435 resultados para 1276


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Wydział Historyczny: Instytut Prahistorii

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A diabetes mellitus do tipo 2 é caracterizada pela resistência à insulina e pela disfunção das células β do pâncreas. Os péptidos gastrintestinais, “gastric inhibitory polypeptide” (GIP) e “glucagon-like peptide-1” (GLP-1), são hormonas incretinas que estimulam, maioritariamente, a produção de insulina pós-prandial. Formulações contendo GLP-1 possuem um grande potencial no tratamento desta doença. Porém, o GLP-1 é eficaz apenas quando administrado por via parentérica. Para o tratamento da diabetes mellitus tipo 2 são usados análogos do GLP‑ 1 ou miméticos da incretina os quais são eficazes por via subcutânea. The pathogenesis of diabetes mellitus type 2 includes insulin resistance and progressive β-cell dysfunction. The gastrointestinal peptides, gastric inhibitory polypeptide (GIP) and glucagon‑like peptide-1 (GLP-1), are incretin hormones which are responsible for the major part of postprandial insulin secretion. Formulations containing GLP-1 have a great potential in the treatment of diabetes mellitus type 2. Nonetheless, GLP-1 is only efficient by continuous parenteral administration. GLP-1 analogues or incretin mimetics, exendine-4, are active after subcutaneous injection and can be used in the treatment of diabetes mellitus of type 2.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper describes an autonomics development tool which serves as both a powerful and flexible policy-expression language and a policy-based framework that supports the integration and dynamic composition of several autonomic computing techniques including signal processing, automated trend analysis and utility functions. Each of these technologies has specific advantages and applicability to different types of dynamic adaptation. The AGILE platform enables seamless interoperability of the different technologies to each perform various aspects of self-management within a single application. Self-management behaviour is specified using the policy language semantics to bind the various technologies together as required. Since the policy semantics support run-time re-configuration, the self-management architecture is dynamically composable. The policy language and implementation library have integrated support for self-stabilising behaviour, enabling oscillation and other forms of instability to be handled at the policy level with very little effort on the part of the application developer. Example applications are presented to illustrate the integration of different autonomics techniques, and the achievement of dynamic composition.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We consider the optimum design of pilot-symbol-assisted modulation (PSAM) schemes with feedback. The received signal is periodically fed back to the transmitter through a noiseless delayed link and the time-varying channel is modeled as a Gauss-Markov process. We optimize a lower bound on the channel capacity which incorporates the PSAM parameters and Kalman-based channel estimation and prediction. The parameters available for the capacity optimization are the data power adaptation strategy, pilot spacing and pilot power ratio, subject to an average power constraint. Compared to the optimized open-loop PSAM (i.e., the case where no feedback is provided from the receiver), our results show that even in the presence of feedback delay, the optimized power adaptation provides higher information rates at low signal-to-noise ratios (SNR) in medium-rate fading channels. However, in fast fading channels, even the presence of modest feedback delay dissipates the advantages of power adaptation.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conceptual art and communicator role has influenced the work of Chilean architect Alfredo Jaar, which has been proposed report, with other codes [verbal and nonverbal], global events influencing contemporary society. His early training as an architect has driven innovation in the design of artistic space , using the message to convey to the viewer the reason for his work for more than three decades, highlights the artistic composition with various material resources whose purpose lies in conceptualizing various topics relevant in considering the role of artistic communication. Jaar’s style is the sum of his own life experience in relation to the contradictions of the world today, which is exposed and from the perspective of postmodernism from the exploitation of the notion of space as an open stage for visual and expressiveness beyond national borders, societies and cultures of the world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The finite state Markov-chain approximation methods developed by Tauchen (1986) and Tauchen and Hussey (1991) are widely used in economics, finance and econometrics to solve functional equations in which state variables follow autoregressive processes. For highly persistent processes, the methods require a large number of discrete values for the state variables to produce close approximations which leads to an undesirable reduction in computational speed, especially in a multivariate case. This paper proposes an alternative method of discretizing multivariate autoregressive processes. This method can be treated as an extension of Rouwenhorst's (1995) method which, according to our finding, outperforms the existing methods in the scalar case for highly persistent processes. The new method works well as an approximation that is much more robust to the number of discrete values for a wide range of the parameter space.