Assessing platelet function using a novel microtitre platelet aggregation assay

Assessing platelet function using a novel microtitre platelet aggregation assa

Investigating climate change intervention strategies in opencast mining contracting and plant hire companies: a case of mutual construction company group of companies, South Africa

Climate change has come to be understood as a deleterious phenomenon, which threatens business, society and ecological systems, thus making it imperative to understand its impact on human, social and economic activities as well as the impact of these activities on climate change. Against this background, this research sought to determine climate change intervention strategies in the mining supply chain in general, specifically focussing on opencast mining contracting and plant hire companies’ practices. This focus on the mining industry was driven by its importance in South Africa and globally, despite its significant direct and indirect contribution to climatic changes. The mixed-methods multiple case study focused on the climate change management of the Mutual Construction Company Group of Companies (MCCGC), an open cast toll mining firm and equipment supplier. Limited to two sites, Pilanesberg Platinum Mines (PPM) and Tharisa Minerals (Tharisa) Mines, the researcher gathered data through interviews, questionnaires, observations and document review. Data was analysed through deductive content analysis. The research made three major findings: (i) the MCCGC, like its principals PPM and Tharisa, does not have an explicit climate change management strategy. Instead, climate change is managed indirectly through implicit strategies seeking to manage environment, health and safety concerns of the mines, (ii) as a contractor, the MCCGC has had to adopt PPM and Tharisa’s implicit approach to climate change management strategies to meet contractual obligations, instead of an explicit approach and, (iii) the MCCGC and its principals’ commitment to environment, health and safety management, and implicitly climate change management, is not mere rhetoric but is being put into practice. The research concluded that MCCGC’s lack of expressed climate change management intentions and practices exposed the firm to climate change risks, most notably financial risks and reputation risks. Financial risks arise from possible ex post climate change liability. In addition, MCCGC is risking its contract tenures, particularly if the two mines change ownership and the new owners insist on an explicit rather than implied climate change strategy with all its suppliers. Reputational risks arise from the possible failure to attract new clientele and investors who may perceive MCCGC as a risky partner, due to an inept climate change intervention strategyCollege of Agriculture and Environmental SciencesM. Sc. (Environmental Management

Clopidogrel discontinuation and platelet reactivity following coronary stenting.

Aims: Antiplatelet therapy with aspirin and clopidogrel are recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischaemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient \u22rebound\u22 increase in platelet reactivity within three months of clopidogrel discontinuation. Methods and Results: In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and, collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, 20 μM) and epinephrine (5, 20 μM) was significantly increased at 1 month compared to 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. Conclusions: This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations