3,645 research outputs found

    On the P-representable subset of all bipartite Gaussian separable states

    Get PDF
    P-representability is a necessary and sufficient condition for separability of bipartite Gaussian states only for the special subset of states whose covariance matrix are Sp(2,R)Sp(2,R)Sp(2,R)\otimes Sp(2,R) locally invariant. Although this special class of states can be reached by a convenient Sp(2,R)Sp(2,R)Sp(2,R)\otimes Sp(2,R) transformation over an arbitrary covariance matrix, it represents a loss of generality, avoiding inference of many general aspects of separability of bipartite Gaussian states.Comment: Final version with new results added. Slightly more detailed than the accepted manuscript (to appear in Phys. Rev. A

    Temperature in Machining of Aluminum Alloys

    Get PDF
    The objective this work is to study the effect of the mechanical property of the workpiece (tensile strength) and cutting conditions (cutting speed, feed rate, depth of cut and lubri-cooling system) over the cutting temperature in turning of aluminum alloys. A 2k factorial planning was used to determine the machining test conditions. ANOVA and Regression Analysis of the results were performed. The main contribution of this work lies on its efficiency of describing the behavior of the cutting temperature as a function of the input variables. The results found in the present work have considered the interactions of the input variables, describing the cutting temperature in a complete way, not seen previously in the literature

    SAMBA: Stochastic Analytical Model with a Bayesian Approach

    Get PDF
    We develop and estimate a DSGE model for the Brazilian economy, to be used as part of the macroeconomic modeling framework at the Central Bank of Brazil. The model combines the building blocks of standard DSGE models (e.g., price and wage rigidities and adjustment costs) with the following features that better describe the Brazilian economy: (i) a fiscal authority pursuing an explicit target for the primary surplus; (ii) administered or regulated prices as part of consumer prices; (iii) external finance for imports, amplifying the effects of changes in external financial conditions on the economy; and (iv) imported goods used in the production function of differentiated goods. It also includes the presence of financially constrained households. We estimate the model with Bayesian techniques, using data starting in 1999, when inflation targeting was implemented. Model evaluation, based on impulse response functions, moment conditions, variance error decomposition and initial forecasting exercises, suggests that the model can be a useful tool for policy analysis and forecasting.

    Perspectives of social entrepreneurship in Portugal: comparison and contrast with international theoretical approaches

    Get PDF
    The aim of this article is to present and discuss the perspectives of social entrepreneurship conveyed by third sector organizations in Portugal in the context of the main international theoretical approaches. As part of a research project on social entrepreneurship in Portugal, the article analyses the content of 20 semi-structured interviews with key actors within the Portuguese third sector. It is assumed that the roles these actors play are a clear indicator of the importance their views can hold in defining the social entrepreneurship field in Portugal. This analysis enables us to conclude that heterogeneous views and blurred defined boundaries frame the debate on social entrepreneurship’s processes and definitions, with some actors even rejecting it in favour of other concepts such as “social economy” or “solidarity economy”. Nevertheless, the central issues that arose are associated with the individual qualities of the entrepreneur, as well as the sustainability of the initiatives

    Asymptotically Almost Periodic Solutions for Abstract Partial Neutral Integro-Differential Equation

    Get PDF
    The existence of asymptotically almost periodic mild solutions for a class of abstract partial neutral integro-differential equations with unbounded delay is studied

