Modelling the impact of climate and land cover change on hydrology and water quality in a forest watershed in the Basque Country (Northern Spain)

International audienc

Evaluation of hydrology, suspended sediment and Nickel loads in a small watershed in Basque Country (Northern Spain) using eco-hydrological SWAT model

Suspended sediment transportation and associated pollutants from catchment to stream networks are responsible for aquatic habitat degradation, reservoir sedimentation and the transportation of sediment bound pollutants. Quantifying suspended sediment loads from lands to watercourses is essential in controlling soil erosion and in implementing appropriate mitigation practices to reduce stream sediment and associated pollutant loads, and hence improve surface water quality downstream.The main objective of this study is to evaluate the temporal variability of hydrology, sediment and nickel loads using Soil and Water Assessment Tool in Oka watershed located in north Spain. Model simulation was completed using 11 years historical records (2001–2009 for validation and 2009–2012 for calibration) of streamflow and suspended sediment concentration (SSC). Thestreamflow, SSC and sediment load estimated from the model were compared with observed data using statistical parameters, which indicates a successful simulation. The annual production of simulated sediments shows variability between 662 and 1515 t, with a mean specific yield of 33 t km−2 y−1. The annual load of nickel simulated ranged from 32 to 72 kg, representing a mean specific of 1.63 kg km−2 year−1. The information obtained from this research is of interest to understand long term interannual variability of suspended sediment and nickel yield.Nickel concentration was computed from simulated SSS by SWAT. Temporal variability of Nickel load is related with suspended sediments. In terms of temporal dynamics in the sediments and Nickel transport, Oka catchment showed a high temporal variability. The mean specific of sediment load was 33 t/km−2/y−1and Nickel load was 1.63 kg/km−2/y−1

Análisis de la problemática para la adquisición de los antirretrovirales VIH/SIDA en los países del Tercer Mundo Analysis of the problem to acquire HIV/AIDS antiretroviral drugs in the Third World countries

El objetivo del presente trabajo es exponer la problemática existente para la adquisición de los medicamentos antirretrovirales para el VIH/SIDA en el ámbito mundial, fundamentalmente la situación que confrontan los países en vías de desarrollo, que para poder obtener el acceso global al tratamiento tienen que invertir recursos económicos suficientes en la esfera de la salud, no disponibles actualmente en los países más pobres. Esto es motivado por los altos precios que tienen los antirretrovirales en el mercado internacional por parte las compañías transnacionales farmacéuticas, aspecto que repercute considerablemente en el incremento de los costos del tratamiento, y es uno de los principales obstáculos para su disposición en los países del Tercer Mundo. Ante el dramático panorama del VIH/SIDA a escala mundial, la comunidad internacional se ha pronunciado en favor de concretar diferentes acuerdos entre los productores de antirretrovirales y los gobiernos de los países en vías de desarrollo, para lograr una reducción importante en el costo del tratamiento antirretrovírico. También existen iniciativas locales de algunas naciones del mundo subdesarrollado, de producir nacionalmente estos fármacos, con el objetivo de garantizar sostenidamente el acceso global de los pacientes a esta terapia. Todos estos esfuerzos están encaminadas a un mismo propósito, disponer de la mayor cantidad de antirretrovirales en el arsenal terapéutico para el tratamiento del VIH/SIDA, así como buscar distintas vías para la adquisición de estos fármacos en condiciones económicas más favorables para los países más pobres del mundo, que las existentes actualmente en el mercado farmacéutico internacional, y de esta forma, posibilitar la obtención del beneficio en términos de salud para los pacientes, a un costo más razonable para las maltrechas economías de los países subdesarrollados.<br>The objective of the present paper is to deal with the existing problem for the acquisition of the HIV/AIDS antiretroviral drugs in the world context, mainly with the situation of the developing countries, which have to invest enough economic resources in the health sphere that are not available at present in the poorest countries in order to obtain global acces to treatment. This is motivated by the high prices of the antiretroviral drugs set by the pharmaceutical transnationals at the world market This aspect has a considerable impact in the increase of the treatment costs and it is one of the main obstacles for their availabilty in the Third World countries. Due to the dramatic panorama of HIV/AIDS in the world, the international community has pronounced itself in favor of reaching different agreements between the antiretroviral drugs producers and the goverments of the developing countries to attain an important reduction of the antiretroviral treatment cost. There are also local initiatives of some underdeveloped nations to produce these drugs to guarantee a sustained global access of patients to this therapy. All these efforts are directed to a common purpose: to have the greatest amount of antiretrovirals in the therapeutic arsenal for treating HIV/AIDS, as well as to look for different ways for the acquisition of these drugs under more favorable economic conditions than the existing at the international pharmaceutical market for the poorest countries, making possible the obtention of the health benefit for patients at a more reasonable cost for the damaged economies of the underdeveloped countrties

Modelling of acetaminophen release from hydroxyethylcellulose/polyacrylamide hydrogel

Hydroxyethylcellulose (HEC) is a biodegradable, biocompatible polymer which is responsive to the temperature and pH values that can be reached by the human body. Polyacrylamide (PAAm) is a biocompatible and absorbent material which is highly used as a Drug Delivery System (DDS) due to its swelling capacity. In this work, a composite of HEC and PAAm was synthesized at a ratio of 25/75 wt% in order to evaluate its use as a transdermal DDS for acetaminophen. Drug release tests were performed in a phosphate buffer solution (PBS) at 35, 37, and 39 °C. The Korsmeyer-Peppas model was presented as a mathematical optimization problem and solved by Differential Evolution (DE) algorithm. Additionally, drug release data was modelled by Multigene Symbolic Regression (MSR) based on Genetic Programming (GP) algorithm. A drug release mathematical model was generated by MSR. The model is capable to reliably describe the kinetics of acetaminophen release from HEC/PAAm and to predict the concentrations of drug that is released in times beyond the experiment runtime