954 resultados para Rising interest rates
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Background: Worldwide, a high proportion of HIV-infected individuals enter into HIV care late. Here, our objective was to estimate the impact that late entry into HIV care has had on AIDS mortality rates in Brazil. Methodology/Principal Findings: We analyzed data from information systems regarding HIV-infected adults who sought treatment at public health care facilities in Brazil from 2003 to 2006. We initially estimated the prevalence of late entry into HIV care, as well as the probability of death in the first 12 months, the percentage of the risk of death attributable to late entry, and the number of avoidable deaths. We subsequently adjusted the annual AIDS mortality rate by excluding such deaths. Of the 115,369 patients evaluated, 50,358 (43.6%) had entered HIV care late, and 18,002 died in the first 12 months, representing a 16.5% probability of death in the first 12 months (95% CI: 16.3-16.7). By comparing patients who entered HIV care late with those who gained timely access, we found that the risk ratio for death was 49.5 (95% CI: 45.1-54.2). The percentage of the risk of death attributable to late entry was 95.5%, translating to 17,189 potentially avoidable deaths. Averting those deaths would have lowered the 2003-2006 AIDS mortality rate by 39.5%. Including asymptomatic patients with CD4(+) T cell counts >200 and <= 350 cells/mm(3) in the group who entered HIV care late increased this proportion by 1.8%. Conclusions/Significance: In Brazil, antiretroviral drugs reduced AIDS mortality by 43%. Timely entry would reduce that rate by a similar proportion, as well as resulting in a 45.2% increase in the effectiveness of the program for HIV care. The World Health Organization recommendation that asymptomatic patients with CD4(+) T cell counts <= 350 cells/mm(3) be treated would not have a significant impact on this scenario.
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1. Little is known about the role of deep roots in the nutrition of forest trees and their ability to provide a safety-net service taking up nutrients leached from the topsoil. 2. To address this issue, we studied the potential uptake of N, K and Ca by Eucalyptus grandis trees (6 years of age - 25 m mean height), in Brazil, as a function of soil depth, texture and water content. We injected NO(3)(-)- (15)N, Rb(+) (analogue of K(+)) and Sr(2+) (analogue of Ca(2+)) tracers simultaneously in a solution through plastic tubes at 10, 50, 150 and 300 cm in depth in a sandy and a clayey Ferralsol soil. A complete randomized design was set up with three replicates of paired trees per injection depth and soil type. Recently expanded leaves were sampled at various times after tracer injection in the summer, and the experiment was repeated in the winter. Soil water contents were continuously monitored at the different depths in the two soils. 3. Determination of foliar Rb and Sr concentrations and (15)N atom % made it possible to estimate the relative uptake potential (RUP) of tracer injections from the four soil depths and the specific RUP (SRUP), defined as RUP, per unit of fine root length density in the corresponding soil layer. 4. The highest tracer uptake rates were found in the topsoil, but contrasting RUP distributions were observed for the three tracers. Whilst the RUP was higher for NO(3)(-)- (15)N than for Rb(+) and Sr(2+) in the upper 50 cm of soil, the highest SRUP values for Sr(2+) and Rb(+) were found at a depth of 300 cm in the sandy soil, as well as in the clayey soil when gravitational solutions reached that depth. 5. Our results suggest that the fine roots of E. grandis trees exhibit contrasting potential uptake rates with depth depending on the nutrient. This functional specialization of roots might contribute to the high growth rates of E. grandis trees, efficiently providing the large amounts of nutrients required throughout the development of these fast-growing plantations.
