A field experimental study on recolonization and succession of subtidal macrobenthic community in sediment contaminated with industrial wastes

A field experiment was carried out in Hong Kong to study the patterns of recolonization and succession of subtidal macrobenthos in defaunated sediment contaminated with industrial wastes and to determine the time required for benthic recovery in the industrial-contaminated sediment. A total of 50 species was found with an average of 172 animals/tray and 24 species/tray recorded one month after deployment. Initial colonizers were predominantly polychaetes (96 animals/tray, accounting for 55.7%) and gastropods (47 animals/tray, accounting for 27.2%). Abundance of macrobenthos increased quickly to a peak (505 animals/tray) after four months, declined afterwards, and increased again till the end of the experiment. Species number peaked (57 species/tray) in the same month as abundance did, and gradually declined thereafter. Abundance, species number and diversity were significantly lower in the industrial-contaminated sediment as compared to the controls during the early successional stages, indicating the harmful effects of industrial wastes on recolonization and succession of macrobenthos. Although no significant differences in community parameters between the industrial-contaminated and the control sediments were found after eleven months, significant difference in species composition still existed after fourteen months, showing a relatively long-term impact of industrial wastes on macrobenthic community structure. © 2006 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

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