920 resultados para commitment towards the supervisor
Resumo:
The alpha1b-adrenergic receptor (AR) is a member of the large superfamily of seven transmembrane domain (TMD) G protein-coupled receptors (GPCR). Combining site-directed mutagenesis of the alpha1b-AR with computational simulations of receptor dynamics, we have explored the conformational changes underlying the process of receptor activation, i.e. the transition between the inactive and active states. Our findings suggest that the structural constraint stabilizing the alpha1b-AR in the inactive form is a network of H-bonding interactions amongst conserved residues forming a polar pocket and R143 of the DRY sequence at the end of TMDIII. We have recently reported that point mutations of D142, of the DRY sequence and of A293 in the distal portion of the third intracellular loop resulted in ligand-independent (constitutive) activation of the alpha1b-AR. These constitutively activating mutations could induce perturbations resulting in the shift of R143 out of the polar pocket. The main role of R143 may be to mediate receptor activation by triggering the exposure of several basic amino acids of the intracellular loops towards the G protein. Our investigation has been extended also to the biochemical events involved in the desensitization process of alpha1b-AR. Our results indicate that immediately following agonist-induced activation, the alpha1b-AR can undergo rapid agonist-induced phosphorylation and desensitization. Different members of the G protein coupled receptor kinase family can play a role in agonist-induced regulation of the alpha1b-AR. In addition, constitutively active alpha1b-AR mutants display different phosphorylation and internalization features. The future goal is to further elucidate the molecular mechanism underlying the complex equilibrium between activation and inactivation of the alpha1b-AR and its regulation by pharmacological substances. These findings can help to elucidate the mechanism of action of various agents displaying properties of agonists or inverse agonists at the adrenergic system.
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The strategy for the control of schistosomiasis has shifted from one directed towards the interruption of transmission to one of reducing morbidity. As a consequence of this change, it appears prudent to reassess the role of the malacologist and malacology and identify the future direction to be taken by the discipline. The present paper addresses these concerns; first, by reviewing the role of the snail-hosts in the epidemiology and control of schistosomiasis, and, secondly, by suggesting areas for future study. The possible application of newer methods in biotechnology for the resolution of malacological problems are discussed.
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New G-banded karyotypes from populations of the common shrew Sorex araneus Linnaeus, 1758 provide a clearer picture of the distribution of chromosome races in central Europe. As expected according to their occurrence in neighbouring countries, the Jutland (kq, no), Laska (k/o) and Drnholec (ko, nr) races are also found in Germany. A new chromosome race "Rugen" (kq) is described from this Baltic Island. Together with the previously recorded races Ulm and Mooswald (kr), six chromosome races are now known from Germany. The resulting distribution pattern is characterized by high frequencies of different race-specific metacentrics at the periphery of the country and clines with decreasing frequencies towards the centre which is occupied by the Ulm race. This race is acrocentric for all chromosome arms involved in the observed race-specific fusions and represents a buffer between the surrounding, more metacentric races. According to the present distribution of these metacentrics, a scenario for the postglacial recolonization of central Europe by S. araneus populations on three different routes is proposed: from the east along the northern slopes of the Carpathian Arc, from the south-east along the Danube Valley and from the south-west through the Upper Rhine Valley.
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This article presents and explores the axioms and core ideas, or idées-force, of the Fascist ideologies of the first third of the twentieth century. The aim is to identify the features that define the term “Classical Fascism” as a conceptual category in the study of politics and to uncover the core ideas of its political theory. This analysis requires an appraisal of both the idées-force themselves and the political use that is made of them. If these appreciations are correct, Classical Fascism is characterized by a set of ideological and political aims and methods in which ideas, attitudes and behaviours are determined by an anti-democratic palingenetic ultranationalism underpinned by a sacralized ideology; the quest for a united, indissoluble society as apolitical system and, at the same time, the collective myth that mobilizes and redeems the nation; and third, violence as a political vehicle applied unchecked against internal opposition and against external enemies who challenge the nation´s progression towards the dream of rebirth and the culmination of this progression in the form of an empire.
