Population genetic diversity and fitness in multiple environments

<p>Abstract</p> <p>Background</p> <p>When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of populations to adapt to altered environments. However, it is not clear how much genetic diversity within populations may be lost before populations are put at significant risk. Development of tools to evaluate this relationship would be a valuable contribution to conservation biology. To address these issues, we have created an experimental system that uses laboratory populations of an estuarine crustacean, <it>Americamysis bahia </it>with experimentally manipulated levels of genetic diversity. We created replicate cultures with five distinct levels of genetic diversity and monitored them for 16 weeks in both permissive (ambient seawater) and stressful conditions (diluted seawater). The relationship between molecular genetic diversity at presumptive neutral loci and population vulnerability was assessed by AFLP analysis.</p> <p>Results</p> <p>Populations with very low genetic diversity demonstrated reduced fitness relative to high diversity populations even under permissive conditions. Population performance decreased in the stressful environment for all levels of genetic diversity relative to performance in the permissive environment. Twenty percent of the lowest diversity populations went extinct before the end of the study in permissive conditions, whereas 73% of the low diversity lines went extinct in the stressful environment. All high genetic diversity populations persisted for the duration of the study, although population sizes and reproduction were reduced under stressful environmental conditions. Levels of fitness varied more among replicate low diversity populations than among replicate populations with high genetic diversity. There was a significant correlation between AFLP diversity and population fitness overall; however, AFLP markers performed poorly at detecting modest but consequential losses of genetic diversity. High diversity lines in the stressful environment showed some evidence of relative improvement as the experiment progressed while the low diversity lines did not.</p> <p>Conclusions</p> <p>The combined effects of reduced average fitness and increased variability contributed to increased extinction rates for very low diversity populations. More modest losses of genetic diversity resulted in measurable decreases in population fitness; AFLP markers did not always detect these losses. However when AFLP markers indicated lost genetic diversity, these losses were associated with reduced population fitness.</p

Rehabilitation medicine summit: building research capacity Executive Summary

The general objective of the "Rehabilitation Medicine Summit: Building Research Capacity" was to advance and promote research in medical rehabilitation by making recommendations to expand research capacity. The five elements of research capacity that guided the discussions were: 1) researchers; 2) research culture, environment, and infrastructure; 3) funding; 4) partnerships; and 5) metrics. The 100 participants included representatives of professional organizations, consumer groups, academic departments, researchers, governmental funding agencies, and the private sector. The small group discussions and plenary sessions generated an array of problems, possible solutions, and recommended actions. A post-Summit, multi-organizational initiative is called to pursue the agendas outlined in this report (see Additional File 1)

Pharmacy Student Engagement, Performance, and Perception in a Flipped Satellite Classroom

Objective. To determine whether “flipping” a traditional basic pharmaceutics course delivered synchronously to 2 satellite campuses would improve student academic performance, engagement, and perception

How are falls and fear of falling associated with objectively measured physical activity in a cohort of community-dwelling older men?

BACKGROUND: Falls affect approximately one third of community-dwelling older adults each year and have serious health and social consequences. Fear of falling (FOF) (lack of confidence in maintaining balance during normal activities) affects many older adults, irrespective of whether they have actually experienced falls. Both falls and fear of falls may result in restrictions of physical activity, which in turn have health consequences. To date the relation between (i) falls and (ii) fear of falling with physical activity have not been investigated using objectively measured activity data which permits examination of different intensities of activity and sedentary behaviour. METHODS: Cross-sectional study of 1680 men aged 71-92 years recruited from primary care practices who were part of an on-going population-based cohort. Men reported falls history in previous 12 months, FOF, health status and demographic characteristics. Men wore a GT3x accelerometer over the hip for 7 days. RESULTS: Among the 12% of men who had recurrent falls, daily activity levels were lower than among non-fallers; 942 (95% CI 503, 1381) fewer steps/day, 12(95% CI 2, 22) minutes less in light activity, 10(95% CI 5, 15) minutes less in moderate to vigorous PA [MVPA] and 22(95% CI 9, 35) minutes more in sedentary behaviour. 16% (n = 254) of men reported FOF, of whom 52% (n = 133) had fallen in the past year. Physical activity deficits were even greater in the men who reported that they were fearful of falling than in men who had fallen. Men who were fearful of falling took 1766(95% CI 1391, 2142) fewer steps/day than men who were not fearful, and spent 27(95% CI 18, 36) minutes less in light PA, 18(95% CI 13, 22) minutes less in MVPA, and 45(95% CI 34, 56) minutes more in sedentary behaviour. The significant differences in activity levels between (i) fallers and non-fallers and (ii) men who were fearful of falling or not fearful, were mediated by similar variables; lower exercise self-efficacy, fewer excursions from home and more mobility difficulties. CONCLUSIONS: Falls and in particular fear of falling are important barriers to older people gaining health benefits of walking and MVPA. Future studies should assess the longitudinal associations between falls and physical activity

