5,810 research outputs found
Corporate Hierarchies and the Size of Nations: Theory and Evidence
Corporate organization varies within a country and across countries with country size. The paper starts by establishing some facts about corporate organization based on unique data of 660 Austrian and German corporations. The larger country (Germany) has larger firms with flatter more decentral corporate hierarchies compared to the smaller country (Austria). Firms in the larger country change their organization less fast than firms in the smaller country. Over time firms have been introducing less hierarchical organizations by delegating power to lower levels of the corporation. We develop a theory which explains these facts and which links these features to the trade environment that countries and firms face. We introduce firms with internal hierarchies in a Krugman (1980) model of trade. We show that international trade and the toughness of competition in international markets induce a power struggle in firms which eventually leads to decentralized corporate hierarchies. We offer econometric evidence which is consistent with the models predictions
Nanocrystals of a New Complex Perovskite Dielectric Ba2TmSbO6
Nanocrystals of a new complex perovskites ceramic oxide, barium thulium antimony oxide – Ba2TmSbO6,were synthesized using a single step auto-ignition combustion process. The combustion product was single phase and composed of aggregates of nanocrystals of sizes in the range 20–50 nm. Ba2TmSbO6 crystallized in cubic perovskite structure with lattice parameter, a = 8.4101A˚ . The polycrystalline fluffy combustion product was sintered to high density (∼97%) at ∼1450 ◦C for 4 h. Resistivity of the sintered specimen was ∼5 M/cm. The Ba2TmSbO6 has dielectric constant (ε) and dielectric loss (tan ı) of 17 and ∼10−4 at 5 MHz; the new material would probably be developed as a low-loss dielectric material
Correlation between Oxidative Stress and Thyroid Function in Patients with Nephrotic Syndrome
Background. The present study is to look for a correlation between oxidative stress and thyroid function in patients with the nephrotic syndrome in the remission phase as well as in a persistent proteinuric state. Introduction. Nephrotic syndrome is a form of chronic kidney disease due to which blood loses protein through the urine. We wanted to know if there was an increased loss of thyroid hormones in urine affecting thyroid function. Methods. 60 patients with nephrotic syndrome and 20 healthy non-proteinuric individuals as control subjects were enrolled in the study. We measured their serum tri-iodothyronine, thyroxine and thyroid-stimulating hormone. Estimation of lipid peroxidation (LPx) catalase, superoxide dismutase (SOD), and Glutathione peroxidase (GPx) were carried out by standard methods. Results. TSH was elevated in the nephrotic patients compared to controls, while TT4 and TT3 were significantly lower in the patients than in controls. Lipid Peroxidation and GPx were significantly higher in the nephrotic syndrome patients than in the controls, while SOD and catalase were significantly lower than in patients than in the control subjects. Conclusion. Nephrotic patients can lose significant amounts of thyroid hormones along with protein in urine, which can affect thyroid status, but this is reversible on remission
pion scattering amplitude with Wilson fermions
We present an exploratory calculation of the scattering
amplitude at threshold using Wilson fermions in the quenched approximation,
including all the required contractions. We find good agreement with the
predictions of chiral perturbation theory even for pions of mass 560-700 MeV.
