500 research outputs found

    Sources of individual variation in plasma testosterone levels

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    The steroid hormone testosterone (T) plays a central role in the regulation of breeding in males, because many physiological, morphological and behavioural traits related to reproduction are T dependent. Moreover, in many seasonally breeding vertebrates, male plasma T levels typically show a pronounced peak during the breeding season. While such population-level patterns are fairly well worked out, the sources and the implications of the large variability in individual T levels within the seasonal cycle remain surprisingly little understood. Understanding the potential sources of individual variation in T levels is important for behavioural and evolutionary ecologists, for at least two reasons. First, in ‘honest signalling’ theory, T is hypothesized to play a critical role as the assumed factor that enforces honesty of the expression of sexually selected quality indicators. Second, T is often considered a key mediator of central life-history trade-offs, such as investment in survival versus reproduction or in mating versus parental care. Here, we discuss the patterns of within- and between-individual variation in male plasma T levels in free-living populations of birds. We argue that it is unclear whether this variability mainly reflects differences in underlying individual quality (intrinsic factors such as genetic or maternal effects) or in the environment (extrinsic factors including time of day, individual territorial status and past experience). Research in avian behavioural endocrinology has mainly focused on the effects of extrinsic factors, while other sources of variance are often ignored. We suggest that studies that use an integrative approach and investigate the relative importance of all potential sources of variation are essential for the interpretation of data on individual plasma T levels

    Detection and Isolation of Viable Mouse IL-17-Secreting T Cells

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    The MACS Cytokine Secretion Assay technology allows detection of secreted cytokines on the single cell level and sensitive isolation of viable cytokine-secreting cells. In order to label IL-17-secreting cells, a single cell suspension of mouse splenocytes is prepared and stimulated at 37°C with PMA/ionomycin to induce cytokine secretion. To stop secretion cells are then placed on ice and are exposed to the IL-17 Catch Reagent a bi-specific antibody that binds to CD45 on the cell surface of leukocytes and to IL-17 as it is secreted and caught near the cell surface. Secretion is then re-started by increasing the temperature to 37°C and IL-17 is trapped by the Catch Reagent. Secretion is then stopped again, by placing cells on ice. To detect the trapped IL-17, cells are incubated with a second IL-17-specific antibody conjugated to biotin and an Anti-Biotin-PE antibody. Cells can now be directly analyzed by flow cytometry or prepared for isolation and enrichment by subsequent labeling with Anti-PE conjugated MicroBeads

    Towards the construction of an educational model for dual career parenting:the EMPATIA project

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    The European Union supports innovative transnational cooperation and practices between Member States on relevant issues in the field of sports, including a balanced combination of higher education and sporting careers of talented and elite athletes (dual career). Ten European academic and sport institutions aimed to construct an educational programme for parents supporting the dual career of their elite athletes. The innovative methodological approach to the co-construction of a parent education based on evidence and eminence of the actual needs of parents in relation to the age, sex, sport typology, competition and academic levels of student-athletes is described. Finally, the potentially far-reaching effects of digital technologies on adult learning and the innovative aspects of a multi-lingual and demand-driven dual career parenting education are envisaged.</p

    Lifestyle, dietary factors and antibody levels to oral bacteria in cancer-free participants of a European cohort study

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    Background—Increasing evidence suggests that oral microbiota play a pivotal role in chronic diseases, in addition to the well-established role in periodontal disease. Moreover, recent studies suggest that oral bacteria may also be involved in carcinogenesis; periodontal disease has been linked several cancers. In this study, we examined whether lifestyle factors have an impact on antibody levels to oral bacteria. Methods—Data on demographic characteristics, lifestyle factors, and medical conditions were obtained at the time of blood sample collection. For the current analysis, we measured antibody levels to 25 oral bacteria in 395 cancer-free individuals using an immunoblot array. Combined total immunglobin G (IgG) levels were obtained by summing concentrations for all oral bacteria measured. Results—IgG antibody levels were substantially lower among current and former smokers (1697 and 1677 ng/mL, respectively) than never smokers (1960 ng/mL; p-trend = 0.01), but did not vary by other factors, including BMI, diabetes, physical activity, or by dietary factors, after adjusting for age, sex, education, country and smoking status. The highest levels of total IgG were found among individuals with low education (2419 ng/mL). Conclusions—Our findings on smoking are consistent with previous studies and support the notion that smokers have a compromised humoral immune response. Moreover, other major factors known to be associated with inflammatory markers, including obesity, were not associated with antibody levels to a large number of oral bacteria

    Perceived discrimination amongst the indigenous Mapuche people in Chile : some comparisons with Australia

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    With similar settler-colonial histories having left them occupying the position of marginalized minority groups, indigenous people in Chile and Australia are struggling to assert their rights and retain their cultures. Research in each location suggests that there is widespread prejudice and discrimination against them, even though the mainstream society sees itself as tolerant and harmonious. This paper reports on a study in which thirty Mapuche people in Chile were interviewed about their perceptions of discrimination against them. Their responses were systematically analysed using a taxonomy of racist experiences established in a study of Aborigines in Australia. Like indigenous Australians, the Mapuche people of Chile reported that they experience extensive discrimination in all areas of life. These findings are discussed with respect to the issues related to relationships between settlers and colonized communities.<br /

    Attenuated PDGF signaling drives alveolar and microvascular defects in neonatal chronic lung disease

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    Neonatal chronic lung disease (nCLD) affects a significant number of neonates receiving mechanical ventilation with oxygen-rich gas (MV-O2). Regardless, the primary molecular driver of the disease remains elusive. We discover significant enrichment for SNPs in the PDGF-Rα gene in preterms with nCLD and directly test the effect of PDGF-Rα haploinsufficiency on the development of nCLD using a preclinical mouse model of MV-O2. In the context of MV-O2, attenuated PDGF signal
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