.
Background Newcastle disease (ND) is one of the most important viral diseases reducing poultry production throughout Africa. This is one of the reasons why this disease is subject to a large-scale annual vaccination program. In Burkina Faso, over the past decade, there has been an increase in unconfirmed cases of ND. Our study aimed to identify ND virus (NDV) circulation in traditional livestock farms in Burkina Faso. Results one hundred and ninety-five (195) poultry were sampled in 42 farms from four regions of Burkina Faso in 2022. NDV seroconversion was assessed using the ID Screen® Newcastle Disease Indirect kit. Birds from each farm were swabbed (nasopharyngeal and cloacal) to detect the presence of the virus, for a total of 102 swab pools. RNA extracted from the swab samples was tested by RT-qPCR using the OneStep RT-PCR Kit (Qiagen, Hilden). Antibodies to Newcastle disease virus were detected in 70.77 ± 6.38% (138/195) of the poultry tested (i.e. chicken, Guinea fowl, ducks, quails and turkey) and 100% of villages were positive for Newcastle disease antibodies. 23.81% of samples were RT-PCR positive. The seroconversion rate shows the presence of antibodies indicate exposure to NDV or NDV vaccine with a significantly higher in vaccinated poultry than in unvaccinated poultry (p = 0,0006). All study regions demonstrated virus circulation and poly-specific farms showed significantly less virus presence than mono-specific farms (p = 0,004). Conclusions the present study provides important information on anti-NDV antibody titers and the circulation of this avian virus in Burkina Faso. It also emphasizes the importance of maintaining vaccination programs and surveillance of avian diseases in Burkina Faso.
Abstract. This study evaluates the performance of the NeQuick-2 model in simulating foE and capturing its variability under geomagnetically quiet conditions at Ouagadougou (latitude 12.4° N; longitude 358.5° E; magnetic dip 1.45° N), considering diurnal, seasonal, and solar-activity effects. The Ouagadougou station falls within the trough belt of the equatorial ionization anomaly region in West Africa. The analysis was carried out during the solar minimum and solar maximum phases of Solar Cycles 21 and 22. Comparisons between NeQuick-2 predictions and ionosonde observations show that the model successfully reproduces the overall diurnal morphology of foE across all seasons and solar activity phases. However, systematic discrepancies are observed mainly at sunrise (transition between nighttime and daytime) and sunset (transition between daytime and nighttime) periods (06:00 LT and 18:00–19:00 LT), as well as during the equinoctial seasons, when the model frequently underestimates the observed values, particularly around the daytime maximum. These limitations are more pronounced during periods of low solar activity. Statistical analysis based on the root mean square error (RMSE) and the coefficient of determination (R²) reveals a significant improvement in the performance of NeQuick-2 during the solar maximum phases of both solar cycles. The best agreement between model predictions and observations is generally obtained during winter and summer, whereas the poorest performance occurs during spring and autumn. This agreement is particularly evident during Solar Cycle 22, for which the coefficients of determination exceed 0.9 for all seasons during the solar maximum phase. These results show that NeQuick-2 performance depends strongly on both season and solar activity level. They confirm the model's robustness in representing the ionospheric E-layer under high solar activity while highlighting persistent limitations in reproducing equinoctial conditions and sunset conditions over the African equatorial region.
De quelques natures ou degrés qu’elle soit, la problématique de la violence ne cesse de faire l’objet de gloses et de réflexions sur ses différentes expressions dans le vécu au quotidien des communautés de référence. Tout autant qu’ils sont des victimes, femme et homme, enfant ou non, font aussi le lot des sujets de cette violence. S’inscrivant dans le champ précis des lettres, le présent article se propose d’en examiner sous deux angles à partir d’un corpus romanesque. Sous la base des outils d’analyse sociocritique, notre examen de la violence met en lumière, d’une part, l’énonciation des communautés de la violence ainsi qu’elles se déclinent et, d’autre part, la dénonciation tous azimuts des violences de communauté de tout ordre qu’elles soient.
