408 research outputs found

    O ensino profissional no distrito da Guarda - o Marketing relacional como ferramenta estratégica

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    O presente trabalho procura analisar o Marketing Relacional como uma ferramenta estratégica para a satisfação e fidelização de alunos às escolas profissionais da região da Guarda. Ao Marketing Relacional ainda não foi dada a importância que deverá merecer, tendo ainda um papel emergente na sociedade. O Marketing Relacional associado a outras estratégias de comunicação, torna-se potencialmente eficaz na consolidação de uma imagem institucional, sobretudo se se tiver em conta a crise que assola o país. As Instituições devem preocupar-se com algo que as diferencie das outras e numa altura em que o Ensino Profissional enfrenta tantas contrariedades cabe aos responsáveis destas escolas encontrarem formas de captar e fidelizar estudantes, já que o alargamento do ensino técnico-profissional foi feito às escolas secundárias do ensino geral e isso afeta a continuidade das escolas profissionais a médio e longo prazo, depois de palmilharem terreno desde há cerca de 25 anos em Portugal, na efetivação e na evolução do ensino técnico-profissional no nosso país. As formas de atuação do Marketing Relacional e as respetivas implicações na gestão das organizações constituem um marco estratégico para o alcance dos objetivos destas Instituições e consequente continuidade. Pretende-se despertar a consciência dos envolvidos para uma maior aplicação das ferramentas que norteiam as relações por parte das organizações. A procura do Ensino Profissional, ano após ano, por parte de formandos mais jovens, significa que o é encarado como uma possibilidade de estudo e de estruturação futura da trajetória pessoal e formativa. Pretende-se proporcionar elementos de reflexão que possam ser utilizados a nível interno para a (re) construção dos olhares sobre estas Instituições com o sentido de elevar, ainda mais, a qualidade da mesma e atingir os níveis de sucesso desejados

    Brain and liver mitochondria isolated from diabeticGoto-Kakizaki rats show different susceptibility to induced oxidative stress

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    Increased oxidative stress and changes in antioxidant capacity observed in both clinical and experimental diabetes mellitus have been implicated in the etiology of chronic diabetic complications. Many authors have shown that hyperglycemia leads to an increase in lipid peroxidation in diabetic patients and animals reflecting a rise in reactive oxygen species production. The aim of the study was to compare the susceptibility of mitochondria from brain and liver of Goto-Kakizaki (12-month-old diabetic) rats (GK rats), a model of non-insulin dependent diabetes mellitus, to oxidative stress and antioxidant defenses.Brain and liver mitochondrial preparations were obtained by differential centrifugation. Oxidative damage injury was induced in vitro by the oxidant pair ADP/Fe2+ and the extent of membrane oxidation was assessed by oxygen consumption, malondialdehyde (MDA) and thiobarbituric acid reactive substances (TBARS) formation. Coenzyme Q and alpha-tocopherol contents were measured by high-performance liquid chromatography (HPLC).Brain mitochondria isolated from 12-month-old control rats displayed a higher susceptibility to lipid peroxidation, as assessed by oxygen consumption and formation of MDA and TBARS, compared to liver mitochondria. In GK rats, mitochondria isolated from brain were more susceptible to invitro oxidative damage than brain mitochondria from normal rats. In contrast, liver mitochondria from diabetic rats were less susceptible to oxidative damage than mitochondria from normal rats. This decreased susceptibility was inversely related to their alpha-tocopherol and coenzyme Q (CoQ) content.The present results indicate that the diabetic state can result in an elevation of both alpha-tocopherol and CoQ content in liver, which may be involved in the elimination of mitochondrially generated reactive oxygen species. The difference in the antioxidant defense mechanisms in the brain and liver mitochondrial preparations of moderately hyperglycemic diabetic GK rats may correspond to a different adaptive response of the cells to the increased oxidative damage in diabetes. Copyright © 2001 John Wiley & Sons, Ltd

    Elasmobranch responses to experimental warming, acidification, and oxygen loss—a meta-analysis

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    Despite the long evolutionary history of this group, the challenges brought by the Anthropocene have been inflicting an extensive pressure over sharks and their relatives. Overexploitation has been driving a worldwide decline in elasmobranch populations, and rapid environmental change, triggered by anthropogenic activities, may further test this group's resilience. In this context, we searched the literature for peer-reviewed studies featuring a sustained (>24 h) and controlled exposure of elasmobranch species to warming, acidification, and/or deoxygenation: three of the most pressing symptoms of change in the ocean. In a standardized comparative framework, we conducted an array of mixed-model meta-analyses (based on 368 control-treatment contrasts from 53 studies) to evaluate the effects of these factors and their combination as experimental treatments. We further compared these effects across different attributes (lineages, climates, lifestyles, reproductive modes, and life stages) and assessed the direction of impact over a comprehensive set of biological responses (survival, development, growth, aerobic metabolism, anaerobic metabolism, oxygen transport, feeding, behavior, acid-base status, thermal tolerance, hypoxia tolerance, and cell stress). Based on the present findings, warming appears as the most influential factor, with clear directional effects, namely decreasing development time and increasing aerobic metabolism, feeding, and thermal tolerance. While warming influence was pervasive across attributes, acidification effects appear to be more context-specific, with no perceivable directional trends across biological responses apart from the necessary to achieve acid-base balance. Meanwhile, despite its potential for steep impacts, deoxygenation has been the most neglected factor, with data paucity ultimately precluding sound conclusions. Likewise, the implementation of multi-factor treatments has been mostly restricted to the combination of warming and acidification, with effects approximately matching those of warming. Despite considerable progress over recent years, research regarding the impact of these drivers on elasmobranchs lags behind other taxa, with more research required to disentangle many of the observed effects. Given the current levels of extinction risk and the quick pace of global change, it is further crucial that we integrate the knowledge accumulated through different scientific approaches into a holistic perspective to better understand how this group may fare in a changing ocean

    Ecosapentanoic acid (EPA) does not affect cell kinetics in peripheral lymphocites from patients with Crohn's disease (CD) according to IL6 174G/C polymorphism

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    Rationale: Omega 3 fatty acids have been shown to be of potential benefit in patients with CD. The aim of the present study was to evaluate whether EPA can modulate the inflammatory response according to different genotypes of IL6G174G/C polymorphism. Methods: Peripheral blood cells were collected from CD patients with different genotypes for IL6 174G/C (GG, n = 16, GC, n = 8, CC, n = 7), and lymphocytes were established in culture media. Replicates with the addition of EPA (25 mM) were analysed in a period of 24h, 48h and 72h. Expression of IL6 e a PGE2 was assessed by ELISA. Apoptosis and cellular proliferation was determined by flow cytometry

    The effect of a remifentanil bolus on the bispectral index of the EEG (BIS) in anaesthetized patients independently from intubation and surgical stimuli

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    Background and objective: Remifentanil boluses are used in different clinical situations and the effects on bispectral index monitoring are unclear. We analysed the effect of a remifentanil bolus on the bispectral index of the electroencephalogram (bispectral index) under total intravenous anaesthesia with propofol and remifentanil. Methods: ASA I–III patients were included in this study. All patients received a 2 µg kg 1 remifentanil bolus in a period free from stimuli. Bispectral index and haemodynamic data were collected from an A-2000XP bispectral index monitor (every second) and an AS/3 Datex monitor (every 5 s). Bispectral index data were analysed using the area under the curve. Mean arterial pressure and heart rate were averaged at each 30-s period and analysed using analysis of variance. Results: A total of 240 bispectral index values were obtained per patient. The area under the curve between 90 and 120 s after the bolus was significantly lower than the basal area under the curve (average of all areas before the bolus, P 0.05). Mean arterial pressure and heart rate were significantly reduced from 96.4 19.9 mmHg at the time of the bolus to 74.2 16.6 mmHg 120 s after, and from 70 16.4 bpm at the time of the bolus to 61 13.6 bpm after (P 0.001), respectively. Conclusions: There was a significant reduction in the areas under the curve between 90–120 s following the bolus. Heart rate and blood pressure also showed significant reductions. Thus, remifentanil bolus given under total intravenous anaesthesia with propofol and remifentanil decreases bispectral index, an effect independent of intubation and surgical stimuli.info:eu-repo/semantics/publishedVersio

