957 resultados para Environmental Action for Survival


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Effects of variation in larval quality on post-metamorphic performance in marine invertebrates are increasingly apparent. Recently, it has been shown that variation in offspring size can also strongly affect post-settlement survival, but variation in environmental conditions can mediate this effect. The quality of habitat into which marine invertebrate larvae settle can vary markedly, and 1 influence on quality is the number of conspecifics present. We tested the effects of settler size and settler density on early (1 wk after settlement) post-settlement survival in the field for the solitary ascidian Ciona intestinalis. Larger settlers survived better than smaller settlers, within and among groups of siblings. Increases in the density of settlers decreased survival, but the density-dependent effects were much stronger for smaller settlers. We suggest that larger settlers are better able to cope with intra-specific competition because they have greater energetic reserves or a greater capacity to feed than smaller settlers.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A two-component survival mixture model is proposed to analyse a set of ischaemic stroke-specific mortality data. The survival experience of stroke patients after index stroke may be described by a subpopulation of patients in the acute condition and another subpopulation of patients in the chronic phase. To adjust for the inherent correlation of observations due to random hospital effects, a mixture model of two survival functions with random effects is formulated. Assuming a Weibull hazard in both components, an EM algorithm is developed for the estimation of fixed effect parameters and variance components. A simulation study is conducted to assess the performance of the two-component survival mixture model estimators. Simulation results confirm the applicability of the proposed model in a small sample setting. Copyright (C) 2004 John Wiley Sons, Ltd.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective-To evaluate the presence of a dominance rank in a group of cats and the relation between agonistic behavior and the use of resources, including environmental enrichment, in these cats. Design-Observational analytic study. Animals-27 neutered cats in a shelter in Sao Paulo, Brazil. Procedures-The cats were video recorded for 4 consecutive days to obtain baseline data. Subsequently, a puzzle feeder was added as an enrichment device every other day over 8 days, for a total of 4 days with enrichment. Cats were also video recorded on these days. All pretreatment and posttreatment agonistic behaviors and interactions with the puzzle feeder were recorded by reviewing the videotapes. Results-143 agonistic encounters were recorded, of which 44 were related to resources and 99 were not. There were insufficient agonistic interactions to determine a dominance rank. Presence or absence of the puzzle feeder did not affect the rate of aggression. There was no significant effect of weight, sex, or coat color on the rate of aggression, and aggressive behavior did not correlate with time spent with the puzzle feeder. Twenty-three of the 27 cats interacted with the puzzle feeder. Conclusions and Clinical Relevance-In a stable group of communally housed cats, environmental enrichment did not cause increased aggression as a result of competition for the source of enrichment. Because environmental enrichment increases the opportunity to perform exploratory behaviors, it may improve the welfare of groups of cats maintained long-term in shelters, sanctuaries, or multicat households. (J Am Vet Med Assoc 2011239:796-802)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study of breast cancer survival is based on analysis of five-year relative survival of 38 362 cases of invasive breast cancer in New South Wales (NSW) women, incident between 1972 and 1991, with follow-up to 1992, using data from the population-based NSW Central Cancer Registry. Survival was ascertained by matching the registry file of breast cancers against NSW death certificates from 1972 to 1992, mainly by automated probabilistic linkage. Absolute survival of cases was compared with expected survival of age- and period-matched NSW women. Proportional hazard regression analysis was used for examination of the effects on excess mortality of age, period of diagnosis and degree of spread at diagnosis. Relative survival at five years increased from 70 per cent in 1972-1976 to 77 per cent in 1987-1991. Survival improved during the 1970s and in the late 1980s. Regression analysis suggested that part of the improved survival in the late 1980s was due to lesser degree of spread at diagnosis, whereas the improved survival during the 1970s may have been due to treatment. Survival was better for those aged 40-49 years (RR = 0.86) and worse for those aged greater than or equal to 70 years (RR = 1.22) compared with the referent group (60-69 years). Excess mortality was much less for those with invasive localised disease than those with regional spread (RR = 3.1) or metastatic cancer (RR = 15.5) at diagnosis. For the most recent period (1987-1991), relative five-year survival was 90, 70 and 18 per cent, respectively, for the three degree-of-spread categories.