Amyloid Beta Peptide Slows Down Sensory-Induced Hippocampal Oscillations

Alzheimer's disease (AD) progresses with a deterioration of hippocampal function that is likely induced by amyloid beta (Aβ) oligomers. Hippocampal function is strongly dependent on theta rhythm, and disruptions in this rhythm have been related to the reduction of cognitive performance in AD. Accordingly, both AD patients and AD-transgenic mice show an increase in theta rhythm at rest but a reduction in cognitive-induced theta rhythm. We have previously found that monomers of the short sequence of Aβ (peptide 25–35) reduce sensory-induced theta oscillations. However, considering on the one hand that different Aβ sequences differentially affect hippocampal oscillations and on the other hand that Aβ oligomers seem to be responsible for the cognitive decline observed in AD, here we aimed to explore the effect of Aβ oligomers on sensory-induced theta rhythm. Our results show that intracisternal injection of Aβ1–42 oligomers, which has no significant effect on spontaneous hippocampal activity, disrupts the induction of theta rhythm upon sensory stimulation. Instead of increasing the power in the theta band, the hippocampus of Aβ-treated animals responds to sensory stimulation (tail pinch) with an increase in lower frequencies. These findings demonstrate that Aβ alters induced theta rhythm, providing an in vivo model to test for therapeutic approaches to overcome Aβ-induced hippocampal and cognitive dysfunctions

Advances in flow cytometry in basic and applied equine andrology

El objetivo de esta revisión es presentar las sondas actuales disponibles que evalúan diferentes compartimentos y funciones de los espermatozoides de los sementales, incluidos ensayos para investigar la funcionalidad de las membranas, el núcleo y las mitocondrias, y estudiar la señalización celular en esta célula en particular. También se presentarán los nuevos protocolos multiparamétricos para la evaluación de espermatozoides de sementales, recientemente desarrollados en el laboratorio de los autores. También se discutirá la aplicabilidad clínica potencial de las pruebas de diagnóstico basadas en citometría de flujo.The aim of this review is to present the current probes available that assess different compartments and functions of stallion spermatozoa, including assays to investigate the functionality of the membranes, nucleus and mitochondria, and to study cell signaling in this particular cell. New multi-parametric protocols for the assessment of stallion sperm, recently developed in the laboratory of the authors, will also be presented. The potential clinical applicability of diagnostic tests based on flow cytometry will also be discussed.Trabajo financiado por: Ministerio de Economía y Competitividad y Fondos FEDER. Ayuda AGL2013-43211-R Junta de Extremadura y Fondos FEDER. Ayuda GR 15029 Ministerio de Educación, Cultura y Deporte. Beca FPU13/03991, para Patricia Martín Muñoz Ministerio de Economía y Competitividad. Beca Juan de la Cierva” IJCI-2014-21671, Cristina Ortega FerrusolapeerReviewe

Microrheology Of Gels Based On Polymers And On Different Colloidal Systems

Gels are ubiquitous materials in Biology and in many technological fields such as cosmetics, pharmacy, food, science. A distinctive feature of gels is their mechanical properties, which are intermediate between those of concentrated polymer solutions and of rigid solids. Focusing on the complex shear modulus, G*, the gelling point at a given temperature is frequently defined as the frequency at which the real, G’, and the imaginary, G”, contributions are equal. Understanding the gelling kinetics is another issue of key importance for designing gels under pre-specified conditions. A short cut in most papers G* is measured in a short low-range frequencies. Passive microrheology is a good tool for extending the frequency range. Despite it is only useful for the linear range, it has the advantage of enabling to probe the spatial heterogeneity. In this communication we will use passive microrheology and standard low-frequency rotational rheology to study the gelling kinetics of concentrate polysaccharide solutions at different concentration and temperatures. It has been found that the use of the extended Jeffrey’s model fits the results and allows one to calculate the short- and long-time node-node diffusion coefficients and mean node-node molecular weight. It was found that the mean-squared displacement does not only depends on the size of the particles, but also on their chemical nature because in some cases, e.g. TiO2, there can be strong particle-monomer interactions that slow down the motion of the microparticles. Similar studies have been done using gels based on colloidal systems such as lamellar phases or emulsions, including active molecules or not. More sophisticated systems are nano- or microgels inside liposomes or giant vesicles. In this case hyaluronic acid is encapsulated and then crosslinked by Fe3+ ions that diffuse through the phospholipidic membrane. In this case a heterogeneous gelling process takes place due to the gradient of Fe3+ ions from the membrane to the center of the capsule. Finally, gel-like materials are formed by adsorption of polyelectrolytes or their mixtures with surfactants from their aqueous solutions on solid substrates. Their mechanical properties at high frequencies can be estimated using a quartz-crystal microbalance with dissipation. In most cases the values of G’ are in the MHz range despite the water content inside the adsorbed film can vary between 20 and 70 wt%. Despite it is possible to follow the adsorption kinetics, the precision on G’ does not allow following the gelling kinetics in terms of the shear modulus

