Fermi-liquid effects in the gapless state of marginally thin superconducting films

We present low temperature tunneling density-of-states measurements in Al films in high parallel magnetic fields. The thickness range of the films, t=6-9 nm, was chosen so that the orbital and Zeeman contributions to their parallel critical fields were comparable. In this quasi-spin paramagnetically limited configuration, the field produces a significant suppression of the gap, and at high fields the gapless state is reached. By comparing measured and calculated tunneling spectra we are able to extract the value of the antisymmetric Fermi-liquid parameter G^0 and thereby deduce the quasiparticle density dependence of the effective parameter G^0_{eff} across the gapless state.Comment: 6 pages, 4 figure

Randomised trials relevant to mental health conducted in low and middle-income countries: protocol for a survey of studies published in 1991, 1995 and 2000 and assessment of their relevance

BACKGROUND A substantial proportion of the psychiatric burden of disease falls on the world's poorest nations. Despite this, relatively little is known about the quality and content of clinical research undertaken in these countries, or the relevance of the interventions evaluated and specifically that of randomised trials. This project aims to survey the content, quality and accessibility of a sample of trials relevant to mental health conducted within low and middle-income countries; to compare these with studies conducted in high-income countries; and to assess their relevance for the needs of low and middle-income countries. METHODS An extensive search for all trials, or possible trials, published in 1991, 1995 and 2000 with participants in low and middle-income countries has already been conducted. Studies evaluating prevention or treatment of a mental health problem within these three years will be identified and further searches conducted to assess completeness of the initial search. Data on study quality and characteristics will be extracted from each report. Accessibility will be estimated based on whether each citation is available on MEDLINE. Trials relevant to schizophrenia will be compared with a random sample of schizophrenia trials from high-income countries in the same years. Topics covered by the trials will be compared with the estimated burden of disease. CONCLUSION Trials and systematic reviews of trials are the gold standard of evaluation of care and increasingly provide the basis for recommendations to clinicians, to providers of care and to policy makers. Results from this study will present the first assessment of the scope, quality and accessibility of mental health trials in low and middle-income countries

The Influence of Federal Laboratory R&D on Industrial Research

Over the past 60 years the United States has created the world's largest system of government laboratories. The impact of the laboratories on the private economy has been little studied though their research accounts for 14% of total U.S. R&D, more than the R&D of all colleges and universities combined. In this paper we study the influence of federal laboratory R&D on industrial research using a sample of industrial laboratories. In head-to-head comparisons with alternative measures, we find that Cooperative Research and Development Agreements or CRADAs, are the primary channel by which federal laboratories increase the patenting and R&D of industrial laboratories. With a CRADA industrial laboratories patent more, spend more on company-financed R&D and spend more of their own money on federal laboratories. Without a CRADA patenting stays about the same and only federally funded R&D increases, mostly because of direct subsidies by government. These results are consistent with the literature on endogenous R&D spillovers, which emphasizes that knowledge spills over when recipients work at making it spill over. CRADAs are legal agreements between federal laboratories and firms to work together on joint research. They are backed by real budgets and accompanied by cost sharing that could bind the parties together in joint research. Moreover, the CRADA instrument is the main form of such agreements. Thus, both in theory and in fact CRADAs may be more beneficial to firms than other public- private interactions, precisely because of the mutual effort that they require of firms and government laboratories.

The Influence of Federal Laboratory R&D on Industrial Research

This paper studies the influence of R&D in the federal laboratory system, the world's largest, on firm research. Our results are based on a sample of 220 industrial research laboratories that work with a variety of federal laboratories and agencies and are owned by 115 firms in the chemicals, machinery, electrical equipment, and motor vehicles industries. Using an indicator of their importance to R&D managers, we find that Cooperative Research and Development Agreements or CRADAs dominate other channels of technology transfer from federal laboratories to firms. With a CRADA industry laboratories patent more, spend more on company-financed R&D, and devote more resources to their federal counterparts. Without this influence patenting stays about the same, and only federally funded R&D increases, mostly because of government support. The Stevenson-Wydler Act and amendments during the 1980s introduced CRADAs, which legally bind federal laboratories and firms together in joint research. In theory the agreements could capitalize on complementarities between public and private research. Our results support this perspective and suggest that CRADAs may be more beneficial to firms than other interactions with federal laboratories, precisely because of the mutual effort that they demand from both parties.

Orbital Response of Evanescent Cooper Pairs in Paramagnetically Limited Al Films

We report a detailed study of the pairing resonance via tunneling density of states in ultra-thin superconducting Al films in supercritical magnetic fields. Particular emphasis is placed on effects of the perpendicular component of the magnetic field on the resonance energy and magnitude. Though the resonance is broadened and attenuated by $H_\bot$ as expected, its energy is shifted upward linearly with $H_\bot$. Extension of the original theory of the resonance to include strong perpendicular fields shows that at sufficiently large $H_\bot$ the overlap of the broadened resonance tail with the underlying degenerate Fermi sea alters the spectral distribution of the resonance via the exclusion principle. This leads to the shift of the the resonance feature to higher energy.Comment: 8 pages, 4 figure

Utilization of a fixed base simulator to study the stall and spin characteristics of fighter airplanes

