817 resultados para Proxy servers
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Sao Paulo Research Foundation (FAPESP) in Brazil
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Stable carbon isotope analyses of wool staples provided insight into the vegetation consumed by sheep at a temporal resolution not previously studied. Contemporary Australian and historic South African samples dating back to 1916 were analyzed for their stable carbon isotope ratio, a proxy for the proportion of C-3 and C-4 plant species consumed by animals. Sheep sample vegetation continuously throughout a year, and as their wool grows it integrates and stores information about their diet. In subtropical and tropical rangelands the majority of grass species are C-4. Since sheep prefer to graze, and their wool is an isotopic record of their diet, we now have the potential to develop a high resolution index to the availability of grass from a sheep's perspective. Isotopic analyses of wool suggest a new direction for monitoring grazing and for the reconstruction of past vegetation changes, which will make a significant contribution to traditional rangeland ecology and management. It is recommended that isotopic and other analyses of wool be further developed for use in rangeland monitoring programs to provide valuable feedback for land managers.
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Wildlife-habitat models are an important tool in wildlife management toda?, and by far the majority of these predict aspects of species distribution (abundance or presence) as a proxy measure of habitat quality. Unfortunately, few are tested on independent data, and of those that are, few show useful predictive st;ill. We demonstrate that six critical assumptions underlie distribution based wildlife-habitat models, all of which must be valid for the model to predict habitat quality. We outline these assumptions in a mete-model, and discuss methods for their validation. Even where all sis assumptions show a high level of validity, there is still a strong likelihood that the model will not predict habitat quality. However, the meta-model does suggest habitat quality can be predicted more accurately if distributional data are ignored, and variables more indicative of habitat quality are modelled instead.
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This paper presents the unique collection of additional features of Qu-Prolog, a variant of the Al programming language Prolog, and illustrates how they can be used for implementing DAI applications. By this we mean applications comprising communicating information servers, expert systems, or agents, with sophisticated reasoning capabilities and internal concurrency. Such an application exploits the key features of Qu-Prolog: support for the programming of sound non-clausal inference systems, multi-threading, and high level inter-thread message communication between Qu-Prolog query threads anywhere on the internet. The inter-thread communication uses email style symbolic names for threads, allowing easy construction of distributed applications using public names for threads. How threads react to received messages is specified by a disjunction of reaction rules which the thread periodically executes. A communications API allows smooth integration of components written in C, which to Qu-Prolog, look like remote query threads.
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Background and Purpose-Subarachnoid hemorrhage (SAH) is more common in women than in men, but the role of hormonal factors in its etiology remains uncertain. The aim of this study was to examine the relationship between hormonal factors and risk of SAH in women. Methods-This was a prospective, multicenter, population-based, case-control study performed in 4 major urban centers in Australia and New Zealand. Two hundred sixty-eight female cases of first-ever aneurysmal SAH occurred during 1995-1998. Controls were 286 frequency-matched women from the general population of each center. Outcome measures included risk of SAH associated with use of oral contraceptive pills (OCPs), hormone replacement therapy (HRT), and various endogenous hormonal factors including menstrual patterns, parity, age at birth of first child, and breast-feeding practices. Results-Cases and controls did not differ with regard to menstrual and reproductive history except in age at bir th of first child, where older age was associated with reduced risk of SAH (odds ratio [OR], 0.63; 95% CI, 0.43, 0.91). Relative to never use of HRT, the adjusted OR for over use of HRT was 0.64 (95% CI, 0.41, 0.98), which did not alter significantly after further adjustment for possible confounding factors. Borderline evidence of an inverse association was detected for past use of HRT (adjusted OR, 0.59; 95% CI, 0.30, 1.13) and current use of HRT (adjusted OR, 0.67; 95% CI, 0.40, 1.13), but there was no evidence of an association for use of OCPs (adjusted OR, 0.97; 95% CI, 0.58, 1.60). Conclusions-The risks of SAH are lower in women whose first pregnancy is at an older age and women who have ever used HRT but not OCPs. The findings suggest an independent etiologic role for hormonal factors in the pathogenesis of aneurysmal SAH and provide support for a protective role fur HRT on risk of SAH in postmenopausal women.
