Photon-added detection

The production of conditional quantum states and quantum operations based on the result of measurement is now seen as a key tool in quantum information and metrology. We propose a different type of photon number detector. It functions nondeterministically, but when successful, it has high fidelity. The detector, which makes use of an n-photon auxiliary Fock state and high efficiency homodyne detection, allows a tunable trade-off between fidelity and probability. By sacrificing probability of operation, an excellent approximation to a photon-number detector is achieved.

Optical experiments beyond the quantum limit: Squeezing entanglement and teleportation

Results of experiments recently performed are reported, in which two optical parametric amplifiers were set up to generate two independently quadrature squeezed continuous wave laser beams. The transformation of quadrature squeezed states into polarization squeezed states and into states with spatial quantum correlations is demonstrated. By utilizing two squeezed laser beams, a polarization squeezed state exhibiting three simultaneously squeezed Stokes operator variances was generated. Continuous variable polarization entanglement was generated and the Einstein-Podolsky-Rosen paradox was observed. A pair of Stokes operators satisfied both the inseparability criterion and the conditional variance criterion. Values of 0.49 and 0.77, respectively, were observed, with entanglement requiring values below unity. The inseparability measure of the observed quadrature entanglement was 0.44. This value is sufficient for a demonstration of quantum teleportation, which is the next experimental goal of the authors.

Contradi????es do processo de implementa????o de pol??ticas p??blicas: uma an??lise do Programa Bolsa Fam??lia 2003 ??? 2006

O Programa Bolsa Fam??lia, programa de transfer??ncia condicionada de renda, vem se firmando no cen??rio mundial como uma das mais expressivas iniciativas dessa natureza para o enfrentamento da pobreza e a redu????o da desigualdade. Presente em todos os 5.564 munic??pios brasileiros, caracteriza- se por ser um programa federal que n??o prescinde dos estados e, em especial, dos munic??pios para a sua execu????o. No sentido de estabelecer uma gest??o compartilhada entre todas as esferas governamentais, o governo federal tem buscado implantar mecanismos flex??veis de parceria, com defini????o clara de pap??is e compartilhamento de responsabilidades, bem como auxiliar os governos subnacionais, por meio da transfer??ncia de recursos para a gest??o, na cria????o das condi????es institucionais e de infra-estrutura necess??rias ?? operacionaliza????o de um programa dessa magnitude. Este texto analisa as rela????es intergovernamentais existentes no ??mbito do Programa Bolsa Fam??lia, identificando os avan??os e os desafios na busca da coordena????o federativa. A primeira parte, sobre o federalismo brasileiro, ap??ia-se basicamente em estudos do pesquisador Luiz Fernando Abrucio. J?? os dados e informa????es sobre o Programa foram fornecidos pelo Minist??rio do Desenvolvimento Social e Combate ?? Fome.

A perspectiva brasileira sobre a pobreza: um estudo de caso do Programa Bolsa Fam??lia

Tendo como pano de fundo a dificuldade de definir a pobreza, este artigo visa retomar parte da discuss??o sobre o tema, utilizando como estudo de caso o Programa Bolsa Fam??lia. Inicia-se com a defini????o institucional de pobreza dada pelo soci??logo alem??o Georg Simmel passando-se, na seq????ncia, a uma abordagem mais substancial da pobreza e da rela????o entre trabalho e precariedade, desenvolvida por Robert Castel. Apresenta uma breve descri????o do funcionamento do Programa Bolsa Fam??lia e alguns aspectos relacionados aos conceitos e modos de tratamento da quest??o da renda e da educa????o, bem como da fam??lia e dos modelos familiares, baseando-se tamb??m nos resultados parciais de uma pesquisa de campo realizada nos estados da Bahia, Pernambuco, Alagoas e Goi??s. O texto trata ainda de alguns desafios administrativos na gest??o do Programa e os preconceitos morais e sociais recorrentemente veiculados em rela????o a ele. Por fim, na conclus??o, busca retomar a an??lise do Programa Bolsa Fam??lia, seus limites e desafios, defendendo a necessidade de participa????o de todos em um pacto social contra a pobreza e a desigualdade no Brasil.