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In previous work we have applied the environmental multi-region input-output (MRIO) method proposed by Turner et al (2007) to examine the ‘CO2 trade balance’ between Scotland and the Rest of the UK. In McGregor et al (2008) we construct an interregional economy-environment input-output (IO) and social accounting matrix (SAM) framework that allows us to investigate methods of attributing responsibility for pollution generation in the UK at the regional level. This facilitates analysis of the nature and significance of environmental spillovers and the existence of an environmental ‘trade balance’ between regions. While the existence of significant data problems mean that the quantitative results of this study should be regarded as provisional, we argue that the use of such a framework allows us to begin to consider questions such as the extent to which a devolved authority like the Scottish Parliament can and should be responsible for contributing to national targets for reductions in emissions levels (e.g. the UK commitment to the Kyoto Protocol) when it is limited in the way it can control emissions, particularly with respect to changes in demand elsewhere in the UK. However, while such analysis is useful in terms of accounting for pollution flows in the single time period that the accounts relate to, it is limited when the focus is on modelling the impacts of any marginal change in activity. This is because a conventional demand-driven IO model assumes an entirely passive supply-side in the economy (i.e. all supply is infinitely elastic) and is further restricted by the assumption of universal Leontief (fixed proportions) technology implied by the use of the A and multiplier matrices. In this paper we argue that where analysis of marginal changes in activity is required, a more flexible interregional computable general equilibrium approach that models behavioural relationships in a more realistic and theory-consistent manner, is more appropriate and informative. To illustrate our analysis, we compare the results of introducing a positive demand stimulus in the UK economy using both IO and CGE interregional models of Scotland and the rest of the UK. In the case of the latter, we demonstrate how more theory consistent modelling of both demand and supply side behaviour at the regional and national levels affect model results, including the impact on the interregional CO2 ‘trade balance’.
Resumo:
The geodynamic forces acting in the Earth's interior manifest themselves in a variety of ways. Volcanoes are amongst the most impressive examples in this respect, but like with an iceberg, they only represent the tip of a more extensive system hidden underground. This system consists of a source region where melt forms and accumulates, feeder connections in which magma is transported towards the surface, and different reservoirs where it is stored before it eventually erupts to form a volcano. A magma represents a mixture of melt and crystals. The latter can be extracted from the source region, or form anywhere along the path towards their final crystallization place. They will retain information of the overall plumbing system. The host rocks of an intrusion, in contrast, provide information at the emplacement level. They record the effects of thermal and mechanical forces imposed by the magma. For a better understanding of the system, both parts - magmatic and metamorphic petrology - have to be integrated. I will demonstrate in my thesis that information from both is complementary. It is an iterative process, using constraints from one field to better constrain the other. Reading the history of the host rocks is not always straightforward. This is shown in chapter two, where a model for the formation of clustered garnets observed in the contact aureole is proposed. Fragments of garnets, older than the intrusive rocks are overgrown by garnet crystallizing due to the reheating during emplacement of the adjacent pluton. The formation of the clusters is therefore not a single event as generally assumed but the result of a two-stage process, namely the alteration of the old grains and the overgrowth and amalgamation of new garnet rims. This makes an important difference when applying petrological methods such as thermobarometry, geochronology or grain size distributions. The thermal conditions in the aureole are a strong function of the emplacement style of the pluton. therefore it is necessary to understand the pluton before drawing conclusions about its aureole. A study investigating the intrusive rocks by means of field, geochemical, geochronologi- cal and structural methods is presented in chapter three. This provided important information about the assembly of the intrusion, but also new insights on the nature of large, homogeneous plutons and the