages, such as needing more time for an exam.

Best practices in active and student-centered learning in physiology classes.

This review article includes our analysis of the literature and our own experiences in using various types of active learning as best practices for evidence-based teaching in physiology. We have evaluated what physiology students should be expected to learn and what are specific challenges to enhancing their learning of physiology principles. We also consider how the instructor should design his or her teaching to improve buy-in from both students and other faculty members. We include a discussion of how the readers can evaluate their teaching approaches for their successes in enhancing student learning of physiology. Thus we have addressed pedagogical improvements specific to student learning of physiology, with additional suggestions from cognitive psychology approaches that can improve physiology teaching and learning.

How do students deal with difficult physiological knowledge?

Physiology courses are considered to be challenging for students to master due to the highly conceptual nature of the discipline and the substantial cognitive effort required to understand disciplinary knowledge. Students must choose appropriate learning strategies to develop their understanding, as their choices may influence both their understanding and their academic achievement. The primary aim of this study was to develop an understanding of why students experience difficulties with physiology and how they respond when facing the challenge of learning this discipline. Undergraduate allied health students ( n = 231) studying physiology were asked to identify the topics they had difficulty understanding, the strategies they used to deal with that difficult knowledge, and the reasons for their difficulties. Consenting students' responses were subjected to inductive and deductive thematic analyses, and their performance on examinations were collated. Students reported that they found physiology difficult due to their lack of familiarity with it and the level of detail required. To aid their understanding of difficult topics, students commonly reported reviewing information, seeking further information, and seeking social assistance, with more high-achieving students reporting reviewing records, and fewer reporting seeking social assistance than poor-achieving students. Most notably, a disconnect was found between students' reporting of difficult modules and their academic achievement on those modules, with students who cited difficulties performing equally well, if not better, than those who do not. Importantly, these findings suggest that students, in recognizing their difficulties and the reasons for them, can implement effective learning strategies to overcome them.

Comparison of knowledge retention between high-fidelity patient simulation and read-only participants in undergraduate biomedical science education.

High-fidelity patient simulation (HFPS) is expensive in money and faculty resources. There has been a recent push to increase the use of HFPS for undergraduates to teach basic science. However, it is still unclear if HFPS is superior to other cost-effective modalities for learning, and there have been limited studies comparing HFPS directly with other methods. The purpose of this study was to compare learning between three groups: 1) students who participated in a HFPS after reading material (RS); 2) students who reread material (RR) individually; and 3) students who had no intervention or reading (CON). Quizzes (10 true/false questions) were given presimulation, immediately after the simulation (post-sim 1), and 1 wk later to all groups (post-sim 2). Ninety-seven undergraduate students consented to include their data in the study. All groups scored the same on the presimulation quiz (median of 6). The RR and RS scored significantly higher than the CON group on post-sim 1 (medians 8 vs. 6). All groups performed similarly on post-sim 2. A questionnaire also showed that students had increased perceived confidence about pathophysiology. These data suggest that a single-time use of HFPS for knowledge learning for undergraduate students is not more effective than other methods. Future studies need to determine whether increasing the number of HFPS and developing social learning networks could make HFPS more effective for undergraduates. Additionally, future studies should focus on soft skill development, such as confidence, critical thinking, and teamwork/communication skills, as opposed to knowledge acquisition.

Understanding the interrelationship between the synthesis of urea and gluconeogenesis by formulating an overall balanced equation.

It is well known that a strong metabolic interrelationship exists between ureagenesis and gluconeogenesis. In this paper, we present a detailed, overall equation, describing a possible metabolic link between ureagenesis and gluconeogenesis. We adopted a guided approach in which we strongly suggest that students, when faced with the problem of obtaining the overall equation of a metabolic pathway, carefully account for all atoms and charges of the single reactions, as well as the cellular localizations of the substrates, and the related transport systems. If this suggestion is always taken into account, a balanced, overall equation of a metabolic pathway will be obtained, which strongly facilitates the discussion of its physiological role. Unfortunately, textbooks often report unbalanced overall equations of metabolic pathways, including ureagenesis and gluconeogenesis. Most likely the reason is that metabolism and enzymology have been neglected for about three decades, owing to the remarkable advances of molecular biology and molecular genetics. In this paper, we strongly suggest that students, when faced with the problem of obtaining the overall reaction of a metabolic pathway, carefully control if the single reactions are properly balanced for atoms and charges. Following this suggestion, we were able to obtain an overall equation describing the metabolic interrelationship between ureagenesis and gluconeogenesis, in which urea and glucose are the final products. The aim is to better rationalize this topic and to convince students and teachers that metabolism is an important and rewarding chapter of human physiology.

