286 research outputs found
Scalable Safe Policy Improvement via Monte Carlo Tree Search
Algorithms for safely improving policies are important to deploy reinforcement learning approaches in real-world scenarios. In this work, we propose an algorithm, called MCTS-SPIBB, that computes safe policy improvement online using a Monte Carlo Tree Search based strategy. We theoretically prove that the policy generated by MCTS-SPIBB converges, as the number of simulations grows, to the optimal safely improved policy generated by Safe Policy Improvement with Baseline Bootstrapping (SPIBB), a popular algorithm based on policy iteration. Moreover, our empirical analysis performed on three standard benchmark domains shows that MCTS-SPIBB scales to significantly larger problems than SPIBB because it computes the policy online and locally, i.e., only in the states actually visited by the agent
Parametric design velocity computation for CAD-based design optimization using adjoint methods
This paper presents an efficient optimization process, where the parameters defining the features in a feature-based CAD model are used as design variables. The process exploits adjoint methods for the computation of gradients, and as such the computational cost is essentially independent of the number of design variables, making it ideal for optimization in large design spaces. The novelty of this paper lies in linking the adjoint surface sensitivity information with geometric sensitivity values, referred to as design velocities, computed for CAD models created in commercial CAD systems (e.g. CATIA V5 or Siemens NX)
Portugal e os BRIC: numa perspectiva da diplomacia pública e da autopoiesis
O sistema internacional post-‐11 de Setembro vem acelerar a movimentação em torno da sociedade civil, alterando, consequentemente, o próprio conceito espácio-temporal da actuação da diplomacia, na sua acepção clássica, na arena internacional enquanto instrumento pacífico de execução da política externa. Assiste-se a uma complexidade crescente no processo de edificação da nova ordem mundial cujo epicentro se circunscreve numa espécie de sub-‐mundialização à escala doméstica de cada Estado quer pela (in)capacidade da elite governante em responder aos estímulos provenientes do ambiente externo ao ritmo vertiginoso da velocidade dos fluxos de informação entre os mais diversos actores das relações internacionais. Daí que a prática da diplomacia tradicional tal como a conhecemos caminha para além da evolução teórica, situando-se cada vez mais em termos concretos num mundo inconstante de caminho incerto com regimes antagónicos de convergências pontuais e imprevisíveis que levam à emergência de outras formas de actuação como sendo o caso da diplomacia pública que representa um recurso estratégico vital para os estados enquanto actores das relações internacionais e concretamente para o caso de Portugal nas suas relações com os BRIC onde se pretende melhorar e influenciar a imagem de um país quer internamente quer externamente como um país/marca num mundo competitivo
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Parental perspectives on negotiations over diet and physical activity: how do we involve parents in adolescent health interventions?
OBJECTIVE: To identify the ways in which parental involvement can be incorporated into interventions to support adolescent health behaviour change.
DESIGN: Data from semi-structured interviews were analysed using inductive thematic analysis.
SETTING: Southampton, Hampshire, UK.
PARTICIPANTS: A convenience sample of twenty-four parents of adolescents.
RESULTS: Parents consider themselves to play an important role in supporting their adolescents to make healthy choices. Parents saw themselves as gatekeepers of the household and as role models to their adolescents but recognised this could be both positive and negative in terms of health behaviours. Parents described the changing dynamics of the relationships they have with their adolescents because of increased adolescent autonomy. Parents stated that these changes altered their level of influence over adolescents' health behaviours. Parents considered it important to promote independence in their adolescents; however, many described this as challenging because they believed their adolescents were likely to make unhealthy decisions if not given guidance. Parents reported difficulty in supporting adolescents in a way that was not viewed as forceful or pressuring.
