900 resultados para Multi-modal information processing
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The vision of the Internet of Things (IoT) includes large and dense deployment of interconnected smart sensing and monitoring devices. This vast deployment necessitates collection and processing of large volume of measurement data. However, collecting all the measured data from individual devices on such a scale may be impractical and time consuming. Moreover, processing these measurements requires complex algorithms to extract useful information. Thus, it becomes imperative to devise distributed information processing mechanisms that identify application-specific features in a timely manner and with a low overhead. In this article, we present a feature extraction mechanism for dense networks that takes advantage of dominance-based medium access control (MAC) protocols to (i) efficiently obtain global extrema of the sensed quantities, (ii) extract local extrema, and (iii) detect the boundaries of events, by using simple transforms that nodes employ on their local data. We extend our results for a large dense network with multiple broadcast domains (MBD). We discuss and compare two approaches for addressing the challenges with MBD and we show through extensive evaluations that our proposed distributed MBD approach is fast and efficient at retrieving the most valuable measurements, independent of the number sensor nodes in the network.
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RESUMO: Os doentes que vão à consulta com sintomas físicos para os quais o médico não encontra uma causa orgânica, são frequentes na Medicina Geral e Familiar, embora não sejam específicos, e são o objecto de estudo do presente trabalho. Não deixar uma doença por diagnosticar (erro de tipo II) sem contudo rotular pessoas saudáveis como doentes (erro de tipo I) é um dos mais difíceis problemas da prática clínica diária e para o qual não existe uma orientação infalível e não é previsível que alguma vez venha a existir. Mas se o diagnóstico de doença ou não-doença é difícil, o tratamento dos que não tem doença, embora com sofrimento, também não é mais fácil, sobretudo, se estivermos conscientes do sofrimento que determina a medicalização e a iatrogenia. O presente trabalho está estruturado em 3 partes. Na primeira parte descrevemos a nossa visão integrada do que apreendemos da leitura da literatura publicada e à qual tivemos acesso. À semelhança do que se verifica na maioria das áreas da Medicina esta é também uma em que o conhecimento cresce a ritmo exponencial. No entanto, à falta de conceitos precisos e de definições consensuais sucede um conhecimento, por vezes, pouco consistente, tanto mais que estamos na fronteira entre a cultura leiga e a cultura erudita médica em que os significados devem, a todo o momento, ser validados. Fizemos uma revisão sobre as definições do que está em questão, sobre o que se sabe sobre a frequência dos sintomas físicos na população, quantos recorrem aos serviços de saúde e o que lhes é feito. Passámos por uma revisão da fisiologia destes sintomas e algumas explicações fisiopatológicas para terminarmos sobre o que os doentes pensam sobre os seus sintomas e os cuidados que recebem e o que os profissionais pensam sobre estes doentes. Esta parte termina com uma revisão das propostas de abordagem para este tipo de doentes. Na segunda parte, descrevemos os estudos empíricos focados no problema dos pacientes com sintomas físicos mas sem evidência de doença orgânica. Começa por uma apresentação dos aspectos processuais e metodológicos dos estudos realizados, mais especificamente, de dois estudos quantitativos e um qualitativo. No primeiro estudo pretendeu-se avaliar quais são os sintomas físicos e a sua frequência na população em geral e a frequência de pacientes que procuram (ou não) os serviços de saúde tendo como motivo este tipo de sintomas. O objectivo deste estudo é contribuir para a demonstração que este tipo de sintomas faz parte da vida do dia-a-dia e que, na maioria das vezes, só por si não significa doença, sem contudo negar que representa sofrimento, por vezes até maior do que quando há patologia orgânica. Se no primeiro estudo era demonstrar que os sintomas físicos são frequentes na população, no segundo estudo o objectivo é demonstrar que pacientes com este tipo de sintomas são igualmente frequentes e que o tipo de sintomas apresentados na consulta não difere dos referidos pela população em geral. Pretendia-se ainda saber o que é feito ou proposto pelo médico a estes doentes e se estes doentes traziam ou não, junto com os sintomas, ideias explicativas para os mesmos. Finalmente e não menos importante, é avaliar o grau de fidedignidade do diagnóstico de sintoma somatoforme, chamando assim ao sintoma físico que foi “levado” à consulta e que o médico diagnosticou como não tendo causa orgânica. O terceiro estudo parte do conhecimento adquirido que a Medicina tem muitas respostas para este problema, mas poucas que se possam considerar satisfatórias se usadas isoladamente. Que a maioria das soluções é procurada entre a cultura médica e num paradigma reducionista de separação mente-corpo. Contudo, se o sintoma é “construído” pelo doente, se o principal problema não está no sintoma mas na forma como o paciente o vê, então pareceu-nos lógico que a solução também tem que passar por integrarmos no plano de abordagem o que o doente entende ser melhor para si. Nesta sequência, entrevistaram-se alguns doentes cujo diagnóstico de sintomas somatoformes estava demonstrado pelo teste do tempo. Por isso, entrevistaram-se doentes que já tinham ido à consulta de MGF há mais de 6 meses por sintomas somatoformes e, na data da entrevista, o diagnóstico se mantinha inalterado, independentemente da sua evolução. As entrevistas visaram conhecer as ideias dos doentes sobre o que as motivou a procurarem a consulta, o que pensavam da forma como foram cuidados e que ideias tinham sobre o que os profissionais de saúde devem