Learning Mazes with Aliasing States: An LCS Algorithm with Associative Perception

Learning classifier systems (LCSs) belong to a class of algorithms based on the principle of self-organization and have frequently been applied to the task of solving mazes, an important type of reinforcement learning (RL) problem. Maze problems represent a simplified virtual model of real environments that can be used for developing core algorithms of many real-world applications related to the problem of navigation. However, the best achievements of LCSs in maze problems are still mostly bounded to non-aliasing environments, while LCS complexity seems to obstruct a proper analysis of the reasons of failure. We construct a new LCS agent that has a simpler and more transparent performance mechanism, but that can still solve mazes better than existing algorithms. We use the structure of a predictive LCS model, strip out the evolutionary mechanism, simplify the reinforcement learning procedure and equip the agent with the ability of associative perception, adopted from psychology. To improve our understanding of the nature and structure of maze environments, we analyze mazes used in research for the last two decades, introduce a set of maze complexity characteristics, and develop a set of new maze environments. We then run our new LCS with associative perception through the old and new aliasing mazes, which represent partially observable Markov decision problems (POMDP) and demonstrate that it performs at least as well as, and in some cases better than, other published systems

Feasibility of an Audit and Feedback Intervention to Facilitate Journal Policy Change Towards Greater Promotion of Transparency and Openness in Sports Science Research

Objectives: To evaluate (1) the feasibility of an audit-feedback intervention to facilitate sports science journal policy change, (2) the reliability of the Transparency of Research Underpinning Social Intervention Tiers (TRUST) policy evaluation form, and (3) the extent to which policies of sports science journals support transparent and open research practices. Methods: We conducted a cross-sectional, audit-feedback, feasibility study of transparency and openness standards of the top 38 sports science journals by impact factor. The TRUST form was used to evaluate journal policies support for transparent and open research practices. Feedback was provided to journal editors in the format of a tailored letter. Inter-rater reliability and agreement of the TRUST form was assessed using intraclass correlation coefficients and the standard error of measurement, respectively. Time-based criteria, fidelity of intervention delivery and qualitative feedback were used to determine feasibility. Results: The audit-feedback intervention was feasible based on the time taken to rate journals and provide tailored feedback. The mean (SD) score on the TRUST form (range 0–27) was 2.05 (1.99), reflecting low engagement with transparent and open practices. Inter-rater reliability of the overall score of the TRUST form was moderate [ICC (2,1) = 0.68 (95% CI 0.55–0.79)], with standard error of measurement of 1.17. However, some individual items had poor reliability. Conclusion: Policies of the top 38 sports science journals have potential for improved support for transparent and open research practices. The feasible audit-feedback intervention developed here warrants large-scale evaluation as a means to facilitate change in journal policies. Registration: OSF (https://osf.io/d2t4s/)

Late Effects Screening Guidelines after Hematopoietic Cell Transplantation for Inherited Bone Marrow Failure Syndromes: Consensus Statement From the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects After Pediatric HCT

Transplantation and immunomodulatio

What Drives Fitness Apps Usage? An Empirical Evaluation

Part 3: Creating Value through ApplicationsInternational audienceThe increased health problems associated with lack of physical activity is of great concern around the world. Mobile phone based fitness applications appear to be a cost effective promising solution for this problem. The aim of this study is to develop a research model that can broaden understanding of the factors that influence the user acceptance of mobile fitness apps. Drawing from Unified Theory of Acceptance and Use of Technology (UTAUT) and Elaboration Likelihood Model (ELM), we conceptualize the antecedents and moderating factors of fitness app use. We validate our model using field survey. Implications for research and practice are discussed

Gravity, Twistors and the MHV Formalism

We give a self-contained derivation of the MHV amplitudes for gravity and use the associated twistor generating function to define a twistor action for the MHV diagram approach to gravity. Starting from a background field calculation on a spacetime with anti self-dual curvature, we obtain a simple spacetime formula for the scattering of a single, positive helicity linearized graviton into one of negative helicity. Re-expressing our integral in terms of twistor data allows us to consider a spacetime that is asymptotic to a superposition of plane waves. Expanding these out perturbatively yields the gravitational MHV amplitudes of Berends, Giele & Kuijf. We go on to take the twistor generating function off-shell at the perturbative level. Combining this with a twistor action for the anti self-dual background, we obtain a twistor action for the MHV diagram approach to perturbative gravity. We finish by extending these results to supergravity, in particular N=4 and N=8.Comment: 39 pages, 3 figures. Minor typos corrected, some clarification adde

From long-term follow-up Recommendations for clinical practice to plain language summaries for childhood, adolescent, and young adult cancer survivors

Background: Having sufficient knowledge of cancer diagnosis, treatment and late effects in survivors of childhood, adolescent, and young adult (CAYA) cancer is important for effective self-management and optimising health outcomes. Therefore, in collaboration with different stakeholders, the PanCare PLAIN Information Group converted the PanCareFollowUp Recommendations for late effects surveillance into information summaries that are Person-centred, written in Lay language, Accessible, Internationally relevant, and Navigable (PLAIN). Methods: The PanCare PLAIN Information Group, comprising 21 stakeholders from seven European countries, collaborated to provide concise information for survivors and their families. The aim was to deliver PLAIN summaries that are clear and accessible for the majority of survivors, while providing links to additional sources of information. The PLAIN summaries were drafted by the PanCare PLAIN Information Group and subjected to two internal and one external consultation round, the latter involving experts, CAYA cancer survivors and parents/caregivers. Results: In total, 45 PLAIN summaries were developed, each corresponding to one of the PanCareFollowUp Recommendations for late effects surveillance. The summaries provide information about late effects, personal health risks, important symptoms and signs, recommended surveillance strategies, possible referral and treatment options, and self-care. Conclusions: The PLAIN summaries are meant to increase knowledge in survivors and their families, while they may also inform healthcare professionals. Along with their translations, the PLAIN summaries will be made freely available on the PanCare website, with a link provided on the European Network of Youth Cancer Survivors information platform. In addition, they will become and integral part of the Survivorship Passport

Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector

A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance