Policies for inventory/distribution systems: The effect of centralization vs. decentralization

This paper concerns with a multi-echelon inventory/distribution system considering one-warehouse and N-retailers. The retailers are replenished from the warehouse. We assume that the demand rate at each retailer is known. The problem consists of determining the optimal reorder policy which minimizes the overall cost, that is, the sum of the holding and replenishment costs. Shortages are not allowed and lead times are negligible. We study two situations: when the retailers make decisions independently and when the retailers are branches of the same firm. Solution methods to determine near-optimal policies in both cases are provided. Computational results on several randomly generated problems are reported

Optimal policy for multi-item systems with stochastic demands, backlogged shortages and limited storage capacity

Producción CientíficaIn this paper, an inventory model for multiple products with stochastic demands is developed. The scheduling period or inventory cycle is known and prescribed. Demands are independent random variables and they follow power patterns throughout the inventory cycle. For each product, an aggregate cycle demand is realized first and then the demand is released to the inventory system gradually according to power patterns within a cycle. These demand patterns express different ways of drawing units from inventory and can be a good approach to modelling customer demands in inventory systems. Shortages are allowed and they are fully backlogged. It is assumed that the warehouse where the items are stored has a limited capacity. For this inventory system, we determine the inventory policy that maximizes the expected profit per unit time. An efficient algorithmic approach is proposed to calculate the optimal inventory levels at the beginning of the inventory cycle and to obtain the maximum expected profit per unit time. This inventory model is applicable to on-line sales of a wide variety of products. In this type of sales, customers do not receive the products at the time of purchase, but sellers deliver goods a few days later. Also, this model can be used to represent inventories of products for in-shop sales when the withdrawal of items from the inventory is not at the purchasing time, but occurs in a period after the sale of the products. This inventory model extends various inventory systems studied by other authors. Numerical examples are introduced to illustrate the theoretical results presented in this work.Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project MTM2017-84150-P

Recomendaciones del Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa (GETECCU) sobre el tratamiento de pacientes con enfermedad inflamatoria intestinal asociada a espondiloartritis

Las manifestaciones extraintestinales en general, y entre ellas las articulares en particular, suponen un problema frecuente en los pacientes con enfermedad inflamatoria intestinal. De hecho, la relación entre ambas entidades parece estrecha y cada vez hay más datos que sugieren que el intestino desempeña un importante papel en la patogenia de las espondiloartritis. La asociación de la enfermedad inflamatoria intestinal con algún tipo de espondiloartritis supone un escenario clínico complejo. Es necesario, por tanto, que gastroenterólogos y reumatólogos puedan trabajar juntos y establecer una comunicación fluida que permita a cada paciente recibir el tratamiento más adecuado para cada situación concreta. El objetivo de esta revisión es el de establecer unas recomendaciones sobre el tratamiento de los pacientes con enfermedad inflamatoria intestinal y espondiloartritis asociada, en cada uno de los distintos escenarios clínicos

Acontecimientos vitales y hospitalización psiquiátrica en pacientes maniacos.

Se investigó la incidencia de AV en los seis meses previos al ingreso psiquiátrico y de AV ocurridos durante la infancia en un grupo de 27 pacientes ingresados por un episodio maníaco en un Hospital Psiquiátrico y se comparó con 24 pacientes traumatológicos ingresados en un Hospital General por patología aguda. El grupo de pacientes maniacos presentó más del doble de AV independientes que el grupo control, sin que se encontrasen diferencias significativas en cuanto a la incidencia de AV precoces. Se estudió también el tipo de A V yla relación entre la presencia de éstos y el número de ingresos psiquiátrico

Acontecimientos vitales y hospitalización psiquiátrica en pacientes maniacos.

Se investigó la incidencia de AV en los seis meses previos al ingreso psiquiátrico y de AV ocurridos durante la infancia en un grupo de 27 pacientes ingresados por un episodio maníaco en un Hospital Psiquiátrico y se comparó con 24 pacientes traumatológicos ingresados en un Hospital General por patología aguda. El grupo de pacientes maniacos presentó más del doble de AV independientes que el grupo control, sin que se encontrasen diferencias significativas en cuanto a la incidencia de AV precoces. Se estudió también el tipo de A V yla relación entre la presencia de éstos y el número de ingresos psiquiátrico

Treatment patterns and intensification within 5 year of follow-up of the first-line anti-TNFα used for the treatment of IBD : Results from the VERNE study

