Browsing by Issue Date, starting with "2021-02-18"
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- Maternal thyroid hormones role in Zebrafish neural developmentPublication . Silva, Nádia Margarida Rosário; Campinho, Marco António de Jesus; Power, DeborahThyroid hormones (TH) are essential for proper embryonic development of the central nervous system. During this period maternal supply of TH is the only source of these hormones to the embryo. Using a zebrafish MCT8 knockdown model, with consequent inhibition of maternal thyroid hormones (MTH) uptake to the target cells, the aim of this thesis is to start a comprehensive understanding of the role of MTH during embryonic neural development. We characterised the transcriptome in 25hpf CTRL and MCT8MO zebrafish embryos and found 4,343 differentially expressed genes. Reactome analysis show that MTH regulate the expression of core developmental pathways such as NOTCH, SHH and WNT. The cellular distribution of neural MTH-target genes demonstrated their cell specific action on neural stem cells and differentiated neuron classes. We identified a series of genes involved in several key neurogenic processes to be modulated by MTH. By analysing these genes by qPCR in a temporal series, from the start of segmentation through hatching, we determined the developmental time-window where MTH are required for appropriate CNS development. We show MTH are involved in the regulation of NOTCH pathway components such as notch1a, dla, dld, her2 and her4 during neurogenesis, whereas neuroectodermal genes are not affected. Response to MTH begins at 12hpf, and the time window between 22-25hpf is particularly sensitive to MTH action. Overall, these results, show that MTH is not involved in neuroectoderm specification nor CNS compartmentalisation but stress the involvement of MTH in the early stages of neurogenesis by promoting the maintenance of specific neural progenitor populations. Analyzing the cytoarchitecture of the spinal cord we found that by the end of embryogenesis cells populating the spinal cord of control and MCT8 MO zebrafish are substantially different. Lack of thyroid hormone uptake leads to a generalized disorganization of the neural tissue, together with a decrease in: neural stem cells population, subpopulations of neuron progenitor cells, radial glial cells, mature glial cells and oligodendrocyte precursors, while the primary motor neuron domain was maintained. Colocalization analysis of neural progenitors with thraa, thrab and mct8 allowed identifying cells under the regulation of MTH via MCT8. Survival and proliferation of neural progenitor cells are compromised in MCT8MO, which could later impact on the diversity of neural cell populations obtained in the end of embryogenesis. Analysis of cell autonomous Notch activation showed it cannot rescue the phenotype induced by the lack of MTH demonstrating the niche importance in the regulation of TH action. Given that MTH regulate several important morphogenetic pathways it is likely that its action occurs as an integrator enabling an adequate equilibrium between all these signals in a time a context dependent manner. MTH actions are reflected on the timely development of neurons and glial cells. It is of great interest to continue to explore the significance of these findings to further clarify the genetic and cellular causes underlying human AHDS syndrome. In conclusion with this work, we show that thyroid hormone transferred from the mother to the embryo allows the enrichment of neural progenitor pools and the generation of cell diversity necessary to produce a fully functional central nervous tissue.
- Short Inflammatory Bowel Disease Questionnaire: translation and validation to the Portuguese languagePublication . Roseira, Joana; Sousa, Helena Tavares; Marreiros, Ana; Contente, Luís F.; Magro, FernandoBackground The Short Inflammatory Bowel Disease Questionnaire (SIBDQ) is a widely used instrument to assess Health-related Quality of Life (HRQoL) among inflammatory bowel disease (IBD) patients. Our aim was to translate and adapt the SIBDQ so that it could be adequately used in Portugal. Methods This is a prospective design cohort study undertaken at a tertiary hospital. This study took place simultaneously with the first part of the SexIDI study, a study aiming to assess the impact of IBD on patients’ sexual QoL. The original SIBDQ was translated by two independent translators and adapted by an IBD expert panel following the opinions of a convenient sample of 5 IBD patients. Afterwards, IBD patients from the outpatient clinic were consecutively invited to fill the Portuguese version of the questionnaire (SIBDQ-PT) at three different timepoints (0, 2, 4 weeks). Ninety-two patients completed the SIBDQ-PT at baseline, whereas 33 did so after 2 and 4 weeks (approximately). Statistical analysis was performed using SPSS version 25, and the following aspects were analysed: reliability (through internal consistency, test–retest and intraclass correlation), validity (through exploratory factor analysis [EFA], and Pearson correlation coefficient for linear correlations), score distribution, and responsiveness analysis (through t-student tests). Results Overall, SIBDQ-PT was shown to have a high internal consistency (Cronbach's α = 0.80) and a high test–retest reliability (0.80 [CI 0.74–0.86] and 0.69 [CI 0.50–0.82]). EFA detected four dimensions—bowel, social, emotional and systemic. As expected, an overall SIBDQ-PT score was positively correlated with sexual satisfaction (r = 0.27; p < 0.05) and negatively correlated with depression (r = − 0.63; p < 0.01). Moreover, SIBDQ-PT was found to have an adequate score distribution, and to be responsive, as there was a significant subscore change for patients who reported an “overall worsening in general well-being” (0.93 ± 0.13 decrease; p < 0.01). Conclusions The Portuguese version of the SIBDQ hereby presented is a reliable, valid and responsive instrument that can be used to measure HRQoL among Portuguese IBD patients.
