Structural optimization of rotor blades with straight and swept tips subject to aeroelastic constraints

The main conclusions obtained in the present study are summarized. Their application to the structural optimization of a helicopter blade should be limited by the assumptions used in obtaining the numerical results presented here. The optimum design procedure described here is very efficient, and can produce improved designs with a very limited number of precise analyses. The method of constructing the approximate problem is such that previously conducted aeroelastic analyses can be reused in a new optimization problem. For example, if an optimization study is preceded by a parametric study in which the effect of various combinations of blade design parameters is examined, all the aeroelastic analyses performed for the parametric study can be reutilized in the optimization study. This is not possible when the approximate problem is built from Taylor series expansions. The results of the optimization are quite sensitive to the aeroelastic stability margins required of the blade. In the optimization of case 2, changing the aeroelastic stability constraints from simply requiring that the blade be stable in hover, to requiring that the stability margins be maintained during the course of the optimization, reduced the gains in n/rev vibration levels by more than 50 percent. The introduction of tip sweep can reduce the n/rev vertical hub shears beyond the level that can be obtained by just modifying the mass and stiffness distributions of the blade

A High-Order, Linear Time-Invariant Model for Application to Higher Harmonic Control and Flight Control System Interaction

This research describes a new methodology for the extraction of a high-order, linear time invariant model, which allows the periodicity of the helicopter response to be accurately captured. This model provides the needed level of dynamic fidelity to permit an analysis and optimization of the AFCS and HHC algorithms. The key results of this study indicate that the closed-loop HHC system has little influence on the AFCS or on the vehicle handling qualities, which indicates that the AFCS does not need modification to work with the HHC system. However, the results show that the vibration response to maneuvers must be considered during the HHC design process, and this leads to much higher required HHC loop crossover frequencies. This research also demonstrates that the transient vibration responses during maneuvers can be reduced by optimizing the closed-loop higher harmonic control algorithm using conventional control system analyses

Aliskiren, a renin inhibitor, downregulates TNF-α-induced tissue factor expression in HUVECS

Angiotensin (Ang)II, the effector arm of the locally active renin—angiotensin system (RAS), modulates Tissue Factor (TF), the principal initiator of blood coagulation and a key promoter of atherothrombotic events. Consistent with that knowledge, previous data showed inhibitory properties of angiotensin-converting enzyme inhibitor (ACEI)s and angiotensin II type-1 receptor blocker (ARB)s, but no data are available about the effect of renin inhibition. We aimed to evaluate whether aliskiren, a direct renin inhibitor (DRI), modulates TNF-α-stimulated TF expression in cultured human umbilical vein endothelial cells (HUVECs). Zofenopril, an ACEI, and olmesartan, an ARB, were the controls. HUVECs were incubated with experimental drugs (1 nM) 30 min prior to TNF-α stimulation (0.1 ng/ml × 4 h). Main evaluation variables were procoagulant activity (single-stage clotting assay), TF antigen (ELISA) and mRNA expression (real-time polymerase chain reaction) in cell lysates. TNF-α stimulated procoagulant activity and increased TF antigen and mRNA expression. Aliskiren inhibited TNF-α-mediated TF stimulation; zofenopril and olmesartan exerted a comparable effect. We conclude that aliskiren, a DRI, downregulates TNF-α-stimulated TF expression in HUVECs, possibly as a reflection of endothelial renin activation by the cytokine

O ler e o escrever na construção do conhecimento matemático no ensino médio

Esta pesquisa teve como objetivo investigar a utilização de diferentes estratégias de leitura e escrita no ensino de Matemática do ensino médio, e de instrumentos nos quais os alunos externaram as suas percepções durante o processo de ensino e aprendizagem. Para tanto, realizou-se uma pesquisa qualitativa com análise interpretativa sobre as atividades e os instrumentos propostos, os quais foram organizados em um portfólio. A formulação e a aplicação da pesquisa, bem como a análise dos resultados e as conclusões foram baseadas no enfoque histórico-cultural de Vigotski e estudos sobre a linguagem matemática e a utilização da leitura e escrita nas aulas de Matemática, de diversos pesquisadores. As categorias emergentes da análise dos dados foram: a construção do conhecimento matemático, a semântica dos termos matemáticos, os valores demonstrados pelos alunos e a potencialidade das atividades. Os resultados, considerando-se todas as categorias, indicam que o processo pode tornar a relação professor-aluno e aluno-aluno mais interativa e mais efetiva para a construção do conhecimento matemático

