995 resultados para 25-245


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The present study focusses attention on the effects of blocking estrogen synthesis, during follicular phase, on follicular maturation in the adult female bonnet monkey (Macaca radiata). Administration of cycling females (n = 4) with an aromatase inhibitor CGS 16949A (AI) by Alzet mini-pump (2.5 mg/day) from day 3 of cycle resulted in significant reduction in basal (by 53%) and surge levels of estrogen (by 70%) but this had no effect on follicular maturation, ovulation and luteal function as assessed by serum hormone profiles as well as laparotomy. This lack of need for estrogen for completion of follicular maturation process was confirmed by administering cycling monkeys hFSH (25 IU/day) from day 3 till day 8 of the cycle along with (5 mg AI/day) or without Al (n = 3/group). Administration of Al resulted in suppression of FSH induced increase in serum estrogen (by 100%) and elevation in circulating androstenedione. Aromatase inhibitor treatment had no effect on either the number of follicles developed or their size relative to control. Testing the ability of both granulosa and thecal cells, removed on day 9 of treatment cycle, to respond to gonadotropins in vitro showed no change indicating that cellular development and maturation of follicular cells had occurred normally. It is concluded that follicular maturation in the primate can occur even when increase in estrogen synthesis is blocked.

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Temperature dependent Mossbauer measurements are done on the samples of La1- xCaxMn1-y (FeyO3)-Fe-57 with x=0 and 0.25, and y=0.01. With decreasing temperature, the specimen with x=0.25 shows a paramagnetic to ferromagnetic transition around 175 K. In the specimen x=0.0, the temperature dependence of both the center shift (delta) and the recoilless fraction (f) can be fitted very well with the Debye theory with a theta(D)=320+/-50 K. But for the specimens with x=0.25, f and delta show distinct deviations from the Debye behavior in the temperature range in which the resistivity shows a sharp decrease. Dips observed in both the f and delta around the transition temperature suggest that the Jahn-Teller distortion observed in these systems is dynamic in nature.

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Although some researchers have published friction and wear data of Plasma Nitride (PN) coatings, the tribological behavior of PN/PN Pairs in high vacuum environment has not been published so far In order to bridge this knowledge gap, tribological tests under dry conditions have been conducted on PN/PN Pairs for varying temperatures of 25, 200, 400 and 500 degrees C in high vacuum (1.6 x 10(-4) bar) environment. The PN coatings showed good wear resistance layer on the ring surface. The PN coatings were removed only from the pin surface for all the tests since it contacts at a point. The friction and wear were low at lower temperatures and it eliminated adhesion between the contact surfaces until the coating was completely removed from the pin surface. (C) 2011 Journal of Mechanical Engineering. All rights reserved.

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There is a research knowledge gap for the dry wear data of nitride treated Stainless Steel in high temperature and high vacuum environment. In order to fill this gap, plasma nitriding was done on austenitic Stainless Steel type AISI 316LN (316LN SS) and dry sliding wear tests have been conducted at 25 degrees C, 200 degrees C and 400 degrees C in high vacuum of 1.6 x 10(-4) bar. The two different slider material (316LN SS and Colmonoy) and two different sliding speeds (0.0576 m/s and 0.167 m/s) have been used. The tribological parameters such as friction coefficient, wear mechanism and volume of metal loss have been evaluated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of the worn pins and rings. Electronic balancing machine was used to record the mass of metal loss during wear tests. The 2D optical profilometer was used to measure the depth of the wear track. The Plasma Nitride treated 316LN SS rings (PN rings) exhibit excellent wear resistance against 316LN SS pin and Colmonoy pin at all temperatures. However, PN ring vs. Colmonoy pin Pair shows better wear resistance than PN ring vs. 316LN SS pin Pair at higher temperature. (C) 2012 Elsevier B.V. All rights reserved.

