145,839 research outputs found
Electric foot-shock stress drives TNF-alpha production in the liver of IL-6-deficient mice
No full textObjectives: Accumulating evidence has shown that interleukin-6 (IL-6) has pleiotropic effects on a variety of biological functions, including its antiapoptotic potential during liver injury. Our previous work demonstrated that restraint stress-induced elevation of plasma IL-6 negatively regulates plasma tumor necrosis factor-alpha (TNF-alpha). Herein, we further clarified the mechanism underlying the above finding and investigated the effect of IL-6 on liver apoptosis triggered by stress. Methods: Male C57BL/6J and IL-6-deficient C57BL/SV129 mice were exposed to 1 h of electric foot-shock stress. Thereafter, the serum, liver and spleen TNF-alpha levels were measured at several time points. Serum alanine aminotransferase (ALT), liver caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling ( TUNEL) activities were analyzed to evaluate the severity of liver injury and apoptosis. Results: The liver, but not the spleen, of the IL-6-deficient mice exhibited a significant increase in TNF-alpha level after stress in parallel with serum TNF-alpha elevation, whereas no such TNF-alpha responses were found in the wild animals. No significant differences in stress-induced elevation of serum ALT levels, liver caspase-3 activities and the number of TUNEL-positive hepatocytes were found between the wild and IL-6-deficient mice. Conclusions: Taken together, these results indicate that IL-6 may play a critical role in suppressing TNF-alpha production in the liver, thereby decreasing the blood TNF-alpha level. In contrast, IL-6 secretion was shown to have no protective effect on stress-triggered liver injury. Copyright (C) 2004 S. Karger AG, Basel
Green–Kubo formula for Boltzmann and Fermi–Dirac statistics
No full textShear viscosity of nuclear matter is extracted via the Green–Kubo formula and the Gaussian thermostated SLLOD algorithm (the shear rate method) in a periodic box by using an improved quantum molecular dynamic (ImQMD) model without mean field, also it is calculated by a Boltzmann-type equation. Here a new form of the Green–Kubo formula is put forward in the present work. For classical limit at nuclear matter densities of and , shear viscosity by the traditional and new form of the Green–Kubo formula as well as the SLLOD algorithm are coincident with each other. However, for non-classical limit, shear viscosity by the traditional form of the Green–Kubo formula is higher than those obtained by the new form of the Green–Kubo formula as well as the SLLOD algorithm especially in low temperature region. In addition, shear viscosity from the Boltzmann-type equation is found to be less than that by the Green–Kubo method or the SLLOD algorithm for both classical and non-classical limits
Fabricación y comercialización kubo didáctico “Wayru”
No full textNuestro producto por comercializar es Kubo Didáctico Wayru, el cual está formado
por cubos de madera articulados entre sí, a través de su manipulación se propone hacer
llegar información histórica peruana de manera divertida a los niños. Se presenta como
una idea innovadora en el mercado de educación mediante el juego, ya que su contenido
se refiere a las leyendas de la fundación del Imperio Incaico y Culturas Preincaicas, su uso
además fortalece el desarrollo de habilidades motoras finas.Trabajo de Investigació
Green-Kubo representation of the viscosity of granular gases
No full textThe Green-Kubo representation of the shear viscosity of a dilute gas of inelastic hard disks derived from the Boltzmann equation is evaluated by means of the direct simulation Monte Carlo method. The relationship between the oneparticle dynamics of the original expression and the N-particle dynamics needed for the simulation is analyzed. The presence of velocity correlations in the latter is identified and their possible implications are discussed.Ministerio de Ciencia y Tecnología (MCYT). España BFM2002- 0030
Características do conhecimento produzido em psicologia nos planos de ensino de cursos de graduação em administração de empresas
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Psicologia, Florianópolis, 2009.A formação em Administração de Empresas está mais orientada ao mercado de trabalho, com preocupação em preencher vagas oferecidas. A ênfase em uma formação tecnicista derivada desse tipo de orientação não prepara o aluno a desenvolver as possibilidades ainda não exploradas e que podem constituir parte do campo de atuação profissional do administrador. O fato dos administradores de empresas apresentarem pouca produção científica publicada dificulta a constituição de uma área de conhecimento, problema que tem raízes históricas, tanto da desvinculação do curso de Administração de Empresas da construção científica como da "modernização reflexa" que ocorreu e ainda se faz presente nas universidades. Produção científica e atividades profissionais poderiam ser fontes de informações uma da outra, complementares na produção de conhecimento e aumento da eficiência e da eficácia dos processos de gerir comportamento nos administradores. Os professores que planejam o ensino dos cursos de Administração de Empresas, assim como outras formações de ensino superior, necessitam de subsídios de áreas básicas do conhecimento para que possam propor objetivos de ensino que possibilitem capacitar seus alunos para agir na sociedade onde estarão inseridos de forma eficiente e eficaz. Identificar qual o fenômeno psicológico, seus componentes e como interfere nos processos de ensinar nos professores e de aprender nos alunos deveria ser parte integrante na formação dos professores, sejam os que estão em 'sala de aula' como os na função de coordenadores de curso, para que os administradores de empresas aprendam como as pessoas se comportam, os determinantes de seus próprios comportamentos e como transformar esse conhecimento em comportamentos próprios da profissão de administrador. O curso de graduação de Administração de Empresas apresenta muitos dos equívocos da formação de outros tipos de profissionais, diferentes formas de conhecer estão presentes onde o conhecimento científico deveria ser prioritário em outros casos o conhecimento é científico mas não há garantias de que seja utilizado pois não fazem parte de objetivos de ensino e com isso a avaliação de seu aprendizado é incerta. Esses equívocos na formação podem resultar em prejuízos para as organizações que prestam