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A review of wind power generation steady-state reactive power support requirements and improvement strategies
Ncwane, Siyanda; Bansal, Ramesh C. (Elsevier, 2026-05)
The penetration of wind power generation (WPG) facilities into power systems continues to increase globally. Wind power generation facilities have become increasingly important in providing reactive power support to help regulate power system voltage. To ensure that WPG facilities can provide adequate support, grid codes have been developed with specific requirements that must be met before they can reach commercial operation. However, WPG facilities are sometimes unable to meet the required reactive power support levels. Controller based solutions are commonly used to improve the reactive power capability of WPG facilities. This paper reviews recent developments in control strategies. Their response speed, benefits, and limitations are discussed to identify gaps and to propose future improvements. Current control strategies are not implemented using hybrid control structures, and mostly rely on classical and metaheuristic optimization algorithms. These control strategies can be slow, and sometimes increase the operation of the WPG facility's grid integration transformer on-load tap changer. Machine learning based hybrid control strategies have the potential to improve performance and enable WPG facilities to efficiently provide reactive power support. HIGHLIGHTS • Wind power generation reactive power control grid code requirements are reviewed. • Wind power generation reactive power control strategies are discussed. • Reactive power control strategies are classified into three control structures. • Machine learning based hybrid control strategies are proposed to control reactive power production.
A review of rabies in Southern African wildlife : reservoir hosts, transmission dynamics, and control implications
Eze, Ukamaka Uchenna; Sabeta, Claude Taurai (Eldaghayes Publisher, 2026-01)
Rabies is a fatal zoonotic disease that affects warm-blooded vertebrates and is caused primarily by members of the Lyssavirus genus (family Rhabdoviridae, order Mononegavirales). Three Lyssavirus species, namely Lyssavirus duvenhage and the putative lyssaviruses Lyssavirus matlo and Lyssavirus phyla, were first identified in insectivorous bat species in South Africa through lyssavirus surveillance activities. For the proposed and effective global elimination of dog-mediated human rabies by 2030; it is important to contextualize the pivotal role of wildlife in the maintenance and the likely spillover of rabies virus infections into naive dog populations that could potentially derail the progress toward rabies elimination. This review on rabies in wildlife identifies the current reservoir host species for sylvatic rabies, species predominantly affected by rabies (and non-rabies lyssaviruses) in southern African wildlife, and rabies transmission dynamics between these species. Canid rabies is maintained in a variety of southern African wildlife carnivores, including the black-backed jackal species (Canis mesomelas), side-striped jackals (Canis adustus), bat-eared foxes (Otocyon megalotis), and most recently, aardwolves (Proteles cristatus). In addition, the yellow mongooses (Cynictis penicillata) and slender mongooses (Galerella sanguinea) are reservoirs of the mongoose rabies virus (RABV) biotype (in South Africa and Zimbabwe, respectively). In Namibia, rabies virus infection is associated with wild ruminants, especially the kudu antelope (Tragelaphus strepsiceros), thereby posing a conservation threat to specific wildlife species. Oral rabies vaccination of wild carnivores using baited vaccines has been used as a complementary approach to mass dog vaccinations to mitigate infection spillover into domestic host species.
Fish loss and waste across value chains in low- and lower middle-income countries : a review
Ngwenyama, Patrick; Ward, Ansen Ronald; Peñarubia, Omar Riego; Peter, Soni Maria Jacob; Emmambux, Mohammad Naushad; Bottema, Mariska; Frankfort, Abigail; Parmar, Aditya (IOP Publishing, 2026-02-12)
Estimation and reduction of fish loss and waste (FLW) is essential for improving the contribution of fisheries and aquaculture to the achievement of national development objectives related to food security, income, employment, livelihoods and trade. Despite various FLW estimation and evaluation of interventions for loss reduction, a lack of consolidated data to support evidence-based investments and policy choices at national level still exist. The study aimed to evaluate FLW in low- and lower middle-income countries, identify gaps in assessment and examine causes and mitigation measures. A systematic review was performed using predefined criteria, and extracted quantitative data from eligible studies were used to calculate the average fish weight loss and the corresponding financial losses. The literature search was conducted without date restrictions. After applying the inclusion criteria and removing duplicates, 48 articles published between 1996–2024 were retained from an initial 247 for detailed analysis. Results indicate variation in estimated fish weight losses across various value chain stages. While small-scale FLW studies are more prevalent in Africa than in Asia or Latin America, data remains limited especially for distribution, marketing and consumption stages. In Africa, the greatest fish losses occur during processing (15%) and marketing (14.5%), while Asia fish loss is most pronounced during capture and distribution stages (12.6% and 10%, respectively). In Latin America, processing accounts for the largest share of losses (13%). Fish waste at the consumption stage is minimal (1.5%). Research focuses on small pelagic fish species, with most studies estimating physical losses. Assessment of quality, nutritional and financial losses are limited, and few studies incorporate gender disaggregated and responsive data. A multidimensional intervention approach is recommended to sustainably reduce losses, thereby ensuring food and nutrition security, while contributing to economic development.
