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Sample records for west african squall

  1. Leading and Trailing Anvil Clouds of West African Squall Lines

    Science.gov (United States)

    Centrone, Jasmine; Houze, Robert A.

    2011-01-01

    The anvil clouds of tropical squall-line systems over West Africa have been examined using cloud radar data and divided into those that appear ahead of the leading convective line and those on the trailing side of the system. The leading anvils are generally higher in altitude than the trailing anvil, likely because the hydrometeors in the leading anvil are directly connected to the convective updraft, while the trailing anvil generally extends out of the lower-topped stratiform precipitation region. When the anvils are subdivided into thick, medium, and thin portions, the thick leading anvil is seen to have systematically higher reflectivity than the thick trailing anvil, suggesting that the leading anvil contains numerous larger ice particles owing to its direct connection to the convective region. As the leading anvil ages and thins, it retains its top. The leading anvil appears to add hydrometeors at the highest altitudes, while the trailing anvil is able to moisten a deep layer of the atmosphere.

  2. West African Journal of Medicine

    African Journals Online (AJOL)

    The West African Journal of Medicine is owned by the West African College of Physicians and the West African College of Surgeons. Aims: The aims of the Journal are: To provide a medium for international dissemination of information about medical science in West Africa and elsewhere. To furnish a means whereby ...

  3. West African crystalline maculopathy.

    Science.gov (United States)

    Browning, David J

    2004-05-01

    To report new observations in West African crystalline maculopathy. Retrospective, observational case series. Three patients drawn from a private retina practice. Review of clinical charts and photographic studies. Distribution of intraretinal crystals and changes after laser photocoagulation, and history of ingesting foods typical in a West African diet but atypical for an American diet. All patients were older than 50 years, had diabetic retinopathy, ate green vegetables not found in American diets, and showed no deleterious effects of the crystals. Kola nut ingestion in 2 patients was remote and sparse, and was unknown in a third patient. The first 2 affected patients originating outside the Ibo tribe of Nigeria are reported. The pattern of retinal crystals can be changed, and the quantity of crystals reduced, by laser photocoagulation of associated diabetic retinopathy. West African crystalline retinopathy is distinguishable from other causes of crystalline retinopathy. It may reflect a component of the West African diet, seems to have diabetic retinopathy as a promoting factor via breakdown of the blood-retina barrier, and can be modified by laser photocoagulation of diabetic retinopathy. Increased awareness of the condition will allow physicians seeing West African immigrants to make the diagnosis and treat the patients appropriately.

  4. West African Journal of Radiology

    African Journals Online (AJOL)

    The West African Journal of Radiology is an annual publication and the official organ of the Association of Radiologists of West Africa. ... clinical case reports, discoveries and engineering design/fabrication reports related to any branch of imaging modalities, Radiotherapy and allied subjects. ... Table of Contents. Articles ...

  5. West African Journal of Radiology: Journal Sponsorship

    African Journals Online (AJOL)

    West African Journal of Radiology: Journal Sponsorship. Journal Home > About the Journal > West African Journal of Radiology: Journal Sponsorship. Log in or Register to get access to full text downloads.

  6. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    West African Journal of Medicine Vol. 31, No. 1 January–March, 2012. Departments of *Community Health, University of Uyo Teaching Hospital, Uyo, Nigeria, †Community Medicine, University College. Hospital, Ibadan, Nigeria ...... (Okada) crashes in Benin City, Nigeria. Prehosp Disaster Med 2009 Jul–Aug;. 24: 356–9 .

  7. West African Journal of Medicine

    African Journals Online (AJOL)

    _ WEST AFRICAN JOURNAL OF MEDICINE. CLINI CAL PRA CTI CE. Pain Management inAdult Acute Sickle Cell Pain Crisis: A Viewpoint. Chagriner la direction dans la crise de douleur de cellule de faucille adulte: un point de Vue . E. Udezue*, E. HerreraT. ABSTRACT. BACKGROUND: The acute pain crisis of sickle cell ...

  8. Improvisation in West African Musics.

    Science.gov (United States)

    Locke, David

    1980-01-01

    Discussed is music of the sub-Sahara. Vocal, instrumental, and dance drumming from the Sudan Desert, the North Coast, East Horn, Central and West Africa, and contrapuntal yodeling of Pygmies is described. For African musicians, the ability to improvise, and creativity, are gifts from God. Includes selected readings and recordings. (KC)

  9. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    user1

    Mots-clés: maladie de Parkinson, l'homocystéine, le Nigeria, la gravité, le handicap. WEST AFRICAN JOURNAL OF MEDICINE. ORIGINAL ARTICLE. ABSTRACT. BACKGROUND:Hyperhomocysteinaemia (HHcy) is as a long- term sequelum of levodopa therapy in Parkinson's disease. (PD). Information on its frequency and ...

  10. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    be a form of reversal to childhood.11. Among the American Indians dementia is considered to be a ..... to stigma.15. The Hausa- Fulani communities are found in many countries of the West-. African sub-region and cultural and religious inclinations are similar. It is thus reasonable to speculate that the findings of this study ...

  11. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    user1

    Mots-clés: dyspepsie, gastrite, ulcère duodénal, sensibilité, spécificité. WEST AFRICAN JOURNAL OF MEDICINE. ORIGINAL ARTICLE. ABSTRACT. BACKGROUND: Increasing endoscopy workload in open- access services necessitates adoption of appropriateness criteria to check abuse and improve yield. OBJECTIVE: ...

  12. Archives: West African Journal of Medicine

    African Journals Online (AJOL)

    Items 1 - 40 of 40 ... Archives: West African Journal of Medicine. Journal Home > Archives: West African Journal of Medicine. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 40 of ...

  13. A modeling study on Sumatra squall lines using WRF

    Science.gov (United States)

    LO, C. F.

    2014-12-01

    Sumatra Squall Line (SSL) is a tropical squall line system that usually forms over Sumatra at night and then sweeps towards the west coast of Peninsular Malaysia and Singapore in the early morning. SSL is one of the dominant rain-bearing systems in the region, particularly between April and November each year. In this study, we examine a series of short term (cases, we identify the general features of SSL and discuss its formation and propagation mechanisms. Through inter-comparison of simulations driven by GFS and ECMWF re-analyses, we also discuss the triggering effects of large scale atmospheric conditions on SSL.

  14. West African Journal of Applied Ecology

    African Journals Online (AJOL)

    The focus of the West African Journal of Applied Ecologyis on ecology, agriculture and water pollution. It aims to serve as an avenue for lecturers and researchers in West Africa to publish their work. Other websites related to this journal are http://apps.ug.edu.gh/wajae/.

  15. Children Ask Questions about West African Art.

    Science.gov (United States)

    Abercrombie, Denice; Cochran, Mathilda; Mims, Margaret

    1997-01-01

    Presents a collection of questions that fifth-grade students asked about African artwork and answers provided by staff from the Museum of Fine Arts in Houston, Texas. Observes that students' interest in important visual aspects of the art creates lead-ins to more detailed discussions of West African art and culture. (DSK)

  16. Archives: West African Journal of Industrial and Academic Research

    African Journals Online (AJOL)

    Items 1 - 15 of 15 ... Archives: West African Journal of Industrial and Academic Research. Journal Home > Archives: West African Journal of Industrial and Academic Research. Log in or Register to get access to full text downloads.

  17. Glucose intolerance in the West African Diaspora

    DEFF Research Database (Denmark)

    Nielsen, Jannie; Christensen, Dirk Lund

    2011-01-01

    In the United States, Black Americans are largely descendants of West African slaves; they have a higher relative proportion of obesity and experience a higher prevalence of diabetes than White Americans. However, obesity rates alone cannot explain the higher prevalence of type 2 diabetes. Type 2...

  18. Democracy & Development: Journal of West African Affairs

    African Journals Online (AJOL)

    Public policy research (empirical and theoretical) on the democracy, security, and development nexus. Democracy & Development: Journal of West African Affairs is the only one of its kind entirely devoted to reporting and explaining democratic developments in the sub-region. It is read widely by researchers, journalists, ...

  19. Wildlife resources of the West African savanna

    NARCIS (Netherlands)

    Bie, de S.

    1991-01-01

    The wild fauna in Africa is a renewable resource and its overexploitation has led to the depletion of animal populations. This thesis focusses on the ecological characterization of the ungulate community of the West African savanna, with special reference to the Biosphere Reserve 'Boucle du

  20. West African Journal of Medicine: Submissions

    African Journals Online (AJOL)

    Author Guidelines. The West African Journal of Medicine (WAJM) like any other medical Journal has adopted the “Uniform requirements for manuscripts submitted to Biomedical Journals” established by editors in the US, Canada and the United Kingdom (N. Engl J. Med 1997; 336: 309- 315). Papers for publication in this ...

  1. West African Journal of Applied Ecology: Submissions

    African Journals Online (AJOL)

    Author Guidelines. Instructions To Authors Papers for submission to the West African Journal of Applied Ecology should be written in English and should not exceed 8,000 words in total length. Papers should not have been submitted or be considered for submission for publication elsewhere. Ideas expressed in papers that ...

  2. anaesthesia in west-african dwarf goat

    African Journals Online (AJOL)

    0.05/10mg/kg) intramuscularly (1M), xylazine/lignocaine (0.05/10mg/kg) IM lsubcutaneously (SC) and Lignocaine. (lOmg/kg) SC were evaluated in mature, non-fasted West- African Dwarf (WAD) goats for a period of 80 minutes during ...

  3. Students' Perception of West African Agricultural Productivity ...

    African Journals Online (AJOL)

    E M IGBOKWE

    index.php/jae. Email: editorinchief@aesonnigeria.org. 159. Students' Perception of West African Agricultural Productivity Programme. Adopted Schools Programme in Oyo State, Nigeria http://dx.doi.org/10.4314/jae.v20i2.12. Samuel, J. E..

  4. Students' Perception of West African Agricultural Productivity ...

    African Journals Online (AJOL)

    It was recommended that West African Agricultural Productivity Programme officials should focus more attention on educating students in areas that are more technologically inclined such as in animal breeding, vaccination and crop processing instead of only in areas involving manual labour such as in planting, weeding ...

  5. Energy Generation Potential of West African Ocean Current ...

    African Journals Online (AJOL)

    A review of the West African ocean current energy generating potential is carried out. The peculiarity of the West African ocean characteristic is discussed and the challenges noted. Based on this review, it is found that ocean current represents an alternative source of renewable energy in West Africa in a streamed regular ...

  6. Haematological and serum biochemical parameters of West African ...

    African Journals Online (AJOL)

    The study was conducted to evaluate the haematological and serum biochemical parameters of West African dwarf goats fed ensiled cassava leaves with molasses and caged layer waste. Eighteen West African dwarf goats were randomly assigned to three experimental diets consisting of cassava leaves ensiled alone ...

  7. Complicating Culturally Relevant Pedagogy: Unpacking West African Immigrants' Cultural Identities

    Science.gov (United States)

    Allen, Keisha McIntosh; Jackson, Iesha; Knight, Michelle G.

    2012-01-01

    This study presents findings from a case study of 18 second- and 1.5-generation West African immigrants. We draw upon notions of elusive culture and indigenous knowledges to highlight participants' complex cultural identities and respond to anti-immigration discourses through positioning West African immigrant students as assets in American…

  8. Performance Of West African Dwarf Sheep Fed Diets Supplemented ...

    African Journals Online (AJOL)

    An experiment to investigate the possible growth promoting effect of rare earth elements (REE) in growing West African dwarf sheep as well as their influence on the haematological and blood serum biochemical changes was conducted for 12 weeks. Forty West African dwarf sheep were allotted to four dietary treatments: a ...

  9. The West African currency board and economic integration of British ...

    African Journals Online (AJOL)

    WACB) as an economic integration effort in British West Africa. Through a collaborative effort between this public institution and a private company, the Bank of British West Africa, British West African colonies were not only unified but also the way ...

  10. Regionalization in West Africa : the process of developing a common West African currency

    OpenAIRE

    Sveen, Heidi Walbye

    2004-01-01

    Monetary integration has been on the West African political agenda for a long time. It has been regarded as an important development strategy by for instance the Economic Community of West African States (ECOWAS) where 15 states are organized. Eight ECOWAS countries have a monetary co-operation through the Franc Zone, which is a unique post-colonial relation between France and former French colonies. In West Africa the Zone is organized in Union Économic et Monetaire Ouest Africaine (UEMOA). ...

  11. Natural Resources of Okyeman- an Overview | Owusu | West African ...

    African Journals Online (AJOL)

    West African Journal of Applied Ecology. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 3 (2012) >. Log in or Register to get access to full text downloads.

  12. Nuclear Medicine Practice in Africa | Obioha | West African Journal ...

    African Journals Online (AJOL)

    West African Journal of Radiology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2008) >. Log in or Register to get access to full text downloads.

  13. Maxillary haemangiopericytoma: A case report | Fatusi | West African ...

    African Journals Online (AJOL)

    West African Journal of Medicine ... by wide surgical resection with a careful microscopical examination of the resection margins and the institution of adjuvant radiotherapy in incompletely resected ... Key Words: Haemangiopericytoma, Embolisation, Afferent vessel ligation, Radiotherapy Chemotherapy, Prognostic factors.

  14. Observations on placentome diameters in gestating West African ...

    African Journals Online (AJOL)

    ADEYEYE

    2015-09-09

    com. Abstract. This study investigated the effect of experimental Trypanosoma brucei infection on the placentome diameter (PD) of twenty four gestating West African dwarf does. The does were randomized into 4 equal groups ...

  15. Natural resources endowment and economic growth: The West African Experience

    OpenAIRE

    Mohamed Jalloh

    2013-01-01

    This study aims at investigating the nexus between natural resource endowment and economic growth using a sample of West African countries. The study adopted a Barrow-type growth model to analyse the impact of natural resource wealth on economic growth. A dynamic panel estimation technique was employed using relevant data from West African Countries. The results from the panel regressions indicate that natural resource endowments have very minimal impact in terms of promoting economic growth ...

  16. West African Journal of Applied Ecology: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. The focus of the West African Journal of Applied Ecology is on ecology, agriculture and water pollution. It aims to serve as an avenue for lecturers and researchers in West Africa to publish their work. Section Policies. Articles. Checked Open Submissions, Checked Indexed, Checked Peer Reviewed ...

  17. Genetic relationships among West African okra (Abelmoschus caillei ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... to a different species. Key words: West African okra, genetic relationship, Abelmoschus caillei, Abelmoschus esculentus. INTRODUCTION. Okra is an important vegetable crop in India, West Africa,. South-East, Asia, U.S.A, Brazil, Australia and Turkey. In some regions, the leaves are also used for human.

  18. Toward a Historical Archaeology of West African Borderlands ...

    African Journals Online (AJOL)

    The duo-field of historical archaeology is increasingly being recognized around the world for its contributions. However, most of the existing surveys have concentrated on the coastal and hinterland locations in West Africa. Whereas, the ethnographic cum archival study of West African borderlands abounds in the literature, ...

  19. Energy Generation Potential of West African Ocean Current ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    2015-12-01

    Dec 1, 2015 ... benefit to marine operations with respect to renewable energy conversion system installations offshore. ... extreme wave condition in the West African area is quite .... [6] J. Vincent Cordone, C.K. Cooper and D. Szabo, “A hindcast study of the extreme wave climate of offshore West Africa. (WAX)”, OTC ...

  20. West and Central African Research and Education Networking ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    West and Central African Research and Education Networking (WACREN). For universities and research centres around the world, the Internet has become an important resource for teaching, learning and research. But, African universities have always faced important challenges to accessing cheap and reliable bandwidth ...

  1. familiarity with modern health management trends by west african

    African Journals Online (AJOL)

    2010-09-09

    Sep 9, 2010 ... September 2010. EAST AFRICAN MEDICAL JOURNAL. 372. Table 5. Rating of the application of Information Communication Technology (ICT) in their health institutions by West. African surgeons. ICT aspect. Number of None. Somewhat Satisfactory Very. Total respondents (%) satisfactory (%) satisfactory.

  2. Y chromosome lineages in men of west African descent.

    Directory of Open Access Journals (Sweden)

    Jada Benn Torres

    Full Text Available The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called "Grain Coast" of western Africa (Senegal to Sierra Leone. Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations, 188 Caribbeans (from 2 islands, 532 African Americans (AAs from Washington, DC and Columbia, SC, and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30-40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations.

  3. Y chromosome lineages in men of west African descent.

    Science.gov (United States)

    Torres, Jada Benn; Doura, Menahem B; Keita, Shomarka O Y; Kittles, Rick A

    2012-01-01

    The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called "Grain Coast" of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30-40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations.

  4. Bacterial pneumonia in the AIDS patients | Salami | West African ...

    African Journals Online (AJOL)

    No Abstract. West African Journal of Medicine Vol. 25 (1) 2006: pp. 1-5. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/wajm.v25i1.28236 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  5. Haematological characteristics and performance of West African ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-02-18

    Feb 18, 2009 ... African Journal of Biotechnology Vol. 8 (4), pp. 699-702, 18 ..... resistance to viruses and foreign bodies (Bhattacharya and Sarkar, 1968 .... Petroleum Hydrocarbons in Marine Ecosystems and Organisms. Pergamon Press ...

  6. Genome-wide patterns of population structure and admixture in West Africans and African Americans.

    Science.gov (United States)

    Bryc, Katarzyna; Auton, Adam; Nelson, Matthew R; Oksenberg, Jorge R; Hauser, Stephen L; Williams, Scott; Froment, Alain; Bodo, Jean-Marie; Wambebe, Charles; Tishkoff, Sarah A; Bustamante, Carlos D

    2010-01-12

    Quantifying patterns of population structure in Africans and African Americans illuminates the history of human populations and is critical for undertaking medical genomic studies on a global scale. To obtain a fine-scale genome-wide perspective of ancestry, we analyze Affymetrix GeneChip 500K genotype data from African Americans (n = 365) and individuals with ancestry from West Africa (n = 203 from 12 populations) and Europe (n = 400 from 42 countries). We find that population structure within the West African sample reflects primarily language and secondarily geographical distance, echoing the Bantu expansion. Among African Americans, analysis of genomic admixture by a principal component-based approach indicates that the median proportion of European ancestry is 18.5% (25th-75th percentiles: 11.6-27.7%), with very large variation among individuals. In the African-American sample as a whole, few autosomal regions showed exceptionally high or low mean African ancestry, but the X chromosome showed elevated levels of African ancestry, consistent with a sex-biased pattern of gene flow with an excess of European male and African female ancestry. We also find that genomic profiles of individual African Americans afford personalized ancestry reconstructions differentiating ancient vs. recent European and African ancestry. Finally, patterns of genetic similarity among inferred African segments of African-American genomes and genomes of contemporary African populations included in this study suggest African ancestry is most similar to non-Bantu Niger-Kordofanian-speaking populations, consistent with historical documents of the African Diaspora and trans-Atlantic slave trade.

