Finite Size Polyelectrolyte Bundles at Thermodynamic Equilibrium

We present the results of extensive computer simulations performed on solutions of monodisperse charged rod-like polyelectrolytes in the presence of trivalent counterions. To overcome energy barriers we used a combination of parallel tempering and hybrid Monte Carlo techniques. Our results show that for small values of the electrostatic interaction the solution mostly consists of dispersed single rods. The potential of mean force between the polyelectrolyte monomers yields an attractive interaction at short distances. For a range of larger values of the Bjerrum length, we find finite size polyelectrolyte bundles at thermodynamic equilibrium. Further increase of the Bjerrum length eventually leads to phase separation and precipitation. We discuss the origin of the observed thermodynamic stability of the finite size aggregates

Large magnetoresistance using hybrid spin filter devices

A magnetic "spin filter" tunnel barrier, sandwiched between a non-magnetic metal and a magnetic metal, is used to create a new magnetoresistive tunnel device, somewhat analogous to an optical polarizer-analyzer configuration. The resistance of these trilayer structures depends on the relative magnetization orientation of the spin filter and the ferromagnetic electrode. The spin filtering in this configuration yields a previously unobserved magnetoresistance effect, exceeding 100%.Comment: 3.5 pages, 3 figures, submitted to Appl. Phys. Let

Photocatalytic antimicrobial activity of thin surface films of TiO2, CuO and TiO2 /CuO dual layers on Escherichia coli and bacteriophage T4

TiO2 coated surfaces are increasingly studied for their ability to inactivate microorganisms. The activity of glass coated with thin films of TiO2, CuO and hybrid CuO/TiO2 prepared by atmospheric Chemical Vapour Deposition (Ap-CVD) and TiO2 prepared by a sol-gel process was investigated using the inactivation of bacteriophage T4 as a model for inactivation of viruses. The chemical oxidising activity was also determined by measuring stearic acid oxidation. The results showed that the rate of inactivation of bacteriophage T4 increased with increasing chemical oxidising activity with the maximum rate obtained on highly active sol-gel preparations. However these were delicate and easily damaged unlike the Ap-CVD coatings. Inactivation rates were highest on CuO and CuO/TiO2 which had the lowest chemical oxidising activities. The inactivation of T4 was higher than that of Escherichia coli on low activity surfaces. The combination of photocatalysis and toxicity of copper acted synergistically to inactivate bacteriophage T4 and retained some selfcleaning activity. The presence of phosphate ions slowed inactivation but NaCl had no effect. The results show that TiO2/CuO coated surfaces are highly antiviral and may have applications in the food and healthcare industries

Green Function of the Sutherland Model with SU(2) internal symmetry

We obtain the hole propagator of the Sutherland model with SU(2) internal symmetry for coupling parameter $\beta=1$, which is the simplest nontrivial case. One created hole with spin down breaks into two quasiholes with spin down and one quasihole with spin up. While these elementary excitations are energetically free, the form factor reflects their anyonic character. The expression for arbitrary integer $\beta$ is conjectured.Comment: 13pages, Revtex, one ps figur

Devenir professionnel de salariés des Pays de la Loire souffrant de troubles musculo-squelettiques

The objective was to study the employment and occupational outcomes of workers who were diagnosed with upper limb musculoskeletal disorders (UL-MSDs) or had complained of upper limb musculoskeletal pain a few years before, compared to workers without upper limb pain. In 2002-2005, 83 occupational physicians examined 3,710 randomly selected workers. Three groups were constituted between 2007 and 2009: a “UL-MSD” group (workers with a clinically diagnosed UL-MSD); a “MS PAIN” group (workers with pain in the previous seven days and without any clinically diagnosed form); and a “HEALTHY” group (workers with no disorder or upper limb pain). A total of 2,287 responded to a questionnaire. Fewer subjects were still working in the “UL-MSD” group (79.3%) than in the “MS PAIN” (85.9%) and “HEALTHY” (90.4%) groups. Among the subjects still working, 24% had changed their position in the same company in the “MS PAIN” group, compared to 21% in the “UL-MSD” group, and 19% in the “HEALTHY” group. This study showed the impact of UL-MSDs on employment outcome and of musculoskeletal pain on occupational outcome

Employment and occupational outcomes of workers with musculoskeletal pain in a French region

OBJECTIVES: To study the employment and occupational outcomes of workers who were diagnosed with upper limb musculoskeletal disorders (UL-MSDs) or had complained of upper limb musculoskeletal pain a few years before compared with workers who had no upper limb pain. METHODS: In 2002-2005, an epidemiological surveillance system was set up. Occupational physicians examined 3710 randomly selected workers. It focused on six UL-MSDs: rotator cuff syndrome, lateral epicondylitis, flexor-extensor peritendinitis of the hands and fingers, de Quervain\u27s disease, carpal tunnel syndrome and ulnar tunnel syndrome. Three groups were constituted: a \u27UL-MSD\u27 group (workers with a clinically diagnosed UL-MSD at baseline, 13% of the cohort); a \u27PAIN\u27 group (workers with pain in the previous 7 days at baseline and without any clinically diagnosed form, 38%); and a \u27HEALTHY\u27 group (workers with no disorder or upper limb pain in the previous 7 days, 49%). They completed a questionnaire between 2007 and 2009. RESULTS: A total of 2332 responded. Fewer subjects were still in work in the \u27UL-MSD\u27 group (79.3%) than in the \u27PAIN\u27 (85.9%) and \u27HEALTHY\u27 (90.4%) groups, the difference remaining significant after adjusting for gender, age, occupational category, type of company and comorbidities. Of the subjects still in work, 24% had changed their work station in the same company in the \u27PAIN\u27 group compared with 19% in the \u27HEALTHY\u27 group and 21% in the \u27UL-MSD\u27 group. CONCLUSIONS: This study showed the impact of musculoskeletal pain on employment outcome and the difficulty of keeping workers with musculoskeletal problems at work

Sparse Deterministic Approximation of Bayesian Inverse Problems

We present a parametric deterministic formulation of Bayesian inverse problems with input parameter from infinite dimensional, separable Banach spaces. In this formulation, the forward problems are parametric, deterministic elliptic partial differential equations, and the inverse problem is to determine the unknown, parametric deterministic coefficients from noisy observations comprising linear functionals of the solution. We prove a generalized polynomial chaos representation of the posterior density with respect to the prior measure, given noisy observational data. We analyze the sparsity of the posterior density in terms of the summability of the input data's coefficient sequence. To this end, we estimate the fluctuations in the prior. We exhibit sufficient conditions on the prior model in order for approximations of the posterior density to converge at a given algebraic rate, in terms of the number $N$ of unknowns appearing in the parameteric representation of the prior measure. Similar sparsity and approximation results are also exhibited for the solution and covariance of the elliptic partial differential equation under the posterior. These results then form the basis for efficient uncertainty quantification, in the presence of data with noise