955 resultados para Concavifiability of preferences


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Language experience clearly affects the perception of speech, but little is known about whether these differences in perception extend to non-speech sounds. In this study, we investigated rhythmic perception of non-linguistic sounds in speakers of French and German using a grouping task, in which complexity (variability in sounds, presence of pauses) was manipulated. In this task, participants grouped sequences of auditory chimeras formed from musical instruments. These chimeras mimic the complexity of speech without being speech. We found that, while showing the same overall grouping preferences, the German speakers showed stronger biases than the French speakers in grouping complex sequences. Sound variability reduced all participants' biases, resulting in the French group showing no grouping preference for the most variable sequences, though this reduction was attenuated by musical experience. In sum, this study demonstrates that linguistic experience, musical experience, and complexity affect rhythmic grouping of non-linguistic sounds and suggests that experience with acoustic cues in a meaningful context (language or music) is necessary for developing a robust grouping preference that survives acoustic variability.

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Partially ordered preferences generally lead to choices that do not abide by standard expected utility guidelines; often such preferences are revealed by imprecision in probability values. We investigate five criteria for strategy selection in decision trees with imprecision in probabilities: “extensive” Γ-maximin and Γ-maximax, interval dominance, maximality and E-admissibility. We present algorithms that generate strategies for all these criteria; our main contribution is an algorithm for Eadmissibility that runs over admissible strategies rather than over sets of probability distributions.

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Environmental transport of pollutants comprises distinct processes such as volatilization, leaching and surface runoff. Sorption is one of the most important phenomena that affects leaching, and thus the fate of hydrophobic organic pollutants in soils and also control their distribution in the soil/water environment. The work developed focuses the optimization of analytical techniques for monitoring the sorption behaviour of organic pollutants, 17α- ethinylestradiol (EE2) and atrazine, and their fate in aqueous environment. Initially, the development of several analytical techniques, such as micellar electrokinetic chromatography, spectral deconvolution, using UV-Vis and fluorescence spectroscopy, and also enzyme linked immunosorbent assay was performed. Optimization, method performance and recovery tests are described and results discussed. Moreover, in order to evaluate the applicability of the previously optimized method, atrazine and EE2 sorption to soil samples was performed. The work developed provide several options, in terms of methodology to follow sorption of atrazine onto soils, however the choice depends on the laboratory conditions and on the analyst preferences. The advantages and disadvantages of each methodology should be evaluated first. The second part of this work consisted in the sorption behaviour study of those two different hydrophobic organic pollutants onto different soil samples. Soil organic matter chemical characterization, being essential to understand the binding mechanism responsible for the interactions, was made. The results of atrazine binding to organic matter pointed out that carboxyl units and aromaticrich organic matter are the most efficient binding agents for atrazine. EE2 adsorbs strongly to soil organic matter and is mainly stabilized by hydrophobic interactions, through aromatic nuclei face to face with surface and/or another EE2 molecule association. Farmyard manure soil contains higher aromatic and carboxyl units, indicating that this type of manure can be effectively used to minimize the residual toxicity of EE2 and atrazine present in soils, increasing the sorption and reducing leaching onto water resources. Since the final destination of organic pollutants can be ground, surface and/or waste water, atrazine and 17α-ethinylestradiol were quantified in several water samples.

