1,204 research outputs found

    Fluctuating asymmetry, parasitism and reproductive fitness in two species of gammarid crustacean

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    Fluctuating asymmetry (FA), defined as random deviations from perfect bilateral symmetry, is assumed to reflect developmental instability. FA is predicted to increase in response to environmental stress, including parasite infection. In addition, based on theory we predict a higher FA in sexually selected traits, due to their greater sensitivity to stress. We investigated the relationships between FA, parasitism and reproductive fitness in 2 species of gammarid crustacean, incorporating both sexual and non-sexual traits. We tested the hypothesis that gammarids infected by vertically transmitted Microsporidia will display higher levels of FA than those infected by horizontally transmitted trematodes, because vertically transmitted Microsporidia can be present at the earliest stages of host development. We found little evidence for a relationship between FA and fecundity in Gammarus spp.; however, egg diameter for infected female Gammarus duebeni was significantly smaller than uninfected female G. duebeni. FA was not correlated with brood size in females or with sperm number in males. In contrast to our prediction, we report a lower relative FA in response to sexual traits than non-sexual traits. However, FA in sexual traits was found to be higher in males than females, supporting the theory that sexual selection leads to increased FA. Additionally, we report a negative correlation between FA and both trematode (Podocotyle atomon) and PCR-positive microsporidian (Nosema granulosis and Dictyocoela duebenum) infections and interpret these results in the context of the parasitesā€™ transmission strategies. FA in G. duebeni and G. zaddachi appears to associate with trematode and microsporidian presence, although reproductive fitness is less altered by infection

    Podocotyle atomon (Trematoda: Digenea) impacts reproductive behaviour, survival and physiology in Gammarus zaddachi (Amphipoda)

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    The Trematoda are a group of phylogenetically diverse metazoan parasites that exhibit complex life cycles that often pass through invertebrate and vertebrate hosts. Some trematodes influence their hostā€™s behaviour to benefit transmission. Their parasitic influence may impact host population size by inhibiting an individualā€™s reproductive capacity. We assessed the impact of infection by Podocotyle atomon on the reproductive behaviour and fecundity of its amphipod intermediate host, Gammarus zaddachi, using laboratory and field studies. Parasite prevalence was high in the field, with males more likely to be infected (prevalence in males 64%, in females 39%). Males also suffered a higher parasite burden than females. Infected females were less active, but we found no evidence for a reduction in female reproductive success. Infected females also had comparable pairing success to uninfected females. In males, infection reduced survival and fecundity, with mortality being highest, and sperm numbers lowest, in heavily infected individuals. Trematode parasites are sometimes associated with altered host fecundity, but studies often lack the relevant experimental data to explore the evolution of the trait. We discuss this among information specific to the effect of P. atomon infection in G. zaddachi

    Promoting proactive bystander responses to racism and racial discrimination in primary schools: a mixed methods evaluation of the ā€˜Speak Out Against Racismā€™ program pilot

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    BackgroundRacism and racial discrimination are fundamental causes and determinants of health and health inequalities globally, with children and adolescents particularly vulnerable. Racial discrimination is a common stressor in the lives of many children and adolescents, with growing evidence of negative associations between racial discrimination and multiple domains of child and adolescent health. Addressing racism and racial discrimination must be core public health priorities, even more so among children and young people. Schools are key settings in the lives of children and adolescents and become increasingly more important to identity formation. School communities, teachers and peers greatly influence children and adolescents' beliefs about race and difference. Schools are therefore key sites for the delivery of population-based programs to reduce racism and promote proactive bystander behaviour and healthy resistance to racism among all children and adolescents as well as among the adults.MethodsThis study examines the feasibility and acceptability of the 'Speak Out Against Racism (SOAR)' program, a whole of school, multi-level, multi-strategy program that aimed to promote effective bystander responses to racism and racial discrimination in primary schools. A mixed-methods, quasi-experimental design was used. Students in Years 5 and 6 (10-12ā€‰years) across six schools completed surveys pre- and post- intervention (Nā€‰=ā€‰645; 52% female; 6% Indigenous, 10% Middle Eastern, African, Latinx or Pacific Islander, 21% Asian, 52% Anglo/European). Focus groups with students and interviews with staff collected qualitative data about their experiences of the program and their views about the program's perceived need, implementation, impacts and suggested improvements.ResultsQuantitative data showed student prosocial skills and teacher inter-racial climate improved in intervention schools compared to comparison schools. Qualitative data highlighted teacher attitudinal and behaviour change regarding racism, and student reduced interpersonal racial discrimination, improved peer prosocial norms, commitment to anti-racism, knowledge of proactive bystander responses and confidence and self-efficacy to intervene to address racism.ConclusionsThis study provides quantitative evidence of the potential of the SOAR program to improve the prosocial skills of students and their perceptions of the inter-racial school climate provided by their teachers. This program also provided qualitative evidence of the potential to promote teacher and student attitudinal and behavioural change. Further refinement and testing of the program in a large scale implementation trial is recommended

    Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae

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    Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.Jennifer R. Bellon, Frank Schmid, Dimitra L. Capone, Barbara L. Dunn, Paul J. Chamber

    Simvastatin improves the sexual health-related quality of life in men aged 40 years and over with erectile dysfunction : Additional data from the Erectile Dysfunction and Statin trial

