944 resultados para parental investment theory
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Diferentes critérios utilizados para a escolha de parceiros entre homens e mulheres têm sido identificados. Essa diferença, provavelmente, origina-se pelos diferentes graus de investimento parental entre gêneros. Mulheres parecem ter predisposição a selecionar parceiros com características de investimento emocional, material e com bons indicativos de saúde. Já homens podem utilizar os mesmos critérios que as mulheres, porém dão mais importância que estas à aparência física e juventude. Em relacionamentos de curto e longo prazo a literatura indica que há uma diferença nas escolhas entre mulheres. No primeiro caso, elas têm demonstrando preferir características relacionadas à saúde física, comparado ao segundo tipo de relacionamento, no qual a ênfase tem sido voltada à parceiros bons provedores de recursos e com alto nível de investimento emocional. Há poucas pesquisas que investigaram os critérios que mulheres homossexuais utilizam na escolha de suas parceiras amorosas. Estudos que investigaram a origem da homossexualidade apontaram a possibilidade de influências biológicas. Em termos evolutivos, a homossexualidade poderia ter surgido, em parte, como subproduto da evolução do prazer característico das atividades sexuais. Se esta hipótese estiver correta, o potencial para o desenvolvimento de uma orientação homo, hetero ou bissexual pode ser potencializado por ambientes característicos dos indivíduos em particular. Tal hipótese pode sugerir que os mecanismos psicológicos para escolha de parceiros sejam semelhantes entre as mulheres de variadas orientações sexuais. Para testar esta hipótese, investigou-se as preferências na escolha de parceiras de 100 mulheres em período reprodutivo, entre 18 e 40 anos, que se auto-classificaram como “homossexual exclusivo” ou “homossexual, e às vezes heterossexual”. Para a coleta de dados foram utilizados dois instrumentos, um para seleção das participantes e outro para a coleta de informações. O instrumento de coleta de dados foi dividido em: 1) Dados Demográficos; 2) Dados da parceira; 3) Critérios valorizados na escolha de uma parceira; 4) Critérios valorizados na escolha de uma parceira de curto e longo prazo; 5) Variáveis relacionadas ao desempenho sexual. As participantes foram contatadas pelo método a) “snow ball”, b) bares frequentados por grupos homossexuais e c) associações GLBT. Especificamente, investigou-se as variáveis envolvidas na escolha de parceiras de curto e longo prazo e comparou-se os resultados com os dados coletados por Cruz (2009), com mulheres heterossexuais em período reprodutivo. Os resultados indicaram que há maior preferência por atributos físicos em relacionamentos de curto prazo entre mulheres homo e heterossexuais. Atributos referentes à formação de vínculo foram mais solicitados em relacionamentos de longo prazo, possivelmente porque 75,6% dessas mulheres têm renda e não dependem do parceiro(a) para o provimento na relação, diminuindo a necessidade de parceiro(a)s que invistam recursos materiais. Mulheres homossexuais parecem ter os mesmos padrões de escolha de parceiros que heterossexuais.
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Este estudo utilizou como referencia teórico o Modelo de Investimento Parental proposto por Heidi Keller, que indica seis sistemas parentais – cuidados primários, contato corporal, estimulação corporal, estimulação por objeto, troca face-a-face e envelope narrativo – e três mecanismos de interação – atenção, contingência e calor emocional, os quais são independentes entre si e a predominância de um ou outro dependerá da cultura e de características socioeconômicas. Os objetivos desse trabalho foram caracterizar o investimento parental de díades mãe-bebê pertencentes às classes socioeconômicas baixa (CEB) e média (CEM) da cidade de Belém e o estilo conversacional utilizado nas emissões verbais das mães quando em interação verbal com seus bebês. Participaram 20 mães, sendo nove da CEB e 11 da CEM. A média da idade das mães da CEB foi 24,5, a maioria tinha o nível de escolaridade fundamental (77,8%) e médio (22,2%), completos ou não, apresentaram renda mensal inferior que as mães do outro grupo e residiam em áreas periféricas. Quanto a CEM, a média da idade das mães foi 30,7, e a maioria tinha nível educacional superior (63,3%) e residiam no centro da cidade. Foram observadas e gravadas as interações mãe-bebê em sessões de banho e troca, na casa da díade, para posterior análise e transcrição do comportamento verbal com o aplicativo Transana 2.41. Os resultados indicaram que as mães da CEB priorizaram as práticas parentais que valorizam a interdependência durante suas interações, embora também tenham apresentado práticas distais, porém com menor frequência. As mães da CEM, apresentaram práticas parentais que valorizam tanto a autonomia quanto a relacionalidade. Quanto aos mecanismos de interação, observou-se que as mães de ambos os grupos foram mais contingentes aos sinais positivos do que aos negativos do bebê, característica própria de sociedades que priorizam a independência e autonomia do sujeito; e evidenciaram mais calor emocional ao responder aos sinais positivos em comparação com os negativos. Em relação ao estilo conversacional, as mães de CEB utilizaram com maior frequência o estilo diretivo, e as mães de CEM, utilizaram os dois estilos com freqências muito próximas. Os resultados deste estudo sugerem um perfil interdependente para o grupo CEB e um perfil autônomo-relacionado para a amostra de mães urbanas de classe média.