Feasibility of using fixed simulator to determine stall and spin characteristics of fighter aircraf

A retrospective study of the prevalence of the canine degenerative myelopathy associated superoxide dismutase 1 mutation (SOD1: c. 118G> A) in a referral population of German Shepherd dogs from the UK

BACKGROUND: Canine degenerative myelopathy (CDM) is an adult onset, progressive neurodegenerative disease of the spinal cord. The disease was originally described in the German Shepherd dog (GSD), but it is now known to occur in many other dog breeds. A previous study has identified a mutation in the superoxide dismutase 1 gene (SOD1:c.118G > A) that is associated with susceptibility to CDM. In the present study, restriction fragment length polymorphism (RFLP) analysis was used to genotype GSD for SOD1:c.118G > A in order to estimate the prevalence of the mutation in a referral population of GSD in the UK. RESULTS: This study demonstrated that the RFLP assay, based on use of PCR and subsequent digestion with the Eco571 enzyme, provided a simple genotyping test for the SOD1:c.118G > A mutation. In a young GSD population (i.e. dogs less than 6 years of age, before clinical signs of the disease usually become apparent), 8 of 50 dogs were found to be homozygous and a further 19 were heterozygous for the mutation. In dogs over 8 years of age, 21 of 50 dogs admitted to a tertiary referral hospital with pelvic limb ataxia as a major clinical sign were homozygous for the mutation, compared to none of 50 dogs of similar age, but where no neurological disease was reported on referral. CONCLUSIONS: This data suggests that genotyping for the SOD1:c.118G > A mutation is clinically applicable and that the mutation has a high degree of penetrance. Genotyping might also be useful for screening the GSD population to avoid mating of two carriers, but since the allele frequency is relatively high in the UK population of GSD, care should be taken to avoid reduction in genetic diversity within the breed

Study of the volume and spin collapse in orthoferrite LuFeO_3 using LDA+U

Rare earth (R) orthoferrites RFeO_3 exhibit large volume transitions associated with a spin collapse. We present here ab initio calculations on LuFeO_3. We show that taking into account the strong correlation among the Fe-3d electrons is necessary. Indeed, with the LDA+U method in the Projector Augmented Wave (PAW), we are able to describe the isostructural phase transition at 50 GPa, as well as a volume discontinuity of 6.0% at the transition and the considerable reduction of the magnetic moment on the Fe ions. We further investigate the effect of the variation of U and J and find a linear dependence of the transition pressure on these parameters. We give an interpretation for the non-intuitive effect of J. This emphasizes the need for a correct determination of these parameters especially when the LDA+U is applied to systems (e.g in geophysical investigations) where the transition pressure is a priori unknown

Upsilon cross section in p+p collisions at STAR

The main focus of the heavy flavor program at RHIC is to investigate the properties of the dense matter produced in heavy-ion collisions by studying its effect on open heavy flavor and quarkonia production. This in turn requires a detailed understanding of their production in elementary p+p collisions so that the dense matter effects can be later unfolded. In this paper, we present the first mid-rapidity cross section measurement of bottomonium at $\sqrt{s}=200$ GeV with the STAR experiment. We compare our results with perturbative QCD calculations. A brief status on the study of charmonium in STAR is given.Comment: 4 pages, 4 figures. To appear in the proceedings of Quark Matter 2006 as a special issue of Journal of Physics G: Nuclear and Particle Physic

Dissipative hydrodynamics in 2+1 dimension

In 2+1 dimension, we have simulated the hydrodynamic evolution of QGP fluid with dissipation due to shear viscosity. Comparison of evolution of ideal and viscous fluid, both initialised under the same conditions e.g. same equilibration time, energy density and velocity profile, reveal that the dissipative fluid evolves slowly, cooling at a slower rate. Cooling get still slower for higher viscosity. The fluid velocities on the otherhand evolve faster in a dissipative fluid than in an ideal fluid. The transverse expansion is also enhanced in dissipative evolution. For the same decoupling temperature, freeze-out surface for a dissipative fluid is more extended than an ideal fluid. Dissipation produces entropy as a result of which particle production is increased. Particle production is increased due to (i) extension of the freeze-out surface and (ii) change of the equilibrium distribution function to a non-equilibrium one, the last effect being prominent at large transverse momentum. Compared to ideal fluid, transverse momentum distribution of pion production is considerably enhanced. Enhancement is more at high $p_T$ than at low $p_T$. Pion production also increases with viscosity, larger the viscosity, more is the pion production. Dissipation also modifies the elliptic flow. Elliptic flow is reduced in viscous dynamics. Also, contrary to ideal dynamics where elliptic flow continues to increase with transverse momentum, in viscous dynamics, elliptic flow tends to saturate at large transverse momentum. The analysis suggest that initial conditions of the hot, dense matter produced in Au+Au collisions at RHIC, as extracted from ideal fluid analysis can be changed significantly if the QGP fluid is viscous.Comment: 11 pages, 10 figures (revised). In the revised version, calculations are redone with ADS/CFT and perurbative estimate of viscosity. Comments on the unphysical effects like early reheating of the fluid, in 1st order dissipative theories are added. The particle spectra calculations are redone with modified programm