975 resultados para normalization constant
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La rédaction de ce mémoire a été possible grâce à la bourse d’études supérieures du Canada (BESC M), Joseph-Armand-Bombardier du Centre de Recherche en Sciences Humaines (CRSH) du gouvernement du Canada, 2015.
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Traditionally, densities of newly built roadways are checked by direct sampling (cores) or by nuclear density gauge measurements. For roadway engineers, density of asphalt pavement surfaces is essential to determine pavement quality. Unfortunately, field measurements of density by direct sampling or by nuclear measurement are slow processes. Therefore, I have explored the use of rapidly-deployed ground penetrating radar (GPR) as an alternative means of determining pavement quality. The dielectric constant of pavement surface may be a substructure parameter that correlates with pavement density, and can be used as a proxy when density of asphalt is not known from nuclear or destructive methods. The dielectric constant of the asphalt can be determined using ground penetrating radar (GPR). In order to use GPR for evaluation of road surface quality, the relationship between dielectric constants of asphalt and their densities must be established. Field measurements of GPR were taken at four highway sites in Houghton and Keweenaw Counties, Michigan, where density values were also obtained using nuclear methods in the field. Laboratory studies involved asphalt samples taken from the field sites and samples created in the laboratory. These were tested in various ways, including, density, thickness, and time domain reflectometry (TDR). In the field, GPR data was acquired using a 1000 MHz air-launched unit and a ground-coupled unit at 200 and 500 MHz. The equipment used was owned and operated by the Michigan Department of Transportation (MDOT) and available for this study for a total of four days during summer 2005 and spring 2006. The analysis of the reflected waveforms included “routine” processing for velocity using commercial software and direct evaluation of reflection coefficients to determine a dielectric constant. The dielectric constants computed from velocities do not agree well with those obtained from reflection coefficients. Perhaps due to the limited range of asphalt types studied, no correlation between density and dielectric constant was evident. Laboratory measurements were taken with samples removed from the field and samples created for this study. Samples from the field were studied using TDR, in order to obtain dielectric constant directly, and these correlated well with the estimates made from reflection coefficients. Samples created in the laboratory were measured using 1000 MHz air-launched GPR, and 400 MHz ground-coupled GPR, each under both wet and dry conditions. On the basis of these observations, I conclude that dielectric constant of asphalt can be reliably measured from waveform amplitude analysis of GJPR data, based on the consistent agreement with that obtained in the laboratory using TDR. Because of the uniformity of asphalts studied here, any correlation between dielectric constant and density is not yet apparent.
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La rédaction de ce mémoire a été possible grâce à la bourse d’études supérieures du Canada (BESC M), Joseph-Armand-Bombardier du Centre de Recherche en Sciences Humaines (CRSH) du gouvernement du Canada, 2015.
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This study evaluates hypercholesterolemic rabbits, examining the retinal changes in Müller cells and astrocytes as well as their variations after a period of normal blood-cholesterol values induced by a standard diet. New Zealand rabbits were divided into three groups: G0, fed a standard diet; G1A, fed a 0.5% cholesterol-enriched diet for 8 months; and G1B, fed as G1A followed by standard diet for 6 months. Eyes were processed for transmission electron microscopy and immunohistochemistry (GFAP). While G1B resembled G0 more than did G1A, they shared alterations with G1A: a) as in G1A, Müller cells were GFAP+, filled spaces left by axonal degeneration, formed glial scars and their nuclei were displaced to the nerve-fibre layer. The area occupied by the astrocytes associated with the nerve-fibre bundles (AANFB) and by perivascular astrocytes (PVA) in G1A and G1B was significantly lower than in controls. However, no significant differences in PVA were found between G1A and G1B. In G1B, type I PVA was absent and replaced by hypertrophic type II cells; b) Bruch's membrane (BM) was thinner in G1B than in G1A; c) the retinal pigment epithelium (RPE) cytoplasm contained fewer lipids in G1B than in G1A; d) in G1A and G1B choriocapillaris and retinal vessel showed alterations with respect to G0; e) cell death and axonal degeneration in the retina were similar in G1A and G1B. The substitution of a hyperlipemic diet by a standard one normalizes blood-lipid levels. However, the persistence of damage at retinal vessels and BM-RPE could trigger chronic ischemia.
