1,385 research outputs found

    Peer-to-Peer Sharing of Social Media Messages on Sexual Health in a School-Based Intervention: Opportunities and Challenges Identified in the STASH Feasibility Trial

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    Background: There is a strong interest in the use of social media to spread positive sexual health messages through social networks of young people. However, research suggests that this potential may be limited by a reluctance to be visibly associated with sexual health content on the web or social media and by the lack of trust in the veracity of peer sources. Objective: The aim of this study was to investigate opportunities and challenges of using social media to facilitate peer-to-peer sharing of sexual health messages within the context of STASH (Sexually Transmitted Infections and Sexual Health), a secondary school-based and peer-led sexual health intervention. Methods: Following training, and as a part of their role, student-nominated peer supporters (aged 14-16 years) invited school friends to trainer-monitored, private Facebook groups. Peer supporters posted curated educational sex and relationship content within these groups. Data came from a feasibility study of the STASH intervention in 6 UK schools. To understand student experiences of the social media component, we used data from 11 semistructured paired and group interviews with peer supporters and their friends (collectively termed students; n=42, aged 14-16 years), a web-based postintervention questionnaire administered to peer supporters (n=88), and baseline and follow-up questionnaires administered to students in the intervention year group (n=680 and n=603, respectively). We carried out a thematic analysis of qualitative data and a descriptive analysis of quantitative data. Results: Message sharing by peer supporters was hindered by variable engagement with Facebook. The trainer-monitored and private Facebook groups were acceptable to student members (peer supporters and their friends) and reassuring to peer supporters but led to engagement that ran parallel to—rather than embedded in—their routine social media use. The offline context of a school-based intervention helped legitimate and augment Facebook posts; however, even where friends were receptive to STASH messages, they did not necessarily engage visibly on social media. Preferences for content design varied; however, humor, color, and text brevity were important. Preferences for social media versus offline message sharing varied. Conclusions: Invitation-only social media groups formed around peer supporters’ existing friendship networks hold potential for diffusing messages in peer-based sexual health interventions. Ideally, interactive opportunities should not be limited to single social media platforms and should run alongside offline conversations. There are tensions between offering young people autonomy to engage flexibly and authentically and the need for adult oversight of activities for information accuracy and safeguarding

    The origin of life: chemical evolution of a metabolic system in a mineral honeycomb?

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    For the RNA-world hypothesis to be ecologically feasible, selection mechanisms acting on replicator communities need to be invoked and the corresponding scenarios of molecular evolution specified. Complementing our previous models of chemical evolution on mineral surfaces, in which selection was the consequence of the limited mobility of macromolecules attached to the surface, here we offer an alternative realization of prebiotic group-level selection: the physical encapsulation of local replicator communities into the pores of the mineral substrate. Based on cellular automaton simulations we argue that the effect of group selection in a mineral honeycomb could have been efficient enough to keep prebiotic ribozymes of different specificities and replication rates coexistent, and their metabolic cooperation protected from extensive molecular parasitism. We suggest that mutants of the mild parasites persistent in the metabolic system can acquire useful functions such as replicase activity or the production of membrane components, thus opening the way for the evolution of the first autonomous protocells on Earth

    Feasibility study of peer-led and school-based social network Intervention (STASH) to promote adolescent sexual health.

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    BACKGROUND: Effective sex education is the key to good sexual health. Peer-led approaches can augment teacher-delivered sex education, but many fail to capitalise on mechanisms of social influence. We assessed the feasibility of a novel intervention (STASH) in which students (aged 14-16) nominated as influential by their peers were recruited and trained as Peer Supporters (PS). Over a 5-10-week period, they spread positive sexual health messages to friends in their year group, both in-person and via social media, and were supported to do so via weekly trainer-facilitated meetings. The aims of the study were to assess the feasibility of STASH (acceptability, fidelity and reach), to test and refine the programme theory and to establish whether the study met pre-set progression criteria for continuation to larger-scale evaluation. METHODS: The overall design was a non-randomised feasibility study of the STASH intervention in 6 schools in Scotland. Baseline (n=680) and follow-up questionnaires (approx. 6 months later; n=603) were administered to the intervention year group. The control group (students in year above) completed the follow-up questionnaire only (n=696), 1 year before the intervention group. The PS (n=88) completed a brief web survey about their experience of the role; researchers interviewed participants in key roles (PS (n=20); PS friends (n=22); teachers (n=8); trainers (n=3)) and observed 20 intervention activities. Activity evaluation forms and project monitoring data also contributed information. We performed descriptive quantitative analysis and thematic qualitative analysis. RESULTS: The PS role was acceptable; on average across schools >50% of students nominated as influential by their friends, signed up and were trained (n=104). This equated to 13% of the year group. Trained PS rarely dropped out (97% completion rate) and 85% said they liked the role. Fidelity was good (all bar one trainer-led activity carried out; PS were active). The intervention had good reach; PS were reasonably well connected and perceived as 'a good mix' and 58% of students reported exposure to STASH. Hypothesised pre-conditions, contextual influences and mechanisms of change for the intervention were largely confirmed. All bar one of the progression criteria was met. CONCLUSION: The weight of evidence supports continuation to full-scale evaluation. TRIAL REGISTRATION: Current controlled trials ISRCTN97369178

    Plant structural changes due to herbivory: Do changes in Aceria-infested coconut fruits allow predatory mites to move under the perianth?

