34 research outputs found

    The influence of food texture and liquid consistency modification on swallowing physiology and function: a systematic review

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    Texture modification has become one of the most common forms of intervention for dysphagia, and is widely considered important for promoting safe and efficient swallowing. However, to date, there is no single convention with respect to the terminology used to describe levels of liquid thickening or food texture modification for clinical use. As a first step towards building a common taxonomy, a systematic review was undertaken to identify empirical evidence describing the impact of liquid consistency and food texture on swallowing behavior. A multi-engine search yielded 10,147 non-duplicate articles, which were screened for relevance. A team of 10 international researchers collaborated to conduct full-text reviews for 488 of these articles, which met the study inclusion criteria. Of these, 36 articles were found to contain information comparing oral processing or swallowing behaviors for at least two liquid consistencies or food textures. Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing: thicker liquids reduce the risk of penetration-aspiration, but also increase the risk of post-swallow residue in the pharynx. The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes. With respect to food texture, the literature pointed to properties of hardness, cohesiveness and slipperiness as relevant both for physiological behaviors and bolus flow patterns. The literature suggests a need to classify food and fluid behavior in the context of the physiological processes involved in oral transport and flow initiation

    Evolution of cuticular hydrocarbons in the hymenoptera : a meta-analysis

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    Chemical communication is the oldest form of communication, spreading across all organisms of life. In insects, cuticular hydrocarbons (CHC) function as the chemical recognition cues for the recognition of mates, species and nest-mates in social insects. Although much is known about the function of individual hydrocarbons and their biosynthesis, a phylogenetic overview is lacking. Here we review the CHC profiles of 241 species of hymenoptera, one of the largest and important insect orders, including the Symphyta (sawflies), the polyphyletic Parasitica (parasitoid wasps) and the Aculeata (wasps, bees and ants). We investigated whether these five major taxonomic groups differed in the presence and absence of CHC classes and whether the sociality of a species (solitarily vs. social) had an effect on CHC profile complexity. We found that the main CHC classes (i.e., n-alkanes, alkenes and methylalkanes) were all present early in the evolutionary history of the hymenoptera, as evidenced by their presence in ancient Symphyta and primitive Parasitica wasps. Throughout all groups within the Hymenoptera the more complex a CHC the fewer species that produce it, which may reflect the Occam's razor principle that insects’ only biosynthesize the most simple compound that fulfil its needs. Surprisingly there was no difference in the complexity of CHC profiles between social and solitary species, with some of the most complex CHC profiles belonging to the Parasitica. This profile complexity has been maintained in the ants, but some specialisation in biosynthetic pathways has led to a simplification of profiles in the aculeate wasps and bees. The absence of CHC classes in some taxa or species may be due to gene silencing or down-regulation rather than gene loss, as evidenced by sister species having highly divergent CHC profiles, and cannot be predicted by their phylogenetic history. The presence of highly complex CHC profiles prior to the vast radiation of the social hymenoptera indicates a 'spring-loaded' system where the diverse CHC needed for the complex communication systems of social insects, were already present for natural selection to act upon rather than evolve independently. This would greatly aid the multiple evolution of sociality in the Aculeata

    Distribuição espacial dos casos novos de tuberculose em Vitória, Estado do Espírito Santo, no período entre 2000 e 2005 Spatial distribution of new tuberculosis cases in Vitória, State of Espírito Santo, between 2000 and 2005

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    Realizou-se um estudo ecológico com a análise da distribuição espacial dos 979 novos casos de tuberculose entre 2000 e 2005. Utilizou-se o Método Bayesiano Empírico Local para estimação do risco. O Índice de Moram Local foi calculado para avaliação das autocorrelações entre as incidências de bairros limítrofes. Observou-se que a tuberculose distribui-se heterogeneamente entre os bairros, sendo possível identificar regiões com alto risco de adoecimento.<br>We carried out an ecological study in which the spatial distribution of 979 new tuberculosis cases between 2000 and 2005 were analyzed. The risk was estimated using the local empirical Bayesian method. The local indicators of spatial association were calculated to evaluate autocorrelations of incidence between adjoining districts. We found that the tuberculosis cases were heterogeneously distributed between districts, and it was possible to identify regions in which there was a high risk of becoming ill
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