913 resultados para Constant Relative Risk Aversion
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In Brazil, sugarcane fields are often burned to facilitate manual harvesting, and this burning causes environmental pollution from the large amounts of soot released into the atmosphere. This material contains numerous organic compounds such as PAHs. In this study, the concentrations of PAHs in two particulate-matter fractions (PM2.5 and PM10) in the city of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugarcane plantations) were determined during the sugarcane harvest (HV) and non-harvest (NHV) seasons in 2008 and 2009. The sampling strategy included four campaigns, with 60 samples in the NHV season and 220 samples in the HV season. The PM2.5 and PM10 fractions were collected using a dichotomous sampler (10 L min(-1), 24 h) with Teflon (TM) filters. The filter sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/Fluorescence. The median concentration for total PAHs (PM2.5 in 2009) was 0.99 ng m(-3) (NHV) and 3.3 ng m(-3) (HV). In the HV season, the total concentration of carcinogenic PAHs (benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene) was 5 times higher than in the NHV season. B(a)P median concentrations were 0.017 ng m(-3) and 0.12 ng m(-3) for the NHV and HV seasons, respectively. The potential cancer risk associated with exposure through inhalation of these compounds was estimated based on the benzo[a]pyrene toxic equivalence (BaPeq), where the overall toxicity of a PAR mixture is defined by the concentration of each compound multiplied by its relative toxic equivalence factor (TEF). BaPeq median (2008 and 2009 years) ranged between 0.65 and 1.0 ng m(-3) and 1.2-1.4 ng m(-3) for the NHV and HV seasons, respectively. Considering that the maximum permissible BaPeq in ambient air is 1 ng m(-3), related to the increased carcinogenic risk, our data suggest that the level of human exposure to PAHs in cities surrounded by sugarcane crops where the burning process is used is cause for concern. (C) 2010 Published by Elsevier Ltd.
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A infecção pelo Toxoplasma gondii tem sido diagnosticada em suínos em todo o mundo. Perdas econômicas geralmente estão relacionadas a distúrbios reprodutivos. A infecção pelo Toxoplasma tem também importância em saúde pública, já que cistos teciduais do parasito podem persistir na carne e subprodutos oriundos de suínos, que servirão de fontes de infecção para o ser humano. O objetivo deste trabalho foi verificar a frequência e os fatores de risco associados à infecção pelo Toxoplasma em granjas de reprodutores suídeos certificados ou não da microrregião de Toledo, no Paraná, que inclui os municípios de Toledo, Nova Santa Rosa, São José das Palmeiras e São Pedro do Iguaçú. A frequência relativa de infecção foi 13,4%, sem diferença com o tipo de granja. A análise de regressão logística demonstrou os seguintes fatores associados à infecção: não utilização de funcionários separados por área da granja, o acesso de animais ao cocho de ração e ao reservatório de água, a não utilização de tampa neste reservatório, a não prevenção de roedores, o número e peso médio de leitões ao desmame por porca.
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This investigation was carried out within the Parana sedimentary basin, Brazil, involved the sampling of groundwater and air, and was realized with the purpose of evaluating the radioactivity, due to radon gas, in a thermal spa utilizing the waters from Guarani (Botucatu-Piramboia) aquifer. The results reported here provide additional information relative to that of previous studies focusing on the presence of radionuclides in the aquifer, which have mainly characterized those belonging to uranium and thorium series decay, such as the uranium isotopes (U-238 and U-234), radium isotopes (Ra-226 and Ra-228), radon daughters (Bi-214 and Pb-214) and radon (Rn-222) itself the results obtained were compared with the maximum permissible concentration limits in air and drinking water defined by international standards, such as the guidelines for drinking water quality established by the World Health Organization. The possible processes responsible for the presence of radon in the aquifer were also considered in order to evaluate the data obtained.
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Arenaeus cribrarius is a mainly tropical crab that occurs in the Western Atlantic Ocean, Brazil being its type-locality. The species ranges from Vinevard Sound, Massachusetts, USA to La Paloma, Uruguay. Information about this species is scarce. The relative growth of A. cribrarius was analyzed, based on some morphometric relations, where the carapace width, excluding lateral spines (CW), was used as an independent variable. A total of 403 specimens (189 males and 214 females), was collected in Ubatuba, State of São Paulo, Brazil, with otter-trawls. The animals were sexed and sorted to maturation phase (juvenile or adult). Some measurements were made: carapace (length and width excluding lateral spines), abdomen (greatest width of the fifth somite in females and the sixth in males) and major chela (greatest length, width and height, dactylus length). This study was made by the application of the power function (y=a.x(b)) which was fitted to the data and the pattern of growth established for each parameter by the ''b''-value (constant of allometry), as positive allometry (b>1), negative allometry (b<1) or isometry (b=1). The morphometric relations of the carapace showed a tendency to isometry. In females, the abdominal width grew in positive allometry, higher in juveniles (b=1.33) than in adults (b=1.18). In this case, an overlap and discontinuity was noticed between the phases over a carapace width range of 55 to 70 mm, where the puberty molt occurs. The majority of relationships showed that the major chela of the males grew in positive allometry, however, the greatest allometric difference between the phases was observed towards the propodus length with 1.09 as juvenile and 1.26 as adult ''b''values. In the males, this variable showed an inflection between the CW range of 45' to 55 mm, where the transition to the maturation phase occurs. The relative growth of this species is similar to those of previously studied species. This indicates, that the propodus length and the abdominal width are the morphometric variables most appropriate to estimate the size of the beginning of the sexual maturity for males and females of this species, respectively.
