Abalearn: a risk-sensitive approach to self-play learning in Abalone

This paper presents Abalearn, a self-teaching Abalone pro gram capable of automatically reaching an intermediate level of play without needing expert-labeled training examples, deep searches or ex posure to competent play. Our approach is based on a reinforcement learning algorithm that is risk seeking, since defensive players in Abalone tend to never end a game. We show that it is the risk-sensitivity that allows a successful self-play training. We also propose a set of features that seem relevant for achiev ing a good level of play. We evaluate our approach using a fixed heuristic opponent as a bench mark, pitting our agents against human players online and comparing samples of our agents at different times of training.info:eu-repo/semantics/publishedVersio

Short-term Feature Space and Music Genre Classification

In music genre classification, most approaches rely on statistical characteristics of low-level features computed on short audio frames. In these methods, it is implicitly considered that frames carry equally relevant information loads and that either individual frames, or distributions thereof, somehow capture the specificities of each genre. In this paper we study the representation space defined by short-term audio features with respect to class boundaries, and compare different processing techniques to partition this space. These partitions are evaluated in terms of accuracy on two genre classification tasks, with several types of classifiers. Experiments show that a randomized and unsupervised partition of the space, used in conjunction with a Markov Model classifier lead to accuracies comparable to the state of the art. We also show that unsupervised partitions of the space tend to create less hubs

Characterization of stellar companion from high-contrast long-slit spectroscopy data: The EXtraction Of SPEctrum of COmpanion (EXOSPECO) algorithm

High-contrast long-slit spectrographs can be used to characterize exoplanets. High-contrast long-slit spectroscopic data are however corrupted by stellar leakages which largely dominate other signals and make the process of extracting the companion spectrum very challenging. This paper presents a complete method to calibrate the spectrograph and extract the signal of interest. The proposed method is based on a flexible direct model of the high-contrast long-slit spectroscopic data. This model explicitly accounts for the instrumental response and for the contributions of both the star and the companion. The contributions of these two components and the calibration parameters are jointly estimated by solving a regularized inverse problem. This problem having no closed-form solution, we propose an alternating minimization strategy to effectively find the solution. We have tested our method on empirical long-slit spectroscopic data and by injecting synthetic companion signals in these data. The proposed initialization and the alternating strategy effectively avoid the self-subtraction bias, even for companions observed very close to the coronagraphic mask. Careful modeling and calibration of the angular and spectral dispersion laws of the instrument clearly reduce the contamination by the stellar leakages. In practice, the outputs of the method are mostly driven by a single hyper-parameter which tunes the level of regularization of the companion SED.Comment: Paper under review by Astronomy & Astrophysic

Opioid prescribing practices and training needs of Québec family physicians for chronic noncancer pain

Abstract : AIM: To examine medical practices and training needs of Québec family physicians with respect to pain management and opioid prescription for chronic noncancer pain (CNCP). METHODOLOGY: An online survey was carried out in 2016. RESULTS: Of 636 respondents (43.0% men; 54.3% ≥ 50 years old), 15.2% and 70.9% felt very or somewhat confident that they could properly prescribe opioids for CNCP. Concerns related to abuse (72.5% strongly/somewhat agree), dependence (73.2%), and lack of support (75.4%) were the main barriers reported. Only 19.7% always/often screened their patients for risks of abuse and dependence using a screening tool. About two-thirds of participants (65.7%) had recently (last five years) taken part in continuing education programs on opioid use for CNCP and 73.4% on CNCP management. Patient evaluation and differential diagnoses of chronic pain syndromes were rated as a top priority for further training. CONCLUSIONS: This study provides insights into Québec family physicians' concerns, practices, and needs with respect to the management of CNCP. Physicians' difficulties around the application of strategies to mitigate the problem of opioid abuse and addiction are worrying. The need to better train physicians in the field of pain and addiction cannot be emphasized enough

Utilizing individual fish biomass and relative abundance models to map environmental niche associations of adult and juvenile targeted fishes

Many fishes undergo ontogenetic habitat shifts to meet their energy and resource needs as they grow. Habitat resource partitioning and patterns of habitat connectivity between conspecific fishes at different life-history stages is a significant knowledge gap. Species distribution models were used to examine patterns in the relative abundance, individual biomass estimates and environmental niche associations of different life stages of three iconic West Australian fishes. Continuous predictive maps describing the spatial distribution of abundance and individual biomass of the study species were created as well predictive hotspot maps that identify possible areas for aggregation of individuals of similar life stages of multiple species (i.e. spawning grounds, fisheries refugia or nursery areas). The models and maps indicate that processes driving the abundance patterns could be different from the body size associated demographic processes throughout an individual's life cycle. Incorporating life-history in the spatially explicit management plans can ensure that critical habitat of the vulnerable stages (e.g. juvenile fish, spawning stock) is included within proposed protected areas and can enhance connectivity between various functional areas (e.g. nursery areas and adult populations) which, in turn, can improve the abundance of targeted species as well as other fish species relying on healthy ecosystem functioning

Prior mucosal exposure to heterologous cells alters the pathogenesis of cell-associated mucosal feline immunodeficiency virus challenge

