977 resultados para mixed transfer functions
Resumo:
Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] used a simple phytoplanktonzooplankton-nutrient model and a genetic algorithm to determine the parameter values that would maximize the value of certain goal functions. These goal functions were to maximize biomass, maximize flux, maximize flux to biomass ratio, and maximize resilience. It was found that maximizing goal functions maximized resilience. The objective of this study was to investigate whether the Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] result was indicative of a general ecosystem principle, or peculiar to the model and parameter ranges used. This study successfully replicated the Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise resilience? Ecology. In press] experiment for a number of different model types, however, a different interpretation of the results is made. A new metric, concordance, was devised to describe the agreement between goal functions. It was found that resilience has the highest concordance of all goal functions trialled. for most model types. This implies that resilience offers a compromise between the established ecological goal functions. The parameter value range used is found to affect the parameter versus goal function relationships. Local maxima and minima affected the relationship between parameters and goal functions, and between goal functions. (C) 2003 Elsevier B.V. All rights reserved.
Resumo:
Sulfite dehydrogenase (SDH) from Starkeya novella, a sulfite-oxidizing molybdenum-containing enzyme, has a novel tightly bound αβ-heterodimeric structure in which the Mo cofactor and the c-type heme are located on different subunits. Flash photolysis studies of intramolecular electron transfer (IET) in SDH show that the process is first-order, independent of solution viscosity, and not inhibited by sulfate, which strongly indicates that IET in SDH proceeds directly through the protein medium and does not involve substantial movement of the two subunits relative to each other. The IET results for SDH contrast with those for chicken and human sulfite oxidase (SO) in which the molybdenum domain is linked to a b-type heme domain through a flexible loop, and IET shows a remarkable dependence on sulfate concentration and viscosity that has been ascribed to interdomain docking. The results for SDH provide additional support for the interdomain docking hypothesis in animal SO and clearly demonstrate that dependence of IET on viscosity and sulfate is not an inherent property of all sulfite-oxidizing molybdenum enzymes.
Resumo:
Deterioration of concrete or reinforcing steel through excessive contaminant concentration is often the result of repeated wetting and drying cycles. At each cycle, the absorption of water carries new contaminants into the unsaturated concrete. Nuclear Magnetic Resonance (NMR) is used with large concrete samples to observe the shape of the wetting profile during a simple one-dimensional wetting process. The absorption of water by dry concrete is modelled by a nonlinear diffusion equation with the unsaturated hydraulic diffusivity being a strongly nonlinear function of the moisture content. Exponential and power functions are used for the hydraulic diffusivity and corresponding solutions of the diffusion equation adequately predict the shape of the experimental wetting profile. The shape parameters, describing the wetting profile, vary little between different blends and are relatively insensitive to subsequent re-wetting experiments allowing universal parameters to be suggested for these concretes.
Resumo:
Electronic energy transfer (EET) rate constants between a naphthalene donor and anthracene acceptor in [ZnL4a](ClO4)(2) and [ZnL4b](ClO4)(2) were determined by time-resolved fluorescence where L-4a and L-4b are the trans and cis isomers of 6-((anthracen-9-yl-methyl)amino)-6,13-dimethyl-13-((naphthalen-1-yl-methyl)amino)-1,4,8,11-tetraazacyclotetradecane, respectively. These isomers differ in the relative disposition of the appended chromophores with respect to the macrocyclic plane. The trans isomer has an energy transfer rate constant (k(EET)) of 8.7 x 10(8) s(-1), whereas that of the cis isomer is significantly faster (2.3 x 10(9) s(-1)). Molecular modeling was used to determine the likely distribution of conformations in CH3CN solution for these complexes in an attempt to identify any distance or orientation dependency that may account for the differing rate constants observed. The calculated conformational distributions together with analysis by H-1 NMR for the [ZnL4a](2+) trans complex in the common trans-III N-based isomer gave a calculated Forster rate constant close to that observed experimentally. For the [ZnL4b](2+) cis complex, the experimentally determined rate constant may be attributed to a combination of trans-Ill and trans-I N-based isomeric forms of the complex in solution.
Resumo:
In this paper we present a technique for visualising hierarchical and symmetric, multimodal fitness functions that have been investigated in the evolutionary computation literature. The focus of this technique is on landscapes in moderate-dimensional, binary spaces (i.e., fitness functions defined over {0, 1}(n), for n less than or equal to 16). The visualisation approach involves an unfolding of the hyperspace into a two-dimensional graph, whose layout represents the topology of the space using a recursive relationship, and whose shading defines the shape of the cost surface defined on the space. Using this technique we present case-study explorations of three fitness functions: royal road, hierarchical-if-and-only-if (H-IFF), and hierarchically decomposable functions (HDF). The visualisation approach provides an insight into the properties of these functions, particularly with respect to the size and shape of the basins of attraction around each of the local optima.
Resumo:
Electrochemistry of bacterial cytochrome P450cin (CYP176A) reveals that, unusually, substrate binding does not affect the heme redox potential, although a marked pH dependence is consistent with a coupled single electron/single proton transfer reaction in the range 6 < pH < 10.