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Background: Prevalence rates of smoking are rising in developing countries. Previous trials evaluating the efficacy and tolerability of the smoking-cessation medication varenicline have used largely participants of Caucasian origin. Objective: This study was conducted to evaluate the efficacy and tolerability of varenicline in populations of participants from Latin America, Africa, and the Middle East to investigate potential differences in the therapeutic response to varenicline. Methods: This multinational, randomized, double-blind, placebo-controlled trial was conducted at 42 centers in 11 countries (Latin America: Brazil, Colombia, Costa Rica, Mexico, and Venezuela; Africa: Egypt and South Africa; Middle East: Jordan, Lebanon, Saudi Arabia, and the United Arab Emirates). Participants were male and female smokers aged 18 to 75 years who were motivated to stop smoking; smoked >= 10 cigarettes/d, with no cumulative period of abstinence >3 months in the previous year; and who had no serious or unstable disease within the previous 6 months. Subjects were randomized in a 2:1 ratio to receive varenicline 1 mg or placebo, BID for 12 weeks, with a 12-week nontreatment follow-up. Brief smoking-cessation counseling was provided. The main outcome measures were carbon monoxide confirmed continuous abstinence rate (CAR) at weeks 9 to 12 and weeks 9 to 24. Adverse events (AEs) were recorded for tolerability assessment. Results: Overall, 588 subjects (varenicline, 390; placebo, 198) were randomized and treated. The mean (SD) ages of subjects in the varenicline and placebo groups were 43.1 (10.8) and 43.9 (10.8) years, respectively; 57.7% and 65.7% were male; and the mean (SD) weights were 75.0 (16.0) and 76.7 (16.3) kg (range, 40.0-130.0 and 45.6-126.0 kg). CAR at weeks 9 to 12 was significantly higher with varenicline than with placebo (53.59% vs 18.69%; odds ratio [OR] = 5.76; 95% CI, 3.74-8.88; P < 0.0001), and this rate was maintained during weeks 9 to 24 (39.74% vs 13.13%; OR = 4.78; 95% CI, 2.97-7.68; P < 0.0001). Nausea, headache, and insomnia were the most commonly reported AEs with varenicline and were reported numerically more frequently in the varenicline group compared with the placebo group. Serious AEs (SAEs) were reported in 2.8% of varenicline recipients compared with 1.0% in the placebo group, with 6 subjects reporting psychiatric SAEs compared with none in the placebo group. Conclusion: Based on these data, varenicline was apparently efficacious and generally well tolerated as a smoking-cessation aid in smokers from selected sites in Latin America, Africa, and the Middle East. ClinicalTrials. gov identifier: NCT00594204. (Clin Ther. 2011;33:465-477) (C) 2011 Published by Elsevier HS Journals, Inc.
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Seven food grade commercially available lipases were immobilized by covalent binding on polysiloxane-polyvinyl alcohol (POS-PVA) hybrid composite and screened to mediate reactions of industrial interest. The synthesis of butyl butyrate and the interesterification of tripalmitin with triolein were chosen as model reactions. The highest esterification activity (240.63 mu M/g min) was achieved by Candida rugosa lipase, while the highest interesterification yield (31%, in 72 h) was achieved by lipase from Rhizopus oryzae, with the production of about 15 mM of the triglycerides C(50) and C(52). This lipase also showed a good performance in butyl butyrate synthesis, with an esterification activity of 171.14 mu M/g min. The results demonstrated the feasibility of using lipases from C. rugosa for esterification and R. oryzae lipase for both esterification and interesterification reactions.
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To analyse the sensitivity and specificity of clinical indicators of ineffective airway clearance in children with congenital heart disease and to identify the indicators that have high predictive power. The precise establishment of nursing diagnoses has been found to be one of the factors contributing to higher quality of care and cost reduction in healthcare institutions. The use of indicators to diagnose ineffective airway clearance could improve care of children with congenital heart disease. Longitudinal study. Participants consisted of 45 children, <= 1 year of age, with congenital heart disease, who had not had definitive or palliative surgical correction. Six assessments were made at 2-day intervals. Each clinical indicator was defined based on previously established operational criteria. Sensitivity, specificity and positive and negative predictive values of each indicator were calculated based on a model for the longitudinal data. A nursing diagnosis of ineffective airway clearance was made in 31% of patients on the first assessment, rising to 71% on the last assessment, for a 40% increase. Sensitivity was highest for Changes in Respiratory Rates/Rhythms (0.99), followed by Adventitious Breath Sounds (0.97), Sputum Production (0.85) and Restlessness (0.53). Specificity was higher for Sputum Production (0.92), followed by Restlessness (0.73), Adventitious Breath Sounds (0.70) and Changes in Respiratory Rates/Rhythms (0.17). The best positive predictive values occurred for Sputum Production (0.93) and Adventitious Breath Sounds (0.80). Adventitious Breath Sounds followed by Sputum Production were the indicators that had the best overall sensitivity and specificity as well as the highest positive predictive values. The use of simple indicators in nursing diagnoses can improve identification of ineffective airway clearance in children with congenital heart disease, thus leading to early treatment of the problem and better care for these children.