Intersetorialidade e transversalidade: a estrat??gia dos programas complementares do Bolsa Fam??lia

O artigo analisa a estrat??gia implementada em 2006 e 2007 pelo Programa Bolsa Fam??lia (PBF) para a articula????o de programas complementares ??s transfer??ncias condicionadas de renda, enfatizando sua contribui????o para o enfrentamento da desigualdade e da exclus??o social no Brasil, e apresenta resultados preliminares alcan??ados por alguns destes programas executados em n??vel federal. A articula????o de programas complementares possibilita o reconhecimento de necessidades de grupos populacionais em situa????o de risco social e promove a oferta de a????es espec??ficas para as suas necessidades, para uma inclus??o cidad?? diferenciada. A estrat??gia implementada em 2006 e 2007 foi caracterizada pela intersetorialidade e transversalidade e a cria????o de um espa??o prop??cio para o desenvolvimento de inova????es no campo das pol??ticas sociais. Apesar do car??ter recente dos programas complementares e das dificuldades de monitoramento, os resultados obtidos em programas federais e o comprometimento dos governos municipais na articula????o de programas municipais demonstram que essa pode ser uma op????o na agenda das pol??ticas sociais dos tr??s n??veis de governo no Brasil.

Programas de transfer??ncia condicionada de renda na Am??rica Latina: uma abordagem comparada entre Brasil, M??xico, Chile e Col??mbia

O artigo desenvolve um estudo comparado qualitativo acerca das Pol??ticas de Transfer??ncia Condicionada de Renda na Am??rica Latina. Esta modalidade de pol??tica, considerada a mais nova gera????o das pol??ticas sociais, compartilha tr??s componentes b??sicos: transfer??ncia monet??ria direta ao cidad??o ou fam??lia; foco nos segmentos mais pobres e a cobran??a de condicionalidades. Na ??ltima d??cada, seus impactos sobre a melhoria das condi????es de vida da popula????o t??m chamado a aten????o de governos, organismos multilaterais e do meio acad??mico. Todavia, a literatura tem focado predominantemente na an??lise dos seus impactos e menos nos fatores relativos ?? operacionaliza????o desses programas. Por isso, o objetivo principal do artigo ?? descrever as estruturas de funcionamento dessas pol??ticas, haja vista sua influ??ncia sobre os seus resultados. Para fins de compara????o s??o selecionados os programas dos governos do Brasil, M??xico, Chile e Col??mbia, uma vez que s??o as experi??ncias mais consolidadas da regi??o. O trabalho conclui que embora os modelos de implementa????o sejam bastante diversificados, todos compactuam com a percep????o multidimensional da pobreza e, portanto, seu enfrentamento demanda a????es de car??ter intersetorial. Ademais, os bons resultados na focaliza????o desses programas s??o consequ??ncia da prioriza????o de estrat??gias de descentraliza????o que potencializam a coordena????o e coopera????o nas a????es governamentais.

Historicidade, entropia e não-linearidade : algumas aplicações possíveis na Ciência Econômica

The objective of this paper is to definite Historicity in Economic Sciences applying the principles of Entropy and methodological indeterminism. This implies the definition of two kinds of economic universes: one characterized by ergodicity and reversibility of Time and processes and the other by the opposite properties. The first part will deal with the construction of the subject of study and the nature of the proper analysis to these two universes. Taking such dichotomy into account, the second part will examine its implications as regards to the nature of equilibrium, the properties of stability and instability and the closure of the systems.

Efeitos do comitê de auditoria e do conselho fiscal na qualidade da informação contábil no Brasil

