Will Elephants Soon Disappear from West African Savannahs?

PubMed Central

Bouché, Philippe; Douglas-Hamilton, Iain; Wittemyer, George; Nianogo, Aimé J.; Doucet, Jean-Louis; Lejeune, Philippe; Vermeulen, Cédric

2011-01-01

Precipitous declines in Africa's native fauna and flora are recognized, but few comprehensive records of these changes have been compiled. Here, we present population trends for African elephants in the 6,213,000 km2 Sudano-Sahelian range of West and Central Africa assessed through the analysis of aerial and ground surveys conducted over the past 4 decades. These surveys are focused on the best protected areas in the region, and therefore represent the best case scenario for the northern savanna elephants. A minimum of 7,745 elephants currently inhabit the entire region, representing a minimum decline of 50% from estimates four decades ago for these protected areas. Most of the historic range is now devoid of elephants and, therefore, was not surveyed. Of the 23 surveyed elephant populations, half are estimated to number less than 200 individuals. Historically, most populations numbering less than 200 individuals in the region were extirpated within a few decades. Declines differed by region, with Central African populations experiencing much higher declines (−76%) than those in West Africa (−33%). As a result, elephants in West Africa now account for 86% of the total surveyed. Range wide, two refuge zones retain elephants, one in West and the other in Central Africa. These zones are separated by a large distance (∼900 km) of high density human land use, suggesting connectivity between the regions is permanently cut. Within each zone, however, sporadic contacts between populations remain. Retaining such connectivity should be a high priority for conservation of elephants in this region. Specific corridors designed to reduce the isolation of the surveyed populations are proposed. The strong commitment of governments, effective law enforcement to control the illegal ivory trade and the involvement of local communities and private partners are all critical to securing the future of elephants inhabiting Africa's northern savannas. PMID:21731620

The Lion in West Africa Is Critically Endangered

PubMed Central

Henschel, Philipp; Coad, Lauren; Burton, Cole; Chataigner, Beatrice; Dunn, Andrew; MacDonald, David; Saidu, Yohanna; Hunter, Luke T. B.

2014-01-01

The African lion has declined to <35,000 individuals occupying 25% of its historic range. The situation is most critical for the geographically isolated populations in West Africa, where the species is considered regionally endangered. Elevating their conservation significance, recent molecular studies establish the genetic distinctiveness of West and Central African lions from other extant African populations. Interventions to save West African lions are urgently required. However formulating effective conservation strategies has been hampered by a lack of data on the species' current distribution, status, and potential management deficiencies of protected areas (PAs) harboring lions. Our study synthesized available expert opinion and field data to close this knowledge gap, and formulate recommendations for the conservation of West African lions. We undertook lion surveys in 13 large (>500 km2) PAs and compiled evidence of lion presence/absence for a further eight PAs. All PAs were situated within Lion Conservation Units, geographical units designated as priority lion areas by wildlife experts at a regional lion conservation workshop in 2005. Lions were confirmed in only 4 PAs, and our results suggest that only 406 (273–605) lions remain in West Africa, representing <250 mature individuals. Confirmed lion range is estimated at 49,000 km2, or 1.1% of historical range in West Africa. PAs retaining lions were larger than PAs without lions and had significantly higher management budgets. We encourage revision of lion taxonomy, to recognize the genetic distinctiveness of West African lions and highlight their potentially unique conservation value. Further, we call for listing of the lion as critically endangered in West Africa, under criterion C2a(ii) for populations with <250 mature individuals. Finally, considering the relative poverty of lion range states in West Africa, we call for urgent mobilization of investment from the international community to assist range

Markets, Climate Change and Food Security in West Africa

NASA Technical Reports Server (NTRS)

Brown, Molly E.; Hintermann, Beat; Higgins, Nathaniel

2009-01-01

West Africa is one of the most food insecure regions of the world. Sharply increased food and energy prices in 2008 brought the role of markets in food access and availability around the world into the spotlight, particularly in urban areas. The period of high prices had the immediate consequence of sharply increasing the number of hungry people in the region without boosting farmer incomes significantly. In this article, the interaction between markets, food prices, agricultural technology and development is explored in the context of West Africa. To improve food security in West Africa, sustained commitment to investment in the agriculture sector will be needed to provide some protection against global swings in both production and world markets. Climate change mitigation programs are likely to force global energy and commodity price increases in the coming decades, putting pressure on regions like West Africa to produce more food locally to ensure stability in food security for the most vulnerable.

Asymmetric forcing from stratospheric aerosols impacts Sahelian rainfall

NASA Astrophysics Data System (ADS)

Haywood, Jim M.; Jones, Andy; Bellouin, Nicolas; Stephenson, David

2013-07-01

The Sahelian drought of the 1970s-1990s was one of the largest humanitarian disasters of the past 50 years, causing up to 250,000 deaths and creating 10 million refugees. It has been attributed to natural variability, over-grazing and the impact of industrial emissions of sulphur dioxide. Each mechanism can influence the Atlantic sea surface temperature gradient, which is strongly coupled to Sahelian precipitation. We suggest that sporadic volcanic eruptions in the Northern Hemisphere also strongly influence this gradient and cause Sahelian drought. Using de-trended observations from 1900 to 2010, we show that three of the four driest Sahelian summers were preceded by substantial Northern Hemisphere volcanic eruptions. We use a state-of-the-art coupled global atmosphere-ocean model to simulate both episodic volcanic eruptions and geoengineering by continuous deliberate injection into the stratosphere. In either case, large asymmetric stratospheric aerosol loadings concentrated in the Northern Hemisphere are a harbinger of Sahelian drought whereas those concentrated in the Southern Hemisphere induce a greening of the Sahel. Further studies of the detailed regional impacts on the Sahel and other vulnerable areas are required to inform policymakers in developing careful consensual global governance before any practical solar radiation management geoengineering scheme is implemented.

Melioidosis Imported from West Africa to Europe

PubMed Central

Cuadros, Juan; Gil, Horacio; Miguel, Julio De; Marabé, Graciela; Gómez-Herruz, Teresa Arroyo Peña; Lobo, Bruno; Marcos, Ruth; Anda, Pedro

2011-01-01

We report the first case of imported melioidosis in Spain from a diabetic immigrant who visited West Africa during the rainy season. Because of the unusual presentation of this disease in Africa, clinical and microbiological diagnosis of imported melioidosis from this continent can be very elusive. PMID:21813848

Operational-scale application of entomopathogenic fungi for control of Sahelian grasshoppers

PubMed Central

Kooyman, C.; Bateman, R. P.; Langewald, J.; Lomer, C. J.; Ouambama, Z.; Thomas, M. B.

1997-01-01

Locusts and grasshoppers regularly threaten agricultural production across large parts of the developed and developing worlds. Recent concerns over the health and environmental impacts of standard chemical control measures have led to a demand for alternative, more environmentally benign control technologies. Here we present the results of a field study to investigate the potential of inundative biological control for control of grasshoppers in the Sahelian region of Africa. The biocontrol agent was an oil-based biopesticide formulation of a naturally occurring entomopathogenic fungus, Metarhizium flavoviride. This was applied at a rate of 2l ha-1 to a total area of 150 ha using standard equipment normally used for the application of chemical pesticides. Twenty-one days after application, an 80 per cent reduction in grasshopper populations was recorded in treated plots, relative to control populations in equivalent unsprayed areas. We think that this is the first operational-scale application of a biopesticide to demonstrate significant population reductions of key Sahelian grasshopper pests. This represents a substantial development in locust and grasshopper control, and should open the way for a new era of integrated control strategies where reliance on conventional chemicals is reduced.

The WASCAL high-resolution climate projection ensemble for West Africa

NASA Astrophysics Data System (ADS)

Kunstmann, Harald; Heinzeller, Dominikus; Dieng, Diarra; Smiatek, Gerhard; Bliefernicht, Jan; Hamann, Ilse; Salack, Seyni

2017-04-01

With climate change being one of the most severe challenges to rural Africa in the 21st century, West Africa is facing an urgent need to develop effective adaptation and mitigation measures to protect its constantly growing population. We perform ensemble-based regional climate simulations at a high resolution of 12km for West Africa to allow a scientifically sound derivation of climate change adaptation measures. Based on the RCP4.5 scenario, our ensemble consist of three simulation experiments with the Weather Research & Forecasting Tool (WRF) and one additional experiment with the Consortium for Small-scale Modelling Model COSMO in Climate Mode (COSMO-CLM). We discuss the model performance over the validation period 1980-2010, including a novel, station-based precipitation database for West Africa obtained within the WASCAL (West African Science Service Centre for Climate Change and Adapted Land Use) program. Particular attention is paid to the representation of the dynamics of the West African Summer Monsoon and to the added value of our high-resolution models over existing data sets. We further present results on the climate change signal obtained for the two future periods 2020-2050 and 2070-2100 and compare them to current state-of-the-art projections from the CORDEX-Africa project. While the temperature change signal is similar to that obtained within CORDEX-Africa, our simulations predict a wetter future for the Coast of Guinea and the southern Soudano area and a slight drying in the northernmost part of the Sahel.

Sources of Sahelian-Sudan moisture: Insights from a moisture-tracing atmospheric model

NASA Astrophysics Data System (ADS)

Salih, Abubakr A. M.; Zhang, Qiong; Pausata, Francesco S. R.; Tjernström, Michael

2016-07-01

The summer rainfall across Sahelian-Sudan is one of the main sources of water for agriculture, human, and animal needs. However, the rainfall is characterized by large interannual variability, which has attracted extensive scientific efforts to understand it. This study attempts to identify the source regions that contribute to the Sahelian-Sudan moisture budget during July through September. We have used an atmospheric general circulation model with an embedded moisture-tracing module (Community Atmosphere Model version 3), forced by observed (1979-2013) sea-surface temperatures. The result suggests that about 40% of the moisture comes with the moisture flow associated with the seasonal migration of the Intertropical Convergence Zone (ITCZ) and originates from Guinea Coast, central Africa, and the Western Sahel. The Mediterranean Sea, Arabian Peninsula, and South Indian Ocean regions account for 10.2%, 8.1%, and 6.4%, respectively. Local evaporation and the rest of the globe supply the region with 20.3% and 13.2%, respectively. We also compared the result from this study to a previous analysis that used the Lagrangian model FLEXPART forced by ERA-Interim. The two approaches differ when comparing individual regions, but are in better agreement when neighboring regions of similar atmospheric flow features are grouped together. Interannual variability with the rainfall over the region is highly correlated with contributions from regions that are associated with the ITCZ movement, which is in turn linked to the Atlantic Multidecadal Oscillation. Our result is expected to provide insights for the effort on seasonal forecasting of the rainy season over Sahelian Sudan.

Ability of WRF to Simulate Rainfall Distribution Over West Africa: Role of Horizontal Resolution and Dynamical Processes

NASA Astrophysics Data System (ADS)

Kouadio, K.; Konare, A.; Bastin, S.; Ajayi, V. O.

2016-12-01

This research work focused on the thorny problem of the representation of rainfall over West Africa and particularly in the Gulf of Guinea and its surroundings by Regional Climate Models (RCMs). The sensitivities of Weather Research and Forecasting (WRF) Model are tested for changes in horizontal resolution (convective permitting versus parameterized) on the replication of West African Climate in year 2014 and also changes in microphysics (MP) and planetary boundary layer (PBL) schemes on June 2014. The sensitivity to horizontal resolution study show that both runs at 24km and 4km (explicit convection) resolution fairly replicate the general distribution of the rainfall over West African region. The analysis also reveals a good replication of the dynamical features of West African monsoon system including Tropical Easterly Jet (TEJ), African Easterly Jet (AEJ), monsoon flow and the West African Heat Low (WAHL). Some differences have been noticed between WRF and ERA-interim outputs irrespective to the spectral nudging used in the experiment which then suggest strong interactions between scales. The link between the seasonal displacement of the WAHL and the spatial distribution of the rainfall and the Sahelian onset is confirmed in this study. The results also show an improvement on the replication of rainfall with the very high resolution run observed at daily scale over the Sahel while a dry bias is observed in WRF simulations of the rainfall over Ivorian Coast and in the Gulf of Guinea. Generally, over the Guinean coast the high resolution run did not provide subsequent improvement on the replication of rainfall. The sensitivity of WRF to MP and PBL on rainfall replication study reveals that the most significant added value over the Guinean coast and surroundings area is provided by the configurations that used the PBL Asymmetric Convective Model V2 (ACM2) suggesting more influence of the PBL compared to MP. The change on microphysics and planetary boundary layer

Trends and Issues in Vocational Technical Education in Francophone West Africa.

ERIC Educational Resources Information Center

Kogoe, Akrima

Francophone West Africa has committed itself to the goal of universal formal education as the most effective method of insuring rapid economic and national development. (Francophone West Africa is composed of Senegal, Mauritania, Guinea, Mali, Ivory Coast, Togo, Benin, Niger, and Burkina-Faso.) The costly investments of limited fiscal resources in…

Marriage in West Africa--A Composite. Mini-Module.

ERIC Educational Resources Information Center

African-American Inst., New York, NY. School Services Div.

This module contains a description of the responsibilities and ceremony of marriage in west Africa, seven discussion questions exploring the differences between Western and African marriage customs, five enrichment activities, and a bibliography of five books about love and marriage in Africa. The general discussion relates the engagement of a…

Library Literature in English-Speaking West Africa; Its Achievements, Problems and Prospects.

ERIC Educational Resources Information Center

Nyarko, K.

This report surveys the development of librarianship in West Africa since 1954, focusing primarily on the production of professional library literature in Gambia, Ghana, Nigeria, Sierra Leone, and Liberia, the five countries which constitute the sub-region of English-speaking West Africa. An overview of library developments is presented, and three…

Internal diversification of non-Sub-Saharan haplogroups in Sahelian populations and the spread of pastoralism beyond the Sahara.

PubMed

Kulichová, Iva; Fernandes, Verónica; Deme, Alioune; Nováčková, Jana; Stenzl, Vlastimil; Novelletto, Andrea; Pereira, Luísa; Černý, Viktor

2017-10-01

Today, African pastoralists are found mainly in the Sahel/Savannah belt spanning 6,000 km from west to east, flanked by the Sahara to the north and tropical rainforests to the south. The most significant group among them are the Fulani who not only keep cattle breeds of possible West Eurasian ancestry, but form themselves a gene pool containing some paternally and maternally-transmitted West Eurasian haplogroups. We generated complete sequences for 33 mitogenomes belonging to haplogroups H1 and U5 (23 and 10, respectively), and genotyped 16 STRs in 65 Y chromosomes belonging to haplogroup R1b-V88. We show that age estimates of the maternal lineage H1cb1, occurring almost exclusively in the Fulani, point to the time when the first cattle herders settled the Sahel/Savannah belt. Similar age estimates were obtained for paternal lineage R1b-V88, which occurs today in the Fulani but also in other, mostly pastoral populations. Maternal clade U5b1b1b, reported earlier in the Berbers, shows a shallower age, suggesting another possibly independent input into the Sahelian pastoralist gene pool. Despite the fact that animal domestication originated in the Near East ∼ 10 ka, and that it was from there that animals such as sheep, goats as well as cattle were introduced into Northeast Africa soon thereafter, contemporary cattle keepers in the Sahel/Savannah belt show uniparental genetic affinities that suggest the possibility of an ancient contact with an additional ancestral population of western Mediterranean ancestry. © 2017 Wiley Periodicals, Inc.

Pedo-sedimentary constituents as paleoenvironmental proxies in the Sudano-Sahelian belt during the Late Quaternary (southwestern Chad Basin)

NASA Astrophysics Data System (ADS)

Diaz, Nathalie; Dietrich, Fabienne; Sebag, David; King, Georgina E.; Valla, Pierre G.; Durand, Alain; Garcin, Yannick; de Saulieu, Geoffroy; Deschamps, Pierre; Herman, Frédéric; Verrecchia, Eric P.

2018-07-01

Climate and environmental changes since the Last Glacial Maximum in the tropical zone of West Africa are usually inferred from marine and continental records. In this study, the potential of carbonate pedo-sedimentary geosystems, i.e. Vertisol relics, to record paleoenvironmental changes in the southwestern part of Chad Basin are investigated. A multi-dating approach was applied on different pedogenic organo-mineral constituents. Optically stimulated luminescence (OSL) dating was performed on the soil K-rich feldspars and was combined with radiocarbon dating on both the inorganic (14Cinorg) and organic carbon (14Corg) soil fractions. Three main pedo-sedimentary processes were assessed over the last 20 ka BP: 1) the soil parent material deposition, from 18 ka to 12 ka BP (OSL), 2) the soil organic matter integration, from 11 cal ka to 8 cal ka BP (14Corg), and 3) the pedogenic carbonate nodule precipitation, from 7 cal ka to 5 cal ka BP (14Cinorg). These processes correlate well with the Chad Basin stratigraphy and West African records and are shown to be related to significant changes in the soil water balance responding to the evolution of continental hydrology during the Late Quaternary. The last phase affecting the Vertisol relics is the increase of erosion, which is hypothesized to be due to a decrease of the vegetation cover triggered by (i) the onset of drier conditions, possibly strengthened by (ii) anthropogenic pressure. Archaeological data from Far North Cameroon and northern Nigeria, as well as sedimentation times in Lake Tilla (northeastern Nigeria), were used to test these relationships. The increase of erosion is suggested to possibly occur between c. 3 cal ka and 1 cal ka BP. Finally, satellite images revealed similar geosystems all along the Sudano-Sahelian belt, and initial 14Cinorg ages of the samples collected in four sites gave similar ages to those reported in this study. Consequently, the carbonate pedo-sedimentary geosystems are valuable

The DACCIWA 2016 radiosonde campaign in southern West Africa

NASA Astrophysics Data System (ADS)

Fink, Andreas H.; Maranan, Marlon; Knippertz, Peter; Ngamini, Jean-Blaise; Francis, Sabastine

2017-04-01

Operational upper-air stations are very sparsely distributed over West Africa, resulting in the necessity to enhance radiosonde observations for the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) experimental period during June-July 2016. Building on the AMMA (African Monsoon - Multidisciplinary Analyses) experience, existing infrastructures, as well as human networks, the upper air network was successfully augmented to a spatial density that is unprecedented for southern West Africa. Altogether, more than 750 experimental radiosondes were launched at seven stations in three countries along the Guinea Coast. From its outset, the DACCIWA radiosonde campaign had three pillars: (a) enhancing soundings at operational or quiescent AMMA radiosonde stations; (b) launching sondes at DACCIWA supersites and two additional DACCIWA field sites; and (c) collecting standard and - if possible - high-resolution data from other operational RS stations. In terms of (a), it was found during preparing recce visits to West Africa, that the AMMA-activated stations of Cotonou (Benin) and Abuja (Nigeria) were operational though almost "invisible" on the World Meteorological Organisation's Global Teleconnection System (GTS). These and other AMMA legacies facilitated the implementation of enhanced, four-times daily soundings at Abidjan (Ivory Coast), Cotonou and Parakou (both Benin). Two well-instrumented DACCIWA ground sites at Kumasi (Ghana) and Savé (Benin) performed 06 UTC soundings, being enhanced to four-times daily ascents during fifteen Intensive Observing Periods (IOPs). In addition, research staff and students from the Karlsruhe Institute of Technology (KIT) and African partners conducted up to five-times daily soundings at Lamto (Ivory Coast) and Accra (Ghana). Almost all of the experimental DACCIWA ascents were submitted to the GTS in real time and assimilated at least at three European numerical weather prediction centres that helped to improve their

Epidemiology: Malaria in a warmer West Africa

NASA Astrophysics Data System (ADS)

Caminade, C.; Jones, A. E.

2016-11-01

Malaria risk in West Africa is expected to fall (western region) or remain the same (eastern region) in response to climate change over the twenty-first century. This is primarily due to extreme temperature conditions projected under a high greenhouse gas emissions scenario.

Simulation of Rainfall Variability Over West Africa

NASA Astrophysics Data System (ADS)

Bader, J.; Latif, M.

The impact of sea surface temperature (SST) and vegetation on precipitation over West Africa is investigated with the atmospheric general circulation model ECHAM4.x/T42. Ensemble experiments -driven with observed SST- show that At- lantic SST has a significant influence on JJA precipitation over West Africa. Four- teen experiments were performed in which the climatological SST was enhanced or decreased by one Kelvin in certain ocean areas. Changing SST in the eastern tropi- cal Atlantic only caused significant changes along the Guinea Coast, with a positive SSTA increasing rainfall and a negative reducing it. The response was nearly linear. Changing SST in other ocean areas caused significant changes over West Africa, es- pecially in the Sahel area. The response is found to be non linear, with only negative SSTA leading to significant reduction in Sahel rainfall. Also, the impact of the SSTAs from the different ocean regions was not additive with respect to the rainfall. Four simulations with a coupled model (the simple dynamic vegetation model (SVege) and the ECHAM4-AGCM were coupled) were also performed, driven with observed SST from 1945 to 1998. The standard ECHAM-AGCM -forced by the same observed SST- was able to reproduce the drying trend from the fifties to the mid-eighties in the Sahel, but failed to mirror the magnitude of the rainfall anomalies. The coupled model was not only able to reproduce this drying trend, but was also able to better reproduce the amplitudes of the rainfall anomalies. The dynamic vegetation acted like an amplifier, increasing the SST induced rainfall anomalies.

West Nile Disease Epidemiology in North-West Africa: Bibliographical Review.

PubMed

Benjelloun, A; El Harrak, M; Belkadi, B

2016-12-01

West Nile fever (WNF) or West Nile disease (WND) is a mosquito-borne viral disease that can affect birds, humans and horses. West Nile virus (WNV) is a member of the genus Flavivirus in the family Flaviviridae. WNV is maintained in a mosquito-bird-mosquito transmission cycle, whereas humans and horses are considered dead-end hosts. In human and horses, symptoms range from unapparent infection to mild febrile illness, meningitis, encephalitis or death. WNV has a wide geographical range that includes portions of Europe, Asia, Africa, Australia (Kunjin virus), and in North, Central and South America. Migratory birds are thought to be primarily responsible for virus dispersal, including reintroduction of WNV from endemic areas into regions that experience sporadic outbreaks (Fields Virology, 2001, Lippincott Williams and Wilkins, Philadelphia, Pennsylvania, USA, 1043-1125). The occurrence of disease in humans and animals along with birds and mosquitoes surveillance for WNV activity demonstrates that the virus range has dramatically expanded including North, Central and South America as well as Europe and countries facing the Mediterranean Basin. WND infection in humans has been reported in Morocco in 1996 (Virologie, 1, 1997, 248), in Tunisia in 2007 (Ann. N. Y. Acad., 951, 2001, 117) (Med. Trop., 61, 2001, 487) and 2003 (Epidémiologie de la fièvre West Nile, 2012, Thèse de doctorat, Université Montpellier II, Sciences et techniques du Langueduc, Montpellier, France), and in Algeria in 1994 (Rev. Sci. Tech., 31, 2012, 829). Outbreaks of equine encephalitis have been also reported in Morocco in 1996 (Bull. OIE, 11, 1996, 867), in 2003 (Emerg. Infect. Dis., 11, 2005, 306) and in 2010 (World Animal Health Information Database. WAHID, 2010). Serological evidence of WNV has been demonstrated in the three countries in many species. The aim of this review was to assess the epidemiological situation of WND in north-west Africa comprising Morocco, Algeria and Tunisia, with

Lassa fever: another threat from West Africa.

PubMed

Brosh-Nissimov, Tal

2016-01-01

Lassa fever, a zoonotic viral infection, is endemic in West Africa. The disease causes annual wide spread morbidity and mortality in Africa, and can be imported by travelers. Possible importation of Lassa fever and the potential for the use of Lassa virus as an agent of bioterrorism mandate clinicians in Israel and other countries to be vigilant and familiar with the basic characteristics of this disease. The article reviews the basis of this infection and the clinical management of patients with Lassa fever. Special emphasis is given to antiviral treatment and infection control.

Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air

USGS Publications Warehouse

Garrison, Virginia H.; Majewski, Michael S.; Konde, Lassana; Wolf, Ruth E.; Otto, Richard D.; Tsuneoka, Yutaka

2014-01-01

Saharan dust incursions and particulates emitted from human activities degrade air quality throughout West Africa, especially in the rapidly expanding urban centers in the region. Particulate matter (PM) that can be inhaled is strongly associated with increased incidence of and mortality from cardiovascular and respiratory diseases and cancer. Air samples collected in the capital of a Saharan–Sahelian country (Bamako, Mali) between September 2012 and July 2013 were found to contain inhalable PM concentrations that exceeded World Health Organization (WHO) and US Environmental Protection Agency (USEPA) PM2.5 and PM10 24-h limits 58 – 98% of days and European Union (EU) PM10 24-h limit 98% of days. Mean concentrations were 1.2-to-4.5 fold greater than existing limits. Inhalable PM was enriched in transition metals, known to produce reactive oxygen species and initiate the inflammatory response, and other potentially bioactive and biotoxic metals/metalloids. Eroded mineral dust composed the bulk of inhalable PM, whereas most enriched metals/metalloids were likely emitted from oil combustion, biomass burning, refuse incineration, vehicle traffic, and mining activities. Human exposure to inhalable PM and associated metals/metalloids over 24-h was estimated. The findings indicate that inhalable PM in the Sahara–Sahel region may present a threat to human health, especially in urban areas with greater inhalable PM and transition metal exposure.

Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air.

PubMed

Garrison, V H; Majewski, M S; Konde, L; Wolf, R E; Otto, R D; Tsuneoka, Y

2014-12-01

Saharan dust incursions and particulates emitted from human activities degrade air quality throughout West Africa, especially in the rapidly expanding urban centers in the region. Particulate matter (PM) that can be inhaled is strongly associated with increased incidence of and mortality from cardiovascular and respiratory diseases and cancer. Air samples collected in the capital of a Saharan-Sahelian country (Bamako, Mali) between September 2012 and July 2013 were found to contain inhalable PM concentrations that exceeded World Health Organization (WHO) and US Environmental Protection Agency (USEPA) PM2.5 and PM10 24-h limits 58 - 98% of days and European Union (EU) PM10 24-h limit 98% of days. Mean concentrations were 1.2-to-4.5 fold greater than existing limits. Inhalable PM was enriched in transition metals, known to produce reactive oxygen species and initiate the inflammatory response, and other potentially bioactive and biotoxic metals/metalloids. Eroded mineral dust composed the bulk of inhalable PM, whereas most enriched metals/metalloids were likely emitted from oil combustion, biomass burning, refuse incineration, vehicle traffic, and mining activities. Human exposure to inhalable PM and associated metals/metalloids over 24-h was estimated. The findings indicate that inhalable PM in the Sahara-Sahel region may present a threat to human health, especially in urban areas with greater inhalable PM and transition metal exposure. Published by Elsevier B.V.

What factors might have led to the emergence of Ebola in West Africa?

PubMed

Alexander, Kathleen A; Sanderson, Claire E; Marathe, Madav; Lewis, Bryan L; Rivers, Caitlin M; Shaman, Jeffrey; Drake, John M; Lofgren, Eric; Dato, Virginia M; Eisenberg, Marisa C; Eubank, Stephen

2015-01-01

An Ebola outbreak of unprecedented scope emerged in West Africa in December 2013 and presently continues unabated in the countries of Guinea, Sierra Leone, and Liberia. Ebola is not new to Africa, and outbreaks have been confirmed as far back as 1976. The current West African Ebola outbreak is the largest ever recorded and differs dramatically from prior outbreaks in its duration, number of people affected, and geographic extent. The emergence of this deadly disease in West Africa invites many questions, foremost among these: why now, and why in West Africa? Here, we review the sociological, ecological, and environmental drivers that might have influenced the emergence of Ebola in this region of Africa and its spread throughout the region. Containment of the West African Ebola outbreak is the most pressing, immediate need. A comprehensive assessment of the drivers of Ebola emergence and sustained human-to-human transmission is also needed in order to prepare other countries for importation or emergence of this disease. Such assessment includes identification of country-level protocols and interagency policies for outbreak detection and rapid response, increased understanding of cultural and traditional risk factors within and between nations, delivery of culturally embedded public health education, and regional coordination and collaboration, particularly with governments and health ministries throughout Africa. Public health education is also urgently needed in countries outside of Africa in order to ensure that risk is properly understood and public concerns do not escalate unnecessarily. To prevent future outbreaks, coordinated, multiscale, early warning systems should be developed that make full use of these integrated assessments, partner with local communities in high-risk areas, and provide clearly defined response recommendations specific to the needs of each community.

What Factors Might Have Led to the Emergence of Ebola in West Africa?

PubMed Central

Alexander, Kathleen A.; Sanderson, Claire E.; Marathe, Madav; Lewis, Bryan L.; Rivers, Caitlin M.; Shaman, Jeffrey; Drake, John M.; Lofgren, Eric; Dato, Virginia M.; Eisenberg, Marisa C.; Eubank, Stephen

2015-01-01

An Ebola outbreak of unprecedented scope emerged in West Africa in December 2013 and presently continues unabated in the countries of Guinea, Sierra Leone, and Liberia. Ebola is not new to Africa, and outbreaks have been confirmed as far back as 1976. The current West African Ebola outbreak is the largest ever recorded and differs dramatically from prior outbreaks in its duration, number of people affected, and geographic extent. The emergence of this deadly disease in West Africa invites many questions, foremost among these: why now, and why in West Africa? Here, we review the sociological, ecological, and environmental drivers that might have influenced the emergence of Ebola in this region of Africa and its spread throughout the region. Containment of the West African Ebola outbreak is the most pressing, immediate need. A comprehensive assessment of the drivers of Ebola emergence and sustained human-to-human transmission is also needed in order to prepare other countries for importation or emergence of this disease. Such assessment includes identification of country-level protocols and interagency policies for outbreak detection and rapid response, increased understanding of cultural and traditional risk factors within and between nations, delivery of culturally embedded public health education, and regional coordination and collaboration, particularly with governments and health ministries throughout Africa. Public health education is also urgently needed in countries outside of Africa in order to ensure that risk is properly understood and public concerns do not escalate unnecessarily. To prevent future outbreaks, coordinated, multiscale, early warning systems should be developed that make full use of these integrated assessments, partner with local communities in high-risk areas, and provide clearly defined response recommendations specific to the needs of each community. PMID:26042592

Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa.

PubMed

Bertola, Laura D; Tensen, Laura; van Hooft, Pim; White, Paula A; Driscoll, Carlos A; Henschel, Philipp; Caragiulo, Anthony; Dias-Freedman, Isabela; Sogbohossou, Etotépé A; Tumenta, Pricelia N; Jirmo, Tuqa H; de Snoo, Geert R; de Iongh, Hans H; Vrieling, Klaas

2015-01-01

The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted.

Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa

PubMed Central

Bertola, Laura D.; Tensen, Laura; van Hooft, Pim; White, Paula A.; Driscoll, Carlos A.; Henschel, Philipp; Caragiulo, Anthony; Dias-Freedman, Isabela; Sogbohossou, Etotépé A.; Tumenta, Pricelia N.; Jirmo, Tuqa H.; de Snoo, Geert R.

2015-01-01

The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted. PMID:26466139

The Training of Librarians in West Africa

ERIC Educational Resources Information Center

Stanley, Janet L.

1972-01-01

The great debate, as to whether prospective librarians from the developing countries of West Africa should travel abroad to receive library training or whether money and efforts should be devoted to the creation of indigenous library schools, has practically subsided, resolved in favor of the latter course. (21 references) )Author)

[Migration and urbanization in the Sahel. Consequences of the Sahelian migrations].

PubMed

Traore, S

1997-10-01

The consequences of Sahelian migration are multiple and diverse. In rural areas there may be a loss of income in the short run and a reduced possibility of development in the long run. Apart from its implications for urban growth, Sahelian migration may have four series of consequences in the places of origin. In detaching peasants from their lands, migration may contribute to loss of appreciation and reverence for the lands. Attachment to the lands of the ancestors loses its meaning as soon as questions of survival or economic rationality are raised. Migration contributes to the restructuring of the societies of origin. Increasing monetarization of market relations and introduction of new needs create new norms that favor stronger integration into the world economy. Migration may cause a decline in production because of the loss of the most active population, and it changes the age and sex distribution of households and usually increases their dependency burden. The effects on fertility and mortality are less clear. The effects of migration on the zones of arrival in the Sahel depend on the type of area. Conflicts between natives and in-migrants are common in rural-rural migration. Degradation of land may result from the increased demands placed upon it. Migrants to cities in Africa, and especially in the Sahel, appear to conserve their cultural values and to transplant and reinterpret their village rules of solidarity.

Simulating malaria transmission in the current and future climate of West Africa

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Bomblies, A.; Eltahir, E. A. B.

2015-12-01

Malaria transmission in West Africa is closely tied to climate, as rain fed water pools provide breeding habitat for the anopheles mosquito vector, and temperature affects the mosquito's ability to spread disease. We present results of a highly detailed, spatially explicit mechanistic modelling study exploring the relationships between the environment and malaria in the current and future climate of West Africa. A mechanistic model of human immunity was incorporated into an existing agent-based model of malaria transmission, allowing us to move beyond entomological measures such as mosquito density and vectorial capacity to analyzing the prevalence of the malaria parasite within human populations. The result is a novel modelling tool that mechanistically simulates all of the key processes linking environment to malaria transmission. Simulations were conducted across climate zones in West Africa, linking temperature and rainfall to entomological and epidemiological variables with a focus on nonlinearities due to threshold effects and interannual variability. Comparisons to observations from the region confirmed that the model provides a reasonable representation of the entomological and epidemiological conditions in this region. We used the predictions of future climate from the most credible CMIP5 climate models to predict the change in frequency and severity of malaria epidemics in West Africa as a result of climate change.

Qur'anic and "Ajami" Literacies in Pre-Colonial West Africa

ERIC Educational Resources Information Center

Diallo, Ibrahima

2012-01-01

Traditional African literacy practices have often been ignored in the wake of European colonialism and the educational policies of colonial governments. Nonetheless, literacy had been established in parts of Africa following the introduction of Islam. This paper will examine the developments of literacy in pre-colonial West Africa. In this region,…

Response of the Water Cycle of West Africa and Atlantic to Radiative Forcing by Saharan Dust

NASA Technical Reports Server (NTRS)

Lau, K. M.; Kim, Kyu-Myong; Sud, Yogesh C.; Walker, Gregory L.

2010-01-01

The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence in support of the "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summer, as a result of large-scale atmospheric feed back triggered by absorbing dust aerosols, rainfall and cloudiness are enhanced over the West Africa/Easter Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean. region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while long wave has the opposite response. The elevated dust layer warms the air over Nest Africa and the eastern Atlantic. The condensation heating associated with the induced deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in northward shift of the West Africa precipitation over land, increased low-level westerlies flow over West Africa at the southern edge of the dust layer, and a near surface energy fluxes, resulting in cooling of the Nest African land and the eastern Atlantic, and a warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at 0.95 or higher.

Modelling the potential impacts of afforestation on extreme precipitation over West Africa

NASA Astrophysics Data System (ADS)

Odoulami, Romaric C.; Abiodun, Babatunde J.; Ajayi, Ayodele E.

2018-05-01

This study examines how afforestation in West Africa could influence extreme precipitation over the region, with a focus on widespread extreme rainfall events (WEREs) over the afforestation area. Two regional climate models (RegCM and WRF) were applied to simulate the present-day climate (1971-2000) and future climate (2031-2060, under IPCC RCP 4.5 emission scenario) with and without afforestation of the Savannah zone in West Africa. The models give a realistic simulation of precipitation indices and WEREs over the subcontinent. On average, the regional models projected future decreases in total annual wet day precipitation (PRCPTOT) and total annual daily precipitation greater than or equal to the 95th percentile of daily precipitation threshold (R95pTOT) and increases in maximum number of consecutive dry days (CDD) over Sahel. Over Savannah, the models projected decreases in PRCPTOT but increases in R95pTOT and CDD. Also, an increase in WEREs frequency is projected over west, central and east Savannah, except that RegCM simulated a decrease in WEREs over east Savannah. In general, afforestation increases PRCPTOT and R95pTOT but decreases CDD over the afforestation area. The forest-induced increases in PRCPTOT and decreases in CDD affect all ecological zones in West Africa. However, the simulations show that afforestation of Savannah also decreases R95pTOT over the Guinea Coast. It further increases WEREs over west and central Savannah and decreases them over east Savannah because of the local decrease in R95pTOT. Results of this study suggest that the future changes in characteristics of extreme precipitation events over West Africa are sensitive to the ongoing land modification.

Ebola in West Africa--CDC's Role in Epidemic Detection, Control, and Prevention.

PubMed

Frieden, Thomas R; Damon, Inger K

2015-11-01

Since Ebola virus disease was identified in West Africa on March 23, 2014, the Centers for Disease Control and Prevention (CDC) has undertaken the most intensive response in the agency's history; >3,000 staff have been involved, including >1,200 deployed to West Africa for >50,000 person workdays. Efforts have included supporting incident management systems in affected countries; mobilizing partners; and strengthening laboratory, epidemiology, contact investigation, health care infection control, communication, and border screening in West Africa, Nigeria, Mali, Senegal, and the United States. All efforts were undertaken as part of national and global response activities with many partner organizations. CDC was able to support community, national, and international health and public health staff to prevent an even worse event. The Ebola virus disease epidemic highlights the need to strengthen national and international systems to detect, respond to, and prevent the spread of future health threats.

Lessons of Risk Communication and Health Promotion - West Africa and United States.

PubMed

Bedrosian, Sara R; Young, Cathy E; Smith, Laura A; Cox, Joanne D; Manning, Craig; Pechta, Laura; Telfer, Jana L; Gaines-McCollom, Molly; Harben, Kathy; Holmes, Wendy; Lubell, Keri M; McQuiston, Jennifer H; Nordlund, Kristen; O'Connor, John; Reynolds, Barbara S; Schindelar, Jessica A; Shelley, Gene; Daniel, Katherine Lyon

2016-07-08

During the response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC addressed the disease on two fronts: in the epidemic epicenter of West Africa and at home in the United States. Different needs drove the demand for information in these two regions. The severity of the epidemic was reflected not only in lives lost but also in the amount of fear, misinformation, and stigma that it generated worldwide. CDC helped increase awareness, promoted actions to stop the spread of Ebola, and coordinated CDC communication efforts with multiple international and domestic partners. CDC, with input from partners, vastly increased the number of Ebola communication materials for groups with different needs, levels of health literacy, and cultural preferences. CDC deployed health communicators to West Africa to support ministries of health in developing and disseminating clear, science-based messages and promoting science-based behavioral interventions. Partnerships in West Africa with local radio, television, and cell phone businesses made possible the dissemination of messages appropriate for maximum effect. CDC and its partners communicated evolving science and risk in a culturally appropriate way to motivate persons to adapt their behavior and prevent infection with and spread of Ebola virus. Acknowledging what is and is not known is key to effective risk communication, and CDC worked with partners to integrate health promotion and behavioral and cultural knowledge into the response to increase awareness of the actual risk for Ebola and to promote protective actions and specific steps to stop its spread. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Public policies and health systems in Sahelian Africa: theoretical context and empirical specificity

PubMed Central

2015-01-01

This research on user fee removal in three African countries is located at the interface of public policy analysis and health systems research. Public policy analysis has gradually become a vast and multifaceted area of research consisting of a number of perspectives. But the context of public policies in Sahelian Africa has some specific characteristics. They are largely shaped by international institutions and development agencies, on the basis of very common 'one-size-fits-all' models; the practical norms that govern the actual behaviour of employees are far removed from official norms; public goods and services are co-delivered by a string of different actors and institutions, with little coordination between them; the State is widely regarded by the majority of citizens as untrustworthy. In such a context, setting up and implementing health user fee exemptions in Burkina Faso, Mali and Niger was beset by major problems, lack of coherence and bottlenecks that affect public policy-making and implementation in these countries. Health systems research for its part started to gain momentum less than twenty years ago and is becoming a discipline in its own right. But French-speaking African countries scarcely feature in it, and social sciences are not yet fully integrated. This special issue wants to fill the gap. In the Sahel, the bad health indicators reflect a combination of converging factors: lack of health centres, skilled staff, and resources; bad quality of care delivery, corruption, mismanagement; absence of any social security or meaningful commitment to the worst-off; growing competition from drug peddlers on one side, from private clinics on the other. Most reforms of the health system have various 'blind spots'. They do not take in account the daily reality of its functioning, its actual governance, the implicit rationales of the actors involved, and the quality of healthcare provision. In order to document the numerous neglected problems of the health

The British and curriculum development in West Africa: A historical discourse

NASA Astrophysics Data System (ADS)

Ofori-Attah, Kwabena Dei

2006-09-01

THE BRITISH AND CURRICULUM DEVELOPMENT IN WEST AFRICA: A HISTORICAL STUDY - Only recently have African nations begun to make their way towards establishing genuinely autonomous education systems incorporating elements of indigenous culture. The present study examines the historical development of curriculum in British West Africa in its links with the educational activities of the early Christian missionaries and the imposition of British colonial rule. For over 300 years, the curriculum content was essentially European in nature. African interests and cultural practices were largely excluded, as "bookwork" was favored over "handwork". The colonial curriculum also helped introduce a new social order to West Africa, leading to the rise of new local elites reading, writing, and speaking foreign European languages. This study explores how the idea of a "civilized" person, promoted through the colonial school curriculum, developed new local elites with different sets of values and expectations that often made them strangers in their own societies. It also describes the connection between this curriculum and the repeated failure of education-reform efforts.

Building Sustainable Local Capacity for Global Health Research in West Africa.

PubMed

Sam-Agudu, Nadia A; Paintsil, Elijah; Aliyu, Muktar H; Kwara, Awewura; Ogunsola, Folasade; Afrane, Yaw A; Onoka, Chima; Awandare, Gordon A; Amponsah, Gladys; Cornelius, Llewellyn J; Mendy, Gabou; Sturke, Rachel; Ghansah, Anita; Siberry, George K; Ezeanolue, Echezona E

Global health research in resource-limited countries has been largely sponsored and led by foreign institutions. Thus, these countries' training capacity and productivity in global health research is limited. Local participation at all levels of global health knowledge generation promotes equitable access to evidence-based solutions. Additionally, leadership inclusive of competent local professionals promotes best outcomes for local contextualization and implementation of successful global health solutions. Among the sub-Saharan African regions, West Africa in particular lags in research infrastructure, productivity, and impact in global health research. In this paper, experts discuss strategies for scaling up West Africa's participation in global health evidence generation using examples from Ghana and Nigeria. We conducted an online and professional network search to identify grants awarded for global health research and research education in Ghana and Nigeria. Principal investigators, global health educators, and representatives of funding institutions were invited to add their knowledge and expertise with regard to strengthening research capacity in West Africa. While there has been some progress in obtaining foreign funding, foreign institutions still dominate local research. Local research funding opportunities in the 2 countries were found to be insufficient, disjointed, poorly sustained, and inadequately publicized, indicating weak infrastructure. As a result, research training programs produce graduates who ultimately fail to launch independent investigator careers because of lack of mentoring and poor infrastructural support. Research funding and training opportunities in Ghana and Nigeria remain inadequate. We recommend systems-level changes in mentoring, collaboration, and funding to drive the global health research agenda in these countries. Additionally, research training programs should be evaluated not only by numbers of individuals graduated but

Prevalence, determinants and systems-thinking approaches to optimal hypertension control in West Africa

PubMed Central

2014-01-01

Background In West Africa, hypertension, once rare, has now emerged as a critical health concern and the trajectory is upward and factors are complex. The true magnitude of hypertension in some West African countries, including in-depth knowledge of underlying risk factors is not completely understood. There is also a paucity of research on adequate systems-level approaches designed to mitigate the growing burden of hypertension in the region. Aims In this review, we thematically synthesize available literature pertaining to the prevalence of hypertension in West Africa and discuss factors that influence its diagnosis, treatment and control. We aimed to address the social and structural determinants influencing hypertension in the sub-region including the effects of urbanization, health infrastructure and healthcare workforce. Findings The prevalence of hypertension in West Africa has increased over the past decade and is rising rapidly with an urban-rural gradient that places higher hypertension prevalence on urban settings compared to rural settings. Overall levels of awareness of one’s hypertension status remain consistently low in West African. Structural and economic determinants related to conditions of poverty such as insufficient finances have a direct impact on adherence to prescribed antihypertensive medications. Urbanization contributes to the increasing incidence of hypertension in the sub-region and available evidence indicates that inadequate health infrastructure may act as a barrier to optimal hypertension control in West Africa. Conclusion Given that optimal hypertension control in West Africa depends on multiple factors that go beyond simply modifying the behaviors of the individuals alone, we conclude by discussing the potential role systems-thinking approaches can play to achieve optimal control in the sub-region. In the context of recent advances in hypertension management including new therapeutic options and innovative solutions to expand

The change-makers of West Africa.

PubMed

Godt, Sue; Mhatre, Sharmila; Schryer-Roy, Anne-Marie

2017-07-12

West Africa was the focus of global attention during the Ebola virus disease outbreak, when systemic health system weaknesses compounded a serious emergency and complicated response efforts. Following the crisis, calls were made to strengthen health systems, but investments to date have fallen short of delivering the support needed to build strong health systems able to prevent and manage future outbreaks.In part, this reality serves to highlight the shortcomings of the solutions being repeatedly prioritised by external funders and experts, solutions that often fail to consider the wealth of West African evidence and actors actively working to strengthen the leadership and health systems needed to drive and sustainably improve national health outcomes. Unfortunately, this knowledge and experience are rarely heard in the global arena.This journal supplement is a contribution, although small, to changing this practice by putting the perspectives, experiences and knowledge of West Africans on the table. It presents findings from a series of research and capacity development projects in West Africa funded by the International Development Research Centre's Maternal and Child Health programme (formerly Governance for Equity in Health Systems).The evidence presented here centres around two key themes. First, the theme that context matters. The evidence shows how context can change the shape of externally imposed interventions or policies resulting in unintended outcomes. At the same time, it highlights evidence showing how innovative local actors are developing their own approaches, usually low-cost and embedded in the context, to bring about change. Second, the collection of articles discusses the critical need to overcome the existing fragmentation of expertise, knowledge and actors, and to build strong working relationships amongst all actors so they can effectively work together to identify priority issues that can realistically be addressed given the available

A Survey of Synoptic Waves over West Africa

NASA Astrophysics Data System (ADS)

Cheng, Yuan-Ming; Thorncroft, Chris D.; Kiladis, George N.

2017-04-01

Motivated by the pronounced wave-to-wave variability in African easterly wave (AEW) circulation, the three-dimensional structure of synoptic waves over West Africa is revisited with an Empirical Orthogonal Function (EOF) approach to isolate the dominant wave pattern. In this talk we present results of EOF analyses conducted with brightness temperature (Tb) derived from satellite observation and meridional wind at multiple levels from reanalysis data to examine the characteristics and variability of synoptic waves. The structure of waves is extracted by projecting the wind fields and Tb onto the principle components associated with EOF patterns of appropriately filtered parameters. The Tb EOF shows a confined AEW circulation centered around 7.5°N and a distinct evolution of convection within the wave in line with previous research. However, in striking contrast to the confined flow pattern in the Tb EOF, the EOF of 700-hPa meridional wind is distinguished by a meridionally broad AEW circulation. While the peak in circulation is centered around 10°N, there is marked cross-equatorial flow that is associated with an antisymmetric geopotential signature across the equator. This suggests the presence of a mixed Rossby-gravity wave (MRG) structure consistent with Matsuno's shallow water theory. Granted that the vast majority of studies on MRGs focus on the central and western Pacific region, this "hybrid" between AEWs and MRGs over West Africa and Atlantic sector has received little attention and more work regarding the nature and causes of its wave structure and behavior is needed. In addition, an upper-level synoptic wave is captured by EOFs of 200-hPa meridional wind. The kinematic fields reveal a continental-scale wave straddling the equator that resembles an MRG. This upper-level MRG appears to develop in situ over the Horn of Africa and intensifies as it moves across the continent. The associated lower-level structure shows an AEW-like circulation but with a

The development of cardiac surgery in West Africa-the case of Ghana

PubMed Central

Edwin, Frank; Tettey, Mark; Aniteye, Ernest; Tamatey, Martin; Sereboe, Lawrence; Entsua-Mensah, Kow; Kotei, David; Baffoe-Gyan, Kofi

2011-01-01

West Africa is one of the poorest regions of the world. The sixteen nations listed by the United Nations in this sub-region have some of the lowest gross domestic products in the world. Health care infrastructure is deficient in most of these countries. Cardiac surgery, with its heavy financial outlay is unavailable in many West African countries. These facts notwithstanding, some West African countries have a proud history of open heart surgery not very well known even in African health care circles. Many African health care givers are under the erroneous impression that the cardiovascular surgical landscape of West Africa is blank. However, documented reports of open-heart surgery in Ghana dates as far back as 1964 when surface cooling was used by Ghanaian surgeons to close atrial septal defects. Ghana's National Cardiothoracic Center is still very active and is accredited by the West African College of Surgeons for the training of cardiothoracic surgeons. Reports from Nigeria indicate open-heart surgery taking place from 1974. Cote D'Ivoire had reported on its first 300 open-heart cases by 1983. Senegal reported open-heart surgery from 1995 and still runs an active center. Cameroon started out in 2009 with work done by an Italian group that ultimately aims to train indigenous surgeons to run the program. This review traces the development and current state of cardiothoracic surgery in West Africa with Ghana's National Cardiothoracic Center as the reference. It aims to dispel the notion that there are no major active cardiothoracic centers in the West African sub-region. PMID:22355425

Diagnoses of HIV-1 and HIV-2 in England, Wales, and Northern Ireland associated with west Africa.

PubMed

Dougan, S; Patel, B; Tosswill, J H; Sinka, K

2005-08-01

To describe HIV diagnoses, including those of HIV-2 infection, made in England, Wales, and Northern Ireland (E,W&NI) among those probably infected in west Africa, and to consider whether there is evidence for ongoing heterosexual transmission within the United Kingdom. Reports of new HIV diagnoses received at the Communicable Disease Surveillance Centre were analysed. Individuals probably infected in west Africa and those infected through heterosexual intercourse within the United Kingdom by a heterosexual partner infected in west Africa were included. Between 1985 and 2003 inclusive, 1324 individuals diagnosed and reported with HIV had probably been infected in west Africa, with 222 diagnoses made in 2003. 917 (69%) were HIV-1 infected and 52 (6%) HIV-2 or HIV-1/HIV-2 co-infected. For 355 (27%) the HIV type was not reported. The proportion of HIV-2 and HIV-1/HIV-2 infections varied by country of infection (p<0.001): ranging from the Gambia (11.7%-15.2%) to Nigeria (0.7%-1.0%). A further 130 individuals were probably infected through heterosexual intercourse within the United Kingdom by a heterosexual partner infected in west Africa. 89 (68%) were HIV-1 infected and three (2%) HIV-2 infected or HIV-1/HIV-2 co-infected. For 38 (29%) HIV type was not reported. The number of people infected with HIV in west Africa and diagnosed in E,W&NI has increased in recent years, and there is evidence of heterosexual transmission within the United Kingdom from people infected in west Africa. While numbers of HIV-2 diagnoses remain relatively low, an appreciable proportion of people infected in some west African countries and diagnosed in the United Kingdom may be HIV-2 positive, with implications for prognosis and treatment.

A pilot survey of pediatric surgical capacity in West Africa.

PubMed

Okoye, Mekam T; Ameh, Emmanuel A; Kushner, Adam L; Nwomeh, Benedict C

2015-03-01

While some data exist for the burden of pediatric surgical disease in low- and middle-income countries (LMICs), little is known about pediatric surgical capacity. In an effort to better plan and allocate resources for pediatric surgical care in LMICs, a survey of pediatric surgical capacity using specific tool was needed. Based on the previously published Surgeons OverSeas Personnel, Infrastructure, Procedure, Equipment, and Supplies (PIPES) survey, a pediatric PIPES (PediPIPES) survey was created. To ensure relevance to local needs and inclusion of only essential items, a draft PediPIPES survey was reviewed by nine pediatric surgeons and modifications were incorporated into a final tool. The survey was then distributed to surgeons throughout sub-Saharan Africa. Data from West Africa (37 hospitals in 10 of the 16 countries in the subregion) were analyzed. Fewer than 50% (18/37) of the hospitals had more than two pediatric surgeons. Neonatal or general intensive care units were not available in 51.4% (19/37) of hospitals. Open procedures such as appendectomy were performed in all the hospitals whereas less-invasive interventions such as non-operative intussusception reduction were done in only 41% (15/37). Life-saving pediatric equipment such as apnea monitors were not available in 65% (24/37) of the hospitals. The PediPIPES survey was useful in documenting the pediatric surgical capacity in West Africa. Many hospitals in West Africa are not optimally prepared to undertake pediatric surgery. Our study showed shortages in personnel, infrastructure, procedures, equipment, and supplies necessary to adequately and appropriately provide surgical care for pediatric patients.

Logical Demonomy Among the Ewe in West Africa

ERIC Educational Resources Information Center

Dzobo, N. K.

1974-01-01

Examines the indigenous pattern of moral behavior among the Ewe, an ethnic and linguistic group in West Africa, and assesses its role in moral education within the African context. The author develops a conceptual framework he calls "logical demonomy" that he uses to define the Ewe system of moral laws. (JT)

Identification of statistically independent climatic pattern in GRACE and hydrological model data over West-Africa

NASA Astrophysics Data System (ADS)

Kusche, J.; Forootan, E.; Eicker, A.; Hoffmann-Dobrev, H.

2012-04-01

West-African countries have been exposed to changes in rainfall patterns over the last decades, including a significant negative trend. This causes adverse effects on water resources, for instance reduced freshwater availability, and changes in the frequency, duration and magnitude of droughts and floods. Extracting the main patterns of water storage change in West Africa from remote sensing and linking them to climate variability, is therefore an essential step to understand the hydrological aspects of the region. In this study, the higher order statistical method of Independent Component Analysis (ICA) is employed to extract statistically independent water storage patterns from monthly Gravity Recovery And Climate Experiment (GRACE), from the WaterGAP Global Hydrology Model (WGHM) and from Tropical Rainfall Measuring Mission (TRMM) products over West Africa, for the period 2002-2012. Then, to reveal the influences of climatic teleconnections on the individual patterns, these results were correlated to the El Nino-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) indices. To study the predictability of water storage changes, advanced statistical methods were applied on the main independent Sea Surface Temperature (SST) patterns over the Atlantic and Indian Oceans for the period 2002-2012 and the ICA results. Our results show a water storage decrease over the coastal regions of West Africa (including Sierra Leone, Liberia, Togo and Nigeria), associated with rainfall decrease. The comparison between GRACE estimations and WGHM results indicates some inconsistencies that underline the importance of forcing data for hydrological modeling of West Africa. Keywords: West Africa; GRACE-derived water storage; ICA; ENSO; IOD

First highlights of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) field campaigns

NASA Astrophysics Data System (ADS)

Liousse, C.; Knippertz, P.; Flamant, C.; Adon, J.; Akpo, A.; Annesi-Maesano, I.; Assamoi, E.; Baeza, A.; Julien, B.; Bedou, M.; Brooks, B. J.; Chiu, J. Y. C.; Chiron, C.; Coe, H.; Danuor, S.; Djossou, J.; Evans, M. J.; Fayomi, B.; Fink, A. H.; Galy-Lacaux, C.; Gardrat, E.; Jegede, O.; Kalthoff, N.; Kedote, M.; Keita, S.; Kouame, K.; Konare, A.; Leon, J. F.; Mari, C. H.; Lohou, F.; Roblou, L.; Schlager, H.; Schwarzenboeck, A.; Toure, E. N.; Veronique, Y.

2016-12-01

The EU-funded project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) is investigating the relationship between weather, climate, air pollution and health in southern West Africa. The air over the coastal region of West Africa is a unique mixture of natural and anthropogenic gases, liquids and particles, emitted in an environment, in which multi-layer cloud decks frequently form. These exert a large influence on the local weather and climate, which has never been studied in detail over West Africa: this information is currently not included in the majority of weather and climate models. For the first time, the entire chain of impacts of natural and manmade emissions on the West African atmosphere was investigated in a coordinated field campaign. As part of this campaign, three research aircraft (Falcon 20, Twin Otter and ATR) based in Lomé (Togo) flew targeted 50 missions over West Africa from 27 June to 16 July 2016. In that campaign also, three highly instrumented measuring sites inland were set up with weather balloons launched several times a day across the region. The main objective was to build robust statistics of cloud properties in southern West Africa in different chemical landscapes (background state, ship/flaring emissions, polluted megacities, agricultural and forest areas, dust from the Sahel/Sahara). In addition, DACCIWA scientists working on measurements of urban emissions, air pollution, and health have set up four urban sites in Abidjan (Cote d'Ivoire) and Cotonou (Benin) focusing on main specific regional combustion sources (domestic fires, traffic and waste burning). Long-term measurements of gases and particles and census of hospital admissions for respiratory diseases were started in January 2015 and will continue until March 2017 to determine the links between human health and air pollution. Intensive measurement periods took place in July 2015, January 2016, and July 2016 (a final one is planned for January 2017) in

Vulnerability to changes in malaria transmission due to climate change in West Africa

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Eltahir, E. A.

2012-12-01

Malaria transmission in West Africa is strongly tied to climate; temperature affects the development rate of the malaria parasite, as well as the survival of the mosquitoes that transmit the disease, and rainfall is tied to mosquito abundance, as the vector lays its eggs in rain-fed water pools. As a result, the environmental suitability for malaria transmission in this region is expected to change as temperatures rise and rainfall patterns are altered. The vulnerability to changes in transmission varies throughout West Africa. Areas where malaria prevalence is already very high will be less sensitive to changes in transmission. Increases in environmental suitability for malaria transmission in the most arid regions may still be insufficient to allow sustained transmission. However, areas were malaria transmission currently occurs at low levels are expected to be the most sensitive to changes in environmental suitability for transmission. Here, we use data on current environment and malaria transmission rates to highlight areas in West Africa that we expect to be most vulnerable to an increase in malaria under certain climate conditions. We then analyze climate predictions from global climate models in vulnerable areas, and make predictions for the expected change in environmental suitability for malaria transmission using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS), a mechanistic model developed to simulate village-scale response of malaria transmission to environmental variables in West Africa.

Evaluation of rainfall simulations over West Africa in dynamically downscaled CMIP5 global circulation models

NASA Astrophysics Data System (ADS)

Akinsanola, A. A.; Ajayi, V. O.; Adejare, A. T.; Adeyeri, O. E.; Gbode, I. E.; Ogunjobi, K. O.; Nikulin, G.; Abolude, A. T.

2018-04-01

This study presents evaluation of the ability of Rossby Centre Regional Climate Model (RCA4) driven by nine global circulation models (GCMs), to skilfully reproduce the key features of rainfall climatology over West Africa for the period of 1980-2005. The seasonal climatology and annual cycle of the RCA4 simulations were assessed over three homogenous subregions of West Africa (Guinea coast, Savannah, and Sahel) and evaluated using observed precipitation data from the Global Precipitation Climatology Project (GPCP). Furthermore, the model output was evaluated using a wide range of statistical measures. The interseasonal and interannual variability of the RCA4 were further assessed over the subregions and the whole of the West Africa domain. Results indicate that the RCA4 captures the spatial and interseasonal rainfall pattern adequately but exhibits a weak performance over the Guinea coast. Findings from the interannual rainfall variability indicate that the model performance is better over the larger West Africa domain than the subregions. The largest difference across the RCA4 simulated annual rainfall was found in the Sahel. Result from the Mann-Kendall test showed no significant trend for the 1980-2005 period in annual rainfall either in GPCP observation data or in the model simulations over West Africa. In many aspects, the RCA4 simulation driven by the HadGEM2-ES perform best over the region. The use of the multimodel ensemble mean has resulted to the improved representation of rainfall characteristics over the study domain.

The Predictability of Dry-Season Precipitation in Tropical West Africa

NASA Astrophysics Data System (ADS)

Knippertz, P.; Davis, J.; Fink, A. H.

2012-04-01

Precipitation during the boreal winter dry season in tropical West Africa is rare but occasionally connected to high-impacts for the local population. Previous work has shown that these events are usually connected to a trough over northwestern Africa, an extensive cloud plume on its eastern side, unusual precipitation at the northern and western fringes of the Sahara, and reduced surface pressure over the southern Sahara and Sahel, which allows an inflow of moist southerlies from the Gulf of Guinea to feed the unusual dry-season rainfalls. These results also suggest that the extratropical influence enhances the predictability of these events on the synoptic timescale. Here we further investigate this question for the 11 dry seasons (November-March) 1998/99-2008/09 using rainfall estimates from TRMM (Tropical Rainfall Measuring Mission) and GPCP (Global Precipitation Climatology Project), and operational ensemble predictions from the European Centre for Medium-Range Forecasts (ECMWF). All fields are averaged over the study area 7.5-15°N, 10°W-10°E that spans most of southern West Africa. For each 0000 UTC analysis time, the daily precipitation estimates are accumulated to pentads and compared with 120-hour predictions starting at the same time. Compared to TRMM, the ensemble mean shows a weak positive bias, whereas there is a substantial negative bias with regard to GPCP. Temporal correlations reach a high value of 0.8 for both datasets, showing similar synoptic variability despite the differences in total amount. Standard probabilistic evaluation methods such as relative operating characteristic (ROC) diagrams indicate remarkably good reliability, resolution and skill, particularly for lower precipitation thresholds. Not surprisingly, forecasts cluster at low probabilities for higher thresholds, but the reliability and ROC score are still reasonably high. The results show that global ensemble prediction systems are capable to predict dry-season rainfall events

Impact of the Indian part of the summer MJO on West Africa using nudged climate simulations

NASA Astrophysics Data System (ADS)

Mohino, Elsa; Janicot, Serge; Douville, Hervé; Li, Laurent Z. X.

2012-06-01

Observational evidence suggests a link between the summer Madden Julian Oscillation (MJO) and anomalous convection over West Africa. This link is further studied with the help of the LMDZ atmospheric general circulation model. The approach is based on nudging the model towards the reanalysis in the Asian monsoon region. The simulation successfully captures the convection associated with the summer MJO in the nudging region. Outside this region the model is free to evolve. Over West Africa it simulates convection anomalies that are similar in magnitude, structure, and timing to the observed ones. In accordance with the observations, the simulation shows that 15-20 days after the maximum increase (decrease) of convection in the Indian Ocean there is a significant reduction (increase) in West African convection. The simulation strongly suggests that in addition to the eastward-moving MJO signal, the westward propagation of a convectively coupled equatorial Rossby wave is needed to explain the overall impact of the MJO on convection over West Africa. These results highlight the use of MJO events to potentially predict regional-scale anomalous convection and rainfall spells over West Africa with a time lag of approximately 15-20 days.

Teaching in West Africa: Dig beneath the Surface

ERIC Educational Resources Information Center

Briam, Carol

2007-01-01

In this article, the author shares her experience teaching English to adult learners at the American Cultural Center in Dakar, Senegal, a poor, primarily Muslim country and former French colony in West Africa. Her class was composed of about 30 students, whose age ranged from about 18 to 50. They were mostly men and mostly Senegalese, along with a…

AIDS wanes in West, grows in Africa and Asia.

PubMed

Worldwide, at least 22 million people have been infected with HIV. The overwhelming majority of these cases, however, are in sub-Saharan Africa, Thailand, and India; approximately 15-20 million people are infected with the total number rapidly increasing. Approximately two million people are infected in the West, and the rate and extent of HIV infection are either plateauing or decreasing. In the West, HIV is contracted primarily through homosexual contact and IV drug use. HIV1-B is the prevalent strain of HIV in such settings. HIV in South Asia and sub-Saharan Africa, however, is mainly transmitted through heterosexual contact and consists of HIV-1 strains A, C, and E. There are therefore two distinct HIV epidemics taking place. Professor Max Essex of the Harvard AIDS Institute noted in his address at a conference on infectious diseases in New Delhi, India, that most planned vaccines and therapy for AIDS were developed in the West and thus targeted to combat HIV1-B. It seems likely, however, that other HIV subtypes will also take hold in the West and that an heterosexual epidemic of considerable magnitude should be anticipated. The high rate of HIV genetic mutation is of concern for both AIDS prevention and treatment. Essex further pointed out that the growing cost of treating AIDS patients with increasingly long lives has prompted a shift in the core of AIDS research from therapy to prevention. That levels of awareness about HIV/AIDS and the extent of sex education among youth are higher in more developed countries compared to in developing countries may play a role in the relatively lower incidence of new HIV cases in the West.

On the stationarity of Floods in west African rivers

NASA Astrophysics Data System (ADS)

NKA, B. N.; Oudin, L.; Karambiri, H.; Ribstein, P.; Paturel, J. E.

2014-12-01

West Africa undergoes a big change since the years 1970-1990, characterized by very low precipitation amounts, leading to low stream flows in river basins, except in the Sahelian region where the impact of human activities where pointed out to justify the substantial increase of floods in some catchments. More recently, studies showed an increase in the frequency of intense rainfall events, and according to observations made over the region, increase of flood events is also noticeable during the rainy season. Therefore, the assumption of stationarity on flood events is questionable and the reliability of flood evolution and climatic patterns is justified. In this work, we analyzed the trends of floods events for several catchments in the Sahelian and Sudanian regions of Burkina Faso. We used thirteen tributaries of large river basins (Niger, Nakambe, Mouhoun, Comoé) for which daily rainfall and flow data were collected from national hydrological and meteorological services of the country. We used Mann-Kendall and Pettitt tests to detect trends and break points in the annual time series of 8 rainfall indices and the annual maximum discharge records. We compare the trends of precipitation indices and flood size records to analyze the possible causality link between floods size and rainfall pattern. We also analyze the stationary of the frequency of flood exceeding the ten year return period level. The samples were extracted by a Peak over threshold method and the quantification of change in flood frequency was assessed by using a test developed by Lang M. (1995). The results exhibit two principal behaviors. Generally speaking, no trend is detected on catchments annual maximum discharge, but positive break points are pointed out in a group of three right bank tributaries of the Niger river that are located in the sahelian region between 300mm to 650mm. These same catchments show as well an increase of the yearly number of flood greater than the ten year flood since

77 FR 74265 - In the Matter of the Designation of Movement for Unity and Jihad in West Africa; Also Known as...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

... DEPARTMENT OF STATE [Public Notice 8114] In the Matter of the Designation of Movement for Unity and Jihad in West Africa; Also Known as Movement for Oneness and Jihad in West Africa; Also Known as Unity Movement for Jihad in West Africa; Also Known as Jamat Tawhid Wal Jihad Fi Garbi Afriqqiya; Also...

Contrasting modes of rifting: The Benue Trough and Cameroon Volcanic Line, West Africa

NASA Astrophysics Data System (ADS)

Okereke, C. S.

1988-08-01

The Benue trough of west Africa is commonly believed to be a rift feature that originated in the Cretaceous at about the time that Africa and South America began to separate. Bouguer gravity and available geological data in the trough indicate that its formation was probably the result of regional horizontal stresses in the lithosphere, causing crustal extension and surface subsidence. By contrast, the data for the adjoining Cameroon volcanic line suggests that the associated tensional stresses relate to mantle upwarp causing thinning of the lithosphere and regional crustal uplift similar to that associated with the Kenya rift. Thus the association of passive and active rifts seen in the Afro-Arabia rift system is also a feature of the Cretaceous rift system in west Africa.

Sahelian springtime heat waves and their evolution over the past 60 years

NASA Astrophysics Data System (ADS)

Barbier, Jessica; Guichard, Françoise; Bouniol, Dominique; Couvreux, Fleur; Roehrig, Romain

2017-04-01

hotter. The explanations for the differences between the heat indexes will be discussed. The ability of the three reanalyses ERA-Interim, NCEP2 and MERRA to reproduce Sahelian heat wave properties and their associated trends was further assessed on the period 1979-2010. At this shorter scale, we did not find any significant heat wave trend. Furthermore, reanalyses strongly differed in the representation of the heat wave inter-annual variability. These results raise concern about the utilization of meteorological reanalyses for the study of heat wave trends in West Africa.

Infection Prevention and Control for Ebola in Health Care Settings - West Africa and United States.

PubMed

Hageman, Jeffrey C; Hazim, Carmen; Wilson, Katie; Malpiedi, Paul; Gupta, Neil; Bennett, Sarah; Kolwaite, Amy; Tumpey, Abbigail; Brinsley-Rainisch, Kristin; Christensen, Bryan; Gould, Carolyn; Fisher, Angela; Jhung, Michael; Hamilton, Douglas; Moran, Kerri; Delaney, Lisa; Dowell, Chad; Bell, Michael; Srinivasan, Arjun; Schaefer, Melissa; Fagan, Ryan; Adrien, Nedghie; Chea, Nora; Park, Benjamin J

2016-07-08

The 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa underscores the need for health care infection prevention and control (IPC) practices to be implemented properly and consistently to interrupt transmission of pathogens in health care settings to patients and health care workers. Training and assessing IPC practices in general health care facilities not designated as Ebola treatment units or centers became a priority for CDC as the number of Ebola virus transmissions among health care workers in West Africa began to affect the West African health care system and increasingly more persons became infected. CDC and partners developed policies, procedures, and training materials tailored to the affected countries. Safety training courses were also provided to U.S. health care workers intending to work with Ebola patients in West Africa. As the Ebola epidemic continued in West Africa, the possibility that patients with Ebola could be identified and treated in the United States became more realistic. In response, CDC, other federal components (e.g., Office of the Assistant Secretary for Preparedness and Response) and public health partners focused on health care worker training and preparedness for U.S. health care facilities. CDC used the input from these partners to develop guidelines on IPC for hospitalized patients with known or suspected Ebola, which was updated based on feedback from partners who provided care for Ebola patients in the United States. Strengthening and sustaining IPC helps health care systems be better prepared to prevent and respond to current and future infectious disease threats.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Biological and phylogenetic characteristics of yellow fever virus lineages from West Africa.

PubMed

Stock, Nina K; Laraway, Hewád; Faye, Ousmane; Diallo, Mawlouth; Niedrig, Matthias; Sall, Amadou A

2013-03-01

The yellow fever virus (YFV), the first proven human-pathogenic virus, although isolated in 1927, is still a major public health problem, especially in West Africa where it causes outbreaks every year. Nevertheless, little is known about its genetic diversity and evolutionary dynamics, mainly due to a limited number of genomic sequences from wild virus isolates. In this study, we analyzed the phylogenetic relationships of 24 full-length genomes from YFV strains isolated between 1973 and 2005 in a sylvatic context of West Africa, including 14 isolates that had previously not been sequenced. By this, we confirmed genetic variability within one genotype by the identification of various YF lineages circulating in West Africa. Further analyses of the biological properties of these lineages revealed differential growth behavior in human liver and insect cells, correlating with the source of isolation and suggesting host adaptation. For one lineage, repeatedly isolated in a context of vertical transmission, specific characteristics in the growth behavior and unique mutations of the viral genome were observed and deserve further investigation to gain insight into mechanisms involved in YFV emergence and maintenance in nature.

Biological and Phylogenetic Characteristics of Yellow Fever Virus Lineages from West Africa

PubMed Central

Laraway, Hewád; Faye, Ousmane; Diallo, Mawlouth; Niedrig, Matthias

2013-01-01

The yellow fever virus (YFV), the first proven human-pathogenic virus, although isolated in 1927, is still a major public health problem, especially in West Africa where it causes outbreaks every year. Nevertheless, little is known about its genetic diversity and evolutionary dynamics, mainly due to a limited number of genomic sequences from wild virus isolates. In this study, we analyzed the phylogenetic relationships of 24 full-length genomes from YFV strains isolated between 1973 and 2005 in a sylvatic context of West Africa, including 14 isolates that had previously not been sequenced. By this, we confirmed genetic variability within one genotype by the identification of various YF lineages circulating in West Africa. Further analyses of the biological properties of these lineages revealed differential growth behavior in human liver and insect cells, correlating with the source of isolation and suggesting host adaptation. For one lineage, repeatedly isolated in a context of vertical transmission, specific characteristics in the growth behavior and unique mutations of the viral genome were observed and deserve further investigation to gain insight into mechanisms involved in YFV emergence and maintenance in nature. PMID:23269797

Vectorborne diseases in West Africa: geographic distribution and geospatial characteristics.

