250 research outputs found
Perception of Nuclear Energy and Coal in France and the Netherlands
This study focuses on the perception of large scale application of nuclear energy and coal in the Netherlands and France. The application of these energy-sources and the risks and benefits are judged differently by various group in society. In Europe, France has the highest density of nuclear power plants and the Netherlands has one of the lowest. In both countries scientists and social scientists completed a questionnaire assessing the perception of the large scale application of both energy sources. Furthermore, a number of variables relating to the socio cultural and political circumstances were measured. The results indicate that the French had a higher risk perception and a more negative attitude toward nuclear power than the Dutch. But they also assess the benefits of the use of nuclear power to be higher. Explanations for these differences are discussed
Coverage-dependent adsorption and desorption of oxygen on Pd(100)
Catalysis and Surface Chemistr
Fermi liquid theory for the nonequilibrium Kondo effect at low bias voltages
In this report, we describe a recent development in a Fermi liquid theory for
the Kondo effect in quantum dots under a finite bias voltage . Applying the
microscopic theory of Yamada and Yosida to a nonequilibrium steady state, we
derive the Ward identities for the Keldysh Green's function, and determine the
low-energy behavior of the differential conductance exactly up to terms
of order for the symmetric Anderson model. These results are deduced
from the fact that the Green's function at the impurity site is a functional of
a nonequilibrium distribution , which at
coincides with the Fermi function. Furthermore, we provide an alternative
description of the low-energy properties using a renormalized perturbation
theory (RPT). In the nonequilibrium state the unperturbed part of the RPT is
determined by the renormalized free quasiparticles, the distribution function
of which is given by . The residual interaction between
the quasiparticles , which is defined by the full vertex part at
zero frequencies, is taken into account by an expansion in the power series of
. We also discuss the application of the RPT to a high-bias
region beyond the Fermi-liquid regime.Comment: 8 pages, to appear in a special edition of JPSJ "Kondo Effect -- 40
Years after the Discovery", typos are correcte
NRG approach to the transport through a finite Hubbard chain connected to reservoirs
We study the low-energy properties of a Hubbard chain of finite size N_C
connected to two noninteracting leads using the numerical renormalization group
(NRG) method. The results obtained for N_C = 3 and 4 show that the low-lying
eigenstates have one-to-one correspondence with the free quasi-particle
excitations of a local Fermi liquid. It enables us to determine the transport
coefficients from the fixed-point Hamiltonian. At half-filling, the conductance
for even N_C decreases exponentially with increasing U showing a tendency
towards the development of a Mott-Hubbard gap. In contrast, for odd N_C, the
Fermi-liquid nature of the low-energy states assures perfect transmission
through the Kondo resonance. Our formulation to deduce the conductance from the
fixed-point energy levels can be applied to various types of interacting
systems.Comment: One typo found in Eq.(3) in previous version has been correcte
Dimensional Crossover in Quantum Antiferromagnets
The dimensional crossover in a spin- nearest neighbor Heisenberg
antiferromagnet is discussed as it is tuned from a two-dimensional square
lattice, of lattice spacing , towards a spin chain by varying the width
of a semi-infinite strip . For integer spins and arbitrary
, and for half integer spins with an arbitrary even integer,
explicit analytical expressions for the zero temperature correlation length and
the spin gap are given. For half integer spins and an odd inetger, it
is shown that the behavior of the WZW fixed point is squeezed
out as the width ; here is the conformal charge. The results
specialized to are relevant to spin-ladder systems.Comment: RevTeX, 4 pages, 1 embedded postscript figur
How is rape a weapon of war?: feminist international relations, modes of critical explanation and the study of wartime sexual violence
Rape is a weapon of war. Establishing this now common claim has been an achievement of feminist scholarship and activism and reveals wartime sexual violence as a social act marked by gendered power. But the consensus that rape is a weapon of war obscures important, and frequently unacknowledged, differences in ways of understanding and explaining it. This article opens these differences to analysis. Drawing on recent debates regarding the philosophy of social science in IR and social theory, it interprets feminist accounts of wartime sexual violence in terms of modes of critical explanation – expansive styles of reasoning that foreground particular actors, mechanisms, reasons and stories in the formulation of research. The idea of a mode of critical explanation is expanded upon through a discussion of the role of three elements (analytical wagers, narrative scripts and normative orientations) which accomplish the theoretical work of modes. Substantive feminist accounts of wartime sexual violence are then differentiated in terms of three modes – of instrumentality, unreason and mythology – which implicitly structure different understandings of how rape might be a weapon of war. These modes shape political and ethical projects and so impact not only on questions of scholarly content but also on the ways in which we attempt to mitigate and abolish war rape. Thinking in terms of feminist modes of critical explanation consequently encourages further work in an unfolding research agenda. It clarifes the ways in which an apparently commonality of position can conceal meaningful disagreements about human action. Exposing these disagreements opens up new possibilities for the analysis of war rape