Raman spectral signatures for the differentiation of benzodiazepine drugs

The identification of benzodiazepine drugs is important in the forensics field because they are used in drugfacilitated crimes. Raman spectroscopy has been proven as a non-invasive, fast and reliable technique highly promising for the analysis of drug products. Until recently, attention has been paid to active ingredients, but the spectral drug product signature has rarely been used in spite of having potential valuable information. In this work, confocal Raman microscopy was used to obtain the spectral signature of the most widely used benzodiazepine products. Firstly, the study aimed at determining appropriate Raman mapping spectra to obtain each benzodiazepine signature with low sampling error. Then, PCA scores and loadings showed that the variability, measured on the variance, among batches of the same benzodiazepine drug was similar to the variability of the spectral signature of the same tablet (or capsule content) and the same batch, mainly attributed to the heterogeneity of such drug products. Interestingly, differentiation among doses of the same active ingredient (AI), benzodiazepine drugs with different AIs manufactured by the same pharmaceutical company, and drugs with the same AI but manufactured by different companies were demonstrated. It is remarkable that for low doses, the active ingredient is almost absent of the spectral signature, but the differentiation is mainly achieved by excipients. As a consequence, the spectral signature obtained by confocal Raman microscopy can be used for discriminating among these benzodiazepine drugs without requiring a clearly identifiable band related to the active ingredient in the corresponding Raman spectra

Suplementación de quitosano en la dieta de pollitas Rhode Island Red y su efecto en el comportamiento productivo y variables hematológicas

Chitosan is a polymer obtained from crustacean byproducts, which has antioxidant, antimicrobial and immunostimulant properties that can be used to promote growth in poultry without altering their health status. The objective of the study was to evaluate the effect of dietary inclusion of chitosan (0.55 % and 0.65 %) on productive behavior and hematological parameters in Rhode Island Red pullets. Forty-five pullets with an average weight of 36 ± 7.8 g were used, which were housed in cages of 1.0 m2 (5 animals/cage). The pullets were fed for 21 days with diets with different inclusions of chitosan: 1) control diet (commercial type), 2) control diet + 0.55 % chitosan (CH55), 3) control diet + 0.65 % chitosan (CH65). At the end of the feeding trial, growth, feed conversion ratio (FCR), blood biometry and blood biochemistry were analyzed. Dietary supplementation with chitosan increased the final weight of the pullets and, by up to 27 %, the daily weight gain (P0.05). It is concluded that the addition of chitosan in both doses favors growth without altering the health status of the pullets.El quitosano es un polímero que se obtiene a partir de subproductos de crustáceos, el cual posee propiedades antioxidantes, antimicrobianas e inmunoestimulantes que pueden ser aprovechadas para la promoción del crecimiento en aves de corral sin alterar su estado de salud.  El objetivo del estudio fue evaluar el efecto de la inclusión dietética de quitosano (0.55 % y 0.65 %) sobre el comportamiento productivo y los parámetros hematológicos en pollitas Rhode Island Red. Se utilizaron 45 pollitas con un peso promedio de 36 ± 7.8 g, las cuales fueron alojadas en jaulas de 1.0 m2 (5 animales/jaula). Las pollitas fueron alimentadas por 21 días con dietas con diferentes inclusiones de quitosano: 1) dieta testigo (tipo comercial), 2) dieta testigo + quitosano al 0.55 % (CH55),  3) dieta testigo + quitosano al 0.65 % (CH65). Al final del ensayo de alimentación, el crecimiento, el índice de conversión alimentaria (ICA), la biometría hemática y bioquímica sanguínea fueron analizados. La suplementación dietética con quitosano incrementó el peso final de las pollitas y hasta 27 % la ganancia diaria de peso (P0.05). Se concluye que la adición de quitosano en ambas dosis favorece el crecimiento sin alterar el estado de salud de las pollitas

