Gestión óptima de aguas subterráneas : regulación frente a no regulación

En este artículo se comparan dos modelos de gestión de aguas subterráneas: control y no-control. La diferencia entre ambos viene dada porque en el primero de ellos se computa el coste de uso del recurso, mientras que en el segundo no. La demanda de agua subterránea se desagrega por cultivos lo que permite obtener una asignación inter e intratemporal del recurso. Asimismo se realiza la aplicación sobre el acuífero de Ascoy-Sopalmo (Cuenca del Segura). La obtención del valor presente del excedente neto de los agricultores en ambos escenarios permite concluir que la pérdida de eficiencia es mínima para unos valores normales de las tasas de descuento y recarga.In this paper two management models of groundwater (control and no-control) are compared. The difference between these models is that in the first one user cost is considered whilst in the second one is not. The groundwater demand is disaggregated by crops, which makes possible to obtain an inter and intratemporal resource allocation. Furthermore, an application to the aquifer of Ascoy-Sopalmo (Segura Basin) is carried out. From the present value of the farmer's net surplus, derived in both models, we can conclude that the efficiency loss is minimum for normal values of the discount rate and recharge rate

Short range order of CCl4: RMC and MD methods

The main objective of this paper is to present a method to fully determine the six degrees of freedom regarding position and orientation of a neighboring molecule around a central one, i.e. the g(rCM,¿) distribution function. This is accomplished by completely determining the short range structure of liquid carbon tetrachloride, while employing results from two different methods, Molecular Dynamics (MD) [1] and Reverse Monte Carlo (RMC) [2]. Exclusively, the structural ordering of the first four molecules will be detailed.Postprint (published version

Seed Germination Technologies for Helophyte Production Used in Wastewater Treatment

Constructed green wetlands with horizontal surface for wastewater treatment are gaining acceptance. Many countries have published innovative experiences with this technology. A great variety of wastewaters from industries have been treated. Different plant species have been tested. Seed technology development provides interesting tools to produce these species in nurseries. It is a sustainable new business. But studies on seed germination of aquatic and lacustrine plants are very few. That is why we have made the following bibliographic review. We have summarised and analysed the state of the art of this innovative topic, concluding that seed technology for multiplication of helophytes needs further experimental work. But there is enough information to produce right now, tens of different species. Significant efforts have been done. Even though it is a challenge to produce from now on, experimental results are ready to be transferred to those who are trading with this type of plants. Helophytes have a promising future as sustainable elements of the upcoming sewage equipment. Improvements on the biotechnology of these species are a worthwhile researching line. To this aim, the following revision is an essential compilation with which to begin

Comparación de la eficacia y seguridad diagnóstica entre el estudio isotópico hepatobiliar y la ecografía en la colecistitis aguda

Hemos estudiado en 67 pacientes con el diagnóstico de colecistitis aguda (CA) confirmado mediante intervención quirúrgica precoz, la sensibilidad diagnóstica del estudio isotópico con HIDA comparándola con la de la ecografía. El estudio se llevó a cabo de forma retrospectiva. La sensibilidad del estudio isotópico (97%) ha sido claramente superior a la de la ecografía (82%), aunque esta última ofrece ventajas en cuanto a la rapidez y economía de valor indudable. Asimismo hemos intentado establecer la seguridad de ambas técnicas en el diagnóstico de la coledocolitiasis asociada a la CA, que en nuestro estudio ha mostrado una incidencia alta (26%), siendo mala para ambas técnicas; la sensibilidad en este caso para la ecografía ha sido del 50% mientras que para el HIDA ha sido del 12,5%. Por tanto creemos conveniente realizar como primer estudio diagnóstico para la confirmación de la sospecha clínica de CA una ecografía abdominal, reservando la escintigrafía para los casos, por otra parte numéricamente apreciables, en que persista la duda diagnóstica. Asimismo recomendamos la realización de colangiografía intraoperatoria debido a la deficiente fiabilidad que ambas exploraciones han demostrado en la detección de coledocolitiasis en los pacientes con C

Trasplante pancreático

Diabetes mellitus is a health concern of the first order, given the high level of associated morbidity and mortality. The objective, in order to slow down the advance of its complications before they become irreversible, is based on correct metabolic control. The high rate of morbidity associated with the surgery of the vascularized pancreas transplant and the high index of rejection have for three decades formed an obstacle to this being considered a valid alternative in the treatment of these patients. Nowadays the pancreas transplant has come to occupy a key position, thanks to the new regimes of immunosuppression and to the perfection of surgical techniques. In this article we review the evolution of the pancreas transplant from its beginnings to its present state