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Thermal action on timber causes it to degrade through combustion of its chemical components, which leads to the release of vapors, combustible gases and surface char. This diminishes its load capacity, due to the reduction of its cross section by charring and to changes in its mechanical properties of strength and stiffness as a function of its exposure to high temperatures. This paper reports the charring rates observed on Eucalyptus structural beams and presents a numerical and experimental study of the behavior of these beams when exposed to fire, in which the properties of strength and stiffness were evaluated as a function of rising temperatures, allowing an analysis of the effect of the section factor on the internal rise in temperature of structural Eucalyptus beams.
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Collapsible soils are usually nonsaturated, low density, and metastable-structured soils that are known to exhibit a volume reduction following an episode of moisture increase or suction reduction. This paper describes the collapsible behavior of clayey sand based on controlled soil suction tests carried out on undisturbed samples from the city of Pereira Barreto, in the State of Sao Paulo, Brazil. Foundation settlements due to soil collapse are common in this region and occurred during the filling of the reservoir of the Tres Irmaos Dam, which induced the elevation of the groundwater table in different parts of Pereira Barreto. This paper shows that collapse strains depend on the stress and soil suction acting in the sample and that saturation is not necessary for a collapse to occur. The influence of soil suction, gradual wetting, and the wetting and drying cycle on the collapsible behavior of the soil is also shown and discussed.
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In the present work the squeeze flow technique was used to evaluate the rheological behavior of cement-based mortars containing macroscopic aggregates up to 1.2 mm. Compositions with different water and air contents were tested at three squeezing rates (0.01, 0.1 and 1 mm/s) 15 and 60 min after mixing. The mortars prepared with low (13 wt.%) and usual water content (15 wt.%) presented opposite behaviors as a function of elapsed time and squeezing speed. The first lost its cohesion with time and required higher loads when squeezed faster, while the latter became stiffer with time and was more difficult to be squeezed slowly as a result of phase segregation. Due to the increase of air content, the effects of this compressible phase became more significant and a more complex behavior was observed. Rheological properties such as elongational viscosity and yield stress were also determined. (C) 2009 Elsevier Ltd. All rights reserved.
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The abrasive wear resistance of white cast iron was studied. The iron was solidified using two solidification rates of 1.5 and 15 degrees C/s. Mass loss was evaluated with tests of the type pin on abrasive disc using alumina of different sizes. Two matrices were tested: one predominantly austenitic and the other predominantly martensitic, containing M(3)C carbides. Samples with cooling rate of 15 degrees C/s showed higher hardness and more refined microstructure compared with those solidified at 1.5 degrees C/s. During the test, the movement of successive abrasives gave rise to the strain hardening of the austenite phase, leading to the attainment of similar levels of surface hardness, which explains why the wear rate showed no difference compared to the austenite samples with different solidification rates. For the austenitic matrix the wear rate seems to depend on the hardness of the worn surface and not on the hardness of the material without deformation. The austenitic samples showed cracking and fracture of M(3)C carbides. For the predominantly martensitic matrix, the wear rate was higher at the solidification rate of 1.5 degrees C/s, for grain size of 66 and 93 mu m. Higher abrasive sizes were found to produce greater penetration and strain hardening of austenitic matrices. However, martensitic iron produces more microcutting, increasing the wear rate of the material. The analysis of the worn surface by scanning electron microscopy indicated abrasive wear mechanisms such as: microcutting, microfatigue and microploughing. Yet, for the iron of austenitic matrix, the microploughing mechanism was more severe. (C) 2009 Elsevier B.V. All rights reserved.
