Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

The mineralogical and chemical compositions of Lower Carboniferous (Tournaisian) marine black shale from the Kowala quarry, the Holy Cross Mountains, Poland, were investigated. This study focuses on disturbances in palaeoenvironmental proxies caused by palaeoweathering, which progressively changed the major and trace element abundances. Palaeomagnetic investigations reveal that the Devonian – Carboniferous succession was weathered during the Permian-Triassic by the infiltration of oxidizing fluids related to karstification following post-Variscan exhumation. The weathering process led to vermiculitization of chlorite, partial dissolution of calcite and replacement of pyrite by hematite and goethite. Moreover, the concentrations of some trace metals, including Co, Cu, Pb, Mo, Ni, As and U, significantly decreased. Consequently, some elemental abundance ratios that are used as environmental proxies, including U/Th, Ni/Co and V/Cr, were altered. Elements that are bound to iron sulphides (e.g., Mo) appear to be especially prone to mobilization by even a lightly weathered black shale. The documented weathering, including changes in elemental concentrations, can potentially create misinterpretations of the original palaeoenvironmental conditions. In addition, the palaeoweathering of the studied samples appears to have substantially changed the carbon, oxygen, nitrogen and molybdenum stable isotope values. The nitrogen and molybdenum stable isotope ratios, in particular, appear to be most sensitive to the effects of weathering and therefore are good indicators of (palaeo)weathering processes. The major cause of these changes is the decay of organic matter and pyrite. For the organic carbon stable isotopes ratios, the main factor that controlls this process appears to be the preferential degradation of labile organic matter. A combination of the total organic carbon (TOC), total sulphur (TS) content, Mo concentration and stable isotope compositions seems to be the most useful for identify (palaeo)weathering. Our results suggest that reductions in TS and Mo in tandem with diminished Mo stable isotope values in the absence of obvious changes to the TOC content provide the most compelling evidence of (palaeo)weathering

A Multicenter, Randomized, Open-Labeled, Parallel Group Trial of Sildenafil in Alcohol-Associated Erectile Dysfunction: The Impact on Psychosocial Outcomes

To examine the effect of sildenafil on erectile dysfunction (ED) and psychosocial outcomes in alcohol-dependent (AD) men, 108 men with these diagnoses were randomly assigned to either take sildenafil (50 mg) as add-on to standard treatment for AD, or the same treatment without sildenafil, for 12 weeks. Only 50 patients in sildenafil group and 51 in control group twice completed the International Index of Erectile Function (IIEF) and a battery of self-report questionnaires. IIEF scores and psychosocial functioning, self-esteem and support from friends improved only for sildenafil-treated patients (P < 0.001). The high effect sizes suggest that the observed benefits are unlikely to be a placebo effect, although their unspecific nature could not be ruled out. In men with ED associated with AD, sildenafil improves both ED and psychosocial outcomes. Further placebo-controlled clinical trial is warranted

Gluten-free diet may improve obstructive sleep apnea-related symptoms in children with celiac disease

Abstract Background Enlarged tonsils and adenoids are the major etiology of obstructive sleep apnea (OSA) in children. Lymphatic hyperplasia is common to both OSA and celiac disease. We aimed to investigate the effect of a gluten-free diet on OSA symptoms in children with celiac disease. Methods Children with celiac disease aged 2–18 years were prospectively recruited before the initiation of a gluten-free diet. Children with negative celiac serology who underwent gastrointestinal endoscopies for other indications served as controls. All participants completed a validated OSA-related symptoms questionnaire and the pediatric sleep questionnaire (PSQ) at baseline and 6 months later. Results Thirty-four children with celiac disease (mean age 6.6 ± 3.5 years) and 24 controls (mean age 7.3 ± 4.6 years, P = 0.5) were recruited. There were no significant differences in gender, body mass index or season at recruitment between the two groups. The rate of positive PSQ scores was higher (more OSA-related symptoms) in the control group compared to the celiac group, both at recruitment and at the 6-month follow-up (33.3% vs. 11.8%, P = 0.046, and 16.7% vs. 0, P = 0.014, respectively). PSQ scores improved significantly in both groups at the 6-month follow-up (P < 0.001 for both). Improvement was significantly higher in the celiac group compared to controls (0.1 ± 0.09 vs.0.06 ± 0.06, respectively, P = 0.04). Conclusions Children with celiac disease had fewer OSA-related symptoms than controls, but the degree of improvement following the initiation of a gluten-free diet was significantly higher. These findings suggest that a gluten-free diet may improve OSA-related symptoms in children with celiac disease

Fungal Recognition and Host Defense Mechanisms

We thank the Wellcome Trust Strategic Award, Wellcome Trust and Medical Research Council Centre for Medical Mycology, and the University of Aberdeen for funding.Peer reviewedPostprin