This paper reports on tests validating a fast voltage stability analysis method, envisaged for operational planning and real-time applications. The simulation method relies on quasi-steady-state approximation, replacing the transient dynamics with equilibrium equations and focusing on the long-term dynamics. Various comparisons have been performed with full time simulation, on the 514-bus Hydro-QuBbec system. The accuracy is equivalent while the new method is up to 3 orders of magnitude faster. Q automatic/manual preventive controls: e.g. optimization of the amount and loc&zation of reactive reserves, secondary voltage control, etc. o automatic/manual emergency controls : e.g. Automatic approximation is likely to yield the high computatio Shunt compensation Switching (ASCS), Load T~~ Changer (LTC) blocking, nndervoltage load shedding, etc. Q voltage security assessment in operational planning and realtime environments.This paper addresses the last aspect. The objective is to develop a truly interactive tool, handling numerous contingencies while taking into account preventive and emergency controls.There are several lines of defence against voltage collapse :On a real-life system. 'named mid-term in [8, 9, 101, with reference to the simulated time interval. However, as discussed in [2] (p.1078), a distinction between mid-and long-term appears less and less justified 96 wM 280-8 PWRS and approved by the IEEE power system Engineering Committee of the IEEE Power Engineering society for presentation at the

Background and Purpose Inflammatory biomarkers predict incident and recurrent cardiac events, but their relationship to stroke prognosis is uncertain. We hypothesized that high-sensitivity C-reactive protein (hsCRP) predicts recurrent ischemic stroke after recent lacunar stroke. Methods Levels of Inflammatory Markers in the Treatment of Stroke (LIMITS) was an international, multicenter, prospective ancillary biomarker study nested within Secondary Prevention of Small Subcortical Strokes (SPS3), a Phase III trial in patients with recent lacunar stroke. Patients were assigned in factorial design to aspirin versus aspirin plus clopidogrel, and higher versus lower blood pressure targets. Patients had blood samples collected at enrollment, and hsCRP measured using nephelometry at a central laboratory. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals (HR, 95%CI) for recurrence risks before and after adjusting for demographics, comorbidities, and statin use. Results Among 1244 lacunar stroke patients (mean 63.3 ± 10.8 years), median hsCRP was 2.16 mg/L. There were 83 recurrent ischemic strokes (including 45 lacunes), and 115 major vascular events (stroke, myocardial infarction, vascular death). Compared with the bottom quartile, those in the top quartile (hsCRP >4.86 mg/L) were at increased risk of recurrent ischemic stroke (unadjusted HR 2.54, 95%CI 1.30–4.96), even after adjusting for demographics and risk factors (adjusted HR 2.32, 95%CI 1.15–4.68). HsCRP predicted increased risk of major vascular events (top quartile adjusted HR 2.04, 95%CI 1.14–3.67). There was no interaction with randomized antiplatelet treatment. Conclusions Among recent lacunar stroke patients, hsCRP levels predict risk of recurrent strokes and other vascular events. HsCRP did not predict response to dual antiplatelets.

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Recent studies undertaken by Hydro-Québec evaluate three aspects of the integration of wind generation on their system reliability/security. In an operations setting, the impacts on intra-hourly operating reserves and on extra-hourly balancing reserves are examined. On an operations planning horizon, the wind power capacity credit is evaluated for winter peak loading conditions, when very cold temperatures risk disabling part of the wind generation. Depending on the study, various mathematical tools were used to generate the statistical characteristics of the load and anticipated wind generation: time-series analysis, wind simulation at new/future wind plant sites, power system simulation and a posteriori determination of forecast errors. However, in each case the measure used to quantify the impact of wind generation has been related to the change in the variance of the total system uncertainty as a result of the addition of wind power generation.