425 research outputs found
Pseudo-differential Operators with Semi-Quasielliptic Symbols Over p-adic Fields
In this article, we study pseudo-differential equations involving
semi-quasielliptic symbols over p-adics. We determine the function spaces where
such equations have solutions. We introduce the space of infinitely
pseudo-differentiable functions with respect to a semi-quasielliptic operator.
By using these spaces we show the existence of a regularization effect for
certain parabolic equations over p-adics.Comment: Accepted in Journal of Mathemaatical Analysis and its Application
Regulation of Interferon Stimulated Genes in West Nile Virus Infected Mouse Embryofibroblasts
The induction of type I interferon (IFN) and subsequent activation of interferon stimulated genes (ISGs) represent a first line of defense against viral infection. Typically type I IFN signaling leads to the phosphorylation of the STAT1 and STAT2 transcription factors (TFs) which then form a trimetric complex with IRF-9 and translocate to the nucleus to induce ISG expression. However, the results of this study showed that IFN-mediated upregulation of the ISG Oas1b, the product of which confers resistance to flavivirus induced disease, can be induced in a STAT1-independent manner. Since numerous ISGs have antiviral functions, many viruses have evolved strategies to disrupt the type I IFN-signaling pathway. In cases when STAT1 activation is blocked by a viral infection, STAT1-independent upregulation of ISGs provides an additional strategy for the cell to mount an effective antiviral response. Infection of mouse embryofibroblasts (MEFs) with West Nile virus (WNV) induced the production of IFN beta and STAT1 and STAT2 phosphorylation but blocked nuclear translocation and binding of these TFs to the promoters of the ISGs, Oas1a, Oas1a, Irf7 and Irf1. However, each of these antiviral ISGs was efficiently upregulated in infected cells and IRF-9 was shown to be crucial for the upregulation of Oas1a, Oas1b and Irf-7. IRF-3 or IRF-7 was needed to maintain the upregulation of these genes at later times of infection. In contrast, the upregulation of Irf1 by WNV infection did not depend on the tested IRFs but was reduced by inhibition of the p38 or NF-kappa B pathways. Although Irf1 mRNA was efficiently upregulated in WNV-infected cells IRF-1 protein synthesis was blocked. The precise mechanism of the IRF-1 translational suppression is not yet known, but the suppression was shown not to be due to increased proteasomal degradation of IRF-1 nor to alternative splicing of Irf1 mRNA. Preliminary results suggest miRNAs may play an indirect role in regulating IRF-1 translation.
The results of this study expand knowledge about the strategies evolved by viruses to evade host cell antiviral responses and also provide valuable insights about alternative mechanisms utilized by the host cell to counteract viral infections
Obscured clusters.IV. The most massive stars in [DBS2003]179
Aims. We report new results for the massive evolved and main sequence members
of the young galactic cluster DBS2003 179. We determine the physical parameters
and investigate the high-mass stellar content of the cluster, as well as of its
close vicinity. Methods. Our analysis is based on ISAAC/VLT moderate-resolution
(R\approx4000) infrared spectroscopy of the brightest cluster members. We
derive stellar parameters for sixteen of the stellar members, using full
non-LTE modeling of the obtained spectra. Results. The cluster contains three
late WN or WR/LBV stars (Obj 4, Obj 15, and Obj 20:MDM32) and at least 5 OIf
and 5 OV stars. According to the Hertzsprung-Russell diagram for DBS2003 179,
the WR stars show masses above 85Msun, the OIf stars are between 40 and 80Msun,
and the main sequence O stars are >20Msun. There are indications of binarity
for Obj 4 and Obj 11, and Obj 3 shows a variable spectrum. The cluster is
surrounded by a continuous protostar formation region most probably triggered
by DBS2003 179. Conclusions. We confirm that DBS2003 179 is young massive
cluster (2.5 10^4Msun) very close to the Galactic center at the distance of
7.9+-0.8 kpc.Comment: 14 pages, 16 figures, accepted in A&
Modelos mentales : ejecutivos sector privado-publico en las ciudades de Talca-Chile y Lujan-Argentina
134 p.La presente investigación tiene por objetivo analizar y comparar desde una perspectiva descriptiva los Modelos Mentales de los ejecutivos pertenecientes a la ciudad de Lujan-Argentina y de Talca-Chile, ya sean tanto del sector privado como publico. Entendiendose como Modelos Mentales según Peter Senge, en su libro La Quinta Disciplina, a los supuestos hondamente arraigados, generalizaciones e imágenes que influyen sobre nuestro modo de comprender el mundo y actuar. Para tal motivo, fragmentaremos nuestro trabajo en las fases de: Fundamentación Teórica: Donde obtuvimos la información adecuada, a través de la revisión de bibliografía pertinente, apoyándonos en la Memoria de Grado titulada "Modelos Mentales Ejecutivos sector publico y privado de la ciudad de Talca", efectuada por los alumnos Gabriela Fuentes Moreno y Ariel Schleef Sommer de la Universidad de Talca, tomando como base dicha investigación para analizar comparativamente las diferencias sustanciales entre los Modelos Mentales de los ejecutivos de la ciudad de Lujan y Talca, según sean del sector publico y privado, donde llegamos a establecer similitudes y diferencias entre los ejecutivos Argentinos de la ciudad de Lujan y Chilenos de la ciudad de Talca.