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    Ā© 2014 Trivedi et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Erectile dysfunction is prevalent in men over 40 years, affecting their quality of life and that of their partners. The aims of this study were:a)To evaluate the internal reliability of the male erectile dysfunction specific quality of life (MED-QoL) scale and explore its factor structure.b)To evaluate the effect of simvastatin on subscales of the MED-QoL in men over forty years with erectile dysfunction. Methods: This is a double blind randomised controlled trial of 40 mg simvastatin or placebo given once daily for six months to men over forty years with untreated erectile dysfunction, who were not at high cardiovascular risk and were not on anti-hypertensive or lipid-lowering medication. 173 eligible men were recruited from 10 general practices in East of England. Data were collected at two points over 30 weeks. We report on the factor structure of MED-QoL, the internal reliability of the scale and the derived subscales, and the effect of simvastatin on MED-QoL subscales. Results: An initial analysis of the MED-QoL items suggested that a number of items should be removed (MED-QoL-R). Exploratory factor analysis identified three subscales within the MED-QoL-R which accounted for 96% of the variance, related to feelings of Control, initiating Intimacy, and Emotional response to erectile dysfunction. The alpha value for the revised scale (MED-Qol-R) was >0.95 and exceeded .82 for each subscale. Regression analysis showed that patients in the placebo group experienced a significantly reduced feeling of Control over erectile dysfunction than those in the statin group. Those in the placebo group had significantly lower Emotional response than those in the statin group at the close of trial, but there was no significant treatment effect on Intimacy. Conclusions: Our revised MED-QoL-R identified three subscales. Secondary analysis showed a significant improvement in sexual health related quality of life, specifically in relation to perception of control and emotional health in men with untreated erectile dysfunction given 40 mg simvastatin for six months. Trial registration: Current Controlled Trials ISRCTN66772971.Peer reviewe

    Efficient assembly of very short oligonucleotides using T4 DNA Ligase

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    <p>Abstract</p> <p>Background</p> <p>In principle, a pre-constructed library of all possible short oligonucleotides could be used to construct many distinct gene sequences. In order to assess the feasibility of such an approach, we characterized T4 DNA Ligase activity on short oligonucleotide substrates and defined conditions suitable for assembly of a plurality of oligonucleotides.</p> <p>Findings</p> <p>Ligation by T4 DNA Ligase was found to be dependent on the formation of a double stranded DNA duplex of at least five base pairs surrounding the site of ligation. However, ligations could be performed effectively with overhangs smaller than five base pairs and oligonucleotides as small as octamers, in the presence of a second, complementary oligonucleotide. We demonstrate the feasibility of simultaneous oligonucleotide phosphorylation and ligation and, as a proof of principle for DNA synthesis through the assembly of short oligonucleotides, we performed a hierarchical ligation procedure whereby octamers were combined to construct a target 128-bp segment of the beta-actin gene.</p> <p>Conclusions</p> <p>Oligonucleotides as short as 8 nucleotides can be efficiently assembled using T4 DNA Ligase. Thus, the construction of synthetic genes, without the need for custom oligonucleotide synthesis, appears feasible.</p

    Bringing pupils into the ORBYTS of research

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    Most scientists would consider themselves lucky to publish a research paper while still an undergraduate, but a group of pupils at Highams Park School in East London has co-authored a paper at age 18, thanks to ORBYTS. Original Research By Young Twinkle Scientists (ORBYTS) comprises the core part of EduTwinkle, the education and outreach arm of the upcoming exoplanet space mission Twinkle, led by UK scientists and engineers, and is aimed at A-level students. ORBYTS was founded in 2016 by Clara Sousa-Silva, who was splitting her time teaching at Highams Park School and working as a postdoc at University College London, via the Researchers in Schools programme. This blend of education and research inspired her to set up a scheme enabling young postdoc and PhD students from her research group at UCL, ExoMol, to perform novel research with some of her sixth-form students. ORBYTS now involves more than 30 pupils in eight schools across the UK

    Testing the theory of immune selection in cancers that break the rules of transplantation

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    Modification of cancer cells likely to reduce their immunogenicity, including loss or down-regulation of MHC molecules, is now well documented and has become the main support for the concept of immune surveillance. The evidence that these modifications, in fact, result from selection by the immune system is less clear, since the possibility that they may result from reorganized metabolism associated with proliferation or from cell de-differentiation remains. Here, we (a) survey old and new transplantation experiments that test the possibility of selection and (b) survey how transmissible tumours of dogs and Tasmanian devils provide naturally evolved tests of immune surveillance

    A Prospective Study of the Association of Metacognitive Beliefs and Processes with Persistent Emotional Distress After Diagnosis of Cancer

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    Two hundred and six patients, diagnosed with primary breast or prostate cancer completed self-report questionnaires on two occasions: before treatment (T1) and 12 months later (T2). The questionnaires included: the Hospital Anxiety and Depression Scale; Impact of Events Scale; the Metacognitions Questionnaire-30 (MCQ-30) and the Illness Perceptions Questionnaire-revised. A series of regression analyses indicated that metacognitive beliefs at T1 predicted between 14 and 19 % of the variance in symptoms of anxiety, depression and trauma at T2 after controlling for age and gender. For all three outcomes, the MCQ-30 subscale ā€˜negative beliefs about worryā€™ made the largest individual contribution with ā€˜cognitive confidenceā€™ also contributing in each case. For anxiety, a third metacognitive variable, ā€˜positive beliefs about worryā€™ also predicted variance in T2 symptoms. In addition, hierarchical analyses indicated that metacognitive beliefs explained a small but significant amount of variance in T2 anxiety (2 %) and T2 depression (4 %) over and above that explained by demographic variables, T1 symptoms and T1 illness perceptions. The findings suggest that modifying metacognitive beliefs and processes has the potential to alleviate distress associated with cancer
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