  7. Mathematical modeling of tornadoes and squall storms

    Directory of Open Access Journals (Sweden)

    Sergey A. Arsen’yev

    2011-04-01

    Full Text Available Recent advances in modeling of tornadoes and twisters consist of significant achievements in mathematical calculation of occurrence and evolution of a violent F5-class tornado on the Fujita scale, and four-dimensional mathematical modeling of a tornado with the fourth coordinate time multiplied by its characteristic velocity. Such a tornado can arise in a thunderstorm supercell filled with turbulent whirlwinds. A theory of the squall storms is proposed. The squall storm is modeled by running perturbation of the temperature inversion on the lower boundary of cloudiness. This perturbation is induced by the action of strong, hurricane winds in the upper and middle troposphere, and looks like a running solitary wave (soliton; which is developed also in a field of pressure and velocity of a wind. If a soliton of a squall storm gets into the thunderstorm supercell then this soliton is captured by supercell. It leads to additional pressure fall of air inside a storm supercell and stimulate amplification of wind velocity here. As a result, a cyclostrophic balance inside a storm supercell generates a tornado. Comparison of the radial distribution of wind velocity inside a tornado calculated by using the new formulas and equations with radar observations of the wind velocity inside Texas Tornado Dummit in 1995 and inside the 3 May 1999 Oklahoma City Tornado shows good correspondence.

  8. Sexual Pelvic Bone Dimorphism in the West African Fruit Bat ...

    African Journals Online (AJOL)

    Patterns of sexual pelvic bone dimorphism in mammals are well documented. However, limited osteo-morphometrical examinations exist of the nature of dimorphism in the bony pelvis of the bat. This study, therefore, investigated the patterns of size and shape dimorphism in the pelvic bone of the West African fruit bat, ...

  9. Quantitative Protein And Fat Metabolism In West African Dwarf ...

    African Journals Online (AJOL)

    Quantitative Protein And Fat Metabolism In West African Dwarf Sheep Fed Margaritaria Discoidea As Supplement. ... Animal Research International ... Protein and energy utilization and quantitative retention of protein, fat and energy was investigated with twelve castrated Djallonke sheep averaging (20.0 ± 2.2kg BW) in ...

  10. Diet composition and habitat use of the West African bushbuck ...

    African Journals Online (AJOL)

    Diet composition and habitat use of the West African bushbuck were investigated in three vegetation units (River, Riverine Forest, Woodland Savannah) along the Baoule River, during the first half of the dry season. Woody plants were the most frequently occurring species in faecal pellets and were thought to represent ...

  11. Characteristics of adult tetanus in Accra | Hesse | West African ...

    African Journals Online (AJOL)

    West African Journal of Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 22, No 4 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should ...

  12. Incidence of udder abnormalities in West African Dwarf and Kalahari ...

    African Journals Online (AJOL)

    A total of 646 goats comprising 580 West African Dwarf (WAD) sampled across Abeokuta South, Abeokuta North and Odeda Local Government Areas of Ogun State and 66 Kalahari Red (KR) goats from the Institute of Food Security, Environmental Resources and Agricultural Research (IFSERAR), Federal University of ...

  13. Design Procedure of 4-Bladed Propeller | Ishiodu | West African ...

    African Journals Online (AJOL)

    West African Journal of Industrial and Academic Research. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 1 (2013) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...

  14. A Microbiological and Nutritional Evaluation of the West African ...

    African Journals Online (AJOL)

    The quality attributes of Kilishi, a West African dried meat product were studied over an eight week storage period comparing traditional production and packaging systems with a potassium sorbate treatment system and simple modern packaging. Changes in chemical composition and microbiological counts are reported.

  15. Performance Evaluation of West African Dwarf (WAD) Goats fed ...

    African Journals Online (AJOL)

    This study investigated the effect of replacing Pennisetum purpureum with unripe plantain peels on the performance of West African Dwarf Goats. Thirty buck kids with an average weight of 7.00 ± 0.55kg were randomly assigned to three dietary treatment groups with ten bucks per treatment in a completely randomized ...

  16. Taste preferences of west African dwarf ewes at different trimester ...

    African Journals Online (AJOL)

    Taste preferences of pregnant West African dwarf (WAD) ewes were studied at different trimester periods using the multiple choice preference test method. A total of twelve WAD ewes of average body weight of 15.96 ± 4.17 kg, divided into two groups (A and B) were used for the study. Six pregnant ewes (in group A) served ...

  17. ( Zingiber officinale ) and West African Black Pepper ( Piper ...

    African Journals Online (AJOL)

    Comparative Studies of Ginger ( Zingiber officinale ) and West African Black Pepper ( Piper guineense ) Extracts at Different Concentrations on the Microbial Quality ... microbial load, thus having more antimicrobial activity and may be preferred to be used as natural antimicrobial preservatives to extend the shelf-life of food.

  18. Agriculture, livelihoods and climate change in the West African Sahel

    NARCIS (Netherlands)

    Sissoko, K.; Keulen, van H.; Verhagen, A.; Tekken, V.; Battaglini, A.

    2011-01-01

    The West African Sahel is a harsh environment stressed by a fast-growing population and increasing pressure on the scarce natural resources. Agriculture is the main source of livelihood of the majority of the people living in the area. Increases in temperature and/or modifications in rainfall

  19. A Comparison of SSCE Questions Set by the West African ...

    African Journals Online (AJOL)

    The purpose of this study was to compare the Senior School Certificate Examination (SSCE) essay questions set by the West African Examinations Council (WAEC) and the National Examinations Council (NECO) in terms of how much they were distributed across the various levels of the cognitive domain. To this effect, the ...

  20. The Internet: Emerging Technologies in Two West African Countries.

    Science.gov (United States)

    Rogers, Jim

    1998-01-01

    Explores issues regarding the Internet, especially its role in education, in two West African countries, Burkina Faso and Ghana. These developing countries share a common border, but their technology reality is very different. Existing differences highlight some of the issues Africa is dealing with concerning the Internet. (Author/AEF)

  1. Toxoplasmosis: A Case Report | Khare | West African Journal of ...

    African Journals Online (AJOL)

    West African Journal of Radiology. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 14, No 1 (2007) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT ...

  2. Coconut milk - citrate as extender for West African dwarf buck ...

    African Journals Online (AJOL)

    JTEkanem

    production to improve livestock productivity. It was introduced by early workers like Philips and. Lardy1 and Salisbury et al2. It has been reported that there is increasing need for use of A.I. in. West African Dwarf (WAD) goats3; this necessitates extension of semen to make A.I. economically beneficial. However, the success.

  3. West African Journal of Industrial and Academic Research - Vol 18 ...

    African Journals Online (AJOL)

    West African Journal of Industrial and Academic Research - Vol 18, No 1 (2017). Journal Home > Archives > Vol 18, No 1 (2017). Log in or Register to get access to full text downloads. ... A framework for diagnosing confusable diseases using neutrosophic based neural network. Okpako Abugor Ejaita, P.O. Asagba, 8-16 ...

  4. Heavy Metal Concentrations In A West African Sahel Reservoir ...

    African Journals Online (AJOL)

    ... mean concentrations varied significantly between stations (P<0.05). The concentrations of heavy metals were below contamination levels and fall within the limits reported for other West African small sahel reservoirs. Keywords: Heavy metals, Pollutants, Environment, Alau reservoir, Sahel, Enrichment Animal Research ...

  5. Nitrogen utilisation and nitrient digestibility of west African dwarf ...

    African Journals Online (AJOL)

    An experiment to evaluate and compare the nitrogen utilization and nutrient digestibility of goat fed a pasture species (Cynodon nlemfuensis) or browse plant leaves (Spondias mombin or Gmelina arborea) based diets was conducted with fifteen (15) growing male West African Dwarf goats aged 7 – 7.5 months and ...

  6. Epidemiology of Helminth Parasites of West African Dwarf Goat ...

    African Journals Online (AJOL)

    Michael Horsfall

    affect West African dwarf goats are basically trematodes, cestodes and nematodes (Kumba et al 2005). The transmission success of the majority of this economically important helminthes parasites depends almost entirely on ingestion of the egg through contaminated food or water. The consumption of infective and larva by ...

  7. Reproductive Parameters of the West African Dwarf Bucks Raised in ...

    African Journals Online (AJOL)

    DR Ezihe

    Laboratory, College of Veterinary Medicine, University Agriculture, Makurdi. Scrotal circumference values recorded (18.97+ 1.14, .... maximal and rational utilization of the breeding stock. Gage and Freckleton (2003) further .... West African Dwarf buck in Ibadan, Ph.D Thesis. University of Ibadan, Ibadan . Bitto, I. I. and Aroh, ...

  8. Witchcraft in West African belief system – medical and social ...

    African Journals Online (AJOL)

    Some people even doubt its reality. There are various speculations here and there as it appears that much about the phenomenon of witchcraft is still shrouded in mystery. This paper, therefore, studies the subject of witchcraft from the viewpoint of the West African worldwide, vis a vis the medical and social dimensions.

  9. Childhood heart failure in Ibadan | Lagunju | West African Journal of ...

    African Journals Online (AJOL)

    West African Journal of Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 22, No 1 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should ...

  10. Highlight: Research Chair unites four West African universities in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-14

    Apr 14, 2016 ... Local and regional experts including researchers, consultants, and academics convened in Cotonou, Benin, on February 26, 2015 to launch a Research Chair on EcoHealth. The Chair unites four West African universities that have pledged to reduce air pollution and non-communicable respiratory ...

  11. Morphological studies on rumen development in West African Dwarf ...

    African Journals Online (AJOL)

    We studied the gross and light microscopic structures of rumen in fetal, neonatal and adult West African Dwarf (WAD) goats obtained from Nsukka and Igboeze South Local Government Areas (L.G.A) of Enugu State. After euthanasia the rumen was ligated, dissected out and the volume determined by flotation and ...

  12. Highlight: Research Chair unites four West African universities in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2015-02-26

    2 févr. 2015 ... Local and regional experts including researchers, consultants, and academics convened in Cotonou, Benin, on February 26, 2015 to launch a Research Chair on EcoHealth. The Chair unites four West African universities that have pledged to reduce air pollution and non-communicable respiratory ...

  13. Helicobacter pylori infections and gastric cancer: The West African ...

    African Journals Online (AJOL)

    Helicobacter pylori infections and gastric cancer: The West African experience. ... Although most strains of Hp are positive for the virulent factor cagA gene as well as vacA s1, m1 or s1, m2; there is no consistent association with GC. Some studies have attributed the low incidence of GC to low prevalence of strains with ...

  14. Haematological and physiological parameters of West African dwarf ...

    African Journals Online (AJOL)

    Twenty four West African Dwarf (WAD) goats of both sexes (12 bucks and 12 does) raised under intensive system and weighing between 5 and 11 kg with different coat colours (Black, Brown, Tan and White) were used for this study to evaluate the effects of sex and coat colour on their haematological and physiological ...

  15. Scrotal abnormalities and infertility in west African men: A ...

    African Journals Online (AJOL)

    Objective: To determine and compare the spectrum of scrotal abnormalities in fertile and sub-fertile west African men using scrotal US. Subjects and methods: The study examined 249 subjects over a period of 13 months. The subjects comprised 149 patients with diagnosis of male infertility, as well as 100 healthy ...

  16. West African Journal of Industrial and Academic Research ...

    African Journals Online (AJOL)

    West African Journal of Industrial and Academic Research: Advanced Search ... Combine multiple words with OR to find articles containing either term; e.g., education OR research; Use parentheses to create more complex queries; e.g., archive ((journal OR conference) NOT theses); Search for an exact phrase by putting it ...

  17. West African Journal of Pharmacology and Drug Research ...

    African Journals Online (AJOL)

    West African Journal of Pharmacology and Drug Research: Advanced Search ... Combine multiple words with OR to find articles containing either term; e.g., education OR research; Use parentheses to create more complex queries; e.g., archive ((journal OR conference) NOT theses); Search for an exact phrase by putting it ...

  18. Nigerian Pidgin and West African Pidgins: A sociolinguistic ...

    African Journals Online (AJOL)

    Sociolinguistic factors play a significant role in the emergence and development of pidgins and creoles, and their role in the development of West African Pidgin English based (WAPE) varieties is not an exception. Nigerian Pidgin (NP) along with Ghanaian Pidgin (GP) and Cameroon Pidgin (CP) form a continuum of ...

  19. Reproductive Parameters of the West African Dwarf Bucks Raised in ...

    African Journals Online (AJOL)

    DR Ezihe

    left and right corpus epididymal weights, left and right caudal epididymal weights) from the bucks were .... caudal epididymal weights) of WAD bucks were .... Sperm production rate, gonadal and extragonadal sperm reserves of the West African Dwarf rams in Makurdi.Proc.of the 32ndAnnu. Conf. of Nig. Soc. for Anim. Prod.

  20. Factors influencing the migration of West African health professionals

    African Journals Online (AJOL)

    Introduction: The West African health sector is characterized by a human resource base lacking in numbers and specialized skills. Among the contributory factors to this lack of human resource for health workforce include but not limited to the migration of health professionals. Methods: This cross-sectional survey targeted ...

  1. Performance characteristics and blood profile of West African dwarf ...

    African Journals Online (AJOL)

    A twelve week trial was investigated to evaluate performance and blood profile of West African dwarf (WAD) goats fed malted sorghum sprout with pineapple waste (MSPW) based diet. The malted sorghum sprout and pineapple waste was at ratio 1:2 (weight/weight) respectively. Sixteen WAD goats with average initial ...

  2. Reproductive Performance Of West African Dwarf Sheep And Goats ...

    African Journals Online (AJOL)

    Reproductive performance or 20 pregnant ewes and 20 pregnant does of West African Dwarf breed at village level in Ogun State, Nigeria were compared in a study which lasted for 8 months. Litter size in ewes was 1.50 while that of does was 1.85. The number of males produced by the two species out-numbered that of ...

  3. Testicular torsion on the Jos Plateau | Ugwu | West African Journal ...

    African Journals Online (AJOL)

    West African Journal of Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 22, No 2 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should ...

  4. Epidermal morphology of west african okra Abelmoschus caillei (A ...

    African Journals Online (AJOL)

    A study of the micro-morphology of 53 accessions of West African Okra was undertaken using light microscopy techniques. Results showed that epidermal cells are polygonal, isodiametric and irregularly shaped with different anticlinal cell wall patterns. Stomata type is 100% paracytic and 100% amphistomatic in distribution ...

  5. Response of West African dwarf sheep to differently processed ...

    African Journals Online (AJOL)

    A feeding trial was conducted to assess the response of West African Dwarf sheep to differently processed corncob meal based-diets. Sun-dried corncobs were collected at Teaching and Research farm of Federal University of Technology, Akure, treated with water, lye, urea, poultry litter and fermented for twenty-one (21) ...

  6. Case report - Achondroplastic syndrome in a West African dwarf lamb

    African Journals Online (AJOL)

    A three week old, male, West African Dwarf (WAD) lamb presented with disproportionate hind limb was diagnosed of having achondroplastic syndrome by physical and radiological examination. Physical examination showed the right hind limb was deformed at the level of the tarsus, metatarsus and phalanges. Radiological ...

  7. Carcass characteristics of tropical beef cattle breeds (West African ...

    African Journals Online (AJOL)

    This preliminary study was conducted using 35 animals to provide a means of a more accurate estimation of live and carcass weights of three tropical cattle beef cattle; the Zebu (Plate1), the humpless West African shorthorn (WASH) (Plate2) and the Sanga (Ghana Sanga), a crossbreed between WASH and Zebu (Plate3).

  8. Black English Near its Roots: The Transplanted West African Creoles.

    Science.gov (United States)

    Birmingham, John C., Jr.

    It seems highly likely that many of the features of Black American English can be traced back to the Afro-Portuguese Creole dialects that sprang up in the fifteenth century in Portuguese slave camps along the West African coast, particularly in the Gulf of Guinea area, the area of greatest concentration of activity during the slave trade. This…

  9. Assessment of serum biochemistry in West African Dwarf (WAD ...

    African Journals Online (AJOL)

    Jane

    2011-06-29

    Jun 29, 2011 ... and cycling ewes (Wildeus, 2004; Daniel et al., 2001) and does (Imasuen and Ikhimioya, 2009) has been well documented by several authors. However, its potential application on goats is yet to be fully explored, especially in our local breeds of goats such as West African Dwarf. (WAD) does. Furthermore ...

  10. Chemical Composition, Dry Matter Intake by West African Dwarf ...

    African Journals Online (AJOL)

    The experiment was conducted to determine dry matter intake (DMI) by West African dwarf (WAD) goats, chemical composition, in vitro gas production and dry matter digestibility of Panicum maximum (common name: Guinea grass or Panicum) with graded levels of palm kernel cake (PKC). Five diets were evaluated: ...

  11. Biological and phylogenetic characteristics of West African lineages of West Nile virus.

    Science.gov (United States)

    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.

  12. Rethinking West African economic integration: francophone ...

    African Journals Online (AJOL)

    This paper is both an empirical and historical study of the interface ofinternational trade, law and order, and economic integration from a subaltern perspective. Drawing largely from Nigerian experiences, it interrogates the protocol governing trade across West Africa's international boundaries and confronts this with the ...

