973 resultados para Science and humanism in the enlightenment


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Macroeconomists working with multivariate models typically face uncertainty over which (if any) of their variables have long run steady states which are subject to breaks. Furthermore, the nature of the break process is often unknown. In this paper, we draw on methods from the Bayesian clustering literature to develop an econometric methodology which: i) finds groups of variables which have the same number of breaks; and ii) determines the nature of the break process within each group. We present an application involving a five-variate steady-state VAR.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

NORTH SEA STUDY OCCASIONAL PAPER No. 113

Relevância:

100.00% 100.00%

Publicador:

Resumo:

NORTH SEA STUDY OCCASIONAL PAPER No. 112

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The monetary policy reaction function of the Bank of England is estimated by the standard GMM approach and the ex-ante forecast method developed by Goodhart (2005), with particular attention to the horizons for inflation and output at which each approach gives the best fit. The horizons for the ex-ante approach are much closer to what is implied by the Bank’s view of the transmission mechanism, while the GMM approach produces an implausibly slow adjustment of the interest rate, and suffers from a weak instruments problem. These findings suggest a strong preference for the ex-ante approach.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The monetary policy reaction function of the Bank of England is estimated by the standard GMM approach and the ex-ante forecast method developed by Goodhart (2005), with particular attention to the horizons for inflation and output at which each approach gives the best fit. The horizons for the ex-ante approach are much closer to what is implied by the Bank’s view of the transmission mechanism, while the GMM approach produces an implausibly slow adjustment of the interest rate, and suffers from a weak instruments problem. These findings suggest a strong preference for the ex-ante approach.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is a well-established fact in the literature on simulating Input-Output tables that mechanical methods for estimating intermediate trade lead to biased results where cross-hauling is underestimated and Type-I multipliers are overstated. Repeated findings to this effect have led to a primary emphasis on advocating the accurate estimation of intermediate trade flows. This paper reviews previous research and argues for a qualification of the consensus view: When simulating IO tables, construction approaches need to consider spill-over effects driven by wage and consumption flows. In particular, for the case of metropolitan economies, wage and consumption flows are important if accurate Type-II multipliers are to be obtained. This is demonstrated by constructing an interregional Input-Output table, which captures interdependencies between a city and its commuter belt, nested within the wider regional economy. In addition to identifying interdependencies caused by interregional intermediate purchases, data on subregional household incomes and commuter flows are used to identify interdependencies from wage payments and household consumption. The construction of the table is varied around a range of assumptions on intermediate trade and household consumption to capture the sensitivity of multipliers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