    Image Denoising using Attention-Residual Convolutional Neural Networks

    Full text link
    During the image acquisition process, noise is usually added to the data mainly due to physical limitations of the acquisition sensor, and also regarding imprecisions during the data transmission and manipulation. In that sense, the resultant image needs to be processed to attenuate its noise without losing details. Non-learning-based strategies such as filter-based and noise prior modeling have been adopted to solve the image denoising problem. Nowadays, learning-based denoising techniques showed to be much more effective and flexible approaches, such as Residual Convolutional Neural Networks. Here, we propose a new learning-based non-blind denoising technique named Attention Residual Convolutional Neural Network (ARCNN), and its extension to blind denoising named Flexible Attention Residual Convolutional Neural Network (FARCNN). The proposed methods try to learn the underlying noise expectation using an Attention-Residual mechanism. Experiments on public datasets corrupted by different levels of Gaussian and Poisson noise support the effectiveness of the proposed approaches against some state-of-the-art image denoising methods. ARCNN achieved an overall average PSNR results of around 0.44dB and 0.96dB for Gaussian and Poisson denoising, respectively FARCNN presented very consistent results, even with slightly worsen performance compared to ARCNN.Comment: Published in: 2020 33rd SIBGRAPI Conference on Graphics, Patterns and Images (SIBGRAPI

    On the Effects of Quantum Decoherence in a Future Supernova Neutrino Detection

    Full text link
    Quantum decoherence effects in neutrinos, described by the open quantum systems formalism, serve as a gateway to explore potential new physics, including quantum gravity. Previous research extensively investigated these effects across various neutrino sources, imposing stringent constraints on the spontaneous loss of coherence. In this study, we demonstrate that even within the Supernovae environment, where neutrinos are released as incoherent states, quantum decoherence could influence the flavor equipartition of 3ν3\nu mixing. Additionally, we examine the potential energy dependence of quantum decoherence parameters (Γ=Γ0(E/E0)n\Gamma = \Gamma_0 (E/E_0)^n) with different power laws (n=0,2,5/2n = 0, 2, 5/2). Our findings indicate that future-generation detectors (DUNE, Hyper-K, and JUNO) can significantly constrain quantum decoherence effects under different scenarios. For a Supernova located 10 kpc away from Earth, DUNE could potentially establish 3σ3\sigma bounds of Γ6.2×1014\Gamma \leq 6.2 \times 10^{-14} eV in the normal mass hierarchy (NH) scenario, while Hyper-K could impose a 2σ2\sigma limit of Γ3.6×1014\Gamma \leq 3.6 \times 10^{-14} eV for the inverted mass hierarchy (IH) scenario with n=0n=0 - assuming no energy exchange between the neutrino subsystem and non-standard environment ([H,Vp]=0[H,V_p] = 0). These limits become even more restrictive for a closer Supernova. When we relax the assumption of energy exchange ([H,Vp]0[H,V_p] \neq 0), for a 10 kpc SN, DUNE can establish a 3σ3\sigma limit of Γ84.2×1028\Gamma_8 \leq 4.2 \times 10^{-28} eV for NH, while Hyper-K could constrain Γ81.3×1027\Gamma_8 \leq 1.3 \times 10^{-27} eV for IH (n=0n=0) with 2σ2\sigma, representing the most stringent bounds reported to date. Furthermore, we examine the impact of neutrino loss during propagation for future Supernova detection

    Identification, characterization and localization of chagasin, a tight-binding cysteine protease inhibitor in Trypanosoma cruzi

    Get PDF
    Lysosomal cysteine proteases from mammalian cells and plants are regulated by endogenous tight-binding inhibitors from the cystatin superfamily. The presence of cystatin-like inhibitors in lower eukaryotes such as protozoan parasites has not yet been demonstrated, although these cells express large quantities of cysteine proteases and may also count on endogenous inhibitors to regulate cellular proteolysis. Trypanosoma cruzi, the causative agent of Chagas heart disease, is a relevant model to explore this possibility because these intracellular parasites rely on their major lysosomal cysteine protease (cruzipain) to invade and multiply in mammalian host cells. Here we report the isolation, biochemical characterization, developmental stage distribution and subcellular localization of chagasin, an endogenous cysteine protease inhibitor in T. cruzi. We used high temperature induced denaturation to isolate a heat-stable cruzipain-binding protein (apparent molecular mass, 12 kDa) from epimastigote lysates. This protein was subsequently characterized as a tight-binding and reversible inhibitor of papain-like cysteine proteases. Immunoblotting indicated that the expression of chagasin is developmentally regulated and inversely correlated with that of cruzipain. Gold-labeled antibodies localized chagasin to the flagellar pocket and cytoplasmic vesicles of trypomastigotes and to the cell surface of amastigotes. Binding assays performed by probing living parasites with fluorescein (FITC)-cruzipain or FITC-chagasin revealed the presence of both inhibitor and protease at the cell surface of amastigotes. The intersection of chagasin and cruzipain trafficking pathways may represent a checkpoint for downstream regulation of proteolysis in trypanosomatid protozoa

