146 research outputs found

    Interannual sub-aerial beach variability along a sector of the Tróia- Sines embayed coast

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    The comprehension of sub-aerial beach variability of sandy beaches is essential to describe and predict his behaviour after extreme events (e.g. storms). Around the world coastline beach monitoring plans are established in order to characterize the main morphodynamic changes at different spatial and temporal scales. Within this scope, four field surveys (19th to 28th May 2009; 30th October to 10th November 2009, 21th to 30th May 2010 and 14l to 21 April 2011), using a new coastal survey system named INSHORE system(Differential Global Positioning System) [1], were conducted along the Tróia-Sines embayed beach (INSHORE project -PTDC/AMB/73169/2006). The interannual variability of the sub-aerial beach topography along the Tróia-Sines embayed coast for the first three field surveys were analysed considering the DEM (Digital Elevation Model) analysis regarding the: alongshore coastline configuration; subaerial beach width; beach profile configuration and volumetric changes. The results points to the definition of eight main coastline sectors very similar to the results previously described by [2]. Although a general north-south increasing beach width trend can be observed, [3] one of these main sectors, Sector 6, presents a significant variation of the beach width and beach profile configuration. This sector was selected to describe the morphodynamic pattern responsible for the sediment accommodation (beach width, and profile configuration) during the studied period. The subtraction between the three DEMs points to the importance of the beach width variation that describes the landward or seaward subaerial beach displacement. Although this might affect the beach width, this variable should not be taken as the unique one to describe the shoreline change. In fact, this parameter does not describe the beach variability regarding the profile configuration (e.g. berm width and sediment accommodation). According to our results the volumetric changes are strictly related to the beach width variation but the profile configuration has a particular role in the final budget analysis. The proxies that were used (+2m, +3.4m and +4,3m MSL elevation contours) and the relation between the beach width and subaerial beach volume, has given high correlation values. These results proved that not only the MHW (mean high water) used by others authors [4] can be defined as a proxy to describe the shoreline evolution, but also other morphodynamic meaningful contour elevations can give reliable results

    Evidence of fractal structures in hadrons

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    This study focuses on the presence of (multi)fractal structures in confined hadronic matter through the momentum distributions of mesons produced in proton-proton collisions between 23 GeV and 63 GeV. The analysis demonstrates that the qq-exponential behaviour of the particle momentum distributions is consistent with fractal characteristics, exhibiting fractal structures in confined hadronic matter with features similar to those observed in the deconfined quark-gluon plasma (QGP) regime. Furthermore, the systematic analysis of meson production in hadronic collisions at energies below 1 TeV suggests that specific fractal parameters are universal, independently of confinement or deconfinement, while others may be influenced by the quark content of the produced meson. These results pave the way for further research exploring the implications of fractal structures on various physical distributions and offer insights into the nature of the phase transition between confined and deconfined regimes.Comment: 23 pages, 11 figures, supplementary materia

    Training and Learning Needs for MSc Programs in Sustainable Agriculture

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    Sustainable agriculture is urgently needed to promote conservation and sustainable resources use in an equitable manner through integrated management of land, water, energy and biodiversity. In this way, education in agriculture emerges as a crucial tool for preparing agricultural technicians, researchers and farmers for productive contributions. Higher education institutions arise with an important mission of education in the context of social transformation and to integrate sustainable development into the educational system as a scientific subject. The aim of this study was to identify the training and learning needs to be included in a MSc program in sustainable agriculture. It was based on a questionnaire prepared and distributed to academics’ experts in Agrarian Sciences in Greece, Italy and Portugal. Technologies, legislation, management and business, local community leadership and marketing were the training needs considered very important expertise’s in sustainable agriculture. Traditional face-to-face learning, experienced farmers as mentors and knowledge sharing mechanisms were rated as very applicable and important. Due to COVID-19 pandemic, online learning methods, which were not considered suitable for a MSc program in sustainable agriculture, became important by providing online education. Information and communication technology and technological tools showed to be important skills for sustainable agricultural practices to effectively implement online learning and to improve the efficient access, exposure and use of up-to-date information of the agricultural sector and awareness of sustainable agricultural practices

    Metallochlorophylls of magnesium, copper and zinc: evaluation of the influence of the first coordination sphere on their solvatochromism and aggregation properties