Un estudio sobre el capital financiero en América Latina: el caso ecuatoriano

Anais do IV Encontro de Iniciação Científica da Unila - “UNILA 5 anos: Integração em Ciência, Tecnologia e Cultura na Tríplice Fronteira” - 05 e 06 de novembro de 2015 – Sessão EconomiaEl presente trabajo pretende abordar el capital financiero en América latina, específicamente el caso ecuatoriano, en dos momentos. Primero, mediante un recorrido teórico del capital financiero como elemento central en las dinámicas de reproducción capitalista se aborda la transición del modo de producción feudal al capitalista y el papel de la acumulación primitiva, el surgimiento del crédito en la reproducción capitalista, el papel del dinero en el crédito, el nuevo papel de los bancos, el capital financiero como tal y la economía mundial y el Estado nacional. En un segundo momento, se realiza un abordaje de la coyuntura política latinoamericana de la última década, para contextualizar el incremento de la acumulación de capital en el área de salud ecuatoriana. El objetivo es presentar, a breves rasgos, la complejidad que conlleva hablar de capital financiero; y, por otro lado, mostrar, mediante el caso ecuatoriano, que los llamados gobiernos progresistas latinoamericanos no escapan de las formas de acumulación capitalista, ni del crecimiento del capital financiero. Porque, en efecto, el capital financiero es la centralización y concentración del capital en pocas y poderosas empresas que se valen de los Estados para reproducir sus dinámicas. El caso ecuatoriano muestra que, inclusive con renovadas fórmulas políticas de gobierno, el capital encuentra modos de reconfigurar sus formas de centralización y concentración de la riqueza. Así siendo, queda pendiente cuestionar las formas de acumulación del Estado y la lógica de acumulación capitalista; al tiempo de ser creativos y proponer alternativas.Bolsista PIBIC UNIL

The effect of angiotensin receptor blockers on C-reactive protein and other circulating inflammatory indices in man

Anti-inflammatory properties may contribute to the pharmacological effects of angiotensin II receptor blockers (ARBs), a leading therapeutic class in the management of hypertension and related cardiovascular and renal diseases. That possibility, supported by consistent evidence from in-vitro and animal studies showing pro-inflammatory properties of angiotensin II, has been evaluated clinically by measuring the effect of ARBs on C-reactive protein and other circulating indices of inflammation (e-selectin, adhesion molecules, interleukin-6, tissue necrosis factor-alpha, monocyte chemoattractant protein-1) of potential clinical relevance, a body of evidence that this paper aims to review

Conhecimentos de professores de matemática ao ensinarem estatística

Este artigo decorre de uma dissertação de mestrado na qual se analisou a aprendizagem docente de professores participantes de um curso de extensão sobre educação estatística, a partir de suas narrativas orais e escritas. Discutem-se aqui alguns extratos de narrativas desses professores que atuam nos anos finais do ensino fundamental e no ensino médio, nas redes de ensino municipais e estaduais paulistas. Objetiva-se responder à questão: quais indícios de conhecimento pedagógico do conteúdo de professores de Matemática emergem em relação ao ensino de estatística após a participação em um curso de extensão? Trata-se de um estudo (auto)biográfico que toma as narrativas de si como práticas de formação. Os resultados mostraram que os professores se apropriaram de conhecimentos advindos do curso de extensão, ampliaram seus conhecimentos profissionais, elaborando atividades e projetos adequados ao contexto educacional em que atuavam

