Extremal statistics of curved growing interfaces in 1+1 dimensions

We study the joint probability distribution function (pdf) of the maximum M of the height and its position X_M of a curved growing interface belonging to the universality class described by the Kardar-Parisi-Zhang equation in 1+1 dimensions. We obtain exact results for the closely related problem of p non-intersecting Brownian bridges where we compute the joint pdf P_p(M,\tau_M) where \tau_M is there the time at which the maximal height M is reached. Our analytical results, in the limit p \to \infty, become exact for the interface problem in the growth regime. We show that our results, for moderate values of p \sim 10 describe accurately our numerical data of a prototype of these systems, the polynuclear growth model in droplet geometry. We also discuss applications of our results to the ground state configuration of the directed polymer in a random potential with one fixed endpoint.Comment: 6 pages, 4 figures. Published version, to appear in Europhysics Letters. New results added for non-intersecting excursion

Virulence and antimicrobial resistance genes in human MRSA ST398 isolates in Austria

This study determined the genetic background of virulence and resistance genes of MRSA ST398 in Austria. From 2004 up to 2008 a total of 41 human isolates of MRSA ST398 were investigated for virulence and resistance gene patterns using DNA microarray chip analysis. Highly similar virulence gene profiles were found in 29 (70·7%) of the isolates but genes encoding Panton-Valentine leukocidin, enterotoxins, or toxic shock syndrome toxin were not detected. Genes conferring resistance to tetracycline and erythromycin-lincosamide were common as all but one of the isolates exhibited tetM and/or tetK, which are involved in tetracycline resistance, and 12 (29·9%) were positive for ermC, conferring resistance to erythromycin/lincosamide. SplitsTree analysis showed that 40 isolates were closely related. Changes in virulence and resistance gene patterns were minimal over the observed time perio

Nonintersecting Brownian motions on the half-line and discrete Gaussian orthogonal polynomials

We study the distribution of the maximal height of the outermost path in the model of $N$ nonintersecting Brownian motions on the half-line as $N\to \infty$, showing that it converges in the proper scaling to the Tracy-Widom distribution for the largest eigenvalue of the Gaussian orthogonal ensemble. This is as expected from the viewpoint that the maximal height of the outermost path converges to the maximum of the $\textrm{Airy}_2$ process minus a parabola. Our proof is based on Riemann-Hilbert analysis of a system of discrete orthogonal polynomials with a Gaussian weight in the double scaling limit as this system approaches saturation. We consequently compute the asymptotics of the free energy and the reproducing kernel of the corresponding discrete orthogonal polynomial ensemble in the critical scaling in which the density of particles approaches saturation. Both of these results can be viewed as dual to the case in which the mean density of eigenvalues in a random matrix model is vanishing at one point.Comment: 39 pages, 4 figures; The title has been changed from "The limiting distribution of the maximal height of nonintersecting Brownian excursions and discrete Gaussian orthogonal polynomials." This is a reflection of the fact that the analysis has been adapted to include nonintersecting Brownian motions with either reflecting of absorbing boundaries at zero. To appear in J. Stat. Phy

Osteoarticular Infections in Pediatric Hospitals in Europe: A Prospective Cohort Study From the EUCLIDS Consortium

BACKGROUND: Pediatric osteoarticular infections (POAIs) are serious diseases requiring early diagnosis and treatment. METHODS: In this prospective multicenter cohort study, children with POAIs were selected from the European Union Childhood Life-threatening Infectious Diseases Study (EUCLIDS) database to analyze their demographic, clinical, and microbiological data. RESULTS: A cohort of 380 patients with POAIs, 203 with osteomyelitis (OM), 158 with septic arthritis (SA), and 19 with both OM and SA, was analyzed. Thirty-five patients were admitted to the Pediatric Intensive Care Unit; out of these, six suffered from shock, one needed an amputation of the right foot and of four left toes, and two had skin transplantation. According to the Pediatric Overall Performance Score, 36 (10.5%) showed a mild overall disability, 3 (0.8%) a moderate, and 1 (0.2%) a severe overall disability at discharge. A causative organism was detected in 65% (247/380) of patients. Staphylococcus aureus (S. aureus) was identified in 57.1% (141/247) of microbiological confirmed cases, including 1 (0.7%) methicillin-resistant S. aureus (MRSA) and 6 (4.2%) Panton-Valentine leukocidin (PVL)-producing S. aureus, followed by Group A Streptococcus (18.2%) and Kingella kingae (8.9%). K. kingae and PVL production in S. aureus were less frequently reported than expected from the literature. CONCLUSION: POAIs are associated with a substantial morbidity in European children, with S. aureus being the major detected pathogen. In one-third of patients, no causative organism is identified. Our observations show an urgent need for the development of a vaccine against S. aureus and for the development of new microbiologic diagnostic guidelines for POAIs in European pediatric hospitals

Performance of the FilmArray Blood culture identification panel in positive blood culture bottles and cerebrospinal fluid for the diagnosis of sepsis and meningitis

Sepsis and meningitis are life threatening medical conditions. Culture-based methods are used for identification of the causative pathogens, but they can be improved by implementation of additional test systems. We evaluated the performance of the novel FilmArray blood culture identification (BCID; Biofire Diagnostics) panel for rapid and accurate identification of microorganisms in positive blood cultures and additionally, in this cerebrospinal fluid (CSF) pilot study for direct testing of CSF. A total of 107 positive blood cultures and 20 CSF samples (positive and negative) were investigated and compared to the routine procedures. Of the 107 positive blood cultures, 90.7% (97/107) showed monomicrobial growth and 9.3% (10/107) polymicrobial growth. The FilmArray BCID panel covered 89.3% (25/28) of the bacteria and 100% (2/2) of the yeasts found in this study and accurately identified all of them.From the 20 retrospective analyzed CSF, in 9 positive specimens 6 different bacterial species were identified. Discrepant identification results were found in 25% (5/20) and a low sensitivity of 50% (95% CI of 15.7% to 84.3%) was detected.Our study confirms the FilmArray BCID panel as a rapid, easy to handle PCR system with a good performance in positive blood cultures without Gram-staining result. However, our results additionally suggest that the system is not useful for direct CSF testing due to poor sensitivity

Bacterial translocation in short-bowel syndrome in rats

Massive intestinal resection results in short bowel syndrome (SBS) and Is associated with an increased risk of infectious complications mainly caused by the egress of intestinal bacteria to distant organs, a process termed bacterial translocation CBT). The purpose of this experimental study in rats was to investigate in different models of SBS the impact of the type of intestinal resection on bacterial growth in the residual small bowel and on the occurrence of BT