Joaquín Melgarejo Moreno

Neuroprotection by the novel calcium antagonist PCA50938, nimodipine and flunarizine, in gerbil global brain ischemia

Calcium is involved in the physiopathology of cerebral ischemia. Calcium antagonists might prevent the calcium overload and death of cells from ischemically compromised tissue. We compare the neuroprotective effect of various doses (0.2, 0.5 and 1 mg/kg) of two dihydropyridines, nimodipine and the novel 1,4-dihydropyridine derivative PCA50938, and flunarizine in the gerbil model of global ischemia. Improvements in morbidity were observed 2 h after the end of carotid occlusion (McGraws scale) with 0.5 mg/kg of flunarizine, all doses of PCA50938 and 0.2 mg/kg nimodipine. Neuronal loss in the CA1 sector of the hippocampus was examined. The animals treated with 0.5 mg/kg flunarizine and those treated with 1 mg/kg PCA50938 showed a significant reduction in the percentage of damaged neurons in the hippocampal CA1 area, 72 h after transient ischemia. None of the animals treated with 0.5 mg/kg flunarizine had more than 80% of the evaluated neurons altered. We conclude that PCA50938 and flunarizine may act as neuroprotective drugs with different patterns of dose-response and neuroprotective-morbidity-mortality relationships, in the model of global cerebral ischemia in the gerbil. Flunarizine has a narrow therapeutic range.

El trasvase Júcar-Vinalopó. Una respuesta a la sobreexplotación de acuíferos

The Vinalopo-Alicante System in the province of Alicante, Spain, is a space characterized for the shortage of hydric resources but a great development of underground waters. These underground waters have allowed the water supply in most of the municipalities of the province and, at the same time, the development of a very advanced agriculture, well known for its efficiency and productivity. In order to alleviate the serious problems caused by an excessive exploitation of the underground water and to restore the former hydric balance, the Hydrologic Plan of the

Halophytic plant community patterns in Mediterranean saltmarshes: shedding light on the connection between abiotic factors and the distribution of halophytes

AimsEstablishing a vegetation-soil model in Mediterranean saltmarshes based on the relationships between the plant communities and the abiotic factors, considering temporary variation.MethodsRelationships between perennial plant species abundances and plant communities were analysed by DCAs. A CCA was performed to study the relationships between floristic composition and edaphic variables. Sixteen soil variables and Pearson correlations between them were considered. Marginal and conditional effects were supported by mixed ANOVA. Statistical analyses were performed to check temporary variation.ResultsDCAs results showed eight vegetation types. CCA showed E.C. as the main gradient, with the succulent halophyte communities growing in high E.C. soils. SAR and percentage of sand were considered as secondary gradients. Finally, the highest values of the edaphic variables were observed, in general, during the cold period.ConclusionsThe main gradient of salinity, together with sodicity and texture gradients, would markedly influence the plant distribution in Mediterranean saltmarshes. Two principal plant zones were observed: succulent zone vs. non-succulent zone, with a specific edaphic distribution for each plant community and for the proposed Limonium morphotypes treatment. A plant-soil model based on these three gradients is here proposed. Our results would complement the previous knowledge about plant-soil relationships in Mediterranean saltmarshes.

A new algorithm for solving all the real roots of a nonlinear system of equations in a given feasible region

The initiation of iterations and the encounters of all of its solutions are two of the main problems that are derived from iterative methods. These are produced within feasible regions where the problem lies. This paper provides an algorithm to solve both for the general case of nonlinear systems of p unknowns and q equations. Furthermore, some examples of this algorithm implementation are also introduced.

Azudes y acueductos del sistema de riego tradicional de la Vega Baja del Segura (Alicante, España)

This paper describes and discusses the main hydraulic works of traditional irrigation system in the Vega Baja del Segura area, particularly the diversion dams and the aqueducts. The diversion dams, built on the bed of the Segura River, represent the beginning of the system from where part a vast and complex network of aqueducts, constituted by ditches and drainage ditches, as fundamental elements that distribute water for irrigation. An extensive and thorough documentary research has been carried out in this study. Field data and in-situ images have been gathered and, along with the provided diagrams, they are essential to understand the magnitude of the system. The results have served not only to catalog and characterize the elements comprising the hydraulic system of the traditional irrigation of the Vega Baja del Segura, but also to reveal a real example of optimization of water resources in an area of the Spanish peninsular Southeast of low and irregular rainfall. In addition, the study reveals a system of highly efficient irrigation from a quantitative point of view and not so much in the qualitative due to the presence of high concentrations of salts, among other pollutants.