962 resultados para Factor-i Receptor
Resumo:
Se trata de comprobar si los factores de comunicación verbo-icónica en los carteles de propaganda política son similares a los que en su momento se detectaron como características de la publicidad comercial en la investigación de Rodríguez Diéguez 'Publicidad y Enseñanza'. La muestra se compone de 323 carteles de propaganda política, recogidos en diapositivas, pertenecientes a las campañas electorales, efectuadas en el País Valenciano por los distintos partidos con motivo de las elecciones generales de 1977, 79 carteles; elecciones generales de 1979, 79 carteles; referéndum constitucional de 1978, 76 carteles; y elecciones municipales de 1979, 92 carteles. Para comprobar el objetivo, se valora la muestra de carteles políticos con la misma escala que se utilizó para la publicidad comercial que recogía los siguientes factores: factor icónico, factor verbal, factor de función dominante, factor de convergencia formal de contenidos y factor de determinación informativa. Escala de publicidad y enseñanza de Rodríguez Diéguez. Propaganda política. Análisis factorial de componentes principales, rotación Varimax. Análisis de correlación. La matriz factorial es sometida a dos rotaciones más que incrementen la invarianza. Programas de ordenador. Representaciones gráficas. Tras las rotaciones efectuadas se observa que el factor I en ambos casos tienen un alto nivel de concomitancia, aunque el factor resultante de este trabajo es más amplio, dándose una convergencia de aspectos formales de carácter icónico y verbales, por lo que se le denomina factor de determinación cualitativa de la información. El factor II en ambos casos. Tienen una correlación casi perfecta, a pesar de lo cual se le denomina lecturabilidad. El factor III presenta variaciones sustantivas, ya que no entran en la composición, las variables que le dan su sentido de función dominante al original, sino sólo las que aluden a aspectos formales, por lo cual se le denomina factor técnico o de diseño. El factor IV, convergencia formal de contenidos, tiene un sentido equivalente al de la hipótesis. El factor V, queda descartado. La hipótesis global queda aceptada en su mayor parte.
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Estudiar los conceptos más importantes de la dinámica del comportamiento humano para conocer las relaciones entre motivación y personalidad. Para la aplicación del Método de Instrucción Motivacional (MIM) son 237 religiosas en período de formación y para aplicar el Inventario Multifásico de la Personalidad de Minnesota (MMPI) son 379 sujetos. El estudio de la correlación entre los dos cuestionarios utiliza a 216 sujetos. Analiza el concepto y los niveles de integración de la personalidad, explica las dimensiones y variables fundamentales de la misma y examina las teorías existentes. Después estudia el concepto y las teorías relativas a la motivación, y expone la utilidad y el significado de los instrumentos de la investigación. Posteriormente ofrece los resultados obtenidos con la aplicación de los instrumentos y examina la relación entre los mismos . El Método de Inducción Motivacional (MIM) y el Inventario Multifásico de la Personalidad de Minnesota (MMPI). El MIM es un método que utiliza unas categorías para clasificar el contenido motivacional, éstas son: Yo, Realización, Autorealización, Contacto, Exploración, Trascendencia, Posesión y Diversión. mientras que el MMPI tiene como objetivo proporcionar una evaluación objetiva de algunas de las más importantes dimensiones de la personalidad relacionadas con la adaptación personal y social del sujeto. 1) En el contenido motivacional, MIM: a) se diferencian dos zonas, una zona del yo, donde se integran las frecuencias más altas en las categorías del Yo, de la Realización y Autorealización.Y la otra es la zona del Contacto, que recoge las frecuencias significativas en las categorías del Contacto. Por lo cual, podemos hablar de una dirección egótica motivacional en la zona del yo. Resalta la dimensión estática y contemplativa y el aspecto de dinamismo interior; b) Un aspecto que hay que considerar es la dirección alternante referente a las motivaciones de Contacto, ya que la relación interpersonal puede tomar una dirección centrífuga y otra centrípeta. Además, existe otra dirección denominada intencional que pertenece a las motivaciones de trascendencia. Se podría afirmar que las motivaciones centrífugas, con tendencia a las relaciones con las personas, predominando un altruismo y una apertura al mundo y a las cosas, reflejan personalidades equilibradas, abiertas, maduras y sólidas. Sin embargo, las motivaciones centrífugas, que manifiestan cómo los individuos se quedan más en sí mismo, en su limitación, sin abrirse y salir hacia fuera, reflejan personalidades más inmaduras, menos ricas y menos comunicativas. El horizonte abierto a la comunicación en general con personas, ambientes, cosas y a la acción subraya ser más eficaz y constructivo. 