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Thermoelectric generators (TEGs) are solid-state devices that can be used for the direct conversion between heat and electricity. These devices are an attractive option for generating clean energy from heat. There are two modes of operation for TEGs; constant heat and constant temperature. It is a well-known fact that for constant temperature operation, TEGs have a maximum power point lying at half the open circuit voltage of the TEG, for a particular temperature. This work aimed to investigate the position of the maximum power point for Bismuth Telluride TEGs working under constant heat conditions i.e. the heat supply to the TEG is fixed however the temperature across the TEG can vary depending upon its operating conditions. It was found that for constant heat operation, the maximum power point for a TEG is greater than half the open circuit voltage of the TEG.
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Our goal in this paper is to extend previous results obtained for Newtonian and secondgrade fluids to third-grade fluids in the case of an axisymmetric, straight, rigid and impermeable tube with constant cross-section using a one-dimensional hierarchical model based on the Cosserat theory related to fluid dynamics. In this way we can reduce the full threedimensional system of equations for the axisymmetric unsteady motion of a non-Newtonian incompressible third-grade fluid to a system of equations depending on time and on a single spatial variable. Some numerical simulations for the volume flow rate and the the wall shear stress are presented.
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Terceiro maior produtor de frutas frescas do mundo, o Brasil se destaca no mercado agrícola por apresentar um clima tropical favorável à produção de diversas frutas. O melão e a manga são exemplos de frutas frescas que apresentam grandes índices de exportação. Os estados do Ceará e do Rio Grande do Norte são responsáveis pela maior parte da produção do melão brasileiro, já o mercado da União Europeia, é responsável quase que pela totalidade da importação do melão brasileiro. O objetivo desta pesquisa é analisar a competitividade e as parcelas de mercado do melão brasileiro no mercado mundial, no período de 2003 a 2011, tomando como base o modelo Constant Market Share. Os resultados mostram a diferença de direção dos subperíodos analisados. No primeiro subperíodo, têm-se o crescimento da exportação ocasionado pelo crescimento do comércio mundial e pelo fator competitividade, diferente do segundo período em que há uma queda principalmente na competitividade ocasionando o declínio na exportação da fruta produzida no Brasil
Time Estimation (Short Intervals)in Human Subjects under Free Living and Constant Routine Conditions
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A saúde da mulher foi o foco escolhido devido à importância que tem o câncer no Brasil e no mundo, pela sua magnitude social, as condições de acesso da população brasileira à atenção oncologia, os custos cada vez mais elevados na alta complexidade refletem a necessidade de estruturar uma rede de serviços regionalizada e hierarquizada que garanta atenção integral à mulher. A Unidade Básica de Saúde de Benjamin Constant do Sul de tipo SEDE, urbana e rural, vinculada ao Sistema Único de Saúde, conta com uma população de 1200 habitantes. Neste trabalho desenvolvemos um projeto de intervenção junto à população feminina da unidade de Saúde com o objetivo de qualificar o programa de Prevenção do Câncer de Colo de útero e mama à saúde da mulher, foi baseada nos protocolos do Ministério da Saúde. Realizamos uma intervenção durante um período de 12 semanas para as mulheres na faixa etária 25 a 64 anos sendo um total de 421 mulheres e 102 mulheres na faixa etária de 50 a 69 anos pertencente à área de abrangência. O detalhamento das ações foi estruturado em quatro eixos: Monitoramento e avaliação, Organização e gestão do serviço, Engajamento público e Qualificação da prática clínica. Os resultados mais significativos foram o aumento da cobertura do programa. Na intervenção foram cadastradas 183 mulheres, correspondendo 67,8% das mulheres para prevenção do câncer de colo de útero. Em relação à qualidade da atenção das mulheres cadastradas, as 183 (100%) realizaram a coleta da mostra do exame citopatológico de colo de útero satisfatoriamente, monitoramos os resultados de todos os exames para detecção de câncer de colo de útero, bem como o cumprimento da periodicidade de realização dos exames prevista nos protocolos