structure of the plumbing system in general. The incremental nature of the emplacement of the Western Adamello tonalité is documented, and the existence of an intermediate reservoir beneath homogeneous plutons is proposed. In chapter four it is demonstrated that information extracted from the host rock provides further constraints on the emplacement process of the intrusion. The temperatures obtain by combining field observations with phase petrology modeling are used together with thermal models to constrain the magmatic activity in the immediate intrusion. Instead of using the thermal models to control the petrology result, the inverse is done. The model parameters were changed until a match with the aureole temperatures was obtained. It is shown, that only a few combinations give a positive match and that temperature estimates from the aureole can constrain the frequency of ancient magmatic systems. In the fifth chapter, the Anisotropy of Magnetic Susceptibility of intrusive rocks is compared to 3D tomography. The obtained signal is a function of the shape and distribution of ferromagnetic grains, and is often used to infer flow directions of magma. It turns out that the signal is dominated by the shape of the magnetic crystals, and where they form tight clusters, also by their distribution. This is in good agreement with the predictions made in the theoretical and experimental literature. In the sixth chapter arguments for partial melting of host rock carbonates are presented. While at first very surprising, this is to be expected when considering the prior results from the intrusive study and experiments from the literature. Partial melting is documented by compelling microstructures, geochemical and structural data. The necessary conditions are far from extreme and this process might be more frequent than previously thought. The carbonate melt is highly mobile and can move along grain boundaries, infiltrating other rocks and ultimately alter the existing mineral assemblage. Finally, a mineralogical curiosity is presented in chapter seven. The mineral assemblage magne§site and calcite is in apparent equilibrium. It is well known that these two carbonates are not stable together in the system Ca0-Mg0-Fe0-C02. Indeed, magnesite and calcite should react to dolomite during metamorphism. The presented explanation for this '"forbidden" assemblage is, that a calcite melt infiltrated the magnesite bearing rock along grain boundaries and caused the peculiar microstructure. This is supported by isotopie disequilibrium between calcite and magnesite. A further implication of partially molten carbonates is, that the host rock drastically looses its strength so that its physical properties may be comparable to the ones of the intrusive rocks. This contrasting behavior of the host rock may ease the emplacement of the intrusion. We see that the circle closes and the iterative process of better constraining the emplacement could start again. - La Terre est en perpétuel mouvement et les forces tectoniques associées à ces mouvements se manifestent sous différentes formes. Les volcans en sont l'un des exemples les plus impressionnants, mais comme les icebergs, les laves émises en surfaces ne représentent que la pointe d'un vaste système caché dans les profondeurs. Ce système est constitué d'une région source, région où la roche source fond et produit le magma ; ce magma peut s'accumuler dans cette région source ou être transporté à travers différents conduits dans des réservoirs où le magma est stocké. Ce magma peut cristalliser in situ et produire des roches plutoniques ou alors être émis en surface. Un magma représente un mélange entre un liquide et des cristaux. Ces cristaux peuvent être extraits de la source ou se former tout au long du chemin jusqu'à l'endroit final de cristallisation. L'étude de ces cristaux peut ainsi donner des informations sur l'ensemble du système magmatique. Au contraire, les roches encaissantes fournissent des informations sur le niveau d'emplacement de l'intrusion. En effet ces roches enregistrent les effets thermiques et mécaniques imposés par le magma. Pour une meilleure compréhension du système, les deux parties, magmatique et métamorphique, doivent être intégrées. Cette thèse a pour but de montrer que les informations issues de l'étude des roches magmatiques et des roches encaissantes sont complémentaires. C'est un processus itératif qui utilise les contraintes d'un domaine pour améliorer la compréhension de l'autre. Comprendre l'histoire des roches encaissantes n'est pas toujours aisé. Ceci est démontré dans le chapitre deux, où un modèle de formation des grenats observés sous forme d'agrégats dans l'auréole de contact est proposé. Des fragments de grenats plus vieux que les roches intru- sives montrent une zone de surcroissance générée par l'apport thermique produit