924 resultados para Differentiated demand estimates
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This paper examines why practitioners and researchers get different estimates of equity value when they use a discounted cash flow (CF) model versus a residual income (RI) model. Both models are derived from the same underlying assumption -- that price is the present value of expected future net dividends discounted at the cost of equity capital -- but in practice and in research they frequently yield different estimates. We argue that the research literature devoted to comparing the accuracy of these two models is misguided; properly implemented, both models yield identical valuations for all firms in all years. We identify how prior research has applied inconsistent assumptions to the two models and show how these seemingly small errors cause surprisingly large differences in the value estimates. [ABSTRACT FROM AUTHOR]
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Caveolae are small invaginations of the cell surface that are abundant in mature adipocytes. A recent study (Kanzaki, M., and Pessin, J. E. (2002) J. Biol Chem 277, 25867-25869) described novel caveolin- and actin-containing structures associated with the adipocyte cell surface that contain specific signaling proteins. We have characterized these structures, here termed caves, using light and electron microscopy and observe that they represent surface-connected wide invaginations of the basal plasma membrane that are sometimes many micrometers in diameter. Rather than simply a caveolar domain, these structures contain all elements of the plasma membrane including clathrin-coated pits, lipid raft markers, and non-raft markers. GLUT4 is recruited to caves in response to insulin stimulation. Caves can occupy a significant proportion of the plasma membrane area and are surrounded by cortical actin. Caveolae density in caves is similar to that on the bulk plasma membrane, but because these structures protrude much deeper into the plane of focus of the light microscope molecules such as caveolin and other plasma membrane proteins appear more concentrated in caves. We conclude that the adipocyte surface membrane contains numerous wide invaginations that do not represent novel caveolar structures but rather large surface caves.
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Regeneration of osseous defects by a tissue-engineering approach provides a novel means of treatment utilizing cell biology, materials science, and molecular biology. In this study the concept of tissue engineering was tested with collagen type I matrices seeded with cells with osteogenic potential and implanted into sites where osseous damage had occurred. Explant cultures of cells from human alveolar bone and gingiva were established. When seeded into a three-dimensional type I collagen-based scaffold, the bone-derived cells maintained their osteoblastic phenotype as monitored by mRNA and protein levels of the bone-related proteins including bone sialoprotein, osteocalcin, osteopontin, bone morphogenetic proteins 2 and 4, and alkaline phosphatase. These in vitro-developed matrices were implanted into critical-size bone defects in skulls of immunodeficient (SCID) mice. Wound healing was monitored for up to 4 weeks. When measured by microdensitometry the bone density within defects filled with osteoblast-derived matrix was significantly higher compared with defects filled with either collagen scaffold alone or collagen scaffold impregnated with gingival fibroblasts. New bone formation was found at all the sites treated with the osteoblast-derived matrix at 28 days, whereas no obvious new bone formation was identified at the same time point in the control groups. In situ hybridization for the human-specific Alu gene sequence indicated that the newly formed bone tissue resulted from both transplanted human osteoblasts and endogenous mesenchymal stem cells. The results indicate that cells derived from human alveolar bone can be incorporated into bioengineered scaffolds and synthesize a matrix, which on implantation can induce new bone formation.
