865 resultados para Diamond, Jared: Collapse. How Societies Choose to Fail or Succeed


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Cet article présente les résultats de la revue systématique: Singata M, Tranmer J, Gyte GM. Restricting oral fluid and food intake during labour. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD003930. PMID: 20091553.

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PURPOSE: Human immunodeficiency virus (HIV)-positive adolescents face a number of challenges in dealing with their disease, treatment, and developmental tasks. This qualitative study describes some of the reasons why, and the extent to which, adolescents may or may not disclose their condition to others. METHODS: A semistructured interview lasting 40-110 minutes was conducted with each of 29 adolescents 12-20 years old, 22 female and seven male) living in Switzerland. Interviews were tape recorded and transcribed verbatim. The analysis of the content of interviews allowed us to identify salient topics (e.g., disclosure), which were then explored in detail. RESULTS: Of 29 participants, eight had not disclosed their condition to anyone outside the family, 19 had disclosed it to good friends, and 16 had disclosed it to some teachers. Four participants had engaged in public disclosure, and six of 10 sexually active teenagers disclosed their status to their partners. The attitudes toward disclosure among younger adolescents were mostly related to those of the parents, particularly the mother. Older adolescents, engaged in their search for autonomy, tended to decide independently what to say and to whom. Although foster/adoptive parents would often encourage disclosure, biological parents, especially HIV-positive mothers, insisted on not disclosing the adolescent's status for fear of stigma. CONCLUSION: The health care team should systematically address the issue of disclosure with the adolescent and his family (or foster parents), the aim being to balance the right of the adolescent and that adolescent's family to maintain privacy against the concerns of sexual partners, as well as the adolescent's interest in divulging HIV status to relatives, school staff, and friends.

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PURPOSE: The aim of this study was to assess the outcome in patients with penile cancer. METHODS AND MATERIALS: A total of 60 patients with penile carcinoma were included. Of the patients, 45 (n = 27) underwent surgery, and 51 underwent definitive (n = 29) or postoperative (n = 22) radiotherapy (RT). Median follow-up was 62 months. RESULTS: Median time to locoregional relapse was 14 months. Local failure was observed in 3 of 23 patients (13%) treated with surgery with or without postoperative RT vs. in 19 of 33 patients (56%) given organ-sparing treatment (p = 0.0008). Of 22 local failures, 16 (73%) were salvaged with surgery. Of the 33 patients treated with definitive RT (n = 29) and the 4 patients refusing RT after excisional biopsy, local control was obtained with organ preservation in 13 (39%). In the remaining 20, 4 patients with local failure underwent salvage conservatively, resulting in an ultimate penis preservation rate of 17 of 33 (52%) patients treated with definitive RT. The 5-year and 10-year probability of surviving with an intact penis was 43% and 26%, respectively. There was no survival difference between the patients treated with definitive RT and primary surgery (56% vs. 53%; p = 0.16). In multivariate analysis, independent factors influencing survival were N-classification and pathologic grade. Surgery was the only independent predictor for better local control. CONCLUSION: Based on our study findings, in patients with penile cancer, local control is superior with surgery. However, there is no difference in survival between patients treated with surgery and those treated with definitive RT, with 52% organ preservation.

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On en parle ! Il est question de la suppression des règles par l'administration de contraceptifs oestro-progestatifs (pilule, patch ou anneau vaginal) en cycles longs (cycles prolongés ; cycles étendus ; extended cycles) entraînant des périodes d'aménorrhée, rythmées par des intervalles libres de sept jours sans administration hormonale. L'indication à ce mode de prescription est presque unanimement reconnue pour le traitement des pathologies bénéficiant de la suppression des règles et des fluctuations hormonales inhérentes à l'activité ovarienne. Ce traitement suscite cependant également de l'intérêt pour une indication du type mode de vie. Les modalités thérapeutiques, les avantages et inconvénients sont examinés à la lumière de l'attente des femmes et de leur droit au choix éclairé et libre. Let's talk about it ! Suppression of menstruation, by extending the duration of contraceptives containing estro-progestins (oral contraception, patch or vaginal ring) to long cycles, is a new approach in the field of contraception. These extended cycles aim at obtaining prolonged amenorrhea, interrupted periodically by a free interval of 7 days without hormone intake and thus causing breakthrough bleeding. Pathologies, which are supposed to get some benefit from the suppression of menstruation and of hormone level variations related to ovarian activity, are widely recognized as an indication. Some interest is also coming up for so called life style indications. Treatment issues, advantages and disadvantages are examined in the light of women's expectations and right to access to informed consent and independent choice.