Altres ajuts: Takeda Farmacéutica España S.A.Background: Anti-TNFα represent one of the main treatment approaches for the management of inflammatory bowel diseases (IBD). Therefore,the evaluation of their treatment patterns over time provides valuable insights about the clinical value of therapies and associated costs. Aims: To assess the treatment patterns with the first anti-TNFα in IBD. Methods: Retrospective, observational study. Results: 310 IBD patients were analyzed along a 5-year follow-up period. 56.2% of Crohn's disease (CD) patients started with adalimumab (ADA), while 43.8% started with infliximab (IFX). 12.9% of ulcerative colitis (UC) patients initiated with ADA, while 87.1% initiated with IFX. Treatment intensification was required in 28.9% of CD and 37.1% of UC patients. Median time to treatment intensification was shorter in UC than in CD (5.3 vs. 14.3 months; p = 0.028). Treatment discontinuation due to reasons other than remission were observed in 40.7% of CD and 40.5% of UC patients, although, in UC patients there was a trend to lower discontinuation rates with IFX (36.6%) than with ADA (66.7%). Loss of response accounted for approximately one-third of discontinuations, in both CD and UC. Conclusions: Around one-third of IBD biologic-naive patients treated with an anti-TNFα required treatment intensification (earlier in UC) and around 40% discontinued the anti-TNFα due to inappropriate disease control

Impact of comorbidities on anti-TNF alpha response and relapse in patients with inflammatory bowel disease: the VERNE study

Objective: To evaluate the impact of comorbidities and extraintestinal manifestations of inflammatory bowel disease on the response of patients with inflammatory bowel disease to antitumour necrosis factor alpha (anti-TNFalpha) therapy. Design: Data from 310 patients (194 with Crohn's disease and 116 with ulcerative colitis) treated consecutively with the first anti-TNFalpha in 24 Spanish hospitals were retrospectively analysed. Univariate and multivariate logistic regression analyses were performed to assess the associations between inflammatory bowel disease comorbidities and extraintestinal manifestations with anti-TNFalpha treatment outcomes. Key clinical features, such as type of inflammatory bowel disease and concomitant treatments, were included as fixed factors in the model. Results: Multivariate logistic regression analyses (OR, 95% CI) showed that chronic obstructive pulmonary disease (2.67, 1.33 to 5.35) and hepato-pancreato-biliary diseases (1.87, 1.48 to 2.36) were significantly associated with primary non-response to anti-TNFalpha, as was the use of corticosteroids and the type of inflammatory bowel disease (ulcerative colitis vs Crohn's disease). It was also found that myocardial infarction (3.30, 1.48 to 7.35) and skin disease (2.73, 1.42 to 5.25) were significantly associated with loss of response, along with the use of corticosteroids and the type of inflammatory bowel disease (ulcerative colitis vs Crohn's disease). Conclusions: Our results suggest that the presence of some comorbidities in patients with inflammatory bowel disease, such as chronic obstructive pulmonary disease and myocardial infarction, and of certain extraintestinal manifestations of inflammatory bowel disease, such as hepato-pancreato-biliary conditions and skin diseases, appear to be related to failure to anti-TNFalpha treatment. Therefore, their presence should be considered when choosing a treatment. Trial registration number: NCT02861118

Effects of long-term summer deficit irrigation on 'Navelina' citrus trees

[EN] The effects of long-term summer deficitirrigation (RDI) strategies on ‘Navelina’ orange trees (Citrus sinensis L. Osbeck) were assessed in a drip-irrigated commercial orchard located in Senyera (Valencia, Spain). Three irrigation treatments were applied during five consecutive years (2007–2011): a controltreatment, without restriction, and two RDI treatments, in which the water reduction was applied during the summer (initial fruit enlargement phase). During the firstthree seasons,the trees under the controltreatment received 110% of the theoretically required irrigation dose (ID), and the RDI treatments received 40% and 60% of the full ID during the deficit period. During the last two years of the study, the control treatment was irrigated at 100% of the ID and the amount of water applied in the RDI treatments was additionally decreased 20% from the reduced ID of the preceding years. The crop’s response to summer deficit irrigation was analysed in relation to tree water status, which was assessed by relying on midday stem water potential (st). The lowest st values were reached, as expected, at the end of the water deficit period and with the most stressed treatment. These minimum st values ranged between −1.6 MPa in 2008 and −2.5 MPa in 2010. In most occasions, the trees under RDI treatments showed a fast hydric recovery and had completely re-hydrated one week after restarting irrigation. Summer RDI treatments did not cause negative effects on either the amount or on the quality ofthe yield ifthe threshold value of st = −2.0 MPa was not surpassed. According to the results, it can be concluded that long-term RDI strategies may be applied successfully on Navelina orange trees during summer without negatively affecting the studied parameters while allowing water savings between 12% and 27%. © 2016 Elsevier B.V. All rights reserved. 1.This experiment was funded by the company Tecnicas Valencianas del Agua S.A. (TECVASA), with financial support from the Conselleria de Agricultura, Pesca y Alimentacion de la Generalitat Valenciana for this purpose (DOCV 5493, 19 April 2007, no. exp.: 2007TAHAVAL00018).Gasque, M.; Martí, P.; Granero, B.; González Altozano, P. (2016). Effects of long-term summer deficit irrigation on 'Navelina' citrus trees. Agricultural Water Management. 169:140-147. doi:10.1016/j.agwat.2016.02.028S14014716