adotados pela unidade de saúde. Para prevenção do câncer de mama cadastramos 76 mulheres ou 96%. Os exames para detecção de câncer de mama foram feitos a 100% das mulheres cadastradas, assim como seu registro. Pesquisaram-se os sinais de alerta para câncer de colo de útero em 100% das mulheres entre 25 e 64 anos. A avaliação de risco para câncer de mama 100% das mulheres entre 50 e 69 anos. Em relação às mulheres faltosas a consultas se realizou 100% a busca ativa, sendo que os registros ao terminar a intervenção, foram atualizados. O projeto está incorporado na rotina de trabalho da unidade de saúde e constitui uma guia para outros projetos de trabalho sendo este o primeiro trabalho de intervenção feito com a participação da equipe e da comunidade. O diálogo com a comunidade serviu para levar a saúde da família á porta da casa dos brasileiros. A ESF foi fortalecida e o engajamento público foi um dos resultados mais importantes, além de melhorar a atenção da saúde da mulher.
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The mesoporous SBA-15 silica with uniform hexagonal pore, narrow pore size distribution and tuneable pore diameter was organofunctionalized with glutaraldehyde-bridged silylating agent. The precursor and its derivative silicas were ibuprofen-loaded for controlled delivery in simulated biological fluids. The synthesized silicas were characterized by elemental analysis, infrared spectroscopy, (13)C and (29)Si solid state NMR spectroscopy, nitrogen adsorption, X-ray diffractometry, thermogravimetry and scanning electron microscopy. Surface functionalization with amine containing bridged hydrophobic structure resulted in significantly decreased surface area from 802.4 to 63.0 m(2) g(-1) and pore diameter 8.0-6.0 nm, which ultimately increased the drug-loading capacity from 18.0% up to 28.3% and a very slow release rate of ibuprofen over the period of 72.5h. The in vitro drug release demonstrated that SBA-15 presented the fastest release from 25% to 27% and SBA-15GA gave near 10% of drug release in all fluids during 72.5 h. The Korsmeyer-Peppas model better fits the release data with the Fickian diffusion mechanism and zero order kinetics for synthesized mesoporous silicas. Both pore sizes and hydrophobicity influenced the rate of the release process, indicating that the chemically modified silica can be suggested to design formulation of slow and constant release over a defined period, to avoid repeated administration.
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This study aimed to characterize which regulatory logics (other than government regulation) result in healthcare output, using a two-stage qualitative study in two municipalities in the ABCD Paulista region in São Paulo State, Brazil. The first stage included interviews with strategic actors (managers and policymakers) and key health professionals. The second phase collected life histories from 18 individuals with high health-services utilization rates. An analysis of the researchers' involvement in the field allowed a better understanding of the narratives. Four regulatory systems were characterized (governmental, professional, clientelistic, and lay), indicating that regulation is a field in constant dispute, a social production. Users' action produces healthcare maps that reveal the existence of other possible health system arrangements, calling on us to test shared management of healthcare between health teams and users as a promising path to the urgent need to reinvent health.
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Bisphenol A (BPA) is a chemical that has been investigated for it potential to cause prostate diseases. In this study, pregnant Sprague-Dawley rats were treated with 25 or 250 μg/kg BPA from gestational day (GD) 10 to GD21 with or without concurrent indole-3-carbinol (I3C) feeding. I3C is a phytochemical, and it affords chemoprotection against many types of neoplasia. Male F1 rats from different litters were euthanized on post-natal day (PND) 21 and PND180. BPA-treated groups showed a significant increase in histopathological lesions, but I3C feeding reversed many of these changes, mainly at PND180. Maternal I3C feeding increased prostate epithelial apoptosis in the BPA-treated groups and across age groups. Furthermore, I3C induced partial normalization of the prostate histoarchitecture. The results pointed to a protective effect of maternal I3C feeding during pregnancy in the BPA-exposed male offspring, thereby indicating reduction in the harmful effects of gestational BPA imprinting on the prostate.
