368 research outputs found

    Plain Women: Gender and Ritual in the Old Order River Brethren

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    Review of: Plain Women: Gender and Ritual in the Old Order River Brethren. Reynolds, Margaret C

    Diaspora in the Countryside: Two Mennonite Communities and Mid-Twentieth-Century Rural Disjuncture

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    Review of: " Diaspora in the Countryside: Two Mennonite Communities and Mid-Twentieth-Century Rural Disjuncture," by Royden Loewen

    The Amish and the Media

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    Review of: "The Amish and the Media," edited by Diane Zimmerman Umble and David L. Weaver-Zercher

    Diaspora in the Countryside: Two Mennonite Communities and Mid-Twentieth-Century Rural Disjuncture

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    Review of: " Diaspora in the Countryside: Two Mennonite Communities and Mid-Twentieth-Century Rural Disjuncture," by Royden Loewen

    Functional evolution of the vitamin D and pregnane X receptors

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    <p>Abstract</p> <p>Background</p> <p>The vitamin D receptor (VDR) and pregnane X receptor (PXR) are nuclear hormone receptors of the NR1I subfamily that show contrasting patterns of cross-species variation. VDR and PXR are thought to have arisen from duplication of an ancestral gene, evident now as a single gene in the genome of the chordate invertebrate <it>Ciona intestinalis </it>(sea squirt). VDR genes have been detected in a wide range of vertebrates including jawless fish. To date, PXR genes have not been found in cartilaginous fish. In this study, the ligand selectivities of VDRs were compared in detail across a range of vertebrate species and compared with those of the <it>Ciona </it>VDR/PXR. In addition, several assays were used to search for evidence of PXR-mediated hepatic effects in three model non-mammalian species: sea lamprey (<it>Petromyzon marinus</it>), zebrafish (<it>Danio rerio</it>), and African clawed frog (<it>Xenopus laevis</it>).</p> <p>Results</p> <p>Human, mouse, frog, zebrafish, and lamprey VDRs were found to have similar ligand selectivities for vitamin D derivatives. In contrast, using cultured primary hepatocytes, only zebrafish showed evidence of PXR-mediated induction of enzyme expression, with increases in testosterone 6β-hydroxylation activity (a measure of cytochrome P450 3A activity in other species) and flurbiprofen 4-hydroxylation activity (measure of cytochrome P450 2C activity) following exposure to known PXR activators. A separate assay in vivo using zebrafish demonstrated increased hepatic transcription of another PXR target, multidrug resistance gene (ABCB5), following injection of the major zebrafish bile salt, 5α-cyprinol 27-sulfate. The PXR target function, testosterone hydroxylation, was detected in frog and sea lamprey primary hepatocytes, but was not inducible in these two species by a wide range of PXR activators in other animals. Analysis of the sea lamprey draft genome also did not show evidence of a PXR gene.</p> <p>Conclusion</p> <p>Our results show tight conservation of ligand selectivity of VDRs across vertebrate species from Agnatha to mammals. Using a functional approach, we demonstrate classic PXR-mediated effects in zebrafish, but not in sea lamprey or African clawed frog liver cells. Using a genomic approach, we failed to find evidence of a PXR gene in lamprey, suggesting that VDR may be the original NR1I gene.</p

    The evolution of farnesoid X, vitamin D, and pregnane X receptors: insights from the green-spotted pufferfish (Tetraodon nigriviridis) and other non-mammalian species

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    <p>Abstract</p> <p>Background</p> <p>The farnesoid X receptor (FXR), pregnane X receptor (PXR), and vitamin D receptor (VDR) are three closely related nuclear hormone receptors in the NR1H and 1I subfamilies that share the property of being activated by bile salts. Bile salts vary significantly in structure across vertebrate species, suggesting that receptors binding these molecules may show adaptive evolutionary changes in response. We have previously shown that FXRs from the sea lamprey (<it>Petromyzon marinus</it>) and zebrafish (<it>Danio rerio</it>) are activated by planar bile alcohols found in these two species. In this report, we characterize FXR, PXR, and VDR from the green-spotted pufferfish (<it>Tetraodon nigriviridis</it>), an actinopterygian fish that unlike the zebrafish has a bile salt profile similar to humans. We utilize homology modelling, docking, and pharmacophore studies to understand the structural features of the <it>Tetraodon </it>receptors.</p> <p>Results</p> <p><it>Tetraodon </it>FXR has a ligand selectivity profile very similar to human FXR, with strong activation by the synthetic ligand GW4064 and by the primary bile acid chenodeoxycholic acid. Homology modelling and docking studies suggest a ligand-binding pocket architecture more similar to human and rat FXRs than to lamprey or zebrafish FXRs. <it>Tetraodon </it>PXR was activated by a variety of bile acids and steroids, although not by the larger synthetic ligands that activate human PXR such as rifampicin. Homology modelling predicts a larger ligand-binding cavity than zebrafish PXR. We also demonstrate that VDRs from the pufferfish and Japanese medaka were activated by small secondary bile acids such as lithocholic acid, whereas the African clawed frog VDR was not.</p> <p>Conclusions</p> <p>Our studies provide further evidence of the relationship between both FXR, PXR, and VDR ligand selectivity and cross-species variation in bile salt profiles. Zebrafish and green-spotted pufferfish provide a clear contrast in having markedly different primary bile salt profiles (planar bile alcohols for zebrafish and sterically bent bile acids for the pufferfish) and receptor selectivity that matches these differences in endogenous ligands. Our observations to date present an integrated picture of the co-evolution of bile salt structure and changes in the binding pockets of three nuclear hormone receptors across the species studied.</p

