817 research outputs found
Exponential Metric Fields
The Laser Interferometer Space Antenna (LISA) mission will use advanced
technologies to achieve its science goals: the direct detection of
gravitational waves, the observation of signals from compact (small and dense)
stars as they spiral into black holes, the study of the role of massive black
holes in galaxy evolution, the search for gravitational wave emission from the
early Universe. The gravitational red-shift, the advance of the perihelion of
Mercury, deflection of light and the time delay of radar signals are the
classical tests in the first order of General Relativity (GR). However, LISA
can possibly test Einstein's theories in the second order and perhaps, it will
show some particular feature of non-linearity of gravitational interaction. In
the present work we are seeking a method to construct theoretical templates
that limit in the first order the tensorial structure of some metric fields,
thus the non-linear terms are given by exponential functions of gravitational
strength. The Newtonian limit obtained here, in the first order, is equivalent
to GR.Comment: Accepted for publication in Astrophysics and Space Science, 17 page
Empreendedorismo em espaços acadêmicos: Avaliação do Alerta Empreendedor e das Abordagens Causation e Effectuation em uma Universidade Brasileira
O objetivo deste estudo foi identificar e analisar como os gestores das Empresas Juniores (EJs),
de uma universidade federal brasileira, reconhecem as oportunidades e como as exploram. A
pesquisa é exploratória e testa os pressupostos teóricos do Alerta Empreendedor e das
Abordagens Causation e Effectuation, junto a 30 gestores estudantes da Universidade Federal do
Rio de Janeiro (UFRRJ). Conclui que a formação fomentada por experiências educacionais em
empresas juniores estimula atitudes e comportamentos empreendedores, por desenvolver nos
jovens a percepção de si mesmo e do mundo, e também, contribui para a formação de seres
holísticos e contextuais que são capazes de lidar com processos analíticos e racionais. O artigo
argumenta que o empreendedorismo em espaços acadêmicos proporciona um efeito potencial
que precisa de ser estimulado e estudado, pois estimula capacidades cognitivas e psicológicas
essenciais à formação profissional. Entende-se este estudo como original visto que existe pouca
investigação no âmbito do empreendedorismo acadêmico, tratando esse gap da literatura
dentro do estudo. As informações levantadas neste estudo sobre as EJs contribuem para o
melhoramento do sistema de suporte e relacionamento dos atores envolvidos com o meio em
que estão inseridos.Abstract
The objective of this study was to identify and analyze how the managers of Junior Companies
(EJs), from a Brazilian federal university, recognize the opportunities and how they exploit them.
The research is exploratory and tests the theoretical assumptions of the Entrepreneurial Alert
and the Causation and Effectuation Approaches, with 30 student managers at the Federal
University of Rio de Janeiro (UFRRJ). It concludes that the training fostered by educational
experiences in junior companies stimulates entrepreneurial attitudes and behaviors, as it
develops in young people the perception of themselves and the world, and also contributes to
the formation of holistic and contextual beings who are able to deal with analytical processes
and rational. The article argues that entrepreneurship in academic spaces provides a potential
effect that needs to be stimulated and studied, as it stimulates cognitive and psychological
capacities essential to professional training. This study is understood as original since there is
little research in the scope of academic entrepreneurship, dealing with this gap in the literature
within the study. The information collected in this study about the EJs, contribute to the
improvement of the support and relationship system of the actors involved with the
environment they are inserted in.Resumen
El objetivo de este estudio fue identificar y analizar cómo los gerentes de las Empresas Junior
(EJ), de una universidad federal brasileña, reconocen las oportunidades y cómo las explotan. La
investigación es exploratoria y prueba los supuestos teóricos de la Alerta Empresarial y los
Enfoques de Causation y Effectuation, con 30 gerentes estudiantiles en la Universidad Federal de
