323 research outputs found
On details of the thermodynamical derivation of the Ginsburg--Landau equations
We examine the procedure of thermodynamical derivation of the
Ginsburg--Landau equation for current, which is given unclear and contradictory
interpretations in existing textbooks. We clarify all steps of this procedure
and find as a consequence a limitation on the validity range of the
thermodynamic Ginsburg--Landau theory, which does not seem to be explicitely
stated up to now: we conclude that the thermodynamic theory is applicable only
to a superconducting specimen that is not a part of an external
current-carrying loop.Comment: 11 pages. Accepted for publication in 'Superconductor Science and
Technology
A super-Ohmic energy absorption in driven quantum chaotic systems
We consider energy absorption by driven chaotic systems of the symplectic
symmetry class. According to our analytical perturbative calculation, at the
initial stage of evolution the energy growth with time can be faster than
linear. This appears to be an analog of weak anti-localization in disordered
systems with spin-orbit interaction. Our analytical result is also confirmed by
numerical calculations for the symplectic quantum kicked rotor.Comment: 4 pages, 2 figure
Interphase cytogenetics of multicentric renal cell tumours confirm associations of specific aberrations with defined cytomorphologies
To demonstrate associations of certain chromosomal aberrations with defined renal cell tumour (RCT) subtypes, we analysed 239 tumour nephrectomy cases for specimens with multicentric tumours. Chromosomal in situ hybridization was then performed on 15 cases with 34 foci (16 conventional renal cell carcinomas (RCCs), and 18 papillary RCTs (11 carcinomas and seven adenomas) for specific chromosomal aberrations, using α-satellite probes for chromosomes 3, 7 or 17. Particular preference was given to cases which had separate foci with different cytomorphologies. Furthermore, we compared aberrations in relation to tumour size, stage, grade and between different foci in a specimen. Thirty-four cases had multiple tumours. Forty-seven per cent of the multicentric tumours were conventional RCCs and 53% papillary RCTs (against 83% solitary conventional RCCs and 5% solitary papillary RCTs). Three conventional RCCs sized 8 mm (G3), 13 cm (pT2, G2) and 15 cm (pT3b, G3), respectively, revealed monosomy 3, and 13 were disomic. Seventeen papillary RCTs (11 carcinomas and six adenomas) displayed trisomy 17, irrespective of size or grade. Four papillary carcinomas and six papillary adenomas had trisomy 7, and the rest (seven papillary carcinomas and one papillary adenoma) revealed disomy 7. In conclusion, papillary RCTs were tendentially multicentric. Although specific for conventional RCCs heedless of size, monosomy 3 was only observed in high-grade and/or advanced tumours. Trisomy 17 was only detectable in papillary RCTs irrespective of tumour state, showing increased copies with tumour growth. Papillary RCTs also appeared to lose some copies of chromosome 7 with tumour progress, possibly reflecting malignancy. © 2000 Cancer Research Campaig
Metastable bound state of a pair of two-dimensional spatially separated electrons in anti-parallel magnetic fields
We propose a new mechanism for binding of two equally charged carriers in a
double-layer system subjected by a magnetic field of a special form. A field
configuration for which the magnetic fields in adjacent layers are equal in
magnitude and opposite in direction is considered. In such a field an
additional integral of motion - the momentum of the pair P arises. For the case
when in one layer the carrier is in the zero (n=0) Landau level while in the
other layer - in the first (n=1) Landau level the dependence of the energy of
the pair on its momentum E(P} is found. This dependence turns out to be
nonmonotonic one : a local maximum and a local minimum appears, indicating the
emergence of a metastable bound state of two carrier with the same sign of
electrical charge.Comment: 7 page
Switchable collective pinning of flux quanta using magnetic vortex arrays
We constructed a superconducting/ferromagnetic hybrid system in which the
ordering of the pinning potential landscape for flux quanta can be manipulated.
Flux pinning is induced by an array of magnetic nanodots in the magnetic vortex
state, and controlled by the magnetic history. This allows switching on and off
the collective pinning of the flux-lattice. In addition, we observed
field-induced superconductivity that originates from the annihilation of flux
quanta induced by the stray fields from the magnetic vortices.Comment: PDF file 18 pages including 5 figures, accepted for publication in
Phys. Rev.