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Human biomonitoring (HBM) of environmental contaminants plays an important role in estimating exposure and evaluating risk, and thus it has been increasingly applied in the environmental field. The results of HBM must be compared with reference values ( RV). The term ""reference values"" has always been related to the interpretation of clinical laboratory tests. For physicians, RV indicate ""normal values"" or ""limits of normal""; in turn, toxicologists prefer the terms ""background values"" or ""baseline values"" to refer to the presence of contaminants in biological fluids. This discrepancy leads to the discussion concerning which should be the population selected to determine RV. Whereas clinical chemistry employs an altered health state as the main exclusion criterion to select a reference population ( that is, a ""healthy"" population would be selected), in environmental toxicology the exclusion criterion is the abnormal exposure to xenobiotics. Therefore, the choice of population to determine RV is based on the very purpose of the RV to be determined. The present paper discusses the concepts and methodology used to determine RV for biomarkers of chemical environmental contaminants.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: The aims of this study were to analyze the overall survival of patients with cirrhosis and small hepatocellular carcinoma (HCC) and identify independent pretreatment predictors of survival in Brazil. Methods: Between 1998 and 2003, 74 patients with cirrhosis and small HCC were evaluated. Predictors of survival were identified using the Kaplan-Meier survival curves and the Cox model. Results: The overall survival rates were 80%, 41%, and 17% at 12, 36, and 60 months, respectively. The mean length of follow-up after HCC diagnosis was 23 months (median 22 mo, range: I to 86 mo) for the entire group. Univariate analysis showed that model for endstage liver disease (MELD) score (P = 0.016), Child-Pugh classification (P = 0.007), alpha-fetoprotein level (P = 0.006), number of nodules (P = 0.041), tumor diameter (P = 0.009), and vascular invasion (P < 0.0001) were significant predictors Of Survival. Cox regression analysis identified vascular invasion (relative risk = 14.60, confidence interval 95% = 3.3-64.56, P < 0.001) and tumor size > 20 mm (relative risk = 2.14, confidence interval 95% = 1.07-4.2, P = 0.030) as independent predictors of decreased survival. Treatment of HCC was related to increased overall survival. Conclusions: Identification of HCC smaller than 20 mm is associated with longer survival. Presence of vascular invasion, even in small tumors, maybe associated with poor prognosis. Treatment of small tumors Of LIP to 20 mm diameter is related to increased survival.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In early stage (I and II) laryngeal squamous cell carcinoma, both surgery and radiotherapy results in significant local and regional control. In advanced tumors (III and IV), radiotherapy alone has local-regional control rates of 32-43%. Aim: To assess disease-free survival in SCC laryngeal carcinoma patients submitted to radiotherapy alone and/or associated with chemotherapy. Materials and Methods: Retrospective study involving 84 cases of laryngeal SCC treated with radiotherapy or chemotherapy together with radiotherapy. Fifty-three cases were treated with intension to cure and 31 because of impossibility to resect the disease. As to clinical stage (CS), 12 were CS I, 15 II, 21 III and 5 IV. In the second group, 11 cases were EC III and 20 IV. Results: Mean age was 60 years, 84.5% were men. Fifty-eight (69.1%) cases had complete response and 26 (30.9%) had persistent or residual disease. Five-year disease-free survival was of 42.5%; 62.5% of the patients with organ preservation indication and 9.75 in the group of irressecable disease. Conclusion: disease-free survival of those patients submitted to radiotherapy because of laryngeal SCC was of 62.5%

