17 research outputs found
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
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
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