Direct electrochemistry of a bacterial sulfite dehydrogenase

Sulfite dehydrogenase from Starkeya novella is an alphabeta heterodimer comprising a 40.6 kDa subunit (containing the Mo cofactor) and a smaller 8.8 kDa heme c subunit. The enzyme catalyses the oxidation of sulfite to sulfate with the natural electron acceptor being cytochrome c(550). Its catalytic mechanism is thought to resemble that found in eukaryotic sulfite oxiclases. Using protein film voltammetry and redox potentiometry, we have identified both Mo- and heme-centered redox responses from the enzyme immobilized on a pyrolytic graphite working electrode: E-m,E-8 (Fe-III/II) +177 mV; E-m,E-8 (Mo-VI/V) +211 mV and E(m,)8 (Mo-V/IV) -118 mV vs NHE; Upon addition of sulfite to the electrochemical cell a steady-state voltammogram is observed and an apparent Michaelis constant (K-m) of 26(l) muM was determined for the enzyme immobilized on the working electrode surface, which is comparable with the value obtained from solution assays.

Intramolecular electron transfer in a bacterial sulfite dehydrogenase

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.

Opening windows into the mind: mothers' preferences for mental state explanations and children's theory of mind

A new questionnaire, the Maternal Mental State Input Inventory (MMSII) was created to measure mothers' preferences for introducing and elaborating on mental states in conversation with their young children. In two studies, the questionnaire was given to mothers of young children, and the children's theory of mind (ToM) development was assessed with standard tasks. In both studies, the questionnaire exhibited good internal reliability, and significant correlations emerged between mothers' self-reported preferences for elaborated, explanatory talk about the mental states and children's theory of mind performance. Further, mothers' conversational preferences, as measured by the MMSII, were the best predictors of children's theory of mind development when relevant control variables were included in the analyses. These results converge with naturalistic observational research that has demonstrated links between mothers' conversational styles and their children's theory of mind. They go further in suggesting that mothers' tendencies toward elaborated, explanatory talk about a range of mental states is particularly beneficial to children's theory of mind development. (C) 2003 Elsevier Inc. All rights reserved.

Rates of electronic energy transfer in conformationally flexible bichromophoric macrocyclic complexes: a combined experimental and molecular modeling study

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.

Experimental investigation of continuous-variable quantum teleportation

We report the experimental demonstration of quantum teleportation of the quadrature amplitudes of a light field. Our experiment was stably locked for long periods, and was analyzed in terms of fidelity F and with signal transfer T-q=T++T- and noise correlation V-q=Vinparallel to out+Vinparallel to out-. We observed an optimum fidelity of 0.64+/-0.02, T-q=1.06+/-0.02, and V-q=0.96+/-0.10. We discuss the significance of both T-q>1 and V-q

An Australian PR state?

In their 1994 study Taxation and Representation, Deacon and Golding point to the extensive use of press and public relations professionals by governments to promote policy, and to outmanouvre their opponents. With the UK specifically in mind, they warn: 'we cannot ignore the massive expansion of the public relations state.' (p.6). What distinguishes their approach from the more usual preoccupation with the use of 'spin' to 'package' political leaders is a focus on the institutionalisation of public relations within government. In this paper, I explore the utililty of the concept, and consider what the broad features of an Australian 'PR State' might be.

Boletim eletr??nico de bibliografias especializadas: pol??tica de transfer??ncia condicionada de renda

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

Sistema de Gest??o de Conv??nios e Contratos de Repasse (Siconv). Um novo paradigma nas transfer??ncias volunt??rias da Uni??o

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.

Programa de apoio ao desenvolvimento de novas empresas de base tecnol??gica agropecu??ria e ?? transfer??ncia de tecnologia (Proeta)

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

STNet: transfer??ncias para estados e munic??pios

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