PubMed

Ratmanov, Pavel; Mediannikov, Oleg; Raoult, Didier

2013-05-01

This paper provides an overview of the methods in which geographic information systems (GIS) and remote sensing (RS) technology have been used to visualise and analyse data related to vectorborne diseases (VBD) in West Africa and to discuss the potential for these approaches to be routinely included in future studies of VBDs. GIS/RS studies of diseases that are associated with a specific geographic landscape were reviewed, including malaria, human African trypanosomiasis, leishmaniasis, lymphatic filariasis, Loa loa filariasis, onchocerciasis, Rift Valley fever, dengue, yellow fever, borreliosis, rickettsioses, Buruli ulcer and Q fever. RS data and powerful spatial modelling methods improve our understanding of how environmental factors affect the vectors and transmission of VBDs. There is great potential for the use of GIS/RS technologies in the surveillance, prevention and control of vectorborne and other infectious diseases in West Africa.

Influence of Madden-Julian Oscillation (MJO) on Rainfall Variability over West Africa at Intraseasonal Timescale

NASA Astrophysics Data System (ADS)

Niang, C.

2015-12-01

Intraseasonal variability of rainfall over West Africa plays a significant role in the economy of the region and is highly linked to agriculture and water resources. This research study aims to investigate the relationship between Madden Julian Oscillation (MJO) and rainfall over West Africa during the boreal summer in the the state-of-the-art Atmospheric Model Intercomparison Project (AMIP) type simulations performed by Atmosphere General Circulation Models (GCMs) forced with prescribed Sea Surface Temperature (SST). It aims to determine the impact of MJO on rainfall and convection over West Africa and identify the dynamical processes which are involved in the state-of-the-art climate simulations. The simulations show in general good skills in capturing its main characteristics as well as its influence on rainfall over West Africa. On the global scale, most models simulated an eastward spatio-temporal propagation of enhanced and suppressed convection similar to the observed. However, over West Africa the MJO signal is weak in few of the models although there is a good coherence in the eastward propagation. The influence on rainfall is well captured in both Sahel and Guinea regions thereby adequately producing the transition between positive and negative rainfall anomalies through the different phases as seen in the observation. Furthermore, the results show that strong active convective phase is clearly associated with the African Easterly Jet (AEJ) but the weak convective phase is associated with a much weaker AEJ particularly over coastal Ghana. In assessing the mechanisms which are involved in the above impacts the convectively equatorial coupled waves (CCEW) are analysed separately. The analysis of the longitudinal propagation of zonal wind at 850hPa and outgoing longwave radiation (OLR) shows that the CCEW are very weak and their extention are very limited beyong West African region. It was found that the westward coupled equatorial Rossby waves are needed to

Laboratory Response to Ebola - West Africa and United States.

PubMed

Sealy, Tara K; Erickson, Bobbie R; Taboy, Céline H; Ströher, Ute; Towner, Jonathan S; Andrews, Sharon E; Rose, Laura E; Weirich, Elizabeth; Lowe, Luis; Klena, John D; Spiropoulou, Christina F; Rayfield, Mark A; Bird, Brian H

2016-07-08

The 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa highlighted the need to maintain organized laboratory systems or networks that can be effectively reorganized to implement new diagnostic strategies and laboratory services in response to large-scale events. Although previous Ebola outbreaks enabled establishment of critical laboratory practice safeguards and diagnostic procedures, this Ebola outbreak in West Africa highlighted the need for planning and preparedness activities that are better adapted to emerging pathogens or to pathogens that have attracted little commercial interest. The crisis underscored the need for better mechanisms to streamline development and evaluation of new diagnostic assays, transfer of material and specimens between countries and organizations, and improved processes for rapidly deploying health workers with specific laboratory expertise. The challenges and events of the outbreak forced laboratorians to examine not only the comprehensive capacities of existing national laboratory systems to recognize and respond to events, but also their sustainability over time and the mechanisms that need to be pre-established to ensure effective response. Critical to this assessment was the recognition of how response activities (i.e., infrastructure support, logistics, and workforce supplementation) can be used or repurposed to support the strengthening of national laboratory systems during the postevent transition to capacity building and recovery. This report compares CDC's domestic and international laboratory response engagements and lessons learned that can improve future responses in support of the International Health Regulations and Global Health Security Agenda initiatives.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Growth rates and milk production potential of Sahelian and Red Sokoto breeds of goats in northern Guinea Savannah.

PubMed

Makun, H J; Ajanusi, J O; Ehoche, O W; Lakpini, C A M; Otaru, S M

2008-02-15

The milk production potentials and growth rates of Red Sokoto and Sahelian goats fed basal diets of maize stover and Digitaria smutsii (wolly finger grass) supplemented with concentrate was investigated in two separate trials. In experiment 1, ten multi-parous does were allocated to intensive management following kidding. Does were hand-milked twice weekly and the milk production recorded. Body weight changes of dam and kid, milk fat, milk solid were determined weekly over 12 weeks period. The average birth weight of the Sahelian (2.2+/-0.23 kg) was significantly (p<0.05) higher than the Red Sokoto kids (1.0+/-0.17). At weaning age, the average kid weight of the Sahelian (5.6+/-0.42 kg) was significantly higher than the Red Sokoto (3.9+/-0.44 kg). There was no significant difference (p>0.05) in daily milk yield and total lactation between the two breeds. The total solids and milk fat of 16.4+/-0.39 and 3.7+/-0.13% were significantly (p<0.05) higher for the Red Sokoto than the Sahelian (15.1+/-0.39 and 3.2+/-0.13%). The second trial was to evaluate the comparative growth of the Sahelian and Red Sokoto breeds of goats. Animals were group-fed based on sex and fed Digitaria smutsii hay supplemented with concentrate. The growth trial lasted for 150 days with a 14 day digestibility trial. The Average Daily Gain (ADG) were significantly (p<0.05) different for breed, as well as sex. The Red Sokoto (66.9+/-1.59) kids had higher ADG than the Sahelian (46.6+/-1.59). Similarly the males of the Red Sokoto (61.9+/-1.59) had higher ADG than the Sahelian males (46.7+/-0.59) and the females of both breed. The experiments demonstrated a linear increase in weight gains of Red Sokoto over the Sahelian and a slightly higher milk yield obtained from the Sahelian providing the basis to conclude that the Sahelian goat can adapted and fit into the production systems of Sudan Savannah rural farmers.

Provisionally corrected surface wind data, worldwide ocean-atmosphere surface fields, and Sahelian rainfall variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, M.N.

Worldwide ship datasets of sea surface temperature (SST), sea level pressure (SLP), and surface vector wind are analyzed for a July-September composite of five Sahelian wet years (1950, 1952, 1953, 1954, 1958) minus five Sahelian dry years (1972, 1973, 1982, 1983, 1984) (W - D). The results are compared with fields for a number of individual years and for 1988 minus 1987 (88 - 87); Sahelian rainfall in 1988 was near the 1951-80 normal, whereas 1987 was very dry. An extensive study of the geostrophic consistency of trends in pressure gradients and observed wind was undertaken. The results suggest, duringmore » the period 1949-88, a mean increase in reported wind speed of about 16% that cannot be explained by trends in geostrophic winds derived from seasonal mean SLP. Estimates of the wind bias are averaged for 18 ocean regions. A map of correlations between Sahelian rainfall and SLP in all available ocean regions is shown to be field significant. Remote atmospheric associations with Sahelian rainfall are consistent with recent suggestions that SST forcing from the tropical Atlantic and the other ocean basins may contribute to variability in seasonal Sahelian rainfall. It is suggested that wetter years in the Sahel are often accompanied by a stronger surface monsoonal flow over the western Indian Ocean and low SLP in the tropical western Pacific near New Guinea, and that there is increased cyclonicity over the extratropical eastern North Atlantic and northwest Europe. In the tropical Atlantic, W - D shows many of the features identified by previous authors. However, the 88-87 fields do not reflect these large-scale tropical Atlantic changes. Instead there is only local strengthening of the pressure gradient and wind flow from Brazil to Senegal. Further individual years are presented (1958, 1972, 1975) to provide specific examples.« less

Evaluation of high-resolution climate simulations for West Africa using COSMO-CLM

NASA Astrophysics Data System (ADS)

Dieng, Diarra; Smiatek, Gerhard; Bliefernicht, Jan; Laux, Patrick; Heinzeller, Dominikus; Kunstmann, Harald; Sarr, Abdoulaye; Thierno Gaye, Amadou

2017-04-01

The climate change modeling activities within the WASCAL program (West African Science Service Center on Climate Change and Adapted Land Use) concentrate on the provisioning of future climate change scenario data at high spatial and temporal resolution and quality in West Africa. Such information is highly required for impact studies in water resources and agriculture for the development of reliable climate change adaptation and mitigation strategies. In this study, we present a detailed evaluation of high simulation runs based on the regional climate model, COSMO model in CLimate Mode (COSMO-CLM). The model is applied over West Africa in a nested approach with two simulation domains at 0.44° and 0.11° resolution using reanalysis data from ERA-Interim (1979-2013). The models runs are compared to several state-of-the-art observational references (e.g., CRU, CHIRPS) including daily precipitation data provided by national meteorological services in West Africa. Special attention is paid to the reproduction of the dynamics of the West African Monsoon (WMA), its associated precipitation patterns and crucial agro-climatological indices such as the onset of the rainy season. In addition, first outcomes of the regional climate change simulations driven by MPI-ESM-LR are presented for a historical period (1980 to 2010) and two future periods (2020 to 2050, 2070 to 2100). The evaluation of the reanalysis runs shows that COSMO-CLM is able to reproduce the observed major climate characteristics including the West African Monsoon within the range of comparable RCM evaluations studies. However, substantial uncertainties remain, especially in the Sahel zone. The added value of the higher resolution of the nested run is reflected in a smaller bias in extreme precipitation statistics with respect to the reference data.

Precipitation Characteristics in West and East Africa from Satellite and in Situ Observations

NASA Technical Reports Server (NTRS)

Dezfuli, Amin K.; Ichoku, Charles M.; Mohr, Karen I.; Huffman, George J.

2017-01-01

Using in situ data, three precipitation classes are identified for rainy seasons of West and East Africa: weak convective rainfall (WCR), strong convective rainfall (SCR), and mesoscale convective systems (MCSs).Nearly 75% of the total seasonal precipitation is produced by the SCR and MCSs, even though they represent only 8% of the rain events. Rain events in East Africa tend to have a longer duration and lower intensity than in West Africa, reflecting different characteristics of the SCR and MCS events in these two regions. Surface heating seems to be the primary convection trigger for the SCR, particularly in East Africa, whereas the WCR requires a dynamical trigger such as low-level convergence. The data are used to evaluate the performance of the recently launched Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG)project. The IMERG-based precipitation shows significant improvement over its predecessor, the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), particularly in capturing the MCSs, due to its improved temporal resolution.

The West Africa Disaster Preparedness Initiative: Strengthening National Capacities for All-Hazards Disaster Preparedness.

PubMed

Morton Hamer, Melinda J; Reed, Paul L; Greulich, Jane D; Kelen, Gabor D; Bradstreet, Nicole A; Beadling, Charles W

2017-08-01

The Ebola outbreak demonstrated the need for improved disaster response throughout West Africa. The West Africa Disaster Preparedness Initiative was a training and assessment effort led by US Africa Command and partners to strengthen capacities among 12 West African partner nations (PNs). Series of 3-week training sessions with representatives from each PN were held from 13 July through 20 November 2015 at the Kofi Annan International Peacekeeping Training Centre in Accra, Ghana. A team conducted Disaster Management Capabilities Assessments (DMCAs) for each PN, including a review of key data, a survey for leaders, and in-person interviews of key informants. All 12 PNs generated a national Ebola Preparedness and Response Plan and Emergency Operations Center standard operating procedures. DMCA metrics were generated for each PN. Top performers included Ghana, with a plan rated good/excellent, and Benin and Burkina Faso, which both achieved a satisfactory rating for their plans. More than 800 people from 12 nations were trained. PNs have improved disaster management capabilities and awareness of their strengths and weaknesses. The Economic Community of West African States has increased its lead role in this and future planned initiatives. (Disaster Med Public Health Preparedness. 2017;11:431-438).

Child Trafficking in West Africa: Policy Responses. Innocenti Insight.

ERIC Educational Resources Information Center

United Nations Children's Fund, Florence (Italy). Innocenti Research Centre.

This report examines policy responses and programming trends to combat the growing specter of child trafficking, focusing on the region of west and central Africa where strenuous advocacy efforts by UNICEF and its partners have helped to bring this problem to national and international attention. The report focuses on policy trends on child…

Ebola in West Africa.

PubMed

Raka, Lul; Guardo, Monica

2015-03-15

Ebola viral disease (EVD) is a severe and life-threatening disease. The current Ebola outbreak in West Africa entered its second year and is unprecedented because it is the largest one in history, involved urban centers and affected a large number of health care workers. It quickly escalated from medical into a humanitarian, social, economic, and security crisis. The primary pillars to prevent EVD are: early diagnosis, isolation of patients, contact tracing and monitoring, safe burials, infection prevention and control and social mobilization. The implementation of all these components was challenged in the field. Key lessons from this Ebola outbreak are that countries with weak health care systems can't withstand the major outbreaks; preparedness to treat the first confirmed cases is a national emergency; all control measures must be coordinated together and community engagement is the great factor to combat this disease.

Predicted impacts of climate change on malaria transmission in West Africa

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Eltahir, E. A. B.

2014-12-01

Increases in temperature and changes in precipitation due to climate change are expected to alter the spatial distribution of malaria transmission. This is especially true in West Africa, where malaria prevalence follows the current north-south gradients in temperature and precipitation. We assess the skill of GCMs at simulating past and present climate in West Africa in order to select the most credible climate predictions for the periods 2030-2060 and 2070-2100. We then use the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS), a mechanistic model of malaria transmission, to translate the predicted changes in climate into predicted changes availability of mosquito breeding sites, mosquito populations, and malaria prevalence. We investigate the role of acquired immunity in determining a population's response to changes in exposure to the malaria parasite.

Agriculture in West Africa in the Twenty-First Century: Climate Change and Impacts Scenarios, and Potential for Adaptation

PubMed Central

Sultan, Benjamin; Gaetani, Marco

2016-01-01

West Africa is known to be particularly vulnerable to climate change due to high climate variability, high reliance on rain-fed agriculture, and limited economic and institutional capacity to respond to climate variability and change. In this context, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. This review paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature. West Africa is nowadays experiencing a rapid climate change, characterized by a widespread warming, a recovery of the monsoonal precipitation, and an increase in the occurrence of climate extremes. The observed climate tendencies are also projected to continue in the twenty-first century under moderate and high emission scenarios, although large uncertainties still affect simulations of the future West African climate, especially regarding the summer precipitation. However, despite diverging future projections of the monsoonal rainfall, which is essential for rain-fed agriculture, a robust evidence of yield loss in West Africa emerges. This yield loss is mainly driven by increased mean temperature while potential wetter or drier conditions as well as elevated CO2 concentrations can modulate this effect. Potential for adaptation is illustrated for major crops in West Africa through a selection of studies based on process-based crop models to adjust cropping systems (change in varieties, sowing dates and density, irrigation, fertilizer management) to future climate. Results of the cited studies are crop and region specific and no clear conclusions can be made regarding the most effective adaptation options. Further efforts are needed to improve modeling of the monsoon system and to better quantify the uncertainty in its changes under a warmer climate, in the response of the crops to such

Agriculture in West Africa in the Twenty-First Century: Climate Change and Impacts Scenarios, and Potential for Adaptation.

PubMed

Sultan, Benjamin; Gaetani, Marco

2016-01-01

West Africa is known to be particularly vulnerable to climate change due to high climate variability, high reliance on rain-fed agriculture, and limited economic and institutional capacity to respond to climate variability and change. In this context, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. This review paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature. West Africa is nowadays experiencing a rapid climate change, characterized by a widespread warming, a recovery of the monsoonal precipitation, and an increase in the occurrence of climate extremes. The observed climate tendencies are also projected to continue in the twenty-first century under moderate and high emission scenarios, although large uncertainties still affect simulations of the future West African climate, especially regarding the summer precipitation. However, despite diverging future projections of the monsoonal rainfall, which is essential for rain-fed agriculture, a robust evidence of yield loss in West Africa emerges. This yield loss is mainly driven by increased mean temperature while potential wetter or drier conditions as well as elevated CO2 concentrations can modulate this effect. Potential for adaptation is illustrated for major crops in West Africa through a selection of studies based on process-based crop models to adjust cropping systems (change in varieties, sowing dates and density, irrigation, fertilizer management) to future climate. Results of the cited studies are crop and region specific and no clear conclusions can be made regarding the most effective adaptation options. Further efforts are needed to improve modeling of the monsoon system and to better quantify the uncertainty in its changes under a warmer climate, in the response of the crops to such

HIV epidemic among key populations in west Africa.

PubMed

Djomand, Gaston; Quaye, Silas; Sullivan, Patrick S

2014-09-01

Globally, HIV infection remains a significant issue for key populations such as men who have sex with men (MSM) and female sex workers. A review of recent articles was conducted for west African countries to assess the burden of disease among female sex workers and MSM, access to services and identify barriers to implementation of services for key populations. In west Africa, key populations engage in high-risk practices for the acquisition of HIV and other sexually transmitted infections. Available HIV prevalence data fluctuate across and within countries for both MSM and female sex workers and may be five to ten times as high as that of the general population. HIV prevalence varied from 15.9% in The Gambia to 68% in Benin among female sex workers, whereas it ranged from 9.8% in The Gambia to 34.9% in Nigeria for MSM. Yet, important data gaps exist, including key populations size estimations in several countries as well as HIV prevalence, incidence and other biomarkers of HIV risk. Because of sociocultural, legal, political and economic challenges, exacerbated by a poor health system infrastructure, the HIV response is not strategically directed toward programs for key populations in countries with concentrated epidemics. Noteworthy is the low coverage of prevention care and treatment interventions offered to key populations. Sufficient planning and political will with legal and structural frameworks that reconcile public health and human rights are needed to prioritize HIV prevention, care and treatment programming for key populations programs in west Africa.

A GCM Study of Responses of the Atmospheric Water Cycle of West Africa and the Atlantic to Saharan Dust Radiative Forcing

NASA Technical Reports Server (NTRS)

Lau, K. M.; Kim, K. M.; Sud, Y. C.; Walker, G. K.

2009-01-01

The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence of an "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summerr, as a result of large-scale atmospheric feedback triggered by absorbing dust aerosols, rainfall and cloudiness are ehanIed over the West Africa/Eastern Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while longwave has the opposite response. The elevated dust layer warms the air over West Africa and the eastern Atlantic. As the warm air rises, it spawns a large-scale onshore flow carrying the moist air from the eastern Atlantic and the Gulf of Guinea. The onshore flow in turn enhances the deep convection over West Africa land, and the eastern Atlantic. The condensation heating associated with the ensuing deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in a northward shift of the West Africa precipitation over land, increased low-level westerlies flow over West Africa at the southern edge of the dust layer, and a near surface westerly jet underneath the dust layer overr the Sahara. The dust radiative forcing also leads to significant changes in surface energy fluxes, resulting in cooling of the West African land and the eastern Atlantic, and warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at0

Measles Cases during Ebola Outbreak, West Africa, 2013-2106.

PubMed

Colavita, Francesca; Biava, Mirella; Castilletti, Concetta; Quartu, Serena; Vairo, Francesco; Caglioti, Claudia; Agrati, Chiara; Lalle, Eleonora; Bordi, Licia; Lanini, Simone; Guanti, Michela Delli; Miccio, Rossella; Ippolito, Giuseppe; Capobianchi, Maria R; Di Caro, Antonino

2017-06-01

The recent Ebola outbreak in West Africa caused breakdowns in public health systems, which might have caused outbreaks of vaccine-preventable diseases. We tested 80 patients admitted to an Ebola treatment center in Freetown, Sierra Leone, for measles. These patients were negative for Ebola virus. Measles virus IgM was detected in 13 (16%) of the patients.

Ecosystem properties of semiarid savanna grassland in West Africa and its relationship with environmental variability.

PubMed

Tagesson, Torbern; Fensholt, Rasmus; Guiro, Idrissa; Rasmussen, Mads Olander; Huber, Silvia; Mbow, Cheikh; Garcia, Monica; Horion, Stéphanie; Sandholt, Inge; Holm-Rasmussen, Bo; Göttsche, Frank M; Ridler, Marc-Etienne; Olén, Niklas; Lundegard Olsen, Jørgen; Ehammer, Andrea; Madsen, Mathias; Olesen, Folke S; Ardö, Jonas

2015-01-01

The Dahra field site in Senegal, West Africa, was established in 2002 to monitor ecosystem properties of semiarid savanna grassland and their responses to climatic and environmental change. This article describes the environment and the ecosystem properties of the site using a unique set of in situ data. The studied variables include hydroclimatic variables, species composition, albedo, normalized difference vegetation index (NDVI), hyperspectral characteristics (350-1800 nm), surface reflectance anisotropy, brightness temperature, fraction of absorbed photosynthetic active radiation (FAPAR), biomass, vegetation water content, and land-atmosphere exchanges of carbon (NEE) and energy. The Dahra field site experiences a typical Sahelian climate and is covered by coexisting trees (~3% canopy cover) and grass species, characterizing large parts of the Sahel. This makes the site suitable for investigating relationships between ecosystem properties and hydroclimatic variables for semiarid savanna ecosystems of the region. There were strong interannual, seasonal and diurnal dynamics in NEE, with high values of ~-7.5 g C m(-2)  day(-1) during the peak of the growing season. We found neither browning nor greening NDVI trends from 2002 to 2012. Interannual variation in species composition was strongly related to rainfall distribution. NDVI and FAPAR were strongly related to species composition, especially for years dominated by the species Zornia glochidiata. This influence was not observed in interannual variation in biomass and vegetation productivity, thus challenging dryland productivity models based on remote sensing. Surface reflectance anisotropy (350-1800 nm) at the peak of the growing season varied strongly depending on wavelength and viewing angle thereby having implications for the design of remotely sensed spectral vegetation indices covering different wavelength regions. The presented time series of in situ data have great potential for dryland dynamics

Understanding the cryptic nature of Lassa fever in West Africa.

PubMed

Gibb, Rory; Moses, Lina M; Redding, David W; Jones, Kate E

2017-09-01

Lassa fever (LF) is increasingly recognized by global health institutions as an important rodent-borne disease with severe impacts on some of West Africa's poorest communities. However, our knowledge of LF ecology, epidemiology and distribution is limited, which presents barriers to both short-term disease forecasting and prediction of long-term impacts of environmental change on Lassa virus (LASV) zoonotic transmission dynamics. Here, we synthesize current knowledge to show that extrapolations from past research have produced an incomplete picture of the incidence and distribution of LF, with negative consequences for policy planning, medical treatment and management interventions. Although the recent increase in LF case reports is likely due to improved surveillance, recent studies suggest that future socio-ecological changes in West Africa may drive increases in LF burden. Future research should focus on the geographical distribution and disease burden of LF, in order to improve its integration into public policy and disease control strategies.

Propagation of Satelite Rainfall Products uncertainties in hydrological applications : Examples in West-Africa in the framework of the Megha-Tropiques Satellite Mission

NASA Astrophysics Data System (ADS)

Casse, C.; Gosset, M.; Peugeot, C.; Boone, A.; Pedinotti, V.

2013-12-01

The use of satellite based rainfall in research or operational Hydrological application is becoming more and more frequent. This is specially true in the Tropics where ground based gauge (or radar) network are generally scarce and often degrading. Member of the GPM constellation, the new French-Indian satellite Mission Megha-Tropiques (MT) dedicated to the water and energy budget in the tropical atmosphere contributes to a better monitoring of rainfall in the inter-tropical zone. As part of this mission, research is developed on the use of MT rainfall products for hydrological research or operational application such as flood monitoring. A key issue for such applications is how to account for rainfall products biases and uncertainties, and how to propagate them in the end user models ? Another important question is how to choose the best space-time resolution for the rainfall forcing, given that both model performances and rain-product uncertainties are resolution dependent. This talk will present on going investigations and perspectives on this subject, with examples from the Megha_tropiques Ground validation sites in West Africa. The CNRM model Surfex-ISBA/TRIP has been set up to simulate the hydrological behavior of the Niger River. This modeling set up is being used to study the predictability of Niger Floods events in the city of Niamey and the performances of satellite rainfall products as forcing for such predictions. One of the interesting feature of the Niger outflow in Niamey is its double peak : a first peak attributed to 'local' rainfall falling in small to medium size basins situated in the region of Niamey, and a second peak linked to the rainfall falling in the upper par of the river, and slowly propagating through the river towards Niamey. The performances of rainfall products are found to differ between the wetter/upper part of the basin, and the local/sahelian areas. Both academic tests with artificially biased or 'perturbed' rainfield and actual

Insights from clinical research completed during the west Africa Ebola virus disease epidemic

PubMed Central

Rojek, Amanda; Horby, Peter; Dunning, Jake

2018-01-01

The west Africa Ebola virus disease (EVD) epidemic was extraordinary in scale. Now that the epidemic has ended, it is a relevant time to examine published studies with direct relevance to clinical care and, more broadly, to examine the implications of the clinical research response mounted. Clinically relevant research includes literature detailing risk factors for and clinical manifestations of EVD, laboratory and other investigation findings in patients, experimental vaccine and therapeutic clinical trials, and analyses of survivor syndrome. In this Review, we discuss new insights from patient-oriented research completed during the west Africa epidemic, identify ongoing knowledge gaps, and suggest priorities for future research. PMID:28461209

A General Survey of Religious Concepts and Art of North, East, South, and West Africa.

ERIC Educational Resources Information Center

Stewart, Rohn

This paper, a summary of a multi-carousel slide presentation, reviews literature on the cultures, religions, and art of African people. Before focusing on West Africa, highlights of the lifestyles, religions, and icons of non-maskmaking cultures of North, West and South African people are presented. Clarification of West African religious concepts…

Modeling spatial invasion of Ebola in West Africa.

PubMed

D'Silva, Jeremy P; Eisenberg, Marisa C

2017-09-07

The 2014-2016 Ebola Virus Disease (EVD) epidemic in West Africa was the largest ever recorded, representing a fundamental shift in Ebola epidemiology with unprecedented spatiotemporal complexity. To understand the spatiotemporal dynamics of EVD in West Africa, we developed spatial transmission models using a gravity-model framework at both the national and district-level scales, which we used to compare effectiveness of local interventions (e.g. local quarantine) and long-range interventions (e.g. border-closures). The country-level gravity model captures the epidemic data, including multiple waves of initial epidemic growth observed in Guinea. We found that local-transmission reductions were most effective in Liberia, while long-range transmission was dominant in Sierra Leone. Both models illustrated that interventions in one region result in an amplified protective effect on other regions by preventing spatial transmission. In the district-level model, interventions in the strongest of these amplifying regions reduced total cases in all three countries by over 20%, in spite of the region itself generating only ∼0.1% of total cases. This model structure and associated intervention analysis provide information that can be used by public health policymakers to assist planning and response efforts for future epidemics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of Military Coups d’etat on West Africa’s Socio-Economic and Political Development

DTIC Science & Technology

2011-12-16

the 1990s. Under President Doe, the Liberian currency was devalued , corruption was at its peak, and the mismanagement of public funds was the rule...from which they are yet to recover. 15. SUBJECT TERMS Africa, Economic development, Governance, Security, the West, West Africa, Nigeria , Cote... Nigeria and Military Coup d’états 1983-1999 .............................................................. 32 The Second Military Coup after the Second

Using Radio To Deliver Teacher Training in West Africa.

ERIC Educational Resources Information Center

Norman, Douglas

Three radio stations serving the interior of Liberia, West Africa, were used to broadcast inservice training programs to teachers in grades 1-6. Most of the teachers had not attended college and had received only 5 weeks of preservice training before going into the classroom. Poor roads, a 6-month wet season, and lack of vehicles made face-to-face…

Past climate changes explain the phylogeography of Vitellaria paradoxa over Africa

PubMed Central

Allal, F; Sanou, H; Millet, L; Vaillant, A; Camus-Kulandaivelu, L; Logossa, Z A; Lefèvre, F; Bouvet, J-M

2011-01-01

The evolution of the savanna biome has been deeply marked by repeated contraction/expansion phases due to climate perturbations during the Quaternary period. In this study, we investigated the impact of the last glacial maximum (LGM) on the present genetic pattern of Vitellaria paradoxa (shea tree), a major African savanna tree. A range-wide sampling of the species enabled us to sample 374 individuals from 71 populations distributed throughout sub-Sahelian Africa. Trees were genotyped using 3 chloroplasts and 12 nuclear microsatellites, and were sequenced for 2 polymorphic chloroplast intergenic spacers. Analyses of genetic diversity and structure were based on frequency-based and Bayesian methods. Potential distributions of V. paradoxa at present, during the LGM and the last interglacial period, were examined using DIVA-GIS ecological niche modelling (ENM). Haplotypic and allelic richness varied significantly across the range according to chloroplast and nuclear microsatellites, which pointed to higher diversity in West Africa. A high but contrasted level of differentiation was revealed among populations with a clear phylogeographic signal, with both nuclear (FST=0.21; RST=0.28; RST>RST (permuted)) and chloroplast simple sequence repeats (SSRs) (GST=0.81; NST=0.90; NST>NST (permuted)). We identified a strong geographically related structure separating western and eastern populations, and a substructure in the eastern part of the area consistent with subspecies distinction. Using ENM, we deduced that perturbations during the LGM fragmented the potential eastern distribution of shea tree, but not its distribution in West Africa. Our main results suggest that climate variations are the major factor explaining the genetic pattern of V. paradoxa. PMID:21407253

Aircraft-based investigation of Dynamics-Aerosol-Chemistry-Cloud Interactions in Southern West Africa

NASA Astrophysics Data System (ADS)

Flamant, Cyrille

2017-04-01

The EU-funded project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa, http://www.dacciwa.eu) is investigating the relationship between weather, climate and air pollution in southern West Africa. The air over the coastal region of West Africa is a unique mixture of natural and anthropogenic gases, liquids and particles, emitted in an environment, in which multi-layer cloud decks frequently form. These exert a large influence on the local weather and climate, mainly due to their impact on radiation, the surface energy balance and thus the diurnal cycle of the atmospheric boundary layer. The main objective for the aircraft detachment was to build robust statistics of cloud properties in southern West Africa in different chemical landscapes to investigate the physical processes involved in their life cycle in such a complex chemical environment. As part of the DACCIWA field campaigns, three European aircraft (the German DLR Falcon 20, the French SAFIRE ATR 42 and the British BAS Twin Otter) conducted a total of 50 research flights across Ivory Coast, Ghana, Togo, and Benin from 27 June to 16 July 2016 for a total of 155 flight hours, including hours sponsored through 3 EUFAR projects. The aircraft were used in different ways based on their strengths, but all three had comparable instrumentation with the the capability to do gas-phase chemistry, aerosol and clouds, thereby generating a rich dataset of atmospheric conditions across the region. Eight types of flight objectives were conducted to achieve the goals of the DACCIWA: (i) Stratus clouds, (ii) Land-sea breeze clouds, (iii) Mid-level clouds, (iv) Biogenic emission, (v) City emissions, (vi) Flaring and ship emissions, (vii) Dust and biomass burning aerosols, and (viii) air-sea interactions. An overview of the DACCIWA aircraft campaign as well as first highlights from the airborne observations will be presented.

Cost-effectiveness analysis of malaria chemoprophylaxis for travellers to West-Africa

PubMed Central

2010-01-01

Background The importation of malaria to non-endemic countries remains a major cause of travel-related morbidity and a leading cause of travel-related hospitalizations. Currently they are three priority medications for malaria prophylaxis to West Africa: mefloquine, atovaquone/proguanil and doxycycline. We investigate the cost effectiveness of a partial reimbursement of the cheapest effective malaria chemoprophylaxis (mefloquine) for travellers to high risk areas of malaria transmission compared with the current situation of no reimbursement. Methods This study is a cost-effectiveness analysis based on malaria cases imported from West Africa to Switzerland from the perspective of the Swiss health system. We used a decision tree model and made a literature research on the components of travel related malaria. The main outcome measure was the cost effectiveness of malaria chemoprophylaxis reimbursement based on malaria and deaths averted. Results Using a program where travellers would be reimbursed for 80% of the cost of the cheapest malaria chemoprophylaxis is dominant (i.e. cost saving and more effective than the current situation) using the assumption that currently 68.7% of travellers to West Africa use malaria chemoprophylaxis. If the current usage of malaria chemoprophylaxis would be higher, 82.4%, the incremental cost per malaria case averted is € 2'302. The incremental cost of malaria death averted is € 191'833. The most important factors influencing the model were: the proportion of travellers using malaria chemoprophylaxis, the probability of contracting malaria without malaria chemoprophylaxis, the cost of the mefloquine regimen, the decrease in the number of travellers without malaria chemoprophylaxis in the reimbursement strategy. Conclusions This study suggests that a reimbursement of 80% of the cost of the cheapest effective malaria chemoprophylaxis (mefloquine) for travellers from Switzerland to West Africa is highly effective in terms of malaria

A new species of Trachylepis (Squamata: Scincidae) from Central Africa and a key to the Trachylepis of West and Central Africa.

PubMed

Allen, Kaitlin E; N, Walter P Tapondjou; Welton, Luke J; Bauer, Aaron M

2017-05-16

A new species of skink, Trachylepis gonwouoi sp. nov. is described from Cameroon and the Republic of the Congo. It differs from all other species of Trachylepis in Central-West Africa by a combination of number of keels on dorsal scales (3-5); moderate SVL (maximum size of 80 mm); number of scale rows at midbody (28-34); number of supracilliaries (6-10); a well defined lateral white stripe, bordered by black, extending from under the eye to the insertion of the hind limb; and a ventral color in life of bright blue-green. Trachylepis gonwouoi sp. nov. was found in association with disturbed forest at elevations from 50 to 1050m. This species is syntopic with T. affinis and T. maculilabris. In order to aid in the identification of Trachylepis in West and Central Africa with the addition of T. gonwouoi sp. nov., we provide an updated key to the Trachylepis found from Mauritania through the Democratic Republic of the Congo. This key combines previous literature that treated Western and Central African taxa separately and represents the most comprehensive key for Trachylepis in West-Central Africa to date.

Characteristics of mid-level clouds over West Africa

NASA Astrophysics Data System (ADS)

Bourgeois, Elsa; Bouniol, Dominique; Couvreux, Fleur; Guichard, Françoise; Marsham, John; Garcia-Carreras, Luis; Birch, Cathryn; Parker, Doug

2017-04-01

Clouds have a major impact on the distribution of water and energy fluxes within the atmosphere. They also represent one of the main sources of uncertainties in global climate models as a result of the difficulty to parametrize cloud processes. However, in West Africa, the cloud type, occurrence and radiative effects have not been extensively documented. This region is characterized by a strong seasonality with precipitation occurring in the Sahel from June to September (monsoon season). This period also coincides with the annual maximum of the cloud cover. Taking advantage of the one-year ARM Mobile Facility (AMF) deployment in 2006 in Niamey (Niger), Bouniol et al (2012) documented the distinct cloud types and showed the frequent occurrence of mid-level clouds (around 6 km height) and their substantial impact on the surface short-wave and long-wave radiative fluxes. Furthermore, in a process-oriented evaluation of climate models, Roehrig et al (2013) showed that these mid-level clouds are poorly represented in numerical models. The aim of this work is to document the macro- and microphysical properties of mid-level clouds and the environment in which such clouds occur across West Africa. To document those clouds, we extensively make use of observations from lidar and cloud radar either deployed at ground-based sites (Niamey and Bordj Badji Mokhtar (Sahara)) or on-board the A-Train constellation (CloudSat/CALIPSO). These datasets reveal the temporal and spatial occurrence of those clouds. They are found throughout the year with a predominance around the monsoon season and are preferentially observed in the Southern and Western part of West Africa which could be linked to the dynamics of the Saharan heat low. Those clouds are usually quite thin (most of them are less than 1000m deep). A clustering method applied to this data allows us to identify three different types of clouds : one with low bases, one with high bases and another with large thicknesses. The first

Namibia [South-West Africa].

PubMed

1983-01-01

Namibia, a country of 1,051,700 inhabitants of whom 85.6% are blacks of diverse ethnic and linguistic origins, 7.5% are white, and the rest are of mixed ancestry, has been illegally administered by South Africa since 1966, when a League of Nations mandate was revoked by the UN. The Namibian Desert was a barrier to European expansion until the late 18th century, when the area came under German and British influence. Efforts to bring about an orderly and peaceful transition to independent status are hampered at present by the lack of parallel progress toward withdrawal of Cuban combat forces from Angola. Beginning in 1980, considerable executive power was transferred from the administrator general appointed by the South African Government to an interim 3-tier system of elected representatives dividing responsibility between central, ethnic, and local authorities. The judicial structure has separate overlapping systems for whites, westernized blacks and coloreds and for indigenous blacks. Namibian society is highly politicized, with 4 white and about 40 nonwhite political groups. The South West Africa People's Organization (SWAPO) remains an active party inside Namibia despite simultaneous detention of its entire leadership in 1979 by the South African Government. Namibia's economy is dual, with a modern market sector of mining, ranching and fishing producing most of the wealth and a traditional subsistence sector supporting most of the labor force. About 60% of the work force of 500,000 in 1981 worked in agriculture, 19% in industry and commerce, 6% in mining, 8% in services, and 7% in government. Namibia's gross domestic product in 1980 was $1.712 billion, representing an average growth rate of 2.5% from 1970-80. However, real growth since 1978 has been negative because of persistent drought, political uncertainty, low demand for mineral products, and previous overfishing. Namibia has no separate representation in any international body. The country may have the

Climate change mitigation by carbon stock - the case of semi-arid West Africa

NASA Astrophysics Data System (ADS)

Lykke, A. M.; Barfod, A. S.; Tinggaard Svendsen, G.; Greve, M.; Svenning, J.-C.

2009-11-01

Semi-arid West Africa has not been integrated into the afforestation/reforestation (AR) carbon market. Most projects implemented under the Clean Development Mechanism (CDM) have focused on carbon emission reductions from industry and energy consumption, whereas only few (only one in West Africa) have been certified for AR carbon sequestration. A proposed mechanism, Reducing Emissions from Deforestation and Degradation (REDD) to be discussed under COP15 aims to reduce emissions by conserving already existing forests. REDD has high potential for carbon stocking at low costs, but focuses primarily on rain forest countries and excludes semi-arid West Africa from the preliminary setup. African savannas have potential to store carbon in the present situation with degrading ecosystems and relatively low revenues from crops and cattle, especially if it is possible to combine carbon stocking with promotion of secondary crops such as food resources and traditional medicines harvested on a sustainable basis. Methods for modelling and mapping of potential carbon biomass are being developed, but are still in a preliminary state. Although economic benefits from the sale of carbon credits are likely to be limited, carbon stocking is an interesting option if additional benefits are considered such as improved food security and protection of biodiversity.

Apollo 4 Mission - Atlantic Ocean,coastal Brazil and West Africa

NASA Image and Video Library

1967-11-09

AS04-01-200 (9 Nov. 1967) --- Coastal Brazil, Atlantic Ocean, West Africa, Sahara, looking northwest, as photographed from the unmanned Apollo 4 (Spacecraft 017/Saturn 501) earth-orbital space mission. This picture was taken when the Spacecraft 017 and the Saturn IVB stage were orbiting Earth at an altitude of 9,060 nautical miles.

The DACCIWA project: Dynamics-aerosol-chemistry-cloud interactions in West Africa

NASA Astrophysics Data System (ADS)

Knippertz, Peter

2017-04-01

This contribution provides an overview of the EU-funded DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) project. DACCIWA consists of 16 European and African research organisations and has strong links to universities, weather services and government organisations across West Africa. The project runs from 2010 to 2018 and is built around a major international field campaign in 2016. A key motivation for DACCIWA is the expected tripling of anthropogenic emissions in southern West Africa (SWA) between 2000 and 2030, whose impacts on human health, ecosystems, food security and the regional climate are largely unknown. An integrated assessment of this problem, which is mostly due to massive economic and population growth and urbanization, is challenging due to (a) a superposition of regional effects with global climate change, (b) a strong dependence on the variable West African monsoon, (c) incomplete scientific understanding of interactions between emissions, clouds, radiation, precipitation and regional circulations, and (d) a lack of observations. DACCIWA combines measurements in the field in SWA with extensive modelling activities and work on satellite data. In particular during the main DACCIWA field campaign in June-July 2016 high-quality observations of emissions, atmospheric composition and meteorological parameters were sampled. The campaign involved three research aircraft, three ground-based supersites, enhanced radiosonde launches, and intensive measurements at urban sites in Abidjan and Cotonou. These data have already been quality-controlled and will be freely available to the research community through a database at http://baobab.sedoo.fr/DACCIWA/ after the end of the project. The resulting benchmark dataset is currently combined with a wide range of modelling and satellite-based research activities that will ultimately allow (a) an assessment of the roles of relevant physical, chemical and biological processes, (b) an improvement

Comparison of Agricultural Drought Indicators over West Africa

NASA Astrophysics Data System (ADS)

Husak, G. J.; Turner, W.; McNally, A.; Shukla, S.; Funk, C. C.

2017-12-01

The Famine Early Warning Systems Network (FEWS NET) monitors critical environmental variables that impact food production in developing countries, including over 30 countries in Africa. Much of this work focuses on the identification of agricultural drought using remotely sensed and modeled estimates of conditions. These variables estimate precipitation, potential evapotranspiration, water availability for crops and soil moisture - among others - at a critical time, or accumulated over intervals within the season. Frequently, these variables are used in a "convergence of evidence" approach to identify the location and severity of agricultural drought over a region. While much work has gone into identifying and calculating these key indicators, little attention has been given to the relationships between these variables. This work explores the relationship between four key agricultural drought indicators over West Africa to determine the extent to which they are providing unique information and also to expose where certain variables may not be adding independent information to the identification of agricultural drought and the potential for food insecurity. These variables investigated in this study are the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), the Water Requirement Satisfaction Index (WRSI) and modeled soil moisture (SM) from the FEWSNET Land Data Assimilation System (FLDAS). We look at 35 years of data (1982-2016) over West Africa and identify the primary growing season for the region, then compare the four variables above during this prime season. Because the computational costs of calculating these different indicators varies, we seek to identify where products that are less cost/data intensive adequately capture the same information as the more intensive indicators. The outcome highlights where particular products are most useful for the identification of agricultural drought over the region.

Enabling Data Access for Environmental Monitoring: SERVIR West Africa

NASA Astrophysics Data System (ADS)

Yetman, G.; de Sherbinin, A. M.

2017-12-01

SERVIR is a join effort between NASA and the U.S. Agency for International Development to form regional partnerships and bring satellite-based earth monitoring and geographic information technologies to bear on environmental issues. The recently established SERVIR node for West Africa aims to "connect space to villages" and enable response to environmental change at the national and local level through partnering with a network of organizations in the region. Comprehensive services—data streams, analysis methods and algorithms, and information products for decision making—to support environmental monitoring of five critical issues identified by West African network members are being designed and developed: ephemeral water, charcoal production, locusts, groundwater, and land use/land cover change. Additionally, climate change information is critical for planning and context in each of these issues. The selection of data and methods is a collaborative effort, with experts in the region working with experts at NASA and the scientific community to best meet information monitoring requirements. Design and delivery of these services requires capacity development in a number of areas, including best practices in data management, analysis methods for combining multiple data streams, and information technology infrastructure. Two research centers at Columbia University are implementing partners for SERVIR West Africa, acting to support capacity development in network members through a combination of workshops, training, and implementation of technologies in the region. The presentation will focus on efforts by these centers to assess current capabilities and improve capacity through gathering requirements, system design, technology selection, technology deployment, training, and workshops.

Effect of mineralogical, geochemical and biological properties on soils reflectance to assess temporal and spatial dynamics of BSCs in Sahelian ecosystems

NASA Astrophysics Data System (ADS)

Bourguignon, A.; Cerdan, O.; Desprats, J. F.; Marin, B.; Malam Issa, O.; Valentin, C.; Rajot, J. L.

2012-04-01

Land degradation and desertification are among the major environmental problems, resulting in reduced productivity and development of bare surfaces in arid and semi-arid areas of the world. One important factor that acts to increase soil stability and nutrient content, and thus to prevent water and wind erosion and enhance soil productivity of arid environment, is the presence of biological soil crusts (BSCs). They are the dominant ground cover and a key component of arid environments built up mainly by cyanobacteria. They enhance degraded soil quality by providing a stable and water-retaining substratum and increasing fertility by N and C fixations. The BioCrust project, funded by ANR (VMCS 2008), focuses on BSCs in the Sahelian zone of West Africa (Niger), a highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use. Unlike arid areas of developed countries (USA, Australia and Israel) or China where BSCs have been extensively studied, studies from Sahelian zone (Africa) are limited (neither the inventory of their different form nor the estimation of their spatial extension has been carried out). The form, structure and composition of BSCs vary depending on characteristics related to soils and biological composition. This study focuses on the soils characterisation using ground-based spectroradiometry. An extensive database was built included spectral measurements on BSCs, bare soils and vegetation that occur in the same area, visual criteria, in situ and laboratory measurements on the physical, chemical and biological characteristics of BSCs and their substratum. The work is carried out on geo-statistical processing of data acquired in sites along a north-south climatic gradient and three types of representative land uses. The investigated areas are highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic

International trends in health science librarianship part 15: West Africa (Ghana, Nigeria, Senegal).

PubMed

Sulemani, Solomon Bayugo; Afarikumah, Ebenezer; Aggrey, Samuel Bentil; Ajuwon, Grace A; Diallo, Ousmane

2015-09-01

This is the 15th in a series of articles exploring international trends in health science librarianship in the 21st century. It is the third of four articles pertaining to different regions in the African continent. The present issue focuses on countries in West Africa (Ghana, Nigeria and Senegal). The next feature column will investigate trends in North Africa. JM. © 2015 Health Libraries Group.

The DACCIWA Project: Dynamics-Aerosol-Chemistry-Cloud interactions in West Africa

NASA Astrophysics Data System (ADS)

Knippertz, Peter

2014-05-01

Massive economic and population growth and urbanisation are expected to lead to a tripling of anthropogenic emissions from southern West Africa (SWA) between 2000 and 2030, the impacts of which on human health, ecosystems, food security and the regional climate are largely unknown. An assessment of these impacts is complicated by (a) a superposition with effects of global climate change, (b) the strong dependence of SWA on the sensitive West African monsoon, (c) incomplete scientific understanding of interactions between emissions, clouds, radiation, precipitation and regional circulations and (d) by a lack of observations to advance our understanding and improve predictions. The purpose of this contribution is to introduce the research consortium DACCIWA (Dynamics-Aerosol-Chemistry-Cloud interactions in West Africa), which comprises 16 partners in six European and West African countries. The interdisciplinary DACCIWA team will build on the scientific and logistical foundations established by the African Monsoon Multidisciplinary Analysis (AMMA) project and collaborate closely with operational centres. DACCIWA will receive funding of about M8.75€ from the European Commission as part of Framework Programme 7 from 2015 until 2018. The DACCIWA project will conduct extensive fieldwork in SWA to collect high-quality observations, spanning the entire process chain from surface-based natural and anthropogenic emissions to impacts on health, ecosystems and climate. This will include a major field campaign in summer 2015 with three research aircrafts and two ground-based supersites. Combining the resulting benchmark dataset with a wide range of modelling activities will allow us: (a) to assess all relevant physical and chemical processes, (b) to improve the monitoring of climate and compositional parameters from space, (c) to determine health impacts from air pollution, and (d) to develop the next generation of weather and climate models capable of representing coupled

West Africa - A Safe Haven for Frogs? A Sub-Continental Assessment of the Chytrid Fungus (Batrachochytrium dendrobatidis)

PubMed Central

Penner, Johannes; Adum, Gilbert B.; McElroy, Matthew T.; Doherty-Bone, Thomas; Hirschfeld, Mareike; Sandberger, Laura; Weldon, Ché; Cunningham, Andrew A.; Ohst, Torsten; Wombwell, Emma; Portik, Daniel M.; Reid, Duncan; Hillers, Annika; Ofori-Boateng, Caleb; Oduro, William; Plötner, Jörg; Ohler, Annemarie; Leaché, Adam D.; Rödel, Mark-Oliver

2013-01-01

A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries - Bénin, Burkina Faso, Côte d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone - and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds) environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continent - especially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni (“Vulnerable”) and Petropedetes natator (“Near Threatened”)) as well as the “Critically Endangered” viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis). PMID:23426141

School Leadership in West Africa: Findings from a Systematic Literature Review

ERIC Educational Resources Information Center

Bush, Tony; Glover, Derek

2016-01-01

The literature shows that leadership is the second most important factor influencing school and learner outcomes, including levels of literacy and numeracy, school leaving examination results, and progression to secondary and higher education. This article focuses on school leadership in West Africa, drawing on a systematic review of the academic…

[Several cases of giant epulis observed in West Africa].

PubMed

Cantaloube, D; Larroque, G; Ndiaye, R; Rives, J M; Seurat, P

1987-01-01

The presenting symptomatology in 9 cases of giant epulis seen in West Africa was constantly difficulties in mastication or even speech, and on some occasions tumefaction of the face. A certain number of factors are involved in the development of these benign tumors, and although inflammation represents the primum movens of this affection, other causes, including some specific to the African continent, must be considered with a view to a pathogenic approach.

Ecosystem carbon stocks of mangroves across broad environmental gradients in West-Central Africa: Global and regional comparisons.

PubMed

Kauffman, J Boone; Bhomia, Rupesh K

2017-01-01

Globally, it is recognized that blue carbon ecosystems, especially mangroves, often sequester large quantities of carbon and are of interest for inclusion in climate change mitigation strategies. While 19% of the world's mangroves are in Africa, they are among the least investigated of all blue carbon ecosystems. We quantified total ecosystem carbon stocks in 33 different mangrove stands along the Atlantic coast of West-Central Africa from Senegal to Southern Gabon spanning large gradients of latitude, soil properties, porewater salinity, and precipitation. Mangrove structure ranged from low and dense stands that were <1m in height and >35,000 trees ha-1 to tall and open stands >40m in height and <100 ha-1. Tremendous variation in ecosystem carbon (C) stocks was measured ranging from 154 to 1,484 Mg C ha-1. The mean total ecosystem carbon stock for all mangroves of West-Central Africa was 799 Mg C ha-1. Soils comprised an average of 86% of the total carbon stock. The greatest carbon stocks were found in the tall mangroves of Liberia and Gabon North with a mean >1,000 Mg C ha-1. The lowest carbon stocks were found in the low mangroves of the semiarid region of Senegal (463 Mg C ha-1) and in mangroves on coarse-textured soils in Gabon South (541 Mg C ha-1). At the scale of the entirety of West-Central Africa, total ecosystem carbon stocks were poorly correlated to aboveground ecosystem carbon pools, precipitation, latitude and soil salinity (r2 = ≤0.07 for all parameters). Based upon a sample of 158 sites from Africa, Asia and Latin America that were sampled in a similar manner to this study, the global mean of carbon stocks for mangroves is 885 Mg C ha-1. The ecosystem carbon stocks of mangroves for West-Central Africa are slightly lower than those of Latin America (940 Mg C ha-1) and Asia (1049 Mg C ha-1) but substantially higher than the default Intergovernmental Panel on Climate Change (IPCC) values for mangroves (511 Mg C ha-1). This study provides an improved

Ecosystem carbon stocks of mangroves across broad environmental gradients in West-Central Africa: Global and regional comparisons

PubMed Central

Bhomia, Rupesh K.

2017-01-01

Globally, it is recognized that blue carbon ecosystems, especially mangroves, often sequester large quantities of carbon and are of interest for inclusion in climate change mitigation strategies. While 19% of the world’s mangroves are in Africa, they are among the least investigated of all blue carbon ecosystems. We quantified total ecosystem carbon stocks in 33 different mangrove stands along the Atlantic coast of West-Central Africa from Senegal to Southern Gabon spanning large gradients of latitude, soil properties, porewater salinity, and precipitation. Mangrove structure ranged from low and dense stands that were <1m in height and >35,000 trees ha-1 to tall and open stands >40m in height and <100 ha-1. Tremendous variation in ecosystem carbon (C) stocks was measured ranging from 154 to 1,484 Mg C ha-1. The mean total ecosystem carbon stock for all mangroves of West-Central Africa was 799 Mg C ha-1. Soils comprised an average of 86% of the total carbon stock. The greatest carbon stocks were found in the tall mangroves of Liberia and Gabon North with a mean >1,000 Mg C ha-1. The lowest carbon stocks were found in the low mangroves of the semiarid region of Senegal (463 Mg C ha-1) and in mangroves on coarse-textured soils in Gabon South (541 Mg C ha-1). At the scale of the entirety of West-Central Africa, total ecosystem carbon stocks were poorly correlated to aboveground ecosystem carbon pools, precipitation, latitude and soil salinity (r2 = ≤0.07 for all parameters). Based upon a sample of 158 sites from Africa, Asia and Latin America that were sampled in a similar manner to this study, the global mean of carbon stocks for mangroves is 885 Mg C ha-1. The ecosystem carbon stocks of mangroves for West-Central Africa are slightly lower than those of Latin America (940 Mg C ha-1) and Asia (1049 Mg C ha-1) but substantially higher than the default Intergovernmental Panel on Climate Change (IPCC) values for mangroves (511 Mg C ha-1). This study provides an

Addressing the Challenges of Collective Security in West Africa: In View of Recent Conflicts

DTIC Science & Technology

2017-06-09

Distribution is Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Understanding that achieving peace and security is a primary condition for an economic ...condition for an economic integration, ECOWAS has developped various approachs in resolving crises and overcoming threats within West Africa. Using...System CS Collective Security CSO Civil Society Organizations CSS Center for Security Studies EAC East Africa Community ECCAS Economic Community of

Genetic history of the African Sahelian populations.

PubMed

Černý, V; Kulichová, I; Poloni, E S; Nunes, J M; Pereira, L; Mayor, A; Sanchez-Mazas, A

2018-03-01

From a biogeographic perspective, Africa is subdivided into distinct horizontal belts. Human populations living along the Sahel/Savannah belt south of the Sahara desert have often been overshadowed by extensive studies focusing on other African populations such as hunter-gatherers or Bantu in particular. However, the Sahel together with the Savannah bordering it in the south is a challenging region where people had and still have to cope with harsh climatic conditions and show resilient behaviours. Besides exponentially growing urban populations, several local groups leading various lifestyles and speaking languages belonging to three main linguistic families still live in rural localities across that region today. Thanks to several years of consistent population sampling throughout this area, the genetic history of the African Sahelian populations has been largely reconstructed and a deeper knowledge has been acquired regarding their adaptation to peculiar environments and/or subsistence modes. Distinct exposures to pathogens-in particular, malaria-likely contributed to their genetic differentiation for HLA genes. In addition, although food-producing strategies spread within the Sahel/Savannah belt relatively recently, during the last five millennia according to recent archaeological and archaeobotanical studies, remarkable amounts of genetic differences are also observed between sedentary farmers and more mobile pastoralists at multiple neutral and selected loci, reflecting both demographic effects and genetic adaptations to distinct cultural traits, such as dietary habits. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mapping transmission risk of Lassa fever in West Africa: the importance of quality control, sampling bias, and error weighting.

PubMed

Peterson, A Townsend; Moses, Lina M; Bausch, Daniel G

2014-01-01

Lassa fever is a disease that has been reported from sites across West Africa; it is caused by an arenavirus that is hosted by the rodent M. natalensis. Although it is confined to West Africa, and has been documented in detail in some well-studied areas, the details of the distribution of risk of Lassa virus infection remain poorly known at the level of the broader region. In this paper, we explored the effects of certainty of diagnosis, oversampling in well-studied region, and error balance on results of mapping exercises. Each of the three factors assessed in this study had clear and consistent influences on model results, overestimating risk in southern, humid zones in West Africa, and underestimating risk in drier and more northern areas. The final, adjusted risk map indicates broad risk areas across much of West Africa. Although risk maps are increasingly easy to develop from disease occurrence data and raster data sets summarizing aspects of environments and landscapes, this process is highly sensitive to issues of data quality, sampling design, and design of analysis, with macrogeographic implications of each of these issues and the potential for misrepresenting real patterns of risk.

Evolution of the atmospheric boundary layer in southern West Africa - an overview from the DACCIWA field campaign

NASA Astrophysics Data System (ADS)

Kalthoff, Norbert; Lohou, Fabienne; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Ajao, Adewale; Ayoola, Muritala; Babić, Karmen; Bessardon, Geoffrey; Delon, Claire; Dione, Cheikh; Handwerker, Jan; Jambert, Corinne; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas

2017-04-01

In southern West Africa, extended low-level stratus clouds form very frequently during night-time and persist long into the following day influencing the diurnal cycle of the atmospheric boundary layer (ABL). During the course of the day, a transition from nocturnal low-level stratus to stratocumulus, cumulus, and sometimes congestus and possibly cumulonimbus clouds is observed. In June and July 2016, a ground-based field campaign took place in southern West Africa within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project with the aim to identify the meteorological controls on the stratus and the evolution of the ABL. During the measurement period, extensive remote sensing and in-situ measurements were performed at three supersites in Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). We give an overview of the atmospheric conditions during the whole measurement period focusing on the vertical and temporal distribution of the stratus and relevant related atmospheric features.

Antimicrobial resistance in West Africa: a systematic review and meta-analysis.

PubMed

Bernabé, Kerlly J; Langendorf, Céline; Ford, Nathan; Ronat, Jean-Baptiste; Murphy, Richard A

2017-11-01

Growing data suggest that antimicrobial-resistant bacterial infections are common in low- and middle-income countries. This review summarises the microbiology of key bacterial syndromes encountered in West Africa and estimates the prevalence of antimicrobial resistance (AMR) that could compromise first-line empirical treatment. We systematically searched for studies reporting on the epidemiology of bacterial infection and prevalence of AMR in West Africa within key clinical syndromes. Within each syndrome, the pooled proportion and 95% confidence interval were calculated for each pathogen-antibiotic pair using random-effects models. Among 281 full-text articles reviewed, 120 met the eligibility criteria. The majority of studies originated from Nigeria (70; 58.3%), Ghana (15; 12.5%) and Senegal (15; 12.5%). Overall, 43 studies (35.8%) focused on urinary tract infections (UTI), 38 (31.7%) on bloodstream infections (BSI), 27 (22.5%) on meningitis, 7 (5.8%) on diarrhoea and 5 (4.2%) on pneumonia. Children comprised the majority of subjects. Studies of UTI reported moderate to high rates of AMR to commonly used antibiotics including evidence of the emergence of cephalosporin resistance. We found moderate rates of AMR among common bloodstream pathogens to typical first-line antibiotics including ampicillin, cotrimoxazole, gentamicin and amoxicillin/clavulanate. Among S. pneumoniae strains isolated in patients with meningitis, levels of penicillin resistance were low to moderate with no significant resistance noted to ceftriaxone or cefotaxime. AMR was common in this region, particularly in hospitalized patients with BSI and both outpatient and hospitalized patients with UTI. This raises concern given the limited diagnostic capability and second-line treatment options in the public sector in West Africa. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Systemic Evaluation of Advisory Services to Family Farms in West Africa

ERIC Educational Resources Information Center

Faure, Guy; Rebuffel, Pierre; Violas, Dominique

2011-01-01

In West Africa, advisory services for family farms have been promoted to better address producers' needs. The paper aims to show that these services can be understood as a system whose functioning is strongly determined by the financing mechanisms, the governance mechanisms put in place, the quality of human resources delivering advice, and the…

Acute arboviral infections in Guinea, West Africa, 2006.

PubMed

Jentes, Emily S; Robinson, Jaimie; Johnson, Barbara W; Conde, Ibrahima; Sakouvougui, Yosse; Iverson, Jennifer; Beecher, Shanna; Bah, M Alpha; Diakite, Fousseny; Coulibaly, Mamadi; Bausch, Daniel G; Bryan, Juliet

2010-08-01

Acute febrile illnesses comprise the majority of the human disease burden in sub-Saharan Africa. We hypothesized that arboviruses comprised a considerable proportion of undiagnosed febrile illnesses in Guinea and sought to determine the frequency of arboviral disease in two hospitals there. Using a standard case definition, 47 suspected cases were detected in approximately 4 months. Immunoglobulin M antibody capture enzyme-linked immunosorbent assays and plaque-reduction neutralization assays revealed that 63% (30/47) of patients were infected with arboviruses, including 11 West Nile, 2 yellow fever, 1 dengue, 8 chikungunya, and 5 Tahyna infections. Except for yellow fever, these are the first reported cases of human disease from these viruses in Guinea and the first reported cases of symptomatic Tahyna infection in Africa. These results strongly suggest that arboviruses circulate and are common causes of disease in Guinea. Improving surveillance and laboratory capacity for arbovirus diagnoses will be integral to understanding the burden posed by these agents in the region.

Acute Arboviral Infections in Guinea, West Africa, 2006

PubMed Central

Jentes, Emily S.; Robinson, Jaimie; Johnson, Barbara W.; Conde, Ibrahima; Sakouvougui, Yosse; Iverson, Jennifer; Beecher, Shanna; Bah, M. Alpha; Diakite, Fousseny; Coulibaly, Mamadi; Bausch, Daniel G.

2010-01-01

Acute febrile illnesses comprise the majority of the human disease burden in sub-Saharan Africa. We hypothesized that arboviruses comprised a considerable proportion of undiagnosed febrile illnesses in Guinea and sought to determine the frequency of arboviral disease in two hospitals there. Using a standard case definition, 47 suspected cases were detected in approximately 4 months. Immunoglobulin M antibody capture enzyme-linked immunosorbent assays and plaque-reduction neutralization assays revealed that 63% (30/47) of patients were infected with arboviruses, including 11 West Nile, 2 yellow fever, 1 dengue, 8 chikungunya, and 5 Tahyna infections. Except for yellow fever, these are the first reported cases of human disease from these viruses in Guinea and the first reported cases of symptomatic Tahyna infection in Africa. These results strongly suggest that arboviruses circulate and are common causes of disease in Guinea. Improving surveillance and laboratory capacity for arbovirus diagnoses will be integral to understanding the burden posed by these agents in the region. PMID:20682888

Future impacts of global warming and reforestation on drought patterns over West Africa

NASA Astrophysics Data System (ADS)

Diasso, Ulrich; Abiodun, Babatunde J.

2017-07-01

This study investigates how a large-scale reforestation in Savanna (8-12°N, 20°W-20°E) could affect drought patterns over West Africa in the future (2031-2060) under the RCP4.5 scenario. Simulations from two regional climate models (RegCM4 and WRF) were analyzed for the study. The study first evaluated the performance of both RCMs in simulating the present-day climate and then applied the models to investigate the future impacts of global warming and reforestation on the drought patterns. The simulated and observed droughts were characterized with the Standardized Precipitation and Evapotranspiration Index (SPEI), and the drought patterns were classified using a Self-organizing Map (SOM) technique. The models capture essential features in the seasonal rainfall and temperature fields (including the Saharan Heat Low), but struggle to reproduce the onset and retreat of the West African Monsoon as observed. Both RCMs project a warmer climate (about 1-2 °C) over West Africa in the future. They do not reach a consensus on future change in rainfall, but they agree on a future increase in frequency of severe droughts (by about 2 to 9 events per decade) over the region. They show that reforestation over the Savanna could reduce the future warming by 0.1 to 0.8 °C and increase the precipitation by 0.8 to 1.2 mm per day. However, the impact of reforestation on the frequency of severe droughts is twofold. While reforestation decreases the droughts frequency (by about 1-2 events per decade) over the Savanna and Guinea coast, it increases droughts frequency (by 1 event per decade) over the Sahel, especially in July to September. The results of this study have application in using reforestation to mitigate impacts of climate change in West Africa.

Weekend Warriors for Water: Combating Water Scarcity in West Africa with United States Army National Guard and Reserve Forces

DTIC Science & Technology

2017-06-09

if leveraged appropriately. Primary Research Question Water scarcity issues affect many areas of the world and are expected to become a significant... water scarcity in West Africa and the RC leads us to the primary research question, "should the DOD leverage existing RC programs over the next ten...RC in combating water scarcity in West Africa without becoming the primary stakeholder in any particular program. Secondary Research Questions

Agrometeorological services for smallholder farmers in West Africa

NASA Astrophysics Data System (ADS)

Tarchiani, Vieri; Camacho, José; Coulibaly, Hamidou; Rossi, Federica; Stefanski, Robert

2018-04-01

Climate variability and change are recognised as a major threat for West African agriculture, particularly for smallholder farmers. Moreover, population pressure, poverty, and food insecurity, are worsening the vulnerability of production systems to climate risks. Application of Climate Services in agriculture, specifically Agrometeorological Services, is acknowledged as a valuable innovation to assist decision-making and develop farmers' specific adaptive capacities. In West Africa, the World Meteorological Organisation and National Meteorological Services deployed considerable efforts in the development of Agrometeorological Services. Nevertheless, the impacts of such services on West African farming communities are still largely unknown. This paper aims to delineate the added value of agrometeorological services for farmers within the Agriculture Innovation System of Mauritania. The results of this quali-quantitative assessment demonstrate that farmers use agrometeorological information for a variety of choices: making strategic choice on the seed variety and on the geographical distribution of plots, choosing the most appropriate planting date, better tuning crop development cycle with the rhythm of the rains and choosing favourable periods for different cultural operations. Globally, the effects of all these good practices can be summarized by an increase of crops productivity and a decrease of cropping costs (including opportunity cost) in terms of inputs and working time.

Male Circumcision and the Epidemic Emergence of HIV-2 in West Africa.

PubMed

Sousa, João Dinis; Temudo, Marina Padrão; Hewlett, Barry Stephen; Camacho, Ricardo Jorge; Müller, Viktor; Vandamme, Anne-Mieke

2016-01-01

Epidemic HIV-2 (groups A and B) emerged in humans circa 1930-40. Its closest ancestors are SIVsmm infecting sooty mangabeys from southwestern Côte d'Ivoire. The earliest large-scale serological surveys of HIV-2 in West Africa (1985-91) show a patchy spread. Côte d'Ivoire and Guinea-Bissau had the highest prevalence rates by then, and phylogeographical analysis suggests they were the earliest epicenters. Wars and parenteral transmission have been hypothesized to have promoted HIV-2 spread. Male circumcision (MC) is known to correlate negatively with HIV-1 prevalence in Africa, but studies examining this issue for HIV-2 are lacking. We reviewed published HIV-2 serosurveys for 30 cities of all West African countries and obtained credible estimates of real prevalence through Bayesian estimation. We estimated past MC rates of 218 West African ethnic groups, based on ethnographic literature and fieldwork. We collected demographic tables specifying the ethnic partition in cities. Uncertainty was incorporated by defining plausible ranges of parameters (e.g. timing of introduction, proportion circumcised). We generated 1,000 sets of past MC rates per city using Latin Hypercube Sampling with different parameter combinations, and explored the correlation between HIV-2 prevalence and estimated MC rate (both logit-transformed) in the 1,000 replicates. Our survey reveals that, in the early 20th century, MC was far less common and geographically more variable than nowadays. HIV-2 prevalence in 1985-91 and MC rates in 1950 were negatively correlated (Spearman rho = -0.546, IQR: -0.553--0.546, p≤0.0021). Guinea-Bissau and Côte d'Ivoire cities had markedly lower MC rates. In addition, MC was uncommon in rural southwestern Côte d'Ivoire in 1930.The differential HIV-2 spread in West Africa correlates with different historical MC rates. We suggest HIV-2 only formed early substantial foci in cities with substantial uncircumcised populations. Lack of MC in rural areas exposed to

Testing Modeling Assumptions in the West Africa Ebola Outbreak

NASA Astrophysics Data System (ADS)

Burghardt, Keith; Verzijl, Christopher; Huang, Junming; Ingram, Matthew; Song, Binyang; Hasne, Marie-Pierre

2016-10-01

The Ebola virus in West Africa has infected almost 30,000 and killed over 11,000 people. Recent models of Ebola Virus Disease (EVD) have often made assumptions about how the disease spreads, such as uniform transmissibility and homogeneous mixing within a population. In this paper, we test whether these assumptions are necessarily correct, and offer simple solutions that may improve disease model accuracy. First, we use data and models of West African migration to show that EVD does not homogeneously mix, but spreads in a predictable manner. Next, we estimate the initial growth rate of EVD within country administrative divisions and find that it significantly decreases with population density. Finally, we test whether EVD strains have uniform transmissibility through a novel statistical test, and find that certain strains appear more often than expected by chance.

Telecommunications companies and health in West Africa: the issues.

PubMed

Ankri, R; Maroune, M-H

2017-11-01

West Africa still faces important public health issues today: improving the health infrastructure, compensating for the lack of medical personnel, and bringing the rural "lost-to-follow-up" population into an inclusive healthcare system. At the same time, the boom in the mobile telephone market is providing important business opportunities for telecommunications companies in this field, leading to the rapid propagation of eHealth solutions. Thus, the telecom companies' technical innovations enable the creation of digital health solutions adapted to the specific needs of the West African market. The companies can thus increase their business through eHealth and simultaneously generate positive externalities (a healthier population), meeting the goals of their corporate social responsibility policies. We will see how these companies, aware of this opportunity, build these solutions and they meet the challenges they will confront.

The West Africa Field Epidemiology and Laboratory Training Program, a strategy to improve disease surveillance and epidemic control in West Africa

PubMed Central

Mutabaruka, Evariste; Sawadogo, Mamadou; Tarnagda, Zekiba; Ouédraogo, Lauren; Sangare, Lassana; Ousmane, Badolo; Ndjakani, Yassa; Namusisi, Olivia; Mukanga, David; Evering-Watley, Michele; Hounton, Sennen; Nsubuga, Peter

2011-01-01

The West Africa Field Epidemiology and Laboratory Training Program (WA-FELTP) which was established in September 2007, is an inter-country, competency-based, in-service and post -graduate training program in applied epidemiology and public health that builds the capacity to strengthen the surveillance and response system as well as epidemic control in the French-speaking countries where they are implemented. The overall purpose is to provide epidemiological and public health laboratory services to the public health systems at national, provincial, district and local levels. The program includes four countries: Burkina Faso, Mali, Niger, and Togo with an overarching goal to progressively cover all French speaking countries in West Africa through a phased-in approach. WA-FELTP's 2- year Master's program was launched in 2010 with 12 residents, three from each country, and consists of medical and veterinary doctors, pharmacists, and laboratory scientists. The training comprises 25% didactic sessions and 75% practical in-the-field mentored training. During the practical training, residents rovide service to their respective ministries of health and ministries of animal resources by contributing to outbreak investigations and activities that help to improve national surveillance systems at national, regional, district and local levels. The pressing challenges that the program must address consist of the lack of funds to support the second cohort of trainees, though trainee selection was completed, inadequate funds to support staff compensation, and shortage of funds to support trainees’ participation in critical activities in field epidemiology practice, and a need to develop a 5-year plan for sustainability. PMID:22359698

Ebola viral hemorrhagic disease outbreak in West Africa- lessons from Uganda.