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: To evaluate overall and relapse-free survival (RFS) in patients with nonmycosis fungoides (non-MF) primary cutaneous lymphoma (PCL). Methods: Thirty-eight patients with PCL excluding cases of MF treated between 1993 and 2006 were analyzed retrospectively. Survival statistics were estimated by the methods of Kaplan and Meier, and univariate and multivariate significance testing were performed by Cox regression analysis. Results: The median follow-up was 34.6 months (range, 2-138.3 months). The overall survival for the entire study population, at 5 and 10 years, was 97% and 78%, respectively. The RFS for the entire study population, at 5 and 10 years, was 30% and 22%, respectively. For those who received radiotherapy (RT) as a component of their initial therapy, the RFS at 5 and 10 years was 48% and 36%, respectively. Among those receiving RT who relapsed, the site of relapse was out-of-field in 82% of the cases. In our multivariate analysis, only RT as a component of the initial therapy and the absence of bulky disease had a statistically significant improvement in RFS (P = 0.01 and < 0.01, respectively). Conclusion: RT improves the local control and RFS of patients with non-MF PCL.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The presence of domestic animals in protected areas has been a growing world concern, including in the Brazilian Amazon. Introduced domestic carnivores can put the conservation of carnivores and other wild mammals at risk in protected areas. These risks can be associated with direct factors, such as the dogs` hunting habit, and indirect factors, such as the domestic carnivores` potential for transmitting infectious agents to wild populations. The objective of this study was to analyze the potential implications of humans and domestic animals staying in fragmented and altered areas such as the Wildlife Protection Areas (WPA) in the Tucuruf Lake Environmental Protection Area (Para, Brazil), created for the full protection of its fauna and flora. This evaluation was made through interviews conducted with riparian inhabitants living in the WPA and surrounding area, involving issues related to the presence of dogs (number of animals per domicile, birth rate, mortality rate, vaccination status, hunting habit) and wild carnivores (occurrence and location) in the study area. The results indicated risks mainly due to the presence of on average three dogs per domicile, as well as the high canine birth rate, their hunting habits, low vaccination rates and evidence of direct and indirect contact with the human, canine and wild carnivore populations. These factors represent risks to the health and conservation of Tucurui EPA wild carnivores since they provide favorable conditions for the transmission of pathogens from domestic fauna to wild fauna, as well as the risks brought about by hunting.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Paracoccidioidomycosis, a debilitating pulmonary mycosis, is caused by the dimorphic fungus Paracoccidioides brasiliensis. The infection results in the formation of granulomas containing viable yeast cells that are the fungal sources for disease reactivation. Because CD4(+)CD25(+) regulatory T cells (Tregs) are in the lesions of patients with paracoccidioidomycosis, the migration of Treg cells is dependent on the axis chemokine-chemokine receptors, and CCR5 ligands are produced in P. brasiliensis-induced lesions, we investigated the role of CCR5 in the control of the infection. The results showed that CCR5(-/-) mice are more efficient in controlling fungal growth and dissemination and exhibited smaller granulomas than wild-type (WT) mice. In the absence of CCR5, the percentage of CD4(+)CD25(+) T cells expressing Foxp3, glucocorticoid-induced TNFR (GITR), CD103, CD45(low), and CTLA-4 in the granulomas was significantly decreased. Interestingly, P. brasiliensis infection resulted in an absence of T cell proliferation in response to Con A in WT but not CCR5(-/-) mice that was abrogated by anti-CTLA-4 mAb and anti-GITR mAb. Moreover, the adoptive transfer of CD4(+)CD25(+) but not CD4(+)CD25(-) T cells from infected WT to infected CCR5(-/-) mice resulted in a significant increase in fungal load. Overall, CCR5 is a key receptor for the migration of Treg cells to the site of P. brasiliensis infections leading to down-modulation of effector immune response and the long-term presence of the fungus in the granulomas. Thus, a tight control of Treg cell migration to the granulomatous lesions could be an important mechanism for avoiding exacerbation and reactivation of the disease.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Relationships were examined between environmental conditions mediated by packaging and handling and the deterioration of harvested Geraldton waxflower cv. 