2) En el MMPI, el perfil de los sujetos está definido por los tres factores encontrados en el análisis factorial: a) El factor I, que se define como personalidad problemática incontrolada, presenta un comportamiento problemático en la lima de desviación de la personalidad; b) El factor II está definido como introversión social y clínicamente representa la disposición psicológica de la personalidad; c) El factor III es el definido como depresión social que en límites clínicos se puede dar una introversión psicotécnica y esquizofrénica. 3) La interrelación de los dos instrumentos MMI y MMPI se da en dos direcciones: a) Se puede hablar de una estabilización del yo contra las desviaciones de personalidad, sugeridas por los extremos clínicos de las escalas del MMPI. Se pueden agrupar en el núcleo antipsicótico y antineurótico. Las escalas de motivaciones de estabilización del yo son Realización, Autorealización y Contacto centrífugo. b) Por otro lado, se puede hablar de una debilidad psicótica y neurótica, propia de las categorías con dimensión más egocéntrica y pasiva. Se manifiesta en las categorías Contacto centrípedo, Exploración y el yo según sus orientaciones estáticas y pasivas. 1) Se da convergencia de formas motivacionales y de estructura de personalidad. 2) El hecho de que los impulsos motivacionales vienen a dar una orientación determina el tipo de personalidad. Es decir, la personalidad queda expresada con sus características determinadas en los contenidos y en las formas motivacionales.
Resumo:
Investigación que forma parte de un programa más general que pretende una evaluación formativa del proceso docente, ofreciendo una información al profesor que favorezca cambios en la calidad docente. Intentar obtener datos más generales sobre la Enseñanza Universitaria y construir un instrumento de evaluación adecuado. Intentar encontrar criterios de validez para el cuestionario, con especial interés por los criterios empáticos. Muestra no especificada de alumnos de la Universidad Autónoma de Madrid (16069 encuestas). Muestra de profesores no especificada de la misma universidad (123 encuestas). Diseño correlacional-factorial en el que se evalúa la percepción de la calidad docente por parte de los alumnos a la vez que se estudia la fiabilidad, validez y composición factorial de una versión mejorada de un cuestionario desarrollado anteriormente. Cada alumno evalúa varios profesores (con el orden de presentación balanceado) en una serie de dimensiones. Como criterio de validez se utiliza un ítem en el que el sujeto da una valoración global (grado en el que considera que se han alcanzado los objetivos docentes). El cuestionario incluye 3 ítems de sugestión para controlar el efecto de esta variable en la evaluación de la calidad.. Cuestionario (27 ítems referidos al profesor, 10 a los objetivos didácticos y 6 a la asignatura). Fiabilidad: técnica de las dos mitades. Validez: correlación con el ítem criterio. Análisis factorial (rotación ortogonal). La fiabilidad de los ítems es adecuada. No se observan efectos del orden de cumplimentación de las encuestas. La validez es superior a la observada en el primer cuestionario. No se observa una relación muy fuerte entre los objetivos y los métodos didácticos, aunque sí entre determinados ítems y los objetivos a conseguir. El análisis factorial confirma las dimensiones obtenidas en el trabajo anterior (factor I: interacción con el grupo y preocupación por los resultados, factor II: claridad de exposición, organización y preocupación por la enseñanza, factor III: entusiasmo y dominio de la asignatura). Respecto al factor de sugestión los resultados no son claros, ya que puede indicar bien un efecto de sugestión o bien una habilidad para motivar. Por último en el análisis por Facultades se obtienen perfiles heterogéneos, aunque hay ciertas diferencias entre Ciencias y Derecho (factores I, II y III). Sin embargo, las diferencias del tamaño de las muestras relativizan los resultados.
Resumo:
Intentar descubrir los elementos básicos de la estructura de la personalidad y así estudiar de forma adecuada las interacciones que se efectuan en el organismo y predecir las conductas del individuo. 2287 alumnos de edades de 12 a 18 años. Cuestionario HSPQ. Estadística descriptiva. Los resultados han sido positivos y satisfactorios dado que tanto en las comparaciones de grupos como en el estudio de casos individuales se han cumplido las predicciones de la teoría de Cattell. Se comprueba que las puntuaciones bajas en las dimensiones 'E' y 'F', las altas en 'Q4', responden a frustracciones importantes y que las puntuaciones elevadas en el factor 'I' van asociadas a los hogares superprotegidos de cultura delicada y son así mismo, reflejo de una educación demasiado indulgente en la infancia.
