283 research outputs found

    Amplification of the Signal-to-Noise Ratio in Cosmic Ray Maps Using the Mexican Hat Wavelet Family

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    In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the amplification of the signal-to-noise ratio for several background patterns (noise) and different number of events coming from a simulated source (signal) for an ideal detector capable of observing the full sky with uniform coverage. We extend this analysis for a virtual observatory with two sites, one in the northern hemisphere, the other in the southern, considering an acceptance law.Comment: Contributions to the 32nd International Cosmic Ray Conference, Beijing, China, August 201

    Wavelets Applied to the Detection of Point Sources of UHECRs

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    In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the amplification of the signal-to-noise ratio for several anisotropy patterns (noise) and different number of events coming from a simulated source (signal) for an ideal detector capable of observing the full sky with equal probability. We extend this analysis for a virtual detector located within the array of detectors of the Pierre Auger Observatory, considering an acceptance law.Comment: 9 pages, 8 figures. Proceedings of the Young Researchers Meeting, 2010. Available in: http://www.ifi.unicamp.br/physicae/ojs-2.1.1/index.php/physicae/article/view/191; Physicae, Proceedings of the Young Researchers Meeting, Vol 1, 201

    Detection of Point Sources in Cosmic Ray Maps using the Mexican Hat Wavelet Family

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    An analysis of the sensitivity of gaussian and mexican hat wavelet family filters to the detection of point sources of ultra-high energy cosmic rays was performed. A source embedded in a background was simulated and the number of events and amplitude of this source was varied aiming to check the sensitivity of the method to detect faint sources with low statistic of events.Comment: Proceedings of the Second International Symposium on Strong Electromagnetic Fields and Neutron Stars (Havana, Cuba, 2011). 6 pages, 4 figure

    Fundamentos básicos para a cirurgia e cuidados perioperatórios

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    The development of minimally invasive surgery by use of endoscopy, interventional radiology, endoscopic surgery and robotics has led to the revision of concepts, practices and organization of surgicalservices. On the other hand, the incorporation of technological and scientific surgical procedures fromthe simplest to most complex, yet involves knowledge of the basics of surgery and perioperative care.O desenvolvimento da cirurgia minimamente invasiva, mediante emprego da via  endoscópica, daradiologia intervencionista, da cirurgia videoendoscópica e da robótica tem induzido à revisão dosconceitos, das práticas e da organização dos serviços de cirurgia. Por outro lado, a incorporação daevolução  tecnológica e científica aos procedimentos cirúrgicos, dos mais simples aos mais complexos, ainda envolve o conhecimento dos fundamentos básicos para a cirurgia e  cuidados perioperatórios

    Evaluating a Master's Degree Program via Distance Education

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    TTVN Conference, Galveston, TX, January 18, 200

    Influence of biliary anastomosis on recovery from secondary biliary cirrhosis

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    Objective The influence of choledochoduodenostomy and choledochojejunostomy on the repair of hepatic lesions secondary to biliary obstruction is not well known. The aim of the present study was to compare the effects of choledochoduodenostomy and choledochojejunostomy on the recovery of these lesions in rats with biliary obstruction. Methods Rats subjected to 4 weeks of biliary obstruction underwent choledochoduodenostomy (n=10) or choledochojejunostomy (n=10). The following variables were measured: total bilirubin, alkaline phosphatase, aminotransferases, and albumin. Hepatic mitochondrial energy metabolism was evaluated by calculating the respiratory control ratio and the oxidative phosphorylation index. Hepatic morphometry was used to estimate the mass of the hepatocytes, bile ducts, and fibrosis, as well as the hepatic stellate cell count. Results After choledochoduodenostomy and choledochojejunostomy, there was a regression in cholestasis and a reduction in the oxidative phosphorylation index. However, the total bilirubin, alkaline phosphatase, albumin, and respiratory control ratio values improved only after choledochojejunostomy. The mass of the liver, spleen, and fibrosis was reduced after both choledochoduodenostomy and choledochojejunostomy, but the number of hepatic stellate cells increased. After choledochojejunostomy, the hepatic mass recovered completely, and the spleen mass was significantly reduced compared with that after choledochoduodenostomy. After both choledochoduodenostomy and choledochojejunostomy, enterobiliary reflux, biliary contamination, and an exacerbation in hepatic inflammation developed. Conclusion Choledochojejunostomy was more effective than choledochoduodenostomy, but both techniques induced enterobiliary reflux and biliary contamination, which may explain the maintenance of hepatic alterations, especially after choledochoduodenostomy. Eur J Gastroenterol Hepatol 24: 1039-1050 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

    A influência da regulação do acesso aos serviços de saúde e da incorporação tecnológica no perfil de mortalidade da pancreatite aguda biliar

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    PURPOSE: The influence of treatment access regulation and technological resources on the mortality profile of acute biliary pancreatitis (ABP) was evaluated. METHODS: The cases seen in a tertiary hospital were studied during two periods of time: 1995-1999 and 2000-2004, i.e., before and after the implementation of medical regulation. RESULTS: Among the 727 patients with acute pancreatitis, 267 had ABP and were classified according to APACHE II scores. The cases being referred to the tertiary hospital decreased from 441 to 286 (p < 0.001). The patients' profile regarding age, gender, severity, cholestasis incidence and mortality were similar during the first and second periods of study (n = 154 and n = 113, respectively). The number of patients with hematocrit > 44% was smaller during the second study period (p<0.002). The use of magnetic resonance cholangiography, videolaparoscopic cholecystectomy, and access to the ICU were found to be more frequent during the second study period. Regarding the deaths occurring within 14 days of hospitalisation, 73.4% and 81.3% were observed during the first and second study periods, respectively. CONCLUSION: Since the improvement in clinical and technological approach was not enough to modify the mortality profile of ABP, further studies on the treatment of inflammatory responses should be carried out.OBJETIVO: Avaliou-se a influência do acesso aos recursos assistenciais e tecnológicos sobre a mortalidade na pancreatite aguda biliar (PAB). MÉTODOS: Os casos de PAB tratados num hospital universitário foram estudados em dois períodos: 1995 a 1999 e 2000 a 2004, antes e depois da implantação da Regulação Médica. RESULTADOS: Do total de 727 casos com pancreatite aguda atendidos, 267 apresentavam PAB e tiveram a gravidade avaliada pelo escore de APACHE II. Houve redução dos encaminhamentos de casos entre os períodos, de 441 para 286 (p < 0,001). O perfil dos pacientes com PAB no primeiro período (n = 154) e no segundo (n =113) foi semelhante quanto à idade, sexo, gravidade, incidência de colestase e mortalidade. A incidência de pacientes com hematócrito > 44 foi menor no segundo período (p < 0,002). O emprego de colangiografia por ressonância magnética, da colecistectomia por videolaparoscopia e do acesso à terapia intensiva foi significantemente maior no segundo período. A maioria dos óbitos ocorreu até os 14 dias de admissão, 73,4% no primeiro período e 81,3% no segundo. CONCLUSÃO:A melhora do suporte tecnológico e clínico não foi suficiente para modificar o perfil de mortalidade na PAB, o que indica a necessidade de avaliar terapêuticas para a sua resposta inflamatória.FAEP
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