An enhanced concave program relaxation for choice network revenue management

The network choice revenue management problem models customers as choosing from an offer-set, andthe firm decides the best subset to offer at any given moment to maximize expected revenue. The resultingdynamic program for the firm is intractable and approximated by a deterministic linear programcalled the CDLP which has an exponential number of columns. However, under the choice-set paradigmwhen the segment consideration sets overlap, the CDLP is difficult to solve. Column generation has beenproposed but finding an entering column has been shown to be NP-hard. In this paper, starting with aconcave program formulation based on segment-level consideration sets called SDCP, we add a class ofconstraints called product constraints, that project onto subsets of intersections. In addition we proposea natural direct tightening of the SDCP called ?SDCP, and compare the performance of both methodson the benchmark data sets in the literature. Both the product constraints and the ?SDCP method arevery simple and easy to implement and are applicable to the case of overlapping segment considerationsets. In our computational testing on the benchmark data sets in the literature, SDCP with productconstraints achieves the CDLP value at a fraction of the CPU time taken by column generation and webelieve is a very promising approach for quickly approximating CDLP when segment consideration setsoverlap and the consideration sets themselves are relatively small.

Predicting Adverse Events in Children with Fever and Chemotherapy-Induced Neutropenia. Results of the Prospective Multicenter SPOG 2003 FN Study

PURPOSE To develop a score predicting the risk of adverse events (AEs) in pediatric patients with cancer who experience fever and neutropenia (FN) and to evaluate its performance. PATIENTS AND METHODS Pediatric patients with cancer presenting with FN induced by nonmyeloablative chemotherapy were observed in a prospective multicenter study. A score predicting the risk of future AEs (ie, serious medical complication, microbiologically defined infection, radiologically confirmed pneumonia) was developed from a multivariate mixed logistic regression model. Its cross-validated predictive performance was compared with that of published risk prediction rules. Results An AE was reported in 122 (29%) of 423 FN episodes. In 57 episodes (13%), the first AE was known only after reassessment after 8 to 24 hours of inpatient management. Predicting AE at reassessment was better than prediction at presentation with FN. A differential leukocyte count did not increase the predictive performance. The score predicting future AE in 358 episodes without known AE at reassessment used the following four variables: preceding chemotherapy more intensive than acute lymphoblastic leukemia maintenance (weight = 4), hemoglobin > or = 90 g/L (weight = 5), leukocyte count less than 0.3 G/L (weight = 3), and platelet count less than 50 G/L (weight = 3). A score (sum of weights) > or = 9 predicted future AEs. The cross-validated performance of this score exceeded the performance of published risk prediction rules. At an overall sensitivity of 92%, 35% of the episodes were classified as low risk, with a specificity of 45% and a negative predictive value of 93%. CONCLUSION This score, based on four routinely accessible characteristics, accurately identifies pediatric patients with cancer with FN at risk for AEs after reassessment.

Climatic conditions for crop production in Nordic countries

Selostus: Kasvintuotannon ilmasto-olosuhteet Pohjoismaissa

Peut-on intégrer l'islam et les musulmans en Suisse

La compatibilité de l'islam aux démocraties occidentales et l'intégration des musulmans dans les sociétés européennes préoccupent aujourd'hui politiques et citoyens. Les défis incontestables de la cohabitation côtoient dans l'arène médiatique les enjeux fantsamés de la présence musulmane. On constate ainsi une réduction de la question musulmane à la visibilité de ses expressions dans l'espace public, avec pour conséquence un détournement de l'attention des paris réels de la sédentarisation des musulmans en Suisse et en Europe. Peut-on être musulman et européen ? Peut-on être une femme musulmane 'libre' ? Peut-on intégrer les musulmans au multiculturalisme helvétique ? Ce sont là quelques questionnements qui jalonneront la réflexion de cette ouvrage.

La judiciarisation à l'épreuve de la démocratie directe. L'interdiction de construire des minarets en Suisse

Impulsée par des élus de l'UDC pour contourner des décisions politiques et judiciaires prises au niveau local, puis national, l'initiative populaire acceptée en 2009 visant l'interdiction de construire des minarets a réactivé la stigmatisation des musulmans établis en Suisse, ainsi qu'un ensemble de controverses opposant systématiquement, dans une configuration institutionnelle particulière, la démocratie directe aux droits fondamentaux, la « volonté populaire » au « pouvoir des juges », nationaux et internationaux. Polysémique, le concept de judiciarisation est appréhendé ici dans une perspective processuelle et relationnelle, non pas comme transfert vers l'arène judiciaire de questions politiques touchant la régulation publique du religieux, mais sous l'angle de la juridicisation de la controverse suscitée par l'initiative populaire que produit l'anticipation des décisions de justice dans les échanges politiques.