Browsing by Issue Date, starting with "2017-12-13"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Clinical application of extracellular vesicles in vascular calcificationPublication . Marreiros, Catarina Isabel Lousada; Simes, Dina; Viegas, Carla Alexandra São BentoCellular communication and signaling are essential for the organization, preservation, and proper functioning of different cell types in multicellular organisms. Recently the study of the mechanisms for intercellular communication mediated by extracellular vesicles (EVs) has been the focus of research within the scientific community. Extracellular vesicles exert diverse physiological and pathophysiological functions by serving as vehicles of horizontal transfer of protein, lipids, DNA, and RNA between cells. These cellular interaction processes can influence, among others, the developmental patterning of tissues, as the case of vascular smooth muscle cells (VSMCs) differentiation with the generation of EVs playing an important role in vessel calcification. These calcification-competent EVs are thought to create the first nidus for calcification through the clustering of calcium-phosphate (Ca/P) minerals within the extracellular matrix of blood vessels, resembling skeletal mineralization. Extracellular vesicles are a promise and fresh therapeutic area for the delivery of different synthetic and biological molecules in cellular therapy. Indeed, EVs-based drug delivery is an experimental field that has evolved greatly in the past few years, with an especial attention for miRNA therapeutics. The potential advantages over the existing synthetic delivery systems are attracting much attention, adding a new pharmacological mean of intervention using EVs as an encouraging drug transportation system in the treatment of cardiovascular diseases. However, in order to speed up the clinical application of EVs as the next generation of targeted gene delivery vehicles, much work still needs to be done focusing the features of EVs-mediated vascular calcification in order to highlight potential therapeutic targets within this pathology and achieve progress in diagnosis and treatment in the cardiovascular filed.
- Técnicas de detecção remota na monitorização da vegetação e a contribuição da Ria Formosa no ciclo do carbonoPublication . Faracini, Julia Cristina Bonani; Martins, Fernando; Veiga-Pires, C.Localizada no sul de Portugal, a Ria Formosa corresponde a um sistema lagunar com ilhas barreiras e um sapal de grande importância ambiental. Além de ser considerada um dos mais belos parques do Algarve, ela também corresponde a um importante habitat de aves aquáticas, tornando-se uma região de reconhecimento internacional (Guimarães et al, 2012). O presente trabalho tem como objetivos a delimitação e caracterização da vegetação de uma área especifica da Ria Formosa através de técnicas de Detecção Remota, bem como a análise da contribuição dessa vegetação no ciclo do carbono, num determinado período de tempo. Através da análise de imagens de satélite (Landsat) pretende-se calcular índices de vegetação (‘Índice de Vegetação de Diferença Normalizada – NDVI‘ e ‘Índice de Vegetação Fotossintético – PRI’) das imagens, e, através destes dois índices, obter o índice CO2flux, relacionado ao fluxo de carbono, proposto por Rahman, 2000. Posteriormente estes resultados foram correlacionados com os de Gross Primary Production GPP, disponíveis no conjunto de imagens MODIS. Os resultados deste estudo são fundamentais para o reconhecimento, preservação e manutenção da região e podem servir como material para futuras pesquisas tanto nesta, como em diferentes zonas e áreas do conhecimento.
- A tributação dos trabalhadores transfronteiriçosPublication . Fernandes, Sílvio Filipe Gonçalves; Rosado, Pedro BastosConsideram-se trabalhadores transfronteiriços aqueles que exercem uma atividade, por conta própria ou por conta de outrem, no território de um Estado-Membro diferente daquele em que residem, regressando a este último todos os dias ou, pelo menos, uma vez por semana. O tema assume no presente particular importância, devido à internacionalização das empresas portuguesas. A grande recessão de 2008, que ainda hoje se faz sentir, após a crise financeira internacional, veio elevar ainda mais o histórico de um país com grande tradição na emigração, daí esta opção de desenvolvimento de um tema útil à sociedade em geral. Trata-se de um assunto complexo que implica não só uma abordagem da fiscalidade, mas também da parafiscalidade (Segurança Social - destacamentos) e até, do Direito do Trabalho (mobilidade internacional). Procurando simplificar todas as questões complexas com que se depara um trabalhador que vive num Estado diferente daquele onde exerce a sua atividade profissional, apresentarei uma compilação quer da legislação nacional, quer ao nível da UE (União Europeia), exemplificando sempre que possível e aplicável. O principal objetivo será o de compreender que respostas dará, por um lado, o sistema fiscal e por outro a Segurança Social fazendo sempre o paralelo com a UE.
