Quantum Vacuum Experiments Using High Intensity Lasers

The quantum vacuum constitutes a fascinating medium of study, in particular since near-future laser facilities will be able to probe the nonlinear nature of this vacuum. There has been a large number of proposed tests of the low-energy, high intensity regime of quantum electrodynamics (QED) where the nonlinear aspects of the electromagnetic vacuum comes into play, and we will here give a short description of some of these. Such studies can shed light, not only on the validity of QED, but also on certain aspects of nonperturbative effects, and thus also give insights for quantum field theories in general.Comment: 9 pages, 8 figur

Vancomycin Sensitivity of Staphylococcus aureus isolates from hospital patients

Methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA), resistant to all antibiotics including Vancomycin, has been reported in Japan, USA, Canada and Brazil. Hence, the main objective of this study was to evaluate the possible presence of Vancomycin resistant or intermediate S.aureus in Karachi. A total of 850 clinical isolates were collected from two civil hospitals in the city between February 2006 and January 2007. They were identified using standard bacteriological methods. Sensitivity to recommended antibiotics was determined by disc diffusion, agar dilution, and E-test quantitative minimum inhibitory concentration (MIC). Susceptibility to natural or semi-natural products was determined by the agar dilution method. Out of 850 isolates, 250 were MRSA, of which 22% were resistant to 4 μg/ml Vancomycin, 24% to 8 μg/ml, 15.2% to 16 μg/ml, 10% to 20 μg/ml, and 13.2% to 30 μg/ml; the remaining 15.6% were sensitive to all used concentrations. Although we did not detect any Vancomycin-resistant S. aureus (VRSA), we found that 13% of the strains were intermediates (VISA), i.e. resistant to 30 μg/ml of Vancomycin. Because of the continuously increasing prevalence of VISA, it is imperative to minimize the use of Vancomycin. Indeed, the drug should only be prescribed for the treatment of documented, culture-proven infections with MRSA that are not susceptible to routine or alternative agents. This should help avoid the consequences of the development of Vancomycin resistant S. aureus (VRSA) in our environment

Comparison of manual and automated digital image analysis systems for quantification of cellular protein expression

Objective. Quantifying protein expression in immunohistochemically stained histological slides is an important tool for oncologic research. The use of computer-aided evaluation of IHC-stained slides significantly contributes to objectify measurements. Manual digital image analysis (mDIA) requires a userdependent annotation of the region of interest (ROI). Others have built-in machine learning algorithms with automated digital image analysis (aDIA) and can detect the ROIs automatically. We aimed to investigate the agreement between the results obtained by aDIA and those derived from mDIA systems. Methods. We quantified chromogenic intensity (CI) and calculated the positive index (PI) in cohorts of tissue microarrays (TMA) using mDIA and aDIA. To consider the different distributions of staining within cellular subcompartments and different tumor architecture our study encompassed nuclear and cytoplasmatic stainings in adenocarcinomas and squamous cell carcinomas. Results. Within all cohorts, we were able to show a high correlation between mDIA and aDIA for the CI (p<0.001) along with high agreement for the PI. Moreover, we were able to show that the cell detections of the programs were comparable as well and both proved to be reliable when compared to manual counting. Conclusion. mDIA and aDIA show a high correlation in acquired IHC data. Both proved to be suitable to stratify patients for evaluation with clinical data. As both produce the same level of information, aDIA might be preferable as it is time-saving, can easily be reproduced, and enables regular and efficient output in large studies in a reasonable time period

Perpetration of violence by female sex workers in Papua New Guinea: 'we will crush their bones'

There is a small but important body of literature on female sex workers' (FSWs) violence towards others, but little of that focused on low- and middle-income countries. Drawn from a larger biobehavioural study of FSWs in three cities in Papua New Guinea, we analyse the interviews from 19 FSWs who reported having perpetrated physical violence towards four major groups: (1) ex-husbands; (2) clients; (3) other sex workers and (4) other people (mainly women). Our study demonstrates that FSWs' use of violence arises from a complex set of social, material and gendered circumstances and cannot be addressed in isolation from other aspects of their lives