986 resultados para Limit states
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When the in-plane bias magnetic field acting on a flat circular magnetic dot is smaller than the saturation field, there are two stable competing magnetization configurations of the dot: the vortex and the quasi-uniform (C-state). We measured microwave absorption properties in an array of non-interacting permalloy dots in the frequency range 1-8 GHz when the in-plane bias magnetic field was varied in the region of the dot magnetization state bi-stability. We found that the microwave absorption properties in the vortex and quasi-uniform stable states are substantially different, so that switching between these states in a fixed bias field can be used for the development of reconfigurable microwave magnetic materials.
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Esse estudo aborda a relação entre o Legislativo e o Executivo na produção de políticas. Identifica os elementos do sistema de produção legislativa do Brasil (regras estruturantes, atores, recursos, instâncias de decisão e tipos de políticas produzidas) e propõe um modelo para o caso brasileiro de presidencialismo de coalizão, com base em estudos sobre a relação entre o presidente e o Congresso dos EUA e também na vasta produção existente sobre o contexto nacional. O sistema é estruturado pelo marco normativo de maior hierarquia, a Constituição, determinado historicamente, o qual privilegia a governabilidade com accountability e também orienta políticas segundo princípios de equidade, mas com responsabilidade orçamentária. O modelo considera que as agendas estratégicas dos atores são produto de variadas influências, incluindo o status quo (políticas existentes) e as demandas provenientes das conexões normativa e eleitoral. A primeira cria path dependencies e limita opções de política, realçando questões de capacidade de governar. A segunda agrega preferências em torno do pertencimento à coalizão de governo ou à oposição. As proposições legislativas decorrentes das agendas dos atores são processadas em instâncias de decisão pré-determinadas do Congresso Nacional, segundo conteúdo e relevância das matérias, onde os atores interagem por meio da seleção de vias legislativas e de outros recursos estratégicos. O arcabouço sistêmico é integrado às interações estratégicas que ocorrem nas fases de iniciação, apreciação e conclusão da tramitação de proposições legislativas (em três vias distintas: a constitucional, a complementar e a ordinária). Essa estrutura é reforçada por regras que centralizam o processo decisório durante a tramitação no Congresso. Os produtos do sistema são as leis com impacto em políticas públicas. A partir desse modelo, o estudo analisa seus elementos e relações, aplicando-o a um conjunto abrangente de propostas egislativas (cerca de 21 mil proposições sobre todos os temas, apresentadas no Congresso entre 1999 e 2006, nas três vias). São observados indícios de quatro tipos de interação, segundo padrões de conflito e liderança dos atores: liderança da coalizão, liderança do Legislativo, cooperação e impasse. Os dados opõem-se à demarcação da agenda entre os Poderes e indicam que o êxito do Executivo variou inversamente com a hierarquia da via e que o desempenho do Legislativo superou o do Executivo na via constitucional, com destaque para a atividade do Senado, e na via ordinária (apenas no caso dos projetos de lei ordinária, pois os privilégios de iniciativa exclusiva do Executivo para leis orçamentárias e de edição de medidas provisórias, com força imediata de lei, garantem maior desempenho quantitativo a esse Poder nessa via). Contudo, a coalizão predominou amplamente em todas as vias. Análises qualitativas com foco na política de saúde e seu financiamento reforçam esses achados e sugerem que, apesar das muitas regularidades identificadas no sistema (rejeitando teses como a paralisia decisória ou a completa predominância do Executivo), fragmentações na sociedade e no Estado, persistem como fatores que limitam a produção de políticas mais equitativas
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Idioma: Inglés Abstract: This project focuses on two indicators of prices, the GDP deflator and the consumer price index (CPI), and analyzes the differences and similarities they present. These price indexes have been chosen taking into account its great representativeness and importance to economic and social level, and its direct relationship to the overall functioning of the economy and, in particular, inflation. It should be also mentioned that this study was conducted for cases of the euro area and the United States, as the impact of these economies in the economic and social situation at international level is very significant.
