Single Stellar Populations in the Near-Infrared - I. Preparation of the IRTF spectral stellar library

We present a detailed study of the stars of the IRTF spectral library to understand its full extent and reliability for use with Stellar Population (SP) modeling. The library consist of 210 stars, with a total of 292 spectra, covering the wavelength range of 0.94 to 2.41 micron at a resolution R = 2000. For every star we infer the effective temperature (Teff), gravity (logg) and metallicity ([Z/Zsun]) using a full-spectrum fitting approach in a section of the K band (2.19 to 2.34 micron) and temperature-NIR colour relations. We test the flux calibration of these stars by calculating their integrated colours and comparing them with the Pickles library colour-temperature relations. We also investigate the NIR colours as a function of the calculated effective temperature and compared them in colour-colour diagrams with the Pickles library. This latter test shows a good broad-band flux calibration, important for the SP models. Finally, we measure the resolution R as a function of wavelength. We find that the resolution increases as a function of lambda from about 6 angstrom in J to 10 angstrom in the red part of the K-band. With these tests we establish that the IRTF library, the largest currently available general library of stars at intermediate resolution in the NIR, is an excellent candidate to be used in stellar population models. We present these models in the next paper of this series.Comment: 17 pages, 19 figures. Accepted for publication in Astronomy and Astrophysic

Comparação entre protocolos para extração de DNA total de Ricinus communis L.

bitstream/CNPA/19674/1/COMTEC252.pd

Interaction Effects on the Magneto-optical Response of Magnetoplasmonic Dimers

The effect that dipole-dipole interactions have on the magneto-optical (MO) properties of magnetoplasmonic dimers is theoretically studied. The specific plasmonic versus magnetoplasmonic nature of the dimer's metallic components and their specific location within the dimer plays a crucial role on the determination of these properties. We find that it is possible to generate an induced MO activity in a purely plasmonic component, even larger than that of the MO one, therefore dominating the overall MO spectral dependence of the system. Adequate stacking of these components may allow obtaining, for specific spectral regions, larger MO activities in systems with reduced amount of MO metal and therefore with lower optical losses. Theoretical results are contrasted and confirmed with experiments for selected structures

Carbon stars in the X-shooter Spectral Library

We provide a new collection of spectra of 35 carbon stars obtained with the ESO/VLT X-shooter instrument as part of the X-shooter Spectral Library project. The spectra extend from 0.3$\mu$m to 2.4$\mu$m with a resolving power above $\sim$ 8000. The sample contains stars with a broad range of (J-K) color and pulsation properties located in the Milky Way and the Magellanic Clouds. We show that the distribution of spectral properties of carbon stars at a given (J-K) color becomes bimodal (in our sample) when (J-K) is larger than about 1.5. We describe the two families of spectra that emerge, characterized by the presence or absence of the absorption feature at 1.53$\mu$m, generally associated with HCN and C$_2$H$_2$. This feature appears essentially only in large-amplitude variables, though not in all observations. Associated spectral signatures that we interpret as the result of veiling by circumstellar matter, indicate that the 1.53$\mu$m feature might point to episodes of dust production in carbon-rich Miras.Comment: 29 pages, 21 figures, 9 tables, Accepted for publication in A&

Comparação entre protocolos de extração de DNA para Amphobotrys ricini.

bitstream/CNPA/19683/1/COMTEC239.pd

Transcriptomic analysis of the hepatic response to stress in the red cusk-eel (Genypterus chilensis): Insights into lipid metabolism, oxidative stress and liver steatosis

Indexación: Scopus.Teleosts exhibit a broad divergence in their adaptive response to stress, depending on the magnitude, duration, and frequency of stressors and the species receiving the stimulus. We have previously reported that the red cusk-eel (Genypterus chilensis), an important marine farmed fish, shows a physiological response to stress that results in increased skeletal muscle atrophy mediated by over-expression of components of the ubiquitin proteasome and autophagy-lysosomal systems. To better understand the systemic effects of stress on the red cusk-eel metabolism, the present study assessed the transcriptomic hepatic response to repetitive handling-stress. Using high-Throughput RNA-seq, 259 up-regulated transcripts were found, mostly associated with angiogenesis, gluconeogenesis, and triacylglyceride catabolism. Conversely, 293 transcripts were down-regulated, associated to cholesterol biosynthesis, PPARα signaling, fatty acid biosynthesis, and glycolysis. This gene signature was concordant with hepatic metabolite levels and hepatic oxidative damage. Moreover, the increased plasmatic levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase) and AP (alkaline phosphatase), as well as liver histology suggest stress-induced liver steatosis. This study offers an integrative molecular and biochemical analysis of the hepatic response to handling-stress, and reveals unknown aspects of lipid metabolism in a non-model teleost.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.017644

Staphylococcus sp, tratamiento antimicrobiano y resistencia en pioderma bacteriana superficial canina

En la Provincia de Buenos Aires, Argentina, existen pocos estudios sobre la frecuencia del tratamiento antimicrobiano en pioderma canina y el nivel de resistencia antimicrobiana de Staphylococcus sp. Los principales objetivos de este estudio fueron analizar la resistencia antimicrobiana de Staphylococcus sp, la frecuencia del tratamiento antimicrobiano y sus recidivas en caninos con pioderma. Se analizaron 39 caninos con diagnóstico clínico de pioderma, procedentes de clínicas veterinarias privadas del área de Buenos Aires. Se recogieron, en el momento de la pioderma activa, hisopados de lesiones cutáneas para cultivo bacteriano y análisis por espectrometría de masas. Además, se registró raza, sexo, clasificación clínica de la pioderma, tratamiento antimicrobiano y recaídas de la enfermedad. El 76% de los animales estudiados recibieron cefalexina por vía oral después del examen clínico, y dentro de este porcentaje, el 31,6% también recibió otros tipos de agentes antimicrobianos debido a recaídas. El 24% restante recibió como tratamiento antimicrobiano lincomicina, minociclina y/o doxiciclina. En el 60% de los animales estudiados, la pioderma diagnosticada tenía una causa alérgica, que a su vez coincidió con las recaídas y fue similar al porcentaje de resistencia a la meticilina (51%) de los diferentes aislamientos de Staphylococcus sp. El 80% de las resistencias a meticilina observadas se trataron previamente con cefalexina. Inesperadamente, el mayor porcentaje de resistencia observada fue a eritromicina, clindamicina (demostrando fenotipo constitutivo MLSB) y sulfatrimetoprim