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Aim. The aim of the study was to verify whether endurance training may induce changes on the percentage of peak heart rate (% peak HR) at the lactate threshold (LT) intensity in untrained elderly. Methods. Sixteen healthy men (64.3 ± 4.1 yrs) underwent an incremental test on cycloergometer to determine the LT and the corresponding % peak HR at LT intensity. Afterwards, they were randomly distributed into two groups (n = 8 each): endurance training (ET) and control (C). The ET exercised 3 days a week for 12 weeks. The training session was divided into warm-up (5 min at 50% of LT;), a main part, and a cool-down (5 min 50% below of LT). The main part had a gradual increased volume through the weeks of 2 min. The initial volume on the 1st week was 25 min reaching 47 min at the 12th week. The relative intensity was kept constant (90 to 100% of LT). Results. After 12 weeks, the % peak HR at LT did not change significantly for both groups P > 0.05 (ET 82.9 ± 4.1 vs. 82.5 ± 3.4 and Ç 80.2 ± 7.1 vs. 81.8 ± 7.1). Conclusion. We conclude that endurance training proposed does not change the relative intensity at LT in elderly.
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In businesses such as the software industry, which uses knowledge as a resource, activities are knowledge intensive, requiring constant adoption of new technologies and practices. Another feature of this environment is that the industry is particularly susceptible to failure; with this in mind, the objective of this research is to analyze the integration of Knowledge Management techniques into the activity of risk management as it applies to software development projects of micro and small Brazilian incubated technology-based firms. Research methods chosen were the Multiple Case Study. The main risk factor for managers and developers is that scope or goals are often unclear or misinterpreted. For risk management, firms have found that Knowledge Management techniques of conversion combination would be the most applicable for use; however, those most commonly used refer to the conversion mode as internalization.. © 2013 Elsevier Ltd. APM and IPMA.
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This investigation aimed to study the relative growth, morphological sexual maturity and fecundity of the swimming crab Achelous spinicarpus in a tropical region, on the south-eastern continental shelf of Brazil (25°S). Biometry of all specimens was conducted, including measurements of the cephalothorax, cheliped, abdomen and gonopods. Relative growth was described based on the equation for allometry (y = axb), and size at sexual maturity was determined from inflections in relations involving the cheliped, gonopods (males), and abdomen (females), as dependent variables, related to the cephalothorax width (independent variable). Fecundity was estimated by the gravimetric method. The relations of the length of the chelar propodus and carpal spine to the carapace width without the lateral spines (CW) showed positive allometry in both sexes, with a significant variation in the constant 'b' for males between the developmental stages (juvenile and adult) and the size at maturity estimated at 37 mm CW. In females, the abdomen was most appropriate for the estimate of morphological maturity, which occurred at a smaller size (32 mm CW), with a change in the growth pattern between the stages, passing from isometric (juveniles) to positive allometric (adults). The gonopods also showed different growth rates between developmental stages, in synchrony with the variables of the cheliped. Mean fecundity for the species was 53,984 eggs, with a positive correlation between the number of eggs exteriorized and the size of the female; the equations allowed interconversion between these variables, due to the adjustment of the power function (r2 ≥ 86%). © 2012 Marine Biological Association of the United Kingdom.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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OBJETIVOAnalisar os efeitos de 20 semanas de treinamento concorrente sobre as variáveis de composição corporal, perfil lipídico e diagnóstico da esteatose hepática em adolescentes obesos.MÉTODOSRealizou-se um ensaio clínico aberto com 34 adolescentes obesos com idades entre 12 e 15 anos. Foram analisados gordura corporal total e de tronco, colesterol total e suas frações (HDL, LDL e VLDL) e triglicérides, sendo realizado exame de ultrassonografia de abdome superior para diagnosticar esteatose hepática. Os participantes foram submetidos ao treinamento concorrente (associação de treino com pesos e exercício aeróbio) três vezes por semana, com duração de uma hora-aula durante 20 semanas. Para o tratamento estatístico, foram realizados o teste t de Student pareado e a análise de frequência, a fim de verificar as reduções relativa e absoluta do diagnóstico da esteatose hepática, adotando-se p<0,05.RESULTADOSOs adolescentes estudados apresentaram melhoras significativas da composição corporal, com diminuição do percentual de gordura total, da massa gorda total, da gordura de tronco e do aumento da massa magra, além de redução do tamanho dos lóbulos do fígado, dos índices de prevalência da esteatose hepática, do colesterol total e LDL-colesterol.CONCLUSÕESO treinamento concorrente foi efetivo por promover melhorias significativas de variáveis da composição corporal e do perfil lipídico, além de reduzir a prevalência da esteatose hepática.
