883 resultados para corpus diacrônico


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The rapid recent increase in microarray-based gene expression studies in the corpus luteum (CL) utilizing macaque models gathered increasing volume of data in publically accessible microarray expression databases. Examining gene pathways in different functional states of CL may help to understand the factors that control luteal function and hence human fertility. Co-regulation of genes in microarray experiments may imply common transcriptional regulation by sequence-specific DNA-binding transcriptional factors. We have computationally analyzed the transcription factor binding sites (TFBS) in a previously reported macaque luteal microarray gene set (n = 15) that are common targets of luteotropin (luteinizing hormone (LH) and human chorionic gonadotropin (hCG)) and luteolysin (prostaglandin (PG) F-2 alpha). This in silico approach can reveal transcriptional networks that control these important genes which are representative of the interplay between luteotropic and luteolytic factors in the control of luteal function. Our computational analyses revealed 6 matrix families whose binding sites are significantly over-represented in promoters of these genes. The roles of these factors are discussed, which might help to understand the transcriptional regulatory network in the control of luteal function. These factors might be promising experimental targets for investigation of human luteal insufficiency. (C) 2012 Elsevier B.V. All rights reserved.

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Background: During female reproductive cycles, a rapid fall in circulating progesterone (P4) levels is one of the earliest events that occur during induced luteolysis in mammals. In rodents, it is well recognized that during luteolysis, P4 is catabolized to its inactive metabolite, 20alpha-hydroxyprogesterone (20alpha-OHP) by the action of 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) enzyme and involves transcription factor, Nur77. Studies have been carried out to examine expression of 20alpha-HSD and its activity in the corpus luteum (CL) of buffalo cow. Methods: The expression of 20alpha-HSD across different bovine tissues along with CL was examined by qPCR analysis. Circulating P4 levels were monitored before and during PGF2alpha treatment. Expression of 20alpha-HSD and Nur77 mRNA was determined in CL at different time points post PGF2alpha treatment in buffalo cows. The chromatographic separation of P4 and its metabolite, 20alpha-OHP, in rat and buffalo cow serum samples were performed on reverse phase HPLC system. To further support the findings, 20alpha-HSD enzyme activity was quantitated in cytosolic fraction of CL of both rat and buffalo cow. Results: Circulating P4 concentration declined rapidly in response to PGF2alpha treatment. HPLC analysis of serum samples did not reveal changes in circulating 20alpha-OHP levels in buffalo cows but serum from pseudo pregnant rats receiving PGF2alpha treatment showed an increased 20alpha-OHP level at 24 h post treatment with accompanying decrease in P4 concentration. qPCR expression of 20alpha-HSD in CL from control and PGF2alpha-treated buffalo cows showed higher expression at 3 and 18 h post treatment, but its specific activity was not altered at different time points post PGF2alpha treatment. The Nur77 expression increased several fold 3 h post PGF2alpha treatment similar to the increased expression observed in the PGF2alpha-treated pseudo pregnant rats which perhaps suggest initiation of activation of apoptotic pathways in response to PGF2alpha treatment. Conclusions: The results taken together suggest that synthesis of P4 appears to be primarily affected by PGF2alpha treatment in buffalo cows in contrast to increased metabolism of P4 in rodents.

