984 resultados para Hardy, Eliphalet, 1786-1806.
Resumo:
Let D denote the open unit disk in C centered at 0. Let H-R(infinity) denote the set of all bounded and holomorphic functions defined in D that also satisfy f(z) = <(f <(z)over bar>)over bar> for all z is an element of D. It is shown that H-R(infinity) is a coherent ring.
Resumo:
We begin by giving an example of a smoothly bounded convex domain that has complex geodesics that do not extend continuously up to partial derivative D. This example suggests that continuity at the boundary of the complex geodesics of a convex domain Omega (sic) C-n, n >= 2, is affected by the extent to which partial derivative Omega curves or bends at each boundary point. We provide a sufficient condition to this effect (on C-1-smoothly bounded convex domains), which admits domains having boundary points at which the boundary is infinitely flat. Along the way, we establish a Hardy-Littlewood-type lemma that might be of independent interest.
Resumo:
Resumen: José Fernando de Abascal y Sousa recibió la noticia de la invasión inglesa de 1806 a Buenos Aires, en el inicio de su administración como virrey del Virreinato del Perú. A partir de esta primera misiva enviada por el virrey Rafael de Sobre Monte, comenzó un intercambio epistolar entre las dos autoridades sobre dicho acontecimiento, a partir del cual se fueron perfi lando las preocupaciones, cuidados y políticas iniciales de defensa aplicadas por Abascal a su jurisdicción.
Resumo:
This paper includes information about the Pribilof Islands since their discovery by Russia in 1786 and the population of northern fur seals, Cailorhinus ursinus, that return there each summer to bear young and to breed. Russia exterminated the native population of sea Oilers, Enhydra lulris, here and nearly subjected the northern fur seal to the same fate before providing proper protection. The northern fur seal was twice more exposed to extinction following the purchase of Alaska and the Pribilof Islands by the United States in 1867. Excessive harvesting was stopped as a result of strict management by the United States of the animals while on land and a treaty between Japan, Russia, Great Britain (for Canada), and the United States that provided needed protection at sea. In 1941, Japan abrogated this treaty which was replaced by a provisional agreement between Canada and the United States that protected the fur seals in the eastern North Pacific Ocean. Japan, the U.S.S.R., Canada, and the United States again insured the survival of these animals with ratification in 1957 of the "Interim Convention on the Conservation of North Pacific Fur Seals," which is still in force. Under the auspices of this Convention, the United States launched an unprecedented manipulation of the resource through controlled removal during 1956-68 of over 300,000 females considered surplus. The biological rationale for the reduction was that production of fewer pups would result in a higher pregnancy rate and increased survival, which would, in turn, produce a sustained annual harvest of 55,000-60,000 males and 10,000-30,000 females. Predicted results did not occur. The herd reduction program instead coincided with the beginning of a decline in the number of males available for harvest. Suspected but unproven causes were changes in the toll normally accounted for by predation, disease, adverse weather, and hookworms. Depletion of the animals' food supply by foreign fishing Heets and the entanglement of fur seals in trawl webbing and other debris discarded at sea became a prime suspect in altering the average annual harvest of males on the Pribilof Islands from 71,500 (1940-56) to 40,000 (1957-59) to 36,000 (1960) to 82,000 (1961) and to 27,347 (1972-81). Thus was born the concept of a research control area for fur seals, which was agreed upon by members of the Convention in 1973 and instituted by the United States on St. George Island beginning in 1974. All commercial harvesting of fur seals was stopped on St. George Island and intensive behavioral studies were begun on the now unharvested population as it responds to the moratorium and attempts to reach its natural ceiling. The results of these and other studies here and on St. Paul Island are expected to eventually permit a comparison between the dynamics of unharvested and harvested populations, which should in turn permit more precise management of fur seals as nations continue to exploit the marine resources of the North Pacific Ocean and Bering Sea. (PDF file contains 32 pages.)
