600 research outputs found
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
Subgap anomaly and above-energy-gap structure in chains of diffusive SNS junctions
We present the results of low-temperature transport measurements on chains of
superconductor--normal-constriction--superconductor (SNS) junctions fabricated
on the basis of superconducting PtSi film. A comparative study of the
properties of the chains, consisting of 3 and 20 SNS junctions in series, and
single SNS junctions reveals essential distinctions in the behavior of the
current-voltage characteristics of the systems: (i) the gradual decrease of the
effective suppression voltage for the excess conductivity observed at zero bias
as the quantity of the SNS junctions increases, (ii) a rich fine structure on
the dependences dV/dI-V at dc bias voltages higher than the superconducting gap
and corresponding to some multiples of 2\Delta/e. A model to explain this
above-energy-gap structure based on energy relaxation of electron via
Cooper-pair-breaking in superconducting island connecting normal metal
electrods is proposed.Comment: RevTex, 5 pages, 4 figure
Theory of AC Josepson Effect in Superconducting Constrictions
We have developed a microscopic theory of ac Josephson effect in short
ballistic superconducting constrictions with arbitrary electron transparency
and in constrictions with diffusive electron transport. The theory is valid for
arbitrary miscroscopic structure of the superconducting electrodes of the
constriction. As applications of the theory we study smearing of the subgap
current singularities by pair-breaking effects and also the structure of these
singularities in the constrictions between the composite S/N electrodes with
the proximity-induced gap in the normal layer.Comment: 11 pages, RevTex, 3 figures available on reques
Effect of an extract of Centella asiatica on the biodistribution of sodium pertechnetate (Na<sup>99m</sup>TcO<sub>4</sub>) and on the fixation of radioactivity on blood constituents
This study evaluates the effects of an acute treatment with a Centella asiatica (CA) extract on the biodistribution of the radiopharmaceutical Na99mTcO4 and on the fixation of technetium-99m on blood constituents. Wistar rats were treated with CA extract and, 1 hour after, Na99mTcO4 was administered; organs/tissues were withdrawn and weighted. The radioactivity was counted to calculate the percentage of activity per gram (%ATI/g). Also, blood samples were withdrawn, plasma (P), blood cells (BC), insoluble fraction (IF) and soluble fractions of P and BC were isolated and the radioactivity was counted to calculate the percentage of activity (%ATI). Data indicated that the acute treatment with CA extract changed significantly (p99mTcO4 and the fixation of the technetium-99m on blood constituents in an acute treatment
Circuit theory of multiple Andreev reflections in diffusive SNS junctions: the incoherent case
The incoherent regime of Multiple Andreev Reflections (MAR) is studied in
long diffusive SNS junctions at applied voltages larger than the Thouless
energy. Incoherent MAR is treated as a transport problem in energy space by
means of a circuit theory for an equivalent electrical network. The current
through NS interfaces is explained in terms of diffusion flows of electrons and
holes through tunnel and Andreev resistors. These resistors in diffusive
junctions play roles analogous to the normal and Andreev reflection
coefficients in OTBK theory for ballistic junctions. The theory is applied to
the subharmonic gap structure (SGS); simple analytical results are obtained for
the distribution function and current spectral density for the limiting cases
of resistive and transparent NS interfaces. In the general case, the exact
solution is found in terms of chain-fractions, and the current is calculated
numerically. SGS shows qualitatively different behavior for even and odd
subharmonic numbers, and the maximum slopes of the differential resistance
correspond to the gap subharmonics. The influence of inelastic scattering on
the subgap anomalies of the differential resistance is analyzed.Comment: 14 pages, 9 figures, title and text revised, to appear in PR
Potentiality in Biology
We take the potentialities that are studied in the biological sciences (e.g., totipotency) to be an important subtype of biological dispositions. The goal of this paper is twofold: first, we want to provide a detailed understanding of what biological dispositions are. We claim that two features are essential for dispositions in biology: the importance of the manifestation process and the diversity of conditions that need to be satisfied for the disposition to be manifest. Second, we demonstrate that the concept of a disposition (or potentiality) is a very useful tool for the analysis of the explanatory practice in the biological sciences. On the one hand it allows an in-depth analysis of the nature and diversity of the conditions under which biological systems display specific behaviors. On the other hand the concept of a disposition may serve a unificatory role in the philosophy of the natural sciences since it captures not only the explanatory practice of biology, but of all natural sciences. Towards the end we will briefly come back to the notion of a potentiality in biology