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The Notch signalling pathway is implicated in a wide variety of cellular processes throughout metazoan development. Although the downstream mechanism of Notch signalling has been extensively studied, the details of its ligand-mediated receptor activation are not clearly understood. Although the role of Notch ELRs EGF (epidermal growth factor)-like-repeats] 11-12 in ligand binding is known, recent studies have suggested interactions within different ELRs of the Notch receptor whose significance remains to be understood. Here, we report critical inter-domain interactions between human Notch1 ELRs 21-30 and the ELRs 11-15 that are modulated by calcium. Surface plasmon resonance analysis revealed that the interaction between ELRs 21-30 and ELRs 11-15 is similar to 10-fold stronger than that between ELRs 11-15 and the ligands. Although there was no interaction between Notch 1 ELRs 21-30 and the ligands in vitro, addition of pre-clustered Jagged1Fc resulted in the dissociation of the preformed complex between ELRs 21-30 and 11-15, suggesting that inter-domain interactions compete for ligand binding. Furthermore, the antibodies against ELRs 21-30 inhibited ligand binding to the full-length Notch1 and subsequent receptor activation, with the antibodies against ELRs 25-26 being the most effective. These results suggest that the ELRs 25-26 represent a cryptic ligand-binding site which becomes exposed only upon the presence of the ligand. Thus, using specific antibodies against various domains of the Notch1 receptor, we demonstrate that, although ELRs 11-12 are the principal ligand-binding site, the ELRs 25-26 serve as a secondary binding site and play an important role in receptor activation.

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This paper describes the development and evolution of research themes in the Design Theory and Methodology (DTM) conference. Essays containing reflections on the history of DTM, supported by an analysis of session titles and papers winning the ``best paper award'', describe the development of the research themes. A second set of essays describes the evolution of several key research themes. Two broad trends in research themes are evident, with a third one emerging. The topics of the papers in the first decade or so reflect an underlying aim to apply artificial intelligence toward developing systems that could `design'. To do so required understanding how human designers behave, formalizing design processes so that they could be computed, and formalizing representations of design knowledge. The themes in the first DTM conference and the recollections of the DTM founders reflect this underlying aim. The second decade of DTM saw the emergence of product development as an underlying concern and included a growth in a systems view of design. More recently, there appears to be a trend toward design-led innovation, which entails both executing the design process more efficiently and understanding the characteristics of market-leading designs so as to produce engineered products and systems of exceptional levels of quality and customer satisfaction.

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El objetivo del experimento fue evaluar el efecto del Hidroxicolecalciferol [HyD (25 –OH- D3)] en pollos de engorde, atraves de porcentajes de ceniza, calcio, fosforo y diagnostico de síndrome de hueso negro, se evaluaron dos tratamientos ( HyD y Testigo) con seis repeticiones para cada uno en dos tiempos a los 21 y 35 días de edad en análisis de ceniza, calcio y fosforo para lo cual se extrajo una tibia por pollo, dichos análisis resultaron con diferencias no significativas en ambas edades, las evaluaciones dieron como resultado que de los 21 día a los 35 días disminuyen su valor, ceniza baja de 43.8% a 36.8% en el testigo y de 42.4% a 37.7% en HyD, calcio de 15.6% a 13.4% para el testigo y de 16% a 14.5% para HyD de igual manera para los porcentaje de fosforo de 21 a 35 días con 7.6% a 6.5% para testigo y 7.5% a 6.7% para HyD. A los 35 días los resultados son mayores en el grupo HyD, 37.7% HyD,36.8% testigo en ceniza, calcio 14.5% HyD, testigo 13.4% y fosforo 6.7% HyD , 6.5% para testigo, las diferencias de 21 a 35 días son notorias y conservan la parte proporcional en que los porcentajes estan en ceniza calcio y fosforo, pero estas disminuyen para una misma variable de los 21 días de edad a los 35, sin encontrar diferencia significativas. A los 35 días se realizo análisis de síndrome de hueso negro con un total de 22 repeticiones por tratamiento, la extracción de dicha muestra (tibia) se realizo en planta de proceso, el análisis determino diferencias entre las aves muestreadas dando los mejores resultados aquellas que fueron alimentadas con Hidroxicolecalciferol [HyD (25 –OH- D3)], se observo en los resultados que en el grupo con HyD alcanzo un 91% de individuos sanos superando significativamente al testigo que solo llego a un 77% de individuos sanos, empleando un grado de libertad y 0.05 de significancia, lo que indica diminución de la presencia del síndrome de hueso negro, producto del HyD, empleando la línea genética Cobb 500, y alimentando los pollos del día cero al día 21 con diferencias de tratamiento e igual alimento del día 22 al día 35.

