6,139 research outputs found

    Europe needs initiative and leadership to overcome the crisis

    Get PDF
    This paper applies the interpretative scheme “crisis-initiative-leadership” - developed with reference to the European unification process as a whole – to the current crises to analyse if and how the crises are being exploited by adequate initiative and leadership in the EU

    The early years of Bruno Maximovich Pontecorvo at Dubna

    Get PDF
    At the beginning of September 1950, while on a short vacation in Italy with his family, Bruno Pontecorvo suddenly disappeared. Nobody knew of him until 4th March 1955, when he gave a press conference in Moscow at the Academy of Sciences where he explained the motivations that had led him to decide to live in Russia. He arrived in Moscow in September 1950 and at the end of October of the same year he moved in Dubna and started his research work at the Institute of Nuclear Problems where, at the time,the most powerful particle accelerator in the world was in operation. A historical reconstruction of the early years of his scientific activity is done through the pages of his first logbook. This “laboratory notebook”, dated November 1, 1950, contains unpublished notes, ideas and considerations that Bruno wrote by hand, mostly in English, at the beginning of his work in Russia

    A Sensorimotor Numerosity System

    Get PDF

    Theoretical status of Bs-mixing and lifetimes of heavy hadrons

    Get PDF
    We review the theoretical status of the lifetime ratios τB+/τBd, τBs/τBd, τΛb/τBd and τBc and of the mixing quantities ΔMs, ΔΓs and ϕs. ΔMs and ΔΓs suffer from large uncertainties due to the badly known decay constants, while the ratio ΔΓs/ΔMs can be determined with almost no non-perturbative uncertainties, therefore it can be used perfectly to find possible new physics contributions in the mixing parameters. We suggest a very clear method of visualizing the bounds on new physics and demonstrate this by combining the latest experimental numbers on the mixing quantities quantities with theory – one already gets some hints for new physics contributions, but more precise experimental numbers are needed to draw some definite conclusions. We conclude with a ranking list of all the discussed quantities according to their current theoretical uncertainties and point out possible improvements

    Long tree-ring chronologies provide evidence of recent tree growth decrease in a central african tropical forest

    Get PDF
    It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2.It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2

    A multi-indicator approach to compare the sustainability of organic vs. integrated management of grape production

    Get PDF
    Sustainable agricultural practices are increasingly becoming a strategic asset for global and national environmental policies and economy. A big challenge is the selection of appropriate indicators to describe the complexity of the agroecosystem management. In the present work, the sustainability of grape production, in vineyard trials of Pinot blanc and Rhine Riesling, managed with integrated (INT) and organic management (organic, with cattle manure ORG1 and organic with green manure ORG2), was compared using a multi-indicator approach. The experiment was set in 2011 (1.5 ha in Trento, Italy) and carbon footprint (CF), nitrogen footprint (NF), water footprint (WF), soil microbial diversity (alpha diversity of bacteria, fungi, oomycetes communities) and soil C stock change, were evaluated in 2018. The CF was 0.213—0.227 kg CO2-eq/kg in the INT, 0.144—0.168 kg CO2-eq/kg in ORG1 and 0.134—0.147 kg CO2-eq/kg in ORG2. The NF was around 1 g Nr/kg for the INT, 0.4 g Nr/kg for ORG1 and 0.5 g Nr/kg for ORG2. The WF, excluding the pesticides impact on grey water, was 666—708 L/kg for INT, 605—655 L/kg for ORG1 and 529—580 L/kg for ORG2. The impact of farming practices on soil microbial alpha diversity showed no significant difference among treatments for oomycetes and significantly higher indexes for fungi and bacteria in the ORG1, with INT and ORG2, being similar. No difference in bulk organic C were observed among treatments. Overall, the multi-indicator approach allowed to demonstrate that the organic management was more beneficial for most of the environmental spheres of the agroecosystem compared to integrated management, without affecting the grape yiel

    A multilevel carbon and water footprint dataset of food commodities

    Get PDF
    Informing and engaging citizens to adopt sustainable diets is a key strategy for reducing global environmental impacts of the agricultural and food sectors. In this respect, the first requisite to support citizens and actors of the food sector is to provide them a publicly available, reliable and ready to use synthesis of environmental pressures associated to food commodities. Here we introduce the SU-EATABLE LIFE database, a multilevel database of carbon (CF) and water (WF) footprint values of food commodities, based on a standardized methodology to extract information and assign optimal footprint values and uncertainties to food items, starting from peer-reviewed articles and grey literature. The database and its innovative methodological framework for uncertainty treatment and data quality assurance provides a solid basis for evaluating the impact of dietary shifts on global environmental policies, including climate mitigation through greenhouse gas emission reductions. The database ensures repeatability and further expansion, providing a reliable science-based tool for managers and researcher in the food sector

    Hadronic sizes and observables in high-energy scattering

    Get PDF
    The functional dependence of the high-energy observables of total cross section and slope parameter on the sizes of the colliding hadrons predicted by the model of the stochastic vacuum and the corresponding relations used in the geometric model of Povh and H\"ufner are confronted with the experimental data. The existence of a universal term in the expression for the slope, due purely to vacuum effects, independent of the energy and of the particular hadronic system, is investigated. Accounting for the two independent correlation functions of the QCD vacuum, we improve the simple and consistent description given by the model of the stochastic vacuum to the high-energy pp and pbar-p data, with a new determination of parameters of non-perturbative QCD. The increase of the hadronic radii with the energy accounts for the energy dependence of the observables.Comment: Latex, using Revtex.style . 2 ps figures. To be published in Physical Review D , July 199
    • …
    corecore