839 research outputs found
Intravenous magnesium in subarachnoid hemorrhage
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Learning on the Edge: Online Learning with Stochastic Feedback Graphs
The framework of feedback graphs is a generalization of sequential decision-making with bandit or full information feedback. In this work, we study an extension where the directed feedback graph is stochastic, following a distribution similar to the classical Erdős-Rényi model. Specifically, in each round every edge in the graph is either realized or not with a distinct probability for each edge. We prove nearly optimal regret bounds of order (Equation presented) (ignoring logarithmic factors), where αε and δε are graph-theoretic quantities measured on the support of the stochastic feedback graph G with edge probabilities thresholded at ε. Our result, which holds without any preliminary knowledge about G, requires the learner to observe only the realized out-neighborhood of the chosen action. When the learner is allowed to observe the realization of the entire graph (but only the losses in the out-neighborhood of the chosen action), we derive a more efficient algorithm featuring a dependence on weighted versions of the independence and weak domination numbers that exhibits improved bounds for some special cases
Homotopy techniques for multiplication modulo triangular sets
International audienceWe study the cost of multiplication modulo triangular families of polynomials. Following previous work by Li et al. (2007), we propose an algorithm that relies on homotopy and fast evaluation-interpolation techniques. We obtain a quasi-linear time complexity for substantial families of examples, for which no such result was known before. Applications are given notably to additions of algebraic numbers in small characteristic
Integrating Geodesign and game experiments for negotiating urban development
In this article we explore an expansion of geodesign to analyze processes of competition and cooperation by combining it with game-theoretical modelling and experiments. We test the applicability of facilitating these two fields in an integrated workshop by analysing the case study of oversupply of development sites in the Liemers corridor. Two workshops were held, with representatives of the six municipalities involved and with the regional and provincial authority, in which participants negotiated over the distribution of the supply of development sites. The workshops were performed around an interactive MapTable, with spatial information (from GIS) and financial information (from the game-theoretical model) being visualized in real-time. The integrated workshops were assessed to discover differences in terms of process and outcomes, and they examine whether and how learning takes place. We conclude that the combination of game theory and geodesign provides added value for planning support by facilitating a realistic discussion, and negotiation that is strongly connected to real-life locations, and by aiming at designing a common, collaborative solution. Through the integrated workshop learning about the problem of oversupply in financial and geographical terms and also about each other’s motives and behaviour is stimulated
Endotoxemia-induced inflammation and the effect on the human brain
Introduction: Effects of systemic inflammation on cerebral function are not clear, as both inflammation-induced encephalopathy as well as stress-hormone mediated alertness have been described.Methods: Experimental endotoxemia (2 ng/kg Escherichia coli lipopolysaccharide [LPS]) was induced in 15 subjects, whereas 10 served as controls. Cytokines (TNF-?, IL-6, IL1-RA and IL-10), cortisol, brain specific proteins (BSP), electroencephalography (EEG) and cognitive function tests (CFTs) were determined.Results: Following LPS infusion, circulating pro- and anti inflammatory cytokines, and cortisol increased (P < 0.0001). BSP changes stayed within the normal range, in which neuron specific enolase (NSE) and S100-? changed significantly. Except in one subject with a mild encephalopathic episode, without cognitive dysfunction, endotoxemia induced no clinically relevant EEG changes. Quantitative EEG analysis showed a higher state of alertness detected by changes in the central region, and peak frequency in the occipital region. Improved CFTs during endotoxemia was found to be due to a practice effect as CFTs improved to the same extent in the reference group. Cortisol significantly correlated with a higher state of alertness detected on the EEG. Increased IL-10 and the decreased NSE both correlated with improvement of working memory and with psychomotor speed capacity. No other significant correlations between cytokines, cortisol, EEG, CFT and BSP were found.Conclusions: Short-term systemic inflammation does not provoke or explain the occurrence of septic encephalopathy, but primarily results in an inflammation-mediated increase in cortisol and alertness
Construct Validity and Reliability of the SARA Gait and Posture Sub-scale in Early Onset Ataxia
Aim: In children, gait and posture assessment provides a crucial marker for the early characterization, surveillance and treatment evaluation of early onset ataxia (EOA). For reliable data entry of studies targeting at gait and posture improvement, uniform quantitative biomarkers are necessary. Until now, the pediatric test construct of gait and posture scores of the Scale for Assessment and Rating of Ataxia sub-scale (SARA) is still unclear. In the present study, we aimed to validate the construct validity and reliability of the pediatric (SARA(GAIT/POSTURE)) sub-scale.Methods: We included 28 EOA patients [15.5 (6-34) years; median (range)]. For inter-observer reliability, we determined the ICC on EOA SARA(GAIT/POSTURE) subscores by three independent pediatric neurologists. For convergent validity, we associated SARA(GAIT/POSTURE) sub-scores with: (1) Ataxic gait Severity Measurement by Klockgether (ASMK; dynamic balance), (2) Pediatric Balance Scale (PBS; static balance), (3) Gross Motor Function Classification Scale-extended and revised version (GMFCSE& R), (4) SARA-kinetic scores (SARA(KINETIC); kinetic function of the upper and lower limbs), (5) Archimedes Spiral (AS; kinetic function of the upper limbs), and (6) total SARA scores (SARA(TOTAL); i.e., summed SARA(GAIT/POSTURE), SARA(KINETIC), and SARA(SPEECH) sub-scores). For discriminant validity, we investigated whether EOA co-morbidity factors (myopathy and myoclonus) could influence SARA(GAIT/POSTURE) sub-scores.Results: The inter-observer agreement (ICC) on EOA SARA(GAIT/POSTURE) sub-scores was high (0.97). SARA(GAIT/POSTURE) was strongly correlated with the other ataxia and functional scales [ASMK (r(s) = -0.819; p <0.001); PBS (r(s) = -0.943; p <0.001); GMFCS-E& R (rs = -0.862; p <0.001); SARA(KINETIC) (r(s) = 0.726; p <0.001); AS (r(s) = 0.609; p = 0.002); and SARATOTAL (rs = 0.935; p <0.001)]. Comorbid myopathy influenced SARA(GAIT/POSTURE) scores by concurrent muscle weakness, whereas comorbid myoclonus predominantly influenced SARA(KINETIC) scores.Conclusion: In young EOA patients, separate SARA(GAIT/POSTURE) parameters reveal a good inter-observer agreement and convergent validity, implicating the reliability of the scale. In perspective of incomplete discriminant validity, it is advisable to interpret SARA(GAIT/POSTURE) scores for comorbid muscle weakness.</p
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