Río de Janeiro (UFRRJ). Concluye que la capacitación fomentada por las experiencias educativas
en las empresas junior estimula las actitudes y los comportamientos empresariales, ya que
desarrolla en los jóvenes la percepción de sí mismos y del mundo, y también contribuye a la
formación de seres holísticos y contextuales que son capaces de lidiar con los procesos
analíticos. y racional El artículo argumenta que el emprendimiento en espacios académicos
proporciona un efecto potencial que necesita ser estimulado y estudiado, ya que estimula las
capacidades cognitivas y psicológicas esenciales para la formación profesional. Este estudio se
entiende como original ya que hay poca investigación en el ámbito del emprendimiento
académico, que trata esta brecha en la literatura dentro del estudio. La información recopilada
en este estudio sobre los EJ, contribuye a la mejora del sistema de apoyo y relación de los
actores involucrados con el entorno en el que se insertan.Résumé
L'objectif de cette étude était d'identifier et d'analyser comment les dirigeants de Junior-
Entreprise (EJ), d'une université fédérale brésilienne, reconnaissent les opportunités et
comment ils les exploitent. La recherche est exploratoire et teste les hypothèses théoriques de
l'alerte entrepreneuriale et des approches de Causation et Effectuation, avec 30 étudiants
gestionnaires à l'Université fédérale de Rio de Janeiro (UFRRJ). Il conclut que la formation
favorisée par les expériences éducatives dans les petites entreprises stimule les attitudes et les
comportements entrepreneuriaux, car elle développe chez les jeunes la perception d'euxmêmes
et du monde, et contribue également à la formation d'êtres holistiques et contextuels
capables de gérer des processus analytiques et rationnel. L'article soutient que l'entrepreneuriat
dans les espaces académiques fournit un effet potentiel qui doit être stimulé et étudié, car il
stimule les capacités cognitives et psychologiques essentielles à la formation professionnelle.
Cette étude est considérée comme originale car il y a peu de recherches dans le cadre de
l'entrepreneuriat universitaire, traitant de cette lacune dans la littérature au sein de l'étude. Les
informations collectées dans cette étude sur les JE contribuent à l'amélioration du système d'accompagnement et de relation des acteurs impliqués dans l'environnement dans lequel ils
s'insèrent.info:eu-repo/semantics/publishedVersio
Interesting magnetic properties of FeCoSi alloys
Solid solution between nonmagnetic narrow gap semiconductor FeSi and
diamagnetic semi-metal CoSi gives rise to interesting metallic alloys with
long-range helical magnetic ordering, for a wide range of intermediate
concentration. We report various interesting magnetic properties of these
alloys, including low temperature re-entrant spin-glass like behaviour and a
novel inverted magnetic hysteresis loop. Role of Dzyaloshinski-Moriya
interaction in the magnetic response of these non-centrosymmetric alloys is
discussed.Comment: 11 pages and 3 figure
Directly converted astrocytes retain the ageing features of the donor fibroblasts and elucidate the astrocytic contribution to human CNS health and disease
Astrocytes are highly specialised cells, responsible for CNS homeostasis and neuronal activity. Lack of human in vitro systems able to recapitulate the functional changes affecting astrocytes during ageing represents a major limitation to studying mechanisms and potential therapies aiming to preserve neuronal health. Here, we show that induced astrocytes from fibroblasts donors in their childhood or adulthood display age‐related transcriptional differences and functionally diverge in a spectrum of age‐associated features, such as altered nuclear compartmentalisation, nucleocytoplasmic shuttling properties, oxidative stress response and DNA damage response. Remarkably, we also show an age‐related differential response of induced neural progenitor cells derived astrocytes (iNPC‐As) in their ability to support neurons in co‐culture upon pro‐inflammatory stimuli. These results show that iNPC‐As are a renewable, readily available resource of human glia that retain the age‐related features of the donor fibroblasts, making them a unique and valuable model to interrogate human astrocyte function over time in human CNS health and disease
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