F. John's stability conditions vs. A. Carasso's SECB constraint for backward parabolic problems

In order to solve backward parabolic problems F. John [{\it Comm. Pure. Appl. Math.} (1960)] introduced the two constraints "$\|u(T)\|\le M$" and $\|u(0) - g \| \le \delta$ where $u(t)$ satisfies the backward heat equation for $t\in(0,T)$ with the initial data $u(0).$ The {\it slow-evolution-from-the-continuation-boundary} (SECB) constraint has been introduced by A. Carasso in [{\it SIAM J. Numer. Anal.} (1994)] to attain continuous dependence on data for backward parabolic problems even at the continuation boundary $t=T$. The additional "SECB constraint" guarantees a significant improvement in stability up to $t=T.$ In this paper we prove that the same type of stability can be obtained by using only two constraints among the three. More precisely, we show that the a priori boundedness condition $\|u(T)\|\le M$ is redundant. This implies that the Carasso's SECB condition can be used to replace the a priori boundedness condition of F. John with an improved stability estimate. Also a new class of regularized solutions is introduced for backward parabolic problems with an SECB constraint. The new regularized solutions are optimally stable and we also provide a constructive scheme to compute. Finally numerical examples are provided.Comment: 15 pages. To appear in Inverse Problem

Imaging spectrum and prevalence of variant branching pattern of aortic arch

Background: Variant branching patterns of the aortic arch are not infrequent but are commonly under reported. This study was conducted to determine the spectrum of Variant branching pattern of aortic arch and their prevalence using contrast enhanced computed tomography (CECT) images of the cases from a tertiary care centre.Methods:  Contrast enhanced computed tomography (CECT) images of aortic arch region from 1116(629 male and 487 female) cases from 18 to 85 years of age were examined retrospectively. The images were reviewed for normal and variant anatomy of aortic arch and the results were analyzed statistically.Results: Of 1116 patients, 878 (78.6%) cases showed normal and 238 (21.3%) cases had variant branching pattern of the aortic arch. The most common variation was the common origin of brachiocephalic trunk (BCT) and the left common carotid artery (LCCA) which was observed in 160 (14.3%) cases. In 8 (0.7%) cases, BCT and LCCA took origin from a single common trunk arising from the aortic arch. In 60(5.4%) cases, the left vertebral artery (LVA) originated directly from the aortic arch between the origin of the LCCA and left subclavian artery (SCA). 8 (0.7%) cases had aberrant right subclavian artery. Two (0.2%) cases showed right aortic arch.Conclusions: Interventional radiologists and surgeons should be well aware of variant anatomy of aortic arch. Contrast CT is a highly reliable imaging method for demonstrating anatomical features and variations of the arch

Continuing professional development requirements for UK health professionals: a scoping review

Abstract Objectives This paper sets out to establish the numbers and titles of regulated healthcare professionals in the UK and uses a review of how continuing professional development (CPD) for health professionals is described internationally to characterise the postqualification training required of UK professions by their regulators. It compares these standards across the professions and considers them against the best practice evidence and current definitions of CPD. Design A scoping review. Search strategy We conducted a search of UK health and social care regulators’ websites to establish a list of regulated professional titles, obtain numbers of registrants and identify documents detailing CPD policy. We searched Applied Social Sciences Index and Abstracs (ASSIA), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medline, EMCare and Scopus Life Sciences, Health Sciences, Physical Sciences and Social Sciences & Humanities databases to identify a list of common features used to describe CPD systems internationally and these were used to organise the review of CPD requirements for each profession. Results CPD is now mandatory for the approximately 1.5 million individuals registered to work under 32 regulated titles in the UK. Eight of the nine regulators do not mandate modes of CPD and there is little requirement to conduct interprofessional CPD. Overall 81% of those registered are required to engage in some form of reflection on their learning but only 35% are required to use a personal development plan while 26% have no requirement to engage in peer-to-peer learning. Conclusions Our review highlights the wide variation in the required characteristics of CPD being undertaken by UK health professionals and raises the possibility that CPD schemes are not fully incorporating the best practice

Genetic diversity of Mycobacterium tuberculosis in Peru and exploration of phylogenetic associations with drug resistance.