Critical Nature of Non-Fermi Liquid in Spin 3/2 Multipolar Kondo Model
A multipolar Kondo model of an impurity spin S_I=3/2 interacting with
conduction electrons with spin s_c=3/2 is investigated using boundary conformal
field theory. A two-channel Kondo (2CK) -like non-Fermi liquid (NFL) under the
particle-hole symmetry is derived explicitly using a ``superspin absorption''
in the sector of a hidden symmetry, SO(5). We discuss the difference between
the usual spin-1/2 2CK NFL fixed point and the present one. In particular, we
find that, unlike the usual 2CK model, the low temperature impurity specific
heat is proportional to temperature.Comment: 4 pages, 2 figure
Experimental techniques for aberration retrieval with through-focus intensity images
Measurement techniques to determine the aberration of an optical system, by obtaining through-focus intensity images that are produced when the object is a point source at infinity, are shown. The analysis of the aberrations is made using the extended version of the Nijboer-Zernike diffraction theory. This theory provides a semi analytical solution of the Debye diffraction integral and thus a direct relation between the intensity distribution of the field at the focal region and the exit pupil of the optical syste
Random matrix theory and
We suggest that the spectral properties near zero virtuality of three
dimensional QCD, follow from a Hermitean random matrix model. The exact
spectral density is derived for this family of random matrix models both for
even and odd number of fermions. New sum rules for the inverse powers of the
eigenvalues of the Dirac operator are obtained. The issue of anomalies in
random matrix theories is discussed.Comment: 10p., SUNY-NTG-94/1
Statins for children with familial hypercholesterolemia
BACKGROUND: Familial hypercholesterolemia is one of the most common inherited metabolic diseases and is an autosomal dominant disorder meaning heterozygotes, or carriers, are affected. Those who are homozygous have severe disease. The average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500, although recent genetic epidemiological data from Denmark and next generation sequencing data suggest the frequency may be closer to 1 in 250. Diagnosis of familial hypercholesterolemia in children is based on elevated total cholesterol and low-density lipoprotein cholesterol levels or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong treatment, started in childhood, is needed to reduce the risk of cardiovascular disease. In children with the disease, diet was the cornerstone of treatment but the addition of lipid-lowering medications has resulted in a significant improvement in treatment. Anion exchange resins, such as cholestyramine and colestipol, were found to be effective, but they are poorly tolerated. Since the 1990s studies carried out on children aged 6 to 17 years with heterozygous familial hypercholesterolemia have demonstrated significant reductions in their serum total and low-density lipoprotein cholesterol levels. While statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established. This is an update of a previously published version of this Cochane Review. OBJECTIVES: To assess the effectiveness and safety of statins in children with heterozygous familial hypercholesterolemia. SEARCH METHODS: Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 20 February 2017. SELECTION CRITERIA: Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone. DATA COLLECTION AND ANALYSIS: Two authors independently assessed studies for inclusion and extracted data. MAIN RESULTS: We found 26 potentially eligible studies, of which we included nine randomized placebo-controlled studies (1177 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points (moderate quality evidence). Serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations, did not differ between treated and placebo groups at any time point (low quality evidence). The risks of myopathy (low quality evidence) and clinical adverse events (moderate quality evidence) were very low and also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilatation of the brachial artery (low quality evidence), and in another study treatment with pravastatin for two years induced a significant regression in carotid intima media thickness (low quality evidence). AUTHORS' CONCLUSIONS: Statin treatment is an effective lipid-lowering therapy in children with familial hypercholesterolemia. No significant safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety remains unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians and their care transferred to an adult lipidologist once they reach 18 years of age. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins
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