  13. West African donkey's liveweight estimation using body measurements

    Directory of Open Access Journals (Sweden)

    Pierre Claver Nininahazwe

    2017-10-01

    Full Text Available Aim: The objective of this study was to determine a formula for estimating the liveweight in West African donkeys. Materials and Methods: Liveweight and a total of 6 body measurements were carried out on 1352 donkeys from Burkina Faso, Mali, Niger, and Senegal. The correlations between liveweight and body measurements were determined, and the most correlated body measurements with liveweight were used to establish regression lines. Results: The average weight of a West African donkey was 126.0±17.1 kg, with an average height at the withers of 99.5±3.67 cm; its body length was 104.4±6.53 cm, and a heart girth (HG of 104.4±6.53 cm. After analyzing the various regression lines and correlations, it was found that the HG could better estimate the liveweight of West African donkeys by simple linear regression method. Indeed, the liveweight (LW showed a better correlation with the HG (R2=0.81. The following formulas (Equations 1 and 2 could be used to estimate the LW of West Africa donkeys. Equation 1: Estimated LW (kg = 2.55 x HG (cm - 153.49; Equation 2: Estimated LW (kg = Heart girth (cm2.68 / 2312.44. Conclusion: The above formulas could be used to manufacture weighing tape to be utilized by veterinary clinicians and farmers to estimate donkey's weight in the view of medication and adjustment of load.

  14. Back to Africa: Second Chances for the Children of West African Immigrants

    Science.gov (United States)

    Bledsoe, Caroline H.; Sow, Papa

    2011-01-01

    This paper examines the phenomenon of West African parents living in Europe and North America who send their older children back home: from places of high immigrant aspiration to those of hardship and privation. Drawing on a project on West African immigration to Europe and on previous field studies in Africa, we conclude that West African…

  15. Genetic signatures for Helicobacter pylori strains of West African origin.

    Directory of Open Access Journals (Sweden)

    Kennady K Bullock

    Full Text Available Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of H. pylori strains from seven globally distributed populations or subpopulations and identified encoded proteins that exhibited the highest levels of sequence divergence. These included secreted proteins, an LPS glycosyltransferase, fucosyltransferases, proteins involved in molybdopterin biosynthesis, and Clp protease adaptor (ClpS. Among proteins encoded by the cag pathogenicity island, CagA and CagQ exhibited the highest levels of sequence diversity. We then identified proteins in strains of Western African origin (classified as hspWAfrica by MLST analysis with sequences that were highly divergent compared to those in other populations of strains. These included ATP-dependent Clp protease, ClpS, and proteins of unknown function. Three of the divergent proteins sequences identified in West African strains were characterized by distinct insertions or deletions up to 8 amino acids in length. These polymorphisms in rapidly evolving proteins represent robust genetic signatures for H. pylori strains of West African origin.

  16. Contribution of "Women's Gold" to West African livelihoods

    DEFF Research Database (Denmark)

    Pouliot, Mariéve

    2012-01-01

    Contribution of ``Women's Gold'' to West African Livelihoods: The Case of Shea ( Vitellaria paradoxa ) in Burkina Faso. This paper (i) quantifies the contribution that Vitellaria paradoxa makes to the total income of rural households belonging to different economic groups in two areas of Burkina...... Faso; (ii) quantifies the involvement of women in shea nuts and fruits collection and processing; and (iii) empirically verifies the ``gap filling'' function of shea products in Burkina Faso by quantifying the commercialization and subsistence use of shea fruits, nuts, and butter between agricultural...

  17. Will Elephants Soon Disappear from West African Savannahs?

    Science.gov (United States)

    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

  18. Will elephants soon disappear from West African savannahs?

    Directory of Open Access Journals (Sweden)

    Philippe Bouché

    Full Text Available 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.

  19. A Observational and Theoretical Study of Squall Line Evolution

    Science.gov (United States)

    Rasmussen, Erik Nels

    By utilizing a number of Doppler radar observations of ten squall lines, a certain class of squall lines is documented that is quasi-two-dimensional and has a solid leading edge at some time during the life cycle. It is found that the kinematic structure of these systems can be described as being due to a sloping zone of negative horizontal vorticity which extends across the entire squall line. Further, the evolution of these systems can be characterized by the sloping of this vorticity zone from erect to more horizontal orientations. The existence of the vorticity zone appears to be due to buoyancy gradients extending across the system. The primary difference between the systems studied is the rate at which tilting occurs. Motivated by the observations, a new theory is developed for squall line evolution. The theory allows for an environment with two layers characterized by differing shear values, and the squall line is characterized by a sloping region with a specified average vorticity. Using a circulation tendency approach, the rate of change of squall line slope is predicted based on environmental shear and cold pool strength. The predictions of the theory compare well with observations, and previously published theoretical and modelling results.

  20. Genetic structure in four West African population groups

    Directory of Open Access Journals (Sweden)

    Chen Guanjie

    2005-06-01

    Full Text Available Abstract Background Africa contains the most genetically divergent group of continental populations and several studies have reported that African populations show a high degree of population stratification. In this regard, it is important to investigate the potential for population genetic structure or stratification in genetic epidemiology studies involving multiple African populations. The presences of genetic sub-structure, if not properly accounted for, have been reported to lead to spurious association between a putative risk allele and a disease. Within the context of the Africa America Diabetes Mellitus (AADM Study (a genetic epidemiologic study of type 2 diabetes mellitus in West Africa, we have investigated population structure or stratification in four ethnic groups in two countries (Akan and Gaa-Adangbe from Ghana, Yoruba and Igbo from Nigeria using data from 372 autosomal microsatellite loci typed in 493 unrelated persons (986 chromosomes. Results There was no significant population genetic structure in the overall sample. The smallest probability is associated with an inferred cluster of 1 and little of the posterior probability is associated with a higher number of inferred clusters. The distribution of members of the sample to inferred clusters is consistent with this finding; roughly the same proportion of individuals from each group is assigned to each cluster with little variation between the ethnic groups. Analysis of molecular variance (AMOVA showed that the between-population component of genetic variance is less than 0.1% in contrast to 99.91% for the within population component. Pair-wise genetic distances between the four ethnic groups were also very similar. Nonetheless, the small between-population genetic variance was sufficient to distinguish the two Ghanaian groups from the two Nigerian groups. Conclusion There was little evidence for significant population substructure in the four major West African ethnic groups

  1. Migration patterns and influence of support networks: A case study of West Africans in the Netherlands

    NARCIS (Netherlands)

    Chelpi-den Hamer, M.

    2008-01-01

    This article explores the influence of support networks in the migration process of West African migrants to the Netherlands. Taking a case-oriented biographic approach, the article analyzes the migration stories of several West African migrants with a focus on the networks that facilitated their

  2. Strain characterization of West African Dwarf goats of Ogun State II ...

    African Journals Online (AJOL)

    The West African Dwarf (WAD) goat presents variable coat colours, ranging from black, brown, gray, red and white and sometimes combinations of these variety of patterns. In this study, strains of West African Dwarf (WAD) goat were characterized using linear body measurement. The WAD goat included the chocolate, white ...

  3. Spatial air pollution modelling for a West-African town.

    Science.gov (United States)

    Gebreab, Sirak Zenebe; Vienneau, Danielle; Feigenwinter, Christian; Bâ, Hâmpaté; Cissé, Guéladio; Tsai, Ming-Yi

    2015-11-26

    Land use regression (LUR) modelling is a common approach used in European and Northern American epidemiological studies to assess urban and traffic related air pollution exposures. Studies applying LUR in Africa are lacking. A need exists to understand if this approach holds for an African setting, where urban features, pollutant exposures and data availability differ considerably from other continents. We developed a parsimonious regression model based on 48-hour nitrogen dioxide (NO2) concentrations measured at 40 sites in Kaédi, a medium sized West-African town, and variables generated in a geographic information system (GIS). Road variables and settlement land use characteristics were found to be important predictors of 48-hour NO2 concentration in the model. About 68% of concentration variability in the town was explained by the model. The model was internally validated by leave-one-out cross-validation and it was found to perform moderately well. Furthermore, its parameters were robust to sampling variation. We applied the model at 100 m pixels to create a map describing the broad spatial pattern of NO2 across Kaédi. In this research, we demonstrated the potential for LUR as a valid, cost-effective approach for air pollution modelling and mapping in an African town. If the methodology were to be adopted by environmental and public health authorities in these regions, it could provide a quick assessment of the local air pollution burden and potentially support air pollution policies and guidelines.

  4. Spatial air pollution modelling for a West-African town

    Directory of Open Access Journals (Sweden)

    Sirak Zenebe Gebreab

    2015-11-01

    Full Text Available Land use regression (LUR modelling is a common approach used in European and Northern American epidemiological studies to assess urban and traffic related air pollution exposures. Studies applying LUR in Africa are lacking. A need exists to understand if this approach holds for an African setting, where urban features, pollutant exposures and data availability differ considerably from other continents. We developed a parsimonious regression model based on 48-hour nitrogen dioxide (NO2 concentrations measured at 40 sites in Kaédi, a medium sized West-African town, and variables generated in a geographic information system (GIS. Road variables and settlement land use characteristics were found to be important predictors of 48-hour NO2 concentration in the model. About 68% of concentration variability in the town was explained by the model. The model was internally validated by leave-one-out cross-validation and it was found to perform moderately well. Furthermore, its parameters were robust to sampling variation. We applied the model at 100 m pixels to create a map describing the broad spatial pattern of NO2 across Kaédi. In this research, we demonstrated the potential for LUR as a valid, cost-effective approach for air pollution modelling and mapping in an African town. If the methodology were to be adopted by environmental and public health authorities in these regions, it could provide a quick assessment of the local air pollution burden and potentially support air pollution policies and guidelines.

  5. The West African International Summer School for Young Astronomers

    Science.gov (United States)

    Strubbe, Linda; Okere, Bonaventure I.; Chibueze, James; Lepo, Kelly; White, Heidi; Zhang, Jielai; Izuikedinachi Okoh, Daniel; Reid, Michael; Hunter, Lisa; EKEOMA Opara, Fidelis

    2015-08-01

    In October 2013 over 75 undergraduate science students and teachers from Nigeria and Ghana attended the week-long West African International Summer School for Young Astronomers. We expect an even broader audience for the second offering of the school (to be held July 2015), supported by a grant from the OAD (TF1). These schools are organized by a collaboration of astronomers from the University of Toronto, the University of Nigeria, and the Nigerian National Space Research and Development Agency. We design and lead activities that teach astronomy content, promote students' self-identity as scientists, and encourage students to think critically and figure out solutions themselves. Equally important, we design intertwined evaluation strategies to assess the effectiveness of our programs. We will describe the broader context for developing astronomy in West Africa, the inquiry-based and active learning techniques used in the schools, and results from the qualitative and quantitative evaluations of student performance. We will also describe longer-term plans for future schools, supporting our alumni, and building a sustainable partnership between North American and Nigerian universities.

  6. Simulation of West African air pollution during the DACCIWA experiment with the GEOS-Chem West African regional model.

    Science.gov (United States)

    Morris, Eleanor; Evans, Mathew

    2017-04-01

    Pollutant emissions from West African cities are forecast to increase rapidly in future years because of extensive economic and population growth, together with poorly regulated industrialisation and urbanisation. Observational constraints in this region are few, leading to poor understanding of present-day air pollution in this region. To increase our understanding of the processes controlling air pollutants over the region, airborne observations were made from three research aircraft based out of Lomé, Togo during the DACCIWA field campaign in June-July 2016. A new 0.25x0.3125 degree West Africa regional version of the GEOS-Chem offline chemical transport model has also been developed to explore the processes controlling pollutants over the region. We evaluate the model using the aircraft data and focus on primary (CO, SO2, NOx, VOCs) and secondary pollutants (O3, aerosol). We find significant differences between the model and the measurements for certain primary compounds which is indicative of significant uncertainties in the base (EDGAR) emissions. For CO (a general tracer of pollution) we evaluate the role of different emissions sources (transport, low temperature combustion, power generation) in determining its concentration in the region. We conclude that the leading cause of uncertainty in our simulation is associated with the emissions datasets and explore the impact of using differing datasets.

  7. Renin angiotensinogen system gene polymorphisms and essential hypertension among people of West African descent

    DEFF Research Database (Denmark)

    Reiter, L M; Christensen, D L; Gjesing, A P

    2016-01-01

    This systematic review investigates the high level of hypertension found among urban dwellers in West Africa and in the West African Diaspora in the Americas in relation to variants within the genes encoding the renin angiotensinogen system. For comparison, the results from the Caucasian populati......This systematic review investigates the high level of hypertension found among urban dwellers in West Africa and in the West African Diaspora in the Americas in relation to variants within the genes encoding the renin angiotensinogen system. For comparison, the results from the Caucasian...

  8. Regional distribution of large blowdown patches across Amazonia in 2005 caused by a single convective squall line

    Science.gov (United States)

    Araujo, Raquel Fernandes; Nelson, Bruce Walker; Celes, Carlos Henrique Souza; Chambers, Jeffrey Q.

    2017-08-01

    In mid-January 2005 a convective squall line traversed 4.5 × 106 km2 of Amazonia from southwest to northeast. As seen in Landsat images, this atypical convective storm left blowdown imprints with diffuse geometry, unlike the fan-shaped wind disturbance of much more frequent east-to-west propagating squall lines. Previous work reported 0.2% of the forest area damaged by this one relatively rare event within one Landsat image and assumed similar disturbance across the entire traverse. We mapped convective wind damage impact to the region in 2005 by identifying large-scale (>4 ha) blowdown imprints in 30 Landsat images. The diffuse-type imprints associated with this single squall line contributed up to 60-72% of total 2005 wind-disturbed area detected across the region, but damage was highly concentrated in central Amazonia. Consequently, the distribution of large wind damage patches in 2005 across Amazonia was very different from long-term average. Regional distribution of wind-driven tree mortality for smaller patch sizes remains unknown.

  9. Prevalence of acquired cystic disease in black Africans on hemodialysis in West Africa

    National Research Council Canada - National Science Library

    Gnionsahe, D A; Lagou, D A; Tia, W M

    2007-01-01

    .... To determine the prevalence of ACKD in black African patients on chronic hemodialysis in West Africa, we examined by ultrasonography the native kidneys of 83 patients from February to August 2002...

  10. Composition and specific gravity of milk of West African Dwarf sheep ...

    African Journals Online (AJOL)

    Composition and specific gravity of milk of West African Dwarf sheep as affected by stage of lactation and parity. TJ Williams, IJ James, MR Abdulateef, LO Onabegun, SO Jinadu, YO Falade, FT Solola, OO Adewumi, OE Oke ...

  11. Modelling weighted mean temperature in the West African region: implications for GNSS meteorology

    National Research Council Canada - National Science Library

    Isioye, Olalekan Adekunle; Combrinck, Ludwig; Botai, Joel

    2016-01-01

    ...‐based Global Navigation Satellite System ( GNSS ) receivers. In the present study, three models of T m are developed for GNSS meteorological applications in the West African region in general and Nigeria in particular...

  12. West African Power Pool: Planning and Prospects for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Miketa, Asami [IRENA, Bonn (Germany); Merven, Bruno [Energy Research Centre, Univ. of Cape Town (South Africa)

    2013-06-25

    With the energy systems of many African countries dominated by fossil-fuel sources that are vulnerable to global price volatility, regional and intra-continental power systems with high shares of renewable energy can provide least-cost option to support continued economic growth and address the continent’s acute energy access problem. Unlocking Africa’s huge renewable energy potential could help to take many people out of poverty, while ensuring the uptake of sustainable technologies for the continent’s long-term development. The report examines a ''renewable scenario'' based on a modelling tool developed by IRENA and tested with assistance from the Economic Community of West African States (ECOWAS). Initial results from the ECOWAS Renewable Energy Planning (EREP) model for continental ECOWAS countries show that the share of renewable technologies in the region could increase from the current 22% of electricity generation to as much as 52% in 2030, provided that the cost of these technologies continues to fall and fossil fuel prices continue to rise. In this scenario, nearly half of the envisaged capacity additions between 2010 and 2030 would be with renewable technologies. Analysis using EREP – along with a similar model developed for Southern Africa – can provide valuable input for regional dialogue and energy projects such as the East and Southern Africa Clean Energy Corridor and the Programme for Infrastructure and Development in Africa (PIDA). IRENA, together with partner organisations, has started plans to set up capacity building and development support for energy system modelling and planning for greater integration of renewables in Africa. IRENA is also completing a similar model and study for East Africa and intends to extend this work to Central and North Africa.

  13. Living Beyond Boundaries: West African Servicemen in French Colonial Conflicts, 1908-1962

    OpenAIRE

    Zimmerman, Sarah Jean

    2011-01-01

    Living Beyond Boundaries: West African Servicemen in French Colonial Conflicts, 1908-1962, is a history of French West African colonial soldiers who served in French Empire. Known by the misnomer tirailleurs sénégalais, these servicemen contributed to the expansion, maintenance, and defense of France's presence on several continents. The complex identity and shifting purpose of this institution were directly linked to French colonialism, but determined by numerous actors and settings. The...

  14. Desertification and a shift of forest species in the West African Sahel

    Science.gov (United States)

    Gonzalez, Patrick

    2001-01-01

    Original field data show that forest species richness and tree density in the West African Sahel declined in the last half of the 20th century. Average forest species richness of areas of 4 km2 in Northwest Senegal fell from 64 ?? 2 species ca 1945 to 43 ?? 2 species in 1993, a decrease significant at p desertification in the West African Sahel. These documented impacts of desertification foreshadow possible future effects of climate change.

  15. Thermorespiratory Response of West African Dwarf Does to Progestagen Injection

    Directory of Open Access Journals (Sweden)

    Ogundana, FA.

    2005-01-01

    Full Text Available The physiological responses in terms of respiration rate (RR and rectal temperature (RT of 30 West African Dwarf (WAD does were monitored after a single im injection of different doses of progestagens meant for synchronising oestrus. The treatments involved im injection of 1 2 ml of sterile water (Control; 2 25 mg Medroxy Progesterone Acetate, MPA; 3 50 mg MPA; 4 50 mg Progesterone and 5 100 mg progesterone. The RR and RT of each animal were measured at 9:00, 13:00 and 17:00 h for 21 days after each injection. In all the treatment groups the RT did not change significantly (P> 0.05 during the weeks following treatment. On the contrary the RR was significantly higher (P< 0.05 in the week after injection than in the pre-injection period. Both the RR and the RT were higher at 13:00 h and 17:00 h than at 9:00 h. The RR was more influenced by the animal body size than the RT, while the ambient temperature and humidity affected both the animal's RT and RR. These results indicate that the thermorespiratory function of WAD does under their native humid environment is not negatively affected by injecting ≤ 100 mg progesterone or ≤ 50 mg MPA to synchronize oestrus.

