906 resultados para Transitional


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Includes bibliography

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Includes bibliography

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The aim of the present study was to describe the species composition and reproductive modes of an anuran community from a transition area between the Amazonia and Cerrado biomes. Data were collected in habitats exhibiting different degrees of anthropogenic degradation. The community (35 species) identified during the present study presented a larger number of reproductive modes when compared with those from Cerrado communities, but smaller than those of other sites in the Amazon. While all nine modes were recorded in the gallery forests of local rivers and streams, anthropogenic habitats (rubber tree orchards and soybean fields) were occupied only by species adapted to environments where humidity is low, typical of the Cerrado. Overall, the anuran fauna of the study area was characterized by species that depend on access to water bodies for their reproduction, with only a few specialized species able to reproduce in dry environments.

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The expansion of soybean cultivation into the Amazon in Brazil has potential hydrological effects at local to regional scales. To determine the impacts of soybean agriculture on hydrology, a comparison of net precipitation (throughfall, stemflow) in undisturbed tropical forest and soybean fields on the southern edge of the Amazon Basin in the state of Mato Grosso is needed. This study measured throughfall with troughs and stemflow with collar collectors during two rainy seasons. The results showed that in forest 91.6% of rainfall was collected as throughfall and 0.3% as stemflow, while in soybean fields with two-month old plants, 46.2% of rainfall was collected as throughfall and 9.0% as stemflow. Hence, interception of precipitation in soybean fields was far greater than in intact forests. Differences in throughfall, stemflow and net precipitation were found to be mainly associated with differences in plant structure and stem density in transitional forest and soybean cropland. Because rainfall interception in soybean fields is higher than previously believed and because both the area of cropland and the frequency of crop cycles (double cropping) are increasing rapidly, interception needs to be reconsidered in regional water balance models when consequences of land cover changes are analyzed in the Amazon soybean frontier region. Based on the continued expansion of soybean fields across the landscape and the finding that net precipitation is lower in soy agriculture, a reduction in water availability in the long term can be assumed. (C) 2012 Elsevier B.V. All rights reserved.

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An 84-year-old woman underwent hysterectomy due to a friable endometrial mass infiltrating almost half way through the myometrial wall. The tumor consisted of papillary structures with thin fibrovascular cores covered by several layers of pleomorphic cells. The deeply located neoplastic cells were ovoid with a pale eosinophilic cytoplasm resembling urothelial cells. A diagnosis of papillary squamous cell carcinoma of the endometrium with transitional cell differentiation was made. Although she recovered well after surgery, she died one year later because of disseminated disease. In an attempt to obtain new insights into the physiopathology of this very rare tumor, an immunohistochemical panel with 32 markers was performed. The neoplastic cells were positive for cytokeratin 5, vimentin, p63, p21, VEGF, Ki67, BAG1, and bcl-2. The expression of BAG-1 and bcl-2 may suggest that anti-apoptotic stimuli are preponderant in this neoplasm.

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Research has shown that public pay-as-you-go, defined-benefit pension plans penalise those who stay at work beyond a certain age by reducing the present discounted value of future retirement benefits. In discussions on the effectiveness of policies aimed at eliminating the age-dependency factor in workers' decisions to retire, it is often assumed either that the benefits in all future periods have the same weight in the present discounted value or that the discount rate is close to unity due to low real interest rates used in this case. Galuscak first considered the U.S. pension scheme, showing that discounting plays a crucial role since the formula for the present discounted value of future retirement benefits is sensitive to the discount rate used. He then analysed the role of social security incentives and retirement provisions on older workers' behaviour in the labour markets of the Czech and Slovak Republics and the effect of the macroeconomic environment on workers' decisions to retire. He calculated the optimal parameters of the Czech and Slovak pension rules and assessed the potential effectiveness of changes to the Czech scheme introduced in January 1996.

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This project examined the change in values in the still unfinished transitional period in Serbia during the 1990s and compared it with Greece in the same period. During this period the social and political transition affected the ruling value system primarily through changes in the modes of the production and representation of reality. The most remarkable trait of this period in Serbia is the parallel and interweaving existence of different value systems. The very perception of reality has been blurred by the emergence of a very complex technical and ideological structure. Reality is presented by and through extensions and additions, the models of which are language and media. With the development of media technology and global communication and information systems, representation has become the only available reality. This enables the media to overtly and unlimitedly intervene in reality, to manage and change it without constraint and thus have a direct impact on values. The difference between public and private is abolished, so the media start promoting exclusive collective values. However, since the collective thus loses its counterpart, it itself needs to be redefined. This confusion of values make the possible results of their change uncertain. It will either open up a space for multiculturalism and social pluralism and thus completely replace the old systems of values, or result in an indefinite survival of different, often contradictory, value systems and conceptions of reality, which often lead to all forms of exclusivity and intolerance.

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PURPOSE: We evaluated the incidence of pathological findings of the ureter at cystectomy for transitional cell carcinoma of the bladder and assessed the usefulness of intraoperative frozen section examination of the ureter. MATERIALS AND METHODS: Histopathological findings of ureteral frozen section examination were compared to the corresponding permanent sections and the diagnostic accuracy of frozen section examination was evaluated. These segments were then compared to the more proximal ureteral segments resected at the level where they cross over the common iliac arteries. The histopathological findings of the ureteral segments were then correlated for upper urinary tract recurrence and overall survival. RESULTS: Transitional cell carcinoma or carcinoma in situ was found on frozen section examination of the distal ureter in 39 of 805 patients (4.8%) and on permanent sections in 29 (3.6%). In 755 patients the false-negative rate of frozen section examination of the ureters was 0.8%. Of the patients with carcinoma in situ diagnosed on the first frozen section examination 80% also had carcinoma in situ in the bladder. Transitional cell carcinoma or carcinoma in situ in the most proximally resected ureteral segments was found in 1.2% of patients. After radical cystectomy there was tumor recurrence in the upper urinary tract in 3% of patients with negative ureteral frozen section examination and in 17% with carcinoma in situ on frozen section examination. CONCLUSIONS: Routine frozen section examination of the ureters at radical cystectomy is only recommended for patients with carcinoma in situ of the bladder, provided the ureters are resected where they cross the common iliac arteries.

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This paper proposes Poisson log-linear multilevel models to investigate population variability in sleep state transition rates. We specifically propose a Bayesian Poisson regression model that is more flexible, scalable to larger studies, and easily fit than other attempts in the literature. We further use hierarchical random effects to account for pairings of individuals and repeated measures within those individuals, as comparing diseased to non-diseased subjects while minimizing bias is of epidemiologic importance. We estimate essentially non-parametric piecewise constant hazards and smooth them, and allow for time varying covariates and segment of the night comparisons. The Bayesian Poisson regression is justified through a re-derivation of a classical algebraic likelihood equivalence of Poisson regression with a log(time) offset and survival regression assuming piecewise constant hazards. This relationship allows us to synthesize two methods currently used to analyze sleep transition phenomena: stratified multi-state proportional hazards models and log-linear models with GEE for transition counts. An example data set from the Sleep Heart Health Study is analyzed.