Soil and seedling response to dehydrated septic tank sludge versus forest floor additions at a disturbed site

Over a period of 2 yr, the effects of dehydrated septic tank sludge application on the chemical properties of a severely disturbed forest clayey soil were assessed and compared with application of native forest floor (i.e., from neighboring forest). Six treatments [fresh and mature sludges × two depths (15 and 25 cm), forest floor, and a control] were replicated three times according to a complete random design. Total organic C and N concentrations of amendments and their chemical structure, based on 13C nuclear magnetic resonance (NMR) spectroscopy, were determined. Mineral soil C and N concentrations and C mineralization rates were monitored as well as nutrient supply rates using Plant Root Simulator™ probes. White spruce [Picea glauca (Moench) Voss] seedling foliar nutrition and growth were also monitored. NMR spectroscopy revealed differences among amendments, with the forest floor spectra displaying lower O-alkyl C and higher alkyl C and carbonyl C proportions relative to sludge. Neither soil C concentrations nor mineralization were significantly improved in the mineral soil under any treatment, even at application rates exceeding 700 t sludge ha−1 (dry mass). The sludges supplied more NO3 and P, and less NH4 and K to the mineral soil than the forest floor and control. Increased nutrient availability under sludge and forest floor generally resulted in improved foliar nutrition and growth of white spruce seedlings. Despite differences in organic matter quality and mineral N form supplied by sludge and forest floor, sludge application is a valid restoration approach

A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee

Many clinical trials have evaluated the benefit of long-term use of antiplatelet drugs in reducing the risk of clinical thrombotic events. Aspirin and ticlopidine have been shown to be effective, but both have potentially serious adverse effects. Clopidogrel, a new thienopyridine derivative similar to ticlopidine, is an inhibitor of platelet aggregation induced by adenosine diphosphate. METHODS: CAPRIE was a randomised, blinded, international trial designed to assess the relative efficacy of clopidogrel (75 mg once daily) and aspirin (325 mg once daily) in reducing the risk of a composite outcome cluster of ischaemic stroke, myocardial infarction, or vascular death; their relative safety was also assessed. The population studied comprised subgroups of patients with atherosclerotic vascular disease manifested as either recent ischaemic stroke, recent myocardial infarction, or symptomatic peripheral arterial disease. Patients were followed for 1 to 3 years. FINDINGS: 19,185 patients, with more than 6300 in each of the clinical subgroups, were recruited over 3 years, with a mean follow-up of 1.91 years. There were 1960 first events included in the outcome cluster on which an intention-to-treat analysis showed that patients treated with clopidogrel had an annual 5.32% risk of ischaemic stroke, myocardial infarction, or vascular death compared with 5.83% with aspirin. These rates reflect a statistically significant (p = 0.043) relative-risk reduction of 8.7% in favour of clopidogrel (95% Cl 0.3-16.5). Corresponding on-treatment analysis yielded a relative-risk reduction of 9.4%. There were no major differences in terms of safety. Reported adverse experiences in the clopidogrel and aspirin groups judged to be severe included rash (0.26% vs 0.10%), diarrhoea (0.23% vs 0.11%), upper gastrointestinal discomfort (0.97% vs 1.22%), intracranial haemorrhage (0.33% vs 0.47%), and gastrointestinal haemorrhage (0.52% vs 0.72%), respectively. There were ten (0.10%) patients in the clopidogrel group with significant reductions in neutrophils (< 1.2 x 10(9)/L) and 16 (0.17%) in the aspirin group. INTERPRETATION: Long-term administration of clopidogrel to patients with atherosclerotic vascular disease is more effective than aspirin in reducing the combined risk of ischaemic stroke, myocardial infarction, or vascular death. The overall safety profile of clopidogrel is at least as good as that of medium-dose aspirin