78 resultados para regulatory elements


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[spa] Mediante el Análisis de Elementos Finitos es posible evaluar un diseño cerámico en función de su tipologia y de las propiedades mecánicas del material. Su aplicación permite considerar los factores tecnológicos que puedan haber condicionado el cambio de una tipologia cerámica. Este análisis se ilustra con los primeros tipos anfóricos romanos producidos en la actual Cataluña (Dressel 1, Tarraconense 1 y Pascuai 7).

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6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB)catalyzes the synthesis and degradation of fructose-2,6-bisphosphate, a key modulator of glycolysis-gluconeogenesis. To gain insight into the molecular mechanism behind hormonal and nutritional regulation of PFKFB expression, we have cloned and characterized the proximal promoter region of the liver isoform of PFKFB (PFKFB1) from gilthead sea bream (Sparus aurata). Transient transfection of HepG2 cells with deleted gene promoter constructs and electrophoretic mobility shift assays allowed us to identify a sterol regulatory element (SRE) to which SRE binding protein-1a (SREBP-1a)binds and transactivates PFKFB1 gene transcription. Mutating the SRE box abolished SREBP-1a binding and transactivation. The in vivo binding of SREBP-1a to the SRE box in the S. aurata PFKFB1 promoter was confirmed by chromatin immunoprecipitation assays. There is a great deal of evidence for a postprandial rise of PFKB1 mRNA levels in fish and rats. Consistently, starved-to-fed transition and treatment with glucose or insulin increased SREBP-1 immunodetectable levels, SREBP-1 association to PFKFB1 promoter, and PFKFB1 mRNA levels in the piscine liver. Our findings demonstrate involvement of SREBP-1a in the transcriptional activation of PFKFB1, and we conclude that SREBP-1a may exert a key role mediating postprandial activation of PFKFB1 transcription.

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El pràcticum és un entorn privilegiat per a la transferència de competències. Des d"aquesta perspectiva, s"ha desenvolupat el projecte «Anàlisi i avaluació de la transferibilitat de competències professionals de l"Educació Social en els centres de pràctiques» (2008MQD155) a la Universitat de Barcelona durant els cursos 2008-2010. La complexitat de l"objecte d"estudi aconsellava la utilització de mètodes qualitatius. Es va optar per un disseny d"investigació-acció a partir d"espais de reflexió. Des de la percepció dels participants, s"han identificat un conjunt d"elements que afavoreixen la transferència de competències en el marc del pràcticum, entre els quals cal destacar la necessitat d"una planificació conjunta i d"una planificació específica des de cadascun dels escenaris formatius vertebrada des de la reflexió-acció de la pràctica de l"estudiant. Per fer-ho possible, és necessari que els centres de pràctiques i els centres universitaris es reconeguin corresponsables de la formació pràctica.

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The origin and evolution of the complex regulatory landscapes of some vertebrate developmental genes, often spanning hundreds of Kbp and including neighboring genes, remain poorly understood. The Sonic Hedgehog (Shh) genomic regulatory block (GRB) is one of the best functionally characterized examples, with several discrete enhancers reported within its introns, vast upstream gene-free region and neighboring genes (Lmbr1 and Rnf32). To investigate the origin and evolution of this GRB, we sequenced and characterized the Hedgehog (Hh) loci from three invertebrate chordate amphioxus species, which share several early expression domains with Shh. Using phylogenetic footprinting within and between chordate lineages, and reporter assays in zebrafish probing >30 Kbp of amphioxus Hh, we report large sequence and functional divergence between both groups. In addition, we show that the linkage of Shh to Lmbr1 and Rnf32, necessary for the unique gnatostomate-specific Shh limb expression, is a vertebrate novelty occurred between the two whole-genome duplications.