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The effect of number of samples and selection of data for analysis on the calculation of surface motor unit potential (SMUP) size in the statistical method of motor unit number estimates (MUNE) was determined in 10 normal subjects and 10 with amyotrophic lateral sclerosis (ALS). We recorded 500 sequential compound muscle action potentials (CMAPs) at three different stable stimulus intensities (10–50% of maximal CMAP). Estimated mean SMUP sizes were calculated using Poisson statistical assumptions from the variance of 500 sequential CMAP obtained at each stimulus intensity. The results with the 500 data points were compared with smaller subsets from the same data set. The results using a range of 50–80% of the 500 data points were compared with the full 500. The effect of restricting analysis to data between 5–20% of the CMAP and to standard deviation limits was also assessed. No differences in mean SMUP size were found with stimulus intensity or use of different ranges of data. Consistency was improved with a greater sample number. Data within 5% of CMAP size gave both increased consistency and reduced mean SMUP size in many subjects, but excluded valid responses present at that stimulus intensity. These changes were more prominent in ALS patients in whom the presence of isolated SMUP responses was a striking difference from normal subjects. Noise, spurious data, and large SMUP limited the Poisson assumptions. When these factors are considered, consistent statistical MUNE can be calculated from a continuous sequence of data points. A 2 to 2.5 SD or 10% window are reasonable methods of limiting data for analysis. Muscle Nerve 27: 320–331, 2003
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Background Estimates of the disease burden due to multiple risk factors can show the potential gain from combined preventive measures. But few such investigations have been attempted, and none on a global scale. Our aim was to estimate the potential health benefits from removal of multiple major risk factors. Methods We assessed the burden of disease and injury attributable to the joint effects of 20 selected leading risk factors in 14 epidemiological subregions of the world. We estimated population attributable fractions, defined as the proportional reduction in disease or mortality that would occur if exposure to a risk factor were reduced to an alternative level, from data for risk factor prevalence and hazard size. For every disease, we estimated joint population attributable fractions, for multiple risk factors, by age and sex, from the direct contributions of individual risk factors. To obtain the direct hazards, we reviewed publications and re-analysed cohort data to account for that part of hazard that is mediated through other risks. Results Globally, an estimated 47% of premature deaths and 39% of total disease burden in 2000 resulted from the joint effects of the risk factors considered. These risks caused a substantial proportion of important diseases, including diarrhoea (92%-94%), lower respiratory infections (55-62%), lung cancer (72%), chronic obstructive pulmonary disease (60%), ischaemic heart disease (83-89%), and stroke (70-76%). Removal of these risks would have increased global healthy life expectancy by 9.3 years (17%) ranging from 4.4 years (6%) in the developed countries of the western Pacific to 16.1 years (43%) in parts of sub-Saharan Africa. Interpretation Removal of major risk factors would not only increase healthy life expectancy in every region, but also reduce some of the differences between regions, The potential for disease prevention and health gain from tackling major known risks simultaneously would be substantial.
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Recent advances in molecular biology have made it possible to use the trace amounts of DNA in faeces to non-invasively sample endangered species for genetic studies. Here we use faeces as a source of DNA and mtDNA sequence data to elucidate the relationship among Spanish and Moroccan populations of great bustards. 834 bp of combined control region and cytochrome-b mtDNA fragments revealed four variable sites that defined seven closely related haplotypes in 54 individuals. Morocco was fixed for a single mtDNA haplotype that occurs at moderate frequency (28%) in Spain. We could not differentiate among the sampled Spanish populations of Caceres and Andalucia but these combined populations were differentiated from the Moroccan population. Estimates of gene flow (Nm = 0.82) are consistent with extensive observations on the southern Iberian peninsular indicating that few individuals fly across the Strait of Gibraltar. We demonstrate that both this sea barrier and mountain barriers in Spain limit dispersal among adjacent great bustard populations to a similar extent. The Moroccan population is of high ornithological significance as it holds the only population of great bustards in Africa. This population is critically small and genetic and observational data indicate that it is unlikely to be recolonised via immigration from Spain should it be extirpated. In light of the evidence presented here it deserves the maximum level of protection.
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Objective: Current prevalence of smoking, even where data are available, is a poor proxy for cumulative hazards of smoking, which depend on several factors including the age at which smoking began, duration of smoking, number of cigarettes smoked per day, degree of inhalation, and cigarette characteristics such as tar and nicotine content or filter type. Methods: We extended the Peto-Lopez smoking impact ratio method to estimate accumulated hazards of smoking for different regions of the world. Lung cancer mortality data were obtained from the Global Burden of Disease mortality database. The American Cancer Society Cancer Prevention Study, phase 11 (CPS-II) with follow up for the years 1982 to 1988 was the reference population. For the global application of the method, never-smoker lung cancer mortality rates were chosen based on the estimated use of coal for household energy in each region. Results: Men in industrialised countries of Europe, North America, and the Western Pacific had the largest accumulated hazards of smoking. Young and middle age males in many regions of the developing world also had large smoking risks. The accumulated hazards of smoking for women were highest in North America followed by Europe. Conclusions: In the absence of detailed data on smoking prevalence and history, lung cancer mortality provides a robust indicator of the accumulated hazards of smoking. These hazards in developing countries are currently more concentrated among young and middle aged males.
