104 research outputs found

    Unrepeatered DP-QPSK transmission over 352.8 km SMF using random DFB fiber laser amplification

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    Unrepeatered 100 Gbit/s per channel wave-divisionmultiplexed dual-polarization-QPSK transmission with random distributed feedback fiber laser-based Raman amplification using fiber Bragg grating is demonstrated. Transmission of 1.4 Tb/s (14 × 100 Gbit/s) was possible in 352.8 km link and 2.2 Tb/s (22 × 100 Gbit/s) was achieved in 327.6 km without employing remote optically pumped amplifier or speciality fibers

    Upper limits on bolometric luminosities of ten type Ia supernova progenitors from Chandra observations

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    We present an analysis of Chandra observations of the position of ten nearby (< 25 Mpc) type Ia supernovae, taken before the explosions. No sources corresponding to progenitors were found in any of the observations. We calculated upper limits on the bolometric luminosities of the progenitors assuming black-body X-ray spectra with temperatures of 30-150 eV. This is inspired by the fact that luminous super-soft X-ray sources have been suggested as the direct progenitors of type Ia supernovae. The upper limits of two supernovae in our sample are comparable to the luminosities of the brightest observed super-soft sources, ruling out such sources as the progenitors of these supernovae. In contrast to Liu et al (2012) we find that for SN2011fe we can rule out Eddington luminosity systems for black body temperatures as low as 40 eV. Our findings are consistent with statistical studies comparing the observed type Ia supernova rate to the number of super-soft sources or the integrated X-ray luminosity in external galaxies. This suggest that either the progenitors of type Ia supernovae are not accreting, nuclear burning white dwarfs, or that they do not look like the classical super-soft sources, e.g. because they are obscured.Comment: Accepted, MNRAS. 10 pages, 11 figures, 3 table

    How might educational research into children’s ideas about light be of use to teachers?

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    This paper offers a synthesis of research evidence around teaching light to primary and secondary school pupils, as part of the Institute of Physics (IOP) Promoting and Interpreting Physics Education Research (PIPER) project. Conceptual change literature describes many difficulties young people have with understanding the phenomenon of light, and this knowledge can be useful in the classroom. Pupil teacher dialogue is used to illustrate some of the pedagogical challenges teachers face in this topic. This paper highlights a range of influences on pupils from everyday life and from the classroom, with a view to promoting teacher awareness of conceptual change research evidence

    The p38/MK2/Hsp25 Pathway Is Required for BMP-2-Induced Cell Migration

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    Background: Bone morphogenetic proteins (BMPs) have been shown to participate in the patterning and specification of several tissues and organs during development and to regulate cell growth, differentiation and migration in different cell types. BMP-mediated cell migration requires activation of the small GTPase Cdc42 and LIMK1 activities. In our earlier report we showed that activation of LIMK1 also requires the activation of PAKs through Cdc42 and PI3K. However, the requirement of additional signaling is not clearly known. Methodology/Principal Findings: Activation of p38 MAPK has been shown to be relevant for a number of BMP-2¿s physiological effects. We report here that BMP-2 regulation of cell migration and actin cytoskeleton remodelling are dependent on p38 activity. BMP-2 treatment of mesenchymal cells results in activation of the p38/MK2/Hsp25 signaling pathway downstream from the BMP receptors. Moreover, chemical inhibition of p38 signaling or genetic ablation of either p38¿ or MK2 blocks the ability to activate the downstream effectors of the pathway and abolishes BMP-2-induction of cell migration. These signaling effects on p38/MK2/Hsp25 do not require the activity of either Cdc42 or PAK, whereas p38/MK2 activities do not significantly modify the BMP-2-dependent activation of LIMK1, measured by either kinase activity or with an antibody raised against phospho-threonine 508 at its activation loop. Finally, phosphorylated Hsp25 colocalizes with the BMP receptor complexes in lamellipodia and overexpression of a phosphorylation mutant form of Hsp25 is able to abolish the migration of cells in response to BMP-2. Conclusions: These results indicate that Cdc42/PAK/LIMK1 and p38/MK2/Hsp25 pathways, acting in parallel and modulating specific actin regulatory proteins, play a critical role in integrating responses during BMP-induced actin reorganization and cell migration

    Human germline heterozygous gain-of-function STAT6 variants cause severe allergic disease

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    STAT6 (signal transducer and activator of transcription 6) is a transcription factor that plays a central role in the pathophysiology of allergic inflammation. We have identified 16 patients from 10 families spanning three continents with a profound phenotype of early-life onset allergic immune dysregulation, widespread treatment-resistant atopic dermatitis, hypereosinophilia with esosinophilic gastrointestinal disease, asthma, elevated serum IgE, IgE-mediated food allergies, and anaphylaxis. The cases were either sporadic (seven kindreds) or followed an autosomal dominant inheritance pattern (three kindreds). All patients carried monoallelic rare variants in STAT6 and functional studies established their gain-of-function (GOF) phenotype with sustained STAT6 phosphorylation, increased STAT6 target gene expression, and TH2 skewing. Precision treatment with the anti-IL-4Rα antibody, dupilumab, was highly effective improving both clinical manifestations and immunological biomarkers. This study identifies heterozygous GOF variants in STAT6 as a novel autosomal dominant allergic disorder. We anticipate that our discovery of multiple kindreds with germline STAT6 GOF variants will facilitate the recognition of more affected individuals and the full definition of this new primary atopic disorder

