Natural selection reduced diversity on human Y chromosomes

The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. Instead, we show that models of purifying selection are consistent with observed Y diversity. Further, the number of sites estimated to be under purifying selection greatly exceeds the number of Y-linked coding sites, suggesting the importance of the highly repetitive ampliconic regions. While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area.Comment: 43 pages, 11 figure

Title on page 1: Moral distress : values and barriers experience by critical care nurses

Includes vita.This dissertation explores the presence of moral distress and effective interventions to lessen its impact on critical care nurses. Manuscript one was completed prior to entering the doctor of philosophy in nursing program but was instrumental in building the foundation for successive work within this dissertation. An exploratory, descriptive designed study was used to examine moral distress and identify situations in which nurse's experienced high levels of moral distress. Nurses completed a 38-item moral distress scale, a coping questionnaire, and indicated their preferred methods for institutional support in managing distressing situations. Manuscript two includes a formal analysis of the Moral Distress Theory and identified limitations in the existing theoretical model based on a review of literature. Finally, manuscript three is a study identifying barriers and values during moral distress situations that can be used to potentially target interventions aimed at lessening the impact of moral distress.Dr. Gregory Alexander, Dissertation Supervisor.|Includes vita.Includes bibliographical references

Weight discrimination: Are colleges preparing their graduates for successful employment and careers?

Background: Colleges are uniquely positioned to influence both the short and long-term health and well-being of students through implementation of interventions to prevent and/or treat obesity among students; and have a vested interest given obesity has the potential to impact students' matriculation, graduation, and career prospects.Aim: To illustrate the essential roles of colleges to influence obesity prevention and treatment given the potential to influence the students' matriculation, graduation, and career prospects.Methods: The discussion begins with an overview of the prevalence and societal implications of obesity. Next the implications for higher education with respect to matriculation and graduation, the influence of higher education on lifestyle behaviors, and the influence of obesity on academic performance. This is followed by the influence of obesity on students' post-higher education lives, including potential discrimination when seeking employment, and the impact that the nature of the jobs that graduates attain may have on their health and well-being.Results: There exists a great need to reduce the prevalence of obesity and colleges are well positioned to provide leadership and direction.Conclusions: Implications for colleges are set forth, with ways in which they can play a role in promoting student health detailed

Fluctuations in depression and well-being are associated with sexual risk episodes among HIV-positive men

Peer reviewedPostprin

Encouraging bus use on a college campus: perception and usage of fixed route service

Master of Regional and Community PlanningDepartment of Landscape Architecture/Regional and Community PlanningGregory L. NewmarkAt Kansas State University, there is not an issue of opposition to public bus services. Instead, there is a perception that taking the bus is too complicated to figure out or cannot appropriately serve the community’s needs. This, combined with dependence and attachment to the automobile, caused local buses to become unpopular mode choices. Since the service is still relatively new, it has not been engrained into campus culture and ridership is very low. This study looked at the local bus system, ATA bus, used to access the Manhattan, KS campus of Kansas State University (KSU). According to the ATA Annual Report from 2014, 75% of off-campus students at KSU and 35% of employees live within five minutes of ATA city-wide routes (FHATA 2014). Ideally, all those students and employees would take the bus to class or work, but in reality, most walk or drive. A very small minority of students use the fixed route service, and many are unfamiliar with how the system works. A campus access survey distributed in March 2017 to the KSU community aimed to ascertain familiarity with the system, current level of use, as well as attitudes towards the existing public transportation system. The data recovered from the survey contradicts the hypothesis that the disuse of the bus system was due to an active opposition to public buses. Conversely, it pointed to the conclusion that disuse resulted from a lack of information about the bus service and a deep-set attachment to private automobiles. This research aimed to increase ridership by identifying attitudes towards transit among the KSU community and suggesting strategies for improving service

Infants With Congenital Adrenal Hyperplasia Are at Risk for Hypercalcemia, Hypercalciuria, and Nephrocalcinosis

In a retrospective study, most young children with CAH had at least one episode of hypercalcemia, whereas a smaller percentage was found to have hypercalciuria and/or nephrocalcinosis

Comparison of College Student Hypertension Prevalence between the JNC7 and ACC/AHA Diagnostic Criteria

International Journal of Exercise Science 12(3): 898-903, 2019. Hypertension is highly prevalent and associated with non-communicable diseases and increased premature mortality risk. However, the impact of the new hypertension diagnostic criteria on the prevalence of hypertension diagnoses has yet to be examined among college students. The purpose of this study was to compare the prevalence of hypertension between the JNC7 and the ACC/AHA hypertension diagnostic criteria among college students. The blood pressure of 5,945 college students was assessed, and chi-square tests for independence examined differences between JNC7 and ACC/AHA criteria. The mean age of participants was 21.30 ± 1.05 years, and the majority identified as men (60.5%). Men were found to have significantly higher systolic (p \u3c .001, η2 = .10) and diastolic (p \u3c .001, η2 = .04) blood pressure, so all analyses were separated by sex. Hypertension guideline changes resulted in significant changes in hypertension categorization of both men, χ2 = 7,178, p \u3c .001, Фc = .816 and women, χ2 = 4,670, p \u3c .001, Фc = .816. Under the JNC7 guidelines, 292 (8.2%) men and 67 (2.8%) women were hypertensive. Using the ACC/AHA guidelines, 1455 (40.5%) men and 521 (22.3%) women were hypertensive. Hypertension guideline changes resulted in a significant increase in the prevalence of hypertension among college students, highlighting the potential demand for targeted prevention programs focused on fostering healthy lifestyle behaviors, i.e. physical activity and healthy eating, among students

Changes in Health Behaviors and Outcomes Following Graduation from Higher Education

International Journal of Exercise Science 13(5): 131-139, 2020. The purpose of this study was to examine changes in health behaviors and outcomes of higher education (college) students following graduation. Undergraduate students (n= 206) enrolled at a large, northeastern United States university in general education health and wellness courses were assessed pre and post-graduation. Participants self-reported their demographics, physical activity behaviors, dietary behaviors, sleep, and stress pre and post-graduation via an online survey. Paired sample t-tests examined changes health behaviors pre and post-graduation. Following graduation, fruit and vegetable consumption increased significantly, moderate physical activity declined significantly, and both vigorous physical activity and energy expenditure, as well as weight remained stable. There was a significant reduction in stress, for men but not women, and, an increase in restful nights of sleep among women but not men. College students tended to maintain the seemingly healthy lifestyles they had as students during the period immediately following graduation. Findings highlight the value of general health and wellness courses within college given vigorous physical activity and energy expenditure did not decline following graduation

Cap mesenchyme cell swarming during kidney development is influenced by attraction, repulsion, and adhesion to the ureteric tip

Morphogenesis of the mammalian kidney requires reciprocal interactions between two cellular domains at the periphery of the developing organ: the tips of the epithelial ureteric tree and adjacent regions of cap mesenchyme. While the presence of the cap mesenchyme is essential for ureteric branching, how it is specifically maintained at the tips is unclear. Using ex vivo timelapse imaging we show that cells of the cap mesenchyme are highly motile. Individual cap mesenchyme cells move within and between cap domains. They also attach and detach from the ureteric tip across time. Timelapse tracks collected for >800 cells showed evidence that this movement was largely stochastic, with cell autonomous migration influenced by opposing attractive, repulsive and cell adhesion cues. The resulting swarming behaviour maintains a distinct cap mesenchyme domain while facilitating dynamic remodelling in response to underlying changes in the tip