Key considerations in the treatment of complicated staphylococcal infections

AbstractSubstantial increases in antimicrobial resistance among Gram-positive pathogens, particularly Staphylococcus aureus, are compromising traditional therapies for serious bacterial infections. There has been an alarming increase in the rates of methicillin-resistant S. aureus (MRSA) over the past two decades, and the more recent emergence of heterogenous vancomycin-intermediate (hVISA), vancomycin-intermediate (VISA) and vancomycin-resistant S. aureus (VRSA) strains limits the use of vancomycin, the current standard of care for MRSA infections. Tolerance to vancomycin, which represents a lack of bactericidal activity of vancomycin, is another troublesome property of some S. aureus strains that can adversely affect the outcome of antimicrobial therapy. Increasing MICs of vancomycin for staphylococci, poor tissue penetration by the drug and a slow rate of bactericidal action of the drug have also raised concerns about its efficacy in the contemporary treatment of MRSA infections. There is an increasingly apparent need for new agents for the treatment of staphylococcal infections, ideally with potent bactericidal activity against MRSA, hVISA, VISA and VRSA and with superior susceptibility profiles as compared with glycopeptides

Changes in the ultrastructure of the amphids of the potato cyst nematode, Globodera rostochiensis, during development and infection

La structure des amphides de #Globodera rostochiensis$ a été observée aux différents stades de son cycle. Après l'éclosion, la structure des amphides ne change pas. Les amphides des juvéniles de deuxième stade (J2) venant d'éclore, des juvéniles présents dans les racines et des adultes mâles sont identiques et semblables à celles précédemment décrites chez d'autres nématodes phytoparasites. Cependant, chez la plupart des J2 non éclos, cette structure est différente : la cavité réceptrice ne comprote pas de matière sécrétée et la cellule-gaine ne contient aucun des granules sécréteurs présents chez les J2 éclos et les adultes. Le passage d'un état apparemment inactif à celui observé chez les J2 éclos n'est pas directement influencé par une stimulation préalable à l'aide de diffusat de racines de pomme de terre. Il n'existe aucune évidence que le bouchon de prise de nourriture tire son origine des amphides. (Résumé d'auteur

The English are healthier than the Americans: really?

Background: When comparing the health of two populations, it is not enough to compare the prevalence of chronic diseases. The objective of this study is therefore to propose a metric of health based on domains of functioning to determine whether the English are healthier than the Americans. Methods: We analysed representative samples aged 50 to 80 years from the 2008 wave of the Health and Retirement Study (N?=?10?349) for the US data, and wave 4 of the English Longitudinal Study of Ageing (N?=?9405) for English counterpart data. We first calculated the age-standardized disease prevalence of diabetes, hypertension, all heart diseases, stroke, lung disease, cancer and obesity. Second, we developed a metric of health using Rasch analyses and the questions and measured tests common to both surveys addressing domains of human functioning. Finally, we used a linear additive model to test whether the differences in health were due to being English or American. Results: The English have better health than the Americans when population health is assessed only by prevalence of selected chronic health conditions. The English health advantage disappears almost completely, however, when health is assessed with a metric that integrates information about functioning domains. Conclusions: It is possible to construct a metric of health, based on data directly collected from individuals, in which health is operationalized as domains of functioning. Its application has the potential to tackle one of the most intractable problems in international research on health, namely the comparability of health across countries

Accounting for risk of non linear portfolios: a novel Fourier approach

The presence of non linear instruments is responsible for the emergence of non Gaussian features in the price changes distribution of realistic portfolios, even for Normally distributed risk factors. This is especially true for the benchmark Delta Gamma Normal model, which in general exhibits exponentially damped power law tails. We show how the knowledge of the model characteristic function leads to Fourier representations for two standard risk measures, the Value at Risk and the Expected Shortfall, and for their sensitivities with respect to the model parameters. We detail the numerical implementation of our formulae and we emphasizes the reliability and efficiency of our results in comparison with Monte Carlo simulation.Comment: 10 pages, 12 figures. Final version accepted for publication on Eur. Phys. J.

Observable Neutron-Antineutron Oscillations in Seesaw Models of Neutrino Mass

We show that in a large class of supersymmetric models with spontaneously broken B-L symmetry, neutron--antineutron oscillations occur at an observable level even though the scale of B-L breaking is very high, v_{B-L} ~ 2 x 10^{16} GeV, as suggested by gauge coupling unification and neutrino masses. We illustrate this phenomenon in the context of a recently proposed class of seesaw models that solves the strong CP problem and the SUSY phase problem using parity symmetry. We obtain an upper limit on N-\bar{N} oscillation time in these models, \tau_{N-\bar{N}} < 10^{9} -10^{10} sec. This suggests that a modest improvement in the current limit on \tau_{N-\bar{N}} of 0.86 x 10^8 sec will either lead to the discovery of N-\bar{N} oscillations, or will considerably restrict the allowed parameter space of an interesting class of neutrino mass models.Comment: 11 pages RevTeX, 1 figur

Parity violating pion electroproduction off the nucleon

Parity violating (PV) contributions due to interference between $\gamma$ and $Z^0$ exchange are calculated for pion electroproduction off the nucleon. A phenomenological model with effective Lagrangians is used to determine the resulting asymmetry for the energy region between threshold and $\Delta(1232)$ resonance. The $\Delta$ resonance is treated as a Rarita-Schwinger field with phenomenological $N \Delta$ transition currents. The background contributions are given by the usual Born terms using the pseudovector $\pi N$ Lagrangian. Numerical results for the asymmetry are presented.Comment: 17 pages, RevTeX, 6 figures (in separate file figs.uu), uses epsf, accepted for publication in Z. Phys.

Plasma Magnetosphere Formation Around Oscillating Magnetized Neutron Stars

The notion of death line of rotating pulsars is applied to model of oscillating neutron stars. It is shown that the magnetosphere of typical non-rotating oscillating stars may not contain secondary plasma to support the generation of radio emission in the region of open field lines of plasma magnetosphere.Comment: Accepted for publication in Astrophysics & Space Scienc

A Honeycomb Proportional Counter for Photon Multiplicity Measurement in the ALICE Experiment

A honeycomb detector consisting of a matrix of 96 closely packed hexagonal cells, each working as a proportional counter with a wire readout, was fabricated and tested at the CERN PS. The cell depth and the radial dimensions of the cell were small, in the range of 5-10 mm. The appropriate cell design was arrived at using GARFIELD simulations. Two geometries are described illustrating the effect of field shaping. The charged particle detection efficiency and the preshower characteristics have been studied using pion and electron beams. Average charged particle detection efficiency was found to be 98%, which is almost uniform within the cell volume and also within the array. The preshower data show that the transverse size of the shower is in close agreement with the results of simulations for a range of energies and converter thicknesses.Comment: To be published in NIM