947 research outputs found

    Análise sobre a Viabilidade de Revitalização da Indústria de Defesa Brasileira

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    Since 2003, the Brazilian government and certain sectors of Brazilian society have been debating the revitalization of the Brazilian defense industry (BDI). This article analyses some of the arguments in these debates (the rights of nations and duties of governments as regards defense, the possibility of coercive action by the great arms exporters, evidence that the defense industry has always run a deficit, and the export needs the country would have if it decided to revitalize its defense industry) and analyzes other questions that merit scrutiny (the causes of the crisis in the BDI that occurred in the 1980s, the causes of low internal demand, the economic and technological impact of the BDI). This is done by comparing these arguments and exploring these questions based on an analysis of documents. In this way, we aim to provide reliable information from Brazil and elsewhere to contribute to this debate.O governo brasileiro e setores da sociedade brasileira vêm promovendo, desde 2003, debates sobre a revitalização da indústria de defesa brasileira (IDB). O artigo analisa alguns argumentos presentes nestes debates (direito das nações e deveres dos governos em relação à defesa, possibilidade de uma ação coercitiva dos grandes exportadores de armamento, evidência de que a indústria de defesa sempre funciona de maneira deficitária e necessidade de exportar que teria o País como imposição da decisão da revitalizar a IBD) e analisa outras questões que também merecem aprofundamento (as causas da crise da IBD ocorrida na década de 1980, as causas da baixa demanda interna, o impacto econômico e tecnológico da IBD). O método adotado foi o de confrontar aqueles argumentos e explorar aquelas questões baseando-se em análise documental. Pretende-se, assim, proporcionar informação abalizada de origem nacional e estrangeira capaz de propiciar uma maior reflexão sobre o tema pela sociedade

    Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats

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    Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes), infarct size (percentage of the arc with infarct on 3 transverse planes), systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient). Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005). The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction) to 53.1 ± 1.5% (control) and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001) and histology (r = -0.78; P < 00001). The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7) was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3). There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de Fisiologia CardiovascularUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de CardiologiaUNIFESP, EPM, Disciplina de Fisiologia CardiovascularUNIFESP, EPM, Disciplina de CardiologiaSciEL

    A review of techniques for spatial modeling in geographical, conservation and landscape genetics

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    Most evolutionary processes occur in a spatial context and several spatial analysis techniques have been employed in an exploratory context. However, the existence of autocorrelation can also perturb significance tests when data is analyzed using standard correlation and regression techniques on modeling genetic data as a function of explanatory variables. In this case, more complex models incorporating the effects of autocorrelation must be used. Here we review those models and compared their relative performances in a simple simulation, in which spatial patterns in allele frequencies were generated by a balance between random variation within populations and spatially-structured gene flow. Notwithstanding the somewhat idiosyncratic behavior of the techniques evaluated, it is clear that spatial autocorrelation affects Type I errors and that standard linear regression does not provide minimum variance estimators. Due to its flexibility, we stress that principal coordinate of neighbor matrices (PCNM) and related eigenvector mapping techniques seem to be the best approaches to spatial regression. In general, we hope that our review of commonly used spatial regression techniques in biology and ecology may aid population geneticists towards providing better explanations for population structures dealing with more complex regression problems throughout geographic space

    Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction

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    Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether -3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling. ST-elevation MI (STEMI) patients (n=421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (D5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and -3 intake in the last 3months before admission. The intake of -3 below the median (<1.7g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p=0.004], Interleukin-2 [OR:2.46(1.20-5.04); p=0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p=0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p=0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p=0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi. These findings suggest that a reduced daily intake of -3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling.18CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ308550/2010-

    Optical-phonon resonances with saddle-point excitons in twisted-bilayer graphene

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    Twisted-bilayer graphene (tBLG) exhibits van Hove singularities in the density of states that can be tuned by changing the twisting angle θ\theta. A θ\theta-defined tBLG has been produced and characterized with optical reflectivity and resonance Raman scattering. The θ\theta-engineered optical response is shown to be consistent with persistent saddle-point excitons. Separate resonances with Stokes and anti-Stokes Raman scattering components can be achieved due to the sharpness of the two-dimensional saddle-point excitons, similar to what has been previously observed for one-dimensional carbon nanotubes. The excitation power dependence for the Stokes and anti-Stokes emissions indicate that the two processes are correlated and that they share the same phonon.Comment: 5 pages, 6 figure
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