serviços à sociedade onde se insere cada um dos futuros administradores, sejam elas organizações de saúde, de produção, de ensino, privadas ou públicas. Verificar, por meio de análise do discurso, expressões que indicavam aspectos do conhecimento psicológico nos planos de ensino das 'disciplinas' de dois cursos de graduação públicos e dois cursos de graduação privados em Administração de Empresas de um estado da região sul do Brasil possibilitou encontrar grande quantidade de expressões que indicavam conhecimento psicológico não só em 'disciplinas' que apresentassem essas expressões em seus nomes, mas em aproximadamente 60% dos planos de ensino das disciplinas dos quatro cursos examinados. Tal fato indica que os conhecimentos produzidos em Psicologia constituem contribuições para a formação de administradores de empresas e, para que essas contribuições possam se constituir em comportamentos profissionais do administrador de empresas, os professores de cursos de graduação em Administração de Empresas precisariam não só identificar o fenômeno psicológico como ensiná-lo aos alunos dessa graduação
Efficient linear scaling approach for computing the Kubo Hall conductivity
No full textUnder the terms of the Creative Commons Attribution License 3.0 (CC-BY).We report an order-N approach to compute the Kubo Hall conductivity for disorderd two-dimensional systems reaching tens of millions of orbitals, and realistic values of the applied external magnetic fields (as low as a few Tesla). A time-evolution scheme is employed to evaluate the Hall conductivity σxy using a wave-packet propagation method and a continued fraction expansion for the computation of diagonal and off-diagonal matrix elements of the Green functions. The validity of the method is demonstrated by comparison of results with brute-force diagonalization of the Kubo formula, using (disordered) graphene as the system of study. This approach to mesoscopic system sizes is opening an unprecedented perspective for so-called reverse engineering in which the available experimental transport data are used to get a deeper understanding of the microscopic structure of the samples. Besides, this will not only allow addressing subtle issues in terms of resistance standardization of large-scale materials (such as wafer scale polycrystalline graphene), but will also enable the discovery of new quantum transport phenomena in complex two-dimensional materials, out of reach with classical methods.F.O. would like to acknowledge the Deutsche Forschungsgemeinschaft for financial support within the Emmy Noether scheme (Grant No. OR 349/1-1). ICN2 acknowledges support from the Severo Ochoa Program (MINECO, Grant No. SEV-2013-0295).Peer Reviewe
The Green-Kubo formula for locally interacting fermionic open systems
No full textInternational audienceWe consider a model describing finitely many free Fermi gas reservoirs coupled by local interactions and prove the Green-Kubo formulas and the Onsager reciprocity relations for heat and charge fluxes generated by temperature and chemical potential differentials
The role of nailfold videocapillaroscopy in patients with systemic sclerosis.
No full textSystemic sclerosis (SSc) is a complex disease which consists of autoimmunity, fibrosis and vasculopathy. Most organ involvement in SSc patients is related to progressive fibrosis. Once fibrosis progresses, it becomes impossible to maintain a normal structure histologically. Therefore, treatment in cases with advanced fibrosis is quite difficult. On the other hand, the role of vasculopathy is clear in the pathogenesis of SSc. Lethal organ disorders of SSc, such as pulmonary arterial hypertension and scleroderma renal crisis, include severe signs of advanced vasculopathy. Nailfold videocapillaroscopy (NVC) is a safe and crucial method for evaluating microvasculopathy. The morphological changes and their progressions can be detected and scored by NVC. Indeed, the microvascular damage and dysfunction represent early markers of systemic sclerosis. Systemic sclerosis has clinical heterogeneity and the use of NVC has been validated to help with early diagnosis and even treatment. Finally, NVC may be useful in evaluating the pathogenesis of systemic sclerosis and its progression in connection with other early biomarkers and functional tools
An Optical Illusion Pinpoints an Essential Circuit Node for Global Motion Processing
No full textDirection-selective (DS) neurons compute the direction of motion in a visual scene. Brain-wide imaging in larval zebrafish has revealed hundreds of DS neurons scattered throughout the brain. However, the exact population that causally drives motion-dependent behaviors—e.g., compensatory eye and body movements—remains largely unknown. To identify the behaviorally relevant population of DS neurons, here we employ the motion aftereffect (MAE), which causes the well-known “waterfall illusion.” Together with region-specific optogenetic manipulations and cellular-resolution functional imaging, we found that MAE-responsive neurons represent merely a fraction of the entire population of DS cells in larval zebrafish. They are spatially clustered in a nucleus in the ventral lateral pretectal area and are necessary and sufficient to steer the entire cycle of optokinetic eye movements. Thus, our illusion-based behavioral paradigm, combined with optical imaging and optogenetics, identified key circuit elements of global motion processing in the vertebrate brain
Simulation study of the Green-Kubo relations for dilute granular gases
No full textThe Green-Kubo relations for dilute granular gases are employed to compute their transport coefficients by means of the direct simulation Monte Carlo method. This requires not only to follow the dynamics of the system, but also to identify some modified fluxes appearing in the time-correlation functions. The results are compared with those obtained from the Boltzmann equation by means of the Chapman-Enskog procedure in the first Sonine approximation. A good agreement is found for the shear viscosity over a wide range of inelasticities. Nevertheless, for the two transport coefficients associated with the heat flux, significant discrepancies appear for strong inelasticity. Their origin is discussed, showing that they are partially due to the presence of velocity correlations in the homogeneous cooling state of a dilute granular fluid.España Ministerio de Ciencia y Tecnología Grant No. BFM2002- 0030
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