Propuestas metodológicas para la caracterización de testigos de presas con problemas expansivos

[ANGLÈS] Some of the dams built in the region of Cataluña, have expansive processes that take place within its concrete, which is the case of the Graus dam. In this dam, observed movements are related in previous diagnoses to an internal sulfate reaction caused by the oxidation of iron sulfides present in the used aggregates. However, numerical simulations of the movements of the dam indicate that there may be a second expansive mechanism, delayed in time, which also contributes to these damages. With that in mind, the objectives of this study are to develop a methodology that serves as a general proposal to characterize concrete cores in dams, and also make a new diagnosis of the Graus dam to determine the reactions that effectively contributes to the expansion process. To do this, visual inspection was performed first, then critical areas in the dam where identified from the point of view of the damage. In these areas, extraction of concrete cores were realized and will be used in an extensive characterization process (visual inspection, selective dyeing, characterization of porosity, ultrasound tests and determination of permeability in O2) to confirm the real causes of the expansion. The results obtained in this study will serve as the foundations for more accurate diagnosis of the behavior of the Graus dam.[CASTELLÀ] Algunas de las presas construidas en el área de Cataluña presentan daños debido a procesos expansivos que se desarrollan en hormigón, como es el caso de la presa de Graus. Existen diagnósticos previos de esta presa que apuntan a una principal causa de los movimientos observados, es la reacción sulfática interna causada por la oxidación de los sulfuros de hierro presentes en el árido usado. No obstante, las simulaciones numéricas de los movimientos de la presa indican que puede haber un segundo mecanismo expansivo, diferido en el tiempo, que también contribuye para la aparición de los daños. Teniendo eso en cuenta, los objetivos del presente estudio es elaborar una metodología que sirva como propuesta general para la caracterización de testigos en presas y también realizar un nuevo diagnóstico de la presa de Graus para determinar las reacciones que efectivamente contribuyen al proceso expansivo. Para ello, inicialmente se realizó la inspección visual y se identificaron zonas críticas en la presa desde el punto de vista del daño. En esas zonas se llevó a cabo la extracción de testigos los cuales serán sometidos a una amplia caracterización (inspección visual, tinción selectiva, caracterización de porosidad, ensayos de ultrasonido y determinación de permeabilidad al O2) para confirmar las causas reales del proceso expansivo. Los resultados obtenidos en ese estudio servirán como base para realizar previsiones más precisas del comportamiento de la presa de Graus

Richness and distribution of porcupines (Erethizontidae: Coendou) from Colombia

In spite of previous reviews, there is still no consensus on the information associated to the richness of the genus Coendou in Colombia. To clarify some issues concerning the distribution and the taxonomic identity of the species of Coendou in the country, we reviewed specimens from five natural history collections. We introduce the first record of Coendou ichillus from the Orinoco river basin of the country, extending the distribution of the species by more than 600 km to the north from previous known localities in Ecuador and Peru. Additionally, we present new records of C. pruinosus and C. quichua from the Amazonia and inter-Andean valleys, respectively. Only one skull presents the diagnostic characters of C. bicolor; thus, previous records of this species for the country were based on misidentifications. Coendou is distributed in seven of the nine geographic provinces of Colombia. Coendou prehensilis was found in five provinces and is expected to be present in the Amazonia, whereas C. pruinosus was documented in three provinces (North Andean, Orinoco and Guyana). The rest of the species of Coendou were distributed in one or two provinces. The richest provinces were North Andean and Orinoco with six and four Coendou species, respectively. The elevational ranges of C. prehensilis and C. pruinosus are revised to 0-1975 and 90-2200 m, respectively

Adiciones y cambios a la lista de mamíferos de Colombia: 500 especies registradas para el territorio nacional

