Influence of ventilation type in volatile organic compounds exposure: poultry case

Agricultural workers especially poultry farmers are at increased risk of occupational respiratory diseases. Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers. In poultry production volatile organic compounds (VOCs) presence can be due to some compounds produced by molds that are volatile and are released directly into the air. These are known as microbial volatile organic compounds (MVOCs). Because these compounds often have strong and/or unpleasant odors, they can be the source of odors associated with molds. MVOC's are products of the microorganisms primary and secondary metabolism and are composed of low molecular weight alcohols, aldehydes, amines, ketones, terpenes, aromatic and chlorinated hydrocarbons, and sulfur-based compounds, all of which are variations of carbon-based molecules.

Invasion success and development of benthic assemblages: effect of timing, duration of submersion and substrate type

Copyright © 2013 Elsevier Ltd. All rights reserved.

Flavored asymmetries for type II seesaw leptogenesis

A novel contribution to the leptonic CP asymmetries in type II seesaw leptogenesis scenarios is obtained for the cases in which flavor effects are relevant for the dynamics of leptogenesis. In the so-called flavored leptogenesis regime, the interference between the tree-level amplitude of the scalar triplet decaying into two leptons and the one-loop wave function correction with leptons in the loop, leads to a new nonvanishing CP asymmetry contribution. The latter conserves total lepton number but violates lepton flavor. Cases in which this novel contribution may be dominant in the generation of the baryon asymmetry are briefly discussed.

Avaliação experimental do comportamento dinâmico de um edifício do século XIX: aplicação à calibração de modelos numéricos

Trabalho de Dissertação de natureza científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas

As representações da infância na publicidade televisiva

Dissertação de Mestrado, Ciências da Comunicação, 22 de Outubro de 2015, Universidade dos Açores.

Determinação de propriedades mecânicas através de ensaios de provetes miniatura, "Small Punch"

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Visualização com nuvens de tags

Com a evolução da Internet houve uma consequente transformação da forma como os resultados são apresentados e das técnicas de visualização e apresentação de conteúdos. A presente dissertação é sobre visualização com nuvens de tags e foi a conjugação de diversos factores que originou a investigação sobre este tema. Uma nuvem de tags (em inglês: tag clouds) é uma concepção visual de um conjunto de tags isoladas com uma representação ilustrativa da sua importância, ou seja visualmente hierarquizadas e em que cada tag se hiperliga a um ou mais sítios Web ou documentos. São extremamente úteis para a navegação ou para a descoberta de informação genérica, podendo requerer menor carga cognitiva do utilizador durante consultas e pesquisas se alguns aspectos forem considerados na sua construção. Nesta dissertação discutem-se alguns dos factores visuais que podem contribuir para que as nuvens de tags sejam ferramentas efectivas e intuitivas para os utilizadores. O conceito de folksonomia está relacionado com nuvens de tags, permitindo categorizar as definições atribuídas a conteúdos recorrendo a palavras-chave (tags). Neste documento são ainda exploradas as suas vantagens e desvantagens. Discutem-se ainda alguns modos de visualização e apresentação de nuvens de tags, desde o tipo de ordenação ao algoritmo de geração da nuvem de tags. Aborda-se ainda o impacto do tipo de fonte e a utilização de cores monocromáticas ou coloridas que estas possam ter na visualização da nuvem. A própria tag também é categorizada e explorada ao nível do seu posicionamento na nuvem e a percepção que causa no utilizador. Sobre a visualização de nuvens de tags, refere-se ainda que as conclusões obtidas foram utilizadas num repositório de objectos educativos.

How patchy can one get and still condense? The role of dissimilar patches in the interactions of colloidal particles

We investigate the influence of strong directional, or bonding, interactions on the phase diagram of complex fluids, and in particular on the liquid-vapour critical point. To this end we revisit a simple model and theory for associating fluids which consist of spherical particles having a hard-core repulsion, complemented by three short-ranged attractive sites on the surface (sticky spots). Two of the spots are of type A and one is of type B; the interactions between each pair of spots have strengths [image omitted], [image omitted] and [image omitted]. The theory is applied over the whole range of bonding strengths and results are interpreted in terms of the equilibrium cluster structures of the coexisting phases. In systems where unlike sites do not interact (i.e. where [image omitted]), the critical point exists all the way to [image omitted]. By contrast, when [image omitted], there is no critical point below a certain finite value of [image omitted]. These somewhat surprising results are rationalised in terms of the different network structures of the two systems: two long AA chains are linked by one BB bond (X-junction) in the former case, and by one AB bond (Y-junction) in the latter. The vapour-liquid transition may then be viewed as the condensation of these junctions and we find that X-junctions condense for any attractive [image omitted] (i.e. for any fraction of BB bonds), whereas condensation of the Y-junctions requires that [image omitted] be above a finite threshold (i.e. there must be a finite fraction of AB bonds).