    Human germline heterozygous gain-of-function STAT6 variants cause severe allergic disease

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    sharma et al. define a new primary atopic disorder caused by heterozygous gain-of-function variants in STAT6. this results in severe, early-onset allergies, and is seen in 16 patients from 10 families. Anti-IL-4R &amp; alpha; antibody and JAK inhibitor treatment were highly effective.STAT6 (signal transducer and activator of transcription 6) is a transcription factor that plays a central role in the pathophysiology of allergic inflammation. we have identified 16 patients from 10 families spanning three continents with a profound phenotype of early-life onset allergic immune dysregulation, widespread treatment-resistant atopic dermatitis, hypereosinophilia with esosinophilic gastrointestinal disease, asthma, elevated serum IgE, IgE-mediated food allergies, and anaphylaxis. the cases were either sporadic (seven kindreds) or followed an autosomal dominant inheritance pattern (three kindreds). all patients carried monoallelic rare variants in STAT6 and functional studies established their gain-of-function (GOF) phenotype with sustained STAT6 phosphorylation, increased STAT6 target gene expression, and T(H)2 skewing. Precision treatment with the anti-IL-4R &amp; alpha; antibody, dupilumab, was highly effective improving both clinical manifestations and immunological biomarkers. this study identifies heterozygous GOF variants in STAT6 as a novel autosomal dominant allergic disorder. We anticipate that our discovery of multiple kindreds with germline STAT6 GOF variants will facilitate the recognition of more affected individuals and the full definition of this new primary atopic disorder

    Glial contribution to excitatory and inhibitory synapse loss in neurodegeneration

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    Synapse loss is an early feature shared by many neurodegenerative diseases, and it represents the major correlate of cognitive impairment. Recent studies reveal that microglia and astrocytes play a major role in synapse elimination, contributing to network dysfunction associated with neurodegeneration. Excitatory and inhibitory activity can be affected by glia-mediated synapse loss, resulting in imbalanced synaptic transmission and subsequent synaptic dysfunction. Here, we review the recent literature on the contribution of glia to excitatory/inhibitory imbalance, in the context of the most common neurodegenerative disorders. A better understanding of the mechanisms underlying pathological synapse loss will be instrumental to design targeted therapeutic interventions, taking in account the emerging roles of microglia and astrocytes in synapse remodeling

    Certificación de un material de referencia de carne en base a un estudio de colaboración = Certification of a meat reference material based on a collaborative study

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    Mediante un proyecto de colaboración, se llevaron a cabo estudios de comparación para mejorar la capacidad de mediciónde los laboratorios participantes, apoyándolos en la producción, caracterización y distribución de materiales de referencia delsector agroalimentario. El proyecto fue planteado en cuatro etapas anuales (leche, agua, carne y granos). La tercera etapa enespecífico tuvo el objetivo de cuantificar y certificar el contenido de los parámetros nutrimentales (nitrógeno, grasa, sodio ypotasio) de un lote candidato a Material de Referencia Certificado (MRC) de carne bovina enlatada. Dicho estudio fue realizadoen colaboración entre varios Institutos Nacionales de Metrología (INM) y/o laboratorios colaboradores, los cuales, una vez queidentificaron las posibles causas de variabilidad o de sesgo en las mediciones, así como las oportunidades de mejora, lograronla certificación del material de carne bovina. El MRC fue distribuido entre los participantes para cubrir las necesidades de laindustria alimentaria de productos cárnicos y laboratorios de prueba de sus respectivos países

    Discourse and religion in educational practice

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    Despite the existence of long-held binaries between secular and sacred, private and public spaces, school and religious literacies in many contemporary societies, the significance of religion and its relationship to education and society more broadly has become increasingly topical. Yet, it is only recently that the investigation of the nexus of discourse and religion in educational practice has started to receive some scholarly attention. In this chapter, religion is understood as a cultural practice, historically situated and embedded in specific local and global contexts. This view of religion stresses the social alongside the subjective or experiential dimensions. It explores how through active participation and apprenticeship in culturally appropriate practices and behaviors often mediated intergenerationally and the mobilisation of linguistic and other semiotic resources but also affective, social and material resources, membership in religious communities is constructed and affirmed. The chapter reviews research strands that have explored different aspects of discourse and religion in educational practice as a growing interdisciplinary field. Research strands have examined the place and purpose of religion in general and evangelical Christianity in particular in English Language Teaching (ELT) programmes and the interplay of religion and teaching and learning in a wide range of religious and increasingly secular educational contexts. They provide useful insights for scholars of discourse studies to issues of identity, socialisation, pedagogy and language policy

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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