  16. Familiarity with modern health management trends by West African surgeons.

    Science.gov (United States)

    Mahmoud, A O; Nkanga, D; Onakoya, A O

    2010-09-01

    To collate the self-reported assessment of familiarity with some aspects of managerial competencies on the part of some surgeons and their observations on the managerial environment of their health institutions and draw appropriate policy implications. Cross-sectional study using a structured questionnaire. The study was conducted during the 50th Annual Scientific Conference of the West African College of Surgeons, which was held in Calabar, Nigeria, from 6th to It 12th February 2010. One hundred and ten out of 150 surgeons who were attending the conference returned their filled questionnaires. Their familiarity with business and financial concepts was lacking on crucial ones related to marketing strategies. Respondent largely found the listed objections to advertisement of medical services as very appropriate. They preferred largely to interact with themselves in professional associations rather than with others in cross-cultural groupings. Funding (66.4%) and political/ethnic influences (43.9%) were rated as impacting very negatively on their health institutions, while the deployment of information communication technology to institutional processes was adjudged to be unsatisfactory. Most of the indices of core competencies in modern health leadership and management appeared deficient among our study participants and their health institutions managerial environments were equally deficient. We recommend for a well-focussed short time duration health management course for all physicians particularly specialists.

  17. Uterine Torsion in a West African Dwarf Ewe in Ibadan, Nigeria ...

    African Journals Online (AJOL)

    Keywords: Uterine torsion, West African Dwarf Ewe, Ibadan A case of uterine torsion in a 21/2 year old pluriparous West Africa Dwarf (WAD) ewe raised semi intensively with adequate veterinary care before the death of the dam and the lamb is presented. The dam had been off feed for 3 days and was found straining a night ...

  18. Critical Postcolonial Dance Pedagogy: The Relevance of West African Dance Education in the United States

    Science.gov (United States)

    Cruz Banks, Ojeya

    2010-01-01

    This dance ethnography examines work conducted by the Dambe Project--a nonprofit organization that specializes in African performing arts education and mentorship. The study focuses on the implications of the organization's dance pedagogy in light of its postcolonial context and the importance of West African dance education in the United States.…

  19. On the origins of locative for in West African Pidgin English: A ...

    African Journals Online (AJOL)

    African Pidgin Englishes. The development of for is framed componentially, that is, in terms of deriving its constructional meaning from different components that sustained linguistic and cultural contact along the Upper and Lower Guinea Coasts during the Early Modern Period (1500-1800) among West African, Portuguese ...

  20. [RESAOLAB: West African network of laboratories to enhance the quality of clinical biology].

    Science.gov (United States)

    Delorme, L; Machuron, J L; Sow, I; Diagne, R; Sakandé, J; Nikiéma, A; Bougoudogo, F; Keita, A; Longuet, C

    2015-02-01

    The Fondation Mérieux, in partnership with the Ministries of Health of Burkina Faso, Mali and Senegal, implemented for four years a project to reinforce the laboratory sector in the three participating countries: the RESAOLAB project (West African Network of Biomedical Analysis Laboratories).The objective of RESAOLAB project, in partnership with the WHO Office for West Africa and the West African Health Organization, was to strengthen the systems of biomedical laboratories to improve diagnostic services, access, monitoring and management of infectious diseases. Following the successful results achieved under the RESAOLAB project and due to the demand of the neighbour countries ministries, the RESAOLAB project is now extended to four other countries of the West African region: Benin, Guinea-Conakry, Niger and Togo. The RESAOLAB project has become the RESAOLAB programme, its purpose is to strengthen the quality of the medical biology services thanks to a regional and transversal approach.

  1. Observations of an 11 September Sahelian Squall Line and Saharan Air Layer Outbreak during NAMMA-06

    Directory of Open Access Journals (Sweden)

    J. W. Smith

    2012-01-01

    Full Text Available The 2006 NASA-African Monsoon Multidisciplinary Analyses (NAMMA-06 field campaign examined a compact, low-level vortex embedded in the trough of an AEW between 9–12 September. The vortex triggered a squall line (SL in southeastern Senegal in the early morning of 11 September and became Tropical Depression 8 on 12 September. During this period, there was a Saharan Air Layer (SAL outbreak in northwestern Senegal and adjacent Atlantic Ocean waters in the proximity of the SL. Increases in aerosol optical thicknesses in Mbour, Senegal, high dewpoint depressions observed in the Kawsara and Dakar rawinsondes, and model back-trajectories suggest the SAL exists. The close proximity of this and SL suggests interaction through dust entrainment and precipitation invigoration.

  2. Pan African Collisional Tectonics Along the Moroccan West African Craton Continued to Ediacaran-Cambrian Boundary

    Science.gov (United States)

    Hefferan, K. P.; Samson, S. D.; Rice, K.; Soulaimani, A.

    2016-12-01

    Precision geochronologic dating and field mapping in the Anti-Atlas Mountains of Morocco document a Neoproterozoic Pan African orogenic cycle consisting of three distinct orogenic events: Iriri-Tichibanine orogeny (760-700 Ma), Bou Azzer orogeny (680-640 Ma) and the WACadomian orogeny (620 Ma to either 555 or 544 Ma). The Iriri-Tichibanine and Bou Azzer orogenies involved northward directed subduction beneath island arc volcanic terranes. These orogenic events generated calc-alkaline magmatism and supra-subduction zone ophiolites exposed in the Bou Azzer and Siroua erosional inliers. The WACadomian orogeny involved subduction and collision of the Cadomia arc complex with the West African Craton and generation of clastic sedimentary basins. The termination of the WACadomian orogeny has been the subject of debate as calc-alkaline to high K magmatism and folding continued to 544 Ma: Was 620-544 Ma calc-alkaline to high K magmatism and clastic basin development due to a) continental rift basin tectonics or b) southward directed subduction and collisional tectonics with associated back arc basin tectonism? We present field and geochemical data supporting the continuation of subduction-collisional tectonics to the Ediacaran-Cambrian boundary 544 Ma. Field mapping in the Central Anti-Atlas (Agadir Melloul) clearly documents an angular unconformity between Ouarzazate Group and Adoudounian limestones (N 30°31'28.91", W07°48'29.12"). Volcaniclastic rocks of Ouarzazate Group (615-545 Ma) are clearly folded and unconformably overlain by Adoudou Formation (541-529 Ma) limestones to the north. Geochemical discrimination diagrams on Latest Neoproterozoic calc-alkaline to high K igneous rocks throughout the Anti-Atlas plot in subduction and collisional arc magma domains. Back arc basin tectonism is likely responsible for localized extensional basins but continental rift tectonics and passive margin sedimentation did not begin in the Anti-Atlas Mountains until Early

  3. The internet: Emergent technologies in two West African countries

    OpenAIRE

    Rogers, Jim

    1998-01-01

    Being connected for most Africans means something completely different from most of us in more (technologically) "developed" countries. Compared to those who have virtually unlimited and relatively cheap access to e-mail and the World Wide Web (WWW), most Africans have limited access to e-mail only. Outside of South Africa, which hosts 70 full Internet Service Providers (ISPs); Egypt, which hosts 25; and Morocco, which hosts 15, most African countries have well under 10 ISPs, the average bein...

  4. Using peer education to increase sexual health knowledge among West African refugees in Western Australia.

    Science.gov (United States)

    Drummond, Peter D; Mizan, Ayse; Brocx, Katie; Wright, Bernadette

    2011-03-01

    Ten bilingual West African peer educators conducted a 3-hour workshop on sexual health for small groups of West African refugees (N = 58) who recently had settled in Perth, Western Australia. There were significant increases in the participants' knowledge of sexually transmitted infections and HIV, how these infections are spread, and how to protect against infection. In addition, attitudes toward condom use became more positive. We conclude that the peer-education approach was successful in assisting a new and emerging community to work effectively on sexual health topics generally considered "taboo" or too sensitive to discuss.

  5. Pan-African Paleostresses and Reactivation of the Eburnean Basement Complex in Southeast Ghana (West Africa

    Directory of Open Access Journals (Sweden)

    Mahaman Sani Tairou

    2012-01-01

    Full Text Available This faulting tectonics analysis concerns the southernmost segment of the Dahomeyide Orogen and the West-African craton eastern margin in southeast Ghana. The analysis of strike-slip faults in the frontal units of the Dahomeyide Belt indicates that four distinct compressive events (NE-SW, ENE-WSW to E-W, ESE-WNW to SE-NW and SE-NW to SSE-NNW originated the juxtaposition of the Pan-African Mobile Zone and the West-African craton. These paleostress systems define a clockwise rotation of the compressional axis during the structuring of the Dahomeyide Orogen (650–550 Ma. The SE-NW and SSE-NNW to N-S compressional axes in the cratonic domain and its cover (Volta Basin suggest that the reactivation of the eastern edge of the West African craton is coeval with the last stages of the Pan-African tectogenesis in southeast Ghana. An extensional episode expressed as late normal faulting is also recorded in this study. This E-W to SE-NW extension, which is particular to the southernmost part of the Dahomeyide Belt, appears to be post-Pan-African. This extension probably contributed to the formation of a major Jurassic rifting zone that originated the Central Atlantic and the Benue Trough.

  6. Democracy & Development: Journal of West African Affairs - Vol 4 ...

    African Journals Online (AJOL)

    Making in West Africa · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. W Alade Fawole. Reconciling Ethnic and National Identities in a Divided Society: The Nigerian Dilemma of Nation-State Building ...

  7. Globalisation and the integration of West African states | Ojieh ...

    African Journals Online (AJOL)

    African Journal of International Affairs and Development. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 6, No 2 (2001) >. Log in or Register to get access to full text downloads.

  8. The Rise and Fall of Nugormesese in a West African Community ...

    African Journals Online (AJOL)

    In this study, I intend to conceptualize nugormesese as a basis of social capital in a West African farming community on the Ghana side of the Ghana-Togo border area. I will show that, by functioning as an environment of trust, nugormesese served as indigenous social capital that particularly facilitated binary relationships ...

  9. Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment

    DEFF Research Database (Denmark)

    Thorsen, Line; Kando, Christine Kere; Sawadogo, Hagrétou

    2015-01-01

    light on the succession and pathogenic potential of B. cereus species in traditional West African food condiment and clarifies their phylogenetic relatedness to B. cereus biovar anthracis. Future implementation of GMP and HACCP and development of starter cultures for controlled Maari fermentations...

  10. Effect of dietary salt levels on the performance of West African Dwarf ...

    African Journals Online (AJOL)

    A 70-day feeding trial was conducted to estimate the effect of levels (0, 5, 10, and 15g/kg cassava peels, respectively) of common salt and cassava peels (dry and fresh using Gmelina arborea leaves as a basal diet on the average daily gain, dry matter intake, feed conversion efficiency and water consumption in West African ...

  11. A cryptic mitochondrial DNA link between North European and West African dogs.

    Science.gov (United States)

    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.

  12. T-lymphocyte subsets in West African children: impact of age, sex, and season

    DEFF Research Database (Denmark)

    Lisse, I M; Aaby, P; Whittle, H

    1997-01-01

    determinants of T-lymphocyte subset levels. METHODS: A total of 803 healthy West African children younger than 6 years were included in the three community studies of T-lymphocyte subsets among twins and singletons, after measles infection and after measles immunization. We used the immunoalkaline phosphatase...... is particularly high in Africa....

  13. Milk yield and rectal temperature in West African Dwarf goats as ...

    African Journals Online (AJOL)

    This study was conducted to investigate milk yield and rectal temperature in West African Dwarf (WAD) goats as affected by wattle and litter size. A total of 28 lactating does were used for the experiment. 13 does had wattle (bilateral) while 15 had no wattle. 14 does had twin birth while the other 14 had single birth. The goats ...

  14. Soap induced urethral pain in boys | Okeke | West African Journal of ...

    African Journals Online (AJOL)

    West African Journal of Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 23, No 1 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should ...

  15. Prevalence of Eimeria Oocysts in West African Dwarf goats at the ...

    African Journals Online (AJOL)

    An outbreak of acute coccidiosis is reported in West African Dwarf (WAD) goats kept under semi-intensive management system at the University of Ibadan farm. During the period of the outbreak, clinical signs observed among the animal included anorexia, fever, coughing, ocular and nasal discharges and diarrhoea.

  16. Parturient behaviour of Djallonké ewes and West African dwarf does ...

    African Journals Online (AJOL)

    The parturient behaviour of 52 Djallonké ewes and 70 West African dwarf does was observed. The parameters recorded were the duration of parturition, posture during birth, presentation of the neonate at birth, and interventions during birth. The effects of parity, age and number of foetuses carried on the aforementioned ...

  17. Shaping Futures and Feminisms: Qur'anic Schools in West African Francophone Fiction

    Science.gov (United States)

    Edwin, Shirin

    2011-01-01

    This article examines the representation of female education in Qur'anic schools in a selection of West African francophone novels. I argue that in being the earliest form of education for most Muslim women and also a neglected topic of scholarly interest, the Qur'anic school shapes their feminisms in more significant ways than has been…

  18. Distribution of protein fraction in the milk of West African dwarf goat ...

    African Journals Online (AJOL)

    Milks from lactating West African dwarf goat and white Fulani cow were analysed for total protein, casein, whey protein, non protein nitrogen, Globulin and albumin and proteose peptone contents. Milk samples were from healthy goats and cows (n=24) in mid-lactation. The data were grouped and analysed as treatment 1 ...

  19. The interaction between nutrition and metabolism in West African dwarf goats, infected with trypanosomes

    NARCIS (Netherlands)

    Dam, van J.T.P.

    1996-01-01

    In a series of experiments the interaction between nutrition and energy- and nitrogen metabolism of West African Dwarf goats, infected with trypanosomes was studied. Animals were injected with trypanosomes, and feed intake, energy and nitrogen balance and blood metabolites and hormones were measured

  20. Milk Yield and Composition of West African Dwarf (WAD) Does fed ...

    African Journals Online (AJOL)

    Twelve individually housed West African Dwarf (WAD) does in their mid-lactation were used to study the effect of Bambara nut meal on milk yield, composition and mineral content of goat milk. Four experimental diets designated A, B, C and D were formulated to contain 0, 10, 20 and 30% Bambara nut meal (BM), ...

  1. Trans-abdominal scan evidence of superfoetation in a West African ...

    African Journals Online (AJOL)

    All animals were fed with commercial feedstuff (15.23% CP), elephant grass and fresh water ad libitum. One of the does which had earlier been observed to be mated during ... this observation is suggestive of superfoetation. Keywords: Mating, implantation, West African Dwarf (WAD) does, ultrasonography, superfoetation.

  2. Women in west African societies under colonial rule: a study in ...

    African Journals Online (AJOL)

    In the process, West African women demonstrated uncommon resilience that kept the indigenous productive processes and economic systems afloat in the face of the marauding globalization. This study examines the role and place of Uzairhue women of Benin Province in sustaining the internal dynamics of the indigenous ...

  3. Changes In Udder Size And Liveweight Of West African Dwarf, Red ...

    African Journals Online (AJOL)

    Changes in udder size and liveweight (LWT) of ten West African Dwarf (WAD), three Red Sokoto (RS) and three Sahel goats during lactation and their phenotypic relationship with partial daily milk yield (PDM) were studied. Udder length (UL), udder width (UW), udder circumference (UC). udder volume (UV), distance ...

  4. A comparative history of commercial transition in three West African slave trading economies, 1630 to 1860

    NARCIS (Netherlands)

    Dalrymple-Smith, Angus

    2017-01-01

    The nineteenth century ‘commercial transition’ from export economies based on slaves to ones dominated by commodities like palm oil has been a central theme in West African history. However, most studies have tended to focus on the impact of the change and assumed that its causes were

  5. Pre-sowing Treatment for Improving Seed Quality in West African ...

    African Journals Online (AJOL)

    Ten diverse modem West African rice varieties were exposed to six dry heat temperatures (40° C, 45° C, 50° C, 55° C, 60° C and control (32° C) for 24 hours and thereafter seed germination, speed of germination and seedling vigor were investigated. Dry heat temperatures significantly stimulated seed germination above ...

  6. ATM Technology and Banking System in West African Sub-Region ...

    African Journals Online (AJOL)

    Automated Teller Machine (ATM) technology has had its significant impact in banking system in Nigeria and some other West African Countries. The most significant impact of ATM technology is the customer's ability to withdraw money outside banking hours. But this feat achieved by ATM technology is not without ...

  7. Strain characterization of West African Dwarf Goats of Ogun State I ...

    African Journals Online (AJOL)

    Characterization of West African Dwarf goat is an approach to a sustainable use of its great potentials. In this study, strains of WAD goat were characterized using linear body measurement. The WAD goat included the gold (brown), black, buckskin and chaimose of ages 1, 2, 3 and 4 years,raised under extensive system of ...

  8. The pattern of stab injuries in Port Harcourt | Adotey | West African ...

    African Journals Online (AJOL)

    L'arme la plus couramment utilisee était la bouteille brisee et les blessures necessitant de multiples regions anatomiques étaient dans la majorite des cas. Tous les cas necessitant une intervention cherurgicale majeure rapports a moins de 6 heures de accident. Aucune mortalitee n'était enregistres. West African Journal of ...

  9. West African pholcid spiders: an overview, with descriptions of five new species (Araneae, Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard A. Huber

    2013-10-01

    Full Text Available This paper summarizes current knowledge about West African pholcids. West Africa is here defined as the area south of 17°N and west of 5°E, including mainly the Upper Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Senegal, The Gambia, Guinea Bissau, Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo and Benin. An annotated list of the 14 genera and 38 species recorded from this area is given, together with distribution maps and an identification key to genera. Five species are newly described: Anansus atewa sp. nov., Artema bunkpurugu sp. nov., Leptopholcus kintampo sp. nov., Spermophora akwamu sp. nov., and S. ziama sp. nov. The female of Quamtana kitahurira is newly described. Additional new records are given for 16 previously described species, including 33 new country records. Distribution patterns of West African pholcids are discussed, as well as possible explanations for relatively low West African pholcid species diversity as compared to Central and East Africa.