Fundamentación Empírica: Desarrollada con la realización de Prueba Piloto con el fin de adecuar los instrumentos a aplicar a la cultura Argentina. Estudio Descriptivo: Desarrollado con la aplicación de cinco instrumentos de medición de las variables mas relevantes (Aprendizaje, Autoridad, Delegación, Liderazgo y Liderazgo para sus Subordinados), donde establecimos en primera instancia similitudes y diferencias entre los ejecutivos de Lujan; y finalmente realizamos un análisis comparativo de los resultados de nuestro estudio con los de la Memoria anteriormente mencionada
Improving Outcomes for Hispanic Patients Undergoing Peginterferon/Ribavirin Therapy for Chronic Hepatitis C in an Internist-led, Multidisciplinary, Multi-cultural Practice: A Unique Application of the Medical
Derivation and validation of a multivariate model to predict mortality from pulmonary embolism with cancer: The POMPE-C tool
BackgroundClinical guidelines recommend risk stratification of patients with acute pulmonary embolism (PE). Active cancer increases risk of PE and worsens prognosis, but also causes incidental PE that may be discovered during cancer staging. No quantitative decision instrument has been derived specifically for patients with active cancer and PE. Methods Classification and regression technique was used to reduce 25 variables prospectively collected from 408 patients with AC and PE. Selected variables were transformed into a logistic regression model, termed POMPE-C, and compared with the pulmonary embolism severity index (PESI) score to predict the outcome variable of death within 30 days. Validation was performed in an independent sample of 182 patients with active cancer and PE. Results POMPE-C included eight predictors: body mass, heart rate > 100, respiratory rate, SaO2%, respiratory distress, altered mental status, do not resuscitate status, and unilateral limb swelling. In the derivation set, the area under the ROC curve for POMPE-C was 0.84 (95% CI: 0.82-0.87), significantly greater than PESI (0.68, 0.60-0.76). In the validation sample, POMPE-C had an AUC of 0.86 (0.78-0.93). No patient with POMPE-C estimate ≤ 5% died within 30 days (0/50, 0-7%), whereas 10/13 (77%, 46-95%) with POMPE-C estimate > 50% died within 30 days. Conclusion In patients with active cancer and PE, POMPE-C demonstrated good prognostic accuracy for 30 day mortality and better performance than PESI. If validated in a large sample, POMPE-C may provide a quantitative basis to decide treatment options for PE discovered during cancer staging and with advanced cancer
Modelo do erro de taxa de aplicação em função do ângulo de esterçamento de um pulverizador tratorizado.
Coleta de germoplasma de leguminosas no Semi-Árido do Estado da Bahia.
A tradição das famílias rurais do semi-árido nordestino de produzir e guardar sua própria semente em casa tem se consolidado ao longo das décadas, através das práticas de conservação da diversidade agrícola, pela adaptação e seleção de materiais, troca e experimentação do germoplasma, com a comercialização do excedente de produção na comunidade ou em feiras livre. Com o objetivo de coletar essas variedades, ampliando a amostragem dos Bancos de Germoplasma de Feijão, Caupi e Fava, localizados na Embrapa, e identificando preferências das famílias dessa região realizou-se a expedição a Bahia, com apoio da EBDA. Foram coletadas amostras de 91 acessos de germoplasma de feijão, feijão de corda e fava, mantidos por agricultores locais, principalmente para consumo familiar e eventuais trocas com outros agricultores. Observou-se uma grande perda de variabilidade nos últimos anos, decorrente, principalmente, de alterações no regime de chuvas. Ficou evidente, também, a preferência desses consumidores por suas variedades tradicionais, seja por suas características de sabor, seja pelas qualidades agronômicas, e a necessidade de buscar meios para garantir a conservação, em melhores condições técnicas, dos materiais com características de interesse
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