23,287 research outputs found

    POSSIBLE FUTURE SCENARIOS FOR SICILIAN CEREAL CROPPING IN THE LIGHT OF CURRENT TRENDS IN AGRICULTURAL POLICY OF THE EUROPEAN UNION

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    This paper sets out the results of a research project carried out by the University of Palermo and financed by the Sicilian Region, which aims to establish the impact of the Fischler Reform on Sicilian agriculture, and to project future scenarios that take into account some of the changes that the production process may undergo in the Region, following both the application of the Reform itself (now in force) and the eventual application of indications contained in the Health check. The impacts of the Fischler Reform, and especially the application of the Single Payment scheme to companies, were examined in cereal cropping companies, especially considering the significant amount of durum wheat cultivation in vast areas of the Region’s hilly and its strategic importance for many areas where there is a risk of farming being abandoned, with grave consequences for the territory and its farmland, for employment and for the encouragement of food and processing industries. The chosen means for assessing the effects of the reform was that of direct interviews at a statistically representative sample made up of 400 agricultural companies, determining possible earnings within the current situation, but also in the eventuality of some of the indications in the Health check being applied. The results indicate that Community aid plays a crucial role in the companies looked at, allowing them to remain on the market. Indeed, the elimination of the aid planned within the framework of the Common Agricultural Policy in the hypothetical scenarios showed a negative impact on earnings for the companies and could cause their exclusion from the market.CAP, Future of the CAP, Sicilian agriculture, Agricultural and Food Policy, Q10, Q18.,

    A magnetic reconnection model for explaining the multi-wavelength emission of the microquasars Cyg X-1 and Cyg X-3

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    Recent studies have indicated that cosmic ray acceleration by a first-order Fermi process in magnetic reconnection current sheets can be efficient enough in the surrounds of compact sources. In this work, we discuss this acceleration mechanism operating in the core region of galactic black hole binaries (or microquasars) and show the conditions under which this can be more efficient than shock acceleration. In addition, we compare the corresponding acceleration rate with the relevant radiative loss rates obtaining the possible energy cut-off of the accelerated particles and also compute the expected spectral energy distribution (SED) for two sources of this class, namely Cygnus X-1 and Cygnus X-3, considering both leptonic and hadronic processes. The derived SEDs are comparable to the observed ones in the low and high energy ranges. Our results suggest that hadronic non-thermal emission due to photo-meson production may produce the very high energy gamma-rays in these microquasars.Comment: 17 pages and 7 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Society (MNRAS

    Mechanical magnetometry of Cobalt nanospheres deposited by focused electron beam at the tip of ultra-soft cantilevers

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    Using focused-electron-beam-induced deposition, Cobalt magnetic nanospheres with diameter ranging between 100 nm and 300 nm are grown at the tip of ultra-soft cantilevers. By monitoring the mechanical resonance frequency of the cantilever as a function of the applied magnetic field, the hysteresis curve of these individual nanospheres are measured. This enables to evaluate their saturation magnetization, found to be around 430 emu/cm^3 independently of the size of the particle, and to infer that the magnetic vortex state is the equilibrium configuration of these nanospheres at remanence

    Metabolic and functional consequences of cytosolic 5′-nucleotidase-IA overexpression in neonatal rat cardiomyocytes