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Corticosterone, the main stress hormone in birds, mediates resource allocation, allowing animals to adjust their physiology and behaviour to changes in the environment. Incubation is a time and energy-consuming phase of the avian reproductive cycle. It may be terminated prematurely, when the parents' energy stores are depleted or when environmental conditions are severe. In this study, the effects of experimentally elevated baseline corticosterone levels on the parental investment of incubating male Adelie penguins were investigated. Incubation duration and reproductive success of 60 penguins were recorded. The clutches of some birds were replaced by dummy eggs, which recorded egg temperatures and rotation rates, enabling a detailed investigation of incubation behaviour. Corticosterone levels of treated birds were 2.4-fold higher than those of controls 18 days post treatment. Exogenous corticosterone triggered nest desertion in 61% of the treated birds; consequently reducing reproductive success, indicating that corticosterone can reduce or disrupt parental investment. Regarding egg temperatures, hypothermic events became more frequent and more pronounced in treated birds, before these birds eventually abandoned their nest. The treatment also significantly decreased incubation temperatures by 1.3 °C and lengthened the incubation period by 2.1 days. However, the number of chicks at hatching was similar among successful nests, regardless of treatment. Weather conditions appeared to be particularly important in determining the extent to which corticosterone levels affected the behaviour of penguins, as treated penguins were more sensitive to severe weather conditions. This underlines the importance of considering the interactions of organisms with their environment in studies of animal behaviour and ecophysiology.
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Recent signaling resolution models of parent–offspring conflict have provided an important framework for theoretical and empirical studies of communication and parental care. According to these models, signaling of need is stabilized by its cost. However, our computer simulations of the evolutionary dynamics of chick begging and parental investment show that in Godfray’s model the signaling equilibrium is evolutionarily unstable: populations that start at the signaling equilibrium quickly depart from it. Furthermore, the signaling and nonsignaling equilibria are linked by a continuum of equilibria where chicks above a certain condition do not signal and we show that, contrary to intuition, fitness increases monotonically as the proportion of young that signal decreases. This result forces us to reconsider much of the current literature on signaling of need and highlights the need to investigate the evolutionary stability of signaling equilibria based on the handicap principle.
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Tese de doutoramento, Psicologia (Psicologia Clínica), Universidade de Lisboa, Faculdade de Psicologia, 2016
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Recent studies have demonstrated male mate choice for female ornaments in species without sex-role reversal. Despite these empirical findings, little is known about the adaptive dynamics of female signalling, in particular the evolution of male mating preferences. The evolution of traits that signal mate quality is more complex in females than in males because females usually provide the bulk of resources for the developing offspring. Here, we investigate the evolution of male mating preferences using a mathematical model which: (i) specifically accounts for the fact that females must trade-off resources invested in ornaments with reproduction; and (ii) allows male mating preferences to evolve a non-directional shape. The optimal adaptive strategy for males is to develop stabilizing mating preferences for female display traits to avoid females that either invests too many or too few resources in ornamentation. However, the evolutionary stability of this prediction is dependent upon the level of error made by females when allocating resources to either signal or fecundity.