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Os contaminantes provenientes quer de fontes naturais quer como consequência da atividade humana, têm contribuído para a degradação dos ecossistemas aquáticos. Entre estes encontram-se os metais que podem, ou não ser essenciais mediante o papel que desempenham no metabolismo dos organismos. O cobre e o zinco são exemplos de metais essenciais, contudo quando atingem concentrações elevadas podem tornar-se tóxicos. Os detritívoros aquáticos desempenham um papel fundamental na decomposição da matéria orgânica, alimentando-se de carcaças e partes de plantas que caem nos cursos de água. Assim, estes organismos permitem que o ciclo dos nutrientes se complete e servem como elo de ligação entre todos os grupos funcionais do ecossistema mantendo o seu equilíbrio estrutural e funcional. Sendo a matéria orgânica a sua principal fonte de energia estão sujeitos à contaminação existente no meio, pelo que é de todo o interesse proceder-se à avaliação dos efeitos da toxicidade de metais nestes organismos. Uma vez que as diferenças comportamentais consequentes desta exposição podem originar variações na densidade e diversidade, o que se refletirá a nível das comunidades, originando alterações na estrutura e funcionamento do ecossistema. Tendo em vista a avaliação dos efeitos da contaminação por metais em detritívoros, o principal objetivo deste trabalho foi comparar a sensibilidade a metais essenciais de dois detritivoros aquáticos, o camarão Atyaephyra desmarestii e o anfípode Echinogammarus meridionalis. Para tal, avaliaram-se os efeitos do cobre e do zinco a diferentes níveis de organização biológica. Primeiro, foram determinadas as preferências alimentares de A. desmarestii e E. meridionalis considerando tanto a área das folhas como a contaminação por metais das folhas. Em seguida, avaliaram-se os efeitos do cobre e do zinco na sobrevivência e inibição alimentar de ambas as espécies. Finalmente, avaliaram-se os efeitos destes mesmos metais a nível bioquímico utilizando uma bateria de biomarcadores que incluiu enzimas de stresse oxidativo, o sistema de defesa antioxidante e as colinesterases. Ambos os organismos não mostraram preferência em relação a folhas de área diferente. A presença de uma maior ou menor concentração de metais essenciais no alimento não teve qualquer influência na sua escolha pelo alimento (contaminado ou não). Os ensaios agudos de cobre e zinco mostraram que o cobre é mais tóxico para ambas as espécies do que o zinco. O camarão demonstrou ser mais sensível ao zinco que o anfípode, tendo este sido mais sensível ao cobre ( CL50 do cobre para A. desmarestii foi de 0,128 mg.l-1 e o de E. meridionalis foi de 0,050 mg.l-1; os valores correspondentes para o zinco foram 7,951 e 11,860 mg.l-1, respectivamente. Em relação aos efeitos subletais, o cobre teve efeitos notórios na taxa de alimentação de E. meridionalis, mas não afectou a de A. desmarestii. No que diz respeito à exposição ao zinco, ambas as espécies parecem apresentar tendência para inibir a alimentação. A caracterização das colinesterases revelou que a principal forma presente em ambas as espécies é a acetilcolinesterase, a qual que não foi afetada pela presença dos metais, no caso do camarão, mas parece ser inibida pelo zinco no caso do anfípode. O cobre inibiu o sistema de defesa enzimático de ambas as espécies, sem sinais de danos lipídicos. Para além disto, inibiu uma das enzimas antioxidantes (GPx) do anfípode. Apesar de não ter ocorrido dano lipídico após exposição ao cobre, observou-se um ligeiro aumento dos níveis das LPO, o que pode ser indicativo de uma potencial existência de dano oxidativo, como resultado da falha do sistema de defesa antioxidante. Por outro lado, o zinco induziu o sistema de defesa em E. meriodionalis prevenindo o dano lipídico. Enquanto em A. desmarestii o sistema enzimático antioxidante não respondeu, tendo ocorrido dano celular oxidativo considerando-se, assim, que o sistema de defesa antioxidante do camarão pode ser comprometido por exposição a metais. Ainda que os danos celulares oxidativos tivessem ocorrido a baixas concentrações de zinco. A exposição a este metal também induziu a actividade da GST de E. meriodionalis. Considerando que a taxa de alimentação foi severamente reduzida no caso deste organismo, o zinco parece ser o metal cuja concentração no ecossistema requer maior atenção. Integrando as respostas dos biomarcadores parece também evidente que A. desmarestii responde de uma maneira geral a maiores concentrações dos dois metais, enquanto a resposta de E. meridionalis ocorre a concentrações inferiores. Pelo que, E. meridionalis parece ser mais sensível ao nível bioquímico. Neste trabalho, os dois detritívoros, com ligeiras diferenças no modo como utilizam a matéria orgânica disponível, apresentam diferenças na sensibilidade aos metais essenciais a vários níveis de organização biológica, sendo o zinco o metal que poderá causar maior preocupação a nível bioquímico, enquanto o cobre parece ser o mais tóxico ao nível do organismo, causando mortalidade a concentrações mais baixas.