Within the 10\% errors, we do not see the onset of the bad chiral behavior
expected for Wilson fermions. We also derive rigorous inequalities that apply
to 2-particle correlators and as a consequence show that the interaction in the
antisymmetric state of two pions has to be attractive.Comment: This PS file includes 4 tables and figures 1-8 on 25 pages. Los
Alamos Preprint Number LAUR-92-364
RELEASE: A High-level Paradigm for Reliable Large-scale Server Software
Erlang is a functional language with a much-emulated model for building reliable distributed systems. This paper outlines the RELEASE project, and describes the progress in the first six months. The project aim is to scale the Erlang’s radical concurrency-oriented programming paradigm to build reliable general-purpose software, such as server-based systems, on massively parallel machines. Currently Erlang has inherently scalable computation and reliability models, but in practice scalability is constrained by aspects of the language and virtual machine. We are working at three levels to address these challenges: evolving the Erlang virtual machine so that it can work effectively on large scale multicore systems; evolving the language to Scalable Distributed (SD) Erlang; developing a scalable Erlang infrastructure to integrate multiple, heterogeneous clusters. We are also developing state of the art tools that allow programmers to understand the behaviour of massively parallel SD Erlang programs. We will demonstrate the effectiveness of the RELEASE approach using demonstrators and two large case studies on a Blue Gene
Order a improved renormalization constants
We present non-perturbative results for the constants needed for on-shell
improvement of bilinear operators composed of Wilson fermions. We work
at and 6.2 in the quenched approximation. The calculation is done
by imposing axial and vector Ward identities on correlators similar to those
used in standard hadron mass calculations. A crucial feature of the calculation
is the use of non-degenerate quarks. We also obtain results for the constants
needed for off-shell improvement of bilinears, and for the scale and
scheme independent renormalization constants, (Z_A), (Z_V) and (Z_S/Z_P).
Several of the constants are determined using a variety of different Ward
identities, and we compare their relative efficacies. In this way, we find a
method for calculating that gives smaller errors than that used
previously. Wherever possible, we compare our results with those of the ALPHA
collaboration (who use the Schr\"odinger functional) and with 1-loop
tadpole-improved perturbation theory.Comment: 48 pages. Modified "axis" source for figures also included. Typos
corrected (version published in Phys. Rev. D
Financial instability from local market measures
We study the emergence of instabilities in a stylized model of a financial
market, when different market actors calculate prices according to different
(local) market measures. We derive typical properties for ensembles of large
random markets using techniques borrowed from statistical mechanics of
disordered systems. We show that, depending on the number of financial
instruments available and on the heterogeneity of local measures, the market
moves from an arbitrage-free phase to an unstable one, where the complexity of
the market - as measured by the diversity of financial instruments - increases,
and arbitrage opportunities arise. A sharp transition separates the two phases.
Focusing on two different classes of local measures inspired by real markets
strategies, we are able to analytically compute the critical lines,
corroborating our findings with numerical simulations.Comment: 17 pages, 4 figure
Pd/Cu Site Interchange and Non-Fermi-Liquid Behavior in UCu_4Pd
X-ray-absorption fine-structure measurements of the local structure in
UCu_4Pd are described which indicate a probable lattice-disorder origin for
non-Fermi-liquid behavior in this material. Short Pd-Cu distances are observed,
consistent with 24 +/- 3% of the Pd atoms occupying nominally Cu sites. A
"Kondo disorder" model, based on the effect on the local Kondo temperature T_K
of this interchange and some additional bond-length disorder, agrees
quantitatively with previous experimental susceptibility data, and therefore
also with specific heat and magnetic resonance experiments.Comment: 4 pages, 3 PostScript figures, to be published in PR
The Kaon -parameter with Wilson Fermions
We calculate the kaon -parameter in quenched lattice QCD at
using Wilson fermions at and . We use two kinds of
non-local (``smeared'') sources for quark propagators to calculate the matrix
elements between states of definite momentum. The use of smeared sources yields
results with much smaller errors than obtained in previous calculations with
Wilson fermions. By combining results for and , we show that one can carry out the non-perturbative subtraction
necessary to remove the dominant lattice artifacts induced by the chiral
symmetry breaking term in the Wilson action. Our final results are in good
agreement with those obtained using staggered fermions. We also present results
for -parameters of the part of the electromagnetic penguin
operators, and preliminary results for \bk\ in the presence of two flavors of
dynamical quarks.Comment: 39 pages, including 9 PS figures (LA UR-91-3522
In situ characterization of advanced glycation end products (AGEs) in collagen and model extracellular matrix by solid state NMR
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