fazer para os ajudar a restabelecer o equilíbrio com o seu ambiente evitando a medicalização, a iatrogenia e a evolução para a cronicidade. Na terceira parte, discutem-se e integram-se os resultados encontrados no conhecimento previamente existente. Tenta-se teorizar, fazer doutrina sobre o tema e contribuir para abordagens terapêuticas mais personalizadas, abrangentes, variadas e multimodais, baseadas sempre no método clínico centrado no paciente, ou de modo menos correcto mas enfático, baseadas no método centrado na relação. Apresentam-se algumas hipóteses de trabalhos futuros sobre o tema e, sobretudo, esperamos ter contribuído para o reconhecimento da necessidade de a comunicação médico-doente ser uma aprendizagem transversal a todos os profissionais de saúde e ao longo da vida, com a ideia que é sempre possível fazer melhor, caso contrário tenderemos, inexoravelmente, a fazer cada vez pior.-----------ABSTRACT: Patients who go to consultation with physical symptoms, for which the doctor does not find an organic cause, are the subject of the present study. They are common in family medicine, although not specific. Do not let an undiagnosed disease (type II error), but without labeling healthy people as patients with disease (type I error) is one of the most difficult problems in clinical practice and for which doesn’t exist an infallible guide and it is unlikely that any since coming into existence. But, if the diagnosis of disease or non-disease is difficult, the treatment of those who do not have the disease, though suffering, it is not easy, especially if we are aware of the suffering that medicalization and iatrogenic determines. This work is structured in three parts. In the first part we describe our integrated view of what we grasp from reading the published literature and to which we had access. Similar to that found in most areas of medicine, this is also one in which knowledge grows exponentially. However, the absence of precise concepts and consensual definitions determines an inconsistent knowledge, especially because we're on the border between secular culture and medical culture where, at all times, the meaning must be validated. We did a review on the definitions of what is at issue, what is known about the frequency of physical symptoms in the population, how many use the services of health and what they receive as care. We went through a review of the physiology of these symptoms and some pathophysiological explanations, to finish on what patients think about their symptoms and how they perceived the care they received and, finally, what professionals think about these patients. This part ends with a review of the approaches proposed for such patients. In the second part, we describe the empirical studies focused on the problem of patients with physical symptoms but no evidence of organic disease. Begins with a presentation of the procedural and methodological aspects of studies, more specifically, two quantitative and one qualitative. The first study sought to assess which are the physical symptoms, their incidence in the general population and the frequency they seek (or not) health services on behalf of those symptoms. The aim behind this study was to contribute to the demonstration that this type of symptoms is part of life's day-to-day and that, in most cases, does not represent disease by itself, without denying that they represent suffering, sometimes even greater than when there are organic disease. The first study endeavor to demonstrate that the physical symptoms are common in the population. The second study aspires to demonstrate that patients with such symptoms are also common and that the type of symptoms presented in the consultation does not differ from those in the general population. The aim was also to know what is done or proposed by the physician for these patients and if these patients brought or not, along with the symptoms, explanatory ideas for them. Finally and not least, it would try to assess the degree of reliability of diagnosis of somatoform symptoms, thus drawing the physical symptom that patient presents in the consultation and that the doctor diagnosed as having no organic cause. The third study starts from the acquired knowledge that medicine has many answers to this problem, but few can be considered satisfactory if used in isolation. The most solutions are sought in the medical culture and based on a reductionist paradigm of mind-body. However, if the symptom is "built" by the patient, if the main problem is not the symptom but the way the patient sees it, then it seemed logical to us that the solution must integrate the approaches that patients believes are best for them. Subsequently, a few patients, whose diagnosis of somatoform symptoms was demonstrated by the test of time, were interviewed. Therefore, patients who were interviewed had gone to the consultation of family medicine more than 6 months before for somatoform symptoms and. at the moment of the interview, the diagnosis remained unchanged, regardless of their evolution. The interviews aimed to ascertain the patients' ideas about what motivated them to seek consultation, what they thought about the care they got and which ideas they have about what health professionals should do to help these patients to re-establish equilibrium with its environment avoiding medicalization, iatrogenic effects and the evolution to chronicity. In the third section, we discuss and integrate the results found in previously existing knowledge. Attempts to theorize on the subject and contribute to more personalized treatment, comprehensive, varied and multi-modal approaches, always based on patient-centered clinical method, with emphasis on the relationship. We presents some hypotheses for future work on the subject and,above all, defend the recognition of the importance of lifelong learning communication skills for all health professionals, with the idea that we can always do better, otherwise we tend inexorably to do worse.
