821 resultados para Potential Change of Country
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Myasthenia gravis is an autoimmune disease in which T cells specific to epitopes of the autoantigen, the human acetylcholine receptor, play a role. We identified two peptides, p195-212 and p259-271, from the alpha subunit of the receptor, which bound to major histocompatibility complex (MHC) class II molecules on antigen-presenting cells (APCs) from peripheral blood lymphocytes of myasthenia gravis patients and stimulated lymphocytes of >80% of the patients. We have prepared analogs of these myasthenogenic peptides and tested their ability to bind to MHC class II determinants and to interfere specifically with T-cell stimulation. We first determined relative binding efficiency of the myasthenogenic peptides and their analogs to APCs of patients. We found that single substituted analogs of p195-212 (Ala-207) and p259-271 (Lys-262) could bind to human MHC molecules on APCs as efficiently as the original peptides. Moreover, dual analogs containing the two single substituted analogs in one stretch (either sequentially, Ala-207/Lys-262, or reciprocally, Lys-262/Ala-207) could also bind to APCs of patients, including those that failed to bind one of the single substituted analogs. The single substituted analogs significantly inhibited T-cell stimulation induced by their respective myasthenogenic peptides in >95% of the patients. The dual analogs were capable of inhibiting stimulation induced by either of the peptides: They inhibited the response to p195-212 and p259-271 in >95% and >90% of the patients, respectively. Thus, the dual analogs are good candidates for inhibition of T-cell responses of myasthenia gravis patients and might have therapeutic potential.
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Molecular cloning of components of protective antigenic preparations has suggested that related parasite fatty acid-binding proteins could form the basis of the protective immune crossreactivity between the parasitic trematode worms Fasciola hepatica and Schistosoma mansoni. Molecular models of the two parasite proteins showed that both molecules adopt the same basic three-dimensional structure, consisting of a barrel-shaped molecule formed by 10 antiparallel beta-pleated strands joined by short loops, and revealed the likely presence of crossreactive, discontinuous epitopes principally derived from amino acids in the C-terminal portions of the molecules. A recombinant form of the S. mansoni antigen, rSm14, protected outbred Swiss mice by up to 67% against challenge with S. mansoni cercariae in the absence of adjuvant and without provoking any observable autoimmune response. The same antigen also provided complete protection against challenge with F. hepatica metacercariae in the same animal model. The results suggest that it may be possible to produce a single vaccine that would be effective against at least two parasites, F. hepatica and S. mansoni, of veterinary and human importance, respectively.
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Ceramide has been identified as a potential second messenger that may mediate cell differentiation and apoptosis after exposure to hormonal agonists such as 1 alpha, 25-dihydroxyvitamin D3, tumor necrosis factor alpha, or gamma-interferon. The secondary cellular events that follow ceramide generation remain undefined. We report that in NIH WT-3T3 cells, ceramide induces an enhancement of gene transcription of alpha B-crystallin, a small heat shock protein. The levels of alpha B-crystallin, as measured by Northern blot and immunoblot analyses, were increased by the addition of an exogenous short-chain ceramide, N-acetylsphingosine, or by increasing endogenous intracellular ceramide by inhibition of glucosylceramide synthase. Similar effects were not seen in the expression of the closely related gene, Hsp25. To ascertain whether ceramide-mediated gene transcription was a feature of the heat shock response, cell ceramide was measured in heat shocked cells and observed to be elevated 2-fold immediately upon the return of cells to 37 degrees C. Thus ceramide formed after heat shock treatment of 3T3 cells may mediate the transcription events associated with the cell stress response.
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Within the overall framework of the renewal process of coastal tourist destinations, cultural heritage has frequently been used as a key argument for the introduction and development of strategies for the diversification and differentiation of the traditional tourist product based on sun and sand. This is the situation of the province of Alicante, identified with the Costa Blanca geotourism brand, where there are important economic issues that could contribute to the renewal of this coastal tourist destination. One of the most significant heritage values of this space consists of a series of medieval fortresses located along the axis of the Vinalopó River, which has acted since prehistoric times as a natural route from within the provincial mainland to the coast. It is precisely the argument of this historical, territorial and landscape content that has been used repeatedly in recent years to develop initiatives aimed at the creation of a tourist product, currently inexistent, based on the route of the castles of Vinalopó. This communication aims to analyse the degree of tourism potential of the fortresses located in the towns of Biar, Banyeres de Mariola, Sax, Villena, Novelda, Elda, Petrer and Elche, which constitute the core of municipalities where these medieval fortresses are located, finally pointing out some proposals for the creation of a heritage tourism product.