PubMed

Mbonye, Anthony K; Wamala, Joseph F; Nanyunja, Miriam; Opio, Alex; Makumbi, Issa; Aceng, Jane Ruth

2014-09-01

There has been a rapid spread of Ebola Viral Hemorrhagic disease in Guinea, Liberia and Sierra Leone since March 2014. Since this is the first time of a major Ebola outbreak in West Africa; it is possible there is lack of understanding of the epidemic in the communities, lack of experience among the health workers to manage the cases and limited capacities for rapid response. The main objective of this article is to share Uganda's experience in controlling similar Ebola outbreaks and to suggest some lessons that could inform the control of the Ebola outbreak in West Africa. The article is based on published papers, reports of previous Ebola outbreaks, response plans and experiences of individuals who have participated in the control of Ebola epidemics in Uganda. Lessons learnt: The success in the control of Ebola epidemics in Uganda has been due to high political support, effective coordination through national and district task forces. In addition there has been active surveillance, strong community mobilization using village health teams and other community resources persons, an efficient laboratory system that has capacity to provide timely results. These have coupled with effective case management and infection control and the involvement of development partners who commit resources with shared responsibility. Several factors have contributed to the successful quick containment of Ebola outbreaks in Uganda. West African countries experiencing Ebola outbreaks could draw some lessons from the Uganda experience and adapt them to contain the Ebola epidemic.

The Challenge of Improving Soil Fertility in Yam Cropping Systems of West Africa

PubMed Central

Frossard, Emmanuel; Aighewi, Beatrice A.; Aké, Sévérin; Barjolle, Dominique; Baumann, Philipp; Bernet, Thomas; Dao, Daouda; Diby, Lucien N.; Floquet, Anne; Hgaza, Valérie K.; Ilboudo, Léa J.; Kiba, Delwende I.; Mongbo, Roch L.; Nacro, Hassan B.; Nicolay, Gian L.; Oka, Esther; Ouattara, Yabile F.; Pouya, Nestor; Senanayake, Ravinda L.; Six, Johan; Traoré, Orokya I.

2017-01-01

Yam (Dioscorea spp.) is a tuber crop grown for food security, income generation, and traditional medicine. This crop has a high cultural value for some of the groups growing it. Most of the production comes from West Africa where the increased demand has been covered by enlarging cultivated surfaces while the mean yield remained around 10 t tuber ha−1. In West Africa, yam is traditionally cultivated without input as the first crop after a long-term fallow as it is considered to require a high soil fertility. African soils, however, are being more and more degraded. The aims of this review were to show the importance of soil fertility for yam, discuss barriers that might limit the adoption of integrated soil fertility management (ISFM) in yam-based systems in West Africa, present the concept of innovation platforms (IPs) as a tool to foster collaboration between actors for designing innovations in yam-based systems and provide recommendations for future research. This review shows that the development of sustainable, feasible, and acceptable soil management innovations for yam requires research to be conducted in interdisciplinary teams including natural and social sciences and in a transdisciplinary manner involving relevant actors from the problem definition, to the co-design of soil management innovations, the evaluation of research results, their communication and their implementation. Finally, this research should be conducted in diverse biophysical and socio-economic settings to develop generic rules on soil/plant relationships in yam as affected by soil management and on how to adjust the innovation supply to specific contexts. PMID:29209341

Safe and Effective Deployment of Personnel to Support the Ebola Response - West Africa.

PubMed

Rouse, Edward N; Zarecki, Shauna Mettee; Flowers, Donald; Robinson, Shawn T; Sheridan, Reed J; Goolsby, Gary D; Nemhauser, Jeffrey; Kuwabara, Sachiko

2016-07-08

From the initial task of getting "50 deployers within 30 days" into the field to support the 2014-2016 Ebola virus disease (Ebola) epidemic response in West Africa to maintaining well over 200 staff per day in the most affected countries (Guinea, Liberia, and Sierra Leone) during the peak of the response, ensuring the safe and effective deployment of international responders was an unprecedented accomplishment by CDC. Response experiences shared by CDC deployed staff returning from West Africa were quickly incorporated into lessons learned and resulted in new activities to better protect the health, safety, security, and resiliency of responding personnel. Enhanced screening of personnel to better match skill sets and experience with deployment needs was developed as a staffing strategy. The mandatory predeployment briefings were periodically updated with these lessons to ensure that staff were aware of what to expect before, during, and after their deployments. Medical clearance, security awareness, and resiliency programs became a standard part of both predeployment and postdeployment activities. Response experience also led to the identification and provision of more appropriate equipment for the environment. Supporting the social and emotional needs of deployed staff and their families also became an agency focus for care and communication. These enhancements set a precedent as a new standard for future CDC responses, regardless of size or complexity.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Education and Economics in West Africa: From Unwritten Languages to the Internet

ERIC Educational Resources Information Center

Alibrandi, Marsha; Bull, Prince Hycy

2005-01-01

Global distribution of West African goods--coffee, chocolate, gold, diamonds (and at one time, ivory)--has linked this region to the outside world for centuries, yet its development remains slow. Not simply the ancestral home of humankind, Africa's western legacies include colonization, partition, and loss of untold millions to slavery and wars of…

Relative Contributions of the Saharan and Sahelian Sources to the Atmospheric Dust Load Over the North Atlantic

NASA Technical Reports Server (NTRS)

Ginoux, Paul; Chin, M.; Torres, O.; Prospero, J.; Dubovik, O.; Holben, B.; Einaudi, Franco (Technical Monitor)

2000-01-01

It has long been recognized that Saharan desert is the major source for long range transport of mineral dust over the Atlantic. The contribution from other natural sources to the dust load over the Atlantic has generally been ignored in previous model studies or been replaced by anthropogenically disturbed soil emissions. Recently, Prospero et.at. have identified the major dust sources over the Earth using TOMS aerosol index. They showed that these sources correspond to dry lakes with layers of sediment deposed in the late Holocene or Pleistocene. One of the most active of these sources seem to be the Bodele depression. Chiapello et al. have analyzed the mineralogical composition of dust on the West coast of Africa. They found that Sahelian dust events are the most intense but are less frequent than Saharan plumes. This suggests that the Bodele depression could contribute significantly to the dust load over the Atlantic. The relative contribution of the Sahel and Sahara dust sources is of importance for marine biogeochemistry or atmospheric radiation, because each source has a distinct mineralogical composition. We present here a model study of the relative contributions of Sahara and Sahel sources to the atmospheric dust aerosols over the North Atlantic. The Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model is used to simulate dust distribution in 1996-1997. Dust particles are labeled depending on their sources. In this presentation, we will present the comparison between the model results and observations from ground based measurements (dust concentration, optical thickness and size distribution) and satellite data (TOMS aerosol index). The relative contribution of each source will then be analyzed spatially and temporally.

USSOF OPERATIONS IN AFRICA: PROSPECTS FOR FUTURE ENGAGEMENTS IN THE SAHEL

DTIC Science & Technology

2017-04-03

Mechanical Engineering. He also obtained a Master of Arts degree in Terrorism , Organized Crime and Global Security from the Coventry University, United...was a staff officer in the Headquarters Nigerian Air Force, Abuja. iv Abstract As part of the Global War on Terror , AFRICOM was established...to secure the US security interests in Africa. AFRICOM, through the Trans-Saharan Counter Terrorism Partnership uses USSOF to engage Sahelian

Epidemiological features and trends of Ebola virus disease in West Africa.

PubMed

Wang, Ligui; Yang, Guang; Jia, Leili; Li, Zhenjun; Xie, Jing; Li, Peng; Qiu, Shaofu; Hao, Rongzhang; Wu, Zhihao; Ma, Hui; Song, Hongbin

2015-09-01

According to a World Health Organization report, the epidemiological features of Ebola virus disease (EVD) have changed significantly in West Africa. In this study, the new epidemiological features and prevalence trends for EVD in Guinea, Liberia, and Sierra Leone are described. It was predicted that the Ebola outbreak would end in June 2015. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

What aspects of future rainfall changes matter for crop yields in West Africa?

NASA Astrophysics Data System (ADS)

Guan, Kaiyu; Sultan, Benjamin; Biasutti, Michela; Baron, Christian; Lobell, David B.

2015-10-01

How rainfall arrives, in terms of its frequency, intensity, the timing and duration of rainy season, may have a large influence on rainfed agriculture. However, a thorough assessment of these effects is largely missing. This study combines a new synthetic rainfall model and two independently validated crop models (APSIM and SARRA-H) to assess sorghum yield response to possible shifts in seasonal rainfall characteristics in West Africa. We find that shifts in total rainfall amount primarily drive the rainfall-related crop yield change, with less relevance to intraseasonal rainfall features. However, dry regions (total annual rainfall below 500 mm/yr) have a high sensitivity to rainfall frequency and intensity, and more intense rainfall events have greater benefits for crop yield than more frequent rainfall. Delayed monsoon onset may negatively impact yields. Our study implies that future changes in seasonal rainfall characteristics should be considered in designing specific crop adaptations in West Africa.

Evaluating the performance of remotely sensed and reanalysed precipitation data over West Africa using HBV light

NASA Astrophysics Data System (ADS)

Jütten, Thomas; Jackisch, Dominik; Diekkrüger, Bernd; Kusche, Jürgen; Eicker, Annette; Springer, Anne

2016-04-01

Water is one of the most crucial natural resources in West Africa, where the livelihoods of large parts of the population rely heavily on rain-fed agriculture. Therefore, the modelling of the water balance is an important tool to aid in water resource management. Precipitation is one of most important atmospheric drivers of hydrological models. However, ground-based observation networks are sparse in Western Africa and a further decline in station numbers due to a variety of reasons such as the deterioration of stations or political unrest has been observed in recent years. In ungauged river basins, or basins with insufficiently available precipitation data, several studies have shown that remotely sensed or reanalysed precipitation data may be used to compliment or replace missing information. However, the uncertainties of these datasets over Western Africa are not well examined and a need for further studies is apparent. For validation purposes, precipitation datasets are traditionally compared to in-situ ground measurements. This is not possible in ungauged basins. A new approach to assess the quality of satellite and reanalysis data which is gaining popularity among researchers compares different precipitation datasets using hydrological models. In this so-called hydrological evaluation, ground-truth data is no longer necessary in order to validate a product. The chosen model is calibrated for different precipitation products and the simulated streamflow generated for each product is compared to the measured streamflow. Multiple state of the art satellite and reanalysis precipitation datasets with various spatial resolutions were used in this study, namely: CFSR (0.3125°), CHIRPS (0.05°), CMORPH (0.25°), PERSIANN (0.25°), RFE 2.0 (0.1°), TAMSAT (0.0375°), TRMM 3B42 v7 (0.25°) and TRMM 3B42RT (real time) (0.25°). These datasets were evaluated at the regional as well as local scale using the HBV light conceptual hydrological model for several basins

A Cornerstone of National Development: Senior High School Leadership in Liberia, West Africa.

ERIC Educational Resources Information Center

Reed, Rodney J.

This study focuses on reasons for the perceived superiority of mission senior high schools in contrast to private and government senior high schools in Liberia, West Africa. Since an effective principal may be equated with an effective school, the study examines background preparation, experience, and professional characteristics of Liberian…

Relationships between climate, soil moisture and phenology of the woody cover in two sites located along the West African latitudinal gradient

NASA Astrophysics Data System (ADS)

Seghieri, Josiane; Vescovo, Aude; Padel, Karine; Soubie, Remy; Arjounin, Marc; Boulain, Nicolas; de Rosnay, Patricia; Galle, Sylvie; Gosset, Marielle; Mouctar, Abakar H.; Peugeot, Christophe; Timouk, Franck

2009-08-01

SummaryThe study quantifies the relationships at local scale between phenology and determinants of climate and soil water resources at two sites located along the latitudinal gradient of West Africa, one in the central Sahel (Mali), the other in the Sudanian bioclimatic zone (Benin). The aim is to improve our knowledge on possible vegetation response to possible climate change. Within the Sudanian site, average annual rainfall is 1200 mm, extending from April to October, while, in the Sahelian site, it is 370 mm, occurring from June to September. Physical data were collected from the African Monsoon Multidisciplinary Analysis research programme. The phenology of the dominant species was monitored in four types of vegetation cover at the wetter site, and in three types of vegetation cover at the drier site. For each sampled plant, leafing, flowering and fruiting were recorded as binary variables in terms of the presence/absence of phenophases. A small proportion of the variability of each phenophase occurrence is explained by the logit models. However, rainfall rise is significantly linked to leafing probability increase in the Sahelian site but not in the Sudanian site. Day length extension and temperature decrease are significantly correlated with an increase in leafing in the Sudanian site, but not in the Sahelian. On both sites, the increase in cumulative rainfall is not found to be linked to an increased probability of reproductive phenophases (negative or non-significant relationships). Air temperature is positively correlated with flowering rate in the Sudanian site, but, all other factors being constant, no climate factors are found to be highly significant of flowering occurrence in the Sahel. Fruiting probability is positively correlated mainly with temperature within the Sahelian site. Leafing occurrence is positively correlated with soil moisture in the 0-1 m layer for the Sudanian site, but not for the Sahelian site. Significant relationships between

Male Circumcision and the Epidemic Emergence of HIV-2 in West Africa

PubMed Central

Hewlett, Barry Stephen; Camacho, Ricardo Jorge

2016-01-01

Background Epidemic HIV-2 (groups A and B) emerged in humans circa 1930–40. Its closest ancestors are SIVsmm infecting sooty mangabeys from southwestern Côte d'Ivoire. The earliest large-scale serological surveys of HIV-2 in West Africa (1985–91) show a patchy spread. Côte d'Ivoire and Guinea-Bissau had the highest prevalence rates by then, and phylogeographical analysis suggests they were the earliest epicenters. Wars and parenteral transmission have been hypothesized to have promoted HIV-2 spread. Male circumcision (MC) is known to correlate negatively with HIV-1 prevalence in Africa, but studies examining this issue for HIV-2 are lacking. Methods We reviewed published HIV-2 serosurveys for 30 cities of all West African countries and obtained credible estimates of real prevalence through Bayesian estimation. We estimated past MC rates of 218 West African ethnic groups, based on ethnographic literature and fieldwork. We collected demographic tables specifying the ethnic partition in cities. Uncertainty was incorporated by defining plausible ranges of parameters (e.g. timing of introduction, proportion circumcised). We generated 1,000 sets of past MC rates per city using Latin Hypercube Sampling with different parameter combinations, and explored the correlation between HIV-2 prevalence and estimated MC rate (both logit-transformed) in the 1,000 replicates. Results and Conclusions Our survey reveals that, in the early 20th century, MC was far less common and geographically more variable than nowadays. HIV-2 prevalence in 1985–91 and MC rates in 1950 were negatively correlated (Spearman rho = -0.546, IQR: -0.553–-0.546, p≤0.0021). Guinea-Bissau and Côte d'Ivoire cities had markedly lower MC rates. In addition, MC was uncommon in rural southwestern Côte d'Ivoire in 1930.The differential HIV-2 spread in West Africa correlates with different historical MC rates. We suggest HIV-2 only formed early substantial foci in cities with substantial uncircumcised

Geology and total petroleum systems of the West-Central Coastal province (7203), West Africa

USGS Publications Warehouse

Brownfield, Michael E.; Charpentier, Ronald R.

2006-01-01

The West-Central Coastal Province of the Sub-Saharan Africa Region consists of the coastal and offshore areas of Cameroon, Equatorial Guinea, Gabon, Democratic Republic of the Congo, Republic of the Congo, Angola (including the disputed Cabinda Province), and Namibia. The area stretches from the east edge of the Niger Delta south to the Walvis Ridge. The West-Central Coastal Province includes the Douala, Kribi-Campo, Rio Muni, Gabon, Congo, Kwanza, Benguela, and Namibe Basins, which together form the Aptian salt basin of equatorial west Africa. The area has had significant exploration for petroleum; more than 295 oil fields have been discovered since 1954. Since 1995, several giant oil fields have been discovered, especially in the deep-water area of the Congo Basin. Although many total petroleum systems may exist in the West-Central Coastal Province, only four major total petroleum systems have been defined. The area of the province north of the Congo Basin contains two total petroleum systems: the Melania-Gamba Total Petroleum System, consisting of Lower Cretaceous source and reservoir rocks, and the Azile-Senonian Total Petroleum System, consisting of Albian to Turonian source rocks and Cretaceous reservoir rocks. Two assessment units are defined in the West-Central Coastal Province north of the Congo Basin: the Gabon Subsalt and the Gabon Suprasalt Assessment Units. The Congo Basin contains the Congo Delta Composite Total Petroleum System, consisting of Lower Cretaceous to Tertiary source and reservoir rocks. The Central Congo Delta and Carbonate Platform and the Central Congo Turbidites Assessment Units are defined in the Congo Delta Composite Total Petroleum System. The area south of the Congo Basin contains the Cuanza Composite Total Petroleum System, consisting of Lower Cretaceous to Tertiary source and reservoir rocks. The Cuanza-Namibe Assessment Unit is defined in the Cuanza Composite Total Petroleum System. The U.S. Geological Survey (USGS) assessed the

The statistical distribution of aerosol properties in sourthern West Africa

NASA Astrophysics Data System (ADS)

Haslett, Sophie; Taylor, Jonathan; Flynn, Michael; Bower, Keith; Dorsey, James; Crawford, Ian; Brito, Joel; Denjean, Cyrielle; Bourrianne, Thierry; Burnet, Frederic; Batenburg, Anneke; Schulz, Christiane; Schneider, Johannes; Borrmann, Stephan; Sauer, Daniel; Duplissy, Jonathan; Lee, James; Vaughan, Adam; Coe, Hugh

2017-04-01

The population and economy in southern West Africa have been growing at an exceptional rate in recent years and this trend is expected to continue, with the population projected to more than double to 800 million by 2050. This will result in a dramatic increase in anthropogenic pollutants, already estimated to have tripled between 1950 and 2000 (Lamarque et al., 2010). It is known that aerosols can modify the radiative properties of clouds. As such, the entrainment of anthropogenic aerosol into the large banks of clouds forming during the onset of the West African Monsoon could have a substantial impact on the region's response to climate change. Such projections, however, are greatly limited by the scarcity of observations in this part of the world. As part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, three research aircraft were deployed, each carrying equipment capable of measuring aerosol properties in-situ. Instrumentation included Aerosol Mass Spectrometers (AMS), Single Particle Soot Photometers (SP2), Condensation Particle Counters (CPC) and Scanning Mobility Particle Sizers (SMPS). Throughout the intensive aircraft campaign, 155 hours of scientific flights covered an area including large parts of Benin, Togo, Ghana and parts of Côte D'Ivoire. Approximately 70 hours were dedicated to the measurement of cloud-aerosol interactions, with many other flights producing data contributing towards this objective. Using datasets collected during this campaign period, it is possible to build a robust statistical understanding of aerosol properties in this region for the first time, including size distributions and optical and chemical properties. Here, we describe preliminary results from aerosol measurements on board the three aircraft. These have been used to describe aerosol properties throughout the region and time period encompassed by the DACCIWA aircraft campaign. Such statistics will be invaluable for improving future

An oceanography summer school in Ghana, West Africa

NASA Astrophysics Data System (ADS)

Arbic, B. K.; Ansong, J. K.; Johnson, W.; Nyadjro, E. S.; Nyarko, E.

2016-02-01

Because oceanography is a global science, it clearly benefits from the existence of a world-wide network of oceanographers. As with most STEM disciplines, sub-Saharan Africa is not as well represented in the field of oceanography as it should be, given its large population. The need for oceanographers in sub-Saharan Africa is great, due to a long list of ocean-related issues affecting African development, including but not limited to fishing, oil drilling, sea level rise, coastal erosion, shipping, and piracy. We view this as an opportunity as well as a challenge. Many of the world's fastest growing economies are in sub-Saharan Africa, and STEM capacity building could further fuel this growth. With support from the US National Science Foundation, we ran an oceanography summer school from August 24-27, 2015, at the Regional Maritime University (RMU) in Ghana, West Africa. This first summer school was lecture-based, with a focus on basic chemical oceanography, basic physical oceanography, ocean modeling, and satellite oceanography. About 35 participants came to almost every lecture, and about 20 other participants came to some of the lectures as their time permitted. The participants included RMU faculty, 12 students from the Kwame Nkrumah University of Science and Technology, one Associate Oceanographer from the University of Ghana, and some participants from private sector companies and Ghanaian governmental agencies. There were long and lively discussions at the end of each lecture, and there was a lengthy discussion at the conclusion of the school on how to improve future summer schools. In 2016 and 2017, we plan to divide into smaller groups so that participants can pursue their particular interests in greater depth, and to allow time for student presentations. We also plan to begin exploring the potential for research partnerships, and to utilize distance learning to involve more faculty and students from locations throughout Ghana and perhaps from even other

The Exportation of American Higher Education to West Africa: Liberia College, 1850-1900

ERIC Educational Resources Information Center

Livingston, Thomas W.

1976-01-01

Noting that Liberia College, although not operating until 1862, happens to have been the first American collegiate institution proposed specifically for the higher education of blacks, this article discusses what the first degree granting college in West Africa was, and how it could have been generated or sustained by a Liberian population of…

Overview of the DACCIWA ground-based field campaign in southern West Africa

NASA Astrophysics Data System (ADS)

Lohou, Fabienne; Kalthoff, Norbert; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Ajao, Adewale; Ayoola, Muritala; Babić, Karmen; Bessardon, Geoffrey; Delon, Claire; Dione, Cheikh; Handwerker, Jan; Jambert, Corinne; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas; Derrien, Solène

2017-04-01

During June and July 2016, a ground-based field campaign took place in southern West Africa within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project. In the investigated region, extended low-level stratus clouds form very frequently during night-time and persist long into the following day influencing the diurnal cycle of the atmospheric boundary layer and, hence, the regional climate. The motivation for the measurements was to identify the meteorological controls on the whole process chain from the formation of nocturnal stratus clouds, via the daytime transition to convective clouds and the formation of deep precipitating clouds. During the measurement period, extensive remote sensing and in-situ measurements were performed at three supersites in Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). The gathered observations included the energy-balance components at the Earth's surface, the mean and turbulent conditions in the nocturnal and daytime ABL as well as the de- and entrainment processes between the ABL and the free troposphere. The meteorological measurements were supplemented by aerosol and air-chemistry observations. We will give an overview of the conducted measurements including instrument availability and strategy during intensive observation periods.

Adolescent and Adult Reasoning about Gender Roles and Fairness in Benin, West Africa

ERIC Educational Resources Information Center

Conry-Murray, Clare

2009-01-01

This study examined reasoning about gender roles in a traditional society in Benin, West Africa. Ninety-seven male and female adolescents and adults evaluated conflicts between a husband and a wife over gender norms to determine whether gender norms, are judged to be moral or conventional. Although most attributed decision-making power to the…

Modelling the Dynamics of Post-Vaccination Immunity Rate in a Population of Sahelian Sheep after a Vaccination Campaign against Peste des Petits Ruminants Virus

PubMed Central

Lancelot, Renaud; Lesnoff, Matthieu

2016-01-01

Background Peste des petits ruminants (PPR) is an acute infectious viral disease affecting domestic small ruminants (sheep and goats) and some wild ruminant species in Africa, the Middle East and Asia. A global PPR control strategy based on mass vaccination—in regions where PPR is endemic—was recently designed and launched by international organizations. Sahelian Africa is one of the most challenging endemic regions for PPR control. Indeed, strong seasonal and annual variations in mating, mortality and offtake rates result in a complex population dynamics which might in turn alter the population post-vaccination immunity rate (PIR), and thus be important to consider for the implementation of vaccination campaigns. Methods In a context of preventive vaccination in epidemiological units without PPR virus transmission, we developed a predictive, dynamic model based on a seasonal matrix population model to simulate PIR dynamics. This model was mostly calibrated with demographic and epidemiological parameters estimated from a long-term follow-up survey of small ruminant herds. We used it to simulate the PIR dynamics following a single PPR vaccination campaign in a Sahelian sheep population, and to assess the effects of (i) changes in offtake rate related to the Tabaski (a Muslim feast following the lunar calendar), and (ii) the date of implementation of the vaccination campaigns. Results The persistence of PIR was not influenced by the Tabaski date. Decreasing the vaccination coverage from 100 to 80% had limited effects on PIR. However, lower vaccination coverage did not provide sufficient immunity rates (PIR < 70%). As a trade-off between model predictions and other considerations like animal physiological status, and suitability for livestock farmers, we would suggest to implement vaccination campaigns in September-October. This model is a first step towards better decision support for animal health authorities. It might be adapted to other species, livestock

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study

PubMed Central

Ekouevi, Didier K.; Balestre, Eric; Coffie, Patrick A.; Minta, Daouda; Messou, Eugene; Sawadogo, Adrien; Minga, Albert; Sow, Papa Salif; Bissagnene, Emmanuel; Eholie, Serge P.; Gottlieb, Geoffrey S.; Dabis, François; Zannou, Djimon Marcel; Ahouada, Carin; Akakpo, Jocelyn; Ahomadegbé, Christelle; Bashi, Jules; Gougounon-Houéto, Alice; Azon-Kouanou, Angèle; Houngbé, Fabien; Koumakpaï, Sikiratou; Alihonou, Florence; d’Almeida, Marcelline; Hodonou, Irvine; Hounhoui, Ghislaine; Sagbo, Gracien; Tossa-Bagnan, Leïla; Adjide, Herman; Drabo, Joseph; Bognounou, René; Dienderé, Arnaud; Traore, Eliezer; Zoungrana, Lassane; Zerbo, Béatrice; Sawadogo, Adrien Bruno; Zoungrana, Jacques; Héma, Arsène; Soré, Ibrahim; Bado, Guillaume; Tapsoba, Achille; Yé, Diarra; Kouéta, Fla; Ouedraogo, Sylvie; Ouédraogo, Rasmata; Hiembo, William; Gansonré, Mady; Messou, Eugène; Gnokoro, Joachim Charles; Koné, Mamadou; Kouakou, Guillaume Martial; Bosse, Clarisse Amani; Brou, Kouakou; Assi, Achi Isidore; Chenal, Henri; Hawerlander, Denise; Soppi, Franck; Minga, Albert; Abo, Yao; Bomisso, Germain; Eholié, Serge Paul; Amego, Mensah Deborah Noelly; Andavi, Viviane; Diallo, Zelica; Ello, Frédéric; Tanon, Aristophane Koffi; Koule, Serge Olivier; Anzan, Koffi Charles; Guehi, Calixte; Aka, Edmond Addi; Issouf, Koffi Ladji; Kouakou, Jean-Claude; N’Gbeche, Marie-Sylvie; Touré, Pety; Avit-Edi, Divine; Kouakou, Kouadio; Moh, Magloire; Yao, Valérie Andoblé; Folquet, Madeleine Amorissani; Dainguy, Marie-Evelyne; Kouakou, Cyrille; Méa-Assande, Véronique Tanoh; Oka-Berete, Gladys; Zobo, Nathalie; Acquah, Patrick; Kokora, Marie-Berthe; Eboua, Tanoh François; Timité-Konan, Marguerite; Ahoussou, Lucrèce Diecket; Assouan, Julie Kebé; Sami, Mabéa Flora; Kouadio, Clémence; Renner, Lorna; Goka, Bamenla; Welbeck, Jennifer; Sackey, Adziri; Owiafe, Seth Ntiri; Wejse, Christian; Silva, Zacarias José Da; Paulo, Joao; Rodrigues, Amabelia; da Silva, David; Medina, Candida; Oliviera-Souto, Ines; Østergaard, Lars; Laursen, Alex; Sodemann, Morten; Aaby, Peter; Fomsgaard, Anders; Erikstrup, Christian; Eugen-Olsen, Jesper; Maïga, Moussa Y; Diakité, Fatoumata Fofana; Kalle, Abdoulaye; Katile, Drissa; Traore, Hamar Alassane; Minta, Daouda; Cissé, Tidiani; Dembelé, Mamadou; Doumbia, Mohammed; Fomba, Mahamadou; Kaya, Assétou Soukho; Traoré, Abdoulaye M; Traoré, Hamady; Toure, Amadou Abathina; Dicko, Fatoumata; Sylla, Mariam; Berthé, Alima; Traoré, Hadizatou Coulibaly; Koïta, Anta; Koné, Niaboula; N'Diaye, Clémentine; Coulibaly, Safiatou Touré; Traoré, Mamadou; Traoré, Naïchata; Charurat, Man; Ajayi, Samuel; Dapiap, Stephen; Otu; Igbinoba, Festus; Benson, Okwara; Adebamowo, Clément; James, Jesse; Obaseki; Osakede, Philip; Olasode, John; Sow, Papa Salif; Diop, Bernard; Manga, Noël Magloire; Tine, Judicael Malick; Signate Sy, Haby; Ba, Abou; Diagne, Aida; Dior, Hélène; Faye, Malick; Gueye, Ramatoulaye Diagne; Mbaye, Aminata Diack; Patassi, Akessiwe; Kotosso, Awèrou; Kariyare, Benjamin Goilibe; Gbadamassi, Gafarou; Komi, Agbo; Mensah-Zukong, Kankoé Edem; Pakpame, Pinuwe; Lawson-Evi, Annette Koko; Atakouma, Yawo; Takassi, Elom; Djeha, Améyo; Ephoévi-gah, Ayoko; Djibril, Sherifa El-Hadj; Dabis, François; Bissagnene, Emmanuel; Arrivé, Elise; Coffie, Patrick; Ekouevi, Didier; Jaquet, Antoine; Leroy, Valériane; Lewden, Charlotte; Sasco, Annie; Azani, Jean-Claude; Allou, Gérard; Balestre, Eric; Bohossou, Franck; Karcher, Sophie; Gonsan, Jules Mahan; Carrou, Jérôme Le; Lenaud, Séverin; Nchot, Célestin; Malateste, Karen; Yao, Amon Roseamonde; Siloué, Bertine; Clouet, Gwenaelle; Djetouan, Hugues; Doring, Alexandra; Kouakou, Adrienne; Rabourdin, Elodie; Rivenc, Jean; Anglaret, Xavier; Ba, Boubacar; Essanin, Jean Bosco; Ciaranello, Andrea; Datté, Sébastien; Desmonde, Sophie; Diby, Jean-Serge Elvis; Gottlieb, Geoffrey S.; Horo, Apollinaire Gninlgninrin; Kangah, Serge N'zoré; Malvy, Denis; Meless, David; Mounkaila-Harouna, Aida; Ndondoki, Camille; Shiboski, Caroline; Thiébaut, Rodolphe; PAC-CI; Abidjan

2013-01-01

Background HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA). Methods We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d’Ivoire, Mali, and Senegal, in the West Africa region. Results Data was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3–51.7) and 42.4 years, IQR (37.0–47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm3, IQR (83–247) among HIV-2 infected patients and 146 cells/mm3, IQR (55–249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm3 after 24 months on ART for HIV-2 patients and 169 cells/mm3 for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7–4.3). Conclusions This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population. PMID:23824279

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study.

PubMed

Ekouevi, Didier K; Balestre, Eric; Coffie, Patrick A; Minta, Daouda; Messou, Eugene; Sawadogo, Adrien; Minga, Albert; Sow, Papa Salif; Bissagnene, Emmanuel; Eholie, Serge P; Gottlieb, Geoffrey S; Dabis, François; Zannou, Djimon Marcel; Ahouada, Carin; Akakpo, Jocelyn; Ahomadegbé, Christelle; Bashi, Jules; Gougounon-Houéto, Alice; Azon-Kouanou, Angèle; Houngbé, Fabien; Koumakpaï, Sikiratou; Alihonou, Florence; d'Almeida, Marcelline; Hodonou, Irvine; Hounhoui, Ghislaine; Sagbo, Gracien; Tossa-Bagnan, Leïla; Adjide, Herman; Drabo, Joseph; Bognounou, René; Dienderé, Arnaud; Traore, Eliezer; Zoungrana, Lassane; Zerbo, Béatrice; Sawadogo, Adrien Bruno; Zoungrana, Jacques; Héma, Arsène; Soré, Ibrahim; Bado, Guillaume; Tapsoba, Achille; Yé, Diarra; Kouéta, Fla; Ouedraogo, Sylvie; Ouédraogo, Rasmata; Hiembo, William; Gansonré, Mady; Messou, Eugène; Gnokoro, Joachim Charles; Koné, Mamadou; Kouakou, Guillaume Martial; Bosse, Clarisse Amani; Brou, Kouakou; Assi, Achi Isidore; Chenal, Henri; Hawerlander, Denise; Soppi, Franck; Minga, Albert; Abo, Yao; Bomisso, Germain; Eholié, Serge Paul; Amego, Mensah Deborah Noelly; Andavi, Viviane; Diallo, Zelica; Ello, Frédéric; Tanon, Aristophane Koffi; Koule, Serge Olivier; Anzan, Koffi Charles; Guehi, Calixte; Aka, Edmond Addi; Issouf, Koffi Ladji; Kouakou, Jean-Claude; N'gbeche, Marie-Sylvie; Touré, Pety; Avit-Edi, Divine; Kouakou, Kouadio; Moh, Magloire; Yao, Valérie Andoblé; Folquet, Madeleine Amorissani; Dainguy, Marie-Evelyne; Kouakou, Cyrille; Méa-Assande, Véronique Tanoh; Oka-Berete, Gladys; Zobo, Nathalie; Acquah, Patrick; Kokora, Marie-Berthe; Eboua, Tanoh François; Timité-Konan, Marguerite; Ahoussou, Lucrèce Diecket; Assouan, Julie Kebé; Sami, Mabéa Flora; Kouadio, Clémence; Renner, Lorna; Goka, Bamenla; Welbeck, Jennifer; Sackey, Adziri; Owiafe, Seth Ntiri; Wejse, Christian; Silva, Zacarias José Da; Paulo, Joao; Rodrigues, Amabelia; da Silva, David; Medina, Candida; Oliviera-Souto, Ines; Ostergaard, Lars; Laursen, Alex; Sodemann, Morten; Aaby, Peter; Fomsgaard, Anders; Erikstrup, Christian; Eugen-Olsen, Jesper; Maïga, Moussa Y; Diakité, Fatoumata Fofana; Kalle, Abdoulaye; Katile, Drissa; Traore, Hamar Alassane; Minta, Daouda; Cissé, Tidiani; Dembelé, Mamadou; Doumbia, Mohammed; Fomba, Mahamadou; Kaya, Assétou Soukho; Traoré, Abdoulaye M; Traoré, Hamady; Toure, Amadou Abathina; Dicko, Fatoumata; Sylla, Mariam; Berthé, Alima; Traoré, Hadizatou Coulibaly; Koïta, Anta; Koné, Niaboula; N'diaye, Clémentine; Coulibaly, Safiatou Touré; Traoré, Mamadou; Traoré, Naïchata; Charurat, Man; Ajayi, Samuel; Dapiap, Stephen; Otu; Igbinoba, Festus; Benson, Okwara; Adebamowo, Clément; James, Jesse; Obaseki; Osakede, Philip; Olasode, John; Sow, Papa Salif; Diop, Bernard; Manga, Noël Magloire; Tine, Judicael Malick; Signate Sy, Haby; Ba, Abou; Diagne, Aida; Dior, Hélène; Faye, Malick; Gueye, Ramatoulaye Diagne; Mbaye, Aminata Diack; Patassi, Akessiwe; Kotosso, Awèrou; Kariyare, Benjamin Goilibe; Gbadamassi, Gafarou; Komi, Agbo; Mensah-Zukong, Kankoé Edem; Pakpame, Pinuwe; Lawson-Evi, Annette Koko; Atakouma, Yawo; Takassi, Elom; Djeha, Améyo; Ephoévi-Gah, Ayoko; Djibril, Sherifa El-Hadj; Dabis, François; Bissagnene, Emmanuel; Arrivé, Elise; Coffie, Patrick; Ekouevi, Didier; Jaquet, Antoine; Leroy, Valériane; Lewden, Charlotte; Sasco, Annie; Azani, Jean-Claude; Allou, Gérard; Balestre, Eric; Bohossou, Franck; Karcher, Sophie; Gonsan, Jules Mahan; Carrou, Jérôme Le; Lenaud, Séverin; Nchot, Célestin; Malateste, Karen; Yao, Amon Roseamonde; Siloué, Bertine; Clouet, Gwenaelle; Djetouan, Hugues; Doring, Alexandra; Kouakou, Adrienne; Rabourdin, Elodie; Rivenc, Jean; Anglaret, Xavier; Ba, Boubacar; Essanin, Jean Bosco; Ciaranello, Andrea; Datté, Sébastien; Desmonde, Sophie; Diby, Jean-Serge Elvis; Gottlieb, Geoffrey S; Horo, Apollinaire Gninlgninrin; Kangah, Serge N'zoré; Malvy, Denis; Meless, David; Mounkaila-Harouna, Aida; Ndondoki, Camille; Shiboski, Caroline; Thiébaut, Rodolphe; Pac-Ci; Abidjan

2013-01-01

HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA). We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d'Ivoire, Mali, and Senegal, in the West Africa region. Data was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3-51.7) and 42.4 years, IQR (37.0-47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm(3), IQR (83-247) among HIV-2 infected patients and 146 cells/mm(3), IQR (55-249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm(3) after 24 months on ART for HIV-2 patients and 169 cells/mm(3) for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7-4.3). This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population.

Challenges in the management of chronic HBV infection in West Africa: The clinician's perspective.

PubMed

Okonkwo, Uchenna C; Onyekwere, Charles A

2016-01-01

Hepatitis B infection has become a public health issue in recent years. Approximately 350 million of the world's population are chronically infected reaching endemic proportions in West Africa. Guidelines for treatment are continuously improving but are becoming more complex. To determine the challenges hepatologists experience in the management of patients with chronic hepatitis B. This was a cross-sectional descriptive study conducted among hepatologists in West Africa during a regional hepatitis conference in 2013. Forty-six hepatologists completed the questionnaire. When evaluating a patient for chronic hepatitis B, the preferred investigations were: LFT (100%); abdominal ultrasound (93.5%); HBeAg (93.5%); HBV DNA (78%); HBsAg measure (22%); HBV genotype (15.2%); and liver biopsy (34.8%). Most had their patients on nucleoside/nucleotide analogue but follow-up visits after 1 year were problematic. The majority of hepatologists had good intentions regarding the evaluation of their patients, but only a small percentage of patients are properly investigated. © The Author(s) 2014.

Measles mortality reduction--West Africa, 1996-2002.

PubMed

2004-01-23

The World Health Organization (WHO) estimates that, during 2000, measles accounted for approximately 777,000 deaths worldwide, of which 452,000 (58%) occurred in Africa. In response, in 2000, WHO's African Regional Office (AFRO) adopted a plan to reduce measles mortality >50% by 2005. The plan recommended 1) increasing measles vaccination by strengthening routine health services; 2) providing a second opportunity for measles vaccination for all children, primarily through wide--age-range supplemental immunization activities (SIAs); 3) enhancing measles surveillance; and 4) improving management of measles cases. The initial wide--age-range SIA targets all children aged 9 months-14 years, regardless of history of measles disease or vaccination. Follow-up SIAs are needed 3-5 years after the initial SIA to provide a second opportunity for vaccination to children born since the previous SIA (i.e., those aged 9 months-4 years). During the 1990s, the countries of the Americas and seven countries in southern Africa used this strategy to reduce the number of measles deaths to near zero. This report describes the recent implementation of this strategy in three West African countries, where reported measles cases declined 83%-97% during the first year after SIAs. Successful implementation of this strategy by other African countries should result in achieving the goal of >50% reduction in measles mortality by 2005.

The oldest Stone Age occupation of coastal West Africa and its implications for modern human dispersals: New insight from Tiémassas

NASA Astrophysics Data System (ADS)

Niang, Khady; Blinkhorn, James; Ndiaye, Matar

2018-05-01

Examinations of modern human dispersals are typically focused on expansions from South, East or North Africa into Eurasia, with more limited attention paid to dispersals within Africa. The paucity of the West African fossil record means it has typically been overlooked in appraisals of human expansions in the Late Pleistocene, yet regions such as Senegal occur in key biogeographic transitional zones that may offer significant corridors for human occupation and expansion. Here, we report the first evidence for Middle Stone Age occupation of the West African littoral from Tiémassas, dating to ∼44 thousand years ago, coinciding with a period of enhanced humidity across the region. Prehistoric populations mainly procured raw material from exposed Ypresian limestone horizons with Levallois, discoidal and informal reduction sequences producing flake blanks for retouched tools. We discuss this mid-Marine Isotope Stage 3 occupation in the context of the site's unique, ecotonal position amongst Middle Stone Age sites across West Africa, and its significance for Later Stone Age colonization of near coastal forests in the region. The results also support previous suggestions for connections between Middle Stone Age populations in West Africa and the Maghreb, for which the coastline may also have played a significant role.

Impact of dynamical regionalization on precipitation biases and teleconnections over West Africa

NASA Astrophysics Data System (ADS)

Gómara, Iñigo; Mohino, Elsa; Losada, Teresa; Domínguez, Marta; Suárez-Moreno, Roberto; Rodríguez-Fonseca, Belén

2018-06-01

West African societies are highly dependent on the West African Monsoon (WAM). Thus, a correct representation of the WAM in climate models is of paramount importance. In this article, the ability of 8 CMIP5 historical General Circulation Models (GCMs) and 4 CORDEX-Africa Regional Climate Models (RCMs) to characterize the WAM dynamics and variability is assessed for the period July-August-September 1979-2004. Simulations are compared with observations. Uncertainties in RCM performance and lateral boundary conditions are assessed individually. Results show that both GCMs and RCMs have trouble to simulate the northward migration of the Intertropical Convergence Zone in boreal summer. The greatest bias improvements are obtained after regionalization of the most inaccurate GCM simulations. To assess WAM variability, a Maximum Covariance Analysis is performed between Sea Surface Temperature and precipitation anomalies in observations, GCM and RCM simulations. The assessed variability patterns are: El Niño-Southern Oscillation (ENSO); the eastern Mediterranean (MED); and the Atlantic Equatorial Mode (EM). Evidence is given that regionalization of the ENSO-WAM teleconnection does not provide any added value. Unlike GCMs, RCMs are unable to precisely represent the ENSO impact on air subsidence over West Africa. Contrastingly, the simulation of the MED-WAM teleconnection is improved after regionalization. Humidity advection and convergence over the Sahel area are better simulated by RCMs. Finally, no robust conclusions can be determined for the EM-WAM teleconnection, which cannot be isolated for the 1979-2004 period. The novel results in this article will help to select the most appropriate RCM simulations to study WAM teleconnections.

Assessing climate adaptation options and uncertainties for cereal systems in West Africa

NASA Astrophysics Data System (ADS)

Guan, K.; Sultan, B.; Biasutti, M.; Lobell, D. B.

2015-12-01

The already fragile agriculture production system in West Africa faces further challenges in meeting food security in the coming decades, primarily due to a fast increasing population and risks of climate change. Successful adaptation of agriculture should not only benefit in the current climate but should also reduce negative (or enhance positive) impacts for climate change. Assessment of various possible adaptation options and their uncertainties provides key information for prioritizing adaptation investments. Here, based on the several robust aspects of climate projections in this region (i.e. temperature increases and rainfall pattern shifts), we use two well-validated crop models (i.e. APSIM and SARRA-H) and an ensemble of downscaled climate forcing to assess five possible and realistic adaptation options (late sowing, intensification, thermal time increase, water harvesting and increased resilience to heat stress) in West Africa for the staple crop production of sorghum. We adopt a new assessment framework to account for both the impacts of adaptation options in current climate and their ability to reduce impacts of future climate change, and also consider changes in both mean yield and its variability. Our results reveal that most proposed "adaptation options" are not more beneficial in the future than in the current climate, i.e. not really reduce the climate change impacts. Increased temperature resilience during grain number formation period is the main adaptation that emerges. We also find that changing from the traditional to modern cultivar, and later sowing in West Sahel appear to be robust adaptations.

Socioeconomic consequences of blinding onchocerciasis in west Africa.

PubMed Central

Evans, T. G.

1995-01-01

Onchocerciasis or river blindness, a major cause of irreversible blindness among adults, has been the focus of international disease control efforts for over 20 years in West Africa. This paper employs the international classification of impairment, disability and handicap (ICIDH) to interpret results from a field study to assess the socioeconomic consequences of onchocerciasis in Guinea in 1987. In a sample of 136 blind, 94 visually impaired and 89 well-sighted persons, decreasing visual acuity is strongly associated with mobility, occupational and marital handicaps. Individual, household and disease correlates were explored. The implications of these findings for the ICIDH concept of handicap are discussed with particular emphasis on the need to extend analysis beyond the individual when assessing the socioeconomic consequences of disabling disease. PMID:7554022

The Foraging Ecology of the Endangered Cape Verde Shearwater, a Sentinel Species for Marine Conservation off West Africa.

PubMed

Paiva, Vitor H; Geraldes, Pedro; Rodrigues, Isabel; Melo, Tommy; Melo, José; Ramos, Jaime A

2015-01-01

Large Marine Ecosystems such as the Canary Current system off West Africa sustains high abundance of small pelagic prey, which attracts marine predators. Seabirds are top predators often used as biodiversity surrogates and sentinel species of the marine ecosystem health, thus frequently informing marine conservation planning. This study presents the first data on the spatial (GPS-loggers) and trophic (stable isotope analysis) ecology of a tropical seabird-the endangered Cape Verde shearwater Calonectris edwardsii-during both the incubation and the chick-rearing periods of two consecutive years. This information was related with marine environmental predictors (species distribution models), existent areas of conservation concern for seabirds (i.e. marine Important Bird Areas; marine IBAs) and threats to the marine environment in the West African areas heavily used by the shearwaters. There was an apparent inter-annual consistency on the spatial, foraging and trophic ecology of Cape Verde shearwater, but a strong alteration on the foraging strategies of adult breeders among breeding phases (i.e. from incubation to chick-rearing). During incubation, birds mostly targeted a discrete region off West Africa, known by its enhanced productivity profile and thus also highly exploited by international industrial fishery fleets. When chick-rearing, adults exploited the comparatively less productive tropical environment within the islands of Cape Verde, at relatively close distance from their breeding colony. The species enlarged its trophic niche and increased the trophic level of their prey from incubation to chick-rearing, likely to provision their chicks with a more diversified and better quality diet. There was a high overlap between the Cape Verde shearwaters foraging areas with those of European shearwater species that overwinter in this area and known areas of megafauna bycatch off West Africa, but very little overlap with existing Marine Important Bird Areas. Further

Exon-Enriched Libraries Reveal Large Genic Differences Between Aedes aegypti from Senegal, West Africa, and Populations Outside Africa

PubMed Central

Dickson, Laura B.; Campbell, Corey L.; Juneja, Punita; Jiggins, Francis M.; Sylla, Massamba; Black, William C.

2016-01-01

Aedes aegypti is one of the most studied mosquito species, and the principal vector of several arboviruses pathogenic to humans. Recently failure to oviposit, low fecundity, and poor egg-to-adult survival were observed when Ae. aegypti from Senegal (SenAae) West Africa were crossed with Ae. aegypti (Aaa) from outside of Africa, and in SenAae intercrosses. Fluorescent in situ hybridization analyses indicated rearrangements on chromosome 1, and pericentric inversions on chromosomes 2 and 3. Herein, high throughput sequencing (HTS) of exon-enriched libraries was used to compare chromosome-wide genetic diversity among Aaa collections from rural Thailand and Mexico, a sylvatic collection from southeastern Senegal (PK10), and an urban collection from western Senegal (Kaolack). Sex-specific polymorphisms were analyzed in Thailand and PK10 to assess genetic differences between sexes. Expected heterozygosity was greatest in SenAae. FST distributions of 15,735 genes among all six pairwise comparisons of the four collections indicated that Mexican and Thailand collections are genetically similar, while FST distributions between PK10 and Kaolack were distinct. All four comparisons of SenAae with Aaa indicated extreme differentiation. FST was uniform between sexes across all chromosomes in Thailand, but were different, especially on the sex autosome 1, in PK10. These patterns correlate with the reproductive isolation noted earlier. We hypothesize that cryptic Ae. aegypti taxa may exist in West Africa, and the large genic differences between Aaa and SenAae detected in the present study have accumulated over a long period following the evolution of chromosome rearrangements in allopatric populations that subsequently cause reproductive isolation when these populations became sympatric. PMID:28007834

Maternal anaemia in West and Central Africa: time for urgent action.

PubMed

Ayoya, Mohamed Ag; Bendech, Mohamed Ag; Zagré, Noel Marie; Tchibindat, Félicité

2012-05-01

To review the prevalence, severity and determinants of anaemia among women in West and Central Africa (WCA) and raise awareness among policy makers and programme planners in the region. Systematic descriptive review of data in the public domain of the ORC Macro MEASURE Demographic and Health Surveys, national nutrition surveys, oral and technical communications at regional meetings, studies published in scientific journals, and WHO and UNICEF databases. West and Central Africa region. Women of childbearing age. The prevalence of anaemia among pregnant and non-pregnant women is higher than 50 % and 40 %, respectively, in all countries. Within countries, this prevalence varies by living setting (rural v. urban), women's age and education. Across countries, socio-economic and climatic differences have no apparent association with the prevalence of anaemia among women. Several factors contribute either alone or jointly to the high rates of maternal anaemia in this region. These include widespread nutritional deficiencies; high incidence of infectious diseases; low access to and poor quality of health services; low literacy rates; ineffective design, implementation and evaluation of anaemia control programmes; and poverty. Addressing the multiple causes and minimizing the consequences of anaemia on maternal and child health and development in WCA require integrated multifactorial and multisectoral strategies. This also calls for unprecedented, historical and stronger political will and commitment that put adolescent girls and maternal health at the centre of the development agenda.

An interventional model to develop health professionals in West Africa.

PubMed

Sanou, Anselme Simeon; Awoyale, Florence Adeola; Diallo, Abdoulaye

2014-01-01

The health sector is characterized by a human resource base lacking in numbers, specialized skills, and management skills. West African Health Organization (WAHO) recognizes the need within the West Africa sub-region for bilingual professionals who are skilled in public health, management, leadership, and information technology to build human capacity in public health and developed the Young Professionals Internship Program (YPIP). Our study explores the evolution of the programme. YPIP program has successfully carried out its original aims and objectives to equip young professionals with basic principles of public health, management, and leadership, acquire competence in a second official language (French, English, and Portuguese), information and communication technology. Contributing factors towards this successful evaluation included positive ratings and commentary from previous interns about the relevance, usefulness, and quality of the programme, encouraging feedback from WAHO management, trainers, administrators, and intern employers on the impact of the YPIP program on young professionals, supporting evidence that demonstrates increased knowledge in professional skills and language competency.

An interventional model to develop health professionals in West Africa

PubMed Central

Sanou, Anselme Simeon; Awoyale, Florence Adeola; Diallo, Abdoulaye

2014-01-01

The health sector is characterized by a human resource base lacking in numbers, specialized skills, and management skills. West African Health Organization (WAHO) recognizes the need within the West Africa sub-region for bilingual professionals who are skilled in public health, management, leadership, and information technology to build human capacity in public health and developed the Young Professionals Internship Program (YPIP). Our study explores the evolution of the programme. YPIP program has successfully carried out its original aims and objectives to equip young professionals with basic principles of public health, management, and leadership, acquire competence in a second official language (French, English, and Portuguese), information and communication technology. Contributing factors towards this successful evaluation included positive ratings and commentary from previous interns about the relevance, usefulness, and quality of the programme, encouraging feedback from WAHO management, trainers, administrators, and intern employers on the impact of the YPIP program on young professionals, supporting evidence that demonstrates increased knowledge in professional skills and language competency. PMID:25419290

Statistical analysis of the time and space characteristic scales for large precipitating systems in the equatorial, tropical, sahelian and mid-latitude regions.

NASA Astrophysics Data System (ADS)

Duroure, Christophe; Sy, Abdoulaye; Baray, Jean luc; Van baelen, Joel; Diop, Bouya

2017-04-01

Precipitation plays a key role in the management of sustainable water resources and flood risk analyses. Changes in rainfall will be a critical factor determining the overall impact of climate change. We propose to analyse long series (10 years) of daily precipitation at different regions. We present the Fourier densities energy spectra and morphological spectra (i.e. probability repartition functions of the duration and the horizontal scale) of large precipitating systems. Satellite data from the Global precipitation climatology project (GPCP) and local pluviometers long time series in Senegal and France are used and compared in this work. For mid-latitude and Sahelian regions (North of 12°N), the morphological spectra are close to exponential decreasing distribution. This fact allows to define two characteristic scales (duration and space extension) for the precipitating region embedded into the large meso-scale convective system (MCS). For tropical and equatorial regions (South of 12°N) the morphological spectra are close to a Levy-stable distribution (power law decrease) which does not allow to define a characteristic scale (scaling range). When the time and space characteristic scales are defined, a "statistical velocity" of precipitating MCS can be defined, and compared to observed zonal advection. Maps of the characteristic scales and Levy-stable exponent over West Africa and south Europe are presented. The 12° latitude transition between exponential and Levy-stable behaviors of precipitating MCS is compared with the result of ECMWF ERA-Interim reanalysis for the same period. This morphological sharp transition could be used to test the different parameterizations of deep convection in forecast models.

The Effects of Atmospheric Constituents on the Normalized Difference Vegetation Index in West Africa.

DTIC Science & Technology

1992-01-01

decades (Nicholson 1989). The combined effects of drought and human activities, such as overgrazing, can adversely effect the Sahelian vegetation. In recent...KOUT) Tillabery, Niger (TILL) Aioun El Atrous, Mauritania (AIOU) Kaolack, Senegal (KAOL) Akjoujt, Mauritania (AKJO) Rufisque, Senegal (RUFI) Atar ...Mauritania ( ATAR ) St. Louis, Senegal (ST L) Boutilimit, Mauritania (BOUT) Letters in parenthesis correspond to Figure 6 parameters in a individual month

Economics of Malaria Prevention in US Travelers to West Africa

PubMed Central

Adachi, Kenji; Coleman, Margaret S.; Khan, Nomana; Jentes, Emily S.; Arguin, Paul; Rao, Sowmya R.; LaRocque, Regina C.; Sotir, Mark J.; Brunette, Gary; Ryan, Edward T.; Meltzer, Martin I.

2014-01-01

Background. Pretravel health consultations help international travelers manage travel-related illness risks through education, vaccination, and medication. This study evaluated costs and benefits of that portion of the health consultation associated with malaria prevention provided to US travelers bound for West Africa. Methods. The estimated change in disease risk and associated costs and benefits resulting from traveler adherence to malaria chemoprophylaxis were calculated from 2 perspectives: the healthcare payer's and the traveler's. We used data from the Global TravEpiNet network of US travel clinics that collect de-identified pretravel data for international travelers. Disease risk and chemoprophylaxis effectiveness were estimated from published medical reports. Direct medical costs were obtained from the Nationwide Inpatient Sample and published literature. Results. We analyzed 1029 records from January 2009 to January 2011. Assuming full adherence to chemoprophylaxis regimens, consultations saved healthcare payers a per-traveler average of $14 (9-day trip) to $372 (30-day trip). For travelers, consultations resulted in a range of net cost of $20 (9-day trip) to a net savings of $32 (30-day trip). Differences were mostly driven by risk of malaria in the destination country. Conclusions. Our model suggests that healthcare payers save money for short- and longer-term trips, and that travelers save money for longer trips when travelers adhere to malaria recommendations and prophylactic regimens in West Africa. This is a potential incentive to healthcare payers to offer consistent pretravel preventive care to travelers. This financial benefit complements the medical benefit of reducing the risk of malaria. PMID:24014735

Robust features of future climate change impacts on sorghum yields in West Africa

NASA Astrophysics Data System (ADS)

Sultan, B.; Guan, K.; Kouressy, M.; Biasutti, M.; Piani, C.; Hammer, G. L.; McLean, G.; Lobell, D. B.

2014-10-01

West Africa is highly vulnerable to climate hazards and better quantification and understanding of the impact of climate change on crop yields are urgently needed. Here we provide an assessment of near-term climate change impacts on sorghum yields in West Africa and account for uncertainties both in future climate scenarios and in crop models. Towards this goal, we use simulations of nine bias-corrected CMIP5 climate models and two crop models (SARRA-H and APSIM) to evaluate the robustness of projected crop yield impacts in this area. In broad agreement with the full CMIP5 ensemble, our subset of bias-corrected climate models projects a mean warming of +2.8 °C in the decades of 2031-2060 compared to a baseline of 1961-1990 and a robust change in rainfall in West Africa with less rain in the Western part of the Sahel (Senegal, South-West Mali) and more rain in Central Sahel (Burkina Faso, South-West Niger). Projected rainfall deficits are concentrated in early monsoon season in the Western part of the Sahel while positive rainfall changes are found in late monsoon season all over the Sahel, suggesting a shift in the seasonality of the monsoon. In response to such climate change, but without accounting for direct crop responses to CO2, mean crop yield decreases by about 16-20% and year-to-year variability increases in the Western part of the Sahel, while the eastern domain sees much milder impacts. Such differences in climate and impacts projections between the Western and Eastern parts of the Sahel are highly consistent across the climate and crop models used in this study. We investigate the robustness of impacts for different choices of cultivars, nutrient treatments, and crop responses to CO2. Adverse impacts on mean yield and yield variability are lowest for modern cultivars, as their short and nearly fixed growth cycle appears to be more resilient to the seasonality shift of the monsoon, thus suggesting shorter season varieties could be considered a potential

Bibliographic analysis of scientific research on selected topics in public health nutrition in West Africa: Review of articles published from 1998 to 2008.

PubMed

Aaron, Grant J; Wilson, Shelby E; Brown, Kenneth H

2010-01-01

Few countries in West Africa have the capacity for carrying out advanced training in nutrition and public health. To provide additional information on current regional applied nutrition research capacity and productivity, we analysed peer-reviewed articles on key public health nutrition topics that were published from 1998 to 2008. Using MEDLINE/PubMed, the following terms were searched: 'breast feeding', 'infant nutrition physiology' (comprising complementary feeding and weaning), 'protein energy malnutrition', 'nutrition and infection', 'vitamin A', 'iodine', 'zinc' and 'overweight', each linked with the term 'Western Africa'. In total, 412 unique articles (37±6 articles per year) were identified. Most research focused on infant and young child feeding practices, selected micronutrient deficiencies, and the emerging problem of overweight and obesity. The primary author of nearly half (46%) the publications was located in an institution outside of West Africa. Most articles were published in English (90%), and nearly half of all articles (41%) were cross-sectional studies. Our findings indicate that few peer-reviewed research studies are being published on key public health topics in the West African region, considering the magnitude of nutrition problems in this region. New approaches are needed to encourage and support research capacity and output in West Africa.

Anthropogenic plumes from metropolitan areas and biomass burning emissions in West Africa during DACCIWA - airborne measurements on board the DLR Falcon 20

NASA Astrophysics Data System (ADS)

Stratmann, Greta; Schlager, Hans; Sauer, Daniel; Brocchi, Vanessa; Catoire, Valery; Baumann, Robert

2017-04-01

The DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions over West Africa) airborne field campaign was conducted in Southern West Africa in June/July 2016. Three European research aircraft (DLR - Falcon 20, SAFIRE - ATR 42 and BAS - Twin Otter) were deployed from Lomé/Togo and conducted research flights across Ivory Coast, Ghana, Togo and Benin. On board the DLR Falcon O3, SO2, CO, NO2 and aerosol fine mode particle number concentration and size distribution were measured during a total of 12 scientific flights. Until now only few airborne trace gas measurements were conducted in Southern West Africa. Therefore, this field experiment contributes to the knowledge of the chemical composition of the lower troposphere between 0 - 4 km. During several flights pollution plumes from major population centers - Lomé/Togo, Accra/Ghana, Kumasi/Ghana, and Abidjan/Ivory Coast - were probed below, inside and above clouds. Here, enhanced trace gas and particle concentrations were observed. In addition, plumes from biomass burning emissions were detected which were transported to West Africa. The composition of the pollution plumes are presented as well as transport pathways using HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectories) trajectory calculations. Ozone enhancements in the biomass burning pollution plumes of up to 70 ppb were observed compared to background concentrations of 30-40 ppb. Furthermore, HYSPLIT atmospheric dispersion simulations are used to estimate anthropogenic SO2 city emissions.

Impact of immigration on HIV-1 molecular epidemiology in West Africa, Maghreb and Southern Europe.

PubMed

Miri, Lamia; Wakrim, Lahcen; Kassar, Hassène; Hemminki, Kari; Khyatti, Meriem

2014-01-01

There is global concern about the relation between international migration and the course of the AIDS epidemic. Maghreb is a North African region, which lies between sub-Saharan Africa and Europe. It has been turned recently into a region of immigration, since there are more and more flows of West African migrants hoping to reach European countries. Here we provide an overview on HIV-1 molecular epidemiology particularly in West African countries, Maghreb (Morocco, Algeria, Tunisia) and southern European countries (Spain, France, and Italy). The studies conducted in several countries of the region revealed different features of HIV-1 molecular epidemiology, especially for the distribution of viral subtypes and for transmitted drug resistance profiles. Furthermore, migration from West Africa to Europe seems to be a potential source of non-B subtype mobility to Maghreb and eventually to southern Europe, where HIV-1 non-B variants significantly increased in the last 10 to 15 years. As genetic differences between subtypes might impact the drug resistance pathways, it is important to provide continuous surveillance programs for the early detection of new variants spreading in the population before they become more prevalent, and to identify resistance profiles in different infected populations, especially migrants.

Prevention of malaria during pregnancy in West Africa: policy change and the power of subregional action.

PubMed

Newman, Robert D; Moran, Allisyn C; Kayentao, Kassoum; Benga-De, Elizabeth; Yameogo, Mathias; Gaye, Oumar; Faye, Ousmane; Lo, Youssoufa; Moreira, Philippe Marc; Doumbo, Ogobara; Parise, Monica E; Steketee, Richard W

2006-04-01

Despite a broadening consensus about the effectiveness of intermittent preventive treatment (IPTp) in preventing the adverse outcomes of malaria during pregnancy, policy change to IPTp was initially limited to East Africa. In West Africa, where the policy change process for the prevention of malaria during pregnancy started much later, IPTp has been taken up swiftly. To describe the factors that contributed to the rapid adoption of policies to prevent malaria during pregnancy in West Africa. Several factors appear to have accelerated the process: (1) recognition of the extent of the problem of malaria during pregnancy and its adverse consequences; (2) a clear, evidence-based program strategy strongly articulated by an important multilateral organization (World Health Organization); (3) subregionally generated evidence to support the proposed strategy; (4) a subregional forum for dissemination of data and discussion regarding the proposed policy changes; (5) widespread availability of the proposed intervention drug (sulfadoxine-pyrimethamine); (6) technical support from reputable and respected institutions in drafting new policies and planning for implementation; (7) donor support for pilot experiences in integrating proposed policy change into a package of preventive services; and (8) financial support for scaling up the proposed interventions.

Neoproterozoic paleomagnetic poles in the Taoudeni basin (West Africa)

NASA Astrophysics Data System (ADS)

Boudzoumou, Florent; Vandamme, Didier; Affaton, Pascal; Gattacceca, Jérôme

2011-04-01

A palaeomagnetic study was carried out on Neoproterozoic samples from seven sites of the sub-basins of Gourma and Bobo Dioulasso, which include a Marinoan glaciogenic deposit. Magnetic mineralogy is represented essentially by magnetite and hematite. The mean directions of the sites are calculated on the high temperature component (500-670 °C). Two locations provide data constrained by statistical reversal and fold tests and determining Neoproterozoic virtual geomagnetic poles. The palaeolatitudes display very low values which place the West-African craton in the sub-equatorial position during the Marinoan glaciation. This result enhances the Snowball Earth hypothesis, which places most of the continental landmasses, and notably Africa, at low latitudes during the Neoproterozoic.

Using CHIRPS Rainfall Dataset to detect rainfall trends in West Africa

NASA Astrophysics Data System (ADS)

Blakeley, S. L.; Husak, G. J.

2016-12-01

In West Africa, agriculture is often rain-fed, subjecting agricultural productivity and food availability to climate variability. Agricultural conditions will change as warming temperatures increase evaporative demand, and with a growing population dependent on the food supply, farmers will become more reliant on improved adaptation strategies. Development of such adaptation strategies will need to consider West African rainfall trends to remain relevant in a changing climate. Here, using the CHIRPS rainfall product (provided by the Climate Hazards Group at UC Santa Barbara), I examine trends in West African rainfall variability. My analysis will focus on seasonal rainfall totals, the structure of the rainy season, and the distribution of rainfall. I then use farmer-identified drought years to take an in-depth analysis of intra-seasonal rainfall irregularities. I will also examine other datasets such as potential evapotranspiration (PET) data, other remotely sensed rainfall data, rain gauge data in specific locations, and remotely sensed vegetation data. Farmer bad year data will also be used to isolate "bad" year markers in these additional datasets to provide benchmarks for identification in the future of problematic rainy seasons.

Model-Based Geostatistical Mapping of the Prevalence of Onchocerca volvulus in West Africa

PubMed Central

O’Hanlon, Simon J.; Slater, Hannah C.; Cheke, Robert A.; Boatin, Boakye A.; Coffeng, Luc E.; Pion, Sébastien D. S.; Boussinesq, Michel; Zouré, Honorat G. M.; Stolk, Wilma A.; Basáñez, María-Gloria

2016-01-01

Background The initial endemicity (pre-control prevalence) of onchocerciasis has been shown to be an important determinant of the feasibility of elimination by mass ivermectin distribution. We present the first geostatistical map of microfilarial prevalence in the former Onchocerciasis Control Programme in West Africa (OCP) before commencement of antivectorial and antiparasitic interventions. Methods and Findings Pre-control microfilarial prevalence data from 737 villages across the 11 constituent countries in the OCP epidemiological database were used as ground-truth data. These 737 data points, plus a set of statistically selected environmental covariates, were used in a Bayesian model-based geostatistical (B-MBG) approach to generate a continuous surface (at pixel resolution of 5 km x 5km) of microfilarial prevalence in West Africa prior to the commencement of the OCP. Uncertainty in model predictions was measured using a suite of validation statistics, performed on bootstrap samples of held-out validation data. The mean Pearson’s correlation between observed and estimated prevalence at validation locations was 0.693; the mean prediction error (average difference between observed and estimated values) was 0.77%, and the mean absolute prediction error (average magnitude of difference between observed and estimated values) was 12.2%. Within OCP boundaries, 17.8 million people were deemed to have been at risk, 7.55 million to have been infected, and mean microfilarial prevalence to have been 45% (range: 2–90%) in 1975. Conclusions and Significance This is the first map of initial onchocerciasis prevalence in West Africa using B-MBG. Important environmental predictors of infection prevalence were identified and used in a model out-performing those without spatial random effects or environmental covariates. Results may be compared with recent epidemiological mapping efforts to find areas of persisting transmission. These methods may be extended to areas where

Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa.

PubMed

Coulibaly, Boubacar; Kone, Raymond; Barry, Mamadou S; Emerson, Becky; Coulibaly, Mamadou B; Niare, Oumou; Beavogui, Abdoul H; Traore, Sekou F; Vernick, Kenneth D; Riehle, Michelle M

2016-04-08

Malaria remains a pervasive public health problem in sub-Saharan West Africa. Here mosquito vector populations were explored across four sites in Mali and the Republic of Guinea (Guinea Conakry). The study samples the major ecological zones of malaria-endemic regions in West Africa within a relatively small distance. Mosquito vectors were sampled from larval pools, adult indoor resting sites, and indoor and outdoor human-host seeking adults. Mosquitoes were collected at sites spanning 350 km that represented arid savannah, humid savannah, semi-forest and deep forest ecological zones, in areas where little was previously known about malaria vector populations. 1425 mosquito samples were analysed by molecular assays to determine species, genetic attributes, blood meal sources and Plasmodium infection status. Anopheles gambiae and Anopheles coluzzii were the major anophelines represented in all collections across the ecological zones, with A. coluzzii predominant in the arid savannah and A. gambiae in the more humid sites. The use of multiple collection methodologies across the sampling sites allows assessment of potential collection bias of the different methods. The L1014F kdr insecticide resistance mutation (kdr-w) is found at high frequency across all study sites. This mutation appears to have swept almost to fixation, from low frequencies 6 years earlier, despite the absence of widespread insecticide use for vector control. Rates of human feeding are very high across ecological zones, with only small fractions of animal derived blood meals in the arid and humid savannah. About 30 % of freshly blood-fed mosquitoes were positive for Plasmodium falciparum presence, while the rate of mosquitoes with established infections was an order of magnitude lower. The study represents detailed vector characterization from an understudied area in West Africa with endemic malaria transmission. The deep forest study site includes the epicenter of the 2014 Ebola virus epidemic

Policy Review on Adult Learning: The Adult Non-Formal Education Policy of Mali, West Africa

ERIC Educational Resources Information Center

Gadio, Moussa

2011-01-01

This article focuses on the issue of policy development for adult learning in Mali, West Africa. On January 2007, the Malian government adopted the "Adult Non-formal Education Policy Document," which was intended to regulate the adult learning sector and federate the actions of policy makers, adult education providers, and adult…

The evolution of nocturnal boundary-layer clouds in southern West Africa - a case study from DACCIWA

NASA Astrophysics Data System (ADS)

Adler, Bianca; Kalthoff, Norbert; Babić, Karmen; Lohou, Fabienne; Dione, Cheikh; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier

2017-04-01

During the monsoon season, the atmospheric boundary layer in southern West Africa is characterised by various kinds of low-level clouds which experience a distinct diurnal cycle. During the night, extensive low-level stratiform clouds frequently form with a cloud base often less than few hundred metres above ground. After sunrise the cloud base slowly starts rising and eventually a transition to convective clouds occurs. While the existence of the clouds is documented in satellite images and synoptic observations, little is known about the mechanisms controlling their evolution. To provide observational evidence, a field campaign was conducted in southern West Africa in June and July 2016 within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project. Comprehensive ground-based in situ and remote sensing measurements were performed at three different supersites in Ghana, Benin and Nigeria. In this contribution, we present the diurnal cycle of boundary-layer clouds for a typical day using data from a supersite at Savè in Benin. Due to the synergy of various instruments, we are able to obtain detailed information on the evolution of the clouds as well as on the boundary-layer structure with high temporal and vertical resolution. By combining ceilometer, cloud radar and microwave radiometer data we determined the cloud base, -depth and -density. The clouds form in the same layer as a nocturnal low-level jet (NLLJ), which we probe by sodar and UHF profiler. There is evidence for a strong link between the height and strength of the NLLJ and the density of the nocturnal clouds.

The Foraging Ecology of the Endangered Cape Verde Shearwater, a Sentinel Species for Marine Conservation off West Africa

PubMed Central

Paiva, Vitor H.; Geraldes, Pedro; Rodrigues, Isabel; Melo, Tommy; Melo, José; Ramos, Jaime A.