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Pós-graduação em Química - IQ
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A central question in evolutionary biology is how interactions between organisms and the environment shape genetic differentiation. The pathogen Batrachochytrium dendrobatidis (Bd) has caused variable population declines in the lowland leopard frog (Lithobates yavapaiensis); thus, disease has potentially shaped, or been shaped by, host genetic diversity. Environmental factors can also influence both amphibian immunity and Bd virulence, confounding our ability to assess the genetic effects on disease dynamics. Here, we used genetics, pathogen dynamics, and environmental data to characterize L.yavapaiensis populations, estimate migration, and determine relative contributions of genetic and environmental factors in predicting Bd dynamics. We found that the two uninfected populations belonged to a single genetic deme, whereas each infected population was genetically unique. We detected an outlier locus that deviated from neutral expectations and was significantly correlated with mortality within populations. Across populations, only environmental variables predicted infection intensity, whereas environment and genetics predicted infection prevalence, and genetic diversity alone predicted mortality. At one locality with geothermally elevated water temperatures, migration estimates revealed source-sink dynamics that have likely prevented local adaptation. We conclude that integrating genetic and environmental variation among populations provides a better understanding of Bd spatial epidemiology, generating more effective conservation management strategies for mitigating amphibian declines.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of this study was to analyze the association between risk behaviors and adiposity indicators in adolescents and to discuss some methodological aspects related to this relationship. We evaluated 1,321 adolescents (55.2% female) aged 10-16 years. Relative body fat (%fat) by measurement of triceps and subscapular skinfold thickness and waist circumference (WC) were used as total and central adiposity indicators, respectively. Physical inactivity, time spent in front of the TV, the consumption of soda and/or chocolate, alcohol, and tobacco smoking were analyzed as risk behaviors. Information about the socioeconomic status (categorized into three levels) and nutritional status of the mother (overweight or normal weight) were used as adjustment factors in the analyses of prevalence ratio (PR) of the outcomes and their associated 95% confidence intervals (95% CI). The chi-square test and Poisson regression were used for statistical analyses. Low associations were found between risk behaviors and adiposity indicators. Tobacco smoking was the most positively correlated behavior with adiposity in girls (%fat: PR = 1.61; 95% CI = 1.04-2.47; WC: PR = 1.90; 95% CI = 1.17-3.08) and in adolescents whose mothers were normal weight (%fat: PR = 2.31; 95% CI = 1.33-4.03; WC: PR: 2.31; CI: 1.19-4.46). Additionally, as an important methodological issue, we highlighted the assessment of risk behaviors in adolescents as crucial to producing more robust evidence on the subject. Of the investigated behaviors, we concluded that tobacco smoking is the behavior most associated with adiposity indicators.
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Anaerobic efforts are commonly required through repeated sprint during efforts in many sports, making the anaerobic pathway a target of training. Nevertheless, to identify improvements on such energetic way it is necessary to assess anaerobic capacity or power, which is usually complex. For this purpose, authors have postulated the use of short running performances to anaerobic ability assessment. Thus, the aim of this study was to find a relationship between running performances on anaerobic power, anaerobic capacity or repeated sprint ability. Methods Thirteen military performed maximal running of 50 (P50), 100 (P100) and 300 (P300) m on track, beyond of running-based anaerobic sprint test (RAST; RSA and anaerobic power test), maximal anaerobic running test (MART; RSA and anaerobic capacity test) and the W′ from critical power model (anaerobic capacity test). Results By RAST variables, peak and average power (absolute and relative) and maximum velocity were significantly correlated with P50 (r = −0.68, p = 0.03 and −0.76, p = 0.01; −0.83, p < 0.01 and −0.83, p < 0.01; and −0.78, p < 0.01), respectively. The maximum intensity of MART was negatively and significantly correlated with P100 (r = −0.59) and W′ was not statistically correlated with any of the performances. Conclusion MART and W′ were not correlated with short running performances, having a weak performance predicting probably due to its longer duration in relation to assessed performances. Observing RAST outcomes, we postulated that such a protocol can be used during daily training as short running performance predictor.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)