467 research outputs found
Nonsingular potentials from excited state factorization of a quantum system with position dependent mass
The modified factorization technique of a quantum system characterized by
position-dependent mass Hamiltonian is presented. It has been shown that the
singular superpotential defined in terms of a mass function and a excited state
wave function of a given position-dependent mass Hamiltonian can be used to
construct non-singular isospectral Hamiltonians. The method has been
illustrated with the help of a few examples.Comment: Improved version accepted in J. Phys.
The Localization of -Wave and Quantum Effective Potential of a Quasi-Free Particle with Position-Dependent Mass
The properties of the s-wave for a quasi-free particle with
position-dependent mass(PDM) have been discussed in details. Differed from the
system with constant mass in which the localization of the s-wave for the free
quantum particle around the origin only occurs in two dimensions, the
quasi-free particle with PDM can experience attractive forces in dimensions
except D=1 when its mass function satisfies some conditions. The effective mass
of a particle varying with its position can induce effective interaction which
may be attractive in some cases. The analytical expressions of the
eigenfunctions and the corresponding probability densities for the s-waves of
the two- and three-dimensional systems with a special PDM are given, and the
existences of localization around the origin for these systems are shown.Comment: 12pages, 8 figure
A generalized quantum nonlinear oscillator
We examine various generalizations, e.g. exactly solvable, quasi-exactly
solvable and non-Hermitian variants, of a quantum nonlinear oscillator. For all
these cases, the same mass function has been used and it has also been shown
that the new exactly solvable potentials possess shape invariance symmetry. The
solutions are obtained in terms of classical orthogonal polynomials
Pharmacological restoration and therapeutic targeting of the B-cell phenotype in classical Hodgkin's lymphoma
Classical Hodgkin's lymphoma (cHL), although originating from B-cells, is characterized by the virtual lack of gene products whose expression constitutes the B-cell phenotype. Epigenetic repression of B-cell-specific genes via promoter hypermethylation and histone deacetylation as well as compromised expression of B-cell-committed transcription factors were previously reported to contribute to the lost B-cell phenotype in cHL. Restoring the B-cell phenotype may not only correct a central malignant property, but render cHL susceptible to clinically established antibody therapies targeting B-cell surface receptors or small compounds interfering with B-cell receptor signaling. We conducted now a high-throughput pharmacological screening based on more than 28,000 compounds in cHL cell lines carrying a CD19 reporter to identify drugs that promote re-expression of the B-cell phenotype. Three chemicals were retrieved that robustly enhanced CD19 transcription. Subsequent chromatin immunoprecipitation-based analyses indicated that action of two of these compounds was associated with lowered levels of the transcriptionally repressive lysine 9-trimethylated histone H3 mark at the CD19 promoter. Moreover, the anti-leukemia agents all-trans retinoic acid and arsenic trioxide (ATO) were found to reconstitute the silenced B-cell transcriptional program and reduce viability of cHL cell lines. When applied in combination with a screening-identified chemical, ATO evoked re-expression of the CD20 antigen, which could be further therapeutically exploited by enabling CD20 antibody-mediated apoptosis of cHL cells. Furthermore, restoration of the B-cell phenotype also rendered cHL cells susceptible to the B-cell Non-Hodgkin's lymphoma-tailored small compound inhibitors Ibrutinib and Idelalisib. In essence, we report here a conceptually novel, re-differentiation-based treatment strategy for cHL
Why Global Inequality Matters: Derivative Global Egalitarianism
This article integrates empirical and normative discussions about why global economic inequalities matter in critically examining an approach known as derivative global egalitarianism (DGE). DGE is a burgeoning perspective that opposes excessive global economic inequality not based on the intrinsic value of equality but inequality\u27s negative repercussions on other values. The article aims to advance the research agenda by identifying and critically evaluating four primary varieties of DGE arguments from related but distinct literatures, which span a number of disciplines, including economics, international relations, and political philosophy. Overall, DGE offers a number of persuasive arguments as to why current levels of global inequality are of concern, but aspects of DGE beg further philosophical and empirical examination. By situating DGE within the wider theoretical and empirical contexts, this article provides resources for its critical assessment and theoretical development
Privatization and State Capacity in Postcommunist Society
Economists have used cross-national regression analysis to argue that postcommunist economic failure is the result of inadequate adherence liberal economic policies. Sociologists have relied on case study data to show that postcommunist economic failure is the outcome of too close adherence to liberal policy recommendations, which has led to an erosion of state effectiveness, and thus produced poor economic performance. The present paper advances a version of this statist theory based on a quantitative analysis of mass privatization programs in the postcommunist world. We argue that rapid large-scale privatization creates severe supply and demand shocks for enterprises, thereby inducing firm failure. The resulting erosion of tax revenues leads to a fiscal crisis for the state, and severely weakens its capacity and bureaucratic character. This, in turn, reacts back on the enterprise sector, as the state can no longer support the institutions necessary for the effective functioning of a modern economy, thus resulting in deindustrialization. Using cross-national regression techniques we find that the implementation of mass privatization programs negatively impacts measures of economic growth, state capacity and the security of property rights.http://deepblue.lib.umich.edu/bitstream/2027.42/40192/3/wp806.pd
Income distribution trends and future food demand
This paper surveys the theoretical literature on the relationship between income distribution and food demand, and identifies main gaps of current food modelling techniques that affect the accuracy of food demand projections. At the heart of the relationship between income distribution and food demand is Engel's law. Engel's law establishes that as income increases, households' demand for food increases less than proportionally. A consequence of this law is that the particular shape of the distribution of income across individuals and countries affects the rate of growth of food demand. Our review of the literature suggests that existing models of food demand fail to incorporate the required Engel flexibility when (i) aggregating different food budget shares among households; and (ii) changing budget shares as income grows. We perform simple simulations to predict growth in food demand under alternative income distribution scenarios taking into account nonlinearity of food demand. Results suggest that (i) distributional effects are to be expected from changes in between-countries inequality, rather than within-country inequality; and (ii) simulations of an optimistic and a pessimistic scenario of income inequality suggest that world food demand in 2050 would be 2.7 per cent higher and 5.4 per cent lower than distributional-neutral growth, respectively
The Dynamics of Adverse Incorporation in Global Production Networks: Poverty, Vulnerability and ‘Slave Labour’ in Brazil
Metastability, negative specific heat and weak mixing in classical long-range many-rotator system
We perform a molecular dynamical study of the isolated classical
Hamiltonian , known to
exhibit a second order phase transition, being disordered for and ordered otherwise ( total energy
and ). We focus
on the nonextensive case and observe that, for , a
basin of attraction exists for the initial conditions for which the system
quickly relaxes onto a longstanding metastable state (whose duration presumably
diverges with like ) which eventually crosses over to the
microcanonical Boltzmann-Gibbs stable state. The temperature associated with
the (scaled) average kinetic energy per particle is lower in the metastable
state than in the stable one. It is exhibited for the first time that the
appropriately scaled maximal Lyapunov exponent
, where, for all values of ,
numerically coincides with {\it one third} of its value for , hence
decreases from 1/9 to zero when increases from zero to unity,
remaining zero thereafter. This new and simple {\it connection between
anomalies above and below the critical point} reinforces the nonextensive
universality scenario.Comment: 9 pages and 4 PS figure
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