Esta dissertação foi desenvolvida com o objetivo de investigar os efeitos da instalação e das características do Conselho Fiscal e do Comitê de Auditoria sobre a qualidade das informações contábeis no Brasil. As características estudadas foram à independência e a qualificação dos membros. As proxies da qualidade da informação contábil foram relevância, tempestividade e conservadorismo condicional. A amostra utilizada foi composta por empresas brasileiras, listadas na Bolsa de Valores, Mercadorias e Futuros de São Paulo (BM&FBovespa), com liquidez anual superior a 0,001, no período de 2010 a 2013. Os dados foram coletados na base de dados Comdinheiro e nos Formulários de Referência das empresas, disponíveis no sítio eletrônico da Comissão de Valores Mobiliários (CVM) ou BM&FBovespa. Os modelos de qualidade da informação foram adaptados ao recorte metodológico e estimados pelo método dos mínimos quadrados ordinários (MQO), com erros-padrão robustos clusterizados por firma. Os resultados revelaram efeitos da instalação dos órgãos analisados sobre as proxies de qualidade da informação contábil. A instalação do Conselho Fiscal impactou positivamente a relevância do patrimônio líquido, enquanto a instalação do Comitê de Auditoria, a relevância do lucro. Esses resultados podem indicar diferenças no direcionamento da atenção desses órgãos: em proteger o patrimônio da entidade para os acionistas (Conselho Fiscal) ou em assegurar números mais confiáveis sobre o desempenho dos administradores (Comitê de Auditoria). Paralelamente, os resultados para a instalação do Conselho Fiscal de forma permanente inferiu força desse órgão como mecanismo de controle, ao invés da instalação somente a pedido dos acionistas. Já, a implementação do Conselho Fiscal Turbinado se mostrou ineficiente no controle da qualidade das informações contábeis. Na análise das características, a independência dos membros do Comitê de Auditoria impactou a relevância do lucro. Ao passo que a independência do Conselho Fiscal impactou a relevância do patrimônio líquido e o conservadorismo condicional (reconhecimento oportuno de perdas econômicas). Essas associações foram mais significantes quando os membros do Conselho Fiscal eram independentes dos acionistas controladores. Na análise da qualificação dos membros, foram encontradas evidências positivas na relação entre a relevância do patrimônio líquido e a maior proporção de membros do Conselho Fiscal com qualificação em Business (Contabilidade, Administração e Economia). O conservadorismo condicional foi maior na medida em que a qualificação dos membros do Conselho Fiscal convergia para a Contabilidade. Os resultados da qualificação dos membros do Comitê de Auditoria demonstraram relevância do lucro na presença de, ao menos, um Contador e na maior proporção de membros com qualificação tanto em Contabilidade como em Business; sendo mais significante conforme a qualificação dos membros do Comitê de Auditoria convergia para a Contabilidade.

Conditioning information in mutual fund performance evaluation: Portuguese evidence

We estimate and compare the performance of Portuguese-based mutual funds that invest in the domestic market and in the European market using unconditional and conditional models of performance evaluation. Besides applying both partial and full conditional models, we use European information variables, instead of the most common local ones, and consider stochastically detrended conditional variables in order to avoid spurious regressions. The results suggest that mutual fund managers are not able to outperform the market, presenting negative or neutral performance. The incorporation of conditioning information in performance evaluation models is supported by our findings, as it improves the explanatory power of the models and there is evidence of both time-varying betas and alphas related to the public information variables. It is also shown that the number of lags to be used in the stochastic detrending procedure is a critical choice, as it will impact the significance of the conditioning information. In addition, we observe a distance effect, since managers who invest locally seem to outperform those who invest in the European market. However, after controlling for public information, this effect is slightly reduced. Furthermore, the results suggest that survivorship bias has a small impact on performance estimates.

Measuring fund performance using multi-factor models: evidence for the Portuguese market

This paper examines the performance of Portuguese equity funds investing in the domestic and in the European Union market, using several unconditional and conditional multi-factor models. In terms of overall performance, we find that National funds are neutral performers, while European Union funds under-perform the market significantly. These results do not seem to be a consequence of management fees. Overall, our findings are supportive of the robustness of conditional multi-factor models. In fact, Portuguese equity funds seem to be relatively more exposed to smallcaps and more value-oriented. Also, they present strong evidence of time-varying betas and, in the case of the European Union funds, of time-varying alphas too. Finally, in terms of market timing, our tests suggest that mutual fund managers in our sample do not exhibit any market timing abilities. Nevertheless, we find some evidence of timevarying conditional market timing abilities but only at the individual fund level.