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Metal pollution in rivers is in great concern with human activities in the fluvial watershed. This thesis aims to investigate the potential use of chl-a fluorescence parameters as biomarkers of metal toxicity, and to find cause-effect relationships between metal exposures, other environmental factor (i.e. light), and functional and structural biofilm responses. This thesis demonstrates that the use of chl-a fluorescence parameters allows detect early effects on biofilms caused by zinc toxicity, both in the laboratory as in polluted rivers. In microcosm experiments, the use of chl-a fluorescence parameters allows evaluates structural changes on photosynthetic apparatus and in algal groups’ composition of biofilms long-term exposed to zinc. In order to evaluate the effects of chronic metal pollution in rivers, it is recommended the use of biofilm translocation experiments and the use of a multi-biomarker approach.
Resumo:
Cows in severe negative energy balance after calving have reduced fertility, mediated by metabolic signals influencing the reproductive system. We hypothesised that transition diet could alter metabolic status after calving, and thus influence fertility. Multiparous dairy cows were assigned to four transition groups 6 weeks pre-calving and fed: (a) basal control diet (n = 10); (b) basal diet plus barley (STARCH, n = 10); (c) basal diet plus Soypass (high protein, HiPROT, n = 11); or (d) no transition management (NoTRANS, n = 9). All cows received the same lactational diet. Blood samples, body weights and condition scores (BCS) were collected weekly. Fertility parameters were monitored using milk progesterone profiles and were not affected by transition diet. Data from all cows were then combined and analysed according to the pattern of post-partum ovarian activity. Cows with low progesterone profiles had significantly lower insulin-like growth factor-I (IGF-I) and insulin concentrations accompanied by reduced dry matter intakes (DMIs), BCS and body weight. Cows with prolonged luteal activity (PLA) were older and tended to have lower IGF-I. Analysis based on the calving to conception interval revealed that cows which failed to conceive (9/40) also had reduced IGF-I, BCS and body weight. Fertility was, therefore, decreased in cows which were in poor metabolic status following calving. This was reflected in reduced circulating IGF-I concentrations and compromised both ovarian activity and conception. There was little effect of the transition diets on these parameters. (C) 2003 Elsevier Science Inc. All rights reserved.
Resumo:
This study investigated the ovarian function, metabolic profiles and fertility in first lactation Holstein-Friesian dairy cows (mean 305 day milk yield: 7417 +/- 191 kg, n = 37). Reproductive profiles obtained from milk progesterone analysis were categorized into normal (n = 17) and four abnormal profiles (delayed ovulation, DOV1, n = 9; DOV2, n = 2; persistent corpus luteum, PCL1, n = 6; PCL2, n = 4; 1: immediately post-calving, 2: subsequent cycles). Fifty-five percent of cows had abnormal profiles with half of these being categorized as DOV1. Fertility of DOV1 and DOV2 cows was reduced whereas PCL1 and PCL2 cows had similar reproductive competence to normal profile cows. DOV1 animals had higher milk energy values, lower energy balances, lower dry matter intakes (DMI) and greater body weight and body condition score (BCS) losses post-calving than normal profile animals. DOV1 animals also had lower insulin-like growth factor-I (IGF-I) and higher betahydroxybutyrate (BHB) concentrations and tended to have the lower insulin and glucose concentrations in the pre-service period than normal profile cows. All PCL animals had vulval discharges postpartum. Despite this, the DMI, body weight and BCS changes, IGF-I concentrations and fertility of PCL1 animals was similar to normal profile cows. In conclusion, the high prevalence of delayed ovulation post-calving (DOV1) in primiparous high yielding cows lasted long enough (71 +/- 8.3 days) to have a detrimental impact on fertility and was associated with significant physiological changes. This study did not establish any detrimental effects of PCL profiles on fertility or production parameters. (C) 2002 Elsevier Science Inc. All rights reserved.
