Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia

Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusions

Fatores que influenciam a cooperação em humanos

Human cooperation is fundamentally affected by reciprocal exchange, but it is also remarkably common on the context of large and symbolically marked in-groups, which promote cooperation through the feeling of belonging to a group. In this thesis, two empirical articles were produced in order to investigate how human cooperation is affected by factors such as reciprocity, in-group behavior, in-group markers and gender. We investigated this subject through the administration of online games consisting of token donations, on which the subjects faced virtual players controlled by the experiment. We found that cooperative behavior is strongly influenced by reciprocity, and it is also affected by the in-group behavior, observed on the context of the social variables place of birth, ethnicity, and religions, once all of them acted as in-group markers. The subjects´ in-group behavior was enhanced when they played with generous in-group opponents, but weakened when their in-group opponents were non-generous. It was also found that cooperation is not affected by gender, but men and women cooperated in different ways under the influence of reciprocity and in-group behavior. Women are much more reciprocal on their cooperative behavior and men are less willing to cooperate with outgroupers, even when they act generously. The overall results contribute to a better understanding of the adaptive value of cooperation, reciprocity and in-group behavior on the solution of important challenges through the human evolutionary history

Analysis of Semi-solid Processing for Metal Matrix Composite Synthesis Using Factorial Design

The main goal in this work is to conduct a quantitative analysis of the mechanical stir casting process for obtaining particulate metal matrix composites. A combined route of stirring at semi-solid state followed by stirring at liquid state is proposed. A fractional factorial design was developed to investigate the influence and interactions of factors as: time, rotation, initial fraction and particle size, on the incorporated fraction. The best incorporations were obtained with all factors at high levels, as well as that very long stirring periods have no strong influence being particle size and rotation the most important factors on the incorporated fraction. Particle wetting occurs during stirring at semisolid state, highlighting the importance of the interactions between particles and the alloy globularized phase. The role of the alloying element Mg as a wettability-promoting agent is discussed. The shear forces resulting from the stirring system is emphasized and understood as the effect of rotation itself added to the propeller blade geometry.

Variable parameter and double sampling (X)over-bar charts in the presence of correlation: The Markov chain approach

The general assumption under which the (X) over bar chart is designed is that the process mean has a constant in-control value. However, there are situations in which the process mean wanders. When it wanders according to a first-order autoregressive (AR (1)) model, a complex approach involving Markov chains and integral equation methods is used to evaluate the properties of the (X) over bar chart. In this paper, we propose the use of a pure Markov chain approach to study the performance of the (X) over bar chart. The performance of the chat (X) over bar with variable parameters and the (X) over bar with double sampling are compared. (C) 2011 Elsevier B.V. All rights reserved.

Control charts for individual observations of a bivariate Poisson process

In this paper, three single-control charts are proposed to monitor individual observations of a bivariate Poisson process. The specified false-alarm risk, their control limits, and ARLs were determined to compare their performances for different types and sizes of shifts. In most of the cases, the single charts presented better performance rather than two separate control charts ( one for each quality characteristic). A numerical example illustrates the proposed control charts.

Quantitative variation in the tropical maize population, ESALQ-PB1

A boa produtividade e os valores intermediários para altura da planta e altura da espiga caracterizam a população de milho ESALQ-PB1 como agronomicamente promissora. São relatadas estimativas de parâmetros para 13 caracteres: altura da planta (PH), altura da espiga (EH), posição relativa da espiga (EP), comprimento do pendão (TL), peso do pendão (TW), número de ramificações do pendão (TB), peso de espigas (EW), peso de grãos (GW), comprimento da espiga (EL), diâmetro da espiga (ED), número de fileiras de grãos (RN), número de grãos por fileira (KR) e prolificidade (PR). Os resultados se referem a um único ambiente (um local e um ano). Foi detectada variação genética para todos os caracteres, e são apresentadas estimativas da variância genética aditiva. Os coeficientes de herdabilidade (indivíduos) variaram de 0,14 a 0,72 e foram considerados altos para PH, EH e TB; intermediários para EP, TL, TW, EL e ED, e baixos para EW, GW, KR e PR. O coeficiente de herdabilidade para médias de progênies mostrou aproximadamente a mesma tendência, variando de 0,40 a 0,75. O maior ganho esperado por seleção foi para TB (27% por ciclo) sob seleção massal e para TW (16,4%) por seleção entre progênies; o menor ganho esperado foi para ED, tanto por seleção massal (1,9%) como por seleção entre progênies (2,9%). Coeficientes de correlação aditiva (rA) 0.5