    A study on the relationship between muscle function, functional mobility and level of physical activity in community-dwelling elderly

    Get PDF
    OBJETIVOS: Avaliar a relação da função muscular de membros inferiores (MMII), circunferência de panturrilha (CP), força de preensão palmar (FPP), mobilidade funcional e nível de atividade física (NAF) em idosos comunitários ativos com idades entre 65-69, 70-79 e 80 ou mais anos e identificar a melhor medida clínica para rastreamento de redução de função muscular de MMII em idosos. MÉTODOS: Oitenta e um idosos (42 mulheres e 39 homens) submeteram-se à avaliação da velocidade de marcha (Kit Multisprint), FPP (dinamômetro Jamar), força e potência muscular de MMII (dinamômetro isocinético Biodex), NAF (Perfil de Atividade Humana) e CP (fita métrica). Procedeu-se à análise estatística com ANOVA, correlação de Pearson e curva ROC. RESULTADOS: Os idosos de 80 ou mais anos apresentaram valores menores que os de 65-69 para CP dominante (34,9±3 vs 37,7±3,6), velocidade de marcha habitual (VMH) (1,1±0,2 vs 1,2±0,2) e velocidade de marcha máxima (VMM) (1,4±0,3 vs 1,7±0,3), FPP (23,8±7,5 vs 31,8±10,3), média de pico de torque (MPT) e potência média (PM) de quadril, joelho e tornozelo (p<0,05). O NAF não apresentou diferença significativa entre os grupos. A força e potência muscular apresentaram correlações moderadas com VMH, VMM e FPP e correlações baixas com a CP e com o NAF (p<0,05). A curva ROC sugeriu o ponto de corte de FPP de 14,51 Kgf para rastreamento de redução de função muscular nas mulheres idosas (p=0,03). CONCLUSÕES: Existe associação entre a função muscular de MMII, FPP e VMM: esses parâmetros diminuem com o envelhecimento, e a FPP pode prever redução de função muscular de MMII em idosas.Objectives: to evaluate the relationship between lower extremity muscle function, calf circumference (CC), handgrip strength (HG), functional mobility and level of physical activity among age groups (65-69, 70-79, 80+) of older adults (men and women) and to identify the best parameter for screening muscle function loss in the elderly. Methods: 81 community-dwelling elderly (42 women and 39 men) participated. Walking speed (Multisprint Kit), HG (Jamar dynamometer), hip, knee and ankle muscle function (Biodex isokinetic dynamometer), level of physical activity (Human Activity Profle) and CC (tape measure) were evaluated. ANOVA, Pearson correlation and ROC curves were used for statistical analysis. Results: Dominant CC (34.9±3 vs 37.7±3.6), habitual (1.1±0.2 vs 1.2±0.2) and fast (1.4±0.3 vs 1.7±0.3) walking speed, HG (23.8±7.5 vs 31.8±10.3), average peak torque and average hip, knee and ankle power (p<0.05) were lower for the 80+ group than for the 65-69 year-olds. There were no differences in physical activity level among age groups. Moderate signifcant correlations were found between muscle function parameters, walking speed and HG; a fair degree of relationship was found between muscle function parameters, CC and level of physical activity (p<0.05). The ROC curve analysis suggested a cutoff point of 14.51 Kgf for screening muscle function loss in elderly women (p=0.03). Conclusions: This study demonstrated an association between muscle function, HG and fast walking speed, a decrease in these parameters with age and the possibility of using HG to screen for muscle function of the lower extremities
    corecore