Quantum Cosmology in Scalar-Tensor Theories With Non Minimal Coupling

Quantization in the minisuperspace of non minimal scalar-tensor theories leads to a partial differential equation which is non separable. Through a conformal transformation we can recast the Wheeler-DeWitt equation in an integrable form, which corresponds to the minimal coupling case, whose general solution is known. Performing the inverse conformal transformation in the solution so found, we can construct the corresponding one in the original frame. This procedure can also be employed with the bohmian trajectories. In this way, we can study the classical limit of some solutions of this quantum model. While the classical limit of these solutions occurs for small scale factors in the Einstein's frame, it happens for small values of the scalar field non minimally coupled to gravity in the Jordan's frame, which includes large scale factors.Comment: latex, 18 page

Nonclassical correlation in NMR quadrupolar systems

The existence of quantum correlation (as revealed by quantum discord), other than entanglement and its role in quantum-information processing (QIP), is a current subject for discussion. In particular, it has been suggested that this nonclassical correlation may provide computational speedup for some quantum algorithms. In this regard, bulk nuclear magnetic resonance (NMR) has been successfully used as a test bench for many QIP implementations, although it has also been continuously criticized for not presenting entanglement in most of the systems used so far. In this paper, we report a theoretical and experimental study on the dynamics of quantum and classical correlations in an NMR quadrupolar system. We present a method for computing the correlations from experimental NMR deviation-density matrices and show that, given the action of the nuclear-spin environment, the relaxation produces a monotonic time decay in the correlations. Although the experimental realizations were performed in a specific quadrupolar system, the main results presented here can be applied to whichever system uses a deviation-density matrix formalism.Comment: Published versio

Optimizing Opponents Selection in Bilateral Contracts Negotiation with Particle Swarm

This paper proposes a model based on particle swarm optimization to aid electricity markets players in the selection of the best player(s) to trade with, to maximize their bilateral contracts outcome. This approach is integrated in a Decision Support System (DSS) for the pre-negotiation of bilateral contracts, which provides a missing feature in the state-of-art, the possible opponents analysis. The DSS determines the best action of all the actions that the supported player can take, by applying a game theory approach. However, the analysis of all actions can easily become very time-consuming in large negotiation scenarios. The proposed approach aims to provide the DSS with an alternative method with the capability of reducing the execution time while keeping the results quality as much as possible. Both approaches are tested in a realistic case study where the supported player could take almost half a million different actions. The results show that the proposed methodology is able to provide optimal and near-optimal solutions with an huge execution time reduction.This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 641794 (project DREAM-GO) and grant agreement No 703689 (project ADAPT); from the CONTEST project - SAICT-POL/23575/2016; and from FEDER Funds through COMPETE program and from National Funds through FCT under the project UID/EEA/00760/2013.info:eu-repo/semantics/publishedVersio

Assessment of Exoskeleton Related Changes in Kinematics and Muscle Activity

Work-related musculoskeletal disorders, reported at shoulder and low back regions, rank among the most serious health problems in industry. Owing to their ability in providing support to the shoulder and back regions during sustained and repetitive tasks, passive exoskeletons are expected to prevent work-related disorders. In this work, experimental protocols were conducted for the extraction of relevant information regarding the neuromuscular activation and kinematics during simulated working activities with passive exoskeletons. Our results support the notion these passive exoskeletons have the potential to alleviate muscular loading and therefore to prevent musculoskeletal disorders in the industrial sector

Multi-agent Electricity Markets and Smart Grids Simulation with Connection to Real Physical Resources

