The effect of foreknowledge of demand in case of a restricted capacity: the single-stage, singleproduct case with lost sales

Foreknowledge of demand is useful in the control of a production-inventory system. Knowingthe customer orders in advance makes it possible to anticipate properly. It is an importantcondition to produce and deliver the right quantity of the right product “just-in-time”. Itreduces the need of safety stock and spare capacity. But the question of the effectiveness offoreknowledge is not an easy one. Having foreknowledge of the customer orders does notremove the demand uncertainty completely. The effect of foreknowledge has to be consideredin a stochastic dynamic setting. The subject of this paper is the effect of foreknowledge incombination with a restricted production capacity. The lost-sales case is considered. The mainresult is that for high utilization rates and small forecast horizon, the inventory reduction dueto foreknowledge is equal to (1- pi).h, with h the forecast horizon

Decomposed versus integrated control of a one-stage production system

This paper considers the case of a one-stage production system with several products and operating under tight production capacity constraints. The production schedule is cyclical, and there are long and sequence dependent setup times. The production system is regarded to consist of two components, namely a production unit and an inventory unit. The performance, with respect to inventory costs, timing and production quantity determination, of two types of control of the production system are compared, namely so-called decomposed and integrated control. For the generation of production orders, decomposed control uses only information from the inventory unit, while integrated control combines the information from both units. The main conclusion, based on simulation experiments, is that the inventory costs are just slightly lower in case of integrated control. Integration outperforms decomposition with respect to timing and quantity determination. However, since the differences between both approaches are small, the less sophisticated approach of decomposition is preferable when choices between both types of control have to be made.

Clinical evidence of parenteral glutamine supplementation in critical illness

Treballs Finals de Grau de Farmàcia, Facultat de Farmàcia, Universitat de Barcelona, 2017. Tutor/a: Maria Badia Tahull.[eng] Glutamine is a non-essential amino acid mostly synthetized and released to the blood stream by the skeletal muscle and the lungs. The enterocytes and the immune system cells are great glutamine consumers and glutamine is crucial for their correct function. Due to metabolic changes occurred during critical illness, the plasma level of glutamine becomes low and skeletal muscle becomes depleted. Treatment with glutamine tries to normalize plasma levels and improve the immune cell response. Glutamine’s chemical properties are unfavorable for their storage and so new ways of glutamine delivery are enveloped. The most current used alternative source are glutamine dipeptides. Administration of glutamine can be supplying the artificial nutrition support or being administrated independently; by parenteral or by enteral route. Traditional trials of glutamine supplementation demonstrate favorable results in patients with critical illness. However, newer trials which included more study population, among which the REDOX trial, where not able to confirm these results. A trend towards favorable outcomes were found in surgical and oncological patients with intravenous glutamine supplementation on physiological doses without renal and/or liver dysfunction. In contrast, there was also found high glutamine baseline levels in a subgroup of critically ill patients. With all the available clinical research information, it is still not clear if glutamine should be included in the routine clinical use.[cast] La glutamina es un aminoácido no esencial sintetizado y liberado a la circulación sanguínea mayoritariamente por la musculatura esquelética y los pulmones. Los enterocitos y las células del sistema inmunitario son grandes metabolizadores de la glutamina y ésta es crucial para su funcionamiento óptimo. Debido a cambios metabólicos sufridos en el paciente crítico, los niveles sanguíneos de glutamina disminuyen significativamente y se observa una depleción de glutamina en la musculatura esquelética. El tratamiento con glutamina tiene como objetivo normalizar los niveles plasmáticos y mejorar la respuesta del sistema inmunitario. Las propiedades químicas de la glutamina son desfavorables para su almacenaje y por eso se han desarrollado nuevas estructuras químicas de glutamina para ser administradas. La fuente alternativa más utilizada actualmente son los dipéptidos de glutamina. La administración de glutamina se puede realizar suplementando a la nutrición artificial o administrándose de forma independiente; por vía parenteral o bien por vía enteral. Los estudios tradicionales sobre la suplementación con glutamina demuestran resultados favorables en el paciente crítico. En cambio, estudios posteriores que incluyen un mayor número de pacientes, entre los cuales destaca el estudio REDOX, no han sido capaces de confirmar dichos resultados. Los estudios demuestran una tendencia favorable en pacientes quirúrgicos y oncológicos con suplementación de glutamina por vía parenteral en dosis fisiológicas que no presentaban insuficiencia renal y/o hepática. En cambio, también se han detectado en un subgrupo de pacientes niveles elevados de glutamina. Aun así, con toda la información clínica disponible actualmente, sigue siendo poco concluyente la inclusión de la glutamina en la práctica clínica habitual

Convé introduir el PrEP a Espanya?

Premis Pharmanews-Fedefarma 2016La teràpia PrEP ha estat aprovada per la European Medicines Agency (EMA) el mes de Juliol del 2016, per ser usada en conjunt amb altres mesures preventives (com el preservatiu) en la reducció del risc d’infecció del VIH. Són les autoritats competents de cada país i els seus sistemes sanitaris que han de decidir si volen (o no) incorporar el seu ús a la sanitat pública. França és l’únic país de la Unió Europea on actualment es troba finançat. Al 2012, als Estats Units ja va ser aprovat per la Food and Drug Administration (FDA) i s’ha posat en pràctica la seva utilització

Minimizing weighted total earliness, total tardiness and setup costs

The paper considers a (static) portfolio system that satisfies adding-up contraints and the gross substitution theorem. The paper shows the relationship of the two conditions to the weak dominant diagonal property of the matrix of interest rate elasticities. This enables to investigate the impact of simultaneous changes in interest rates on the asset demands.