CONCLUSIONS: When designing adolescent health interventions that include parental components, researchers need to be aware of the disconnect between public health recommendations and the everyday reality for adolescents and their parents. Parental involvement in adolescent interventions could be helpful but needs to be done in a manner that is acceptable to both adolescents and parents. The findings of this study may be useful to inform interventions which need to consider the transitions and negotiations which are common in homes containing adolescents
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STANDARDS ASSESSMENT OF BUSINESS USE CASES PROPOSED IN TDX-ASSIST
The Transmission System Operator and Distribution System Operator information exchange has been identified as a key subject to improve the performance of power systems. The standard assessment of the business objects needed to improve this exchange of information is illustrated in the paper. The standard assessment is based on the pertinent business and system Use Cases identified in European project TDX-ASSIST and on EC Core Standards as defined in IEC 63097 Technical Report Smart Grid Roadmap. These standards are considered as standards having an enormous effect on any Smart Grid application and solution. They are seen as a backbone of a future Smart Grid. The used methodology based in three main steps is detailed and some examples of the standard assessment are described.European Union’s Horizon 202
A new interministerial strategy for the promotion of healthy eating in Portugal: implementation and initial results
ObjectiveTo describe the implementation, main intervention areas and initial results of the Integrated Strategy for the Promotion of Healthy Eating (EIPAS) in Portugal.MethodsEIPAS was published as a Law, in December of 2017, as a result of a collaboration between several ministries, including the Finance, Internal Affairs, Education, Health, Economy, Agriculture, and Sea Ministries, aiming at improving the dietary habits of the Portuguese population. The working group, led by the Ministry of Health, developed this strategy for over a year. The framework produced was based on WHO and European Commission recommendations as well as on relevant data from the last Portuguese dietary intake survey (2015/2016). EIPAS also reflects the results of a public hearing, including the food industry, among others, and the experience gathered, since 2012, through the National Programme for the Promotion of Healthy Eating. It considers the health in all policies' challenge set by WHO and has four different strategic areas, namely (1) creation of healthier food environments, (2) improvement of the quality and accessibility of healthy food choices for consumers, (3) promotion and development of literacy, in order to encourage healthy food choices, and (4) promotion of innovation and entrepreneurship. In order to achieve these goals, a set of 51 actions was established and assigned to the seven ministries involved.ResultsUnder the scope of this strategy, Portugal has already implemented several actions, including (1) definition of standards for food availability at all public healthcare institutions; (2) implementation of a sugar tax on sweetened beverages; (3) implementation of a voluntary agreement with the food industry sector for food reformulation (work in progress); (4) design of a proposal for an interpretative model of front-of-pack food labelling; (5) improvement of the nutritional quality of food aid programmes for low-income groups; and (6) regulation of marketing of unhealthy foods to children.ConclusionsFor the first time, Portugal has a nutrition policy based on the WHO concept of health in all policies' and on the national data on food intake. The implementing process of all 51 actions and the inherent complexities and difficulties found so far have made this process be an authentic political and social laboratory that deserves to be followed
Search for CP violation in D0 and D+ decays
A high statistics sample of photoproduced charm particles from the FOCUS
(E831) experiment at Fermilab has been used to search for CP violation in the
Cabibbo suppressed decay modes D+ to K-K+pi+, D0 to K-K+ and D0 to pi-pi+. We
have measured the following CP asymmetry parameters: A_CP(K-K+pi+) = +0.006 +/-
0.011 +/- 0.005, A_CP(K-K+) = -0.001 +/- 0.022 +/- 0.015 and A_CP(pi-pi+) =
+0.048 +/- 0.039 +/- 0.025 where the first error is statistical and the second
error is systematic. These asymmetries are consistent with zero with smaller
errors than previous measurements.Comment: 12 pages, 4 figure
Evaluation of different methods of determining the angle of attack on wind turbine blades under yawed inflow conditions
As part of the AVATAR and Mexnext projects, this study compares several methods used to derive lifting line variables from CFD simulations of the MEXICO rotor in yawed inflow. The results from six partners within the AVATAR/Mexnext consortium using five different methods of extraction were compared. Overall comparison of the induced velocities at the mid and tip parts of blade shows fairly good agreement between the tested methods, where the derived angle of attack differs within 1°, within the linear range this accounts to ˂ 10% uncertainty on the aerodynamic forces. The presented comparison shows inadequate agreement between the methods for application towards the root
New therapeutic targets for osteoarthritis pain
Osteoarthritis (OA), the most common form of arthritis, causes pain and disability, as well as emotional distress. While total joint replacement is one of the most effective treatments available for improving the quality of life in people with severe OA, it is not suitable for all patients and all joints. Current pharmacological analgesics have limited efficacy, and their use is often restricted by adverse events. Medications that might reduce pain by slowing or preventing structural disease remain elusive. Our increasing understanding of the complex mechanisms that underlie OA pain offers a wide range of potential new treatment targets. New drugs for OA pain might come from repurposing those developed for other conditions, as well as novel compounds targeting pain mechanisms specific to the joint. Here we discuss the mechanisms of OA pain and its therapeutic implications. We explore evolving treatment modalities, including combination treatment. We review recent research and patents pointing to future OA therapies. We discuss the potential for biomarkers to facilitate drug development and targeting
Microcalcifications in breast cancer: novel insights into the molecular mechanism and functional consequence of mammary mineralisation.
BACKGROUND: Mammographic microcalcifications represent one of the most reliable features of nonpalpable breast cancer yet remain largely unexplored and poorly understood.
METHODS: We report a novel model to investigate the in vitro mineralisation potential of a panel of mammary cell lines. Primary mammary tumours were produced by implanting tumourigenic cells into the mammary fat pads of female BALB/c mice.
RESULTS: Hydroxyapatite (HA) was deposited only by the tumourigenic cell lines, indicating mineralisation potential may be associated with cell phenotype in this in vitro model. We propose a mechanism for mammary mineralisation, which suggests that the balance between enhancers and inhibitors of physiological mineralisation are disrupted. Inhibition of alkaline phosphatase and phosphate transport prevented mineralisation, demonstrating that mineralisation is an active cell-mediated process. Hydroxyapatite was found to enhance in vitro tumour cell migration, while calcium oxalate had no effect, highlighting potential consequences of calcium deposition. In addition, HA was also deposited in primary mammary tumours produced by implanting the tumourigenic cells into the mammary fat pads of female BALB/c mice.
CONCLUSION: This work indicates that formation of mammary HA is a cell-specific regulated process, which creates an osteomimetic niche potentially enhancing breast tumour progression. Our findings point to the cells mineralisation potential and the microenvironment regulating it, as a significant feature of breast tumour development
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