Quantitative image analysis as a tool for Yarrowia lipolytica dimorphic growth evaluation in different culture media

Yarrowia lipolytica, a yeast strain with a huge biotechnological potential, capable to produce metabolites such as γ-decalactone, citric acid, intracellular lipids and enzymes, possesses the ability to change its morphology in response to environmental conditions. In the present study, a quantitative image analysis (QIA) procedure was developed for the identification and quantification of Y. lipolytica W29 and MTLY40-2P strains dimorphic growth, cultivated in batch cultures on hydrophilic (glucose and N-acetylglucosamine (GlcNAc) and hydrophobic (olive oil and castor oil) media. The morphological characterization of yeast cells by QIA techniques revealed that hydrophobic carbon sources, namely castor oil, should be preferred for both strains growth in the yeast single cell morphotype. On the other hand, hydrophilic sugars, namely glucose and GlcNAc caused a dimorphic transition growth towards the hyphae morphotype. Experiments for γ-decalactone production with MTLY40-2P strain in two distinct morphotypes (yeast single cells and hyphae cells) were also performed. The obtained results showed the adequacy of the proposed morphology monitoring tool in relation to each morphotype on the aroma production ability. The present work allowed establishing that QIA techniques can be a valuable tool for the identification of the best culture conditions for industrial processes implementation.

O erro médico na imprensa portuguesa: quando os pacientes fazem parte da notícia

Esta investigação aborda a qualidade da produção noticiosa sobre o erro médico, como um fator essencial na construção do conhecimento público sobre o tema, com o objetivo de compreender que características definem tal produção e até que ponto poderão ser explicadas pela periodicidade e orientação editorial dos jornais; que conceito de erro médico é veiculado pela produção noticiosa sobre o tema; e quais são os protagonistas no discurso jornalístico sobre o erro médico. Foram analisadas as edições de três jornais portugueses, de 2008 a 2011, resultando num corpus de 266 (4,2%) artigos, que foram classificados de acordo com as seguintes variáveis: as fontes de informação citadas (o seu estatuto e especialidade, no caso dos médicos); os temas que são tratados; as características de enquadramento da informação publicada (tom, género jornalístico; e a presença e número de fontes de informação). Pela análise de conteúdo quantitativa, apurou-se que esse tema está em crescimento, essencialmente com notícias de tom negativo e fontes de informação habitualmente identificadas. Não há evidência para afirmar que a periodicidade e a orientação editorial expliquem as variações dessas características, a não ser relativamente ao número de fontes citadas. Vigoram as notícias centradas nos resultados dos erros (mortes ou lesões), provocados por "erros de omissão" e por "erros de comissão", envolvendo uma diversidade de protagonistas: são, tal como acontece na informação sobre saúde em geral, fontes oficiais e especializadas do campo da saúde. Destacam-se os médicos e os juristas e é dado relevo aos pacientes.

The role of the mammalian DNA end-processing enzyme polynucleotide kinase 3'-phosphatase in spinocerebellar ataxia Type 3 pathogenesis

DNA strand-breaks (SBs) with non-ligatable ends are generated by ionizing radiation, oxidative stress, various chemotherapeutic agents, and also as base excision repair (BER) intermediates. Several neurological diseases have already been identified as being due to a deficiency in DNA end-processing activities. Two common dirty ends, 3'-P and 5'-OH, are processed by mammalian polynucleotide kinase 3'-phosphatase (PNKP), a bifunctional enzyme with 3'-phosphatase and 5'-kinase activities. We have made the unexpected observation that PNKP stably associates with Ataxin-3 (ATXN3), a polyglutamine repeat-containing protein mutated in spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph Disease (MJD). This disease is one of the most common dominantly inherited ataxias worldwide; the defect in SCA3 is due to CAG repeat expansion (from the normal 14-41 to 55-82 repeats) in the ATXN3 coding region. However, how the expanded form gains its toxic function is still not clearly understood. Here we report that purified wild-type (WT) ATXN3 stimulates, and by contrast the mutant form specifically inhibits, PNKP's 3' phosphatase activity in vitro. ATXN3-deficient cells also show decreased PNKP activity. Furthermore, transgenic mice conditionally expressing the pathological form of human ATXN3 also showed decreased 3'-phosphatase activity of PNKP, mostly in the deep cerebellar nuclei, one of the most affected regions in MJD patients' brain. Finally, long amplicon quantitative PCR analysis of human MJD patients' brain samples showed a significant accumulation of DNA strand breaks. Our results thus indicate that the accumulation of DNA strand breaks due to functional deficiency of PNKP is etiologically linked to the pathogenesis of SCA3/MJD.

Formação de professores no programa nacional para a alfabetização na idade certa com uso das TIC: um estudo de caso no ensino fundamental

Dissertação de mestrado em Ciências da Educação (área de especialização em Tecnologia Educativa)

A new empirical system for rock slope stability analysis in exploitation stage

An empirical system was developed to obtain a quality index for rock slopes in road infrastructures, named Slope Quality Index (SQI), and it was applied to a set of real slopes.The SQI is supported in nine factors affecting slope stability that contemplate the evaluation of different parameters. Consequently, each factor is classified by the degree of importance and influence by assigned weights. These weights were established through a statistical analysis of replies to a survey that was distributed to several experienced professionals in the field. The proposed SQI varies between1 and 5, corresponding to slopes in very good and very bad condition state, respectively. Besides the advantage linked to a quantitative and qualitative evaluation of slopes, theSQI also allows identifying the most critical factors on the slope stability, which is a fundamental issue for an efficient management of the slope network in the road infrastructure, namely in the planning of conservation and maintenance operations.