Prevalencia de Burkholderia glumae en cultivos de arroz en Ecuador

Burkholderia glumae is the agent responsible for bacterial panicle blight disease (BPBD) of rice that causes severe damage to this crop worldwide. During 2012 and 2013, symptoms of BPBD were observed in Palestina city, located in Guayas province, Ecuador. In 2014, the presence of B. glumae was confirmed at this location. In view of the socio-economic importance of rice in Ecuador, this research aimed to investigate the prevalence of B. glumae in other rice-producing regions. Eighteen bacterial isolates obtained from blighted kernels were characterized. Physiological, biochemical, serological, and molecular assays and the amplification of the 16S-23S rRNA ITS of the bacterial isolates collected confirmed the identity of the BPBD-associated bacterium. Pathogenicity assays verified the ability of these isolates to produce discoloration, spotting, and empty grains, symptoms associated with BPBD. Antibiotic assays showed that EC-EELS-01 isolate was sensitive to ciprofloxacin and tetracycline, and resistant to polymyxin. The dissemination and prevalence of B. glumae were confirmed in the rice-producing areas of El Oro, Cañar, Guayas, and Los Rios provinces. This research will serve to develop genetic studies to characterize the population in the B. glumae isolates in Ecuador.Burkholderia glumae es el agente causal de la enfermedad del añublo bacterial de la panícula (bacterial panicle blight disease, BPBD) que causa daños severos al cultivo de arroz mundialmente. Del 2012 al 2013, los síntomas del BPBD se observaron en el cantón de Palestina, de la provincia del Guayas, Ecuador. En el 2014, se confirmó la presencia de B. glumae en este cantón. En vista de la importancia socio económica del cultivo del arroz en Ecuador, el objetivo de esta investigación fue investigar la prevalencia de B. glumae en otras localidades productoras de arroz. Se caracterizaron dieciocho aislados de bacterias obtenidas de granos afectados. Ensayos fisiológicos, bioquímicos, serológicos y moleculares que incluyeron la amplificación de la región ITS 16S-23S del ARNr de los aislados confirmaron la identidad de B. glumae. Ensayos de patogenicidad realizados en panículas de la variedad de arroz INIAP 15 verificaron la habilidad de cuatro aislados (i.e., EC-EELS-01, -02, -03 y -07) para causar descoloración, manchado y granos vanos que corresponden a síntomas asociados a BPBD. Los ensayos con antibióticos mostraron que el aislado EC-EELS-01 era sensible a la ciprofloxacina y a la tetraciclina y resistente a la polimixina. La diseminación y prevalencia de B. glumae se corroboraron en las áreas productoras de arroz en las provincias de El Oro, Cañar, Guayas y Los Ríos. Esta investigación proveerá una base para desarrollar un estudio genético y caracterizar la estructura poblacional de B. glumae en Ecuador

miR-19a and miR-20a and tissue factor expression in activated human peripheral blood mononuclear cells

Background and Aims. To investigate the behaviour of miR-19a and miR-20a, two microRNAs involved in posttranscriptional modulation of TF expression in peripheral blood mononuclear cells (PBMCs) exposed to high glucose (HG) and lipopolysaccharide (LPS), and to evaluate the involvement of angiotensin II in that process. Methods. TF Procoagulant Activity (PCA, one-stage clotting assay), antigen (Ag, ELISA), and miR-19a and miR-20a levels (specific TaqMan® MicroRNA Assays) were evaluated in PBMCs exposed to high glucose (HG, 50 mM), LPS (100 ng/mL), and Olmesartan (OLM, 10−6 M), an angiotensin II type 1 receptor antagonist. Results. HG increased TF expression and decreased both miRs as compared to control glucose conditions (11.1 mM). In HG-activated PBMCs, LPS stimulated TF expression and downregulated miR-20a, an effect reverted by OLM (10−6 M); miR-19a expression was unchanged by LPS in both CG and HG conditions. Conclusions. miR-19a and miR-20a are inhibited by inflammatory stimuli active on TF expression and their response differs by the stimulus under investigation; angiotensin II may participate in that mechanism