Nonzero-sum Stochastic Games

This paper treats of stochastic games. We focus on nonzero-sum games and provide a detailed survey of selected recent results. In Section 1, we consider stochastic Markov games. A correlation of strategies of the players, involving ``public signals'', is described, and a correlated equilibrium theorem proved recently by Nowak and Raghavan for discounted stochastic games with general state space is presented. We also report an extension of this result to a class of undiscounted stochastic games, satisfying some uniform ergodicity condition. Stopping games are related to stochastic Markov games. In Section 2, we describe a version of Dynkin's game related to observation of a Markov process with random assignment mechanism of states to the players. Some recent contributions of the second author in this area are reported. The paper also contains a brief overview of the theory of nonzero-sum stochastic games and stopping games which is very far from being complete

Thickness patterns of the wool of Polish sheep

Соответствующие исследования касаются разработки эталонов толщины шерсти польских овец. Материал составляла шерсть низинных и длинношерстных овец. Измеряли толщину шерсти и определяли связанные с ней признаками (длину и извитость). Полученные результаты показали, что дифференциация толщины шерсти в пределах номинальных диаметров не зависит от ее происхождения. Наблюдалась различная извитость для данной толщины, что может иметь решающее значение в выборе штапелей на эталонные пробы. Шерсть длинношерстных овец оказалась слишком короткой для данной группы.The respective investigations concern working out thickness patterns of the wool of Polish sheep. The material constituted wool of lowland and long-wooled sheep. Wool thickness and traits connected therewith (length and crimpness) were measured. The results obtained have proved that differentiation in the wool thickness within the nominal diameters does not depend on its origin. Different crimpness for the given thickness was observed, which can be decisive for the choice of staples for the pattern tests. The wool of long-wooled sheep appeared to be too short for this group

The predictive value of specific immunoglobulin E levels for the first diagnosis of cow's milk allergy. A critical analysis of pediatric literature.

Investigators have tried to identify a level of seric specific immunoglobulin E (IgE) that had a sufficient predictive value to diagnose a food allergy without having will resort to the food challenge. To search in literature, all the studies that have estimated the possibility to identify a level of seric specific cow milk IgE with a positive predictive value (PPV) of 95% for the first diagnosis of cow's milk allergy (CMA) in pediatric age. We have identified six studies, nearly all studies suffer from relevant methodological bias. Proposed cut-off are all different. The studied pediatric populations were highly selected. Also neglecting the methodological bias of the studies and the great difference of value between the proposed cut-off, it always remains to consider that the pre-test probability of having a CMA between the children enrolled in the six studies included in this review is particularly high. The likelihood ratio helps to transfer the results of a study on a diagnostic test just to our population, and it is more realistic rather than to entrust itself to the PPV or the negative predictive value, that are much influenced from the prevalence of the disease in the studied population

Does treatment with proton pump inhibitors for gastroesophageal reflux disease (GERD) improve asthma symptoms in children with asthma and GERD? A systematic review.

OBJECTIVE: To evaluate pediatric studies of the effect on asthma symptoms of treatment with proton pump inhibitors (PPI) used to treat gastroesophageal reflux disease (GERD). METHODS: We entered the MeSH terms "gastroesophageal reflux AND asthma AND children" in the PubMed tool Clinical Queries, selecting "therapy" and "broad, sensitive search." The search ended on April 14, 2008. We included only clinical trials performed in pediatric patients. RESULTS: Four studies were considered to be relevant, although only 1 was a randomized, double-blind, placebo-controlled trial. The 3 nonrandomized trials showed that PPIs benefited patients with asthma. The randomized, double-blind, placebo-controlled trial found that omeprazole did not improve asthma symptoms. An improved (although not statistically significant) score was observed in the quality of life questionnaire in children with a reflux index greater than 10% and in those with more severe asthma treated with omeprazole compared with the placebo group. CONCLUSIONS: Scant data in these studies mean that we cannot make solid recommendations. However, in specific cases, we think that treatment of asthma symptoms with a PPI is valid as long as at least 2 conditions are satisfied: asthma must not respond to standard treatment, and 1 instrumental parameter of GERD severity must be satisfied, that is, a reflux index greater than or equal to 10 must be present

A short-term, randomized, double-blind, parallel-group study to evaluate the efficacy and safety of dronedarone versus amiodarone in patients with persistent atrial fibrillation: the DIONYSOS study

Dronedarone versus Amiodarone in Patients with AF. Introduction: We compared the efficacy and safety of amiodarone and dronedarone in patients with persistent atrial fibrillation (AF). Methods: Five hundred and four amiodarone-naïve patients were randomized to receive dronedarone 400 mg bid (n = 249) or amiodarone 600 mg qd for 28 days then 200 mg qd (n = 255) for at least 6 months. Primary composite endpoint was recurrence of AF (including unsuccessful electrical cardioversion, no spontaneous conversion and no electrical cardioversion) or premature study discontinuation. Main safety endpoint (MSE) was occurrence of thyroid-, hepatic-, pulmonary-, neurologic-, skin-, eye-, or gastrointestinal-specific events, or premature study drug discontinuation following an adverse event. Results: Median treatment duration was 7 months. The primary composite endpoint was 75.1 and 58.8% with dronedarone and amiodarone, respectively, at 12 months (hazard ratio [HR] 1.59; 95% confidence interval [CI] 1.28-1.98; P < 0.0001), mainly driven by AF recurrence with dronedarone compared with amiodarone (63.5 vs 42.0%). AF recurrence after successful cardioversion was 36.5 and 24.3% with dronedarone and amiodarone, respectively. Premature drug discontinuation tended to be less frequent with dronedarone (10.4 vs 13.3%). MSE was 39.3 and 44.5% with dronedarone and amiodarone, respectively, at 12 months (HR = 0.80; 95% CI 0.60-1.07; P = 0.129), and mainly driven by fewer thyroid, neurologic, skin, and ocular events in the dronedarone group. Conclusion: In this short-term study, dronedarone was less effective than amiodarone in decreasing AF recurrence, but had a better safety profile, specifically with regard to thyroid and neurologic events and a lack of interaction with oral anticoagulants