856 resultados para Expectations hypothesis


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Hamilton and Zuk [Hamilton, W. D. & Zuk, M. (1982) Science 218, 384-387] proposed that females choosing mates based on the degree of expression of male characters obtain heritable parasite resistance for their offspring. Alternatively, the "contagion indicator" hypothesis posits that females choose mates based on the degree of expression of male characters because the latter indicate a male's degree of infestation of parasites and thus the risk that choosing females and their offspring will acquire these parasites. I examined whether parasite transmittability affects the probability that parasite intensity and male mating success are negatively correlated in intraspecific studies of parasite-mediated sexual selection. When females risk infection of themselves or their future offspring as a result of mating with a parasitized male, negative relationships between parasite intensity and male mating success are significantly more likely to occur than when females do not risk such infection. The direct benefit to females of avoiding parasitic infection is proposed to lead to the linkage between variable secondary sexual characters and the intensity of transmittable parasites. The direct benefits of avoiding associatively transmittable parasites should be considered in future studies of parasite-mediated sexual selection.

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Vicarious trial-and-error (VTE) is a term that Muenzinger and Tolman used to describe the rat's conflict-like behavior before responding to choice. Recently, VTE was proposed as a mechanism alternative to the concept of "cognitive map" in accounts of hippocampal function. That is, many phenomena of impaired learning and memory related to hippocampal interventions may be explained by behavioral first principles: reduced conflicting, incipient, pre-choice tendencies to approach and avoid. The nonspatial black-white discrimination learning and VTE behavior of the rat were investigated. Hippocampal-lesioned and sham-lesioned animals were trained for 25 days (20 trials per day) starting at 60 days of age. Each movement of the head from one discriminative stimulus to the other was counted as a VTE instance. Lesioned rats had fewer VTEs than sham controls, and the former learned much more slowly or never learned. After learning, VTE frequency declined. Male and female rats showed no significant differences in VTE behavior or discrimination learning.

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An attempt has been made to put forward a unifying hypothesis explaining the role hormones play in the genesis of mammary cancers of different phenotypes and genotypes in mice, rats, and humans. Most mammary cancers in these species originate in luminal mammary epithelial cells lining the mammary ducts and alveoli. These cancers are histopathologically diverse and are classified on the basis of growth requirements as hormone-dependent or hormone-independent tumors. In most strains of mice, mammary cancers at the time of detection are largely of the hormone-independent type; in rats, almost all mammary cancers are hormone-dependent, while humans have both phenotypes. In spite of these differences, in vivo studies show that hormones (ovarian and pituitary) are essential for luminal mammary epithelial cell proliferation and also for the development of mammary cancers of both hormone-independent and hormone-dependent types. This article, based on our extensive in vivo and in vivo studies and on current literature, proposes a model to explain the central role of hormones in the genesis of all types of mammary cancers. The model attempts to address the following questions: (i) how hormones regulate luminal mammary epithelial cell proliferation, (ii) why hormones are required for the genesis of mammary cancers of all phenotypes and genotypes, including those which are always classified as hormone-independent tumors, and (iii) why the three species (mouse, rat, and human) have consistently different ratios of hormone-dependent to hormone-independent tumors.

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We examine the predictive ability and consistency properties of exchange rate expectations for the dollar/euro using a survey conducted in Spain by PwC among a panel of experts and entrepreneurs. Our results suggest that the PwC panel have some forecasting ability for time horizons from 3 to 9 months, although only for the 3-month ahead expectations we obtain marginal evidence of unbiasedness and efficiency in the forecasts. As for the consistency properties of the exchange rate expectations formation process, we find that survey participants form stabilising expectations in the short-run and destabilising expectations in the long- run and that the expectation formation process is closer to fundamentalists than chartists.

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This dissertation engages the question of why German political elites accepted the use of force during the 1990s and started to commit the country's armed forces to multilateral peacekeeping missions. Previous governments of the Federal Republic had opposed foreign deployment of the military and Germany was characterized by a unique strategic culture in which the efficacy of military force was widely regarded as negative. The rediscovery of the use of force constituted a significant reorientation of German security policy with potentially profound implications for international relations. I use social role theory to explain Germany's security policy reorientation. I argue that political elites shared a national role conception of their country as a dependable and reliable ally. Role expectations of the international security environment changed as a result of a general shift to multilateral intervention as means to address emerging security problems after the Cold War. Germany's resistance to the use of force was viewed as inappropriate conduct for a power possessing the economic and military wherewithal of the Federal Republic. Elites from allied countries exerted social pressure to have Germany contribute commensurate with capabilities. German political elites adapted role behavior in response to external expectations in an effort to preserve the national role conception of a dependable and reliable ally. Security policy reorientation to maintain Germany's national role conception was pursued by conservative elites who acted as 'role entrepreneurs'. CDU/CSU politicians initiated a process of role adaptation to include the use of force for non-defensive missions. They persuaded Social Democrats and Alliance 90/Green party politicians that the maintenance of the country's role conception necessitated a reorientation in security policy to accommodate the changes in the security environment.

