9,069 research outputs found

    RBSC-NVSS Sample. I. Radio and Optical Identifications of a Complete Sample of 1500 Bright X-ray Sources

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    We cross-identified the ROSAT Bright Source Catalog (RBSC) and the NRAO VLA Sky Survey (NVSS) to construct the RBSC-NVSS sample of the brightest X-ray sources (>= 0.1 counts/s or ~1E-12 ergs/cm/cm/s in the 0.1-2.4 keV band) that are also radio sources (S >= 2.5 mJy at 1.4 GHz) in the 7.8 sr of extragalactic sky with |b| > 15 degrees. and delta > -40 degrees. The sky density of NVSS sources is low enough that they can be reliably identified with RBSC sources having average rms positional uncertainties = 10 arcsec. We used the more accurate radio positions to make reliable X-ray/radio/optical identifications down to the POSS plate limits. We obtained optical spectra for many of the bright identifications lacking published redshifts. The resulting X-ray/radio sample is unique in its size (N ~ 1500 objects), composition (a mixture of nearly normal galaxies, Seyfert galaxies, quasars, and clusters), and low average redshift ( ~ 0.1).Comment: 35 LaTeX pages including 6 eps figures + 40 LaTeX page table2 (landscape) w/ AASTeX 5.0; accepted to ApJ

    Effect of weaning of kid goats on productive and reproductive parameters of the mother and kid goats. Communication

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    Trabajo presentado al 43º Congreso Argentino de Producción AnimalLa producción caprina en el área de sierras y mesetas occidental del noroeste de Chubut es una de las principales actividades de los sistemas minifundistas. En estos sistemas, en general, el destete de los chivitos se realiza naturalmente. Se han probado diferentes métodos de destetes y recría de chivos (Ceballos et al., 2014; Ceballos et. al., 2016) con efectos positivos sobre la condición corporal de las madres y menor mortandad de las crías, pero con una disminución en el crecimiento y producción de mohair de las crías destetadas. En este contexto se evaluó nuevamente el efecto del destete y recría a corral de chivitos y su efecto sobre paramentos productivos y reproductivos de las madres.EEA EsquelFil: Ceballos, Demian. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur. Estación Experimental Agroforestal Esquel; ArgentinaFil: Villa, Martín. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur. Estación Experimental Agroforestal Esquel; ArgentinaFil: Apóstolo, Romina. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur. Estación Experimental Agroforestal Esquel; ArgentinaFil: Li, Sebastián. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur. Estación Experimental Agroforestal Esquel; Argentin

    Effect of kid weaning on stress blood biomarkers

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    Trabajo presentado al 43º Congreso Argentino de Producción AnimalLa producción caprina en el área de sierras y mesetas occidentales del noroeste de la provincia de Chubut es una de las principales actividades de los sistemas minifundistas. En estos sistemas, en general, el destete de los chivitos se realiza naturalmente, sin ningún manejo. Se han probado diferentes métodos de destetes y recría de chivos (Ceballos et al., 2014, 2016, 2018) y su efecto sobre parámetros productivos, pero no se han determinado indicadores sanguíneos de estrés por el destete. No obstante, a nivel regional existen algunos trabajos en ovinos (Cancino et al., 2014). En este contexto se evaluó el efecto del destete de chivos sobre algunos indicadores sanguíneos de estrés en un sistema real de producción.EEA EsquelFil: Ceballos, Demian. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Patagonia Sur. Estación Experimental Agroforestal Esquel (EEAf Esquel); ArgentinaFil: Apóstolo, Romina María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agroforestal Esquel; ArgentinaFil: Villa, Martín. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agroforestal Esquel; ArgentinaFil: Li, Sebastián. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agroforestal Esquel; Argentin

    Quadrupolar and dipolar contributions to x-ray magnetic circular dichroism at the Tb L3,2 edges: Experiment versus theory

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    We investigate the x-ray magnetic circular dichroism (XMCD) at the L3,2 edges using a single crystal of Tb as a prototype system for a one-element magnet in order to ascertain the multipolar nature of the features in the dichroic spectra. The high resolution of the experimental data allows for a clear identification of the dipolar (E1: 2p→5d) and quadrupolar (E2: 2p→4f) transitions. On the basis of ab initio calculations we developed a simple procedure to extract the quadrupolar part by subtracting the derivative of the spin-averaged absorption spectra from the experimental XMCD data. The deconvolution has to be carried out before applying sum rules to determine 4f and 5d moments

    A Mechanical Mass Sensor with Yoctogram Resolution

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    Nanoelectromechanical systems (NEMS) have generated considerable interest as inertial mass sensors. NEMS resonators have been used to weigh cells, biomolecules, and gas molecules, creating many new possibilities for biological and chemical analysis [1-4]. Recently, NEMS-based mass sensors have been employed as a new tool in surface science in order to study e.g. the phase transitions or the diffusion of adsorbed atoms on nanoscale objects [5-7]. A key point in all these experiments is the ability to resolve small masses. Here we report on mass sensing experiments with a resolution of 1.7 yg (1 yg = 10^-24 g), which corresponds to the mass of one proton, or one hydrogen atom. The resonator is made of a ~150 nm long carbon nanotube resonator vibrating at nearly 2 GHz. The unprecedented level of sensitivity allows us to detect adsorption events of naphthalene molecules (C10H8) and to measure the binding energy of a Xe atom on the nanotube surface (131 meV). These ultrasensitive nanotube resonators offer new opportunities for mass spectrometry, magnetometry, and adsorption experiments.Comment: submitted version of the manuscrip

    Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz)

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    Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding

    Estimation of daily global solar radiation from measured temperatures at Cañada de Luque, Córdoba, Argentina

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    Solar radiation is the most important source of renewable energy in the planet; it's important to solar engineers, designers and architects, and it's also fundamental for efficiently determining irrigation water needs and potential yield of crops, among others. Complete and accurate solar radiation data at a specific region are indispensable. For locations where measured values are not available, several models have been developed to estimate solar radiation. The objective of this paper was to calibrate, validate and compare five representative models to predict global solar radiation, adjusting the empirical coefficients to increase the local applicability and to develop a linear model. All models were based on easily available meteorological variables, without sunshine hours as input, and were used to estimate the daily solar radiation at Cañada de Luque (Córdoba, Argentina). As validation, measured and estimated solar radiation data were analyzed using several statistic coefficients. The results showed that all the analyzed models were robust and accurate (R2 and RMSE values between 0.87 to 0.89 and 2.05 to 2.14, respectively), so global radiation can be estimated properly with easily available meteorological variables when only temperature data are available. Hargreaves-Samani, Allen and Bristow-Campbell models could be used with typical values to estimate solar radiation while Samani and Almorox models should be applied with calibrated coefficients. Although a new linear model presented the smallest R2 value (R2 = 0.87), it could be considered useful for its easy application. The daily global solar radiation values produced for these models can be used to estimate missing daily values, when only temperature data are available, and in hydrologic or agricultural applications

    Theoretical Overview: The New Mesons

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    After commenting on the state of contemporary hadronic physics and spectroscopy, I highlight four areas where the action is: searching for the relevant degrees of freedom, mesons with beauty and charm, chiral symmetry and the D_{sJ} levels, and X(3872) and the lost tribes of charmonium.Comment: 10 pages, uses jpconf.cls; talk at First Meeting of the APS Topical Group on Hadronic Physic

    AHR signaling is induced by infection with coronaviruses

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    Coronavirus infection in humans is usually associated to respiratory tract illnesses, ranging in severity from mild to life-threatening respiratory failure. The aryl hydrocarbon receptor (AHR) was recently identified as a host factor for Zika and dengue viruses; AHR antagonists boost antiviral immunity, decrease viral titers and ameliorate Zika-induced pathology in vivo. Here we report that AHR is activated by infection with different coronaviruses, potentially impacting antiviral immunity and lung epithelial cells. Indeed, the analysis of single-cell RNA-seq from lung tissue detected increased expression of AHR and AHR transcriptional targets, suggesting AHR signaling activation in SARS-CoV-2-infected epithelial cells from COVID-19 patients. Moreover, we detected an association between AHR expression and viral load in SARS-CoV-2 infected patients. Finally, we found that the pharmacological inhibition of AHR suppressed the replication in vitro of one of the causative agents of the common cold, HCoV-229E, and the causative agent of the COVID-19 pandemic, SARS-CoV-2. Taken together, these findings suggest that AHR activation is a common strategy used by coronaviruses to evade antiviral immunity and promote viral replication, which may also contribute to lung pathology. Future studies should further evaluate the potential of AHR as a target for host-directed antiviral therapy.Fil: Giovannoni, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Harvard Medical School; Estados UnidosFil: Li, Zhaorong. Harvard Medical School; Estados UnidosFil: Remes Lenicov, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Dávola, María E.. McMaster University; CanadáFil: Elizalde, Maria Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Paletta, Ana Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Ashkar, Ali A.. McMaster University; CanadáFil: Mossman, Karen L.. McMaster University; CanadáFil: Dugour, Andrea Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Figueroa, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; ArgentinaFil: Barquero, Andrea Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Laboratorio de Virología; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Garcia, Cybele. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Quintana, Francisco Javier. Broad Institute; Estados Unidos. Harvard Medical School; Estados Unido

    Analysis of the airflow at the centre of the upper plateau on the Iberian Peninsula and its link to CO2 and CH4 concentrations

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    Air trajectories are useful tools to investigate the airflow and transport of substances released into the atmosphere. Web-based models are widely used to calculate trajectories reaching places that are being studied. This articleconsiders 6 years of air trajectories as of October 2010 together with CO2 and CH4 concentrations. A bivariate smoothing function that employs the radial distance and direction of the trajectory to the measuring site was used to form trajectory groups from the minima of this function. Varied radial and angular windows were assayed to investigate the behaviour of the smoothing function. Curves associated with the number of minima were L-shaped and the windows selected corresponded to the ‘knee’ of the curves. Seven trajectory groups were considered to observe the response of the procedure against the radial distance and the direction. Seasonal evolution revealed the greatest radial extent for winter and the lowest for summer. Moreover, trajectories from the Atlantic Ocean were the most frequent. CO2 and CH4 concentrations were detrended using a linear function, and average trends were 2.34 and 0.0085 ppm year−1, respectively. Annual cycles of detrended concentrations were very soft and were linked to the site’s ecosystem. CO2 presented one maximum in spring linked to substantial vegetation growth, and one minimum in summer, when vegetation dies and dispersion is maximum. CH4 maximum was observed in winter although the minimum was found in summer and attributed to oxidation with the hydroxyl radical in the troposphere and to dispersion in this season. Analysis of concentration trends for the groups proposed revealed the opposite behaviour of both gases in summer. Finally, maximum CO2 concentrations were marked by trajectories from North Africa affected by nearby cities, whereas minimum concentrations for both gases were noticeable for trajectories from the ocean in summer
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