Search results for "west Africa"

Targeted application of an organophosphate-based paint applied on windows and doors against Anopheles coluzzii resistant to pyrethroids under real li…

2017

Abstract Background A novel strategy applying an organophosphate-based insecticide paint on doors and windows in combination with long-lasting insecticide-treated nets (LLINs) was tested for the control of pyrethroid-resistant malaria vectors in a village setting in Vallée du Kou, a rice-growing area west of Burkina Faso. Methods Insecticide Paint Inesfly 5A IGR™, comprised of two organophosphates and an insect growth regulator, was applied to doors and windows and tested in combination with pyrethroid-treated LLINs. The killing effect was monitored for 5 months by early morning collections of anophelines and other culicids. The residual efficacy was evaluated monthly by WHO bioassays using…

Adolescentes del África Occidental: motivaciones y reflexiones del proceso migratorio. Un análisis comparado

2021

Este artículo presenta la percepción de profesionales-expertos y de adolescentes del África Occidental sobre su proceso migratorio, y su paso por España cuando se dirigen hacia Europa. Tiene por objetivo 1) identificar estímulos para migrar, 2) analizar la influencia de la familia en la toma de decisión y 3) señalar condicionantes del proceso migratorio. Se utilizaron técnicas cualitativas como relato de vida, panel de profesionales-expertos, Delphi y DAFO. Los resultados profundizan en la escasez de recursos económicos familiares, el estatus de adulto que el adolescente recibe en origen, bajos ingresos y escasa cualificación como estímulos motivacionales para decidir migrar. Como conclusió…

Interacción entre el Monzón de África Occidental y el clima Mediterráneo en verano: Artículo de revisión

2014

Although in the framework of the global climate research the Mediterranean climate variability and the West African Monsoon (WAM) dynamics have been considered for a long time as “passive” systems, i.e., prone to the influence of large scale ocean and atmospheric variability, over the last decade many studies have been dedicated to the WAM-Mediterranean interaction and the active role of these climate systems has been highlighted. This article presents the WAM-Mediterranean teleconnection through an overview of the recent literature, describing the observational evidences and the dynamical mechanisms underlying this climate teleconnection. The influence of the Mediterranean Sea thermal anom…

Intraseasonal variations of June?September rainfall and upper-air circulation over Kenya

1996

In the Northern Summer, Kenya is located under the influence of the divergent Indian monsoon flow, and therefore is dry except for two separate areas: the coastal strip and the western regions. Analysis of daily rainfall data for June–September 1982 to 1988 has revealed that, although there are many distinct rainfall events between the two regions, an out-of-phase relationship is also evident, rain on the Coast being frequently accompanied by a drop in the precipitation over the Rift Valley area. It is shown that two types of wind forcing accompany these patterns. Alternating westerly and easterly anomalies at the 700 hPa level are associated with persistent wet and dry conditions (respecti…

Role of Indian fluxes in the intraseasonal 10-30 days variability of the African monsoon.

2018

12 pages; International audience; This study focused on the influence of Indian monsoon on the 10-30 days variability of the West African monsoon. One relies on the 500-300 hPa moisture fluxes calculated from specific wind and moisture fields from the ERAInterim reanalysis over the 1998-2008 period. These fluxes carry a signal of a spatio-temporal Rossby wave structure propagating westward from India. In the active phase of high convection of this wave, 500-300 hPa fluxes are Easterly. This high-tropospheric Rossby wave signal from the Indian monsoon area would modulate the dynamics over the Sahel.

Interaction between the West African Monsoon and the summer Mediterranean climate: An overview.

2013

15 pages; International audience; Although in the framework of the global climate research the Mediterranean climate variability andthe West African Monsoon (WAM) dynamics have been considered for a long time as “passive”systems, i.e., prone to the influence of large scale ocean and atmospheric variability, over the lastdecade many studies have been dedicated to the WAM-Mediterranean interaction and the active roleof these climate systems has been highlighted. This article presents the WAM-Mediterraneanteleconnection through an overview of the recent literature, describing the observational evidencesand the dynamical mechanisms underlying this climate teleconnection. The influence of the Me…

Comment on “Worldwide Distribution of PK Deficiency: the Defect Seems Mainly Concentrated in West African Countries and the United States.”

2021

First carboniferous conulariids from Niger (west Africa)

1995

Abstract Two new conulariid species, Paraconularia feldmanni sp. nov. and P. sahara sp. nov., are described from the Lower Carboniferous (Visean) Talak Formation of northern Niger. These are the first example of the genus Paraconularia to be reported from Africa and the first Carboniferous conulariids from that continent to be assigned to species level. Previously reported Carboniferous conulariids from Africa were collected from Morocco, assigned to other genera, and left in open nomenclature. Paraconularia is interpreted to have been cosmopolitan by the Early Carboniferous, and is the dominant genus in most assemblages of Carboniferous conulariids.

Rb-Sr geochronology in favour of polymetamorphism in the Pan African Damara belt of Namibia (South West Africa)

1978

New Rb-Sr whole rock age data are reported from two metasedimentary sequences of the Damara Supergroup in the central Pan African Damara belt of Namibia (South West Africa).

Sensitivity of low-level clouds and precipitation to anthropogenic aerosol emission in southern West Africa: a DACCIWA case study

2021

Abstract. During the West African summer monsoon, pollutants emitted in urbanized coastal areas modify cloud cover and precipitation patterns. The Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa (DACCIWA) field campaign provided numerous aircraft-based and ground-based observations, which are used here to evaluate two experiments made with the coupled WRF-CHIMERE model, integrating both the direct and indirect aerosol effect on meteorology. During one well-documented week (1–7 July 2016), the impacts of anthropogenic aerosols on the diurnal cycle of low-level clouds and precipitation are analyzed in detail using high and moderate intensity of anthropogenic emissions in the expe…