1,085 research outputs found

    Dynamical Renormalization Group Study for a Class of Non-local Interface Equations

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    We provide a detailed Dynamic Renormalization Group study for a class of stochastic equations that describe non-conserved interface growth mediated by non-local interactions. We consider explicitly both the morphologically stable case, and the less studied case in which pattern formation occurs, for which flat surfaces are linearly unstable to periodic perturbations. We show that the latter leads to non-trivial scaling behavior in an appropriate parameter range when combined with the Kardar-Parisi-Zhang (KPZ) non-linearity, that nevertheless does not correspond to the KPZ universality class. This novel asymptotic behavior is characterized by two scaling laws that fix the critical exponents to dimension-independent values, that agree with previous reports from numerical simulations and experimental systems. We show that the precise form of the linear stabilizing terms does not modify the hydrodynamic behavior of these equations. One of the scaling laws, usually associated with Galilean invariance, is shown to derive from a vertex cancellation that occurs (at least to one loop order) for any choice of linear terms in the equation of motion and is independent on the morphological stability of the surface, hence generalizing this well-known property of the KPZ equation. Moreover, the argument carries over to other systems like the Lai-Das Sarma-Villain equation, in which vertex cancellation is known {\em not to} imply an associated symmetry of the equation.Comment: 34 pages, 9 figures. Journal of Statistical Mechanics: Theory and Experiments (in press

    Analytical approximation for the sphere-sphere Coulomb potential

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    A simple analytical expression, which closely approximates the Coulomb potential between two uniformly charged spheres, is presented. This expression can be used in the optical potential semiclassical analyses which require that the interaction be analytic on and near the real r-axis.Comment: 4 pages including 3 figures and 1 tabl

    Refractive elastic scattering of carbon and oxygen nuclei: The mean field analysis and Airy structures

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    The experimental data on the 16^{16}O+12+^{12}C and 18^{18}O+12+^{12}C elastic scatterings and their optical model analysis are presented. Detailed and complete elastic angular distributions have been measured at the Strasbourg Vivitron accelerator at several energies covering the energy range between 5 and 10 MeV per nucleon. The elastic scattering angular distributions show the usual diffraction pattern and also, at larger angles, refractive effects in the form of nuclear rainbow and associated Airy structures. The optical model analysis unambiguously shows the evolution of the refractive scattering pattern. The observed structure, namely the Airy minima, can be consistently described by a nucleus-nucleus potential with a deep real part and a weakly absorptive imaginary part. The difference in absorption in the two systems is explained by an increased imaginary (mostly surface) part of the potential in the 18^{18}O+12+^{12}C system. The relation between the obtained potentials and those reported for the symmetrical 16^{16}O+16+^{16}O and 12^{12}C+12+^{12}C systems is drawn.Comment: 10 pages, 9 figures, Phys. rev. C in pres

    Evaluation of an in-capillary approach for performing quantitative cytochrome P450 activity studies

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    An automated in-capillary assay requiring very small quantities of reagents was developed for performing in vitro cytochrome P450 (CYP450) drug metabolism studies. The approach is based on the following: (i) hydrodynamic introduction of nanoliter volumes of substrate and enzyme solutions in the sandwich mode, within a capillary; (ii) mixing the reagents by diffusion across the interfaces between the injected solutions; (iii) collection of the capillary content at the end of the in-capillary assay; and (iv) off-line analysis of the incubation mixture by ultrahigh pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). After optimizing the injection sequence of the reagents, the in-capillary approach was applied to the quantitative determination of the kinetics of drug metabolism reactions catalyzed by three CYP450 isozymes involved in human drug metabolism: CYP1A2, CYP2D6, and CYP3A4. It was demonstrated that this in-capillary method was able to provide similar kinetic parameters for CYP450 activity (e.g., Michaelis constants and turnover values) as the classical in vitro method, with a drastic reduction of reagent consumption. Injection setups used for in-capillary CYP450 assay

    Is european attachment sufficiently strong to support an EU fiscal capacity: Evidence from a conjoint experiment

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    Based on a conjoint survey experiment with 10,000 respondents from France, Germany, Italy, Netherlands and Spain at the end of March/beginning of April 2020, we explore how individual characteristics shape support among Eurozone citizens for a European Union (EU) budgetary assistance instrument to combat adverse temporary or permanent economic shocks hitting EU Member States. We consider particularly the role of socioeconomic factors, such as income and education, covid fears and European attachment. Remarkably, how covid worries and European attachment affect the support for specific designs of the assistance instrument is not affected by other factors, in particular not by socioeconomic factors. These latter factors play an important role affecting support, independent of European attachment. Programs with European Commission monitoring (and recommendations) and cross-country redistribution, possibly even mandatory towards poor countries, can count on stronger support from those with higher European attachment. Those with strong covid fears are generally more in favour of EU budgetary assistance, mandatory spending of assistance on healthcare and redistribution to poor countries. Programs with Commission monitoring (and recommendations) receive extra support from high-income and highly-educated individuals. Also, the latter group specifically favors potential or mandatory cross-border redistribution. The independent role of individual European attachment suggests that instruments other than socioeconomic policies, e.g. better information provision about its use, may help raise support for an EU assistance instrument

    Notes on the carpet beetle Attagenus lobatus in Italy

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    Morphological, distributional and eco-ethological data on the carpet beetle Attagenus lobatus Rosenhauer (Coleoptera Dermestidae) are reported, based on original observations. A. lobatus is a household and stored product species with a primarily Palaearctic distribution, secondarily Holarctic due to passive dispersion by man. This species is not very common in temperate climates and is here recorded for the first time in northern Italy

    Integration of crops, livestock, and forestry: a system of production for the Brazilian Cerrados.

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    Some of the most promising and at the same time some of the most challenging areas of future food production are found in the savannas of South America. Integrating cropping, livestock, and forestry in these regions can increase the eco-efficiency of agricultural production. This chapter presents a case study of an integrated crop, livestock, and forestry system in Brazil. The study area is in Goiás State in the Cerrado region, a vast savanna covering almost one quarter of Brazil's land area. About half of the area suited to agriculture in the Cerrado is under cultivated pasture, but much of this is degraded as a result of overgrazing. The systems studied in this report include different arrangements to test productivity, profitability and sustainability of eucalyptus, crops, and pastures. Findings demonstrated that integrated crop, livestock, and forestry systems are economically and technically feasible in the Cerrados. In addition to producing food of high biological value (meat and milk), cultivated pasture provides other important environmental benefits, including long-term ground cover, carbon fixation, increases in soil organic matter content; and reduction in the emission of greenhouse gases

    Public support for European cooperation in the procurement, stockpiling and distribution of medicines

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    Background: The COVID-19 outbreak has heightened ongoing political debate about the international joint procurement of medicines and medical countermeasures. The European Union (EU) has developed what remains largely contractual and decentralized international procurement cooperation. The corona crisis has broadened and deepened public debate on such cooperation, in particular on the scope of cooperation, solidarity in the allocation of such cooperation, and delegation of cooperative decision-making. Crucial to political debate about these issues are public attitudes that constrain and undergird international cooperation. Methods: Our survey includes a randomized survey experiment (conjoint analysis) on a representative sample in five European countries in March 2020, informed by legal and policy debate on medical cooperation. Respondents choose and rate policy packages containing randomized mixes of policy attributes with respect to the scope of medicines covered, the solidarity in conferring priority access and the level of delegation. Results: In all country populations surveyed, the experiment reveals considerable popular support for European cooperation. Significant majorities preferred cooperation packages with greater rather than less scope of medicines regulated; with priority given to most in-need countries; and with delegation to EU-level rather than national expertise. Conclusion: Joint procurement raises delicate questions with regard to its scope, the inclusion of cross-border solidarity and the delegation of decision-making, that explain reluctance toward joint procurement among political decision-makers. This research shows that there is considerable public support across different countries in favor of centralization, i.e. a large scope and solidarity in the allocation and delegation of decision-making

    Airy-like patterns in heavy ion elastic scattering

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    A semiclassical analysis of an optical potential cross section is presented. The cross section considered is characterized by the appearance of an Airy-like pattern. This pattern is similar to that which is present in many cross sections, which fit the recent measurements of light heavy ion elastic scattering, and is considered as a manifestation of a rainbow phenomenon. The semiclassical analysis shows that, in the case considered, the oscillations arise from the interference between the contributions from two different terms of a multi-reflection expansion of the scattering function, and, therefore, cannot be associated with the rainbow phenomenon.Comment: 10 pages, 5 figure
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