Perfil de mortalidade de idosos no Rio Grande do Norte: estudo comparativo entre duas faixas etárias e fatores relacionados

Measures of mortality represent one of the most important indicators of health conditions. For comprising the larger rate of deaths, the study of mortality in the elderly population is regarded as essential to understand the health situation. In this sense, the present study aims to analyze the mortality profile of the population from 60 to 69 (young elders) and older than 80 years old (oldest old) in the Rio Grande do Norte state (Brazil) in the period 2001 to 2011, and to identify the association with contextual factors and variables about the quality of the Mortality Information System (SIM). For this purpose, Mortality Proportional (MP) was calculated for the state and Specific Mortality Rate by Age (CMId) , according to chapters of ICD- 10, to the municipalities of Rio Grande do Norte , through data from the Mortality Information System (SIM) and the Brazilian Institute of Geography and Statistics (IGBE). In order to identify groups of municipalities with similar mortality profiles, Nonhierarchical Clustering K-means method was applied and the Factor Analysis by the Principal Components Analysis was resort to reduce contextual variables. The spatial distribution of these groups and the factors were visualized using the Spatial Analysis Areas technique. During the period investigated, 21,813 younger elders deaths were recorded , with a predominance of deaths from circulatory diseases (32.75%) and neoplasms (22.9 %) . Among the oldest old, 50,637 deaths were observed, which 35.26% occurred because of cardiovascular diseases and 17.27% of ill-defined causes. Clustering Analysis produced three clusters to the two age groups and Factor Analysis reduced the contextual variables into three factors, also the sum of the factor scores was considered. Among the younger elders, the groups are called misinformation profile, development profile and development paradox, which showed a statistically significant association with education and poverty and extreme poverty factors, factorial sum and the variable related to underreporting of deaths. Misinformation profile remained in the oldest old group, accompanied by the epidemiological transition profile and the epidemiological paradox, that were statistically associated with the development and health factor, as well as with the variables that indicate the SIM quality: proportion of blank fields about the schooling and underreporting. It proposed that the mortality profiles of the younger elders and oldest old differ on the importance of the basic causes and that are influenced by different contextual aspects , observing that 60 to 69 years group is more affected by such aspects. Health inequalities can be reduced by measures aimed to improve levels of education and poverty, especially in younger elders, and by optimizing the use of health services, which is more associated to the oldest old health situation. Furthermore, it is important to improve the quality of information for the two age groups

Fonoaudiologia: epistemologia, implicações pedagógicas e educacionais

Tendo em vista os atuais preceitos socioconstrutivistas da Ciência e da Educação em Ciências, neste estudo, o nosso objetivo foi analisar a vertente epistemológica em artigos científicos que tratam de linguagem escrita. Para tanto, analisamos o conteúdo de seis desses artigos, baseando-nos em indicadores educacionais: concepções de ciência, de sujeito, de linguagem e de intervenção fonoaudiológica. A análise destas concepções, em seu conjunto, nos permitiu o enquadramento do conteúdo desses artigos em uma vertente epistemológica mais ou menos técnica ou humanista, lógico-positivista ou pós-positivista, e, ainda, inferir sobre as implicações dessas vertentes na construção de um conhecimento pedagógico e educacional no campo da Fonoaudiologia, para a formação continuada e em serviço de um profissional fonoaudiólogo capaz de atuar também na escola. Os resultados mostraram que as visões dos autores dos artigos analisados se enquadram em uma vertente predominantemente lógico-positivista, o que aponta para a importância de reestruturar os cursos formadores desses profissionais com base em preceitos de Educação em Ciência e à luz de uma nova Filosofia da Ciência.

Uma abordagem sistemática para implementação, gerenciamento e customização de testes de linhas de produto de software