The increasing penetration of distributed energy sources, mainly based on renewable generation, calls for an urgent emergence of novel advanced methods to deal with the associated problems. The consensus behind smart grids (SGs) as one of the most promising solutions for the massive integration of renewable energy sources in power systems has led to the development of several prototypes that aim at testing and validating SG methodologies. The urgent need to accommodate such resources require alternative solutions. This chapter presents a multi-agent based SG simulation platform connected to physical resources, so that realistic scenarios can be simulated. The SG simulator is also connected to the Multi-Agent Simulator of Competitive Electricity Markets, which provides a solid framework for the simulation of electricity markets. The cooperation between the two simulation platforms provides huge studying opportunities under different perspectives, resulting in an important contribution to the fields of transactive energy, electricity markets, and SGs. A case study is presented, showing the potentialities for interaction between players of the two ecosystems: a SG operator, which manages the internal resources of a SG, is able to participate in electricity market negotiations to trade the necessary amounts of power to fulfill the needs of SG consumers.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement N. 641794 (project DREAM-GO). It has also received FEDER Funds through the COMPETE program and National Funds through FCT under the project UID/EEA/00760/2013. The authors gratefully acknowledge the valuable contribution of Bruno Canizes, Daniel Paiva, Gabriel Santos and Marco Silva to the work presented in the chapter.info:eu-repo/semantics/publishedVersio

Efeito na produção e incidência de viroses em híbridos comerciais de milho.

Quatro ensaios foram conduzidos para se avaliar a incidencia e prejuizos causados por viroses em milho. Observou-se a ocorrencia principalmente de rayado fino e de mosaico comum, causando perdas, respectivamente, de 28,64 e 47,50% no peso de graos. Notou-se variacao de 0 a 100% na incidencia dessa viroses nos hibridos comerciais de milho. Os hibridos mais resistentes ao mosaico comum foram: "C 969", "C 901" and "Agromen 3060" e os mais resistente ao rayado fino foram: "AGX 9332", "AG 5012" e "EXP. 31029 (CAC)"

The Effect of Passive Exoskeleton on Shoulder Muscles Activity during Different Static Tasks

In this study we used the bipolar surface electromyography to investigate whether a passive exoskeleton reduces the degree of activity of shoulder muscles. Twelve young healthy volunteers participated in the study. Subjects were asked to hold four different static postures: (P1) shoulder abducted at 90°, elbow flexed at 90°, elbow pronated at 90°; (P2) shoulder flexed at 90°, elbow flexed at 90°, elbow pronated at 90°; (P3) shoulder flexed at 90°, elbow pronated at 90°; (P4) shoulder abducted at 90°, elbow pronated at 90°. Subjects maintained each posture for 20 seconds five consecutive times, with a rest time in-between of 20 seconds. Surface EMG signals were collected from anterior, medial and posterior deltoids and upper trapezius muscles. Our main statistical results showed a significant (p < 0.05) attenuation effect of exoskeleton on the RMS amplitude computed for all muscles evaluated, though not for all postures. For the anterior, medial deltoids and upper trapezius a lower level of activity was observed in all postures with than without exoskeleton, while for posterior deltoid only for P2-P3 and P1-P4 respectively. These findings suggest the passive exoskeleton evaluated in this study attenuates the shoulder muscles’ effort during static work-related tasks, with implications on the prevention of musculoskeletal disorders

Changes in the distribution of muscle activity when using a passive trunk exoskeleton depend on the type of working task: A high-density surface EMG study

Exoskeleton effectiveness in reducing muscle efforts has been usually assessed from surface electromyograms (EMGs) collected locally. It has been demonstrated, however, muscle activity redistributes within the low back muscles during static and dynamic contractions, suggesting the need of detecting surface EMGs from a large muscle region to reliably investigate changes in global muscle activation. This study used high-density surface EMG to assess the effects of a passive trunk exoskeleton on the distribution of low back muscles’ activity during different working tasks. Ten, male volunteers performed a static and a dynamic task with and without the exoskeleton. Multiple EMGs were sampled bilaterally from the lumbar erector spinae muscles while the hip and knee angles were measured unilaterally. Key results revealed for the static task exoskeleton led to a decrease in the average root mean square (RMS) amplitude (∼10%) concomitantly with a stable mean frequency and a redistribution of muscle activity (∼0.5 cm) in the caudal direction toward the end of the task. For the dynamic task, the exoskeleton reduced the RMS amplitude (∼5%) at the beginning of the task and the variability in the muscle activity distribution during the task. Moreover, a reduced range of motion in the lower limb was observed when using the exoskeleton during the dynamic task. Current results support the notion the passive exoskeleton has the potential to alleviate muscular loading at low back level especially for the static task

Persistência dos efeitos da escarificação sobre a compactação de Nitossolo sob plantio direto em região subtropical úmida.

