987 resultados para common pool resource


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Obesity and depression represent a growing health concern worldwide. For many years, basic science and medicine have considered obesity as a metabolic illness, while depression was classified a psychiatric disorder. Despite accumulating evidence suggesting that obesity and depression may share commonalities, the causal link between eating and mood disorders remains to be fully understood. This etiology is highly complex, consisting of multiple environmental and genetic risk factors that interact with each other. In this review, we sought to summarize the preclinical and clinical evidence supporting a common etiology for eating and mood disorders, with a particular emphasis on signaling pathways involved in the maintenance of energy balance and mood stability, among which orexigenic and anorexigenic neuropeptides, metabolic factors, stress responsive hormones, cytokines, and neurotrophic factors.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

NR2E3, a photoreceptor-specific nuclear receptor (PNR), represses cone-specific genes and activates several rod-specific genes. In humans, mutations in NR2E3 have been associated with the recessively-inherited enhanced short-wavelength sensitive S-cone syndrome (ESCS) and, recently, with autosomal dominant (ad) retinitis pigmentosa (RP) (adRP). In the present work, we describe two additional families affected by adRP that carry a heterozygous c.166G>A (p.G56R) mutation in the NR2E3 gene. Functional analysis determined the dominant negative activity of the p.G56R mutant protein as the molecular mechanism of adRP. Interestingly, in one pedigree, the most common causal variant for ESCS (p.R311Q) cosegregated with the adRP-linked p.G56R mutation, and the compound heterozygotes exhibited an ESCS-like phenotype, which in 1 of the 2 cases was strikingly "milder" than the patients carrying the p.G56R mutation alone. Impaired repression of cone-specific genes by the corepressors atrophin-1 (dentatorubral-pallidoluysian atrophy [DRPLA] gene product) and atrophin-2 (arginine-glutamic acid dipeptide repeat [RERE] protein) appeared to be a molecular mechanism mediating the beneficial effect of the p.R311Q mutation. Finally, the functional dominance of the p.R311Q variant to the p.G56R mutation is discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We consider a common investment project that is vulnerable to a self-ful lling coordination failure and hence is strategically risky. Based on their private information, agents - who have heterogeneous investment incentives - form expectations or 'sentiments' about the project's outcome. We find that the sum of these sentiments is constant across di erent strategy profiles and it is independent of the distribution of incentives. As a result, we can think of sentiment as a scarce resource divided up among the di erent payo types. Applying this nding, we show that agents who bene t little from the project's success have a large impact on the coordination process. The agents with small bene ts invest only if their sentiment towards the project is large per unit investment cost. As the average sentiment is constant, a subsidy decreasing the investment costs of these agents will \free up" a large amount of sentiment, provoking a large impact on the whole economy. Intuitively, these agents, insensitive to the project's outcome and hence to the actions of others, are in uential because they modify their equilibrium behavior only if the others change theirs substantially.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Existing empirical evidence suggests that the Uncovered Interest Rate Parity (UIRP) condition may not hold due to an exchange risk premium. For a panel data set of eleven emerging European economies we decompose this exchange risk premium into an idiosyncratic (country-specific) elements and a common factor using a principal components approach. We present evidence of a stationary idiosyncratic component and nonstationary common factor. This result leads to the conclusion of a nonstationary risk premium for these countries and a violation of the UIRP in the long-run, which is in contrast to previous studies often documenting a stationary premium in developed countries. Furthermore, we report that the variation in the premium is largely attributable to a common factor influenced by economic developments in the United States.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The application of multi-region environmental input-output (IO) analysis to the problem of accounting for emissions generation (and/or resource use) under different accounting principles has become increasingly common in the ecological and environmental economics literature in particular, with applications at the international and interregional subnational level. However, while environmental IO analysis is invaluable in 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. Where analysis of marginal changes in activity is required, extension from an IO accounting framework to a more flexible interregional computable general equilibrium (CGE) approach, where behavioural relationships can be modelled in a more realistic and theory-consistent manner, is appropriate. Our argument is illustrated by comparing the results of introducing a positive demand stimulus in the UK economy using 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 effect model results, including the impact on the interregional CO2 ‘trade balance’.