Through the adoption of the software product line (SPL) approach, several benefits are achieved when compared to the conventional development processes that are based on creating a single software system at a time. The process of developing a SPL differs from traditional software construction, since it has two essential phases: the domain engineering - when common and variables elements of the SPL are defined and implemented; and the application engineering - when one or more applications (specific products) are derived from the reuse of artifacts created in the domain engineering. The test activity is also fundamental and aims to detect defects in the artifacts produced in SPL development. However, the characteristics of an SPL bring new challenges to this activity that must be considered. Several approaches have been recently proposed for the testing process of product lines, but they have been shown limited and have only provided general guidelines. In addition, there is also a lack of tools to support the variability management and customization of automated case tests for SPLs. In this context, this dissertation has the goal of proposing a systematic approach to software product line testing. The approach offers: (i) automated SPL test strategies to be applied in the domain and application engineering, (ii) explicit guidelines to support the implementation and reuse of automated test cases at the unit, integration and system levels in domain and application engineering; and (iii) tooling support for automating the variability management and customization of test cases. The approach is evaluated through its application in a software product line for web systems. The results of this work have shown that the proposed approach can help the developers to deal with the challenges imposed by the characteristics of SPLs during the testing process

Dos requisitos à arquitetura em linhas de produtos de software: uma estratégia de transformações entre modelos

The tracking between models of the requirements and architecture activities is a strategy that aims to prevent loss of information, reducing the gap between these two initial activities of the software life cycle. In the context of Software Product Lines (SPL), it is important to have this support, which allows the correspondence between this two activities, with management of variability. In order to address this issue, this paper presents a process of bidirectional mapping, defining transformation rules between elements of a goaloriented requirements model (described in PL-AOVgraph) and elements of an architectural description (defined in PL-AspectualACME). These mapping rules are evaluated using a case study: the GingaForAll LPS. To automate this transformation, we developed the MaRiPLA tool (Mapping Requirements to Product Line Architecture), through MDD techniques (Modeldriven Development), including Atlas Transformation Language (ATL) with specification of Ecore metamodels jointly with Xtext , a DSL definition framework, and Acceleo, a code generation tool, in Eclipse environment. Finally, the generated models are evaluated based on quality attributes such as variability, derivability, reusability, correctness, traceability, completeness, evolvability and maintainability, extracted from the CAFÉ Quality Model

Reqsys-MDD: uma ferramenta para mapeamento entre modelos de features e requisitos em linhas de produto de software

The approach Software Product Line (SPL) has become very promising these days, since it allows the production of customized systems on large scale through product families. For the modeling of these families the Features Model is being widely used, however, it is a model that has low level of detail and not may be sufficient to guide the development team of LPS. Thus, it is recommended add the Features Model to other models representing the system from other perspectives. The goals model PL-AOVgraph can assume this role complementary to the Features Model, since it has a to context oriented language of LPS's, which allows the requirements modeling in detail and identification of crosscutting concerns that may arise as result of variability. In order to insert PL-AOVgraph in development of LPS's, this paper proposes a bi-directional mapping between PL-AOVgraph and Features Model, which will be automated by tool ReqSys-MDD. This tool uses the approach of Model-Driven Development (MDD), which allows the construction of systems from high level models through successive transformations. This enables the integration of ReqSys-MDD with other tools MDD that use their output models as input to other transformations. So it is possible keep consistency among the models involved, avoiding loss of informations on transitions between stages of development

Sistema de apoio à interatividade em revisões sistemáticas em engenharia de software

A colaboração na pesquisa é uma das tarefas centrais da área acadêmica. Atualmente, muitos pesquisadores estão utilizando meios modernos de troca de arquivos digitais através de ferramentas assíncronas e também com o uso de ferramentas mais sofisticadas, do tipo síncronas. Juntamente com o fato da crescente quantidade de artigos sendo gerados, mais complexos, diversificados e aumentando de forma desorganizada, o que trás ao pesquisador uma tarefa difícil para organizá-los de forma a se extrair o melhor conteúdo destes, isto ocorre porque uma subárea da Engenharia de Software (ES) ainda é bastante mal aproveitada, a Engenharia de Software Experimental (ESE). Utilizando-se de um dos tipos de experimentos que a ESE oferece, as revisões sistemáticas entram como uma solução bastante robusta, na qual o pesquisador pode identificar o conhecimento existente em uma área e planejar devidamente sua pesquisa, evitando a repetição de erros em pesquisas já efetivadas por outros pesquisadores no passado. Contudo, estas duas abordagens, a colaboração virtual de pesquisadores e a utilização de revisões sistemáticas, contem problemas: na primeira, sistemas colaborativos são geralmente difíceis de configurar e usar; na segunda, apesar da robustez da metodologia de revisões sistemáticas, ainda se torna necessário uma rigorosa revisão na literatura para se conseguir um resultado satisfatório. Assim, com o foco de unir estas duas abordagens, este trabalho propõe uma maneira de produzir revisões sistemáticas de forma organizada e com a possibilidade de interação entre usuários, com o desenvolvimento de um sistema interativo, no qual as revisões sistemáticas possam ser geradas por usuários em colaboração com outros e também ser avaliadas seguindo a orientação de um profissional da área, tornando o seu conteúdo mais consistente e de melhor qualidade. O sistema não possui níveis de acesso, ou seja, qualquer pessoa pode se cadastrar e usufruir de seus recursos, seja na área acadêmica ou mesmo na área profissional