2015-01-01

Large Marine Ecosystems such as the Canary Current system off West Africa sustains high abundance of small pelagic prey, which attracts marine predators. Seabirds are top predators often used as biodiversity surrogates and sentinel species of the marine ecosystem health, thus frequently informing marine conservation planning. This study presents the first data on the spatial (GPS-loggers) and trophic (stable isotope analysis) ecology of a tropical seabird—the endangered Cape Verde shearwater Calonectris edwardsii–during both the incubation and the chick-rearing periods of two consecutive years. This information was related with marine environmental predictors (species distribution models), existent areas of conservation concern for seabirds (i.e. marine Important Bird Areas; marine IBAs) and threats to the marine environment in the West African areas heavily used by the shearwaters. There was an apparent inter-annual consistency on the spatial, foraging and trophic ecology of Cape Verde shearwater, but a strong alteration on the foraging strategies of adult breeders among breeding phases (i.e. from incubation to chick-rearing). During incubation, birds mostly targeted a discrete region off West Africa, known by its enhanced productivity profile and thus also highly exploited by international industrial fishery fleets. When chick-rearing, adults exploited the comparatively less productive tropical environment within the islands of Cape Verde, at relatively close distance from their breeding colony. The species enlarged its trophic niche and increased the trophic level of their prey from incubation to chick-rearing, likely to provision their chicks with a more diversified and better quality diet. There was a high overlap between the Cape Verde shearwaters foraging areas with those of European shearwater species that overwinter in this area and known areas of megafauna bycatch off West Africa, but very little overlap with existing Marine Important Bird Areas

A Regional Model Study of Synoptic Features Over West Africa

NASA Technical Reports Server (NTRS)

Druyan, Leonard M.; Fulakeza, Matthew; Lonergan, Patrick; Saloum, Mahaman; Hansen, James E. (Technical Monitor)

2001-01-01

Synoptic weather features over West Africa were studied in simulations by the regional simulation model (RM) at the NASA/Goddard Institute for Space Studies. These pioneering simulations represent the beginning of an effort to adapt regional models for weather and climate prediction over West Africa. The RM uses a cartesian grid with 50 km horizontal resolution and fifteen vertical levels. An ensemble of four simulations was forced with lateral boundary conditions from ECMWF global analyses for the period 8-22 August 1988. The simulated mid-tropospheric circulation includes the skillful development and movement of several African wave disturbances. Wavelet analysis of mid-tropospheric winds detected a dominant periodicity of about 4 days and a secondary periodicity of 5-8 days. Spatial distributions of RM precipitation and precipitation time series were validated against daily rain gauge measurements and ISCCP satellite infrared cloud imagery. The time-space distribution of simulated precipitation was made more realistic by combining the ECMWR initial conditions with a 24-hr spin-up of the moisture field and also by damping high frequency gravity waves by dynamic initialization. Model precipitation "forecasts" over the Central Sahel were correlated with observations for about three days, but reinitializing with observed data on day 5 resulted in a dramatic improvement in the precipitation validation over the remaining 9 days. Results imply that information via the lateral boundary conditions is not always sufficient to minimize departures between simulated and actual precipitation patterns for more than several days. In addition, there was some evidence that the new initialization may increase the simulations' sensitivity to the quality of lateral boundary conditions.

Epidemiology and vectors of Dracunculus medinensis in northwest Burkina Faso, West Africa.

PubMed

Steib, K; Mayer, P

1988-04-01

The epidemiology of the guinea worm, Dracunculus medinensis, was studied in the dry savanna zone of West Africa. The monthly incidence data collected over a period of four years showed peak transmission occurring in June and July at the beginning of the rainy season. The different types of local water sources (i.e. wells, periodic streams, seasonal cattle waterings, natural ponds and man-made ponds) were examined for infected cyclopoid copepods. Small hand-dug ponds or water-holes situated in the fields proved to be the most important sites of transmission. While the domestic water supply is obtained from draw-wells in the villages throughout the year, the villagers take additional drinking water from these ponds during the planting season when farm activities require long stays in the fields. Four cyclopoid species were found for the first time acting as natural intermediate hosts of D. medinensis. Thermocyclops inopinus was the most frequently infected cyclopoid, and small man-made ponds are the preferred habitats of this species. Occurrence of T. inopinus is confined to the first half of the rainy season, coinciding with peak transmission. The epidemiology of dracunculiasis in dry and humid regions of West Africa is compared with regard to seasonality. The use of protective water filters proved to be the only adequate method for guinea worm control in the project area.

Hybrid insolation forcing of Pliocene monsoon dynamics in West Africa

NASA Astrophysics Data System (ADS)

Kuechler, Rony R.; Dupont, Lydie M.; Schefuß, Enno

2018-01-01

The Pliocene is regarded as a potential analogue for future climate with conditions generally warmer-than-today and higher-than-preindustrial atmospheric CO2 levels. Here we present the first orbitally resolved records of continental hydrology and vegetation changes from West Africa for two Pliocene time intervals (5.0-4.6 Ma, 3.6-3.0 Ma), which we compare with records from the last glacial cycle (Kuechler et al., 2013). Our results indicate that changes in local insolation alone are insufficient to explain the full degree of hydrologic variations. Generally two modes of interacting insolation forcings are observed: during eccentricity maxima, when precession was strong, the West African monsoon was driven by summer insolation; during eccentricity minima, when precession-driven variations in local insolation were minimal, obliquity-driven changes in the summer latitudinal insolation gradient became dominant. This hybrid monsoonal forcing concept explains orbitally controlled tropical climate changes, incorporating the forcing mechanism of latitudinal gradients for the Pliocene, which probably increased in importance during subsequent Northern Hemisphere glaciations.

Fatalism and HIV/AIDS beliefs in rural Mali, West Africa.

PubMed

Hess, Rosanna F; McKinney, Dawn

2007-01-01

To examine beliefs about HIV/AIDS of rural Malians and to measure their level of fatalism in context of HIV/AIDS and prevention behaviors. Descriptive, correlational. An AIDS Knowledge and Beliefs survey and the Powe Fatalism Inventory (PFI)-HIV/AIDS version were administered to a convenience sample of 84 people at three health center maternity clinics in southeastern Mali, West Africa. The sample's HIV/AIDS fatalism mean was 9.2 on a 15-point scale, with an internal consistency of .89. Health workers and more educated participants had significantly lower fatalism scores. Fatalism also varied by the combination of gender and ethnicity. People who believed that AIDS was not real, was a punishment from God, was fabricated by the West, was a curse, and that it was taboo to talk about AIDS had higher fatalism means. None of the prevention indicators were significantly related to fatalism scores. These rural Malians had a high overall fatalism mean and their beliefs about AIDS based on traditional culture may affect prevention behaviors. More research is needed to understand the influence of fatalism on prevention behaviors.

DACCIWA Cloud-Aerosol Observations in West Africa Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, J Christine; Blanchard, Yann; Hill, Peter

Interactions between aerosols and clouds, and their effects on radiation, precipitation, and regional circulations, are one of the largest uncertainties in understanding climate. With reducing uncertainties in predictions of weather, climate, and climate impacts in mind, the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, funded by the European Commission, set out to improve our understanding of cloud-aerosol interactions in southern West Africa. This region is ideal for studying cloud-aerosol interactions because of its rich mix of natural and anthropogenic aerosols and diverse clouds, and because of the strong dependence on the regional and global climate of the sensitive West Africanmore » monsoon. The overview of DACCIWA is described in Knippertz et al. 2015. The interdisciplinary DACCIWA team includes not only several European and African universities, but also Met Centres in the UK, France, Germany, Switzerland, Benin, Ghana, and Nigeria. One of the crucial research activities in DACCIWA is the major field campaign in southern West Africa from June to July 2016, comprising a benchmark data set for assessing detailed processes on natural and anthropogenic emissions; atmospheric composition; air pollution and its impacts on human and ecosystem health; boundary layer processes; couplings between aerosols, clouds, and rainfall; weather systems; radiation; and the monsoon circulation. Details and highlights of the campaign can be found in Flamant et al. 2017. To provide aerosol/cloud microphysical and optical properties that are essential for model evaluations and for the linkage between ground-based, airborne, and spaceborne observations, the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility loaned two sun photometers to the DACCWIA team for the campaign from June 8 to July 29, 2016. The first sun photometer was deployed at Kumasi, Ghana (6.67962°N, 1.56019°W) by the University of

An Assessment of the U.S. Peacekeeping Training in West Africa: Is it on the Road to Stability?

DTIC Science & Technology

2003-01-01

iv ACKNOWLEDGMENTS First I would like to thank MAJ John Silkman for steering me towards the topic of the African Crisis Response Initiative; I would...Leone, Togo, and Burkina Faso ( Schiavone 1993, 89-93). Economic Community of West Africa Monitoring Group (ECOMOG): A peacekeeping body within ECOWAS...operations. It forms the base for all regional West African peacekeeping operations ( Schiavone 1993, 92-93). Executive Outcomes: One of the better known

Evaluation of rainfall retrievals from SEVIRI reflectances over West Africa using TRMM-PR and CMORPH

NASA Astrophysics Data System (ADS)

Wolters, E. L. A.; van den Hurk, B. J. J. M.; Roebeling, R. A.

2011-02-01

This paper describes the evaluation of the KNMI Cloud Physical Properties - Precipitation Properties (CPP-PP) algorithm over West Africa. The algorithm combines condensed water path (CWP), cloud phase (CPH), cloud particle effective radius (re), and cloud-top temperature (CTT) retrievals from visible, near-infrared and thermal infrared observations of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) satellites to estimate rain occurrence frequency and rain rate. For the 2005 and 2006 monsoon seasons, it is investigated whether the CPP-PP algorithm is capable of retrieving rain occurrence frequency and rain rate over West Africa with sufficient accuracy, using Tropical Monsoon Measurement Mission Precipitation Radar (TRMM-PR) as reference. As a second goal, it is assessed whether SEVIRI is capable of monitoring the seasonal and daytime evolution of rainfall during the West African monsoon (WAM), using Climate Prediction Center Morphing Technique (CMORPH) rainfall observations. The SEVIRI-detected rainfall area agrees well with TRMM-PR, with the areal extent of rainfall by SEVIRI being ~10% larger than from TRMM-PR. The mean retrieved rain rate from CPP-PP is about 8% higher than from TRMM-PR. Examination of the TRMM-PR and CPP-PP cumulative frequency distributions revealed that differences between CPP-PP and TRMM-PR are generally within +/-10%. Relative to the AMMA rain gauge observations, CPP-PP shows very good agreement up to 5 mm h-1. However, at higher rain rates (5-16 mm h-1) CPP-PP overestimates compared to the rain gauges. With respect to the second goal of this paper, it was shown that both the accumulated precipitation and the seasonal progression of rainfall throughout the WAM is in good agreement with CMORPH, although CPP-PP retrieves higher amounts in the coastal region of West Africa. Using latitudinal Hovmüller diagrams, a fair correspondence between CPP-PP and CMORPH was found, which is reflected

The Association between Bullying and Psychological Health among Senior High School Students in Ghana, West Africa

ERIC Educational Resources Information Center

Owusu, Andrew; Hart, Peter; Oliver, Brittney; Kang, Minsoo

2011-01-01

Background: School-based bullying, a global challenge, negatively impacts the health and development of both victims and perpetrators. This study examined the relationship between bullying victimization and selected psychological variables among senior high school (SHS) students in Ghana, West Africa. Methods: This study utilized data from the…

A new inventory for two-wheel vehicle emissions in West Africa for 2002

NASA Astrophysics Data System (ADS)

Assamoi, Eric-Michel; Liousse, Catherine

2010-10-01

Rather surprisingly, urban atmospheric particulate levels in West Africa compare with measured concentrations in Europe and Asia megacities (Liousse, C., Galy-Lacaux, C., Assamoi, E.-M., Ndiaye, A., Diop, B., Cachier, H., Doumbia, T., Gueye, P., Yoboue, V., Lacaux, J.-P., Guinot, B., Guillaume, B., Rosset, R., Castera, P., Gardrat, E., Zouiten, C., Jambert, C., Diouf, A., Koita, O., Baeza, A., Annesi-Maesano, I., Didier, A., Audry, S., Konare, A., 2009. Integrated Focus on West African Cities (Cotonou, Bamako, Dakar, Ouagadougou, Abidjan, Niamey): Emissions, Air Quality and Health Impacts of Gases and Aerosols. Third International AMMA Conference on Predictability of the West African Moosoon Weather, Climate and Impacts. Ouagadougou, Burkina Faso. July 20-24). This pollution mainly derives from road traffic emissions with, in some capitals (e.g. Cotonou), the strong contribution of two-wheel vehicles. Two key questions arise: are presently available emission inventories (e.g. Junker, C., Liousse, C., 2008. A global emission inventory of carbonaceous aerosol from historic records of fossil fuel and biofuel consumption for the period 1860-1997. Atmospheric Chemistry Physics, 8, 1-13; Bond, T.C., Streets, D.G., Yarber, K.F., Nelson, S.M., Woo, J.H., Klimont, Z., 2004. A technology-based global inventory of black and organic carbon emissions from combustion. Journal of Geophysical Research, 1009, D14203, DOI:10.1029/2003JD003697) able to account for these emissions? And, if not, how can we remedy this? The aim of this paper is to develop a methodology to estimate emissions produced by two-wheel vehicles in West Africa for 2002 in a context where reliable information is hardly available. Fuel consumption ratios between two-wheel engines (in this work) and all vehicles issued from UN database ( http://data.un.org/Data.aspx?d=EDATA&f=cmID%3aMO%3btrID%3a1221) are as high as 169%, 264% and 628%, for Burkina Faso, Mali and Chad respectively, indicating that this global

Ocean climate data for user community in West and Central Africa: Needs, opportunities, and challenges

NASA Technical Reports Server (NTRS)

Ojo, S. O.

1992-01-01

The urgent need to improve data delivery systems needed by scientists studying ocean role in climate and climate characteristics has been manifested in recent years because of the unprecedented climatic events experienced in many parts of the world. Indeed, there has been a striking and growing realization by governments and the general public indicating that national economies and human welfare depend on climate and its variability. In West and Central Africa, for instance climatic events, which have resulted in floods and droughts, have caused a lot of concern to both governments and people of the region. In particular, the droughts have been so widespread that greater awareness and concern have become generated for the need to find solutions to the problems created by the consequences of the climatic events. Particularly in the southern border regions of the Sahara Desert as well as in the Sahel region, the drought episodes considerably reduced food production and led to series of socioeconomic problems, not only in the areas affected by the droughts, but also in the other parts of West Africa. The various climatic variabilities which have caused the climatic events are no doubt related to the ocean-atmosphere interactions. Unfortunately, not much has been done on the understanding of these interactions, particularly as they affect developing countries. Indeed, not much has been done to develop programs which will reflect the general concerns and needs for researching into the ocean-atmosphere systems and their implications on man-environmental systems in many developing countries. This is for example, true of West and Central Africa, where compared with the middle latitude countries, much less is known about the characteristics of the ocean-atmosphere systems and their significance on man-environmental systems of the area.

Constructing Ebola transmission chains from West Africa and estimating model parameters using internet sources.

PubMed

Pettey, W B P; Carter, M E; Toth, D J A; Samore, M H; Gundlapalli, A V

2017-07-01

During the recent Ebola crisis in West Africa, individual person-level details of disease onset, transmissions, and outcomes such as survival or death were reported in online news media. We set out to document disease transmission chains for Ebola, with the goal of generating a timely account that could be used for surveillance, mathematical modeling, and public health decision-making. By accessing public web pages only, such as locally produced newspapers and blogs, we created a transmission chain involving two Ebola clusters in West Africa that compared favorably with other published transmission chains, and derived parameters for a mathematical model of Ebola disease transmission that were not statistically different from those derived from published sources. We present a protocol for responsibly gleaning epidemiological facts, transmission model parameters, and useful details from affected communities using mostly indigenously produced sources. After comparing our transmission parameters to published parameters, we discuss additional benefits of our method, such as gaining practical information about the affected community, its infrastructure, politics, and culture. We also briefly compare our method to similar efforts that used mostly non-indigenous online sources to generate epidemiological information.

Assessment of Undiscovered Oil and Gas Resources of Four West Africa Geologic Provinces

USGS Publications Warehouse

Brownfield, Michael E.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.; Pitman, Janet K.; Pollastro, Richard M.; Schenk, Christopher J.; Tennyson, Marilyn E.

2010-01-01

Four geologic provinces located along the northwest and west-central coast of Africa recently were assessed for undiscovered oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 71.7 billion barrels of oil, 187.2 trillion cubic feet of natural gas, and 10.9 billion barrels of natural gas liquids.

Improving regional health care in West Africa using current space systems and technology

NASA Technical Reports Server (NTRS)

Jemison, Mae C.; Thomas, J. Segun

1992-01-01

This paper discusses the issues involved with establishing an integrated satellite health network in West Africa based on currently available technology. The system proposed makes use of a central national facility capable of transmitting and receiving voice/data and video signals from the entire country. Regional, field and local facilities provide timely epidemiologic information, sharing of medical expertise through telemedical consultations, enhance optimized resource distribution and build a framework for telecommunications for the entire country.

Improving regional health care in West Africa using current space systems and technology

NASA Technical Reports Server (NTRS)

Jemison, Mae C.; Thomas, J. S.

1992-01-01

This paper discusses the issues involved with establishing an integrated satellite health network in West Africa based on currently available technology. The system proposed makes use of a central national facility capable of transmitting and receiving voice/data and video signals from the entire country. Regional, field and local facilities provides timely epidemiologic information, sharing of medical expertise through telemedical consultations, enhances optimized resource distribution and builds a framework for telecommunications for the entire country.

Modes, tempo and spatial variability of Cenozoic cratonic denudation: morphoclimatic constraints from West Africa

NASA Astrophysics Data System (ADS)

Beauvais, Anicet; Chardon, Dominique

2010-05-01

After the onset of Gondwana break-up in the Early Mesozoic, the emerged part of the African plate underwent long Greenhouse effect climatic periods and epeirogeny. The last Greenhouse effect period in the Early Cenozoic and the alternation of wet and dry climatic periods since the Eocene enhanced episodes of rock chemical weathering and laterite production, forming bauxites and ferricretes, interrupted by drier periods of dominantly mechanical denudation, shaping glacis [1]. In Sub-Saharan West Africa, this evolution resulted in pulsate and essentially climatically-forced denudation that has shaped an ubiquitous sequence of five stepped lateritic paleosurfaces that synchronously developed over Cenozoic times. The modes, timing and spatial variability of continental denudation of the region are investigated by combining geomorphologic and geochronological data sets. The geomorphologic data set comprises the altitudinal distribution of the lateritic paleosurfaces relicts and their differential elevation from 42 locations in Sub-Saharan West Africa where the sequence (or part of it) has been documented. The geochronological data set consists in the age ranges of each paleosurface tackled by radiometric 39Ar-40Ar dating of the neoformed oxy-hydroxides (i.e., cryptomelane, K1-2Mn8O16, nH2O, [4]) carried by their laterites at the Tambao reference site, Burkina Faso [1, 3]. Five groups of 39Ar-40Ar ages, ~ 59 - 45 Ma, ~ 29 - 24 Ma, ~ 18 - 11.5 Ma, ~ 7.2 - 5.8 Ma, and ~ 3.4 - 2.9 Ma, characterize periods of chemical weathering whereas the time laps between these groups of ages correspond to episodes of mechanical denudation that reflect physical shaping of the paleosurfaces. For the last 45 Ma, the denudation rate estimates (3 to 8 m Ma-1) are comparable with those derived on shorter time scale (103 to 106 y.) in the same region by the cosmogenic radionuclide method [2]. Combined with the geomorphologic data set, these age ranges allow the visualization of the regional

Rural Development in Africa: A Bibliography (Part II: North, South, West). Training & Methods Series, Number 17.

ERIC Educational Resources Information Center

Wisconsin Univ., Madison. Land Tenure Center.

Compiled in December 1971, this bibliography lists approximately 940 books, journals, periodicals, and unpublished mimeographs dealing with rural development in north, west, and southern Africa. All materials are dated between 1953 and 1971. Entries are listed by country under the following headings: agriculture, economic affairs, social affairs,…

Geostatistical Model-Based Estimates of Schistosomiasis Prevalence among Individuals Aged ≤20 Years in West Africa

PubMed Central

Schur, Nadine; Hürlimann, Eveline; Garba, Amadou; Traoré, Mamadou S.; Ndir, Omar; Ratard, Raoult C.; Tchuem Tchuenté, Louis-Albert; Kristensen, Thomas K.; Utzinger, Jürg; Vounatsou, Penelope

2011-01-01

Background Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis prevalence maps. Methodology We analyzed survey data compiled on a newly established open-access global neglected tropical diseases database (i) to create smooth empirical prevalence maps for Schistosoma mansoni and S. haematobium for individuals aged ≤20 years in West Africa, including Cameroon, and (ii) to derive country-specific prevalence estimates. We used Bayesian geostatistical models based on environmental predictors to take into account potential clustering due to common spatially structured exposures. Prediction at unobserved locations was facilitated by joint kriging. Principal Findings Our models revealed that 50.8 million individuals aged ≤20 years in West Africa are infected with either S. mansoni, or S. haematobium, or both species concurrently. The country prevalence estimates ranged between 0.5% (The Gambia) and 37.1% (Liberia) for S. mansoni, and between 17.6% (The Gambia) and 51.6% (Sierra Leone) for S. haematobium. We observed that the combined prevalence for both schistosome species is two-fold lower in Gambia than previously reported, while we found an almost two-fold higher estimate for Liberia (58.3%) than reported before (30.0%). Our predictions are likely to overestimate overall country prevalence, since modeling was based on children and adolescents up to the age of 20 years who are at highest risk of infection. Conclusion/Significance We

Impact of land use changes on surface feedbacks in sudanian region of West Africa

NASA Astrophysics Data System (ADS)

Cohard, J. M.; Galle, S.; Mamadou, O.; Peugeot, C.; Seghieri, J.; Kounouhewa, B.; Awanou, N. C.

2014-12-01

In West Africa, surface atmosphere exchanges have been found to impact both regional and local features of the Monsoon. At local scale the spatial patterns of Evaporative Fraction can drive the trajectories of mesoscale convective systems. Under Sudanian climate a mean of ~80% of the precipitation return to atmosphere through evapotranspiration but this important amount and its dynamics may vary with the vegetation cover. In consequence, any land use or climate changes can lead to modifications on the surface feedbacks and thus on both the atmospheric and the continental water cycle. In West Africa, Sudanian regions are submitted to a ~3% demographical increase per year, which leads to regular deforestation to the benefit of cultivated areas. This study aims at quantifying the changes in evapotranspiration regime caused by such a land use change under Sudanian climate. Within the framework of The AMMA-CATCH observatory, energy and water vapor fluxes were investigated in west Africa since 2007. Herein, a pluri-annual (2007 - 2010) energy budget of a clear forest and a cultivated area located in northern Benin are analysed. Results show that evapotranspiration rates over the sudanian forest are higher than those of cultivated area, because of agricultural practice and water availability for trees. After harvest, the residual vegetation is burned to bring nutriment to soil and to clean the landscape around the villages. Thus, during the dry season, the cultivated areas are bare. At the same time, a significant evapotranspiration is measured over the forest area despite the lack of precipitations. The deep root system of such vegetation allow the trees to get access to water during the dry season. During the rainy season, a significant difference in evapotransiration rates are also observed. These differences lead to a large deficit of water vapor that returns to the atmosphere and will significantly change the continental water cycle when forests will be replaced by

The Use of Lactic Acid Bacteria Starter Cultures during the Processing of Fermented Cereal-based Foods in West Africa: A Review.

PubMed

Soro-Yao, Amenan Anastasie; Brou, Kouakou; Amani, Georges; Thonart, Philippe; Djè, Koffi Marcelin

2014-12-01

Lactic acid bacteria (LAB) are the primary microorganisms used to ferment maize-, sorghum- or millet-based foods that are processed in West Africa. Fermentation contributes to desirable changes in taste, flavour, acidity, digestibility and texture in gruels (ogi, baca, dalaki), doughs (agidi, banku, komé) or steam-cooked granulated products (arraw, ciacry, dégué). Similar to other fermented cereal foods that are available in Africa, these products suffer from inconsistent quality. The use of LAB starter cultures during cereal dough fermentation is a subject of increasing interest in efforts to standardise this step and guaranty product uniformity. However, their use by small-scale processing units or small agro-food industrial enterprises is still limited. This review aims to illustrate and discuss major issues that influence the use of LAB starter cultures during the processing of fermented cereal foods in West Africa.

Yield Mapping for Different Crops in Sudano-Sahelian Smallholder Farming Systems: Results Based on Metric Worldview and Decametric SPOT-5 Take5 Time Series

NASA Astrophysics Data System (ADS)

Blaes, X.; Lambert, M.-J.; Chome, G.; Traore, P. S.; de By, R. A.; Defourny, P.

2016-08-01

Efficient yield mapping in Sudano-Sahelian Africa, characterized by a very heterogeneous landscape, is crucial to help ensure food security and decrease smallholder farmers' vulnerability. Thanks to an unprecedented in-situ data and HR and VHR remote sensing time series collected in the Koutiala district (in south-eastern Mali), the yield and some key factors of yield estimation were estimated. A crop-specific biomass map was derived with a mean absolute error of 20% using metric WorldView and 25% using decametric SPOT-5 TAKE5 image time series. The very high intra- and inter-field heterogeneity was captured efficiently. The presence of trees in the fields led to a general overestimation of yields, while the mixed pixels at the field borders introduced noise in the biomass predictions.

Phylogeographic reconstruction of African yellow fever virus isolates indicates recent simultaneous dispersal into east and west Africa.

PubMed

Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B; Barrett, Alan D T

2013-01-01

Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease.

Regional Model Nesting Within GFS Daily Forecasts Over West Africa

NASA Technical Reports Server (NTRS)

Druyan, Leonard M.; Fulakeza, Matthew; Lonergan, Patrick; Worrell, Ruben

2010-01-01

The study uses the RM3, the regional climate model at the Center for Climate Systems Research of Columbia University and the NASA/Goddard Institute for Space Studies (CCSR/GISS). The paper evaluates 30 48-hour RM3 weather forecasts over West Africa during September 2006 made on a 0.5 grid nested within 1 Global Forecast System (GFS) global forecasts. September 2006 was the Special Observing Period #3 of the African Monsoon Multidisciplinary Analysis (AMMA). Archived GFS initial conditions and lateral boundary conditions for the simulations from the US National Weather Service, National Oceanographic and Atmospheric Administration were interpolated four times daily. Results for precipitation forecasts are validated against Tropical Rainfall Measurement Mission (TRMM) satellite estimates and data from the Famine Early Warning System (FEWS), which includes rain gauge measurements, and forecasts of circulation are compared to reanalysis 2. Performance statistics for the precipitation forecasts include bias, root-mean-square errors and spatial correlation coefficients. The nested regional model forecasts are compared to GFS forecasts to gauge whether nesting provides additional realistic information. They are also compared to RM3 simulations driven by reanalysis 2, representing high potential skill forecasts, to gauge the sensitivity of results to lateral boundary conditions. Nested RM3/GFS forecasts generate excessive moisture advection toward West Africa, which in turn causes prodigious amounts of model precipitation. This problem is corrected by empirical adjustments in the preparation of lateral boundary conditions and initial conditions. The resulting modified simulations improve on the GFS precipitation forecasts, achieving time-space correlations with TRMM of 0.77 on the first day and 0.63 on the second day. One realtime RM3/GFS precipitation forecast made at and posted by the African Centre of Meteorological Application for Development (ACMAD) in Niamey, Niger

Promoting research to improve maternal, neonatal, infant and adolescent health in West Africa: the role of the West African Health Organisation.

PubMed

Sombie, Issiaka; Bouwayé, Aissa; Mongbo, Yves; Keita, Namoudou; Lokossou, Virgil; Johnson, Ermel; Assogba, Laurent; Crespin, Xavier

2017-07-12

West Africa has adopted numerous strategies to counter maternal and infant mortality, provides national maternal and infant health programmes, and hosts many active technical and financial partners and non-governmental organisations. Despite this, maternal and infant morbidity and mortality indicators are still very high. In this commentary, internal actors and officials of the West African Health Organisation (WAHO) examine the regional organisation's role in promoting research as a tool for strengthening maternal and infant health in West Africa.As a specialised institution of the Economic Community of West African States (ECOWAS) responsible for health issues, WAHO's mission is to provide the sub-region's population with the highest possible health standards by harmonising Member States' policies, resource pooling, and cooperation among Member States and third countries to collectively and strategically combat the region's health problems. To achieve this, WAHO's main intervention strategy is that of facilitation, as this encourages the generation and use of evidence to inform decision-making and reinforce practice.WAHO's analysis of interventions since 2000 showed that it had effected some changes in research governance, management and funding, as well as in individual and institutional capacity building, research dissemination, collaboration and exchanges between the various stakeholders. It also revealed several challenges such as process ownership, member countries' commitment, weak individual and institutional capacity, mobilisation, and stakeholder commitment. To better strengthen evidence-based decision-making, in 2016, WAHO created a unique programme aimed at improving the production, dissemination and use of research information and results in health programme planning to ultimately improve population health.While WAHO's experiences to date demonstrate how a regional health institution can integrate research promotion into the fight against maternal and

Assessing the link between Atlantic Niño 1 and drought over West Africa using CORDEX regional climate models

NASA Astrophysics Data System (ADS)

Adeniyi, Mojisola Oluwayemisi; Dilau, Kabiru Alabi

2018-02-01

The skill of Coordinated Regional Climate Downscaling Experiment (CORDEX) models (ARPEGE, CCLM, HIRHAM, RACMO, REMO, PRECIS, RegCM3, RCA, WRF and CRCM) in simulating the climate (precipitation, temperature and drought) of West Africa is determined using a process-based metric. This is done by comparing the CORDEX models' simulated and observed correlation coefficients between Atlantic Niño Index 1 (ATLN1) and the climate over West Africa. Strong positive correlation is observed between ATLN1 and the climate parameters at the Guinea Coast (GC). The Atlantic Ocean has Niño behaviours through the ATLN indices which influence the climate of the tropics. Drought has distinct dipole structure of correlation with ATLN1 (negative at the Sahel); precipitation does not have distinct dipole structure of correlation, while temperature has almost a monopole correlation structure with ATLN1 over West Africa. The magnitude of the correlation increases with closeness to the equatorial eastern Atlantic. Correlations between ATLN1 and temperature are mostly stronger than those between ATLN1 and precipitation over the region. Most models have good performance over the GC, but ARPEGE has the highest skill at GC. The PRECIS is the most skilful over Savannah and RCA over Sahel. These models can be used to downscale the projected climate at the region of their highest skill.

A French-speaking speech-language pathology program in West Africa: transfer of training between Minority and Majority World countries.

PubMed

Topouzkhanian, Sylvia; Mijiyawa, Moustafa

2013-02-01

In West Africa, as in Majority World countries, people with a communication disability are generally cut-off from the normal development process. A long-term involvement of two partners (Orthophonistes du Monde and Handicap International) allowed the implementation in 2003 of the first speech-language pathology qualifying course in West Africa, within the Ecole Nationale des Auxiliaires Medicaux (ENAM, National School for Medical Auxiliaries) in Lome, Togo. It is a 3-year basic training (after the baccalaureate) in the only academic training centre for medical assistants in Togo. This department has a regional purpose and aims at training French-speaking African students. French speech-language pathology lecturers had to adapt their courses to the local realities they discovered in Togo. It was important to introduce and develop knowledge and skills in the students' system of reference. African speech-language pathologists have to face many challenges: creating an African speech and language therapy, introducing language disorders and their possible cure by means other than traditional therapies, and adapting all the evaluation tests and tools for speech-language pathology to each country, each culture, and each language. Creating an African speech-language pathology profession (according to its own standards) with a real influence in West Africa opens great opportunities for schooling and social and occupational integration of people with communication disabilities.

The Epidemiology and Geographic Distribution of Relapsing Fever Borreliosis in West and North Africa, with a Review of the Ornithodoros erraticus Complex (Acari: Ixodida)

PubMed Central

Trape, Jean-François; Diatta, Georges; Arnathau, Céline; Bitam, Idir; Sarih, M’hammed; Belghyti, Driss; Bouattour, Ali; Elguero, Eric; Vial, Laurence; Mané, Youssouph; Baldé, Cellou; Pugnolle, Franck; Chauvancy, Gilles; Mahé, Gil; Granjon, Laurent; Duplantier, Jean-Marc

2013-01-01

Background Relapsing fever is the most frequent bacterial disease in Africa. Four main vector / pathogen complexes are classically recognized, with the louse Pediculus humanus acting as vector for B. recurrentis and the soft ticks Ornithodoros sonrai, O. erraticus and O. moubata acting as vectors for Borrelia crocidurae, B. hispanica and B. duttonii, respectively. Our aim was to investigate the epidemiology of the disease in West, North and Central Africa. Methods And Findings From 2002 to 2012, we conducted field surveys in 17 African countries and in Spain. We investigated the occurrence of Ornithodoros ticks in rodent burrows in 282 study sites. We collected 1,629 small mammals that may act as reservoir for Borrelia infections. Using molecular methods we studied genetic diversity among Ornithodoros ticks and Borrelia infections in ticks and small mammals. Of 9,870 burrows investigated, 1,196 (12.1%) were inhabited by Ornithodoros ticks. In West Africa, the southern and eastern limits of the vectors and Borrelia infections in ticks and small mammals were 13°N and 01°E, respectively. Molecular studies revealed the occurrence of nine different Ornithodoros species, including five species new for science, with six of them harboring Borrelia infections. Only B. crocidurae was found in West Africa and three Borrelia species were identified in North Africa: B. crocidurae, B. hispanica, and B. merionesi. Conclusions Borrelia Spirochetes responsible for relapsing fever in humans are highly prevalent both in Ornithodoros ticks and small mammals in North and West Africa but Ornithodoros ticks seem absent south of 13°N and small mammals are not infected in these regions. The number of Ornithodoros species acting as vector of relapsing fever is much higher than previously known. PMID:24223812

Phytoplankton off the West Coast of Africa

NASA Technical Reports Server (NTRS)

2002-01-01

Just off the coast of West Africa, persistent northeasterly trade winds often churn up deep ocean water. When the nutrients in these deep waters reach the ocean's surface, they often give rise to large blooms of phytoplankton. This image of the Mauritanian coast shows swirls of phytoplankton fed by the upwelling of nutrient-rich water. The scene was acquired by the Medium Resolution Imaging Spectrometer (MERIS) aboard the European Space Agency's ENVISAT. MERIS will monitor changes in phytoplankton across Earth's oceans and seas, both for the purpose of managing fisheries and conducting global change research. NASA scientists will use data from this European instrument in the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) program. The mission of SIMBIOS is to construct a consistent long-term dataset of ocean color (phytoplankton abundance) measurements made by multiple satellite instruments, including the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate-Resolution Imaging Spectroradiometer (MODIS). For more information about MERIS and ENVISAT, visit the ENVISAT home page. Image copyright European Space Agency

Epidemiology of influenza in West Africa after the 2009 influenza A(H1N1) pandemic, 2010-2012.

PubMed

Talla Nzussouo, Ndahwouh; Duque, Jazmin; Adedeji, Adebayo Abel; Coulibaly, Daouda; Sow, Samba; Tarnagda, Zekiba; Maman, Issaka; Lagare, Adamou; Makaya, Sonia; Elkory, Mohamed Brahim; Kadjo Adje, Herve; Shilo, Paul Alhassan; Tamboura, Boubou; Cisse, Assana; Badziklou, Kossi; Maïnassara, Halima Boubacar; Bara, Ahmed Ould; Keita, Adama Mamby; Williams, Thelma; Moen, Ann; Widdowson, Marc-Alain; McMorrow, Meredith

2017-12-04

Over the last decade, capacity for influenza surveillance and research in West Africa has strengthened. Data from these surveillance systems showed influenza A(H1N1)pdm09 circulated in West Africa later than in other regions of the continent. We contacted 11 West African countries to collect information about their influenza surveillance systems (number of sites, type of surveillance, sampling strategy, populations sampled, case definitions used, number of specimens collected and number of specimens positive for influenza viruses) for the time period January 2010 through December 2012. Of the 11 countries contacted, 8 responded: Burkina Faso, Cote d'Ivoire, Mali, Mauritania, Niger, Nigeria, Sierra Leone and Togo. Countries used standard World Health Organization (WHO) case definitions for influenza-like illness (ILI) and severe acute respiratory illness (SARI) or slight variations thereof. There were 70 surveillance sites: 26 SARI and 44 ILI. Seven countries conducted SARI surveillance and collected 3114 specimens of which 209 (7%) were positive for influenza viruses. Among influenza-positive SARI patients, 132 (63%) were influenza A [68 influenza A(H1N1)pdm09, 64 influenza A(H3N2)] and 77 (37%) were influenza B. All eight countries conducted ILI surveillance and collected 20,375 specimens, of which 2278 (11%) were positive for influenza viruses. Among influenza-positive ILI patients, 1431 (63%) were influenza A [820 influenza A(H1N1)pdm09, 611 influenza A(H3N2)] and 847 (37%) were influenza B. A majority of SARI and ILI case-patients who tested positive for influenza (72% SARI and 59% ILI) were children aged 0-4 years, as were a majority of those enrolled in surveillance. The seasonality of influenza and the predominant influenza type or subtype varied by country and year. Influenza A(H1N1)pdm09 continued to circulate in West Africa along with influenza A(H3N2) and influenza B during 2010-2012. Although ILI surveillance systems produced a robust number of samples

Gambian-British and Nigerian-British Children's and Families' Experiences of Migration "Back" to West Africa. Research Briefing No. 13

ERIC Educational Resources Information Center

Roberts-Holmes, Guy

2013-01-01

This research looks at the factors motivating Gambian-British and Nigerian-British parents to send their children "back" to West Africa and what this means for parents, children and families on both continents.

Spatiotemporal evolutionary epidemiology of H5N1 highly pathogenic avian influenza in West Africa and Nigeria, 2006-2015.

PubMed

Ekong, P S; Fountain-Jones, N M; Alkhamis, M A

2018-02-01

H5N1 highly pathogenic avian influenza virus (HPAIV) was first observed in Nigeria in early 2006 and has now spread to more than 17 African countries having severe economic and public health implications. Here, we explore the spatiotemporal patterns of viral dispersal both among West African countries and within Nigeria using sequence data from hemagglutinin (HA) gene region of the virus. Analyses were performed within a statistical Bayesian framework using phylodynamic models on data sets comprising of all publically available HA sequence data collected from seven West African countries and Egypt between 2006 and 2015. Our regional-level analyses indicated that H5N1 in West Africa originated in Nigeria in three geopolitical regions, specifically north central and north-east, where backyard poultry and wild birds are in frequent contact, as well as south-west, a major commercial poultry area, then dispersed to West African countries. We inferred significant virus dispersal routes between Niger and Nigeria on one side and Burkina Faso, Ivory Coast, Ghana and Egypt on the other. Furthermore, south-west Nigeria identified as a primary source for virus dispersal within Nigeria as well as to Niger in 2006 and 2008. Niger was an important epicentre for the virus spread into other West African countries in 2015. Egyptian introductions from West Africa were sporadic and resulted most likely from poultry trade with Nigeria rather than contact with infected wild birds. Our inferred viral dispersal routes reflected the large-scale unrestricted movements of infected poultry in the region. Our study illustrates the ability of phylodynamic models to trace important HPAIV dispersal routes at a regional and national level. Our results have clear implications for the control and prevention of this pathogen across scales and will help improve molecular surveillance of transboundary HPAIVs. © 2017 Blackwell Verlag GmbH.

The Use of Lactic Acid Bacteria Starter Cultures during the Processing of Fermented Cereal-based Foods in West Africa: A Review

PubMed Central

Soro-Yao, Amenan Anastasie; Brou, Kouakou; Amani, Georges; Thonart, Philippe; Djè, Koffi Marcelin

2014-01-01

Lactic acid bacteria (LAB) are the primary microorganisms used to ferment maize-, sorghum- or millet-based foods that are processed in West Africa. Fermentation contributes to desirable changes in taste, flavour, acidity, digestibility and texture in gruels (ogi, baca, dalaki), doughs (agidi, banku, komé) or steam-cooked granulated products (arraw, ciacry, dégué). Similar to other fermented cereal foods that are available in Africa, these products suffer from inconsistent quality. The use of LAB starter cultures during cereal dough fermentation is a subject of increasing interest in efforts to standardise this step and guaranty product uniformity. However, their use by small-scale processing units or small agro-food industrial enterprises is still limited. This review aims to illustrate and discuss major issues that influence the use of LAB starter cultures during the processing of fermented cereal foods in West Africa. PMID:27073601

Thinking ahead about reproductive health: contingency planning and emergency preparedness in crisis situations (Iraq and West Africa).

PubMed

DeLargy, Pamela; Alakbarov, Ramiz

2004-09-01

The United Nations Population Fund (UNFPA) coordinated efforts to integrate RH into contingency planning for the 2003 Iraq crisis and the 2003 regional response for displaced populations in West Africa. Using UNFPA's network of country offices in the Middle East, staff developed logistics plans, conducted workshops and pre-positioned RH supplies. Though refugee movements did not occur, the contingency planning enhanced the response capacity of UNFPA offices and made it possible to rapidly provide assistance inside Iraq. In West Africa, multi-country workshops and follow-up resulted in country-level and regional action plans useful during the renewed crises of 2003; scarce funding, however, limited their full implementation. UNFPA's experiences show that contingency planning requires committing resources for crises, some of which will not occur; new staff skills; and follow-up. Moreover, RH is considered by some to be additional to the core elements of contingency planning. RH's political sensitivity, particularly with certain donors, further complicated integrated planning.

The 2014 Ebola virus outbreak in West Africa highlights no evidence of rapid evolution or adaptation to humans.

PubMed

Li, Xingguang; Zai, Junjie; Liu, Haizhou; Feng, Yi; Li, Fan; Wei, Jing; Zou, Sen; Yuan, Zhiming; Shao, Yiming

2016-10-21

Following its immergence in December 2013, the recent Zaire Ebola virus (EBOV) outbreak in West Africa has spread and persisted for more than two years, making it the largest EBOV epidemic in both scale and geographical region to date. In this study, a total of 726 glycoprotein (GP) gene sequences of the EBOV full-length genome obtained from West Africa from the 2014 outbreak, combined with 30 from earlier outbreaks between 1976 and 2008 were used to investigate the genetic divergence, evolutionary history, population dynamics, and selection pressure of EBOV among distinct epidemic waves. Results from our dataset showed that no non-synonymous substitutions occurred on the GP gene coding sequences of EBOV that were likely to have affected protein structure or function in any way. Furthermore, the significantly different dN/dS ratios observed between the 2014 West African outbreak and earlier outbreaks were more likely due to the confounding presence of segregating polymorphisms. Our results highlight no robust evidence that the 2014 EBOV outbreak is fast-evolving and adapting to humans. Therefore, the unprecedented nature of the 2014 EBOV outbreak might be more likely related to non-virological elements, such as environmental and sociological factors.

Continental margin subsidence from shallow mantle convection: Example from West Africa

NASA Astrophysics Data System (ADS)

Lodhia, Bhavik Harish; Roberts, Gareth G.; Fraser, Alastair J.; Fishwick, Stewart; Goes, Saskia; Jarvis, Jerry

2018-01-01

Spatial and temporal evolution of the uppermost convecting mantle plays an important role in determining histories of magmatism, uplift, subsidence, erosion and deposition of sedimentary rock. Tomographic studies and mantle flow models suggest that changes in lithospheric thickness can focus convection and destabilize plates. Geologic observations that constrain the processes responsible for onset and evolution of shallow mantle convection are sparse. We integrate seismic, well, gravity, magmatic and tomographic information to determine the history of Neogene-Recent (<23 Ma) upper mantle convection from the Cape Verde swell to West Africa. Residual ocean-age depths of +2 km and oceanic heat flow anomalies of +16 ± 4 mW m-2 are centered on Cape Verde. Residual depths decrease eastward to zero at the fringe of the Mauritania basin. Backstripped wells and mapped seismic data show that 0.4-0.8 km of water-loaded subsidence occurred in a ∼500 × 500 km region centered on the Mauritania basin during the last 23 Ma. Conversion of shear wave velocities into temperature and simple isostatic calculations indicate that asthenospheric temperatures determine bathymetry from Cape Verde to West Africa. Calculated average excess temperatures beneath Cape Verde are > + 100 °C providing ∼103 m of support. Beneath the Mauritania basin average excess temperatures are < - 100 °C drawing down the lithosphere by ∼102 to 103 m. Up- and downwelling mantle has generated a bathymetric gradient of ∼1/300 at a wavelength of ∼103 km during the last ∼23 Ma. Our results suggest that asthenospheric flow away from upwelling mantle can generate downwelling beneath continental margins.

Potential climate effect of mineral aerosols over West Africa. Part I: model validation and contemporary climate evaluation

NASA Astrophysics Data System (ADS)

Ji, Zhenming; Wang, Guiling; Pal, Jeremy S.; Yu, Miao

2016-02-01

Mineral dusts present in the atmosphere can play an important role in climate over West Africa and surrounding regions. However, current understanding regarding how dust aerosols influence climate of West Africa is very limited. In this study, a regional climate model is used to investigate the potential climatic impacts of dust aerosols. Two sets of simulations driven by reanalysis and Earth System Model boundary conditions are performed with and without the representation of dust processes. The model, regardless of the boundary forcing, captures the spatial and temporal variability of the aerosol optical depth and surface concentration. The shortwave radiative forcing of dust is negative at the surface and positive in the atmosphere, with greater changes in the spring and summer. The presence of mineral dusts causes surface cooling and lower troposphere heating, resulting in a stabilization effect and reduction in precipitation in the northern portion of the monsoon close to the dust emissions region. This results in an enhancement of precipitation to the south. While dusts cause the lower troposphere to stabilize, upper tropospheric cooling makes the region more prone to intense deep convection as is evident by a simulated increase in extreme precipitation. In a companion paper, the impacts of dust emissions on future West African climate are investigated.

Spatial spread of the West Africa Ebola epidemic.

PubMed

Kramer, Andrew M; Pulliam, J Tomlin; Alexander, Laura W; Park, Andrew W; Rohani, Pejman; Drake, John M

2016-08-01

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013-2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.

Spatial spread of the West Africa Ebola epidemic

PubMed Central

Pulliam, J. Tomlin; Alexander, Laura W.; Rohani, Pejman; Drake, John M.

2016-01-01

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013–2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value. PMID:27853607

Spatiotemporal Analysis of the Ebola Hemorrhagic Fever in West Africa in 2014

NASA Astrophysics Data System (ADS)

Xu, M.; Cao, C. X.; Guo, H. F.

2017-09-01

Ebola hemorrhagic fever (EHF) is an acute hemorrhagic diseases caused by the Ebola virus, which is highly contagious. This paper aimed to explore the possible gathering area of EHF cases in West Africa in 2014, and identify endemic areas and their tendency by means of time-space analysis. We mapped distribution of EHF incidences and explored statistically significant space, time and space-time disease clusters. We utilized hotspot analysis to find the spatial clustering pattern on the basis of the actual outbreak cases. spatial-temporal cluster analysis is used to analyze the spatial or temporal distribution of agglomeration disease, examine whether its distribution is statistically significant. Local clusters were investigated using Kulldorff's scan statistic approach. The result reveals that the epidemic mainly gathered in the western part of Africa near north Atlantic with obvious regional distribution. For the current epidemic, we have found areas in high incidence of EVD by means of spatial cluster analysis.

On the politics and practice of Muslim fertility: comparative evidence from West Africa.

PubMed

Johnson-Hanks, Jennifer

2006-03-01

Recent popular works have represented Muslim fertility as dangerously high, both a cause and consequence of religious fundamentalism. This article uses comparative, statistical methods to show that this representation is empirically wrong, at least in West Africa. Although religion strongly inflects reproductive practice, its effects are not constant across different communities. In West African countries with Muslim majorities, Muslim fertility is lower than that of their non-Muslim conationals; in countries where Muslims are in the minority, their apparently higher reproductive rates converge to those of the majority when levels of education and urban residence are taken into account. A similar pattern holds for infant mortality. By contrast, in all seven countries, Muslim women are more likely to report that their most recent child was wanted. The article concludes with a discussion of the relationship between autonomy and fertility desires.

Phylogeographic Reconstruction of African Yellow Fever Virus Isolates Indicates Recent Simultaneous Dispersal into East and West Africa

PubMed Central

Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B.; Barrett, Alan D. T.

2013-01-01

Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease. PMID:23516640

Crude childhood vaccination coverage in West Africa: Trends and predictors of completeness.

PubMed

Kazungu, Jacob S; Adetifa, Ifedayo M O

2017-02-15

Background : Africa has the lowest childhood vaccination coverage worldwide. If the full benefits of childhood vaccination programmes are to be enjoyed in sub-Saharan Africa, all countries need to improve on vaccine delivery to achieve and sustain high coverage. In this paper, we review trends in vaccination coverage, dropouts between vaccine doses and explored the country-specific predictors of complete vaccination in West Africa.  Methods : We utilized datasets from the Demographic and Health Surveys Program, available for Benin, Burkina Faso, The Gambia, Ghana, Guinea, Cote d'Ivoire, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone and Togo, to obtain coverage for Bacillus Calmette-Guerin, polio, measles, and diphtheria, pertussis and tetanus (DPT) vaccines in children aged 12 - 23 months. We also calculated the DPT1-to-DPT3 and DPT1-to-measles dropouts, and proportions of the fully immunised child (FIC). Factors predictive of FIC were explored using Chi-squared tests and multivariable logistic regression.  Results : Overall, there was a trend of increasing vaccination coverage. The proportion of FIC varied significantly by country (range 24.1-81.4%, mean 49%). DPT1-to-DPT3 dropout was high (range 5.1% -33.9%, mean 16.3%). Similarly, DPT1-measles dropout exceeded 10% in all but four countries. Although no single risk factor was consistently associated with FIC across these countries, maternal education, delivery in a health facility, possessing a vaccine card and a recent post delivery visit to a health facility were the key predictors of complete vaccination.  Conclusions : The low numbers of fully immunised children and high dropout between vaccine doses highlights weaknesses and the need to strengthen the healthcare and routine immunization delivery systems in this region. Country-specific correlates of complete vaccination should be explored further to identify interventions required to increase vaccination coverage. Despite the promise of an

The Contribution of the Society of the Holy Child Jesus to Catholic Education in West Africa

ERIC Educational Resources Information Center

Aidoo, Philomena

2016-01-01

This article discusses the extent to which the charism and the philosophy of education of Venerable Cornelia Connelly founder of the Society of the Holy Child Jesus are being maintained in the twenty-first century in West Africa (Nigeria and Ghana). Using data gathered from Sisters and former students of Holy Child schools as evidence it seeks to…

Moko Jumbies: Dancing Spirits from Africa

ERIC Educational Resources Information Center

Bennett, S. A.; Phillips, Claire; Moore, Natalie

2009-01-01

The original Moko Jumbie was a spirit dancer from West Africa. "Moko" is a West African word that refers to gods and "Jumbie" means ghost. In West Africa, Moko Jumbies are known to kidnap and eat disobedient children, steal dreams and see into evildoers' hearts and terrorize them. They walk through villages on 10- to…

Brazil-Africa geological links

NASA Astrophysics Data System (ADS)

Torquato, Joaquim Raul; Cordani, Umberto G.

1981-04-01

In this work, the main evidence and conclusions regarding geological links between Brazil and Africa are summarized, with emphasis on the geochronological aspects. Taking into account the geographical position, as well as the similarities in the geochronological pattern, the following main provinces of the two continents are correlated: The Imataca and Falawatra complexes in the Guayana Shield and the Liberian Province of West Africa. The Paraguay-Araguaia and the Rockelide Fold Belts. The Sa˜o Luiz and the West African cratonic areas. The Caririan Fold Belt of northeastern Brazil and the Pan-Africa Belt of Nigeria and Cameroon. The JequiéComplex of Bahia, the Ntem Complex of Cameroon and similar rocks of Gabon and Angola. The Ribeira Fold Belt in Brazil and the West Congo and Damara Belts in West and South Africa. In addition, other geological links are considered, such as some of the major linear fault zones which can be traced across the margins of South America and Africa, in the pre-drift reconstructions. Correlations are also made of the tectonic and stratigraphic evolution of the Paranáand Karroo syneclises, and the Brazilian and African marginal basins around the South Atlantic, during their initial stages. Finally, several similarities in the tectonic evolution of South America and Africa, during and after the onset of drifting, are shown to be compatible with a recent origin for the South Atlantic floor, as required by sea-floor spreading and continental drift between South America and Africa.

Impact of the Mycobaterium africanum West Africa 2 Lineage on TB Diagnostics in West Africa: Decreased Sensitivity of Rapid Identification Tests in The Gambia.

PubMed

Ofori-Anyinam, Boatema; Kanuteh, Fatoumatta; Agbla, Schadrac C; Adetifa, Ifedayo; Okoi, Catherine; Dolganov, Gregory; Schoolnik, Gary; Secka, Ousman; Antonio, Martin; de Jong, Bouke C; Gehre, Florian

2016-07-01

MPT64 rapid speciation tests are increasingly being used in diagnosis of tuberculosis (TB). Mycobacterium africanum West Africa 2 (Maf 2) remains an important cause of TB in West Africa and causes one third of disease in The Gambia. Since the introduction of MPT64 antigen tests, a higher than expected rate of suspected non-tuberculous mycobacteria (NTM) was seen among AFB smear positive TB suspects, which led us to prospectively assess sensitivity of the MPT64 antigen test in our setting. We compared the abundance of mRNA encoded by the mpt64 gene in sputa of patients with untreated pulmonary TB caused by Maf 2 and Mycobacterium tuberculosis (Mtb). Subsequently, prospectively collected sputum samples from presumptive TB patients were inoculated in the BACTEC MGIT 960 System. One hundred and seventy-three acid fast bacilli (AFB)-positive and blood agar negative MGIT cultures were included in the study. Cultures were tested on the day of MGIT positivity with the BD MGIT TBc Identification Test. A random set of positives and all negatives were additionally tested with the SD Bioline Ag MPT64 Rapid. MPT64 negative cultures were further incubated at 37°C and retested until positive. Bacteria were spoligotyped and assigned to different lineages. Maf 2 isolates were 2.52-fold less likely to produce a positive test result and sensitivity ranged from 78.4% to 84.3% at the beginning and end of the recommended 10 day testing window, respectively. There was no significant difference between the tests. We further showed that the decreased rapid test sensitivity was attributable to variations in mycobacterial growth behavior and the smear grades of the patient. In areas where Maf 2 is endemic MPT64 tests should be cautiously used and MPT64 negative results confirmed by a second technique, such as nucleic acid amplification tests, to avoid their misclassification as NTMs.

Emigration dynamics in West Africa.

PubMed

Makinwa-adebusoye, P K

1995-01-01

This report on the emigration dynamics at work in Western Africa opens by noting that this region comprises an important migration system with large legal and illegal movements of people within the region and to industrialized countries. Migration has been fueled by high growth rates coupled with lower growth rates of per capital income. Migration takes the form of continuing inflow into receiving countries, such as the Ivory Coast, sudden changes in migration status (in Ghana and Nigeria) reflecting sudden economic changes, a brain drain to developed countries, and an influx of refugees. The second section of the report presents a brief look at historical migratory patterns, including those of nomads which continue today. Data limitations are addressed in section 3, and the drawbacks of census data for migration information are noted. The next section describes the economic and demographic factors in the region which contribute to migration. These include the long lasting effects of colonization in general, the exploitation of minerals, patterns of agricultural development, poverty, and population growth. A closer examination of these forces at work is provided in case studies of Ghana, Nigeria, and the migration stream from Burkina Faso to the Ivory Coast. Section 5 looks at the economic causes and effects of the brain drain. Social and cultural factors are covered in section 6, with an emphasis placed on family and migration networks. Section 7 covers political factors influencing migration, such as the efforts of people to retain contact with other members of their ethnic group who may live on the opposite side of an arbitrarily drawn (by colonizers) international border, the designation of administrative capital cities, and the ease in crossing borders without documentation. The next section describes the 1975 formation of the Economic Community for West Africa (ECOWAS) and its protocols regarding free movement of citizens within the states which comprise the

Lineage 2 west nile virus as cause of fatal neurologic disease in horses, South Africa.

PubMed

Venter, Marietjie; Human, Stacey; Zaayman, Dewald; Gerdes, Gertruida H; Williams, June; Steyl, Johan; Leman, Patricia A; Paweska, Janusz Tadeusz; Setzkorn, Hildegard; Rous, Gavin; Murray, Sue; Parker, Rissa; Donnellan, Cynthia; Swanepoel, Robert

2009-06-01

Serologic evidence suggests that West Nile virus (WNV) is widely distributed in horses in southern Africa. However, because few neurologic cases have been reported, endemic lineage 2 strains were postulated to be nonpathogenic in horses. Recent evidence suggests that highly neuroinvasive lineage 2 strains exist in humans and mice. To determine whether neurologic cases are being missed in South Africa, we tested 80 serum or brain specimens from horses with unexplained fever (n = 48) and/or neurologic signs (n = 32) for WNV. From March 2007 through June 2008, using reverse transcription-PCR (RT-PCR) and immunoglobulin (Ig) M ELISA, we found WNV RNA or IgM in 7/32 horses with acute neurologic disease; 5 horses died or were euthanized. In 5/7 horses, no other pathogen was detected. DNA sequencing for all 5 RT-PCR-positive cases showed the virus belonged to lineage 2. WNV lineage 2 may cause neurologic disease in horses in South Africa.

Projected changes in crop yield mean and variability over West Africa in a world 1.5 K warmer than the pre-industrial era

NASA Astrophysics Data System (ADS)

Parkes, Ben; Defrance, Dimitri; Sultan, Benjamin; Ciais, Philippe; Wang, Xuhui

2018-02-01

The ability of a region to feed itself in the upcoming decades is an important issue. The West African population is expected to increase significantly in the next 30 years. The responses of crops to short-term climate change is critical to the population and the decision makers tasked with food security. This leads to three questions: how will crop yields change in the near future? What influence will climate change have on crop failures? Which adaptation methods should be employed to ameliorate undesirable changes? An ensemble of near-term climate projections are used to simulate maize, millet and sorghum in West Africa in the recent historic period (1986-2005) and a near-term future when global temperatures are 1.5 K above pre-industrial levels to assess the change in yield, yield variability and crop failure rate. Four crop models were used to simulate maize, millet and sorghum in West Africa in the historic and future climates. Across the majority of West Africa the maize, millet and sorghum yields are shown to fall. In the regions where yields increase, the variability also increases. This increase in variability increases the likelihood of crop failures, which are defined as yield negative anomalies beyond 1 standard deviation during the historic period. The increasing variability increases the frequency of crop failures across West Africa. The return time of crop failures falls from 8.8, 9.7 and 10.1 years to 5.2, 6.3 and 5.8 years for maize, millet and sorghum respectively. The adoption of heat-resistant cultivars and the use of captured rainwater have been investigated using one crop model as an idealized sensitivity test. The generalized doption of a cultivar resistant to high-temperature stress during flowering is shown to be more beneficial than using rainwater harvesting.

The spatial genetic differentiation of the legume pod borer, Maruca vitrata F. (Lepidoptera: Pyralidae) populations in West Africa

USDA-ARS?s Scientific Manuscript database

The legume pod borer, Maruca vitrata, is an endemic insect pest that causes significant yield loss to the cowpea crop in West Africa, and contributes to food shortages and malnutrition in native human populations. The genetic structure of Maruca vitrata was investigated among five sites from Burkin...

Nocturnal low-level clouds over southern West Africa analysed using high-resolution simulations

NASA Astrophysics Data System (ADS)

Adler, Bianca; Kalthoff, Norbert; Gantner, Leonhard

2017-01-01

We performed a high-resolution numerical simulation to study the development of extensive low-level clouds that frequently form over southern West Africa during the monsoon season. This study was made in preparation for a field campaign in 2016 within the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project and focuses on an area around the city of Savè in southern Benin. Nocturnal low-level clouds evolve a few hundred metres above the ground around the same level as a distinct low-level jet. Several processes are found to determine the spatio-temporal evolution of these clouds including (i) significant cooling of the nocturnal atmosphere caused by horizontal advection with the south-westerly monsoon flow during the first half of the night, (ii) vertical cold air advection due to gravity waves leading to clouds in the wave crests and (iii) enhanced convergence and upward motion upstream of existing clouds that trigger new clouds. The latter is caused by an upward shift of the low-level jet in cloudy areas leading to horizontal convergence in the lower part and to horizontal divergence in the upper part of the cloud layer. Although this single case study hardly allows for a generalisation of the processes found, the results added to the optimisation of the measurements strategy for the field campaign and the observations will be used to test the hypotheses for cloud formation resulting from this study.

Clinical manifestations of Waardenburg syndrome in a male adolescent in Mali, West Africa.

PubMed

Imperato, Pascal James; Imperato, Gavin H

2015-02-01

Waardenburg syndrome (WS) is a genetic disorder of which there are four distinct types. These four types are differentiated by the physical defects which they produce. Presented here is the case of a 13-year-old boy with WS Type I who was observed and physically assessed in Mali, West Africa in 1969. His physical findings included a bright blue coloring to the irises of the eyes, profound sensorineural deafness, mutism, dystopia canthorum (lateral displacement of the inner canthi of the eyes), broad nasal root, bushy eyebrows, and scaphoid deformities of the supraorbital portions of the frontal bone. Because family members were not available for interviews or physical examinations, it was not possible to determine if this patient was suffering from a congenital form of the disorder or from a spontaneous mutation. Given the patient's then location in a remote rural area of Mali where electricity was absent, it was not possible to perform additional diagnostic tests. The patient described here is the first with WS in Mali, West Africa to have been medically observed and evaluated and later documented in the medical literature. A second case of the syndrome in Mali was described in the medical literature in 2011 in an 18-month-old infant who did not have sensorineural hearing loss, but who did have a bilateral cleft lip. An historical overview of WS is presented along with details concerning the characteristics of the four types of the disorder.

Evaporation from cultivated and semi-wild Sudanian Savanna in west Africa

NASA Astrophysics Data System (ADS)

Ceperley, Natalie C.; Mande, Theophile; van de Giesen, Nick; Tyler, Scott; Yacouba, Hamma; Parlange, Marc B.

2017-08-01

Rain-fed farming is the primary livelihood of semi-arid west Africa. Changes in land cover have the potential to affect precipitation, the critical resource for production. Turbulent flux measurements from two eddy-covariance towers and additional observations from a dense network of small, wireless meteorological stations combine to relate land cover (savanna forest and agriculture) to evaporation in a small (3.5 km2) catchment in Burkina Faso, west Africa. We observe larger sensible and latent heat fluxes over the savanna forest in the headwater area relative to the agricultural section of the watershed all year. Higher fluxes above the savanna forest are attributed to the greater number of exposed rocks and trees and the higher productivity of the forest compared to rain-fed, hand-farmed agricultural fields. Vegetation cover and soil moisture are found to be primary controls of the evaporative fraction. Satellite-derived vegetation index (NDVI) and soil moisture are determined to be good predictors of evaporative fraction, as indicators of the physical basis of evaporation. Our measurements provide an estimator that can be used to derive evaporative fraction when only NDVI is available. Such large-scale estimates of evaporative fraction from remotely sensed data are valuable where ground-based measurements are lacking, which is the case across the African continent and many other semi-arid areas. Evaporative fraction estimates can be combined, for example, with sensible heat from measurements of temperature variance, to provide an estimate of evaporation when only minimal meteorological measurements are available in remote regions of the world. These findings reinforce local cultural beliefs of the importance of forest fragments for climate regulation and may provide support to local decision makers and rural farmers in the maintenance of the forest areas.

Relief inversion in the geomorphological evolution of sub-Saharan West Africa

NASA Astrophysics Data System (ADS)

Butt, C. R. M.; Bristow, A. P. J.

2013-03-01

The geomorphology of much of sub-Saharan West Africa is dominated by the presence of plateaux and plains with ferruginous and, locally, aluminous (bauxitic) duricrusts. The plateaux occur at different elevations and have been correlated as two or more palaeosurfaces across much of the region. The duricrusts have generally been considered to be residual, formed by conformable erosion and chemical wasting of immediately underlying bedrock. This concept has been central to interpretations as diverse as the formation and evolution of the landscape and the development of geochemical exploration models. Recent regolith landform mapping, field observations and experience from mineral exploration in southern Mali and Burkina Faso, however, demonstrate that the duricrusts are mainly ferricretes, i.e., Fe oxide-cemented sediments. These observations require a re-interpretation of the geomorphological evolution of the region during the Cenozoic. The landscape has evolved by several cycles of weathering and erosion-deposition, triggered by climatic, tectonic or other environmental changes. It is proposed that an initial bauxitic/lateritic regolith was partly eroded following uplift and/or a change to a more arid climate, and that the detritus, rather than being removed, was deposited on slopes and valleys. During a subsequent humid period of lateritic weathering, Fe oxide cementation of this detritus formed ferricrete. Dehydration and hardening of the ferricrete after further uplift or aridity increased its resistance to erosion, resulting in relief inversion, with the detritus, in turn, being deposited downslope. This too has been weathered and cemented, to form a younger ferricrete. The occurrence of ferricrete landforms in adjacent countries, noted by field observation and inferred from satellite imagery, demonstrates that relief inversion is a very widespread and important phenomenon in southern Mali, Burkina Faso and adjacent countries in semi-arid West Africa.

Regional assessment of the hydropower potential of rivers in West Africa

NASA Astrophysics Data System (ADS)

Kling, Harald; Stanzel, Philipp; Fuchs, Martin

2016-04-01

The 15 countries of the Economic Community of West African States (ECOWAS) face a constant shortage of energy supply, which limits sustained economic growth. Currently there are about 50 operational hydropower plants and about 40 more are under construction or refurbishment. The potential for future hydropower development - especially for small-scale plants in rural areas - is assumed to be large, but exact data are missing. This study supports the energy initiatives of the "ECOWAS Centre for Renewable Energy and Energy Efficiency" (ECREEE) by assessing the hydropower potential of all rivers in West Africa. For more than 500,000 river reaches the hydropower potential was computed from channel slope and mean annual discharge. In large areas there is a lack of discharge observations. Therefore, an annual water balance model was used to simulate discharge. The model domain covers 5 Mio km², including e.g. the Niger, Volta, and Senegal River basins. The model was calibrated with observed data of 410 gauges, using precipitation and potential evapotranspiration data as inputs. Historic variations of observed annual discharge between 1950 and 2010 are simulated well by the model. As hydropower plants are investments with a lifetime of several decades we also assessed possible changes in future discharge due to climate change. To this end the water balance model was driven with bias-corrected climate projections of 15 Regional Climate Models for two emission scenarios of the CORDEX-Africa ensemble. The simulation results for the river network were up-scaled to sub-areas and national summaries. This information gives a regional quantification of the hydropower potential, expected climate change impacts, as well as a regional classification for general suitability (or non-suitability) of hydropower plant size - from small-scale to large projects.

Consequences of rapid ice sheet melting on the Sahelian population vulnerability

PubMed Central

Ramstein, Gilles; Charbit, Sylvie; Vrac, Mathieu; Famien, Adjoua Moïse; Sultan, Benjamin; Swingedouw, Didier; Dumas, Christophe; Gemenne, François; Alvarez-Solas, Jorge; Vanderlinden, Jean-Paul

2017-01-01

The acceleration of ice sheet melting has been observed over the last few decades. Recent observations and modeling studies have suggested that the ice sheet contribution to future sea level rise could have been underestimated in the latest Intergovernmental Panel on Climate Change report. The ensuing freshwater discharge coming from ice sheets could have significant impacts on global climate, and especially on the vulnerable tropical areas. During the last glacial/deglacial period, megadrought episodes were observed in the Sahel region at the time of massive iceberg surges, leading to large freshwater discharges. In the future, such episodes have the potential to induce a drastic destabilization of the Sahelian agroecosystem. Using a climate modeling approach, we investigate this issue by superimposing on the Representative Concentration Pathways 8.5 (RCP8.5) baseline experiment a Greenland flash melting scenario corresponding to an additional sea level rise ranging from 0.5 m to 3 m. Our model response to freshwater discharge coming from Greenland melting reveals a significant decrease of the West African monsoon rainfall, leading to changes in agricultural practices. Combined with a strong population increase, described by different demography projections, important human migration flows could be potentially induced. We estimate that, without any adaptation measures, tens to hundreds million people could be forced to leave the Sahel by the end of this century. On top of this quantification, the sea level rise impact over coastal areas has to be superimposed, implying that the Sahel population could be strongly at threat in case of rapid Greenland melting. PMID:28584113

Consequences of rapid ice sheet melting on the Sahelian population vulnerability.

PubMed

Defrance, Dimitri; Ramstein, Gilles; Charbit, Sylvie; Vrac, Mathieu; Famien, Adjoua Moïse; Sultan, Benjamin; Swingedouw, Didier; Dumas, Christophe; Gemenne, François; Alvarez-Solas, Jorge; Vanderlinden, Jean-Paul

2017-06-20

The acceleration of ice sheet melting has been observed over the last few decades. Recent observations and modeling studies have suggested that the ice sheet contribution to future sea level rise could have been underestimated in the latest Intergovernmental Panel on Climate Change report. The ensuing freshwater discharge coming from ice sheets could have significant impacts on global climate, and especially on the vulnerable tropical areas. During the last glacial/deglacial period, megadrought episodes were observed in the Sahel region at the time of massive iceberg surges, leading to large freshwater discharges. In the future, such episodes have the potential to induce a drastic destabilization of the Sahelian agroecosystem. Using a climate modeling approach, we investigate this issue by superimposing on the Representative Concentration Pathways 8.5 (RCP8.5) baseline experiment a Greenland flash melting scenario corresponding to an additional sea level rise ranging from 0.5 m to 3 m. Our model response to freshwater discharge coming from Greenland melting reveals a significant decrease of the West African monsoon rainfall, leading to changes in agricultural practices. Combined with a strong population increase, described by different demography projections, important human migration flows could be potentially induced. We estimate that, without any adaptation measures, tens to hundreds million people could be forced to leave the Sahel by the end of this century. On top of this quantification, the sea level rise impact over coastal areas has to be superimposed, implying that the Sahel population could be strongly at threat in case of rapid Greenland melting.

Marine communities on oil platforms in Gabon, West Africa: high biodiversity oases in a low biodiversity environment.

PubMed

Friedlander, Alan M; Ballesteros, Enric; Fay, Michael; Sala, Enric

2014-01-01

The marine biodiversity of Gabon, West Africa has not been well studied and is largely unknown. Our examination of marine communities associated with oil platforms in Gabon is the first scientific investigation of these structures and highlights the unique ecosystems associated with them. A number of species previously unknown to Gabonese waters were recorded during our surveys on these platforms. Clear distinctions in benthic communities were observed between older, larger platforms in the north and newer platforms to the south or closer to shore. The former were dominated by a solitary cup coral, Tubastraea sp., whereas the latter were dominated by the barnacle Megabalanus tintinnabulum, but with more diverse benthic assemblages compared to the northerly platforms. Previous work documented the presence of limited zooxanthellated scleractinian corals on natural rocky substrate in Gabon but none were recorded on platforms. Total estimated fish biomass on these platforms exceeded one ton at some locations and was dominated by barracuda (Sphyraena spp.), jacks (Carangids), and rainbow runner (Elagatis bipinnulata). Thirty-four percent of fish species observed on these platforms are new records for Gabon and 6% are new to tropical West Africa. Fish assemblages closely associated with platforms had distinct amphi-Atlantic affinities and platforms likely extend the distribution of these species into coastal West Africa. At least one potential invasive species, the snowflake coral (Carijoa riisei), was observed on the platforms. Oil platforms may act as stepping stones, increasing regional biodiversity and production but they may also be vectors for invasive species. Gabon is a world leader in terrestrial conservation with a network of protected areas covering >10% of the country. Oil exploration and biodiversity conservation currently co-exist in terrestrial and freshwater ecosystems in Gabon. Efforts to increase marine protection in Gabon may benefit by including oil

Atmospheric Pollution from Shipping and Oil platforms of West Africa (APSOWA) observed during the airborne DACCIWA campaign

NASA Astrophysics Data System (ADS)

Krysztofiak-Tong, Gisèle; Brocchi, Vanessa; Catoire, Valéry; Stratmann, Greta; Sauer, Daniel; Deroubaix, Adrien; Deetz, Konrad; Schlager, Hans

2017-04-01

In the framework of the European DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) project, the airborne study APSOWA (Atmospheric Pollution from Shipping and Oil platforms of West Africa) has been conducted in July 2016 to study emissions from oil rigs and maritime traffic in the Gulf of Guinea. The measurements were performed during four flights of about 3-4 hours including meandering transects through emission plumes in the planetary boundary layer (around 300 m asl) off the coast of West Africa from Ivory Coast to Togo. Several instruments have been used on-board the DLR Falcon-20, providing measurements of the pollutants O3, CO, NO2, SO2, aerosol content and meteorological parameters. This set of trace gases can be used to fingerprint different sources of local air pollution. The first part of our study is focused on the FPSO Kwame Nkrumah facility operating in the Jubilee oil field off the coast of Ghana. Aircraft observations have been combined with a nested-grid regional scale Lagrangian particle dispersion model (FLEXPART) to estimate surface emission fluxes from this platform. A simplified inverse method is used and repeated until the modelling output and aircraft observations converged. The estimated fluxes of CO, SO2, NO2 are compared to global (EDGAR, MACCity) and regional (Deetz and Vogel, 2017, in press) inventories. A second part of the study provides the first results of the APSOWA flights for the study of the impact of shipping emissions on the regional air quality. Using data from Marine Traffic, ship positions during the campaign are identified. Then, FLEXPART is used to quantify the contributions of the ship emissions to the aircraft observations. Finally, direct measurements in the MBL around 4°N latitude along the Ghana coast show no strong evidence of the presence of an atmospheric pollution maritime corridor simulated by MACCity.