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A motion that the case not be tried in Suffolk County, on the grounds that the judges and jurors were residents of the colony. Pratt was attorney to Paxton, an attorney and commissioner of customs, who had incurred a debt to the Colony.
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In recent decades wild boar have greatly increased in Europe due a combination of environmental and human factors. Because of a high reproduction rate, wild boar cause conflicts with human activities and in particularly agriculture. However, there are concerns also about environmental impact and in particular on ground nesting birds. Our study aim to evaluate the potential impact of wild boar on pheasants nests. Predation rates were compared between two areas with different wild boar abundance and between nests placed in fenced plots with no wild boar access (but accessible to other predators) and open plots in which the wild boar gains access. Predation rate by wild boar in the area with higher wild boar abundance was 61.5% whereas in the area with lower abundance was 16.0%. In plots with free access, wild boar predation was 34.2% whereas in exclusion plots we did not registered predation by wild boar. Moreover, wild boar resulted the main nest predator (total loss 22.8%). Our findings suggest that wild boar could have e strong impact on pheasant reproductive success.
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This paper assesses the impact of decarbonisation of the energy sector on employment in Europe. Setting the stage for such an assessment, the paper provides an analysis of possible pathways to decarbonise Europe’s energy system, taking into account EU greenhouse gas emissions reduction targets for 2020 and 2050. It pays particular attention to various low-carbon technologies that could be deployed in different regions of the EU. It concludes that efficiency and renewables play a major role in any decarbonisation scenario and that the power sector is the main enabler for the transition to a low-carbon economy in Europe, despite rising electricity demand. The extent of the decline in the share of fossil fuels will largely depend on the existence of carbon capture and storage (CCS), which remains a major source of uncertainty.
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The paper studies country risk in two Central and Eastern European countries - Bulgaria and Poland. The long run relationship between the yield differential (spread) of Eastern European national bonds (denominated in US dollars) over a US Treasury bond on one the hand and the country’s fundamentals as well as an US interest rate on the other hand, is examined. The cointegrated VAR model is used. First, the yield differentials are analyzed on a country by country basis to extract stochastic trends which are common for all bonds in a given country. Thereafter, the risk is disentangled into country and higher level risk. This paper is among the first ones which use time series data to study the evidence from sovereign bond spreads in Eastern Europe.
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Over the last 15 years, Member States have been quite reluctant to address labour migration issues at EU level. Will the forthcoming years reverse the tide and lead to the developement of ambitious and common actions in this policy field? There are currently no strong signs of such a move towards a greater management of labour migration policy at EU level. However, Yves Pascouau argues in this FIERI Working paper that the deadlock may be broken with the development of new policy tools taking place in the field of economic governance. More precisely, he underlines that recipes adopted to overcome the so-called ‘euro crisis’ may well have an impact on labour migration issues.As a consequence, this could initiate a coordination process which was not called for by home affairs decision-makers.
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Organic-organic heterojunctions are nowadays highly regarded materials for light-emitting diodes, field-effect transistors, and photovoltaic cells with the prospect of designing low-cost, flexible, and efficient electronic devices.1-3 However, the key parameter of optimized heterojunctions relies on the choice of the molecular compounds as well as on the morphology of the organic-organic interface,4 which thus requires fundamental studies. In this work, we investigated the deposition of C60 molecules at room temperature on an organic layer compound, the salt bis(benzylammonium)bis(oxalato)cupurate(II), by means of noncontact atomic force microscopy. Three-dimensional molecular islands of C60 having either triangular or hexagonal shapes are formed on the substrate following a "Volmer-Weber" type of growth. We demonstrate the dynamical reshaping of those C60 nanostructures under the local action of the AFM tip at room temperature. The dissipated energy is about 75 meV and can be interpreted as the activation energy required for this migration process.
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Mode of access: Internet.
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Issued July 1978.