Uso De Un Polímero Hidrófilo A Base De Poliacrilamida Para Mejorar La Eficiencia En El Uso Del Agua

As an alternative in search of new options to reduce overexploitation of groundwater that allow us to increase agricultural profitability in water scarce areas, the behavior of a commercial hydrophilic polymer based in polyacrylamide (PAM) Lluvia solida®, was analyzed by evaluating the polymer hydration capacity. The tests that we used showed that this polymer is capable of absorbing its own weight in 268 times when using distilled water. When salts are dissolved in the water, the polymer reduces its water absorbing capacity, the hydration capacity being lower as the salt content increases, with a water absorption reduction up to 116 times its weight. The polymer hydration capacity also decreases significantly when a complete nutritive solution is used, reducing water absorption up to 55 times its weight; in the presence of divalent (Ca2+ and Mg2+) and monovalent (K+ and NH4 +) cations the polymer hydration capacity reduces proportionally to the cation concentration as an exponential function. Urea did not have any effect in the polymer hydration, thus this fertilizer may be used along with the polymer. The use of this hydrophilic polymer is a tool that improves the water use efficiency but the effect depends on water quality, being reduced by the presence of salts in water

El yacimiento arqueológico de El Saucedo (Talavera La Nueva, Toledo): balance y perspectivas

En este artículo presentamos una síntesis de los trabajos de investigación, conservación y difusión reali-zados en el yacimiento de b'l Saucedo hasta el presente, así como un esbozo de los planes de actuación para el futuro

Unveiling a Novel Transient Druggable Pocket in BACE-1 through Molecular Simulations: Conformational Analysis and Binding Mode of Multisite Inhibitors

The critical role of BACE-1 in the formation of neurotoxic ß-amyloid peptides in the brain makes it an attractive target for an efficacious treatment of Alzheimer's disease. However, the development of clinically useful BACE-1 inhibitors has proven to be extremely challenging. In this study we examine the binding mode of a novel potent inhibitor (compound 1, with IC50 80 nM) designed by synergistic combination of two fragments - huprine and rhein - that individually are endowed with very low activity against BACE-1. Examination of crystal structures reveals no appropriate binding site large enough to accommodate 1. Therefore we have examined the conformational flexibility of BACE-1 through extended molecular dynamics simulations, paying attention to the highly flexible region shaped by loops 8-14, 154-169 and 307-318. The analysis of the protein dynamics, together with studies of pocket druggability, has allowed us to detect the transient formation of a secondary binding site, which contains Arg307 as a key residue for the interaction with small molecules, at the edge of the catalytic cleft. The formation of this druggable 'floppy' pocket would enable the binding of multisite inhibitors targeting both catalytic and secondary sites. Molecular dynamics simulations of BACE-1 bound to huprine-rhein hybrid compounds support the feasibility of this hypothesis. The results provide a basis to explain the high inhibitory potency of the two enantiomeric forms of 1, together with the large dependence on the length of the oligomethylenic linker. Furthermore, the multisite hypothesis has allowed us to rationalize the inhibitory potency of a series of tacrine-chromene hybrid compounds, specifically regarding the apparent lack of sensitivity of the inhibition constant to the chemical modifications introduced in the chromene unit. Overall, these findings pave the way for the exploration of novel functionalities in the design of optimized BACE-1 multisite inhibitors

Novedades para las aráceas costarricenses (Araceae) con notas nomenclaturales

Background and Aims: Araceae is a worldwide family of herbaceous plants, most notable for its striking morphological diversity and broad habitat diversity. It comprises eight subfamilies, 143 genera, and 3667 species. The Central American region has about 780 species, of which 262 are distributed in Costa Rica. In this contribution, we include four new aroid records for the Costa Rican flora belonging to the genera Anthurium, Philodendron, and Spathiphyllum. In addition, nomenclatural aspects of A. myosuroides are discussed. Methods: The new records resulted from fieldwork on Fila Anguciana, Cerro Turrubares, and Volcán Miravalles. The correct taxonomic identity of the species was confirmed based on literature and comparison with herbarium specimens, especially type specimens from the herbaria of the Universidad de Panama (PMA) and the Missouri Botanical Garden (MO), as well as consultation of the JSTOR Global Plants database and the collections of the Muséum National d'Histoire Naturelle de Paris (P) online. Descriptions, taxonomic discussions, and figures of the morphological characteristics of the new records are provided. Key results: We present Anthurium roseospadix, A. myosuroides, Philodendron pseudauriculatum and Spathiphyllum dressleri as new records for the Costa Rican flora. Moreover, lectotypification for Pothos myosuroides is proposed. Conclusions: Considering the new records presented in this work, the aroid flora of Costa Rica now comprises 266 species, and the total species numbers for Anthurium, Philodendron, and Spathiphyllum increased to 94, 63, and 10, respectively.Antecedentes y Objetivos: Araceae es una familia de plantas herbáceas ampliamente distribuida en el mundo, es notable por su sorprendente diversidad morfológica y su vasta variedad de hábitats. La familia comprende ocho subfamilias, 143 géneros y 3667 especies. La región centroamericana posee alrededor de 780 especies, de las cuales 262 se encuentran en Costa Rica. En esta contribución, incluimos cuatro nuevos registros de aráceas para la flora de Costa Rica, pertenecientes a los géneros Anthurium, Philodendron y Spathiphyllum. Adicionalmente, se discuten aspectos nomenclaturales de A. myosuroides. Métodos: Los nuevos registros se realizaron mediante trabajo de campo en Fila Anguciana, Cerros Turrubares y Volcán Miravalles. La correcta identidad taxonómica de las especies se confirmó mediante la revisión de literatura y por comparación con especímenes de herbario, especialmente los ejemplares tipo provistos por los herbarios de la Universidad de Panamá (PMA) y el Jardín Botánico de Missouri (MO). También se consultó, en línea, la base de datos de JSTOR Global Plants y la colección del Muséum National d’Histoire Naturelle de París (P). Se proporcionan descripciones, discusiones taxonómicas e ilustraciones de las características morfológicas de los nuevos registros. Resultados clave: Se presentan Anthurium roseospadix, A. myosuroides, Philodendron pseudauriculatum y Spathiphyllum dressleri como nuevos registros para la flora de Costa Rica. Además, se propone una lectotipificación para Pothos myosuroides. Conclusiones: Considerando los nuevos registros presentados en este trabajo, la flora de aráceas de Costa Rica ahora comprende 266 especies, donde la diversidad de Anthurium, Philodendron y Spathiphyllum aumentó a 94, 63 y 10 especies, respectivamente