Select pyrimidinones inhibit the propagation of the malarial parasite, Plasmodium falciparum
Plasmodium falciparum, the Apicomplexan parasite that is responsible for the most lethal forms of human malaria, is exposed to radically different environments and stress factors during its complex lifecycle. In any organism, Hsp70 chaperones are typically associated with tolerance to stress. We therefore reasoned that inhibition of P. falciparum Hsp70 chaperones would adversely affect parasite homeostasis. To test this hypothesis, we measured whether pyrimidinone-amides, a new class of Hsp70 modulators, could inhibit the replication of the pathogenic P. falciparum stages in human red blood cells. Nine compounds with IC50 values from 30 nM to 1.6 μM were identified. Each compound also altered the ATPase activity of purified P. falciparum Hsp70 in single-turnover assays, although higher concentrations of agents were required than was necessary to inhibit P. falciparum replication. Varying effects of these compounds on Hsp70s from other organisms were also observed. Together, our data indicate that pyrimidinone-amides constitute a novel class of anti-malarial agents. © 2009 Elsevier Ltd. All rights reserved
Evidence of Vortices on the Insulating Side of the Superconductor-Insulator Transition
The magnetoresistance of ultrathin insulating films of Bi has been studied
with magnetic fields applied parallel and perpendicular to the plane of the
sample. Deep in the strongly localized regime, the magnetoresistance is
negative and independent of field orientation. As film thicknesses increase,
the magnetoresistance becomes positive, and a difference between values
measured in perpendicular and parallel fields appears, which is a linear
function of the magnetic field and is positive. This is not consistent with the
quantum interference picture. We suggest that it is due to vortices present on
the insulating side of the superconductor-insulator transition.Comment: 4 pages, 3 figure
Structural and spatially-resolved studies on the hardening of a commercial resin-modified glass-ionomer cement
A commercial photopolymerizable resinmodified glass-ionomer (Fuji II LC) was studied using a variety of nuclear magnetic resonance (NMR) techniques. H and F stray-field imaging (STRAFI) enabled to follow the acid–base reaction kinetics in self-cured (SC) samples. Gelation and maturation processes with 25 min and 40 h average time constants, respectively, were distinguished. In self- & photo-cured (SPC) samples, two processes were also observed, which occurred with 2 s and 47 s average time constants. H, Al and Si magic angle spinning (MAS) NMR, C cross-polarization (CP)/MAS NMR and 27Al multiple quanta (MQ)MAS NMR spectroscopy were used to obtain structural information on the glass and cements that were either SC or SPC. The presence of methacrylate groups was identified in the solid component. Unreacted hydroxyl ethylmethacrylate (HEMA) was detected in self-cured cement. Al data showed that approximately 28% and 20% of Al is leached out from glass particles in SC and SPC samples, respectively. The upfield shift detected in 25Si MAS NMR spectra of the cements is consistent with a decrease in the number of Al species in the second coordination sphere of the silicon structures. Scanning electron microscopy (SEM) showed existence of 3D shrinkage of the cement matrix in photo-cured cements.(undefined
DISTRIBUTION AND PROPERTIES OF CDP-DIGLYCERIDE:INOSITOL TRANSFERASE FROM BRAIN 1
CDP-diglyceride is converted to phosphatidyl inositol by several particulate subcellular fractions of guinea pig brain, with highest specific activity in the microsomal fraction. Optimal conditions with respect to pH, metal ion concentration, and substrate concentrations have been determined. The reaction was stimulated by the addition of bovine serum albumin and by Tween 80. Of several dl-CDP-diglycerides synthesized and used as substrates in a spectrophoto-metric assay for the enzyme, dl-CDP-didecanoin was the most active. The enzyme showed a high selectivity for myo-inositol. Of a number of compounds tested, only scyllo -inosose and epi -inosose served as substrates. Three inositol isomers and three myo -inositol monophosphates inhibited the reaction slightly. The most potent inhibitor found was galactinol, a myo -inositol galactoside.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66197/1/j.1471-4159.1969.tb06850.x.pd
- …