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The effect of different microstructures on the polarization resistance (Rp) and the hydrogen-induced cracking (HIC) of a micro-alloyed steel austenitized and submitted to different cooling rates was studied. Samples 19.1 x 6 x 2 mm, containing the whole thickness of the plate were extracted from a 20 mm plate and heat treated on a quenching dilatometer, were submitted to Rp and HIC corrosion tests. Both Rp and HIC tests followed as close as possible ASTM G59 and NACE standard TM0284-2003, in this case, modified only with regard to the size of the samples. Steel samples transformed from austenite by a slow cooling (cooling rate of 0.5 degrees C.s(-1)) showed higher susceptibility to hydrogen-induced cracking, with large cracks in the middle of the sample propagating along segregation bands, corresponding to the centerline of the plate thickness. For cooling rates of 10 degrees C.s(-1), only small cracks were found in the matrix and micro cracks nucleated at non-metallic inclusions. For higher cooling rates (40 degrees C.s(-1)) very few small cracks were detected, linked to non-metallic inclusions. This result suggests that structures formed by polygonal structures and segregation bands (were cutectoid microconstituents predominate) have higher susceptibility to HIC. Structures predominantly formed by acicular ferrite make it difficult to propagate the cracks among non-oriented and interlaced acicular ferrite crystals. Smaller segregation bands containing eutectoid products also help inhibit cracking and crack propagation; segregation bands can function as pipelines for hydrogen diffusion and offer a path of stress concentration for the propagation of cracks, frequently associated to non-metallic inclusions. Polarization resistance essays performed on the steel in theas received condition, prior to any heat treatment, showed larger differences between the regions of the plate, with a considerably lower Rp in the centerline. The austenitization heat treatments followed by cooling rates of 0.5 e 10 degrees C.s(-1) made more uniform the corrosion resistance along the thickness of the plate. The effects of heat treatments on the corrosion resistance are probably related to the microconstituent formed, allied to the chemical homogenization of the impurities concentrated on the centerline of the plate.
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Cooling towers are widely used in many industrial and utility plants as a cooling medium, whose thermal performance is of vital importance. Despite the wide interest in cooling tower design, rating and its importance in energy conservation, there are few investigations concerning the integrated analysis of cooling systems. This work presents an approach for the systemic performance analysis of a cooling water system. The approach combines experimental design with mathematical modeling. An experimental investigation was carried out to characterize the mass transfer in the packing of the cooling tower as a function of the liquid and gas flow rates, whose results were within the range of the measurement accuracy. Then, an integrated model was developed that relies on the mass and heat transfer of the cooling tower, as well as on the hydraulic and thermal interactions with a heat exchanger network. The integrated model for the cooling water system was simulated and the temperature results agree with the experimental data of the real operation of the pilot plant. A case study illustrates the interaction in the system and the need for a systemic analysis of cooling water system. The proposed mathematical and experimental analysis should be useful for performance analysis of real-world cooling water systems. (C) 2009 Elsevier Ltd. All rights reserved.
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The sustainability of fast-growing tropical Eucalyptus plantations is of concern in a context of rising fertilizer costs, since large amounts of nutrients are removed with biomass every 6-7 years from highly weathered soils. A better understanding of the dynamics of tree requirements is required to match fertilization regimes to the availability of each nutrient in the soil. The nutrition of Eucalyptus plantations has been intensively investigated and many studies have focused on specific fluxes in the biogeochemical cycles of nutrients. However, studies dealing with complete cycles are scarce for the Tropics. The objective of this paper was to compare these cycles for Eucalyptus plantations in Congo and Brazil, with contrasting climates, soil properties, and management practices. The main features were similar in the two situations. Most nutrient fluxes were driven by crown establishment the two first years after planting and total biomass production thereafter. These forests were characterized by huge nutrient requirements: 155, 10, 52, 55 and 23 kg ha(-1) of N, P, K, Ca and Mg the first year after planting at the Brazilian study site, respectively. High growth rates the first months after planting were essential to take advantage of the large amounts of nutrients released into the soil solutions by organic matter mineralization after harvesting. This study highlighted the predominant role of biological and biochemical cycles over the geochemical cycle of nutrients in tropical Eucalyptus plantations and indicated the prime importance of carefully managing organic matter in these soils. Limited nutrient losses through deep drainage after clear-cutting in the sandy soils of the two study sites showed the remarkable efficiency of Eucalyptus trees in keeping limited nutrient pools within the ecosystem, even after major disturbances. Nutrient input-output budgets suggested that Eucalyptus plantations take advantage of soil fertility inherited from previous land uses and that long-term sustainability will require an increase in the inputs of certain nutrients. (C) 2009 Elsevier B.V. All rights reserved.