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Throughout the brain, patterns of activity in postsynaptic neurons influence the properties of synaptic inputs. Such feedback regulation is central to neural network stability that underlies proper information processing and feature representation in the central nervous system. At the cellular level, tight coupling of presynaptic and postsynaptic function is fundamental to neural computation and synaptic plasticity. The cohort of protein complexes at the pre and postsynaptic membrane allows for tight synapse-specific segregation and integration of diverse molecular and electrical signals.(...)
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Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação
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The Symbol Digit Modalities Test (SDMT) is a widely used instrument to assess information processing speed, attention, visual scanning, and tracking. Considering that repeated evaluations are a common need in neuropsychological assessment routines, we explored test–retest reliability and practice effects of two alternate SDMT forms with a short inter-assessment interval. A total of 123 university students completed the written SDMT version in two different time points separated by a 150-min interval. Half of the participants accomplished the same form in both occasions, while the other half filled different forms. Overall, reasonable test–retest reliabilities were found (r = .70), and the subjects that completed the same form revealed significant practice effects (p < .001, dz = 1.61), which were almost non-existent in those filling different forms. These forms were found to be moderately reliable and to elicit a similar performance across participants, suggesting their utility in repeated cognitive assessments when brief inter-assessment intervals are required.
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Do stars govern our actions? Astrocyte involvement in rodent behavior
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"Series Title: IFIP - The International Federation for Information Processing, ISSN 1868-4238"
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Tese de Doutoramento em Tecnologias e Sistemas de Informação.
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Close homolog of L1, neural cell recognition molecules, c-fos, arg3.1, arc, immediat early genes, novelty, information processing, behavioral tests
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Oxytocin (OT) is thought to play an important role in human interpersonal information processing and behavior. By inference, OT should facilitate empathic responding, i.e. the ability to feel for others and to take their perspective. In two independent double-blind, placebo-controlled between-subjects studies, we assessed the effect of intranasally administered OT on affective empathy and perspective taking, whilst also examining potential sex differences (e.g., women being more empathic than men). In study 1, we provided 96 participants (48 men) with an empathy scenario and recorded self reports of empathic reactions to the scenario, while in study 2, a sample of 120 individuals (60 men) performed a computerized implicit perspective taking task. Whilst results from Study 1 showed no influence of OT on affective empathy, we found in Study 2 that OT exerted an effect on perspective taking ability in men. More specifically, men responded faster than women in the placebo group but they responded as slowly as women in the OT group. We conjecture that men in the OT group adopted a social perspective taking strategy, such as did women in both groups, but not men in the placebo group. On the basis of results across both studies, we suggest that self-report measures (such as used in Study 1) might be less sensitive to OT effects than more implicit measures of empathy such as that used in Study 2. If these assumptions are confirmed, one could infer that OT effects on empathic responses are more pronounced in men than women, and that any such effect is best studied using more implicit measures of empathy rather than explicit self-report measures.