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Para la realización de este estudio se plantearon los siguientes objetivos: contribuir al conocimiento y mejoramiento del sistema de producción de leche "El Corpus" El Menco, Rivas, y de manera específica caracterizar y analizar los componentes del sistema, realizar un anál isis biológico y económico a partir de un estudio de eficiencia y realizar un estudio comparativo de la eficiencia del sistema en dos momentos en el tiempo. Este estudio se realizo en la finca "El Corpus" El Menco, Rivas en el período enero-diciembre del año 2000 y el período julio 2001-junio 2002. La unidad de producción se encuentra localizada a la altura del kilómetro 85 ½ carretera panamericana y 13 kilómetros al este a orilla del lago de Nicaragua, a 70 msnm y una latitud norte de 11°50'16" y una longitud oeste de 85°50'16". Para llevar a cabo la presente investigación se definieron las siguientes etapas generales: Caracterización e identificación del sistema de producción, análisis y comparación del sistema de los dos periodos en estudio, a través de un diagnóstico estático y dinámico. Durante la caracterización se observó que la mayoría de los componentes del sistema presentan óptimas condiciones para lograr una eficiente producción lográndose determinar que existe mal manejo en algunos de ellos. Así mismo en el análisis de eficiencia se logró determinar que las variables productivas del año 2000 en las que se obtuvieron mejores resultados con respecto al período julio 2001-junio 2002 fueron: El porcentaje de parición, porcentaje de mortalidad de terneras y la carga animal, lo cual fue lo contrario para la variable del porcentaje de descarte, la producción de leche/vaca/día y la producción de leche/ha/año. En lo que respecta a las variables reproductivas en las que se obtuvieron mejores resultados fue solamente el numero de servicios por concepción; mientras que para la edad de incorporación, peso de incorporación, edad al primer parto, período de servicio, intervalo entre parto fue lo contrario, no obstante la edad de incorporación y el peso de incorporación, se obtuvieron diferencias significativas a través de la prueba de "t" (a = 0.05); mientras que en la edad al primer parto, período de servicio, intervalo entre parto, no se obtuvieron diferencias. En lo que se refiere a la eficiencia económica del sistema los mejores resultados se obtuvieron en el periodo julio 2001 –junio 2002 el cual fue mas rentable y mas eficiente.

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Resumen: Para analizar cuál es el lugar de Héctor Viel Temperley en las letras argentinas tomamos el movimiento editorial en torno de él, sobre todo la edición y reedición de sus obras y, por otro lado, relevamos antologías poéticas. En la labor, sorpresivamente, aparecen rasgos reveladores que desmienten el supuesto acerca de su haber sido ignoto; por otro lado, hemos hallado elementos que iluminan áreas no estudiadas, las que en nuestra investigación —aún en marcha— se van mostrando fundantes. Asimismo, consideramos su papel como ícono motivador en algunas obras recientes, movilizador, afectiva y conceptualmente, de cierto cúmulo de contenidos.

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In this article we describe the methodology developed for the semiautomatic annotation of EPEC-RolSem, a Basque corpus labeled at predicate level following the PropBank-VerbNet model. The methodology presented is the product of detailed theoretical study of the semantic nature of verbs in Basque and of their similarities and differences with verbs in other languages. As part of the proposed methodology, we are creating a Basque lexicon on the PropBank-VerbNet model that we have named the Basque Verb Index (BVI). Our work thus dovetails the general trend toward building lexicons from tagged corpora that is clear in work conducted for other languages. EPEC-RolSem and BVI are two important resources for the computational semantic processing of Basque; as far as the authors are aware, they are also the first resources of their kind developed for Basque. In addition, each entry in BVI is linked to the corresponding verb-entry in well-known resources like PropBank, VerbNet, WordNet, Levin’s Classification and FrameNet. We have also implemented several automatic processes to aid in creating and annotating the BVI, including processes designed to facilitate the task of manual annotation.

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592 p. (versión en euskera) ; 117 p. (versión en alemán)

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The present corpus study aimed to examine whether Basque (OV) resorts more often than Spanish (VO) to certain grammatical operations, in order to minimi ze the number of arguments to be processed before the verb. Ueno & Polinsky (2009) argue that VO/OV languages use certain grammatical resources with different frequencies in order to facilitate real-time processing. They observe that both OV and VO languages in their sample (Japanese, Turkish and Spanish) have a similar frequency of use of subject pro-drop; however, they find that OV languages (Japanese, Turkish) use more intransitive sentences than VO languages (English, Spanish), and conclude this is an OV-specific strategy to facilitate processing. We conducted a comparative corpus study of Spanish (VO) and Basque (OV). Results show (a) that the fre- quency of use of subject pro-drop is higher in Basque than in Spanish; and (b) Basque does not use more intransitive sentences than Spanish; both languages have a similar frequency of intransitive sentences. Based on these findings, we conclude that the frequency of use of grammatical resources to facilitate the processing does not depend on a single typological trait (VO/OV) but it is modulated by the concurrence of other grammatical feature.