Balancing the dilution and oddity effects: Decisions depend on body size

Background Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack). Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the ‘oddity’ effect). Thus, animals should choose group mates close in appearance to themselves (eg. similar size), whilst also choosing a large group. Methodology and Principal Findings We used the Trinidadian guppy (Poecilia reticulata), a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity. Conclusions and Significance Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling decisions

Clinical and molecular genetic features of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia

BACKGROUND: Most patients with familial primary pulmonary hypertension have defects in the gene for bone morphogenetic protein receptor II (BMPR2), a member of the transforming growth factor beta (TGF-beta) superfamily of receptors. Because patients with hereditary hemorrhagic telangiectasia may have lung disease that is indistinguishable from primary pulmonary hypertension, we investigated the genetic basis of lung disease in these patients. METHODS: We evaluated members of five kindreds plus one individual patient with hereditary hemorrhagic telangiectasia and identified 10 cases of pulmonary hypertension. In the two largest families, we used microsatellite markers to test for linkage to genes encoding TGF-beta-receptor proteins, including endoglin and activin-receptor-like kinase 1 (ALK1), and BMPR2. In subjects with hereditary hemorrhagic telangiectasia and pulmonary hypertension, we also scanned ALK1 and BMPR2 for mutations. RESULTS: We identified suggestive linkage of pulmonary hypertension with hereditary hemorrhagic telangiectasia on chromosome 12q13, a region that includes ALK1. We identified amino acid changes in activin-receptor-like kinase 1 that were inherited in subjects who had a disorder with clinical and histologic features indistinguishable from those of primary pulmonary hypertension. Immunohistochemical analysis in four subjects and one control showed pulmonary vascular endothelial expression of activin-receptor-like kinase 1 in normal and diseased pulmonary arteries. CONCLUSIONS: Pulmonary hypertension in association with hereditary hemorrhagic telangiectasia can involve mutations in ALK1. These mutations are associated with diverse effects, including the vascular dilatation characteristic of hereditary hemorrhagic telangiectasia and the occlusion of small pulmonary arteries that is typical of primary pulmonary hypertension

HIV positive men as fathers: Accounts of displacement, ir/responsibility and paternal emergence

It is now apparent that socio-cultural constructions of masculinity variously impact men’s experiences of their HIV positive status, yet how being a father can feature in this mix remains under-researched. This study employed in-depth semi-structured interviews and Foucauldian-informed discourse analysis to explore the accounts of six self-identifying heterosexual fathers (four black African migrants, two white European) who had been living with HIV from five to 24 years. While the HIV-related literature calls for the need to subvert ‘traditional’ expressions of masculinity as a means of promoting HIV prevention and HIV health, we argue that the lived experience for HIV positive men as fathers is more socially, discursively and thus more psychologically nuanced. We illustrate this by highlighting ways in which HIV positive men as fathers are not simply making sense of themselves as a HIV positive man for whom the modern (new) man and father positions are useful strategies for adapting to HIV and combating associated stigma. Discourses of modern and patriarchal fatherhoods, a gender-specific discourse of irresponsibility, and the neoliberal conflation of heath and self-responsibility are also at work in the sense making frames that HIV positive men, who are also fathers, can variously deploy. Our analysis shows how this discursive mix can underpin possibilities of often conflicted meaning and identity when living as a man and father with HIV in the UK, and specifically how discourses of fatherhood and HIV ‘positive’ health can complicate these men’s expressions and inhabitations of masculinity

Exploring the usability of a connected autonomous vehicle human machine interface designed for older adults

Users of Level 4–5 connected autonomous vehicles (CAVs) should not need to intervene with the dynamic driving task or monitor the driving environment, as the system will handle all driving functions. CAV human-machine interface (HMI) dashboards for such CAVs should therefore offer features to support user situation awareness (SA) and provide additional functionality that would not be practical within non-autonomous vehicles. Though, the exact features and functions, as well as their usability, might differ depending on factors such as user needs and context of use. The current paper presents findings from a simulator trial conducted to test the usability of a prototype CAV HMI designed for older adults and/or individuals with sensory and/or physical impairments: populations that will benefit enormously from the mobility afforded by CAVs. The HMI was developed to suit needs and requirements of this demographic based upon an extensive review of HMI and HCI principles focused on accessibility, usability and functionality [1, 2], as well as studies with target users. Thirty-one 50-88-year-olds (M 67.52, three 50–59) participated in the study. They experienced four seven-minute simulated journeys, involving inner and outer urban settings with mixed speed-limits and were encouraged to explore the HMI during journeys and interact with features, including a real-time map display, vehicle status, emergency stop, and arrival time. Measures were taken pre-, during- and post- journeys. Key was the System Usability Scale [3] and measures of SA, task load, and trust in computers and automation. As predicted, SA decreased with journey experience and although cognitive load did not, there were consistent negative correlations. System usability was also related to trust in technology but not trust in automation or attitudes towards computers. Overall, the findings are important for those designing, developing and testing CAV HMIs for older adults and individuals with sensory and/or physical impairments

UK policy on social networking sites and online health: from informed patient to informed consumer?