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La salud es un aspecto muy importante en la vida de cualquier persona, de forma que, al ocurrir cualquier contingencia que merma el estado de salud de un individuo o grupo de personas, se debe valorar estrictamente y en detalle las distintas alternativas destinadas a combatir la enfermedad. Esto se debe a que, la calidad de vida de los pacientes variará dependiendo de la alternativa elegida. La calidad de vida relacionada con la salud (CVRS) se entiende como el valor asignado a la duración de la vida, modificado por la oportunidad social, la percepción, el estado funcional y la disminución provocadas por una enfermedad, accidente, tratamiento o política (Sacristán et al, 1995). Para determinar el valor numérico asignado a la CVRS, ante una intervención, debemos beber de la teoría económica aplicada a las evaluaciones sanitarias para nuevas intervenciones. Entre los métodos de evaluación económica sanitaria, el método coste-utilidad emplea como utilidad, los años de vida ajustado por calidad (AVAC), que consiste, por un lado, tener en cuenta la calidad de vida ante una intervención médica, y por otro lado, los años estimados a vivir tras la intervención. Para determinar la calidad de vida, se emplea técnicas como el Juego Estándar, la Equivalencia Temporal y la Escala de Categoría. Estas técnicas nos proporcionan un valor numérico entre 0 y 1, siendo 0 el peor estado y 1 el estado perfecto de salud. Al entrevistar a un paciente a cerca de la utilidad en términos de salud, puede haber riesgo o incertidumbre en la pregunta planteada. En tal caso, se aplica el Juego Estándar con el fin de determinar el valor numérico de la utilidad o calidad de vida del paciente ante un tratamiento dado. Para obtener este valor, al paciente se le plantean dos escenarios: en primer lugar, un estado de salud con probabilidad de morir y de sobrevivir, y en segundo lugar, un estado de certeza. La utilidad se determina modificando la probabilidad de morir hasta llegar a la probabilidad que muestra la indiferencia del individuo entre el estado de riesgo y el estado de certeza. De forma similar, tenemos la equivalencia temporal, cuya aplicación resulta más fácil que el juego estándar ya que valora en un eje de ordenadas y abscisas, el valor de la salud y el tiempo a cumplir en esa situación ante un tratamiento sanitario, de forma que, se llega al valor correspondiente a la calidad de vida variando el tiempo hasta que el individuo se muestre indiferente entre las dos alternativas. En último lugar, si lo que se espera del paciente es una lista de estados de salud preferidos ante un tratamiento, empleamos la Escala de Categoría, que consiste en una línea horizontal de 10 centímetros con puntuaciones desde 0 a 100. La persona entrevistada coloca la lista de estados de salud según el orden de preferencia en la escala que después es normalizado a un intervalo entre 0 y 1. Los años de vida ajustado por calidad se obtienen multiplicando el valor de la calidad de vida por los años de vida estimados que vivirá el paciente. Sin embargo, ninguno de estas metodologías mencionadas consideran el factor edad, siendo necesario la inclusión de esta variable. Además, los pacientes pueden responder de manera subjetiva, situación en la que se requiere la opinión de un experto que determine el nivel de discapacidad del aquejado. De esta forma, se introduce el concepto de años de vida ajustado por discapacidad (AVAD) tal que el parámetro de utilidad de los AVAC será el complementario del parámetro de discapacidad de los AVAD Q^i=1-D^i. A pesar de que este último incorpora parámetros de ponderación de edad que no se contemplan en los AVAC. Además, bajo la suposición Q=1-D, podemos determinar la calidad de vida del individuo antes del tratamiento. Una vez obtenido los AVAC ganados, procedemos a la valoración monetaria de éstos. Para ello, partimos de la suposición de que la intervención sanitaria permite al individuo volver a realizar las labores que venía realizando. De modo que valoramos los salarios probables con una temporalidad igual a los AVAC ganados, teniendo en cuenta la limitación que supone la aplicación de este enfoque. Finalmente, analizamos los beneficios derivados del tratamiento (masa salarial probable) si empleamos la tabla GRF-95 (población femenina) y GRM-95 (población masculina).