    Assessment and intervention issues and models in School Psychology : the case of Europe and North America

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    As práticas da Psicologia Escolar parecem ser cada vez mais marcadas pelas necessidades de referenciação/diagnóstico de crianças para o subsistema de educação especial, em detrimento do desenho e implementação de intervenções dirigidas aos problemas específicos dos alunos. A aparente insatisfação dos psicólogos escolares com essa tendência, bem como as dificuldades na utilização de modelos categoriais de diagnóstico em contexto escolar, têm dado origem à progressiva implementação de modelos alternativos de avaliação e intervenção, principalmente de modelos Response to Intervention, Curriculum-Based Measurement e Problem Solving. A controvérsia quanto à natureza verdadeiramente alternativa desses modelos parece, no entanto, longe de se esgotar. Neste artigo são discutidas vantagens e limitações dos diferentes modelos, de acordo com a melhor evidência disponível na literatura, e são ainda equacionadas as suas implicações nas práticas da Psicologia Escolar. Practices in School Psychology seem to be increasingly restricted to referrals/diagnosis of children for the sub-system of special education instead of being focused on the design and implementation of interventions for students with specific problems. The apparent dissatisfaction of school psychologists with this trend and the difficulties dealing with categorical diagnostic models within the school context have stimulated a movement toward the implementation of alternative assessment and intervention models, such as Response to Intervention, Curriculum-Based Measurement and Problem-Solving. However, the controversy about the true alternative nature of these models seems far from being exhausted. The aim of this paper is to discuss the benefits and limitations of the different models according to the best evidence available. We also consider the implications for practices in School PsychologyPractices in School Psychology seem to be increasingly restricted to referrals/diagnosis of children for the sub-system of special education instead of being focused on the design and implementation of interventions for students with specific problems. The apparent dissatisfaction of school psychologists with this trend and the difficulties dealing with categorical diagnostic models within the school context have stimulated a movement toward the implementation of alternative assessment and intervention models, such as Response to Intervention, Curriculum-Based Measurement and Problem-Solving. However, the controversy about the true alternative nature of these models seems far from being exhausted. The aim of this paper is to discuss the benefits and limitations of the different models according to the best evidence available. We also consider the implications for practices in School Psychology(undefined

    All different or all the same? Exploring the diversity of professional practices in Portuguese school psychology

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    "Published online: 29 March 2016"Studies have generally characterized school psychologists as a relative homogenous population. Understanding the differences in professional practices and related variables is important for the development of the profession. Using a sample of 446 Portuguese school psychologists, this study used cluster analysis to identify distinct profiles of professional activity, based on practitioners’ time distribution among different target audiences (i.e.,students, parents, teachers, school board members, school non-professional staff, and other professionals within the school community). Three distinct profiles emerged from the data: a group highly oriented to work with students, a group that distributes time almost equitably between adults and students, and a group that concentrates attention and professional expertise on adults. Practice setting variables, such as school-psychologists-to-student ratio, schoolpsychologists-to-school ratio, number of referrals per year, and school community level of demand for different activities, were found to be significantly related to cluster membership. No personal- or professional-background-related variables differentiated the three groups. The main implications of these findings are discussed in light of recent literature regarding the models of service delivery for school psychologists

    Examining the validity of the Athlete Engagement Questionnaire (AEQ) within a Portuguese sport setting

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    Sport psychology literature suggests that understanding engagement levels is pivotal to promote positive sporting experiences among athletes. The purpose of this study was to examine the psychometric properties of the Athlete Engagement Questionnaire among Portuguese sport athletes. Two distinct samples of Portuguese athletes from different competitive levels were collected, and the results of a confirmatory factor analysis demonstrated a good fit of the model to the data. A review of the psychometric properties indicated that all factors showed good composite reliability, convergent validity, and discriminant validity. In addition, a multi-groups analysis showed the invariance of the model in two independent samples providing evidence of cross validity. Implications of these results for scholars and coaches are discussed and guidelines for future studies are suggested
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