24 resultados para Proxy


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Abstract OBJECTIVE To analyze the evidences of construct validity of the Katz Index for the retrospective assessment of activities of daily living (ADL) by informants, to assist neuropathological studies in the elderly. METHOD A cross-sectional study analyzed the functional ability of ADL measure by the Katz Index, of 650 cases randomly selected from the Brazilian Brain Bank of the Ageing Brain Study Group (BBBABSG) database. Sample was divided in two subsamples for the analysis (N=325, each) and then stratified according to cognitive decline assessed by the Clinical Dementia Rating Scale (CDR). Factor analyses with calculations of internal consistency and invariance were performed. RESULTS Factor analysis evidenced a unidimensional instrument with optimal internal consistency, in all subgroups. Goodness of fit indices were obtained after two treatments of covariance, indicating adequacy of the scale for assessing ADL by informants. The scale is invariant to cognitive decline meaning that it can be used for subjects with or without cognitive impairment. CONCLUSION Katz Index is valid for the retrospective assessment of basic ADL by informants, with optimal reliability.

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ABSTRACT The population dynamics of a species tends to change from the core to the periphery of its distribution. Therefore, one could expect peripheral populations to be subject to a higher level of stress than more central populations (the center–periphery hypothesis) and consequently should present a higher level of fluctuating asymmetry. To test these predictions we study asymmetry in wing shape of five populations of Drosophila antonietae collected throughout the distribution of the species using fluctuating asymmetry as a proxy for developmental instability. More specifically, we addressed the following questions: (1) what types of asymmetry occur in populations of D. antonietae? (2) Does the level of fluctuating asymmetry vary among populations? (3) Does peripheral populations have a higher fluctuating asymmetry level than central populations? We used 12 anatomical landmarks to quantify patterns of asymmetry in wing shape in five populations of D. antonietae within the framework of geometric morphometrics. Net asymmetry – a composite measure of directional asymmetry + fluctuating asymmetry – varied significantly among populations. However, once net asymmetry of each population is decomposed into directional asymmetry and fluctuating asymmetry, most of the variation in asymmetry was explained by directional asymmetry alone, suggesting that populations of D. antonietae have the same magnitude of fluctuating asymmetry throughout the geographical distribution of the species. We hypothesize that larval development in rotting cladodes might play an important role in explaining our results. In addition, our study underscores the importance of understanding the interplay between the biology of a species and its geographical patterns of asymmetry.

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The distribution and abundance of specific lipid biomarkers in marine sediments can play an important rule for the reconstruction of past climatic changes. Here, it is shown the use of a widely known paleo Sea Surface Temperature (SST) proxy based on the unsaturation ratio of a suite of long-chain C37 alkenones: the alkenone unsaturation index, U K37'. These compounds are biosynthesised by only a restricted group of prymnesiophyte algae, mostly notably the coccolithophorid Emiliania huxleyi. To ilustrate the importance of the U K37' index as a molecular tool, the correlation between the SST signal derived from the U K37' and other paleoclimatic records examined in a core from the North Atlantic is discussed.

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The monitoring of the pollution status of the Brazilian coast is hampered by the lack of a consistent environmental indicator. We propose Hg as an environmental proxy to anthropogenic pollution of coastal regions due to its absence in the Brazilian geology, its ubiquity in anthropogenic effluents, and its toxicity. Available data suggest Hg "backgrounds" in coastal sediments of 1-10 ng g-1, in the East and 15-30 ng g-1 in the South. We suggest short sediment cores to establish these values estimating a geo-accumulation index to compare all areas. The distribution of index values showed the majority of southern coast at least moderately contaminated whereas many eastern areas are still pristine.

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Phosphorus geochemistry as a proxy of environmental estuarine processes at the Jaguaribe River, Northeastern Brazil. Sedimentation of different phosphorus geochemical fractions can characterize the natural or anthropogenic processes dominant in the watershed. Selective chemical extraction of different phosphorus geochemical forms in estuarine sediments showed the predominance of inorganic over organic forms suggesting an increase in inorganic phosphorus input from anthropogenic sources. Local hydrochemistry favors the dominance of inorganic ferric and carbonatic phosphorus. Ongoing changes in the estuarine throphy, from mesothrophic to euthrophic, may decrease the immobilization of these forms, increasing dissolved phosphorus and favoring euthrophy. Detritic phosphorus suggests a fluvial origin of this fraction and acts as a tracer of river influence upon the estuary.

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This research investigates relations between communication and the development of family farmers from the Pontal do Paranapanema region (state of São Paulo), mainly in the municipality of Teodoro Sampaio. Family agriculture in this municipality is represented basically by beneficiaries the Agrarian Reform program. The main hypothesis is that communication contributes positively to the development of those family farmers. Thus, this study aimed to understand communication practices of these farmers and relate them with the development of their families. Quantitative and qualitative research methods were used. Development proxy is understood as the combination between the family living conditions and production. Among the main results, it was found that the effect of communication for "life and production conditions" increases as farmers at superior levels of "development" are analyzed; thus the main hypothesis should not be rejected for those farmers with higher development condition. For the others, communication did not have the same effect because many settled families are not focused on agricultural activities. The main suggestion is to improve ways for producers and professionals from public services related to them to access information.

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This paper investigates the role that economic variables play in the determination of happiness, using reported happiness as a proxy to individual well-being. We use microdata extracted from the World Values Survey for five countries, emphasizing the Brazilian case. Our findings suggest that there is a positive and significant correlation between happiness and income. Unemployment is also a large source of unhappiness. In most cases, happiness appears to be positively correlated to being married. Moreover, happiness is apparently U-shaped in age (minimizing at 50's).

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Infrastructure and productivity in Brazil. This article analyses the relationship between infrastructure and total factor productivity (TFP) in Brazil during the second half of the twenty century. Public capital is used as a proxy for infrastructure capital. The hypothesis to be tested is that an increase in infrastructure - more than than a rise in the private capital stock - has a positive effect on productivity on the long run. In that sense, it was used the Johansen methodology for testing the cointegration between TFP and the public/private capital ratio. In fact, it was found that this complementary relation (public-private) helps in explanning TFP's path from 1950 to 2000. The results were robust to different measures of productivity and the public/private ratio. In addition, the short (medium) run analysis has indicated that shocks in this ratio have a significant effect over the TFP, but the opposite is not true. Therefore, the cuts in infrastructure investment could be a possible explanation for the TFP's fall during the 70's and 80's.

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Consolidated democracy and size of the State. Common sense suggests that the more consolidated democracies and advanced economies tend to be more efficient and produce smaller States. What is observed in practice, however, is a positive correlation between "democratic consolidation" and "tax burden" (as a proxy for"size of Government"). This finding, while not expressing any causal relationship between the two variables, is an evidence that a more republican and democratic State, as defined in Bresser-Pereira, must be able to provide, effectively and efficiently, broader public services with better quality. This is, in consolidated democracies, the State should not be small.