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Artisanal gold mining is recognized as a long-standing activity in the Siguiri prefecture in general and the Doko sub-prefecture in particular. Despite its significant contribution to community development, it has disastrous consequences for both the environment and the lives of gold miners. The collapse of underground galleries as a result of gold panning is a phenomenon that plunges families into mourning in gold panning areas in Africa. Unlike other land movements, despite their dangerous nature, there has been almost no scientific interest in limiting the consequences of collapsing underground galleries in goldmines. Working to mitigate their effects is more than a necessity for those involved in gold panning.This study aims to understand the perceptions of those involved in gold panning regarding the conditions of occurrence and the main causes of underground gallery collapses, to formulate recommendations to the authorities and gold miners to minimize the risk of these accidents occurring and their impact. The methodology used was based on semi-structured and structured interviews. The results of this survey show that the human factor is certainly the main cause of accidents (collapse of underground galleries), but the design of structures without taking into account the study of the geomechanical properties of the ground, the weakness of the safety measures put in place, and the lack of involvement of the country’s authorities are not negligible factors. This study identified the causes and consequences of these accidents, as well as the responsibilities of those involved.

Knowledge of insect dispersal is relevant to the control of agricultural pests, vector-borne transmission of human and veterinary pathogens, and insect biodiversity. Previous studies in a malaria endemic area of the Sahel region in West Africa revealed high-altitude, long-distance migration of insects and various mosquito species. The objective of the current study was to assess whether similar behavior is exhibited by mosquitoes and other insects around the Lake Victoria basin region of Kenya in East Africa. Insects were sampled monthly from dusk to dawn over 1 year using sticky nets suspended on a tethered helium-filled balloon. A total of 17,883 insects were caught on nets tethered at 90, 120, and 160 m above ground level; 818 insects were caught in control nets. Small insects (0.5 cm, n = 2,334) and mosquitoes (n = 299). Seven orders were identified; dipteran was the most common. Barcoding molecular assays of 184 mosquitoes identified 7 genera, with Culex being the most common (65.8%) and Anopheles being the least common (5.4%). The survival rate of mosquitoes, experimentally exposed to high-altitude overnight, was significantly lower than controls maintained in the laboratory (19% vs. 85%). There were no significant differences in mosquito survival and oviposition rate according to capture height. These data suggest that windborne dispersal activity of mosquito vectors of malaria and other diseases occurs on a broad scale in sub-Saharan Africa.

In recent decades, remote sensing has been shown to be useful for crop cover monitoring over smallholder agricultural landscapes, such as agroforestry parklands. However, the fraction of green vegetation cover (FCover) has received little attention. Indeed, the collection of FCover ground data representative of the within-field heterogeneity is time-consuming. Thus, this article aims to bridge this gap by proposing an original methodological framework combining FCover data derived from unmanned aerial vehicle (UAV) and Sentinel-2 (S2) images for estimating millet FCover at the landscape scale in an agroforestry parkland of the groundnut basin of Senegal during the 2021 and 2022 cropping seasons. UAV-based FCover was computed over a 3 m × 3 m grid using a thresholding approach for six dates over the cropping seasons and then used as ground observation for the upscaling of millet FCover at the landscape scale with S2 data. Various spectral vegetation indices and textural features were derived from S2, and several modeling approaches based on machine learning algorithms were benchmarked. Our results showed that the modeling approach using the full-time series in combination with a random forest algorithm was able to explain 73% (root mean square error = 12.13%) of the UAV-FCover variability after validation in 2021 and 2022. In addition, UAV images are suitable for consistent monitoring of millet FCover over heterogeneous agricultural landscapes by training S2 satellite images. To further check its robustness, this approach should be tested for different crops and practices across a variety of agricultural landscapes in sub-Saharan Africa.

The clinical manifestations of neurofibromatosis type-1 have in common the presence of neurofibromas, schwannomas and cafe`-au-lait macules, which can potentially appear within any organ system of the body, involving primarily the skeleton, skin and soft tissues. The spinal thoracic tuberculoma in neurofibromatosis is exceptional. We report here, the case of a 31-year-old male with neurofibromatosis type-1 who presented a year agoa spinal thoracic pain. The evolution was marked by the appearance of a dorsal para-vertebral mass, progressively increasing in volume for 03 months. Neurological Examination revealed normal muscle bulk and tone, and power was grade 5/5. Deep tendon reflexes were brisk and the Babinski sign was present. The sensory deficit was present below the D9 level. The remainder of the examination found a voluminous dorsal para vertebral mass ovoid, renitent, and adhering to the superficial and the deep planes. There were also "café-au-lait" spots disseminated on his body. The imagery showed a formation with respect to D11-D12, isointense on T1 and T2, heterogeneously enhanced after contrast with central necrosis, with a foraminal starting point measuring 85x78x66 mm, with external canal extension. Laminectomy D11-D12 was performed with incomplete excision of the lesion. The histological examination showed casein-follicular vertebral tuberculosis, with secondary abdominal changes. Then the patient was put on anti-bacillary drugs. The evolution was marked two weeks later by the reappearance of the back pain and the back mass. On the 42nd day of treatment, the patient had a febrile consciousness disorder with a GCS of 8, right mydriasis and meningeal stiffness. Paraclinic investigations revealed tuberculosis meningoencephalitis, responsible for an active ventricular hydrocephalus associated with a left temporoparietal extrudal hematoma. An external ventricular shunt was performed as well as a left temporo-parietal extrudal hematoma evacuation. The patient died 7 days later in a poly visceral failure chart.