Below are the additions and changes presented since the most recent publication of the list of mammals in Colombia, which included a total of 492 native species (Solari et al. 2013). In total, 13 new species have been recorded: seven bats (order Chiroptera), three carnivores (Carnivora), a primate (Primates), a rodent (Rodentia) and a perisodáctil (Perissodactyla) (Table 1). Three species of bats and one species of primate are reported based on nomenclature and taxonomic changes: Uroderma convexum (Mantilla-Meluk 2014), Myotis caucensis (Moratelli et al. 2013), Myotis pilosatibialis (Mantilla-Meluk & Muñoz-Garay 2014) and Pithecia milleri (Marsh 2014).A continuación indicamos las adiciones y cambios presentados desde la publicación más reciente de la lista de chequeo de mamíferos de Colombia, en la que se incluyeron un total de 492 especies nativas (Solari et al. 2013). En total, se han registrado 13 nuevas especies: siete murciélagos (orden Chiroptera), tres carnívoros (Carnivora), un primate (Primates), un roedor (Rodentia) y un perisodáctilo (Perissodactyla) (Tabla 1). Tres especies de murciélagos y una especie de primate son reportadas con base en cambios nomenclaturales y taxonómicos: Uroderma convexum (Mantilla-Meluk 2014), Myotis caucensis (Moratelli et al. 2013), Myotis pilosatibialis (Mantilla-Meluk & Muñoz-Garay 2014) y Pithecia milleri (Marsh 2014)

High prevalence of secondary resistance mutations in Venezuelan HIV-1 isolates.

The genetic variability was studied in HIV-1 from Venezuelan patients with and without treatment, in order to evaluate the presence of polymorphisms and drug resistance mutations. Proviral DNA from peripheral blood mononuclear cells or viral RNA from plasma was extracted from the blood of 30 patients. Two regions from the polymerase gene, protease (Pr) and reverse transcriptase (RT) and one genomic fragment from the envelope (Env) gene were amplified and sequenced. All HIV-1 samples analyzed were classified as subtype B, without evidence of recombination. Although no primary protease mutations were detected, a high frequency of secondary mutations (86%, 19/22), associated to restoration of viral replicative fitness, was observed in strains circulating both in treated and non-treated patients. Resistance mutations to nucleoside RT inhibitors (NRTI) and non-nucleoside RT inhibitors (NNRTI) were detected in 35% (6/17) and 12% (2/17) of the viruses circulating in treated patients, respectively. Resistance mutations were also present in the virus infecting one antiretroviral naive individual (7.7%), suggesting that local screening for resistant mutation in naive patient might be important to minimize therapy failure. Future studies are warranted to assess the role of secondary mutation in the success of viral infection

Cambios recientes a la lista de los mamíferos de Colombia

Due to the progress in the development of research of various kinds involving mammals, changes in the richness of species registered in the national territory are reported every year. A notable effort aimed at updating the knowledge of this group in the country indicated the presence of 492 species by 2013 (Solari et al. 2013). This number increased to 500 species by 2014, based on systematic reviews or additions of new distribution locations for several neotropical species (Ramírez-Chaves & Suárez-Castro 2014) and in this review the number of species is increased to 518 for the country. The increase has been greater for bats (Chiroptera order), a group that currently has the highest number of mammalian species registered in Colombia (205 species). However, the use of new techniques and field explorations carried out by different researchers have generated a great deal of knowledge for other groups, so it is necessary to synthesize the information constantly so that it is available to all those involved in studying and conserving the biodiversity of the country In order to update the number of mammalian species registered in the national territory, we present an assessment and update with the recent changes for Colombia during the last months.Debido al avance en el desarrollo de investigaciones de diversa índole que involucran mamíferos, cada año se reportan cambios en la riqueza de especies registradas en el territorio nacional. Un esfuerzo notable encaminado a actualizar el conocimiento de este grupo en el país señaló la presencia de 492 especies para el año 2013 (Solari et al. 2013). Este número se incrementó a 500 especies para el año 2014, a partir de revisiones sistemáticas o adiciones de nuevas localidades de distribución para varias especies neotropicales (Ramírez-Chaves & Suárez-Castro 2014) y en esta revisión se aumenta el número de especies a 518 para el país. El incremento ha sido mayor para murciélagos (orden Chiroptera), grupo que actualmente cuenta con el número más alto de especies de mamíferos registradas en Colombia (205 especies). Sin embargo, el uso de nuevas técnicas y exploraciones de campo realizadas por diferentes investigadores han generado una gran cantidad de conocimiento para otros grupos, por lo que es necesario sintetizar la información de manera constante para que estédisponible a todos aquellos involucrados en estudiar y conservar la biodiversidad del país. Con el fin de actualizar el número de especies de mamíferos registradas en el territorio nacional, presentamos una valoración y actualización con los cambios recientes para Colombia durante los últimos meses

