199,383 research outputs found
Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke
No full textGenetic factors have been implicated in stroke risk, but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) for ischemic stroke and its subtypes in 3,548 affected individuals and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 affected individuals and 6,281 controls. We replicated previous associations for cardioembolic stroke near PITX2 and ZFHX3 and for large vessel stroke at a 9p21 locus. We identified a new association for large vessel stroke within HDAC9 (encoding histone deacetylase 9) on chromosome 7p21.1 (including further replication in an additional 735 affected individuals and 28,583 controls) (rs11984041; combined P = 1.87 × 10<sup>−11</sup>; odds ratio (OR) = 1.42, 95% confidence interval (CI) = 1.28–1.57). All four loci exhibited evidence for heterogeneity of effect across the stroke subtypes, with some and possibly all affecting risk for only one subtype. This suggests distinct genetic architectures for different stroke subtypes
Métodos de Krylov-Newton aplicados à simulação numérica de reservatórios de petróleo
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico.A simulação do processo de extração de óleo em um reservatório de petróleo é um problema complexo que envolve o escoamento multifásico em um meio poroso de geometria arbitrária, podendo conter falhas geológicas e outras irregularidades. A modelagem numérica implícita deste problema requer a solução de um complexo sistema de equações não-lineares que pode ser resolvido de diversas formas, mais ou menos eficientes. A forma mais comum de solução deste sistema emprega o método de linearização de Newton ou alguma de suas variantes. O foco deste trabalho está na análise de uma extensa classe de métodos de Newton conhecidos como métodos de Newton inexatos. Estes métodos empregam um segundo método iterativo na solução da equação linearizada resolvendo-a até uma certa tolerância; daí serem chamados de inexatos. Os métodos inexatos abordados neste trabalho concentram-se na escolha de processos iterativos baseados em métodos de projeção no espaço de Krylov, tais como: GMRES, BICGSTAB, TFQMR. Estes métodos, que formam uma subclasse dos métodos de Newton inexatos, são conhecidos como métodos de Krylov-Newton. São abordados também métodos quase-newtonianos baseados na aproximação da matriz Jacobiana considerando apenas os termos ortogonais da discretização em sistemas curvilíneos não-ortogonais. Vários problemas com diferentes graus de não-ortogonalidade da malha e não-linearidades são resolvidos e comparados usando os diferentes métodos implementados
Pseudo-loadflow formulation as a starting process for the Newton Raphson
No full textThis paper introduces new models which approximate the AC loadflow problem, but are able to converge (using the Newton Raphson algorithm) from a wider range of starting points. The solution of the pseudo-loadflow models can provide a robust starting process for the Newton Raphson solution of the conventional loadflow problem. It is also shown that pseudo-loadflow solutions exist in many cases where the AC loadflow equations do not appear to have any solution, and in such cases the pseudo-loadflow solution can provide useful information to assist in locating the cause of infeasibility of the AC loadflow model. Test results are presented for illustrative small network examples and also for larger test networks. The computational requirements of the proposed methods are similar to those of the conventional Newton Raphson loadflow algorithm
The Shadow of the Soul Breaker: Solitary Confinement, Cocaine, and the Disintegration of Huey P. Newton
No full textThe article probes the impact of prison on Huey P. Newton, founder of the Black Panther Party. Incarcerated for three years in various locations in California, Newton descended into cocaine addiction and criminality soon after his 1970 release. The current literature fails to account for the impact of solitary confinement on Newton’s life and consequently misinterprets his descent into criminality. The article suggests that the immense pressures placed on Newton in prison and after freedom were related to the decline of the rehabilitative experiment in California’s prison system. It reveals the psychological effect of prison on Newton before linking his fragile mental state to his drug addiction. It concludes by demonstrating how FBI surveillance unwittingly took advantage of Newton’s fragility to compound his psychological stress, indicating the extent to which prison successfully prevented Newton reclaiming his position as a significant force in the African American political struggle
Perkins, Newton C. - An inaugural dissertation on the anatomy and physiology of the liver
No full textHandwritten inaugural dissertation on the anatomy and physiology of the liver by Newton C. Perkins, of Tennessee.Inaugural dissertation; no. 228
Miller, Newton C. - An inaugural dissertation on the diversity of the human species
No full textHandwritten inaugural dissertation on the diversity of the human species by Newton C. Miller, of Tennessee.Inaugural dissertation; no. 321
Métodos de Newton inexatos
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Matemática.Sistemas de equações algébricas não lineares representam modelos matemáticos elaborados de muitos problemas das ciências aplicadas e engenharias. Modelos representativos, em geral, apresentam muitas equações e variáveis e para sua resolução métodos numéricos robustos devem ser empregados. Este também é o caso de problemas de otimização, nos quais procura-se minimizar ou maximizar funções não lineares. Muitas vezes sujeitos As restrições de factibilidade que precisam ser respeitadas. Os métodos numéricos mais famosos e eficientes trabalham com a filosofia de linearização. Esta é a ideia dos métodos do tipo Newton [2], nos quais diferentes estratégias de linearização são consideradas
Filtered-Stochastic-Newton
No full textWe apply sequential Bayesian inference with a discriminatively specified observation model to the subsampled gradients and Hessians used by the stochastic Newton method for online optimization
Latest results on Jovian disk X-rays from XMM-Newton
No full textWe present the results of a spectral study of the soft X-ray emission (0.2–2.5 keV) from low-latitude (‘disk’) regions of Jupiter. The data were obtained during two observing campaigns with XMM-Newton in April and November 2003. While the level of the emission remained approximately the same between April and the first half of the November observation, the second part of the latter shows an enhancement by about 40% in the 0.2–2.5 keV flux. A very similar, and apparently correlated increase, in time and scale, was observed in the solar X-ray and EUV flux.
The months of October and November 2003 saw a period of particularly intense solar activity, which appears reflected in the behavior of the soft X-rays from Jupiter's disk. The X-ray spectra, from the XMM-Newton EPIC CCD cameras, are all well fitted by a coronal model with temperatures in the range 0.4–0.5 keV, with additional line emission from Mg XI (1.35 keV) and Si XIII (1.86 keV): these are characteristic lines of solar X-ray spectra at maximum activity and during flares.
The XMM-Newton observations lend further support to the theory that Jupiter's disk X-ray emission is controlled by the Sun, and may be produced in large part by scattering, elastic and fluorescent, of solar X-rays in the upper atmosphere of the planet
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