Promoting the APS Chapter Program by sharing its history, best practices, and how-to guide for establishing new chapters.

Early establishment of physiological societies in Oklahoma and Ohio demonstrated the benefits of networking physiologists and paved the way for establishing the APS Chapter Program. Designed to promote the general objectives of the APS, the Chapter Program was officially launched in 1995, with Ohio being the first recognized chapter. There are 13 active chapters regularly engaged in numerous activities designed to advance physiology education and research. In the hopes that others will recognize the important offerings of state chapters and consider organizing one, the aims for this paper are to 1) share a brief history, 2) provide rationale for chapter initiation, and 3) describe the process involved in establishing a chapter. In light of current changes in American Medical Association and Liaison Committee on Medical Education guidelines, the present time may be critical in promoting chapters, as they play a vital role in sustaining recognition and support for the discipline.

Physiology undergraduate degree requirements in the U.S.

Course-level learning objectives and core concepts for undergraduate physiology teaching exist. The next step is to consider how these resources fit into generalizable program-level guidelines for Bachelor of Science (BS) degrees in Physiology. In the absence of program-level guidelines for Physiology degree programs, we compiled a selective internal report to review degree requirements from 18 peer BS programs entitled "Physiology" in the United States (U.S.). There was a range of zero to three required semesters of math, physics, physics laboratory, general biology, biology laboratory, general chemistry, chemistry laboratory, organic chemistry, organic chemistry laboratory, biochemistry, biochemistry laboratory, anatomy, anatomy laboratory, core systems physiology, and physiology laboratory. Required upper division credits ranged from 11 to 31 and included system-specific, exercise and environmental, clinically relevant, pathology/disease-related, and basic science options. We hope that this information will be useful for all programs that consider themselves to be physiology, regardless of name. Reports such as this can serve as a starting point for collaboration among BS programs to improve physiology undergraduate education and best serve our students.

Evaluation of chest ultrasound integrated teaching of respiratory system physiology to medical students.

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term concept retention. A lecture about respiratory physiology was integrated with ultrasound and delivered to third-year medical students. It included basic concepts of ultrasound imaging and the physiology of four anatomic sectors of the body of a male volunteer, shown with a portable ultrasound device (pleural sliding, diaphragmatic movement, inferior vena cava diameter variations, cardiac movements). Students' perceptions of the integrated lecture were assessed, and attendance recorded. After 4 mo, four multiple-choice questions about respiratory physiology were administered during the normal human physiology examinations, and the results of students who attended the lesson and those of who did not were compared. One hundred thirty-four students attended the lecture. Most of them showed encouragement for the study of the subject and considered the ultrasound integrated lecture more interesting than a traditional one and pertinent to the syllabus. Exposed students achieved a better score at the examination and committed less errors than did nonexposed students. The chest ultrasound integrated lecture was appreciated by students. A possible association between the exposure to the lecture and short-term concept retention is shown by better performances of the exposed cohort at the examination. A systematic introduction of ultrasound into physiology traditional teaching will be promoted by the Ultrasound-Based Medical Education movement.

Methods and pitfalls of measuring thermal preference and tolerance in lizards.

Understanding methodological and biological sources of bias during the measurement of thermal parameters is essential for the advancement of thermal biology. For more than a century, studies on lizards have deepened our understanding of thermal ecophysiology, employing multiple methods to measure thermal preferences and tolerances. We reviewed 129 articles concerned with measuring preferred body temperature (PBT), voluntary thermal tolerance, and critical temperatures of lizards to offer: a) an overview of the methods used to measure and report these parameters, b) a summary of the methodological and biological factors affecting thermal preference and tolerance, c) recommendations to avoid identified pitfalls, and d) directions for continued progress in our application and understanding of these thermal parameters. We emphasize the need for more methodological and comparative studies. Lastly, we urge researchers to provide more detailed methodological descriptions and suggest ways to make their raw data more informative to increase the utility of thermal biology studies.