176 resultados para Vázquez,
Resumo:
En aquest article presentem el projecte ReSim: representació simbòlica de preguntes, que ha consistit en la creació d'un sistema automàtic capaç de representar en un llenguatge formal una pregunta en llenguatge natural. Tenint en compte la complexitat de l'objectiu, el projecte es va centrar en un àmbit temàtic concret. El tipus de representació usada està basada en el model de les Estructures Lèxico-Conceptuals de Jackendoff 1990.
Resumo:
En aquest article es defi neix la classe dels verbs d'actitud, tant intensionalment, a partir de criteris sint àctics i sem àntics, com extensionalment. Quant a la sintaxi, s'observa que els verbs que pertanyen a aquest grup presenten almenys una estructura distintiva compartida; pel que fa a la sem àntica, a m és d'identifi car-hi els mateixos components de signifi cat, s'ha observat que presenten també el mateix tipus general d'estructura esdevenimental. La hipòtesi de treball és la de Levin [6] -els verbs que tenen el mateix signifi cat comparteixen el mateix comportament sintàctic-, encara que amb alguns matisos. El punt de partida és tamb é la classifi cació d'aquesta autora, sobre la qual es proposa una reagrupaci ó en funci ó dels criteris esmentats.
Resumo:
L'objectiu d'aquest article és defensar la responsabilitat del component lèxic pel que fa a la presència (o l'absència) del clític en la construcció anticausativa. Es presenten proves que justifiquen que les argumentacions sobre aquest fenomen des de la semàntica o l'estructura eventual, que són les més prolíferes en la bibliografia, no són vàlides per a tots els verbs que participen en l'estructura sintàctica esmentada. Es considera que ni la sintaxi ni la morfologia tampoc poden donar llum dels fets i es proposa que l'explicació de la manca d'uniformitat pel que fa a l'aparició del pronom ha de trobar-se a partir de fenòmens que no es poden discernir en observar només l'estat actual de la llengua.
Resumo:
Aquest treball presenta un anàlisi comparatiu de l’evolució de l’estructura econòmica i financera que presenten las empreses familiars (EF) i las empreses no familiars (EnF) des de l’any 2007 fins l’any 2011, amb una mostra d’empreses de Catalunya. La comparació d’aquests dos grups es basa amb dades dels estats financers extrets de la base de dades SABI. Aquesta mostra ha permès contrastar les hipòtesis establertes sobre el finançament de les mateixes i concloure que las EF presenten una estructura financera diferent a las EnF. Als seus balanços las EF reflecteixen un major nivell d’autofinançament que las EnF gràcies a la menor distribució de dividends. A més, s’observa que las EF es financen amb un cost de capital aliè inferior al de les EnF. No existeix correlació entre la rendibilitat econòmica i l’endeutament en las EF, és a dir, las EF mantenen un endeutament estable en el temps independentment de la seva rendibilitat, mentre que en el cas de les EnF si que hi ha correlació entre las dos variables, però aquesta és indirecta, de forma que las empreses més endeutades són les menys rentables, posant de manifest major dependència del capital aliè en les EnF que en les EF.
Resumo:
Este trabajo presenta un análisis comparativo de la evolución de la estructura económica y financiera que presentan las empresas familiares (EF) y las empresas no familiares (EnF) desde el año 2007 hasta el año 2011, en una muestra de empresas de Cataluña. La comparación de estos dos grupos se basa en datos de los estados financieros extraídos de la base de datos SABI. Esta muestra ha permitido contrastar las hipótesis establecidas sobre la financiación de las mismas y concluir que las EF presentan una estructura financiera diferente a las EnF. En sus balances las EF reflejan mayor nivel de autofinanciación que las EnF gracias a la menor distribución de dividendos. Además se observa que las EF se financian con un coste de capital ajeno inferior al de las EnF. No existe correlación entre rentabilidad económica y endeudamiento en las EF, es decir las EF mantienen un endeudamiento estable en el tiempo independientemente de su rentabilidad, mientras que en el caso de EnF si hay correlación entre las dos variables, pero esta es indirecta, de manera que las empresas más endeudadas son las menos rentables, poniendo de manifiesto mayor dependencia del capital ajeno en las EnF que en las EF.
Resumo:
L'objectiu d'aquest treball final de màster (TFM) ha sigut el de realitzar una aplicació per a dispositius mòbils que permeti als usuaris poder rebre informació detallada de certs productes, en aquest cas cerveses, donar la seva valoració i veure la valoració que hagin fet altres usuaris.