Lessons from New Experiences in Extension in West Africa: Management Advice for Family Farms and Farmers' Governance

ERIC Educational Resources Information Center

Faure, Guy; Kleene, Paul

2004-01-01

The emergence of Management Advice for Family Farms in West Africa is closely related to the increased integration of farmers into an open market economy. This is creating a strong demand from farmers for advisory support services, focusing on management of the farm. With the gradual withdrawal of the State from extension services delivery, a…

Spanning maternal, newborn and child health (MNCH) and health systems research boundaries: conducive and limiting health systems factors to improving MNCH outcomes in West Africa.

PubMed

Agyepong, Irene Akua; Kwamie, Aku; Frimpong, Edith; Defor, Selina; Ibrahim, Abdallah; Aryeetey, Genevieve C; Lokossou, Virgil; Sombie, Issiaka

2017-07-12

Despite improvements over time, West Africa lags behind global as well as sub-Saharan averages in its maternal, newborn and child health (MNCH) outcomes. This is despite the availability of an increasing body of knowledge on interventions that improve such outcomes. Beyond our knowledge of what interventions work, insights are needed on others factors that facilitate or inhibit MNCH outcome improvement. This study aimed to explore health system factors conducive or limiting to MNCH policy and programme implementation and outcomes in West Africa, and how and why they work in context. We conducted a mixed methods multi-country case study focusing predominantly, but not exclusively, on the six West African countries (Burkina Faso, Benin, Mali, Senegal, Nigeria and Ghana) of the Innovating for Maternal and Child Health in Africa initiative. Data collection involved non-exhaustive review of grey and published literature, and 48 key informant interviews. We validated our findings and conclusions at two separate multi-stakeholder meetings organised by the West African Health Organization. To guide our data collection and analysis, we developed a unique theoretical framework of the link between health systems and MNCH, in which we conceptualised health systems as the foundations, pillars and roofing of a shelter for MNCH, and context as the ground on which the foundation is laid. A multitude of MNCH policies and interventions were being piloted, researched or implemented at scale in the sub-region, most of which faced multiple interacting conducive and limiting health system factors to effective implementation, as well as contextual challenges. Context acted through its effect on health system factors as well as on the social determinants of health. To accelerate and sustain improvements in MNCH outcomes in West Africa, an integrated approach to research and practice of simultaneously addressing health systems and contextual factors alongside MNCH service delivery

The roles of fire in Holocene ecosystem changes of West Africa

NASA Astrophysics Data System (ADS)

Dupont, L. M.; Schefuß, E.

2018-01-01

The climate changes associated with the Holocene wet phase in the Sahara, the African Humid Period, are subject to ongoing debate discussing interactions between climate and vegetation and possible feedbacks between vegetation, albedo, desertification, and dust. However, very little attention has been given to the role of fire in shaping the land cover, although it is known that fires are important in the formation and consolidation of the African savanna. To fill this gap, we investigated the interaction between precipitation changes, vegetation shifts, and fire occurrence in West Africa by combining stable isotope measurements on plant waxes with pollen and micro-charcoal counts of marine sediments retrieved offshore of Cape Blanc. Our study focuses on the roles of fire at the dry limit of savanna during the Holocene evolution of precipitation changes indicating that the impact of fire during a relative wet climate differs from that during aridification. During the humid early Holocene, increased savanna extension and diversification ran parallel to increased fire occurrence. In contrast, after aridification of northern Africa started at the end of the African Humid Period, a maximum in fire occurrence correlated with a deterioration of the vegetation promoting desertification.

Severe morbidity after antiretroviral (ART) initiation: active surveillance in HIV care programs, the IeDEA West Africa collaboration.

PubMed

Abo, Yao; Zannou Djimon, Marcel; Messou, Eugène; Balestre, Eric; Kouakou, Martial; Akakpo, Jocelyn; Ahouada, Carin; de Rekeneire, Nathalie; Dabis, François; Lewden, Charlotte; Minga, Albert

2015-04-09

The causes of severe morbidity in health facilities implementing Antiretroviral Treatment (ART) programmes are poorly documented in sub-Saharan Africa. We aimed to describe severe morbidity among HIV-infected patients after ART initiation, based on data from an active surveillance system established within a network of specialized care facilities in West African cities. Within the International epidemiological Database to Evaluate AIDS (IeDEA)--West Africa collaboration, we conducted a prospective, multicenter data collection that involved two facilities in Abidjan, Côte d'Ivoire and one in Cotonou, Benin. Among HIV-infected adults receiving ART, events were recorded using a standardized form. A simple case-definition of severe morbidity (death, hospitalization, fever>38°5C, Karnofsky index<70%) was used at any patient contact point. Then a physician confirmed and classified the event as WHO stage 3 or 4 according to the WHO clinical classification or as degree 3 or 4 of the ANRS scale. From December 2009 to December 2011, 978 adults (71% women, median age 39 years) presented with 1449 severe events. The main diagnoses were: non-AIDS-defining infections (33%), AIDS-defining illnesses (33%), suspected adverse drug reactions (7%), other illnesses (4%) and syndromic diagnoses (16%). The most common specific diagnoses were: malaria (25%), pneumonia (13%) and tuberculosis (8%). The diagnoses were reported as syndromic in one out of five events recorded during this study. This study highlights the ongoing importance of conventional infectious diseases among severe morbid events occurring in patients on ART in ambulatory HIV care facilities in West Africa. Meanwhile, additional studies are needed due to the undiagnosed aspect of severe morbidity in substantial proportion.

Walking the Path: A Reflection on How I Got Started at Tuskegee International School, Ghana, West Africa

ERIC Educational Resources Information Center

Greenberg, Bev

2011-01-01

The author has given meaning to global citizenship over the past four years through the work and connections she has made with students at her school in Chicago, Francis W. Parker, and a school in the village of Madina, Ghana, West Africa, Tuskegee International. She has motivated other teachers to make connections as they traveled with her to…

'FAN the SUN brighter': fortifying Africa nutritionally (FAN) - the role of public private partnership in scaling up nutrition (SUN) in West Africa.

PubMed

Sablah, Mawuli; Baker, Shawn K; Badham, Jane; De Zayas, Alfred

2013-11-01

The scaling up nutrition (SUN) policy framework requires extensive public–private partnership (PPP). Malnutrition is multi-dimensional and should engage multi-sectoral platforms. The SUN policy however did not fully embrace the dynamics of harnessing PPP. The objectives of the present paper are to highlight the reasons for the apprehension around PPP and illustrate how effective coordination of PPP in West Africa has contributed to implementing large-scale food fortification with micronutrients as a complementary nutrition intervention. The experience of Helen Keller International (HKI) in scaling up food fortification was emphasised with understanding of the factors contributing to indifference by the international community to private sector contribution to SUN. The roles of different stakeholders in a PPP are elucidated and the process linked to who, why and how to engage. The private sector provides direct nutrition services while the public sector creates the enabling environment for the private sector to thrive on social values. Through this approach fortified vegetable oil and wheat flour are now reaching over 70% of the population in West Africa. As a neutral broker HKI coordinated and facilitated dialogue among the different stakeholders. The core competencies of each stakeholder were harnessed and each partner was held accountable. It concludes that multi-sectoral relationship must be transparent, equitable and based on shared mutual interests. The rules and values of PPP offer opportunities for SUN.

AMMA-CATCH a Hydrological, Meteorological and Ecological Long Term Observatory on West Africa : Some Recent Results

NASA Astrophysics Data System (ADS)

Galle, S.; Grippa, M.; Peugeot, C.; Bouzou Moussa, I.; Cappelaere, B.; Demarty, J.; Mougin, E.; Lebel, T.; Chaffard, V.

2015-12-01

AMMA-CATCH is a multi-scale observation system dedicated to long-term monitoring of the water cycle, the vegetation dynamics and their interaction with climate and water resources in West Africa. In the context of the global change, long-term observations are required to i) gain understanding in eco-hydrological processes over this highly contrasted region, ii) help their representation in Earth System Models, and iii) detect trends and infer their impacts on water resources and living conditions. It is made of three meso-scale sites (~ 1°x1°) in Mali, Niger and Benin, extending along the West African eco-climatic gradient. Within this regional window (5° by 9°), each of the three sites comprises a multi-scale set-up which helps documenting the components of the hydrologic budget and the evolutions of the surface conditions over a range of time scales: raingages, piezometers, river discharge stations, soil moisture and temperature profiles, turbulent fluxes measurements, LAI/biomass monitoring. This observation system has been continuously generating coherent datasets for 10 to 25 years depending on the datasets. It is jointly operated by French and African (Mali, Niger and Benin) research institutions. The data-base is available to the community through the website (www.amma-catch.org). AMMA-CATCH is a member of the French critical zone observatory network "Réseau des Bassins Versants", (RBV). AMMA-CATH participates to several global or regional observation networks, such as FluxNet, CarboAfrica, International Soil Moisture Networks (ISMN) and to calibration/validation campaigns for satellite missions such as SMOS (CNES, ESA), MEGHA-TROPIQUES (France/India) or SWAP(NASA). AMMA-CATCH fills a gap over a region, West Africa, where environmental data are largely lacking, and thus, it can usefully contribute to the international networking effort for environmental monitoring and research. Recent results on regional evolution of land cover, rainfall intensity and

Skill of ENSEMBLES seasonal re-forecasts for malaria prediction in West Africa

NASA Astrophysics Data System (ADS)

Jones, A. E.; Morse, A. P.

2012-12-01

This study examines the performance of malaria-relevant climate variables from the ENSEMBLES seasonal ensemble re-forecasts for sub-Saharan West Africa, using a dynamic malaria model to transform temperature and rainfall forecasts into simulated malaria incidence and verifying these forecasts against simulations obtained by driving the malaria model with General Circulation Model-derived reanalysis. Two subregions of forecast skill are identified: the highlands of Cameroon, where low temperatures limit simulated malaria during the forecast period and interannual variability in simulated malaria is closely linked to variability in temperature, and northern Nigeria/southern Niger, where simulated malaria variability is strongly associated with rainfall variability during the peak rain months.

Impacts of Climate Change on Malaria Transmission in Africa

NASA Astrophysics Data System (ADS)

Eltahir, E. A. B.; Endo, N.; Yamana, T. K.

2017-12-01

Malaria is a major vector-borne parasitic disease transmitted to humans by Anopheles spp mosquitoes. Africa is the hotspot for malaria transmission where more than 90% of malaria deaths occur every year. Malaria transmission is an intricate function of climatic factors, which non-linearly affect the development of vectors and parasites. We project that the risk of malaria will increase towards the end of the 21st century in east Africa, but decrease in west Africa. We combine a novel malaria transmission simulator, HYDREMATS, that has been developed based on comprehensive multi-year field surveys both in East Africa and West Africa, and the most reliable climate projections through regional dynamical downscaling and rigorous selection of GCMs from among CMIP5 models. We define a bell-shaped relation between malaria intensity and temperature, centered around a temperature of 30°C. Future risks of malaria are projected for two highly populated regions in Africa: the highlands in East Africa and the fringes of the desert in West Africa. In the highlands of East Africa, temperature is substantially colder than this optimal temperature; warmer future climate exacerbate malaria conditions. In the Sahel fringes in West Africa, temperature is around this optimal temperature; warming is not likely to exacerbate and might even reduce malaria burden. Unlike the highlands of East Africa, which receive significant amounts of annual rainfall, dry conditions also limit malaria transmission in the Sahel fringes in West Africa. This disproportionate risk of malaria due to climate change should guide strategies for climate adaptation over Africa.

Comparative phylogeography of African fruit bats (Chiroptera, Pteropodidae) provide new insights into the outbreak of Ebola virus disease in West Africa, 2014-2016.

PubMed

Hassanin, Alexandre; Nesi, Nicolas; Marin, Julie; Kadjo, Blaise; Pourrut, Xavier; Leroy, Éric; Gembu, Guy-Crispin; Musaba Akawa, Prescott; Ngoagouni, Carine; Nakouné, Emmanuel; Ruedi, Manuel; Tshikung, Didier; Pongombo Shongo, Célestin; Bonillo, Céline

Both Ebolavirus and Marburgvirus were detected in several fruit bat species of the family Pteropodidae, suggesting that this taxon plays a key role in the life cycle of filoviruses. After four decades of Zaire Ebolavirus (ZEBOV) outbreaks in Central Africa, the virus was detected for the first time in West Africa in 2014. To better understand the role of fruit bats as potential reservoirs and circulating hosts between Central and West Africa, we examine here the phylogeny and comparative phylogeography of Pteropodidae. Our phylogenetic results confirm the existence of four independent lineages of African fruit bats: the genera Eidolon and Rousettus, and the tribes Epomophorini and Scotonycterini, and indicate that the three species suspected to represent ZEBOV reservoir hosts (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata) belong to an African clade that diversified rapidly around 8-7 Mya. To test for phylogeographic structure and for recent gene flow from Central to West Africa, we analysed the nucleotide variation of 675 cytochrome b gene (Cytb) sequences, representing eight fruit bat species collected in 48 geographic localities. Within Epomophorina, our mitochondrial data do not support the monophyly of two genera (Epomops and Epomophorus) and four species (Epomophorus gambianus, Epomops franqueti, Epomops buettikoferi, and Micropteropus pusillus). In Epomops, however, we found two geographic haplogroups corresponding to the Congo Basin and Upper Guinea forests, respectively. By contrast, we found no genetic differentiation between Central and West African populations for all species known to make seasonal movements, Eidolon helvum, E. gambianus, H. monstrosus, M. pusillus, Nanonycteris veldkampii, and Rousettus aegyptiacus. Our results suggest that only three fruit bat species were able to disperse directly ZEBOV from the Congo Basin to Upper Guinea: E. helvum, H. monstrosus, and R. aegyptiacus. Copyright © 2016 Académie des

Multilingual Validation of the Questionnaire for Verifying Stroke-Free Status in West Africa.

PubMed

Sarfo, Fred; Gebregziabher, Mulugeta; Ovbiagele, Bruce; Akinyemi, Rufus; Owolabi, Lukman; Obiako, Reginald; Akpa, Onoja; Armstrong, Kevin; Akpalu, Albert; Adamu, Sheila; Obese, Vida; Boa-Antwi, Nana; Appiah, Lambert; Arulogun, Oyedunni; Mensah, Yaw; Adeoye, Abiodun; Tosin, Aridegbe; Adeleye, Osimhiarherhuo; Tabi-Ajayi, Eric; Phillip, Ibinaiye; Sani, Abubakar; Isah, Suleiman; Tabari, Nasir; Mande, Aliyu; Agunloye, Atinuke; Ogbole, Godwin; Akinyemi, Joshua; Laryea, Ruth; Melikam, Sylvia; Uvere, Ezinne; Adekunle, Gregory; Kehinde, Salaam; Azuh, Paschal; Dambatta, Abdul; Ishaq, Naser; Saulson, Raelle; Arnett, Donna; Tiwari, Hemnant; Jenkins, Carolyn; Lackland, Dan; Owolabi, Mayowa

2016-01-01

The Questionnaire for Verifying Stroke-Free Status (QVSFS), a method for verifying stroke-free status in participants of clinical, epidemiological, and genetic studies, has not been validated in low-income settings where populations have limited knowledge of stroke symptoms. We aimed to validate QVSFS in 3 languages, Yoruba, Hausa and Akan, for ascertainment of stroke-free status of control subjects enrolled in an on-going stroke epidemiological study in West Africa. Data were collected using a cross-sectional study design where 384 participants were consecutively recruited from neurology and general medicine clinics of 5 tertiary referral hospitals in Nigeria and Ghana. Ascertainment of stroke status was by neurologists using structured neurological examination, review of case records, and neuroimaging (gold standard). Relative performance of QVSFS without and with pictures of stroke symptoms (pictograms) was assessed using sensitivity, specificity, positive predictive value, and negative predictive value. The overall median age of the study participants was 54 years and 48.4% were males. Of 165 stroke cases identified by gold standard, 98% were determined to have had stroke, whereas of 219 without stroke 87% were determined to be stroke-free by QVSFS. Negative predictive value of the QVSFS across the 3 languages was 0.97 (range, 0.93-1.00), sensitivity, specificity, and positive predictive value were 0.98, 0.82, and 0.80, respectively. Agreement between the questionnaire with and without the pictogram was excellent/strong with Cohen k=0.92. QVSFS is a valid tool for verifying stroke-free status across culturally diverse populations in West Africa. © 2015 American Heart Association, Inc.

The prevalence, awareness, and control of hypertension among workers in West Africa: a systematic review

PubMed Central

Bosu, William K.

2015-01-01

Background Interventions in workplace settings are considered to be cost-effective in preventing cardiovascular diseases. A systematic review was conducted to assess the prevalence of hypertension and the level of awareness and control among workers in West Africa. Design A systematic search for studies on formal and informal sector workers aged ≥15 years in West Africa published between 1980 and September 2014 was undertaken using the Ovid Medline, Embase, PubMed, and Google Scholar databases. Clinical and obstetric studies and studies that did not report prevalence were excluded. Data on study settings, characteristics of workers, blood pressure (BP) levels, prevalence of hypertension, and associated demographic factors were extracted. Results A total of 45 studies from six countries were identified involving 30,727 formal and informal sector workers. In 40 studies with a common definition of hypertension, the prevalence ranged from 12.0% among automobile garage workers to 68.9% among traditional chiefs. In 15 of these studies, the prevalence exceeded 30%. Typically sedentary workers such as traders, bank workers, civil servants, and chiefs were at high risk. Among health care workers, the prevalence ranged from 17.5 to 37.5%. The prevalence increased with age and was higher among males and workers with higher socio-economic status. Complications of hypertension, co-morbidities, and clustering of risk factors were common. The crude prevalence of hypertension increased progressively from 12.9% in studies published in the 1980s to 34.4% in those published in 2010–2014. The proportion of hypertensives who were previously aware of their diagnosis, were on treatment or had their BP controlled was 19.6–84.0%, 0–79.2%, and 0–12.7%, respectively. Hypertensive subjects, including health workers, rarely checked their BP except when they were ill. Conclusions There is a high prevalence of hypertension among West Africa's workforce, of which a significant

The prevalence, awareness, and control of hypertension among workers in West Africa: a systematic review.

PubMed

Bosu, William K

2015-01-01

: Interventions in workplace settings are considered to be cost-effective in preventing cardiovascular diseases. A systematic review was conducted to assess the prevalence of hypertension and the level of awareness and control among workers in West Africa. A systematic search for studies on formal and informal sector workers aged ≥15 years in West Africa published between 1980 and September 2014 was undertaken using the Ovid Medline, Embase, PubMed, and Google Scholar databases. Clinical and obstetric studies and studies that did not report prevalence were excluded. Data on study settings, characteristics of workers, blood pressure (BP) levels, prevalence of hypertension, and associated demographic factors were extracted. A total of 45 studies from six countries were identified involving 30,727 formal and informal sector workers. In 40 studies with a common definition of hypertension, the prevalence ranged from 12.0% among automobile garage workers to 68.9% among traditional chiefs. In 15 of these studies, the prevalence exceeded 30%. Typically sedentary workers such as traders, bank workers, civil servants, and chiefs were at high risk. Among health care workers, the prevalence ranged from 17.5 to 37.5%. The prevalence increased with age and was higher among males and workers with higher socio-economic status. Complications of hypertension, co-morbidities, and clustering of risk factors were common. The crude prevalence of hypertension increased progressively from 12.9% in studies published in the 1980s to 34.4% in those published in 2010-2014. The proportion of hypertensives who were previously aware of their diagnosis, were on treatment or had their BP controlled was 19.6-84.0%, 0-79.2%, and 0-12.7%, respectively. Hypertensive subjects, including health workers, rarely checked their BP except when they were ill. There is a high prevalence of hypertension among West Africa's workforce, of which a significant proportion is undiagnosed, severe or complicated. The

Glory over clouds off West Africa

NASA Image and Video Library

2017-12-08

On April 23, 2013 NASA’s Terra satellite passed off the coast of West Africa, allowing the Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard to capture a curious phenomenon over the cloud deck below. The rainbow-like discoloration that can be seen streaking across the bank of marine cumulus clouds near the center of this image is known as a “glory”. A glory is caused by the scattering of sunlight by a cloud made of water droplets that are all roughly the same size, and is only produced when the light is just right. In order for a glory to be viewed, the observer’s anti-solar point must fall on the cloud deck below. In this case the observer is the Terra satellite, and the anti-solar point is where the sun is directly behind you – 180° from the MODIS line of sight. Water and ice particles in the cloud bend the light, breaking it into all its wavelengths, and the result is colorful flare, which may contain all of the colors of the rainbow. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

The Affect of Drug Trafficking in West Africa on the National Security Interests of the United States of America

DTIC Science & Technology

2015-06-12

officials at all levels in this criminal activity inhibits a complete assessment and resolution of the problem. Guinea-Bissau’s political systems remain......seizures in West Africa are currently less than the peak levels several years ago, it is assessed that the cocaine trafficking between South America and

External quality assessment study for ebolavirus PCR-diagnostic promotes international preparedness during the 2014 - 2016 Ebola outbreak in West Africa.

PubMed

Ellerbrok, Heinz; Jacobsen, Sonja; Patel, Pranav; Rieger, Toni; Eickmann, Markus; Becker, Stephan; Günther, Stephan; Naidoo, Dhamari; Schrick, Livia; Keeren, Kathrin; Targosz, Angelina; Teichmann, Anette; Formenty, Pierre; Niedrig, Matthias

2017-05-01

During the recent Ebola outbreak in West Africa several international mobile laboratories were deployed to the mainly affected countries Guinea, Sierra Leone and Liberia to provide ebolavirus diagnostic capacity. Additionally, imported cases and small outbreaks in other countries required global preparedness for Ebola diagnostics. Detection of viral RNA by reverse transcription polymerase chain reaction has proven effective for diagnosis of ebolavirus disease and several assays are available. However, reliability of these assays is largely unknown and requires serious evaluation. Therefore, a proficiency test panel of 11 samples was generated and distributed on a global scale. Panels were analyzed by 83 expert laboratories and 106 data sets were returned. From these 78 results were rated optimal and 3 acceptable, 25 indicated need for improvement. While performance of the laboratories deployed to West Africa was superior to the overall performance there was no significant difference between the different assays applied.

Enough Room for the Eagle and Dragon Chinese Resource Extraction and its Impact on U.S. on U.S Military Operations in West Africa

DTIC Science & Technology

2017-06-09

Africa, China was already firmly rooted with deep economic ties, and a plethora of trade deals to extract resources. Simultaneously, trans- national...In West Africa, China was already firmly rooted with deep economic ties, and a plethora of trade deals to extract resources. Simultaneously, trans...60 viii ACRONYMS CCDR Combatant Commander DoD Department of Defense ECOWAS Economic

Region-wide assessment of the capacity for human nutrition training in West Africa: current situation, challenges, and way forward.

PubMed

Sodjinou, Roger; Fanou, Nadia; Deart, Lucie; Tchibindat, Félicité; Baker, Shawn; Bosu, William; Pepping, Fré; Delisle, Hélène

2014-01-01

There is a dearth of information on existing nutrition training programs in West Africa. A preliminary step in the process of developing a comprehensive framework to strengthen human capacity for nutrition is to conduct an inventory of existing training programs. This study was conducted to provide baseline data on university-level nutrition training programs that exist in the 16 countries in West Africa. It also aimed to identify existing gaps in nutrition training and propose solutions to address them. Participating institutions were identified based on information provided by in-country key informants, UNICEF offices or through internet searches. Data were collected through semi-structured interviews during on-site visits or through self-administered questionnaires. Simple descriptive and bivariate analyses were performed. In total, 83 nutrition degree programs comprising 32 B.Sc. programs, 34 M.Sc. programs, and 17 Ph.D. programs were identified in the region. More than half of these programs were in Nigeria. Six countries (Cape Verde, Guinea-Bissau, Liberia, Mali, The Gambia, and Togo) offered no nutrition degree program. The programs in francophone countries were generally established more recently than those in anglophone countries (age: 3.5 years vs. 21.4 years). Programs were predominantly (78%) run by government-supported institutions. They did not provide a comprehensive coverage of all essential aspects of human nutrition. They were heavily oriented to food science (46%), with little emphasis on public health nutrition (24%) or overnutrition (2%). Annual student intakes per program in 2013 ranged from 3 to 262; 7 to 40; and 3 to 10, respectively, for bachelor's, master's, and doctoral programs while the number of graduates produced annually per country ranged from 6 to 271; 3 to 64; and 1 to 18, respectively. External collaboration only existed in 15% of the programs. In-service training programs on nutrition existed in less than half of the countries

Nitrogen emission and deposition budget in West and Central Africa

NASA Astrophysics Data System (ADS)

Galy-Lacaux, C.; Delon, C.

2014-12-01

Atmospheric nitrogen depends on land surface exchanges of nitrogen compounds. In Sub Saharan Africa, deposition and emission fluxes of nitrogen compounds are poorly quantified, and are likely to increase in the near future due to land use change and anthropogenic pressure. This work proposes an estimate of atmospheric N compounds budget in West and Central Africa, along an ecosystem transect, from dry savanna to wet savanna and forest, for years 2000-2007. The budget may be considered as a one point in time budget, to be included in long term studies as one of the first reference point for Sub Saharan Africa. Gaseous dry deposition fluxes are estimated by considering N compounds concentrations measured in the frame of the IDAF network (IGAC/DEBITS/AFrica) at the monthly scale and modeling of deposition velocities at the IDAF sites, taking into account the bi directional exchange of ammonia. Particulate dry deposition fluxes are calculated using the same inferential method. Wet deposition fluxes are calculated from measurements of ammonium and nitrate chemical content in precipitations at the IDAF sites combined with the annual rainfall amount. In terms of emission, biogenic NO emissions are simulated at each IDAF site with a surface model coupled to an emission module elaborated from an artificial neural network equation. Ammonia emissions from volatilization are calculated from literature data on livestock quantity in each country and N content in manure. NOx and NH3 emission from biomass burning and domestic fires are estimated from satellite data and emission factors. The total budget shows that emission sources of nitrogen compounds are in equilibrium with deposition fluxes in dry and wet savannas, with respectively 7.40 (±1.90) deposited and 9.01 (±3.44) kgN ha-1 yr-1 emitted in dry savanna, 8.38 (±2.04) kgN ha-1 yr-1 deposited and 9.60 (±0.69) kgN ha-1 yr-1 emitted in wet savanna. In forested ecosystems, the total budget is dominated by wet plus dry

Impact of long-range transport pollution on aerosol properties over West Africa: observations during the DACCIWA airborne campaign

NASA Astrophysics Data System (ADS)

Denjean, Cyrielle; Bourrianne, Thierry; Burnet, Frederic; Deroubaix, Adrien; Brito, Joel; Dupuy, Régis; Colomb, Aurélie; Schwarzenboeck, Alfons; Sellegri, Karine; Chazette, Patrick; Duplissy, Jonathan; Flamant, Cyrille

2017-04-01

Southern West Africa (SWA) is a region highly vulnerable to climate change. Emissions of anthropogenic pollution have increased substantially over the past decades in the region and are projected to keep increasing. The region is also strongly impacted by important natural pollution from distant locations. Biomass burning mainly from vegetation fires in Central Africa and mineral dust from the Saharan and Sahel-Sudan regions are advected by winds to the SWA region especially in summer. Both biomass burning and mineral dust aerosols scatter and absorb solar radiation and are able to significantly modify the regional radiative budget. Presently, the potential radiative impact of dust and biomass burning particles on SWA is unclear due to inadequate data information on the aerosols properties and vertical distribution. In the framework of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, an unprecedented field campaign took place in summer 2016 in West Africa. The ATR-42 research aircraft operated by SAFIRE performed twenty flights to sample the local air pollution from maritime traffic and coastal megacities, as well as regional pollution from biomass burning and desert dust. The aircraft was equipped with state of the art in situ instrumentation to measure the aerosol optical properties (CAPS, nephelometer, PSAP), the aerosol size distribution (SMPS, GRIMM, USHAS, PCASP, FSSP) and the aerosol chemical composition (SP2, AMS). A mini backscattered lidar system provided additional measurements of the aerosol vertical structure and the aerosol optical properties such as the particulate depolarization ratio. The CHIMERE chemistry and transport model has been used to characterize the source area and the long-range transport of dust and biomass burning plumes. Here, we investigate the aerosol microphysical, chemical and optical properties of biomass burning and dust aerosols transported in SWA. In particular the following questions will be

Perspectives on West Africa Ebola Virus Disease Outbreak, 2013-2016

DOE PAGES

Spengler, Jessica R.; Ervin, Elizabeth D.; Towner, Jonathan S.; ...

2016-06-01

The variety of factors that contributed to the initial undetected spread of Ebola virus disease in West Africa during 2013-2016 and the difficulty controlling the outbreak once the etiology was identified highlight priorities for disease prevention, detection, and response. These factors include occurrence in a region recovering from civil instability and lacking experience with Ebola response; inadequate surveillance, recognition of suspected cases, and Ebola diagnosis; mobile populations and extensive urban transmission; and the community's insufficient general understanding about the disease. The magnitude of the outbreak was not attributable to a substantial change of the virus. Finally, continued efforts during themore » outbreak and in preparation for future outbreak response should involve identifying the reservoir, improving in-country detection and response capacity, conducting survivor studies and supporting survivors, engaging in culturally appropriate public education and risk communication, building productive interagency relationships, and continuing support for basic research.« less

Perspectives on West Africa Ebola Virus Disease Outbreak, 2013-2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spengler, Jessica R.; Ervin, Elizabeth D.; Towner, Jonathan S.

The variety of factors that contributed to the initial undetected spread of Ebola virus disease in West Africa during 2013-2016 and the difficulty controlling the outbreak once the etiology was identified highlight priorities for disease prevention, detection, and response. These factors include occurrence in a region recovering from civil instability and lacking experience with Ebola response; inadequate surveillance, recognition of suspected cases, and Ebola diagnosis; mobile populations and extensive urban transmission; and the community's insufficient general understanding about the disease. The magnitude of the outbreak was not attributable to a substantial change of the virus. Finally, continued efforts during themore » outbreak and in preparation for future outbreak response should involve identifying the reservoir, improving in-country detection and response capacity, conducting survivor studies and supporting survivors, engaging in culturally appropriate public education and risk communication, building productive interagency relationships, and continuing support for basic research.« less

Perspectives on West Africa Ebola Virus Disease Outbreak, 2013-2016.

PubMed

Spengler, Jessica R; Ervin, Elizabeth D; Towner, Jonathan S; Rollin, Pierre E; Nichol, Stuart T

2016-06-01

The variety of factors that contributed to the initial undetected spread of Ebola virus disease in West Africa during 2013-2016 and the difficulty controlling the outbreak once the etiology was identified highlight priorities for disease prevention, detection, and response. These factors include occurrence in a region recovering from civil instability and lacking experience with Ebola response; inadequate surveillance, recognition of suspected cases, and Ebola diagnosis; mobile populations and extensive urban transmission; and the community's insufficient general understanding about the disease. The magnitude of the outbreak was not attributable to a substantial change of the virus. Continued efforts during the outbreak and in preparation for future outbreak response should involve identifying the reservoir, improving in-country detection and response capacity, conducting survivor studies and supporting survivors, engaging in culturally appropriate public education and risk communication, building productive interagency relationships, and continuing support for basic research.

Identifying the pattern of molecular evolution for Zaire ebolavirus in the 2014 outbreak in West Africa.

PubMed

Liu, Si-Qing; Deng, Cheng-Lin; Yuan, Zhi-Ming; Rayner, Simon; Zhang, Bo

2015-06-01

The current Ebola virus disease (EVD) epidemic has killed more than all previous Ebola outbreaks combined and, even as efforts appear to be bringing the outbreak under control, the threat of reemergence remains. The availability of new whole-genome sequences from West Africa in 2014 outbreak, together with those from the earlier outbreaks, provide an opportunity to investigate the genetic characteristics, the epidemiological dynamics and the evolutionary history for Zaire ebolavirus (ZEBOV). To investigate the evolutionary properties of ZEBOV in this outbreak, we examined amino acid mutations, positive selection, and evolutionary rates on the basis of 123 ZEBOV genome sequences. The estimated phylogenetic relationships within ZEBOV revealed that viral sequences from the same period or location formed a distinct cluster. The West Africa viruses probably derived from Middle Africa, consistent with results from previous studies. Analysis of the seven protein regions of ZEBOV revealed evidence of positive selection acting on the GP and L genes. Interestingly, all putatively positive-selected sites identified in the GP are located within the mucin-like domain of the solved structure of the protein, suggesting a possible role in the immune evasion properties of ZEBOV. Compared with earlier outbreaks, the evolutionary rate of GP gene was estimated to significantly accelerate in the 2014 outbreak, suggesting that more ZEBOV variants are generated for human to human transmission during this sweeping epidemic. However, a more balanced sample set and next generation sequencing datasets would help achieve a clearer understanding at the genetic level of how the virus is evolving and adapting to new conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

The landscapes of West Africa—40 years of change

USGS Publications Warehouse

Cotillon, Suzanne E.

2017-02-16

What has driven changes in land use and land cover in West Africa over the past 40 years? What trends or patterns can be discerned in those changes? To answer these questions, the U.S. Geological Survey West Africa Land Use Dynamics project partnered with the Permanent Interstate Committee for Drought Control in the Sahel and the U.S. Agency for International Development/West Africa to map land use and land cover across the region for  three time periods (years): 1975, 2000, and 2013. This cooperative effort has resulted in the publication of a 219-page atlas, “Landscapes of West Africa: A Window on a Changing World.” The atlas uses satellite imagery, maps, and pictures to tell a complex story of landscape change at regional and national scales. It includes a collection of focused studies, some of which raise cause for concern, and others that provide considerable hope.

Multilingual Validation of the Questionnaire for Verifying Stroke-Free Status in West Africa

PubMed Central

Sarfo, Fred; Gebregziabher, Mulugeta; Ovbiagele, Bruce; Akinyemi, Rufus; Owolabi, Lukman; Obiako, Reginald; Akpa, Onoja; Armstrong, Kevin; Akpalu, Albert; Adamu, Sheila; Obese, Vida; Boa-Antwi, Nana; Appiah, Lambert; Arulogun, Oyedunni; Mensah, Yaw; Adeoye, Abiodun; Tosin, Aridegbe; Adeleye, Osimhiarherhuo; Tabi-Ajayi, Eric; Phillip, Ibinaiye; Sani, Abubakar; Isah, Suleiman; Tabari, Nasir; Mande, Aliyu; Agunloye, Atinuke; Ogbole, Godwin; Akinyemi, Joshua; Laryea, Ruth; Melikam, Sylvia; Uvere, Ezinne; Adekunle, Gregory; Kehinde, Salaam; Azuh, Paschal; Dambatta, Abdul; Ishaq, Naser; Saulson, Raelle; Arnett, Donna; Tiwari, Hemnant; Jenkins, Carolyn; Lackland, Dan; Owolabi, Mayowa

2015-01-01

Background and Purpose The Questionnaire for Verifying Stroke-free Status (QVSFS), a method for verifying stroke-free status in participants of clinical, epidemiological and genetic studies, has not been validated in low-income settings where populations have limited knowledge of stroke symptoms. We aimed to validate QVSFS in 3 languages-Yoruba, Hausa and Akan- for ascertainment of stroke-free status of control subjects enrolled in an ongoing stroke epidemiological study in West Africa. Methods Data were collected using a cross-sectional study design where 384 participants were consecutively recruited from neurology and general medicine clinics of 5 tertiary referral hospitals in Nigeria and Ghana. Ascertainment of stroke status was by neurologists using structured neurological examination, review of case records and neuro-imaging (Gold standard). Relative performance of QVSFS without and with pictures of stroke symptoms (pictograms) was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results The overall median age of the study participants was 54 years and 48.4% were males. Of 165 stroke cases identified by Gold standard, 98% were determined to have had stroke while of 219 without stroke 87% were determined to be stroke-free by QVSFS. NPV of the QVSFS across the 3 languages was 0.97 (range, 0.93 – 1.00), sensitivity, specificity and PPV were 0.98, 0.82 and 0.80 respectively. Agreement between the questionnaire with and without the pictogram was excellent/strong with Cohen’s k=0.92. Conclusions QVSFS is a valid tool for verifying stroke-free status across culturally diverse populations in West Africa. PMID:26578660

STS-65 Earth observation of Lake Chad, Africa, taken aboard Columbia, OV-102

NASA Technical Reports Server (NTRS)

1994-01-01

STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, shows Lake Chad, Africa. This is another long term ecological monitoring site for NASA scientists. Lake Chad was first photographed from space in 1965. A 25-year length-of-record data set exists for this environmentally important area. A number of these scenes have been digitized, rectified, classified and results show that the lake area has been shrinking and only 15% to 20% of the surface water is visible on space images. NASA's objective in monitoring this lake is to document the intra- and interannual areal changes of the largest standing water body in the Sahelian biome of North Africa. These areal changes are an indicator of the presence or absence of drought across the arguably overpopulated, overgrazed, and over biological carrying capacity limits nations of the Sahel.

The development and state of health and safety in the workplace in west Africa: perspectives from Nigeria.

PubMed

Asuzu, M C

1996-01-01

Occupational health practice originated in Europe following the systematic work of Bernadino Ramazzini in Italy at the turn of the 17th century. It grew mostly under the notion of Industrial health, concentrating on the chemical, mechanical and social conditions of labourers as well as the work of the arts and trades, until the work of Charles Turner Thackrah in Britain broadened its understanding to include the professions and certain civic ways of living. In West Africa, as in most of the developing world, occupational health and safety practice came to us mostly as side products of the colonial company health work, in their attempt to fulfil the requirements of their national health laws to their citizens here. The first organised effort to boost occupational health and practice for the Africans among the Africans, and involving mainly Africans, came in the 1960s with the first African Conference on Occupational health in Africa in Lagos in 1968. This process has gone on now, albeit rather slowly, until the citing of a Chair of Occupational health at the University of Ibadan by the Society of Occupational Health Physicians of Nigeria in the 1992/93 academic year. The health and safety in industries in Nigeria have however not been in anyway adequate from studies in that area, especially among the indigenous small and medium sized companies. This paper reviews these developments and proposes some suggestions on how to improve on the speed and accuracy of these developments, specifically in Nigeria; and by extrapolation, for the West Africa sub-region as well.

Characterization of the impact of land degradation in the Sahel on the West African monsoon using an ensemble of climate models from the WAMME project

NASA Astrophysics Data System (ADS)

Boone, A. A.; Xue, Y.; Ruth, C.; De Sales, F.; Hagos, S.; Mahanama, S. P. P.; Schiro, K.; Song, G.; Wang, G.; Koster, R. D.; Mechoso, C. R.

2014-12-01

There is increasing evidence from numerical studies that anthropogenic land-use and land-cover changes (LULCC) can potentially induce significant variations on the regional scale climate. However, the magnitude of these variations likely depends on the local strength of the coupling between the surface and the atmosphere, the magnitude of the surface biophysical changes and how the key processes linking the surface with the atmosphere are parameterized within a particular model framework. One key hot-spot which has received considerable attention is the Sahelian region of West Africa, for which numerous studies have reported a significant increase in anthropogenic pressure on the already limited natural resources in this region, notably in terms of land use conversion and degradation. Thus, there is a pressing need to better understand the impacts of potential land degradation on the West African Monsoon (WAM) system. One of the main goals of the West African Monsoon Modeling andEvaluation project phase 2 (WAMMEII) is to provide basic understandingof LULCC on the regional climate over West Africa, and to evaluate thesensitivity of the seasonal variability of the WAM to LULCC. Theprescribed LULCC is based on recent 50 year period which represents amaximum feasible degradation scenario. In the current study, the LULCCis applied to five state of the art global climate models over afive-year period. The imposed LULCC results in a model-average 5-7%increase in surface albedo: the corresponding lower surface netradiation mainly results in a significant reduction in surfaceevaporation (upwards of 1 mm per day over a large part of the Sahel)which leads to less convective heating of the atmosphere, lowermoisture convergence, increased subsidence and reduced cloud coverover the LULCC zone. The overall impact can be characterized as asubstantial drought effect resulting in a reduction in annual rainfallof 20-40% in the Sahel and a southward shift of the monsoon. In

The mineralogy of global magnetic anomalies. [rock magnetic signatures and MAGSAT geological, and gravity correlations in West Africa

NASA Technical Reports Server (NTRS)

Haggerty, S. E. (Principal Investigator)

1982-01-01

Problems with the Curie balance, which severely hindered the acquisition of data, were rectified. Chemical analytical activities are proceeding satisfactorily. The magnetization characteristics of metamorphic suites were analyzed and susceptibility data for a wide range of metamorphic and igneous rocks. These rock magnetic signatures are discussed as well as the relationships between geology, gravity and MAGSAT anomalies of West Africa.

External quality assessment study for ebolavirus PCR-diagnostic promotes international preparedness during the 2014 – 2016 Ebola outbreak in West Africa

PubMed Central

Jacobsen, Sonja; Patel, Pranav; Rieger, Toni; Eickmann, Markus; Becker, Stephan; Günther, Stephan; Naidoo, Dhamari; Schrick, Livia; Keeren, Kathrin; Targosz, Angelina; Teichmann, Anette; Formenty, Pierre; Niedrig, Matthias

2017-01-01

During the recent Ebola outbreak in West Africa several international mobile laboratories were deployed to the mainly affected countries Guinea, Sierra Leone and Liberia to provide ebolavirus diagnostic capacity. Additionally, imported cases and small outbreaks in other countries required global preparedness for Ebola diagnostics. Detection of viral RNA by reverse transcription polymerase chain reaction has proven effective for diagnosis of ebolavirus disease and several assays are available. However, reliability of these assays is largely unknown and requires serious evaluation. Therefore, a proficiency test panel of 11 samples was generated and distributed on a global scale. Panels were analyzed by 83 expert laboratories and 106 data sets were returned. From these 78 results were rated optimal and 3 acceptable, 25 indicated need for improvement. While performance of the laboratories deployed to West Africa was superior to the overall performance there was no significant difference between the different assays applied. PMID:28459810

Conservation of soil organic carbon, biodiversity and the provision of other ecosystem services along climatic gradients in West Africa

NASA Astrophysics Data System (ADS)

Marks, E.; Aflakpui, G. K. S.; Nkem, J.; Poch, R. M.; Khouma, M.; Kokou, K.; Sagoe, R.; Sebastiã, M.-T.

2009-08-01

Terrestrial carbon resources are major drivers of development in West Africa. The distribution of these resources co-varies with ecosystem type and rainfall along a strong Northeast-Southwest climatic gradient. Soil organic carbon, a strong indicator of soil quality, has been severely depleted in some areas by human activities, which leads to issues of soil erosion and desertification, but this trend can be altered with appropriate management. There is significant potential to enhance existing soil carbon stores in West Africa, with benefits at the global and local scale, for atmospheric CO2 mitigation as well as supporting and provisioning ecosystem services. Three key factors impacting carbon stocks are addressed in this review: climate, biotic factors, and human activities. Climate risks must be considered in a framework of global change, especially in West Africa, where landscape managers have few resources available to adapt to climatic perturbations. Among biotic factors, biodiversity conservation paired with carbon conservation may provide a pathway to sustainable development, and biodiversity conservation is also a global priority with local benefits for ecosystem resilience, biomass productivity, and provisioning services such as foodstuffs. Finally, human management has largely been responsible for reduced carbon stocks, but this trend can be reversed through the implementation of appropriate carbon conservation strategies in the agricultural sector, as shown by multiple studies. Owing to the strong regional climatic gradient, country-level initiatives will need to consider carbon sequestration approaches for multiple ecosystem types. Given the diversity of environments, global policies must be adapted and strategies developed at the national or sub-national levels to improve carbon storage above and belowground. Initiatives of this sort must act locally at farmer scale, and focus on ecosystem services rather than on carbon sequestration solely.

Conservation of soil organic carbon, biodiversity and the provision of other ecosystem services along climatic gradients in West Africa

NASA Astrophysics Data System (ADS)

Marks, E.; Aflakpui, G. K. S.; Nkem, J.; Poch, R. M.; Khouma, M.; Kokou, K.; Sagoe, R.; Sebastiã, M.-T.

2008-11-01

Terrestrial carbon resources are major drivers of development in West Africa. The distribution of these resources co-varies with ecosystem type and rainfall along a strong Northeast-Southwest climatic gradient. Soil organic carbon, a strong indicator of soil quality, has been severely depleted in some areas by human activities, which leads to issues of soil erosion and desertification, but this trend can be altered via appropriate management. There is significant potential to enhance existing soil carbon stores in West Africa, with benefits at the global and local scales, for atmospheric CO2 mitigation and supporting, and provisioning ecosystem services, respectively. Three key factors impacting carbon stocks are addressed in this review: climate, biotic factors, and human activities. Climate risks must be considered in a framework of global change, especially in West Africa, where landscape managers have few resources available to adapt to climatic perturbations. Among biotic factors, biodiversity conservation paired with carbon conservation may provide a pathway to sustainable development, as evidence suggests that both may be inter-linked, and biodiversity conservation is also a global priority with local benefits for ecosystem resilience, biomass productivity, and provisioning services such as foodstuffs. Finally, human management has largely been responsible for reduced carbon stocks, but this trend can be reversed through the implementation of appropriate carbon conservation strategies in the agricultural sector, as shown by multiple studies. Owing to the strong regional climatic gradient, country-level initiatives will need to consider carbon sequestration approaches for multiple ecosystem types. Given the diversity of environments, global policies must be adapted and strategised at the national or sub-national levels to improve C storage above and belowground. Initiatives of this sort must act locally at farmer scale, and focus on ecosystem services rather

Strategy and technology to prevent hospital-acquired infections: Lessons from SARS, Ebola, and MERS in Asia and West Africa.

PubMed

Rajakaruna, Sanjeewa Jayachandra; Liu, Wen-Bin; Ding, Yi-Bo; Cao, Guang-Wen

2017-10-27

Hospital-acquired infections (HAIs) are serious problems for healthcare systems, especially in developing countries where public health infrastructure and technology for infection preventions remain undeveloped. Here, we characterized how strategy and technology could be mobilized to improve the effectiveness of infection prevention and control in hospitals during the outbreaks of Ebola, Middle East respiratory syndrome (MERS), and severe acute respiratory syndrome (SARS) in Asia and West Africa. Published literature on the hospital-borne outbreaks of SARS, Ebola, and MERS in Asia and West Africa was comprehensively reviewed. The results showed that healthcare systems and hospital management in affected healthcare facilities had poor strategies and inadequate technologies and human resources for the prevention and control of HAIs, which led to increased morbidity, mortality, and unnecessary costs. We recommend that governments worldwide enforce disaster risk management, even when no outbreaks are imminent. Quarantine and ventilation functions should be taken into consideration in architectural design of hospitals and healthcare facilities. We also recommend that health authorities invest in training healthcare workers for disease outbreak response, as their preparedness is essential to reducing disaster risk.

Experiences and Psychosocial Impact of West Africa Ebola Deployment on US Health Care Volunteers

PubMed Central

Gershon, Robyn; Dernehl, Liza A.; Nwankwo, Ezinne; Zhi, Qi; Qureshi, Kristine

2016-01-01

Background: This qualitative study was designed to assess health care volunteers’ experiences and psychosocial impacts associated with deployment to the West Africa Ebola epidemic. Methods: In 2015, using snowball sampling, 16 US health care volunteers who had recently returned from West Africa were recruited for this study. Semi-structured interviews were conducted to collect information associated with each phase of deployment (pre, peri, and post). Results: Participants reported that they were motivated to volunteer because of a sense of responsibility and feelings of empathy and altruism. Immediately prior to deployment, most reported fear of contagion and death, as well as doubts regarding the adequacy of their training. Family members and close friends expressed high levels of concern regarding participants’ decisions to volunteer. During the deployment, participants were fearful of exposure and reported feeling emotionally and physically exhausted. They also reported feeling frustrated by extreme resource limitations, poor management of the mission, lack of clearly defined roles and responsibilities, and inability to provide high quality care. Upon return home, participants felt a sense of isolation, depression, stigmatization, interpersonal difficulties, and extreme stress. Conclusion: Preparedness of volunteers was suboptimal at each stage of deployment. All stakeholders, including volunteers, sponsoring organizations, government agencies, and professional organizations have a shared responsibility in ensuring that volunteers to medical missions are adequately prepared. This is especially critical for high risk deployments. Effective policies and practices need to be developed and implemented in order to protect the health and well-being of health care volunteers to the fullest extent possible. PMID:27803840

South Africa

NASA Technical Reports Server (NTRS)

2002-01-01

This true-color image of South Africa was acquired on May 14, 2000, by NASA's Moderate-resolution Imaging Spectroradiometer, or MODIS. The image was produced using a combination of the sensor's 250-m and 500-m resolution visible wavelength bands. As part of the opening ceremony to begin the joint U.S.-South Africa SAFARI Field Experiment, NASA presented print copies of this image as GIFts to Dr. Ben Ngubane, Minister of Arts, Science and Technology, and Honorable Advocate Ngoaka Ramathlodi, Premier of the Northern Province, South Africa. The area shown in this image encompasses seven capital cities and a number of the region's distinctive geological features can be seen clearly. Toward the northern (top) central part of the image, the browns and tans comprise the Kalahari Desert of southern Botswana. The Tropic of Capricorn runs right through the heart of the Kalahari and the Botswanan capital city of Gaborone sits on the Limpopo River, southeast of the Kalahari. Along the western coastline of the continent is the country of Namibia, where the Namib Desert is framed against the sea by the Kaokoveld Mountains. The Namibian capital of Windhoek is obscured by clouds. Looking closely in the center of the image, the Orange River can be seen running from east to west, demarcating the boundary between Namibia and South Africa. On the southwestern corner of the continent is the hook-like Cape of Good Hope peninsula and Cape Town, the parliamentary capital of South Africa. Running west to east away from Cape Town are the Great Karroo Mountains. The shadow in this image conveys a sense of the very steep grade of the cliffs along the southern coast of South Africa. Port Elizabeth sits on the southeasternmost point of South Africa, and a large phytoplankton bloom can be seen in the water about 100 miles east of there. Moving northward along the east coast, the Drakensberg Mountains are visible. The two small nations of Lesotho and Swaziland are in this region, completely

Training of School Teachers in West Africa: Remediation of Reading Difficulties through Training in Phonological Awareness and Letter Names

ERIC Educational Resources Information Center

Briquet-Duhazé, Sophie

2014-01-01

The training of teachers of West Africa is carried out by the Academy of Rouen (France) and organized around an annual training plan approved by the AEFE. Each trainer only supervises twenty teachers for 5 days. Teachers from eight countries (Mauritania, Cape Verde, Senegal, Gambia, Mali, Guinea, Côte d'Ivoire and Burkina Faso), come to Dakar for…

Strengthened Ebola surveillance in France during a major outbreak in West Africa: March 2014-January 2016.

PubMed

Mailles, A; Noel, H; Pannetier, D; Rapp, C; Yazdanpanah, Y; Vandentorren, S; Chaud, P; Philippe, J M; Worms, B; Bruyand, M; Tourdjman, M; Nahon, M; Belchior, E; Lucas, E; Durand, J; Zurbaran, M; Vaux, S; Coignard, B; DE Valk, H; Baize, S; Quelet, S; Bourdillon, F

2017-12-01

Introduction An unprecedented outbreak of Ebola virus diseases (EVD) occurred in West Africa from March 2014 to January 2016. The French Institute for Public Health implemented strengthened surveillance to early identify any imported case and avoid secondary cases. Febrile travellers returning from an affected country had to report to the national emergency healthcare hotline. Patients reporting at-risk exposures and fever during the 21st following day from the last at-risk exposure were defined as possible cases, hospitalised in isolation and tested by real-time polymerase chain reaction. Asymptomatic travellers reporting at-risk exposures were considered as contact and included in a follow-up protocol until the 21st day after the last at-risk exposure. From March 2014 to January 2016, 1087 patients were notified: 1053 were immediately excluded because they did not match the notification criteria or did not have at-risk exposures; 34 possible cases were tested and excluded following a reliable negative result. Two confirmed cases diagnosed in West Africa were evacuated to France under stringent isolation conditions. Patients returning from Guinea (n = 531; 49%) and Mali (n = 113; 10%) accounted for the highest number of notifications. No imported case of EVD was detected in France. We are confident that our surveillance system was able to classify patients properly during the outbreak period.

Changes in Intense Precipitation Events in West Africa and the central U.S. under Global Warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, Kerry H.; Vizy, Edward

The purpose of the proposed project is to improve our understanding of the physical processes and large-scale connectivity of changes in intense precipitation events (high rainfall rates) under global warming in West Africa and the central U.S., including relationships with low-frequency modes of variability. This is in response to the requested subject area #2 “simulation of climate extremes under a changing climate … to better quantify the frequency, duration, and intensity of extreme events under climate change and elucidate the role of low frequency climate variability in modulating extremes.” We will use a regional climate model and emphasize an understandingmore » of the physical processes that lead to an intensification of rainfall. The project objectives are as follows: 1. Understand the processes responsible for simulated changes in warm-season rainfall intensity and frequency over West Africa and the Central U.S. associated with greenhouse gas-induced global warming 2. Understand the relationship between changes in warm-season rainfall intensity and frequency, which generally occur on regional space scales, and the larger-scale global warming signal by considering modifications of low-frequency modes of variability. 3. Relate changes simulated on regional space scales to global-scale theories of how and why atmospheric moisture levels and rainfall should change as climate warms.« less

Development of reference transcriptomes for the major insect pests of cowpea: a toolbox for insect pest management approaches in West Africa

USDA-ARS?s Scientific Manuscript database

Cowpea crops are widely cultivated and a major nutritional source of protein for indigenous human populations in West Africa. Annual yields and longevity of grain storage is greatly reduced by feeding damage caused by a complex of insect pests that include Anoplocnemis curvipes, Aphis craccivora, Cl...

U.S. Counterterrorism in Sub-Saharan Africa: Understanding Costs, Cultures, and Conflicts

DTIC Science & Technology

2008-09-01

counterterrorism in SSA. Vast and diverse, SSA is divided subregionally into East, West, and Southern Africa so as to highlight the different ...divided into East, West, and Southern Africa subregions so as to highlight the different geographies, histories, threats, and perceptions. Section...subregional approach. It divides SSA into East, West, and Southern Africa to highlight the different geogra- phies, histories, threats, and perceptions

Why has the Ebola outbreak in West Africa been so challenging to control?

PubMed Central

Semalulu, T; Wong, G; Kobinger, G; Huston, P

2014-01-01

West Africa is in the midst of the largest Ebola outbreak ever; there have been over 1000 deaths and many new cases are reported each day. The World Health Organization (WHO) declared it an outbreak in March 2014 and on August 6, 2014 the WHO declared the outbreak a public health emergency of international concern. Based on the number of deaths and total number of cases reported to the WHO as of August 11, 2014, the current outbreak has an overall mortality rate of 55%. Outbreak control measures against Ebola virus disease are effective. Why then, has this outbreak been so challenging to control? Ebola is transmitted through bodily fluids and immediately attacks the immune system, then progressively attacks the major organs and the lining of blood vessels. Sierra Leone, Guinea and Liberia are small countries that have limited resources to respond to prolonged outbreaks, especially in rural areas. This has been made more challenging by the fact that health care workers are at risk of contracting Ebola virus disease. Treatment to date has been supportive, not curative and outbreak control strategies have been met with distrust due to fear and misinformation. However, important progress is being made. The international response to Ebola is gaining momentum, communication strategies have been developed to address the fear and mistrust, and promising treatments are under development, including a combination of three monoclonal antibodies that has been administered to two American Ebola infected health care workers. The National Microbiology Laboratory of the Public Health Agency of Canada (PHAC) has been supporting laboratory diagnostic efforts in West Africa and PHAC has been working with the provinces and territories and key stakeholders to ensure Canada is prepared for a potential Ebola importation. PMID:29769855

Why has the Ebola outbreak in West Africa been so challenging to control?

PubMed

Semalulu, T; Wong, G; Kobinger, G; Huston, P

2014-08-14

West Africa is in the midst of the largest Ebola outbreak ever; there have been over 1000 deaths and many new cases are reported each day. The World Health Organization (WHO) declared it an outbreak in March 2014 and on August 6, 2014 the WHO declared the outbreak a public health emergency of international concern. Based on the number of deaths and total number of cases reported to the WHO as of August 11, 2014, the current outbreak has an overall mortality rate of 55%. Outbreak control measures against Ebola virus disease are effective. Why then, has this outbreak been so challenging to control? Ebola is transmitted through bodily fluids and immediately attacks the immune system, then progressively attacks the major organs and the lining of blood vessels. Sierra Leone, Guinea and Liberia are small countries that have limited resources to respond to prolonged outbreaks, especially in rural areas. This has been made more challenging by the fact that health care workers are at risk of contracting Ebola virus disease. Treatment to date has been supportive, not curative and outbreak control strategies have been met with distrust due to fear and misinformation. However, important progress is being made. The international response to Ebola is gaining momentum, communication strategies have been developed to address the fear and mistrust, and promising treatments are under development, including a combination of three monoclonal antibodies that has been administered to two American Ebola infected health care workers. The National Microbiology Laboratory of the Public Health Agency of Canada (PHAC) has been supporting laboratory diagnostic efforts in West Africa and PHAC has been working with the provinces and territories and key stakeholders to ensure Canada is prepared for a potential Ebola importation.

High number of diarrhoeal co-infections in travellers to Benin, West Africa.

PubMed

Lääveri, Tinja; Pakkanen, Sari H; Antikainen, Jenni; Riutta, Jukka; Mero, Sointu; Kirveskari, Juha; Kantele, Anu

2014-02-12

Travellers' diarrhoea (TD) is the most frequent health problem among travellers to the tropics. Using routine techniques, the aetiology mostly remains unresolved, whereas modern molecular methods enable reducing the number of equivocal cases considerably. While many studies address the aetiology of TD in Asian, Central American and North African tourist resorts, only few focus on Western Africa. Stool samples from 45 travellers travelling in Benin, West Africa, were analyzed by a new multiplex qPCR assay for Salmonella, Yersinia, Campylobacter, Vibrio cholerae, Shigella or enteroinvasive (EIEC), enterohaemorrhagic (EHEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), and enteropathogenic Escherichia coli (EPEC). All 18 pre-travel samples proved negative for bacterial pathogens. Of the 39/45 (87%) travellers having had TD, EPEC was detected in post-travel samples in 30 (77%) cases, EAEC in 23 (59%), ETEC in 22 (56%), Shigella or EIEC in 7 (18%), EHEC in two (5%), and Salmonella in one (3%). In 31(79%) of the TD cases two or more bacterial pathogens were identified. Two (8%) samples remained negative: both patients had taken antimicrobials for TD. EPEC, EAEC and ETEC were the most common findings. 79% of the cases had a co-infection. As modern diagnostics reveals in most patients a multitude of pathogens, the role of each pathogen should be re-evaluated.

Quantitative targets in DND and ICPD-PA: the prospects for West Africa.

PubMed

1999-01-01

This article presents an overview of the population estimates and projections of the UN for total fertility rates (TFRs), contraceptive prevalence rates, infant mortality rates (IMRs), and life expectancy at birth (LEAB) in West Africa. Countries with a good potential to reach a TFR of 4 children or less within 10-15 years are Cote d'Ivoire, Ghana, Nigeria, and perhaps Gambia and Guinea, while the TFRs of countries such as Niger and Mali will remain above 5 in the coming decade. Low contraceptive prevalence is one of the reasons behind the slow progress in attaining low fertility levels in the subregion. When basing the data on this indicator, it appears that only Ghana and Cape Verde will attain the target of 20% by the year 2000 and 40% by the year 2010. Moreover, IMRs will continue to decline, but none of the West African countries will reach the quantitative objectives set in the Dakar/Ngor Declaration (DND) and in the International Conference on Population and Development Programme of Action (ICPD-PA). Similarly, considerable improvements will be seen in the LEAB during the next decade, but, with the exception of Cape Verde and Ghana, none of the other countries are expected to come close to the goals set in the DND and ICPD-PA.

Morphological and molecular identification of Rhipicephalus (Boophilus) microplus in Nigeria, West Africa: a threat to livestock health.

PubMed

Kamani, J; Apanaskevich, D A; Gutiérrez, R; Nachum-Biala, Y; Baneth, G; Harrus, S

2017-10-01

The cattle tick Rhipicephalus (Boophilus) microplus was first reported in West Africa in Ivory Coast, in 2007. Since then it has made an aggressive eastward advancement having been reported in four other West African countries: Mali, Burkina Faso, Togo and Benin. We herein report the first molecular identification of this tick species in Nigeria, West Africa, and highlight the threat it poses to livestock health. A nation-wide tick survey was conducted in 12 out of 36 states across the various agro ecological zones of Nigeria over a 1 year period (April 2014-March 2015). In total 1498 ticks belonging to three genera collected from cattle were morphologically identified. Overall, Amblyomma species constituted the highest percentage of sampled ticks, 50.2% (752/1498), followed by Rhipicephalus (including the subgenus Boophilus) species, 29.4% (440/1498) and Hyalomma species, 20.4% (306/1498). The presence of Rh. (B.) microplus was identified morphologically from four out of the 12 states. This finding was confirmed for the first time in Nigeria using a molecular method targeting the ITS-2 region of the ticks in three of the 12 states. This study ascertained the presence of Rh. (B.) microplus in Nigeria in addition to a broad variety of cattle tick species, most of which are of veterinary importance. The implication of this finding is that there may be additional economic burden to livestock farmers due to increased cost of tick control occasioned by the acaricide resistance by this tick species widely reported from different climes. Additionally, there may be a potential upsurge in incidence of hemoparasitic infections in cattle leading to increased morbidity, cost of treatment and mortalities.

Atlas international de la vitalite linguistique. Volume 3: L'Afrique Occidentale = International Atlas of Language Vitality. Volume 3: West Africa.

ERIC Educational Resources Information Center

McConnell, Grant D., Ed.; Gendron, Jean-Denis, Ed.

The third volume in a series of atlases of language vitality covers 13 countries of West Africa (Benin, Burkina Faso, Ivory Coast, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Senegal, Sierra Leone, Togo) and 59 major languages. The atlas consists of four main parts. The first offers comparative data, in bar graph and tabular…

Climate variability and environmental stress in the Sudan-Sahel zone of West Africa.

PubMed

Mertz, Ole; D'haen, Sarah; Maiga, Abdou; Moussa, Ibrahim Bouzou; Barbier, Bruno; Diouf, Awa; Diallo, Drissa; Da, Evariste Dapola; Dabi, Daniel

2012-06-01

Environmental change in the Sudan-Sahel region of West Africa (SSWA) has been much debated since the droughts of the 1970s. In this article we assess climate variability and environmental stress in the region. Households in Senegal, Mali, Burkina Faso, Niger, and Nigeria were asked about climatic changes and their perceptions were compared across north-south and west-east rainfall gradients. More than 80% of all households found that rainfall had decreased, especially in the wettest areas. Increases in wind speeds and temperature were perceived by an overall 60-80% of households. Contrary to household perceptions, observed rainfall patterns showed an increasing trend over the past 20 years. However, August rainfall declined, and could therefore potentially explain the contrasting negative household perceptions of rainfall trends. Most households reported degradation of soils, water resources, vegetation, and fauna, but more so in the 500-900 mm zones. Adaptation measures to counter environmental degradation included use of manure, reforestation, soil and water conservation, and protection of fauna and vegetation. The results raise concerns for future environmental management in the region, especially in the 500-900 mm zones and the western part of SSWA.

Ebola viral disease outbreak--West Africa, 2014.

PubMed

Dixon, Meredith G; Schafer, Ilana J

2014-06-27

On March 21, 2014, the Guinea Ministry of Health reported the outbreak of an illness characterized by fever, severe diarrhea, vomiting, and a high case-fatality rate (59%) among 49 persons. Specimens from 15 of 20 persons tested at Institut Pasteur in Lyon, France, were positive for an Ebola virus by polymerase chain reaction. Viral sequencing identified Ebola virus (species Zaïre ebolavirus), one of five viruses in the genus Ebolavirus, as the cause. Cases of Ebola viral disease (EVD) were initially reported in three southeastern districts (Gueckedou, Macenta, and Kissidougou) of Guinea and in the capital city of Conakry. By March 30, cases had been reported in Foya district in neighboring Liberia (1), and in May, the first cases identified in Sierra Leone were reported. As of June 18, the outbreak was the largest EVD outbreak ever documented, with a combined total of 528 cases (including laboratory-confirmed, probable, and suspected cases) and 337 deaths (case-fatality rate = 64%) reported in the three countries. The largest previous outbreak occurred in Uganda during 2000-2001, when 425 cases were reported with 224 deaths (case-fatality rate = 53%). The current outbreak also represents the first outbreak of EVD in West Africa (a single case caused by Taï Forest virus was reported in Côte d'Ivoire in 1994 [3]) and marks the first time that Ebola virus transmission has been reported in a capital city.

Satellite-based Assessment of Fire Impacts on Ecosystem Changes in West Africa

NASA Technical Reports Server (NTRS)

Ichoku, Charles

2008-01-01

Fires bum many vegetated regions of the world to a variety of degrees and frequency depending on season. Extensive biomass burning occurs in most parts of sub-Saharan Africa, posing great threat to ecosystem stability among other real and potential adverse impacts. In Africa, such landscape-scale fires are used for various agricultural purposes, including land clearing and hunting, although there may be a limited number of cases of fires ignited by accident or due to arson. Satellite remote sensing provides the most practical means of mapping fires, because of their sudden and aggressive nature coupled with the tremendous heat they generate. Recent advancements in satellite technology has enabled, not only the identification of fire locations, but also the measurement of fire radiative energy (FRE) release rate or power (FRP), which has been found to have a direct linear relationship with the rate of biomass combustion. A recent study based on FRP measurements from the Moderate-resolution imaging Spectro-radiometer (MODIS) sensor aboard the Terra and Aqua satellites revealed that, among all the regions of the world where fires occur, African regions rank the highest in the intensity of biomass burning per unit area of land during the peak of the burning season. In this study, we will analyze the burning patterns in West Africa during the last several years and examine the extent of their impacts on the ecosystem dynamics, using a variety of satellite data. The study introduces a unique methodology that can be used to build up the knowledge base from which decision makers can obtain scientific information in fomulating policies for regulating biomass burning in the region.

Implementation of Information Communication Technology in the Teaching/Learning Process for Sustainable Development of Adults in West Africa Sub Sahara Region

ERIC Educational Resources Information Center

Nwobi, Anthonia; Ngozi, Ugwuoke; Rufina, Nwachukwu; Ogbonnaya, Kingsley A.

2016-01-01

This study examines the implementation of information technology in the teaching/learning process for sustainable development of adults in West Africa Sub Sahara Region (WASSR). Three research questions and two hypotheses guided the study. The population for the study was 3071 participants and instructors drawn from 10 education centres that were…

Perspectives on West Africa Ebola Virus Disease Outbreak, 2013–2016

PubMed Central

Spengler, Jessica R.; Ervin, Elizabeth D.; Towner, Jonathan S.; Rollin, Pierre E.

2016-01-01

The variety of factors that contributed to the initial undetected spread of Ebola virus disease in West Africa during 2013–2016 and the difficulty controlling the outbreak once the etiology was identified highlight priorities for disease prevention, detection, and response. These factors include occurrence in a region recovering from civil instability and lacking experience with Ebola response; inadequate surveillance, recognition of suspected cases, and Ebola diagnosis; mobile populations and extensive urban transmission; and the community’s insufficient general understanding about the disease. The magnitude of the outbreak was not attributable to a substantial change of the virus. Continued efforts during the outbreak and in preparation for future outbreak response should involve identifying the reservoir, improving in-country detection and response capacity, conducting survivor studies and supporting survivors, engaging in culturally appropriate public education and risk communication, building productive interagency relationships, and continuing support for basic research. PMID:27070842

University-level nutrition training in West Africa: cost and financing issues.

PubMed

Sodjinou, Roger; Bosu, William; Fanou, Nadia; Zagre, Noel; Tchibindat, Félicité; Baker, Shawn; Delisle, Helene

2015-01-01

There is a serious shortage of skilled nutrition professionals in West Africa. Investing in nutrition training is one of the strategies for strengthening the human resource base in nutrition. However, little is known about how nutrition training in the region is financed and the levels of tuition fees charged. The purpose of this study was to provide a comprehensive assessment about the levels of tuition fees charged for nutrition training in the West Africa region and to determine to what extent this is of reach to the average student. The data for this study were obtained from 74 nutrition degree programs operating in nine West African countries in 2013 through semi-structured interviews during on-site visits or through self-administered questionnaires. They included the age of the programs, school ownership, tuition fees, financial assistance, and main sources of funding. Tuition fees (in 2013 US$) were expressed per program to enable uniformity and comparability. Simple descriptive and bivariate analyses were performed. Results from 74 nutrition training programs in nine countries showed a wide variation in tuition fees within and between countries. The tuition fees for bachelor's, master's, and doctoral programs, respectively, ranged from 372 to 4,325 (mean: 2,353); 162 to 7,678 (mean: 2,232); and 369 to 5,600 (mean: 2,208). The tuition fees were significantly higher (p<0.05) in private institutions than in public institutions (mean: US$3,079 vs. US$2,029 for bachelor's programs; US$5,118 vs. US$1,820 for master's programs; and US$3,076 vs. US$1,815 for doctoral programs). The difference in the tuition fees between Francophone and Anglophone countries was not statistically significant (mean: US$2,570 vs. US$2,216 for bachelor's programs; US$2,417 vs. US$2,147 for master's programs; US$3,285 vs. US$2,055 for doctoral programs). In most countries, the tuition fees appeared to be out of reach of the average student. Recent master's programs appeared to charge

West African Oil: Will It Make a Difference?

DTIC Science & Technology

1982-12-01

West Africa: Estimated Proved Reserves, 1 January 1982 -i-----------------------------------i1 10. West Africa: Crude Oil Export Potential... Exporting Countries sq. km. Square kilometers 12 I. INTRODUCTION In the 1950s, petroleum became the world’s dominant source of commercial energy, and in the...in 1973 the Organization of Petroleum Exporting Countries (OPEC) abruptly and permanently ended the era of inexpensive petroleum, and in the process

Population genomics reveals that an anthropophilic population of Aedes aegypti mosquitoes in West Africa recently gave rise to American and Asian populations of this major disease vector.