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This paper summarizes current information on the American shad, Alosa sapidissima, and describes the species and its fishery. Emphasis is placed on (1) life history of the fish, (2) condition of the fishery by State and water areas in 1960 compared to 1896 when the last comprehensive description was made, (3) factors responsible for decline in abundance, and (4) management measures. The shad fishery has changed little over the past three-quarters of a century, except in magnitude of yield. Types of shad-fishing gear have remained relatively unchanged, but many improvements have been made in fishing techniques, mostly to achieve economy. In 1896 the estimated catch was more than 50 million pounds. New Jersey ranked first in production with about 14 million pounds, and Virginia second with 11 million pounds. In 1960 the estimated catch was slightly more than 8 million pounds. Maryland ranked first in production with slightly more than 1.5 million pounds, Virginia second with slightly less than 1.4 million pounds, and North Carolina third with about 1.3 million pounds. Biological and economic factors blamed for the decline in shad abundance, such as physical changes in the environment, construction of dams, pollution, over-fishing, and natural cycles of abundance, are discussed. Also discussed are methods used for the rehabilitation and management of the fishery, such as artificial propagation, installation of fish-passage facilities at impoundments, and fishing regulations. With our present knowledge, we can manage individual shad populations; but, we probably cannot restore the shad to its former peak of abundance.
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In the framework of dielectric theory, the static non-local self-energy of an electron near an ultra-thin polarizable layer has been calculated and applied to study binding energies of image-potential states near free-standing graphene. The corresponding series of eigenvalues and eigenfunctions have been obtained by numerically solving the one-dimensional Schrodinger equation. The imagepotential state wave functions accumulate most of their probability outside the slab. We find that the random phase approximation (RPA) for the nonlocal dielectric function yields a superior description for the potential inside the slab, but a simple Fermi-Thomas theory can be used to get a reasonable quasi-analytical approximation to the full RPA result that can be computed very economically. Binding energies of the image-potential states follow a pattern close to the Rydberg series for a perfect metal with the addition of intermediate states due to the added symmetry of the potential. The formalism only requires a minimal set of free parameters: the slab width and the electronic density. The theoretical calculations are compared with experimental results for the work function and image-potential states obtained by two-photon photoemission.
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O estudo descreve o resseguro no âmbito do Direito Internacional, partindo da constatação da pulverização dos riscos através do mercado global para abordar temas relevantes, tais como: a diferenciação entre resseguro internacional e contrato internacional de resseguro, os usos e costumes internacionalmente aceitos e a autonomia da vontade das partes como fundamento aos contratos de resseguro. São perquiridas também as fontes do direito ressecuritário no âmbito internacional. As relações jurídicas entre Estado e resseguradores e as relações contratuais entre seguradores e resseguradores devem ser regidos pela máxima boa-fé. Essa abordagem reporta-se a princípios consagrados no Direito Internacional do Investimento como padrão de referência para a regulação da atividade ressecuritária e como limite à intervenção dos Estados Descreve-se ainda o resseguro no Brasil, traçando um histórico evolutivo do monopólio à abertura do mercado e constatando algumas iniciativas nacionais do uso do seguro e do resseguro como ferramenta de atração e proteção de investimentos.
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The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it. Herein, we discuss the lack of a data system for monitoring the wildlife aquarium trade and analyze problems that arise when trying to monitor the trade using a system not specifically designed for this purpose. To do this, we examined an entire year of import records of marine tropical fish entering the United States in detail, and discuss the relationship between trade volume, biodiversity and introduction of non-native marine fishes. Our analyses showed that biodiversity levels are higher than previous estimates. Additionally, more than half of government importation forms have numerical or other reporting discrepancies resulting in the overestimation of trade volumes by 27%. While some commonly imported species have been introduced into the coastal waters of the USA (as expected), we also found that some uncommon species in the trade have also been introduced. This is the first study of aquarium trade imports to compare commercial invoices to government forms and provides a means to, routinely and in real time, examine the biodiversity of the trade in coral reef wildlife species.
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Commercial fisheries that are managed with minimum size limits protect small fish of all ages and may affect size-selective mortality by the differential removal of fast growing fish. This differential removal may decrease the average size at age, maturation, or sexual transition of the exploited population. When fishery-independent data are not available, a comparison of life history parameters of landed with those of discarded fish (by regulation) will indicate if differential mortality is occurring with the capture of young but large fish (fast growing phenotypes). Indications of this differential size-selective mortality would include the following: the discarded portion of the target fish would have similar age ranges but smaller sizes at age, maturation, and sexual transition as that of landed fish. We examined three species with minimum size limits but different exploitation histories. The known heavily exploited species (Rhomboplites aurorubens [vermilion snapper] and Pagrus pagrus [red porgy]) show signs of this differential mortality. Their landed catch includes many young, large fish, whereas discarded fish had a similar age range and mean ages but smaller sizes at age than the landed fish. The unknown exploited species, Mycteroperca phenax (scamp), showed no signs of differential mortality due to size-selective fishing. Landed catch consisted of old, large fish and discarded scamp had little overlap in age ranges, had significantly different mean ages, and only small differences in size at age when compared to comparable data for landed fish.
