Searching for complexity in the human pupillary light reflex

This article aims to examine the dynamical characteristics of the pupillary light reflex and to provide a contribution towards their explanation based on the nonlinear theory of dynamical systems. To introduce the necessary concepts, terminology, and relevant features of the pupillary light reflex and its associated delay, we start with an overview of the human eye anatomy and physiology with emphasis on the iris, pupil, and retina. We also present the most highly regarded models for pupil dynamics found in the current scientific literature. Then we consider the model developed by Longtin and Milton, which models the human pupillary light reflex, defined by a nonlinear differential equation with delay, and present our study carried out on the qualitative and quantitative dynamic behavior of that neurophysiological control system.info:eu-repo/semantics/publishedVersio

Apparent dominance of the G1-G3 genetic cluster of echinococcus granulosus strains in the central inland region of Portugal

Infection by the larval stage of the cestode Echinococcus granulosus causes a disease known as cystic echinococcosis or hydatidosis, which is one of the most widespread zoonotic infections of veterinary and medical importance. Numerous studies have shown that E. granulosus exists as a complex of strains differing in a wide variety of criteria. Ten distinct genotypes (G1-G10) have been identified with potential impact on the pathology, epidemiology and the effect of the measures implemented for the control of hydatidosis. Our main objective was to carry out a preliminary analysis of the genotypes of E. granulosus circulating in the central inland region of Portugal. Parasite samples (hydatid cysts, n=27) were isolated from the liver and lung of sheep and cattle. The DNA extracted from protoscoleces isolated from the fertile cysts served a template for the PCR amplification of part of the mitochondrial cytochrome c oxidase subunit 1 (cox1), ATP synthase F0 subunit 6 (atp6) as well as the large (rrnL/16S) and small (rrnS/12S) ribosomal RNA genes. Similarity searches with homologous sequences in the databanks indicated very high similarity with references assigned to the G1, G3 and/or G1-G3 complex of Echinococcus strains. Phylogenetic analysis (Bayesian approach) supported these observations, and confirmed the assignment of all the analyzed sequences to the G1-G3 genetic cluster

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Comparação de diferentes métodos de extracção de DNA em amostras de echinococcus granulosus

O céstode E. granulosus, agente causal da hidatidose/equinococose, está presente em diversas espécies de animais e, ocidentalmente, em humanos. Este apresenta uma grande variabilidade genética, com dez genótipos diferentes descritos (G1 – G10) onde alguns destes já são considerados novas espécies. Estes genótipos encontram-se distribuídos um pouco por todo o mundo, inclusive Portugal. O presente trabalho tem como objectivo comparar diferentes métodos de extracção de DNA para E. granulosus. MATERIAL E MÉTODOS: Procedeu-se à extracção de DNA de 20 amostras usando 3 kits comerciais, “High pure PCR template preparation kit”, “Easy spin kit”, “QIAamp DNA mini kit” e a extracção manual, com algumas modificações. Posteriormente foi efectuada a quantificação do DNA extraído, com obtenção do grau de pureza por densidade óptica (DO) a 230nm, 260nm e 280nm (GeneQuant, BIORAD) RESULTADOS: Foram obtidos diferentes resultados consoante método utilizado, variando a concentração de DNA entre 9,72±8,49ng/µL para “QIAamp DNA mini kit” (Qiagen) e 224,1±6,5ng/µL para o método de extracção manual (modificado). Em relação pureza do DNA, obtida a uma densidade óptica (DO) de 260/280nm, houve uma variação entre 0,21±0,12 para “Easy spin kit” (Citomed) e 1,82±0,34 para “High pure PCR template preparation kit” (Roche). DISCUSSÃO: O método de extracção manual modificado revelou-se o mais eficiente na extracção. Em relação à pureza do DNA obtido, os que melhores razões obtiveram foram o “High pure PCR template preparation kit” (Roche, Portugal) e o método de extracção manual (modificado), sendo que todos os outros registaram valores que indicam a presença de impurezas no DNA. Assim, poderemos inferir que o melhor kit para a extracção de DNA de E.granulosus é o método manual (modificado), visto ser aquele que maior quantidade de DNA extrai

Assessment van Kinderen en jongeren: noodzaak om de blik te verruimen

Het onderwijs wordt geconfrnteerd met het dilemma om deprstaties en rendement van leerlingen te verhogen en anderzids ook iets te doen voor een groelend aantal uitvallers of onderpresteerders. Het Daffodil.project is een Europees Comenius- project is een Europees Comenius_multilateral samenwerkingsproject met partners uit 7 landen (Belgie, Hongarije, Zweden,Portugal, Noorwegen, Roemenie en de Britse Maagdeneilanden)met als doel een model te ontwikkelen dat bruikbaar is om het functioneren van kinderen met een probleem beter in kaart te brege