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    Adenosine exerts a spectrum of energy-preserving actions on the heart negative chronotropic effects. The pathways leading to adenosine formation have remained controversial. In particular, although cytosolic 5′-nucleotidases can catalyze adenosine formation in cardiomyocytes, their contribution to the actions of adenosine has not been documented previously. We recently cloned two closely related AMP-preferring cytosolic 5′-nucleotidases (cN-IA and -IB); the A form predominates in the heart. In this study, we overexpressed pigeon cN-IA in neonatal rat cardiomyocytes using an adenovirus. cN-IA overexpression increased adenosine formation and release into the medium caused by simulated hypoxia and by isoproterenol in the absence and presence of inhibitors of adenosine metabolism. Adenosine release was not affected by an ecto-5′-nucleotidase inhibitor, α,β-methylene-ADP, but was affected by a nucleoside transporter, dipyridamole. The positive chronotropic effect of isoproterenol (130 ±3 vs. 100 ±4 beats/min) was inhibited (107 ±3 vs. 94 ±3 beats/min) in cells overexpressing cN-IA, and this was reversed by the addition of the adenosine receptor antagonist 8-(p-sulfophenyl)theophilline (120 ± 3 vs. 90 ± 4 beats/min). Our results demonstrate that overexpressed cN-IA can be sufficiently active in cardiomyocytes to generate physiologically effective concentrations of adenosine at its receptors.Fil: Sala-Newby, Graciela B.. University of Bristol; Reino UnidoFil: Freeman, Nicola V. E.. University of Bristol; Reino UnidoFil: Curto, Maria de Los Angeles. University of Bristol; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Newby, Andrew C.. University of Bristol; Reino Unid

    Charge instabilities and topological phases in the extended Hubbard model on the honeycomb lattice with enlarged unit cell

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    We study spontaneous symmetry breaking in a system of spinless fermions in the Honeycomb lattice paying special emphasis to the role of an enlarged unit cell on time reversal symmetry broken phases. We use a tight binding model with nearest neighbor hopping t and Hubbard interaction V1 and V2 and extract the phase diagram as a function of electron density and interaction within a mean field variational approach. The analysis completes the previous work done in Phys. Rev. Lett. 107, 106402 (2011) where phases with non--trivial topological properties were found with only a nearest neighbor interaction V1 in the absence of charge decouplings. We see that the topological phases are suppressed by the presence of metallic charge density fluctuations. The addition of next to nearest neighbor interaction V2 restores the topological non-trivial phases

    Descripción y caracterización de micorrizas de los géneros Tuber y Genea de una formación natural de carrasca (Quercus ilex L. subsp. ballota (Desf.) Samp.).

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    En las últimas décadas se ha producido un incremento muy importante del número de ectomicorrizas descritas. Así mismo, estas descripciones han pasado de ser muy someras a ser muy detalladas, incluyendo no solo caracteres morfológicos, sino también anatómicos. Sin embargo, las ectomicorrizas de hongos hipógeos siguen siendo, en general muy desconocidas, dado que son muy pocas las especies descritas en detalle hasta el momento. En el presente trabajo se describen y caracterizan cuatro micorrizas de los géneros Tuber y Genea reconocidas en un carrascal maduro (Quercus ilex L. subsp. ballota (Desf.) Samp.) de Navarra, con el objetivo de aportar datos que contribuyan a su identificación

    Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination.

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    BACKGROUND: In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases. METHODS: A comparison of two control groups in a case control study of the efficacy of BCG revaccination. One group was selected from subjects presenting to the heath unit the case attended for routine prevention and care; the second group was selected from the neighbourhood of cases. All Health Units from which controls were selected offered BCG revaccination. Efficacy estimated in a randomized control trial of BCG revaccination was used to establish that the neighbourhood control group was the one that gave unbiased results. RESULTS: The proportion of controls with scars indicating BCG revaccination was higher among the control group selected from Health Unit attenders than among neighbourhood controls. This excess was not removed after control for social variables and history of exposure to tuberculosis, and appears to have resulted from the fact that people attending the Health Unit were more likely to have been revaccinated than neighbourhood controls, although we can not exclude an effect of other unmeasured variables. CONCLUSION: In this study, controls selected from people presenting to a Health Unit overrepresented exposure to BCG revaccination. Had the results from the HU attenders control group been accepted this would have resulted in overestimation of vaccine efficacy. When the exposure of interest is offered in a health facility, selection of controls from attenders at the facility may result in over representation of exposure in controls and selection bias
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