914 resultados para Hand-held cameras


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El present projecte s'ha dut a terme a l'American Museum of Natural History (AMNH, New York) entre el 31 de Desembre de 2010 i el 30 de Desembre de 2012. L'objectiu del projecte era elucidar la història evolutiva de la mà humana: traçar els canvis evolutius en la seva forma i proporcions que van propiciar la seva estructura moderna que permet als humans manipular amb precisió. El treball realitzat ha inclòs recol•lecció de dades i anàlisis, redacció de resultats i formació en mètodes analítics específics. Durant aquest temps, l'autor a completat la seva de base de dades existent en mesures lineals de la mà a hominoides. També s'han agafat dades del peu; d'aquesta forma ara mateix es compta amb una base de dades amb més de 500 individus, amb més de 200 mesures per cada un. També s'han agafat dades en tres imensions utilitzant un làser escàner. S'han après tècniques de morfometria geomètrica 3D directament dels pioners al camp a l'AMNH. Com a resultat d'aquesta feina s'han produït 10 resums (publicats a congressos internacionals) i 9 manuscrits (molts d'ells ja publicats a revistes internacionals) amb resultats de gran rellevància: La mà humana posseeix unes proporcions relativament primitives, que són més similars a les proporciones que tenien els hominoides fòssils del Miocè que no pas a la dels grans antropomorfs actuals. Els darrers tenen unes mans allargades amb un polzes molt curts que reflexen l'ús de la mà com a eina de suspensió sota les branques. En canvi, els hominoides del Miocè tenien unes mans relativament curtes amb un polze llarg que feien servir per estabilitzar el seu pes quan caminaven per sobre de les branques. Una vegada els primers homínids van aparèixer al final del Miocè (fa uns 6 Ma) i van començar a fer servir el bipedisme com a mitjà més comú de locomoció, les seves mans van ser "alliberades" de les seves funcions locomotores. La selecció natural—ara només treballant en la manipulació—va convertir les proporcions ja existents de la mà d'aquests primats en l'òrgan manipulatori que representa la mà humana avui dia.

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The vision-for-action literature favours the idea that the motor output of an action - whether manual or oculomotor - leads to similar results regarding object handling. Findings on line bisection performance challenge this idea: healthy individuals bisect lines manually to the left of centre, and to the right of centre when using eye fixation. In case that these opposite biases for manual and oculomotor action reflect more universal compensatory mechanisms that cancel each other out to enhance overall accuracy, one would like to observe comparable opposite biases for other material. In the present study, we report on three independent experiments in which we tested line bisection (by hand, by eye fixation) not only for solid lines, but also for letter lines; the latter, when bisected manually, is known to result in a rightward bias. Accordingly, we expected a leftward bias for letter lines when bisected via eye fixation. Analysis of bisection biases provided evidence for this idea: manual bisection was more rightward for letter as compared to solid lines, while bisection by eye fixation was more leftward for letter as compared to solid lines. Support for the eye fixation observation was particularly obvious in two of the three studies, for which comparability between eye and hand action was increasingly adjusted (paper-pencil versus touch screen for manual action). These findings question the assumption that ocular motor and manual output are always inter-changeable, but rather suggest that at least for some situations ocular motor and manual output biases are orthogonal to each other, possibly balancing each other out.

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This article originates from a panel with the above title, held at IEEE VTC Spring 2009, in which the authors took part. The enthusiastic response it received prompted us to discuss for a wider audience whether research at the physical layer (PHY) is still relevant to the field of wireless communications. Using cellular systems as the axis of our exposition, we exemplify areas where PHY research has indeed hit a performance wall and where any improvements are expected to be marginal. We then discuss whether the research directions taken in the past have always been the right choice and how lessons learned could influence future policy decisions. Several of the raised issues are subsequently discussed in greater details, e.g., the growing divergence between academia and industry. With this argumentation at hand, we identify areas that are either under-developed or likely to be of impact in coming years - hence corroborating the relevance and importance of PHY research.