BACKGROUND: There is limited available data on the strain diversity of M tuberculosis in Peru, though there may be interesting lessons to learn from a setting where multidrug resistant TB has emerged as a major problem despite an apparently well-functioning DOTS control programme. METHODS: Spoligotyping was undertaken on 794 strains of M tuberculosis collected between 1999 and 2005 from 553 community-based patients and 241 hospital-based HIV co-infected patients with pulmonary tuberculosis in Lima, Peru. Phylogenetic and epidemiologic analyses permitted identification of clusters and exploration of spoligotype associations with drug resistance. RESULTS: Mean patient age was 31.9 years, 63% were male and 30.4% were known to be HIV+. Rifampicin mono-resistance, isoniazid mono-resistance and multidrug resistance (MDR) were identified in 4.7%, 8.7% and 17.3% of strains respectively. Of 794 strains from 794 patients there were 149 different spoligotypes. Of these there were 27 strains (3.4%) with novel, unique orphan spoligotypes. 498 strains (62.7%) were clustered in the nine most common spoligotypes: 16.4% SIT 50 (clade H3), 12.3% SIT 53 (clade T1), 8.3% SIT 33 (LAM3), 7.4% SIT 42 (LAM9), 5.5% SIT 1 (Beijing), 3.9% SIT 47 (H1), 3.0% SIT 222 (clade unknown), 3.0% SIT1355 (LAM), and 2.8% SIT 92 (X3). Amongst HIV-negative community-based TB patients no associations were seen between drug resistance and specific spoligotypes; in contrast HIV-associated MDRTB, but not isoniazid or rifampicin mono-resistance, was associated with SIT42 and SIT53 strains. CONCLUSION: Two spoligotypes were associated with MDR particularly amongst patients with HIV. The MDR-HIV association was significantly reduced after controlling for SIT42 and SIT53 status; residual confounding may explain the remaining apparent association. These data are suggestive of a prolonged, clonal, hospital-based outbreak of MDR disease amongst HIV patients but do not support a hypothesis of strain-specific propensity for the acquisition of resistance-conferring mutations

Effect of Impurity Scattering on the Nonlinear Microwave Response in High-Tc Superconductors

We theoretically investigate intermodulation distortion in high-Tc superconductors. We study the effect of nonmagnetic impurities on the real and imaginary parts of nonlinear conductivity. The nonlinear conductivity is proportional to the inverse of temperature owing to the dependence of the damping effect on energy, which arises from the phase shift deviating from the unitary limit. It is shown that the final-states interaction makes the real part predominant over the imaginary part. These effects have not been included in previous theories based on the two-fluid model, enabling a consistent explanation for the experiments with the rf and dc fields

Proteome Profiling of Breast Tumors by Gel Electrophoresis and Nanoscale Electrospray Ionization Mass Spectrometry

We have conducted proteome-wide analysis of fresh surgery specimens derived from breast cancer patients, using an approach that integrates size-based intact protein fractionation, nanoscale liquid separation of peptides, electrospray ion trap mass spectrometry, and bioinformatics. Through this approach, we have acquired a large amount of peptide fragmentation spectra from size-resolved fractions of the proteomes of several breast tumors, tissue peripheral to the tumor, and samples from patients undergoing noncancer surgery. Label-free quantitation was used to generate protein abundance maps for each proteome and perform comparative analyses. The mass spectrometry data revealed distinct qualitative and quantitative patterns distinguishing the tumors from healthy tissue as well as differences between metastatic and non-metastatic human breast cancers including many established and potential novel candidate protein biomarkers. Selected proteins were evaluated by Western blotting using tumors grouped according to histological grade, size, and receptor expression but differing in nodal status. Immunohistochemical analysis of a wide panel of breast tumors was conducted to assess expression in different types of breast cancers and the cellular distribution of the candidate proteins. These experiments provided further insights and an independent validation of the data obtained by mass spectrometry and revealed the potential of this approach for establishing multimodal markers for early metastasis, therapy outcomes, prognosis, and diagnosis in the future. © 2008 American Chemical Society

Directed flow of antiprotons in Au+Au collisions at AGS

Directed flow of antiprotons is studied in Au+Au collisions at a beam momentum of 11.5A GeV/c. It is shown that antiproton directed flow is anti-correlated to proton flow. The measured transverse momentum dependence of the antiproton flow is compared with predictions of the RQMD event generator.Comment: 16 pages, 6 figure

Solving parabolic equations on the unit sphere via Laplace transforms and radial basis functions

We propose a method to construct numerical solutions of parabolic equations on the unit sphere. The time discretization uses Laplace transforms and quadrature. The spatial approximation of the solution employs radial basis functions restricted to the sphere. The method allows us to construct high accuracy numerical solutions in parallel. We establish $L_2$ error estimates for smooth and nonsmooth initial data, and describe some numerical experiments.Comment: 26 pages, 1 figur

Two-Proton Correlations from 14.6A GeV/c Si+Pb and 11.5A GeV/c Au+Au Central Collisions

Two-proton correlation functions have been measured in Si+Pb collisions at 14.6A GeV/c and Au+Au collisions at 11.5A GeV/c by the E814/E877 collaboration. Data are compared with predictions of the transport model RQMD and the source size is inferred from this comparison. Our analysis shows that, for both reactions, the characteristic size of the system at freeze-out exceeds the size of the projectile, suggesting that the fireball created in the collision has expanded. For Au+Au reactions, the observed centrality dependence of the two-proton correlation function implies that more central collisions lead to a larger source sizes.Comment: RevTex, 12 pages, 5 figure