5,765 research outputs found

    OpenLab ESEV: novas aventuras no desenvolvimento de software

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    OpenLab ESEV is the Free Software project of the School of Education - Polytechnic Institute of Viseu (ESEV). The project aims to establish a platform to aggregate activities that foster the use of Free/Libre and Open Source Software (F/LOSS), Free Culture and more flexible licenses for creative and educational purposes in the ESEV's domains of activity (education, arts, media). OpenLab exists since 2009. It emerged in an environment characterized by the lack of knowledge of the existing Libre alternatives and by work habits exclusively built around proprietary software. Today, OpenLab activities are implemented within four key areas of action: dissemination, training, support and production. This paper presents two of the most important ongoing projects: Ottographer and StudiozCollabPress. StudiozCollabPress is a customized version of a popular WordPress plugin for project management that was developed to support short movie projects management. We'll present its main features and results from real-case scenarios of use, specifically, finished and ongoing 3D animation students' projects. Ottographer is a webcam time-lapse tool for operating systems based on Debian GNU/Linux. Besides the main features, we'll present some examples and suggestions for educational settings as well as for creative and educational purposes. Both projects are distributed as F/LOSS, meaning that they can be used, studied, and modified without restrictions, as well as copied and redistributed in modified or unmodified form. These projects might help us launch a new trend at our school community that we highly antecipate: the development and sharing of our own tools

    Delta multicopy integration for improved β-galactosidase production in recombinant Saccharomyces cerevisiae

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    The β-galactosidase industrial production is hampered by the high costs associated with its production and purification. One way to improve the overall productivity of galactosidase β-galactosidase fermentation system would be to use continuous high-cell-density systems. Among these, the ones that use flocculent cells are surely attractive due to its simplicity and low cost. We have previously reported the construction of a flocculent Saccharomyces cerevisiae strain secreting high levels of Aspergillus niger β-galactosidase. Due to the cell flocculation characteristics, the recombinant yeast may be used in a high-cell-density system operating in continuous mode. However, when operating at high dilution rates we have observed some plasmid instability which led to a decrease in the β-galactosidase production. With this work we aim at obtaining stable yeast transformants with at least the same β-galactosidase production level of the previously constructed strain1'1 (construction based on an epissomal plasmid) but with enhanced stability which would allow to increase the enzyme productivity in the continuous system. For that, the lacA gene from A. niger (coding to β-galactosidase) was integrated into the genome of the flocculent yeasts S. cerevisiae NCYC 869 and S. cerevisiae NCYC 869-A3 (ura) using integrative vectors with a G418 and ura3 marker, respectively. The repeated cromossomal δ sequences of the yeasts were employed as target sites for the integration. The S. cerevisiae NCYC 869 integrants were selected by resistance to the aminoglycoside G418 (0.2-1.5 g/I) while for the auxothrophic strain S. cerevisiae NCYC869-A3 the selection of integrants was made on minimal medium. Some transforming colonies that presented a deep blue tonality (due to the presence of the X-gal in the plates of selective medium) were randomly selected for growth in nonselective liquid media containing lactose or glucose. Different levels of β-galactosidase expression were observed independently of the selection marker used. For ones that presented more enzyme activity, expression levels of β-galactosidase, cell growth and substrate consumption were found to be similar with the previous y constructed strain (with a 2μ-based plasmid). Unexpectedly, the flocculation of the original strains was affected by the integration. The most flocculants were from transformation using the ura3 marker selection system and the second ones were from transformation using 1.5 g/I G418 as selective marker. Nevertheless, all transformants were less flocculent when compare with the original strain. Transformants genetic characterization by Southern analysis confirmed the multicopy tandem integration pattern. For the analysed transformants, one or two different integration sites were observed. For the most promising transformants, physiological and genetic characterization is being conducted in order to select for a new recombinant strain to be used in a continuous high-cell-density β-galactosidase producing system