Style and performance of international socially responsible funds in Europe

This paper analyses the performance and investment styles of internationally oriented Socially Responsible Investment (SRI)funds, domiciled in eight European markets, in comparison with characteristics-matched conventional funds. To the best of our knowledge, this is the first multi-country study, focused on international SRI funds (investing in Global and in European equities), to combine the matched-pairs approach with the use of robust conditional multi-factor performance evaluation models, which allow for both time-varying alphas and betas and also control for home biases and spurious regression biases.In general, the results show that differences in the performance of international SRI funds and their conventional peers are not statistically significant. Regarding investment styles, SRI and conventional funds exhibit similar factor exposures in most cases. In addition,conventional benchmarks present a higher explaining power of SRI fund returns than SRI benchmarks. Our results also show significant differences in the investment styles of SRI funds according to whether they use “best-in-class” screening strategies or not. When compared to SRI funds that employ simple negative and/or positive screens, SRI “best-in-class” funds present significantly lower exposures to small caps and momentum strategies and significantly higher exposures to local stocks.

Automated image analysis of lung branching morphogenesis from microscopic images of fetal rat explants

Background: Regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. This work presents a new methodology to accurately quantify the epithelial, outer contour and peripheral airway buds of lung explants during cellular development from microscopic images. Methods: The outer contour was defined using an adaptive and multi-scale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelial was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds were counted as the skeleton branched ends from a skeletonized image of the lung inner epithelial. Results: The time for lung branching morphometric analysis was reduced in 98% in contrast to the manual method. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Non-significant differences were found between the automatic and manual results in all culture days. Conclusions: The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lightning characteristics and allowing a reliable comparison between different researchers.

Automated image analysis of lung branching morphogenesis

Regulating mechanisms of branchingmorphogenesis of fetal lung rat explants have been an essential tool formolecular research.This work presents a new methodology to accurately quantify the epithelial, outer contour, and peripheral airway buds of lung explants during cellular development frommicroscopic images. Methods.Theouter contour was defined using an adaptive and multiscale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelium was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds was counted as the skeleton branched ends from a skeletonized image of the lung inner epithelia. Results. The time for lung branching morphometric analysis was reduced in 98% in contrast to themanualmethod. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Nonsignificant differences were found between the automatic and manual results in all culture days. Conclusions. The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lighting characteristics and allowing a reliable comparison between different researchers.

Survival Analysis Employed in Predicting Corporate Failure: A Forecasting Model Proposal

In face of the current economic and financial environment, predicting corporate bankruptcy is arguably a phenomenon of increasing interest to investors, creditors, borrowing firms, and governments alike. Within the strand of literature focused on bankruptcy forecasting we can find diverse types of research employing a wide variety of techniques, but only a few researchers have used survival analysis for the examination of this issue. We propose a model for the prediction of corporate bankruptcy based on survival analysis, a technique which stands on its own merits. In this research, the hazard rate is the probability of ‘‘bankruptcy’’ as of time t, conditional upon having survived until time t. Many hazard models are applied in a context where the running of time naturally affects the hazard rate. The model employed in this paper uses the time of survival or the hazard risk as dependent variable, considering the unsuccessful companies as censured observations.

Quantifying chaos for ecological stoichiometry

The theory of ecological stoichiometry considers ecological interactions among species with different chemical compositions. Both experimental and theoretical investigations have shown the importance of species composition in the outcome of the population dynamics. A recent study of a theoretical three-species food chain model considering stoichiometry [B. Deng and I. Loladze, Chaos 17, 033108 (2007)] shows that coexistence between two consumers predating on the same prey is possible via chaos. In this work we study the topological and dynamical measures of the chaotic attractors found in such a model under ecological relevant parameters. By using the theory of symbolic dynamics, we first compute the topological entropy associated with unimodal Poincareacute return maps obtained by Deng and Loladze from a dimension reduction. With this measure we numerically prove chaotic competitive coexistence, which is characterized by positive topological entropy and positive Lyapunov exponents, achieved when the first predator reduces its maximum growth rate, as happens at increasing delta(1). However, for higher values of delta(1) the dynamics become again stable due to an asymmetric bubble-like bifurcation scenario. We also show that a decrease in the efficiency of the predator sensitive to prey's quality (increasing parameter zeta) stabilizes the dynamics. Finally, we estimate the fractal dimension of the chaotic attractors for the stoichiometric ecological model.