105 research outputs found
Custo de capital de distribuição de energia elétrica: revisão tarifária 2007-2009
Bibliografia: p. 262-265O objetivo deste trabalho é contribuir com a Agência Nacional de Energia Elétrica (Aneel) no que se refere à metodologia de estimação da taxa de remuneração de capital (ou custo de capital), que é parte da revisão tarifária das distribuidoras de energia elétrica. Recomendamos a metodologia do CAPM global ajustado ao mercado brasileiro e, contrariamente à regulação vigente, a adoção da totalidade do risco-país. Essa abordagem torna desnecessário o acréscimo de um prêmio de risco cambial ao custo de capital. Por ser um parâmetro volátil e ter apresentado acentuada queda nos últimos três anos, consideramos ainda diversos cenários para a variável risco-país. A taxa de remuneração foi estimada na faixa de 10.6% – 12.3% em termos reais. Ressaltamos que o estabelecimento da adequada taxa de remuneração de capital é questão atual e presente nas discussões sobre as melhores práticas em economia de regulação e se justifica pelo reconhecimento de que, no longo prazo, o ente regulado privado deve recuperar pelo menos seu custo de oportunidade de capital, incluindo o risco-país, o risco do negócio, o risco regulatório e outros específicos dos projetos em que opera.The aim of this paper is to contribute with the Brazilian Electricity Regulatory Agency [Aneel] regarding the Weighted Average Cost of Capital (WACC) estimation methodology, which is an importante component of the regulatory electricity distribution tariff review. We recommend the adjusted global CAPM methodology and, as opposing to the current regulation, the adoption of the total sovereign risk instead of a segmented one. We further consider diferente scenarios for the sovereign risk variable, which presented significant volatility and outstanding decrease trend in the last three years. The WACC was estimated between 10,6% and 12,3% in real terms. We highlight that the establishment of the proper capital remuneration rate is a current and present issue in the discussions on the best practices in regulation economy and is justified by the recognition that, at long term, the private regulated body shall recover at least its capital opportunity cost, including the sovereign risk, the business risk, the regulatory risk and other specific risks of the project in which it operates
A taxa de remuneração do capital e a nova regulação das telecomunicações
Bibliografia: p. 188-191Estabelecer uma meta adequada para o retorno sobre o capital das operadoras é o assunto central relacionado à nova orientação a custos adotada pela Agência Nacional de Telecomunicações (Anatel). Nesse contexto, especial atenção deve ser dada à estimação do custo médio ponderado do capital [Weighted Average Cost of Capital (WACC)]. Estimativas excessivamente baixas podem prejudicar as futuras decisões de investimento em inovação e infra-estrutura e estimativas muito altas contrariam o objetivo governamental inicial de reduzir tarifas e fomentar a competição. De fato, ambas as inconsistências implicam a redução do bem-estar social. Diante disso, o artigo propõe princípios metodológicos, baseados em conceitos teóricos amplamente aceitos na economia de regulação e teoria de finanças, assim como nas melhores práticas internacionais, para a tarefa de estimar um WACC para o setor de telecomunicações, levando-se também em conta as especificidades regulatórias e setoriais brasileiras
Wild dogs at stake: deforestation threatens the only Amazon endemic canid, the short-eared dog (Atelocynus microtis)
The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the most understudied wild dogs worldwide. We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestation across the entire Amazon (regional scale). Second, we used systematic camera trap surveys and occupancy models to investigate how forest cover and forest fragmentation affect the space use of this species in the Southern Brazilian Amazon (local scale). Species distribution models suggested that the short-eared dog potentially occurs over an extensive and continuous area, through most of the Amazon region south of the Amazon River. However, approximately 30% of the short-eared dog's current distribution is expected to be lost or suffer sharp declines in habitat suitability by 2027 (within three generations) due to forest loss. This proportion might reach 40% of the species distribution in unprotected areas and exceed 60% in some interfluves (i.e. portions of land separated by large rivers) of the Amazon basin. Our local-scale analysis indicated that the presence of forest positively affected short-eared dog space use, while the density of forest edges had a negative effect. Beyond shedding light on the ecology of the short-eared dog and refining its distribution range, our results stress that forest loss poses a serious threat to the conservation of the species in a short time frame. Hence, we propose a re-assessment of the short-eared dog's current IUCN Red List status (Near Threatened) based on findings presented here. Our study exemplifies how data can be integrated across sources and modelling procedures to improve our knowledge of relatively understudied species