A Comparative Ultrastructural Study of Chondrosarcoma, Chordoid Sarcoma, and Chordoma

A morphologic and electron microscopic study was made of two chordoid sarcomas. These lesions were compared with two classical chondrosarcomas and two chordomas. These chondrosarcoma cells showed many features common to chondrocytes, such as abundant RER, well-developed Golgi complexes, and microvillous cytoplasmatic membranes. The chordoid sarcomas bore a close morphologic resemblance to the chordomas but the ultrastructural features revealed a close relationship to the chondrosarcomas. The chordoid sarcoma and chondrosarcoma cells had scalloped cytoplasmatic membranes, variable amounts of glycogen, round or oval nuclei and microfibrils, collagen, and electron-dense granules in the ground substance. The chordoma was characterized by the presence of stellate and physalipherous cells, as well as many transitional cells, with varying nuclear morphology; dilated and irregular RER in contact with mitochondria and morphologically varied vacuoles are the main features in the cytoplasm. This study suggests that chordoid sarcoma represents a variety of the chondrosarcoma rather than a form of chordoma. These findings also support the suggestion of Weiss that chordoid sarcoma is an extraskeletal myxoid chondrosarcom

Herpes Zoster After Liver Transplantation: Incidence, Risk Factors, and Complications

Herpes zoster is the consequence of the reactivation of latent varicella-zoster infection. Immunosuppression may be a predisposing factor for herpes zoster. We have retrospectively assessed the risk of herpes zoster, the risk factors for its occurrence, and its evolution in a population of 209 consecutive liver transplant recipients. Herpes zoster developed in 25 (12%) of patients. One-, 3-, 5-, and 10-year actuarial rates of herpes zoster were 3%, 10%, 14%, and 18%, respectively. In a case-control study, patients developing herpes zoster were younger, received a higher number of immunosuppressive drugs, and were more frequently receiving mycophenolate mofetil or azathioprine. In multivariate analysis, the only factor related to herpes zoster occurrence was treatment with mycophenolate mofetil or azathioprine. Eight patients (31%) developed postherpetic neuralgia. In conclusion, herpes zoster is a relatively common complication after liver transplantation. It is related to immunosuppressive therapy. Postherpetic neuralgia develops in one third of patients with posttransplant herpes zoster

Portal Revascularization in the Setting of Cavernous Transformation Through a Paracholedocal Vein: A Case Report

Diffuse thrombosis of the entire portal system (PVT) and cavernomatous transformation of the portal vein (CTPV) represents a demanding challenge in liver transplantation. We present the case of a patient with nodular regenerative hyperplasia and recurrent episodes of type B hepatic encephalopathy concomitant with PVT as well as CTPV, successfully treated with orthotopic liver transplantation. The portal inflow to the graft was carried out through the confluence of 2 thin paracholedochal varicose veins, obtaining good early graft function and recovery of the encephalopatic episodes. This alternative should be kept in mind as an option to assure hepatopetal splanchnic flow in those cases of diffuse thrombosis and cavernomatous transformation of portal vein. CI - Copyright (c) 2010 Elsevier Inc. All rights reserved

Conversion From Calcineurin Inhibitors to Mycophenolate Mofetil in Liver Transplant Recipients With Diabetes Mellitus

Diabetes mellitus, a frequent metabolic complication in liver transplant recipients, may be produced by the diabetogenic effect of calcineurin inhibitors cyclosporine and tacrolimus. The aim of this study was to investigate the safety and metabolic effects of a gradual switch from cyclosporine or tacrolimus to mycophenolate mofetil among 12 diabetic liver transplant recipients. One patient was withdrawn from the study due to gastrointestinal side effects. Of the 11 remaining patients, cyclosporine or tacrolimus was completely withdrawn in five patients. Two patients developed suspected acute rejection episodes that were controlled by increasing the tacrolimus dosage. Glycosylated hemoglobin A1C and C-peptide levels were significantly lower at 3 and 6 months after the initiation of mycophenolate mofetil (P<.03 in all cases). Furthermore, urea and uric acid levels were significantly reduced after the change of treatment. In conclusion, a switch from cyclosporine/tacrolimus to mycophenolate mofetil may produce beneficial metabolic effects in diabetic liver transplant recipients, but poses a risk of graft rejection