857 research outputs found

    Analysis of the pedagogical perspective of the MOOCs available in Portuguese

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    After an initial stage of exponential growth in MOOCs, a need has arisen of to address several different aspects of these innovations in order to understand and develop them from different perspectives, such as this one, with the analysis of pedagogical dimensions aimed at improving course design. This paper presents an updated review of the literature and proposes five research lines for an in-depth approach. This study is part of a broader research project1 and here analyses 356 MOOCs delivered in Portuguese by 16 different platforms. The research design is quantitative, non-experimental and transversal. An adaptation of the MOOC Educational and Interactive Indicators Instrument —INdiMOOC-EdI— was used in the data collection process. The reliability and internal consistency analysis of that adaptation for the whole sample resulted in a Cronbach alpha score of 0.731. The data obtained enable us to classify the existing MOOCs in Portuguese according to descriptive, formative, and interactive components. These different types correlate with the quality indices, being negative in the first dimension (descriptive) and positive in the second and third ones (formative and interactive).Funded by the call for R&D&i projects named: «Estudio del impacto de las erubricas federada en evaluación de las competencias en el practicum» (Study on the impact of federated eRubrics in the evaluation of the competences in the practicum). Plan Nacional de I+D+i de Excelencia (National R&D&i Excellence Plan) (2014-16) no. EDU2013-41974-

    Bioactivity of wollastonite/aerogels composites obtained from a TEOS-MTES matrix

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    Organic-inorganic hybrid materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS), methyltrimethoxysilane (MTES), synthetic wollastonite powders and polydimethylsiloxane (PDMS) in an ethanol solution. Aerogels were prepared from acid hydrolysis of TEOS and MTES with different volume ratio in ethanol, followed by addition of wollastonite powder and PDMS in order to obtain aerogels with 20 wt% of PDMS and 5 wt% of CaO of the total silica. Finally, when the wet gels were obtained, they were supercritically dried at 260°C and 90 bar, in ethanol. In order to obtain its bioactivity, one method for surface activation is based on a wet chemical alkaline treatment. The particular interest of this study is that we introduce hybrid aerogels, in a 1 M solution of NaOH, for 30 s at room temperature. We evaluate the bioactivity of TEOS-MTES aerogel when immersed in a static volume of simulated body fluid (SBF). An apatite layer of spherical-shaped particles of uniform size smaller than 5 microns is observed to form on the surface of the aerogels after 25 days soaking in SBF.Ministerio de Ciencia e Innovación MAT2005-01583Junta de Andalucía TEP 79

    Principales hábitos nocivos odontológicos para el alto rendimiento en deportes colectivos

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    Oral health when integrated into the general health of the athlete is an essential aspect to take into account. The main purpose of this research is to know those habits presented by elite or high-performance athletes from the Autonomous Community of Aragon that can degenerate in situations harmful to their oral health. Aragonese athletes who competed in the main teams in the region were included both nationally and internationally. A total of 112 athletes were submitted to study. 59.8% of the athletes analyzed presented dental clenching or bruxism; 43.8% denotes onychophagy or nail-biting habit; 82.1% state that they breathe through the oral cavity and, on average, they go to the dentist every 14 months. Aragonese athletes who practice a collective sport do not have a high incidence of harmful habits for their oral health, although they could be reduced by implementing multidisciplinary actions. La salud bucodental al integrarse en la salud general del deportista supone un aspecto esencial y a tener en cuenta. El propósito principal de esta investigación es conocer aquellos hábitos presentados por los deportistas de élite o alto rendimiento de la Comunidad Autónoma de Aragón que pueden degenerar en situaciones nocivas para su salud bucodental. Se incluyó a los deportistas aragoneses que competían en los principales equipos de la región tanto a nivel nacional como internacional. Un total de 112 deportistas fueron sometidos a estudio. Un 59,8% de los deportistas analizados presenta apretamiento dentario o bruxismo; un 43,8% denota onicofagia o hábito de morderse las uñas; un 82,1% afirma respirar por la cavidad oral y de media acuden al dentista cada 14 meses. Los deportistas aragoneses que practican un deporte colectivo no presentan una elevada incidencia de hábitos nocivos para su salud bucodental, si bien se podrían reducir implementando acciones multidisciplinares

    Enhanced endosomal signaling and desensitization of GLP-1R versus GIPR in pancreatic beta cells

