1,366 research outputs found

    P298 Comparison between clinical and patient-reported symptoms among Crohn's disease and ulcerative colitis patients

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    Background: There is no symptom-based patient-reported outcomes (PRO) measurement available in IBD. Disease scores contain a mixture of PRO and physician's observations and have shown serious limitations in clinical trials. Comparison between healthcare professionals (HCP) and patient (P) reports on scores' items is a first step toward disease scores refinement. In our IBD cohort study, we were able to collect P and HCP-reported symptoms independently. We assessed the agreement between both measures, and tested the correlation between the general well-being item (GWB) and two health-related quality of life (HRQoL) measures. Methods: Between 2012 and 2015, we collected CDAI and MTWAI items 1) during follow-up medical visits, 2) through P self-reported follow-up questionnaire, except lab values. We compared items independently reported by HCP and P, stratified by diagnostic and Δt HCP-P reports. We calculated the Cohen's kappa (κ) statistic for agreement. A quadratic weight was applied for more severely serious disagreements. For EIM & complications, we computed a pooled κ based on the average between observed and expected probability of agreement over sub-items. A pooled κ was computed to summarize agreement over all examined variables. We also collected SF-36 and IBDQ scores. Pearson correlation coefficients r were calculated between both scores and GWB reports of HCP and P. Results: 2427 reports could be evaluated (Δt: 537<1 month, 390 1–2, 1500 2–6), referring to 1385 patients (52% females, 58% CD)

    Near-infrared oxygen airglow from the Venus nightside

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    Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus

    Organisation spatiale des sites de repos des sangliers en milieu méditerranéen.

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    En France, malgré la diversité des paysages, le sanglier est présent dans tous les départements. Tous les milieux aussi contrastés qu'ils soient (forêt, bocage, Camargue, garrigue etc...). Le développement des populations méditerranéennes a surtout été spectaculaire dans les garrigues à chêne vert du fait du vieillissement des peuplements et donc d'une augmentation de la nourriture liée à une production plus massive de glands. Le suivi rapproché d'individus par télémétrie a permis de montrer la sédentarité de cette espèce avec un attachement au domaine vital de naissance et a permis de mettre en évidence un choix quant à la structure de la végétation abritant les zones à bauges

    Information Needs and Concerns of Patients with Inflammatory Bowel Disease: What Can We Learn from Participants in a Bilingual Clinical Cohort?

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    BACKGROUND: Inflammatory Bowel Disease (IBD) patients are confronted with needs and concerns related to their disease. AIM: To explore information expectations of patients included in a national bilingual IBD cohort in Switzerland (SIBDC). METHODS: This is a mixed-methods study, comprising 1) a semi-narrative survey sent to 1506 patients from the SIBDC and 2) two focus groups conducted with 14 patients to explore and assess the relevance of the survey's findings. Data collected within the framework of the SIBDC was used to characterize survey's responders. RESULTS: 728 patients (48%) replied to the survey: 52.5% females, 56% Crohn's disease (CD), 87% secondary/tertiary level educated, 70% full/part-time employed. On average, 47% of patients sought for information, regardless of the disease stage; 27% of them were dissatisfied with information received at the time of first symptoms. During flares, 43% were concerned about drugs and therapies; in remission, 57% had concerns on research and developments; 27% searched for information linked to daily disease management. Information-seeking increased when active disease, for CD with high levels of perceived stress (OR = 2.47; p = 0.003), and for all with higher posttraumatic stress symptoms. The focus groups confirmed a perceived lack of information about general functioning, disease course, treatments and their risks, extra-intestinal symptoms and manifestations. CONCLUSIONS: Information remains insufficient for IBD patients. Lack of information in specific domains can potentially cause stress and hinder detection of symptoms. Better information should be considered as a potentially important component in improving patients' outcomes in IBD

    Extreme State Aggregation Beyond MDPs

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    We consider a Reinforcement Learning setup where an agent interacts with an environment in observation-reward-action cycles without any (esp.\ MDP) assumptions on the environment. State aggregation and more generally feature reinforcement learning is concerned with mapping histories/raw-states to reduced/aggregated states. The idea behind both is that the resulting reduced process (approximately) forms a small stationary finite-state MDP, which can then be efficiently solved or learnt. We considerably generalize existing aggregation results by showing that even if the reduced process is not an MDP, the (q-)value functions and (optimal) policies of an associated MDP with same state-space size solve the original problem, as long as the solution can approximately be represented as a function of the reduced states. This implies an upper bound on the required state space size that holds uniformly for all RL problems. It may also explain why RL algorithms designed for MDPs sometimes perform well beyond MDPs.Comment: 28 LaTeX pages. 8 Theorem

    Holonomic functions of several complex variables and singularities of anisotropic Ising n-fold integrals