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O gênero neotropical Thecomyia (Sciomyzidae) consiste de quatro espécies descritas e onze ainda não descritas (Steyskal & Knutson em preparação), sendo a maioria não muito comum. As espécies são muito próximas e grande número delas somente pode ser separado com base na genitália do macho. Somente é conhecida a biologia e uma espécie, T. limbata (Wiedermann), que, preferentemente, preda moluscos aquáticos (Abercrombie & Berg, 1975). A análise de registros de coletas de espécies relativamente raras e relativamente comuns de Thecomyia (172 especimens do Museu Goeldi coletados em Mocambo, Belém, Pará, Brasil) proporcionam informações sobre a distribuição sazonal de espécies tropicais e sua relativa abundância. Deste material 160 especimens pertencem à T. longicornis Perty e 12 à Thecomyia sp. n. A primeira foi registrada durante todos os meses do ano, mas a espécie nova somente durante junho e dezembro, sugerindo esta última uma população de adultos anual bimodal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper studies the aggregate and distributional implications of Markov-perfect tax-spending policy in a neoclassical growth model with capitalists and workers. Focusing on the long run, our main fi ndings are: (i) it is optimal for a benevolent government, which cares equally about its citizens, to tax capital heavily and to subsidise labour; (ii) a Pareto improving means to reduce ine¢ ciently high capital taxation under discretion is for the government to place greater weight on the welfare of capitalists; (iii) capitalists and workers preferences, regarding the optimal amount of "capitalist bias", are not aligned implying a conflict of interests.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this study is the empirical identification of the monetary policy rules pursued in individual countries of EU before and after the launch of European Monetary Union. In particular, we have employed an estimation of the augmented version of the Taylor rule (TR) for 25 countries of the EU in two periods (1992-1998, 1999-2006). While uniequational estimation methods have been used to identify the policy rules of individual central banks, for the rule of the European Central Bank has been employed a dynamic panel setting. We have found that most central banks really followed some interest rate rule but its form was usually different from the original TR (proposing that domestic interest rate responds only to domestic inflation rate and output gap). Crucial features of policy rules in many countries have been the presence of interest rate smoothing as well as response to foreign interest rate. Any response to domestic macroeconomic variables have been missing in the rules of countries with inflexible exchange rate regimes and the rules consisted in mimicking of the foreign interest rates. While we have found response to long-term interest rates and exchange rate in rules of some countries, the importance of monetary growth and asset prices has been generally negligible. The Taylor principle (the response of interest rates to domestic inflation rate must be more than unity as a necessary condition for achieving the price stability) has been confirmed only in large economies and economies troubled with unsustainable inflation rates. Finally, the deviation of the actual interest rate from the rule-implied target rate can be interpreted as policy shocks (these deviation often coincided with actual turbulent periods).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The behavior of commodities is critical for developing and developed countries alike. This paper contributes to the empirical evidence on the co-movement and determinants of commodity prices. Using nonstationary panel methods, we document a statistically significant degree of co-movement due to a common factor. Within a Factor Augmented VAR approach, real interest rate and uncertainty, as postulated by a simple asset pricing model, are both found to be negatively related to this common factor. This evidence is robust to the inclusion of demand and supply shocks, which both positively impact on the co-movement of commodity prices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