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How can an ex-orphan be adopted? Is it possible to do so by attributing to it a key endogenous ligand that regulates its central functions? In the recent issue of Cell, Chakravarthy et al. attempted to answer this question by characterizing a new physiologically relevant ligand for the ex-orphan receptor peroxisome proliferator activated receptor alpha (PPARalpha).

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Hypertension is a common heritable cardiovascular risk factor. Some rare monogenic forms of hypertension have been described, but the majority of patients suffer from essential hypertension, for whom the underlying genetic mechanisms are not clear. Essential hypertension is a complex trait, involving multiple genes and environmental factors. Recently, progress in the identification of common genetic variants associated with essential hypertension has been made due to large-scale international collaborative projects. In this article we review the new research methods used as well as selected recent findings in this field.

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Social identity is a double-edged sword. On the one hand, identifying with a social group is a prerequisite for the sharing of common norms and values, solidarity, and collective action. On the other hand, in-group identification often goes together with prejudice and discrimination. Today, these two sides of social identification underlie contradictory trends in the way European nations and European nationals relate to immigrants and immigration. Most European countries are becoming increasingly multicultural, and anti-discrimination laws have been adopted throughout the European Union, demonstrating a normative shift towards more social inclusion and tolerance. At the same time, racist and xenophobic attitudes still shape social relations, individual as well as collective behaviour (both informal and institutional), and political positions throughout Europe. The starting point for this chapter is Sanchez-Mazas' (2004) interactionist approach to the study of racism and xenophobia, which in turn builds on Axel Honneth's (1996) philosophical theory of recognition. In this view, the origin of attitudes towards immigrants cannot be located in one or the other group, but in a dynamic of mutual influence. Sanchez-Mazas' approach is used as a general framework into which we integrate social psychological approaches of prejudice and recent empirical findings examining minority-majority relations. We particularly focus on the role of national and European identities as antecedents of anti-immigrant attitudes held by national majorities. Minorities' reactions to denials of recognition are also examined. We conclude by delineating possible social and political responses to prejudice towards immigrants.

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Notre travail de thèse vise à analyser, d'une part, les principales réformes du Parlement fédéral adoptées au cours du 20e siècle et, d'autre part, l'évolution du profil sociographique pour six cohortes d'élus fédéraux (1910, 1937, 1957, 1980, 2000 et 2010), sous l'angle de sa démocratisation et de sa professionnalisation. La thèse comprend trois axes de recherche principaux. Premièrement, nous nous penchons sur les deux réformes institutionnelles censées favoriser la démocratisation du recrutement parlementaire, à savoir l'adoption de la proportionnelle pour l'élection du Conseil national en 1918 et l'introduction du suffrage féminin à l'échelon fédéral en 1971. Nous abordons également les réformes du Parlement visant, depuis les années 1970, à sa revalorisation et à sa professionnalisation. Le deuxième axe porte sur la réalisation d'un portrait collectif des élus fédéraux pour la période 1910-1980, dans le but de vérifier l'impact des réformes des règles électorales (proportionnelle et suffrage féminin) sur le profil des députés et sénateurs. Enfin, dans le troisième axe, nous abordons les transformations du profil socio-professionnel des parlementaires pendant la période plus récente (1980-2010), en lien avec la professionnalisation accrue de l'Assemblée fédérale et les changements des rapports de force partisans. Nos résultats permettent de mettre en évidence plusieurs éléments de continuité (prédominance de la catégories des indépendants, notamment des avocats, des chefs d'entreprise et des agriculteurs, et sous-représentation des salariés du secteur public ; fort ancrage local), ainsi que certains facteurs de rupture (présence accrue des femmes, moindre importance de la carrière militaire). D'autres changements dans le profil sont liés au processus récent de professionnalisation, contesté et inachevé, qui a favorisé néanmoins l'émergence de nouveaux profils sociologiques d'élus, en termes de formation, de profession (apparition du groupe des parlementaires professionnels) et de cumul des mandats économiques et politiques, avec cependant de fortes variations entre les partis et entre les deux Chambres. - Our PhD thesis aims at analysing, on the one hand, the main reforms of the Federal Parliament adopted during the 20th century and, on the other hand, the evolution of sociographical profile for six cohorts of Swiss MPs (1910, 1937, 1957, 1980, 2000 and 2010) in terms of their democratization and professionalization. Our research is composed of three main parts. Firstly, we analyse two institutional reforms which intended to promote the democratization of parliamentary recruitment, namely the adoption of proportional representation (PR) in 1918 for the election of the National Council and the introduction of women's suffrage at the federal level in 1971. We also deal with parliamentary reforms that, since the 1970s, have aimed at reasserting the political status of the Federal Assembly and at professionalizing its members. Secondly, we carry out a collective biography of Swiss MPs during the period 1910-1980, in order to verify the impact of electoral reforms (PR and women's suffrage) on the profiles of deputies and senators. Finally, we discuss the transformation of the MPs' socio-_professional profiles during the recent period (1980-2010) in connection with the increased professionalization of the Federal Assembly and the changes of the power relations within the Parliament. Our results allow us to highlight several elements of continuity (the predominance of self-employed persons, especially lawyers, business managers and farmers, and the underrepresentation of public employees; stronger background in local politics), as well as some factors of discontinuity (increased presence of women and lesser importance of the military career). Other changes of the parliamentarians' profile are related to the recent process of professionalization. Although contested and unfinished, it has promoted new sociological profiles in terms of educational background, profession (growth of the professional parliamentarians) and number of political and economic mandates held simultaneously, however with important variations between parties and between Lower and Upper House.