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    The incretin receptors, glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR), are prime therapeutic targets for the treatment of type 2 diabetes (T2D) and obesity. They are expressed in pancreatic beta cells where they potentiate insulin release in response to food intake. Despite GIP being the main incretin in healthy individuals, GLP-1R has been favored as a therapeutic target due to blunted GIPR responses in T2D patients and conflicting effects of GIPR agonists and antagonists in improving glucose tolerance and preventing weight gain. There is, however, a recently renewed interest in GIPR biology following the realization that GIPR responses can be restored after an initial period of blood glucose normalization and the recent development of dual GLP-1R/GIPR agonists with superior capacity for controlling blood glucose levels and weight. The importance of GLP-1R trafficking and subcellular signaling in the control of receptor outputs is well established, but little is known about the pattern of spatiotemporal signaling from the GIPR in beta cells. Here, we have directly compared surface expression, trafficking and signaling characteristics of both incretin receptors in pancreatic beta cells to identify potential differences that might underlie distinct pharmacological responses associated with each receptor. Our results indicate increased cell surface levels, internalization, degradation, and endosomal versus plasma membrane activity for the GLP-1R, while the GIPR is instead associated with increased plasma membrane recycling, reduced desensitization, and enhanced downstream signal amplification. These differences might have potential implications for the capacity of each incretin receptor to control beta cell function

    An inducible offense: carnivore morph tadpoles induced by tadpole carnivory

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    Phenotypic plasticity is commonplace, and plasticity theory predicts that organisms should often evolve mechanisms to detect and respond to environmental cues that accurately predict future environmental conditions. Here, we test this prediction in tadpoles of spadefoot toads, Spea multiplicata. These tadpoles develop into either an omnivore ecomorph, which is a dietary generalist, or a carnivore ecomorph, which specializes on anostracan shrimp and other tadpoles. We investigated a novel proximate cue – ingestion of Scaphiopus tadpoles – and its propensity to produce carnivores by rearing tadpoles on different diets. We found that diets containing tadpoles from the genus Scaphiopus produced more carnivores than diets without Scaphiopus tadpoles. We discuss why Scaphiopus tadpoles are an excellent food source and why it is therefore advantageous for S. multiplicata tadpoles to produce an inducible offense that allows them to better utilize this resource. In general, such inducible offenses provide an excellent setting for investigating the proximate and evolutionary basis of phenotypic plasticity

    Determinants of a transcriptionally competent environment at the GM-CSF promoter

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    Granulocyte macrophage-colony stimulating factor (GM-CSF) is produced by T cells, but not B cells, in response to immune signals. GM-CSF gene activation in response to T-cell stimulation requires remodelling of chromatin associated with the gene promoter, and these changes do not occur in B cells. While the CpG methylation status of the murine GM-CSF promoter shows no correlation with the ability of the gene to respond to activation, we find that the basal chromatin environment of the gene promoter influences its ability to respond to immune signals. In unstimulated T cells but not B cells, the GM-CSF promoter is selectively marked by enrichment of histone acetylation, and association of the chromatin-remodelling protein BRG1. BRG1 is removed from the promoter upon activation concomitant with histone depletion and BRG1 is required for efficient chromatin remodelling and transcription. Increasing histone acetylation at the promoter in T cells is paralleled by increased BRG1 recruitment, resulting in more rapid chromatin remodelling, and an associated increase in GM-CSF mRNA levels. Furthermore, increasing histone acetylation in B cells removes the block in chromatin remodelling and transcriptional activation of the GM-CSF gene. These data are consistent with a model in which histone hyperacetylation and BRG1 enrichment at the GM-CSF promoter, generate a chromatin environment competent to respond to immune signals resulting in gene activation

    BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation

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    Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function

    GTM-3, an extra-large pore enantioselective chiral zeolitic catalyst

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    The development of chiral zeolitic catalysts possessing extra-large pores and endowed with the capability of enantioselectively processing bulky products represents one of the greatest challenges in chemistry. Here, we report the discovery of GTM-3, an enantio-enriched extra-large pore chiral zeolite material with -ITV framework structure, obtained using a simple enantiopure organic cation derived from the chiral pool, N,N-ethyl-methyl-pseudoephedrinium, as the chiral-inductor agent. We demonstrate the enantio-enrichment of GTM-3 in one of the two enantiomorphic polymorphs using the two enantiomers of the organic cation. Interestingly, we prove the ability of this zeolitic material to perform enantioselective catalytic operations with very large substrates, here exemplified by the catalytic epoxide aperture of the bulky trans-stilbene oxide with alcohols, yielding unprecedented product enantiomeric excesses up to 30%. Our discovery opens the way for the use of accessible chiral zeolitic materials for the catalytic asymmetric synthesis of chiral pharmaceutical compounds
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