TNF family ligands and receptors fulfill a number of functions, mainly in the immune system. For example, the ligands BAFF and APRIL control growth and survival of mature Β cells at various stages of differentiation. TNF family ligands usually form homotrimers, but heteromers have also been described for lymphotoxin α1β2 and for BAFF and APRIL. Interestingly, twenty BAFF homotrimers can assemble into virus-like particles coined BAFF 60-mer, which are superior to BAFF 3-mer regarding their ability to signal in primary Β cells. A screen was performed in 293T cells, by co-transfecting differently tagged ligands, to identify six novel heteromers. The specificity of these novel heteromers, however, did not correspond to that of orphan receptors in the TNFR family. Little is known about heteromers of BAFF and APRIL, in particular their receptor-binding specificity and their ability to signal. A method to produce and purify heteromers of defined stoechiometry was developed, and the resulting reagents were used to demonstrate that BAFF2APRIL, like BAFF, binds to all BAFF receptors - namely BAFFR, TACI and Β CM A -, while APRIL2BAFF and APRIL only binds to TACI and BCMA. Heteromers could signal via their cognate receptors, sometimes as potently and sometimes less potently than homomers, depending on the receptors. A promising system to measure the activity of single-chain homo- and heteromers in vivo was set up: it measures mature Β cell rescue upon administration of single-chain ligands into BAFF-ko mice. To tackle the question of the physiological importance of BAFF 60-mer, a point mutation that prevents assembly of mouse BAFF into 60-mer while retaining its ability to form trimers was identified. This mutation (E247K) was introduced by homologous recombination into mouse embryonic stem cells that are now being used to generate knock-in mice. Results obtained in this work will help to better understand the role of various BAFF and APRIL forms that are elevated in a several autoimmune diseases. - Les ligands et récepteurs de la famille du TNF joue un rôle prédominant dans le système immunitaire. Par exemple, les ligands BAFF et APRIL contrôlent la croissance et la survie des cellules Β matures à différents stades de différenciation. Ces ligands existent souvent sous forme d'homotrimères (3-mer), bien que des héteromères aient été décrits pour la lymphotoxine α1β2 et pour BAFF et APRIL. Dans le cas de BAFF, vingt trimères peuvent, telle une particule virale, s'assembler en 60-mer qui surpasse le 3-mer pour signaler dans des cellules Β primaires. Un crible effectué dans des cellules 293T, par co-transfection de ligands différemment marqués, a permis d'identifier six nouveaux heteromères dont la spécificité n'a, hélas, pas correspondu à celle d'un récepteur orphelin de la famille du TNFR. Les connaissances sur la spécificité de liaison aux récepteurs et la capacité à signaler des heteromères de BAFF et d'APRIL sont fragmentaires. Une méthode pour produire et purifier des heteromères "simple chaîne" de stoechiométrie déterminée a été mise au point, et les réactifs ainsi obtenus utilisés pour démontrer que BAFF2APRIL, comme BAFF, lie tous les récepteurs de BAFF - c'est-à-dire BAFFR, TACI et BCMA -, alors qu'APRIL2BAFF et APRIL ne lient que TACI et BCMA. Les héteromères peuvent transmettre des signaux, parfois aussi bien et parfois plus faiblement que les homomères, selon les récepteurs. Un système prometteur pour mesurer l'activité des ligands simple chaîne in vivo a été mis au point. Il mesure la réapparition de cellules Β matures dans des souris déficientes pour BAFF après administration des ligands. Pour s'attaquer à la question de l'importance physiologique du 60-mer de BAFF, ime mutation empêchant l'assemblage en 60-mer sans affecter la capacité à former des trimères a été identifiée. Cette mutation (E247K) a été introduite par recombinaison homologue dans des cellules souches embryonnaires de souris qui sont utilisées pour obtenir des souris déficientes en BAFF 60-mer. Les résultats de ces travaux contribueront à mieux cerner le rôle des différentes formes de BAFF et d'APRIL produites en excès dans plusieurs maladies auto-immunes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The last several years have seen an increasing number of studies that describe effects of oxytocin and vasopressin on the behavior of animals or humans. Studies in humans have reported behavioral changes and, through fMRI, effects on brain function. These studies are paralleled by a large number of reports, mostly in rodents, that have also demonstrated neuromodulatory effects by oxytocin and vasopressin at the circuit level in specific brain regions. It is the scope of this review to give a summary of the most recent neuromodulatory findings in rodents with the aim of providing a potential neurophysiological basis for their behavioral effects. At the same time, these findings may point to promising areas for further translational research towards human applications.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El Delta del Ebro se halla situado en el Mediterráneo, en NE de la Península Ibérica (sur de Cataluña). Su formación ha sido resultado de la interacción del mar y del Ebro, un río que con sus 910 km de longitud drena una cuenca de unos 85.362 km2. Sus características dependen de los diferentes regímenes climáticos de su extensa cuenca, lo que explica la complejidad de su régimen. A lo largo del periodo estudiado el Delta fue siempre una realidad geológica aunque experimentó importantes cambios en su morfología. En consecuencia, sus recursos naturales siempre pudieron ser explotados, aunque estas actividades se hubieron de adaptar a su cambiante morfología y a sus peculiares condiciones naturales, diferentes de las zonas terrestres más inmediatas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article proposes a framework for the analysis of attitudes to foreign trade policies that challenges the traditional skill-endowment approach. The traditional approach assumes informed individuals who calculate the costs and benefits of alternative policies. We propose that individuals lack information and that their positions rest on economic vulnerability, as mediated through risk-aversion. We also stress the role of environmental signals and political endorsements in guiding individuals' views on trade policy. We test this alternative approach with a Spanish survey conducted in May 2009 and the ISSP survey conducted in 2003 in a large number of less developed and more developed countries. The Spanish data show that the population is largely uninformed and that their ideas about the consequences of free trade policy do not explain attitudes among different socio-demographic groups. Meanwhile, the ISSP data contradict important aspects of the traditional approach and are consistent with the alternative approach.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily that can be activated by various xenobiotics and natural fatty acids. These transcription factors primarily regulate genes involved in lipid metabolism and also play a role in adipocyte differentiation. We present the expression patterns of the PPAR subtypes in the adult rat, determined by in situ hybridization using specific probes for PPAR-alpha, -beta and -gamma, and by immunohistochemistry using a polyclonal antibody that recognizes the three rat PPAR subtypes. In numerous cell types from either ectodermal, mesodermal, or endodermal origin, PPARs are coexpressed, with relative levels varying between them from one cell type to the other. PPAR-alpha is highly expressed in hepatocytes, cardiomyocytes, enterocytes, and the proximal tubule cells of kidney. PPAR-beta is expressed ubiquitously and often at higher levels than PPAR-alpha and -gamma. PPAR-gamma is expressed predominantly in adipose tissue and the immune system. Our results suggest new potential directions to investigate the functions of the different PPAR subtypes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The mammalian ortholog of the conserved Drosophila adaptor protein Numb (Nb) and its homolog Numblike (Nbl) modulate neuronal cell fate determination at least in part by antagonizing Notch signaling. Because the Notch pathway has been implicated in regulating hemopoietic stem cell self-renewal and T cell fate specification in mammals, we investigated the role of Nb and Nbl in hemopoiesis using conditional gene targeting. Surprisingly simultaneous deletion of both Nb and Nbl in murine bone marrow precursors did not affect the ability of stem cells to self-renew or to give rise to differentiated myeloid or lymphoid progeny, even under competitive conditions in mixed chimeras. Furthermore, T cell fate specification and intrathymic T cell development were unaffected in the combined absence of Nb and Nbl. Collectively our data indicate that the Nb family of adaptor proteins is dispensable for hemopoiesis and lymphopoiesis in mice, despite their proposed role in neuronal stem cell development.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