    MALDI-TOF MS for the identification of cultivable organic-degrading bacteria in contaminated groundwater near unconventional natural gas extraction sites

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    Groundwater quality and quantity is of extreme importance as it is a source of drinking water in the United States. One major concern has emerged due to the possible contamination of groundwater from unconventional oil and natural gas extraction activities. Recent studies have been performed to understand if these activities are causing groundwater contamination, particularly with respect to exogenous hydrocarbons and volatile organic compounds. The impact of contaminants on microbial ecology is an area to be explored as alternatives for water treatment are necessary. In this work, we identified cultivable organic-degrading bacteria in groundwater in close proximity to unconventional natural gas extraction. Pseudomonas stutzeri and Acinetobacter haemolyticus were identified using matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF MS), which proved to be a simple, fast, and reliable method. Additionally, the potential use of the identified bacteria in water and/or wastewater bioremediation was studied by determining the ability of these microorganisms to degrade toluene and chloroform. In fact, these bacteria can be potentially applied for in situ bioremediation of contaminated water and wastewater treatment, as they were able to degrade both compounds.info:eu-repo/semantics/publishedVersio

    Crosstalk between ROS Homeostasis and Secondary Metabolism in S. natalensis ATCC 27448: Modulation of Pimaricin Production by Intracellular ROS

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    Streptomyces secondary metabolism is strongly affected by oxygen availability. The increased culture aeration enhances pimaricin production in S. natalensis, however the excess of O2 consumption can lead to an intracellular ROS imbalance that is harmful to the cell. The adaptive physiological response of S. natalensis upon the addition of exogenous H2O2 suggested that the modulation of the intracellular ROS levels, through the activation of the H2O2 inducible catalase during the late exponential growth phase, can alter the production of pimaricin. With the construction of defective mutants on the H2O2 related enzymes SodF, AhpCD and KatA1, an effective and enduring modulation of intracellular ROS was achieved. Characterization of the knock-out strains revealed different behaviours regarding pimaricin production: whilst the superoxide dismutase defective mutant presented low levels of pimaricin production compared to the wild-type, the mutants defective on the H2O2-detoxifying enzymes displayed a pimaricin overproducer phenotype. Using physiological and molecular approaches we report a crosstalk between oxidative stress and secondary metabolism regulatory networks. Our results reveal that the redox-based regulation network triggered by an imbalance of the intracellular ROS homeostasis is also able to modulate the biosynthesis of pimaricin in S. natalensis

    Process simulation and techno-economic assessment for direct production of advanced bioethanol using a genetically modified Synechocystis sp.

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    ABSTRACT: A techno-economic assessment for the direct production of ethanol using a genetically-modified microalgae has been studied. It was considered two main scenarios for process modelling: i) bioenergy-driven microalgae plant, i.e., focused on the production of fuel-grade ethanol and biogas for CHP and, ii) biorefinery-driven microalgae plant, focused on the recovery of added-value bioproducts (zeaxanthin and phycocyanin) along with ethanol and CHP production. These main scenarios and several variants were modelled and optimized for a small-scale demo plant of 1000 Lethanol/day and extrapolated for larger production capacities. Results showed that despite the innovative approach of direct production of ethanol by microalgae, the bioenergy-driven scenario is non-feasible under the studied conditions. Conversely, ethanol production becomes economically feasible as co-product in the biorefinery-driven scenario although having payback periods>10 years. Furthermore, if only bio-based products are produced the NPV and the payback are even more positive, 104.8 M€ and ca. 5 years, respectively.info:eu-repo/semantics/publishedVersio