Tratamiento y presencia de las mujeres em la prensa

Este artículo presenta los resultados de un análisis de contenido sobre la representación de la mujer en la prensa española que forma parte de una investigación más amplia que abarca el periodo de 1974-2000. Nuestra investigación supone una importante contribución a otras investigaciones ya que analiza de forma comparativa, sistemática y longitudinal las representaciones sociales y políticas enfocadas en la prensa. Examinamos como en los medios de comunicación los periodistas utilizan frecuentemente distintas referencias para los diferentes tipos de actores a partir de recursos estilísticos que ayudan a enfatizar sus argumentos. En la mayoría de los casos, estos pasan desapercibidos pero en ocasiones se convierten en generalizaciones que parten de ideas preconcebidas y prejuicios. Nuestros resultados demuestran que los actores a los que los medios de comunicación dedican menos espacio son también los que reciben un peor tratamiento. Específicamente, las mujeres reciben una menor atención como colectivo en los medios de comunicación analizados. Además, aparecen como personajes pasivos, no son enfocadas como representantes públicas y son relegadas a la vida privada. Principalmente, las mujeres son enfocadas realizando actividades deportivas, culturales o de entretenimiento o cuando son víctimas, mientras que sólo una minoría de ellas merecen atención efectuando acciones políticas. Después de exponer este diagnóstico, realizaremos propuestas de estilo, lenguaje y producción de noticias para fomentar que los periódicos muestren de forma positiva una sociedad con igualdad de oportunidades.

Influencing factors on bread-derived exposure to ochratoxin A: type, origin and composition

The nearly ubiquitous consumption of cereals all over the world renders them an important position in international nutrition, but concurrently allocates exposure to possible contained contaminants. Mycotoxins are natural food contaminants, difficult to predict, evade, and reduce, so it is important to establish the real contribution of each contaminated food product, with the aim to evaluate mycotoxin exposure. This was the key objective of this survey and analysis for ochratoxin A content on 274 samples of commercialized bread in the Portuguese market, during the winter 2007. Different bread products were analyzed through an HPLC-FD method, including traditional types, novel segments, and different grain based bread products. A wide-ranging low level contamination was observed in all regions and types of bread products analyzed, especially in the Porto and Coimbra regions, and in the maize and whole-grain or fiber-enriched bread. Nevertheless, the exposure through contaminated wheat bread continues to be the most significant, given its high consumption and dominance in relation to the other types of bread.

Categorical data clustering using a minimum message length criterion

Research on cluster analysis for categorical data continues to develop, new clustering algorithms being proposed. However, in this context, the determination of the number of clusters is rarely addressed. We propose a new approach in which clustering and the estimation of the number of clusters is done simultaneously for categorical data. We assume that the data originate from a finite mixture of multinomial distributions and use a minimum message length criterion (MML) to select the number of clusters (Wallace and Bolton, 1986). For this purpose, we implement an EM-type algorithm (Silvestre et al., 2008) based on the (Figueiredo and Jain, 2002) approach. The novelty of the approach rests on the integration of the model estimation and selection of the number of clusters in a single algorithm, rather than selecting this number based on a set of pre-estimated candidate models. The performance of our approach is compared with the use of Bayesian Information Criterion (BIC) (Schwarz, 1978) and Integrated Completed Likelihood (ICL) (Biernacki et al., 2000) using synthetic data. The obtained results illustrate the capacity of the proposed algorithm to attain the true number of cluster while outperforming BIC and ICL since it is faster, which is especially relevant when dealing with large data sets.

Differences in Mismatch Negativity (MMN) response to Pure-tone and Speech sounds in normal subjects: an additional explanation

The relation of automatic auditory discrimination, measured with MMN, with the type of stimuli has not been well established in the literature, despite its importance as an electrophysiological measure of central sound representation. In this study, MMN response was elicited by pure-tone and speech binaurally passive auditory oddball paradigm in a group of 8 normal young adult subjects at the same intensity level (75 dB SPL). The frequency difference in pure-tone oddball was 100 Hz (standard = 1 000 Hz; deviant = 1 100 Hz; same duration = 100 ms), in speech oddball (standard /ba/; deviant /pa/; same duration = 175 ms) the Portuguese phonemes are both plosive bi-labial in order to maintain a narrow frequency band. Differences were found across electrode location between speech and pure-tone stimuli. Larger MMN amplitude, duration and higher latency to speech were verified compared to pure-tone in Cz and Fz as well as significance differences in latency and amplitude between mastoids. Results suggest that speech may be processed differently than non-speech; also it may occur in a later stage due to overlapping processes since more neural resources are required to speech processing.

Observação e controlo da segurança estrutural de barragens de betão: utilização integrada de modelos numéricos e de modelos de separação de efeitos

Dissertação de Natureza Científica elabora da no âmbito do protocolo de cooperação entre o ISEL e o LNEC para obtenção do grau de Mestre em Engenharia Civil

Tensile behaviour of a structural adhesive at high temperatures by the extended finite element method

Component joining is typically performed by welding, fastening, or adhesive-bonding. For bonded aerospace applications, adhesives must withstand high-temperatures (200°C or above, depending on the application), which implies their mechanical characterization under identical conditions. The extended finite element method (XFEM) is an enhancement of the finite element method (FEM) that can be used for the strength prediction of bonded structures. This work proposes and validates damage laws for a thin layer of an epoxy adhesive at room temperature (RT), 100, 150, and 200°C using the XFEM. The fracture toughness (G Ic ) and maximum load ( ); in pure tensile loading were defined by testing double-cantilever beam (DCB) and bulk tensile specimens, respectively, which permitted building the damage laws for each temperature. The bulk test results revealed that decreased gradually with the temperature. On the other hand, the value of G Ic of the adhesive, extracted from the DCB data, was shown to be relatively insensitive to temperature up to the glass transition temperature (T g ), while above T g (at 200°C) a great reduction took place. The output of the DCB numerical simulations for the various temperatures showed a good agreement with the experimental results, which validated the obtained data for strength prediction of bonded joints in tension. By the obtained results, the XFEM proved to be an alternative for the accurate strength prediction of bonded structures.

Estudo do comportamento sísmico de barragens de gravidade com ancoragens passivas

Dissertação de Natureza Científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Estruturas