Para o estudo da evolução do ensino e da formação em administração educacional em Portugal

Estudos sobre a evolução do ensino de disciplinas, na formação de professores em Portugal, são recentes. O controle burocrático centralizado reteve as dimensões do controle político-administrativo. De certo modo, protegeu a esfera educativa das influências modernizantes, do capitalismo industrial e das lógicas mercantis e gerencialistas. Defendeu a educação do domínio político, da intervenção de movimentos sociais, das propagandas de ideais democráticos e da cidadania. A utilização da designação "Administração educacional" ilustra as dificuldades sentidas, ao longo dos últimos anos, em termos da construção acadêmica de uma área, seja pela falta de tradição, seja pelos antecedentes históricos.In Portugal, studies about the evolution of disciplines teaching in the teachers formation are recent. The centralized bureaucratic control has held back the dimensions of politic administrative control. In a certain way, it has protected the education against the new-fashioned influences, manufacturing capitalism, and mercantile and managerial logics. This centralized bureaucratic control has also profected the education against the politic dominion, the intervention of social movements, the advertising of democratic ideals, and against the citizenship. The use of the term "Educational administration" shows the difficulties met by the searchers along the latest years, since there is no tradiction nor historic antecedence

Enhanced transverse shear strain shell formulation applied to large elasto-plastic deformation problems

In this work, a previously proposed Enhanced Assumed Strain (EAS) finite element formulation for thin shells is revised and extended to account for isotropic and anisotropic material non-linearities. Transverse shear and membrane-locking patterns are successfully removed from the displacement-based formulation. The resultant EAS shell finite element does not rely on any other mixed formulation, since the enhanced strain field is designed to fulfil the null transverse shear strain subspace coming from the classical degenerated formulation. At the same time, a minimum number of enhanced variables is achieved, when compared with previous works in the field. Non-linear effects are treated within a local reference frame affected by the rigid-body part of the total deformation. Additive and multiplicative update procedures for the finite rotation degrees-of-freedom are implemented to correctly reproduce mid-point configurations along the incremental deformation path, improving the overall convergence rate. The stress and strain tensors update in the local frame, together with an additive treatment of the EAS terms, lead to a straightforward implementation of non-linear geometric and material relations. Accuracy of the implemented algorithms is shown in isotropic and anisotropic elasto-plastic problems. Copyright (C) 2004 John Wiley Sons, Ltd

National Assessment of Human Health Effects of Climate Change in Portugal: Approach and Key Findings

In this study we investigated the potential impact of climate change in Portugal on heat-related mortality, air pollution–related health effects, and selected vectorborne diseases. The assessment used climate scenarios from two regional climate models for a range of future time periods. The annual heat-related death rates in Lisbon may increase from between 5.4 and 6 per 100,000 in 1980–1998 to between 8.5 and 12.1 by the 2020s and to a maximum of 29.5 by the 2050s, if no adaptations occur. The projected warmer and more variable weather may result in better dispersion of nitrogen dioxide levels in winter, whereas the higher temperatures may reduce air quality during the warmer months by increasing tropospheric ozone levels. We estimated the future risk of zoonoses using ecologic scenarios to describe future changes in vectors and parasites. Malaria and schistosomiasis, which are currently not endemic in Portugal, are more sensitive to the introduction of infected vectors than to temperature changes. Higher temperatures may increase the transmission risk of zoonoses that are currently endemic to Portugal, such as leishmaniasis, Lyme disease, and Mediterranean spotted fever

La gestion démocratique des écoles: de l´autogouvernement à l’émergence d’une post-démocratie gestionnaire?

O autor assinala três elementos básicos que têm sido historicamente associados à gestão democrática das escolas: eleição, colegialidade, participação na decisão. A combinação ou rejeição de algumas dessas diferentes dimensões, em contextos sociais específicos, pode resultar em várias concepções de gestão democrática das escolas, desde o autogoverno até à possível ascensão de uma pós-democracia gestionária.The author points out three basic elements that have been historically associated with the democratic management of schools: election, collegiality, participation in decision-making. The combination or the rejection of some of those different dimensions in specific social contexts may result in various conceptions of democratic management of schools, from selfgovernment to the possible rise of a managerial post-democracyL’auteur souligne trois éléments de base qui ont été historiquement associés à la gestion démocratique des écoles: l’élection, la collégialité, la participation à la décision. La combinaison ou le rejet de certaines de ces différentes dimensions, dans des contextes sociaux spécifiques, peuvent entraîner des diverses conceptions de la gestion démocratique des écoles, de l’autogouvernement à l’émergence d’une post-démocratie gestionnaire(undefined