    Effects of Isometric Handgrip Training in Patients With Peripheral Artery Disease: A Randomized Controlled Trial

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    BackgroundMeta‐analyses have shown that isometric handgrip training (IHT) can reduce brachial systolic and diastolic blood pressure (BP) by >6/4 mm Hg, respectively. However, whether IHT promotes these effects among patients with peripheral artery disease, who exhibit severe impairment in cardiovascular function, is currently unknown. This study aimed to evaluate the effects of IHT on the cardiovascular function of patients with peripheral artery disease. Methods and ResultsA randomized controlled trial with peripheral artery disease patients assigned to either the IHT or control group was conducted. The IHT group performed 3 sessions per week, for 8 weeks, of unilateral handgrip exercises, consisting of 4 sets of isometric contractions for 2 minutes at 30% of maximum voluntary contraction and a 4‐minute interval between sets. The control group received a compression ball in order to minimize the placebo effects, representing sham training. The primary outcome was brachial BP. The secondary outcomes were central BP, arterial stiffness parameters, cardiac autonomic modulation, and vascular function. The IHT program reduced diastolic BP (75 [10] mm Hg preintervention versus 72 [11] mm Hg postintervention), with no change in the control group (74 [11] mm Hg preintervention versus 74 [11] mm Hg postintervention), with this between‐group difference being significant (P=0.04). Flow‐mediated dilation improved in the IHT group (6.0% [5.7] preintervention versus 9.7% [5.5] postintervention), with no change in the control group (7.6% [5.5] preintervention versus 7.4% [5.1] postintervention), with this between‐group difference being significant (P=0.04). There was no change in other measured variables over the intervention period. ConclusionsIHT reduced brachial diastolic BP and improved local vascular function in patients with peripheral artery disease

    Production of β-galactosidase from recombinant Saccharomyces cerevisiae grown on lactose

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    Improved productivity and costs reduction in fermentation processes may be attained by using flocculating cell cultures. The production of extracellular heterologous β-galactosidase by recombinant flocculating Saccharomyces cerevisiae cells, expressing the lacA gene (coding for β-galactosidase) of Aspergillus niger under the ADHI promotor and terminator in a bioreactor was studied. The effects of lactose concentration and yeast extract concentration on β-galactosidase production in a semi-synthetic medium were analysed. The extracellular β-galactosidase activity increased linearly with increasing initial lactose concentrations (5–150 g dmˉ³ ). β-Galactosidase production also increased with increased yeast extract concentration. During the entire fermentation, no accumulation of the hydrolysed sugars, glucose and galactose, was observed. The catabolic repression of the recombinant strain when cultured in a medium containing equal amounts of glucose and galactose was confirmed. In complete anaerobiosis, the fermentation of lactose resulted in a very slow fermentation pattern with lower levels of β-galactosidase activity. The bioreactor operation together with optimisation of culture conditions (lactose and yeast extract concentration) led to a 21-fold increase in the extracellular β-galactosidase activity produced when compared with preliminary Erlenmeyer fermentations

    Development of stable flocculent Saccharomyces cerevisiae strain for continuous Aspergillus niger β-galactosidase production

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    A flocculent Saccharomyces cerevisiae strain was engineered to stably secrete Aspergillus niger β-galactosidase in a continuous high-cell-density bioreactor. The δ-sequences from the yeast retrotransposon Ty1 were used as target sites for the integration of the β-galactosidase expression cassette. High-copy-number transformants were successfully obtained using the δ-integration system together with the dominant selection antibiotic, G418. The integration of multiple copies was confirmed by genomic Southern blot analysis. Integrants with the highest β-galactosidase levels (approximately eight gene copies) had similar β-galactosidase activities as a recombinant strain carrying the β-galactosidase expression cassette in a YEp-based vector. The β-galactosidase expression cassettes integrated into the yeast genome were stably maintained after eight sequential batch cultures in a nonselective medium. In continuous high-cell-density culture under the same operating conditions, the integrant strain was more stable than the plasmid-carrying strain. To our knowledge, this is the first study of multicopy δ-integrant stability in a continuous bioreactor operating at different dilution rates.Fundação para a Ciência e a Tecnologia (FCT) - Bolsa SFRH/BD/19099/2004Technical Research Centre (VTT) - Biotechnology, Espoo, Finland

