Radio imaging of core-dominated high redshift quasars

VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum quasars, consistent with these objects being observed at sight lines close to their (relativistic, $\gamma \approx$ 4-7) jet axes. The usefulness of the radio source orientation indicator R_V, being defined as ratio of radio core and rest frame optical V-band luminosity, is confirmed.Comment: 11 pages, 11 postscript figures, uses aa.cls 4.03 for LaTeX2e To appear in Astronomy and Astrophysic

Nematode migration and nutrient diffusion between vetch and barley material in soil

This paper deals with migration of nematodes along nutrient gradients in soil. Portions of barley straw and green vetch leaves were mixed with soil and buried at 6, 12, 18, and 50mm distance from each other in soil. During the following 12 weeks respiration activity, microbial (SIR) biomass, nitrogen limitation of respiration activity in soil slurries all indicated that nitrogen was transferred in the soil from the nutrient rich vetch to the nutrient poor barley at least during the first 3 weeks of the experiment. Twelve out of 39 taxonomic groups of nematodes showed different growth in the two plant material-soil mixtures. Only one of these taxonomic groups (long rhabditid larvae) suggested that migration could have contributed to population development; for three other groups (short rhabditid larvae, Aphelenchoides, and Bursilla) nutrient transport through the soil was the likely mechanism for a distance-dependant population development. We suggest that for most microbivorous nematodes, except larvae of fast growing bacterivores, migration over distances exceeding one centimetre does not contribute markedly to population development even when cues such as nutrient gradients to stimulate the activity exis

The Evidence for Efficacy of Osteoporosis Treatment in Men with Primary Osteoporosis: A Systematic Review and Meta-Analysis of Antiresorptive and Anabolic Treatment in Men

Purpose. Fragility fractures in men constitute a major worldwide public health problem with a life-time risk of 13%. It cannot be directly inferred that antiosteoporotic drugs effective in women have the same effect in men. Our aim was to appraise the existing evidence for efficacy of osteoporosis treatment in men. Methods. This study was a systematic review of the published literature on the clinical efficacy of medical osteoporosis therapy in the reduction of fracture risk in men (age > 50 years). Studies included were randomised, placebo-controlled trials of men. Results. Five BMD studies of antiresorptive treatment were included. All studies showed an increase in BMD, but there was only a nonsignificant trend in the reduction of clinical fractures. Three BMD studies of anabolic treatment with teriparatide were also included. These showed a significant mean increase in spine BMD and for vertebral fractures a non-significant trend towards a reduction was seen. Conclusion. The evidence of medical osteoporosis treatment in men is scant and inconclusive due to the lack of prospective RCT studies with fracture prevention as primary end point. So far, all evidence is based on BMD increases in small RCT studies showing BMD increases comparable to those reported in postmenopausal women

Association of insulin regimens with severe hypoglycaemia in patients with type 1 diabetes:A Danish case–control study

AIMS: To evaluate the risk of severe hypoglycaemia for patients with Type 1 diabetes (T1D) when exposed to insulin regimens including human insulin only or insulin analogues. METHODS: A total of 19 896 patients with T1D were extracted from the Danish National Patient Register. Of these, 6379 T1D patients experiencing 1 of more severe hypoglycaemic episodes (total of 17 242 episodes) were matched 1:1 with T1D patients without severe hypoglycaemia. A logistic regression model with last insulin regimen used as exposure was constructed to analyse the effect on severe hypoglycaemia. RESULTS: People on a basal–bolus regimen with insulin analogues had a reduced risk of severe hypoglycaemia of 39% (odds ratio: 0.61, 95% confidence interval: 0.54–0.68) compared to patients on a basal–bolus human insulin only regimen. Furthermore, patients on a premixed regimen containing an insulin analogue had a 58% (odds ratio: 0.42, 95% confidence interval: 0.36–0.49) reduced risk of severe hypoglycaemia compared to patients on premixed human insulin only. CONCLUSION: This study indicates that use of a basal–bolus insulin regimen with an insulin analogue is safer with respect to severe hypoglycaemia in patients with T1D than the use of a basal–bolus human insulin only regimen

A fractal based model of diffusion MRI in cortical grey matter

Diffusion Weighted Magnetic Resonance (DWMR) Imaging is an important tool in diagnostic neuroimaging, but the biophysical basis of the DWMR signal from biological tissue is not entirely understood. Testable, theoretical models relating the DWMR signal to the tissue, therefore, are crucial. This work presents a toy version of such a model of water DWMR signals in brain grey matter. The model is based on biophysical characteristics and all model parameters are directly interpretable as biophysical properties such as diffusion coefficients and membrane permeability allowing comparison to known values. In the model, a computer generated Diffusion Limited Aggregation (DLA) cluster is used to describe the collected membrane morphology of the cells in cortical grey matter. Using credible values for all model parameters model output is compared to experimental DWMR data from normal human grey matter and it is found that this model does reproduce the observed signal. The model is then used for simulating the effect on the DWMR signal of cellular events known to occur in ischemia. These simulations show that a combination of effects is necessary to reproduce the signal changes observed in ischemic tissue and demonstrate that the model has potential for interpreting DWMR signal origins and tissue changes in ischemia. Further studies are required to validate these results and compare them with other modeling approaches. With such models, it is anticipated that sensitivity and specificity of DWMR in tissues can be improved, leading to better understanding of the origins of MR signals in biological tissues, and improved diagnostic capability