Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event System (DES) models. This technical note presents a new algorithm that tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure, called OP-Verifier, can be applied to (potentially nondeterministic) automata, with no restriction on the existence of cycles of 'non-relevant' events. This procedure has quadratic complexity in the number of states. The performance of the algorithm is illustrated by a set of experiments

Analysing vagus nerve spontaneous activity using finite element modelling

Objective. Finite element modelling has been widely used to understand the effect of stimulation on the nerve fibres. Yet the literature on analysis of spontaneous nerve activity is much scarcer. In this study, we introduce a method based on a finite element model, to analyse spontaneous nerve activity with a typical bipolar electrode recording setup, enabling the identification of spontaneously active fibres. We applied our method to the vagus nerve, which plays a key role in refractory epilepsy. Approach. We developed a 3D model including dynamic action potential propagation, based on the vagus nerve geometry. The impact of key recording parameters – inter-electrode distance and temperature – and uncontrolled parameters – fibre size and position in the nerve – on the ability to discriminate active fibres were quantified. A specific algorithm was implemented to detect and classify action potentials from recordings and tested on six rats in vivo vagus nerve recordings. Main results. Fibre diameters can be discriminated if they are below 3 µm and 7 µm, respectively for inter-electrode distances of 2 mm and 4 mm. The impact of the position of the fibre inside the nerve on fibre diameter discrimination, is limited. The range of active fibres identified by modelling in the vagus nerve of rats is in agreement with ranges found at histology. Significance. The nerve fibre diameter, directly proportional to the action potential propagation velocity, is related to a specific physiological function. Estimating the source fibre diameter is thus essential to interpret neural recordings. Among many possible applications, the present method was developed in the context of a project to improve vagus nerve stimulation therapy for epilepsy

Avaliação do conhecimento de alunos de medicina sobre instalação da cárie dentária em lactentes e pré-escolares

O quadro epidemiológico de cárie em pré-escolares brasileiros ainda é preocupante, considerando-se sua manifestação precoce e a forte associação com os fatores socioeconômicos. Sabe-se que quando hábitos saudáveis são ensinados em idade precoce, as ações educativas em saúde a serem implementadas mais tarde podem se basear no reforço de rotinas já estabelecidas. Assim, mães de crianças jovens e gestantes devem ser a população- alvo para programas de educação em saúde bucal. Médicos pediatras que acompanham o desenvolvimento da criança rotineiramente desde o nascimento estão em condições ideais para orientar os pais sobre os cuidados preventivos, incluindo hábitos dietéticos, higiene oral e uso de flúor, e também detectar precocemente sinais de cárie dentária, alertando os pais quando estes são identificados. Para efetivação desse trabalho está sendo realizado uma revisão de literatura e a aplicação de um questionário pelos responsáveis do projeto aos alunos do sétimo e oitavo períodos do curso de medicina do UniFOA. Justifica-se com isso, possibilitar aos alunos da medicina conhecimentos sobre etiologia da cárie dentária na infância, bem com seus fatores de risco. O objetivo do trabalho é avaliar o conhecimento dos alunos de medicina do UniFOA sobre etiologia e fatores de risco da cárie dentária na infância. O presente trabalho não apresenta resultados, pois encontrasse em fase de coleta inicial de dados

Elaboração de painéis educativos em odontologia

Este trabalho objetiva a construção de práticas pedagógicas, a serem empregadas no Programa de Saúde Coletiva do Curso de Odontologia do UniFOA de Volta Redonda, tendo como base, prevenção e educação em saúde bucal. O Projeto tem como estratégia a elaboração de um álbum seriado, que atenda de modo simples e objetivo a todas as faixas etárias e cenários de ensino-aprendizagem. Utilizando temas relacionados à saúde bucal, como “Dieta e Saúde”, “Etiologia da Cárie Dentária” e “Higiene Oral”, objetivamos uma maior conscientização da população alvo visando melhorias na precária situação de saúde bucal, sempre pautando promoção da saúde e buscando interação com o público, pois a informação capacita os indivíduos a serem responsáveis por sua saúde, possibilitando uma odontologia menos curativa e mais preventiva

Left ventricular T2 distribution in Duchenne Muscular Dystrophy

<p>Abstract</p> <p>Background</p> <p>Although previous studies have helped define the natural history of Duchenne Muscular Dystrophy (DMD)-associated cardiomyopathy, the myocardial pathobiology associated with functional impairment in DMD is not yet known.</p> <p>The objective of this study was to assess the distribution of transverse relaxation time (T2) in the left ventricle (LV) of DMD patients, and to determine the association of myocardial T2 heterogeneity to the severity of cardiac dysfunction. DMD patients (n = 26) and normal control subjects (n = 13) were studied by Cardiovascular Magnetic Resonance (CMR). DMD subject data was stratified based on subject age and LV Ejection Fraction (EF) into the following groups: A (<12 years old, n = 12); B (≥12 years old, EF ≤ 55%, n = 8) and C (≥12 years old, EF = 55%, n = 6). Controls were also stratified by age into Groups N1 (<12 years, n = 6) and N2 (>12 years, n = 5). LV mid-slice circumferential myocardial strain (ε_cc) was calculated using tagged CMR imaging. T2 maps of the LV were generated for all subjects using a black blood dual spin echo method at two echo times. The Full Width at Half Maximum (<it>FWHM</it>) was calculated from a histogram of LV T2 distribution constructed for each subject.</p> <p>Results</p> <p>In DMD subject groups, <it>FWHM </it>of the T2 histogram rose progressively with age and decreasing EF (Group A <it>FWHM</it>= 25.3 ± 3.8 ms; Group B <it>FWHM</it>= 30.9 ± 5.3 ms; Group C <it>FWHM</it>= 33.0 ± 6.4 ms). Further, <it>FWHM </it>was significantly higher in those with reduced circumferential strain (|ε_cc| ≤ 12%) (Group B, and C) than those with |ε_cc| > 12% (Group A). Group A <it>FWHM </it>was not different from the two normal groups (N1 <it>FWHM </it>= 25.3 ± 3.5 ms; N2 <it>FWHM</it>= 24.0 ± 7.3 ms).</p> <p>Conclusion</p> <p>Reduced EF and ε_cccorrelates well with increased T2 heterogeneity quantified by <it>FWHM</it>, indicating that subclinical functional impairments could be associated with pre-existing abnormalities in tissue structure in young DMD patients.</p