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Astrocytes participate in information processing by actively modulating synaptic properties via gliotransmitter release. Various mechanisms of astrocytic release have been reported, including release from storage organelles via exocytosis and release from the cytosol via plasma membrane ion channels and pumps. It is still not fully clear which mechanisms operate under which conditions, but some of them, being Ca(2+)-regulated, may be physiologically relevant. The properties of Ca(2+)-dependent transmitter release via exocytosis or via ion channels are different and expected to produce different extracellular transmitter concentrations over time and to have distinct functional consequences. The molecular aspects of these two release pathways are still under active investigation. Here, we discuss the existing morphological and functional evidence in support of either of them. Transgenic mouse models, specific antagonists and localization studies have provided insight into regulated exocytosis, albeit not in a systematic fashion. Even more remains to be uncovered about the details of channel-mediated release. Better functional tools and improved ultrastructural approaches are needed in order fully to define specific modalities and effects of astrocytic gliotransmitter release pathways.
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When an agent chooses between prospects, noise in information processing generates an effect akin to the winner’s curse. Statistically unbiased perception systematically overvalues the chosen action because it fails to account for the possibility that noise is responsible for making the preferred action appear to be optimal. The optimal perception patterns share key features with prospect theory, namely, overweighting of small probability events (and corresponding underweighting of high probability events), status quo bias, and reference-dependent S-shaped valuations. These biases arise to correct for the winner’s curse effect.
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We conducted two experiments to demonstrate the relevance of group membership (in-group vs. out-group) in the processing of conflictual social interactions as described by Dodge (1980; Dodge, Pettit, Mcclaskey, & Brown, 1986). In the first study, we highlighted the impact of group membership on the attribution of hostile intents and on reactions to a provocation. In the second study we found that the impact of group membership on aggressive reaction intents is moderated by the status of people in the interaction, and that this effect is partially mediated by attribution of hostile intents. We conclude by stressing the necessity to integrate intergroup dynamics in the social information processing model elaborated by Dodge.
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Detection and discrimination of visuospatial input involve at least extracting, selecting and encoding relevant information and decision-making processes allowing selecting a response. These two operations are altered, respectively, by attentional mechanisms that change discrimination capacities, and by beliefs concerning the likelihood of uncertain events. Information processing is tuned by the attentional level that acts like a filter on perception, while decision-making processes are weighed by subjective probability of risk. In addition, it has been shown that anxiety could affect the detection of unexpected events through the modification of the level of arousal. Consequently, purpose of this study concerns whether and how decision-making and brain dynamics are affected by anxiety. To investigate these questions, the performance of women with either a high (12) or a low (12) STAI-T (State-Trait Anxiety Inventory, Spielberger, 1983) was examined in a decision-making visuospatial task where subjects have to recognize a target visual pattern from non-target patterns. The target pattern was a schematic image of furniture arranged in such a way as to give the impression of a living room. Non-target patterns were created by either the compression or the dilatation of the distances between objects. Target and non-target patterns were always presented in the same configuration. Preliminary behavioral results show no group difference in reaction time. In addition, visuo-spatial abilities were analyzed trough the signal detection theory for quantifying perceptual decisions in the presence of uncertainty (Green and Swets, 1966). This theory treats detection of a stimulus as a decision-making process determined by the nature of the stimulus and cognitive factors. Astonishingly, no difference in d' (corresponding to the distance between means of the distributions) and c (corresponds to the likelihood ratio) indexes was observed. Comparison of Event-related potentials (ERP) reveals that brain dynamics differ according to anxiety. It shows differences in component latencies, particularly a delay in anxious subjects over posterior electrode sites. However, these differences are compensated during later components by shorter latencies in anxious subjects compared to non-anxious one. These inverted effects seem indicate that the absence of difference in reaction time rely on a compensation of attentional level that tunes cortical activation in anxious subjects, but they have to hammer away to maintain performance.
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Astrocytes are now considered as key players in brain information processing because of their newly discovered roles in synapse formation and plasticity, energy metabolism and blood flow regulation. However, our understanding of astrocyte function is still fragmented compared to other brain cell types. A better appreciation of the biology of astrocytes requires the development of tools to generate animal models in which astrocyte-specific proteins and pathways can be manipulated. In addition, it is becoming increasingly evident that astrocytes are also important players in many neurological disorders. Targeted modulation of protein expression in astrocytes would be critical for the development of new therapeutic strategies. Gene transfer is valuable to target a subpopulation of cells and explore their function in experimental models. In particular, viral-mediated gene transfer provides a rapid, highly flexible and cost-effective, in vivo paradigm to study the impact of genes of interest during central nervous system development or in adult animals. We will review the different strategies that led to the recent development of efficient viral vectors that can be successfully used to selectively transduce astrocytes in the mammalian brain.