8,820 research outputs found

    Evaluation and Utilization of a Tall Fescue Germplasm Collection at Pergamino INTA, Argentina

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    One hundred and fifty four accessions of tall fescue (Festuca arundinacea Schreb.) representing different types grown around the world were evaluated at Pergamino Inta Experimental Station. A multivariate analysis was carried out to evaluate individual and group variations. Three principal components (PCs) explained 70 % of the variation. Cluster analysis (Ward method) allowed the identification of 7 groups of populations. Plants from the most promising populations were selected in order to form a new breeding gene pool. The main objective of this study is to develop a new cultivar with improved winter herbage yield. Selected genotypes were mostly of Mediterranean origin

    Flowering Distribution Pattern in White Clover Cultivars

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    A trial was carried out at Pergamino Agricultural Experimental Station to examine the distribution pattern and the profuseness of inflorescence production of white clover (Trifolium repens L.). The treatments were 16 cultivars (Churrinche, El Lucero MAG, Bayucuá, Estanzuela Zapicán, Lucero Plus Inta, Haifa, California, Ladino Gigante Lodigiano, Dubrava, Susi, Merwi, Blanca, Sonja, Espanso, Nora, S 184) of different origins and leaf size. The experimental design was a lattice with four replications. Southamerican cultivars showed a similar distribution pattern and had the highest inflorescence production. They also flowered earlier than foreign cultivars, except Haifa. Some of the cultivars evaluated did not have an acceptable inflorescence production. Some others produced seeds at the end of the season under bad weather conditions. Small-leaved varieties tended to have less inflorescence density. The spread of flowering during the reproductive cycle and the number of inflorescence per unit area are important characters that must be considered during breeding and before releasing introduced cultivars to the market

    White adipose tissue and circadian rhythm dysfunctions in obesity : Pathogenesis and available therapies

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    A combined neuroendocrine, metabolic, and chronobiological view can help to better understand the multiple and complex mechanisms involved in obesity development and maintenance, as well as to provide new effective approaches for its control and treatment. Indeed, we have currently updated data on the whole adipogenic process involved in white adipose tissue (WAT) mass expansion, namely due to a mechanism whereby WAT cells become hypertrophic, thus inducing a serious local (WAT) inflammatory condition that in turn, will impair not only the cross-talk between the hypothalamus and the WAT, but also favoring the development of deep and widespread neuroendocrine-metabolic dysfunction. Moreover, we also have revisited the circadian clock genes involved in dysfunctional WAT mass expansion and the mechanisms that may lead to obesity development, including early metabolic dysfunctions, enhanced oxidative stress and distorted energy homeostasis. The epigenetic changes of clock genes driving metabolic disease and obesity development have also been included in this review. Finally, we have also underlined the relevance of metabolic homeostasis regulation by central and peripheral organ clocks, sleep disturbances, nutrients, and feeding time, as key factors in obesity development as well as both, classical and chronotherapeutic approaches for its prevention and treatment.Centro de Endocrinología Experimental y Aplicad

    Charge density waves enhance the electronic noise of manganites

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    The transport and noise properties of Pr_{0.7}Ca_{0.3}MnO_{3} epitaxial thin films in the temperature range from room temperature to 160 K are reported. It is shown that both the broadband 1/f noise properties and the dependence of resistance on electric field are consistent with the idea of a collective electrical transport, as in the classical model of sliding charge density waves. On the other hand, the observations cannot be reconciled with standard models of charge ordering and charge melting. Methodologically, it is proposed to consider noise-spectra analysis as a unique tool for the identification of the transport mechanism in such highly correlated systems. On the basis of the results, the electrical transport is envisaged as one of the most effective ways to understand the nature of the insulating, charge-modulated ground states in manganites.Comment: 6 two-column pages, 5 figure

    Dipolar degrees of freedom and Isospin equilibration processes in Heavy Ion collisions

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    Background: In heavy ion collision at the Fermi energies Isospin equilibration processes occur- ring when nuclei with different charge/mass asymmetries interacts have been investigated to get information on the nucleon-nucleon Iso-vectorial effective interaction. Purpose: In this paper, for the system 48Ca +27 Al at 40 MeV/nucleon, we investigate on this process by means of an observable tightly linked to isospin equilibration processes and sensitive in exclusive way to the dynamical stage of the collision. From the comparison with dynamical model calculations we want also to obtain information on the Iso-vectorial effective microscopic interaction. Method: The average time derivative of the total dipole associated to the relative motion of all emitted charged particles and fragments has been determined from the measured charges and velocities by using the 4? multi-detector CHIMERA. The average has been determined for semi- peripheral collisions and for different charges Zb of the biggest produced fragment. Experimental evidences collected for the systems 27Al+48Ca and 27Al+40Ca at 40 MeV/nucleon used to support this novel method of investigation are also discussed.Comment: Submitted for publication on Phys. Rev. C. 0n 24-oct-201

    Coordinated X-ray and Optical observations of Star-Planet Interaction in HD 17156

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    The large number of close-in Jupiter-size exoplanets prompts the question whether star-planet interaction (SPI) effects can be detected. We focused our attention on the system HD 17156, having a Jupiter-mass planet in a very eccentric orbit. Here we present results of the XMM-Newton observations and of a five months coordinated optical campaign with the HARPS-N spectrograph. We observed HD 17156 with XMM-Newton when the planet was approaching the apoastron and then at the following periastron passage, quasi simultaneously with HARPS-N. We obtained a clear (5.5σ\approx 5.5\sigma) X-ray detection only at the periastron visit, accompanied by a significant increase of the RHKR'_{\rm HK} chromospheric index. We discuss two possible scenarios for the activity enhancement: magnetic reconnection and flaring or accretion onto the star of material tidally stripped from the planet. In any case, this is possibly the first evidence of a magnetic SPI effect caught in action
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