  10. Prevalence of electrocardiographic abnormalities in West-Asian and African male athletes

    Science.gov (United States)

    Wilson, M G; Chatard, J C; Carre, F; Hamilton, B; Whyte, G P; Sharma, S; Chalabi, H

    2012-01-01

    Objectives To evaluate the electrocardiographic (ECG) characteristics of West-Asian, black and Caucasian male athletes competing in Qatar using the 2010 recommendations for 12-lead ECG interpretation by the European Society of Cardiology (ESC). Design Cardiovascular screening with resting 12-lead ECG analysis of 1220 national level athletes (800 West-Asian, 300 black and 120 Caucasian) and 135 West-Asian controls was performed. Results Ten per cent of athletes presented with ‘uncommon’ ECG findings. Black African descent was an independent predictor of ‘uncommon’ ECG changes when compared with West-Asian and Caucasian athletes (pathletes also demonstrated a significantly greater prevalence of lateral T-wave inversions than both West-Asian and Caucasian athletes (6.1% vs 1.6% and 0%, pathletes was comparable (7.9% vs 5.8%, p>0.05). Seven athletes (0.6%) were identified with a disease associated with sudden death; this prevalence was two times higher in black athletes than in West-Asian athletes (1% vs 0.5%), and no cases were reported in Caucasian athletes and West-Asian controls. Eighteen West-Asian and black athletes were identified with repolarisation abnormalities suggestive of a cardiomyopathy, but ultimately, none were diagnosed with a cardiac disease. Conclusion West-Asian and Caucasian athletes demonstrate comparable rates of ECG findings. Black African ethnicity is positively associated with increased frequencies of ‘uncommon’ ECG traits. Future work should examine the genetic mechanisms behind ECG and myocardial adaptations in athletes of diverse ethnicity, aiding in the clinical differentiation between physiological remodelling and potential cardiomyopathy or ion channel disorders. PMID:21596717

  11. familiarity with modern health management trends by west african

    African Journals Online (AJOL)

    2010-09-09

    Sep 9, 2010 ... ones related to marketing strategies. Respondent largely found the listed ..... Rating of the ease with which customers could effect some transactions without being physically present with their health institutions by West ... crucial to marketing strategies that facilitate build-up and retention of loyal patients.

  12. West African Research and Training Hub on Environmental and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In West Africa, nine in 10 workers have informal jobs in economic activities related to agriculture, mining, transport, trade, and commerce. ... The initial research focuses on documenting and reducing health threats associated with processing electronic waste (e-waste), small-scale gold mining, and air pollution impacts from ...

  13. Mixed farming : scope and constraints in West African savanna

    NARCIS (Netherlands)

    Slingerland, M.

    2000-01-01

    Since colonial times the crop livestock integration concept has been a leading development model in francophone West Africa. So far, it has failed in certain aspects, such as cultivation of fodder crops, intensification of cereal production through animal traction, and sedentarisation of

  14. Learning Across Disciplines: An Approach to West African Music.

    Science.gov (United States)

    Morin, Francine

    2003-01-01

    Describes how to teach about world music, specifically music of West Africa, using an interdisciplinary inquiry approach. Explains that questions are generated and the teacher develops the learning experience. Provides examples at the fourth grade level as well as information on resources and musical examples. (CMK)

  15. Journal supplement features 10 years of West African health ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2017-07-20

    Jul 20, 2017 ... In the wake of the devastating Ebola virus outbreak in 2014, increased attention has been paid to West Africa's poorly functioning health systems. This includes how their weaknesses compounded the emergency and complicated the response to the health crisis. A new supplement published on July 13, ...

  16. West and Central African Partnership for Maternal, Newborn, Child ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    High rates of maternal death and teen pregnancy persist in West and Central Africa. Research and programming efforts are not sustainably reducing these rates. The challenge is how to link the evidence on useful health interventions with evidence on how to deliver the interventions effectively. This project aims to build the ...

  17. Scenarios on future land changes in the West African Sahel

    DEFF Research Database (Denmark)

    Lambin, Eric; D'haen, Sarah Ann Lise; Mertz, Ole

    2014-01-01

    In an attempt to anticipate possible futures of drylands of West Africa in the face of rapid socio-economic and environmental changes, we developed four scenarios based on recent survey data, the literature and our knowledge of the region. The four scenarios are inspired by those developed...

  18. Gender Inequality and Contradictions In West African Development ...

    African Journals Online (AJOL)

    The convergence and almost absolute uniformity among communities in West Africa on the issue of gender inequity remains one of the central challenges of globalisation. The centrality of this phenomenon is given that women constitute almost 50% of the population in most of these societies. Hence, any policy or ...

  19. Acute oral toxicity test and phytochemistry of some west african ...

    African Journals Online (AJOL)

    Background: Although there is increased acceptance and utilization of medicinal plants worldwide, many are used indiscriminately without recourse to any safety test. Thus, the need for toxicity tests to determine the safe dose for oral consumption. Objective: LD and phytochemistry of four medicinal plants 50 of West Africa ...

  20. West African Journal of Pharmacology and Drug Research: Editorial ...

    African Journals Online (AJOL)

    Advertisements. Enquiries concerning advertisement spaces and rates should be addressed to: Editorial Office, c/o Dept. of. Pharmacology and Therapeutics/Dept. of Medicine, College of Medicine, University of Nigeria, Enugu Campus. ISSN: 0303-691X. AJOL African Journals Online. HOW TO USE AJOL.

  1. West African Journal of Medicine - Vol 21, No 4 (2002)

    African Journals Online (AJOL)

    Alveolar bone regeneration pattern following surgical and non-surgical treatment in Juvenile Periodontitis · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Traumatic dislocation of the hip joint - pattern and management in a Tropical African Population · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  2. Strategic Implications of Emerging Threats to West African Countries

    Science.gov (United States)

    2012-03-14

    West Africa is particularly prone to the extremes of climate change. Furthermore, locust invasions, prevalent diseases like malaria, heavy...countries of Senegal, Nigeria, Guinea and Mali45. In addition to cocaine, the region has also been used for the trafficking of heroin and cannabis ...resolving an immediate crisis, and 24 focusing on structural conflict prevention by addressing the root causes of state fragility in order to

  3. Tropical Atlantic Hurricanes, Easterly Waves, and West African Mesoscale Convective Systems

    Directory of Open Access Journals (Sweden)

    Yves K. Kouadio

    2010-01-01

    Full Text Available The relationship between tropical Atlantic hurricanes (Hs, atmospheric easterly waves (AEWs, and West African mesoscale convective systems (MCSs is investigated. It points out atmospheric conditions over West Africa before hurricane formation. The analysis was performed for two periods, June–November in 2004 and 2005, during which 12 hurricanes (seven in 2004, five in 2005 were selected. Using the AEW signature in the 700 hPa vorticity, a backward trajectory was performed to the African coast, starting from the date and position of each hurricane, when and where it was catalogued as a tropical depression. At this step, using the Meteosat-7 satellite dataset, we selected all the MCSs around this time and region, and tracked them from their initiation until their dissipation. This procedure allowed us to relate each of the selected Hs with AEWs and a succession of MCSs that occurred a few times over West Africa before initiation of the hurricane. Finally, a dipole in sea surface temperature (SST was observed with a positive SST anomaly within the region of H generation and a negative SST anomaly within the Gulf of Guinea. This SST anomaly dipole could contribute to enhance the continental convergence associated with the monsoon that impacts on the West African MCSs formation.

  4. Recent radiation in West African Taterillus (Rodentia, Gerbillinae): the concerted role of chromosome and climatic changes.

    Science.gov (United States)

    Dobigny, G; Aniskin, V; Granjon, L; Cornette, R; Volobouev, V

    2005-11-01

    West African gerbils of the genus Taterillus constitute a complex of seven sibling species distributed from sudano-guinean to saharo-sahelian regions. They display radically rearranged karyotypes despite low genic divergence and a very recent differentiation, that is, within the last 0.4 Myr for the six most derived species. We here provide a comparison of the seven specific karyotypes and perform a cladistic analysis using chromosomal rearrangements character states. When a posteriori polarized mutations were mapped onto the phylogenetic tree, 38 rearrangements were identified as fixed during the evolution of these rodents. This makes Taterillus one of the most striking examples of accelerated chromosomal evolution within placental mammals. Taking into account the types of chromosomal changes involved, divergence times between lineages, genetic distances, as well as reassessed geographic distributions, we suggest that (1) speciation in West African Taterillus was driven by chromosomal changes, and (2) the paleoclimatic oscillations of the Sahara desert have played a major role in their evolution. In particular, elevated plasticity of the Taterillus genome, as suggested by the patterns observed for some repetitive elements, would have led to a higher probability of mutation. We hypothesize that the process underpinning cladogenesis most probably involved highly underdominant genomic rearrangements that were fixed following pronounced populational bottlenecks resulting from drastic climatic and subsequent environmental changes. Major African rivers formed significant barriers to dispersal, limiting expansion during the more moist and so favorable periods. This scenario would explain the current parapatric species distributions and their relationship to the West African hydrographic features.

  5. Evidence of henipavirus infection in West African fruit bats.

    Directory of Open Access Journals (Sweden)

    David T S Hayman

    Full Text Available Henipaviruses are emerging RNA viruses of fruit bat origin that can cause fatal encephalitis in man. Ghanaian fruit bats (megachiroptera were tested for antibodies to henipaviruses. Using a Luminex multiplexed microsphere assay, antibodies were detected in sera of Eidolon helvum to both Nipah (39%, 95% confidence interval: 27-51% and Hendra (22%, 95% CI: 11-33% viruses. Virus neutralization tests further confirmed seropositivity for 30% (7/23 of Luminex positive serum samples. Our results indicate that henipavirus is present within West Africa.

  6. Serum 25-hydroxyvitamin D in a West African population of tuberculosis patients and unmatched healthy controls

    DEFF Research Database (Denmark)

    Wejse, Christian; Olesen, Rikke; Rabna, Paulo

    2007-01-01

    BACKGROUND: Little is known regarding vitamin D deficiency (VDD) in African populations and in tuberculosis (TB) patients. VDD has been shown to be associated with TB. OBJECTIVE: We aimed to compare the degree of vitamin D insufficiency (VDI) and VDD in TB patients and healthy adult controls...... in a West African population. DESIGN: An unmatched case-control study was performed at a Demographic Surveillance Site in Guinea-Bissau. Serum 25-hydroxyvitamin D(3) [25(OH)D(3)] concentrations were measured in 362 TB patients and in 494 controls. RESULTS: Hypovitaminosis D [25(OH)D(3) Udgivelsesdato: 2007...

  7. Serum 25-hydroxyvitamin D in a West African population of tuberculosis patients and unmatched healthy controls

    DEFF Research Database (Denmark)

    Wejse, Christian; Olesen, Rikke; Rabna, Paulo

    2007-01-01

    BACKGROUND: Little is known regarding vitamin D deficiency (VDD) in African populations and in tuberculosis (TB) patients. VDD has been shown to be associated with TB. OBJECTIVE: We aimed to compare the degree of vitamin D insufficiency (VDI) and VDD in TB patients and healthy adult controls...... in a West African population. DESIGN: An unmatched case-control study was performed at a Demographic Surveillance Site in Guinea-Bissau. Serum 25-hydroxyvitamin D(3) [25(OH)D(3)] concentrations were measured in 362 TB patients and in 494 controls. RESULTS: Hypovitaminosis D [25(OH)D(3)...

  8. Effects of Climate and Land Use on Herbaceous Species Richness and Vegetation Composition in West African Savanna Ecosystems

    National Research Council Canada - National Science Library

    Zerbo, Issouf; Bernhardt-Römermann, Markus; Ouédraogo, Oumarou; Hahn, Karen; Thiombiano, Adjima

    2016-01-01

    .... Introduction West African Savanna ecosystems are undergoing severe changes in their vegetation composition and species cover due to the impact of human land use and changes in climatic conditions....

  9. Migration of the Common Redstart (Phoenicurus phoenicurus): A Eurasian Songbird Wintering in Highly Seasonal Conditions in the West African Sahel

    National Research Council Canada - National Science Library

    Mikkel Willemoes Kristensen; Anders P. Tøttrup; Kasper Thorup

    2013-01-01

    .... Fall migration passed west of the Mediterranean Sea and along the northwest African coast before the birds made an abrupt change of direction at the southern edge of the Sahara toward the winter area...

  10. Comparison of Different Pretreatment Strategies for Ethanol Production of West African Biomass

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe; Gonzalez Londono, Jorge Enrique; Schmidt, Jens Ejbye

    2015-01-01

    Pretreating lignocellulosic biomass for cellulosic ethanol production in a West African setting requires smaller scale and less capital expenditure compared to current state of the art. In the present study, three low-tech methods applicable for West African conditions, namely Boiling Pretreatment...... husks, cocoa pods, maize cobs, maize stalks, rice straw, groundnut straw and oil palm empty fruit bunches. It was found that four biomass’ (plantain peelings, plantain trunks, maize cobs and maize stalks) were most promising for production of cellulosic ethanol with profitable enzymatic conversion...... of glucan (>30 g glucan per 100 g total solids (TS)). HTT did show better results in both enzymatic convertibility and fermentation, but evaluated on the overall ethanol yield the low-tech pretreatment methods are viable alternatives with similar levels to the HTT (13.4–15.2 g ethanol per 100 g TS raw...

  11. REER Imbalances and Macroeconomic Adjustments in the Proposed West African Monetary Union

    OpenAIRE

    Asongu, Simplice A

    2013-01-01

    With the spectre of the Euro crisis hunting embryonic monetary unions, we use a dynamic model of a small open economy to analyze REERs imbalances and examine whether the movements in the aggregate real exchange rates are consistent with the underlying macroeconomic fundamentals in the proposed West African Monetary Union (WAMU). Using both country-oriented and WAMU panel-based specifications, we show that the long-run behavior of the REERs can be explained by fluctuations in the terms of trad...

  12. Enacted Destiny: West African Charismatic Christians in Berlin and the Immanence of God

    OpenAIRE

    Nieswand, Boris

    2010-01-01

    "The focus of this article is the concept of enacted destiny, which was identified among charismatic Christians of West African origin in Berlin. Different from more fatalistic concepts of destiny, it combines a strong notion of free agency with a strong notion of a good, almighty, and immanent God. The imaginary of enacted destiny is constituted by two components: 1. presituational religious empowerment by which charismatic Christians can reduce complexities, anxieties, and insecurities in t...

  13. A genome-wide association study of prostate cancer in West African men

    Science.gov (United States)

    Cook, Michael B.; Wang, Zhaoming; Yeboah, Edward D.; Tettey, Yao; Biritwum, Richard B.; Adjei, Andrew A.; Tay, Evelyn; Truelove, Ann; Niwa, Shelley; Chung, Charles C.; Chokkalingam, Annand P.; Chu, Lisa W.; Yeager, Meredith; Hutchinson, Amy; Yu, Kai; Rand, Kristin A.; Haiman, Christopher A.; Hoover, Robert N.; Hsing, Ann W.; Chanock, Stephen J.

    2013-01-01

    Background Age-adjusted mortality rates for prostate cancer are higher for African American men compared with those of European ancestry. Recent data suggest that West African men also have elevated risk for prostate cancer relative to European men. Genetic susceptibility to prostate cancer could account for part of this difference. Methods We conducted a genome-wide association study (GWAS) of prostate cancer in West African men in the Ghana Prostate Study. Association testing was performed using multivariable logistic regression adjusted for age and genetic ancestry for 474 prostate cancer cases and 458 population-based controls on the Illumina HumanOmni-5 Quad BeadChip. Results The most promising association was at 10p14 within an intron of a long non-coding RNA (lncRNA RP11-543F8.2) 360 kb centromeric of GATA3 (p=1.29E−7). In sub-analyses, SNPs at 5q31.3 were associated with high Gleason score (≥7) cancers, the strongest of which was a missense SNP in PCDHA1 (rs34575154, p=3.66E−8), and SNPs at Xq28 (rs985081, p=8.66E−9) and 6q21 (rs2185710, p=5.95E−8) were associated with low Gleason score (Asian or African American ancestry, we were able to test 81 in the Ghana Prostate Study, and 10 of these replicated at p<0.05. Conclusion Further genetic studies of prostate cancer in West African men are needed to confirm our promising susceptibility loci. PMID:24185611

  14. Impact of the Madden Julian Oscillation on the summer West African monsoon in AMIP simulations

    Science.gov (United States)

    Niang, Coumba; Mohino, Elsa; Gaye, Amadou T.; Omotosho, J. Bayo

    2017-04-01

    At intraseasonal timescales, convection over West Africa is modulated by the Madden Julian Oscillation (MJO). In this work we investigate the simulation of such relationship by 11 state-of-the-art atmospheric general circulation models runs with prescribed observed sea surface temperatures. In general, the Atmospheric Model Intercomparison Project simulations show good skill in capturing the main characteristics of the summer MJO as well as its influence on convection and rainfall over West Africa. Most models simulate an eastward spatiotemporal propagation of enhanced and suppressed convection similar to the observed MJO, although their signal over West Africa is weaker in some models. In addition, the ensemble average of models' composites gives a better performance in reproducing the main features and timing of the MJO and its impact over West Africa. 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 in the observations. Furthermore, the results show that a strong active convection phase is clearly associated with a stronger African Easterly Jet (AEJ) but the weak convective phase is associated with a much weaker AEJ. Our analysis of the equatorial waves suggests that the main impact over West Africa is established by the propagation of low-frequency waves within the MJO and Rossby spectral peaks. Results from the simulations confirm that it may be possible to predict anomalous convection over West Africa with a time lead of 15-20 day.

  15. Tobacco prevention policies in west-African countries and their effects on smoking prevalence.

    Science.gov (United States)

    Winkler, Volker; Lan, Yong; Becher, Heiko

    2015-12-08

    The WHO Framework Convention on Tobacco Control was shown to effectively lower smoking prevalence in in high income countries, however knowledge for low and middle income settings is sparse. The objective of this study was to describe WHO MPOWER policy measures in thirteen West-African countries and to investigate their correlation with smoking prevalence. Age-standardized smoking prevalence data and policy measures were collected from various WHO reports. For analysis MPOWER measures from 2008 and 2010, were combined with prevalence data from 2009 and 2011. Multiple linear regression models were set up. In West-Africa mean smoking prevalence was approximately 20% among males and approximately 3% among females. Policy measures were mostly at a middle or low level. Regression analysis showed that tobacco cessation programs, health warnings on cigarettes, and higher price of cigarettes were negatively correlated with smoking prevalence. Significant effects were observed for only one policy measure (tobacco cessation programs) and only within the male population where smoking prevalence is generally higher. Tobacco control policies are enforced at relatively low levels in West-African countries. However, improving tobacco control policy implementation according to the WHO Framework Convention on Tobacco Control should assist in the reduction of smoking prevalence in African countries, thereby counteracting pro-smoking initiatives set forth by the tobacco industry.