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    In this study the role of different metal centers (magnesium, zinc and copper) on the enhancement of the hydrophilic character of metallochlorophylls, was evaluated. The solvatochromism as well as the aggregation process for these compounds in water/ethanol mixtures at different volume ratios were evaluated using Fluorescence, and Resonant Light Scattering (RLS) measurements, aiming to characterize the behavior of these compounds. Independently on the studied metallochlorophyll, the presence of at least 60% of water results in a considerable increase in the fluorescence emission, probably a direct consequence of a lower aggregation of these compounds, which is confirmed by the results from RLS measurements. Additionally, the results suggest that magnesium and zinc chlorophyll should be promising phototherapeutic agents for Photodynamic Therapy.No presente estudo, o papel de diferentes centros metálicos (magnésio, zinco e cobre) sobre o caráter hidrofílico de metaloclorofilas foi avaliado. O solvatocromismo, assim como o processo de agregação para esses compostos, em misturas água/etanol foram avaliados usando medidas de fluorescência e de espalhamento de luz ressonante (ELR), visando caracterizar o comportamento desses compostos. Independente da metaloclorofila estudada, a presença de ao menos 60% de água resulta em incremento considerável na emissão de fluorescência apresentada por esses compostos. Isso, provavelmente, é uma conseqüência direta de uma menor agregação, o que é confirmado pelos resultados de ELR. Adicionalmente, os resultados sugerem que as clorofilas de magnésio e de zinco devem ser promissores agentes fototerapêuticos para emprego em Terapia Fotodinâmica.FAPESPFundação AraucáriaFAPEMIGCNPqNanobra

    β-Hydroxy-β-Methylbutyrate (HMB) Normalizes Dexamethasone-Induced Autophagy-Lysosomal Pathway in Skeletal Muscle

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    Dexamethasone-induced muscle atrophy is due to an increase in protein breakdown and a decrease in protein synthesis, associated with an over-stimulation of the autophagy-lysosomal pathway. These effects are mediated by alterations in IGF-1 and PI3K/Akt signaling. In this study, we have investigated the effects of β-Hydroxy-β-methylbutyrate (HMB) on the regulation of autophagy and proteosomal systems. Rats were treated during 21 days with dexamethasone as a model of muscle atrophy. Co-administration of HMB attenuated the effects promoted by dexamethasone. HMB ameliorated the loss in body weight, lean mass and the reduction of the muscle fiber cross-sectional area (shrinkage) in gastrocnemius muscle. Consequently, HMB produced an improvement in muscle strength in the dexamethasone-treated rats. To elucidate the molecular mechanisms responsible for these effects, rat L6 myotubes were used. In these cells, HMB significantly attenuated lysosomal proteolysis induced by dexamethasone by normalizing the changes observed in autophagosome formation, LC3 II, p62 and Bnip3 expression after dexamethasone treatment. HMB effects were mediated by an increase in FoxO3a phosphorylation and concomitant decrease in FoxO transcriptional activity. The HMB effect was due to the restoration of Akt signaling diminished by dexamethasone treatment. Moreover, HMB was also involved in the regulation of the activity of ubiquitin and expression of MurF1 and Atrogin-1, components of the proteasome system that are activated or up-regulated by dexamethasone. In conclusion, in vivo and in vitro studies suggest that HMB exerts protective effects against dexamethasone-induced muscle atrophy by normalizing the Akt/FoxO axis that controls autophagy and ubiquitin proteolysis.This project has been funded by Abbott Nutrition R&D

    Lithium chloride therapy fails to improve motor function in a transgenic mouse model of Machado-Joseph disease

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    The accumulation of misfolded proteins in neurons, leading to the formation of cytoplasmic and nuclear aggregates, is a common theme in age-related neurodegenerative diseases, possibly due to disturbances of the proteostasis and insufficient activity of cellular protein clearance pathways. Lithium is a well-known autophagy inducer that exerts neuroprotective effects in different conditions and has been proposed as a promising therapeutic agent for several neurodegenerative diseases. We tested the efficacy of chronic lithium 10.4 mg/kg) treatment in a transgenic mouse model of Machado-Joseph disease, an inherited neurodegenerative disease, caused by an expansion of a polyglutamine tract within the protein ataxin-3. A battery of behavioral tests was used to assess disease progression. In spite of activating autophagy, as suggested by the increased levels of Beclin-1, Atg7, and LC3II, and a reduction in the p62 protein levels, lithium administration showed no overall beneficial effects in this model concerning motor performance, showing a positive impact only in the reduction of tremors at 24 weeks of age. Our results do not support lithiumchronic treatment as a promising strategy for the treatment of Machado-Joseph disease (MJD).FCT -Fundação para a Ciência e a Tecnologia(SFRH/BD/51059/2010

    Desenvolvimento e avaliação de uma fonte DC de alta tensão para utilização em sistema de deposição de filmes finos por pulverização catódica

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    RESUMO O trabalho em questão está relacionado ao projeto e construção de uma fonte de alta tensão em corrente contínua utilizando materiais e dispositivos adquiridos no comércio local visando sua aplicação no processo de pulverização catódica. Essa técnica permite a deposição de filmes finos de metais, óxidos e nitretos sobre substratos sólidos. Como teste de funcionamento e aplicação da fonte DC, com a mesma instalada em canhão de pulverização em alto vácuo, filmes finos de diferentes espessuras de cobre, aço inoxidável 304 e tungstênio foram depositados e estudados. Análise de espessura, morfologia, e resistência elétrica e resistividade foram conduzidas. Filmes com resistividade elétrica dependente das espessuras foram obtidos. A fonte DC se mostrou confiável em operação e permite a deposição de uma infinidade de materiais nas mais diferentes espessuras sobre vários tipos de substratos

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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