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Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.

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Cytomegalovirus (CMV) is generally considered the most significant pathogen to infect patients following organ transplantation. Significant improvements have been achieved in the management of CMV disease over recent years, especially since the introduction of oral drugs such as oral ganciclovir followed by valganciclovir (VGC), a prodrug of ganciclovir with enhanced bioavailability. Several randomized controlled trials have shown that VGC is an efficacious and convenient oral drug to prevent or treat CMV disease in solid-organ transplant recipients. In this article, we discuss the clinical and pharmacological experience with the use of VGC for the management of CMV in solid-organ transplant recipients. Finally, novel strategies to further reduce the incidence of CMV disease after transplantation are also reviewed.

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We conduct a large-scale comparative study on linearly combining superparent-one-dependence estimators (SPODEs), a popular family of seminaive Bayesian classifiers. Altogether, 16 model selection and weighing schemes, 58 benchmark data sets, and various statistical tests are employed. This paper's main contributions are threefold. First, it formally presents each scheme's definition, rationale, and time complexity and hence can serve as a comprehensive reference for researchers interested in ensemble learning. Second, it offers bias-variance analysis for each scheme's classification error performance. Third, it identifies effective schemes that meet various needs in practice. This leads to accurate and fast classification algorithms which have an immediate and significant impact on real-world applications. Another important feature of our study is using a variety of statistical tests to evaluate multiple learning methods across multiple data sets.

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Highway maintenance engineers and administrators are often confronted with a number of problems related to highway maintenance work programs. One of these problems is concerned with determining the optimum number and locations of highway maintenance garages in a given area. Serious decline in highway revenues and a high inflation rate have made it necessary to examine existing maintenance practices and to allocate reduced financial resources more effectively and efficiently. Searching for and providing of reasonable solutions to these problems is the focus of this research project. The methodology used is to identify and modify for use (if necessary) those models which have already been developed. Models which could give optimum number and locations of highway maintenance garages were found to be too theoretical and/or practically infeasible. Consequently, research focus was shifted from these models to other models that could compare alternatives and select the best among these alternatives. Three such models -- the Alabama model, California model, and Louisiana model, were identified and studied.

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Cilengitide is a cyclic peptide antagonist of integrins alphavbeta3 and alphavbeta5 that is currently being evaluated as a novel therapeutic agent for recurrent and newly diagnosed glioblastoma. Its mode of action is thought to be mainly antiangiogenic but may include direct effects on tumor cells, notably on attachment, migration, invasion, and viability. In this study we found that, at clinically relevant concentrations, cilengitide (1-100 microM) induces detachment in some but not all glioma cell lines, while the effect on cell viability is modest. Detachment induced by cilengitide could not be predicted by the level of expression of the cilengitide target molecules, alphavbeta3 and alphavbeta5, at the cell surface. Glioma cell death induced by cilengitide was associated with the generation of caspase activity, but caspase activity was not required for cell death since ectopic expression of cytokine response modifier (crm)-A or coexposure to the broad-spectrum caspase inhibitor zVAD-fmk was not protective. Moreover, forced expression of the antiapoptotic protein marker Bcl-X(L) or altering the p53 status did not modulate cilengitide-induced cell death. No consistent effects of cilengitide on glioma cell migration or invasiveness were observed in vitro. Preliminary clinical results indicate a preferential benefit from cilengitide added to temozolomide-based radiochemotherapy in patients with O(6)-methylguanine DNA methyltransferase (MGMT) gene promoter methylation. Accordingly, we also examined whether the MGMT status determines glioma cell responses to cilengitide alone or in combination with temozolomide. Neither ectopic expression of MGMT in MGMT-negative cells nor silencing the MGMT gene in MGMT-positive cells altered glioma cell responses to cilengitide alone or to cilengitide in combination with temozolomide. These data suggest that the beneficial clinical effects derived from cilengitide in vivo may arise from altered perfusion, which promotes temozolomide delivery to glioma cells.