Tomographic Image Reconstruction of Fan-Beam Projections with Equidistant Detectors using Partially Connected Neural Networks

We present a neural network approach for tomographic imaging problem using interpolation methods and fan-beam projections. This approach uses a partially connected neural network especially assembled for solving tomographic\ud reconstruction with no need of training. We extended the calculations to perform reconstruction with interpolation and to allow tomography of fan-beam geometry. The main goal is to aggregate speed while maintaining or improving the quality of the tomographic reconstruction process

Angular Power Spectrum Estimation of Cosmic Ray Anisotropies with Full or Partial Sky Coverage

We study the angular power spectrum estimate in order to search for large scale anisotropies in the arrival directions distribution of the highest-energy cosmic rays. We show that this estimate can be performed even in the case of partial sky coverage and validated over the full sky under the assumption that the observed fluctuations are statistically spatial stationary. If this hypothesis - which can be tested directly on the data - is not satisfied, it would prove, of course, that the cosmic ray sky is non isotropic but also that the power spectrum is not an appropriate tool to represent its anisotropies, whatever the sky coverage available. We apply the method to simulations of the Pierre Auger Observatory, reconstructing an input power spectrum with the Southern site only and with both Northern and Southern ones. Finally, we show the improvement that a full-sky observatory brings to test an isotropic distribution, and we discuss the sensitivity of the Pierre Auger Observatory to large scale anisotropies.Comment: 16 pages, 6 figures, version accepted for publication by JCA

Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

Sulphate reducing bacteria are known to play a major role in anaerobic microbiological influenced corrosion of steels, but mechanisms behind their influence are still source of debates as certain phenomena remain unexplained. Some experiments have shown that hydrogen consumption by SRB or hydrogenase increased the corrosion rate of mild steel. This was observed only in the presence of phosphate species. Here the cathodic behaviour of phosphate species on steel was studied to elucidate the role of phosphate in anaerobic corrosion of steel. Results showed: a linear correlation between reduction waves in linear voltammetry and phosphate concentration at a constant pH value; that phosphate ions induced considerable anaerobic corrosion of mild steel, which was sensitive to hydrogen concentration in the solution; and that the corrosion potential of stainless steel in presence of phosphate was shifted to more negative values as molecular hydrogen was added to the atmosphere in the reaction vessel. Phosphate species, and possibly other weak acids present in biofilms, are suggested to play an important role in the anaerobic corrosion of steels via a reversible mechanism of electrochemical deprotonation that may be accelerated by hydrogen removal

Taking the perspectives of many people: Humanization matters

In a busy space, people encounter many other people with different viewpoints, but classic studies of perspective-taking examine only one agent at a time. This paper explores the issue of selectivity in visual perspective-taking (VPT) when different people are available to interact with. We consider the hypothesis that humanization impacts on VPT in four studies using virtual reality methods. Experiments 1 and 2 use the director task to show that for more humanized agents (an in-group member or a virtual human agent), participants were more likely to use VPT to achieve lower error rate. Experiments 3 and 4 used a two-agent social mental rotation task to show that participants are faster and more accurate to recognize items which are oriented towards a more humanized agent (an in-group member or a naturally moving agent). All results support the claim that humanization alters the propensity to engage in VPT in rich social contexts

Interleukin-7 is necessary to maintain the B cell potential in common lymphoid progenitors

Interleukin-7 (IL-7) promotes survival and expansion of lymphoid precursors. We show here that, in addition, IL-7 has a fundamental role, as early as the stage of the multipotent (B/T/NK) common lymphoid progenitor (CLP), in maintaining the B cell differentiation program open. CLPs generated in the absence of IL-7 have normal T/NK differentiation potential, but severely impaired B potential. Accordingly, CLPs from IL-7–deficient mice express lower amounts of early B cell factor (EBF) and Pax5 than wild-type CLPs, but similar amounts of GATA-3. Importantly, induced overexpression of EBF is sufficient to restore the B potential in these cells. These results indicate that IL-7 directs commitment of CLPs by modulating EBF expression. This is the first example of a cytokine influencing lymphoid lineage commitment in multipotent progenitors and highlights the relevance of the expression of a functional IL-7 receptor at the CLP stage

More surgeons, less trauma

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Curso de Direitos Humanos na América Latina

Neste presente trabalho podemos observar os objetivos, metas, motivações e o desenvolvimento do projeto de extensão “Curso de Direitos Humanos na América Latina”, além de seu impacto na comunidade interna e externa. Destaca-se a parceria dos representantes de movimentos sociais e professores doutores da Universidade Federal da Integração Latino-Americana (UNILA) e da Universidade Estadual do Oeste do Paraná (UNIOESTE). Desta forma, com as aulas expositivas e os recursos audiovisuais oferecidos quinzenalmente nas salas de aula da UNILA – campus Jardim Universitário, observou-se a importância do debate, da luta e da militância por direitos humanos fundamentais na América Latina

(Meta-)stability and Core–Shell Dynamics of Gold Nanoclusters at Finite Temperature

Gold nanoclusters have been the focus of numerous computational studies, but an atomistic understanding of their structural and dynamical properties at finite temperature is far from satisfactory. To address this deficiency, we investigate gold nanoclusters via ab initio molecular dynamics, in a range of sizes where a core–shell morphology is observed. We analyze their structure and dynamics using state-of-the-art techniques, including unsupervised machine-learning nonlinear dimensionality reduction (sketch-map) for describing the similarities and differences among the range of sampled configurations. In the examined temperature range between 300 and 600 K, we find that whereas the gold nanoclusters exhibit continuous structural rearrangement, they are not amorphous. Instead, they clearly show persistent motifs: a cationic core of 1–5 atoms is loosely bound to a shell which typically displays a substructure resulting from the competition between locally spherical versus planar fragments. Besides illuminating the properties of core–shell gold nanoclusters, the present study proposes a set of useful tools for understanding their nature in operando

Subutilização de recursos humanos: aspectos teóricos

A subutilização de recursos humanos em nações não desenvolvidas é um problema que tem preocupado sobremaneira não somente a economistas como também a outros cientistas sociais. Infelizmente ainda não possuímos um instrumental analítico que explique todos os diferentes matizes em que o problema aparece. Um modelo que representasse extensivamente esse fenômeno poderia apresentar um grau tal de complexidade e especificação que se tornaria inviável