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Résumé en français La thèse de doctorat porte, de manière générale, sur le rôle des acteurs administratifs dans la mise en oeuvre de l'action publique. En particulier, dans le contexte de l'implémentation de la politique suisse d'assurance-chômage, la recherche se focalise sur l'étude de la bureaucratie de guichet, à savoir un type spécifique d'administrations et d'agents publics situés aux premières lignes de l'action étatique et qui sont en contact direct et quotidien avec les usagers. La thèse a pour objectif principal d'obtenir une compréhension détaillée des impacts concrets dont sont porteurs deux types de réformes majeures du secteur public : les réformes de Nouvelle Gestion Publique (NGP) et les nouvelles technologies informatiques. Le questionnement central de la recherche consiste en une étude approfondie des effets de ces réformes sur les bureaucraties de guichet, et en particulier sur deux aspects centraux les concernant : d'une part, le niveau de pouvoir discrétionnaire que les agents publics de base disposent dans l'application de la loi fédérale sur l'assurance-chômage, autrement dit leur marge de manoeuvre ; d'autre part, les manières au travers desquelles ces mêmes agents sont appelés à rendre des comptes quant à leurs actions et leurs décisions, à savoir l'enjeu plus large de la redevabilité publique des acteurs administratifs. Ces enjeux ont été analysés au niveau empirique dans le contexte organisationnel d'une caisse publique cantonale de chômage ayant expérimenté les réformes évoquées ci-dessus. L'organisation choisie a été investiguée au travers d'une étude de cas ethnographique approfondie (observation directe du travail quotidien des agents, entretiens semi-directifs, analyse de documents) pendant une période de six mois environ entre 2008 et 2009. L'analyse empirique fournit quatre résultats : a) de manière générale, les taxateurs de la caisse de chômage disposent d'un faible niveau de pouvoir discrétionnaire ; b) le degré de pouvoir discrétionnaire varie selon le type de tâche ; c) les agents sur le terrain rendent des comptes auprès d'une multiplicité d'acteurs, sur une variété d'aspects de leur travail et au travers de différents mécanismes de contrôle ; d) les outils de NGP et les nouvelles technologies informatiques ont peu d'impact sur l'étendue du pouvoir discrétionnaire des agents mais contribuent à influencer le type de redevabilité publique pratiquée à ce niveau. Summary in English This PhD dissertation deals with the role of public administration in policy implementation. In the Swiss context of unemployment insurance policy, it focuses on street-level bureaucracy, a specific type of public organisations and agents located at the frontline of public action, that is to say low-level civil servants who are in direct, daily and face-to-face contact with citizens. The dissertation aims at a deep understanding of what are the concrete impacts of two main important changes touching public sector organizations : New Public Management reforms (NPM) and Information and Communication technologies (ICT). The main research question consists in assessing the impacts of those reforms on two central issues regarding street-level bureaucrats : on the one hand, the effective degree of discretion frontline agents do have in implementing the federal law on unemployment insurance ; on the other hand, the ways through which these bureaucrats are held accountable about their action and decisions, i.e. accountability regimes at the street-level. These issues have been empirically addressed in the organisational context of a cantonal Unemployment Insurance Funds having experienced the above mentioned reforms. The organisation has been investigated through an in-depth ethnographic case-study (direct observation of daily work, semi-structured interwiews, documentary analysis) in 2008 and 2009 for approximately six months. The empirical analysis indicates that a) in general, street-level agents do exert low degree of policy discretion; b) the level of discretion is variable from one specific task to another ; c) frontline workers are held accountable to many actors, on various aspects of their work and through different mechanisms of control ; d) NPM and ICT instruments have few impact on the issue of policy discretion but more on the type of street-level accountability which is concretely practised at this level.