Avalia a persistência dos efeitos da escarificação sobre a compactação de Nitossolo Vermelho, manejado sob plantio direto (PD), na região subtropical úmida do Brasil. O experimento foi realizado em blocos ao acaso, com quatro repetições e seis tratamentos, constituídos pelo tempo de manutenção do solo sob PD após escarificação: PD contínuo por 24 meses após escarificação, realizada setembro de 2009; PD contínuo por 18 meses após escarificação, realizada em março de 2010; PD contínuo por 12 meses após escarificação, realizada em setembro de 2010; PD contínuo por seis meses após escarificação, realizada em março de 2011; plantio realizado em solo recém escarificado, em setembro de 2011; e PD contínuo e sem escarificação (testemunha). As espécies cultivadas na área foram: milho, safra 2009/2010; trigo, em 2010; soja, safra 2010/2011; centeio, em 2011; e milho, safra 2011/2012. Os efeitos dos tratamentos foram avaliados a partir de parâmetros físicos do solo e de parâmetros morfológicos e produtivos da cultura do milho, na safra 2011/2012. A escarificação do Nitossolo sob plantio direto, em região de clima subtropical úmido, não aumenta a produtividade de grãos de milho, e os seus efeitos sobre a estrutura do solo não persistem por mais de 18 meses

Avoidable mortality in acute myocardial infarction at hospital level : where to look for answers?

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017Background: Outcomes assessment is very important for improving health care outcomes and control spending. Acute myocardial infarction (AMI) was chosen for its prevalence, high morbidity and mortality, relevant mortality variability and high treatment costs. Purpose: To study the differences between hospitals in AMI mortality and the associated waste from unjustified variation. Methods: Patients with AMI discharged from public hospitals in our country in 2011–13 were selected and anonymized administrative data was utilized. The relevant variables to explain the differences in mortality were: patient characteristics (demographics, AMI type, comorbidities, and procedures), hospital characteristics (hospital with “coronary green way”, volume, and university hospital), and travel time to hospital. Generalized linear mixed models (1st level: patient, 2nd level: hospital) were used and specifically binary logistic regression was applied. The differences in mortality explained by each group of variables were evaluated with a percentual rate of Pseudo-r2. We considered as waste the number of additional deaths in each hospital compared to patients with the same characteristics, through the hospital random effect variance (difference of each hospital to the global odds). Results: 22.380 patients treated in 17 hospitals were included. Mortality rate was 9.5%. The mortality rate varied between 5.4% (H11) and 14.1% (H3). Our model explained 29.8% of the differences in mortality. Comorbidities explained 23.2% of mortality differences, demographic variables 7.8%, procedures 6.6%, and type of AMI 2.8%. Angioplasty and primary angioplasty procedures were protective factors, since all other procedures showed a comparatively increased risk of death, particularly fibrinolysis without angioplasty (OR 5.9; CI 3.2–10.9). Across all hospitals, there were 137 avoidable deaths, with a variation between -81 deaths (hospital with lower mortality) and +133 deaths (hospital with higher mortality). As shown in Fig. 1, there was a risk of death 3.5 times higher at H8 than at H7. The model showed excellent discrimination (area under the ROC curve: 0.871). Conclusion: We observed significant differences in mortality in acute myocardial infarction between hospitals, therefore indicating variability of practices. The scale of avoidable deaths justifies an investigation of its causes, mainly in the hospitals with worse performance. The hospital characteristics had little impact on the detected differences, so the inefficiencies are probably more related with the internal organization of hospitals and the way care is provided. These results raise relevant concerns at the health system and hospitals levels, in particular about the compliance with AMI guidelines.info:eu-repo/semantics/publishedVersio