Pion and Sigma Polarizabilities and Radiative Transitions

Fermilab E781 plans measurements of gamma-Sigma and $\gamma$-pion interactions using a 600 GeV beam of Sigmas and pions, and a virtual photon target. Pion polarizabilities and radiative transitions will be measured in this experiment. The former can test a precise prediction of chiral symmetry; the latter for a_1(1260) ----> pi + gamma is important for understanding the polarizability. The experiment also measures polarizabilities and radiative transitions for Sigma hyperons. The polarizabilities can test predictions of baryon chiral perturbation theory. The radiative transitions to the Sigma*(1385) provide a measure of the magnetic moment of the s-quark. Previous experimental and theoretical results for gamma-pi and gamma-Sigma interactions are given. The E781 experiment is described.Comment: 13 pages text (tex), Tel Aviv U. Preprint TAUP 2204-94, uses Springer-Verlag TEX macro package lecproc.cmm (appended at end of tex file, following \byebye), which requires extracting lecproc.cmm and putting this file in your directory in addition to the tex file (mmcd.tex) before tex processing. lecproc.cmm should be used following instructions and guidelines available from Springer-Verlag. Submitted to the Proceedings of Workshop on Chiral Dynamics, Massachusetts Institute of Technology, July 1994, Eds. A. Bernstein, B. Holstein. Replaced Oct. 4 to add TAUP preprint number. Replaced Oct. 12 to correct Pb target thickness from 1.3% interaction to 0.3

Analysis of risk factors for low bone mineral density in inflammatory bowel disease

BACKGROUND/AIM: Several risk factors have been suggested for osteoporosis which frequently occurs in inflammatory bowel disease (IBD) patients. We studied prevalence and risk factors for reduced bone mineral density (BMD) in IBD patients at the University Hospital of Zurich, Switzerland. METHODS: The BMD was determined by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck in 88 IBD patients (55 with Crohn's disease, 30 with ulcerative colitis, and 3 with indeterminate colitis). Z scores were obtained by comparison with age- and sex-matched normal values, and T scores by comparison with sex-matched healthy young adults. Osteopenia and osteoporosis were defined according to the WHO guidelines. Predictive factors for BMD were analyzed by group comparison and stepwise regression analysis. RESULTS: Osteopenia was present in 43% of the patients at the lumbar spine and in 42% of them at the femoral neck. Osteoporosis was present in 14% of the patients at the lumbar spine and in 5% of them at the femoral neck. At the lumbar spine, stepwise regression analysis showed that body mass index, age, number of bowel resections, topic steroids, and azathioprine correlated with the Z scores. Cumulative steroid dose, topic steroids, age and bowel resection were found to be predictors for a pathological T score. At the femoral neck, regression analysis showed that body mass index, age, topic steroids, and azathioprine correlated with the Z scores. Only a low body mass index was a significant predictor for pathological femoral T scores. CONCLUSIONS: Osteopenia and osteoporosis are commonly found in IBD patients. Steroid treatment and bowel resection were significant risk factors for osteoporosis of the lumbar spine. However, disease-inherent factors also appear to confer a major risk, indicating that the BMD should be determined in all IBD patients, irrespective of steroid treatment

Estimating the aquatic emissions and fate of perfluorooctane sulfonate (PFOS) into the river Rhine

The sources, distribution, levels and sinks of perfluorooctane sulfonate (PFOS) estimated to be released from areas of high population density, have been explored using the river Rhine as a case study. A comparison between modelled and measured data is presented, along with analysis of the importance of PFOS sorption in riverine systems. PFOS releases into the Rhine were estimated to be 325-690 kg/yr based on per capita emission rates of 27-57 [small mu ]g day-1 from a population of 33 million living within a 50 km zone either side of the river. Sorption of PFOS to suspended particles and sediments may alter its fate in the aquatic environment. Therefore available measured and modelled partitioning data was assessed, and Kd values (sorption coefficient) of 7.5 and 20 were selected. This resulted in sediment-water ratios of 23-76 : 1, which are similar to ratios reported in the literature, and resulted in modelled estimates tha