par la mise en place du pluton adjacent. La formation des agrégats de grenats n'est donc pas le résultat d'un seul événement, comme on le décrit habituellement, mais d'un processus en deux phases, soit l'altération de vieux grains engendrant une fracturation de ces grenats, puis la formation de zone de surcroissance autour de ces différents fragments expliquant la texture en agrégats observée. Cette interprétation en deux phases est importante, car elle engendre des différences notables lorsque l'on applique des méthodes pétrologiques comme la thermobarométrie, la géochronologie ou encore lorsque l'on étudie la distribution relative de la taille des grains. Les conditions thermales dans l'auréole de contact dépendent fortement du mode d'emplacement de l'intrusion et c'est pourquoi il est nécessaire de d'abord comprendre le pluton avant de faire des conclusions sur son auréole de contact. Une étude de terrain des roches intrusives ainsi qu'une étude géochimique, géochronologique et structurale est présente dans le troisième chapitre. Cette étude apporte des informations importantes sur la formation de l'intrusion mais également de nouvelles connaissances sur la nature de grands plutons homogènes et la structure de système magmatique en général. L'emplacement incrémental est mis en évidence et l'existence d'un réservoir intermédiaire en-dessous des plutons homogènes est proposé. Le quatrième chapitre de cette thèse illustre comment utiliser l'information extraite des roches encaissantes pour expliquer la mise en place de l'intrusion. Les températures obtenues par la combinaison des observations de terrain et l'assemblage métamorphique sont utilisées avec des modèles thermiques pour contraindre l'activité magmatique au contact directe de cette auréole. Au lieu d'utiliser le modèle thermique pour vérifier le résultat pétrologique, une approche inverse a été choisie. Les paramètres du modèle ont été changés jusqu'à ce qu'on obtienne une correspondance avec les températures observées dans l'auréole de contact. Ceci montre qu'il y a peu de combinaison qui peuvent expliquer les températures et qu'on peut contraindre la fréquence de l'activité magmatique d'un ancien système magmatique de cette manière. Dans le cinquième chapitre, les processus contrôlant l'anisotropie de la susceptibilité magnétique des roches intrusives sont expliqués à l'aide d'images de la distribution des minéraux dans les roches obtenues par tomographie 3D. Le signal associé à l'anisotropie de la susceptibilité magnétique est une fonction de la forme et de la distribution des grains ferromagnétiques. Ce signal est fréquemment utilisé pour déterminer la direction de mouvement d'un magma. En accord avec d'autres études de la littérature, les résultats montrent que le signal est dominé par la forme des cristaux magnétiques, ainsi que par la distribution des agglomérats de ces minéraux dans la roche. Dans le sixième chapitre, une étude associée à la fusion partielle de carbonates dans les roches encaissantes est présentée. Si la présence de liquides carbonatés dans les auréoles de contact a été proposée sur la base d'expériences de laboratoire, notre étude démontre clairement leur existence dans la nature. La fusion partielle est documentée par des microstructures caractéristiques pour la présence de liquides ainsi que par des données géochimiques et structurales. Les conditions nécessaires sont loin d'être extrêmes et ce processus pourrait être plus fréquent qu'attendu. Les liquides carbonatés sont très mobiles et peuvent circuler le long des limites de grain avant d'infiltrer d'autres roches en produisant une modification de leurs assemblages minéralogiques. Finalement, une curiosité minéralogique est présentée dans le chapitre sept. L'assemblage de minéraux de magnésite et de calcite en équilibre apparent est observé. Il est bien connu que ces deux carbonates ne sont pas stables ensemble dans le système CaO-MgO-FeO-CO.,. En effet, la magnésite et la calcite devraient réagir et produire de la dolomite pendant le métamorphisme. L'explication présentée pour cet assemblage à priori « interdit » est que un liquide carbonaté provenant des roches adjacentes infiltre cette roche et est responsable pour cette microstructure. Une autre implication associée à la présence de carbonates fondus est que la roche encaissante montre une diminution drastique de sa résistance et que les propriétés physiques de cette roche deviennent comparables à celles de la roche intrusive. Cette modification des propriétés rhéologiques des roches encaissantes peut faciliter la mise en place des roches intrusives. Ces différentes études démontrent bien le processus itératif utilisé et l'intérêt d'étudier aussi bien les roches intrusives que les roches encaissantes pour la compréhension des mécanismes de mise en place des magmas au sein de la croûte terrestre.
