136 resultados para continuity of generations
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In this work we obtain some continuity properties on the parameter p at p = 2 for the Takeuchi-Yamada problem which is a degenerate p-Laplacian version of the Chafee-Infante problem. We prove the continuity of the flows and the equilibrium sets, and the upper semicontinuity of the global attractors. (C) 2009 Elsevier Ltd. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Population structure and reproductive season of the portunid crab Callinectes ornatus were studied in animals collected from the Ubatuba bays, Sao Paulo, Brazil (23°20' to 23°35' S and 44°50' to 45°14' W). The samples were taken in three trawls performed every other month from January 1991 to May 1993. A total of 3,829 specimens of C. ornatus were obtained. Their size ranged from 9.3 to 84.6 mm (carapace width). Their median size based on their cephalothoracic width and their size frequency were determined as well. Their reproduction was continuous, with variable proportions of ovigerous females. The highest incidence of ovigerous females occurred in January 1991, 1992 and 1993 and March and November 1992. The oscillations of the environmental factors between the seasons are not so intense in subtropical regions, therefore allowing the continuity of the physiological process of growth and reproduction throughout the year.
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The aim of present work was to study, through means and variances of generations, the genetic control of fruit-set percentage in tomatoes, in a biparental cross between line Jab-95 (resistant to fruit-set) and 'Caribe' cultivar (susceptible to fruit-set) after being subjected to high temperatures. F1, F2, and backcross generations for both parents (P 1, P2) were produced in a greenhouse at FCAVUNESP, Jaboticabal-SP, Brazil. A randomized complete block experimental design with four replications was used to evaluate the different generations. Estimates of genetic parameters were obtained according to Mather and Jinks (1982). An additive-dominant model was fitted to explain the variation observed. The mean degree of dominance (0.54), indicated incomplete dominance in the direction of increasing fruit-set percentage at high temperatures. The genetic control of fruit-set percentage, at high temperatures, for tomato was found to be oligogenic or polygenic (3.54 genes). The heritability in a limited sense was 83.91%, suggesting that the selection of individuals based on the characteristic evaluated can be efficient.
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Motivated by return maps near saddles for three-dimensional flows and also by return maps in the torus associated to Cherry flows, we study gap maps with derivative positive and smaller than one outside the discontinuity point. We prove that the lamination of infinitely renormalizable maps (or else maps with irrational rotation numbers) has analytic leaves in a natural subset of a Banach space of analytic maps of this kind. With maps having Hölder continuous derivative and derivative bounded away from zero, we also prove Hölder continuity of holonomies of the lamination and also of conjugacies between maps having the same combinatorics. © 2011 Springer Basel AG.
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With the aim of analyzing the information search behavior of investors working in the stock market, this research sought to raise the aspects related to this behavior with focus on the cognitive and causal aspects which pervade the need for information of these investors. For that, the general pattern of informational behavior proposed by Wilson [10], and also the analysis of a report from an investor of the stock market area were used as basis for the analysis and reflection. The report of only one investor was used as basis for investigation, turning it impossible to extrapolate such result to a greater universe. The objective of this research was to investigate the need for information, the context and the intervenient variables which might interfere or not in the information search behavior of investors, in an attempt to get a deeper comprehension about the subject, as well as to propose the continuity of studies with basis on this study proposal.