  16. The West in Africa and African women in the West: shifting identity and the migration of heroines in the work of African women writers

    Directory of Open Access Journals (Sweden)

    Nataša Hrastnik

    2009-12-01

    Full Text Available In the works of African women writers, Africa is seen in the grip of change – through the combined eff ects of colonialism and post-colonialism, the growth of urbanization, the redefi ning of traditional culture, and the blending of the traditional and the modern. Th e ideas of transition and transformation, the blending of old and new values, the increasing disintegration of traditional culture, and uncritical adoption of western values all frequently underpin the plots and themes of African women writers’ literature. One of the main points of convergence between their various works is a critique of the West as well as of western values and the western way of life, which have taken root in Africa and now pervade all areas of life. These writers use literature as means of bringing to the fore the diffi culties that they face and as a means of exploring African women’s identity in a time of changing values, in the interplay between the post-colonial and traditional systems.

  17. The relationship between the Guinea Highlands and the West African offshore rainfall maximum

    Science.gov (United States)

    Hamilton, H. L.; Young, G. S.; Evans, J. L.; Fuentes, J. D.; Núñez Ocasio, K. M.

    2017-01-01

    Satellite rainfall estimates reveal a consistent rainfall maximum off the West African coast during the monsoon season. An analysis of 16 years of rainfall in the monsoon season is conducted to explore the drivers of such copious amounts of rainfall. Composites of daily rainfall and midlevel meridional winds centered on the days with maximum rainfall show that the day with the heaviest rainfall follows the strongest midlevel northerlies but coincides with peak low-level moisture convergence. Rain type composites show that convective rain dominates the study region. The dominant contribution to the offshore rainfall maximum is convective development driven by the enhancement of upslope winds near the Guinea Highlands. The enhancement in the upslope flow is closely related to African easterly waves propagating off the continent that generate low-level cyclonic vorticity and convergence. Numerical simulations reproduce the observed rainfall maximum and indicate that it weakens if the African topography is reduced.

  18. The EU Migration Regime and West African Clandestine Migrants

    Directory of Open Access Journals (Sweden)

    Hannah M. Cross

    2009-08-01

    Full Text Available This article examines the relationship between the EU migration regime and clandestine migration from West Africa to Europe. A review of the development of EU border and immigration policy reveals significant and sustained moves towards securitisation of migrants and the externalisation of border controls to countries of origin and transit. This emphasis on repression limits the scope of cooperation with ‘third countries’ (those outside Europe in co-development, labour mobility, sea patrols and repatriation, which are examined separately as deterrents to uncontrolled emigration. This paper then analyses the motivations and intentions of Senegalese youth around the Cap Vert peninsula. This analysis includes the role of emigration in development and more recently, the impact of human losses and repatriations resulting from the clandestine journey by pirogue (open fishing boat to the Canary Islands. This article argues that in this case, youth are excluded both from labour and asylum policies and instead are managed as a security threat, contradicting the factors driving this journey.

  19. Human Adaptation of Ebola Virus during the West African Outbreak.

    Science.gov (United States)

    Urbanowicz, Richard A; McClure, C Patrick; Sakuntabhai, Anavaj; Sall, Amadou A; Kobinger, Gary; Müller, Marcel A; Holmes, Edward C; Rey, Félix A; Simon-Loriere, Etienne; Ball, Jonathan K

    2016-11-03

    The 2013-2016 outbreak of Ebola virus (EBOV) in West Africa was the largest recorded. It began following the cross-species transmission of EBOV from an animal reservoir, most likely bats, into humans, with phylogenetic analysis revealing the co-circulation of several viral lineages. We hypothesized that this prolonged human circulation led to genomic changes that increased viral transmissibility in humans. We generated a synthetic glycoprotein (GP) construct based on the earliest reported isolate and introduced amino acid substitutions that defined viral lineages. Mutant GPs were used to generate a panel of pseudoviruses, which were used to infect different human and bat cell lines. These data revealed that specific amino acid substitutions in the EBOV GP have increased tropism for human cells, while reducing tropism for bat cells. Such increased infectivity may have enhanced the ability of EBOV to transmit among humans and contributed to the wide geographic distribution of some viral lineages. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Attitudes of West African Immigrants in the United States toward Substance Misuse: Exploring Culturally Informed Prevention and Treatment Strategies.

    Science.gov (United States)

    Senreich, Evan; Olusesi, Olatunde A

    2016-01-01

    There is a lack of literature exploring substance misuse issues of the West African-born population in the United States. Thirty-four participants born in West Africa participated in one of three focus groups in a U.S. city to discuss their attitudes toward alcohol and drug use. Based on a qualitative analysis of the discussions, stigmatization of substance abusers and negative attitudes toward U.S. substance abuse treatment were identified as barriers to service utilization for West African immigrants. Community cohesion, importance of family, and a strong sense of spirituality were identified as essential resources to inform substance misuse prevention and treatment strategies.

  1. Mineral dust indirect effects and cloud radiative feedbacks of a simulated idealized nocturnal squall line

    Directory of Open Access Journals (Sweden)

    R. B. Seigel

    2013-04-01

    Full Text Available Mineral dust is arguably the most abundant aerosol species in the world and as such potentially plays a large role in aerosol indirect effects (AIEs. This study assesses and isolates the individual responses in a squall line that arise (1 from radiation, (2 from dust altering the microphysics, as well as (3 from the synergistic effects between (1 and (2. To accomplish these tasks, we use the Regional Atmospheric Modeling System (RAMS set up as a cloud-resolving model (CRM. The CRM contains aerosol and microphysical schemes that allow mineral dust particles to nucleate as cloud drops and ice crystals, replenish upon evaporation and sublimation, be tracked throughout hydrometeor transition, and be scavenged by precipitation and dry sedimentation. Factor separation is used on four simulations of the squall line in order to isolate the individual roles of radiation (RADIATION, microphysically active dust (DUST MICRO, and the nonlinear interactions of those factors (SYNERGY. Results indicate that RADIATION acts to increase precipitation, intensify the cold pool, and enhance the mesoscale organization of the squall line due to changes in microphysics originating from cloud top cooling. Conversely, DUST MICRO decreases precipitation, weakens the cold pool, and weakens the mesoscale organization of the squall line due to an enhancement of the warm rain process. SYNERGY shows little impact on the squall line, except near the freezing level, where an increase in mesoscale organization takes place. The combined effect of the mineral dust AIE due to both DUST MICRO and SYNERGY is to weaken the squall line.

  2. On the stationarity of Floods in west African rivers

    Science.gov (United States)

    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

  3. Preliminary studies on the performance and productivity indices of N'Dama and west African shorthorn cattle in Ghana.

    Science.gov (United States)

    Tuah, A K; Danso, Y N

    1985-05-01

    The performance of N'Dama and West African Shorthorn cattle in the humid forest zone of Ghana was evaluated using records (1969-1979) on these breeds kept at the UST livestock farm. The mean age at first calving for N'Dama was 32.07 months. Calving intervals of 501.92 and 462.83 days were obtained for N'Dama and West African Shorthorn cattle respectively. The secondary sex ratio for N'Dama calves was not significantly different from the expected theoretical value of 50%; that of the West African Shorthorn was, however, significantly different from the expected theoretical value mainly due to the small size of the population. Average birth weight for the two breeds was not significantly affected by breed, season of birth, weight and age of dam. Sex significantly affected the birth weight of the N'Dama calves. Pre-weaning and post-weaning growth rates of N'Dama male calves were significantly greater than the pre-weaning and post-weaning growth rates of females. For the West African Shorthorn sex did not significantly (P greater than 0.05) affect these traits. Calf mortalities for the two breeds were 10.53% for N'Dama and 21.05% for the West African Shorthorn. Calving percentage was not affected by breed. The productivity indices per cow per year were 72.7 kg for N'Dama and 32.1 kg for the West African Shorthorn. The productivity indices per 100 kg cow maintained per year were 36.8 kg for N'Dama and 16.6 kg for the West African Shorthorn.

  4. Glucose intolerance in the West African Diaspora: a skeletal muscle fibre type distribution hypothesis.

    Science.gov (United States)

    Nielsen, J; Christensen, D L

    2011-08-01

    In the United States, Black Americans are largely descendants of West African slaves; they have a higher relative proportion of obesity and experience a higher prevalence of diabetes than White Americans. However, obesity rates alone cannot explain the higher prevalence of type 2 diabetes. Type 2 diabetes is characterized by insulin resistance and beta-cell dysfunction. We hypothesize that the higher prevalence of type 2 diabetes in African Americans (as compared to White Americans) is facilitated by an inherited higher percentage of skeletal muscle fibre type II and a lower percentage of skeletal muscle fibre type I. Skeletal muscle fibre type II is less oxidative and more glycolytic than skeletal muscle fibre type I. Lower oxidative capacity is associated with lower fat oxidation and a higher disposal of lipids, which are stored as muscular adipose tissue in higher amounts in Black compared to White Americans. In physically active individuals, the influence of muscle fibre composition will not be as detrimental as in physically inactive individuals. This discrepancy is caused by the plasticity in the skeletal muscle fibre characteristics towards a higher activity of oxidative enzymes as a consequence of physical activity. We suggest that a higher percentage of skeletal muscle fibre type II combined with physical inactivity has an impact on insulin sensitivity and high prevalence of type 2 diabetes in Blacks of West African ancestry. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

  5. The flight of physicians from West Africa: views of African physicians and implications for policy.

    Science.gov (United States)

    Hagopian, Amy; Ofosu, Anthony; Fatusi, Adesegun; Biritwum, Richard; Essel, Ama; Gary Hart, L; Watts, Carolyn

    2005-10-01

    West African-trained physicians have been migrating from the sub-continent to rich countries, primarily the US and the UK, since medical education began in Nigeria and Ghana in the 1960s. In 2003, we visited six medical schools in West Africa to investigate the magnitude, causes and consequences of the migration. We conducted interviews and focus groups with faculty, administrators (deans and provosts), students and post-graduate residents in six medical schools in Ghana and Nigeria. In addition to the migration push and pull factors documented in previous literature, we learned that there is now a well-developed culture of medical migration. This culture is firmly rooted, and does not simply fail to discourage medical migration but actually encourages it. Medical school faculty are role models for the benefits of migration (and subsequent return), and they are proud of their students who successfully emigrate.

  6. The genetic contribution of West-African ancestry to protection against central obesity in African-American men but not women: results from the ARIC and MESA studies

    Directory of Open Access Journals (Sweden)

    Yann C Klimentidis

    2016-06-01

    Full Text Available Over 80% of African-American (AA women are overweight or obese. A large racial disparity between AA and European-Americans (EA in obesity rates exists among women, but curiously not among men. Although socio-economic and/or cultural factors may partly account for this race-by-sex interaction, the potential involvement of genetic factors has not yet been investigated. Among 2,814 self-identified AA in the Atherosclerosis Risk in Communities study, we estimated each individual’s degree of West-African genetic ancestry using 3,437 ancestry informative markers. We then tested whether sex modifies the association between West-African genetic ancestry and body mass index (BMI, waist-circumference (WC, and waist-to-hip ratio (WHR, adjusting for income and education levels, and examined associations of ancestry with the phenotypes separately in males and females. We replicated our findings in the Multi-Ethnic Study of Atherosclerosis (n=1,611 AA. In both studies, we find that West-African ancestry is negatively associated with obesity, especially central obesity, among AA men, but not among AA women (pinteraction= 1.24 x 10-5 in pooled analysis of WHR. In conclusion, our results suggest that the combination of male sex and West-African genetic ancestry is associated with protection against central adiposity, and suggest that the large racial disparity that exists among women, but not men, may be at least partly attributed to genetic factors.

  7. The Genetic Contribution of West-African Ancestry to Protection against Central Obesity in African-American Men but Not Women: Results from the ARIC and MESA Studies.

    Science.gov (United States)

    Klimentidis, Yann C; Arora, Amit; Zhou, Jin; Kittles, Rick; Allison, David B

    2016-01-01

    Over 80% of African-American (AA) women are overweight or obese. A large racial disparity between AA and European-Americans (EA) in obesity rates exists among women, but curiously not among men. Although socio-economic and/or cultural factors may partly account for this race-by-sex interaction, the potential involvement of genetic factors has not yet been investigated. Among 2814 self-identified AA in the Atherosclerosis Risk in Communities study, we estimated each individual's degree of West-African genetic ancestry using 3437 ancestry informative markers. We then tested whether sex modifies the association between West-African genetic ancestry and body mass index (BMI), waist-circumference (WC), and waist-to-hip ratio (WHR), adjusting for income and education levels, and examined associations of ancestry with the phenotypes separately in males and females. We replicated our findings in the Multi-Ethnic Study of Atherosclerosis (n = 1611 AA). In both studies, we find that West-African ancestry is negatively associated with obesity, especially central obesity, among AA men, but not among AA women (pinteraction = 4.14 × 10(-5) in pooled analysis of WHR). In conclusion, our results suggest that the combination of male gender and West-African genetic ancestry is associated with protection against central adiposity, and suggest that the large racial disparity that exists among women, but not men, may be at least partly attributed to genetic factors.

  8. Barriers to accessing health care services for West African refugee women living in Western Australia.

    Science.gov (United States)

    Drummond, Peter D; Mizan, Ayse; Brocx, Katie; Wright, Bernadette

    2011-03-01

    Help-seeking pathways and barriers to accessing health care services were surveyed in 51 West African refugee women who had settled recently in Perth, Western Australia, and in 100 Australian women. Shame or fear of what family and friends might think, fear of being judged by the treatment provider, fear of hospitalization, and logistical difficulties were significant impediments to accessing health care services for the refugee women. Surprisingly, barriers often were greater for the more-educated refugee women and strengthened with years of residence in Australia. Strategies to help at-risk women overcome these barriers need to be implemented to ensure appropriate access to health care services.

  9. Mineral elements in milk of the West African dwarf ewes as affected ...

    African Journals Online (AJOL)

    Analysis of ewe's milk from twenty West African dwarf ewes collected from day one after parturition showed that the cplostrum contained (mg/ l00ml) Ca 115.0 ± 1.82, P 65.8 ± 4 .08 Na 108.3 ± 2.0, K J63.2 ± 1.74, Mg 17.9 ± 0.78, CI217.7 ± 27.42,and{inmg/ litre) Fe 4.3±0.20, Cu 3 .2 ± 0.17 Mn 0.21 ± 0.03, Zn 13 .6 ;t 0.62, and ...

  10. Instrumental evidence of an unusually strong West African Monsoon in the 19th century

    Science.gov (United States)

    Gallego, David; Ordoñez, Paulina; Ribera, Pedro; Peña-Ortiz, Cristina; Garcia-Herrera, Ricardo; Vega, Inmaculada; Gomez, Francisco de Paula

    2016-04-01

    The precipitation in the Sahel -which is mainly controlled by the dynamics of the West African Monsoon-, has been in the spot of the climate community for the last three decades due to the persistence of the drought period that started in the 1970s. Unfortunately, reliable meteorological series in this area are only available since the beginning of the 20th Century, thus limiting our understanding of the significance of this period from a long term perspective. Currently, our knowledge of what happened in times previous to the 20th Century essentially relies in documentary or proxy sources. In this work, we present the first instrumental evidence of a 50 year-long period characterised by an unusually strong West African monsoon in the19th Century. Following the recent advances in the generation of climatic indices based on data from ship's logbooks, we used historical wind observations to compute a new index (the so-called ASWI) for characterising the strength of the West African Monsoon. The ASWI is based in the persistence of the southwesterly winds in the [29°W-17°W;7°N-13°N] area and it has been possible to compute it since 1790 for July and since 1839 for August and September. We show that the ASWI is a reliable measure of the monsoon's strength and the Sahelian rainfall. Our new series clearly shows the well-known drought period starting in the 1970s. During this dry period, the West African Monsoon was particularly weak and interestingly, we found that since then, the correlations with different climatic patterns such as the Pacific and Atlantic "El Niño" changed significantly in relation to those of the previous century. Remarkably, our results also show that the period 1839-1890 was characterised by an unusually strong and persistent monsoon. Notwithstanding, two of the few dry years within this period were concurrent with large volcanic eruptions in the Northern Hemisphere. This latter result supports the recently suggested relationship between major

  11. On the mathematical analysis of Ebola hemorrhagic fever: deathly infection disease in West African countries.

    Science.gov (United States)

    Atangana, Abdon; Goufo, Emile Franc Doungmo

    2014-01-01

    For a given West African country, we constructed a model describing the spread of the deathly disease called Ebola hemorrhagic fever. The model was first constructed using the classical derivative and then converted to the generalized version using the beta-derivative. We studied in detail the endemic equilibrium points and provided the Eigen values associated using the Jacobian method. We furthered our investigation by solving the model numerically using an iteration method. The simulations were done in terms of time and beta. The study showed that, for small portion of infected individuals, the whole country could die out in a very short period of time in case there is not good prevention.