Horizon area-angular momentum inequality in higher dimensional spacetimes
We consider -dimensional spacetimes which are axisymmetric--but not
necessarily stationary (!)--in the sense of having isometry group ,
and which satisfy the Einstein equations with a non-negative cosmological
constant. We show that any black hole horizon must have area A \ge 8\pi |J_+
J_-|^\half, where are distinguished components of the angular momentum
corresponding to linear combinations of the rotational Killing fields that
vanish somewhere on the horizon. In the case of , where there is only one
angular momentum component , we recover an inequality of 1012.2413
[gr-qc]. Our work can hence be viewed as a generalization of this result to
higher dimensions. In the case of with horizon of topology , the quantities are the same angular momentum component (in the
direction). In the case of with horizon topology , the
quantities are the distinct components of the angular momentum. We
also show that, in all dimensions, the inequality is saturated if the metric is
a so-called ``near horizon geometry''. Our argument is entirely quasi-local,
and hence also applies e.g. to any stably outer marginally trapped surface.Comment: 16 pages, Latex, no figure
Estimating Correlated Jumps and Stochastic Volatilities
We formulate a bivariate stochastic volatility jump-diffusion model with correlated jumps and volatilities. An MCMC Metropolis-Hastings sampling algorithm is proposed to estimate the model's parameters and latent state variables (jumps and stochastic volatilities) given observed returns. The methodology is successfully tested on several artificially generated bivariate time series and then on the two most important Czech domestic financial market time series of the FX (CZK/EUR) and stock (PX index) returns. Four bivariate models with and without jumps and/or stochastic volatility are compared using the deviance information criterion (DIC) confirming importance of incorporation of jumps and stochastic volatility into the model
Tumor growth rate as a metric of progression, response, and prognosis in pancreatic and intestinal neuroendocrine tumors
Background: Lanreotide depot/autogel antitumor activity in intestinal/pancreatic neuroendocrine tumors (NETs) was demonstrated in the phase-3 CLARINET study (NCT00353496), based on significantly prolonged progression-free survival (PFS) versus placebo.
Methods: During CLARINET, patients with metastatic intestinal/pancreatic NETs received lanreotide depot/autogel 120 mg or placebo every 4 weeks for 96 weeks. Imaging data (response evaluation criteria in solid tumors [RECIST] v1.0, centrally reviewed) were re-evaluated in this post hoc analysis of tumor growth rate (TGR) in NETs. TGR (%/month) was calculated from two imaging scans during relevant periods: pre-treatment (TGR0); 12-24 weeks before randomization versus baseline; each treatment visit versus baseline (TGRTx-0); between consecutive treatment visits (TGRTx-Tx). To assess TGR as a measure of prognosis, PFS was compared for TGR0 subgroups stratified by optimum TGR0 cut-off; a multivariate analysis was conducted to identify prognostic factors for PFS.
Results: TGR0 revealed tumors growing during pre-treatment (median [interquartile range] TGR0: lanreotide 2.1%/month [0.2; 6.1]; placebo 2.7%/month [0.15; 6.8]), contrary to RECIST status. TGR was significantly reduced by 12 weeks with lanreotide versus placebo (difference in least-square mean TGR0-12 of - 2.9 [- 5.1, - 0.8], p = 0.008), a difference that was maintained at most subsequent visits. TGR0 > 4%/month had greater risk of progression/death than ≤4%/month (hazard ratio 4.1; [95% CI 2.5-6.5]; p < 0.001); multivariate analysis revealed lanreotide treatment, progression at baseline, TGR0, hepatic tumor load, and primary tumor type were independently associated with PFS.
Conclusions: TGR provides valuable information on tumor activity and prognosis in patients with metastatic intestinal/pancreatic NETs, and identifies early lanreotide depot/autogel antitumor activity.
Trial registration: Retrospective registration, 18 July 2006; EudraCT: 2005-004904-35; ClinicalTrials.gov: NCT00353496
Economic Aspects of Sanitation in Developing Countries
Improved sanitation has been shown to have great impacts on people's health and economy. However, the progress of achieving the Millennium Development Goals (MDGs) on halving the proportion of people without access to clean water and basic sanitation by 2015 has thus far been delayed. One of the reasons for the slow progress is that policy makers, as well as the general public, have not fully understood the importance of the improved sanitation solutions. This paper, by gathering relevant research findings, aims to report and discuss currently available evidence on the economic aspects of sanitation, including the economic impacts of unimproved sanitation and the costs and economic benefits of some common improved sanitation options in developing countries.; DATA USED IN THIS PAPER WERE OBTAINED FROM DIFFERENT INFORMATION SOURCES: international and national journal articles and reports, web-based statistics, and fact sheets. We used both online search and hand search methods to gather the information.; Scientific evidence has demonstrated that the economic cost associated with poor sanitation is substantial. At the global level, failure to meet the MDG water and sanitation target would have ramifications in the area of US142 billion (US28 for sanitation. Annually, this translates to roughly US1 invested, achieving the sanitation MDG target and universal sanitation access in the non-OECD countries would result in a global return of US11.2, respectively.; Given the current state of knowledge, sanitation is undeniably a profitable investment. It is clear that achieving the MDG sanitation target not only saves lives but also provides a foundation for economic growth
ORGANIZATION OF ANTI-EPIDEMIC MEASURES DURING THE ANTHRAX OUTBREAK IN THE YAMALO-NENETS AUTONOMOUS DISTRICT IN 2016
The organizational peculiarities of anti-epidemic measures during the anthrax outbreak in the Yamalo-Nenets Autonomous District in 2016 are presented. Complex of these measures provided for anthrax patients active identification and hospitalization, preventive immunization and emergency antibiotic prophylaxis of risk groups, vaccination of reindeer, utilization of fallen animals. Disinfection, deratization and desinsection measures were performed. Native residents were evacuated from infection focus and sensitization campaign among the population was carried out. Organized were sanitary inspection stations and temporary accommodation points. Due to operational implementation of anti-epidemic measures in the interagency format the anthrax focus was localized within one incubation period
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