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Durante o último século, as populações de cervídeos têm aumentado substancialmente um pouco por toda a Europa. O veado Cervus elaphus não foi exceção, apresentando atualmente uma ampla distribuição geográfica. Após a quase extinção de todas as populações selvagens desta espécie em Portugal, o número de efetivos de veado e a área de distribuição da espécie têm aumentado significativamente nas últimas décadas. Esta proliferação deveu-se fundamentalmente aos processos de reintrodução implementados em algumas zonas do país, como foi o caso da Serra da Lousã. Dez anos após a reintrodução, a expansão geográfica e demográfica é já uma realidade e a espécie assume um papel relevante tanto do ponto de vista cinegético como turístico. Com o aumento das populações de ungulados, surge a necessidade de aumentar o conhecimento existente sobre estas espécies, particularmente ao nível das estimativas populacionais, do uso e seleção de habitat, do comportamento e da fisiologia das populações. Neste sentido, um dos objetivos foi comparar quatro métodos de contagem de excrementos em termos de estimativa populacional, aplicabilidade e eficiência. Face aos resultados obtidos, o método de transectos lineares com distance sampling revelou-se o mais eficiente, providenciando uma boa precisão num menor tempo. Relativamente ao uso e seleção do habitat, recorrendo a transectos de contagem de excrementos e a observações diretas, verificou-se que o veado seleciona positivamente habitats que lhe proporcionam simultaneamente alimento e refúgio, como é o caso das áreas de ecótono. A preferência por áreas de ecótono evidencia um comportamento adaptativo de maximização de energia, no qual os animais optam por procurar refúgio na proximidade das áreas de alimentação de forma a minimizarem os dispêndios energéticos. Em termos de dinâmica populacional, verificou-se uma relação entre a densidade de veado e o tamanho dos seus grupos, bem como o efeito nos mesmos do coberto vegetal. Contudo, dado o seu alto dimorfismo sexual em termos de tamanho corporal, as preferências de habitat podem também ser em parte responsáveis pela segregação sexual fora da época de reprodução. Face aos resultados obtidos através do método de observação direta de animais, a segregação sexual surge como consequência da interação entre fatores sociais e de habitat, que resultam de diferentes estratégias reprodutivas por parte de ambos os sexos. As diferentes estratégias reprodutivas são também notórias em termos de condição física e imunológica, com os machos a aumentarem a sua condição durante as épocas de primavera e verão de forma a melhorarem a sua performance durante o cio, e as fêmeas a viverem grande parte do ano no limiar da condição física devido ao seu investimento na sobrevivência da sua descendência. Globalmente, o veado apresenta uma boa adaptação à Serra da Lousã e representa um importante recurso natural para esta região. Contudo, para que a proliferação desta população selvagem continue, é necessária a implementação de medidas de gestão adequadas a este ecossistema mediterrâneo.

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Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

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This interdisciplinary study examines the contribution that a book-review magazine makes to the cultural identity of its readers. It is the result of reflections on the cultural work of Books in Canada , on whether or not this periodical was a cultural worksite and if that is the case how it performed that cultural work. In addition, it interrogates factors that may have contributed to the magazine's demise. The study affirms that Books in Canada, a cultural enterprise from 1971 to 2008, mirrored and helped to shape book and literary culture in Canada through its circulation, through the personalities of its editors, through its front covers and through its reviewers and their reviews. Furthermore, it proposes that the demise of the enterprise was due to a combination of factors. The study begins with an introduction to book reviewing and special-interest magazines. Chapter I examines the interplay between selected visual and textual contents published in Books in Canada in its founding years. These components reflected and helped to fuel the cultural nationalism that was sweeping Canada subsequent to the 1967 World's Fair in Montreal. There were also persistent rumours and comments about the magazine that caused certain"cracks in the foundation" to appear. Chapter II compares the aims and editorial challenges of Val Clery, founder of Books in Canada , with those of Adrien Thério, founder of Lettres québécoises, and of the editors of the magazines' twentieth-anniversary issues, Paul Stuewe in the case of the former and André Vanasse in the case of the latter. Evidence in the content of the magazine, editorial and otherwise, indicated that the"contracts" that the editors made with their readers over the years were similar, to reflect and shape a cultural identity, but the result of their"projects," that is, the nature of those identities, was distinctly different. Evidently then, personal aims, preferences and political leanings of editors can have a major impact on the content of a book-review magazine and thus on the cultural work that it does. Therefore, in Chapter III, I focus on selected contents published during the tenures of two of Books in Canada 's key editors, Paul Stuewe and Olga Stein, in order to understand ways that their choices constituted a form of cultural work. The second part of this chapter moves from an analysis of the cultural work of editors to an examination of the cultural work of reviewers. Here, through a close-reading of a selection of reviews published in Books in Canada, and in other periodicals, I argue that reviewers do cultural work in the way that they negotiate their presence in a review, and in how they signal that presence through lexical choices and through the degree of intellectual interaction that they invite. Intellectual interaction is at the core of Chapter IV.This chapter consists of close readings of some of the"billboards" of the enterprise, that is, the front covers of Books in Canada , in order to show how these important components do cultural work by requiring readers to make an intellectual leap from image to text. Chapter V suggests that book reviews, the company's"bills of goods," do cultural work in much the same way as the paratexts of a book. One of my own reviews is offered as a case-study along with a number of other reviews of how central components of a book-review magazine do cultural work through the illocutionary force of their sentences. The first part of Chapter VI, the final chapter, measures the legacy of the magazine, in particular, the annual Books in Canada First Novel Award. Created in 1976, this prize is awarded to the author of the novel judged by a Books in Canada prize committee to be the best first novel in English of the year. The second part of Chapter VI sheds light on factors that may have contributed to the closure of the enterprise, including the copyright uproar that accompanied the agreement that Adrian Stein, publisher of Books in Canada and Olga Stein's husband, made in 2001 with the online book merchant, Amazon.com. Furthermore, this penultimate section of the study suggests that one of the most important factors in the magazine's demise was the decision by the Steins to exploit their position as owners, publisher, and editor of a book-review periodical, a government-subsidized one at that, to publish their own lengthy pre-trial defense of Conrad Black. The chapter then zooms back from the particular to the general with a broader consideration of the impact of technology and globalization on the book industry and on the ability of Books in Canada to survive in any form, print or digital.