- A geoarqueologia da jazida da idade da pedra superior de Txina-Txina, Massingir, MoçambiquePublication . Raja, Mussa Iussufo Muhamad; Bicho, Nuno Gonçalo Viana Pereira Ferreira; Achimo, MussaAs alterações paleoambientais ocorridas durante o Último Máximo Glacial com mais destaque na África Austral terão favorecido um conjunto de mudanças bioculturais e por conseguinte ocupações de espaços. É neste sentido que o presente trabalho, sob perspectiva geoarqueológica, apresenta os resultados de um estudo sobre as alterações paleoambientais e formação do sítio arqueológico de Txina-Txina, Massingir, Moçambique durante a Idade da Pedra Superior. Estudos anteriores e de caráter regional sustentam a hipótese de que Moçambique é um corredor biocultural, por ser um país que se localiza entre duas regiões onde foram descobertos restos fósseis dos humanos anatomicamente modernos associados à um conjunto de materiais artefatuais. Para testar a hipótese supra mencionada, o trabalho centrou a atenção em uso de indicadores sedimentológicos, geoquímicos e arqueológicos, para compreender a história do processo de formação do sítio de Txina-Txina. Este estudo contribui ainda para o aumento do conhecimento sobre as alterações paleoambientais ocorridas nesta área e os seus impactos sobre a evolução do comportamento dos humanos anatomicamente modernos. Concluiu-se, através das análises dos indicadores geoarqueológicos, que o sítio de Txina-Txina, apresenta depósitos fluviais na sua base que foram cobertos principalmente por depósitos coluviais (intercalados por alguns depósitos fluviais) que contêm horizontes arqueológicos datados desde há ca. de 32 000 anos. Assim, verificou-se que este sítio foi ocupado tanto em períodos quentes e húmidos como em frios e secos.As evidências arqueológicas mostram que os humanos anatomicamente modernos que habitaram Txina-Txina se adaptaram a esses ambientes explorando os ecossistemas terrestres e fluviais, evidenciando, assim, resiliência às alterações paleoambientais.
- Valorization of figs (Ficus carica L.) for an extended shelf lifePublication . Amanze, Janet Omolayo; Vieira, M. M. C.Fig fruit (Ficus carica L.) is an important food product of the Middle East, Mediterranean region and well appreciated by most elderly groups in Portugal, as the symbol of longevity. This study aims to develop two ways of adding value to highly perishable figs with no commercial acceptability, by accelerating fig drying with the use of a solar oven and producing a fig gum jelly which can be made available all year round with longer shelf life. A higher drying rate was observed with the blanched product in the solar oven dryer than in the direct solar drying. The optimization of the gum composition was carried out by using Response Surface Methodology (RSM) along with a mixture design, while the independent variables are: % fig paste, x1; % k-Carrageenan, x2 and % honey, x3. The sensory panel composed of 10 elements of both sexes evaluated nine (9) responses Y1 - Brilliance, Y2 - Transparency, Y3 - Aroma, Y4 - Texture A, Y5 -Texture C, Y6 - Sweetness A, Y7 - Sweetness B, Y8 - Mouthfeel and Y9 - Overall Opinion, originating nine polynomial models. Numerical optimization achieved the best fig gum jelly composition with: 55 % fig paste, 15 % k-carrageenan and 30 % honey. The validation of optimum product was achieved by the same panel and the panelists preference of the optimum formulation for all responses with 0.3 desirability was stunning. The shelf life of twenty-one days was achieved for unrefrigerated products while the refrigerated ones twenty-five days through microbiological analysis. The physicochemical analysis showed that the fig gum jelly contained a minimum amount of protein and minerals with low ash content. Also, the moisture and water activity were found to be lower in the fig gum jelly than in the fresh fig.
- Recreational anglers´ preferences and expenditures on live bait in AlgarvePublication . Araújo, Davide Morais; Erzini, Karim; Ressureição, AdrianaMarine recreational fishing has a great diversity of activities which can be linked to one another. Such is the case of shore-based angling and the use and harvest of live bait. The quantity and economic value referring to this activity is unsupervised in many parts of the world, especially in Europe, creating a “parallel economy” difficulting the assess of these characteristics. Most of these resources are marine polychaetes, but significant use and harvest of small crustaceans and sipunculids for their use in marine recreational fishing is observed globally. As several taxonomic groups are used all over the world, this study aimed to explore the preference, perceptions, quantities and expenditures of marine recreational rod shore-based anglers on live bait species, destined to increase the information needed to better understand the ecologic and socioeconomic impacts and help the development of management measures that can ensure the sustainability of harvesting activity. Interviews to rod shore-based anglers in main fishing location around the Algarve were conducted during summer months and was found that anglers preferred the use of both native and exotic live bait in their recreational fishing activity, mainly the Diopatra neapolitana, Perinereis sp., and Solen marginatus mostly obtained through local live bait shops. Extrapolation of direct expenses on live bait was estimated to be approximately 2.2 million €, of which comprised around 1.2 million € of native polychaete marine worms, 354000 € of the exotic Perinereis sp., 290000 € of S. marginatus, and 200000 € ghost shrimps (Upogebia sp.). The results of this study indicate that polychaete harvesting should be given equivalent attention to other fisheries, the need of research on the biology and densities of the most used polychaetes in Ria Formosa lagoon, efforts to provide updated information to recreational anglers and the continuous assessment of the live bait harvesting activity.