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Red bream (Beryx decadactylus) is a commercially important deep-sea benthopelagic fish with a circumglobal distribution on insular and continental slopes and seamounts. In the United States, small numbers are caught incidentally in the wreckfish (Polyprion americanus) fishery which operates off the southeastern coast, but no biological information exists for the management of the U.S. red bream population. For this study, otoliths (n=163) and gonads (n=161) were collected from commercially caught red bream between 2003 and 2008 to determine life history parameters. Specimens ranged in size from 410 to 630 mm fork length and were all determined to be mature by histological examination of the gonads. Females in spawning condition were observed from June through September, and reproductively active males were found year-round. Sectioned otoliths were difficult to interpret, but maximum age estimates were much higher than the 15 years previously reported for this species from the eastern North Atlantic based on whole-otolith analysis. Estimated ages ranged from 8 to 69 years, and a minimum lifespan of 49 years was validated by using bomb radiocarbon dating. Natural mortality was estimated at 0.06/yr. This study shows that red bream are longer lived and more vulnerable to overfishing than previously assumed and should be managed carefully to prevent overexploitation.
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Assessing the vulnerability of stocks to fishing practices in U.S. federal waters was recently highlighted by the National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, as an important factor to consider when 1) identifying stocks that should be managed and protected under a fishery management plan; 2) grouping data-poor stocks into relevant management complexes; and 3) developing precautionary harvest control rules. To assist the regional fishery management councils in determining vulnerability, NMFS elected to use a modified version of a productivity and susceptibility analysis (PSA) because it can be based on qualitative data, has a history of use in other fisheries, and is recommended by several organizations as a reasonable approach for evaluating risk. A number of productivity and susceptibility attributes for a stock are used in a PSA and from these attributes, index scores and measures of uncertainty are computed and graphically displayed. To demonstrate the utility of the resulting vulnerability evaluation, we evaluated six U.S. fisheries targeting 162 stocks that exhibited varying degrees of productivity and susceptibility, and for which data quality varied. Overall, the PSA was capable of differentiating the vulnerability of stocks along the gradient of susceptibility and productivity indices, although fixed thresholds separating low-, moderate-, and highly vulnerable species were not observed. The PSA can be used as a flexible tool that can incorporate regional-specific information on fishery and management activity.
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The Pacific sardine (Sardinops sagax) is distributed along the west coast of North America from Baja California to British Columbia. This article presents estimates of biomass, spawning biomass, and related biological parameters based on four trawl-ichthyoplankton surveys conducted during July 2003 –March 2005 off Oregon and Washington. The trawl-based biomass estimates, serving as relative abundance, were 198,600 t (coefficient of variation [CV] = 0.51) in July 2003, 20,100 t (0.8) in March 2004, 77,900 t (0.34) in July 2004, and 30,100 t (0.72) in March 2005 over an area close to 200,000 km2. The biomass estimates, high in July and low in March, are a strong indication of migration in and out of this area. Sardine spawn in July off the Pacific Northwest (PNW) coast and none of the sampled fish had spawned in March. The estimated spawning biomass for July 2003 and July 2004 was 39,184 t (0.57) and 84,120 t (0.93), respectively. The average active female sardine in the PNW spawned every 20–40 days compared to every 6–8 days off California. The spawning habitat was located in the southeastern area off the PNW coast, a shift from the northwest area off the PNW coast in the 1990s. Egg production in off the PNW for 2003–04 was lower than that off California and that in the 1990s. Because the biomass of Pacific sardine off the PNW appears to be supported heavily by migratory fish from California, the sustainability of the local PNW population relies on the stability of the population off California, and on local oceanographic conditions for local residence.