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While the numbers are slowly rising, Hispanic students continue to be disproportionately underrepresented in all levels of higher education, including doctoral education. There are many factors that may contribute to the low numbers of Hispanic doctoral students; for Hispanic women, one of these factors may be the perceived conflict between cultural expectations of childrearing and doctoral education. For Hispanic students who hold strong cultural values, this conflict may prevent enrollment in, or result in attrition from, doctoral education. As the number of Hispanic college enrollment increases, we will see more students trying to navigate between the collectivistic value of childrearing and the individualistic value of pursuing higher education. Thus, it is important to understand the needs of these students to aid in recruitment and retention of student-parents in all levels of higher education. This paper explores the barriers and supportive factors for current Hispanic doctoral student-parents. Suggestions are made to increase support which will allow these individuals to successfully complete a doctoral education, while attending to the responsibilities of parenting.

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La consolidación de la Web 2.0 y los medios sociales en nuestra sociedad coincide en el tiempo con el paulatino afianzamiento de un mercado emergente, el de las personas mayores. El objetivo de esta investigación es analizar, en el contexto de las redes sociales, cómo se gestiona la comunicación con el público maduro en España. Dos de los criterios que las empresas normalmente consideran cuando evalúan nuevos mercados son su peso económico y demográfico; en ambas áreas las personas mayores se han convertido en un grupo importante, convirtiéndose en uno de los mercados con mayor futuro del que además habría que destacar no sólo su tamaño y densidad, sino también su carácter heterogéneo, su variedad (Hudson, S., 2010; Westerhof et al., 2010; Imserso, 2009; Sudbury, L. y Simcock, P.,2009; Furlong, 2007; Kohlbacher y Herstatt, 2008: Thornhill y Martin, 2007). ¿Cumplen las redes sociales con las expectativas de los mayores, como público específico? Las redes sociales para mayores ¿son comunidades basadas en actitudes o conocimientos? (Matías Fernández, 2006) Los mayores, además de elegir redes y contenidos, ¿son internautas reales de redes sociales?, ¿son activos en la generación de contenidos hasta controlar la comunicación?... No existen precedentes y el trabajo persigue averiguar el papel de las personas mayores en las redes sociales específicas, así como el papel de las nuevas tecnologías en la comunicación de y con las personas mayores. Además, las conclusiones permitirán definir las hipótesis de estudios posteriores.

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First and second year students enrolled in a four-year movement education based university Physical Education program completed a questionnaire regarding their expectations on entering university. In addition, graduates of the program were interviewed, one year after graduation, with regard to their understanding of and attitude towards movement education and how these had developed relative to their overall degree program. Most students had no knowledge of movement education prior to entering the program and the selection of this particular program was simply coincidental with their desire to pursue physical education. Whereas the students did participate in an activity course and a theory course in Year 1, it was only when participating in a Year 2 movement course which combined theory and practice within the same course that students recognized the movement base of the content. The progress of the students through the program reflects distinct declarative and procedural stages in knowledge development followed by an ability to generalize that knowledge a conceptual stage. The real understanding of movement education came as the students were required to teach movement education to students, children, and other groups.

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Projet de recherche réalisé en 2014-2015 avec l'appui du Fonds de recherche du Québec – Société et culture.

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Before the ECB takes over responsibility for overseeing Europe’s largest banks, as foreseen in the establishment of a eurozone banking union, it plans to conduct an Asset Quality Review (AQR) throughout the coming year, which will identify the capital shortfalls of these banks. This study finds that a comprehensive and decisive AQR will most likely reveal a substantial lack of capital in many peripheral and core European banks. The authors provide estimates of the capital shortfalls of banks that will be stress-tested under the AQR using publicly available data and a series of shortfall measures. Their analysis identifies which banks will most likely need capital, where a public back stop is likely to be needed and, since many countries are already highly leveraged, where an EU-wide backstop might be necessary.

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Lithuania assumed its maiden term running the rotating Presidency of the Council in the 2nd half of 2013 under difficult constraints: the country’s modest administrative capacities and the enormous time pressures brought on by the urgency of certain dossiers and the abbreviated term of the current Parliament, which ends in mid-April. Nevertheless, as assessed by Sonia Piedrafita and Vilde Renman in this new CEPS Commentary, substantial progress was made thanks to the perseverance and strenuous efforts by the Lithuanians. In the end, some 137 legal acts were adopted during its six-month term, including several highly sensitive and complex pieces of legislation. The overall success was only slightly marred by the haste with which a few agreements were negotiated.

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Based on his speech to the European Parliament on July 15th, following his election as President of the European Commission, Jean-Claude Juncker has clearly opted for ‘more Union’ during his five-year term, offering up an ambitious agenda that raises a host of expectations. In this CEPS Commentary, Karel Lannoo outlines the most salient items on Juncker’s agenda, focusing on the most laudable and those that will pose the greatest challenges.

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Since the beginning of its existence in the form of communities, the European Union’s decision-making process underwent constant evolution. There were continuous adjustments that transformed a pure intergovernmental process into one having rather federal features. Based on the hypothesis that changes have occurred at the decision level in regards to the actors, procedures, influence and ways of taking decisions in order for the new realities, needs and will at the European level to be properly addressed, this paper aims to present the reforms performed through the adoption of new treaties and the modification of the existing ones. The reality is that in order for the European dream and integration to go on and also for further development of the European Union, finally becoming an entity far beyond the founders expectations, decision makers had to constantly and carefully adapt the decision-making process. The purpose of this paper will be achieved by conducting a research based on the qualitative method, analyzing the related researches on this topic and the consolidated versions of the treaties. Thus, we will finally validate our research hypothesis that there was an evolution in what the EU’s decision-making process and decision procedures are concerned.