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Rural Cape Verdeans employ a number of mutual-help practices to mitigate the uncertainties surrounding activities fundamental to their subsistence. One of these practices is djunta mon (‘to work together’), a loosely planned, non-monetized system of allocating labor at peak intervals during the growing season. By means of djunta mon, neighbors or family members work in each other’s fields until the tasks of every landowning participant are complete. Alongside djunta mon in rural Cape Verde exist a number of other non-remunerated mutual-help practices, such as djuda mutua (‘mutual help’) and laja kaza (‘to add concrete to one’s house’). While less visible than djunta mon, they are nonetheless important in completing tasks essential to rural life in the islands. In this thesis, I will attempt to show how Cape Verdean immigrants in Lisbon have adapted the mutual-help practices of rural Cape Verde to a new, transnational context. The iterations of these practices in Lisbon differ from their rural counterparts in that they involve fewer people, occur on a year-round basis, and are concerned primarily with domestic work. They also help people find employment, access childcare, secure interest-free credit, and construct or repair houses. I will argue that extensive mutual-help ties ensure Cape Verdean migrants in Lisbon a sufficient pool of family and friends upon which they can rely for support and assistance. An additional element I will explore is the perception among Cape Verdean immigrants that these mutual-help practices seem to be occurring with less frequency. While this shift is in part due to the availability of other means of support, I will contend that the changing attitude of Cape Verdeans towards mutual help is also due to their encountering neoliberal notions of ‘self-accountability.’ Thus, Cape Verdeans perceive that their mutual-help practices are in decline, while simultaneously needing the material support that they provide.

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Economics is the science of want and scarcity. We show that want andscarcity, operating within a simple exchange institution (double auction),are sufficient for an economy consisting of multiple inter--related marketsto attain competitive equilibrium (CE). We generalize Gode and Sunder's(1993a, 1993b) single--market finding to multi--market economies, andexplore the role of the scarcity constraint in convergence of economies to CE.When the scarcity constraint is relaxed by allowing arbitrageurs in multiple markets to enter speculative trades, prices still converge to CE,but allocative efficiency of the economy drops. \\Optimization by individual agents, often used to derive competitive equilibria,are unnecessary for an actual economy to approximately attain such equilibria.From the failure of humans to optimize in complex tasks, one need not concludethat the equilibria derived from the competitive model are descriptivelyirrelevant. We show that even in complex economic systems, such equilibriacan be attained under a range of surprisingly weak assumptions about agentbehavior.