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    Being minute in size, eriophyoid mites can reach places that are small enough to be inaccessible to their predators. The coconut mite, Aceria guerreronis, is a typical example; it finds partial refuge under the perianth of the coconut fruit. However, some predators can move under the perianth of the coconut fruits and attack the coconut mite. In Sri Lanka, the phytoseiid mite Neoseiulus baraki, is the most common predatory mite found in association with the coconut mite. The cross-diameter of this predatory mite is c. 3 times larger than that of the coconut mite. Nevertheless, taking this predator’s flat body and elongated idiosoma into account, it is—relative to many other phytoseiid mites—better able to reach the narrow space under the perianth of infested coconut fruits. On uninfested coconut fruits, however, they are hardly ever observed under the perianth. Prompted by earlier work on the accessibility of tulip bulbs to another eriophyoid mite and its predators, we hypothesized that the structure of the coconut fruit perianth is changed in response to damage by eriophyoid mites and as a result predatory mites are better able to enter under the perianth of infested coconut fruits. This was tested in an experiment where we measured the gap between the rim of the perianth and the coconut fruit surface in three cultivars (‘Sri Lanka Tall’, ‘Sri Lanka Dwarf Green’ and ‘Sri Lanka Dwarf Green × Sri Lanka Tall’ hybrid) that are cultivated extensively in Sri Lanka. It was found that the perianth-fruit gap in uninfested coconut fruits was significantly different between cultivars: the cultivar ‘Sri Lanka Dwarf Green’ with its smaller and more elongated coconut fruits had a larger perianth-fruit gap. In the uninfested coconut fruits this gap was large enough for the coconut mite to creep under the perianth, yet too small for its predator N. baraki. However, when the coconut fruits were infested by coconut mites, the perianth-rim-fruit gap was not different among cultivars and had increased to such an extent that the space under the perianth became accessible to the predatory mites

    Sperm design and variation in the New World blackbirds (Icteridae)

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    Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other taxa, these relationships are negative, and the causes of these different patterns across taxa are poorly understood. In a comparative study using New World blackbirds (Icteridae), we tested whether sperm design was influenced by the level of PCSS and found significant positive associations with the level of PCSS for all sperm components but head length. Additionally, whereas the absolute length of sperm components increased, their variation declined with the intensity of PCSS, indicating stabilizing selection around an optimal sperm design. Given the diversity of, and strong selection on, sperm design, it seems likely that sperm phenotype may influence sperm velocity within species. However, in contrast to other recent studies of passerine birds, but consistent with several other studies, we found no significant link between sperm design and velocity, using four different species that vary both in sperm design and PCSS. Potential reasons for this discrepancy between studies are discussed

    Systematic review of dexketoprofen in acute and chronic pain

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    which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Dexketoprofen, an NSAID used in the management of acute and chronic pains, is licensed in several countries but has not previously been the subjected of a systematic review. We used published and unpublished information from randomised clinical trials (RCTs) of dexketoprofen in painful conditions to assess evidence on efficacy and harm. Methods: PubMed and Cochrane Central were searched for RCTs of dexketoprofen for pain of any aetiology. Reference lists of retrieved articles and reviews were also searched. Menarini Group produced copies of published and unpublished studies (clinical trial reports). Data were abstracted into a standard form. For studies reporting results of single dose administration, the number of patients with at least 50 % pain relief was derived and used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for one patient to achieve at least 50 % pain relief compared with placebo. Results: Thirty-five trials were found in acute pain and chronic pain; 6,380 patients were included, 3,381 receiving dexketoprofen. Information from 16 trials (almost half the total patients) wa

    Smoke-free legislation and child health

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    In this paper, we aim to present an overview of the scientific literature on the link between smoke-free legislation and early-life health outcomes. Exposure to second-hand smoke is responsible for an estimated 166 ,000 child deaths each year worldwide. To protect people from tobacco smoke, the World Health Organization recommends the implementation of comprehensive smoke-free legislation that prohibits smoking in all public indoor spaces, including workplaces, bars and restaurants. The implementation of such legislation has been found to reduce tobacco smoke exposure, encourage people to quit smoking and improve adult health outcomes. There is an increasing body of evidence that shows that children also experience health benefits after implementation of smoke-free legislation. In addition to protecting children from tobacco smoke in public, the link between smoke-free legislation and improved child health is likely to be mediated via a decline in smoking during pregnancy and reduced exposure in the home environment. Recent studies have found that the implementation of smoke-free legislation is associated with a substantial decrease in the number of perinatal deaths, preterm births and hospital attendance for respiratory tract infections and asthma in children, although such benefits are not found in each study. With over 80% of the world’s population currently unprotected by comprehensive smoke-free laws, protecting (unborn) children from the adverse impact of tobacco smoking and SHS exposure holds great potential to benefit public health and should therefore be a key priority for policymakers and health workers alike

    Impaired perception of facial motion in autism spectrum disorder

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    Copyright: © 2014 O’Brien et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Facial motion is a special type of biological motion that transmits cues for socio-emotional communication and enables the discrimination of properties such as gender and identity. We used animated average faces to examine the ability of adults with autism spectrum disorders (ASD) to perceive facial motion. Participants completed increasingly difficult tasks involving the discrimination of (1) sequences of facial motion, (2) the identity of individuals based on their facial motion and (3) the gender of individuals. Stimuli were presented in both upright and upside-down orientations to test for the difference in inversion effects often found when comparing ASD with controls in face perception. The ASD group’s performance was impaired relative to the control group in all three tasks and unlike the control group, the individuals with ASD failed to show an inversion effect. These results point to a deficit in facial biological motion processing in people with autism, which we suggest is linked to deficits in lower level motion processing we have previously reported

    A Survey on Continuous Time Computations

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    We provide an overview of theories of continuous time computation. These theories allow us to understand both the hardness of questions related to continuous time dynamical systems and the computational power of continuous time analog models. We survey the existing models, summarizing results, and point to relevant references in the literature

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes
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