Resumo:
This study investigated possible relationships between measurements of the somatotrophic axis in pre-pubertal dairy calves and subsequent milk yields. Endogenous growth hormone (GH) release was measured through a fed and fasted period in fifty 6-month-old Holstein-Friesian heifers and they were then challenged with growth hormone-releasing factor (GRF) to assess their GH release pattern. Insulin-like growth factor-I (IGF-I), insulin and glucose concentrations were measured in relation to time of feeding. Cows were subsequently monitored through their first three lactations to record peak and 305-day milk yields. In the first lactation, milk energy output for the first 120 days of lactation was also calculated. The mean 305-day milk yield increased from 7417 +/- 191 kg in the first lactation (n = 37) to 8749 +/- 252 kg in the third (n = 25). There were no significant relationships between any measures of GH secretion and peak or 305-day yield in any lactation. A highly significant positive relationship was established between the GH peak measured 10 min post-GRF challenge and 120-day milk energy values in the first lactation. This relationship was, however, only present in the subpopulation of 12 cows culled after one or two lactations and was absent in the 25 animals remaining for the third lactation. There were no significant relationships between pre-pubertal IGF-I and fed or fasted insulin or glucose concentrations and any subsequent measurement of yield. The usefulness of GH secretagogue challenges in calves as a predictive test for future milk production is thus limited but may have some bearing on nutrient partitioning and longevity. (c) 2005 Elsevier Inc. All rights reserved.
Resumo:
Following parturition, all cows display a wave of ovarian follicular growth, but a large proportion fail to generate a preovulatory rise in estradiol, and hence fail to ovulate. Follicle-stimulating hormone (FSH) exists as multiple isoforms in the circulation depending on the type and extent of glycosylation, and this has pronounced effects on its biological properties. This study examined differences in plasma FSH, estradiol, and inhibin A concentrations, and the distribution of FSH isoforms in cows with ovulatory or atretic dominant follicles during the first postpartum follicle wave. Plasma FSH isoform distribution was examined in both groups during the period of final development of the dominant follicle by liquid phase isoelectric focusing. Cows with an ovulatory follicle had higher circulating estradiol and inhibin A concentrations, and lower plasma FSH concentrations. The distribution of FSH isoforms displayed a marked shift toward the less acidic isoforms in cows with ovulatory follicles. A higher proportion of the FSH isoforms had a pl>5.0 in cows with ovulatory follicles compared to those with atretic follicles. In addition, cows with ovulatory follicles had greater dry matter intake, superior energy balance, elevated circulating concentrations of insulin and insulin-like growth factor-I, and lower plasma nonesterified fatty acids. The shift in FSH isoforms toward a greater abundance of the less acidic isoforms appears to be a key component in determining the capability for producing a preovulatory rise in estradiol, and this shift in FSH isoforms was associated with more favorable bioenergetic and metabolic status. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
The extent, causes, and physiological significance of the variation in number of follicles growing during ovarian follicular waves in human beings and cattle are unknown. Therefore, the present study examined the variability and repeatability in numbers of follicles 3 mm or greater in diameter during the follicular waves in bovine estrous cycles, and we determined if the variation in number of follicles during waves was associated with alterations in secretion of FSH, estradiol, inhibin, and insulin-like growth factor I (IGF-I). Dairy cattle were subjected to twice-daily ultrasound analysis to count total number of antral follicles 3 mm or greater in diameter throughout 138 different follicular waves. In another study, blood samples were taken at frequent intervals from cows that consistently had low or very high numbers of follicles during waves and were subjected to immunoassays. Results indicate the following: First, despite an approximately sevenfold variation in number of follicles during waves among animals and marked differences in age, stage of lactation, and season of the year, a very highly repeatable (0.95) number of follicles 3 mm or greater in diameter is maintained during the ovulatory and nonovulatory follicular waves of individuals. Second, variation in number of follicles 3 mm or greater in diameter during waves and the inverse association of number of follicles during waves with FSH are not directly explained by alterations in the patterns of secretion of estradiol, inhibin, or IGF-I. Third, ovarian ultrasound analysis can be used reliably by investigators to identify cattle that consistently have low or high numbers of follicles during waves, thus providing a novel experimental model to determine the causes and physiological significance of the high variation in antral follicle number during follicular waves among single-ovulating species, such as cattle or humans.
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The importance of the second messengers calcium (Ca(2+)) and diacylglycerol (DAG) in platelet signal transduction was established more than 30 years ago. Whereas protein kinase C (PKC) family members were discovered as the targets of DAG, little is known about the molecular identity of the main Ca(2+) sensor(s). We here identify Ca(2+) and DAG-regulated guanine nucleotide exchange factor I (CalDAG-GEFI) as a critical molecule in Ca(2+)-dependent platelet activation. CalDAG-GEFI, through activation of the small GTPase Rap1, directly triggers integrin activation and extracellular signal-regulated kinase-dependent thromboxane A(2) (TxA(2)) release. CalDAG-GEFI-dependent TxA(2) generation provides crucial feedback for PKC activation and granule release, particularly at threshold agonist concentrations. PKC/P2Y12 signaling in turn mediates a second wave of Rap1 activation, necessary for sustained platelet activation and thrombus stabilization. Our results lead to a revised model for platelet activation that establishes one molecule, CalDAG-GEFI, at the nexus of Ca(2+)-induced integrin activation, TxA(2) generation, and granule release. The preferential activation of CalDAG-GEFI over PKC downstream of phospholipase C activation, and the different kinetics of CalDAG-GEFI- and PKC/P2Y12-mediated Rap1 activation demonstrate an unexpected complexity to the platelet activation process, and they challenge the current model that DAG/PKC-dependent signaling events are crucial for the initiation of platelet adhesion.
