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Teixeira Rodrigues A.,University of Aveiro | Teixeira Rodrigues A.,University of Coimbra | Roque F.,University of Aveiro | Roque F.,Polytechnic Institute of Guarda | And 7 more authors.
International Journal of Antimicrobial Agents | Year: 2013

Inappropriate prescription has been associated with mounting rates of antibiotic resistance worldwide, demanding more detailed studies into physicians' decision-making process. Accordingly, this study sought to explore physicians' perceptions of factors influencing antibiotic prescribing. A systematic search was performed for qualitative studies focused on understanding physicians' perceptions of the factors, attitudes and knowledge influencing antibiotic prescription. Of the total of 35 papers selected for review purposes, 18 solely included physicians and the remaining 17 also included patients and/or other healthcare providers. Data collection was based mainly on interviews, followed by questionnaires and focus groups, and the methodologies mainly used for data analysis were grounded theory and thematic analysis. Factors cited by physicians as having an impact on antibiotic prescribing were grouped into those that were intrinsic (group 1) and those that were extrinsic (group 2) to the healthcare professional. Among the former, physicians' attitudes, such as complacency or fear, were rated as being most influential on antibiotic prescribing, whilst patient-related factors (e.g. signs and symptoms) or healthcare system-related factors (e.g. time pressure and policies/guidelines implemented) were the most commonly reported extrinsic factors. These findings revealed that: (i) antibiotic prescribing is a complex process influenced by factors affecting all the actors involved, including physicians, other healthcare providers, healthcare system, patients and the general public; and (ii) such factors are mutually dependent. Hence, by shedding new light on the process, these findings will hopefully contribute to generating new and more effective strategies for improving antibiotic prescribing and allaying global concern about antibiotic resistance. © 2012 Elsevier B.V. and the International Society of Chemotherapy. Source


Cruz Pinto J.J.C.,University of Aveiro | Andre J.R.S.,Polytechnic Institute of Guarda
Polymer Engineering and Science | Year: 2016

We expand our analytical modeling strategy for polymer non-linear stress relaxation (A) to specify the remaining steps to accurately deal with the nonaffine nature of the materials' local strains and stresses relative to their average overall values, and (B) to make it consistent with a new cooperative theory of amorphous materials dynamics, providing a model of tunable fragility that sheds light to most aspects of the behavior, including the glass transition. The stress relaxation models (1) describe a nonlinear (strain-dependent) behavior that becomes linear at very low strains, (2) quantify the effect of temperature, (3) may quantify the effects of changes in free volume, and (4) ensure very fast computations of the materials' response irrespective of the experimental time scale. The models are sensitive to the influence of different initial states of the material, as may result from varying degrees of molecular orientation and aging levels, and are able to predict from experimental stress relaxation moduli (for a poly (methylmethacrylate) - PMMA and a bis-phenol-A polycarbonate - PC) the values of the crossover frequency, νc, crossover temperature, Tc, and the minimum activation energy, in addition to the initial and long-time plateau moduli, in agreement with independently measured values. © 2016 Society of Plastics Engineers. Source


Lopes N.,University of Coimbra | Lopes N.,Polytechnic Institute of Guarda | Ribeiro B.,University of Coimbra
International Journal of Neural Systems | Year: 2011

The Graphics Processing Unit (GPU) originally designed for rendering graphics and which is difficult to program for other tasks, has since evolved into a device suitable for general-purpose computations. As a result graphics hardware has become progressively more attractive yielding unprecedented performance at a relatively low cost. Thus, it is the ideal candidate to accelerate a wide variety of data parallel tasks in many fields such as in Machine Learning (ML). As problems become more and more demanding, parallel implementations of learning algorithms are crucial for a useful application. In particular, the implementation of Neural Networks (NNs) in GPUs can significantly reduce the long training times during the learning process. In this paper we present a GPU parallel implementation of the Back-Propagation (BP) and Multiple Back-Propagation (MBP) algorithms, and describe the GPU kernels needed for this task. The results obtained on well-known benchmarks show faster training times and improved performances as compared to the implementation in traditional hardware, due to maximized floating-point throughput and memory bandwidth. Moreover, a preliminary GPU based Autonomous Training System (ATS) is developed which aims at automatically finding high-quality NNs-based solutions for a given problem. © 2011 World Scientific Publishing Company. Source


Andre J.R.S.,Polytechnic Institute of Guarda
Polymer Engineering and Science | Year: 2016

We expand our analytical modeling strategy for polymer non-linear stress relaxation (A) to specify the remaining steps to accurately deal with the nonaffine nature of the materials' local strains and stresses relative to their average overall values, and (B) to make it consistent with a new cooperative theory of amorphous materials dynamics, providing a model of tunable fragility that sheds light to most aspects of the behavior, including the glass transition. The stress relaxation models (1) describe a nonlinear (strain-dependent) behavior that becomes linear at very low strains, (2) quantify the effect of temperature, (3) may quantify the effects of changes in free volume, and (4) ensure very fast computations of the materials' response irrespective of the experimental time scale. The models are sensitive to the influence of different initial states of the material, as may result from varying degrees of molecular orientation and aging levels, and are able to predict from experimental stress relaxation moduli (for a poly (methylmethacrylate)-PMMA and a bis-phenol-A polycarbonate-PC) the values of the crossover frequency, νc, crossover temperature, Tc, and the minimum activation energy, in addition to the initial and long-time plateau moduli, in agreement with independently measured values. © 2016 Society of Plastics Engineers. Source


Gaspar P.D.,University of Beira Interior | Carrilho Goncalves L.C.,University of Beira Interior | Pitarma R.A.,Polytechnic Institute of Guarda
Applied Thermal Engineering | Year: 2011

The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition. © 2010 Elsevier Ltd. All rights reserved. Source

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