I model the link between political regime and level of diversification following a windfall of natural resource revenues. The explanatory variables I make use of are the political support functions embedded within each type of regime and the disparate levels of discretion, openness, transparency, and accountability of government. I show that a democratic government seeks to maximize the long-term consumption path of the representative consumer, in order to maximize its chances of re-election, while an authoritarian government, in the absence of any electoral mechanism of accountability, seeks to buy off and entrench a group of special interests loyal to the government and potent enough to ensure its short-term survival. Essentially the contrast in the approaches towards resource rent distribution comes down to a variation in political weights on aggregate welfare and rentierist special interests endogenized by distinct political support functions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Type 2 diabetes mellitus (T2DM) is a major disease affecting nearly 280 million people worldwide. Whilst the pathophysiological mechanisms leading to disease are poorly understood, dysfunction of the insulin-producing pancreatic beta-cells is key event for disease development. Monitoring the gene expression profiles of pancreatic beta-cells under several genetic or chemical perturbations has shed light on genes and pathways involved in T2DM. The EuroDia database has been established to build a unique collection of gene expression measurements performed on beta-cells of three organisms, namely human, mouse and rat. The Gene Expression Data Analysis Interface (GEDAI) has been developed to support this database. The quality of each dataset is assessed by a series of quality control procedures to detect putative hybridization outliers. The system integrates a web interface to several standard analysis functions from R/Bioconductor to identify differentially expressed genes and pathways. It also allows the combination of multiple experiments performed on different array platforms of the same technology. The design of this system enables each user to rapidly design a custom analysis pipeline and thus produce their own list of genes and pathways. Raw and normalized data can be downloaded for each experiment. The flexible engine of this database (GEDAI) is currently used to handle gene expression data from several laboratory-run projects dealing with different organisms and platforms. Database URL: http://eurodia.vital-it.ch.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Since 1990, several techniques have been developed to photochemically inactivate pathogens in platelet concentrates, potentially leading to safer transfusion therapy. The three most common methods are amotosalen/UVA (INTERCEPT Blood System), riboflavin/UVA-UVB (MIRASOL PRT), and UVC (Theraflex-UV). We review the biology of pathogen inactivation methods, present their efficacy in reducing pathogens, discuss their impact on the functional aspects of treated platelets, and review clinical studies showing the clinical efficiency of the pathogen inactivation methods and their possible toxicity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Résumé : Les relations entre un parasite et son hôte sont avant tout marquées par le coût pour l'hôte que représente la ponction de ressources au profit du parasite et ses conséquences sur les traits d'histoires de vie de l'hôte. Pour contenir la réduction de leur valeur reproductive, les hôtes ont acquis au cours de l'évolution des mécanismes soit de lutte contre les parasites, soit de réallocations des ressources. Curieusement les effets des ectoparasites sur la biologie de mammifères ont été peu étudiés. Dans une première expérience à long terme, nous avons examiné sous un angle intégratif si les puces Nosopsyllus fasciatus affectent certains paramètres physiologiques des campagnols des champs Microtus arvalis. Nous avons également testé si les puces peuvent réduire la longévité et si oui, si ce pourrait être dû à une accélération de la sénescence. Ensuite nous avons testé si la simple activation répétée du système immunitaire comme lors d'une infestation chronique pouvait aussi réduire la longévité. Dans une dernière expérience, nous avons d'abord testé si l'infestation par des puces de jeunes campagnols au stade néonatal (21 jours) pouvait modifier leur développement et leur phénotype adulte. Puis nous avons testé si la modification du phénotype adulte est une réponse prédite et potentiellement adaptative pour minimiser les effets des puces à l'âge adulte. Nos résultats montrent que l'infestation par des puces réduit la croissance subadulte, induit une forte anémie et une immunodépression, et augmente le métabolisme de repos. De plus les puces réduisent la longévité et la taille des testicules, réduisant fortement le succès reproducteur potentiel des individus parasités. La taille finale, c'est-à-dire le développement pré-adulte, détermine en grande part la longévité. La réduction de longévité ne devrait pas être due à l'investissement au profit du système immunitaire car l'activation chronique seule du système immunitaire ne réduit pas la longévité. L'infestation néonatale retarde légèrement le développement mais surtout modifie l'hématocrite et réduit les performances locomotrices