Erica: Prevalences Of Hypertension And Obesity In Brazilian Adolescents
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS: Data from participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95% CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS: We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95% CI 9.0-10.3); with the lowest being in the North, 8.4% (95% CI 7.7-9.2) and Northeast regions, 8.4% (95% CI 7.6-9.2), and the highest being in the South, 12.5% (95% CI 11.0-14.2). The prevalence of obesity was 8.4% (95% CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95% CI 25.5-31.2), than overweight adolescents, 15.4% (95% CI 17.0-13.8), or eutrophic adolescents, 6.3% (95% CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS: ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5.501Brazilian Department of Science and Technology at the Secretariat of Science and TechnologyStrategic Inputs of the Ministry of Health (Departamento de Ciencia e Tecnologia da Secretaria de Ciencia e Tecnologia e Insumos Estrategicos do Ministerio da Saude - Decit/SCTIE/MS)Health Fund Sector (Fundo Setorial de Saude - CT-health) at the Ministry of science, Technology and Innovation (Ministerio da Ciencia, Tecnologia e Inovacao - MCTI)FINEP [01090421]CNPq [2010/565037-2]hospital research incentive fund for Clinics in Porto Alegre (fundo de incentivo a Pesquisa do Hospital de Clinicas de Porto Alegre - HCPA) [405,009/FIPE-2012-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Erica: Prevalence Of Metabolic Syndrome In Brazilian Adolescents
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To determine the prevalence of metabolic syndrome and its components in Brazilian adolescents. METHODS: We evaluated 37,504 adolescents who were participants in the Study of Cardiovascular Risks in Adolescents (ERICA), a cross-sectional, school-based, national study. The adolescents, aged from 12 to 17 years, lived in cities with populations greater than 100,000 inhabitants. The sample was stratified and clustered into schools and classes. The criteria set out by the International Diabetes Federation were used to define metabolic syndrome. Prevalences of metabolic syndrome were estimated according to sex, age group, school type and nutritional status. RESULTS: Of the 37,504 adolescents who were evaluated: 50.2% were female; 54.3% were aged from 15 to 17 years, and 73.3% were from public schools. The prevalence of metabolic syndrome was 2.6% (95% CI 2.3-2.9), slightly higher in males and in those aged from 15 to 17 years in most macro-regions. The prevalence was the highest in residents from the South macro-region, in the younger female adolescents and in the older male adolescents. The prevalence was higher in public schools (2.8% [95% CI 2.4-3.2]), when compared with private schools (1.9% [95% CI 1.4-2.4]) and higher in obese adolescents when compared with nonobese ones. The most common combinations of components, referring to 3/4 of combinations, were: enlarged waist circumference (WC), low HDL-cholesterol (HDL-c) and high blood pressure; followed by enlarged WC, low HDL-c and high triglycerides; and enlarged WC, low HDL-c, high triglycerides and blood pressure. Low HDL was the second most frequent component, but the highest prevalence of metabolic syndrome (26.8%) was observed in the presence of high triglycerides. CONCLUSIONS: ERICA is the first Brazilian nation-wide study to present the prevalence of metabolic syndrome and describe the role of its components. Despite the prevalence of Metabolic Syndrome being low, the high prevalences of some components and participation of others in the syndrome composition shows the importance of early diagnosis of this changes, even if not grouped within the metabolic syndrome.501Department of Science and Technology of the Secretariat of Science, Technology and Strategic Inputs of the Ministry of Health (Decit/SCTIE/MS)Health Sectorial Fund (Fundo Setorial de Saude - CT-Saude) of the Ministry of Science, Technology and Innovation (MCTI)FINEP [01090421]CNPq [2010/565037-2]Research Incentive Fund of the Hospital de Clinicas de Porto Alegre - (Fundo de Incentivo a Pesquisa do Hospital de Clinicas de Porto Alegre - FIPE-HCPA) [405.009/2012-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location: Amazonia.
Taxon: Angiosperms (Magnoliids; Monocots; Eudicots).
Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
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