Invasive insects threaten ecosystem stability, public health, and food security. Documenting newly invasive species and understanding how they reach into new territories, establish populations, and interact with other species remain vitally important. Here, we report on the invasion of the South American leafhopper, Curtara insularis into Africa, where it has established populations in Ghana, encroaching inland at least 350 km off the coast. Importantly, 80% of the specimens collected were intercepted between 160 and 190 m above ground. Further, the fraction of this species among all insects collected was also higher at altitude, demonstrating its propensity to engage in high-altitude windborne dispersal. Its aerial densities at altitude translate into millions of migrants/km over a year, representing massive propagule pressure. Given the predominant south-westerly winds, these sightings suggest an introduction of C. insularis into at least one of the Gulf of Guinea ports. To assess the contribution of windborne dispersal to its spread in a new territory, we examine records of C. insularis range-expansion in the USA. Reported first in 2004 from central Florida, it reached north Florida (Panhandle) by 2008–2011 and subsequently spread across the southeastern and south-central US. Its expansion fits a "diffusion-like" process with 200—300 km long "annual displacement steps"—a pattern consistent with autonomous dispersal rather than vehicular transport. Most "steps" are consistent with common wind trajectories from the nearest documented population, assuming 2—8 hours of wind-assisted flight at altitude. Curtara insularis has been intercepted at US ports and on trucks. Thus, it uses multiple dispersal modalities, yet its rapid overland spread is better explained by its massive propagule pressure linked with its high-altitude windborne dispersal. We propose that high-altitude windborne dispersal is common yet under-appreciated in invasive insect species. [ABSTRACT FROM AUTHOR]

Over the past two decades efforts to control malaria have halved the number of cases globally, yet burdens remain high in much of Africa and the elimination of malaria has not been achieved even in areas where extreme reductions have been sustained, such as South Africa.sup.1,2. Studies seeking to understand the paradoxical persistence of malaria in areas in which surface water is absent for 3-8 months of the year have suggested that some species of Anopheles mosquito use long-distance migration.sup.3. Here we confirm this hypothesis through aerial sampling of mosquitoes at 40-290 m above ground level and provide--to our knowledge--the first evidence of windborne migration of African malaria vectors, and consequently of the pathogens that they transmit. Ten species, including the primary malaria vector Anopheles coluzzii, were identified among 235 anopheline mosquitoes that were captured during 617 nocturnal aerial collections in the Sahel of Mali. Notably, females accounted for more than 80% of all of the mosquitoes that we collected. Of these, 90% had taken a blood meal before their migration, which implies that pathogens are probably transported over long distances by migrating females. The likelihood of capturing Anopheles species increased with altitude (the height of the sampling panel above ground level) and during the wet seasons, but variation between years and localities was minimal. Simulated trajectories of mosquito flights indicated that there would be mean nightly displacements of up to 300 km for 9-h flight durations. Annually, the estimated numbers of mosquitoes at altitude that cross a 100-km line perpendicular to the prevailing wind direction included 81,000 Anopheles gambiae sensu stricto, 6 million A. coluzzii and 44 million Anopheles squamosus. These results provide compelling evidence that millions of malaria vectors that have previously fed on blood frequently migrate over hundreds of kilometres, and thus almost certainly spread malaria over these distances. The successful elimination of malaria may therefore depend on whether the sources of migrant vectors can be identified and controlled. Aerial sampling in the Sahel of Mali reveals large numbers of windborne malaria mosquitoes that had recently fed on blood and could cover hundreds of kilometres in a single night., Author(s): Diana L. Huestis [sup.1] , Adama Dao [sup.2] , Moussa Diallo [sup.2] , Zana L. Sanogo [sup.2] , Djibril Samake [sup.2] , Alpha S. Yaro [sup.2] [sup.3] , Yossi [...]