des campagnols plus de 3 mois après l'infestation. Les effets immédiats du parasitisme sur la physiologie semblent bien supérieurs comparés aux effets à long terme. Nous n'avons pas d'éléments permettant d'affirmer que le parasitisme néonatal prépare les campagnols à faire face aux puces à l'âge adulte. Au contraire, le parasitisme néonatal interagit sur le parasitisme adulte pour augmenter le métabolisme de repos. Cette thèse offre une vision intégrative des mécanismes par lesquels les puces peuvent affecter la valeur reproductive de leurs hôtes. De façon générale, ces résultats 35 montrent l'importance des puces comme force de sélection chez les campagnols. Il est indispensable de prendre en compte les ectoparasites dans l'étude de l'écologie et des dynamiques de populations chez les mammifères. Summary : The relationship between a parasite and its host is fundamentally marked by the costs for host of the withdrawals of resources by parasite and the subsequent reduction in host life-history traits. Hosts have evolved a number of strategies to reduce these costs, either by fighting against the parasite directly or by reallocating resources to reduce costs on lifetime reproductive value. The effects of ectoparasites on burrowing mammals have been scarcely studied. In a first long-term experiment, we examined how fleas Nosopsyllus fasciatus affect physiological levels of the common vole, Microtus arvalis. We also examined whether fleas reduce longevity and if so, if it is due to an early senescence pattern. Then we tested if experimental activation of the immune system by repeated injections of an antigen could result in a shorter longevity. In the last experiment, we tested if short-lasting neonatal parasitism can have long-term effects on phenotype, and if these effects could induce a predictive response to reduce damages when parasitized at the adult stage. We found that parasitism by flea reduced subadult growth, induced anaemia and immunodepression, and increased energy consumption even when resting. Moreover fleas reduce longevity and testes size associated to splenomegaly, suggesting an overall reduction in fitness but we did not find any pattern of accelerated senescence explaining the early death of parasitized voles compared to non-parasitzed. The cost of mounting an immune response throughout life does not impair longevity, suggesting that it is the cost of parasitism that limits the longevity and not the immune investment. Neonatal infestation by fleas has long-term effects on physiology and reduces motor activity more than 3 months after infestation. The modification of physiology due to long-term effects seems weak compared to the immediate effects of adult infestation. We found no evidence that neonatal parasitism prepares voles to mount a predictive adaptive response in order to reduce effects of fleas on fitness components. On the contrary, neonatal parasitism seems to worsen the effect of adult parasitism. This thesis offers an integrative view of mechanisms by which fleas affect their host at the individual level. Overall, our results demonstrate the importance of fleas as a selective force in voles. These results highlight the importance of ectoparasitism in ecology of micromarnrnals and suggest a role in the dynamic of host populations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We sought to provide a contemporary picture of the presentation, etiology, and outcome of infective endocarditis (IE) in a large patient cohort from multiple locations worldwide. Prospective cohort study of 2781 adults with definite IE who were admitted to 58 hospitals in 25 countries from June 1, 2000, through September 1, 2005. The median age of the cohort was 57.9 (interquartile range, 43.2-71.8) years, and 72.1% had native valve IE. Most patients (77.0%) presented early in the disease (<30 days) with few of the classic clinical hallmarks of IE. Recent health care exposure was found in one-quarter of patients. Staphylococcus aureus was the most common pathogen (31.2%). The mitral (41.1%) and aortic (37.6%) valves were infected most commonly. The following complications were common: stroke (16.9%), embolization other than stroke (22.6%), heart failure (32.3%), and intracardiac abscess (14.4%). Surgical therapy was common (48.2%), and in-hospital mortality remained high (17.7%). Prosthetic valve involvement (odds ratio, 1.47; 95% confidence interval, 1.13-1.90), increasing age (1.30; 1.17-1.46 per 10-year interval), pulmonary edema (1.79; 1.39-2.30), S aureus infection (1.54; 1.14-2.08), coagulase-negative staphylococcal infection (1.50; 1.07-2.10), mitral valve vegetation (1.34; 1.06-1.68), and paravalvular complications (2.25; 1.64-3.09) were associated with an increased risk of in-hospital death, whereas viridans streptococcal infection (0.52; 0.33-0.81) and surgery (0.61; 0.44-0.83) were associated with a decreased risk. In the early 21st century, IE is more often an acute disease, characterized by a high rate of S aureus infection. Mortality remains relatively high.