515 resultados para Free State


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A possible function for the alternative (nonphosphorylating) pathway is to stabilize the reduction state of the ubiquinone pool (Qr/Qt), thereby avoiding an increase in free radical production. If the Qr/Qt were stabilized by the alternative pathway, then Qr/Qt should be less stable when the alternative pathway is blocked. Qr/Qt increased when we exposed roots of Poa annua (L.) to increasing concentrations of KCN (an inhibitor of the cytochrome pathway). However, when salicylhydroxamic acid, an inhibitor of the alternative pathway, was added at the same time, Qr/Qt increased significantly more. Therefore, we conclude that the alternative pathway stabilizes Qr/Qt. Salicylhydroxamic acid increasingly inhibited respiration with increasing concentrations of KCN. In the experiments described here the alternative oxidase protein was invariably in its reduced (high-activity) state. Therefore, changes in the reduction state of the alternative oxidase cannot account for an increase in activity of the alternative pathway upon titration with KCN. The pyruvate concentration in intact roots increased only after the alternative pathway was blocked or the cytochrome pathway was severely inhibited. The significance of the pyruvate concentration and Qr/Qt on the activity of the alternative pathway in intact roots is discussed.

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Calcium binding to the N-domain of troponin C initiates a series of conformational changes that lead to muscle contraction. Calcium binding provides the free energy for a hydrophobic region in the core of N-domain to assume a more open configuration. Fluorescence measurements on a tryptophan mutant (F29W) show that a similar conformational change occurs in the absence of Ca2+ when the temperature is lowered under pressure. The conformation induced by subzero temperatures binds the hydrophobic probe bis-aminonaphthalene sulfonate, and the tryptophan has the same fluorescence lifetime (7 ns) as in the Ca2+-bound form. The decrease in volume (delta V = -25.4 ml/mol) corresponds to an increase in surface area. Thermodynamic measurements suggest an enthalpy-driven conformational change that leads to an intermediate with an exposed N-domain core and a high affinity for Ca2+.

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In many bacteria, accumulation of K+ at high external osmolalities is accompanied by accumulation of glutamate. To determine whether there is an obligatory relationship between glutamate and K+ pools, we studied mutant strains of Salmonella typhimurium with defects in glutamate synthesis. Enteric bacteria synthesize glutamate by the combined action of glutamine synthetase and glutamate synthase (GS/GOGAT cycle) or the action of biosynthetic glutamate dehydrogenase (GDH). Activity of the GS/GOGAT cycle is required under nitrogen-limiting conditions and is decreased at high external ammonium/ammonia ((NH4)+) concentrations by lowered synthesis of GS and a decrease in its catalytic activity due to covalent modification (adenylylation by GS adenylyltransferase). By contrast, GDH functions efficiently only at high external (NH4)+ concentrations, because it has a low affinity for (NH4)+. When grown at low concentrations of (NH4)+ (< or = 2 mM), mutant strains of S. typhimurium that lack GOGAT and therefore are dependent on GDH have a low glutamate pool and grow slowly; we now demonstrate that they have a low K+ pool. When subjected to a sudden (NH4)+ upshift, strains lacking GS adenylyltransferase drain their glutamate pool into glutamine and grow very slowly; we now find that they also drain their K+ pool. Restoration of the glutamate pool in these strains at late times after shift was accompanied by restoration of the K+ pool and a normal growth rate. Taken together, the results indicate that glutamate is required to maintain the steady-state K+ pool -- apparently no other anion can substitute as a counter-ion for free K+ -- and that K+ glutamate is required for optimal growth.

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Lactose, in particular α-lactose monohydrate, is the most used carrier for inhalation. Its surface and solid-state properties are of paramount importance in determining drug aerosolization performance. However, these properties may be altered by processing, such as micronization, thus affecting the product performance and stability. The present research project focused on the study of the effect of lactose solid-state on the aerosolization performance of drug-carrier mixtures, giving particular attention to the impact of micronization on lactose physico-chemical properties. The formation of a fraction of hygroscopic anhydrous α-lactose, rather than amorphous lactose, as a consequence of the mechanical stress stemming from micronization was evidenced by 1H NMR, XRPD and DSC analyses performed on samples of micronized lactose. The development of a new DVS method capable to identify and quantify different forms of α-lactose (hygroscopic anhydrous, stable anhydrous and amorphous), even simultaneously present in the same sample, confirmed the results obtained with the above-mentioned techniques. The influence of lactose solid-state on drug respirability was then evaluated through the preparation and in vitro aerodynamic assessment of ternary and binary mixtures containing two different drugs. In particular, the use, as carriers, of anhydrous forms of α-lactose in place of the conventional α-lactose monohydrate resulted in significantly improved respirability in the case of salbutamol sulphate and poorer performance in the case of budesonide. In an attempt to rationalize the obtained results, IGC was selected as a tool to investigate possible variations in the surface energy of the studied lactose carriers and APIs. A direct correlation between the total surface free energy of lactose carriers and drug respirability was not found. However, salbutamol sulphate and budesonide exhibited different specific surface free energy, to which the difference in the aerosolization performance may be, at least in part, ascribed.

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Sticholysin II (StnII) is a pore-forming toxin that uses sphingomyelin (SM) as the recognition molecule in targeting membranes.After StnII monomers bind to SM, several toxin monomers act in concert to oligomerize into a functional pore. The regulation of StnII binding to SM, and the subsequent pore-formation process, is not fully understood. In this study, we examined how the biophysical properties of bilayers, originating from variations in the SM structure, from the presence of sterol species, or from the presence of increasingly polyunsaturated glycerophospholipids,affected StnII-induced pore formation. StnII-induced pore formation, as determined from calcein permeabilization, was fastest in the pure unsaturated SM bilayers. In 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/saturated SM bilayers (4:1 molar ratio), pore formation became slower as the chain length of the saturated SMs increased from 14 up to 24 carbons. In the POPC/palmitoyl-SM (16:0-SM) 4:1 bilayers, SM could not support pore formation by StnII if dimyristoyl-PC was included at 1:1 stoichiometry with 16:0-SM, suggesting that free clusters of SM were required for toxin binding and/or pore formation. Cholesterol and other sterols facilitated StnII-induced pore formation markedly, but the efficiency did not appear to correlate with the sterol structure. Benzyl alcohol was more efficient than sterols in enhancing the pore-formation process, suggesting that the effect on pore formation originated from alcohol-induced alteration of the hydrogen-bonding network in the SM-containing bilayers. Finally, we observed that pore formation by StnII was enhanced in the PC/16:0-SM 4:1 bilayers, in which the PC was increasingly unsaturated. We conclude that the physical state of bilayer lipids greatly affected pore formation by StnII. Phase boundaries were not required for pore formation, although SM in a gel state attenuated pore formation.

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In the last 30 years, a clear trend has come to define modern immigration law and policy. A set of seemingly disparate developments concerning the constant reinforcement of border controls, tightening of conditions of entry, expanding capacities for detention and deportation and the proliferation of criminal sanctions for migration offences, accompanied by an anxiety on the part of the press, public and political establishment regarding migrant criminality can now be seen to form a definitive shift in the European Union towards the so-called ‘criminalisation of migration’. This paper aims to provide an overview of the ‘state-of-the-art’ in the academic literature and EU research on criminalisation of migration in Europe. It analyses three key manifestations of the so-called ‘crimmigration’ trend: discursive criminalisation; the use of criminal law for migration management; and immigrant detention, focusing both on developments in domestic legislation of EU member states but also the increasing conflation of mobility, crime and security which has accompanied EU integration. By identifying the trends, synergies and gaps in the scholarly approaches dealing with the criminalisation of migration, the paper seeks to provide a framework for on-going research under Work Package 8 of the FIDUCIA project.

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Immigration and freedom of movement of EU citizens are among the main issues debated throughout the European Parliament election campaign and have some potential in determining who tomorrow’s EU leaders will be. This Policy Brief looks at how the two policies are debated at national level – in France, Germany and the UK – and at EU level between the ‘top candidates’ for European Commission Presidency – Jean-Claude Juncker (EPP), Ska Keller (Greens), Martin Schulz (PES) and Guy Verhofstadt (ALDE) – who have participated in several public debates. Two different campaigns have been unfolding in front of EU citizens’ eyes. The tense debate that can be identified at national level on these issues, is not transferred to the EU level, where immigration and free movement are less controversial topics. Furthermore, although participating in European elections, national parties present agendas responding exclusively to the economic and social challenges of their Member State, while the candidates for the Commission Presidency bring forward ‘more European’ programmes. Hence, several aspects need to be reflected upon: What will the consequences of this discontinuity be? How will this impact the future European agenda in terms of immigration and free movement? What institutional consequences will there be? Answering these questions is not a simple task, however, this paper aims to identify the parameters that need to be taken into account and the political landscape which will determine the future EU agenda in terms of immigration and free movement.

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The purpose of this paper is to address the issue of social security benefits that jobseekers, nationals of other Member State, residing in another Member States are in title to, as well as the economic implications of free movement of persons and labour market access. Consequently, it aims to disentangle between labour mobility welfare effects and “benefit tourism” looking in particular at the United Kingdom social security system and analysing the policy framework currently in place that governs the free movement of people across the European Union Member States.

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A major issue in the ongoing Transatlantic Trade and Investment Partnership (TTIP) negotiations is investor-state dispute resolution as it relates to foreign investments. The United States would like to have strong investor protections similar to those of the North American Free Trade Agreement (NAFTA) included in the TTIP agreement. Civil society groups on both sides of the Atlantic object to binding arbitration of investment disputes, fearing that arbitration awards could endanger environmental and other types of regulations. This paper examines the experience with investor-state dispute resolution under NAFTA to determine whether judgments rendered in these cases have had adverse effects.

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We tested the assumption that active relaxation following an ego-depletion task counteracts the negative effects of ego depletion on subsequent performance under evaluative pressure. N = 39 experienced basketball players were randomly assigned to a relaxation condition or to a control condition, and then performed a series of free-throws at two points of measurement (T1: baseline vs. T2: after working on a depleting task and either receiving active relaxation or a simple break). The results demonstrated that performance remained constant in the relaxation condition, whereas it significantly decreased in the control condition. The findings are in line with the notion that active relaxation leads to a quicker recovery from ego depletion.

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Includes bibliographical references (p. 45-51, 54-60).

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"List of local railroads chartered by the state of New Jersey": p. 15-17.

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Diccionarios de las lenguas timmanee, bullom y soosoo: p. 337-362, del primer tomo.