PubMed

Crawford, Jacob E; Alves, Joel M; Palmer, William J; Day, Jonathan P; Sylla, Massamba; Ramasamy, Ranjan; Surendran, Sinnathamby N; Black, William C; Pain, Arnab; Jiggins, Francis M

2017-02-28

The mosquito Aedes aegypti is the main vector of dengue, Zika, chikungunya and yellow fever viruses. This major disease vector is thought to have arisen when the African subspecies Ae. aegypti formosus evolved from being zoophilic and living in forest habitats into a form that specialises on humans and resides near human population centres. The resulting domestic subspecies, Ae. aegypti aegypti, is found throughout the tropics and largely blood-feeds on humans. To understand this transition, we have sequenced the exomes of mosquitoes collected from five populations from around the world. We found that Ae. aegypti specimens from an urban population in Senegal in West Africa were more closely related to populations in Mexico and Sri Lanka than they were to a nearby forest population. We estimate that the populations in Senegal and Mexico split just a few hundred years ago, and we found no evidence of Ae. aegypti aegypti mosquitoes migrating back to Africa from elsewhere in the tropics. The out-of-Africa migration was accompanied by a dramatic reduction in effective population size, resulting in a loss of genetic diversity and rare genetic variants. We conclude that a domestic population of Ae. aegypti in Senegal and domestic populations on other continents are more closely related to each other than to other African populations. This suggests that an ancestral population of Ae. aegypti evolved to become a human specialist in Africa, giving rise to the subspecies Ae. aegypti aegypti. The descendants of this population are still found in West Africa today, and the rest of the world was colonised when mosquitoes from this population migrated out of Africa. This is the first report of an African population of Ae. aegypti aegypti mosquitoes that is closely related to Asian and American populations. As the two subspecies differ in their ability to vector disease, their existence side by side in West Africa may have important implications for disease transmission.

Probabilistic Impact Assessment of Domestic Rainwater Harvesting in Urban Slums: West Africa Case Study

NASA Astrophysics Data System (ADS)

Cowden, J. R.; Watkins, D. W.; Mihelcic, J. R.; Fry, L. M.

2007-12-01

Urban populations now exceed rural populations worldwide, creating unique challenges in providing basic services, especially in developing countries where informal or illegal settlements grow in peri-urban areas. West Africa is an acute example of the problems created by rapid urban growth, with high levels of urban poverty and low water and sanitation access rates. Although considerable effort has been made in providing improved water access and urban services to slum communities, research indicates that clean water access rates are not keeping up with urbanization rates in several areas of the world and that rapidly growing slum communities are beginning to overwhelm many prior water improvements projects. In the face of these challenges, domestic rainwater harvesting is proposed as a technologically appropriate and economically viable option for enhancing water supplies to urban slum households. However, assessing the reliability, potential health impacts, and overall cost-effectiveness of these systems on a regional level is difficult for several reasons. First, long daily rainfall records are not readily available in much of the developing world, including many regions of sub-Saharan Africa. Second, significant uncertainties exist in the relevant cost, water use, and health data. Third, to estimate the potential future impacts at the regional scale, various global change scenarios should be investigated. Finally, in addition to these technical challenges, there is also a need to develop relatively simple and transparent assessment methods for informing policy makers. A procedure is presented for assessment of domestic rainwater harvesting systems using a combination of scenario, sensitivity, and trade-off analyses. Using data from West Africa, simple stochastic weather models are developed to generate rainfall sequences for the region, which are then used to estimate the reliability of providing a range of per capita water supplies. Next, a procedure is

WASCAL - West African Science Service Center on Climate Change and Adapted Land Use Regional Climate Simulations and Land-Atmosphere Simulations for West Africa at DKRZ and elsewhere

NASA Astrophysics Data System (ADS)

Hamann, Ilse; Arnault, Joel; Bliefernicht, Jan; Klein, Cornelia; Heinzeller, Dominikus; Kunstmann, Harald

2014-05-01

Changing climate and hydro-meteorological boundary conditions are among the most severe challenges to Africa in the 21st century. In particular West Africa faces an urgent need to develop effective adaptation and mitigation strategies to cope with negative impacts on humans and environment due to climate change, increased hydro-meteorological variability and land use changes. To help meet these challenges, the German Federal Ministry of Education and Research (BMBF) started an initiative with institutions in Germany and West African countries to establish together a West African Science Service Center on Climate Change and Adapted Land Use (WASCAL). This activity is accompanied by an establishment of trans-boundary observation networks, an interdisciplinary core research program and graduate research programs on climate change and related issues for strengthening the analytical capabilities of the Science Service Center. A key research activity of the WASCAL Competence Center is the provision of regional climate simulations in a fine spatio-temporal resolution for the core research sites of WASCAL for the present and the near future. The climate information is needed for subsequent local climate impact studies in agriculture, water resources and further socio-economic sectors. The simulation experiments are performed using regional climate models such as COSMO-CLM, RegCM and WRF and statistical techniques for a further refinement of the projections. The core research sites of WASCAL are located in the Sudanian Savannah belt in Northern Ghana, Southern Burkina Faso and Northern Benin. The climate in this region is semi-arid with six rainy months. Due to the strong population growth in West Africa, many areas of the Sudanian Savannah have been already converted to farmland since the majority of the people are living directly or indirectly from the income produced in agriculture. The simulation experiments of the Competence Center and the Core Research Program are

The 2014 Ebola virus disease outbreak in West Africa.

PubMed

Gatherer, Derek

2014-08-01

On 23 March 2014, the World Health Organization issued its first communiqué on a new outbreak of Ebola virus disease (EVD), which began in December 2013 in Guinée Forestière (Forested Guinea), the eastern sector of the Republic of Guinea. Located on the Atlantic coast of West Africa, Guinea is the first country in this geographical region in which an outbreak of EVD has occurred, leaving aside the single case reported in Ivory Coast in 1994. Cases have now also been confirmed across Guinea as well as in the neighbouring Republic of Liberia. The appearance of cases in the Guinean capital, Conakry, and the transit of another case through the Liberian capital, Monrovia, presents the first large urban setting for EVD transmission. By 20 April 2014, 242 suspected cases had resulted in a total of 147 deaths in Guinea and Liberia. The causative agent has now been identified as an outlier strain of Zaire Ebola virus. The full geographical extent and degree of severity of the outbreak, its zoonotic origins and its possible spread to other continents are sure to be subjects of intensive discussion over the next months. © 2014 The Authors.

Mantle convective support, drainage patterns and sedimentary flux: Examples from the West Africa passive margin

NASA Astrophysics Data System (ADS)

Lodhia, B. H.; Roberts, G. G.; Fraser, A.; Goes, S. D. B.; Fishwick, S.; Jarvis, J.

2017-12-01

Sedimentary flux measurements, regional subsidence patterns, inversion of drainage patterns, tomographic models and simple isostatic calculations are combined to constrain the history of sub-plate support of North West Africa. Backstripping of 8 commercial wells and mapping of 53,000 line-km of 2D seismic reflection data show that rapid ( 0.03 mm a-1) Neogene-Recent subsidence occurred in a 500 x 500 km region offshore Mauritania. 0.4-0.8 km of water-loaded subsidence occurred in the center of the basin during the last 23 Ma. Salt withdrawal, thin-skinned tectonics, glacio-eustasy and flexure of the lithosphere due to the emplacement of Cape Verde cannot explain the timing or magnitude of this phase of subsidence. Instead, conversion of shear wave velocities into temperature and simple isostatic calculations indicate that asthenospheric temperatures determine bathymetry from Cape Verde to West Africa. Our results indicate that asthenospheric flow from Cape Verde to Mauritania generated a bathymetric gradient of 1/300 at a wavelength of 103 km during the last 23 Ma. We explore the relationship between uplift and erosion onshore and measured solid sedimentary flux offshore. First, the history of sedimentary flux to the margin was determined by depth-converting and decompacting biostratigraphically-dated isopachs. Compaction and velocity errors, determined using check-shot data, were propagated into calculated sedimentary flux history. Solid-sedimentary flux rates of 0.2-0.1+0.2 ×103 km3 /Ma between 23.8-5.6 Ma, and 1.9-1.4+2.0 ×103 km3 /Ma from 5.6-0 Ma are observed. Secondly, a calibrated stream power erosional model was used to invert 14700 river profiles for a history of regional uplift rate. Incision rates were integrated along best-fitting theoretical river profiles to predict sedimentary flux at mouths of the rivers draining NW Africa. Our predicted history of sedimentary flux increases in two stages towards the present-day, in agreement with our offshore

Nocturnal low-level jet and low-level cloud occurrence over Southern West Africa during DACCIWA campaign

NASA Astrophysics Data System (ADS)

Dione, Cheikh; Lohou, Fabienne; Lothon, Marie; Kaltoff, Norbert; Adler, Bianca; Babić, Karmen; Pedruzo-Bagazgoitia, Xabier

2017-04-01

During the summer monsoon period in West Africa, a nocturnal low-level jet (NLLJ) is frequently observed and is associated with the formation of a low-level deck of stratus or stratocumulus clouds over the southern domain of this region. The understanding of the mechanisms controlling the diurnal cycle of the low-level cloud (LLC) is one of the goals of the DACCIWA (Dynamics-aerosol-chemistry-cloud interactions in West Africa) project. During the ground campaign, which took place in June-July 2016, numerous instruments devoted to document the atmospheric boundary-layer dynamics and thermodynamics, clouds, aerosols and precipitation were deployed at Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria) supersites. Several parameters can influence the LLC formation: these are the large-scale conditions, but also local parameters such as stability, the interaction between Monsoon and Harmattan flows and turbulence. It has been pointed out in previous studies that the NLLJ plays a key role in LLC formation. Therefore, based on 49 nights of observations, our study focuses on the possible link between NLLJ and the formation, evolution and dissipation of the LLC over Savè. The characteristics of LLCs (onset, evolution and dissipation time, base height and thickness) are investigated using data from the ceilometer, infrared cloud camera, and frequent and normal radiosoundings. The UHF wind profiler data are used to estimate the occurrence of the NLLJ as well as the depth of the monsoon flow.

Cost-Effectiveness of Antivenoms for Snakebite Envenoming in 16 Countries in West Africa.

PubMed

Hamza, Muhammad; Idris, Maryam A; Maiyaki, Musa B; Lamorde, Mohammed; Chippaux, Jean-Philippe; Warrell, David A; Kuznik, Andreas; Habib, Abdulrazaq G

2016-03-01

Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Antivenom (AV) is the standard treatment, and we assessed the cost-effectiveness of making it available in 16 countries in West Africa. We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. Specific AVs included in the model were Antivipmyn, FAV Afrique, EchiTab-G and EchiTab-Plus. We derived inputs from the literature which included: type of snakes causing bites (carpet viper (Echis species)/non-carpet viper), AV effectiveness against death, mortality without AV, probability of Early Adverse Reactions (EAR), likelihood of death from EAR, average age at envenomation in years, anticipated remaining life span and likelihood of amputation. Costs incurred by the victims include: costs of confirming and evaluating envenomation, AV acquisition, routine care, AV transportation logistics, hospital admission and related transportation costs, management of AV EAR compared to the alternative of free snakebite care with ineffective or no AV. Incremental Cost Effectiveness Ratios (ICERs) were assessed as the cost per death averted and the cost per Disability-Adjusted-Life-Years (DALY) averted. Probabilistic Sensitivity Analyses (PSA) using Monte Carlo simulations were used to obtain 95% Confidence Intervals of ICERs. The cost/death averted for the 16 countries of interest ranged from $1,997 in Guinea Bissau to $6,205 for Liberia and Sierra Leone. The cost/DALY averted ranged from $83 (95% Confidence Interval: $36-$240) for Benin Republic to $281 ($159-457) for Sierra-Leone. In all cases, the base-case cost/DALY averted estimate fell below the commonly accepted threshold of one time per capita GDP, suggesting that AV is highly cost-effective for the treatment of snakebite in all 16 WA countries. The findings were consistent even with variations of inputs in 1-way sensitivity analyses. In addition, the PSA showed that in the

Cost-Effectiveness of Antivenoms for Snakebite Envenoming in 16 Countries in West Africa

PubMed Central

Hamza, Muhammad; Idris, Maryam A.; Maiyaki, Musa B.; Lamorde, Mohammed; Chippaux, Jean-Philippe; Warrell, David A.; Kuznik, Andreas; Habib, Abdulrazaq G.

2016-01-01

Background Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Antivenom (AV) is the standard treatment, and we assessed the cost-effectiveness of making it available in 16 countries in West Africa. Methods We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. Specific AVs included in the model were Antivipmyn, FAV Afrique, EchiTab-G and EchiTab-Plus. We derived inputs from the literature which included: type of snakes causing bites (carpet viper (Echis species)/non-carpet viper), AV effectiveness against death, mortality without AV, probability of Early Adverse Reactions (EAR), likelihood of death from EAR, average age at envenomation in years, anticipated remaining life span and likelihood of amputation. Costs incurred by the victims include: costs of confirming and evaluating envenomation, AV acquisition, routine care, AV transportation logistics, hospital admission and related transportation costs, management of AV EAR compared to the alternative of free snakebite care with ineffective or no AV. Incremental Cost Effectiveness Ratios (ICERs) were assessed as the cost per death averted and the cost per Disability-Adjusted-Life-Years (DALY) averted. Probabilistic Sensitivity Analyses (PSA) using Monte Carlo simulations were used to obtain 95% Confidence Intervals of ICERs. Results The cost/death averted for the 16 countries of interest ranged from $1,997 in Guinea Bissau to $6,205 for Liberia and Sierra Leone. The cost/DALY averted ranged from $83 (95% Confidence Interval: $36-$240) for Benin Republic to $281 ($159–457) for Sierra-Leone. In all cases, the base-case cost/DALY averted estimate fell below the commonly accepted threshold of one time per capita GDP, suggesting that AV is highly cost-effective for the treatment of snakebite in all 16 WA countries. The findings were consistent even with variations of inputs in 1—way sensitivity analyses. In addition

Forest pricing and concession policies: Managing the high forest of west and central Africa. World Bank technical paper; Politique de redevances et de concessions forestieres: gestion des futaies en afrique occidentale et centrale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grut, M.; Gray, J.A.; Egli, N.

1993-12-01

This French edition describes forest revenue systems and concession policies in the tropical moist hardwood forests of West and Central Africa. The paper reviews current issues in silviculture, tenure, concession management, and biological and financial sustainable development. Until the fledgling forestry departments of governments in West and Central Africa are strengthened, the report concludes that a simple system of forest fees should be implemented. The report recommends that such a system emphasize bidding and concession fees.

Ciguatera fish poisoning on the West Africa Coast: An emerging risk in the Canary Islands (Spain).

PubMed

Boada, Luis D; Zumbado, Manuel; Luzardo, Octavio P; Almeida-González, Maira; Plakas, Steven M; Granade, Hudson R; Abraham, Ann; Jester, Edward L E; Dickey, Robert W

2010-12-01

Ciguatera fish poisoning (CFP) is endemic in certain tropical and subtropical regions of the world. CFP had not been described on the West Africa Coast until a 2004 outbreak in the Canary Islands. In 2008-2009, two additional outbreaks of ciguatera occurred. Individuals afflicted had consumed lesser amberjack (Seriola rivoliana) captured from nearby waters. Caribbean ciguatoxin-1 (C-CTX-1) was confirmed in fish samples by LC-MS/MS. Ciguatoxic fish in this region may pose a new health risk for the seafood consumer. Copyright © 2010 Elsevier Ltd. All rights reserved.

Partners in Progress or Economic Enemies China’s Impact on U.S. National Interests in West Africa

DTIC Science & Technology

2017-06-09

PARTNERS IN PROGRESS OR ECONOMIC ENEMIES? CHINA’S IMPACT ON U.S. NATIONAL INTERESTS IN WEST AFRICA A thesis presented to the Faculty...COVERED (From - To) AUG 2016 – JUNE 2017 4. TITLE AND SUBTITLE Partners in Progress or Economic Enemies? China’s Impact on U.S. National Interests...has led to its ability to project power, both economic and military, beyond its borders in ways not seen in centuries. One region where the Chinese

Experiences of Response Measures against the 4 Suspected Cases of Ebola Virus Disease from West Africa in the National Center for Global Health and Medicine, Tokyo, Japan.

PubMed

Kutsuna, Satoshi; Yamamoto, Kei; Takeshita, Nozomi; Hayakawa, Kayoko; Kato, Yasuyuki; Kanagawa, Shuzo; Sugiki, Yuko; Ohmagari, Norio

2018-01-23

In Japan, infectious diseases are classified into 4 types based on how contagious and severe the pathogens are, and Ebola virus disease (EVD) is categorized as a category 1 infectious disease. The National Center for Global Health and Medicine in Tokyo, Japan, is designated as a specified hospital for category 1 infectious disease patients and has experienced 4 probable cases of EVD from West Africa. Even after the outbreak in West Africa is ended, we should continue to pay attention for new EVD outbreaks. Increasing the number of infectious disease specialists with the proper knowledge of viral hemorrhagic fever, including EVD, is a common problem for infectious disease physicians working in Japan, the academic society, and the government.

Forest pricing and concession policies: Managing the high forest of west and Central Africa. World Bank Technical Paper 143; Politique de redevances et de concessions forestires: gestion des futaies en afrique occidentale et centrale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grut, M.; Gray, J.A.; Egli, N.

1993-12-01

This French edition of Forest Pricing and Concession Policies: Managing the High Forest of West and Central Africa describes forest revenue systems and concession policies in the tropical moist hardwood forests of West and Central Africa. Virtually all the forests of Africa are publicly owned by central governments or local communities. Revenues from these forests are generally very low due to low forest fees and low collection rates. The lack of concession fees encourages acquisition and waste rather than management and conservation, leading to the allocation of large areas as logging concessions. This paper reviews current issues in silviculture, tenure,more » concession management, and biological and financial sustainable development. Until the fledgling forestry departments of governments in West and Central Africa are strengthened, the report concludes that a simple system of forest fees should be implemented. The report recommends that such a system emphasize bidding and concession fees. Three specific options in forest pricing are examined for a proposed system; annual concession rent; annual concession rent set by competitive bidding; logging concessions replaced by forest management concessions.« less

Molecular Surveillance Identifies Multiple Transmissions of Typhoid in West Africa

PubMed Central

Wong, Vanessa K.; Holt, Kathryn E.; Okoro, Chinyere; Baker, Stephen; Pickard, Derek J.; Marks, Florian; Page, Andrew J.; Olanipekun, Grace; Munir, Huda; Alter, Roxanne; Fey, Paul D.; Feasey, Nicholas A.; Weill, Francois-Xavier; Le Hello, Simon; Hart, Peter J.; Kariuki, Samuel; Breiman, Robert F.; Gordon, Melita A.; Heyderman, Robert S.; Jacobs, Jan; Lunguya, Octavie; Msefula, Chisomo; MacLennan, Calman A.; Keddy, Karen H.; Smith, Anthony M.; Onsare, Robert S.; De Pinna, Elizabeth; Nair, Satheesh; Amos, Ben; Dougan, Gordon; Obaro, Stephen

2016-01-01

Background The burden of typhoid in sub-Saharan African (SSA) countries has been difficult to estimate, in part, due to suboptimal laboratory diagnostics. However, surveillance blood cultures at two sites in Nigeria have identified typhoid associated with Salmonella enterica serovar Typhi (S. Typhi) as an important cause of bacteremia in children. Methods A total of 128 S. Typhi isolates from these studies in Nigeria were whole-genome sequenced, and the resulting data was used to place these Nigerian isolates into a worldwide context based on their phylogeny and carriage of molecular determinants of antibiotic resistance. Results Several distinct S. Typhi genotypes were identified in Nigeria that were related to other clusters of S. Typhi isolates from north, west and central regions of Africa. The rapidly expanding S. Typhi clade 4.3.1 (H58) previously associated with multiple antimicrobial resistances in Asia and in east, central and southern Africa, was not detected in this study. However, antimicrobial resistance was common amongst the Nigerian isolates and was associated with several plasmids, including the IncHI1 plasmid commonly associated with S. Typhi. Conclusions These data indicate that typhoid in Nigeria was established through multiple independent introductions into the country, with evidence of regional spread. MDR typhoid appears to be evolving independently of the haplotype H58 found in other typhoid endemic countries. This study highlights an urgent need for routine surveillance to monitor the epidemiology of typhoid and evolution of antimicrobial resistance within the bacterial population as a means to facilitate public health interventions to reduce the substantial morbidity and mortality of typhoid. PMID:27657909

Protecting breastfeeding in West and Central Africa: over 25 years of implementation of the International Code of Marketing of Breastmilk Substitutes.

PubMed

Sokol, Ellen; Clark, David; Aguayo, Victor M

2008-09-01

In 1981 the World Health Assembly (WHA) adopted the International Code of Marketing of Breastmilk Substitutes out of concern that inappropriate marketing of breastmilk substitutes was contributing to the alarming decline in breastfeeding worldwide and the increase in child malnutrition and mortality, particularly in developing countries. To document progress, challenges, and lessons learned in the implementation of the International Code in West and Central Africa. Data were obtained by literature review and interviews with key informants. Twelve of the 24 countries have laws, decrees, or regulations that implement all or most of the provisions of the Code, 6 countries have a draft law or decree that is awaiting government approval or have a government committee that is studying how best to implement the Code, 3 countries have a legal instrument that enacts a few provisions of the Code, and 3 countries have not taken any action to implement the Code. International declarations and initiatives for child nutrition and survival have provided impetus for national implementation of the Code. National action to regulate the marketing of breastmilk substitutes needs to be linked to national priorities for nutrition and child survival. A clearly defined scope is essential for effective implementation of national legislation. Leadership and support by health professionals is essential to endorse and enforce national legislation. Training on Code implementation is instrumental for national action; national implementation of the Code requires provisions and capacity to monitor and enforce the legislative framework and needs to be part of a multipronged strategy to advance national child nutrition and survival goals. Nations in West and Central Africa have made important progress in implementing the International Code. More than 25 years after its adoption by the WHA, the Code remains as important as ever for child survival and development in West and Central Africa.

Determinants of Mean Blood Pressure and Hypertension among Workers in West Africa

PubMed Central

Bosu, William K.

2016-01-01

Background. This review was undertaken to estimate the mean blood pressure and evaluate its determinants as well as the determinants of hypertension among workers in West Africa. Methods. In a follow-up to an earlier study, a systematic search for articles published between 1980 and August 2015 was undertaken using major databases. Results. A total of 55 articles involving 34,919 different cadres of workers from six countries were retrieved. The mean systolic blood pressure (BP) ranged from 116.6 ± 1.3 mmHg to 151.7 ± 13.6 mmHg while the mean diastolic BP ranged from 69.6 ± 11.0 mmHg to 97.1 ± 9.1 mmHg. Population-wide prehypertension was common. The major determinants of mean BP and hypertension were similar and included male sex, older age group, higher socioeconomic status, obesity, alcohol consumption, plasma glucose, and sodium excretion. Ethnicity and educational level were inconsistently associated with hypertension. Workers at higher risk of cardiovascular event did not perceive themselves as such. Conclusion. The prevailing mean prehypertensive BP, low perception of risk, and clustering of risk factors call for interventions such as healthy diets, improved physical activity, and a favourable work environment. Successful models for improving the cardiovascular health of sedentary informal sector workers in Africa are urgently needed. PMID:26949543

High number of diarrhoeal co-infections in travellers to Benin, West Africa

PubMed Central

2014-01-01

Background Travellers’ diarrhoea (TD) is the most frequent health problem among travellers to the tropics. Using routine techniques, the aetiology mostly remains unresolved, whereas modern molecular methods enable reducing the number of equivocal cases considerably. While many studies address the aetiology of TD in Asian, Central American and North African tourist resorts, only few focus on Western Africa. Methods Stool samples from 45 travellers travelling in Benin, West Africa, were analyzed by a new multiplex qPCR assay for Salmonella, Yersinia, Campylobacter, Vibrio cholerae, Shigella or enteroinvasive (EIEC), enterohaemorrhagic (EHEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), and enteropathogenic Escherichia coli (EPEC). Results All 18 pre-travel samples proved negative for bacterial pathogens. Of the 39/45 (87%) travellers having had TD, EPEC was detected in post-travel samples in 30 (77%) cases, EAEC in 23 (59%), ETEC in 22 (56%), Shigella or EIEC in 7 (18%), EHEC in two (5%), and Salmonella in one (3%). In 31(79%) of the TD cases two or more bacterial pathogens were identified. Two (8%) samples remained negative: both patients had taken antimicrobials for TD. Conclusions EPEC, EAEC and ETEC were the most common findings. 79% of the cases had a co-infection. As modern diagnostics reveals in most patients a multitude of pathogens, the role of each pathogen should be re-evaluated. PMID:24521079

The DACCIWA model evaluation project: representation of the meteorology of southern West Africa in state-of-the-art weather, seasonal and climate prediction models

NASA Astrophysics Data System (ADS)

Kniffka, Anke; Benedetti, Angela; Knippertz, Peter; Stanelle, Tanja; Brooks, Malcolm; Deetz, Konrad; Maranan, Marlon; Rosenberg, Philip; Pante, Gregor; Allan, Richard; Hill, Peter; Adler, Bianca; Fink, Andreas; Kalthoff, Norbert; Chiu, Christine; Vogel, Bernhard; Field, Paul; Marsham, John

2017-04-01

DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) is an EU-funded project that aims to determine the influence of anthropogenic and natural emissions on the atmospheric composition, air quality, weather and climate over southern West Africa. DACCIWA organised a major international field campaign in June-July 2016 and involves a wide range of modelling activities. Here we report about the coordinated model evaluation performed in the framework of DACCIWA focusing on meteorological fields. This activity consists of two elements: (a) the quality of numerical weather prediction during the field campaign, (b) the ability of seasonal and climate models to represent the mean state and its variability. For the first element, the extensive observations from the main field campaign in West Africa in June-July 2016 (ground supersites, radiosondes, aircraft measurements) will be combined with conventional data (synoptic stations, satellites data from various sensors) to evaluate models against. The forecasts include operational products from centres such as the ECMWF, UK MetOffice and the German Weather Service and runs specifically conducted for the planning and the post-analysis of the field campaign using higher resolutions (e.g., WRF, COSMO). The forecast and the observations are analysed in a concerted way to assess the ability of the models to represent the southern West African weather systems and secondly to provide a comprehensive synoptic overview of the state of the atmosphere. In a second step the process will be extended to long-term modelling periods. This includes both seasonal and climate models, respectively. In this case, the observational dataset contains long-term satellite observations and station data, some of which were digitised from written records in the framework of DACCIWA. Parameter choice and spatial averaging will build directly on the weather forecasting evaluation to allow an assessment of the impact of short-term errors on

A systematic assessment of the current capacity to act in nutrition in West Africa: cross-country similarities and differences.

PubMed

Sodjinou, Roger; Bosu, William K; Fanou, Nadia; Déart, Lucie; Kupka, Roland; Tchibindat, Félicité; Baker, Shawn

2014-01-01

Although it is widely accepted that lack of capacity is one of the barriers to scaling up nutrition in West Africa, there is a paucity of information about what capacities exist and the capacities that need to be developed to accelerate progress toward improved nutrition outcomes in the region. To systematically assess the current capacity to act in nutrition in the West Africa region and explore cross-country similarities and differences. Data were collected from 13 West African countries through interviews with government officials, key development partners, tertiary-level training institutions, and health professional schools. The assessment was based on a conceptual framework of four interdependent levels (tools; skills; staff and infrastructure; and structures, systems and roles). In each of the surveyed countries, we assessed capacity assets and gaps at individual, organizational, and systemic levels. Important similarities and differences in capacity assets and gaps emerged across all the surveyed countries. There was strong momentum to improve nutrition in nearly all the surveyed countries. Most of the countries had a set of policies on nutrition in place and had set up multisectoral, multi-stakeholder platforms to coordinate nutrition activities, although much remained to be done to improve the effectiveness of these platforms. Many initiatives aimed to reduce undernutrition were ongoing in the region, but there did not seem to be clear coordination between them. Insufficient financial resources to implement nutrition activities were a major problem in all countries. The bulk of financial allocations for nutrition was provided by development partners, even though some countries, such as Niger, Nigeria, and Senegal, had a national budget line for nutrition. Sporadic stock-outs of nutrition supplies were reported in most of the countries as a result of a weak logistic and supply chain system. They also had a critical shortage of skilled nutrition

The Response of Environmental Capacity for Malaria Transmission in West Africa to Climate Change

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Eltahir, E. A.

2011-12-01

The climate of West Africa is characterized by north-south gradients in temperature and rainfall. Environmental capacity for malaria transmission (e.g. as measured by vectorial capacity) is strongly tied to these two variables; temperature affects the development rate of the malaria parasite, as well as the lifespan of the mosquitoes that transmit the disease, and rainfall is tied to mosquito abundance, as the vector lays its eggs in rain-fed water pools. A change in climate is therefore expected to lead to changes in the distribution of malaria transmission. Current general circulation models agree that the temperature in West Africa is expected to increase by several degrees in the next century. However they predict a wide range of possible rainfall scenarios in the future, from intense drying to significant increases in rainfall (Christensen et al., 2007). The effects these changes will have on environmental capacity for malaria transmission depend on the magnitude and direction of the changes, and on current conditions. For example, malaria transmission will be more sensitive to positive changes in rainfall in dry areas where mosquito populations are currently limited by water availability than in relatively wet areas. Here, we analyze combinations of changes in rainfall and temperature within the ranges predicted by GCMs, and assess the impact these combinations will have on the environmental capacity for malaria transmission. In particular, we identify climate change scenarios that are likely to have the greatest impact on environmental capacity for malaria transmission, as well as geographic "hot spots" where the greatest changes are to be expected. Christensen, J. H., Busuioc, A., & et al. (2007). Regional climate projections. In S. Solomon (Ed.), Climate change 2007: The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.

Kimberlites of the Man craton, West Africa

NASA Astrophysics Data System (ADS)

Skinner, E. M. W.; Apter, D. B.; Morelli, C.; Smithson, N. K.

2004-09-01

The Man craton in West Africa is an Archaean craton formerly joined to the Guyana craton (South America) that was rifted apart in the Mesozoic. Kimberlites of the Man craton include three Jurassic-aged clusters in Guinea, two Jurassic-aged clusters in Sierra Leone, and in Liberia two clusters of unknown age and one Neoproterozoic cluster recently dated at ∼800 Ma. All of the kimberlites irrespective of age occur as small pipes and prolific dykes. Some of the Banankoro cluster pipes in Guinea, the Koidu pipes in Sierra Leone and small pipes in the Weasua cluster in Liberia contain hypabyssal-facies kimberlite and remnants of the so-called transitional-facies and diatreme-facies kimberlite. Most of the Man craton kimberlites are mineralogically classified as phlogopite kimberlites, although potassium contents are relatively low. They are chemically similar to mica-poor Group 1A Southern African examples. The Jurassic kimberlites are considered to represent one province of kimberlites that track from older bodies in Guinea (Droujba 153 Ma) to progressively younger kimberlites in Sierra Leone (Koidu, 146 Ma and Tongo, 140 Ma). The scarcity of diatreme-facies kimberlites relative to hypabyssal-facies kimberlites and the presence of the so-called transitional-facies indicate that the pipes have been eroded down to the interface between the root and diatreme zones. From this observation, it is concluded that extensive erosion (1-2 km) has occurred since the Jurassic. In addition to erosion, the presence of abundant early crystallizing phlogopite is considered to have had an effect on the relatively small sizes of the Man craton kimberlites.

Smallpox eradication in West and Central Africa.

PubMed

Foege, W H; Millar, J D; Henderson, D A

1975-01-01

The history of smallpox eradication in the 20 countries of West and Central Africa from Mauritania to Zaire is recounted, including background, evolution of strategy, assessment, maintenance, costs, and significance of the campaign. Smallpox was endemic in these countries, peaking each year at the end of the spring dry season, usually occurring in isolated villages only periodically. The average case fatality was 14.5%, but twice as high in infants and older adults. Clinical exams showed that those with actual vaccination scars rarely got smallpox. The campaign was made feasible because of lyophilized heat-stable vaccine and bifurcated needles or jet injectors. The initial strategy called for mass vaccination and assessment of achieved vaccination. Between 1967 and 1969 100 million persons were vaccinated at collecting points; by 1972, 28 million more children had been protected. In 1966 an outbreak of 34 cases in Nigeria was blocked within 3 weeks of initiation of surveillance and containment. This effort also demonstrated that actual smallpox transmission was slow and relatively ineffective, and further that vaccination of contacts even after exposure was effective. The strategy was replaced by surveillance-containment begun in the seasonal low. The results were that smallpox disappeared within 5 months in an area of 12 million, and within 1 year in 19 of the 20 countries. Maintenance vaccination to prevent importation of the virus is continuing. The cost of the program was $15 million to the U.S. sponsors, or 1/10 the yearly price of smallpox control in the U.S.

Sowing the Seeds of Strategic Success Across West Africa: Propagating the State Partnership Program to Shape the Security Environment

DTIC Science & Technology

2017-06-09

ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Command and General Staff College ATTN: ATZL-SWD-GD Fort Leavenworth, KS 66027-2301 8. PERFORMING...The threat to U.S. national interests by the ISIL-affiliated group, Boko Haram and by transnational criminal organizations continue to plague...the ISIL-affiliated group, Boko Haram and by transnational criminal organizations continue to plague West Africa. In the current era of fiscal

Piperaquine Resistance in Plasmodium falciparum, West Africa.

PubMed

Inoue, Juliana; Silva, Miguel; Fofana, Bakary; Sanogo, Kassim; Mårtensson, Andreas; Sagara, Issaka; Björkman, Anders; Veiga, Maria Isabel; Ferreira, Pedro Eduardo; Djimde, Abdoulaye; Gil, José Pedro

2018-08-17

Dihydroartemisinin/piperaquine (DHA/PPQ) is increasingly deployed as antimalaria drug in Africa. We report the detection in Mali of Plasmodium falciparum infections carrying plasmepsin 2 duplications (associated with piperaquine resistance) in 7/65 recurrent infections within 2 months after DHA/PPQ treatment. These findings raise concerns about the long-term efficacy of DHA/PPQ treatment in Africa.

Positive experiences of volunteers working in deployable laboratories in West Africa during the Ebola outbreak

PubMed Central

Mollers, Madelief; Smit, Pieter W.; Hulscher, Marlies; Koopmans, Marion; Reusken, Chantal; Timen, Aura

2018-01-01

The largest outbreak of Ebola virus disease ever started in West Africa in December 2013; it created a pressing need to expand the workforce dealing with it. The aim of this study was to gain insight into the experiences of volunteers from the European Union who worked in deployable laboratories in West Africa during the outbreak. This study is part of the EMERGE project. We assessed the experiences of 251 volunteers with a 19-item online questionnaire. The questions asked about positive aspects of volunteering such as learning new skills, establishing a new path in life, and changing life values. Other questionnaire subjects were the compliance to follow-up measures, the extent to which volunteers felt these measures restricted their daily activities, the fear of stigmatization, and worries about becoming infected or infecting their families. The volunteers reported positive effects that reached far beyond their daily work, such as changes in life priorities and a greater appreciation of the value of their own lives. Although the volunteers did not feel that temperature monitoring restricted their daily activities, full compliance to temperature monitoring and reporting it to the authorities was low. The volunteers did not fear Ebola infection for themselves or their families and were not afraid of stigmatization. With respect to the burden on the families, 50% reported that their family members were worried that the volunteer would be infected with Ebola virus. Altogether, the positive experiences of the volunteers in this study far outweigh the negative implications and constitute an important argument for inspiring people who intend to join such missions and for motivating the hesitant ones. PMID:29698521

Positive experiences of volunteers working in deployable laboratories in West Africa during the Ebola outbreak.

PubMed

Belfroid, Evelien; Mollers, Madelief; Smit, Pieter W; Hulscher, Marlies; Koopmans, Marion; Reusken, Chantal; Timen, Aura

2018-01-01

The largest outbreak of Ebola virus disease ever started in West Africa in December 2013; it created a pressing need to expand the workforce dealing with it. The aim of this study was to gain insight into the experiences of volunteers from the European Union who worked in deployable laboratories in West Africa during the outbreak. This study is part of the EMERGE project. We assessed the experiences of 251 volunteers with a 19-item online questionnaire. The questions asked about positive aspects of volunteering such as learning new skills, establishing a new path in life, and changing life values. Other questionnaire subjects were the compliance to follow-up measures, the extent to which volunteers felt these measures restricted their daily activities, the fear of stigmatization, and worries about becoming infected or infecting their families. The volunteers reported positive effects that reached far beyond their daily work, such as changes in life priorities and a greater appreciation of the value of their own lives. Although the volunteers did not feel that temperature monitoring restricted their daily activities, full compliance to temperature monitoring and reporting it to the authorities was low. The volunteers did not fear Ebola infection for themselves or their families and were not afraid of stigmatization. With respect to the burden on the families, 50% reported that their family members were worried that the volunteer would be infected with Ebola virus. Altogether, the positive experiences of the volunteers in this study far outweigh the negative implications and constitute an important argument for inspiring people who intend to join such missions and for motivating the hesitant ones.

Assessment of moisture budget over West Africa using MERRA-2's aerological model and satellite data

NASA Astrophysics Data System (ADS)

Igbawua, Tertsea; Zhang, Jiahua; Yao, Fengmei; Zhang, Da

2018-02-01

The study assessed the performance of NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) and MERRA-2 aerological (P-E*) model in reproducing the salient features of West Africa water balance including its components from 1980 to 2013. In this study we have shown that recent reanalysis efforts have generated imbalances between regional integrated precipitation (P) and surface evaporation (E), and the effect is more in the newly released MERRA-2. The atmospheric water balance of MERRA and MERRA-2 were inter-compared and thereafter compared with model forecast output of European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-I) and Japanese 55-year Reanalysis (JRA-55). Results indicated that a bias of 12-20 (5-13) mm/month in MERRA-2 (ERA-I) leads to the classification of the Sahel (14°N-20°N) as a moisture source during the West African Summer Monsoon. Comparisons between MERRA/MERRA-2 and prognostic fields from two ERA-I and JRA-55 indicated that the average P-E* in MERRA is 18.94 (52.24) mm/month which is less than ERA-I (JRA-55) over Guinea domain and 25.03 (4.53) mm/month greater than ERA-I (JRA-55) over the Sahel. In MERRA-2, average P-E* indicated 25.76 (59.06) mm/month which is less than ERA-I (JRA-55) over Guinea and 73.72 (94.22) mm/month less than ERA-I (JRA-55) over the Sahel respectively. These imbalances are due to adjustments in data assimilation methods, satellite calibration and observational data base. The change in convective P parameterization and increased re-evaporation of P in MERRA-2 is suggestive of the cause of positive biases in P and E. The little disagreements between MERRA/MERRA-2 and CRU precipitation highlights one of the major challenges associated with climate research in West Africa and major improvements in observation data and surface fluxes from reanalysis remain vital.

Etiology of urethral discharge in West Africa: the role of Mycoplasma genitalium and Trichomonas vaginalis.

PubMed Central

Pépin, J.; Sobéla, F.; Deslandes, S.; Alary, M.; Wegner, K.; Khonde, N.; Kintin, F.; Kamuragiye, A.; Sylla, M.; Zerbo, P. J.; Baganizi, E.; Koné, A.; Kane, F.; Mâsse, B.; Viens, P.; Frost, E.

2001-01-01

OBJECTIVE: To determine the etiological role of pathogens other than Neisseria gonorrhoeae and Chlamydia trachomatis in urethral discharge in West African men. METHODS: Urethral swabs were obtained from 659 male patients presenting with urethral discharge in 72 primary health care facilities in seven West African countries, and in 339 controls presenting for complaints unrelated to the genitourinary tract. Polymerase chain reaction analysis was used to detect the presence of N. gonorrhoeae, C. trachomatis, Trichomonas vaginalis, Mycoplasma genitalium, and Ureaplasma urealyticum. FINDINGS: N. gonorrhoeae, T. vaginalis, C. trachomatis, and M. genitalium--but not U. urealyticum--were found more frequently in men with urethral discharge than in asymptomatic controls, being present in 61.9%, 13.8%, 13.4% and 10.0%, respectively, of cases of urethral discharge. Multiple infections were common. Among patients with gonococcal infection, T. vaginalis was as frequent a coinfection as C. trachomatis. M. genitalium, T. vaginalis, and C. trachomatis caused a similar clinical syndrome to that associated with gonococcal infection, but with a less severe urethral discharge. CONCLUSIONS: M. genitalium and T. vaginalis are important etiological agents of urethral discharge in West Africa. The frequent occurrence of multiple infections with any combination of four pathogens strongly supports the syndromic approach. The optimal use of metronidazole in flowcharts for the syndromic management of urethral discharge needs to be explored in therapeutic trials. PMID:11242818

Potential for broad-scale transmission of Ebola virus disease during the West Africa crisis: lessons for the Global Health security agenda.

PubMed

Undurraga, Eduardo A; Carias, Cristina; Meltzer, Martin I; Kahn, Emily B

2017-12-01

The 2014-2016 Ebola crisis in West Africa had approximately eight times as many reported deaths as the sum of all previous Ebola outbreaks. The outbreak magnitude and occurrence of multiple Ebola cases in at least seven countries beyond Liberia, Sierra Leone, and Guinea, hinted at the possibility of broad-scale transmission of Ebola. Using a modeling tool developed by the US Centers for Disease Control and Prevention during the Ebola outbreak, we estimated the number of Ebola cases that might have occurred had the disease spread beyond the three countries in West Africa to cities in other countries at high risk for disease transmission (based on late 2014 air travel patterns). We estimated Ebola cases in three scenarios: a delayed response, a Liberia-like response, and a fast response scenario. Based on our estimates of the number of Ebola cases that could have occurred had Ebola spread to other countries beyond the West African foci, we emphasize the need for improved levels of preparedness and response to public health threats, which is the goal of the Global Health Security Agenda. Our estimates suggest that Ebola could have potentially spread widely beyond the West Africa foci, had local and international health workers and organizations not committed to a major response effort. Our results underscore the importance of rapid detection and initiation of an effective, organized response, and the challenges faced by countries with limited public health systems. Actionable lessons for strengthening local public health systems in countries at high risk of disease transmission include increasing health personnel, bolstering primary and critical healthcare facilities, developing public health infrastructure (e.g. laboratory capacity), and improving disease surveillance. With stronger local public health systems infectious disease outbreaks would still occur, but their rapid escalation would be considerably less likely, minimizing the impact of public health threats

Lessons from the West Africa Ebola Epidemic: A Systematic Review of Epidemiological and Social and Behavioral Science Research Priorities.

PubMed

Abramowitz, Sharon A; Hipgrave, David B; Witchard, Alison; Heymann, David L

2018-06-23

This systematic literature review compared the epidemiological (EPI) research and the qualitative social and behavioral science (SBS) research published during the West Africa Ebola virus disease (EVD) epidemic. Beginning with an initial capture of over 2,000 articles, we extracted 236 EPI and 171 SBS studies to examine how disciplinary priorities affected research conducted during the EVD response, with implications for epidemic response effectiveness. Building on this research, we set forth a roadmap for the closer integration of EPI and SBS research in all aspects of epidemic preparedness and response that incorporates the lessons of the West Africa EVD outbreak. Key priorities include: (1) developing the capacity to systematically quantify qualitative sociocultural variables, (2) establishing interdisciplinary collaborations to improve "risk segmentation" practices, (3) creating and pre-positioning qualitative indicators and composite sociocultural indexes for rapid deployment in outbreaks; (4) integrating novel systems with community resources; (5) developing new techniques for modeling social mobilization and community engagement; (6) prioritizing good data and complex analyses early in emergencies, and (7) learning from past experiences. Our findings support a program of action that situates data collection and analysis in real-time, recursive, integrated efforts to move community attitudes, behaviors, and responses into epidemiological research.

Evaluation of SEVIRI-Derived Rain Rates and Accumulated Rainfall with TRMM-TMI and Rain Gauge Data over West-Africa

NASA Astrophysics Data System (ADS)

Wolters, E. L. A.; Roebeling, R. A.; Stammes, P.; Wang, P.; Ali, A.; Brissebrat, G.

2009-11-01

Clouds are of paramount importance to the hydrological cycle, as they influence the surface energy balance, thereby constraining the amount of energy available for evaporation, and their contribution through precipitation. Especially in regions where water availability is critical, such as in West-Africa, accurate determination of various terms of the hydrological cycle is warranted. At the Royal Netherlands Meteorological Institute (KNMI), an algorithm to retrieve Cloud Physical Properties (CPP) from mainly visible and near-infrared spectral channel radiances from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard Meteosat-8 and -9 has been developed. Recently, this algorithm as been extended with a rain rate retrieval method. Evaluation of this geophysical quantity has been done with rain radar data over the Netherlands. This paper presents the first results of this rain rate retrieval over West-Africa for June 2006. In addition, the added value of the high temporal and spatial resolution of the SEVIRI instrument is shown. Over land, retrievals are compared with rain gauge observations performed during the African Monsoon Multidisciplinary Analyses (AMMA) project and with a kriged dataset of the Comite Inter-Estate pour la Lutte contre la Secheresse au Sahel (CILSS) rain gauge network, whereas rain rate retrievals over ocean are evaluated using Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) data.

Associations between women's perceptions of domestic violence and contraceptive use in seven countries in West and Central Africa.

PubMed

Olorunsaiye, Comfort Z; Brunner Huber, Larissa; Laditka, Sarah B; Kulkarni, Shanti; Boyd, A Suzanne

2017-10-01

This study examined associations of women's attitudes toward domestic violence (DV) and contraceptive use in West and Central Africa. We used data from the Multiple Indicator Cluster Surveys for women in seven countries in West and Central Africa (2009-2011, n=80,055). We measured contraceptive use as none, traditional, or modern contraceptives. DV approval was measured as no, low, or high tolerance of wife beating. Multinomial logistic regression estimated odds of using traditional or modern methods versus none, adjusting for age, education, wealth, residence, parity, marital structure, spousal age-difference, and religion. Many women had no or low DV tolerance (41%, 44%, respectively); most used no contraception (81%). In adjusted results, women with low DV tolerance had lower odds of using traditional contraceptive methods (odds ratio, OR=0.87; 95% confidence interval, CI: 0.78-0.98) or modern methods (OR=0.86; 95% CI: 0.78-0.95) compared to women with no tolerance. Women with high DV tolerance had 28% lower odds of traditional contraceptive use (95% CI: 0.60-0.90), and 38% lower odds of modern contraceptive use (95% CI: 0.59-0.88) compared to women with no tolerance. The high prevalence of DV approval may threaten the success of programs aimed at improving women's reproductive health, including contraceptive use. Copyright © 2017 Elsevier B.V. All rights reserved.

Disease patterns and causes of death of hospitalized HIV-positive adults in West Africa: a multicountry survey in the antiretroviral treatment era.

PubMed

Lewden, Charlotte; Drabo, Youssoufou J; Zannou, Djimon M; Maiga, Moussa Y; Minta, Daouda K; Sow, Papa S; Akakpo, Jocelyn; Dabis, François; Eholié, Serge P

2014-01-01

We aimed to describe the morbidity and mortality patterns in HIV-positive adults hospitalized in West Africa. We conducted a six-month prospective multicentre survey within the IeDEA West Africa collaboration in six adult medical wards of teaching hospitals in Abidjan, Ouagadougou, Cotonou, Dakar and Bamako. From April to October 2010, all newly hospitalized HIV-positive patients were eligible. Baseline and follow-up information until hospital discharge was recorded using standardized forms. Diagnoses were reviewed by a local event validation committee using reference definitions. Factors associated with in-hospital mortality were studied with a logistic regression model. Among 823 hospitalized HIV-positive adults (median age 40 years, 58% women), 24% discovered their HIV infection during the hospitalization, median CD4 count was 75/mm(3) (IQR: 25-177) and 48% had previously received antiretroviral treatment (ART). The underlying causes of hospitalization were AIDS-defining conditions (54%), other infections (32%), other diseases (8%) and non-specific illness (6%). The most frequent diseases diagnosed were: tuberculosis (29%), pneumonia (15%), malaria (10%) and cerebral toxoplasmosis (10%). Overall, 315 (38%) patients died during hospitalization and the underlying cause of death was AIDS (63%), non-AIDS-defining infections (26%), other diseases (7%) and non-specific illness or unknown cause (4%). Among them, the most frequent fatal diseases were: tuberculosis (36%), cerebral toxoplasmosis (10%), cryptococcosis (9%) and sepsis (7%). Older age, clinical WHO stage 3 and 4, low CD4 count, and AIDS-defining infectious diagnoses were associated with hospital fatality. AIDS-defining conditions, primarily tuberculosis, and bacterial infections were the most frequent causes of hospitalization in HIV-positive adults in West Africa and resulted in high in-hospital fatality. Sustained efforts are needed to integrate care of these disease conditions and optimize earlier

Phylogenetic and Pathotypic Characterization of Newcastle Disease Viruses Circulating in West Africa and Efficacy of a Current Vaccine

PubMed Central

Samuel, Arthur; Nayak, Baibaswata; Paldurai, Anandan; Xiao, Sa; Aplogan, Gilbert L.; Awoume, Kodzo A.; Webby, Richard J.; Ducatez, Mariette F.; Collins, Peter L.

2013-01-01

Newcastle disease (ND) is a deadly avian disease worldwide. In Africa, ND is enzootic and causes large economic losses, but little is known about the Newcastle disease virus (NDV) strains circulating in African countries. In this study, 27 NDV isolates collected from apparently healthy chickens in live-bird markets of the West African countries Benin and Togo in 2009 were characterized. All isolates had polybasic fusion (F)-protein cleavage sites and were shown to be highly virulent in standard pathogenicity assays. Infection of 2-week-old chickens with two of the isolates resulted in 100% mortality within 4 days. Phylogenetic analysis of the 27 isolates based on a partial F-protein gene sequence identified three clusters: one containing all the isolates from Togo and one from Benin (cluster 2), one containing most isolates from Benin (cluster 3), and an outlier isolate from Benin (cluster 1). All the three clusters are related to genotype VII strains of NDV. In addition, the cluster of viruses from Togo contained a recently identified 6-nucleotide insert between the hemagglutinin-neuraminidase (HN) and large polymerase (L) genes in a complete genome of an NDV isolate from this geographical region. Multiple strains that include this novel element suggest local emergence of a new genome length class. These results reveal genetic diversity within and among local NDV populations in Africa. Sequence analysis showed that the F and HN proteins of six West African isolates share 83.2 to 86.6% and 86.5 to 87.9% identities, respectively, with vaccine strain LaSota, indicative of considerable diversity. A vaccine efficacy study showed that the LaSota vaccine protected birds from morbidity and mortality but did not prevent shedding of West African challenge viruses. PMID:23254128

Characterization of the Sahelian-Sudan rainfall based on observations and regional climate models

NASA Astrophysics Data System (ADS)

Salih, Abubakr A. M.; Elagib, Nadir Ahmed; Tjernström, Michael; Zhang, Qiong

2018-04-01

The African Sahel region is known to be highly vulnerable to climate variability and change. We analyze rainfall in the Sahelian Sudan in terms of distribution of rain-days and amounts, and examine whether regional climate models can capture these rainfall features. Three regional models namely, Regional Model (REMO), Rossby Center Atmospheric Model (RCA) and Regional Climate Model (RegCM4), are evaluated against gridded observations (Climate Research Unit, Tropical Rainfall Measuring Mission, and ERA-interim reanalysis) and rain-gauge data from six arid and semi-arid weather stations across Sahelian Sudan over the period 1989 to 2008. Most of the observed rain-days are characterized by weak (0.1-1.0 mm/day) to moderate (> 1.0-10.0 mm/day) rainfall, with average frequencies of 18.5% and 48.0% of the total annual rain-days, respectively. Although very strong rainfall events (> 30.0 mm/day) occur rarely, they account for a large fraction of the total annual rainfall (28-42% across the stations). The performance of the models varies both spatially and temporally. RegCM4 most closely reproduces the observed annual rainfall cycle, especially for the more arid locations, but all of the three models fail to capture the strong rainfall events and hence underestimate its contribution to the total annual number of rain-days and rainfall amount. However, excessive moderate rainfall compensates this underestimation in the models in an annual average sense. The present study uncovers some of the models' limitations in skillfully reproducing the observed climate over dry regions, will aid model users in recognizing the uncertainties in the model output and will help climate and hydrological modeling communities in improving models.

Mineralogical, crystallographic and morphological characteristics of natural kaolins from the Ivory Coast (West Africa)

NASA Astrophysics Data System (ADS)

Sei, J.; Morato, F.; Kra, G.; Staunton, S.; Quiquampoix, H.; Jumas, J. C.; Olivier-Fourcade, J.

2006-10-01

Thirteen clay samples from four deposits in the Ivory Coast (West Africa) were studied using X-ray diffraction, thermogravimetric analysis and chemical analysis. Mineralogical, crystallographic and morphological characteristics of these samples are given. Kaolinite is the principal mineral but other minerals are present in small quantities: illite, quartz, anatase and iron oxides (oxides and oxyhydroxides). The crystallographic, morphological and surface characteristics are influenced by the presence of these impurities. In particular, the presence of iron oxides was associated with reduced structural ordering and thermal stability of kaolinite and increased specific surface area. These clays could be used in the ceramics industry to make tiles and bricks, and also in agronomy as supports for chemical fertilizers or for environmental protection by immobilising potentially toxic waste products.

Environmental Education in Côte d'Ivoire/West Africa: Extra-Curricular Primary School Teaching Shows Positive Impact on Environmental Knowledge and Attitudes

ERIC Educational Resources Information Center

Borchers, Claudia; Boesch, Christophe; Riedel, Julia; Guilahoux, Hilaire; Ouattara, Dabila; Randler, Christoph

2014-01-01

This paper surveys the consequences of pupils' participation in the extra-curricular environmental education (EE) programme Club P.A.N. (Peoples, Animals and Nature) by monitoring changes in their respective knowledge as well as in their environmental attitudes. The programme was conducted in Côte d'Ivoire in West Africa with the help of the local…

Culture and biomedical care in Africa: the influence of culture on biomedical care in a traditional African society, Nigeria, West Africa.

PubMed

Chukwuneke, F N; Ezeonu, C T; Onyire, B N; Ezeonu, P O

2012-01-01

Biomedical Care in Africa and the influence of culture on the health-seeking behaviour of Africans can not be underestimated; many African cultures have different understanding of the causes of disease which more often affect our public health system, policy, planning and implementations. The traditional African healer unlike a doctor trained in western biomedicine, looks for the cause of the patient's ailments as misfortune in relationship between the patient and the social, natural and spiritual environments. The complexity of African society with different cultural and religious practices also reflects on the people's attitude and understanding of their health matters. This paper is an overview of the cultural influence on biomedical care in a traditional African society, Nigeria, West Africa. A research on the patients' health seeking behaviour and Primary Health Care service organization in 10 health centres in the five eastern states of the Federal Republic of Nigeria was carried out using a multistage cross-sectional study. A semi-structured questionnaire was administered to the health care providers and patients while an in-depth semi- structured interview was also conducted. We observed there is underutilization of health care services at the primary level because most people do not accept the model of health care system provided for them. Most people believe diseases are caused by supernatural beings, the handiwork of neighbours or vengeance from an offended god as a result of transgressions committed in the past by an individual or parents. This group of people therefore prefers seeking traditional medicine to seeking orthodox medicine and often ends up in the hands of witch doctors who claim to have cure to almost all the diseases. Biomedical care in Africa is influence by culture because of different understanding of what ailment is and also due to limited knowledge of health matters, poverty and ignorance. There is a need therefore to focus on health

Prevalence of hepatitis B and delta according to HIV-type: a multi-country cross-sectional survey in West Africa.

PubMed

Coffie, Patrick A; Tchounga, Boris K; Bado, Guillaume; Kabran, Mathieu; Minta, Daouda K; Wandeler, Gilles; Gottlieb, Geoffrey S; Dabis, François; Eholie, Serge P; Ekouevi, Didier K

2017-07-04

In West Africa where HIV-1 and HIV-2 co-circulate, the co-infection with hepatitis B virus (HBV) and hepatitis Delta virus (HDV) is not well described. This study aimed at estimating the prevalence of HBV and HBV/HDV co-infection according to HIV types and risk factors for HBV infection among West African HIV-infected patients. A cross-sectional survey was conducted within the IeDEA West Africa cohort from March to December 2012 in Côte d'Ivoire (three sites), Burkina Faso and Mali (one site each). All HIV-infected adult patients on antiretroviral therapy (ART) or not who attended one of the participating HIV clinics during the study period and agreed to participate were included. Blood samples were collected and re-tested for HIV type discrimination, HBV and HDV serology as well as HBV viral load. Logistic regression was used to identify risk factors for HBV infection. A total of 791 patients were included: 192 HIV-1, 447 HIV-2 and 152 HIV-1&2 dually reactive. At time of sampling, 555 (70.2%) were on ART and median CD4+ cell count was 472/mm 3 (inter-quartile range [IQR]: IQR: 294-644). Sixty-seven (8.5%, 95% CI 6.6-10.6) patients were HBsAg positive without any difference according to HIV type (7.9% in HIV-1, 7.2% in HIV-1&2 dually reactive and 9.4% in HIV-2; p = 0.61). In multivariate logistic analysis, age ≤ 30 years old (adjusted odds ratio [aOR] 5.00, 95% CI 1.96-12.76), age between 31 and 49 years old (aOR 1.78, 95% CI 1.00-2.21) and male gender (aOR 2.15, 95% CI 1.25-3.69) were associated with HBsAg positivity. HBV DNA testing was performed in 36 patients with blood sample available (25 on ART) and 8 (22.2%) had detectable HBV DNA. Among the HBsAg-positive individuals, 14.9% (95% CI 7.4-25.7) were also positive for anti-HDV antibody without any difference according to HIV type (28.6% in HIV-1, 14.3% in HIV-2 and 0.0% in HIV-1&2 dually reactive; p = 0.15). HBV and HBV/HDV co-infection are common in West Africa, irrespective of HIV type. Therefore

Insecticide dissipation from soil and plant surfaces in tropical horticulture of southern Benin, West Africa.

PubMed

Rosendahl, Ingrid; Laabs, Volker; Atcha-Ahowé, Cyrien; James, Braima; Amelung, Wulf

2009-06-01

In Sub-Saharan Africa, horticulture provides livelihood opportunities for millions of people, especially in urban and peri-urban areas. Although the vegetable agroecosystems are often characterized by intensive pesticide use, risks resulting therefrom are largely unknown under tropical horticultural conditions. The objective of this study therefore was to study the fate of pesticides in two representative horticultural soils (Acrisol and Arenosol) and plants (Solanum macrocarpon L.) after field application and thus to gain first insight on environmental persistence and dispersion of typical insecticides used in vegetable horticulture in Benin, West Africa. On plant surfaces, dissipation was rapid with half lives ranging from 2 to 87 h (alpha-endosulfan < beta-endosulfan < deltamethrin). Soil dissipation was considerably slower than dissipation from plant surfaces with half-lives ranging from 3 (diazinon) to 74 d (total endosulfan), but persistence of pesticides in soil was still reduced compared to temperate climates. Nevertheless, for deltamethrin and endosulfan, a tendency for mid-term accumulation in soil upon repeated applications was observed. The soil and plant surface concentrations of the metabolite endosulfan sulfate increased during the entire trial period, indicating that this compound is a potential long-term pollutant even in tropical environments.

Study of the mixing and ageing of polluted plumes from major West Africa cities

NASA Astrophysics Data System (ADS)

Tocquer, Flore; Mari, Céline; Leriche, Maud; Dacciwa Team

2017-04-01

Massive economic and population growth, fast urbanization in megacities along the Guinea Coast, would triple anthropogenic emissions by 2030 (Knippertz et al., 2015). Impacts of the rapid increase of atmospheric pollutants on weather and climate in this region are largely unstudied due to a lack of observations. The DACCIWA (Dynamics-aerosol-chemistry-cloud interactions in West Africa) project carried out an important airborne measurements campaign in June-July 2016 together with ground-based observations in urban and remote sites. Urban and industrial, biogenic dominated environment, dust and biomass burning air masses, ship plumes and flaring emissions were sampled successfully. The goal of this work is to investigate the transport and ageing of anthropogenic emissions from major West African megacities during boreal summer. For this purpose, the coupled atmosphere-chemistry mesoscale model Méso-NH was run at kilometric scale and results were compared with in-situ meteorological and chemical data. The study focuses on 06-07-08 July 2016. Three research aircrafts operated over the coastal region sampling downwind pollution from Lomé and Accra and biogenic emissions further inland. Preliminary simulation results will be presented to understand the mixing between and ageing of cities plumes during the post-onset period of the campaign.

MtDNA profile of West Africa Guineans: towards a better understanding of the Senegambia region.

PubMed

Rosa, Alexandra; Brehm, António; Kivisild, Toomas; Metspalu, Ene; Villems, Richard

2004-07-01

The matrilineal genetic composition of 372 samples from the Republic of Guiné-Bissau (West African coast) was studied using RFLPs and partial sequencing of the mtDNA control and coding region. The majority of the mtDNA lineages of Guineans (94%) belong to West African specific sub-clusters of L0-L3 haplogroups. A new L3 sub-cluster (L3h) that is found in both eastern and western Africa is present at moderately low frequencies in Guinean populations. A non-random distribution of haplogroups U5 in the Fula group, the U6 among the "Brame" linguistic family and M1 in the Balanta-Djola group, suggests a correlation between the genetic and linguistic affiliation of Guinean populations. The presence of M1 in Balanta populations supports the earlier suggestion of their Sudanese origin. Haplogroups U5 and U6, on the other hand, were found to be restricted to populations that are thought to represent the descendants of a southern expansion of Berbers. Particular haplotypes, found almost exclusively in East-African populations, were found in some ethnic groups with an oral tradition claiming Sudanese origin.

A Landscape-based model for predicting Mycobacterium ulcerans infection (Buruli Ulcer disease) presence in Benin, West Africa.

PubMed

Wagner, Tyler; Benbow, M Eric; Burns, Meghan; Johnson, R Christian; Merritt, Richard W; Qi, Jiaguo; Small, Pamela L C

2008-03-01

Mycobacterium ulcerans infection (Buruli ulcer [BU] disease) is an emerging tropical disease that causes severe morbidity in many communities, especially those in close proximity to aquatic environments. Research and control efforts are severely hampered by the paucity of data regarding the ecology of this disease; for example, the vectors and modes of transmission remain unknown. It is hypothesized that BU presence is associated with altered landscapes that perturb aquatic ecosystems; however, this has yet to be quantified over large spatial scales. We quantified relationships between land use/land cover (LULC) characteristics surrounding individual villages and BU presence in Benin, West Africa. We also examined the effects of other village-level characteristics which we hypothesized to affect BU presence, such as village distance to the nearest river. We found that as the percent urban land use in a 50-km buffer surrounding a village increased, the probability of BU presence decreased. Conversely, as the percent agricultural land use in a 20-km buffer surrounding a village increased, the probability of BU presence increased. Landscape-based models had predictive ability when predicting BU presence using validation data sets from Benin and Ghana, West Africa. Our analyses suggest that relatively small amounts of urbanization are associated with a decrease in the probability of BU presence, and we hypothesize that this is due to the increased availability of pumped water in urban environments. Our models provide an initial approach to predicting the probability of BU presence over large spatial scales in Benin and Ghana, using readily available land use data.

Provenance history of detrital diamond deposits, West Coast of Namaqualand, South Africa

NASA Astrophysics Data System (ADS)

Phillips, David; Harris, Jeffrey W.; de Wit, Michiel C. J.; Matchan, Erin L.

2018-05-01

The West Coast of Namaqualand in South Africa hosts extensive detrital diamond deposits, but considerable debate exists as to the provenance of these diamonds. Some researchers have suggested derivation of the diamonds from Cretaceous-Jurassic kimberlites (also termed Group I kimberlites) and orangeites (also termed Group II kimberlites) located on the Kaapvaal Craton. However, others favour erosion of diamonds from the ca.300 Ma Dwyka Group sediments, with older, pre-Karoo kimberlites being the original source(s). Previous work has demonstrated that 40Ar/39Ar analyses of clinopyroxene inclusions, extracted from diamonds, yield ages approaching the time(s) of source kimberlite emplacement, which can be used to constrain the provenance of placer diamond deposits. In the current study, 40Ar/39Ar analyses were conducted on clinopyroxene inclusions from two similar batches of Namaqualand detrital diamonds, yielding (maximum) ages ranging from 117.5 ± 43.6 Ma to 3684 ± 191 Ma (2σ) and 120.6 ± 15.4 Ma to 688.8 ± 4.9 Ma (2σ), respectively. The vast majority of inclusions (88%) produced ages younger than 500 Ma, indicating that most Namaqualand diamonds originated from Cretaceous-Jurassic kimberlites/orangeites, with few, if any, derived from the Dwyka tillites. The provenance of the Namaqualand diamonds from ca.115-200 Ma orangeites is consistent with Late Cretaceous paleo-drainage reconstructions, as these localities could have been sampled by the `paleo-Karoo' River and transported to the West Coast via an outlet close to the current Olifants River mouth. At ca.90 Ma, this drainage system appears to have been captured by the `paleo-Kalahari' River, a precursor to the modern Orange River system. This latter drainage is considered to have transported diamonds eroded from both ca.80-90 Ma kimberlites and ca.115-200 Ma orangeites to the West Coast, which were subsequently reworked along the Namibian coast, forming additional placer deposits.

Insecticide resistance in Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Anopheles gambiae Giles (Diptera: Culicidae) could compromise the sustainability of malaria vector control strategies in West Africa.

PubMed

Gnankiné, Olivier; Bassolé, Imael H N; Chandre, Fabrice; Glitho, Isabelle; Akogbeto, Martin; Dabiré, Roch K; Martin, Thibaud

2013-10-01

Insecticides from the organophosphate (OP) and pyrethroid (PY) chemical families, have respectively, been in use for 50 and 30 years in West Africa, mainly against agricultural pests, but also against vectors of human disease. The selection pressure, with practically the same molecules year after year (mainly on cotton), has caused insecticide resistance in pest populations such as Bemisia tabaci, vector of harmful phytoviruses on vegetables. The evolution toward insecticide resistance in malaria vectors such as Anopheles gambiae sensus lato (s.l.) is probably related to the current use of these insecticides in agriculture. Thus, successful pest and vector control in West Africa requires an investigation of insect susceptibility, in relation to the identification of species and sub species, such as molecular forms or biotypes. Identification of knock down resistance (kdr) and acetylcholinesterase gene (Ace1) mutations modifying insecticide targets in individual insects and measure of enzymes activity typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase) are indispensable in understanding the mechanisms of resistance. Insecticide resistance is a good example in which genotype-phenotype links have been made successfully. Insecticides used in agriculture continue to select new resistant populations of B. tabaci that could be from different biotype vectors of plant viruses. As well, the evolution of insecticide resistance in An. gambiae threatens the management of malaria vectors in West Africa. It raises the question of priority in the use of insecticides in health and/or agriculture, and more generally, the question of sustainability of crop protection and vector control strategies in the region. Here, we review the susceptibility tests, biochemical and molecular assays data for B. tabaci, a major pest in cotton and vegetable crops, and An. gambiae, main vector of malaria. The data reviewed was collected in Benin and Burkina

Seasonal variation in wing size and shape between geographic populations of the malaria vector, Anopheles coluzzii in Burkina Faso (West Africa).

PubMed

Hidalgo, Kevin; Dujardin, Jean-Pierre; Mouline, Karine; Dabiré, Roch K; Renault, David; Simard, Frederic

2015-03-01

The mosquito, Anopheles coluzzii is a major vector of human malaria in Africa with widespread distribution throughout the continent. The species hence populates a wide range of environments in contrasted ecological settings often exposed to strong seasonal fluctuations. In the dry savannahs of West Africa, this mosquito population dynamics closely follows the pace of surface water availability: the species pullulates during the rainy season and is able to reproduce throughout the dry season in areas where permanent water bodies are available for breeding. The impact of such environmental fluctuation on mosquito development and the phenotypic quality of emerging adults has however not been addressed in details. Here, we examined and compared phenotypic changes in the duration of pre-imaginal development, body dry mass at emergence and wing size, shape and surface area in young adult females An. coluzzii originated from five distinct geographic locations when they are reared in two contrasting conditions mimicking those experienced by mosquitoes during the rainy season (RS) and at the onset of the dry season (ODS) in Burkina Faso (West Africa). Our results demonstrated strong phenotypic plasticity in all traits, with differences in the magnitude and direction of changes between RS and ODS depending upon the geographic origin, hence the genetic background of the mosquito populations. Highest heterogeneity within population was observed in Bama, where large irrigation schemes allow year-round mosquito breeding. Further studies are needed to explore the adaptive value of such phenotypic plasticity and its relevance for local adaptation in An. coluzzii. Copyright © 2015 Elsevier B.V. All rights reserved.

From institutionalization of user fees to their abolition in West Africa: a story of pilot projects and public policies

PubMed Central

2015-01-01

This article analyzes the historical background of the institutionalization of user fees and their subsequent abolition in West Africa. Based on a narrative review, we present the context that frames the different articles in this supplement. We first show that a general consensus has emerged internationally against user fees, which were imposed widely in Africa in the 1980s and 1990s; at that time, the institutionalization of user fees was supported by evidence from pilot projects funded by international aid agencies. Since then there have been other pilot projects studying the abolition of user fees in the 2000s, but these have not yet had any real influence on public policies, which are often still chaotic. This perplexing situation might be explained more by ideologies and political will than by insufficient financial capacity of states. PMID:26559564

On the impact of anthropogenic emissions on biogenic SOA formation above West Africa: results from DACCIWA aircraft field campaign

NASA Astrophysics Data System (ADS)

Brito, Joel; Freney, Evelyn; Colomb, Aurelie; Dupuy, Régis; Duplissy, Jonathan; Denjean, Cyrielle; Dominutti, Pamela; Batenburg, Anneke; Haslett, Sophie; Schulz, Christiane; Bourrianne, Thierry; Burnet, Frederic; Borbon, Agnès; Schneider, Johannes; Borrmann, Stephan; Coe, Hugh; Sellegri, Karine; Flamant, Cyrille; Knippertz, Peter; Schwarzenboeck, Alfons

2017-04-01

As part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, airborne campaigns were designed to measure a large range of atmospheric constituents focusing on the improvement of our current understanding on the effect of anthropogenic emissions on regional climate. The targeted region, Southern West Africa, holds currently a population of over 340 million people, and is predicted by the United Nations to reach about 800 million by 2050. The climate in the region is characterized by a large-scale atmospheric circulation system which controls precipitation over a land area of about 6 million km2, directly impacting the water resources, agriculture and power generation of hundreds of millions of people. Besides its large natural variability, the West African monsoon system is also expected to be significantly affected by global and regional climate change, with large uncertainties on the role of local pollution. An important aspect assessing the impact of human activities on the local climate is thereby the understanding of aerosol sources and properties. The presented study details results of the DACCIWA measurement campaign using the French ATR42 research aircraft, which in combination with the German Falcon 20 and British Twin Otter aircraft, aimed to characterize physico-chemical properties of aerosols in the region using a suite of aerosol measurement techniques (e.g. C-TOF AMS, APITOF, SMPS, etc.) and supporting information from simultaneous trace gas measurements (e.g. PTRMS). This large dataset has been used to assess how anthropogenic emission (NOx, SO2, SO4) is impacting formation of biogenic secondary organic aerosol formation, in particular through the formation of isoprene epoxydiols (IEPOX). The recently collected data will certainly help understanding the coupling between human activities and regional climate in a sensitive, highly populated area.

Cutaneous anthrax associated with drum making using goat hides from West Africa--Connecticut, 2007.