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Background Smoking is a risk factor for several diseases and has been increasing in many developing countries. Our aim was to estimate global and regional mortality in 2000 caused by smoking, including an analysis of uncertainty. Methods Following the methods of Peto and colleagues, we used lung-cancer mortality as an indirect marker for accumulated smoking risk. Never-smoker lung-cancer mortality was estimated based on the household use of coal with poor ventilation. Relative risks were taken from the American Cancer Society Cancer Prevention Study, phase II, and the retrospective proportional mortality analysis of Liu and colleagues in China. Relative risks were corrected for confounding and extrapolation to other regions. Results We estimated that in 2000, 4.83 (uncertainty range 3.94-5.93) million premature deaths in the world were attributable to smoking; 2.41 (1.80-3.15) million in developing countries and 2.43 (2.13-2.78) million in industrialised countries. 3.84 million of these deaths were in men. The leading causes of death from smoking were cardiovascular diseases (1.69 million deaths), chronic obstructive pulmonary disease (0.97 million deaths), and lung cancer (0.85 million deaths). Interpretation Smoking was an important cause of global mortality in 2000. In view of the expected demographic and epidemiological transitions and current smoking patterns in the developing world, the health loss due to smoking will grow even larger unless effective interventions and policies that reduce smoking among men and prevent increases among women in developing countries are implemented.
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O objetivo desse trabalho foi obter estimativas da tensão de crescimento longitudinal em árvores vivas e verificar a sua relação com algumas características da madeira de Eucalyptus dunnii Maiden aos oito, treze, quinze e dezenove anos de idade. O material foi proveniente da Empresa Procopiak Compensados e Embalagens S.A., localizada no Município de Canoinhas, Santa Catarina. Os níveis de tensão longitudinal de crescimento foram mensurados indiretamente pelo método do "CIRAD-Forêt", na árvore viva, e estimados a partir do módulo de elasticidade dinâmico e do módulo de elasticidade obtido no ensaio de tração paralela à grã. A deformação residual longitudinal (DRL) e as estimativas das tensões de crescimento longitudinais apresentaram tendência de aumento, na média, com a idade do material. A DRL apresentou correlação, positiva e significativa, com todas as estimativas das tensões de crescimento longitudinais, sendo de maior magnitude aos 13, 15 e 19 anos de idade. A densidade básica apresentou maiores correlações, positivas e significativas, com o módulo de elasticidade dinâmico, estimado no sentido longitudinal, para a madeira na condição de saturação e a 12% de umidade, em todas as idades avaliadas. Todas as estimativas das tensões de crescimento longitudinais apresentam elevadas correlações, positivas e significativas, entre si.
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Esta dissertação teve como objeto o Ensino Médio Integrado no Espírito Santo, sua trajetória e implantação a partir do Decreto 5.154/2004. O objetivo principal foi analisar a política do ensino médio integrado à educação profissional técnica de nível médio implementada no Espírito Santo. Investigar a educação pública pressupõe contextualizar a sociedade e as construções sociais que se projetam. O ensino médio no Brasil, enquanto etapa intermediária entre o ensino fundamental e a educação superior constitui-se de grande complexidade na estruturação de políticas públicas, no que tange à sua expansão qualitativa e quantitativa. Foram estabelecidos os seguintes objetivos específicos: identificar os pressupostos teóricos e pedagógicos contidos na Proposta Pedagógica da unidade escolar EEEFM Arnulpho Mattos; analisar a matriz curricular e a proposta pedagógica; relacionar o projeto pedagógico do curso com a prática educacional relatada nos encontros com os alunos; analisar a organização escolar e sua gestão política e pedagógica em face da proposta do EMI; relacionar a proposta do EMI, o princípio da politecnia e os relatos dos alunos; mapear a oferta do EMI no estado e o seu investimento financeiro. Nesse cenário, identificamos a relação entre trabalho e educação que contextualiza a relação da escola com a sociedade no sistema capitalista, em especial no ensino médio. Assim, nossa hipótese foi que esta política tem dificuldades de alcançar seus objetivos porque sua estrutura material segue a lógica da escola capitalista, assentada na perspectiva da Teoria do Capital Humano. A formação profissional no ensino médio é uma demanda social e histórica da classe trabalhadora, que necessita ingressar mais rápido no mercado de trabalho do que os filhos das elites brasileiras. A metodologia empregada foi uma pesquisa do tipo qualitativa, sendo um estudo de caso da EEEF Arnulpho Mattos. Os procedimentos metodológicos adotados para a investigação foram: observação, entrevistas semi-estruturadas, a análise documental, a revisão bibliográfica e os princípios metodológicos inscritos na sociologia da experiência (DUBET, 1994). Na articulação desses procedimentos, verificamos