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Marine protected areas (MPAs) have been widely proposed for conservation purposes and as a tool for fisheries management. The Arrábida Marine Park is the first MPA in continental Portugal having a management plan, fully implemented since 2009. The main objective of this study was to evaluate the effect of protection measures on rocky reef fish assemblages and target invertebrates through before-after and control-effect (no-take vs. fished areas) underwater visual surveys and analysis of landings trends. Second, we used surveys before, during and after implementation of the management plan to understand fishers‟ preferences for fishing grounds and adaptation to the new rules, and evaluated the reserve effect through analysis of both ecological responses and fishing effort density. Third, we identified the main oceanographic drivers influencing the structure of reef fish assemblages and predicted the community structure for the last 50 years, in light of climatic change. Overall results suggest positive responses in biomass but not yet in numbers of some commercial species, with no effects on non-target species. The reserve effect is reinforced by the increase in landings of commercial species, despite increased fishing effort density in some areas, especially with octopus traps. Fishing grounds are mainly chosen based on the distribution of target species and associated habitats, but distance to port, weather conditions and safety also influence fishers‟ choices. Moreover, different fisheries respond differently to the protection measures, and within each fishery, individual fishers show distinct strategies, with some operating in a broader area whereas others keep preferred territories. Our results also show that wind stress and temperature are the main oceanographic drivers for rocky reef fish assemblages, with tropicalization of assemblages and polewards movements of species over the last 50 years consistent with temperature trends. We believe this study provides significant lessons for marine conservation and management of coastal systems.

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We extend Cass and Stiglitz’s analysis of preference-based mutual fund separation. We show that high degrees of fund separation can be constructed by adding inverse marginal utility functions exhibiting lower degrees of separation. However, this method does not allow us to find all utility functions satisfying fund separation. In general, we do not know how to write the primal utility functions in these models in closed form, but we can do so in the special case of SAHARA utility defined by Chen et al. and for a new class of GOBI preferences introduced here. We show that there is money separation (in which the riskless asset can be one of the funds) if and only if there is a fund (which may not be the riskless asset) with a constant allocation as wealth changes.

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Tese de doutoramento, Biologia (Biologia Evolutiva), Universidade de Lisboa, Faculdade de Ciências, 2014

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This is the first in a short series that presents case study examples of the positive work achieved by trusts who participated in the Royal College of Nursing's development programme to improve dementia care in acute hospitals. When a person with dementia is in hospital, poor understanding of individual needs and preferences can contribute to a lack of person-centred care. Similarly, the needs of family carers can often be overlooked and staff do not always appreciate these needs at such a stressful time. This article illustrates how three NHS trusts have addressed these issues. To help staff get to know patients with dementia, Salford Royal NHS Foundation Trust has implemented a patient passport. Similarly, The Shrewsbury and Telford Hospital NHS Trust has implemented a carer passport that overcomes the restrictions imposed by hospital visiting hours. Royal Devon and Exeter NHS Foundation Trust also focused on carers, holding a workshop to elicit feedback on what was important to them. This was a useful means of engaging with carers and helped staff to realise that even simple changes can have a significant effect.

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This study examined the body weight and waist-to-hip ratio (WHR) preferences of “fat admirers” (FAs), that is, individuals who are sexually attracted to heavier partners. Fifty-six heterosexual men involved in the FA community rated a series of line drawings that varied in three levels of body weight and six of WHR for physical attractiveness and health. The results showed significant main effects of body weight and WHR, as well as a significant body weight × WHR interaction for both health ratings. In general, there was a preference for heavyweight figures and high WHRs for ratings of attractiveness and normal-weight figures and mid-ranging WHRs for ratings of health. Limitations of the study and explanations for fat admiration are discussed.

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Thesis (Master's)--University of Washington, 2016-03

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It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low) rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men’s attractiveness ratings based on women’s breast size.

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This paper presents a Multi-Agent Market simulator designed for analyzing agent market strategies based on a complete understanding of buyer and seller behaviors, preference models and pricing algorithms, considering user risk preferences and game theory for scenario analysis. The system includes agents that are capable of improving their performance with their own experience, by adapting to the market conditions, and capable of considering other agents reactions.