The bright optical afterglow of the long GRB 001007

We present optical follow up observations of the long GRB 001007 between 6.14 hours and ~468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light curve at t - to < 3.5 days, as found in other bursts. Upper limits imposed by the LOTIS alerting system 6.14 hours after the gamma ray event provide tentative (1.2 sigma) evidence for a break in the optical light curve. The spectral index beta of the OA yields -1.24 +/- 0.57. These values may be explained both by several fireball jet models and by the cannonball model. Fireball spherical expansion models are not favoured. Late epoch deep imaging revealed the presence of a complex host galaxy system, composed of at least two objects located 1.2" (1.7 sigma) and 1.9" (2.7 sigma) from the afterglow position.Comment: 7 pages, 5 figures, published in A&

The mammary gland in small ruminants: major morphological and functional events underlying milk production - a review

The importance of small ruminants to the dairy industry has increased in recent years, especially in developing countries, where it has a high economic and social impact. Interestingly and despite the fact that the mammary gland is the specialised milk production organ, very few authors studied the modifications occurring in the mammary gland through the lactation period in production animals, particularly in the small ruminants, sheep (Ovis aries) and goat (Capra hircus). Nevertheless, understanding the different mammary gland patterns throughout lactation is essential to improve dairy production. In addition, associating these patterns with different milking frequencies, lactation number or different diets is also of high importance, directly affecting the dairy industry. The mammary gland is commonly composed of parenchyma and stroma, which includes the ductal system, with individual proportions of each changing during the different periods and yields in a lactation cycle. Indeed, during late gestation, as well as during early to mid-lactation, mammary gland expansion occurs, with an increase in the number of epithelial cells and lumen area, which leads to increment of the parenchyma tissue, as well as a reduction of stroma, corresponding macroscopically to the increase in mammary gland volume. Throughout late lactation, the mammary gland volume decreases owing to the regression of the secretory structure. In general, common mammary gland patterns have been shown for both goats and sheep throughout the several lactation stages, although the number of studies is limited. The main objective of this manuscript is to review the colostrogenesis and lactogenesis processes as well as to highlight the mammary gland morphological patterns underlying milk production during the lactation cycle for small ruminants, and to describe potential differences between goats and sheep, hence contributing to a better description of mammary gland development during lactation for these two poorly studied specie

Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles - II. CO line survey of evolved stars: derivation of mass-loss rate formulae

We aim to (1) set up simple and general analytical expressions to estimate mass-loss rates of evolved stars, and (2) from those calculate estimates for the mass-loss rates of asymptotic giant branch (AGB), red supergiant (RSG), and yellow hypergiant stars in our galactic sample. Rotationally excited lines of CO are a very robust diagnostic in the study of circumstellar envelopes (CSEs). When sampling different layers of the CSE, observations of these molecular lines lead to detailed profiles of kinetic temperature, expansion velocity, and density. A state-of-the-art, nonlocal thermal equilibrium, and co-moving frame radiative transfer code that predicts CO line intensities in the CSEs of late-type stars is used in deriving relations between stellar and molecular-line parameters, on the one hand, and mass-loss rate, on the other. We present analytical expressions for estimating the mass-loss rates of evolved stellar objects for 8 rotational transitions of the CO molecule, apply them to our extensive CO data set covering 47 stars, and compare our results to those of previous studies. Our expressions account for line saturation and resolving of the envelope, thereby allowing accurate determination of very high mass-loss rates. We argue that, for estimates based on a single rotational line, the CO(2-1) transition provides the most reliable mass-loss rate. The mass-loss rates calculated for the AGB stars range from 4x10^-8 Msun/yr up to 8x10^-5 Msun/yr. For RSGs they reach values between 2x10^-7 Msun/yr and 3x10^-4 Msun/yr. The estimates for the set of CO transitions allow time variability to be identified in the mass-loss rate. Possible mass-loss-rate variability is traced for 7 of the sample stars. We find a clear relation between the pulsation periods of the AGB stars and their derived mass-loss rates, with a levelling off at approx. 3x10^-5 Msun/yr for periods exceeding 850 days.Comment: Accepted for publication by Astronomy and Astrophysics, 24 pages + 28 pages appendix, 20 figure