Measuring the cosmic ray acceleration efficiency of a supernova remnant

Cosmic rays are the most energetic particles arriving at earth. Although most of them are thought to be accelerated by supernova remnants, the details of the acceleration process and its efficiency are not well determined. Here we show that the pressure induced by cosmic rays exceeds the thermal pressure behind the northeast shock of the supernova remnant RCW 86, where the X-ray emission is dominated by synchrotron radiation from ultra-relativistic electrons. We determined the cosmic-ray content from the thermal Doppler broadening measured with optical spectroscopy, combined with a proper-motion study in X- rays. The measured post-shock proton temperature in combination with the shock velocity does not agree with standard shock heating, implying that >50% of the post-shock pressure is produced by cosmic rays.Comment: Published in Science express, 10 pages, 5 figures and 2 table

HPV type concordance in sexual couples determines the effect of condoms on regression of flat penile lesions

We earlier demonstrated, in a randomised clinical trial, that the regression time of flat penile lsions in male sexual partners of women with cervical intraepithelial neoplasia (CIN) was shorter in men who used condoms compared to those who did not. To further evaluate this finding, we examined whether the effect of condom use on the regression of flat penile lesions depends on the presence of human papillomavirus (HPV) type concordance in sexual couples, as determined in cervical and penile scrapes by GP5+/6+ PCR testing. A Cox model with time-dependent covariates showed a beneficial effect of condoms on regression of flat penile lesions in concordant couples (hazard ratio 2.63, 95% CI 1.07–6.48) but not in those who were nonconcordant. When both partners harboured different HPV types, no effect of condoms was found (hazard ratio 0.90, 95% CI 0.27–2.96). Delayed regression of flat penile lesions was associated with either stable lesions or with new penile lesions developing at sites surrounding pre-existing lesions suggesting reinfection of the penile epithelium. We conclude that condom use blocks sexual HPV transmission by preventing reinfection and development of new penile lesions in men who are susceptible to the same type as present in the female partner

Are Atypical Nevi a Risk Factor for Uveal Melanoma? A Case-Control Study

Atypical nevi and other potential risk factors for uveal melanoma were studied in 109 uveal melanoma patients and 149 controls. Information concerning employment, medical history, drug use, family history of cancer, excess sun exposure, and blistering sunburn before and after the age of 15 was obtained. A total skin examination was performed and skin type, hair color, eye color, freckles, actinic damage, the total number of common acquired nevi, and the number of clinically atypical nevi were noted.More atypical nevi were found in uveal melanoma patients than in controls (age- and sex-adjusted odds ratio of 2.9 [95% confidence interval 1.2-6.3] for one or two atypical nevi versus none; odds ratio of 5.1 [95% CI 1.3 -20.0] for three or more atypical nevi versus none). Light skin types and freckling also prevailed in uveal melanoma cases.In our study, atypical nevi are more common in uveal melanoma patients than in controls. Further studies will have to indicate whether risk factors comparable to those for cutaneous melanoma really exist for uveal melanoma