151 research outputs found

    System for Performing Single Query Searches of Heterogeneous and Dispersed Databases

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    The present invention is a distributed computer system of heterogeneous databases joined in an information grid and configured with an Application Programming Interface hardware which includes a search engine component for performing user-structured queries on multiple heterogeneous databases in real time. This invention reduces overhead associated with the impedance mismatch that commonly occurs in heterogeneous database queries

    4D Imaging and Diffraction Dynamics of Single-Particle Phase Transition in Heterogeneous Ensembles

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    In this Letter, we introduce conical-scanning dark-field imaging in four-dimensional (4D) ultrafast electron microscopy to visualize single-particle dynamics of a polycrystalline ensemble undergoing phase transitions. Specifically, the ultrafast metal–insulator phase transition of vanadium dioxide is induced using laser excitation and followed by taking electron-pulsed, time-resolved images and diffraction patterns. The single-particle selectivity is achieved by identifying the origin of all constituent Bragg spots on Debye–Scherrer rings from the ensemble. Orientation mapping and dynamic scattering simulation of the electron diffraction patterns in the monoclinic and tetragonal phase during the transition confirm the observed behavior of Bragg spots change with time. We found that the threshold temperature for phase recovery increases with increasing particle sizes and we quantified the observation through a theoretical model developed for single-particle phase transitions. The reported methodology of conical scanning, orientation mapping in 4D imaging promises to be powerful for heterogeneous ensemble, as it enables imaging and diffraction at a given time with a full archive of structural information for each particle, for example, size, morphology, and orientation while minimizing radiation damage to the specimen

    GATA2 Mediates Thyrotropin-Releasing Hormone-Induced Transcriptional Activation of the Thyrotropin β Gene

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    Thyrotropin-releasing hormone (TRH) activates not only the secretion of thyrotropin (TSH) but also the transcription of TSHβ and α-glycoprotein (αGSU) subunit genes. TSHβ expression is maintained by two transcription factors, Pit1 and GATA2, and is negatively regulated by thyroid hormone (T3). Our prior studies suggest that the main activator of the TSHβ gene is GATA2, not Pit1 or unliganded T3 receptor (TR). In previous studies on the mechanism of TRH-induced activation of the TSHβ gene, the involvements of Pit1 and TR have been investigated, but the role of GATA2 has not been clarified. Using kidney-derived CV1 cells and pituitary-derived GH3 and TαT1 cells, we demonstrate here that TRH signaling enhances GATA2-dependent activation of the TSHβ promoter and that TRH-induced activity is abolished by amino acid substitution in the GATA2-Zn finger domain or mutation of GATA-responsive element in the TSHβ gene. In CV1 cells transfected with TRH receptor expression plasmid, GATA2-dependent transactivation of αGSU and endothelin-1 promoters was enhanced by TRH. In the gel shift assay, TRH signal potentiated the DNA-binding capacity of GATA2. While inhibition by T3 is dominant over TRH-induced activation, unliganded TR or the putative negative T3-responsive element are not required for TRH-induced stimulation. Studies using GH3 cells showed that TRH-induced activity of the TSHβ promoter depends on protein kinase C but not the mitogen-activated protein kinase, suggesting that the signaling pathway is different from that in the prolactin gene. These results indicate that GATA2 is the principal mediator of the TRH signaling pathway in TSHβ expression

    Readdressing democracy and social justice: coping with inequalities in physical education

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    This research is contextualised by Freirean approaches to teacher education, which promote complex arrangements in the organisation of knowledge communities among teachers. Such communities are supportive of teachers’ learning by providing critique to advance socially-just teaching practices. Recently, Sanches Neto, Venâncio and Ovens (2021) found that collaboration across different settings allowed a better understanding of the teaching complexities. However, it is uncertain how knowledge communities structured based on Sanches, Costa and Ovens (2022) support and promote teachers’ democratic values and thinking towards social justice. We explore this uncertainty by drawing on an action research project within a Brazilian physical education teacher education (PETE) Master’s program (ProEF). Participants included teacher-researchers from different locations in the Northeast of Brazil, who were supervised by two teacher educators and co-authors of this article —Sanches Neto and Venâncio. In this article, the authors used vignettes of one ProEF Master’s student —Silva— to discuss her own teaching and context. Through a complexity thinking lens, our objective was to analyse collaboratively her teaching intentions and dilemmas towards social justice. We found that critical incidents regarding race, gender and class evidenced intersectionalities and how the teacher embodied democratic values while coping with inequalities. The teacher was aware of the inequalities faced by her students. Despite this, her teaching lacked the criticality and full institutional support to address all emerging issues for a more equitable physical education and long term change. The teacher’s advocacy connects to the broad research project aiming to readdress democracy through engaged teaching a pedagogy of discomfort as an alternative to neoliberal educational guidelines

    A influência da estrutura de propriedade e controle sobre o valor de mercado corporativo no Brasil

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    O modelo brasileiro de governança corporativa é caracterizado pela elevada concentração na estrutura societária que, em geral, culmina na sobreposição da propriedade e da administração das companhias. Segundo a literatura, o acúmulo de ações pelo(s) controlador(es) pode impactar o desempenho corporativo devido ao efeito-alinhamento (ou incentivo) e ao efeito-entrincheiramento. A princípio, a presença de grandes acionistas estaria associada a benefícios para a organização, uma vez que poderia aumentar a eficácia do monitoramento da gestão. Todavia, patamares muito elevados de concentração acionária podem permitir que os controladores dominem o processo decisório da corporação, o que poderia resultar na expropriação da riqueza dos acionistas minoritários. A relevância da estrutura societária como mecanismo interno dos sistemas de governança corporativa motivou a realização do presente estudo. Este artigo teve como objetivo testar se a concentração de propriedade e controle influencia o valor de mercado corporativo. Para tanto, foi utilizado um painel não balanceado para o período de 2001 a 2010, composto por 237 empresas brasileiras não financeiras de capital aberto, que somou 1.199 observações. Foram empregados modelos dinâmicos de regressão, estimados pelo Método dos Momentos Generalizado Sistêmico (MMG-Sis), para mitigar possíveis fontes de endogeneidade como a omissão de variáveis, o efeito-feedback e a simultaneidade. Constatou-se a existência de relação quadrática entre concentração no direito sobre o fluxo de caixa do acionista controlador e o valor de mercado das firmas. Ademais, os resultados indicam que o valor de mercado corrigido das ações do maior acionista captou o efeito-incentivo, enquanto a concentração no direito de voto capturou o efeito-entrincheiramento

    NASA web-accessible open Software as a Service framework

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