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Contenido: Palabras del Señor Rector / Guillermo P. Blanco – Testimonio / Juan Roberto Courrèges – Historia de un fervor / Teresa Iris Giovacchini – Homenaje / Luis Martínez Cuitiño – Paul Claudel en una de sus “Odas” / Ángel J. Battistessa – Apertura de Nuevos Mundos: 1492-1969 (Documentos igualmente augurales) / Raúl H. Castagnino – Valor condicional de adjetivos con rasgos de predicativos / Hilda Albano de Vázquez – Buzzati, dos en uno / Daniel H. Capano – La estructura circular de “Adán Buenosayres” / Norma Carricaburo – Una constante poética en la producción dramática de Armando Discépolo: continuidad e innovación en el realismo / Jorge Adrián Dubatti – La Saya/Fuga de J. B. o la novela épico-lúdica de un juglar laborioso / Teresa Iris Giovacchini – Algunas notas sobre el didactismo del Libro de Buen Amor / Elsa C. González Bolia – La “Noche oscura”, de San Juan de la Cruz, poema en diálogo / Teresa Herraiz de Tresca – Bernal Díaz del Castillo y las comunicaciones hispano-aztecas / Ernesto Livacic Gazzano – Hacia una teoría borgeana de la recepción / Luis Martínez Cuitiño – El Árbol, el Bosque y John Fowles (A propósito de la reedición de “The tree”) / Rosa E. M. D. Penna – El orden primero recuperado: “Le livre de Christophe Colomb de Paul Claudel / Paulette Rachou – La Torre de Apolidón y el influjo del Libro de Marco Polo en el Amadís de Gaula / Aquilino Suárez Pallasá – Jorge Manrique en la tradición literaria del amor y de la muerte / Lía Noemí Uriarte Rebaudi – Reseñas bibliográficas

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Resumen: Neste estudo, procuramos definir o sentido da corporeidade em Entralgo, relacionando-o com o pensamento de Lévinas. Segundo Entralgo, o corpo humano era um microcosmos integrado num cosmos. Assim, o corpo é i único objecto do Universo, do qual temos um duplo conhecimento não de fora, como também temos a sua percepção a partir de dentro. Porém, segundo Lévinas, a corporeidade é a expressão do Rosto do Outro, referindo- se como uma prefiguração do Outro, que tem o seu epílogo na parábola do Bom Samaritano. Há, na verdade, uma relação de aproximação antropológica entre o sentido do corpo como forma de manifestar o Outro. Em ti e por ti, tu eras uma pessoa, mas sendo tu uma pessoa, podendo e devendo Eu ver-te e tratar-te como tal pessoa. Os dois pensadores apresentam uma referência em relação à pessoas. Segundo Lévinas a pessoa será responsabilidade.

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Al cumplirse 25 años de la publicación del Informe Warnock (25 de junio de 1984), evaluamos la necesidad de realizar una revisión de los argumentos presentados en ese momento, haciendo un análisis científico comparativo, con los conocimientos actuales, para determinar el valor del mismo y, finalmente, concluir con una reflexión bioética. Esta revisión, sugerida en el mismo Informe y nunca concretada, fue realizada por cinco comisiones de investigación en las cuales se dividió el informe para que sea didáctico: filosofía; aspectos jurídicos y legislación; el embrión humano; técnicas de tratamiento de la esterilidad y técnicas de investigaciones con embriones humanos o sus células. En este apartado se incluyen las consideraciones generales, las expresiones de disentimiento de algunos miembros y la reflexión bioética general.

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Contenido: Contrato internacional y comercio exterior / Raúl Alberto Ramayo – Iusta causa usucapionis / Edmundo J. Carbone -- ¿Es responsable el Estado por la actuación notarial? / Mirta Noemí Agüero – Ciencias políticas: Raíz rousseauniana y raíz calvinista en la democracia contemporánea / Orlando Juan Gallo – “Individuo”, “Sociedad” y “Estado” en el Japón de la posguerra / José Llampart – Integración América Latina – Europa / Francisco Arias Pelerano – La cooperación técnica internacional : concepto, definición y alcances / Marcelo Pablo Camusso – El nacionalismo argentino : su respuesta al problema del acceso al poder (1925-1946) / Leonardo Hekimián – Los acuerdos de integración en un sistema de interdependencia compleja (un estudio de casos: Argentina-Brasil) / Omar Alejandro Avalte – Estática y dinámica del sistema político : instrumento para el análisis del proceso político argentino / Daniel Rodríguez Lamas – Documentos – Libros comentados