323 research outputs found

    On details of the thermodynamical derivation of the Ginsburg--Landau equations

    Full text link
    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

    Full text link
    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

    Get PDF
    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

    Full text link
    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

    Full text link
    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

    Full text link
    We consider nn-dimensional spacetimes which are axisymmetric--but not necessarily stationary (!)--in the sense of having isometry group U(1)n−3U(1)^{n-3}, 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 J±J_\pm 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 n=4n=4, where there is only one angular momentum component J+=J−J_+=J_-, 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 n=5n=5 with horizon of topology S1×S2S^1 \times S^2, the quantities J+=J−J_+=J_- are the same angular momentum component (in the S2S^2 direction). In the case of n=5n=5 with horizon topology S3S^3, the quantities J+,J−J_+, J_- 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

    Full text link
    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

    Get PDF
    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

    Get PDF
    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 US38billion,andsanitationaccountsfor9238 billion, and sanitation accounts for 92% of this amount. In developing countries, the spending required to provide new coverage to meet the MDG sanitation target (not including program costs) is US142 billion (USyear2005).ThistranslatestoapercapitaspendingofUS year 2005). This translates to a per capita spending of US28 for sanitation. Annually, this translates to roughly US14million.Theevidencecompliedinthispaperdemonstratesthatinvestinginsanitationissociallyandeconomicallyworthwhile.ForeveryUS14 million. The evidence complied in this paper demonstrates that investing in sanitation is socially and economically worthwhile. For every US1 invested, achieving the sanitation MDG target and universal sanitation access in the non-OECD countries would result in a global return of US9.1andUS9.1 and 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

    Get PDF
    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
    • …
    corecore