Resumo:
Strategies for expanding hematopoietic stem cells (HSCs) include coculture with cells that recapitulate their natural microenvironment, such as bone marrow stromal stem/progenitor cells (BMSCs). Plastic-adherent BMSCs may be insufficient to preserve primitive HSCs. Here, we describe a method of isolating and culturing human BMSCs as nonadherent mesenchymal spheres. Human mesenspheres were derived from CD45- CD31- CD71- CD146+ CD105+ nestin+ cells but could also be simply grown from fetal and adult BM CD45--enriched cells. Human mesenspheres robustly differentiated into mesenchymal lineages. In culture conditions where they displayed a relatively undifferentiated phenotype, with decreased adherence to plastic and increased self-renewal, they promoted enhanced expansion of cord blood CD34+ cells through secreted soluble factors. Expanded HSCs were serially transplantable in immunodeficient mice and significantly increased long-term human hematopoietic engraftment. These results pave the way for culture techniques that preserve the self-renewal of human BMSCs and their ability to support functional HSCs.
Resumo:
Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium and Synoicum to evaluate the incidence of organic deterrents and their variability. The ether fractions from 15 samples including specimens of the species A. falklandicum, A. fuegiense, A. meridianum, A. millari and S. adareanum were subjected to feeding assays towards two relevant sympatric predators: the starfish Odontaster validus, and the amphipod Cheirimedon femoratus. All samples revealed repellency. Nonetheless, some colonies concentrated defensive chemicals in internal body-regions rather than in the tunic. Four ascidian-derived meroterpenoids, rossinones B and the three derivatives 2,3-epoxy-rossinone B, 3-epi-rossinone B, 5,6-epoxy-rossinone B, and the indole alkaloids meridianins A-G, along with other minoritary meridianin compounds were isolated from several samples. Some purified metabolites were tested in feeding assays exhibiting potent unpalatabilities, thus revealing their role in predation avoidance. Ascidian extracts and purified compound-fractions were further assessed in antibacterial tests against a marine Antarctic bacterium. Only the meridianins showed inhibition activity, demonstrating a multifunctional defensive role. According to their occurrence in nature and within our colonial specimens, the possible origin of both types of metabolites is discussed.
Resumo:
The concerted action of ppGpp and DksA in transcription has been widely documented. In disparity with this model, phenotypic studies showed that ppGpp and DksA might also have independent and opposing roles in gene expression in Escherichia coli. In this study we used a transcriptomic approach to compare the global transcriptional patterns of gene expression in strains deficient in ppGpp (ppGpp0) and/or DksA ( dksA). Approximately 6 and 7% of all genes were significantly affected by more than twofold in ppGpp- and DksAdeficient strains, respectively, increasing to 13% of all genes in the ppGpp0 dksA strain. Although the data indicate that most of the affected genes were copositively or conegatively regulated by ppGpp and DksA, some genes that were independently and/or differentially regulated by the two factors were found. The large functional group of chemotaxis and flagellum synthesis genes were notably differentially affected, with all genes being upregulated in the DksA-deficient strain but 60% of them being downregulated in the ppGpp-deficient strain. Revealingly, mutations in the antipausing Gre factors suppress the upregulation observed in the DksA-deficient strain, emphasizing the importance of the secondary channel of the RNA polymerase for regulation and fine-tuning of gene expression in E. coli.
Resumo:
The concerted action of ppGpp and DksA in transcription has been widely documented. In disparity with this model, phenotypic studies showed that ppGpp and DksA might also have independent and opposing roles in gene expression in Escherichia coli. In this study we used a transcriptomic approach to compare the global transcriptional patterns of gene expression in strains deficient in ppGpp (ppGpp0) and/or DksA ( dksA). Approximately 6 and 7% of all genes were significantly affected by more than twofold in ppGpp- and DksAdeficient strains, respectively, increasing to 13% of all genes in the ppGpp0 dksA strain. Although the data indicate that most of the affected genes were copositively or conegatively regulated by ppGpp and DksA, some genes that were independently and/or differentially regulated by the two factors were found. The large functional group of chemotaxis and flagellum synthesis genes were notably differentially affected, with all genes being upregulated in the DksA-deficient strain but 60% of them being downregulated in the ppGpp-deficient strain. Revealingly, mutations in the antipausing Gre factors suppress the upregulation observed in the DksA-deficient strain, emphasizing the importance of the secondary channel of the RNA polymerase for regulation and fine-tuning of gene expression in E. coli.