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Ecological processes in tropical forests are being affected at unprecedented rates by human activities. Yet, the continuity of ecological functions like seed dispersal is crucial for forest regeneration. It thus becomes increasingly urgent to be able to rapidly assess the health status of these processes in order to take appropriate management measures. We tested a method to rapidly evaluate seed removal rates on two animal-dispersed tree species, Virola kwatae and V.michelii (Myristicaceae), at three sites in French Guiana with increasing levels of anthropogenic disturbance. We counted fallen fruits, fruit valves, and seeds of each focal fruiting tree in a single 1m2 quadrat, and calculated two indices: the proportion of seeds removed and the proportion of fruits opened by mammals. They both provide an indirect and rapid assessment of frugivore activity. Our results showed a significant decrease in the proportion of removed seeds (16%) and fruits opened (19%) at the most impacted site in comparison with the other two sites (79% for seeds, 60% and 35% for fruits). This testifies to an increased impoverishment of the primate and toucan communities at the disturbed sites. This standardized protocol provides fast information about the health status of the community of seed dispersers and predators and of their seed removal services. It is time- and cost-effective and is not species-specific, allowing comparisons among sites or over time. We suggest using it with the pantropical Myristicaceae and any other capsule-producing family to rapidly assess the health status of seed removal processes across the tropics.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Luciferid shrimps have short life spans and a rapid turnover of generations, engage in sequential spawning, and protect their eggs during incubation. This study investigates the ecology of Lucifer faxoni Borradaile, 1915 in the littoral zone, Ubatuba region, São Paulo. Sampling was conducted monthly from July 2005 to December 2006 using a Renfro net trawled over a distance of 50 m for a total sampling effort of 50 m² at each station. Nine stations were sampled, ranging from 1 to 15 m deep. Three stations each were grouped into zones 1, 2 and 3 (Z1, Z2 and Z3). Monthly values of salinity, temperature and rainfall were recorded at each station. The pre-buccal somite length (SL) of each specimen was measured. The results showed that in shallower zones (Z1 and Z2), 6306 individuals were captured, whereas in the deeper zone (Z3), 3808 specimens were captured, but no significant differences in SL was detected between the specimens from Z1 and Z2 and those from Z3 (ANOVA, p=0.25). The abundance of shrimps did not differ significantly between seasons (Tukey’s test, p=0.02) except in the spring. The sex ratio differed significantly over the seasons (χ², p<0.05). The results were closely associated with environmental factors with respect to the spatial and seasonal distribution of L. faxoni. Rainfall affected salinity directly, and contributed to the displacement of these shrimps to deeper areas.
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O desenvolvimento (ovo-adulto) da mosca-branca, Bemisia tabaci (Genn.) biótipo B (=Bemisia argentifolii, Bellows & Perring), foi estudado em condições de campo e em câmaras climatizadas, reguladas nas temperaturas constantes de 15, 20, 25, 30 e 35±1ºC, usando soja, Glycine max (L.) Merrill, cultivar Msoy 8001, como planta hospedeira. O limite térmico inferior de desenvolvimento (Tb) e a constante térmica (K) das fases de ovo, ninfa e ciclo biológico (ovo-adulto) foram 11,1ºC / 98,8 graus-dia, 6,8ºC / 383,8 graus-dia e 8,3ºC / 472,6 graus-dia, respectivamente. Nas temperaturas extremas (15ºC e 35ºC), a viabilidade dos insetos mostrou-se menor. No campo, a emergência de 70% dos adultos ocorreu depois de terem sido acumulados 413,2 graus-dia. O modelo de graus-dia utilizado mostrou-se adequado para a previsão de ocorrência de adultos de Bemisia tabaci biótipo B no campo, podendo também ser utilizado para determinação do número de gerações nas diferentes regiões do País.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Trata-se de um estudo qualitativo que utiliza, como referencial teórico, o Interacionismo Simbólico e, como referencial metodológico, a Grounded Theory, visando a: compreender a experiência interacional voluntário-idoso dependente em um Centro-Dia e elaborar um modelo teórico representativo dessa experiência. A estratégia para a obtenção dos dados foi a entrevista não diretiva. Dos resultados, emergiram dois fenômenos: responsabilizando-se pela continuidade do exercício do voluntariado, junto a idosos dependentes, amparado na expectativa reparadora de ex-cuidadores familiares perante uma sociedade com consciência solidária em declínio, e assumindo o papel de voluntário. A experiência nos permitiu ampliar o conhecimento referente ao movimento que eles empreenderam na vivência denominada: entre o fortalecimento e o declínio do vínculo voluntário-idoso dependente em um centro-dia mediado por (des) motivação.
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In true social hymenopterans, such as many species of bees, wasps and all species of ants, the main characteristics are the overlapping of generations, the care with the offspring and the division of labor among the members of the colony. The first biological feature means that in a same moment there are groups of individuals, with variable ages, that execute different activities in the colony. In order to study the division of labor among the members of the colony, or to estimate the life span of these insects, or even to analyze any kind of behavior in non-social insects, it is necessary to know the exact age of each individual. For this reason, the insects must be identified soon after emergence. The identification of insects with numbers is an important technological improvement in behavioral studies, mainly in honeybee colonies. The aim of this scientific note is to describe an easy and cheaper technique for marking hymenopterans.