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Reproduction is an essential part of humans species’ existence and survival. We are interested in securing it, and having a direct interest in the reproduction of those with whom we have strong genetic relationship. Trivers (1974) featured the parent-offspring conflict, as a divergence about the parents’ investment, which has been mainly studied in the early stages of children’s development. However, the divergence in investment can also be expressed at the time of the reproductive decisions of the offspring. Thus, we investigated whether parents and children have conflicting interests regarding reproductive expectations of the children, understanding reproductive expectations as desired age to marry, have children, have sexual intercourse and desired amount of children. We found that parents and children disagree on some of these points, we also find a more conservative expectation when it comes to daughters, reiterating the daughter-guarding hypothesis. When we consider how much help would be given towards the up bringing of a grandson, we found a clear variation according to the age of the baby's parents: the younger the baby’s parents are, the larger the amount of assistance would be provided by grandparents. Considering the amount and quality of offspring and conditions of reproduction, parental investment is an element that presents itself closely linked to the history of the subject's life. Parents are the first to communicate to children how the environment in which they are inserted is presenting itself. As the life history is closely linked with reproduction, and, therefore, with parental investment, we intend to investigate whether there is a correlation between aspects of the individuals’ history of life (unpredictability and parental care) and their reproductive expectations, seeking further assess on whether there is relationship between parents' life history and their reproductive expectations for their children. We find evidence that partially confirm our expectations; we find relationships of some elements of reproductive expectations with indicators of unpredictability and parental care. The experiences of parents also reflected in their expectations for their children, with a more present correlation to their expectations for daughters. From our results, we find evidence that parent-offspring conflict appears in the reproductive expectations of children and relates to aspects of individuals’ life history.
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An analysis of the alternatives of compensation in relation to international investment disputes is relevant, because a pecuniary award is not always the appropriate remedy to solve disputes arising between investors and States. This is the case because States may be increasingly interested in opting for a different type of compensation. Furthermore, it is still not clear whether arbitral tribunals have recognised alternative types of awarding damages in respect of international investments disputes. This analysis comprises two principal components, the first, is to identify whether or not the tribunals may render an award that not only demands the payment of a sum of money but also considers some other means of compensation. The second, centres on how compliance with these non-pecuniary awards may be demanded. Our approach to these two principal components will always revolve around the idea of respecting the sovereignty of the State, bearing in mind that the execution of an arbitral award, which obliges the State to refrain from or to perform an act in its territory, relies precisely on the sovereignty of the State to execute it.
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Mode of access: Internet.
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This dissertation examines one category of international capital flows, private portfolio investments (private refers to the source of capital). There is an overall lack of a coherent and consistent definition of foreign portfolio investment. We clarify these definitional issues.^ Two main questions that pertain to private foreign portfolio investments (FPI) are explored. The first problem is the phenomenon of home preference, often referred to as home bias. Related to this are the observed cross-investment flows between countries that seem to contradict the textbook rendition of private FPI. A description of the theories purporting to resolve the home preference puzzle (and the cross-investment one) are summarized and evaluated. Most of this literature considers investors from major developed countries. I consider--as well--whether investors in less developed countries have home preference.^ The dissertation shows that home preference is indeed pervasive and profound across countries, in both developed and emerging markets. For the U.S., I examine home bias in both equity and bond holdings as well. I find that home bias is greater when we look at equity and bond holdings than equity holdings solely.^ In this dissertation a model is developed to explain home bias. This model is original and fills a gap in the literature as there have been no satisfactory models that handle at the same time both home preference and cross-border holdings in the context of information asymmetries. This model reflects what we see in the data and permits us to reach certain results by the use of comparative statics methods. The model suggests, counter-intuitively, that as the rate of return in a country relative to the world rate of return increases, home preference decreases. In the context of our relatively simple model we ascribe this result to the higher variance of the now higher return for home assets. We also find, this time as intended, that as risk aversion increases, investors diversify further so that home preference decreases.^ The second question that the dissertation deals with is the volatility of private foreign portfolio investment. Countries that are recipients of these flows have been wary of such flows because of their perceived volatility. Often the contrast is made with the perceived absence of volatility in foreign direct investment flows. I analyze the validity of these concerns using first net flow data and then gross flow data. The results show that FPI is not, in relative terms, more volatile than other flows in our sample of eight countries (half were developed countries and the rest were emerging markets).^ The implication therefore is that restricting FPI flows may be harmful in the sense that private capital may not be allocated efficiently worldwide to the detriment of capital poor economies. More to the point, any such restrictions would in fact be misguided. ^
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This study develops a life-cycle model where investors make investment decisions in a realistic environment. Model results show that personal illiquid projects (housing and children), fixed costs (once-off/per-period participation costs plus variable/fixed transaction costs) and endogenous risky human capital (with permanent, transitory and disastrous shocks) together are able to address both the non-participation puzzle and the age-effects puzzle. Empirical implications of the model are examined using Heckman’s two-step method with the latest five Surveys of Consumer Finance (SCF). Regression results show that liquidity, informational cost and human capital are indeed the major determinants of participation and asset allocation decisions at different stages of an investor’s life.