  12. Interdecadal variation of the West African summer monsoon during 1979-2010 and associated variability

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huanlian [Chinese Academy of Sciences, Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Beijing (China); Graduate University of Chinese Academy of Sciences, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Beijing (China); Wang, Huijun [Chinese Academy of Sciences, Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Beijing (China); Yin, Yizhou [Tsinghua University, Center for Earth System Science, Beijing (China)

    2012-12-15

    This paper addresses the interdecadal variation of the West African summer monsoon (WASM) along with its background of atmospheric circulation and possible physical mechanism over the past 32 years (1979-2010). It is indicated that the WASM starts to strengthen from 1998 as the rainfall begins to increase over western West Africa on the whole, which shows a new interdecadal variation. In this interdecadal variation, the strengthened ascending motion corresponding to enhanced divergence (convergence) movement on the upper (lower) troposphere is prone to develop the local circulation of the monsoon. Moreover, the strengthened southwestern (eastern) wind on the lower (upper) level leads to more moisture from the Atlantic and the Gulf of Guinea transported to the West African continent. In addition, the summer subtropical high over the north Atlantic and western West Africa is strong and northward, and the tropical east wind is also strong. Statistically, the weaker (stronger) the spring North Atlantic Oscillation (NAO) is, the stronger (weaker) the tropical easterly is, and then the WASM is also stronger. But the effect of the NAO on the decadal variation of the WASM is not so significant from the north Atlantic anomaly sensitivity simulation with a single model. This is also an indication that the relationship between the WASM and NAO is complicated in an interdecadal time scale and is needed further study. In terms of sea surface temperature (SST) variation, the tendency is toward warming in the subtropical north Pacific, the south Pacific and north Atlantic. Numerical simulation experiments and data analysis show that the SST variation in the north Pacific plays an important role in the latest interdecadal strengthening of the WASM during the past 32 years, while the influences of the south Pacific and the north Atlantic SST anomalies are not so significant to the associated atmospheric circulation changes. (orig.)

  13. The face of Ebola: changing frequency of haemorrhage in the West African compared with Eastern-Central African outbreaks. A meta-analysis

    OpenAIRE

    S. Petti; Messano, G; Vingolo, E; Marsella, L; Scully, C.

    2015-01-01

    Background The West-African (WA) Zaire Ebolavirus disease (EVD) outbreak was characterized by an exceptionally high number of cases and deaths as compared with the Eastern-Central African (ECA) outbreaks. Despite the Zaire Ebolavirus being the most lethal for humans, case-fatality rate, close to 80?% in ECA outbreaks, almost halved to 47?% in Guinea-Liberia-Sierra Leone (WA). Such an improvement was due to the remarkable implementation of international humanitarian aids. Some studies also sug...

  14. A new perspective on West African hydroclimate during the last deglaciation

    Science.gov (United States)

    Parker, Andrew O.; Schmidt, Matthew W.; Jobe, Zane R.; Slowey, Niall C.

    2016-09-01

    Widespread drought characterized the Heinrich 1 and Younger Dryas cold periods of the last deglaciation throughout much of Africa, causing large increases in dust emissions from the Sahara and Sahel. At the same time, increases in wind strength may have also contributed to dust flux, making it difficult to interpret dust records alone as reflecting changes in rainfall over the region. The Niger River has the third largest drainage basin in Africa and drains most of the Sahara and Sahel and thus preserves and propagates climatic signals. Here, we present new reconstructions of Niger Delta sea surface salinity and Niger River discharge for the last 20,000 years in order to more accurately reconstruct the onset of the Western African Monsoon system. Based on calculated δ18OSEAWATER (δ18OSW) and measured Ba/Ca ratios in planktonic foraminifera, these new records reflect changes in sub-Saharan precipitation across the Niger River Basin in West Africa and reveal that the West African Monsoon system began to intensify several thousand years after the equatorial Monsoon system in Central Africa. We also present new records of primary productivity in the Niger Delta that are related to wind-driven upwelling and show that productivity is decoupled from changes in Niger River discharge. Our results suggest that wind strength, rather than changes in monsoon moisture, was the primary driver of dust emissions from the Sahara and Sahel across the last deglaciation.

  15. The West African Health Organization?s experience in improving the health research environment in the ECOWAS region

    OpenAIRE

    Aidam, Jude; Sombi?, Issiaka

    2016-01-01

    Background The West African Health Organization (WAHO) implemented a research development program in West Africa during 2009?2013 using the Knowledge for Better Health Research Capacity Development Framework, developed by Pang et al. (Bull World Health Organ 81(11):815?820, 2003), on strategies used to improve the research environment. The framework has the following components: stewardship, financing, sustainable resourcing and research utilization. This paper describes how WAHO implemented ...

  16. Circulating adiponectin is associated with obesity and serum lipids in West Africans.

    Science.gov (United States)

    Meilleur, Katherine G; Doumatey, Ayo; Huang, Hanxia; Charles, Bashira; Chen, Guanjie; Zhou, Jie; Shriner, Daniel; Adeyemo, Adebowale; Rotimi, Charles

    2010-07-01

    Adiponectin, a hormone secreted by adipose tissue, has both metabolic and antiinflammatory properties. Although multiple studies have described the relationship between adiponectin and obesity in several human populations, no large studies have evaluated this relationship in Africans. We investigated the relationship between adiponectin and measures of obesity, serum lipids, and insulin resistance in a large African cohort. Participants are from the Africa America Diabetes Mellitus (AADM) Study, a case-control study of genetic and other risk factors associated with development of type 2 diabetes in Africans. Patients were recruited from five academic medical centers in Nigeria and Ghana (Accra and Kumasi in Ghana and Enugu, Ibadan, and Lagos in Nigeria) over 10 yr. Circulating adiponectin levels were measured in 690 nondiabetic controls using an ELISA. The correlation between log-transformed circulating adiponectin levels and age, gender, measures of obesity (body mass index, waist circumference, and percent fat mass), and serum lipid levels was assessed. Linear regression was used to explore the association between adiponectin levels and measures of obesity, lipids, and insulin resistance as measured by homeostasis model assessment. Significant negative associations were observed between log-adiponectin levels and measures of obesity after adjusting for age and gender. Similarly, log-adiponectin levels were significantly negatively associated with serum triglycerides and insulin resistance but positively associated with high-density lipoprotein-cholesterol and total cholesterol after adjusting for age, gender, and body mass index. Circulating adiponectin is significantly associated with measures of obesity, serum lipids, and insulin resistance in this study of West African populations.

  17. Tropospheric ozone production related to West African city emissions during the 2006 wet season AMMA campaign

    Directory of Open Access Journals (Sweden)

    G. Ancellet

    2011-07-01

    Full Text Available During African Monsoon Multidisciplinary Analyses (AMMA airborne measurements of ozone, CO and nitrogen oxides (NOx were collected by French and German Falcon aircraft near three cities in West Africa (Cotonou, Niamey and Ouagadougou. They have been analysed to identify the good conditions to observe ozone plumes related to city emissions during the monsoon season. Results show that an O3 increase of 40–50 ppbv above the summer average concentration took place during two specific events: one near Cotonou on the coast of the Gulf of Guinea, and the other near Niamey in the Sahel region. In both cases a high level of NOx (3–5 ppbv is related to the ozone production. Air mass transport simulations with FLEXPART and a tracer simulation with the BOLAM mesoscale model shows that Southern Hemisphere biomass burning emissions are always at higher altitude (>3 km compared to the city emissions. In Niamey and Ouagadougou, the daily variability of ozone and CO correlates with the FLEXPART analysis showing the role of air mass stagnation near the city for 1–2 days and advection of emissions from the vegetated areas. Absence of ozone enhancements for high CO values can be explained by the occurrence of deep convection near the city. In the Sahel region, convection must be accounted for to understand the small number of observed ozone plumes but also to explain the high level of NOx in the 3–5 ppbv range, due to increasing soil emissions after rainfall. To verify that daily ozone production can reach 20 ppbv day−1 for the NOx and CO conditions encountered near West African cities, a simulation of the CiTTyCAT Lagrangian model was conducted using the observed average chemical composition reported by other aircraft during AMMA. Such ozone production is possible for NOx levels up to 5 ppb showing that West African cities are potentially significant sources of tropospheric

  18. My American Dream: The Interplay Between Structure and Agency in West African Immigrants' Educational Experiences in the United States

    Science.gov (United States)

    Knight, Michelle G.; Roegman, Rachel; Edstrom, Lisa

    2016-01-01

    This article presents findings of a qualitative, interpretive case study of the experiences of 1.5- and 2nd-generation West African immigrants who self-identify as pursuing the American Dream, defined by them as academic attainment and career success. Employing structuration theory, the authors examine the interplay between structures and agency…

  19. Exploring the Interplay of Cultural Capital, "Habitus," and Field in the Life Histories of Two West African Teacher Candidates

    Science.gov (United States)

    Park, Gloria; Rinke, Carol; Mawhinney, Lynnette

    2016-01-01

    This paper captures the life histories of two West African pre-service teachers pursuing their education in the United States. Based on a larger study examining the life histories of 45 undergraduate pre-service teachers, these narratives focus specifically on international student experiences in the US. Grounded in Bourdieu's theory of…

  20. Prevalence and time trends in diabetes and physical inactivity among adult West African populations: the epidemic has arrived

    NARCIS (Netherlands)

    Abubakari, A. R.; Lauder, W.; Jones, M. C.; Kirk, A.; Agyemang, C.; Bhopal, R. S.

    2009-01-01

    To determine the prevalence and distribution of, and trends in, physical inactivity and diabetes in adult West African populations. Systematic review and meta-analysis. Literature searches were conducted using four electronic databases. Journal hand searches and examination of citations of relevant

  1. Evidence of common signatures of selection in the genomes of West African cattle and the Yoruba human population

    Science.gov (United States)

    In 1954, Allison found that the sickle-cell anemia mutation in the beta hemoglobin gene was highly prevalent in West African people because it is protective against malaria, so carriers would thrive and leave offspring in spite of the genetic disease. This is one of the earliest evidences of an envi...

  2. Black-tailed Godwits in West African winter staging areas : habitat use and hunting-related mortality

    NARCIS (Netherlands)

    Kleijn, D.; Kamp, van der J.; Monteiro, H.; Ndiaye, I.; Wymenga, E.; Zwarts, L.

    2010-01-01

    The persistence of the Dutch Black-tailed Godwit population depends largely on high adult survival. Adult survival may be influenced by hunting pressure and land use change in the wintering area, the West African coastal zone. Here we examine hunting pressure on and habitat use of Black-tailed

  3. Breeding performance of the Grasshopper Buzzard (Butastur rufipennis) in a natural and a human-modified West African savanna

    NARCIS (Netherlands)

    Buij, R.; Kortekaas, K.; Krimpen, R.R.D.; Wijk, van H.J.; Zanden, S.; Iongh, de H.H.; Heitkonig, I.M.A.; Snoo, de G.R.; Komdeur, J.

    2013-01-01

    Few studies have examined raptor reproduction in response to land-use change in sub-Saharan Africa, hampering conservation efforts to address regional declines. To further our understanding of mechanisms underlying the dramatic declines of West African raptors, we examined the relationship between

  4. The complex vaginal flora of West African women with bacterial vaginosis.

    Directory of Open Access Journals (Sweden)

    Jacques Pépin

    Full Text Available The spectrum of bacteria associated with bacterial vaginosis (BV has recently expanded through taxonomic changes and the use of molecular methods. These methods have yet to be used in large-scale epidemiological studies in Africa where BV is highly prevalent.An analysis of samples obtained during a clinical trial of the management of vaginal discharge in four West African countries. Samples were available from 1555 participants; 843 (54% had BV. Nucleic acids of 13 bacterial genera or species potentially associated with BV were detected through the polymerase chain reaction.The associations between various components of the vaginal flora were complex. Excluding Lactobacillus, the other 12 micro-organisms were all associated with each other at the p≤0.001 level. The prevalence of various bacterial genera or species varied according to age, sexual activity and HIV status. In multivariate analysis, the presence of Gardnerella vaginalis, Bifidobacterium, Megasphaera elsdenii, Dialister, Mycoplasma hominis, Leptotrichia, and Prevotella were independently associated with BV as was the absence of Lactobacillus and Peptoniphilus. However, Mobiluncus, Atopobium vaginae, Anaerococcus, and Eggerthella were not independently associated with BV. Unexpectedly, after treatment with a regimen that included either metronidazole or tinidazole, the proportion of patients with a complete resolution of symptoms by day 14 increased with the number of bacterial genera or species present at enrolment.Numerous bacterial genera or species were strongly associated with each other in a pattern that suggested a symbiotic relationship. BV cases with a simpler flora were less likely to respond to treatment. Overall, the vaginal flora of West African women with BV was reminiscent of that of their counterparts in industrialized countries.

  5. Niger River Discharge and the Connection to the West African Monsoon Over the Last 25 kyr

    Science.gov (United States)

    Patten, J.; Marcantonio, F.; Slowey, N. C.; Schmidt, M. W.; Parker, A. O.; Thomas, D. J.

    2016-12-01

    The intensity of the West African monsoon is directly tied to the shifting of the Inter-Tropical Convergence Zone and global-scale climate variability. As the West African monsoon varies through time, it affects the precipitation that occurs within the Niger River basin and the Niger River's discharge into the eastern equatorial Atlantic Ocean. The accumulation of marine sediments on the continental slope offshore of the Niger Delta reflects these processes. We seek to better understand how related environmental processes have varied as climate and sea level changed during the latter part of the last glacial-interglacial cycle. Here we present results from our ongoing investigation of sediments collected offshore of the Niger Delta that reflect such changes. The concentrations of 230Th, 232Th, and 234U in the sediments have been measured and combined with ages from radiocarbon dates and planktonic foraminiferal δ18O stratigraphies to estimate how the rate of sediment accumulation has varied through time. This record is considered together with measurements of sediment CaCO3 content and grain-size distribution to better understand the relative importance of environmental processes that control the flux of sediments and thorium to the seafloor - scavenging by particles settling through the water column versus the transport of sediments downslope by turbidity flows. We present xs230Th-derived 232Th fluxes that we suggest approximate the amount of fine-grained detrital material delivered from the Niger River to our sites. We anticipate that the importance of these competing processes will vary as climate/sea-level change influences the flux of sediments from the Niger River and the transport of these sediments to the slope.

  6. Tracking cashew economically important diseases in the West African region using metagenomics

    Science.gov (United States)

    Monteiro, Filipa; Romeiras, Maria M.; Figueiredo, Andreia; Sebastiana, Mónica; Baldé, Aladje; Catarino, Luís; Batista, Dora

    2015-01-01

    During the last decades, agricultural land-uses in West Africa were marked by dramatic shifts in the coverage of individual crops. Nowadays, cashew (Anacardium occidentale L.) is one of the most export-oriented horticulture crops, notably in Guinea-Bissau. Relying heavily on agriculture to increase their income, developing countries have been following a strong trend of moving on from traditional farming systems toward commercial production. Emerging infectious diseases, driven either by adaptation to local conditions or inadvertent importation of plant pathogens, are able to cause tremendous cashew production losses, with economic and social impact of which, in developing countries is often underestimated. Presently, plant genomics with metagenomics as an emergent tool, presents an enormous potential to better characterize diseases by providing extensive knowledge on plant pathogens at a large scale. In this perspective, we address metagenomics as a promising genomic tool to identify cashew fungal associated diseases as well as to discriminate the causal pathogens, aiming at obtaining tools to help design effective strategies for disease control and thus promote the sustainable production of cashew in West African Region. PMID:26175748

  7. Genome-Wide Divergence in the West-African Malaria Vector Anopheles melas

    Directory of Open Access Journals (Sweden)

    Kevin C. Deitz

    2016-09-01

    Full Text Available Anopheles melas is a member of the recently diverged An. gambiae species complex, a model for speciation studies, and is a locally important malaria vector along the West-African coast where it breeds in brackish water. A recent population genetic study of An. melas revealed species-level genetic differentiation between three population clusters. An. melas West extends from The Gambia to the village of Tiko, Cameroon. The other mainland cluster, An. melas South, extends from the southern Cameroonian village of Ipono to Angola. Bioko Island, Equatorial Guinea An. melas populations are genetically isolated from mainland populations. To examine how genetic differentiation between these An. melas forms is distributed across their genomes, we conducted a genome-wide analysis of genetic differentiation and selection using whole genome sequencing data of pooled individuals (Pool-seq from a representative population of each cluster. The An. melas forms exhibit high levels of genetic differentiation throughout their genomes, including the presence of numerous fixed differences between clusters. Although the level of divergence between the clusters is on a par with that of other species within the An. gambiae complex, patterns of genome-wide divergence and diversity do not provide evidence for the presence of pre- and/or postmating isolating mechanisms in the form of speciation islands. These results are consistent with an allopatric divergence process with little or no introgression.

  8. Children’s rights and human trafficking and responsible parenthood in west african country nigeria.

    Directory of Open Access Journals (Sweden)

    Abba Joebarth

    2014-06-01

    Full Text Available Every child has right to life and if so, it is a responsible parent that could make this workable and realistic to uphold the children’s rights and existence to life. Time is now ripped for the society to look into the Children`s Rights and Human Trafficking and Responsible Parents in Western African country Nigeria.  Children have the natural rights to exist, grow maturely and to develop in whichever hemisphere or environment they find themselves. A good child born to a good and responsible parent ought not and should not encounter or experience in anyway the so called children’s problem through one´s  good mother and father’s care in any family. We are to peruse here the issue concerning the West African Nigerian child’s rights a responsible parent. On why a child’s rights should not be violated or trampled upon; the expected parental duties, neglect of a child’s education and upbringing, child’s trafficking, malnutrition and maltreatment sagas, the harms with street children and various problems which different children encounter are what this article is all about.  We shall base our knowledge here basically on descriptive, analytical and evaluative methods.  The issues of solution, suggestions and remedies and the way forward are looked into for the better society of the present era.

  9. Examining the West African Monsoon circulation response to atmospheric heating in a GCM dynamical core

    Science.gov (United States)

    Chadwick, R.; Martin, G. M.; Copsey, D.; Bellon, G.; Caian, M.; Codron, F.; Rio, C.; Roehrig, R.

    2017-03-01

    Diabatic heating plays a crucial role in the formation and maintenance of the West African Monsoon. A dynamical core configuration of a General Circulation Model (GCM) is used to test the influence of diabatic heating from different sources and regions on the strength and northward penetration of the monsoon circulation. The dynamical core is able to capture the main features of the monsoon flow, and when forced with heating tendencies from various different GCMs it recreates many of the differences seen between the full GCM monsoon circulations. Differences in atmospheric short-wave absorption over the Sahara and Sahel regions are a key driver of variation in the models' monsoon circulations, and this is likely to be linked to how aerosols, clouds and surface albedo are represented across the models. The magnitude of short-wave absorption also appears to affect the strength and position of the African easterly jet (AEJ), but not that of the tropical easterly jet (TEJ). The dynamical core is also used here to understand circulation changes that occur during the ongoing model development process that occurs at each modeling centre, providing the potential to trace these changes to specific alterations in model physics.