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The tomato red spider mite, Tetranychus evansi (Acari: Tetranychidae) was recently introduced in Africa and Europe, where there is an increasing interest in using natural enemies to control this pest on solanaceous crops. Two promising candidates for the control of T. evansi were identified in South America, the fungal pathogen, Neozygites floridana and the predatory mite Phytoseiulus longipes. In this study, population dynamics of T. evansi and its natural enemies together with the influence of environmental conditions on these organisms were evaluated during four crop cycles in the field and in a protected environment on nightshade and tomato plants with and without application of chemical pesticides. N. floridana was the only natural enemy found associated with T. evansi in the four crop cycles under protected environment but only in the last crop cycle in the field. In the treatments where the fungus appeared, reduction of mite populations was drastic. N. floridana appeared in tomato plants even when the population density of T. evansi was relatively low (less than 10 mites/3.14 cm(2) of leaf area) and even at this low population density, the fungus maintained infection rates greater than 50%. The application of pesticides directly affected the fungus by delaying epizootic initiation and contributing to lower infection rates than unsprayed treatments. Rainfalls did not have an apparent impact on mite populations. These results indicate that the pathogenic fungus, N. floridana can play a significant role in the population dynamics of T. evansi, especially under protected environment, and has the potential to control this pest in classical biological control programs. (C) 2009 Elsevier Inc. All rights reserved.
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Over the years, crop insurance programs became the focus of agricultural policy in the USA, Spain, Mexico, and more recently in Brazil. Given the increasing interest in insurance, accurate calculation of the premium rate is of great importance. We address the crop-yield distribution issue and its implications in pricing an insurance contract considering the dynamic structure of the data and incorporating the spatial correlation in the Hierarchical Bayesian framework. Results show that empirical (insurers) rates are higher in low risk areas and lower in high risk areas. Such methodological improvement is primarily important in situations of limited data.
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The influence of arbuscular mycorrhizal fungi (AMF) inoculation on Canavalia ensiformis growth. nutrient and Zn uptake, and on some physiological parameters in response to increasing soil Zn concentrations was studied. Treatments were applied in seven replicates in a 2 x 4 factorial design, consisting of the inoculation or not with the AMF Glomus etunicatum, and the addition of Zn to soil at the concentrations of 0, 100, 300 and 900 mg kg(-1). AMF inoculation enhanced the accumulation of Zn in tissues and promoted biomass yields and root nodulation. Mycorrhizal plants exhibited relative tolerance to Zn up to 300 mg kg(-1) without exhibiting visual symptoms of toxicity, in contrast to non-mycorrhizal plants which exhibited a significant growth reduction at the same soil Zn concentration. The highest concentration of Zn added to soil was highly toxic to the plants. Leaves of plants grown in high Zn concentration exhibited a Zn-induced proline accumulation and also an increase in soluble amino acid contents; however proline contents were lower in mycorrhizal jack beans. Plants in association or not with the AMF exhibited marked differences in the foliar soluble amino acid profile and composition in response to Zn addition to soil. In general, Zn induced oxidative stress which could be verified by increased lipid peroxidation rates and changes in catalase, ascorbate peroxidase, glutathione reductase and superoxide dismutase activities. In summary, G. etunicatum was able to maintain an efficient symbiosis with jack bean plants in moderately contaminated Zn-soils, improving plant performance under those conditions, which is likely to be due to a combination of physiological and nutritional changes caused by the intimate relation between fungus and plant. The enhanced Zn uptake by AMF inoculated jack bean plants might be of interest for phytoremediation purposes. (C) 2009 Elsevier Ltd. All rights reserved.