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To reconstruct oceanographic variations in the subtropical South Pacific, 271-year long subseasonal time series of Sr/Ca and delta(18)O were generated from a coral growing at Rarotonga (21.5degreesS, 159.5degreesW). In this case, coral Sr/Ca appears to be an excellent proxy for sea surface temperature (SST) and coral delta(18)O is a function of both SST and seawater delta(18)O composition (delta(18)O(sw)). Here, we focus on extracting the delta(18)O(sw) signal from these proxy records. A method is presented assuming that coral Sr/Ca is solely a function of SST and that coral delta(18)O is a function of both SST and delta(18)O(sw). This method separates the effects of delta(18)O(sw) from SST by breaking the instantaneous changes of coral delta(18)O into separate contributions by instantaneous SST and delta(18)O(sw) changes, respectively. The results show that on average delta(18)O(sw) at Rarotonga explains similar to39% of the variance in delta(18)O and that variations in SST explains the remaining similar to61% of delta(18)O variance. Reconstructed delta(18)O(sw) shows systematic increases in summer months (December-February) consistent with the regional pattern of variations in precipitation and evaporation. The delta(18)O(sw) also shows a positive linear correlation with satellite-derived estimated salinity for the period 1980 to 1997 (r = 0.72). This linear correlation between reconstructed delta(18)O(sw) and salinity makes it possible to use the reconstructed delta(18)O(sw) to estimate the past interannual and decadal salinity changes in this region. Comparisons of coral delta(18)O and delta(18)O(sw) at Rarotonga with the Pacific decadal oscillation index suggest that the decadal and interdecadal salinity and SST variability at Rarotonga appears to be related to basin-scale decadal variability in the Pacific. Copyright (C) 2002 Elsevier Science Ltd.
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Background and Purpose - Unaccustomed strenuous physical exertion can trigger myocardial infarction, but little is known about the mechanisms precipitating subarachnoid hemorrhage (SAH). Methods - We identified all cases of first-ever SAH among the combined populations (2.8 million) of 4 urban centers in Australia and New Zealand. Information on the type, time, and intensity of exposures in the 26 hours before the onset of SAH was ascertained by structured interviews. We used the case-crossover technique to assess the risk of SAH associated with transient exposures of moderate to extreme physical exertion, heavy cigarette smoking, and binge alcohol consumption. Results - We registered 432 first-ever cases of SAH (62% women; mean age, 56.5 years). A definite time of onset of SAH was established for 393 patients (91%), and information on the levels of physical activity in the preceding 26 hours was obtained in 338 ( 78%). Of these patients, 19% engaged in moderate to extreme exertion (greater than or equal to5 metabolic equivalents) in the 2 hours before SAH, which was associated with a tripling in the risk of SAH (odds ratio [OR], 2.7; 95% CI, 1.6 to 4.6). There was no evidence of any association between heavy cigarette smoking or binge drinking and risk of SAH in the subsequent 2 hours ( OR, 1.1; 95% CI, 0.4 to 3.7; and OR, 0.41; 95% CI, -infinity to 5.3). Habitual exercise did not appear to alter the risk of SAH associated with moderate to extreme exertion. Conclusions - Moderate to extreme physical exertion tripled the risk of SAH, but there was no association between transient heavy smoking or binge drinking and risk of SAH. These data suggest that heavy physical activity may trigger SAH.