Resumo:
Hyaluronic acid (HA) is found in high concentrations in cartilage and synovial fluid, and is an important component of the extracellular matrixes- exerting joint lubrication and buffering actions thanks to its viscoelastic properties. The present study examines the scientific evidence found in the current literature on the usefulness of the intraarticular injection of HA in patients with temporomandibular dysfunction. A literature search was made up until May 2008 in the following databases: PubMed / MEDLINE. Of the articles found in the literature, the present review included 18 relevant studies on the application of HA in the temporomandibular joint (TMJ). The quality, level of evidence and strength of recommendation of the articles was evaluated based on the"Strength of Recommendation Taxonomy" criteria. It is concluded that type A level of recommendation exists in favor of the intraarticular injection of HA in dysfunction of the TMJ. However, further studies are needed to establish the true therapeutic effects and to identify the best dosing regimen.
Resumo:
[spa] En este trabajo se analiza la relación entre la heterogeneidad étnica y la redistribución, utilizando la reciente y masiva llegada de inmigrantes a España. En concreto, se estudia el efecto de los cambios en la densidad de inmigrantes, observada entre 1998 y 2006, sobre los cambios en el gasto social municipal. La densidad de inmigrantes se instrumenta utilizando los patrones de establecimiento por país de origen para asignar los flujos predichos de inmigrantes a cada municipio. Los resultados evidencian que el gasto social incrementó menos en los municipios con mayores incrementos en la densidad de inmigrantes. También se proporciona evidencia de la existencia de una relación positiva entre la densidad de inmigrantes y el porcentaje de voto obtenidos por los partidos de derecha. Por tanto, estos resultados son consistentes con las teorías que predicen una relación negativa entre la heterogeneidad étnica y la redistribución.
Resumo:
[spa] En este trabajo se analiza la relación entre la heterogeneidad étnica y la redistribución, utilizando la reciente y masiva llegada de inmigrantes a España. En concreto, se estudia el efecto de los cambios en la densidad de inmigrantes, observada entre 1998 y 2006, sobre los cambios en el gasto social municipal. La densidad de inmigrantes se instrumenta utilizando los patrones de establecimiento por país de origen para asignar los flujos predichos de inmigrantes a cada municipio. Los resultados evidencian que el gasto social incrementó menos en los municipios con mayores incrementos en la densidad de inmigrantes. También se proporciona evidencia de la existencia de una relación positiva entre la densidad de inmigrantes y el porcentaje de voto obtenidos por los partidos de derecha. Por tanto, estos resultados son consistentes con las teorías que predicen una relación negativa entre la heterogeneidad étnica y la redistribución.
Resumo:
Alanine aminotransferase (ALT) plays an important role in amino acid metabolism and gluconeogenesis. The preference of carnivorous fish for protein amino acids instead of carbohydrates as a source of energy lead us to study the transcriptional regulation of the mitochondrial ALT (mALT) gene and to characterize the enzyme kinetics and modulation of mALT expression in the kidney of gilthead sea bream (Sparus aurata) under different nutritional and hormonal conditions. 5′-Deletion analysis of mALT promoter in transiently transfected HEK293 cells, site-directed mutagenesis and electrophoretic mobility shift assays allowed us to identify HNF4α as a new factor involved in the transcriptional regulation of mALT expression. Quantitative RT-PCR assays showed that starvation and the administration of streptozotocin (STZ) decreased HNF4α levels in the kidney of S. aurata, leading to the downregulation of mALT transcription. Analysis of the tissue distribution showed that kidney, liver, and intestine were the tissues with higher mALT and HNF4α expression. Kinetic analysis indicates that mALT enzyme is more efficient in catalyzing the conversion of L-alanine to pyruvate than the reverse reaction. From these results, we conclude that HNF4α transactivates the mALT promoter and that the low levels of mALT expression found in the kidney of starved and STZ-treated fish result from a decreased expression of HNF4α. Our findings suggest that the mALT isoenzyme plays a major role in oxidazing dietary amino acids, and points to ALT as a target for a biotechnological action to spare protein and optimize the use of dietary nutrients for fish culture.
Resumo:
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.