Resumo:
As pol??ticas de Transfer??ncia Condicionada de Renda (TCR) s??o consideradas a mais nova gera????o de pol??ticas sociais. O fato tem chamado a aten????o de profissionais do setor p??blico e de acad??micos de diferentes ??reas. Nos ??ltimos anos, diversas experi??ncias, sobretudo na Am??rica Latina, t??m-se destacado pelo impacto positivo sobre os indicadores sociais da popula????o, entre elas: o Programa Bolsa Fam??lia, no Brasil; o Programa de Desarrollo Humano Oportunidades, no M??xico; e o Sistema Chile Solid??rio, no Chile. O Programa Bolsa Fam??lia, criado em 2003, constitui a maior pol??tica p??blica de TCR da Am??rica Latina, tanto em or??amento quanto em cobertura. Atualmente, atende cerca de 13.800.000 fam??lias, em todos os munic??pios do Pa??s. O Programa tem servido de modelo para a difus??o desse tipo de pol??tica no mundo. O tema envolve v??rias dimens??es da ??rea social, por se tratar de uma pol??tica essencialmente intersetorial. O Bolsa Fam??lia vem se destacando nos debates da administra????o p??blica, devido ?? sua forte capacidade de melhoria das condi????es das fam??lias benefici??rias. Diante disso, a 5a edi????o do Boletim Eletr??nico de Bibliografias Especializadas apresenta uma reuni??o de publica????es do acervo da Biblioteca Graciliano Ramos que abordam os seguintes temas: transfer??ncia condicionada de renda, programas sociais, desigualdade social, combate da pobreza e pol??ticas p??blicas. O objetivo ?? divulgar obras que auxiliem servidores p??blicos na reflex??o e compreens??o desses assuntos
Resumo:
O Sistema de Gest??o de Conv??nios e Contratos de Repasse (Siconv) ?? a iniciativa do Governo Federal respons??vel por todo o ciclo de vida dos conv??nios, contratos de repasse e termos de parceria, no qual s??o registrados os atos, desde a formaliza????o da proposta at?? a presta????o de contas final. O Siconv inova no modelo de gest??o, proporciona celeridade aos procedimentos e desburocratiza as atividades fins, com foco na substitui????o do processo f??sico pelo eletr??nico e no registro de todos os procedimentos, o que permite maior transpar??ncia na execu????o das transfer??ncias volunt??rias da Uni??o. Destaca- se ainda que a disponibiliza????o do sistema aos usu??rios e tamb??m para a sociedade por meio do endere??o eletr??nico www.convenios.gov.br deve ser considerada como grande fator de inova????o, uma vez que, mesmo indiretamente, se apresenta como mais uma ferramenta de controle social.
Resumo:
Em dezembro de 2001, o Proeta foi criado pela Empresa Brasileira de Pesquisa Agropecu??ria (Embrapa) com apoio financeiro do Fundo Multilateral de Investimentos do Banco Interamericano de Desenvolvimento (Fumin/BID), por meio de um acordo de coopera????o t??cnica n??o-reembols??vel. O programa tem o objetivo de contribuir para a transfer??ncia de tecnologias e conhecimentos gerados pela Embrapa para empreendimentos de base tecnol??gica, mediante a utiliza????o do processo de incuba????o de empresas. Para concretizar a iniciativa, foram estabelecidas experi??ncias-piloto em cinco unidades de pesquisa da Embrapa, estrategicamente situadas nas regi??es Nordeste, Centro-Oeste e Sudeste. Entre os resultados e avan??os obtidos merecem destaque 21 tecnologias disponibilizadas, 14 conv??nios firmados com incubadoras, 16 propostas de neg??cios apresentadas, 14 empresas pr??-selecionadas e incubadas, e uma empresa graduada. A consolida????o das alian??as e parcerias no processo de incuba????o resultou em um sistema de inova????o que auxilia o desenvolvimento sustent??vel da cadeia produtiva do agroneg??cio, gerando benef??cios para a sociedade em geral
Resumo:
O projeto trata da moderniza????o da sistem??tica de disponibiliza????o de informa????es referentes aos repasses das principais transfer??ncias constitucionais da Uni??o para Estados e Munic??pios, atrav??s da utiliza????o de v??rios canais de comunica????o, dentre as quais destaca-se a Internet. Com a implanta????o de novas tecnologias v??m-se atingindo os objetivos desejados propiciando de maneira transparente para a sociedade, atrav??s dos diversos mecanismos, a a????o do Governo Federal no cumprimento do dever constitucional de repassar os recursos federais arrecadados aos estados e munic??pios
Resumo:
Esse documento trata de a????es de Saneamento no ??mbito do Programa de Acelera????o do Crescimento; a????es do PAC; Saneamento no ??mbito do Or??amento da Uni??o
Resumo:
Esse documento trata de Planejamento, normatiza????o e operacionaliza????o das a????es do OGU - PAC no Minist??rio das Cidades; Procedimentos gerais de acesso aos programas e a????es do Minist??rio das Cidades; ??rg??os do Minist??rio das Cidades envolvidos nos processos de transfer??ncias de recursos de Saneamento B??sico
Resumo:
Esse documento trata de Regras de sele????o de propostas no ??mbito do OGU - PAC no MCID; Regras T??cnicas dos Programas e A????es/Modalidades do MCID