<p>Abstract</p> <p>Background</p> <p>Several lines of research suggest that exposure to cellular material can alter the susceptibility to infection by HIV-1. Because sexual contact often includes exposure to cellular material, we hypothesized that repeated mucosal exposure to heterologous cells would induce an immune response that would alter the susceptibility to mucosal infection. Using the feline immunodeficiency virus (FIV) model of HIV-1 mucosal transmission, the cervicovaginal mucosa was exposed once weekly for 12 weeks to 5,000 heterologous cells or media (control) and then cats were vaginally challenged with cell-associated or cell-free FIV.</p> <p>Results</p> <p>Exposure to heterologous cells decreased the percentage of lymphocytes in the mucosal and systemic lymph nodes (LN) expressing L-selectin as well as the percentage of CD4+ CD25+ T cells. These shifts were associated with enhanced ex-vivo proliferative responses to heterologous cells. Following mucosal challenge with cell-associated, but not cell-free, FIV, proviral burden was reduced by 64% in cats previously exposed to heterologous cells as compared to media exposed controls.</p> <p>Conclusions</p> <p>The pathogenesis and/or the threshold for mucosal infection by infected cells (but not cell-free virus) can be modulated by mucosal exposure to uninfected heterologous cells.</p

« La blockchain au regard du droit et de l'identité »

L’auteur a procédé à un horodatage cryptographique de cette thèse sur la blockchain Bitcoin. Il certifie avoir en sa possession les clés cryptographiques associées à ces transactions immuables (voir ci-dessous). Il affirme être en mesure de prouver numériquement l’antériorité et la propriété de ses droits d’auteur ainsi que l’authenticité et l’intégrité du présent document.For more than a decade, blockchain technologies have been gradually and deeply redefining the political, legal, and economic boundaries of our social contract. Some of their characteristics both liberate and challenge the established order, i.e. existing governance models. In collaboration with the IN Groupe company and through an interdisciplinary lens, this paper examines how the positioning and perspectives of these new technologies are articulated, opposed, or integrated into current legal and social frameworks. In parallel with societal upheavals analyzed in the context of computer decentralization, the concept of digital identity has been evolving and questioned for several decades to cope with the explosive expansion of online interactions and identification needs of individuals. This insatiable digitization of our lives implies new philosophical, social, and legal considerations considering the many facets of our already ‘phygital’ identities. These attempts at defining and scientifically reclaiming identity also evoke new concrete lines of reflection regarding the emergence of a new digital identity 3.0. Supposedly decentralized, emancipatory, and serving digital rights, we identify how decentralized digital identity and blockchain technologies represent a revolution in search of new legal rules. By examining socio-digital (eco)systems, this study questions the consequences of these new Web 3.0 decentralization technologies, allowing individuals to hold universal proof of digital existence in line with their fundamental, now cryptographic and programmable, rights. A privileged line of reflection suggests that it is crucial not to prohibit or discredit certain open and decentralized blockchains, to satisfy the continuous needs of trust and cryptographic ownership of Internet users and citizens. These infrastructures can indeed serve as an alternative and digital counterbalance, particularly in developing countries.Depuis plus d'une décennie, les technologies blockchains redéfinissent progressivement et en profondeur les frontières politiques, juridiques et économiques de notre contrat social. Certaines de ses caractéristiques libèrent autant qu’elles défient l’ordre établi, c’est-à-dire les modèles de gouvernance existants. En collaboration avec la société IN Groupe, il est étudié à travers un prisme interdisciplinaire comment le positionnement et les perspectives de ces nouvelles technologies s’articulent, s’opposent ou s'inscrivent dans les cadres juridiques et sociaux actuels. En parallèle de bouleversements sociétaux analysés au regard de la décentralisation informatique, le concept d'identité numérique ne cesse depuis plusieurs décennies d'évoluer et d'être interrogé par les sciences pour faire face à l'expansion fulgurante des interactions et des besoins d'identification en ligne des personnes. Cette insatiable numérisation de nos vies implique de nouvelles considérations philosophiques, sociales et juridiques à la lumière des nombreuses facettes de nos identités, d'ores et déjà ‘phygitales’. Avec ces tentatives de définitions et de réappropriations scientifiques de l’identité sont également évoquées de nouvelles pistes de réflexion concrètes et actualisées au regard de l’émergence d’une nouvelle identité numérique 3.0. Supposées décentralisées, émancipatrices et au service de droits numériques, nous identifions en quoi l'identité numérique décentralisée et les technologies blockchains représentent une révolution à la recherche de nouvelles règles de droit. Par une photographie des (éco)systèmes socio-numériques cette étude interroge les conséquences de ces nouvelles technologies de décentralisation du Web 3.0, permettant aux individus de détenir une preuve d’existence numérique universelle en adéquation avec leurs droits fondamentaux, désormais cryptographiques et programmables. Une voie de réflexion privilégiée suggère qu'il est crucial de ne pas interdire ni discréditer certaines blockchains ouvertes et décentralisées, afin de satisfaire les besoins continus de confiance et de propriété cryptographique des internautes et des citoyens. Ces infrastructures peuvent effectivement servir d'alternative et de contre-pouvoir numérique, tout particulièrement dans les pays en voie de développement