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Aims: To characterize the population pharmacokinetics of ranitidine in critically ill children and to determine the influence of various clinical and demographic factors on its disposition. Methods: Data were collected prospectively from 78 paediatric patients (n = 248 plasma samples) who received oral or intravenous ranitidine for prophylaxis against stress ulcers, gastrointestinal bleeding or the treatment of gastro-oesophageal reflux. Plasma samples were analysed using high-performance liquid chromatography, and the data were subjected to population pharmacokinetic analysis using nonlinear mixed-effects modelling. Results: A one-compartment model best described the plasma concentration profile, with an exponential structure for interindividual errors and a proportional structure for intra-individual error. After backward stepwise elimination, the final model showed a significant decrease in objective function value (-12.618; P <0.001) compared with the weight-corrected base model. Final parameter estimates for the population were 32.1lh for total clearance and 285l for volume of distribution, both allometrically modelled for a 70kg adult. Final estimates for absorption rate constant and bioavailability were 1.31h and 27.5%, respectively. No significant relationship was found between age and weight-corrected ranitidine pharmacokinetic parameters in the final model, with the covariate for cardiac failure or surgery being shown to reduce clearance significantly by a factor of 0.46. Conclusions: Currently, ranitidine dose recommendations are based on children's weights. However, our findings suggest that a dosing scheme that takes into consideration both weight and cardiac failure/surgery would be more appropriate in order to avoid administration of higher or more frequent doses than necessary.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A softened strut-and-tie macro model able to reproduce the flexural behaviour of
external beam-column joint is presented. The model is specific for concrete with hooked steel fibres (FRC) and it is designed to calculate the flexural response, as load-deflection curve, of a beam-column sub-assemblages. The model considers the presence of a constant vertical load acting on the column and of a monotonically increasing lateral force applied at the tip of the beam.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We introduce a novel dual-stage algorithm for online multi-target tracking in realistic conditions. In the first stage, the problem of data association between tracklets and detections, given partial occlusion, is addressed using a novel occlusion robust appearance similarity method. This is used to robustly link tracklets with detections without requiring explicit knowledge of the occluded regions. In the second stage, tracklets are linked using a novel method of constraining the linking process that removes the need for ad-hoc tracklet linking rules. In this method, links between tracklets are permitted based on their agreement with optical flow evidence. Tests of this new tracking system have been performed using several public datasets.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Interweaving planar spiral conductors in doubly periodic arrays enable substantially sub-wavelength resonant response along with broadening fractional bandwidth. A self-contained analytical model is proposed to accurately predict the characteristics of the intertwined quadrifilar spiral array near the fundamental resonance. The model, based upon a multiconductor transmission line (MTL) approach, provides physical insight into the unique properties of the distributed interactions between the interleaved counter-wound spiral arms extended beyond a single unit cell and elucidates the mechanisms underlying the array performance at normal and oblique incidence of TE and TM polarised waves. The developed MTL model is instrumental in the design of the artificial surfaces with the specified response.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This article examines the mid-1840s expansion of the British railway network, which was associated with a large deterioration in shareholder value. Using a counterfactual approach and new data on railway competition, we argue that the expansion of the railway companies, and their subsequent decline in financial performance, was not due to managerial failure. Rather, the promotion of new routes by established railways and mergers with other companies was part of a managerial strategy to maintain incumbent positions, and may have been preferable to not expanding whilst their competitors did.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Drug development is being continuously scrutinised for its lack of productivity. Novel drug development is associated with high costs, high failure rates and lengthy development process. These downfalls combined with a huge demand in blood cancer for new therapeutic treatments have led many to consider the method of drug repurposing. Finding new therapeutic indications for already established drug substances is known as redirecting, repositioning, reprofiling, or repurposing of drugs. Off-patent and on-patent drugs can be screened for additional targets and new indications thus bringing them to clinical trials at a faster pace. This approach offers smaller research groups, such as those that are academic based, into the drug development industry. Drug repurposing can make use of previously published data concerning dosage, toxicology and mechanism of activity.