    On the nature of fur evolution: A phylogenetic approach in Actinobacteria

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    <p>Abstract</p> <p>Background</p> <p>An understanding of the evolution of global transcription regulators is essential for comprehending the complex networks of cellular metabolism that have developed among related organisms. The <it>fur </it>gene encodes one of those regulators – the ferric uptake regulator Fur – widely distributed among bacteria and known to regulate different genes committed to varied metabolic pathways. On the other hand, members of the Actinobacteria comprise an ecologically diverse group of bacteria able to inhabit various natural environments, and for which relatively little is currently understood concerning transcriptional regulation.</p> <p>Results</p> <p>BLAST analyses revealed the presence of more than one <it>fur </it>homologue in most members of the Actinobacteria whose genomes have been fully sequenced. We propose a model to explain the evolutionary history of <it>fur </it>within this well-known bacterial phylum: the postulated scenario includes one duplication event from a primitive regulator, which probably had a broad range of co-factors and DNA-binding sites. This duplication predated the appearance of the last common ancestor of the Actinobacteria, while six other duplications occurred later within specific groups of organisms, particularly in two genera: <it>Frankia </it>and <it>Streptomyces</it>. The resulting paralogues maintained main biochemical properties, but became specialised for regulating specific functions, coordinating different metal ions and binding to unique DNA sequences. The presence of syntenic regions surrounding the different <it>fur </it>orthologues supports the proposed model, as do the evolutionary distances and topology of phylogenetic trees built using both Neighbor-Joining and Maximum-Likelihood methods.</p> <p>Conclusion</p> <p>The proposed <it>fur </it>evolutionary model, which includes one general duplication and two in-genus duplications followed by divergence and specialization, explains the presence and diversity of <it>fur </it>genes within the Actinobacteria. Although a few rare horizontal gene transfer events have been reported, the model is consistent with the view of gene duplication as a main force of microbial genomes evolution. The parallel study of Fur phylogeny across diverse organisms offers a solid base to guide functional studies and allows the comparison between response mechanisms in relation with the surrounding environment. The survey of regulators among related genomes provides a relevant tool for understanding the evolution of one of the first lines of cellular adaptability, control of DNA transcription.</p

    Particles’ distribution enhancing in aluminum-based composites produced by upward friction stir processing

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    Funding Information: Open access funding provided by FCT|FCCN (b-on). CV and TGS acknowledge Fundação para a Ciência e a Tecnologia (FCT-MCTES) for its financial support via projects UIDB/00667/2020 and UIDP/00667/2020 (UNIDEMI). PMF also acknowledges FCT-MCTES for its financial support via the PhD scholarship UI/BD/151055/2021. PLI would like to acknowledge FCT-MCTES for its financial support via the PhD scholarship FCT-SFRH /BD/146885/2019. RJCS acknowledges national funds from FCT-MCTES, in the scope of the project UIDB/50025/2020–2023 of the CENIMAT/i3N. Publisher Copyright: © 2023, The Author(s).A new variant of friction stir processing named upward friction stir processing (UFSP) is a promising approach to control particles’ distribution and promote a more uniform distribution over a larger processed area. This variant involves using two sheets with functional particles between them to produce metallic composites. A spacer is used to ensure the desired quantity and uniform distribution of the particles and prevent sputtering. This technique promotes an upward flow to introduce more particles with a uniform distribution in the processed volume, avoiding discrete holes or grooves. This study involved enhancing the particles’ distribution by varying process parameters. The resulting trial with the best particles’ distribution was characterized by means of light microscopy, eddy current testing, microhardness mapping, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The study revealed that UFSP can improve the particles’ distribution in the stir zone of metallic composites, especially when multi-passes are performed towards the retreating side of the plates. The process parameters that produced an improvement in particles’ distribution were six passes with an offset of 1 mm towards the retreating side, the tool rotation and processing speed of 900 rev/min, and 180 mm/min, respectively, and a spacer’s thickness of 0.5 mm. The resulting hardness and electrical conductivity profiles show that the UFSP technique can significantly affect material’s properties, including mechanical strength, particularly when processing with tool offset towards the retreating side. Furthermore, the hardness increased by about 22% in composites produced with the addition of reinforcement particles. However, for some aluminum alloys, the properties decreased under such conditions. These findings highlight the potential of UFSP for producing functionalized materials with tailored properties, while also underscoring the importance of careful parameters selection to optimize the material´s performance. Graphical Abstract: [Figure not available: see fulltext.].publishersversioninpres
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