Background: Social networking sites offer new opportunities for communication between and amongst health care professionals, patients and members of the public. In doing so, they have the potential to facilitate public access to health care information, peer-support networks, health policy fora and online consultations. Government policies and guidance from professional organisations have begun to address the potential of these technologies in the domain of health care and the responsibilities they entail for their users. Objective: Adapting a discourse analytic framework for the analysis of policy documents, this review paper critically examines discussions of social networking sites in recent government and professional policy documents. It focuses particularly on who these organisations claim should use social media, for what purposes, and what the anticipated outcomes of use will be for patients and the organisations themselves. Conclusion: Recent policy documents have configured social media as a new means with which to harvest patient feedback on health care encounters and communicate health care service information with which patients and the general public can be ‘empowered’ to make responsible decisions. In orienting to social media as a vehicle for enabling consumer choice, these policies encourage the marketization of health information through a greater role for non-profit and commercial organisations in the eHealth domain. At the same time, current policy largely overlooks the role of social media in mediating ongoing support and self-management for patients with long-term conditions

Local-Scale Patterns of Genetic Variability, Outcrossing, and Spatial Structure in Natural Stands of Arabidopsis thaliana

As Arabidopsis thaliana is increasingly employed in evolutionary and ecological studies, it is essential to understand patterns of natural genetic variation and the forces that shape them. Previous work focusing mostly on global and regional scales has demonstrated the importance of historical events such as long-distance migration and colonization. Far less is known about the role of contemporary factors or environmental heterogeneity in generating diversity patterns at local scales. We sampled 1,005 individuals from 77 closely spaced stands in diverse settings around Tübingen, Germany. A set of 436 SNP markers was used to characterize genome-wide patterns of relatedness and recombination. Neighboring genotypes often shared mosaic blocks of alternating marker identity and divergence. We detected recent outcrossing as well as stretches of residual heterozygosity in largely homozygous recombinants. As has been observed for several other selfing species, there was considerable heterogeneity among sites in diversity and outcrossing, with rural stands exhibiting greater diversity and heterozygosity than urban stands. Fine-scale spatial structure was evident as well. Within stands, spatial structure correlated negatively with observed heterozygosity, suggesting that the high homozygosity of natural A. thaliana may be partially attributable to nearest-neighbor mating of related individuals. The large number of markers and extensive local sampling employed here afforded unusual power to characterize local genetic patterns. Contemporary processes such as ongoing outcrossing play an important role in determining distribution of genetic diversity at this scale. Local “outcrossing hotspots” appear to reshuffle genetic information at surprising rates, while other stands contribute comparatively little. Our findings have important implications for sampling and interpreting diversity among A. thaliana accessions

Developing lay health worker policy in South Africa: a qualitative study

<p>Abstract</p> <p>Background</p> <p>Over the past half decade South Africa has been developing, implementing and redeveloping its Lay Health Worker (LHW) policies. Research during this period has highlighted challenges with LHW programme implementation. These challenges have included an increased burden of care for female LHWs. The aim of this study was to explore contemporary LHW policy development processes and the extent to which issues of gender are taken up within this process.</p> <p>Methods</p> <p>The study adopted a qualitative approach to exploring policy development from the perspective of policy actors. Eleven policy actors (policy makers and policy commentators) were interviewed individually. Data from the interviews were analysed thematically.</p> <p>Results</p> <p>Considerations of LHW working conditions drove policy redevelopment. From the interviews it seems that gender as an issue never reached the policy making agenda. Although there was strong recognition that the working conditions of LHWs needed to be improved, poor working conditions were not necessarily seen as a gender concern. Our data suggests that in the process of defining the problem which the redeveloped policy had to address, gender was not included. There was no group or body who brought the issue of gender to the attention of policy developers. As such the issue of gender never entered the policy debates. These debates focused on whether it was appropriate to have LHWs, what LHW programme model should be adopted and whether or not LHWs should be incorporated into the formal health system.</p> <p>Conclusion</p> <p>LHW policy redevelopment focused on resolving issues of LHW working conditions through an active process involving many actors and strong debates. Within this process the issue of gender had no champion and never reached the LHW policy agenda. Future research may consider how to incorporate the voices of ordinary women into the policy making process.</p

Etoposide Induces ATM-Dependent Mitochondrial Biogenesis through AMPK Activation

DNA damage such as double-stranded DNA breaks (DSBs) has been reported to stimulate mitochondrial biogenesis. However, the underlying mechanism is poorly understood. The major player in response to DSBs is ATM (ataxia telangiectasia mutated). Upon sensing DSBs, ATM is activated through autophosphorylation and phosphorylates a number of substrates for DNA repair, cell cycle regulation and apoptosis. ATM has been reported to phosphorylate the alpha subunit of AMP-activated protein kinase (AMPK), which senses AMP/ATP ratio in cells, and can be activated by upstream kinases. Here we provide evidence for a novel role of ATM in mitochondrial biogenesis through AMPK activation in response to etoposide-induced DNA damage.Three pairs of human ATM+ and ATM- cells were employed. Cells treated with etoposide exhibited an ATM-dependent increase in mitochondrial mass as measured by 10-N-Nonyl-Acridine Orange and MitoTracker Green FM staining, as well as an increase in mitochondrial DNA content. In addition, the expression of several known mitochondrial biogenesis regulators such as the major mitochondrial transcription factor NRF-1, PGC-1alpha and TFAM was also elevated in response to etoposide treatment as monitored by RT-PCR. Three pieces of evidence suggest that etoposide-induced mitochondrial biogenesis is due to ATM-dependent activation of AMPK. First, etoposide induced ATM-dependent phosphorylation of AMPK alpha subunit at Thr172, indicative of AMPK activation. Second, inhibition of AMPK blocked etoposide-induced mitochondrial biogenesis. Third, activation of AMPK by AICAR (an AMP analogue) stimulated mitochondrial biogenesis in an ATM-dependent manner, suggesting that ATM may be an upstream kinase of AMPK in the mitochondrial biogenesis pathway.These results suggest that activation of ATM by etoposide can lead to mitochondrial biogenesis through AMPK activation. We propose that ATM-dependent mitochondrial biogenesis may play a role in DNA damage response and ROS regulation, and that defect in ATM-dependent mitochondrial biogenesis could contribute to the manifestations of A-T disease