Non-intersecting Brownian Interfaces and Wishart Random Matrices

We study a system of $N$ non-intersecting $(1+1)$-dimensional fluctuating elastic interfaces (`vicious bridges') at thermal equilibrium, each subject to periodic boundary condition in the longitudinal direction and in presence of a substrate that induces an external confining potential for each interface. We show that, for a large system and with an appropriate choice of the external confining potential, the joint distribution of the heights of the $N$ non-intersecting interfaces at a fixed point on the substrate can be mapped to the joint distribution of the eigenvalues of a Wishart matrix of size $N$ with complex entries (Dyson index $\beta=2$), thus providing a physical realization of the Wishart matrix. Exploiting this analogy to random matrix, we calculate analytically (i) the average density of states of the interfaces (ii) the height distribution of the uppermost and lowermost interfaces (extrema) and (iii) the asymptotic (large $N$) distribution of the center of mass of the interfaces. In the last case, we show that the probability density of the center of mass has an essential singularity around its peak which is shown to be a direct consequence of a phase transition in an associated Coulomb gas problem.Comment: 31 pages, 9 figure

The Index Distribution of Gaussian Random Matrices

We compute analytically, for large N, the probability distribution of the number of positive eigenvalues (the index N_{+}) of a random NxN matrix belonging to Gaussian orthogonal (\beta=1), unitary (\beta=2) or symplectic (\beta=4) ensembles. The distribution of the fraction of positive eigenvalues c=N_{+}/N scales, for large N, as Prob(c,N)\simeq\exp[-\beta N^2 \Phi(c)] where the rate function \Phi(c), symmetric around c=1/2 and universal (independent of $\beta$), is calculated exactly. The distribution has non-Gaussian tails, but even near its peak at c=1/2 it is not strictly Gaussian due to an unusual logarithmic singularity in the rate function.Comment: 4 pages Revtex, 4 .eps figures include

Amplified NUP214/ABL1

Review on Amplified NUP214/ABL1, with data on clinics, and the genes involved

Genotypic and phenotypic characterization of a Salmonella Typhimurium strain resistant to pulsed electric fields

Pulsed Electric Fields (PEF) technology is regarded as one of the most interesting alternatives to current food preservation methods, due to its capability to inactivate vegetative microorganisms while leaving the product's organoleptic and nutritional properties mostly unchanged. However, many aspects regarding the mechanisms of bacterial inactivation by PEF are still not fully understood. The aim of this study was to obtain further insight into the mechanisms responsible for the increased resistance to PEF of a Salmonella Typhimurium SL1344 variant (SL1344-RS, Sagarzazu et al., 2013), and to quantify the impact that the acquisition of PEF resistance has on other aspects of S. enterica physiology, such as growth fitness, biofilm formation ability, virulence and antibiotic resistance. WGS, RNAseq and qRT-PCR assays indicated that the increased PEF resistance of the SL1344-RS variant is due to a higher RpoS activity caused by a mutation in the hnr gene. This increased RpoS activity also results in higher resistance to multiple stresses (acidic, osmotic, oxidative, ethanol and UV-C, but not to heat and HHP), decreased growth rate in M9-Gluconate (but not in TSB-YE or LB-DPY), increased ability to adhere to Caco-2 cells (but no significant change in invasiveness) and enhanced antibiotic resistance (to six out of eight agents). This study significantly contributes to the understanding of the mechanisms of the development of stress resistance in Salmonellae and underscores the crucial role played by RpoS in this process. Further studies are needed to determine whether this PEF-resistant variant would represent a higher, equal or lower associated hazard than the parental strain

Evaluation of commercial slides for detection of immunoglobulin G against Bartonella henselae by indirect immunofluorescence

Four commercial slides were compared with in-house slides for the detection of immunoglobulin G (IgG) againstBartonella henselae in 58 healthy persons from a rural region by an indirect immunofluorescence assay. MRL-BA slides (MRL Diagnostics, USA) and Virion slides (Virion, Switzerland) with agar-derivedBartonella henselae showed IgG titers of ≥ 1∶256 in 44.8% and 51.7%, respectively, whereas Bion slides (Bios, Germany), MRL-Vero slides (MRL Diagnostics), and in-house slides with cell-associatedBartonella henselae showed such titers in 3.4%, 5.1% and 3.4%, respectively. The MRL-Vero slides (Bartonella IgG substrate slides, MRL Diagnostics) were further evaluated with 26 patients with cat scratch disease, 20 patients with lymphadenopathy not due to cat scratch disease, 100 blood donors from an urban area, and 120 blood donors from a mixed urban/rural area. In our mixed urban/rural population the IgG titer of 1∶256 had a sensitivity of 84.6% and a specificity of 93.4% for the serodiagnosis of cat scratch disease. Seroprevalence was higher in blood donors from the mixed area (50.8%) than from the urban area (37%). MRL-Vero slides were considered useful for the serodiagnosis of cat scratch disease by indirect immunofluorescence and have replaced our in-house system. However, patients with low IgG titers should be retested three to four weeks after initial sampling to demonstrate a possible rise of IgG titers in paired ser

Prevalence of pre-diabetes and undiagnosed diabetes in the Mollerussa prospective observational cohort study in a semi-rural area of Catalonia

Objectives: To assess the prevalence of undiagnosed diabetes and pre-diabetes in the healthy population in the Mollerussa cohort. As a secondary objective, to identify the variables associated with these conditions and to describe the changes in glycaemic status after 1 year of follow-up in subjects with pre-diabetes. Design: Prospective observational cohort study. Setting: General population from a semi-rural area. Participants: The study included 583 participants without a diagnosis of diabetes recruited between March 2011 and July 2014. Results: The prevalence of undiagnosed diabetes was 20, 3.4% (95% CI 2.6 to 4.2) and that of pre-diabetes was 229, 39.3% (37.3 to 41.3). Among those with pre-diabetes, 18.3% had isolated impaired fasting plasma glucose (FPG) (FPG: 100 to <126 mg/dL), 58.1% had isolated impaired glycated haemoglobin (HbA1c) (HbA1c 5.7 to <6.5) and 23.6% fulfilled both criteria. Follow-up data were available for 166 subjects; 41.6%(37.8 to 45.4) returned to normoglycaemia, 57.6% (57.8 to 61.4) persisted in pre-diabetes and 0.6% (0 to 1.2) progressed to diabetes. Individuals with pre-diabetes had worse cardiometabolic risk profiles and sociodemographic features than normoglycaemic subjects. In the logistic regression model, variables significantly associated with pre-diabetes were older age (OR; 95% CI) (1.033; 1.011 to 1.056), higher physical activity (0.546; 0.360 to 0.827), body mass index (1.121; 1.029 to 1.222) and a family history of diabetes (1.543; 1.025 to 2.323). The variables significantly associated with glycaemic normalisation were older age (0.948; 0.916 to 0.982) and body mass index (0.779; 0.651 to 0.931). Conclusions: Among adults in our region, the estimated prevalence of undiagnosed diabetes was 3.4% and that of pre-diabetes was 39.3%. After a 1-year follow-up, a small proportion of subjects (0.6%) with pre-diabetes progressed to diabetes, while a high proportion (41.6%) returned to normoglycaemia. Individuals with pre-diabetes who returned to normoglycaemia were younger and had a lower body mass inde

t(9;14)(q33;q32) IGH/LHX2

Short Communication on t(9;14)(q33;q32) IGH/LHX2, with data on clinics, and the genes implicated