Oral vitamin B(12 )therapy in the primary care setting: a qualitative and quantitative study of patient perspectives

BACKGROUND: Although oral replacement with high doses of vitamin B(12 )is both effective and safe for the treatment of B(12 )deficiency, little is known about patients' views concerning the acceptability and effectiveness of oral B(12). We investigated patient perspectives on switching from injection to oral B(12 )therapy. METHODS: This study involved a quantitative arm using questionnaires and a qualitative arm using semi-structured interviews, both to assess patient views on injection and oral therapy. Patients were also offered a six-month trial of oral B(12 )therapy. One hundred and thirty-three patients who receive regular B(12 )injections were included from three family practice units (two hospital-based academic clinics and one community health centre clinic) in Toronto. RESULTS: Seventy-three percent (63/86) of respondents were willing to try oral B(12). In a multivariate analysis, patient factors associated with a "willingness to switch" to oral B(12 )included being able to get to the clinic in less than 30 minutes (OR 9.3, 95% CI 2.2–40.0), and believing that frequent visits to the health care provider (OR 5.4, 95% CI 1.1–26.6) or the increased costs to the health care system (OR 16.7, 95% CI 1.5–184.2) were disadvantages of injection B(12). Fifty-five patients attempted oral therapy and 52 patients returned the final questionnaire. Of those who tried oral therapy, 76% (39/51) were satisfied and 71% (39/55) wished to permanently switch. Factors associated with permanently switching to oral therapy included believing that the frequent visits to the health care provider (OR 35.4, 95% CI 2.9–432.7) and travel/parking costs (OR 8.7, 95% CI 1.2–65.3) were disadvantages of injection B(12). Interview participants consistently cited convenience as an advantage of oral therapy. CONCLUSION: Switching patients from injection to oral B(12 )is both feasible and acceptable to patients. Oral B(12 )supplementation is well received largely due to increased convenience. Clinicians should offer oral B(12 )therapy to their patients who are currently receiving injections, and newly diagnosed B(12)-deficient patients who can tolerate and are compliant with oral medications should be offered oral supplementation

Woman-Centered Design through Humanity, Activism, and Inclusion

Women account for over half of the global population, however, continue to be subject to systematic and systemic disadvantage, particularly in terms of access to health and education. At every intersection, where systemic inequality accounts for greater loss of life or limitations on full and healthy living, women are more greatly impacted by those inequalities. The design of technologies is no different, the very definition of technology is historically cast in terms of male activities, and advancements in the field are critical to improve women's quality of life. This article views HCI, a relatively new field, as well positioned to act critically in the ways that technology serve, refigure, and redefine women's bodies. Indeed, the female body remains a contested topic, a restriction to the development of women's health. On one hand, the field of women's health has attended to the medicalization of the body and therefore is to be understood through medical language and knowledge. On the other hand, the framing of issues associated with women's health and people's experiences of and within such system(s) remain problematic for many. This is visible today in, e.g., socio-cultural practices in disparate geographies or medical devices within a clinic or the home. Moreover, the biological body is part of a great unmentionable, i.e., the perils of essentialism. We contend that it is necessary, pragmatically and ethically, for HCI to turn its attention toward a woman-centered design approach. While previous research has argued for the dangers of gender-demarcated design work, we advance that designing for and with women should not be regarded as ghettoizing, but instead as critical to improving women's experiences in bodily transactions, choices, rights, and access to and in health and care. In this article, we consider how and why designing with and for woman matters. We use our design-led research as a way to speak to and illustrate alternatives to designing for and with women within HCI.QC 20200930</p

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO