Análise psicométrica e dados normativos da UWES em adolescentes peruanos

Academic engagement is a relevant characteristic to predict successful academic trajectories and school performance; however, there is a lack of validated instruments in Peru for its evaluation. Therefore, the objective of this study was to analyze the psychometric properties of the Utrecht Work Engagement Scale – 9S (UWES-9S) in Peruvian adolescents: internal structure, measurement invariance, association with academic self-efficacy, reliability, and norms. A total of 868 school adolescents (51.728% women; Mage = 14.263; SDage = 1.430) from six schools in the Constitutional Province of Callao (central coast of Peru) were evaluated. In addition to the UWES-9S, the Specific Perceived Self-Efficacy Scale for Academic Situations was used as a measure of self-efficacy. The results show that the UWES-9S is unidimensional and invariant between men and women, although three items were eliminated, resulting in a new version: UWES-6S. Likewise, the association with academic self-efficacy was moderate (r > .50) and norms were obtained for men and women separately. In addition, the reliability indices were satisfactory for both the scores (alpha coefficient and average inter-item correlation) and the construct (omega coefficient > .80). It is concluded that the UWES-6S has adequate psychometric properties for its application in Peruvian adolescents.El engagement académico es una característica relevante para predecir las trayectorias académicas exitosas y el rendimiento escolar; sin embargo, existe una carencia de instrumentos validados en Perú para su evaluación. Por ello, el objetivo de esta investigación fue analizar las propiedades psicométricas de la Utrech Work Engagement Scale – 9S (UWES-9S) en adolescentes peruanos: estructura interna, invarianza de medición, asociación con la autoeficacia académica, confiabilidad y normas. Fueron evaluados 868 adolescentes escolares (51.728% mujeres; Medad = 14.263; DEedad = 1.430) procedentes de seis colegios de la Provincia Constitucional del Callao (costa central del Perú). Además de la UWES-9S se utilizó la Escala de Autoeficacia Percibida Específica para Situaciones Académicas como medida de autoeficacia. Los resultados indican que la UWES-9S es unidimensional e invariante entre hombres y mujeres, aunque se eliminaron tres ítems derivando en una nueva versión: UWES-6S. Asimismo, la asociación con la medida de autoeficacia académica fue moderada (r > .50) y se obtuvo normas para hombres y mujeres por separado. Los indicadores de confiabilidad fueron satisfactorios tanto para las puntuaciones (coeficiente alfa y correlación inter-ítem promedio) como para el constructo (coeficiente omega > .80). Se concluye que la UWES-6S cuenta con propiedades psicométricas adecuadas para su aplicación en adolescentes peruanos.O engagement académico é uma característica relevante para prever trajetórias académicas bem-sucedidas e o desempenho escolar, no entanto, faltam instrumentos validados no Perú para a sua avaliação. Portanto, o objetivo deste estudo foi analisar as propriedades psicométricas da Utrecht Work Engagement Scale – 9S (UWES-9S) em adolescentes peruanos: estrutura interna, invariância de medidas, associação com a autoeficácia académica, confiabilidade e normas. Foram avaliados 868 adolescentes escolares (51.728% mulheres; Midade = 14.263; DPidade = 1.430) de seis colégios da Província Constitucional de Callao (costa central do Perú). Além da UWES-9S, foi utilizada a Escala de Autoeficácia Percebida Específica para Situações Académicas como medida de autoeficácia. Os resultados mostram que a UWES-9S é unidimensional e invariável entre homens e mulheres, embora três itens tenham sido eliminados, resultando numa nova versão: UWES-6S. A associação com a autoeficácia académica foi moderada (r > 0,50) e as normas foram obtidas para homens e mulheres separadamente. Além disso, os índices de confiabilidade foram satisfatórios tanto para as pontuações (coeficiente alfa e correlação média entre itens) quanto para o constructo (coeficiente ómega > .80). Conclui-se que a UWES-6S possui propriedades psicométricas adequadas para sua aplicação em adolescentes peruanos

Multidrug efflux pumps:structure, function and regulation

Infections arising from multidrug-resistant pathogenic bacteria are spreading rapidly throughout the world and threaten to become untreatable. The origins of resistance are numerous and complex, but one underlying factor is the capacity of bacteria to rapidly export drugs through the intrinsic activity of efflux pumps. In this Review, we describe recent advances that have increased our understanding of the structures and molecular mechanisms of multidrug efflux pumps in bacteria. Clinical and laboratory data indicate that efflux pumps function not only in the drug extrusion process but also in virulence and the adaptive responses that contribute to antimicrobial resistance during infection. The emerging picture of the structure, function and regulation of efflux pumps suggests opportunities for countering their activities

Structure and mechanism of the mammalian fructose transporter GLUT5.

糖分を細胞内に輸送する膜たんぱく質の立体構造と動きを解明 -肥満やがんの抑制策に役立つ新たな知見-. 京都大学プレスリリース. 2015-10-01.The altered activity of the fructose transporter GLUT5, an isoform of the facilitated-diffusion glucose transporter family, has been linked to disorders such as type 2 diabetes and obesity. GLUT5 is also overexpressed in certain tumour cells, and inhibitors are potential drugs for these conditions. Here we describe the crystal structures of GLUT5 from Rattus norvegicus and Bos taurus in open outward- and open inward-facing conformations, respectively. GLUT5 has a major facilitator superfamily fold like other homologous monosaccharide transporters. On the basis of a comparison of the inward-facing structures of GLUT5 and human GLUT1, a ubiquitous glucose transporter, we show that a single point mutation is enough to switch the substrate-binding preference of GLUT5 from fructose to glucose. A comparison of the substrate-free structures of GLUT5 with occluded substrate-bound structures of Escherichia coli XylE suggests that, in addition to global rocker-switch-like re-orientation of the bundles, local asymmetric rearrangements of carboxy-terminal transmembrane bundle helices TM7 and TM10 underlie a 'gated-pore' transport mechanism in such monosaccharide transporters

A nucleoporin is required for induction of Ca(2+) spiking in legume nodule development and essential for rhizobial and fungal symbiosis

Nuclear-cytoplasmic partitioning and traffic between cytoplasmic and nuclear compartments are fundamental processes in eukaryotic cells. Nuclear pore complexes mediate transport of proteins, RNAs and ribonucleoprotein particles in and out of the nucleus. Here we present positional cloning of a plant nucleoporin gene, Nup133, essential for a symbiotic signal transduction pathway shared by Rhizobium bacteria and mycorrhizal fungi. Mutation of Nup133 results in a temperature sensitive nodulation deficient phenotype and absence of mycorrhizal colonization. Root nodules developing with reduced frequency at permissive temperatures are ineffective and electron microscopy show that Rhizobium bacteria are not released from infection threads. Measurement of ion fluxes using a calcium-sensitive dye show that Nup133 is required for the Ca(2+) spiking normally detectable within minutes after application of purified rhizobial Nod-factor signal molecules to root hairs. Localization of NUP133 in the nuclear envelope of root cells and root hair cells shown with enhanced yellow fluorescent protein fusion proteins suggests a novel role for NUP133 nucleoporins in a rapid nuclear–cytoplasmic communication after host–plant recognition of symbiotic microbes. Our results identify a component of an intriguing signal process requiring interaction at the cell plasma membrane and at intracellular nuclear and plastid organelle-membranes to induce a second messenger