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Background: Information about the composition of regulatory regions is of great value for designing experiments to functionally characterize gene expression. The multiplicity of available applications to predict transcription factor binding sites in a particular locus contrasts with the substantial computational expertise that is demanded to manipulate them, which may constitute a potential barrier for the experimental community. Results: CBS (Conserved regulatory Binding Sites, http://compfly.bio.ub.es/CBS) is a public platform of evolutionarily conserved binding sites and enhancers predicted in multiple Drosophila genomes that is furnished with published chromatin signatures associated to transcriptionally active regions and other experimental sources of information. The rapid access to this novel body of knowledge through a user-friendly web interface enables non-expert users to identify the binding sequences available for any particular gene, transcription factor, or genome region. Conclusions: The CBS platform is a powerful resource that provides tools for data mining individual sequences and groups of co-expressed genes with epigenomics information to conduct regulatory screenings in Drosophila.

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Ens han demanat que en aquesta edició de Temps d'Educació es presenti una qüestió difícil, i pel que sembla incomoda, que sobrepassa els idealismes pedagògics destinats als «sants innocents» i ens situa més enllà de certes omnipotències tècniques que semblen voler reduir qualsevol problema infantil o juvenil a l'àmbit d'una educació curricular. Es tracta de la Justícia de Menors. Per aixo agraïm l'aportació de totes les persones que des del coneixement i l'experiència en han ofert generosament els seus escrits i la seva veu com a elements introductoris per a un debat obert.

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Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy. Based on our analysis, we also discuss policy remedies and suggest reforms in different regulatory areas, which could help improve the performance of Spain’s infrastructure policy.

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Nicotine (NIC), the main psychostimulant compound of smoked tobacco, exerts its effects through activation of central nicotinic acetylcholine receptors (nAChR), which become up-regulated after chronic administration. Recent work has demonstrated that the recreational drug 3,4-methylenedioxymethamphetamine (MDMA) has affinity for nAChR and also induces up-regulation of nAChR in PC 12 cells. Tobacco and MDMA are often consumed together. In the present work we studied the in vivo effect of a classic chronic dosing schedule of MDMA in rats, alone or combined with a chronic schedule of NIC, on the density of nAChR and on serotonin reuptake transporters. MDMA induced significant decreases in [3H]paroxetine binding in the cortex and hippocampus measured 24 h after the last dose and these decreases were not modified by the association with NIC. In the prefrontal cortex, NIC and MDMA each induced significant increases in [3H]epibatidine binding (29.5 and 34.6%, respectively) with respect to saline-treated rats, and these increases were significantly potentiated (up to 72.1%) when the two drugs were associated. Also in this area, [3H]methyllycaconitine binding was increased a 42.1% with NIC + MDMA but not when they were given alone. In the hippocampus, MDMA potentiated the a7 regulatory effects of NIC (raising a 25.5% increase to 52.5%) but alone was devoid of effect. MDMA had no effect on heteromeric nAChR in striatum and a coronal section of the midbrain containing superior colliculi, geniculate nuclei, substantia nigra and ventral tegmental area. Specific immunoprecipitation of solubilised receptors suggests that the up-regulated heteromeric nAChRs contain a4 and b2 subunits. Western blots with specific a4 and a7 antibodies showed no significant differences between the groups, indicating that, as reported for nicotine, up-regulation caused by MDMA is due to post-translational events rather than increased receptor synthesis.

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The paper reviews the historical transformation of the European regulatory framework for electronic communications from the era dominated by state-owned enterprises to the presence of regulated competition. In the course of these developments, the vision of the roles of the public and private sectors in electronic communications changed in expected and unexpected ways. While the period is characterized by a shift toward less direct state intervention, the intensity of regulation has increased in many areas. Most recently, in the wake of the financial crisis, new forms of state intervention can be observed, including public investment in communications infrastructure and public-private partnerships. As a result of the reforms, Europe has been able to achieve major successes but it also suffered unanticipated setbacks compared to other regions. The European Union emerged as the global leader in mobile communications during the 1990s and was able to roll-out first-generation broadband access networks more rapidly than many of its peers. Recently, however, Europe as a whole has not performed as well in deploying next-generation networks and advanced mobile communications services. The paper offers a political-economic explanation for these developments and assesses their effects on the performance of the European electronic communications sector and the economy. From this analysis, the European model emerges as a unique institutional arrangement with peculiar advantages and disadvantages. Once these are recognized, sensible next steps to build the strengths while avoiding the weaknesses of the model can be seen more clearly.