'Fortune Cookie'. Disease severity plus flower and leaf drop caused by inoculation with Botrytis cinerea were reduced by lowering handling temperatures to 0, 5 or 5/20 degreesC alternated daily, versus 20 degreesC. They were also reduced by inhibition of ethylene action with a silver thiosulfate pulse pretreatment. Additionally, treatments that enhanced water loss, such as packing dry, keeping forced air-cooling holes open and strategic placement of extra ventilation holes may also reduce disease severity and flower plus leaf fall. Inclusion of KMnO4-based Bloomfresh ethylene scrubbing sachets in packages did not reduce disease severity or lessen flower plus leaf fall. Thus, deterioration of waxflower packaged in commercial cartons can be minimised by keeping temperatures low, packing plant material dry, use of cartons with strategically placed ventilation holes and/or pretreatment with silver thiosulfate.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Economic globalisation is seen by many as a driving force for global economic growth. Yet opinion is divided about the benefits of this process, as highlighted by the WTO meeting in Seattle in late 1999. Proponents of economic globalisation view it as a positive force for environmental improvement and as a major factor increasing the likelihood of sustainable development through its likely boost to global investment. These proponents mostly appeal to analysis based on the environmental Kuznets curve (EKC) to support their views about environmental improvement. But EKC-analysis has significant deficiencies. Furthermore, it is impossible to be confident that the process of economic globalisation will result in sustainable development, if 'weak conditions' only are satisfied. 'Strong conditions' probably need to be satisfied to achieve sustainable development, and given current global institutional arrangements, these are likely to be violated by the economic globalisation process. Global political action seems to be needed-to avert a deterioration in the global environment and to prevent unsustainability of development. This exposition demonstrates the limitations of EKC-analysis, identifies positive and negative effects of economic globalisation on pollution levels, and highlights connections between globalisation and the debate about whether strong or weak conditions are required for sustainable development. The article concludes with a short discussion of the position of WTO in relation to trade and the environment and the seemingly de facto endorsement of WTO of weak conditions for sustainable development. It suggests that WTO's relative neglect of environmental concerns is no longer politically tenable and needs to be reassessed in the light of recent developments in economic analysis. The skew of economic growth, e.g. in favour of developing countries, is shown to be extremely important from a global environmental perspective. (C) 2001 Elsevier Science B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper discusses generally why humans should bother to conserve sea turtles. In doing so, it considers both economic and non-economic reasons and outlines threats to the existence of sea turtles and ways in which tourism may either contribute to the conservation or decline of their populations. Turtle-based ecotourism at Mon Repos in southern Queensland is described. As a result of a survey conducted by the authors, it is shown that turtle-based ecotourism at Mon Repos has positive social (indirect) consequences for the conservation of sea turtles. Furthermore, it is argued that ecotourism operations at Mon Repos have positive direct impacts on the sustainability of populations of sea turtles. However, using a simple model, it is emphasised that this impact is limited because turtles are migratory. A model is also developed to capture the possible relationship between turtle populations and the sustainability of ecotourism dependent on turtle populations, and is extended to other wildlife species. Significant interdependence exists between the sustainability of these two variables. The theory is related to Ciriacy-Wantrup's social safe minimum conservation standard for species' survival.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The motivation for concern about the environment beyond one's neighborhood is still relatively poorly understood. This article examines the determinants of feelings of responsibility at a regional watershed level. Using demographic, attitudinal, self-reported behavior and neighborhood mapping measures from four cities in Australia, five hypotheses were derived. These were that wider environmental concerns would depend on (a) the physical and social characteristics of the respondents' neighborhoods, (b) the size of their perceived neighborhoods, (c) the length of residence at their localities, (d) educational level and attitudes toward environmental moral responsibility (and the interaction between them), and (e) the level of reported environmentally friendly behavior. Support was gained for all hypotheses except length of residence and the role of general moral attitudes toward the environment. It is concluded that to explain community action at the regional level, it is important to include both spatial and psychological insights and methodologies in research.