606 research outputs found

    Acción biocida del jugo de fique (Furcraea gigantea Vent.) sobre Colletotrichum gloeosporioides aislado de tomate de árbol (Solanum betaceum Cav.)

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    The biocidal action of fique juice on the phytopathogen C. gloeosporioides, which causes anthracnose in tamarillo fruit was evaluated. Concentrations of 1,000, 10,000 and 100,000 μg mL-1 amended in the PDA culture medium were analyzed and tree levels of fermentation which were 0, 4 and 8 days. Mycelial discs of 1.1 cm in diameter were placed in different experimental units and the in vitro growth area was measured after a period of 8 days using the ImageJ software. Only statistically significant differences (P<0.05) occurred between concentrations and between the interaction of two factors. The Maximum inhibition of the pathogen was obtained by using a concentration of 100,000 μg mL-1 and 8 days of fermentation

    Maltrato, abuso y violencia en la familia (experiencia profesional dirigida)

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    Tablas, graficas, talleresLa diversidad de casos que se presentan en la Comisaría permite al practicante aplicar los conocimientos adquiridos en la Universidad e investigar acerca de los procesos psicosociales y de las diferentes posibilidades que existen para abordar una situación psicológica. Las expectativas del practicante al llegar a la comisaría fueron atendidas de una forma asertiva en cuanto a la capacitación que se tuvo para conocer la dinámica y el funcionamiento de los problemas que se tratan, la competencia de la institución y sus integrantes, las instituciones que paralelamente colaboran con la comisaría y el rol que como practicantes se tiene dentro de la organización. El objetivo de la experiencia es interactuar con las personas para así poder hacer una intervención en cuanto a la problemática que se encuentre, en este caso sería La Violencia Intrafamiliar y el Maltrato Infantil.No Registr

    Detection of fiber-digesting bacteria in the forestomach contents of llamas (Lama glama) by PCR

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    AbstractThe high fibrolytic activity and large biomass of strictly-anaerobic bacteria that inhabit the rumen makes them primarily responsible for the degradation of the forage consumed by ruminants. Llamas feed mainly on low quality fibrous roughages that are digested by an active and diverse microflora. The products of this fermentation are volatile fatty acids and microbial biomass, which will be used by the animals. The aim of this study was to detect the three major fiber-digesting anaerobic bacteria in the forestomach contents of llamas by PCR. In this study, we detected Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes in the forestomach contents of eight native llamas from Argentina

    A nearby GRB host prototype for z~7 Lyman-break galaxies: Spitzer-IRS and X-shooter spectroscopy of the host galaxy of GRB031203

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    Gamma-ray burst (GRB) host galaxies have been studied extensively in optical photometry and spectroscopy. Here we present the first mid-infrared spectrum of a GRB host, HG031203. It is one of the nearest GRB hosts at z=0.1055, allowing both low and high-resolution spectroscopy with Spitzer-IRS. Medium resolution UV-to-K-band spectroscopy with the X-shooter spectrograph on the VLT is also presented, along with Spitzer IRAC and MIPS photometry, as well as radio and sub-mm observations. These data allow us to construct a UV-to-radio spectral energy distribution with almost complete spectroscopic coverage from 0.3-35 micron of a GRB host galaxy for the first time, potentially valuable as a template for future model comparisons. The IRS spectra show strong, high-ionisation fine structure line emission indicative of a hard radiation field in the galaxy, suggestive of strong ongoing star-formation and a very young stellar population. The selection of HG031203 via the presence of a GRB suggests that it might be a useful analogue of very young star-forming galaxies in the early universe, and hints that local BCDs may be used as more reliable analogues of star-formation in the early universe than typical local starbursts. We look at the current debate on the ages of the dominant stellar populations in z~7 and z~8 galaxies in this context. The nebular line emission is so strong in HG031203, that at z~7, it can reproduce the spectral energy distributions of z-band dropout galaxies with elevated IRAC 3.6 and 4.5 micron fluxes without the need to invoke a 4000A break.Comment: Published in ApJ. 9 pages, 6 figures, emulateapj styl

    Acid mine drainage in semi-arid regions: the extent of the problem in the waters of reservoirs in the Iberian Pyrite Belt (SW Spain)

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    There are many reservoirs in the Iberian Pyrite Belt (IPB), SW Spain, which receive contributions from watercourses affected by acid mine drainage processes, characterised by low pH values and high concentrations of heavy metals and sulphates. When they reach the reservoirs, the waters increase its pH, which will cause most of the metal load carried by the mining channel to precipitate into the reservoir itself and accumulate on its floor. The silting of reservoirs is an environmental problem which can affect the loss of storage capacity, their general functioning and aquatic ecosystems. A study of these is vital to allow both preventative and corrective measures to be established. Climatic conditions are the most significant external controlling factors in terms of the degree and type of mining pollution. The study area presents characteristics typical of the semi-arid Mediterranean climate, with annual precipitation of around 630 mm/year; moderate temperatures with average annual values of 17.1 W C and a temperature range of 50 W C. The aim of this study is to carry out a physical–chemical characterization of the waters where they enter the reservoirs located in the IPB over the course of a hydrological year and to establish possible interdependencies between the various parameters.Financial support for this research was provided by DGCICYT National Plan, project no. CGL2010-21268-C02-01.info:eu-repo/semantics/publishedVersio