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This document provides the findings of an international review of investment decision-making practices in road asset management. Efforts were concentrated on identifying the strategic objectives of agencies in road asset management, establishing and understanding criteria different organisations adopted and ascertaining the exact methodologies used by different countries and international organisations. Road assets are powerful drivers of economic development and social equity. They also have significant impacts on the natural and man-made environment. The traditional definition of asset management is “A systematic process of maintaining, upgrading and operating physical assets cost effectively. It combines engineering principles with sound business practices and economic theory and it provides tools to facilitate a more organised, logical approach to decision-making” (US Dept. of Transportation, 1999). In recent years, the concept has been broadened to cover the complexity of decision making, based on a wider variety of policy considerations as well as social and environmental issues rather than is covered by Benefit-Cost analysis and pure technical considerations. Current international practices are summarised in table 2. It was evident that Engineering-economic analysis methods are well advanced to support decision-making. A range of tools available supports performance predicting of road assets and associated cost/benefit in technical context. The need for considering triple plus one bottom line of social, environmental and economic as well as political factors in decision-making is well understood by road agencies around the world. The techniques used to incorporate these however, are limited. Most countries adopt a scoring method, a goal achievement matrix or information collected from surveys. The greater uncertainty associated with these non-quantitative factors has generally not been taken into consideration. There is a gap between the capacities of the decision-making support systems and the requirements from decision-makers to make more rational and transparent decisions. The challenges faced in developing an integrated decision making framework are both procedural and conceptual. In operational terms, the framework should be easy to be understood and employed. In philosophical terms, the framework should be able to deal with challenging issues, such as uncertainty, time frame, network effects, model changes, while integrating cost and non-cost values into the evaluation. The choice of evaluation techniques depends on the feature of the problem at hand, on the aims of the analysis, and on the underlying information base At different management levels, the complexity in considering social, environmental, economic and political factor in decision-making is different. At higher the strategic planning level, more non-cost factors are involved. The complexity also varies based on the scope of the investment proposals. Road agencies traditionally place less emphasis on evaluation of maintenance works. In some cases, social equity, safety, environmental issues have been used in maintenance project selection. However, there is not a common base for the applications.
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Purpose – The purpose of this paper is to set out to explore the similarities and differences between jargon used to describe future-focussed commercial building product. This is not so much an exercise in semantics as an attempt to demonstrate that responses to challenges facing the construction and property sectors may have more to do with language than is generally appreciated. Design/methodology/approach – This is a conceptual analysis which draws upon relevant literature. Findings – Social responsibility and sustainability are often held to be much the same thing, with each term presupposing the existence of the other. Clearly, however, there are incidences where sustainable commercial property investment (SCPI) may not be particularly socially responsible, despite being understood as an environmentally friendly initiative. By contrast, socially responsible assets, at least in theory, should always be more sustainable than mainstream non-ethically based investment. Put simply, the expression of social responsibility in the built environment may evoke, and thereby deliver, a more sustainable product, as defined by wider socially inclusive parameters. Practical implications – The findings show that promoting an ethic of social responsibility may well result in more SCPI. Thus, the further articulation and celebration of social responsibility concepts may well help to further advance a sustainable property investment agenda, which is arguably more concerned about demonstrability of efficiency than wider public good outcomes. Originality/value – The idea that jargon affects outcomes is not new. However, this idea has rarely, if ever, been applied to the distinctions between social responsibility and sustainability. Even a moderate re-emphasis on social responsibility in preference to sustainability may well provide significant future benefits with respect to the investment, building and refurbishment of commercial property.
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This paper discusses a current research project building new understandings and knowledge relevant to R&D funding strategies in Australia. Building on a retrospective analysis of R&D trends and industry outcomes, an industry roadmap will be developed to inform R&D policies more attuned to future industry needs to improve research investment effectiveness. The project will also include analysis of research team formation and management (involving end users from public and private sectors together with research and knowledge institutions), and dissemination of outcomes and uptake in the Australian building and construction industry. The project will build on previous research extending open innovation system theory and network analysis and procurement, focused on R&D. Through the application of dynamic capabilities and strategic foresighting theory, an industry roadmap for future research investment will be developed, providing a stronger foundation for more targeted policy recommendations. This research will contribute to more effective construction processes in the future through more targeted research funding and more effective research partnerships between industry and researchers.