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    Lattice statistical mechanics, often provides a natural (holonomic) framework to perform singularity analysis with several complex variables that would, in a general mathematical framework, be too complex, or could not be defined. Considering several Picard-Fuchs systems of two-variables "above" Calabi-Yau ODEs, associated with double hypergeometric series, we show that holonomic functions are actually a good framework for actually finding the singular manifolds. We, then, analyse the singular algebraic varieties of the n-fold integrals χ(n) \chi^{(n)}, corresponding to the decomposition of the magnetic susceptibility of the anisotropic square Ising model. We revisit a set of Nickelian singularities that turns out to be a two-parameter family of elliptic curves. We then find a first set of non-Nickelian singularities for χ(3) \chi^{(3)} and χ(4) \chi^{(4)}, that also turns out to be rational or ellipic curves. We underline the fact that these singular curves depend on the anisotropy of the Ising model. We address, from a birational viewpoint, the emergence of families of elliptic curves, and of Calabi-Yau manifolds on such problems. We discuss the accumulation of these singular curves for the non-holonomic anisotropic full susceptibility.Comment: 36 page

    Post-critical set and non existence of preserved meromorphic two-forms

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    We present a family of birational transformations in CP2 CP_2 depending on two, or three, parameters which does not, generically, preserve meromorphic two-forms. With the introduction of the orbit of the critical set (vanishing condition of the Jacobian), also called ``post-critical set'', we get some new structures, some "non-analytic" two-form which reduce to meromorphic two-forms for particular subvarieties in the parameter space. On these subvarieties, the iterates of the critical set have a polynomial growth in the \emph{degrees of the parameters}, while one has an exponential growth out of these subspaces. The analysis of our birational transformation in CP2 CP_2 is first carried out using Diller-Favre criterion in order to find the complexity reduction of the mapping. The integrable cases are found. The identification between the complexity growth and the topological entropy is, one more time, verified. We perform plots of the post-critical set, as well as calculations of Lyapunov exponents for many orbits, confirming that generically no meromorphic two-form can be preserved for this mapping. These birational transformations in CP2 CP_2, which, generically, do not preserve any meromorphic two-form, are extremely similar to other birational transformations we previously studied, which do preserve meromorphic two-forms. We note that these two sets of birational transformations exhibit totally similar results as far as topological complexity is concerned, but drastically different results as far as a more ``probabilistic'' approach of dynamical systems is concerned (Lyapunov exponents). With these examples we see that the existence of a preserved meromorphic two-form explains most of the (numerical) discrepancy between the topological and probabilistic approach of dynamical systems.Comment: 34 pages, 7 figure

    Private Incremental Regression

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    Data is continuously generated by modern data sources, and a recent challenge in machine learning has been to develop techniques that perform well in an incremental (streaming) setting. In this paper, we investigate the problem of private machine learning, where as common in practice, the data is not given at once, but rather arrives incrementally over time. We introduce the problems of private incremental ERM and private incremental regression where the general goal is to always maintain a good empirical risk minimizer for the history observed under differential privacy. Our first contribution is a generic transformation of private batch ERM mechanisms into private incremental ERM mechanisms, based on a simple idea of invoking the private batch ERM procedure at some regular time intervals. We take this construction as a baseline for comparison. We then provide two mechanisms for the private incremental regression problem. Our first mechanism is based on privately constructing a noisy incremental gradient function, which is then used in a modified projected gradient procedure at every timestep. This mechanism has an excess empirical risk of d\approx\sqrt{d}, where dd is the dimensionality of the data. While from the results of [Bassily et al. 2014] this bound is tight in the worst-case, we show that certain geometric properties of the input and constraint set can be used to derive significantly better results for certain interesting regression problems.Comment: To appear in PODS 201

    Fuchs versus Painlev\'e

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    We briefly recall the Fuchs-Painlev\'e elliptic representation of Painlev\'e VI. We then show that the polynomiality of the expressions of the correlation functions (and form factors) in terms of the complete elliptic integral of the first and second kind, K K and E E, is a straight consequence of the fact that the differential operators corresponding to the entries of Toeplitz-like determinants, are equivalent to the second order operator LE L_E which has E E as solution (or, for off-diagonal correlations to the direct sum of LE L_E and d/dt d/dt). We show that this can be generalized, mutatis mutandis, to the anisotropic Ising model. The singled-out second order linear differential operator LE L_E being replaced by an isomonodromic system of two third-order linear partial differential operators associated with Π1 \Pi_1, the Jacobi's form of the complete elliptic integral of the third kind (or equivalently two second order linear partial differential operators associated with Appell functions, where one of these operators can be seen as a deformation of LE L_E). We finally explore the generalizations, to the anisotropic Ising models, of the links we made, in two previous papers, between Painlev\'e non-linear ODE's, Fuchsian linear ODE's and elliptic curves. In particular the elliptic representation of Painlev\'e VI has to be generalized to an ``Appellian'' representation of Garnier systems.Comment: Dedicated to the : Special issue on Symmetries and Integrability of Difference Equations, SIDE VII meeting held in Melbourne during July 200
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