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Discussion opposing the Theory of the Firm to the Theory of Stakeholders are contemporaneous and polemical. One focal point of such debates refers to which objective-function companies, should choose, whether that of the shareholders or that of the stakeholders, and whether it is possible to opt for both simultaneously. Several empirical studies. have attempted-to test a possible correlation between both functions, and there has not been any consensus-so far. The objective of the present research is to examine a gap in such discussions: is there (or not) a subordination of the stakeholders` objective-function to that of the shareholders? The research is empirical,and analytical and employs quantitative methods. Hypotheses were tested and data analyzed by using non-parametrical (chi-square test) and parametrical procedures (frequency. correlation `coefficient). Secondary data was collected from he Economitica database and from the Brazilian Institute of Social and-Economic Analyses (IBASE) website, relative to public companies that have published their Social Balance Statements following the IBASE model from 1999 to 2006, whose sample amounted to 65 companies; In order to assess the objective-function of shareholders a proxy was created based on the following three indices: ROE (return on equity), EnterpriseValue and Tobin`s Q. In order to assess the objective-function of stakeholders a proxy was created by employing the following IBASE social balance indices: internal ones (ISI), external ones (ISE), and environmental ones (IAM). The results have shown no evidence of subordination of stakeholders` objective-function to that of the shareholders in analyzed companies, negating initial expectations and calling for deeper investigation of results. Its main conclusion, which states that the attempted subordination does not take place, is limited to the sample herein investigated and calls for ongoing research aiming at improvements which may lead to sample enlargement and, as a consequence, may make feasible the application of other statistical techniques which may yield a more thorough, analysis of the studied phenomehon.
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We formulated a general unrestricted model of the Brazilian Emerging Markets Bond Index Plus (EMBI+) spreads, a proxy for the country`s default risk. Employing algorithms that perform automated model selection, we found that macroeconomic fundamentals, such as current account deficit ratio to gross domestic product, public deficit ratio to gross domestic product and imports over foreign exchange reserves, can explain a great part of the variation in EMBI+ spreads. There is also robust evidence of systematic contagion from Argentina and Mexico and that the variance of the spread also affects its mean.
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Multitemporal Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) imagery was used to assess coastline morphological changes in southeastern Brazil. A spectral linear mixing approach (SLMA) was used to estimate fraction imagery representing amounts of vegetation, clean water (a proxy for shade) and soil. Fraction abundances were related to erosive and depositional features. Shoreline, sandy banks (including emerged and submerged banks) and sand spits were highlighted mainly by clean water and soil fraction imagery. To evaluate changes in the coastline geomorphic features, the fraction imagery generated for each data set was classified in a contextual approach using a segmentation technique and ISOSEG, an unsupervised classification. Evaluation of the classifications was performed visually and by an error matrix relating ground-truth data to classification results. Comparison of the classification results revealed an intense transformation in the coastline, and that erosive and depositional features are extremely dynamic and subject to change in short periods of time.
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Aims: To present the prevalence of cognitive and functional impairment (CFI) in community-dwelling elderly subjects from the city of Sao Paulo. Methods: The population was aged 60 years and older (n = 1,563; 68.7% women and 31.3% men) and lived in different socioeconomic areas. The following instruments were administered to the elderly: the Mini Mental State Examination and the Fuld Object Memory Evaluation. The Informant Questionnaire on Cognitive Decline in the Elderly and the Bayer-Activities of Daily Living scale were administered to an informant. Results: The prevalence of CFI (n = 250) was 16% (95% confidence interval, CI: 14.2-17.8%) or 15.8% (95% CI: 13.8-17.8%). In regression models, the increase in the odds ratio (OR) of CFI was associated with age, for elderly individuals aged 75 years or older, illiterates or with 1-4 years of schooling, and with a history of stroke and diabetes mellitus. On the other hand, for subjects with a tumor history, the OR of CFI was significantly reduced. Conclusion: CFI was high and increased at older ages and in subjects with low education. Potentially changeable factors were identified (stroke and diabetes), and the possible `protective effect` of tumor/cancer against CFI should be further investigated by longitudinal studies. Copyright (C) 2007 S. Karger AG, Basel.
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In this groundbreaking collection of essays the history of philosophy appears in a new light, not as reason's progressive discovery of its universal conditions, but as a series of unreconciled disputes over the proper way to conduct oneself as a philosopher. By shifting focus from the philosopher as proxy for the universal subject of reason to the philosopher as a... More special persona arising from rival forms of self-cultivation, philosophy is approached in terms of the social office and intellectual deportment of the philosopher, as a personage with a definite moral physiognomy and institutional setting. In so doing, this collection of essays by leading figures in the fields of both philosophy and the history of ideas provides access to key early modern disputes over what it meant to be a philosopher, and to the institutional and larger political and religious contexts in which such disputes took place.