Análisis de la aplicación del pico y placa en la ciudad de Quito

Pese a los esfuerzos realizados por las diferentes administraciones municipales del Distrito Metropolitano de Quito, es muy notorio que el tráfico de la Ciudad, cada vez se vuelve más caótico. Se han aplicado políticas públicas que han sido tomadas como ejemplos de otros países, sin considerar las necesidades reales de la ciudad, tal es el caso del Pico y Placa, utilizado en El Distrito Federal de México, y en Bogotá, y que en vez de solucionar el inconveniente, han hecho posible que las familias de estratos económicos medios y altos, adquieran uno o más vehículos, de la misma forma, los recursos invertidos por los municipios para el control y regulación del tráfico cada vez son más altos.Palabras claves: tráfico, regulación, control, política

Escolas em território mapuche: desigualdades no contexto chileno

Agradecimientos al proyecto PROFONDECYT “Dimensión emocional en la relación educativa entre profesor, estudiantes y educador tradicional en la educación intercultural” y al proyecto Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) 1181531. Universidad Católica de Temuco, Temuco, Chile.El artículo presenta un estudio exploratorio sobre resultados en la prueba de evaluación del Sistema de Medición de la Calidad de la Educación en comprensión lectora, durante los años 2011 al 2015, en La Araucanía, Chile. Metodológicamente, se describen los resultados obtenidos por una muestra de 22 escuelas emplazadas en comunidades Mapuches. Los resultados dan cuenta que las escuelas municipales rurales, obtienen mejores resultados respecto a las escuelas particulares subvencionadas con una diferencia de 8 a 10 puntos. Esto es relevante, porque en comunidades Mapuches existe una supremacía de escuelas particulares subvencionadas, que sistemáticamente obtienen bajos puntajes, lo que continuaría perpetuando las desigualdades sociales y educativas en el territorio entre Mapuches y no Mapuche

Diversity and Genetic Structure of Scarlet Plume (Euphorbia fulgens), an Endemic Plant of Mexico

[EN] Euphorbia fulgens is an ornamental species cultivated in Europe and endemic to Mexico; its ecological, genetic, and evolutionary aspects are not known. The objectives of this study were to determine its distribution, describe the places it inhabits, and analyze the diversity and genetic structures of wild populations of E. fulgens. A bibliographic review of the herbarium specimens and a field evaluation were carried out to develop a potential distribution map based on a multi-criteria analysis of the climatic and topographic variables. Three populations (forty-five individuals) from pine–oak and cloud forests located in the Southern Sierra of Oaxaca were analyzed using ten microsatellite loci. The analysis was conducted using Arlequin v. 3.5, Mega v. 10, and Structure v. 2.3 programs. Eight loci were polymorphic, and a total of thirty-eight alleles were obtained. The average number of alleles per polymorphic locus was 4.6. The average heterozygosity of the three populations was high (Ho = 0.5483), and genetic differentiation between populations were low, with a high genetic flow, suggesting that it could be an ancestral population that became fragmented and was just beginning to differentiate genetically. The information generated on this restricted distribution species can be used in conservation programs pertaining to human activities that endanger the habitats where it is found.S