2,097 research outputs found
Real and complex integral closure, Lipschitz equisingularity and applications on square matrices
Recently the authors investigated the Lipschitz triviality of simple germs of
matrices. In this work, we improve some previous results and we present an
extension of an integral closure result for the real setting. These tools are
applied to investigate classes of square matrices singularities classified by
Bruce and Tari
Weak lensing B-modes on all scales as a probe of local isotropy
This article derives a multipolar hierarchy for the propagation of the
weak-lensing shear and convergence in a general spacetime. The origin of
B-modes, in particular on large angular scales, is related to the local
isotropy of space. Known results assuming a Friedmann-Lema\^itre background are
naturally recovered. The example of a Bianchi I spacetime illustrates our
formalism and its implications for future observations are stressed.Comment: 10 pages, 2 figures. Replaced to match published versio
COMPUTATIONAL MODEL TO EVALUATE ACTIONS IN WHEELRAIL CONTACT INTERACTION
Railway traffic is a big source of vibrations. Over the years, with higher freight capacity and speeds getting higher, excessive stresses are experienced by the subgrade. Then, stress waves propagate through the ground until buildings on the surroundings. This leads to considerable negative impacts on the neighborhood. On this context, this work is immersed in a broader scope of proposing an approach to create a model to simulate railway systems, with the main objective of predicting the vibration and stresses at the subgrade, in different situations, such as to predict the contact forces between the wheels and the rails. In this model, the dynamic characteristics of the vehicles and the contact between their wheels and the track are considered. The numerical model was solved using the software Giraffe. To simulate the traffic of a vehicle, a two-car train composition was modeled. One of the cars is loaded by an imposed torsion moment, applied on the axle of the wheels. A time-varying torsional moment was considered, so the simulation could reproduce an accelerating vehicle, the same vehicle in constant speed, as well as braking. The model, as it was proposed, represented the global mechanical behavior of the cars and it was possible to obtain the contact forces between wheels and a surface that represents the rails
PALEO-PGEM v1.0: a statistical emulator of Pliocene–Pleistocene climate
We describe the development of the “Paleoclimate PLASIM-GENIE (Planet Simulator–Grid-Enabled Integrated Earth system model) emulator” PALEO-PGEM and its application to derive a downscaled high-resolution spatio-temporal description of the climate of the last 5×106 years. The 5×106-year time frame is interesting for a range of paleo-environmental questions, not least because it encompasses the evolution of humans. However, the choice of time frame was primarily pragmatic; tectonic changes can be neglected to first order, so that it is reasonable to consider climate forcing restricted to the Earth's orbital configuration, ice-sheet state, and the concentration of atmosphere CO2. The approach uses the Gaussian process emulation of the singular value decomposition of ensembles of the intermediate-complexity atmosphere–ocean GCM (general circulation model) PLASIM-GENIE. Spatial fields of bioclimatic variables of surface air temperature (warmest and coolest seasons) and precipitation (wettest and driest seasons) are emulated at 1000-year intervals, driven by time series of scalar boundary-condition forcing (CO2, orbit, and ice volume) and assuming the climate is in quasi-equilibrium. Paleoclimate anomalies at climate model resolution are interpolated onto the observed modern climatology to produce a high-resolution spatio-temporal paleoclimate reconstruction of the Pliocene–Pleistocene
Hypercholesterolemia promotes early renal dysfunction in apolipoprotein E-deficient mice
<p>Abstract</p> <p>Background</p> <p>Aging and dyslipidemia are processes which can lead to deleterious consequences to renal function. Therefore, the aim of this study was to determine the effects of both hypercholesterolemia and aging on renal function in mice.</p> <p>Methods</p> <p>Male hypercholesterolemic apolipoprotein E-deficient mice (ApoE, n = 13) and age-matched C57BL/6 control mice (C57, n = 15) were studied at 2 (young) and 8 (adult) month-old. At each time point, animals were placed in metabolic cages for 24 hours to urine volume and urinary creatinine quantification. Blood samples were collected for serum cholesterol, urea and creatinine measurements. Glomerular filtration rate (GFR) was estimated through creatinine clearance determination. Mesangial expansion was evaluated by Periodic Acid Schiff staining, renal fibrosis was determined through Masson's trichrome staining and neuronal nitric oxide synthase (nNOS) expression in the kidney was performed by Western Blotting. To statistical analysis two-way ANOVA followed by Fisher's <it>post hoc </it>test was used.</p> <p>Results</p> <p>Total plasma cholesterol was increased about 5-fold in ApoE mice at both time points compared to C57 animals. At 2-month-old, GFR was already markedly reduced in ApoE compared to C57 mice (187 ± 28 vs 358 ± 92 μL/min, p < 0.05). Adult C57 (-77%) and ApoE (-50%) mice also presented a significant reduction of GFR. In addition, serum urea was significantly increased in young ApoE animals compared to C57 mice (11 ± 1.3 vs 7 ± 0.9 mmol/L, p < 0.01). A significant mesangial expansion was observed at 2-month old ApoE mice compared to C57 mice (35 ± 0.6 vs 30 ± 0.9%, respectively, p < 0.05), which was aggravated at 8-month old animals (40 ± 3 and 35 ± 3%, respectively). Tubulointersticial fibrosis was augmented at both young (17 ± 2%, p < 0.05) and adult (20 ± 1%, p < 0.05) ApoE mice compared to respective C57 age controls (8 ± 1 and 12 ± 2%, respectively). The expression of nNOS was markedly reduced in a time-dependent manner in both strains.</p> <p>Conclusions</p> <p>These data show that both hypercholesterolemia and aging contribute to the loss of renal function in mice.</p
UTILIZAÇÃO DA PROGRESSÃO ARITMÉTICA DO COEFICIENTE DE CORRELAÇÃO DE PEARSON PARA PREVISÃO DA DESCARACTERIZAÇÃO SUPERFICIAL DE ROCHAS ORNAMENTAIS.