Correlación existente entre los tipos de fibras musculares, el ph y la capacidad de retención de agua de la carne en el cerdo chato murciano.

Mediante análisis de correlación se valora la influencia que los tipos de fibras I, IIA y IIX tienen sobre el pH y la capacidad de retención de agua en el músculo longísimo lumbar del cerdo “Chato Murciano”. Los resultados demuestran que los tipos de fibras no influyen sobre el pH a los 45’, pero sí durante la caída del mismo a las 24 h del sacrificio. Por otra parte, nuestros resultados indican que la capacidad de retención de agua está relacionada negativamente con el tamaño de las fibras tipo IIA

Correlaciones existente entre tipos de fibras musculares, color y porcentaje de grasa intramuscular en cerdos de raza "chato murciano"

Mediante análisis de correlación se valora la influencia que los tipos de fibras I, IIA y IIX pueden tener sobre el color y el porcentaje de grasa intramuscular en el músculo longísimo lumbar del cerdo “Chato Murciano”. Los resultados demuestran que las fibras tipo IIX influyen sobre el color de la carne y que no existen correlaciones entre el porcentaje de grasa intramuscular y ninguno de los tipos de fibras analizados

Wireless Optical Communications for Intra-Spacecraft Networks Based on OCDMA with Random Optical Codes

In recent years, spacial agencies have shown a growing interest in optical wireless as an alternative to wired and radio-frequency communications. The use of these techniques for intra-spacecraft communications reduces the effect of take-off acceleration and vibrations on the systems by avoiding the need for rugged connectors and provides a significant mass reduction. Diffuse transmission also eases the design process as terminals can be placed almost anywhere without a tight planification to ensure the proper system behaviour. Previous studies have compared the performance of radio-frequency and infrared optical communications. In an intra-satellite environment optical techniques help reduce EMI related problems, and their main disadvantages - multipath dispersion and the need for line-of-sight - can be neglected due to the reduced cavity size. Channel studies demonstrate that the effect of the channel can be neglected in small environments if data bandwidth is lower than some hundreds of MHz

Hydrogymnastics training program on physical fitness in elderly women

Se evaluó un programa de entrenamiento de hidrogimnasia sobre las capacidades físicas en 26 adultas mayores (grupo experimental n=16, grupo control n=10), determinadas mediante el protocolo senior fitness test, la hidrogimnasia fue 5 veces por semana por 12 semanas, con ejercicios aeróbicos del 50%-60% de la FCmáx. Se utilizó ANOVA 2x2, indicando interacción significativa (p=0.052) entre grupos y mediciones en la prueba de resistencia a la fuerza en extremidades inferiores, la prueba de agilidad de 2.4 metros tuvo interacción significativa (p≤0.01) entre grupos y mediciones, las pruebas de capacidad aeróbica step test de 2 minutos (p=0.02) y caminar 6 minutos indicaron interacción significativa entre grupos y mediciones (p=0.50); Se infiere que la hidrogimnasia en las adultas mayores participantes es eficaz en la mejora de las capacidades físicas principalmente aeróbicas, de resistencia a la fuerza y agilidad de miembros inferioresThe aim of this study was to evaluate the effect of a hydrogymnastics training program on physical fitness in 26 elderly women (experimental group n=16, control group n=10). The physical fitness was determined by the senior fitness test protocol, the hydrogymnastics consisted in aerobic exercise at 50%-60% of maximum heart rate, 5 times a week in a period of 12 weeks. ANOVA 2x2 as statistical test was used, indicating statistically significant interaction (p=0.052) between groups and measurements on test strength endurance in the legs by squatting on chair in 30 s, agility test 2.4 meters was significant interaction (p≤0.01) between groups and measures, testing aerobic capacity test step 2 minutes (p=0.02) and six minutes walk indicated significant interaction between groups and measurements (p=0.50), the results shown that hydrogymnastics in the elderly women participants was effective improving endurance, strength and agility mainly in leg