Resumo:
Report for the scientific sojourn carried out at the Uppsala Universitet, Sweden, from April to July the 2007. Two series of analogue models are used to explore ductile-frictional contrasts of the basal décollement in the development of oblique and transverse structures simultaneously to thin-skinned shortening. These models simulate the evolution of the Central External Sierras (Southern Pyrenees, Spain), which constitute the frontal emerging part of the southernmost Pyrenean thrust sheet. They are characterized by the presence of transverse N-S to NW-SE anticlines, which are perpendicular to the Pyrenean structural trend and developed in the hangingwall of the Santo Domingo thrust system, detaching on an unevenly distributed Triassic materials (evaporitic-dolomitic interfingerings). Model setup performs a décollement made by three patches of silicone neighbouring pure brittle sand. Model series A test the thickness ratio between overburden and décollement. Model series B test the width of frictional detachment areas. Model results show how deformation reaches further in areas detached on ductile layer whereas frictional décollement areas assimilate the strain by means of an additional uplift. This replicates the structural style of Central External Sierras: higher structural relief of N-S anticlines with regard to orogen-parallel structures, absence of a representative ductile décollement in the core, tilting towards the orogen and foreland-side closure not thrusted by the frontal emerging South-Pyrenean thrust.
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Industrial clustering policy is now an integral part of economic development planning in most advanced economies. However, there have been concerns in some quarters over the ability of an industrial cluster-based development strategy to deliver its promised economic benefits and this has been increasingly been blamed on the failure by governments to identify industrial clusters. In a study published in 2001, the DTI identified clusters across the UK based on the comparative scale and significance of industrial sectors. The study identified thirteen industrial clusters in Scotland. However the clusters identified are not a homogeneous set and they seem to vary in terms of their geographic concentration within Scotland. This paper examines the spatial distribution of industries within Scotland, thereby identifying more localised clusters. The study follows as closely as possible the DTI methodology which was used to identify such concentrations of economic activity with particular attention directed towards the thirteen clusters identified by the DTI. The paper concludes with some remarks of the general problem of identifying the existence of industrial clusters.
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The stylized facts suggest a negative relationship between tax progressivity and the skill premium from the early 1960s until the early 1990s, and a positive one thereafter. They also generally imply rising tax progressivity, except for the 1980s. In this paper, we ask whether optimal tax policy is consistent with these observations, taking into account the demographic and technological factors that have also affected the skill premium. To this end, we construct a dynamic general equilibrium model in which the skill premium and the progressivity of the tax system are endogenously determined, with the latter being optimally chosen by a benevolent government. We find that optimal policy delivers both a progressive tax system and model predictions which are generally consistent, except for the 1980s, with the stylized facts relating to the skill premium and progressivity. To capture the patterns in the data over the 1980s requires that we adopt a government policy which is biased towards the interests of skilled agents. Thus, in addition to demographic and technological factors, changes in the preferences of policy-makers appear to be a potentially important factor in determining the evolution of the observed skill premium.
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Workers performing preparation and administration of radiopharmaceuticals in NM departments are likely to receive high local skin doses to the hands which may even surpass the dose limit of 500 mSv whenever radiation protection standards are insufficient. A large measurement campaign was organised within the framework of the ORAMED project to determine the dose distribution across the hands received during preparation and administration of 18F- and 99mTc-labelled radiopharmaceuticals. The final data, collected over almost 3 years, include 641 measurements from 96 workers in 30 NM departments from 6 European countries. Results have provided levels of reference doses for the considered standard NM diagnostic procedures (mean maximum normalised skin dose of 230 μSv/GBq, 430 μSv/GBq, 930 μSv/GBq and 1200 μSv/GBq for the administration of 99mTc, preparation of 99mTc, administration of 18F and preparation of 18F, respectively). Finger dose was analysed as a function of the potential parameters of influence showing that shielding is the most efficient means of radiation protection to reduce skin dose. An appropriate method for routine monitoring of the extremities is also proposed: the base of the index finger of the non-dominant hand is a suitable position to place the ring dosemeter, with its sensitive part oriented towards the palm side; its reading may be multiplied by a factor of 6 to estimate the maximum local skin dose. Finally, results were compared to earlier published data, which correspond mostly to individual works with a reduced number of workers and measurements.