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It is well known that long term use of shampoo causes damage to human hair. Although the Lowry method has been widely used to quantify hair damage, it is unsuitable to determine this in the presence of some surfactants and there is no other method proposed in literature. In this work, a different method is used to investigate and compare the hair damage induced by four types of surfactants (including three commercial-grade surfactants) and water. Hair samples were immersed in aqueous solution of surfactants under conditions that resemble a shower (38 °C, constant shaking). These solutions become colored with time of contact with hair and its UV-vis spectra were recorded. For comparison, the amount of extracted proteins from hair by sodium dodecyl sulfate (SDS) and by water were estimated by the Lowry method. Additionally, non-pigmented vs. pigmented hair and also sepia melanin were used to understand the washing solution color and their spectra. The results presented herein show that hair degradation is mostly caused by the extraction of proteins, cuticle fragments and melanin granules from hair fiber. It was found that the intensity of solution color varies with the charge density of the surfactants. Furthermore, the intensity of solution color can be correlated to the amount of proteins quantified by the Lowry method as well as to the degree of hair damage. UV-vis spectrum of hair washing solutions is a simple and straightforward method to quantify and compare hair damages induced by different commercial surfactants.
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The genera Cochliomyia and Chrysomya contain both obligate and saprophagous flies, which allows the comparison of different feeding habits between closely related species. Among the different strategies for comparing these habits is the use of qPCR to investigate the expression levels of candidate genes involved in feeding behavior. To ensure an accurate measure of the levels of gene expression, it is necessary to normalize the amount of the target gene with the amount of a reference gene having a stable expression across the compared species. Since there is no universal gene that can be used as a reference in functional studies, candidate genes for qPCR data normalization were selected and validated in three Calliphoridae (Diptera) species, Cochliomyia hominivorax Coquerel, Cochliomyia macellaria Fabricius, and Chrysomya albiceps Wiedemann . The expression stability of six genes ( Actin, Gapdh, Rp49, Rps17, α -tubulin, and GstD1) was evaluated among species within the same life stage and between life stages within each species. The expression levels of Actin, Gapdh, and Rp49 were the most stable among the selected genes. These genes can be used as reliable reference genes for functional studies in Calliphoridae using similar experimental settings.
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Health economic evaluations require estimates of expected survival from patients receiving different interventions, often over a lifetime. However, data on the patients of interest are typically only available for a much shorter follow-up time, from randomised trials or cohorts. Previous work showed how to use general population mortality to improve extrapolations of the short-term data, assuming a constant additive or multiplicative effect on the hazards for all-cause mortality for study patients relative to the general population. A more plausible assumption may be a constant effect on the hazard for the specific cause of death targeted by the treatments. To address this problem, we use independent parametric survival models for cause-specific mortality among the general population. Because causes of death are unobserved for the patients of interest, a polyhazard model is used to express their all-cause mortality as a sum of latent cause-specific hazards. Assuming proportional cause-specific hazards between the general and study populations then allows us to extrapolate mortality of the patients of interest to the long term. A Bayesian framework is used to jointly model all sources of data. By simulation, we show that ignoring cause-specific hazards leads to biased estimates of mean survival when the proportion of deaths due to the cause of interest changes through time. The methods are applied to an evaluation of implantable cardioverter defibrillators for the prevention of sudden cardiac death among patients with cardiac arrhythmia. After accounting for cause-specific mortality, substantial differences are seen in estimates of life years gained from implantable cardioverter defibrillators.