- Gestão de recursos humanos numa unidade hoteleiraPublication . Firmino, Maria Beatriz Metelo; Santos, JoanaNa atualidade, num mercado que é cada vez mais competitivo e em constante transformação, é necessário que as organizações se adaptem à realidade, que adotem e definam estratégias de forma a levarem a empresa ao sucesso.
- Age and growth of the blue shark (Prionace glauca) in the Indian OceanPublication . Andrade, Inês Filipa Constantino; Erzini, Karim; Coelho, RuiThe blue shark, Prionace glauca, is a cosmopolitan species considered to be the most abundant pelagic shark in the world. It is frequently caught in pelagic fisheries, being the most captured shark by the Portuguese pelagic longline fishery targeting swordfish. The biology of blue sharks has been relatively well studied in the Atlantic and Pacific oceans. However, high levels of uncertainty still persist regarding many of its biological aspects in the Indian Ocean, specifically in terms of age estimation and growth modelling. For this study, a total of 818 vertebral samples were collected from blue sharks captured by pelagic longliners in the Indian Ocean, between March 2013 and September 2016, with sizes ranging from 82 to 301 cm fork length (FL). The age of individuals was estimated through counting growth band pairs in sectioned vertebrae, assuming annual deposition. Two growth models were fitted to the age data, a three-parameter von Bertalanffy growth function (VBGF) re-parameterized to calculate L0 (size at birth) and a two-parameter VBGF with a fixed L0. The latter was considered the most adequate to describe the growth of the species, with the estimated parameters being Linf = 272.2 cm FL, k = 0.15 year-1 for males and Linf = 283.2 cm FL, k = 0.13 year-1 for females. These results suggest that females have a slower growth than males. The maximum age estimated was 25 years, representing the oldest attributed age to this species so far. Further work is needed regarding blue sharks in the Indian Ocean, but this study adds important life-history information that can contribute for the management and conservation of the species.
- Evaluating the effect of temperature stress on Octopus vulgaris paralarvaePublication . Logose, Maya Millicent GraceParalarval survival of Octopus vulgaris can be limited by temperature via short, abrupt changes (“thermal shocks”) above the natural, geographical temperature range. Thus, temperature stress can affect the growth of paralarvae. Beaks are a tool for stress, registering as darker increments (“stress marks”) during cultivation. Due to minimal knowledge of temperature stress on O. vulgaris paralarval beaks, it must be researched for improved industrialised culture. To evaluate the effect of temperature stress on paralarvae, a group was subjected to induced thermal shocks (16+3°C) for 2 hours (laboratory located ECIMAT, Vigo, Spain). Additional temperature experiments (constant temperatures - 14, 16, 18, 21°C and increasing temperature - 16-21°C) were run to determine the general effect of temperature on paralarvae. Differences in dry weight, morphometrics, stress marks and mean increment width and age (via gelatine mounting microincrement analysis of the rostral sagittal surface), were assessed between groups in the rostral sagittal surface for the thermal shock experiment. Age and mean increment width (measured on the lateral wall surface) were determined for additional temperature experiments. Dry weight and morphometrics in thermally shocked paralarvae were not significantly different compared to the control group (and for morphometrics in additional temperature experiments). Stress marks were found in 2 of 3 thermally shocked paralarvae and corresponded to the thermal shock day, however, were not statistically different to the control group. 1 of 3 paralarvae was negative for stress marks, hinting adaptability to temperature stress. Marks were observed on alternative days, possibly being “post-stress marks” or confounding stress. Increment width was not significantly different on the thermal shock day and between groups (or with increasing temperature). Positively, gelatine mounting could be a novel technique for increment visualisation. Further research is needed to validate all outcomes of this study (removing confounding stressors and increasing the sample size analysed).