PubMed

2008-06-13

On August 29, 2007, the Connecticut Department of Public Health was notified by a physician of suspect cutaneous anthrax involving a drum maker and one of his three children. The drum maker had been working with untreated goat hides from Guinea in West Africa. This report summarizes results of the joint epidemiologic and environmental investigation conducted by public health officials, environmental agencies, and law enforcement authorities. The investigation revealed that the drum maker was exposed while working with a contaminated goat hide from Guinea and that his workplace and home were contaminated with anthrax. His child was most likely exposed from cross-contamination of the home. The findings underscore the potential hazard of working with untreated animal hides from areas with epizootic anthrax and the potential for secondary cases from environmental contamination.

Sub-Saharan Africa Report: No. 2788

DTIC Science & Technology

1983-04-21

Technip CEO, Jacques Celerier Interview Technip Operations Famine Threatens 50 Million Africans (WEST AFRICA, 11 Apr 83...exports. 2 First, Jacques Celerier, chief executive officer of the Technip group, the leading French engineering company which has just been awarded the...Interview With Technip CEO Dakar AFRICA in French Mar 83 pp 79-81 [Interview with Jacques Celerier, chief executive officer of Technip: "Africa Has One

In search of susceptibility genes for type 2 diabetes in West Africa: the design and results of the first phase of the AADM study.

PubMed

Rotimi, C N; Dunston, G M; Berg, K; Akinsete, O; Amoah, A; Owusu, S; Acheampong, J; Boateng, K; Oli, J; Okafor, G; Onyenekwe, B; Osotimehin, B; Abbiyesuku, F; Johnson, T; Fasanmade, O; Furbert-Harris, P; Kittles, R; Vekich, M; Adegoke, O; Bonney, G; Collins, F

2001-01-01

The purpose of this study is to map type 2 diabetes susceptibility genes in West African ancestral populations of African-Americans, through an international collaboration between West African and US investigators. Affected sib-pairs (ASP) along with unaffected spouse controls are being enrolled and examined in West Africa, with two sites established in Ghana (Accra and Kumasi) and three in Nigeria (Enugu, Ibadan, and Lagos). Eligible participants are invited to study clinics to obtain detailed epidemiologic, family, and medical history information. Blood samples are drawn from each participant to measure glucose, insulin, C-peptide, total cholesterol, LDL, HDL, triglycerides, albumin, creatinine, urea, uric acid, total calcium and to detect autoantibodies to glutamic acid decarboxylase (GAD). DNA is isolated from frozen white blood cells obtained from 20 ml of EDTA whole blood samples. With full informed consent, 162 individuals from 78 families have been enrolled and examined since the Africa America Diabetes Mellitus (AADM) study began in June of 1997. Logistics of field examinations and specimen shipping have been successfully established. At the end of the third year of field activity (September 2000) the AADM study will have enrolled and performed comprehensive examination on 400 ASP with type 2 diabetes, for a minimum of 800 cases and 200 controls from Ghana and Nigeria. At the current participation rate, the goal of 400 sib-pairs and 200 controls will be met before the scheduled closing date. The AADM study will create a comprehensive epidemiologic and genetic resource that will facilitate a powerful genome-wide search for West African susceptibility genes to type 2 diabetes.

Particle and VOC emission factor measurements for anthropogenic sources in West Africa

NASA Astrophysics Data System (ADS)

Keita, Sekou; Liousse, Cathy; Yoboué, Véronique; Dominutti, Pamela; Guinot, Benjamin; Assamoi, Eric-Michel; Borbon, Agnès; Haslett, Sophie L.; Bouvier, Laetitia; Colomb, Aurélie; Coe, Hugh; Akpo, Aristide; Adon, Jacques; Bahino, Julien; Doumbia, Madina; Djossou, Julien; Galy-Lacaux, Corinne; Gardrat, Eric; Gnamien, Sylvain; Léon, Jean F.; Ossohou, Money; Touré N'Datchoh, E.; Roblou, Laurent

2018-06-01

A number of campaigns have been carried out to establish the emission factors of pollutants from fuel combustion in West Africa, as part of work package 2 (Air Pollution and Health) of the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) FP7 program. Emission sources considered here include wood (hevea and iroko) and charcoal burning, charcoal making, open trash burning, and vehicle emissions, including trucks, cars, buses and two-wheeled vehicles. Emission factors of total particulate matter (TPM), elemental carbon (EC), primary organic carbon (OC) and volatile organic compounds (VOCs) have been established. In addition, emission factor measurements were performed in combustion chambers in order to reproduce field burning conditions for a tropical hardwood (hevea), and obtain particulate emission factors by size (PM0.25, PM1, PM2.5 and PM10). Particle samples were collected on quartz fiber filters and analyzed using gravimetric method for TPM and thermal methods for EC and OC. The emission factors of 58 VOC species were determined using offline sampling on a sorbent tube. Emission factor results for two species of tropical hardwood burning of EC, OC and TPM are 0.98 ± 0.46 g kg-1 of fuel burned (g kg-1), 11.05 ± 4.55 and 41.12 ± 24.62 g kg-1, respectively. For traffic sources, the highest emission factors among particulate species are found for the two-wheeled vehicles with two-stroke engines (2.74 g kg-1 fuel for EC, 65.11 g kg-1 fuel for OC and 496 g kg-1 fuel for TPM). The largest VOC emissions are observed for two-stroke two-wheeled vehicles, which are up to 3 times higher than emissions from light-duty and heavy-duty vehicles. Isoprene and monoterpenes, which are usually associated with biogenic emissions, are present in almost all anthropogenic sources investigated during this work and could be as significant as aromatic emissions in wood burning (1 g kg-1 fuel). EC is primarily emitted in the ultrafine fraction, with 77 % of

Sensitivity of Sahelian Precipitation to Desert Dust under ENSO variability: a regional modeling study

NASA Astrophysics Data System (ADS)

Jordan, A.; Zaitchik, B. F.; Gnanadesikan, A.

2016-12-01

Mineral dust is estimated to comprise over half the total global aerosol burden, with a majority coming from the Sahara and Sahel region. Bounded by the Sahara Desert to the north and the Sahelian Savannah to the south, the Sahel experiences high interannual rainfall variability and a short rainy season during the boreal summer months. Observation-based data for the past three decades indicates a reduced dust emission trend, together with an increase in greening and surface roughness within the Sahel. Climate models used to study regional precipitation changes due to Saharan dust yield varied results, both in sign convention and magnitude. Inconsistency of model estimates drives future climate projections for the region that are highly varied and uncertain. We use the NASA-Unified Weather Research and Forecasting (NU-WRF) model to quantify the interaction and feedback between desert dust aerosol and Sahelian precipitation. Using nested domains at fine spatial resolution we resolve changes to mesoscale atmospheric circulation patterns due to dust, for representative phases of El Niño-Southern Oscillation (ENSO). The NU-WRF regional earth system model offers both advanced land surface data and resolvable detail of the mechanisms of the impact of Saharan dust. Results are compared to our previous work assessed over the Western Sahel using the Geophysical Fluid Dynamics Laboratory (GFDL) CM2Mc global climate model, and to other previous regional climate model studies. This prompts further research to help explain the dust-precipitation relationship and recent North African dust emission trends. This presentation will offer a quantitative analysis of differences in radiation budget, energy and moisture fluxes, and atmospheric dynamics due to desert dust aerosol over the Sahel.

Variability of aerosol vertical distribution in the Sahel

NASA Astrophysics Data System (ADS)

Cavalieri, O.; Cairo, F.; Fierli, F.; di Donfrancesco, G.; Snels, M.; Viterbini, M.; Cardillo, F.; Chatenet, B.; Formenti, P.; Marticorena, B.; Rajot, J. L.

2010-12-01

In this work, we have studied the seasonal and inter-annual variability of the aerosol vertical distribution over Sahelian Africa for the years 2006, 2007 and 2008, characterizing the different kind of aerosols present in the atmosphere in terms of their optical properties observed by ground-based and satellite instruments, and their sources searched for by using trajectory analysis. This study combines data acquired by three ground-based micro lidar systems located in Banizoumbou (Niger), Cinzana (Mali) and M'Bour (Senegal) in the framework of the African Monsoon Multidisciplinary Analysis (AMMA), by the AEROsol RObotic NETwork (AERONET) sun-photometers and by the space-based Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the CALIPSO satellite (Cloud-Aerosol Lidar and Infrared Pathfinder Observations). During winter, the lower levels air masses arriving in the Sahelian region come mainly from North, North-West and from the Atlantic area, while in the upper troposphere air flow generally originates from West Africa, crossing a region characterized by the presence of large biomass burning sources. The sites of Cinzana, Banizoumbou and M'Bour, along a transect of aerosol transport from East to West, are in fact under the influence of tropical biomass burning aerosol emission during the dry season, as revealed by the seasonal pattern of the aerosol optical properties, and by back-trajectory studies. Aerosol produced by biomass burning are observed mainly during the dry season and are confined in the upper layers of the atmosphere. This is particularly evident for 2006, which was characterized by a large presence of biomass burning aerosols in all the three sites. Biomass burning aerosol is also observed during spring when air masses originating from North and East Africa pass over sparse biomass burning sources, and during summer when biomass burning aerosol is transported from the southern part of the continent by the monsoon flow. During summer

Sustainable Development of Research Capacity in West Africa based on the GLOWA Volta Project

NASA Astrophysics Data System (ADS)

Liebe, Jens R.; Rogmann, Antonio; Falk, Ulrike; Amisigo, Barnabas; Nyarko, Kofi; Harmsen, Karl; Vlek, Paul L. G.

2010-05-01

The Sustainable Development of Research Capacity (SDRC) in West Africa is an 18 month project, funded by the German Ministry of Education and Research, to strengthen the research capacity, give access to data and models, and to support the establishment of the newly formed Volta Basin Authority. The SDRC project largely builds on the results and models developed in the framework of the GLOWA Volta Project (GVP), a nine-year, interdisciplinary research project (May 2000 - May 2009). The GVP's central objectives were to analyze the physical and socio-economic determinants of the hydrological cycle in the Volta Basin in the face of global change, and to develop scientifically sound decision support resources. Another major achievement of GVP was the extensive capacity building. Of the 81 participating students (57 Ph.D.'s), 44 originated from West Africa, and 85% of the West African graduates returned to their home countries. The SDRC makes use of the wide range of research results and decision support tools developed in the course of the GVP. It is based on three columns: I. knowledge transfer and strengthening of human capacity, which focus on a training on the modeling of the onset of the rainy season, hydrological, economic, and hydro-economic modeling, and training of geospatial database managers; II. strengthening of infrastructural research capacity through the support of a research instrumentation network through the operation and transfer of a weather station network, a network of tele-transmitted stream gauges; and III. the transfer of a publicly accessible online Geoportal for the dissemination of various geospatial data and research results. At the center of the SDRC effort is the strengthening of the Volta Basin Authority, a river basin authority with a transnational mandate, especially through the transfer of the Geoportal, and the associated training and promotion efforts. The Geoportal is an effort to overcome the data scarcity previously observed in

An overview of the nutrition transition in West Africa: implications for non-communicable diseases.

PubMed

Bosu, William K

2015-11-01

The nutrition landscape in West Africa has been dominated by the programmes to address undernutrition. However, with increasing urbanisation, technological developments and associated change in dietary patterns and physical activity, childhood and adult overweight, and obesity are becoming more prevalent. There is an evidence of increasing intake of dietary energy, fat, sugars and protein. There is low consumption of fruit and vegetables universally in West Africa. Overall, the foods consumed are predominantly traditional with the component major food groups within recommended levels. Most of the West African countries are at the early stages of nutrition transition but countries such as Cape Verde, Ghana and Senegal are at the latter stages. In the major cities of the region, children consume energy-dense foods such as candies, ice cream and sweetened beverages up to seven times as frequently as fruit and vegetables. Adult obesity rates have increased by 115 % in 15 years since 2004. In Ghana, the prevalence of overweight/obesity in women has increased from 12·8 % in 1993 to 29·9 % in 2008. In Accra, overweight/obesity in women has increased from 62·2 % in 2003 to 64·9 % in 2009. The age-standardised proportion of adults who engage in adequate levels of physical activity ranges from 46·8 % in Mali to 94·7 % in Benin. The lingering stunting in children and the rising overweight in adults have resulted to a dual burden of malnutrition affecting 16·2 % of mother-child pairs in Cotonou. The prevalence of hypertension has been increased and ranges from 17·6 % in Burkina Faso to 38·7 % in Cape Verde. The prevalence is higher in the cities: 40·2 % in Ougadougou, 46·0 % in St Louis and 54·6 % in Accra. The prevalence of diabetes ranges from 2·5 to 7·9 % but could be as high as 17·9 % in Dakar, Senegal. The consequences of nutrition transition are not only being felt by the persons in the high socioeconomic class, but also in cities such as Accra and

Constructing an everywhere and locally relevant predictive model of the West-African critical zone

NASA Astrophysics Data System (ADS)

Hector, B.; Cohard, J. M.; Pellarin, T.; Maxwell, R. M.; Cappelaere, B.; Demarty, J.; Grippa, M.; Kergoat, L.; Lebel, T.; Mamadou, O.; Mougin, E.; Panthou, G.; Peugeot, C.; Vandervaere, J. P.; Vischel, T.; Vouillamoz, J. M.

2017-12-01

Considering water resources and hydrologic hazards, West Africa is among the most vulnerable regions to face both climatic (e.g. with the observed intensification of precipitation) and anthropogenic changes. With +3% of demographic rate, the region experiences rapid land use changes and increased pressure on surface and groundwater resources with observed consequences on the hydrological cycle (water table rise result of the sahelian paradox, increase in flood occurrence, etc.) Managing large hydrosystems (such as transboundary aquifers or rivers basins as the Niger river) requires anticipation of such changes. However, the region significantly lacks observations, for constructing and validating critical zone (CZ) models able to predict future hydrologic regime, but also comprises hydrosystems which encompass strong environmental gradients (e.g. geological, climatic, ecological) with highly different dominating hydrological processes. We address these issues by constructing a high resolution (1 km²) regional scale physically-based model using ParFlow-CLM which allows modeling a wide range of processes without prior knowledge on their relative dominance. Our approach combines multiple scale modeling from local to meso and regional scales within the same theoretical framework. Local and meso-scale models are evaluated thanks to the rich AMMA-CATCH CZ observation database which covers 3 supersites with contrasted environments in Benin (Lat.: 9.8°N), Niger (Lat.: 13.3°N) and Mali (Lat.: 15.3°N). At the regional scale the lack of relevant map of soil hydrodynamic parameters is addressed using remote sensing data assimilation. Our first results show the model's ability to reproduce the known dominant hydrological processes (runoff generation, ET, groundwater recharge…) across the major West-African regions and allow us to conduct virtual experiments to explore the impact of global changes on the hydrosystems. This approach is a first step toward the construction of

The consecutive dry days to trigger rainfall over West Africa

NASA Astrophysics Data System (ADS)

Lee, J. H.

2018-01-01

In order to resolve contradictions in addressing a soil moisture-precipitation feedback mechanism over West Africa and to clarify the impact of antecedent soil moisture on subsequent rainfall evolution, we first validated various data sets (SMOS satellite soil moisture observations, NOAH land surface model, TRMM rainfall, CMORPH rainfall and HadGEM climate models) with the Analyses Multidisciplinaires de la Mousson Africaine (AMMA) field campaign data. Based on this analysis, it was suggested that biases of data sets might cause contradictions in studying mechanisms. Thus, by taking into account uncertainties in data, it was found that the approach of consecutive dry days (i.e. a relative comparison of time-series) showed consistency across various data sets, while the direct comparison approach for soil moisture state and rainfall did not. Thus, it was discussed that it may be difficult to directly relate rain with soil moisture as the absolute value, however, it may be reasonable to compare a temporal progress of the variables. Based upon the results consistently showing a positive relationship between the consecutive dry days and rainfall, this study supports a negative feedback often neglected by climate model structure. This approach is less sensitive to interpretation errors arising from systematic errors in data sets, as this measures a temporal gradient of soil moisture state.

An empirical analysis of the Ebola outbreak in West Africa

NASA Astrophysics Data System (ADS)

Khaleque, Abdul; Sen, Parongama

2017-02-01

The data for the Ebola outbreak that occurred in 2014-2016 in three countries of West Africa are analysed within a common framework. The analysis is made using the results of an agent based Susceptible-Infected-Removed (SIR) model on a Euclidean network, where nodes at a distance l are connected with probability P(l) ∝ l-δ, δ determining the range of the interaction, in addition to nearest neighbors. The cumulative (total) density of infected population here has the form , where the parameters depend on δ and the infection probability q. This form is seen to fit well with the data. Using the best fitting parameters, the time at which the peak is reached is estimated and is shown to be consistent with the data. We also show that in the Euclidean model, one can choose δ and q values which reproduce the data for the three countries qualitatively. These choices are correlated with population density, control schemes and other factors. Comparing the real data and the results from the model one can also estimate the size of the actual population susceptible to the disease. Rescaling the real data a reasonably good quantitative agreement with the simulation results is obtained.

Obtaining land cover changes information from multitemporal analysis of Landsat-TM images: results from a case study in West African dryland

NASA Astrophysics Data System (ADS)

Nutini, F.; Boschetti, M.; Brivio, P. A.; Antoninetti, M.

2012-04-01

The Sahelian belt of West Africa is a semiarid region characterized by wide climate variations, which can in turn affect the livelihood of local populations particularly in rangeland areas, as happens during the dramatic food crisis in the 70-80s caused by rainfall scarcity. The monitoring of natural resources and rainfed agricultural activities, with the aim to provide information to support Sahelian food security action, needs the production of detailed thematic maps as emphasized by several scientific papers. In this framework, a study was conducted to develop a method to exploit time series of remote sensed satellite data to 1) provide reliable land cover (LC) map at local scale in a dry region and 2) obtain a LC change (LCC) map that contribute to identify the plausible causes of local environmental instability. Satellite images used for this work consist in a time series of Landsat Thematic Mapper (TM) (path row 195-50) acquired in the 2000 (6 scenes) and 2007 (9 scenes) from February (Dry season) to September (end of wet season). The study investigates the different contribution provided by spectra information of a single Landsat TM image and by time series of derived NDVI. Different tests have been conducted with different combination of data set (spectral and temporal)in order to identify the best approach to obtain a LC map in five classes of interest: Shrubland, Cultivated Land, Water body, Herbaceous vegetation and Bare soil. The best classification approach is exposed and applied on two years in the last decade. The comparison between this two LC results in land cover change map, that displays the changes of vegetation patterns that have been characterized the area. The discussed results show a largely stable dryland region, but locally characterized by hot-spot of decreasing in natural vegetation inside the rangelands and an increasing of cultivations along fossil valleys where human activities are slightly intense. The discussion shows that this hot

High prevalence of dental caries among HIV-infected children in West Africa compared to uninfected siblings.

PubMed

Rajonson, Noëlla; Meless, David; Ba, Boubacar; Faye, Malick; Diby, Jean-Serge; N'zore, Serge; Datté, Sébastien; Diecket, Lucrèce; N'Diaye, Clémentine; Aka, Edmond Addi; Kouakou, Kouadio; Ba, Abou; Ekouévi, Didier Koumavi; Dabis, François; Shiboski, Caroline; Arrivé, Elise

2017-06-01

The objectives of this study were to investigate the association between HIV infection and dental caries among children in West Africa, and to identify factors associated with dental caries among HIV-infected children. We conducted a multi-center cross-sectional study in Mali, Senegal and Côte d'Ivoire with a random sample of HIV-infected children aged 5-15 years on antiretroviral therapy and their uninfected siblings. A standardized examination was performed by calibrated dentists. The association between the number of decayed, missing or filled permanent and primary teeth surfaces (DMFdefS) and HIV status was investigated by fitting multivariable zero-inflated negative binomial models, for each age group (<12 and ≥12 years). Factors associated with dental caries could be investigated only for HIV-infected children <12 years old. The sample included 420 HIV-infected children and 418 non-infected siblings. The median DMFdefS was 7 for the HIV-infected children and 2 for the uninfected siblings. The proportion of children with DMFdefS ≥1 was significantly higher among the HIV-infected children than uninfected children (86.0 percent versus 64.4 percent, P < 0.001). The HIV-infected children were less likely to be caries-free than the uninfected siblings in both age groups. We found a higher degree of caries experience among HIV-infected children < 12 years old, in whom it was associated with sweet drink consumption, history of night bottle use, immunosuppression, and younger age at study entry. Although preventable, the burden of dental disease was high in children from families affected by HIV in West Africa and was associated with HIV infection and immunosuppression. © 2017 American Association of Public Health Dentistry.

Factors Associated with Variations in Population HIV Prevalence across West Africa: Findings from an Ecological Analysis

PubMed Central

Prudden, Holly J.; Beattie, Tara S.; Bobrova, Natalia; Panovska-Griffiths, Jasmina; Mukandavire, Zindoga; Gorgens, Marelize; Wilson, David; Watts, Charlotte H.

2015-01-01

Background Population HIV prevalence across West Africa varies substantially. We assess the national epidemiological and behavioural factors associated with this. Methods National, urban and rural data on HIV prevalence, the percentage of younger (15–24) and older (25–49) women and men reporting multiple (2+) partners in the past year, HIV prevalence among female sex workers (FSWs), men who have bought sex in the past year (clients), and ART coverage, were compiled for 13 countries. An Ecological analysis using linear regression assessed which factors are associated with national variations in population female and male HIV prevalence, and with each other. Findings National population HIV prevalence varies between 0 4–2 9% for men and 0 4–5.6% for women. ART coverage ranges from 6–23%. National variations in HIV prevalence are not shown to be associated with variations in HIV prevalence among FSWs or clients. Instead they are associated with variations in the percentage of younger and older males and females reporting multiple partners. HIV prevalence is weakly negatively associated with ART coverage, implying it is not increased survival that is the cause of variations in HIV prevalence. FSWs and younger female HIV prevalence are associated with client population sizes, especially older men. Younger female HIV prevalence is strongly associated with older male and female HIV prevalence. Interpretation In West Africa, population HIV prevalence is not significantly higher in countries with high FSW HIV prevalence. Our analysis suggests, higher prevalence occurs where more men buy sex, and where a higher percentage of younger women, and older men and women have multiple partnerships. If a sexual network between clients and young females exists, clients may potentially bridge infection to younger females. HIV prevention should focus both on commercial sex and transmission between clients and younger females with multiple partners. PMID:26698854

Factors Associated with Variations in Population HIV Prevalence across West Africa: Findings from an Ecological Analysis.

PubMed

Prudden, Holly J; Beattie, Tara S; Bobrova, Natalia; Panovska-Griffiths, Jasmina; Mukandavire, Zindoga; Gorgens, Marelize; Wilson, David; Watts, Charlotte H

2015-01-01

Population HIV prevalence across West Africa varies substantially. We assess the national epidemiological and behavioural factors associated with this. National, urban and rural data on HIV prevalence, the percentage of younger (15-24) and older (25-49) women and men reporting multiple (2+) partners in the past year, HIV prevalence among female sex workers (FSWs), men who have bought sex in the past year (clients), and ART coverage, were compiled for 13 countries. An Ecological analysis using linear regression assessed which factors are associated with national variations in population female and male HIV prevalence, and with each other. National population HIV prevalence varies between 0 4-2 9% for men and 0 4-5.6% for women. ART coverage ranges from 6-23%. National variations in HIV prevalence are not shown to be associated with variations in HIV prevalence among FSWs or clients. Instead they are associated with variations in the percentage of younger and older males and females reporting multiple partners. HIV prevalence is weakly negatively associated with ART coverage, implying it is not increased survival that is the cause of variations in HIV prevalence. FSWs and younger female HIV prevalence are associated with client population sizes, especially older men. Younger female HIV prevalence is strongly associated with older male and female HIV prevalence. In West Africa, population HIV prevalence is not significantly higher in countries with high FSW HIV prevalence. Our analysis suggests, higher prevalence occurs where more men buy sex, and where a higher percentage of younger women, and older men and women have multiple partnerships. If a sexual network between clients and young females exists, clients may potentially bridge infection to younger females. HIV prevention should focus both on commercial sex and transmission between clients and younger females with multiple partners.

Mother Tongue Education: The West African Experience.

ERIC Educational Resources Information Center

Bamgbose, Ayo, Ed.

In the rapidly changing political, economic, and social life of West Africa, there is a renewed interest in cultural identity. This book describes the developments and the difficulties experienced by different West African countries in the use of mother tongues in multi-lingual society. The book was commissioned to give scholars, educators, and…

Schistosomiasis in the Gorgol Valley of Mauritania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jobin, W.R.; Negron-Aponte, H.; Michelson, E.H.

1976-07-01

Schistosomiasis may be increasing in West Africa due to the development of water-resource projects which were given a strong impetus by the disastrous Sahelian drought. This report concerns the existing epidemiology of schistosomiasis in West Africa for the Fourth Region of Mauritania, along the Gorgol River. In this area two reservoirs are proposed, to supply a new rice irrigation system. During May and November 1974, field surveys were made to determine the prevalence and intensity of schistosomiasis, and the relevant species of snails. The surveys were made as a basis for designing the irrigation systems to minimize transmission. The onlymore » snails found in the area were two species of Bulinus; therefore, the human population was tested for Schistosoma haematobium. A high prevalence of schistosomiasis was found in M'Bout, the town nearest the proposed reservoir at Foum Gleita. Prevalence rates were lowest in Kaedi near the confluence of the Gorgol and Senegal rivers. During the period between the first and second survey the incidence rate among children in M'Bout became very high (68%), probably because of increased water contact related to the rains that broke the long drought in August 1974.« less

Switching the poles in sexual and reproductive health research: implementing a research capacity-strengthening network in West and North Africa.

PubMed

Dossou, Jean-Paul; Assarag, Bouchra; Delamou, Alexandre; Van der Veken, Karen; Belaid, Loubna; Ouédraogo, Moctar; Khalfallah, Sonia; Aouras, Hayet; Diadhiou, Mohamed; Fassassi, Raïmi; Delvaux, Thérèse

2016-08-08

Health research capacities have been improved in Africa but still remain weak as compared to other regions of the World. To strengthen these research capacities, international collaboration and networking for knowledge and capacity transfer are needed. In this commentary, we present the Network for Scientific Support in the field of Sexual and Reproductive Health in West and North Africa, its priority research topics and discuss its implementation process. Established in January 2014, the Network aims at generating human rights and gender-based research fully carried out and driven by South based institutions. It is composed of 12 institutions including the Institute of Tropical Medicine of Antwerp (Belgium) and 11 institutions from eight Francophone West and North African countries. The key areas of interest of this network are health policies analysis and health system research in family planning, HIV prevention among vulnerable groups, quality of care and breast cancers. Since it started, seventeen research proposals based on locally relevant research questions have been developed. Among the seventeen proposals, eleven have been implemented. Several research institutions enhanced linkages with local representations of international partners such as UNFPA. The network is committed to strengthening methodological research capacities and soft skills such as fundraising, advocacy and leadership. Such competencies are strongly needed for developing an effective South-based leadership in Sexual and Reproductive Health research, and for achieving the Sustainable Development Goals.

Kwame Nkrumah University of Science and Technology School of Veterinary Medicine (KNUST SVM) A Model of "One-Health Concept" Application to Veterinary Education in West Africa.

PubMed

Folitse, R D; Agyemang, T Opoku; Emikpe, B O; Evarefe, O D; Atawalna, J

2014-12-01

Veterinary education in West Africa had been skewed over decades with Nigeria and Senegal leading in the training of veterinarians in the subregion. Most nationals from Ghana, Sierra Leone, Gambia as well as francophone countries within the subregion were trained in East Africa, Europe and South America. The aim of this paper is to provide an insight into the need for veterinary education in other West African countries including Ghana Information was sourced from individuals, literatures and other relevant archives on the history, current state and future approaches to veterinary education in Ghana. The advantages, challenges and coping strategies for application of the Principles of "The One World One Health concept" to veterinary education with the use of the medical professionals in the delivery were presented. This approach to veterinary education by Kwame Nkrumah University of Science and Technology School of Veterinary Medicine showcases a means to meet the health challenges of the twenty first century which demand pragmatic innovation to solve disease challenges.

New alternatives for reference evapotranspiration estimation in West Africa using limited weather data and ancillary data supply strategies.

NASA Astrophysics Data System (ADS)

Landeras, Gorka; Bekoe, Emmanuel; Ampofo, Joseph; Logah, Frederick; Diop, Mbaye; Cisse, Madiama; Shiri, Jalal

2018-05-01

Accurate estimation of reference evapotranspiration ( ET 0 ) is essential for the computation of crop water requirements, irrigation scheduling, and water resources management. In this context, having a battery of alternative local calibrated ET 0 estimation methods is of great interest for any irrigation advisory service. The development of irrigation advisory services will be a major breakthrough for West African agriculture. In the case of many West African countries, the high number of meteorological inputs required by the Penman-Monteith equation has been indicated as constraining. The present paper investigates for the first time in Ghana, the estimation ability of artificial intelligence-based models (Artificial Neural Networks (ANNs) and Gene Expression Programing (GEPs)), and ancillary/external approaches for modeling reference evapotranspiration ( ET 0 ) using limited weather data. According to the results of this study, GEPs have emerged as a very interesting alternative for ET 0 estimation at all the locations of Ghana which have been evaluated in this study under different scenarios of meteorological data availability. The adoption of ancillary/external approaches has been also successful, moreover in the southern locations. The interesting results obtained in this study using GEPs and some ancillary approaches could be a reference for future studies about ET 0 estimation in West Africa.

Education and Indigenous Knowledge in Africa: Traditional Bonesetting and Orthopaedic Medicine in West Africa

NASA Astrophysics Data System (ADS)

Ezeanya, Chika A.

The underlying philosophy of education in contemporary Africa has been established to be alien, and detached from the indigenous knowledge of the people. Modern day formal education in sub-Saharan Africa came about, for the most part, as a result of missionary activities and colonial efforts of Europe. The education bequeathed to Africa was, therefore, fundamentally European in paradigm and lacking in authenticity. The end of colonialism across sub-Saharan Africa did not herald any tangible transformation in the curriculum of study. Education in Africa is still dependent on foreign input for sustainability, thereby stifling research, creativity and innovation. Sustainable development is founded on indigenous knowledge. When such grassroots knowledge assumes the foundation of learning, home-grown development is easily fostered in all sectors of a national economy. In the field of medicine, indigenous knowledge of healing has been considered unscientific by western biomedical practitioners. Since the days of the missionaries, many Africans have considered indigenous medicine to be fetish; the Christian converts would not be associated with its practice and patronage. However, traditional bonesetting has been proven to be highly efficacious with little supernatural content, it continues to attract huge patronage from Africans, cutting across social and religious boundaries. This study attempts an exploration of the disconnect between indigenous knowledge, practices and learning, on the one hand, and formal education in Africa, on the other. With a focus on traditional bonesetting, the study seeks to determine why that branch of indigenous medicine attracts huge patronage, but is granted very little recognition by modern orthopaedic medical education.

Evidence of a Weakly Absorbing Intermediate Mode of Aerosols in AERONET Data from Saharan and Sahelian Sites

NASA Technical Reports Server (NTRS)

Gianelli, Scott M.; Lacis, Andrew A.; Carlson, Barbara E.; Hameed, Sultan

2013-01-01

Accurate retrievals of aerosol size distribution are necessary to estimate aerosols' impact on climate and human health. The inversions of the Aerosol Robotic Network (AERONET) usually retrieve bimodal distributions. However, when the inversion is applied to Saharan and Sahelian dust, an additional mode of intermediate size between the coarse and fine modes is sometimes seen. This mode explains peculiarities in the behavior of the Angstrom exponent, along with the fine mode fraction retrieved using the spectral deconvolution algorithm, observed in a March 2006 dust storm. For this study, 15 AERONET sites in northern Africa and on the Atlantic are examined to determine the frequency and properties of the intermediate mode. The mode is observed most frequently at Ilorin in Nigeria. It is also observed at Capo Verde and multiple sites located within the Sahel but much less frequently at sites in the northern Sahara and the Canary Islands. The presence of the intermediate mode coincides with increases in Angstrom exponent, fine mode fraction, single-scattering albedo, and to a lesser extent percent sphericity. The Angstrom exponent decreases with increasing optical depth at most sites when the intermediate mode is present, but the fine mode fraction does not. Single-scattering albedo does not steadily decrease with fine mode fraction when the intermediate mode is present, as it does in typical mixtures of dust and biomass-burning aerosols. Continued investigation is needed to further define the intermediate mode's properties, determine why it differs from most Saharan dust, and identify its climate and health effects.

Alcohol use and non-adherence to antiretroviral therapy in HIV-infected patients in West Africa

PubMed Central

Antoine, Jaquet; Ekouevi Didier, K; Jules, Bashi; Maiga, Aboubakrine; Eugène, Messou; Moussa, Maiga; Alassane, Traore Hamar; Djimon, Zannou Marcel; Calixte, Guehi; Olivier, Ba-Gomis Franck; Albert, Minga; Gérard, Allou; Paul, Eholie Serge; Emmanuel, Bissagnene; Sasco Annie, J; Francois, Dabis

2015-01-01

AIM To investigate the association between alcohol use and adherence to Highly Active Antiretroviral Treatment (HAART) among HIV-infected patients in sub-Saharan Africa. DESIGN and MEASURES Cross sectional survey conducted in eight adult HIV treatment centers from Benin, Côte d’Ivoire and Mali. During a four-week period, health workers administered the Alcohol Use Disorders Identification Test to HAART-treated patients and assessed treatment adherence using the AIDS Clinical Trials Group follow-up questionnaire. RESULTS A total of 2920 patients were enrolled with a median age of 38 years (IQR 32–45 years) and a median duration on HAART of 3 years (IQR 1–4 years). Overall, 91.8% of patients were identified as adherent to HAART. Non-adherence was associated with current drinking (OR 1.4; 95% CI 1.1–2.0), hazardous drinking (OR 4.7; 95% CI 2.6–8.6) and was inversely associated with a history of counseling on adherence (OR 0.7; 95% CI 0.5–0.9). CONCLUSION Alcohol consumption and hazardous drinking is associated with non-adherence to HAART among HIV-infected patients from West Africa. thus providing a framework for developing and reinforcing the necessary prevention and intervention strategies. PMID:20528816

Recrudescence of Ebola virus disease outbreak in West Africa, 2014-2016.

PubMed

Lee, Hyojung; Nishiura, Hiroshi

2017-11-01

There have been errors in determining the end of the Ebola virus disease (EVD) epidemic when adhering to the criteria of the World Health Organization. The present study aimed to review and learn from all known recrudescence events in West Africa occurring in 2014-2016. Background mechanisms of five erroneous declarations in Guinea, Liberia, and Sierra Leone during 2014-2016 were reviewed. Three cases of recrudescence were suspected to have been caused by sexual contact with survivors, one to be due to international migration, and one was linked to a potentially immunocompromised mother. The three sexual transmission events involving survivors-the first two in Liberia and one in Sierra Leone-required 164 days, >150 days, and approximately 180 days, respectively, from discharge of the survivors to confirmation of the recrudescent case. The events of recrudescence were associated with relatively uncommon routes of transmission other than close contact during burial or care-giving, including sexual transmission, possible immunocompromise, and migration. Recognition of the sexual transmission risk among survivors could potentially involve discrimination, which may lead to under-ascertainment. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Human demography and reserve size predict wildlife extinction in West Africa.

PubMed Central

Brashares, J S; Arcese, P; Sam, M K

2001-01-01

Species-area models have become the primary tool used to predict baseline extinction rates for species in isolated habitats, and have influenced conservation and land-use planning worldwide. In particular, these models have been used to predict extinction rates following the loss or fragmentation of natural habitats in the absence of direct human influence on species persistence. Thus, where direct human influences, such as hunting, put added pressure on species in remnant habitat patches, we should expect to observe extinction rates higher than those predicted by simple species-area models. Here, we show that extinction rates for 41 species of large mammals in six nature reserves in West Africa are 14-307 times higher than those predicted by models based on reserve size alone. Human population and reserve size accounted for 98% of the observed variation in extinction rates between reserves. Extinction occurred at higher rates than predicted by species-area models for carnivores, primates and ungulates, and at the highest rates overall near reserve borders. Our results indicate that, where the harvest of wildlife is common, conservation plans should focus on increasing the size of reserves and reducing the rate of hunting. PMID:11747566

Drought in West Africa: How CHIRPS and Reference Evapotranspiration can be used for Index Insurance in a Non-Stationary Setting

NASA Astrophysics Data System (ADS)

Blakeley, S. L.; Husak, G. J.; Harrison, L.; Funk, C. C.; Osgood, D. E.; Peterson, P.

2017-12-01

Index insurance is increasingly used as a safety net and productivity tool in order to improve the resilience of small-holder farmers in developing countries. In West Africa, there are already index insurance projects in many countries, and various non-governmental organizations are eager to expand implementation of this risk management tool. Often, index insurance payouts rely on rainfall to determine drought years, but designation of years based on precipitation variations is particularly complex in places like West Africa where precipitation is subject to much natural variability across timescales [Giannini 2003, among others]. Furthermore, farmers must also rely on other weather factors for good crop yields, such as the availability of moisture for their plants to absorb and maximum daily temperatures staying within an acceptable range for the crops. In this presentation, the payouts of an index based on rainfall (as measured by the Climate Hazards Group Infrared Precipitation with Stations {CHIRPS} dataset) is compared to the payouts of an index using reference evapotranspiration data (using the ASCE's Penmen-Monteith formula and MERRA-2 drivers). The West African rainfall index exhibits a fair amount of long-term variability, reflective of the Atlantic Multidecadal Oscillation, but the reference evapotranspiration index shows different variability, through changes in radiative forcing and temperatures. Therefore, the use of rainfall for an index is appropriate for capturing rainfall deficits, but reference evapotranspiration may also be an appropriate addition to an index or as a stand-alone index for capturing crop stress. In summary, the results point to farmer input as an invaluable source of knowledge in determining the most appropriate dataset as an index for crop insurance. Alessandra Giannini, R Saravanan, and P Chang. Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales. Science, 302(5647):1027-1030, 2003.

First Report of Outbreaks of the Fall Armyworm Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae), a New Alien Invasive Pest in West and Central Africa

PubMed Central

Sankung, Sagnia B.; Togola, Abou; Tamò, Manuele

2016-01-01

The fall armyworm Spodoptera frugiperda is a prime noctuid pest of maize on the American continents where it has remained confined despite occasional interceptions by European quarantine services in recent years. The pest has currently become a new invasive species in West and Central Africa where outbreaks were recorded for the first time in early 2016. The presence of at least two distinct haplotypes within samples collected on maize in Nigeria and São Tomé suggests multiple introductions into the African continent. Implications of this new threat to the maize crop in tropical Africa are briefly discussed. PMID:27788251

First Report of Outbreaks of the Fall Armyworm Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae), a New Alien Invasive Pest in West and Central Africa.

PubMed

Goergen, Georg; Kumar, P Lava; Sankung, Sagnia B; Togola, Abou; Tamò, Manuele

2016-01-01

The fall armyworm Spodoptera frugiperda is a prime noctuid pest of maize on the American continents where it has remained confined despite occasional interceptions by European quarantine services in recent years. The pest has currently become a new invasive species in West and Central Africa where outbreaks were recorded for the first time in early 2016. The presence of at least two distinct haplotypes within samples collected on maize in Nigeria and São Tomé suggests multiple introductions into the African continent. Implications of this new threat to the maize crop in tropical Africa are briefly discussed.

The enigma of yellow fever in East Africa.

PubMed

Ellis, Brett R; Barrett, Alan D T

2008-01-01

Despite a safe and effective vaccine, there are approximately 200,000 cases, including 30,000 deaths, due to yellow fever virus (YFV) each year, of which 90% are in Africa. The natural history of YFV has been well described, especially in West Africa, but in East Africa yellow fever (YF) remains characterised by unpredictable focal periodicity and a precarious potential for large epidemics. Recent outbreaks of YF in Kenya (1992-1993) and Sudan (2003 and 2005) are important because each of these outbreaks have involved the re-emergence of a YFV genotype (East Africa) that remained undetected for nearly 40 years and was previously unconfirmed in a clinically apparent outbreak. In addition, unlike West Africa and South America, YF has yet to emerge in urban areas of East Africa and be vectored by Aedes (Stegomyia) aegypti. This is a significant public health concern in a region where the majority of the population remains unvaccinated. This review describes historical findings, highlights a number of disease indicators, and provides clarification regarding the natural history, recent emergence and future risk of YF in East Africa. Copyright (c) 2008 John Wiley & Sons, Ltd.

Climate forecasts in disaster management: Red Cross flood operations in West Africa, 2008.

PubMed

Braman, Lisette Martine; van Aalst, Maarten Krispijn; Mason, Simon J; Suarez, Pablo; Ait-Chellouche, Youcef; Tall, Arame

2013-01-01

In 2008, the International Federation of Red Cross and Red Crescent Societies (IFRC) used a seasonal forecast for West Africa for the first time to implement an Early Warning, Early Action strategy for enhanced flood preparedness and response. Interviews with disaster managers suggest that this approach improved their capacity and response. Relief supplies reached flood victims within days, as opposed to weeks in previous years, thereby preventing further loss of life, illness, and setbacks to livelihoods, as well as augmenting the efficiency of resource use. This case demonstrates the potential benefits to be realised from the use of medium-to-long-range forecasts in disaster management, especially in the context of potential increases in extreme weather and climate-related events due to climate variability and change. However, harnessing the full potential of these forecasts will require continued effort and collaboration among disaster managers, climate service providers, and major humanitarian donors. © 2013 The Author(s). Journal compilation © Overseas Development Institute, 2013.

Milk yield and composition of crossbred Sahelian × Anglo-Nubian goats in the semi-intensive system in Mali during the preweaning period.

PubMed

Sanogo, Souleymane; Shaker, Mohamed Momani; Nantoumé, Hamidou; Salem, Abdel-Fattah Z M

2013-01-01

The aim of this study was to evaluate milk yield and its composition during the preweaning period for Sahelian goats (SG) and Anglo-Nubian (AN) crossbred depending on some factors. The experiments were conducted from January to December 2008 for 44 suckled and hand-milked does, randomized, and divided into two equal groups: SG (n = 22) and F(1) Anglo-Nubian × Sahelian goats (1/2AN; n = 22). The does and their offsprings were kept in a pen where they stayed indoors for 45 days before they were allowed outdoors when the weather was suitable. Each category received supplemental feeds depending on the season (rainy season, dry cold season, and dry hot season). The average daily milk yield was recorded weekly from parturition to 100 days of age. Individual milk samples were taken for chemical analysis in connection with the yield measurements twice per month from the fourth week of lactation throughout the different seasons (rainy, cold dry, and hot dry). The daily milk yield differed between breed types (P = 0.001) during the preweaning, while the effect of kids' sex on daily milk production was not significant. Litter size affected milk yield up to day 60 (P = 0.032) where does with twins producing more milk than those with single kid. However, at day 100, both groups had similar (P = 0.001) milk production. Total milk yield at weaning increased by 103 % in 1/2AN over SG. The highest concentration of total solids of milk was (12.76 %) recorded in the hot dry season. The results of this study indicate that crossbreeding native Sahelian goats with high potential Anglo-Nubian buck improved milk production and its composition.

Agro-Forestry system in West Africa: integrating a green solution to cope with soil depletion towards agricultural sustainability

NASA Astrophysics Data System (ADS)

Monteiro, Filipa; Vidigal, Patricia; Romeiras, Maria Manuel; Ribeiro, Ana; Abreu, Maria Manuela; Viegas, Wanda; Catarino, Luís

2017-04-01

During the last decades, agriculture in West Africa has been marked by dramatic shifts with the coverage of single crops, increasing pressure over the available arable land. Yet, West African countries are still striving to achieve sustainable production at an increased scale for global market needs. Market-driven rapid intensification is often a major cause for cropland area expansion at the expense of deforestation and soil degradation, especially to export commodities in times of high prices. Cashew (Anacardium occidentale L.) is nowadays an important export-oriented crop, being produced under intensive cultivation regimes in several tropical regions. Particularly, among the main cashew production areas, West Africa is the most recent and dynamic in the world, accounting for 45% of the world cashew nuts production in 2015. Considering its global market values, several developing countries rely on cashew nuts as national economy revenues, namely in Guinea-Bissau. Considering the intensive regime of cashew production in Guinea-Bissau, and as widely recognized, intensive agriculture linked with extensification can negatively impact ecosystems, affecting natural resources availability, soil erosion and arability compromised by excessive salinity. Ultimately this will result in the disruption of carbon - nitrogen cycle, important to the agricultural ecosystem sustainability. As such, tree intercropped with legumes as cover crops, offers a sustainable management of the land area, thus creating substantial benefits both economically and environmentally, as it enhances diversification of products outputs and proving to be more sustainable than forestry and/or agricultural monocultures. Soil fertility improvement is a key entry point for achieving food security, and also increment agriculture commodities of the agro-system. Without using inorganic fertilizers, the green solution for improving soil management is to incorporate adapted multi-purpose legumes as cover crops

Promiscuous arbuscular mycorrhizal symbiosis of yam (Dioscorea spp.), a key staple crop in West Africa.

PubMed

Tchabi, Atti; Burger, Stefanie; Coyne, Danny; Hountondji, Fabien; Lawouin, Louis; Wiemken, Andres; Oehl, Fritz

2009-08-01

Yam (Dioscorea spp.) is a tuberous staple food crop of major importance in the sub-Saharan savannas of West Africa. Optimal yields commonly are obtained only in the first year following slash-and-burn in the shifting cultivation systems. It appears that the yield decline in subsequent years is not merely caused by soil nutrient depletion but might be due to a loss of the beneficial soil microflora, including arbuscular mycorrhizal fungi (AMF), associated with tropical "tree-aspect" savannas and dry forests that are the natural habitats of the wild relatives of yam. Our objective was to study the AMF communities of natural savannas and adjacent yam fields in the Southern Guinea savanna of Benin. AMF were identified by morphotyping spores in the soil from the field sites and in AMF trap cultures with Sorghum bicolor and yam (Dioscorea rotundata and Dioscorea cayenensis) as bait plants. AMF species richness was higher in the savanna than in the yam-field soils (18-25 vs. 11-16 spp.), but similar for both ecosystems (29-36 spp.) according to the observations in trap cultures. Inoculation of trap cultures with soil sampled during the dry season led to high AMF root colonization, spore production, and species richness (overall 45 spp.) whereas inoculation with wet-season soil was inefficient (two spp. only). The use of D. cayenensis and D. rotundata as baits yielded 28 and 29 AMF species, respectively, and S. bicolor 37 species. AMF root colonization, however, was higher in yam than in sorghum (70-95 vs. 11-20%). After 8 months of trap culturing, the mycorrhizal yam had a higher tuber biomass than the nonmycorrhizal controls. The AMF actually colonizing D. rotundata roots in the field were also studied using a novel field sampling procedure for molecular analyses. Multiple phylotaxa were detected that corresponded with the spore morphotypes observed. It is, therefore, likely that the legacy of indigenous AMF from the natural savanna plays a crucial role for yam

Strengthening malaria prevention and control: integrating West African militaries' malaria control efforts. The inaugural meeting of the West African Malaria Task Force, April 24-26, 2013, Accra, Ghana.

PubMed

McCollum, Jeffrey T; Hanna, Refaat; Halbach, Alaina C; Cummings, James F

2015-01-01

From April 24 to 26, 2013, the Armed Forces Health Surveillance Center and the U.S. Africa Command cosponsored the inaugural meeting of the West Africa Malaria Task Force in Accra, Ghana. The meeting's purpose was to identify common challenges, explore regional and transcontinental collaborations, and to share knowledge about best practices in the fight against malaria in West Africa. Military representatives from Benin, Burkina Faso, Ghana, Liberia, Niger, Nigeria, Senegal, and Togo participated in the Task Force; various U.S. Government agencies were also represented, including the Department of Defense, the Centers for Disease Control and Prevention, and the Agency for International Development. African nation participants presented brief overviews of their military's malaria prevention and control measures, surveillance programs, diagnostic capabilities, and treatment regimens emphasizing gaps within existing programs. Representatives from U.S. agencies discussed activities and capabilities relevant for the region, challenges and lessons learned regarding malaria, and highlighted opportunities for enhanced partnerships to counter malaria in West Africa. This article summarizes the major conclusions of the Task Force meeting, identifies relevant focus areas for future Task Force activities, and outlines opportunities for further inclusion of West African militaries to improve regional malaria surveillance and control efforts. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Precipitation interannual variability and predictions for West Africa from the National Multi-Model Ensemble dataset

NASA Astrophysics Data System (ADS)

Thiaw, W. M.

2013-12-01

The ability of coupled climate models from the national multi-model ensemble (NMME) dataset to reproduce the basic state and interannual variability of precipitation in West Africa and associated teleconnections is examined. The analysis is for the period 1982-2010 for most of the models, which corresponds to the NMME hindcast period, except for the CFS version 1 (CFSv1) which covers the period 1981-2009. The satellite based CPC African Rainfall Climatology (ARC2) data is used as proxy for observed rainfall and to validate the models. We examine rainfall patterns throughout the year. Models are able to reproduce the north-south migration of precipitation from winter and spring when the area of maximum precipitation is located in Central Africa and the Gulf of Guinea region to the summer when it is in northern Sub-Saharan Africa, and the later return to the south. Models also appropriately place precipitation over the Gulf of Guinea region during the equinoxes in MAM and OND. However, there are considerable differences in the representation of the intensities and locations of the rainfall. Three of the models including the two versions of the NCEP CFS and the NASA models also have a systematic dry (wet) bias over the Sahel (Gulf of Guinea region) during the summer rainfall season, while the others show alternating wet and dry biases across West Africa. All models have spatially averaged values of standard deviation lower than that observed. Models are also able to reproduce to some extent the main features of the precipitation variability maximum, but again with deficiencies in the amplitudes and locations. The areas of highest variability are generally depicted, but there are significant differences among the models, and even between the two versions of the CFS. Teleconnections in the models are investigated by first conducting an EOF in the precipitation anomaly fields and then perform a regression of the first or second EOF time series onto the global SST

West Nile virus lineage 2 as a cause of zoonotic neurological disease in humans and horses in southern Africa.

PubMed

Venter, Marietjie; Swanepoel, Robert

2010-10-01

West Nile virus (WNV) is widely distributed in South Africa, but since a few cases of neurological disease have been reported from this region, endemic lineage 2 strains were postulated to be of low virulence. Several cases of nonfatal encephalitis in humans as well as fatal cases in a foal, dog, and ostrich chicks have, however, been associated with lineage 2 WNV in South Africa. The pathogenesis of lineage 2 WNV strains was investigated using mouse neuroinvasive experiments, gene expression experiments, and genome sequence comparisons which indicated that lineage 2 strains that are highly pathogenic exist. To determine whether cases of WNV were being missed in South Africa, horses with fever and neurological disease were investigated. Several cases of WNV were identified, all associated with severe neurological disease, 85% of which had to be euthanized or died. All cases positive by RT-PCR were shown to belong to lineage 2 WNV by DNA sequencing and phylogenetic analysis. Two cases of occupational infection were investigated, including a case of zoonotic transmission to a veterinarian who performed an autopsy on one of the horses as well as a laboratory infection after a needle stick injury with a neuroinvasive lineage 2 strain. Both resulted in neurological disease. Cytokine expression was investigated in the second case to assess the immunopathogenesis of WNV. Collectively, these studies suggest that lineage 2 WNV may be significantly under estimated as a cause of neurological disease in South Africa.

Forecasting the atmospheric composition of southern West Africa with COSMO-ART during the DACCIWA measurement campaign

NASA Astrophysics Data System (ADS)

Deetz, Konrad; Vogel, Bernhard

2017-04-01

The Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project (Knippertz et al., 2015) investigates the influence of anthropogenic and natural emissions on the atmospheric composition over Southern West Africa (SWA). Between 1 June and 31 July 2016 the DACCIWA measurement campaign took place in SWA, including ground based and airborne observations. By using the regional scale comprehensive model system COSMO-ART (Vogel et al., 2009), operational numerical forecasts of the atmospheric composition including aerosols and gas phase compounds were conducted between 8 May and 31 July 2016. The forecasts cover the domain 25°W to 35°E and 20°S to 30°N with a grid mesh size of 28km and a lead time of 57h. The primary assignment of the forecasts was to support the DACCIWA aircraft campaign (27 June to 17 July 2016) in terms of the decision making of the flight routes of the research aircrafts. Visualizations of the forecast results were daily uploaded to the public available server dacciwa.sedoo.fr. Apart from the support of the DACCIWA measurement campaign, the COSMO-ART model dataset is highly valuable for identifying time periods feasible for post-campaign case study simulations, the extensive validation of COSMO-ART with observational data and the derivation of model climatologies to raise knowledge in meteorological and the atmospheric composition characteristics of SWA. The presentation will show validation results of the COSMO-ART forecasts with ground based and airborne measurements from the DACCIWA campaign as well as remote sensing observations. COSMO-ART well reproduces the diurnal cycle of the observed ozone concentration at Savé site and shows very good agreement of mineral dust AOD compared to CAMS model results whereas the anthropogenic aerosol seems to be overestimated by COSMO-ART compared to MODIS AOD and AERONET observations. We will present model climatologies of the NLLS characteristics and the spatial structure of the pollution

The use of seasonal forecasts in a crop failure early warning system for West Africa

NASA Astrophysics Data System (ADS)

Nicklin, K. J.; Challinor, A.; Tompkins, A.

2011-12-01

Seasonal rainfall in semi-arid West Africa is highly variable. Farming systems in the region are heavily dependent on the monsoon rains leading to large variability in crop yields and a population that is vulnerable to drought. The existing crop yield forecasting system uses observed weather to calculate a water satisfaction index, which is then related to expected crop yield (Traore et al, 2006). Seasonal climate forecasts may be able to increase the lead-time of yield forecasts and reduce the humanitarian impact of drought. This study assesses the potential for a crop failure early warning system, which uses dynamic seasonal forecasts and a process-based crop model. Two sets of simulations are presented. In the first, the crop model is driven with observed weather as a control run. Observed rainfall is provided by the GPCP 1DD data set, whilst observed temperature and solar radiation data are given by the ERA-Interim reanalysis. The crop model used is the groundnut version of the General Large Area Model for annual crops (GLAM), which has been designed to operate on the grids used by seasonal weather forecasts (Challinor et al, 2004). GLAM is modified for use in West Africa by allowing multiple planting dates each season, replanting failed crops and producing parameter sets for Spanish- and Virginia- type West African groundnut. Crop yields are simulated for three different assumptions concerning the distribution and relative abundance of Spanish- and Virginia- type groundnut. Model performance varies with location, but overall shows positive skill in reproducing observed crop failure. The results for the three assumptions are similar, suggesting that the performance of the system is limited by something other than information on the type of groundnut grown. In the second set of simulations the crop model is driven with observed weather up to the forecast date, followed by ECMWF system 3 seasonal forecasts until harvest. The variation of skill with forecast date

Challenges Associated with the Content of the Art History Component in the General Knowledge in Art Subject: Implications for Art History Education in West Africa

ERIC Educational Resources Information Center

Adom, Dickson; Kquofi, Steve; Agyem, Joe Adu

2016-01-01

The content of the Art History component in the General Knowledge in Art subject studied by various Senior High Schools in West Africa is largely of foreign art histories at the expense of the histories of African indigenous arts which are shallowly presented in the teaching syllabus to be taught students. This makes the students appreciate more…

Characterization of Foot-and-Mouth Disease Viruses Collected in Nigeria Between 2007 and 2014: Evidence for Epidemiological Links Between West and East Africa.

PubMed

Ularamu, H G; Ibu, J O; Wood, B A; Abenga, J N; Lazarus, D D; Wungak, Y S; Knowles, N J; Wadsworth, J; Mioulet, V; King, D P; Shamaki, D; Adah, M I

2017-12-01

This study describes the molecular characterization of 47 foot-and-mouth disease (FMD) viruses recovered from field outbreaks in Nigeria between 2007 and 2014. Antigen ELISA of viral isolates was used to identify FMD virus serotypes O, A and SAT 2. Phylogenetic analyses of VP1 nucleotide sequences provide evidence for the presence of multiple sublineages of serotype SAT 2, and O/EAST AFRICA 3 (EA-3) and O/WEST AFRICA topotypes in the country. In contrast, for serotype A, a single monophyletic cluster of viruses has persisted within Nigeria (2009-2013). These results demonstrate the close genetic relatedness of viruses in Nigeria to those from other African countries, including the first formal characterization of serotype O/EA-3 viruses in Nigeria. The introductions and persistence of certain viral lineages in Nigeria may reflect transmission patterns via nomadic pastoralism and animal trade. Continuous monitoring of field outbreaks is necessary to dissect the complexity of FMD epidemiology in sub-Saharan Africa. © 2016 Blackwell Verlag GmbH.

Not just malaria: Mary Slessor (1848-1915) and other Victorian missionaries in West Africa.

PubMed

Hardage, Jeanette

2006-11-01

Fear of 'fever' was uppermost in the minds of many travellers to West Africa in Victorian times. 'Not just malaria...' chronicles attitudes, treatments and discoveries regarding malaria from the time of David Livingstone through the early 20th century. Missionaries often found themselves in the position of serving as untrained doctors and nurses among the people they went to evangelize. In addition, they suffered from the same maladies as the people did, and many died from malaria or other afflictions. Mary Slessor arrived in Calabar, in what is now southeastern Nigeria, to serve with the Scottish Presbyterian Mission in 1876. With only a few furloughs, she remained there until her death in 1915. The article relates instances of the illnesses and injuries she treated as well as those she suffered herself. She is remembered in Nigeria with statues and, along with David Livingstone, is one of Scotland's best-known missionary figures.

Quantification of uncertainties related to the regional application of a conceptual hydrological model in Benin (West Africa)

NASA Astrophysics Data System (ADS)

Bormann, H.; Diekkrüger, B.

2003-04-01

A conceptual model is presented to simulate the water fluxes of regional catchments in Benin (West Africa). The model is applied in the framework of the IMPETUS project (an integrated approach to the efficient management of scarce water resources in West Africa) which aims to assess the effects of environmental and anthropogenic changes on the regional hydrological processes and on the water availability in Benin. In order to assess the effects of decreasing precipitation and increasing human activities on the hydrological processes in the upper Ouémé valley, a scenario analysis is performed to predict possible changes. Therefore a regional hydrological model is proposed which reproduces the recent hydrological processes, and which is able to consider the changes of landscape properties.The study presented aims to check the validity of the conceptual and lumped model under the conditions of the subhumid tree savannah and therefore analyses the importance of possible sources of uncertainty. Main focus is set on the uncertainties caused by input data, model parameters and model structure. As the model simulates the water fluxes at the catchment outlet of the Térou river (3133 km2) in a sufficient quality, first results of a scenario analysis are presented. Changes of interest are the expected future decrease in amount and temporal structure of the precipitation (e.g. minus X percent precipitation during the whole season versus minus X percent precipitation in the end of the rainy season, alternatively), the decrease in soil water storage capacity which is caused by erosion, and the increasing consumption of ground water for drinking water and agricultural purposes. Resuming from the results obtained, the perspectives of lumped and conceptual models are discussed with special regard to available management options of this kind of models. Advantages and disadvantages compared to alternative model approaches (process based, physics based) are discussed.

Carbon dioxide fluxes from a degraded woodland in West Africa and their responses to main environmental factors.

PubMed

Ago, Expedit Evariste; Serça, Dominique; Agbossou, Euloge Kossi; Galle, Sylvie; Aubinet, Marc

2015-12-01

In West Africa, natural ecosystems such as woodlands are the main source for energy, building poles and livestock fodder. They probably behave like net carbon sinks, but there are only few studies focusing on their carbon exchange with the atmosphere. Here, we have analyzed CO 2 fluxes measured for 17 months by an eddy-covariance system over a degraded woodland in northern Benin. Specially, temporal evolution of the fluxes and their relationships with the main environmental factors were investigated between the seasons. This study shows a clear response of CO 2 absorption to photosynthetic photon flux density (Q p ), but it varies according to the seasons. After a significant and long dry period, the ecosystem respiration (R) has increased immediately to the first significant rains. No clear dependency of ecosystem respiration on temperature has been observed. The degraded woodlands are probably the "carbon neutral" at the annual scale. The net ecosystem exchange (NEE) was negative during wet season and positive during dry season, and its annual accumulation was equal to +29 ± 16 g C m -2 . The ecosystem appears to be more efficient in the morning and during the wet season than in the afternoon and during the dry season. This study shows diurnal and seasonal contrasted variations in the CO 2 fluxes in relation to the alternation between dry and wet seasons. The Nangatchori site is close to the equilibrium state according to its carbon exchanges with the atmosphere. The length of the observation period was too short to justify the hypothesis about the "carbon neutrality" of the degraded woodlands at the annual scale in West Africa. Besides, the annual net ecosystem exchange depends on the intensity of disturbances due to the site management system. Further research works are needed to define a woodland management policy that might keep these ecosystems as carbon sinks.

Projected effects of vegetation feedbacks on drought characteristics with SPEI over West Africa using the RegCM-CLM-CN-DV

NASA Astrophysics Data System (ADS)

Jaehyeong, L.; Kim, Y.; Erfanian, A.; Wang, G.; Um, M. J.

2017-12-01

This study utilizes the Standardized Precipitation-Evapotranspiration Index (SPEI) to investigate the projected effect of vegetation feedbacks on drought in West Africa using the Regional Climate Model coupled to the NCAR Community Land Model with both the Carbon and Nitrogen module (CN) and Dynamic Vegetation module (DV) activated (RegCM-CLM-CN-DV). The role of vegetation feedbacks is examined based on simulations with and without dynamic vegetation. The four different future climate scenarios from CCSM, GFDL, MIROC and MPI are used as the boundary conditions of RegCM for two historical and future periods, i.e., for 1981 to 2000 and for 2081 to 2100, respectively. Using SPEI, the duration, frequency, severity and spatial extents are quantified over West Africa and analyzed for two regions of the Sahel and the Gulf of Guinea. In this study, we find that the estimated annual SPEIs clearly indicate that the projected future droughts over the Sahel are enhanced and prolonged when DV is activated. The opposite is shown over the Gulf of Guinea in general. AcknowledgementsThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A2A01054800), by the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180 and by the Yonsei University Future-leading Research Initiative of 2015(2016-22-0061).

Foot-and-mouth Disease Transmission in Africa: Implications for Control, a Review.

PubMed

Tekleghiorghis, T; Moormann, R J M; Weerdmeester, K; Dekker, A

2016-04-01

In Africa, for the control of foot-and-mouth disease (FMD), more information is needed on the spread of the disease at local, regional and inter-regional level. The aim of this review is to identify the role that animal husbandry, trade and wildlife have on the transmission of FMD and to provide a scientific basis for different FMD control measures in Africa. Review of literature, published reports and databases shows that there is more long distance spread of FMD virus serotypes within North, West, Central and East Africa than in southern Africa. In North, West, Central and East Africa migratory animal husbandry systems often related with search for grazing and water as well as trade are practiced to a greater extent than in southern Africa. In southern Africa, the role of African buffalo (Syncerus caffer) is more extensively studied than in the other parts of Africa, but based on the densities of African buffalo in Central and East Africa, one would assume that buffalo should also play a role in the epidemiology of FMD in this part of Africa. More sampling of buffalo is necessary in West, Central and East Africa. The genetic analysis of virus strains has proven to be valuable to increase our understanding in the spread of FMD in Africa. This review shows that there is a difference in FMD occurrence between southern Africa and the rest of the continent; this distinction is most likely based on differences in animal husbandry and trade systems. Insufficient data on FMD in wildlife outside southern Africa is limiting our understanding on the role wildlife plays in the transmission of FMD in the other buffalo inhabited areas of Africa. © 2014 Blackwell Verlag GmbH.

Protected Areas in Tropical Africa: Assessing Threats and Conservation Activities

PubMed Central

Tranquilli, Sandra; Abedi-Lartey, Michael; Abernethy, Katharine; Amsini, Fidèle; Asamoah, Augustus; Balangtaa, Cletus; Blake, Stephen; Bouanga, Estelle; Breuer, Thomas; Brncic, Terry M.; Campbell, Geneviève; Chancellor, Rebecca; Chapman, Colin A.; Davenport, Tim R. B.; Dunn, Andrew; Dupain, Jef; Ekobo, Atanga; Eno-Nku, Manasseh; Etoga, Gilles; Furuichi, Takeshi; Gatti, Sylvain; Ghiurghi, Andrea; Hashimoto, Chie; Hart, John A.; Head, Josephine; Hega, Martin; Herbinger, Ilka; Hicks, Thurston C.; Holbech, Lars H.; Huijbregts, Bas; Kühl, Hjalmar S.; Imong, Inaoyom; Yeno, Stephane Le-Duc; Linder, Joshua; Marshall, Phil; Lero, Peter Minasoma; Morgan, David; Mubalama, Leonard; N'Goran, Paul K.; Nicholas, Aaron; Nixon, Stuart; Normand, Emmanuelle; Nziguyimpa, Leonidas; Nzooh-Dongmo, Zacharie; Ofori-Amanfo, Richard; Ogunjemite, Babafemi G.; Petre, Charles-Albert; Rainey, Hugo J.; Regnaut, Sebastien; Robinson, Orume; Rundus, Aaron; Sanz, Crickette M.; Okon, David Tiku; Todd, Angelique; Warren, Ymke; Sommer, Volker

2014-01-01

Numerous protected areas (PAs) have been created in Africa to safeguard wildlife and other natural resources. However, significant threats from anthropogenic activities and decline of wildlife populations persist, while conservation efforts in most PAs are still minimal. We assessed the impact level of the most common threats to wildlife within PAs in tropical Africa and the relationship of conservation activities with threat impact level. We collated data on 98 PAs with tropical forest cover from 15 countries across West, Central and East Africa. For this, we assembled information about local threats as well as conservation activities from published and unpublished literature, and questionnaires sent to long-term field workers. We constructed general linear models to test the significance of specific conservation activities in relation to the threat impact level. Subsistence and commercial hunting were identified as the most common direct threats to wildlife and found to be most prevalent in West and Central Africa. Agriculture and logging represented the most common indirect threats, and were most prevalent in West Africa. We found that the long-term presence of conservation activities (such as law enforcement, research and tourism) was associated with lower threat impact levels. Our results highlight deficiencies in the management effectiveness of several PAs across tropical Africa, and conclude that PA management should invest more into conservation activities with long-term duration. PMID:25469888

Protected areas in tropical Africa: assessing threats and conservation activities.

PubMed

Tranquilli, Sandra; Abedi-Lartey, Michael; Abernethy, Katharine; Amsini, Fidèle; Asamoah, Augustus; Balangtaa, Cletus; Blake, Stephen; Bouanga, Estelle; Breuer, Thomas; Brncic, Terry M; Campbell, Geneviève; Chancellor, Rebecca; Chapman, Colin A; Davenport, Tim R B; Dunn, Andrew; Dupain, Jef; Ekobo, Atanga; Eno-Nku, Manasseh; Etoga, Gilles; Furuichi, Takeshi; Gatti, Sylvain; Ghiurghi, Andrea; Hashimoto, Chie; Hart, John A; Head, Josephine; Hega, Martin; Herbinger, Ilka; Hicks, Thurston C; Holbech, Lars H; Huijbregts, Bas; Kühl, Hjalmar S; Imong, Inaoyom; Yeno, Stephane Le-Duc; Linder, Joshua; Marshall, Phil; Lero, Peter Minasoma; Morgan, David; Mubalama, Leonard; N'Goran, Paul K; Nicholas, Aaron; Nixon, Stuart; Normand, Emmanuelle; Nziguyimpa, Leonidas; Nzooh-Dongmo, Zacharie; Ofori-Amanfo, Richard; Ogunjemite, Babafemi G; Petre, Charles-Albert; Rainey, Hugo J; Regnaut, Sebastien; Robinson, Orume; Rundus, Aaron; Sanz, Crickette M; Okon, David Tiku; Todd, Angelique; Warren, Ymke; Sommer, Volker

2014-01-01

Numerous protected areas (PAs) have been created in Africa to safeguard wildlife and other natural resources. However, significant threats from anthropogenic activities and decline of wildlife populations persist, while conservation efforts in most PAs are still minimal. We assessed the impact level of the most common threats to wildlife within PAs in tropical Africa and the relationship of conservation activities with threat impact level. We collated data on 98 PAs with tropical forest cover from 15 countries across West, Central and East Africa. For this, we assembled information about local threats as well as conservation activities from published and unpublished literature, and questionnaires sent to long-term field workers. We constructed general linear models to test the significance of specific conservation activities in relation to the threat impact level. Subsistence and commercial hunting were identified as the most common direct threats to wildlife and found to be most prevalent in West and Central Africa. Agriculture and logging represented the most common indirect threats, and were most prevalent in West Africa. We found that the long-term presence of conservation activities (such as law enforcement, research and tourism) was associated with lower threat impact levels. Our results highlight deficiencies in the management effectiveness of several PAs across tropical Africa, and conclude that PA management should invest more into conservation activities with long-term duration.

The United States of America and The People’s Republic of China in Africa: Promoting Stability or Chaos

DTIC Science & Technology

2007-06-15

alternative to Middle Eastern sources. The US’ preoccupation with “energy security” makes some African countries, especially Nigeria in West Africa, very...that US oil supplies from West Africa will increase to 25 percent by 2015. This would surpass US oil imports from the entire Persian Gulf. Studies...indicate that the greatest increase in oil production globally in the next decade is likely to come from West Africa, and the US is following this trend

Rainfall intensification in tropical semi-arid regions: the Sahelian case

NASA Astrophysics Data System (ADS)

Panthou, G.; Lebel, T.; Vischel, T.; Quantin, G.; Sane, Y.; Ba, A.; Ndiaye, O.; Diongue-Niang, A.; Diopkane, M.

2018-06-01

An anticipated consequence of ongoing global warming is the intensification of the rainfall regimes meaning longer dry spells and heavier precipitation when it rains, with potentially high hydrological and socio-economic impacts. The semi-arid regions of the intertropical band, such as the Sahel, are facing particularly serious challenges in this respect since their population is strongly vulnerable to extreme climatic events. Detecting long term trends in the Sahelian rainfall regime is thus of great societal importance, while being scientifically challenging because datasets allowing for such detection studies are rare in this region. This study addresses this challenge by making use of a large set of daily rain gauge data covering the Sahel (defined in this study as extending from 20°W–10°E and from 11°N–18°N) since 1950, combined with an unparalleled 5 minute rainfall observations available since 1990 over the AMMA-CATCH Niger observatory. The analysis of the daily data leads to the assertion that a hydro-climatic intensification is actually taking place in the Sahel, with an increasing mean intensity of rainy days associated with a higher frequency of heavy rainfall. This leads in turn to highlight that the return to wetter annual rainfall conditions since the beginning of the 2000s—succeeding the 1970–2000 drought—is by no mean a recovery towards the much smoother regime that prevailed during the 1950s and 1960s. It also provides a vision of the contrasts existing between the West Sahel and the East Sahel, the East Sahel experiencing a stronger increase of extreme rainfall. This regional vision is complemented by a local study at sub-daily timescales carried out thanks to the 5 minute rainfall series of the AMMA-CATCH Niger observatory (12000 km2). The increasing intensity of extreme rainfall is also visible at sub-daily timescales, the annual maximum intensities have increased at an average rate of 2%–6% per decade since 1990 for timescales

Land-use change and infectious disease in West Africa

NASA Astrophysics Data System (ADS)

Thomson, M. C.; Ericksen, P. J.; Mohamed, A. Ben; Connor, S. J.