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There has been much debate regarding the electoral strategy adopted by New Labour in the lead-up to and then during their time in government. This paper addresses the issue from the perspective of left/right and libertarian/authoritarian considerations by examining data on individual attitudes from the British Social Attitudes survey between 1986 and 2009. The analysis indicates that New Labour’s move towards the right on economic and public policy was the main driver towards attracting new centrist voters and could thus be labelled ‘broadly’ populist. The move towards a tougher stance on law and order was more ‘narrowly’ populist in that it was used more to minimise the reduction in support from Labour’s traditional base on the left than to attract new votes.
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We study the impact of organized crime on electoral competition. Assuming that the mafia is able to bring votes to the supported party in exchange of money, we show that (i) the strongest party is willing to pay the highest price to secure mafia services; (ii) the volume of electoral trade with the mafia increases with political competition and with the efficiency of the mafia. Studying in detail parliamentary elections in Sicily for the period 1946- 1992, we document the significant support given by the Sicilian Mafia to the Christian Democratic party, starting at least from the 1970s. This is consistent with our theoretical predictions, as political competition became much tighter during the 1970s and the Sicilian mafia experienced an extensive centralization process towards the end of the 1960s, which increased substantially its control of the territory. We also provide evidence that in exchange for its electoral support the mafia got economic advantages for its activities in the construction industry.
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We estimate a New Keynesian DSGE model for the Euro area under alternative descriptions of monetary policy (discretion, commitment or a simple rule) after allowing for Markov switching in policy maker preferences and shock volatilities. This reveals that there have been several changes in Euro area policy making, with a strengthening of the anti-inflation stance in the early years of the ERM, which was then lost around the time of German reunification and only recovered following the turnoil in the ERM in 1992. The ECB does not appear to have been as conservative as aggregate Euro-area policy was under Bundesbank leadership, and its response to the financial crisis has been muted. The estimates also suggest that the most appropriate description of policy is that of discretion, with no evidence of commitment in the Euro-area. As a result although both ‘good luck’ and ‘good policy’ played a role in the moderation of inflation and output volatility in the Euro-area, the welfare gains would have been substantially higher had policy makers been able to commit. We consider a range of delegation schemes as devices to improve upon the discretionary outcome, and conclude that price level targeting would have achieved welfare levels close to those attained under commitment, even after accounting for the existence of the Zero Lower Bound on nominal interest rates.
Resumo:
We estimate a New Keynesian DSGE model for the Euro area under alternative descriptions of monetary policy (discretion, commitment or a simple rule) after allowing for Markov switching in policy maker preferences and shock volatilities. This reveals that there have been several changes in Euro area policy making, with a strengthening of the anti-inflation stance in the early years of the ERM, which was then lost around the time of German reunification and only recovered following the turnoil in the ERM in 1992. The ECB does not appear to have been as conservative as aggregate Euro-area policy was under Bundesbank leadership, and its response to the financial crisis has been muted. The estimates also suggest that the most appropriate description of policy is that of discretion, with no evidence of commitment in the Euro-area. As a result although both ‘good luck’ and ‘good policy’ played a role in the moderation of inflation and output volatility in the Euro-area, the welfare gains would have been substantially higher had policy makers been able to commit. We consider a range of delegation schemes as devices to improve upon the discretionary outcome, and conclude that price level targeting would have achieved welfare levels close to those attained under commitment, even after accounting for the existence of the Zero Lower Bound on nominal interest rates.
Resumo:
We propose a new theory of the demographic transition based on the evidence that body development during childhood is an important predictor of adult life expectancy. This theory is embodied in an OLG framework where fertility, longevity and education all result from individual decisions. The model displays different regimes, allowing the economy to move slowly from an initial Malthusian regime towards the Modern era. The dynamics reproduces the key features of the demographic transition, including the permanent increase in life expectancy, resulting from improvements in body development, the hump in both population growth and fertility, and a late increase in secondary educational attainments.