This paper presents a response-based backup System Integrity Protection Scheme (SIPS) designed to enhance grid resilience in power systems with embedded high-voltage direct current (HVDC) transmission systems. This response-based SIPS is envisioned to function as backup to the existing primary event-based SIPS, which relies on unsynchronized measurements. The proposed approach addresses the challenge of detecting critical contingencies, such as forced outages of HVDC links, in the event of a failure of the primary event-based SIPS. The proposed triggering logic leverages synchrophasor data obtained during the contingency scenarios and is tailored to the communication latencies of the system under study. Simulation-based analyses validate a strategy designed to determine the appropriate magnitude of remedial actions, illustrating the effectiveness of the designed scheme.
Weeds are the main challenge in onion production, usually controlled with chemicals in conventional systems. Alternatively, the cover crops used in the no-tillage vegetable system (NTVS) reduce these uses through their physical barrier and possible biological interactions, including associations with arbuscular mycorrhizal fungi (AMF). We evaluated how mycotrophic and non-mycotrophic cover crops affect weed diversity in a long-term (13-year-old) no-tillage vegetable system. The treatments were black-oats, oilseed-radish, alone or intercropped, and fallow before onion. We quantified cover crops dry mass, identified weeds, calculated richness and abundance, and classified them into mycotrophic or non-mycotrophic. The treatments with cover crops produced more dry mass than the fallow. We identified 20 weeds from 14 families; two dominant species had the highest dry mass. Cover crops affected weed total dry mass, abundance, and diversity (H′). Weed diversity decreased over the years in no-tillage vegetable systems and tended to stabilize in the long-term. Cover crop mycotrophy (black-oats) did not affect plant dominance, 75% of the weeds were mycotrophic. Non-mycotrophic weeds were only found with the non-mycotrophic, oilseed-radish, as a cover crop. Onion yield in long-term no-tillage onion system did not differ regardless of the winter cover crop.
This paper presents an approach for mapping operation conditions to required levels of generation rejection, with the aim of parameterizing the arming function of the Special Integrity Protection Scheme (SIPS) of the Brazilian North-Southeast High Voltage Direct Current (HVDC) bipoles. The purpose of the SIPS is to ensure the transient stability of the Brazilian Interconnected Power System (BIPS) after contingencies in the Brazilian North-Southeast HVDC bipoles. The proposed approach relies on a boundary search algorithm to characterize security hyperplanes of operation conditions for selected levels of generation rejection. Case studies with data provided by the Brazilian System Operator (BSO) have been used to validate the effectiveness and applicability of the proposed approach.
Synchronized phasor measurements have emerged as a crucial element in the design of modern System Integrity Protection Schemes (SIPSs). However, the design of these schemes often overlooks the intrinsic measurement inaccuracies introduced by the complete instrumentation channels (ICs), specifically the inaccuracies originating from voltage and current transformers, control cables, equipment burden, and the synchrophasor estimation process. This paper proposes an optimization-based approach to determine the lower and upper bounds for active power calculated using synchronized voltage and current measurements, supporting consistent parameterization of synchrophasor-based protection strategies. Numerical results are generated using synthetic data parameterized by the IC characteristics of a pilot Wide-Area Monitoring, Protection, and Control (WAMPAC) design in Brazil, providing quantitative guidance for establishing reliable SIPS arming parametrization.
The utility of antiepileptic drugs (AEDs) for seizure prophylaxis following nontraumatic intracerebral hemorrhage (ICH) remains uncertain, with guidelines based on low-quality evidence that often pools heterogeneous medications. We conducted a network meta-analysis (NMA) to evaluate the utility of AEDs and to compare the efficacy and safety of individual agents in this setting. A comprehensive systematic search of PubMed, Embase, Cochrane Library, and Web of Science up to 22 October 2025 was conducted. We included studies involving adults with nontraumatic ICH that compared individual prophylactic AEDs against each other or a control group. We employed a Bayesian random-effects NMA to synthesize the data. Primary outcomes were early seizure incidence and unfavorable functional outcome. Secondary outcomes included adverse events, serious adverse events, NIHSS score at last follow-up, and mortality. Risk of bias was assessed using Cochrane Risk of Bias 2 (RoB 2) and Risk Of Bias In Non-randomized Studies—of Interventions, Version 2 (ROBINS-I V2) tools, and the certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Out of 2142 identified citations, 17 studies (4 RCTs, 13 observational; N = 6597 patients) met the inclusion criteria. No AED significantly reduced early seizures or improved functional outcomes compared with placebo. However, ranking probabilities (surface under the cumulative ranking curve, SUCRA) suggested valproate was most likely to prevent early seizures (SUCRA = 0.8330) and improve functional outcomes (SUCRA = 0.7938). Valproate also ranked highest for overall safety (SUCRA = 0.8085) and NIHSS improvement (SUCRA = 0.8187), while levetiracetam ranked best for serious adverse events (SUCRA = 0.7935). Eslicarbazepine was associated with increased mortality, whereas valproate showed the most favorable ranking for this outcome (SUCRA = 0.7705). The certainty of evidence across comparisons ranged from low to very low. This NMA found no robust evidence to support the routine prophylactic use of AEDs after nontraumatic ICH. Nonetheless, valproate consistently demonstrated the best efficacy and relative safety profiles. This finding warrants investigation in future RCTs, particularly in subgroups of patients at high risk for post-ICH seizures.
