1,891 research outputs found
Alcohol Prohibition and Cirrhosis
This paper uses state-level data on cirrhosis death rates to examine the impact of state prohibitions, pre-1920 federal anti-alcohol policies, and constitutional prohibition on cirrhosis State prohibitions had a minimal impact on cirrhosis, especially during the pre-1920 period. Pre-1920 federal anti-alcohol policies may have contributed to the decline in cirrhosis that occurred before 1920, although other factors were likely substantial influences as well. Constitutional prohibition reduced cirrhosis by about 10-20 percent.
Lagrange-Fedosov Nonholonomic Manifolds
We outline an unified approach to geometrization of Lagrange mechanics,
Finsler geometry and geometric methods of constructing exact solutions with
generic off-diagonal terms and nonholonomic variables in gravity theories. Such
geometries with induced almost symplectic structure are modelled on
nonholonomic manifolds provided with nonintegrable distributions defining
nonlinear connections. We introduce the concept of Lagrange-Fedosov spaces and
Fedosov nonholonomic manifolds provided with almost symplectic connection
adapted to the nonlinear connection structure.
We investigate the main properties of generalized Fedosov nonholonomic
manifolds and analyze exact solutions defining almost symplectic Einstein
spaces.Comment: latex2e, v3, published variant, with new S.V. affiliatio
Deformation Quantization of Almost Kahler Models and Lagrange-Finsler Spaces
Finsler and Lagrange spaces can be equivalently represented as almost Kahler
manifolds enabled with a metric compatible canonical distinguished connection
structure generalizing the Levi Civita connection. The goal of this paper is to
perform a natural Fedosov-type deformation quantization of such geometries. All
constructions are canonically derived for regular Lagrangians and/or
fundamental Finsler functions on tangent bundles.Comment: the latex 2e variant of the manuscript accepted for JMP, 11pt, 23
page
Extended Defects in the Potts-Percolation Model of a Solid: Renormalization Group and Monte Carlo Analysis
We extend the model of a 2 solid to include a line of defects. Neighboring
atoms on the defect line are connected by ?springs? of different strength and
different cohesive energy with respect to the rest of the system. Using the
Migdal-Kadanoff renormalization group we show that the elastic energy is an
irrelevant field at the bulk critical point. For zero elastic energy this model
reduces to the Potts model. By using Monte Carlo simulations of the 3- and
4-state Potts model on a square lattice with a line of defects, we confirm the
renormalization-group prediction that for a defect interaction larger than the
bulk interaction the order parameter of the defect line changes discontinuously
while the defect energy varies continuously as a function of temperature at the
bulk critical temperature.Comment: 13 figures, 17 page
Research of Gravitation in Flat Minkowski Space
In this paper it is introduced and studied an alternative theory of
gravitation in flat Minkowski space. Using an antisymmetric tensor, which is
analogous to the tensor of electromagnetic field, a non-linear connection is
introduced. It is very convenient for studying the perihelion/periastron shift,
deflection of the light rays near the Sun and the frame dragging together with
geodetic precession, i.e. effects where angles are involved. Although the
corresponding results are obtained in rather different way, they are the same
as in the General Relativity. The results about the barycenter of two bodies
are also the same as in the General Relativity. Comparing the derived equations
of motion for the -body problem with the Einstein-Infeld-Hoffmann equations,
it is found that they differ from the EIH equations by Lorentz invariant terms
of order .Comment: 28 page
Al-Substitution Effects on Physical Properties of the Colossal Magnetoresistance Compouns La0.67ca0.33mno3
We present a detailed study of the polycrystalline perovskite manganites
La0.67Ca0.33AlxMn1-xO3 (x = 0, 0.1, 0.15, 0.5) at low temperatures and high
magnetic fields, including electrical resistance, magnetization, ac
susceptibility. The static magnetic susceptibility was also measured up to 1000
K. All the samples show colossal magnetoresistance behavior and the Curie
temperatures decrease with Al doping. The data suggest the presence of
correlated magnetic clusters near by the ferromagnetic transition. This appears
to be a consequence of the structural and magnetic disorder created by the
random distribution of Al atoms.Comment: 13 pages including 5 figure
What Do Economists Know About Crime?
In this paper we evaluate what economists have learned over the past 40 years about the determinants of crime. We base our evaluation on two kinds of evidence: an examination of aggregate data over long time periods and across countries, and a critical review of the literature. We argue that economists know little about the empirically relevant determinants of crime. Even hypotheses that find some support in U.S. data for recent decades are inconsistent with data over longer horizons or across countries. This conclusion applies both to policy variables like arrest rates or capital punishment and to less conventional factors such as abortion or gun laws. The hypothesis that drug prohibition generates violence, however, is generally consistent with the long times-series and cross-country facts. This analysis is also consistent with a broader perspective in which government policies that affect the nature and amount of dispute resolution play an important role in determining violence.
Potts-Percolation-Gauss Model of a Solid
We study a statistical mechanics model of a solid. Neighboring atoms are
connected by Hookian springs. If the energy is larger than a threshold the
"spring" is more likely to fail, while if the energy is lower than the
threshold the spring is more likely to be alive. The phase diagram and
thermodynamic quantities, such as free energy, numbers of bonds and clusters,
and their fluctuations, are determined using renormalization-group and
Monte-Carlo techniques.Comment: 10 pages, 12 figure
Chirality-induced asymmetric magnetic nucleation in Pt/Co/AlOx ultrathin microstructures
The nucleation of reversed magnetic domains in Pt/Co/AlO
microstructures with perpendicular anisotropy was studied experimentally in the
presence of an in-plane magnetic field. For large enough in-plane field,
nucleation was observed preferentially at an edge of the sample normal to this
field. The position at which nucleation takes place was observed to depend in a
chiral way on the initial magnetization and applied field directions. An
explanation of these results is proposed, based on the existence of a sizable
Dzyaloshinskii-Moriya interaction in this sample. Another consequence of this
interaction is that the energy of domain walls can become negative for in-plane
fields smaller than the effective anisotropy field.Comment: Published version, Physical Review Letters 113, 047203 (2014
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