A systematic review and meta-analysis of mosquito arboviral infections detected through xenosurveillance in Africa : a focus on West Nile, Rift Valley fever, and chikungunya virus infections
Mgongoma, Mxolisi; Bastos, Armanda D.S.; Ramoelo, Abel; Tchouassi, David Poumo (Elsevier, 2026)
This systematic review and meta-analysis comprehensively evaluated the mosquito arboviral infections with West Nile virus (WNV), Rift Valley fever virus (RVFV), and chikungunya virus (CHIV), detected through xenosurveillance, reported in mosquito vectors across Africa in the last 25 years (2000–2024). The study analysed xenosurveillance data from 45 studies conducted with over 115,000 mosquito specimens, and incorporated moderator analyses to assess the influence of trap type, seasonality, regional location, settlement type, and screening methods on virus detection rates. The estimated pooled prevalence of WNV was 1.18% (95% CI: 0.60–3.43%), with higher rates observed in Culex quinquefasciatus and Culex pipiens, particularly in Northern Africa. RVFV prevalence was 2.00% (95% CI: 0.96–4.52%), with notable detections in Cx. tritaeniorhynchus and Aedes mcintoshi in Eastern Africa. Pooled prevalence was highest for CHIV (8.00%, 95% CI: 2.92–22.25%), primarily in Ae. aegypti and Ae. albopictus in Central and Eastern Africa. In meta-regression analysis, qRT-PCR and indirect immunofluorescence were identified as screening methods associated with higher WNV detection, while wet season sampling and CDC light traps were linked to elevated RVFV prevalence. There was substantial heterogeneity (I2 > 97%) in regional and methodological approaches. The disparities underscore the need for standardised xenosurveillance protocols, region-specific strategies, and enhanced diagnostics to mitigate arboviral risks in Africa. Limitations included sparse CHIV data and underrepresentation of studies from Southern and Central Africa, emphasising the need for expanded longitudinal and geographically inclusive research. HIGHLIGHTS • Pooled WNV prevalence was 1.18%, with higher values for Cx. quinquefasciatus and Cx. pipiens in Northern Africa. • Pooled RVFV prevalence was 2.00%, primarily in Cx. tritaeniorhynchus and Ae. mcintoshi in Eastern Africa. • CHIV showed the highest pooled prevalence, mainly in Ae. aegypti and Ae. albopictus in Central and Eastern Africa. • qRT-PCR and indirect immunofluorescence were screening methods associated with higher WNV detection in mosquitoes. • Wet season sampling using CDC light traps was associated with elevated RVFV prevalence.
Detection of novel orthobunyavirus reassortants in fatal neurologic case in horse and culicoides biting midges, South Africa
Rakaki, Matshepo E.; Van der Walt, Miné; Williams, June Heather; Venter, Marietjie (Centers for Disease Control and Prevention, 2025-07)
We detected Shuni virus in horses and ovine fetuses and Shamonda virus in a caprine fetus in South Africa. We identified a Shuni/Shamonda virus reassortant in a horse and Shuni/Caimito, Shamonda/Caimito, and Shamonda/Sango virus reassortants in Culicoides midges. Continued genomic surveillance will be needed to detect orthobunyavirus infections in Africa.