573 research outputs found

    Academic self-concept, gender and single-sex schooling

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    This paper assesses gender differences in academic self-concept for a cohort of children born in 1958 (the National Child Development Study). We address the question of whether attending single-sex or co-educational schools affected students’ perceptions of their own academic abilities (academic self-concept). Academic selfconcept was found to be highly gendered, even controlling for prior test scores. Boys had higher self-concepts in maths and science, and girls in English. Single-sex schooling reduced the gender gap in self-concept, while selective schooling was linked to lower academic self-concept overall

    Contrasting patterns of selection between MHC I and II across populations of Humboldt and Magellanic penguins

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    The evolutionary and adaptive potential of populations or species facing an emerginginfectious disease depends on their genetic diversity in genes, such as the major histocompatibilitycomplex (MHC). In birds, MHC class I deals predominantly with intracellularinfections (e.g., viruses) and MHC class II with extracellular infections (e.g.,bacteria). Therefore, patterns of MHC I and II diversity may differ between species andacross populations of species depending on the relative effect of local and global environmentalselective pressures, genetic drift, and gene flow. We hypothesize thathigh gene flow among populations of Humboldt and Magellanic penguins limits localadaptation in MHC I and MHC II, and signatures of selection differ between markers,locations, and species. We evaluated the MHC I and II diversity using 454 next-generationsequencing of 100 Humboldt and 75 Magellanic penguins from seven differentbreeding colonies. Higher genetic diversity was observed in MHC I than MHCII for both species, explained by more than one MHC I loci identified. Large populationsizes, high gene flow, and/or similar selection pressures maintain diversity but limitlocal adaptation in MHC I. A pattern of isolation by distance was observed for MHC IIfor Humboldt penguin suggesting local adaptation, mainly on the northernmost studiedlocality. Furthermore, trans-speciesalleles were found due to a recent speciationfor the genus or convergent evolution. High MHC I and MHC II gene diversity describedis extremely advantageous for the long-termsurvival of the species.Fil: Sallaberry Pincheira, Nicole. Pontificia Universidad Católica de Chile; Chile. Universidad Andrés Bello; ChileFil: González Acuña, Daniel. Universidad de Concepción; ChileFil: Padilla, Pamela Solange. Pontificia Universidad Católica de Chile; ChileFil: Dantas, Gisele P. M.. Pontificia Universidade Catolica de Minas Gerais.; BrasilFil: Luna Jorquera, Guillermo. Universidad Católica del Norte; ChileFil: Frere, Esteban. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valdés Velásquez, Armando. Universidad Peruana Cayetano Heredia; PerúFil: Vianna, Juliana A.. Pontificia Universidad Católica de Chile; Chil

    Modification of forests by people means only 40% of remaining forests have high ecosystem integrity

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    Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally

    Towards progressive regulatory approaches for agricultural applications of animal biotechnology.

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    Traditional breeding techniques, applied incrementally over thousands of years, have yielded huge benefits in the characteristics of agricultural animals. This is a result of significant, measurable changes to the genomes of those animal species and breeds. Genome editing techniques may now be applied to achieve targeted DNA sequence alterations, with the potential to affect traits of interest to production of agricultural animals in just one generation. New opportunities arise to improve characteristics difficult to achieve or not amenable to traditional breeding, including disease resistance, and traits that can improve animal welfare, reduce environmental impact, or mitigate impacts of climate change. Countries and supranational institutions are in the process of defining regulatory approaches for genome edited animals and can benefit from sharing approaches and experiences to institute progressive policies in which regulatory oversight is scaled to the particular level of risk involved. To facilitate information sharing and discussion on animal biotechnology, an international community of researchers, developers, breeders, regulators, and communicators recently held a series of seven virtual workshop sessions on applications of biotechnology for animal agriculture, food and environmental safety assessment, regulatory approaches, and market and consumer acceptance. In this report, we summarize the topics presented in the workshop sessions, as well as discussions coming out of the breakout sessions. This is framed within the context of past and recent scientific and regulatory developments. This is a pivotal moment for determination of regulatory approaches and establishment of trust across the innovation through-chain, from researchers, developers, regulators, breeders, farmers through to consumers

    Perceptions of mixed-race

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    The psychology of race is in its infancy, particularly in the United Kingdom and especially regarding mixed-race. Most use untimed explicit indexes and qualitative/self-report measures. Here, we used not only explicit responses (participants’ choice of response categories) but also implicit data (participants’ response times, RT). In a Stroop task, 92 Black, White, and mixed-race participants classified photographs of mixed-race persons. Photos were accompanied by a word, such as Black or White. Participants ignored the word, simply deciding whether to categorize photos as White or Black. Averaged across three different instructional sets, White participants categorized mixed-race slightly to the White side of the center point, with Black participants doing the converse. Intriguingly, mixed-race participants placed mixed-race photos further toward Black than did the Black group. But for RT, they now indicated midway between White and Black participants. We conclude that at the conscious (key-press) level, mixed-race persons see being mixed-race as Black, but at the unconscious (RT) level, their perception is a perfect balance between Black and White. Findings are discussed in terms of two recent theories of racial identity

    Immune sensitization of equine bronchus: glutathione, IL-1β expression and tissue responsiveness

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    BACKGROUND: Increasing clinical epidemiological and experimental evidence indicates that excess of production of reactive oxygen free radicals (ROS) induced by an oxidative stress is involved in the pathogenesis of a number of human airway disorders, as well as equine recurrent airway obstruction. Free-radicals modulate the activation of transcription factors, such as nuclear factor-(NF)-κB and activator protein (AP)-1, in several different cells. This activation leads to expression of many pro-inflammatory cytokines, including interleukin (IL)-1β. We have hypothesized that equine airway sensitization might induce an oxidative stress and increase the ROS production, which in turn might enhance a production of IL-1β and airway hyperresponsiveness. METHODS: We have examined the effect of passive sensitization on IL-1β mRNA expression and electrical field stimulation (EFS)-induced contraction in equine isolated bronchi, and the potential interference of reduced-glutathione (GSH), an antioxidant, with these responses. Bronchi passively sensitized with serum from animals suffering from heaves and having high total level of IgE, and control tissues, either pretreated or not with GSH (100 μM), were used to quantify IL-1β mRNA. Other tissues were used to study the effect of EFS (3–10–25 Hz). RESULTS: Mean IL-1β mRNA expression was higher in passively sensitized than in control rings. GSH significantly (p < 0.05) reduced the IL-1β mRNA expression only in passively sensitized bronchi. ELF induced a frequency-dependent contraction in both non-sensitized and passively sensitized tissues, with a significantly greater response always observed in sensitized tissues. GSH did not modify the EFS-induced contraction in non-sensitized bronchi, but significantly (p < 0.05) decreased it in passively sensitized tissues. CONCLUSION: Our data indicate that the passive sensitization of equine bronchi induces inflammation and hyperresponsiveness. These effects might be due to an oxidative stress because a pretreatment with GSH decreased the increased IL-1β mRNA expression and responsiveness to EFS of passively sensitized bronchi
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