    Caractérisation moléculaire de cinq nouveaux allèles-S liés à l’autoincompatibilité chez des cultivars locaux espagnols d’amandier

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    Almond is a highly heterozygous species with a high number of S-alleles controlling its gametophytic self-incompatibility system (GSI). In this work we have analysed Spanish local almond cultivars for S-RNase allele diversity. By cloning and sequencing five new S-RNase alleles were identified: S31 (804 bp) in 'Pou de Felanitx' and 'Totsol', S32 (855 bp) in 'Taiatona', S33 (1165 bp) in 'Pou d'Establiments' and 'Muel', S34 (1663 bp) in 'Pané-Barquets', and S35 (1658 bp) in 'Planeta de les Garrigues'. The high number of new alleles identified reveals the wide diversity of almond germplasm still existing and requiring characterisation, and points to the possibility of new findings by a wider study focusing on other provenancesL'amandier est une espèce hautement hétérozygote avec un nombre très élevé d'allèles-S qui contrôlent son système d'autocompatibilité gamétophytique (GSI). Dans le présent travail on a analysé des cultivars locaux espagnols pour étudier la diversité des allèles de la S-RNase. Par clonage et séquençage, cinq nouveaux allèles ont été identifiés : S31 (804 bp) chez 'Pou de Felanitx' et 'Totsol', S32 (855 bp) chez 'Taiatona', S33 (1165 bp) chez 'Pou d'Establiments' et 'Muel', S34 (1663 bp) chez 'Pané-Barquets', et S35 (1658 bp) chez 'Planeta de les Garrigues'. Le nombre élevé de nouveaux allèles identifiés révèle la grande diversité encore existante chez le germoplasme de l'amandier et ayant besoin d'être caractérisée, montrant la possibilité d'entreprendre de nouveaux travaux plus approfondis avec des génotypes d'autres provenance

    Experimental study of charged particles movement in electric and magnetic fields: velocity selector

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    Neste trabalho é apresentado um experimento incluído no contexto de experimentos longos adotado nas disciplinas experimentais de eletricidade, magnetismo e óptica, e consiste na caracterização de um seletor de velocidades que funciona com campos elétricos e magnéticos cruzados. Utiliza-se um tubo de raios catódicos para gerar um feixe de elétrons. As placas de deflexão vertical do tubo geram o campo elétrico e um par de bobinas, com os eixos perpendiculares ao eixo do tubo, gera o campo magnético. São realizados estudos de trajetória dos elétrons com auxílio de um programa de simulação de elétrons.In this work we present an experiment included in the context of long-duration experiments adopted in the electricity, magnetism and optics experimental disciplines, which consists in characterizing a velocity selector working with crossed electric and magnetic fields. We make use of a cathode ray tube to generate an electron beam. The tube's vertical deflection plates generate the electric field and a pair of coils with their axis perpendicular to the tube, generate the magnetic field. We perform investigations of the electron trajectory with the support of a simulation code

    Adapting Real Quantifier Elimination Methods for Conflict Set Computation

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    The satisfiability problem in real closed fields is decidable. In the context of satisfiability modulo theories, the problem restricted to conjunctive sets of literals, that is, sets of polynomial constraints, is of particular importance. One of the central problems is the computation of good explanations of the unsatisfiability of such sets, i.e.\ obtaining a small subset of the input constraints whose conjunction is already unsatisfiable. We adapt two commonly used real quantifier elimination methods, cylindrical algebraic decomposition and virtual substitution, to provide such conflict sets and demonstrate the performance of our method in practice
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