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The extracellularly-responsive kinase (ERK) subfamily of mitogen-activated protein kinases (MAPKs) has been implicated in the regulation of cell growth and differentiation. Activation of ERKs involves a two-step protein kinase cascade lying upstream from ERK, in which the Raf family are the MAPK kinase kinases and the MEK1/MEK2 isoforms are the MAPK kinases. The linear sequence of Raf --> MEK --> ERK constitutes the ERK cascade. Although the ERK cascade is activated through growth factor-regulated receptor protein tyrosine kinases, they are also modulated through G protein-coupled receptors (GPCRs). All four G protein subfamilies (Gq/11 Gi/o, Gs and G12/13) influence the activation state of ERKs. In this review, we describe the ERK cascade and characteristics of its activation through GPCRs. We also discuss the identity of the intervening steps that may couple agonist binding at GPCRs to activation of the ERK cascade.
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This work aimed at evaluating the effects of the supplementation of starter diet with Arg on breast muscle development in broilers and the activation of satellite cells and the aggregation of myofibrillar protein. Male Cobb chicks (n = 990) were randomly assigned to 1 of 5 treatments in a complete random design. Measurements of 33 chicks per treatment were made in 6 repetitions. The treatments consisted of a basal diet with 1.390% digestible Arg (without supplementation) and 4 dietary levels of Arg (1.490, 1.590, 1.690, and 1.790%) with Arg:Lys ratios of 1.103, 1.183, 1.262, 1.341, and 1.421, respectively. Arginine supplementation was used only in the starter phase (1 to 21 d). Dietary supplementation with Arg had a positive effect (P < 0.05) on breast and breast fillet weight on d 7 and 21 and on myofiber diameter on d 14 and 21. However, no effect was observed (P > 0.05) on the protein: DNA ratio, which demonstrates that Arg does not interfere with the mitotic activity of the satellite cells. Independently from mechanism, Arg affected muscle growth in the starter phase positively. Dietary supplementation with Arg in the starter phase had no effect (P > 0.05) on the carcass yield of broilers on d 42. Diet supplementation with Arg at levels above the ones recommended for the starter phase may be necessary for improved muscle development in broilers.
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IL-1 beta, TNF-alpha, cytokine-induced neutrophil chemoattractant-2 alpha/beta, and IL-10 measurements were performed in elicited peritoneal cells from control, diabetic, and insulin-treated diabetic rats. Production/liberation of these cytokines was decreased in elicited peritoneal cells from diabetic rats. These changes were abolished by insulin treatment of diabetic rats. The alterations observed might be involved in the impaired inflammatory response and high occurrence of apoptosis observed in neutrophils under diabetic states.
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We have previously shown that pathogenic leptospiral strains are able to bind C4b binding protein (C4BP). Surface-bound C4BP retains its cofactor activity, indicating that acquisition of this complement regulator may contribute to leptospiral serum resistance. In the present study, the abilities of seven recombinant putative leptospiral outer membrane proteins to interact with C4BP were evaluated. The protein encoded by LIC11947 interacted with this human complement regulator in a dose-dependent manner. The cofactor activity of C4BP bound to immobilized recombinant LIC11947 (rLIC11947) was confirmed by detecting factor I-mediated cleavage of C4b. rLIC11947 was therefore named LcpA (for leptospiral complement regulator-acquiring protein A). LcpA was shown to be an outer membrane protein by using immunoelectron microscopy, cell surface proteolysis, and Triton X-114 fractionation. The gene coding for LcpA is conserved among pathogenic leptospiral strains. This is the first characterization of a Leptospira surface protein that binds to the human complement regulator C4BP in a manner that allows this important regulator to control complement system activation mediated either by the classical pathway or by the lectin pathway. This newly identified protein may play a role in immune evasion by Leptospira spp. and may therefore represent a target for the development of a human vaccine against leptospirosis.