No envelhecimento acelerado de rochas ornamentais em câmara saturada em SO2, as interações físico-químicas têm o objetivo de simular a exposição das mesmas às chuvas ácidas. As presenças de SO2, de H2O, somadas à incidência de radiação solar (externa) permitem a formação fotoquímica do ácido sulfúrico (H2SO4) e a correlação entre as digitalizações das superfícies dos corpos de prova, antes e após as exposições ao H2SO4, propicia a análise da evolução das alterações causadas. A estimativa do tempo gasto, em anos, para que as alterações descaracterizem totalmente a aparência estética da superfície das amostras é feita com a progressão aritmética do coeficiente de correlação linear de Pearson (r) que permite, quando igual a 0 (zero), afirmar a inexistência de correlação entre imagens de amostras submetidas ao ensaio e suas imagens originais ao natural. Os resultados apontam o Butterfly Gold como o mais susceptível à descaracterização estética superficial (3,08 anos), seguido do Butterfly Green (3,91 anos) e do Butterfly Beige (16,03 anos). Ressalta-se que a descaracterização não implica, necessariamente, em alteração ou comprometimento estrutural ou físico-mecânico da rocha. A concentração do gás na câmara (25 ppm) foi superelevada propositalmente para acelerar o processo de deterioração. É importante lembrar que a câmara simula as condições climáticas em fluxo praticamente contínuo necessitando o pesquisador, para as interpretações, considerar a concentração de SO2 na atmosfera, a duração das estações chuvosas, a incidência de chuvas ácidas e suas intensidades ao longo de um ano nos diferentes territórios. As previsões aqui realizadas não são impeditivos para aplicação destes materiais em ambientes externos nem tampouco internos, pois procedimentos usuais de limpeza podem ser perfeitamente aplicados para conservação dos mesmos
Efficacy of naproxen with or without esomeprazole for pain and inflammation in patients after bilateral third molar extractions : a double blinded crossover study
Using a double-blinded randomized crossover design, this study aimed to evaluate acute postoperative pain management, swelling and trismus in 46 volunteers undergoing extractions of the two lower third molars, in similar positions, at two different appointments who consumed a tablet of either NE (naproxen 500 mg + esomepraz ole 20 mg) or only naproxen (500 mg) every 12 hours for 4 days. Parameters were analyzed: self-reported pain intensity using a visual analog scale (VAS) pre- and postoperative mouth opening; incidence, type and severity of adverse reactions; total quantity consumed of rescue medication; and pre- and postoperative swelling. Female volunteers reported significantly more postoperative pain at 1, 1.5, 2, 3 and 4hrs after surgery while also taking their first rescue medication at a time significantly earlier when consuming NE when compared to naproxen (3.7hrs and 6.7hrs). Conversely, no differences were found between each drug group in males. In conclusion, throughout the entire study, pain was mild after using either drug in both men and women with pain scores on average well below 40mm (VAS), although in women naproxen improved acute postoperative pain management when compared to NE
Differential aspects of stroke and congestive heart failure in quality of life reduction: a case series with three comparison groups
<p>Abstract</p> <p>Background</p> <p>To assess QOL of patients with stroke in comparison to other groups (caregivers and CHF patients), to identify which items of QOL are more affected on each group and what is the functional profile of patients with stroke.</p> <p>Methods</p> <p>Consecutive stroke or congestive heart failure (CHF) patients were evaluated and compared to their caregivers (caregivers). The NIH Stroke Scale (NIHSS) and EuroQoL-5D (EQ-5D) scale were applied.</p> <p>Results</p> <p>We evaluated 67 patients with stroke, 62 with CHF and 67 caregivers. For stroke patients, median NIHSS score was four. EQ-5D score was significantly worse in stroke, as compared to CHF and caregivers (0.52, 0.69 and 0.65, respectively). Mobility and usual activity domains were significantly affected in stroke and CHF patients as compared to caregivers; and self-care was more affected in stroke as compared with the other two groups.</p> <p>Conclusions</p> <p>Despite a mild neurological deficit, there was a significantly worse QOL perception in stroke as compared to CHF patients, mostly in their perception of self-care.</p
CARACTERIZAÇÃO DE FOCOS DE SARAMPO ATRAVÉS DE GEOPROCESSAMENTO EM JOÃO DOURADO/BA
O foco deste estudo foi saber as caracterÃsticas do MunicÃpio de João Dourado, Estado da Bahia, Região Nordeste do Brasil, onde foi detectados o primeiro caso confirmado de sarampo em 2006 e avaliar o impacto das ações de vigilância epidemiológicas adotadas para a contenção do mesmo. Foi avaliado o
número de casos de sarampo por faixa etária, com a utilização de dados secundários existentes na base do Sistema de Informações de Agravos de Notificação, e de cobertura vacinal da base de dados do Sistema de Avaliação do Programa de Imunizações. Bem como na caracterização do local de incidência com o Google Earth e imagens provenientes de sensoriamento remoto. Esta técnica permitiu a identificação do espaço geográfico como um sistema de objetos e ações, que trouxe a tona um novo cenário para a transmissão da doença e o planejamento de ações de controle
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