Land-use change has been associated with changes in the dynamics of infectious disease in West Africa. Here we describe the complex interactions of land-use change with three diseases (both vector- and non-vector-borne) of considerable public health significance in this region, namely, malaria and irrigation; epidemic meningitis and land degradation; onchocerciasis and deforestation. We highlight the confounding effect of climate variability, which acts as a driver of both land-use change and human health. We conclude, as have others, that the scale of observation always matters, and complex and dynamic feedbacks among social-ecological systems are not easily teased apart. We suggest that in order to establish the causal chain of interactions between land-use change and human health outcomes two approaches are necessary. The first is to have a thorough understanding of the aetiology of disease and the specific mechanisms by which land-use and climate variability affect the transmission of pathogens. This is achieved by focused, detailed studies encompassing a wide range of potential drivers, which are inevitably small scale and often cover short time periods. The second consists of large-scale studies of statistical associations between transmission indices or health outcomes and environmental variables stratified by known ecological or socio-economic confounders, and sufficient in size to overcome local biases in results. Such research activities need to be designed to inform each other if we are to develop predictive models for monitoring these diseases and to develop integrated programs for human health and sustainable land use.

A geoethical approach in higher education: the project RUSSADE in cooperation with Sahelian Universities

NASA Astrophysics Data System (ADS)

Semita, Carlo; Ferrero, Elena; Calvo, Angela; Trucchi, Gabriella

2014-05-01

Sahel has been plagued by a continuous process of environment degradation since the droughts of the 70s and 80s. The desertification process has a significant impact also on the natural and artificial water bodies, on the rivers flow and the river ecosystems, damaging human activities. Environmental damage exacerbates inequality by exerting a negative impact on the population, in the meantime, the inequalities of human development amplify also environmental damage. The project "RUSSADE" (Réseau des Universités Sahéliennes pour la Sécurité Alimentaire et la Durabilité Environnement), included in the EuropeAid-ACP-EU Cooperation Programme in higher education (EDULINK II), has the specific objective to enhance higher education systems through the implementation of an interdisciplinary Master. The courses are designed with a geoethical approach in order to integrate Earth and Life Sciences to give the Sahelian students technical, scientific and methodological bases and to develop the skills of managing natural resources and to improve agriculture and food security. The systemic and multidisciplinary approach will involve several fields of knowledge. The programs of the different areas are linked to each other and Italian and Sahelian teachers cooperate together both in the courses planning and in the teaching activities. The partners, three African Higher Education Institutions (HEIs) of Niger (CRESA - Abdou Moumouni University), Burkina Faso (LERNSE - Polytechnic University of Bobo-Dioulasso) and Chad (University Institute of Sciences and Techniques of Abeché), will develop an education project with the main objective to use scientific knowledge to fight hunger and poverty and to promote environmental protection in a sustainable development perspective. The quality of higher education in the management of natural resources in agriculture will improve living conditions of Sahelian people. The Master, planned with innovative connections, includes a field training

Remote sensing experiment in West Africa. [drought effects on desert agriculture and vegetation in Niger

NASA Technical Reports Server (NTRS)

Macleod, N. H.

1974-01-01

There are substantial needs of the Sahelien Zone to detail the state of regional agricultural resources in the face of a sixth year of serious drought conditions. While most of the work has been done in the Republic of Niger, the principles which have emerged from the analysis seem to be applicable to much of the Sahel. The discussion relates to quite specific rehabilitation and development initiations under consideration in Niger which are based in part upon direct analysis of ERTS imagery of the country, in part on field surveys and on discussions with Nigerian officials and technicians. Again, because the entire Sahelien Zone (including Niger) has large zones of similar ecologic characteristics, modificiations of the approaches suggested for Niger are applicable to the solution of rehabilitation of the desert, the savannah and the woodlands of West Africa in general.

Multisensor monitoring of deforestation in the Guinea Highlands of West Africa

NASA Technical Reports Server (NTRS)

Gilruth, Peter T.; Hutchinson, Charles F.

1990-01-01

Multiple remote sensing systems were used to assess deforestation in the Guinea Highlands (Fouta Djallon) of West Africa. Sensor systems included: (1) historical (1953) and current (1989) aerial mapping photography; (2) current large-scale, small format (35mm) aerial photography; (3) current aerial video imagery; and (4) historical (1973) and recent (1985) LANDSAT MSS. Photographic and video data were manually interpreted and incorporated in a vector-based geographic information system (GIS). LANDSAT data were digitally classified. General results showed an increase in permanent and shifting agriculture over the past 35 years. This finding is consistent with hypothesized strategies to increase agricultural production through a shortening of the fallow period in areas of shifting cultivation. However, results also show that the total area of both permanent and shifting agriculture had expanded at the expense of natural vegetation and an increase in erosion. Although sequential LANDSAT MSS cannot be used in this region to accurately map land over, the location, direction and magnitude of changes can be detected in relative terms. Historical and current aerial photography can be used to map agricultural land use changes with some accuracy. Video imagery is useful as ancillary data for mapping vegetation. The most prudent approach to mapping deforestation would incorporate a multistage approach based on these sensors.

An overview of the socio-cultural and psychiatric aspects of women's reproductive health in West Africa.

PubMed

Aina, O F

2007-09-01

The challenges associated with women reproductive health in West African sub region have over the years become a source of concern to relevant world bodies such as WHO, UNFPA, World Bank etc. Some of these challenges include Infertility, Family Planning and Female Genital Mutilation (FGM). However, of greater concern is the scourge of Sexually Transmitted Diseases (STDs) most especially HIV/ AIDS and the unacceptably high maternal mortality in the sub region where Nigeria alone accounts for the highest percentage (10%) of the global 60,000 maternal deaths annually. Significant psychiatric complications such as anxiety and depression are associated with menstruation and menopause. However, the postpartum period is the most vulnerable with significant proportion of women developing such psychopathologies as Puerperal (maternity) blues, Postpartum Depression (PPD) and Acute Organic Brain Syndrome. Sociocultural factors, the dearth of psychiatrists in West Africa coupled with the poor or non-recognition of the psychiatric complications by the obstetric staff have not allowed enough clinical attention to be paid to these problems. It is thus advocated that improvement in the maternal and child health care component of the primary health care (PHC) services will go a long way to attenuate the psychiatric complications associated with childbirth.

Mapping the zoonotic niche of Lassa fever in Africa

PubMed Central

Mylne, Adrian Q. N.; Pigott, David M.; Longbottom, Joshua; Shearer, Freya; Duda, Kirsten A.; Messina, Jane P.; Weiss, Daniel J.; Moyes, Catherine L.; Golding, Nick; Hay, Simon I.

2015-01-01

Background Lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across West Africa. It is a zoonosis, with the primary reservoir species identified as the Natal multimammate mouse, Mastomys natalensis. The host is distributed across sub-Saharan Africa while the virus' range appears to be restricted to West Africa. The majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particularly in hospital settings. Methods Using a species distribution model, the locations of confirmed human and animal infections with Lassa virus (LASV) were used to generate a probabilistic surface of zoonotic transmission potential across sub-Saharan Africa. Results Our results predict that 37.7 million people in 14 countries, across much of West Africa, live in areas where conditions are suitable for zoonotic transmission of LASV. Four of these countries, where at-risk populations are predicted, have yet to report any cases of Lassa fever. Conclusions These maps act as a spatial guide for future surveillance activities to better characterise the geographical distribution of the disease and understand the anthropological, virological and zoological interactions necessary for viral transmission. Combining this zoonotic niche map with detailed patient travel histories can aid differential diagnoses of febrile illnesses, enabling a more rapid response in providing care and reducing the risk of onward transmission. PMID:26085474

Variability and trends of local/regional scale surface climate in northern Africa during the twentieth century

NASA Astrophysics Data System (ADS)

Djomou, Zéphirin Yepdo; Monkam, David; Woafo, Paul

2014-08-01

Four regions are detected in northern Africa (20° W-40° E, 0-30° N) by applying the cluster analysis method on the annual rainfall anomalies of the period 1901-2000. The first region (R1), an arid land, covers essentially the north of 17.75° N from west to east of the study zone. The second region (R2), a semiarid land with a Sahelian climate, less warm than the dry climate of R1, is centred on Chad, with almost regular extension to the west towards Mauritania, and to the east, including the north of the Central African Republic and the Sudan. The region 3 (R3), a wet land, is centred on the Ivory Coast and covers totally Liberia, the south part of Ghana, Togo, Benin and the southwest of Nigeria. The fourth region (R4), corresponding to the wet equatorial forest, covers a part of Senegal, the Central Africa, the south of Sudan and a part of Ethiopia. An analysis of observed temperature and precipitation variability and trends throughout the twentieth century over these regions is presented. Summer, winter and annual data are examined using a range of variability measures. Statistically, significant warming trends are found over the majority of regions. The trends have a magnitude of up to 1.5 K per century. Only a few precipitation trends are statistically significant. Regional temperature and precipitation show pronounced variability at scales from interannual to multi-decadal. The interannual variability shows significant variations and trends throughout the century, the latter being mostly negative for precipitation and both positive and negative for temperature. Temperature and precipitation anomalies show a chaotic-type behaviour in which the regional conditions oscillate around the long-term mean trend and occasionally fall into long-lasting (up to 10 years or more) anomaly regimes. A generally modest temporal correlation is found between anomalies of different regions and between temperature and precipitation anomalies for the same region. This

Biological and phylogenetic characteristics of West African lineages of West Nile virus.

PubMed

Fall, Gamou; Di Paola, Nicholas; Faye, Martin; Dia, Moussa; Freire, Caio César de Melo; Loucoubar, Cheikh; Zanotto, Paolo Marinho de Andrade; Faye, Ousmane; Sall, Amadou Alpha

2017-11-01

The West Nile virus (WNV), isolated in 1937, is an arbovirus (arthropod-borne virus) that infects thousands of people each year. Despite its burden on global health, little is known about the virus' biological and evolutionary dynamics. As several lineages are endemic in West Africa, we obtained the complete polyprotein sequence from three isolates from the early 1990s, each representing a different lineage. We then investigated differences in growth behavior and pathogenicity for four distinct West African lineages in arthropod (Ap61) and primate (Vero) cell lines, and in mice. We found that genetic differences, as well as viral-host interactions, could play a role in the biological properties in different WNV isolates in vitro, such as: (i) genome replication, (ii) protein translation, (iii) particle release, and (iv) virulence. Our findings demonstrate the endemic diversity of West African WNV strains and support future investigations into (i) the nature of WNV emergence, (ii) neurological tropism, and (iii) host adaptation.

Biological and phylogenetic characteristics of West African lineages of West Nile virus

PubMed Central

Faye, Martin; Dia, Moussa; Freire, Caio César de Melo; Loucoubar, Cheikh; Zanotto, Paolo Marinho de Andrade; Faye, Ousmane; Sall, Amadou Alpha

2017-01-01

The West Nile virus (WNV), isolated in 1937, is an arbovirus (arthropod-borne virus) that infects thousands of people each year. Despite its burden on global health, little is known about the virus’ biological and evolutionary dynamics. As several lineages are endemic in West Africa, we obtained the complete polyprotein sequence from three isolates from the early 1990s, each representing a different lineage. We then investigated differences in growth behavior and pathogenicity for four distinct West African lineages in arthropod (Ap61) and primate (Vero) cell lines, and in mice. We found that genetic differences, as well as viral-host interactions, could play a role in the biological properties in different WNV isolates in vitro, such as: (i) genome replication, (ii) protein translation, (iii) particle release, and (iv) virulence. Our findings demonstrate the endemic diversity of West African WNV strains and support future investigations into (i) the nature of WNV emergence, (ii) neurological tropism, and (iii) host adaptation. PMID:29117195

The quest for safe drinking water: an example from Guinea-Bissau (West Africa).

PubMed

Bordalo, Adriano A; Savva-Bordalo, Joana

2007-07-01

While humans require water for life, one-sixth of our species lives without access to safe water. In Africa, the situation is particularly acute because of global warming, the progression of the Sahara desert, civil unrest and poor governance, population growth, migration and poverty. In rural areas, the lack of adequate safe water and sanitary infrastructures leaves millions with doubtful water quality, increasing the harshness of daily life. In this paper, a pilot study was conducted during the wet season on Bolama Island (Guinea-Bissau, West Africa), a UNESCO Man and the Biosphere Reserve. Twenty-eight shallow wells, supplying water to most of the population, were sampled for microbiological, physical and chemical water quality characteristics. A ten-parameter water quality index (WQI) adapted to tropical conditions was applied to compare the different wells. About 79% of the wells showed moderate to heavy fecal contamination. From the surveyed parameters, it was found that chemical contamination was less important, although all samples were acidic, with the pH averaging 5.12+/-0.08. The WQI was 43+/-4% (0%-worst; 100%-best quality), showing that the water from the majority of wells was polluted but should be suitable for domestic use after appropriate treatment. At the onset of the wet season, diarrhea represented 11.5% of all medical cases, 92.5% of which were children aged <15. This paper suggests inexpensive steps to reduce the fecal contamination and control the pH in order to increase the potability of the well water and, concomitantly, to raise the living standards of the population in one of the poorest countries of the world.

A meteorological and chemical overview of the DACCIWA field campaign in West Africa in June-July 2016

NASA Astrophysics Data System (ADS)

Knippertz, Peter; Fink, Andreas H.; Deroubaix, Adrien; Morris, Eleanor; Tocquer, Flore; Evans, Mat J.; Flamant, Cyrille; Gaetani, Marco; Lavaysse, Christophe; Mari, Celine; Marsham, John H.; Meynadier, Rémi; Affo-Dogo, Abalo; Bahaga, Titike; Brosse, Fabien; Deetz, Konrad; Guebsi, Ridha; Latifou, Issaou; Maranan, Marlon; Rosenberg, Philip D.; Schlueter, Andreas

2017-09-01

In June and July 2016 the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project organised a major international field campaign in southern West Africa (SWA) including measurements from three inland ground supersites, urban sites in Cotonou and Abidjan, radiosondes, and three research aircraft. A significant range of different weather situations were encountered during this period, including the monsoon onset. The purpose of this paper is to characterise the large-scale setting for the campaign as well as synoptic and mesoscale weather systems affecting the study region in the light of existing conceptual ideas, mainly using objective and subjective identification algorithms based on (re-)analysis and satellite products. In addition, it is shown how the described synoptic variations influence the atmospheric composition over SWA through advection of mineral dust, biomass burning and urban pollution plumes.The boreal summer of 2016 was characterised by Pacific La Niña, Atlantic El Niño and warm eastern Mediterranean conditions, whose competing influences on precipitation led to an overall average rainy season. During the relatively dusty pre-onset Phase 1 (1-21 June 2016), three westward-propagating coherent cyclonic vortices between 4 and 13° N modulated winds and rainfall in the Guinea coastal area. The monsoon onset occurred in connection with a marked extratropical trough and cold surge over northern Africa, leading to a breakdown of the Saharan heat low and African easterly jet and a suppression of rainfall. During this period, quasi-stationary low-level vortices associated with the trough transformed into more tropical, propagating disturbances resembling an African easterly wave (AEW). To the east of this system, moist southerlies penetrated deep into the continent. The post-onset Phase 2 (22 June-20 July 2016) was characterised by a significant increase in low-level cloudiness, unusually dry conditions and strong northeastward

A cryptic mitochondrial DNA link between North European and West African dogs.

PubMed

Adeola, Adeniyi C; Ommeh, Sheila C; Song, Jiao-Jiao; Olaogun, S Charles; Sanke, Oscar J; Yin, Ting-Ting; Wang, Guo-Dong; Wu, Shi-Fang; Zhou, Zhong-Yin; Lichoti, Jacqueline K; Agwanda, Bernard R; Dawuda, Philip M; Murphy, Robert W; Peng, Min-Sheng; Zhang, Ya-Ping

2017-03-20

Domestic dogs have an ancient origin and a long history in Africa. Nevertheless, the timing and sources of their introduction into Africa remain enigmatic. Herein, we analyse variation in mitochondrial DNA (mtDNA) D-loop sequences from 345 Nigerian and 37 Kenyan village dogs plus 1530 published sequences of dogs from other parts of Africa, Europe and West Asia. All Kenyan dogs can be assigned to one of three haplogroups (matrilines; clades): A, B, and C, while Nigerian dogs can be assigned to one of four haplogroups A, B, C, and D. None of the African dogs exhibits a matrilineal contribution from the African wolf (Canis lupus lupaster). The genetic signal of a recent demographic expansion is detected in Nigerian dogs from West Africa. The analyses of mitochondrial genomes reveal a maternal genetic link between modern West African and North European dogs indicated by sub-haplogroup D1 (but not the entire haplogroup D) coalescing around 12,000 years ago. Incorporating molecular anthropological evidence, we propose that sub-haplogroup D1 in West African dogs could be traced back to the late-glacial dispersals, potentially associated with human hunter-gatherer migration from southwestern Europe. Copyright © 2016 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

The Epi Info Viral Hemorrhagic Fever (VHF) Application: A Resource for Outbreak Data Management and Contact Tracing in the 2014-2016 West Africa Ebola Epidemic.

PubMed

Schafer, Ilana J; Knudsen, Erik; McNamara, Lucy A; Agnihotri, Sachin; Rollin, Pierre E; Islam, Asad

2016-10-15

The Epi Info Viral Hemorrhagic Fever application (Epi Info VHF) was developed in response to challenges managing outbreak data during four 2012 filovirus outbreaks. Development goals included combining case and contact data in a relational database, facilitating data-driven contact tracing, and improving outbreak data consistency and use. The application was first deployed in Guinea, when the West Africa Ebola epidemic was detected, in March 2014, and has been used in 7 African countries and 2 US states. Epi Info VHF enabled reporting of compatible data from multiple countries, contributing to international Ebola knowledge. However, challenges were encountered in accommodating the epidemic's unexpectedly large magnitude, addressing country-specific needs within 1 software product, and using the application in settings with limited Internet access and information technology support. Use of Epi Info VHF in the West Africa Ebola epidemic highlighted the fundamental importance of good data management for effective outbreak response, regardless of the software used. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The gamma-glutamyl transpeptidase to platelet ratio (GPR) predicts significant liver fibrosis and cirrhosis in patients with chronic HBV infection in West Africa.

PubMed

Lemoine, Maud; Shimakawa, Yusuke; Nayagam, Shevanthi; Khalil, Mustapha; Suso, Penda; Lloyd, Jo; Goldin, Robert; Njai, Harr-Freeya; Ndow, Gibril; Taal, Makie; Cooke, Graham; D'Alessandro, Umberto; Vray, Muriel; Mbaye, Papa Saliou; Njie, Ramou; Mallet, Vincent; Thursz, Mark

2016-08-01

Simple and inexpensive non-invasive fibrosis tests are highly needed but have been poorly studied in sub-Saharan Africa. Using liver histology as a gold standard, we developed a novel index using routine laboratory tests to predict significant fibrosis in patients with chronic HBV infection in The Gambia, West Africa. We prospectively assessed the diagnostic accuracy of the novel index, Fibroscan, aspartate transaminase-to-platelet ratio index (APRI), and Fib-4 in Gambian patients with CHB (training set) and also in French and Senegalese CHB cohorts (validation sets). Of 135 consecutive treatment-naïve patients with CHB who had liver biopsy, 39% had significant fibrosis (Metavir fibrosis stage ≥F2) and 15% had cirrhosis (F4). In multivariable analysis, gamma-glutamyl transpeptidase (GGT) and platelet count were independent predictors of significant fibrosis. Consequently, GGT-to-platelet ratio (GPR) was developed. In The Gambia, the area under the receiver operating characteristic curve (AUROC) of the GPR was significantly higher than that of APRI and Fib-4 to predict ≥F2, ≥F3 and F4. In Senegal, the AUROC of GPR was significantly better than Fib-4 and APRI for ≥F2 (0.73, 95% CI 0.59 to 0.86) and better than Fib-4 and Fibroscan for ≥F3 (0.93, 0.87 to 0.99). In France, the AUROC of GPR to diagnose ≥F2 (0.72, 95% CI 0.59 to 0.85) and F4 (0.87, 0.76 to 0.98) was equivalent to that of APRI and Fib-4. The GPR is a more accurate routine laboratory marker than APRI and Fib-4 to stage liver fibrosis in patients with CHB in West Africa. The GPR represents a simple and inexpensive alternative to liver biopsy and Fibroscan in sub-Saharan Africa. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Real-Time RT-PCR Assays for Detection and Genotyping of West Nile Virus Lineages Circulating in Africa.

PubMed

Fall, Gamou; Faye, Martin; Weidmann, Manfred; Kaiser, Marco; Dupressoir, Anne; Ndiaye, El Hadj; Ba, Yamar; Diallo, Mawlouth; Faye, Ousmane; Sall, Amadou Alpha

2016-12-01

West Nile virus (WNV) is an emerging arbovirus, circulating worldwide between birds and mosquitoes, which impacts human and animal health. Since the mid-1990s, WNV outbreaks have emerged in Europe and America and represent currently the primary cause of encephalitis in the United States. WNV exhibits a great genetic diversity with at least eight different lineages circulating in the world, and four (1, 2, Koutango, and putative new) are present in Africa. These different WNV lineages are not readily differentiated by serology, and thus, rapid molecular tools are required for diagnostic. We developed here real-time RT-PCR assays for detection and genotyping of African WNV lineages. The specificity of the assays was tested using other flaviviruses circulating in Africa. The sensitivity was determined by testing serial 10-fold dilutions of viruses and RNA standards. The assays provided good specificity and sensitivity and the analytical detection limit was 10 copies/reaction. The RT-PCR assays allowed the detection and genotyping of all WNV isolates in culture medium, human serum, and vertebrate tissues, as well as in field and experimental mosquito samples. Comparing the ratios of genome copy number/infectious virion (plaque-forming units), our study finally revealed new insight on the replication of these different WNV lineages in mosquito cells. Our RT-PCR assays are the first ones allowing the genotyping of all WNV African variants, and this may have important applications in surveillance and epidemiology in Africa and also for monitoring of their emergence in Europe and other continents.

Robustness and Strategies of Adaptation among Farmer Varieties of African Rice (Oryza glaberrima) and Asian Rice (Oryza sativa) across West Africa

PubMed Central

Maat, Harro; Richards, Paul; Struik, Paul C.

2013-01-01

This study offers evidence of the robustness of farmer rice varieties (Oryza glaberrima and O. sativa) in West Africa. Our experiments in five West African countries showed that farmer varieties were tolerant of sub-optimal conditions, but employed a range of strategies to cope with stress. Varieties belonging to the species Oryza glaberrima – solely the product of farmer agency – were the most successful in adapting to a range of adverse conditions. Some of the farmer selections from within the indica and japonica subspecies of O. sativa also performed well in a range of conditions, but other farmer selections from within these two subspecies were mainly limited to more specific niches. The results contradict the rather common belief that farmer varieties are only of local value. Farmer varieties should be considered by breeding programmes and used (alongside improved varieties) in dissemination projects for rural food security. PMID:23536754

Robustness and strategies of adaptation among farmer varieties of African Rice (Oryza glaberrima) and Asian Rice (Oryza sativa) across West Africa.

PubMed

Mokuwa, Alfred; Nuijten, Edwin; Okry, Florent; Teeken, Béla; Maat, Harro; Richards, Paul; Struik, Paul C

2013-01-01

This study offers evidence of the robustness of farmer rice varieties (Oryza glaberrima and O. sativa) in West Africa. Our experiments in five West African countries showed that farmer varieties were tolerant of sub-optimal conditions, but employed a range of strategies to cope with stress. Varieties belonging to the species Oryza glaberrima - solely the product of farmer agency - were the most successful in adapting to a range of adverse conditions. Some of the farmer selections from within the indica and japonica subspecies of O. sativa also performed well in a range of conditions, but other farmer selections from within these two subspecies were mainly limited to more specific niches. The results contradict the rather common belief that farmer varieties are only of local value. Farmer varieties should be considered by breeding programmes and used (alongside improved varieties) in dissemination projects for rural food security.

Climatic Zones, Soil Moisture Seasonality and Biomass Burning and Their Influence On Ozone Precursor Concentrations Over West Africa as Retrieved from Satellites

NASA Astrophysics Data System (ADS)

Onojeghuo, A. R.; Balzter, H.; Monks, P. S.

2015-12-01

West Africa is a region with six different climatic zones including a rich savannah affected by biomass burning annually, the Niger delta oil producing region with major gas flaring sites and a long coastline. Research on atmospheric pollution using remotely sensed data over West Africa has mostly been conducted at regional scale or for individual countries, with little emphasis on the dynamics of climatic zones and the diversity of land cover types. This study analyses annual seasonal dynamics of emissions of two ozone precursors stratified by climatic zone: nitrogen dioxide (NO2) from OMI and carbon monoxide (CO) from TES. The different sources of these pollutants and their seasonality are explicitly considered. Results indicate that the highest annual wet season NO2 column concentrations were in the semi-arid zone (1.33 x 1015 molecules cm-2) after prolonged periods of low soil moisture while the highest dry season were observed in the wet sub-humid zone (2.62 x 1015 molecules cm-2) where the savannah fires occur annually. The highest annual CO concentrations (> 3.1 x 1018 molecules cm-2) were from the Niger Delta, located in the humid zone. There were indications of atmospheric transport of CO from the southern hemisphere in the west season. Climate change induced soil moisture variability was most prominent in the dry sub-humid and semi-arid climatic zones (±0.015m3m-3) . The causal effects of soil moisture variability on NO2 emissions and their seasonal cycles were tested using the Granger causality test. Causal effects of inter-zonal exchanges/transport of NO2 and CO emissions respectively were inferred using Directed Acyclic Graphs. The results indicate that NO2, CO and their seasonal ratios are strongly affected by changes in soil moisture.

Phylogeography of West Nile virus: from the cradle of evolution in Africa to Eurasia, Australia, and the Americas.

PubMed

May, Fiona J; Davis, C Todd; Tesh, Robert B; Barrett, Alan D T

2011-03-01

West Nile virus (WNV) is the most widely distributed of the encephalitic flaviviruses and is a major cause of encephalitis, with isolates obtained from all continents, apart from Antarctica. Subsequent to its divergence from the other members of the Japanese encephalitis virus complex, presumably in Africa, WNV has diverged into individual lineages that mostly correspond with geographic distribution. Here we elucidate the phylogeography and evolutionary history of isolates from lineage 1 of WNV. Interestingly, there are many examples of the same amino acid having evolved independently on multiple occasions. In Africa, WNV exists in an endemic cycle, whereas it is epidemic in Europe, being reintroduced regularly from Africa either directly (in western Europe) or via the Middle East (in eastern Europe). Significantly, introduction into other geographic areas has occurred on one occasion only in each region, leading to subsequent establishment and expansion of the virus in these areas. Only one endemic genotype each is present in India and Australia, suggesting that WNV was successfully introduced into these locations once only. Each introduction occurred many centuries ago, probably due to trade and exploration during the 19th century. Likewise, in the Americas, WNV was successfully introduced in 1999 and subsequently became endemic across most temperate regions of North America (NA). In contrast to previous suggestions, an isolate from the epidemic in Israel in 1998 was not the direct progenitor of the NA epidemic; rather, both epidemics originated from the same (unknown) location.

A tribute to Sheik Humarr Khan and all the healthcare workers in West Africa who have sacrificed in the fight against Ebola virus disease: Mae we hush.

PubMed

Bausch, Daniel G; Bangura, James; Garry, Robert F; Goba, Augustine; Grant, Donald S; Jacquerioz, Frederique A; McLellan, Susan L; Jalloh, Simbirie; Moses, Lina M; Schieffelin, John S

2014-11-01

The Kenema Government Hospital Lassa Fever Ward in Sierra Leone, directed since 2005 by Dr. Sheikh Humarr Khan, is the only medical unit in the world devoted exclusively to patient care and research of a viral hemorrhagic fever. When Ebola virus disease unexpectedly appeared in West Africa in late 2013 and eventually spread to Kenema, Khan and his fellow healthcare workers remained at their posts, providing care to patients with this devastating illness. Khan and the chief nurse, Mbalu Fonnie, became infected and died at the end of July, a fate that they have sadly shared with more than ten other healthcare workers in Kenema and hundreds across the region. This article pays tribute to Sheik Humarr Khan, Mbalu Fonnie and all the healthcare workers who have acquired Ebola virus disease while fighting the epidemic in West Africa. Besides the emotional losses, the death of so many skilled and experienced healthcare workers will severely impair health care and research in affected regions, which can only be restored through dedicated, long-term programs. Copyright © 2014. Published by Elsevier B.V.

Obstetric fistulae in West Africa: patient perspectives.

PubMed

Nathan, Lisa M; Rochat, Charles H; Grigorescu, Bogdan; Banks, Erika

2009-05-01

The objective of this study is to gain insight into the nature of obstetric fistulae in Africa through patient perspectives. At l'Hôpital Saint Jean de Dieu in Tanguieta, Benin, 37 fistula patients underwent structured interviews about fistula cause, obstacles to medical care, prevention, and reintegration by 2 physicians via interpreters. The majority of participants (43%) thought their fistulae were a result of trauma from the operative delivery. Lack of financial resources (49%) was the most commonly reported obstacle to care, and prenatal care (38%) was most frequently reported as an intervention that may prevent obstetric fistulae. The majority (49%) of the participants requested no further reintegration assistance aside from surgery. Accessible emergency obstetric care is necessary to decrease the burden of obstetric fistulae in Africa. This may be accomplished through increased and improved health care facilities and education of providers and patients.

Evaluation of the onset and length of growing season to define planting date—`a case study for Mali (West Africa)'

NASA Astrophysics Data System (ADS)

Akinseye, F. M.; Agele, S. O.; Traore, P. C. S.; Adam, M.; Whitbread, A. M.

2016-05-01

The agroecological zones (AEZ) of Mali fall within the semi-arid climate, the ability to determine efficiently or predict accurately the onset of growing season (OGS), and length of growing season (LGS) cannot be over-emphasized due to highly variable rainfall pattern and the dependence of smallholder farmers practising on rainfed farming agriculture. In this study, we determined the most suitable method for predicting the onset date of rainfall across AEZ that fitted with the planting windows of major cereal crops (maize, millet, and sorghum). Using long-term daily rainfall records from 22 meteorological stations spread across AEZ of Mali, four (4) known methods were applied to determine the onset dates of the rain. The mean onset dates were statistically compared with the farmer's planting window for the selected weather stations to determine the suitable dates of OGS and LGS. The hypothesis considered a time lag minimum of 7 days between the mean onset date and traditional farmer sowing dates for the crops. Then, the preferred method was used to estimate OGS based on early, normal and late dates respectively across the stations. Also, the estimated LGS according to each zone was evaluated using probability distribution chart with duration to maturity for varieties of the same crops. The results showed that Def_4 was found appropriate for Sahelian and Sudano-Sahelian zones; Def_3 satisfied the criteria and exhibited superior capacity into farmer's average planting date over Sudanian and Guinea Savannah zones. These results have an important application in cropping systems in order to prevent crop failure and ensure a better choice of crop variety according to LGS under climate variability and change being experienced across Mali.

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

NASA Astrophysics Data System (ADS)

Bertola, L. D.; Jongbloed, H.; van der Gaag, K. J.; de Knijff, P.; Yamaguchi, N.; Hooghiemstra, H.; Bauer, H.; Henschel, P.; White, P. A.; Driscoll, C. A.; Tende, T.; Ottosson, U.; Saidu, Y.; Vrieling, K.; de Iongh, H. H.

2016-08-01

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo).

PubMed

Bertola, L D; Jongbloed, H; van der Gaag, K J; de Knijff, P; Yamaguchi, N; Hooghiemstra, H; Bauer, H; Henschel, P; White, P A; Driscoll, C A; Tende, T; Ottosson, U; Saidu, Y; Vrieling, K; de Iongh, H H

2016-08-04

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

PubMed Central

Bertola, L. D.; Jongbloed, H.; van der Gaag, K. J.; de Knijff, P.; Yamaguchi, N.; Hooghiemstra, H.; Bauer, H.; Henschel, P.; White, P. A.; Driscoll, C. A.; Tende, T.; Ottosson, U.; Saidu, Y.; Vrieling, K.; de Iongh, H. H.

2016-01-01

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion. PMID:27488946

Fluid inclusions in quartz crystals from South-West Africa

USGS Publications Warehouse

Kvenvolden, K.A.; Roedder, E.

1971-01-01

Quartz crystals from calcite veins of unknown age in Precambrian metasedimentary rocks at Geiaus No. 6 and Aukam farms in South-West Africa contain both primary and secondary inclusions filled with one or a variable combination of: organic liquid, moderately saline aqueous liquid, dark-colored solid, and vapor. Analysis of these materials by microscopy and by gas chromatography and mass spectrometry shows the presence of constituents of both low and high molecular weights. The former include CH4, C2H6, C3H8 and possibly C4H10 as well as CO, CO2, H2O, N2 and H2. High molecular weight components are dominantly n-alkanes and isoprenoid hydrocarbons. The n-alkanes range from at least n-C10 to n-C33. Concentrations of n-alkanes larger than n-C17 decrease regularly with increasing carbon number. An homologous series of isoprenoid hydrocarbons ranging from at least C14 to C20 is present in unusually high concentrations. Pristane (C19) is most abundant, and C17 isoprenoid is least abundant. The molecular composition and distribution of hydrocarbons suggest biological precursors for these components. Consideration of data provided by freezing, crushing and heating experiments suggests that the pressures at the time these in part supercritical fluids were trapped probably exceeded 30-40 atm, and the minimum trapping temperature was about 120-160??C. Both primary and secondary inclusions apparently containing only organic materials were trapped by the growth of the host quartz from aqueous solution. The data obtained neither prove nor preclude Precambrian, Paleozoic or younger sources for the organic materials. ?? 1971.

Ebola in West Africa—CDC’s Role in Epidemic Detection, Control, and Prevention

PubMed Central

Damon, Inger K.

2015-01-01

Since Ebola virus disease was identified in West Africa on March 23, 2014, the Centers for Disease Control and Prevention (CDC) has undertaken the most intensive response in the agency’s history; >3,000 staff have been involved, including >1,200 deployed to West Africa for >50,000 person workdays. Efforts have included supporting incident management systems in affected countries; mobilizing partners; and strengthening laboratory, epidemiology, contact investigation, health care infection control, communication, and border screening in West Africa, Nigeria, Mali, Senegal, and the United States. All efforts were undertaken as part of national and global response activities with many partner organizations. CDC was able to support community, national, and international health and public health staff to prevent an even worse event. The Ebola virus disease epidemic highlights the need to strengthen national and international systems to detect, respond to, and prevent the spread of future health threats. PMID:26484940

Test of Continental Drift by Comparison of Radiometric Ages: A pre-drift reconstruction shows matching geologic age provinces in West Africa and Northern Brazil.

PubMed

Hurley, P M; Rand, J R; Pinson, W H; Fairbairn, H W; de Almeida, F F; Melcher, G C; Cordani, U G; Kawashita, K; Vandoros, P

1967-08-04

1) The distribution of age values obtained by potassium-argon determinations and whole-rock rubidium-strontium determinations appears to be almost identical for West African rocks of the pervasive Eburnean Orogenic Cycle and basement rocks at opposite locations in South America. 2) There is also a close correlation, with respect to potassium-argon age determinations on micas, rubidium-strontium determinations on total-rock samples, and the extent to which these two sets of values differ, between rocks of the Pan-African Orogenic Cycle and rocks of the Caririan Orogenic Cycle in Brazil, where these two groups of rocks lie opposite each other in the two continents. 3) When Africa and South America are "fitted together," the sharply defined boundary between the Eburnean and the Pan-African age provinces in West Africa strikes directly toward the corresponding age boundary in northeast Brazil. 4) The transition from the 550-million-year Pan-African age province to the 2000-million-year age province in the Congo Craton in Cameroun-Gabon is matched in the rocks near the corresponding part of the east coast of Brazil. However the geological and age data are insufficient to do more than suggest the possibility of another age-boundary correlation here. 5) The evidence reported here supports the hypothesis of continental drift.

Measurements of NO and NH3 soil fluxes at the Savé super site in Benin, West Africa, during the DACCIWA field campaign.

NASA Astrophysics Data System (ADS)

Pacifico, Federica; Delon, Claire; Jambert, Corinne; Durand, Pierre; Lohou, Fabienne; Reinares Martinez, Irene; Brilouet, Pierre-Etienne; Brosse, Fabien; Pedruzo Bagazgoitia, Xabier; Dione, Cheikh; Gabella, Omar

2017-04-01

In the next decades South West Africa will be subject to a strong increase in anthropogenic emissions due to a massive growth in population and urbanization. The impact of global climate change, local or regional land use changes, and the strong sensitivity to the West African monsoon lead to complex interactions between surface emissions and atmospheric dynamics and chemistry. Anthropogenic pollutants are transported northward from the mega cities located on the coast, and react with biogenic emissions, leading to enhanced ozone (O3) production outside urban areas, as well as secondary organic aerosols formation, with detrimental effects on humans, animals, natural vegetation and crops. Nitrogen oxide (NO) emissions from soils, among other sources, directly influence NOx concentrations. Changes in NO sources will consequently modify the rate of O3 production. The largest source of ammonia (NH3) emissions is agriculture, via the application of synthetic fertilizer. When released into the atmosphere, NH3 increases the level of air pollution. Once deposited in water and soils, it can potentially cause two major types of environmental damage, acidification and eutrophication, both of which can harm sensitive vegetation systems, biodiversity and water quality. We investigate the role of soil fluxes of NO and NH3 on atmospheric chemistry in West Africa, making use of the observations taken in June and July 2016 at the Savé super-site, Benin (8°02'03" N, 2°29'11″ E), during the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) field campaign, which took place in June-July 2016. These observations also include meteorological and soil parameters such as air temperature and humidity (at 2 m height), radiation, soil temperature and moisture at different depths (5 cm and 10 cm). The climate in Savé is typical of a wet Guinea savanna, and the wet season takes place from June to October. Soil fluxes of NO and NH3 were measured on: bare soil, grassland

Mapping the zoonotic niche of Lassa fever in Africa.

PubMed

Mylne, Adrian Q N; Pigott, David M; Longbottom, Joshua; Shearer, Freya; Duda, Kirsten A; Messina, Jane P; Weiss, Daniel J; Moyes, Catherine L; Golding, Nick; Hay, Simon I

2015-08-01

Lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across West Africa. It is a zoonosis, with the primary reservoir species identified as the Natal multimammate mouse, Mastomys natalensis. The host is distributed across sub-Saharan Africa while the virus' range appears to be restricted to West Africa. The majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particularly in hospital settings. Using a species distribution model, the locations of confirmed human and animal infections with Lassa virus (LASV) were used to generate a probabilistic surface of zoonotic transmission potential across sub-Saharan Africa. Our results predict that 37.7 million people in 14 countries, across much of West Africa, live in areas where conditions are suitable for zoonotic transmission of LASV. Four of these countries, where at-risk populations are predicted, have yet to report any cases of Lassa fever. These maps act as a spatial guide for future surveillance activities to better characterise the geographical distribution of the disease and understand the anthropological, virological and zoological interactions necessary for viral transmission. Combining this zoonotic niche map with detailed patient travel histories can aid differential diagnoses of febrile illnesses, enabling a more rapid response in providing care and reducing the risk of onward transmission. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

Famines in Africa: is early warning early enough?

PubMed Central

Kim, Jeeyon Janet; Guha-Sapir, Debarati

2012-01-01

Following the second Sahelian famine in 1984–1985, major investments were made to establish Early Warning Systems. These systems help to ensure that timely warnings and vulnerability information are available to decision makers to anticipate and avert food crises. In the recent crisis in the Horn of Africa, alarming levels of acute malnutrition were documented from March 2010, and by August 2010, an impending food crisis was forecast. Despite these measures, the situation remained unrecognised, and further deteriorated causing malnutrition levels to grow in severity and scope. By the time the United Nations officially declared famine on 20 July 2011, and the humanitarian community sluggishly went into response mode, levels of malnutrition and mortality exceeded catastrophic levels. At this time, an estimated 11 million people were in desperate and immediate need for food. With warnings of food crises in the Sahel, South Sudan, and forecast of the drought returning to the Horn, there is an immediate need to institutionalize change in the health response during humanitarian emergencies. Early warning systems are only effective if they trigger an early response. PMID:22745628

Famines in Africa: is early warning early enough?

PubMed

Kim, Jeeyon Janet; Guha-Sapir, Debarati

2012-01-01

Following the second Sahelian famine in 1984-1985, major investments were made to establish Early Warning Systems. These systems help to ensure that timely warnings and vulnerability information are available to decision makers to anticipate and avert food crises. In the recent crisis in the Horn of Africa, alarming levels of acute malnutrition were documented from March 2010, and by August 2010, an impending food crisis was forecast. Despite these measures, the situation remained unrecognised, and further deteriorated causing malnutrition levels to grow in severity and scope. By the time the United Nations officially declared famine on 20 July 2011, and the humanitarian community sluggishly went into response mode, levels of malnutrition and mortality exceeded catastrophic levels. At this time, an estimated 11 million people were in desperate and immediate need for food. With warnings of food crises in the Sahel, South Sudan, and forecast of the drought returning to the Horn, there is an immediate need to institutionalize change in the health response during humanitarian emergencies. Early warning systems are only effective if they trigger an early response.

Water Sources in Cape Verde and West Africa. Water in Africa.

ERIC Educational Resources Information Center

Maher, Robert

The Water in Africa Project was realized over a 2-year period by a team of Peace Corps volunteers, World Wise Schools (WWS) classroom teachers, and WWS staff members. As part of an expanded, detailed design, resources were collected from over 90 volunteers serving in African countries, photos and stories were prepared, and standards-based learning…

Cryptomyrus: a new genus of Mormyridae (Teleostei, Osteoglossomorpha) with two new species from Gabon, West-Central Africa

PubMed Central

Sullivan, John P.; Lavoué, Sébastien; Hopkins, Carl D.

2016-01-01

Abstract We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new species. Cryptomyrus, new genus, is readily distinguished from all other mormyrid genera by a combination of features of squamation, morphometrics, and dental attributes. Cryptomyrus ogoouensis, new species, is differentiated from its single congener, Cryptomyrus ona, new species, by the possession of an anal-fin origin located well in advance of the dorsal fin, a narrow caudal peduncle and caudal-fin lobes nearly as long as the peduncle. In Cryptomyrus ona, the anal-fin origin is located only slightly in advance of the dorsal fin, the caudal peduncle is deep and the caudal-fin lobes considerably shorter than the peduncle. Continued discovery of new taxa within the “Lower Guinea Clade” of Mormyridae highlights the incompleteness of our knowledge of fish diversity in West-Central Africa. We present a revised key to the mormyrid genera of Lower Guinea. PMID:27006619

Out of (South) Africa: Pretoria`s nuclear weapons experience. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horton, R.E.

1998-04-01

The primary focus of this paper is the impact of key South African leaders on the successful developments and subsequent rollbacks of South Africa`s nuclear weapons capability. It highlights the key milestones in the development of South Africa`s nuclear weapon capability. It also relates how different groups within South Africa (scientists, politicians, military and technocrats) interacted to successfully produce South Africa`s nuclear deterrent. It emphasizes the pivotal influence of the senior political leadership to pursue nuclear rollback given the disadvantages of its nuclear means to achieve vital national interests. The conclusions drawn from flu`s effort are the South African nuclearmore » program was an extreme response to its own identity Crisis. Nuclear weapons became a means to achieving a long term end of a closer affiliation with the West. A South Africa yearning to be identified as a Western nation and receive guarantees of its security rationalized the need for a nuclear deterrent. The deterrent was intended to draw in Western support to counter a feared total onslaught by Communist forces in the region. Two decades later, that same South Africa relinquished its nuclear deterrent and reformed its domestic policies to secure improved economic and political integration with the West.« less

Pleistocene refugia and genetic diversity patterns in West Africa: Insights from the liana Chasmanthera dependens (Menispermaceae)

PubMed Central

Schmidt, Marco; Muellner-Riehl, Alexandra Nora; Ogundipe, Oluwatoyin Temitayo; Paule, Juraj

2017-01-01

Processes shaping the African Guineo-Congolian rain forest, especially in the West African part, are not well understood. Recent molecular studies, based mainly on forest tree species, confirmed the previously proposed division of the western African Guineo-Congolian rain forest into Upper Guinea (UG) and Lower Guinea (LG) separated by the Dahomey Gap (DG). Here we studied nine populations in the area of the DG and the borders of LG and UG of the widespread liana species, Chasmanthera dependens (Menispermaceae) by amplified fragment length polymorphism (AFLP), a chloroplast DNA sequence marker, and modelled the distribution based on current as well as paleoclimatic data (Holocene Climate Optimum, ca. 6 kyr BP and Last Glacial Maximum, ca. 22 kyr BP). Current population genetic structure and geographical pattern of cpDNA was related to present as well as historical modelled distributions. Results from this study show that past historical factors played an important role in shaping the distribution of C. dependens across West Africa. The Cameroon Volcanic Line seems to represent a barrier for gene flow in the present as well as in the past. Distribution modelling proposed refugia in the Dahomey Gap, supported also by higher genetic diversity. This is in contrast with the phylogeographic patterns observed in several rainforest tree species and could be explained by either diverging or more relaxed ecological requirements of this liana species. PMID:28301470

Assessment of vaccination coverage, vaccination scar rates, and smallpox scarring in five areas of West Africa.

PubMed

Henderson, R H; Davis, H; Eddins, D L; Foege, W H

1973-01-01

In 1966, nineteen countries of West and Central Africa began a regional smallpox eradication and measles control programme in cooperation with the World Health Organization. This paper summarizes sample survey data collected to assess the results of the programme in Northern Nigeria (Sokoto and Katsina Provinces), Western Nigeria, Niger, Dahomey, and Togo. These data indicate that the programme, which used mass vaccination campaigns based on a collecting-point strategy, was generally successful in reaching a high proportion of the population. Analysis of vaccination coverage and vaccination scar rates by age underlined the importance to the programme of newborn children who accumulate rapidly following the mass campaign. Of all persons without vaccination scars at the time of the surveys, 34.4% were under 5 years of age; in the absence of a maintenance programme, this figure would rise to 40% after 1 year.

Outcomes of antiretroviral therapy in children in Asia and Africa: a comparative analysis of the IeDEA pediatric multiregional collaboration

PubMed Central

Leroy, Valeriane; Malateste, Karen; Rabie, Helena; Lumbiganon, Pagakrong; Ayaya, Samuel; Dicko, Fatoumata; Davies, Mary-Ann; Kariminia, Azar; Wools-Kaloustian, Kara; Aka, Edmond; Phiri, Samuel; Aurpibul, Linda; Yiannoutsos, Constantin; Signaté-Sy, Haby; Mofenson, Lynne; Dabis, François

2013-01-01

Background We investigated 18-month incidence and determinants of death and loss-to-follow-up of children after antiretroviral therapy (ART) initiation in a multiregional collaboration in lower-income countries. Methods HIV-infected children (positive PCR <18 months or positive serology ≥18 months) from IeDEA cohorts, <16 years, initiating ART were eligible. A competing risk regression model was used to analyze the independent risk of two failure types: death and loss-to-follow-up (>6 months). Findings Data on 13611 children, from Asia (N=1454), East-Africa (N=3114), Southern-Africa (N=6212) and West-Africa (N=2881) contributed 20,417 person-years of follow-up. At 18 months, the adjusted risk of death was 4.3% in East-Africa, 5.4% in Asia, 5.7% in Southern-Africa and 7.4% in West-Africa (P=0.01). Age<24 months, WHO stage 4, CD4<10%, attending a private sector clinic, larger cohort size and living in West-Africa were independently associated with poorer survival. The adjusted risk of loss-to-follow-up was 4.1% in Asia, 9.0% in Southern-Africa, 14.0% in East-Africa, and 21.8% in West-Africa (P <0.01). Age<12 months, non NNRTI-based ART regimen, WHO stage 4 at ART start, ART initiation after 2005, attending a public sector or a non-urban clinic, having to pay for laboratory tests or antiretroviral drugs, larger cohort size, and living in East or West-Africa were significantly associated with higher loss-to-follow-up. Conclusion Findings differed substantially across regions but raise overall concerns about delayed ART start, low access to free HIV-services for children, and increased workload on program retention in lower-income countries. Universal free access to ART services and innovative approaches are urgently needed to improve pediatric outcomes at program level. PMID:23187940

International Outreach in Africa - Complementary Efforts Using Common Cyberinfrastructure

NASA Astrophysics Data System (ADS)

Yoksas, T.; Almeida, W. G.; Pandya, R.; Bruintjes, R.; Foote, B.; Heck, S.; Herrmann, S.; Hoswell, E.; Konate, M.; Kucera, P.; Laing, A.; Lamptey, B.; Moncrieff, M.; Ramamurthy, M.; Roberts, R.; Traore, A.; Spangler, T.; Warner, T.; Weingroff, M.; Ribeiro, N. A.; Soares, E.; Nascimento, A.; Lona, J.; Real, J. C.

2008-05-01

For the past few years, the U.S. Unidata Program Center (Unidata, a program in UCAR) and Brazil's Centro de Previsão de Tempo e Estudos Climáticos (CPTEC, a division of INPE) have collaborated in outreach efforts where free-and-open exchange of hydro-meteorological data and the provision of free analysis/visualization tools are helping to build a hemispheric community where data, tools, and best practices in education and research are shared. Data sharing capabilities are being provided by Unidata's Internet Data Distribution (IDD) system, a community-based effort that has been the primary source of real-time meteorological data in the U.S. university community for over a decade. Unidata-CPTEC efforts have resulted in the creation of the Brazilian peer of the North American IDD, the IDD-Brasil, a data sharing network that has extended access to real-time data to over 15 institutions in South America and most recently countries in West Africa and the African Sahel. UCAR and CPTEC are involved in separate, but philosophically-related and complementary outreach efforts in Africa: UCAR has embarked on an effort, The UCAR Africa Initiative, whose goal is assisting in building sustainable atmospheric-sciences capacity in Africa. CPTEC is collaborating with national weather services in three West African countries, universities in Brazil and Portugal, and one private Portuguese company in SICLIMAD, a project aimed at contributing to sustainable development in West Africa. This presentation will provide an overview of the efforts being undertaken as part of The UCAR Africa Initiative; an overview and update on CPTEC's efforts in SICLIMAD; and explore avenues for greater collaboration on African issues and endeavors.

West Africa’s Efforts to Build Regional Security: An Analysis of Past ECOWAS Interventions to Determine what is Needed to Increase its Peacekeeping Capabilities

DTIC Science & Technology

2010-06-11

to foster that development . Thus, in order for West Africa to be at peace and develop politically and economically, an effective security...throughout the Ivorian territory and worked alongside French forces. The UN was very effective and responsive to the developments in the Ivorian...issues that may divide them and negatively impact on the effectiveness of any regional force. Much ink has been spilled in recent years about the

Embargo on Lion Hunting Trophies from West Africa: An Effective Measure or a Threat to Lion Conservation?

PubMed Central

Bouché, Philippe; Crosmary, William; Kafando, Pierre; Doamba, Benoit; Kidjo, Ferdinand Claude; Vermeulen, Cédric; Chardonnet, Philippe

2016-01-01

The W-Arly-Pendjari (WAP) ecosystem, shared among Benin, Burkina Faso and Niger, represents the last lion stronghold of West Africa. To assess the impact of trophy hunting on lion populations in hunting areas of the WAP, we analyzed trends in harvest rates from 1999 to 2014. We also investigated whether the hunting areas with higher initial hunting intensity experienced steeper declines in lion harvest between 1999 and 2014, and whether lion densities in hunting areas were lower than in national parks. Lion harvest rate remained overall constant in the WAP. At initial hunting intensities below 1.5 lions/1000km2, most hunting areas experienced an increase in lion harvest rate, although that increase was of lower magnitude for hunting areas with higher initial hunting intensity. The proportion of hunting areas that experienced a decline in lion harvest rate increased at initial hunting intensities above 1.5 lions/1000km2. In 2014, the lion population of the WAP was estimated with a spoor count at 418 (230–648) adults and sub-adult individuals, comparable to the 311 (123–498) individuals estimated in the previous 2012 spoor survey. We found no significant lion spoor density differences between national parks and hunting areas. Hunting areas with higher mean harvest rates did not have lower lion densities. The ratio of large adult males, females and sub-adults was similar between the national parks and the hunting areas. These results suggested that the lion population was not significantly affected by hunting in the WAP. We concluded that a quota of 1 lion/1000km2 would be sustainable for the WAP. Based on our results, an import embargo on lion trophies from the WAP would not be justified. It could ruin the incentive of local actors to conserve lions in hunting areas, and lead to a drastic reduction of lion range in West Africa. PMID:27182985

Embargo on Lion Hunting Trophies from West Africa: An Effective Measure or a Threat to Lion Conservation?

PubMed

Bouché, Philippe; Crosmary, William; Kafando, Pierre; Doamba, Benoit; Kidjo, Ferdinand Claude; Vermeulen, Cédric; Chardonnet, Philippe

2016-01-01

The W-Arly-Pendjari (WAP) ecosystem, shared among Benin, Burkina Faso and Niger, represents the last lion stronghold of West Africa. To assess the impact of trophy hunting on lion populations in hunting areas of the WAP, we analyzed trends in harvest rates from 1999 to 2014. We also investigated whether the hunting areas with higher initial hunting intensity experienced steeper declines in lion harvest between 1999 and 2014, and whether lion densities in hunting areas were lower than in national parks. Lion harvest rate remained overall constant in the WAP. At initial hunting intensities below 1.5 lions/1000km2, most hunting areas experienced an increase in lion harvest rate, although that increase was of lower magnitude for hunting areas with higher initial hunting intensity. The proportion of hunting areas that experienced a decline in lion harvest rate increased at initial hunting intensities above 1.5 lions/1000km2. In 2014, the lion population of the WAP was estimated with a spoor count at 418 (230-648) adults and sub-adult individuals, comparable to the 311 (123-498) individuals estimated in the previous 2012 spoor survey. We found no significant lion spoor density differences between national parks and hunting areas. Hunting areas with higher mean harvest rates did not have lower lion densities. The ratio of large adult males, females and sub-adults was similar between the national parks and the hunting areas. These results suggested that the lion population was not significantly affected by hunting in the WAP. We concluded that a quota of 1 lion/1000km2 would be sustainable for the WAP. Based on our results, an import embargo on lion trophies from the WAP would not be justified. It could ruin the incentive of local actors to conserve lions in hunting areas, and lead to a drastic reduction of lion range in West Africa.

Toward a Socio-Territorial Approach to Health: Health Equity in West Africa.

PubMed

Vialard, Lucie; Squiban, Clara; Fournet, Florence; Salem, Gérard; Foley, Ellen E

2017-01-22

This study contributes to the literature about the effects of space and place on health by introducing a socio-territorial approach to urban health disparities in West Africa. It explores how urban spaces, specifically neighbourhoods, are shaped by social and economic relations and strategies of territorial control. We examine the potential influence of socio-territorial processes on vulnerability to disease, access to medical care, healthscapes, and illness experiences. Our research was conducted in Senegal and relied on a mixed methods design. We identified four neighbourhoods that represent the socio-spatial heterogeneity of the city of Saint-Louis and utilized the following methods: geographic and anthropological field research, household surveys, health knowledge and behaviour surveys, clinical exams, and illness interviews. Our results highlight the socio-territorial processes at work in each neighbourhood, clinical findings on three health measures (overweight, high blood pressure, and hyperglycaemia) and health experiences of individuals with hypertension or type II diabetes. We found significant differences in the prevalence of the three health measures in the study sites, while experiences managing hypertension and diabetes were similar. We conclude that a socio-territorial approach offers insight into the complex constellation of forces that produce health disparities in urban settings.

Toward a Socio-Territorial Approach to Health: Health Equity in West Africa

PubMed Central

Vialard, Lucie; Squiban, Clara; Fournet, Florence; Salem, Gérard; Foley, Ellen E.

2017-01-01

This study contributes to the literature about the effects of space and place on health by introducing a socio-territorial approach to urban health disparities in West Africa. It explores how urban spaces, specifically neighbourhoods, are shaped by social and economic relations and strategies of territorial control. We examine the potential influence of socio-territorial processes on vulnerability to disease, access to medical care, healthscapes, and illness experiences. Our research was conducted in Senegal and relied on a mixed methods design. We identified four neighbourhoods that represent the socio-spatial heterogeneity of the city of Saint-Louis and utilized the following methods: geographic and anthropological field research, household surveys, health knowledge and behaviour surveys, clinical exams, and illness interviews. Our results highlight the socio-territorial processes at work in each neighbourhood, clinical findings on three health measures (overweight, high blood pressure, and hyperglycaemia) and health experiences of individuals with hypertension or type II diabetes. We found significant differences in the prevalence of the three health measures in the study sites, while experiences managing hypertension and diabetes were similar. We conclude that a socio-territorial approach offers insight into the complex constellation of forces that produce health disparities in urban settings. PMID:28117751

Intercomparison of Evapotranspiration Over the Savannah Volta Basin in West Africa Using Remote Sensing Data

PubMed Central

Opoku-Duah, S.; Donoghue, D.N.M.; Burt, T. P.

2008-01-01

This paper compares evapotranspiration estimates from two complementary satellite sensors – NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and ESA's ENVISAT Advanced Along-Track Scanning Radiometer (AATSR) over the savannah area of the Volta basin in West Africa. This was achieved through solving for evapotranspiration on the basis of the regional energy balance equation, which was computationally-driven by the Surface Energy Balance Algorithm for Land algorithm (SEBAL). The results showed that both sensors are potentially good sources of evapotranspiration estimates over large heterogeneous landscapes. The MODIS sensor measured daily evapotranspiration reasonably well with a strong spatial correlation (R2=0.71) with Landsat ETM+ but underperformed with deviations up to ∼2.0 mm day-1, when compared with local eddy correlation observations and the Penman-Monteith method mainly because of scale mismatch. The AATSR sensor produced much poorer correlations (R2=0.13) with Landsat ETM+ and conventional ET methods also because of differences in atmospheric correction and sensor calibration over land. PMID:27879847

Assessment of undiscovered oil and gas resources of the West African Costal Province, West Africa

USGS Publications Warehouse

Brownfield, Michael E.; Charpentier, Ronald R.; Schenk, Christopher J.; Klett, Timothy R.; Cook, Troy A.; Pollastro, Richard M.

2011-01-01

The West African Coastal Province along the west African coastline recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's USGS World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 3.2 billion barrels of oil, 23.63 trillion cubic feet of natural gas, and 721 million barrels of natural gas liquids.

Potential climate effect of mineral aerosols over West Africa: Part II—contribution of dust and land cover to future climate change

NASA Astrophysics Data System (ADS)

Ji, Zhenming; Wang, Guiling; Yu, Miao; Pal, Jeremy S.

2018-04-01

Mineral dust aerosols are an essential component of climate over West Africa, however, little work has been performed to investigate their contributions to potential climate change. A set of regional climate model experiments with and without mineral dust processes and land cover changes is performed to evaluate their climatic effects under the Representative Concentration Pathway 8.5 for two global climate models. Results suggest surface warming to be in the range of 4-8 °C by the end of the century (2081-2100) over West Africa with respect to the present day (1981-2000). The presence of mineral dusts dampens the warming by 0.1-1 °C in all seasons. Accounting for changes in land cover enhances the warming over the north of Sahel and dampens it to the south in spring and summer; however, the magnitudes are smaller than those resulting from dusts. Overall dust loadings are projected to increase, with the greatest increase occurring over the Sahara and Sahel in summer. Accounting for land cover changes tends to reduce dust loadings over the southern Sahel. Future precipitation is projected to decrease by 5-40 % in the western Sahara and Sahel and increase by 10-150 % over the eastern Sahel and Guinea Coast in JJA. A dipole pattern of future precipitation changes is attributed to dust effects, with decrease in the north by 5-20 % and increase by 5-20 % in the south. Future changes in land cover result in a noisy non-significant response with a tendency for slight wetting in MAM, JJA, and SON and drying in DJF.

Phylogeography of West Nile Virus: from the Cradle of Evolution in Africa to Eurasia, Australia, and the Americas▿ †

PubMed Central

May, Fiona J.; Davis, C. Todd; Tesh, Robert B.; Barrett, Alan D. T.

2011-01-01

West Nile virus (WNV) is the most widely distributed of the encephalitic flaviviruses and is a major cause of encephalitis, with isolates obtained from all continents, apart from Antarctica. Subsequent to its divergence from the other members of the Japanese encephalitis virus complex, presumably in Africa, WNV has diverged into individual lineages that mostly correspond with geographic distribution. Here we elucidate the phylogeography and evolutionary history of isolates from lineage 1 of WNV. Interestingly, there are many examples of the same amino acid having evolved independently on multiple occasions. In Africa, WNV exists in an endemic cycle, whereas it is epidemic in Europe, being reintroduced regularly from Africa either directly (in western Europe) or via the Middle East (in eastern Europe). Significantly, introduction into other geographic areas has occurred on one occasion only in each region, leading to subsequent establishment and expansion of the virus in these areas. Only one endemic genotype each is present in India and Australia, suggesting that WNV was successfully introduced into these locations once only. Each introduction occurred many centuries ago, probably due to trade and exploration during the 19th century. Likewise, in the Americas, WNV was successfully introduced in 1999 and subsequently became endemic across most temperate regions of North America (NA). In contrast to previous suggestions, an isolate from the epidemic in Israel in 1998 was not the direct progenitor of the NA epidemic; rather, both epidemics originated from the same (unknown) location. PMID:21159871

Projecting Future Land Use Changes in West Africa Driven by Climate and Socioeconomic Factors: Uncertainties and Implications for Adaptation

NASA Astrophysics Data System (ADS)

Wang, G.; Ahmed, K. F.; You, L.

2015-12-01

Land use changes constitute an important regional climate change forcing in West Africa, a region of strong land-atmosphere coupling. At the same time, climate change can be an important driver for land use, although its importance relative to the impact of socio-economic factors may vary significant from region to region. This study compares the contributions of climate change and socioeconomic development to potential future changes of agricultural land use in West Africa and examines various sources of uncertainty using a land use projection model (LandPro) that accounts for the impact of socioeconomic drivers on the demand side and the impact of climate-induced crop yield changes on the supply side. Future crop yield changes were simulated by a process-based crop model driven with future climate projections from a regional climate model, and future changes of food demand is projected using a model for policy analysis of agricultural commodities and trade. The impact of human decision-making on land use was explicitly considered through multiple "what-if" scenarios to examine the range of uncertainties in projecting future land use. Without agricultural intensification, the climate-induced decrease of crop yield together with increase of food demand are found to cause a significant increase in agricultural land use at the expense of forest and grassland by the mid-century, and the resulting land use land cover changes are found to feed back to the regional climate in a way that exacerbates the negative impact of climate on crop yield. Analysis of results from multiple decision-making scenarios suggests that human adaptation characterized by science-informed decision making to minimize land use could be very effective in many parts of the region.

Vulnerability to climate change of cocoa in West Africa: Patterns, opportunities and limits to adaptation.

PubMed

Schroth, Götz; Läderach, Peter; Martinez-Valle, Armando Isaac; Bunn, Christian; Jassogne, Laurence

2016-06-15

The West African cocoa belt, reaching from Sierra Leone to southern Cameroon, is the origin of about 70% of the world's cocoa (Theobroma cacao), which in turn is the basis of the livelihoods of about two million farmers. We analyze cocoa's vulnerability to climate change in the West African cocoa belt, based on climate projections for the 2050s of 19 Global Circulation Models under the Intergovernmental Panel on Climate Change intermediate emissions scenario RCP 6.0. We use a combination of a statistical model of climatic suitability (Maxent) and the analysis of individual, potentially limiting climate variables. We find that: 1) contrary to expectation, maximum dry season temperatures are projected to become as or more limiting for cocoa as dry season water availability; 2) to reduce the vulnerability of cocoa to excessive dry season temperatures, the systematic use of adaptation strategies like shade trees in cocoa farms will be necessary, in reversal of the current trend of shade reduction; 3) there is a strong differentiation of climate vulnerability within the cocoa belt, with the most vulnerable areas near the forest-savanna transition in Nigeria and eastern Côte d'Ivoire, and the least vulnerable areas in the southern parts of Cameroon, Ghana, Côte d'Ivoire and Liberia; 4) this spatial differentiation of climate vulnerability may lead to future shifts in cocoa production within the region, with the opportunity of partially compensating losses and gains, but also the risk of local production expansion leading to new deforestation. We conclude that adaptation strategies for cocoa in West Africa need to focus at several levels, from the consideration of tolerance to high temperatures in cocoa breeding programs, the promotion of shade trees in cocoa farms, to policies incentivizing the intensification of cocoa production on existing farms where future climate conditions permit and the establishment of new farms in already deforested areas. Copyright © 2016

New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.

PubMed

Mondol, Samrat; Moltke, Ida; Hart, John; Keigwin, Michael; Brown, Lisa; Stephens, Matthew; Wasser, Samuel K

2015-12-01

The African elephant consists of forest and savanna subspecies. Both subspecies are highly endangered due to severe poaching and habitat loss, and knowledge of their population structure is vital to their conservation. Previous studies have demonstrated marked genetic and morphological differences between forest and savanna elephants, and despite extensive sampling, genetic evidence of hybridization between them has been restricted largely to a few hybrids in the Garamba region of northeastern Democratic Republic of Congo (DRC). Here, we present new genetic data on hybridization from previously unsampled areas of Africa. Novel statistical methods applied to these data identify 46 hybrid samples--many more than have been previously identified--only two of which are from the Garamba region. The remaining 44 are from three other geographically distinct locations: a major hybrid zone along the border of the DRC and Uganda, a second potential hybrid zone in Central African Republic and a smaller fraction of hybrids in the Pendjari-Arli complex of West Africa. Most of the hybrids show evidence of interbreeding over more than one generation, demonstrating that hybrids are fertile. Mitochondrial and Y chromosome data demonstrate that the hybridization is bidirectional, involving males and females from both subspecies. We hypothesize that the hybrid zones may have been facilitated by poaching and habitat modification. The localized geography and rarity of hybrid zones, their possible facilitation from human pressures, and the high divergence and genetic distinctness of forest and savanna elephants throughout their ranges, are consistent with calls for separate species classification. © 2015 John Wiley & Sons Ltd.

Onuphis and Mooreonuphis (Annelida: Onuphidae) from West Africa with the description of three new species and the reinstatement of O. landanaensis Augener, 1918.

PubMed

Arias, Andrés

2016-09-16

The taxonomy of eastern Atlantic species of the genus Onuphis has been confused due to the somewhat cursory and misleading descriptions of species and the disregard of the true identity of the type species of the genus, O. eremita, which has been commonly reported from West Africa, along with O. geophiliformis and O. rullieriana. However, all three species are now considered as unlikely to occur in western Africa. This work recognises three species of Onuphis from this region. Two of them, Onuphis augeneri sp. nov. and O. hanneloreae sp. nov., are newly described from Nyanga estuary (Gabon) and Sal Island (Cape Verde) respectively. Furthermore, Onuphis landanaensis, a species described from the Gulf of Guinea and subsequently synonymised with O. eremita, is formally reinstated and redescribed based upon the re-examination of the original types. Detailed descriptions and illustrations of all species are presented as well as the ontogenetic changes of the brooder O. hanneloreae sp. nov. Furthermore, the genus Mooreonuphis is recorded for the first time in Africa with the description of M. nunezi sp. nov. from Cape Verde archipelago. Additionally, a dichotomous key to all species of the genera Onuphis and Mooreonuphis from the eastern Atlantic is included.

Ebola Virus Epidemic in West Africa: Global Health Economic Challenges, Lessons Learned, and Policy Recommendations.

PubMed

Elmahdawy, Mahmoud; Elsisi, Gihan H; Carapinha, Joao; Lamorde, Mohamed; Habib, Abdulrazaq; Agyie-Baffour, Peter; Soualmi, Redouane; Ragab, Samah; Udezi, Anthony W; Usifoh, Cyril; Usifoh, Stella

2017-09-01

The Ebola virus has spread across several Western Africa countries, adding a significant financial burden to their health systems and economies. In this article the experience with Ebola is reviewed, and economic challenges and policy recommendations are discussed to help curb the impact of other diseases in the future. The West African Ebola virus disease epidemic started in resource-constrained settings and caused thousands of fatalities during the last epidemic. Nevertheless, given population mobility, international travel, and an increasingly globalized economy, it has the potential to re-occur and evolve into a global pandemic. Struggling health systems in West African countries hinder the ability to reduce the causes and effects of the Ebola epidemic. The lessons learned include the need for strengthening health systems, mainly primary care systems, expedited access to treatments and vaccines to treat the Ebola virus disease, guidance on safety, efficacy, and regulatory standards for such treatments, and ensuring that research and development efforts are directed toward existing needs. Other lessons include adopting policies that allow for better flow of relief, averting the adverse impact of strong quarantine policy that includes exaggerating the aversion behavior by alarming trade and business partners providing financial support to strengthen growth in the affected fragile economies by the Ebola outbreak. Curbing the impact of future Ebola epidemics, or comparable diseases, requires increased long-term investments in health system strengthening, better collaboration between different international organizations, more funding for research and development efforts aimed at developing vaccines and treatments, and tools to detect, treat, and prevent future epidemics. Copyright © 2017. Published by Elsevier Inc.

Analysis of the bacterial community composition in acidic well water used for drinking in Guinea-Bissau, West Africa.

PubMed

Machado, Ana; Bordalo, Adriano A

2014-08-01

Potable water is a resource out of reach for millions worldwide, and the available water may be chemically and microbiologically compromised. This is particularly acute in Africa, where water-networks may be non-existent or restricted to a small fraction of the urban population, as in the case of Guinea-Bissau, West Africa. This study was carried out seasonally in Bolama (11°N), where unprotected hand-dug wells with acidic water are the sole source of water for the population. We inspected the free-living bacterial community dynamics by automated rRNA intergenic spacer analyses, quantitative polymerase chain reaction and cloning approaches. The results revealed a clear seasonal shift in bacterial assemblage composition and microbial abundance within the same sampling site. Temperature, pH and turbidity, together with the infiltration and percolation of surface water, which takes place in the wet season, seemed to be the driving factors in the shaping and selection of the bacterial community and deterioration of water quality. Analysis of 16S rDNA sequences revealed several potential pathogenic bacteria and uncultured bacteria associated with water and sediments, corroborating the importance of a culture-independent approach in drinking water monitoring. Copyright © 2014. Published by Elsevier B.V.

Mapping the Risk of Anaemia in Preschool-Age Children: The Contribution of Malnutrition, Malaria, and Helminth Infections in West Africa

PubMed Central

Soares Magalhães, Ricardo J.; Clements, Archie C. A.

2011-01-01

Background Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1–4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. Methods and Findings National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1–4 y in Burkina Faso, Ghana, and Mali in 2003–2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR2–10), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1–2 y (88 g/l). In West Africa, severe malnutrition, Pf PR2–10, and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1–4 y are anaemic in the three

The Plasmodium vivax in China: decreased in local cases but increased imported cases from Southeast Asia and Africa.

PubMed

Feng, Jun; Xiao, Huihui; Zhang, Li; Yan, He; Feng, Xinyu; Fang, Wen; Xia, Zhigui

2015-03-05

Currently the local P. vivax was sharply decreased while the imported vivax malaria increased in China. Despite Southeast Asia was still the main import source of vivax malaria, the trend of Africa become serious, especially for west and central Africa. Herein we have clarified the trend of P. vivax in China from 2004-2012, and made some analysis for the differences of imported vivax back from different regions. There are significantly different of P. vivax between Southeast Asia and Africa, also the difference was observed for different regions in Africa. Additionally, we have explored the possibility for the difference of the P. vivax between migrant workers back from west and central Africa and the prevalence of local population. This reminds us that surveillance and training should be strengthened by medical staffs on the imported P. vivax cases reported especially from west and central Africa, in order to reduce the risk of malaria reintroduction and, specific tools should be developed, as well as the epidemiological study to avoid the misdiagnosis such as P. ovale and P. vivax.