World ecosystems differ significantly and a multidisciplinary malaria control approach must be adjusted to meet these requirements. These include a comprehensive understanding of the malaria vectors, their behavior, seasonal distribution and abundance, susceptibility to insecticides (physiological and behavioral), methods to reduce the numbers of human gametocyte carriers through effective health care systems and antimalarial drug treatment, urban malaria transmission versus rural or forest malaria transmission, and the impact of vaccine development. Many malaria vectors are members of species complexes and individual relationship to malaria transmission, seasonal distribution, bitting behavior, etc. is poorly understood. Additionaly, malaria patients are not examined for circulating gametocytes and both falciparum and vivax malaria patients may be highly infective to mosquitoes after treatment with currently used antimalarial drugs. Studies on the physiological and behavioral effects of DDT and other insecticides are inconclusive and need to be evalusted.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this paper is to discuss the circumstances in which the process of competition between ports takes place in Spain − circumstances arising from the way the port system is currently set up and from the regulations governing it. The importance of this matter lies both in the fact that intensified competition between ports is the way to set about boosting the efficiency of the Spanish port sector and in the relevance of this business to the economies of the regions in which the ports are located. It is precisely for this reason that the reform instituted in 1992 aimed to combine balanced development of the national port system with the defence of the interests of autonomous regions. To this end the current regulatory framework provides for the possibility of port authorities drawing up their own competitive strategies, but makes their implementation conditional upon approval of their business plan by the Spanish state port authority. The latter body coordinates the national port system to ensure the guidelines set by the central government authorities are followed in the field of transport. However, the scale of the differences which exist among both the size of facilities and their relevant markets on the one hand, and the financial and economic circumstances of each of them on the other, suggest that each port authority's needs must be very different. Consequently, their competitive strategies must also be very different. It is therefore valid to ask whether coping with this diversity calls for different guidelines to regulate their freedom of action. Key words: Competition, regulation, port sector JEL classification numbers: L1, L5, L9