A gestão participativa do desenvolvimento rural sustentável: o PRONAF na Subzona de Touros/ RN

To investigate the possibilities and limits of mechanisms of participativa management in the scope of the Pronaf - National Program of Fortalecimento of Familiar Agriculture, and the corresponding effectiveness of its actions in the construction of alternatives of sustainable agricultural development in the Coast North of the State of the Great River of the North, more specifically, in the composed Subzona de Touros for the cities of Bulls, White Well, Pureness, Is Miguel of the Gostoso and Taipu. To carry through this analysis they had been carried through Research of Field with the objective to reconstitute the trajectory of the CMDRS, to trace the profile of the citizens that compose each one of the five advice, its expectations, interests and the level of participation of the local population

O campo e o jogo: uma História do Estádio Castelão (1963-1991)

The study aims to examine the planning, the construction and uses of the stadium Presidente Castelo Branco (Castelão), opened in Natal, capital of Rio Grande do Norte, in 1972. Used as main sources of documents printed newspapers A República, Tribuna do Norte e Diário de Natal; photographs of the 1960s, 1970s and 1980s and, finally, an interview with Moacyr Gomes da Costa, architect responsible for building the stadium Castelão. Seeks to understand the changes and continuities stemming from the construction of this stadium for football history and the city. Articulated in the text the inauguration of the stadium with the process of commodification and massification of football norte-rio-grandense, that occurred from the 1970s. Indicates the places where they practiced football in Natal before the construction of a stadium and analyzes the historical needs that led to the construction of a sports square. Discusses the transformation of football matches in shows profit, which now involve large economic interests. Investigates how political potiguares made use of football stadiums as a mechanism of legitimation and realize this debate with the performances of Djalma Maranhão and the Cortez Pereira, that at different times using this mechanism. Search elements that favored the popularization experienced by football potiguar from the 1970s, the role of the sports press this process and the emergence organized supporters

Aspectos morfológicos de biópsias musculares em equinos com miopatia sob forma de surto

As miopatias em equinos são classificadas de acordo com aspectos clínicos, morfológicos e moleculares, em três grandes grupos: não associadas ao exercício, associadas ao exercício e devido alteração da condução elétrica do sarcolema. Apesar dos avanços no diagnóstico, a literatura ainda relata surtos de miopatia em equinos sem etiologia esclarecida em diversos países. O objetivo desse estudo foi descrever as alterações histológicas e histoquímicas de biópsias musculares de equinos acometidos por miopatia. Sete equinos da raça Quarto de Milha, com 18-24 meses de idade, apresentaram sinais clínicos de miopatia. Dentre esses animais, cinco apresentaram sinais subagudos leves a moderados e dois apresentaram sinais hiperagudos severos e decúbito lateral. Foram realizadas biópsias musculares utilizando a técnica percutânea, por agulha tipo Bergström, no músculo glúteo médio em todos os animais acometidos. As amostras foram processadas por meio de técnicas histológicas (HE, Tricrômio de Gomori modificado) e histoquímicas (PAS, NADH, ATPase). Nos quadros clínicos mais leves, a principal alteração encontrada foi a presença de fibras vermelhas rajadas do tipo I e IIA, que estão associadas às alterações do metabolismo oxidativo e das funções mitocondriais, como ocorrem nas miopatias mitocondriais. Também foram observadas fibras atróficas do tipo I e IIA, além da presença de agregados subsarcolemais. Nos quadros mais severos o tecido muscular apresentou infiltrado inflamatório, aumento de colágeno, fagocitose, necrose, calcificação e regeneração muscular. Diante dos achados morfológicos, da resposta à terapia com vitamina E e Se e da baixa mortalidade quando comparado aos relatos de miopatia atípica, conclui-se que esse surto foi desencadeado por lesões mitocondriais, caracterizadas pelas fibras musculares vermelhas rajadas, possivelmente devido uma quebra da homeostase de vitamina E e Se, sendo compatível com o diagnóstico de miopatia nutricional.