    A High Signal-to-Noise Ratio Composite Spectrum of Gamma-ray Burst Afterglows

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    We present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35<z<6.7 observed with low resolution optical spectra. The composite spectrum covers the wavelength range 700-6600 A in the rest frame and has a mean signal-to-noise ratio of 150 per 1 A pixel and reaches a maximum of ~300 in the range 2500-3500 A. Equivalent widths are measured from metal absorption lines from the Lya line to ~5200 A, and associated metal and hydrogen lines are identified between the Lyman break and Lya line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight. We find a temporal variation in fine structure lines when dividing the sample into bursts observed within 2 hours from their trigger and those observed later. Other lines in the predominantly neutral gas show variations too, but this is most likely a random effect caused by weighting of individual strong absorption lines and which mimics a temporal variation. Bursts characterized with high or low prompt GRB energy release produce afterglows with similar absorption line strengths, and likewise for bursts with bright or faint optical afterglows. Bursts defined as dark from their optical to X-ray spectral index have stronger absorption lines relative to the optically bright bursts. The composite spectrum has strong CaII and MgII absorption lines as commonly found in dusty galaxies, however, we find no evidence for dust or a significant molecular content based on the non-detection of diffuse interstellar bands. Compared to starburst galaxy spectra, the GRB composite has much stronger fine structure lines, while metal absorption lines are weaker.Comment: Accepted for publication in ApJ, 24 page

    The optical/near-IR spectral energy distribution of the GRB 000210 host galaxy

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    We report on UBVRIZJsHKs-band photometry of the dark GRB 000210 host galaxy. Fitting a grid of spectral templates to its Spectral Energy Distribution (SED), we derived a photometric redshift (z=0.842\+0.0540.042) which is in excellent agreement with the spectroscopic one (z=0.8463+/-0.0002; Piro et al. 2002). The best fit to the SED is obtained with a blue starburst template with an age of 0.181\+0.0370.026 Gyr. We discuss the implications of the inferred low value of Av and the age of the dominant stellar population for the non detection of the GRB 000210 optical afterglow.Comment: 4 pages, 1 figure, contribution to the Rome 2002 GRB worksho

    A multi-colour study of the dark GRB 000210 host galaxy and its environment

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    We present UBVRIZJsHKs broad band photometry of the host galaxy of the dark gamma-ray burst (GRB) of February 10, 2000. These observations represent the most exhaustive photometry given to date of any GRB host galaxy. A grid of spectral templates have been fitted to the Spectral Energy Distribution (SED) of the host. The derived photometric redshift is z=0.842^+0.054_-0.042, which is in excellent agreement with the spectroscopic redshift (z=0.8463+/-0.0002) proposed by Piro et al. (2002) based on a single emission line. Furthermore, we have determined the photometric redshift of all the galaxies in an area of 6'x6' around the host galaxy, in order to check for their overdensity in the environment of the host. We find that the GRB 000210 host galaxy is a subluminous galaxy (L ~ 0.5+/-0.2 L*), with no companions above our detection threshold of 0.18+/-0.06 L*. Based on the restframe ultraviolet flux a star formation rate of 2.1+/-0.2 Solar Masses per year is estimated. The best fit to the SED is obtained for a starburst template with an age of 0.181^+0.037_-0.026 Gyr and a very low extinction (Av~0). We discuss the implications of the inferred low value of Av and the age of the dominant stellar population for the non detection of the GRB 000210 optical afterglow.Comment: 10 pages with 4 encapsulated PostScript figures included. Accepted for publication in Astronomy & Astrophysic

    The wideband backend at the MDSCC in Robledo. A new facility for radio astronomy at Q- and K- bands

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    The antennas of NASA's Madrid Deep Space Communications Complex (MDSCC) in Robledo de Chavela are available as single-dish radio astronomical facilities during a significant percentage of their operational time. Current instrumentation includes two antennas of 70 and 34 m in diameter, equipped with dual-polarization receivers in K (18 - 26 GHz) and Q (38 - 50 GHz) bands, respectively. We have developed and built a new wideband backend for the Robledo antennas, with the objectives (1) to optimize the available time and enhance the efficiency of radio astronomy in MDSCC; and (2) to tackle new scientific cases impossible to that were investigated with the old, narrow-band autocorrelator. The backend consists of an IF processor, a FFT spectrometer (FFTS), and the software that interfaces and manages the events among the observing program, antenna control, the IF processor, the FFTS operation, and data recording. The whole system was end-to-end assembled in August 2011, at the start of commissioning activities, and the results are reported in this paper. Frequency tunings and line intensities are stable over hours, even when using different synthesizers and IF channels; no aliasing effects have been measured, and the rejection of the image sideband was characterized. The first setup provides 1.5 GHz of instantaneous bandwidth in a single polarization, using 8192 channels and a frequency resolution of 212 kHz; upgrades under way include a second FFTS card, and two high-resolution cores providing 100 MHz and 500 MHz of bandwidth, and 16384 channels. These upgrades will permit simultaneous observations of the two polarizations with instantaneous bandwidths from 100 MHz to 3 GHz, and spectral resolutions from 7 to 212 kHz.Comment: 9 pages, 8 figures. Accepted to Astronomy and Astrophysic
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