Resumo:
A dissertação comenta criticamente as interpretações recentes referentes ao vitalismo no século XVIII, dedicando atenção especial aos Nouveuax Éléments de la Science de lHomme (publicado primeiramente em 1778), de Paul-Joseph Barthez (1734-1806). Até a segunda metade do século XX, como é primeiramente argumentado nesta dissertação, intérpretes do iluminismo entendiam a doutrina mecanicista como a herdeira direta da Revolução Científica, bem como a corrente dominante no mundo das ciências da vida ao longo de todo o século XVIII. Assim, na historiografia do século passado, o vitalismo era ou escassamente mencionado, ou visto como uma retrógrada corrente anti-iluminista. Mais recentemente, vários historiadores e pesquisadores da história das ciências no século XVIII (sobretudo Williams e Reill) entendem o iluminismo de um modo mais amplo e plural, considerando o vitalismo iluminista (um termo proposto por Reill) como parte integrante de um conceito mais dinâmico de iluminismo. A seguir, são apresentados a doutrina mecanicista e seus conceitos centrais, bem como as ideias de alguns dos principais representantes do mecanicismo no século XVII e início do XVIII, no caso, mais especificamente, do mecanicismo newtoniano. Em seguida, são expostos e comentados a doutrina vitalista e seus conceitos, no que é dado destaque ao vitalismo na Universidade de Montpellier. Nesse contexto, são comentados conceitos vitalistas, tal como apresentados nos Nouveuax Éléments de la Science de lHomme, no qual Barthez propõe uma nova fisiologia baseada no princípio vital; nisso são apresentados sua metodologia de pesquisa, o conceito de princípio vital, as forças sensitivas e motrizes do princípio da vida, além dos conceitos de simpatia, sinergia e, por fim, o conceito de temperamento. Esses conceitos ou essa terminologia , tal como é mostrado, não são originalmente concebidos por Barthez, mas foram por ele reapropriados e reformulados em debate com o newtonianismo e demais correntes filosóficas médicas desde a Antiguidade até o século XVIII, assim como com observações e experimentos próprios às investigações médico-científicas da época. Como resultado, é alcançada uma compreensão da doutrina vitalista como um esforço intelectual inovador tanto interagindo quanto integrado com o debate científico contemporâneo, ou seja, os médicos vitalistas se viam e, em geral, eram vistos como atuando segundo os padrões de cientificidade exigidos por seus pares.
Resumo:
Shell dimensions (length, height, width) and shell volume were evaluated as estimators of growth for Polymesoda erosa in northern Australia. Each parameter was a good estimator when applied to live weight (r2 values of 76-96 percent), but not to soft tissue weight (wet, dry, or ash-free dry weight) (r2 values of 13-32 percent). The b value for shell volume to weight relationship of clams collected during the dry season (June to October) was signifi cantly different than for those collected in the wet season (February to April).
Resumo:
We measured canine teeth from 28 woolly spider monkeys (Brachyteles arachnoides) to assess sexual dimorphism and population differences. The specimens are from the Brazilian states of Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro, and São Paulo. We found strong sexual dimorphism in canine length for individuals belonging to populations south of 22°00′ latitude but no sexual dimorphism in canine length from individuals of populations north of 21°00′ latitude. Canine length did not vary among females of northern and southern populations. However, southern males had significantly longer canines than northern males. This geographical difference in canine morphology, together with the presence or absence of thumbs and published accounts of differences in genetics and social structure between northern and southern populations, suggests that Brachyteles arachnoides may be composed of at least two subspecies, which appear to be separated by the rivers Grande and Paraiba do Sul and the Serra da Mantiqueira. © 1993 Plenum Publishing Corporation.
Resumo:
The Continuous Plankton Recorder (CPR) survey has collected data on basin- scale zooplankton abundance in the North Atlantic since the 1930s. These data have been used in many studies to elucidate seasonal patterns and long-term change in plankton populations, as well as more recently to validate ecosystem models. There has, however, been relatively little comparison of the data from the CPR with that from other samplers. In this study we compare zooplankton abundance estimated from the CPR in the northeast Atlantic with near-surface samples collected by a Longhurst-Hardy Plankton Recorder (LHPR) at Ocean Weather Station India (59 degree N, 19 degree W) between 1971 and 1975. Comparisons were made for six common copepods in the region: Acartia clausi, Calanus finmarchicus, Euchaeta norvegica, Metridia lucens, Oithona sp. and Pleuromamma robusta. Seasonal cycles based on CPR data were similar to those recorded by the LHPR. Differences in absolute abundances were apparent, however, with the CPR underestimating abundances by a factor of between 5 and 40, with the exception of A. clausi. Active avoidance by zooplankton is thought to be responsible. This avoidance is species specific, so that care must be taken describing communities, as the CPR emphasises those species that are preferentially caught, a problem common to many plankton samplers.
Resumo:
Data on the abundance and biomass of zooplankton off the northwestern Portuguese coast, separately estimated with a Longhurst-Hardy Plankton Recorder (LHPR) and a Bongo net, were analysed to assess the comparative performance of the samplers. Zooplankton was collected along four transects perpendicular to the coast, deployments alternating between samplers. Total zooplankton biomass measured using the LHPR was significantly higher than that using the Bongo net. Apart from Appendicularia and Cladocera, abundances of other taxa (Copepoda, Mysidacea, Euphausiacea, Decapoda larvae, Amphipoda, Siphonophora, Hydromedusae, Chaetognatha and Fish eggs) were also consistently higher in the LHPR. Some of these differences were probably due to avoidance by the zooplankton of the Bongo net. This was supported by a comparative analysis of prosome length of the copepod Calanus helgolandicus sampled by the two nets that showed that Calanus in the LHPR samples were on average significantly larger, particularly in day samples. A ratio estimator was used to produce a factor to convert Bongo net biomass and abundance estimates to equate them with those taken with the LHPR. This method demonstrates how results from complementary zooplankton sampling strategies can be made more equivalent.