Dans de nombreux contextes marqués par des contraintes structurelles persistantes, les projets de développement soutenus par l'aide publique au développement opèrent comme de véritables régimes d'exception. Une fois le soutien externe retiré, assurer la pérennité des acquis représente un défi majeur, mais encore trop peu exploré. Cet article examine les mécanismes qui permettent de maintenir les projets éducatifs après leur phase active au Burkina Faso. Pour cela, il a comme cadre d’analyse, le cadre ICC (Shediac-Rizkallah et Bone 1998 ; Scheirer, 2005 et Brinkerhoff, 2000) qui articule trois dimensions à savoir l'ancrage institutionnel, les capacités organisationnelles et l'appropriation communautaire dans une perspective configurationnelle. Et qui trouve son sens dans la pérennisation des interventions de développement, Ce modèle aide à décrypter comment ces éléments s'articulent en phase post-projet. La recherche adopte une méthode mixte, qui combine des données qualitatives avec une analyse quantitative via un modèle de régression linéaire multiple. Les résultats révèlent des trajectoires post-projet très variées : érosion progressive, maintien localisé, reconfiguration ou consolidation relative. Ces parcours s'expliquent moins par la qualité intrinsèque des projets que par la façon dont les dimensions du cadre ICC s'articulent entre elles. Ils soulignent en particulier que renforcer les capacités et favoriser l'appropriation communautaire ne suffit pas sans une institutionnalisation effective, qui inclut un financement récurrent, une supervision continue et une stabilisation des ressources humaines. Cet article propose une lecture ancrée dans les réalités du terrain pour comprendre comment les interventions éducatives peuvent réellement durer dans des contextes institutionnels fragiles.
This study compares electron dynamics in the Van Allen belts and the slot region during two major geomagnetic storms: the Halloween storm (October–November 2003, disturbance storm time index Dst = -383 nT), driven by successive interplanetary coronal mass ejections (ICMEs), and the 10–11 May 2024 storm (Dst = -412 nT), caused by a composite ICME formed by interacting coronal mass ejections. I n the slot region (L = 2–3), the flux enhancement during the main phase of the 2024 storm was very limited (median During/Before ratios: 3.0 at 0.55 MeV, 1.9 at 0.65 MeV, 2.4 at 1.70 MeV), in clear contrast to the Halloween storm’s large immediate increases (136.7 at 3.75 MeV, 31.3 at 8.25 MeV). However, the 2024 event exhibited a remarkable delayed amplification, with median After/Before ratios of 1681, 693, and 317, and After/During ratios exceeding 500, compared to 10–12 in 2003. This result demonstrates that the final slot state depends more on post-storm acceleration efficiency, via very low frequency (VLF) chorus waves, ultra-low frequency (ULF)-driven radial diffusion, and substorm injections, than on storm intensity alone. Post-peak exponential decay fits yield systematically shorter lifetimes that are energy-dependent. In 2024, τ = 3.83 ± 0.26 d at 0.55 MeV, 3.82 ± 0.23 d at 0.65 MeV, and 11.77 ± 0.98 d at 1.70 MeV. For the November 2003 recovery, τ = 8.34 ± 0.78 d (3.75 MeV) and 8.20 ± 1.26 d (8.25 MeV); during the later December phase, the timescales diverge sharply, with τ = 3.13 ± 0.10 d at 3.75 MeV versus 18.77 ± 1.90 d at 8.25 MeV. All fits show good to excellent correlations (R ≥ 0.882), confirming that pure exponential loss dominates once the acceleration ceases. The loss timescales increase with energy, consistent with pitch-angle scattering by plasmaspheric hiss, and the strong divergence in the December 2003 period reveals a pronounced energy filtering effect. Overall, extreme storms can produce significant delayed enhancements when the interplanetary driver sustains wave activity and injections, even with a weak prompt injection. These findings provide valuable new insights for radiation risk forecasting for satellites in medium-Earth orbit (MEO), geostationary Earth orbit (GEO), and low-Earth orbit (LEO).