que a política do ensino médio integrado no ES teve, em seu início, um planejamento de implantação bem estruturado mas interrompido e, posteriormente, caracterizou-se pela descontinuidade das ações. Ademais, constatamos que os alunos ingressam e permanecem no curso sem compreenderem de fato o que significa a formação integrada entre a área geral e a técnica/profissional. Nos grupos de discussão percebemos que bastaram alguns encontros para que se pudesse estabelecer uma visão e relação diferenciadas com a experiência social do ensino médio integrado, principalmente por serem alunos trabalhadores. Acrescentamos às nossas conclusões que há iniciativas da escola acerca da integração entre as disciplinas de formação geral e técnicas, mas sem apoio ou orientação da unidade gestora, ou seja, a Sedu. A ampliação da oferta do EMI ocorreu no estado sem investimento na formação e valorização dos professores, sem concurso público e sem uma infra-estrutura necessária para a formação de jovens e adultos com capacidade de entender e de interferir no mundo do trabalho.
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INTRODUCTION: Morbidity information is easily available from medical records but its scope is limited to the population attended by the health services. Information on the prevalence of diseases requires community surveys, which are not always feasible. These two sources of information represent two alternative assessments of disease occurrence, namely demand morbidity and perceived morbidity. The present study was conceived so as to elicit a potential relationship between them so that the former could be used in the absence of the latter. METHODS: A community of 13,365 families on the outskirts of S. Paulo, Brazil, was studied during the period from 15/Nov/1994 to 15/Jan/1995. Data regarding children less than 5 years old were collected from a household survey and from the 2 basic health units in the area. Prevalence of diseases was ascertained from perceived morbidity and compared to estimates computed from demand morbidity. RESULTS: Data analysis distinguished 2 age groups, infants less than 1 year old and children 1 to less than 5. The most important groups of diseases were respiratory diseases, diarrhoea, skin problems and infectious & parasitical diseases. Basic health units presented a better coverage for infants. Though disease frequencies were not different within or outside these units, a better coverage was found for diarrhoea and infectious & parasitical diseases in the infant group, and for diarrhoea in the older age group. Equivalence between the two types of morbidity was found to be limited to the infant group and concerned only the best covered diseases. The odds of a disease being seen at the health service should be of at least 4:10 to ensure this equivalence. CONCLUSION: It was concluded that, provided that health service coverage is good, demand morbidity can be taken as a reliable estimate of community morbidity.
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Power systems have been suffering huge changes mainly due to the substantial increase of distributed generation and to the operation in competitive environments. Virtual power players can aggregate a diversity of players, namely generators and consumers, and a diversity of energy resources, including electricity generation based on several technologies, storage and demand response. Resource management gains an increasing relevance in this competitive context, while demand side active role provides managers with increased demand elasticity. This makes demand response use more interesting and flexible, giving rise to a wide range of new opportunities.This paper proposes a methodology for managing demand response programs in the scope of virtual power players. The proposed method is based on the calculation of locational marginal prices (LMP). The evaluation of the impact of using demand response specific programs on the LMP value supports the manager decision concerning demand response use. The proposed method has been computationally implemented and its application is illustrated in this paper using a 32 bus network with intensive use of distributed generation.
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The introduction of Electric Vehicles (EVs) together with the implementation of smart grids will raise new challenges to power system operators. This paper proposes a demand response program for electric vehicle users which provides the network operator with another useful resource that consists in reducing vehicles charging necessities. This demand response program enables vehicle users to get some profit by agreeing to reduce their travel necessities and minimum battery level requirements on a given period. To support network operator actions, the amount of demand response usage can be estimated using data mining techniques applied to a database containing a large set of operation scenarios. The paper includes a case study based on simulated operation scenarios that consider different operation conditions, e.g. available renewable generation, and considering a diversity of distributed resources and electric vehicles with vehicle-to-grid capacity and demand response capacity in a 33 bus distribution network.