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This paper examines the role that existing Latin American policy institutions and regulatory coordination mechanisms (otherwise referred to as “regional regulatory spaces”) play in innovation and development of the ICT sector. In doing so, it recognizes that sector regulation does not currently match regional development, thereby limiting its potential progress. In order to shed light on the role that the “regional regulatory space” could potentially play, the author addresses three main questions: · Is there a hierarchy of policies by which it is presumed easy to “coordinate within well-defined technical subjects” but extremely challenging to “agree in matters of public policy?” · What would happen if policy divergence became more important than convergence? Is it reasonable to consider creating “regional regulatory spaces?” or should we focus solely on technological coordination? · Do institutions capable of serving as effective regional regulatory spaces already exist in Latin America or should we consider modifying existing institutions or creating new institutions? After analyzing these three overarching areas of concern, this paper then discusses the need to create a regional space in order to harmonize ICT regulatory frameworks and public policies. Ultimately, this work aims to advance the institutional formulation beyond pre-existing efforts.

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This paper conducts an empirical analysis of the relationship between privatization and regulation drawing on data from a wide sample of European airports. We find that privatization promotes a shift from basic regulation to a situation of more detailed or non-regulation, depending on the specific characteristics of the privatization process and on the type of airport being privatized. Moreover, we report a significant association between high traffic volumes and more detailed regulation. By contrast, airports where slot allocation is noncoordinated are significantly associated with non-regulation.

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La comunicació com a mètode per aprendre no és nou, tot i així les noves tecnologies obren la porta a noves oportunitats i nous projectes entorn aquest concepte. No només es tracta de treballar elements curriculars, sinó també actitudinals a través de la opció de connexió entre contextos. L’objectiu d’aquesta recerca és analitzar quina és l’actitud i els aprenentatges i/o retencions dels infants a partir d’una connexió generada entre dos contextos. Per tal de donar resposta a aquest plantejament de la investigació es crea una intervenció entre les aules i s’utilitzen com a instruments de recollida de dades les observacions, els dibuixos i els grups de discussió. Els resultats mostren una actitud oberta i d’interès per part dels infants davant de la metodologia de comunicació a l’aula, però un aprenentatge i/o retenció relacionat amb els continguts dels elements de l’altre context per sobre dels elements TIC. Es conclou doncs que dins l’aula treballant amb les noves tecnologies es genera un incentiu pels infants fent evident que hi ha hagut un aprenentatge compartit.

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Las características específicas del colectivo de profesionales de la etapa de Educación infantil proyectan una dinámica muy activa que genera nuevas metodologías, estrategias y recursos para una intervención educativa de calidad, en una etapa de vital importancia para el correcto desarrollo infantil. Estas características han de tenerse en cuenta en la formación de formadores del profesorado de esta etapa educativa, para favorecer su desarrollo profesional. Son necesarios proyectos de formación alternativos que conecten los «ámbitos de educación» a partir de propuestas integradas: escuela, familia, instituciones locales y asociaciones. Conjuntamente han de elaborar modelos desinteresados y democráticos, capaces de canalizar la interacción y la reciprocidad entre la cultura de la escuela y la cultura externa a ella.

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It is often assumed that total head losses in a sand filter are solely due to the filtration media and that there are analytical solutions, such as the Ergun equation, to compute them. However, total head losses are also due to auxiliary elements (inlet and outlet pipes and filter nozzles), which produce undesirable head losses because they increase energy requirements without contributing to the filtration process. In this study, ANSYS Fluent version 6.3, a commercial computational fluid dynamics (CFD) software program, was used to compute head losses in different parts of a sand filter. Six different numerical filter models of varying complexities were used to understand the hydraulic behavior of the several filter elements and their importance in total head losses. The simulation results show that 84.6% of these were caused by the sand bed and 15.4% were due to auxiliary elements (4.4% in the outlet and inlet pipes, and 11.0% in the perforated plate and nozzles). Simulation results with different models show the important role of the nozzles in the hydraulic behavior of the sand filter. The relationship between the passing area through the nozzles and the passing area through the perforated plate is an important design parameter for the reduction of total head losses. A reduced relationship caused by nozzle clogging would disproportionately increase the total head losses in the sand filter