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Seroprevalence data from a representative population were used to estimate the annual incidence of congenital toxoplasmosis in Sao Paulo Metropolitan Region (SPMR). Retrospective anti-toxoplasma IgG serological analysis was conducted to determine age-dependent seroprevalence, force of infection, average age of acquisition of infection and curve of decay of maternally derived antibodies. Seroprevalence was used to calculate the number of new infections. Toxoplasmosis in pregnant women was estimated by total number of deliveries in a given year as a proxy for the number of pregnancies per year. Toxoplasma seroprevalence was 64.9% in women of childbearing age. Average age of acquisition of toxoplasmosis was 10.74 years. The estimated annual incidence of congenital toxoplasmosis varied from 9.5 to 10.6/1000 births in the studied period. The toxoplasmosis seroprevalence model allowed a good incidence estimation of congenital disease in SPMR compared to other published data, indicating that this mathematical approach is useful in calculating the potential demand of congenital disease due to Toxoplasma gondii in a given community.
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Kenyan women have more children, especially in rural areas, than in most developing nations. This is widely believed to be an impediment to Kenya’s economic development. Thus, factors influencing family size in the Kenyan context are important for its future. A brief review of economic theories of fertility leads to the conclusion that both economics and social/cultural factors must be considered simultaneously when examining factors that determine the number of children in a family. The need to do this is borne out in Kenya’s situation by utilising responses from a random sample of rural households in the Nyeri district of Kenya. Economic and social/cultural factors intertwine to influence family sizes in this district. After providing a summary of the main statistical results from the survey, we use multiple regression analysis to explore the influences of a woman’s age, level of education, whether she has outside employment, whether the family keeps livestock, whether she expresses a preference for more boys than girls, whether the family uses only family labour (including child labour) and the size of the farm, which is used as a proxy for family income. It was found that preference for male children has an important positive influence on family size in this district. Women were found to have greater preference for male children than their male counterparts possibly because of their fear of being disinherited if they do not produce an heir for their husbands. Preference for sons was also found in allocation of human capital resources at the household level in that the female respondents were found to have lower levels of education than their male counterparts. Various long-term policies are outlined that may help to reduce the number of offspring of women in Kenya.
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OBJECTIVES: The authors prospectively examined the association between bowel movement frequency (used as a proxy for intestinal transit), laxative use, and the risk of symptomatic gallstone disease. METHODS: A total of 79,829 women, aged 36–61 yr, without a history of symptomatic gallstone disease and free of cancer, responded to a mailed questionnaire in 1982 that assessed bowel movement frequency and use of laxatives. Between 1984 and 1996, 4,443 incident cases of symptomatic gallstone disease were documented. Relative risks (RRs) of symptomatic gallstone disease and 95% confidence intervals (CIs) were calculated using logistic regression. RESULTS: After controlling for age and established risk factors, the multivariate RRs were, compared to women with daily bowel movements, 0.97 (95% CI 0.86–1.08) for women with bowel movements every third day or less, and 1.00 (95% CI 0.91–1.11) for women with bowel movement more than once daily. No trend was evident. As compared to women who never used laxatives in 1982, a significant modest inverse association was seen for monthly laxative use, with a multivariate RR of 0.84 (95% CI 0.72–0.98), and weekly to daily laxative use was associated with a RR of 0.88 (95% CI 0.78–1.02). CONCLUSIONS: These findings do not support an association between infrequent bowel movements and risk of symptomatic gallstone disease in women, and indicate that simple questions directed at bowel movement frequency are unlikely to enhance our ability to predict risk of symptomatic gallstone disease. The slightly inverse association between use of laxatives and risk of symptomatic gallstone disease may be due to a mechanism that is not related to bowel movement frequency.