On the Termination of Linear and Affine Programs over the Integers

The termination problem for affine programs over the integers was left open in\cite{Braverman}. For more that a decade, it has been considered and cited as a challenging open problem. To the best of our knowledge, we present here the most complete response to this issue: we show that termination for affine programs over Z is decidable under an assumption holding for almost all affine programs, except for an extremely small class of zero Lesbegue measure. We use the notion of asymptotically non-terminating initial variable values} (ANT, for short) for linear loop programs over Z. Those values are directly associated to initial variable values for which the corresponding program does not terminate. We reduce the termination problem of linear affine programs over the integers to the emptiness check of a specific ANT set of initial variable values. For this class of linear or affine programs, we prove that the corresponding ANT set is a semi-linear space and we provide a powerful computational methods allowing the automatic generation of these $ANT$ sets. Moreover, we are able to address the conditional termination problem too. In other words, by taking ANT set complements, we obtain a precise under-approximation of the set of inputs for which the program does terminate.Comment: arXiv admin note: substantial text overlap with arXiv:1407.455

Abnormalities Of Thyroid Hormone Metabolism During Systemic Illness: The Low T3 Syndrome In Different Clinical Settings

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Thyroid hormone abnormalities are common in critically ill patients. For over three decades, a mild form of these abnormalities has been described in patients with several diseases under outpatient care. These alterations in thyroid hormone economy are a part of the nonthyroidal illness and keep an important relationship with prognosis in most cases. The main feature of this syndrome is a fall in free triiodothyronine (T3) levels with normal thyrotropin (TSH). Free thyroxin (T4) and reverse T3 levels vary according to the underlying disease. The importance of recognizing this condition in such patients is evident to physicians practicing in a variety of specialties, especially general medicine, to avoid misdiagnosing the much more common primary thyroid dysfunctions and indicating treatments that are often not beneficial. This review focuses on the most common chronic diseases already known to present with alterations in serum thyroid hormone levels. A short review of the common pathophysiology of the nonthyroidal illness is followed by the clinical and laboratorial presentation in each condition. Finally, a clinical case vignette and a brief summary on the evidence about treatment of the nonthyroidal illness and on the future research topics to be addressed are presented.FAPESP (Sao Paulo Research Support Foundation) [2013/03295-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Generating invariants for non-linear loops by linear algebraic methods

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We present new computational methods that can automate the discovery and the strengthening of non-linear interrelationships among the variables of programs containing non-linear loops, that is, that give rise to multivariate polynomial and fractional relationships. Our methods have complexities lower than the mathematical foundations of the previous approaches, which used Grobner basis computations, quantifier eliminations or cylindrical algebraic decompositions. We show that the preconditions for discrete transitions can be viewed as morphisms over a vector space of degree bounded by polynomials. These morphisms can, thus, be suitably represented by matrices. We also introduce fractional and polynomial consecution, as more general forms for approximating consecution. The new relaxed consecution conditions are also encoded as morphisms represented by matrices. By so doing, we can reduce the non-linear loop invariant generation problem to the computation of eigenspaces of specific morphisms. Moreover, as one of the main results, we provide very general sufficient conditions allowing for the existence and computation of whole loop invariant ideals. As far as it is our knowledge, it is the first invariant generation methods that can handle multivariate fractional loops.We present new computational methods that can automate the discovery and the strengthening of non-linear interrelationships among the variables of programs containing non-linear loops, that is, that give rise to multivariate polynomial and fractional rela27805829FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2013/04734-9]FAPESP [2011/08947-1]2013/04734-9; 2011/08947-

A video game level analysis model proposal

This paper presents a preliminary model proposal for the analysis of video game level scenarios consisting of four elements: video game, players, metrics, and gaming experience. The selection of parameters from each of these elements defines a specific video game level analysis context. Initial validation of the model is being carried out with a First-person shooter video game and selected metrics (including eye movement behavior) to understand player behavior (both interactive and visual) within a game level. An additional analysis technique based on visual representation techniques applied in this validation context is also described. After validated, this model may be applied in the analysis of player behavior in game levels, in several different situations predicted in the model itself. Information acquired from the application of this model may posteriorly be used in the design (or redesign) of game levels and scenarios driven for optimal use which should generate a greater gaming experience

Biogénese do complexo I (NADH: coQ-Oxidoreductase) da cadeia respiratória de Neurospora crassa

Dissertação de Doutoramento em Ciências Biomédicas, área de especialização em Biologia Molecular, apresentada ao Instituto de Ciências Biomédicas de Abel Salazar da Universidade do Port

Dois Olhares Sobre a Elaboração por Estudantes de Diagramas de Corpo Livre em Aulas de Física

Diagramas de corpo livre (DCL) são um tipo de inscrição científica usado para representar as forças que agem sobre objetos de interesse. Resultados de pesquisa sinalizam que a leitura e elaboração de DCL é uma tarefa desafiadora. O objetivo deste estudo foi analisar a qualidade dos DCL e das experiências de estudantes ao elaborarem esses DCL, bem como comparar o resultado dessas duas análises. O estudo foi conduzido em aulas da 2ª série do Ensino Médio de uma escola técnica federal localizada em Belo Horizonte. Analisamos os dados de dois grupos de quatro estudantes, moças e rapazes com idades entre 15 e 17 anos. Os nossos resultados mostram que a qualidade dos DCL dos estudantes foi mediana, mas, na maioria das vezes, sua elaboração resultou em experiências educativas. A qualidade dos DCL não é um preditor para a qualidade das experiências dos estudantes

Grupos de alunos como grupos de trabalho: um estudo sobre atividades de investigação

Investigamos fatores cognitivos e subjetivos que desviam grupos de alunos da realização das tarefas de aprendizagem numa situação usual de sala de aula. Procuramos desenvolver instrumentos e procedimentos potencialmente úteis para observação de atividades em grupo em situações reais de sala de aula. A coleta de dados envolveu gravações de áudio e vídeo de grupos de alunos da primeira série do ensino médio durante atividade introdutória de Física. A análise desse material foi realizada à luz dos conceitos psicanalíticos de Bion de Grupo de Trabalho e Suposição Básica. Apresentamos as ações dos membros de um grupo frente aos desafios da atividade, suas interações entre si e sua participação em discussões promovidas pelo professor com toda a turma. Distinguimos o papel de cada membro no grupo, os fatores inconscientes a desviá-los da tarefa, os fatores que geraram conflito entre eles e identificamos os mecanismos que mantiveram o grupo em trabalho colaborativo