  10. Anti-Toxoplasma activity of vegetal extracts used in West African traditional medicine

    Directory of Open Access Journals (Sweden)

    Benoit-Vical F.

    2000-03-01

    Full Text Available Both Toxoplasma gondii and Plasmodium are Apicomplexan protozoa that share common metabolic pathways and potential drug targets. The objective of this study was to examine the anti- Toxoplasma activity of nine West African plants with known activity against P. falciparum. The extracts were obtained from parts of plant commonly used, by most traditional healers, in the form of infusion or as water decoction. The in vitro activity of plant extracts on T. gondii was assessed on MRC5 tissue cultures and was quantified by enzyme-linked immunoassay. Aqueous extracts from Vernonia colorata were found to be inhibitory for Toxoplasma growth at concentrations > 10 mg/L, with an IC50 of 16.3 mg/L. A ten-fold gain in activity was obtained when organic solvents such as dichloromethane, acetone or ethanol were used to extract V. colorata's active principles. These extracts were inhibitory at concentrations as low as 1 mg/L, with IC50 of 1.7, 2.6 and 2.9 mg/L for dichloromethane, acetone and ethanol extracts respectively. These results indicate a promising source of new anti-Toxoplasma drugs from V. colorata and African medicinal plants.

  11. Feedback of observed interannual vegetation change: a regional climate model analysis for the West African monsoon

    Science.gov (United States)

    Klein, Cornelia; Bliefernicht, Jan; Heinzeller, Dominikus; Gessner, Ursula; Klein, Igor; Kunstmann, Harald

    2017-05-01

    West Africa is a hot spot region for land-atmosphere coupling where atmospheric conditions and convective rainfall can strongly depend on surface characteristics. To investigate the effect of natural interannual vegetation changes on the West African monsoon precipitation, we implement satellite-derived dynamical datasets for vegetation fraction (VF), albedo and leaf area index into the Weather Research and Forecasting model. Two sets of 4-member ensembles with dynamic and static land surface description are used to extract vegetation-related changes in the interannual difference between August-September 2009 and 2010. The observed vegetation patterns retain a significant long-term memory of preceding rainfall patterns of at least 2 months. The interannual vegetation changes exhibit the strongest effect on latent heat fluxes and associated surface temperatures. We find a decrease (increase) of rainy hours over regions with higher (lower) VF during the day and the opposite during the night. The probability that maximum precipitation is shifted to nighttime (daytime) over higher (lower) VF is 12 % higher than by chance. We attribute this behaviour to horizontal circulations driven by differential heating. Over more vegetated regions, the divergence of moist air together with lower sensible heat fluxes hinders the initiation of deep convection during the day. During the night, mature convective systems cause an increase in the number of rainy hours over these regions. We identify this feedback in both water- and energy-limited regions of West Africa. The inclusion of observed dynamical surface information improved the spatial distribution of modelled rainfall in the Sahel with respect to observations, illustrating the potential of satellite data as a boundary constraint for atmospheric models.

  12. Changes in the interannual SST-forced signals on West African rainfall. AGCM intercomparison

    Energy Technology Data Exchange (ETDEWEB)

    Mohino, Elsa [LOCEAN/IPSL, Universite Pierre et Marie Curie, Paris Cedex 05 (France); Universidad de Sevilla, Sevilla (Spain); Rodriguez-Fonseca, Belen [Universidad Complutense de Madrid, Dpto. Geofisica y Meteorologia, Madrid (Spain); Instituto de Geociencias (CSIC-UCM), Madrid (Spain); Losada, Teresa [Universidad Complutense de Madrid, Dpto. Geofisica y Meteorologia, Madrid (Spain); Gervois, Sebastien [LOCEAN/IPSL, Universite Pierre et Marie Curie, Paris Cedex 05 (France); Janicot, Serge [LOCEAN/IPSL, IRD, Universite Pierre et Marie Curie, Paris (France); Bader, Juergen [Bjerknes Centre for Climate Research, Bergen (Norway); Ruti, Paolo [Progetto Speciale Clima Globale, Ente Nazionale per le Nuove Tecnologie, l' Energia e l' Ambiente, Rome (Italy); Chauvin, Fabrice [GAME/CNRM, Meteo-France/CNRS, Toulouse (France)

    2011-11-15

    Rainfall over West Africa shows strong interannual variability related to changes in Sea Surface Temperature (SST). Nevertheless, this relationship seem to be non-stationary. A particular turning point is the decade of the 1970s, which witnessed a number of changes in the climatic system, including the climate shift of the late 1970s. The first aim of this study is to explore the change in the interannual variability of West African rainfall after this shift. The analysis indicates that the dipolar features of the rainfall variability over this region, related to changes in the Atlantic SST, disappear after this period. Also, the Pacific SST variability has a higher correlation with Guinean rainfall in the recent period. The results suggest that the current relationship between the Atlantic and Pacific El Nino phenomena is the principal responsible for these changes. A fundamental goal of climate research is the development of models simulating a realistic current climate. For this reason, the second aim of this work is to test the performance of Atmospheric General Circulation models in simulating rainfall variability over West Africa. The models have been run with observed SSTs for the common period 1957-1998 as part of an intercomparison exercise. The results show that the models are able to reproduce Guinean interannual variability, which is strongly related to SST variability in the Equatorial Atlantic. Nevertheless, problems in the simulation of the Sahelian interannual variability appear: not all models are able to reproduce the observed negative link between rainfall over the Sahel and El Nino-like anomalies in the Pacific, neither the positive correlation between Mediterranean SSTs and Sahelian rainfall. (orig.)

  13. Climate influence on the North West African fisheries: a large-scale perspective

    Science.gov (United States)

    Lopez-Parages, Jorge; Rodriguez-Fonseca, Belén; Brochier, Timothee; Auger, Pierre-Amaël; Gaetan, Carlo; Rubino, Angelo; Keenlyside, Noel; Zanchettin, Davide; Woldeyes Arisido, Maeregu

    2017-04-01

    There are still many questions about the environmental forcings on marine biological ecosystems that need to be addressed. Of special relevance are those associated with the so-called Eastern Boundary Upwelling Systems (EBUS) due to their great climatic and socio-economic importance, being the latter specially crucial for some regions along the globe such as the North West African region (hereinafter NW Africa). In this study, some possible teleconnections involving large-scale climatic phenomena and the small pelagic fishes dynamics in the NW Africa, have been addressed. These possible teleconnections would be interesting on its own, but those associated with the Sea Surface Temperature (SST) processes are of special importance, since they could noticeably contribute to the development of a seasonal prediction system of fisheries. To this aim, we have used data provided by the couple model compounded by the Regional Oceanic Modeling System ROMS configured for the NW African upwelling system and by the biogeochemical model PISCES, which simulates plankton productivity and carbon biomass based upon the main nutrients. This coupled model has been run over the period 1980-2009 using interannual atmospheric forcings and consistent oceanic boundary conditions (from NCEP Climate Forecast System Reanalysis). Finally, an evolutionary individual-based Lagrangian model has been used to simulate the spatio-temporal behavior of the small pelagic fishes, at different stages, according to the environmental constraints obtained from ROMS. The results obtained, though preliminary, point out that the well known El Niño-Southern Oscillation variability mode (ENSO) could act as a possible large-scale climatic forcing of the NW African fishes, which could open a window of opportunity for the development of an effective seasonal prediction system in the aforementioned region.

  14. The face of Ebola: changing frequency of haemorrhage in the West African compared with Eastern-Central African outbreaks.

    Science.gov (United States)

    Petti, Stefano; Messano, Giuseppe Alessio; Vingolo, Enzo Maria; Marsella, Luigi Tonino; Scully, Crispian

    2015-12-11

    The West-African (WA) Zaire Ebolavirus disease (EVD) outbreak was characterized by an exceptionally high number of cases and deaths as compared with the Eastern-Central African (ECA) outbreaks. Despite the Zaire Ebolavirus being the most lethal for humans, case-fatality rate, close to 80 % in ECA outbreaks, almost halved to 47 % in Guinea-Liberia-Sierra Leone (WA). Such an improvement was due to the remarkable implementation of international humanitarian aids. Some studies also suggested that the long human-to-human transmission cycle occurred in WA, gave rise to human adaptation and consequent immune escape. Haemorrhage, the main feature in seriously infected EVD patients, is due to the immune system that triggers the infected endothelial cells which expose the spike-like glycoprotein (GP) of the virion on their surface. If the human adaptation hypothesis holds true, the proportion of EVD patients with haemorrhage in the WA outbreak should be lower than in the ECA outbreaks due to immune escape. Therefore, the aim of this meta-analysis was to compare the relative frequencies of three typical haemorrhagic symptoms (conjunctival -CB, nasal -NB, gingival -GB- bleedings) in the ECA and WA outbreaks. Literature searches were performed through PubMed and Scopus using generic keywords; surveys including at least ten patients reporting CB, NB, GB relative frequencies were extracted and split into ECA and WA. The meta-analytical methods chosen were based on the levels of between-study heterogeneity and publication bias. Pooled CB, NB, GB relative frequencies in ECA and WA were estimated and compared. Subgroup analysis including only studies on Zaire Ebolavirus also was performed. Fifteen studies (10 ECA, 5 WA) were located with 4,867 (CB), 3,859 (NB), 4,278 (GB) EVD patients overall. GB pooled relative frequency was 45.3 % (95 % confidence interval -95 CI, 34.7-56.1 %) and 18.0 % (95 CI, 6.0-34.5 %), in ECA and WA; NB was 10.6 % (95 CI, 5.7-16.8 %) and 1.3 % (1

  15. The experience of postnatal depression in West African mothers living in the United Kingdom: a qualitative study.

    Science.gov (United States)

    Gardner, Philippa L; Bunton, Penny; Edge, Dawn; Wittkowski, Anja

    2014-06-01

    to explore the lived experience of postnatal depression (PND) in West African mothers living in the United Kingdom (UK). using a qualitative design, semi-structured interviews were undertaken. Interpretative Phenomenological Analysis (IPA) was used to explore and analyse the data. community health services within inner-city suburbs in Manchester, England. six West African mothers (Nigeria=3; Ghana=3), who were experiencing low mood in the postnatal period. five overarching themes emerged: (1) conceptualising PND, (2) isolation, (3) loss of identity, (4) issues of trust and (5) relationships as a protective factor. Women exhibited symptoms of PND but did not regard it as an illness. In their view, postnatal depression and distress resulted from social stress. Participants stated that their cultural background made it difficult to disclose feelings of depression thus adversely influencing their help-seeking behaviour. this is the first study to investigate the experiences of West African mothers with PND who live in the UK, and how they perceive and make sense of their experiences. The themes generated add to the body of existing research on PND in Black and ethnic minority populations and offer insight into the lived experience of West African women residing in England. Such insights are vital in order to deliver effective, culturally sensitive care. these findings have implications on how services should be designed to increase their accessibility to African women, by using a community psychology approach alongside systemic and group interventions. Challenges to help seeking and language used to describe experiences are considered. © 2013 Elsevier Ltd. All rights reserved.

  16. Saghro Group in the Ougnat Massif (Morocco), an evidence for a continuous Cadomian basin along the northern West African Craton

    Science.gov (United States)

    Michard, André; Soulaimani, Abderrahmane; Ouanaimi, Hassan; Raddi, Youssef; Aït Brahim, Lahsen; Rjimati, Ech-Cherki; Baidder, Lahssen; Saddiqi, Omar

    2017-03-01

    The Saghro Group (SG) is a folded, low-grade volcano-sedimentary series up to 8 km thick that crops out within and to the north of the Pan-African suture zone in the central and eastern Anti-Atlas. Here we describe the SG of the Ougnat inliers that are exposed in the easternmost Anti-Atlas beneath the unconformable, Late Ediacaran Ouarzazate Group (OZG) volcanic rocks. The Ougnat SG mostly consists of volcaniclastic greywackes accumulated in a peritidal-to-shallow basin. The basin infilling was deformed by NNE-trending, mostly upright folds with axial-planar slaty cleavage and low-grade metamorphism. The deformed SG rocks were intruded by the ∼550 Ma Mellab hypovolcanic granodiorite. The latter also crosscuts the lowest OZG rocks that are dated to 574-571 Ma in the western Saghro region. The SG rocks that form the Siroua and Saghro inliers have an oldest age of 620-610 Ma and were folded at ∼610-580 Ma at the onset of the Cadomian orogenic events. We show that the SG rocks are similar to the ;Série verte; (SV) rocks that are exposed in the Ougarta and western Hoggar east of the Pan-African suture. We infer that the SG and SV rocks accumulated in a same, continuous basin that was bounding the West African Craton to the north and the east. This strongly subsiding basin formed close to a volcanic arc and was folded during the last Pan-African synmetamorphic events. Fold orientation and age of folding differ however along the edge of the West African Craton. The orogenic greywackes that form the remnants of the SG-SV basin thus constitute a precious record of the diachronic Cadomian event s.l. along the West African Craton northern margin.

  17. West African Monsoon Decadal Variability and Surface-Related Forcings: Second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II)

    Science.gov (United States)

    Xue, Yongkang; De Sales, Fernando; Lau, William K-M; Boone, Aaron; Kim, Kyu-Myong; Mechoso, Carlos R.; Wang, Guiling; Kucharski, Fred; Schiro, Kathleen; Hosaka, Masahiro; hide

    2016-01-01

    The second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedbacks of sea surface temperature (SST), land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales. The WAMME II strategy is to apply prescribed observationally based anomaly forcing, i.e., idealized but realistic forcing, in simulations by climate models to test the relative impacts of such forcings in producingamplifying the Sahelian seasonal and decadal climate variability, including the great 20th century drought. This is the first multi-model experiment specifically designed to simultaneously evaluate relative contributions of multiple external forcings to the Sahel decadal precipitation anomalies between the 1980s and the 1950s that is used to characterize the Sahel 1980s drought in this study. The WAMME II models have consistently demonstrated that SST is the major contributor to the 20th century Sahel drought. Under the influence of the maximum possible SST forcing, WAMME II model ensemble mean can produce up to 60 of the precipitation difference between the 1980s and the 1950s. The present paper also delineated the role of SSTs in triggering and maintaining the Sahel drought. The impact of SSTs in individual oceans is also examined and consensus and discrepancies are reported. Among the different ocean basins, the WAMME II models show the consensus that the Indian Ocean SST has the largest impact on the precipitation temporal evolution associated with the ITCZ movement before the WAM onset while the Pacific Ocean SST greatly contributes to the summer WAM drought. This paper also compares the SST effect with the LULCC effect. Results show that with prescribed land forcing the WAMME II model ensemble mean produces about 40 of the precipitation difference between the 1980s and the 1950s, which is less than the SST contribution but still of first order

  18. Hydrological deformation induced by the West African Monsoon: Comparison of GPS, GRACE and loading models

    Science.gov (United States)

    Nahmani, Samuel; Bock, Olivier; Bouin, Marie-Noëlle; Santamaría-Gómez, Alvaro; Boy, Jean-Paul; Collilieux, Xavier; Métivier, Laurent; Panet, Isabelle; Genthon, Pierre; de Linage, Caroline; Wöppelmann, Guy

    2012-05-01

    Three-dimensional ground deformation measured with permanent GPS stations in West Africa was used for investigating the hydrological loading deformation associated with Monsoon precipitation. The GPS data were processed within a global network for the 2003-2008 period. Weekly station positions were retrieved with a repeatability (including unmodeled loading effects) of 1-2 mm in the horizontal components and between 2.5 and 6 mm in the vertical component. The annual signal in the vertical component for sites located between 9.6°N and 16.7°N is in the range 10-15 mm. It is consistent at the 3 mm-level with the annual regional-scale loading deformations estimated from GRACE satellite products and modeled with a combination of hydrological, atmospheric, and nontidal oceanic models. An additional 6 month transient signal was detected in the vertical component of GPS estimates at most of the West African sites. It takes the form of an oscillation occurring between September and March, and reaching a maximum amplitude of 12-16 mm at Ouagadougou (12.5°N). The analysis of in situ hydro-geological data revealed a strong coincidence between this transient signal and peak river discharge at three sites located along the Niger River (Timbuktu, Gao, and Niamey). At Ouagadougou, a similar coincidence was found with the seasonal variations of the water table depth. We propose a mechanism to account for this signal that involves a sequence of swelling/shrinking of clays combined with local loading effects associated with flooding of the Niger River.

  19. Liberia national disaster preparedness coordination exercise: Implementing lessons learned from the West African disaster preparedness initiative.

    Science.gov (United States)

    Hamer, Melinda J Morton; Reed, Paul L; Greulich, Jane D; Beadling, Charles W

    2017-01-01

    In light of the recent Ebola outbreak, there is a critical need for effective disaster management systems in Liberia and other West African nations. To this end, the West Africa Disaster Preparedness Initiative held a disaster management exercise in conjunction with the Liberian national government on November 24-25, 2015. During this tabletop exercise (TTX), interactions within and between the 15 counties and the Liberian national government were conducted and observed to refine and validate the county and national standard operating procedures (SOPs). The exercise took place in three regional locations throughout Liberia: Monrovia, Buchanan, and Bong. The TTX format allowed counties to collaborate utilizing open-source software platforms including Ushahidi, Sahana, QGIS, and KoBoCollect. Four hundred sixty-seven individuals (representing all 15 counties of Liberia) identified as key actors involved with emergency operations and disaster preparedness participated in the exercise. A qualitative survey with open-ended questions was administered to exercise participants to determine needed improvements in the disaster management system in Liberia. Key findings from the exercise and survey include the need for emergency management infrastructure to extend to the community level, establishment of a national disaster management agency and emergency operations center, customized local SOPs, ongoing surveillance, a disaster exercise program, and the need for effective data sharing and hazard maps. These regional exercises initiated the process of validating and refining Liberia's national and county-level SOPs. Liberia's participation in this exercise has provided a foundation for advancing its preparedness, response, and recovery capacities and could provide a template for other countries to use.

  20. Blindness and Visual Impairment in an Urban West African Population: The Tema Eye Survey

    Science.gov (United States)

    Budenz, Donald L.; Bandi, Jagadeesh R.; Barton, Keith; Nolan, Winifred; Herndon, Leon; Whiteside-de Vos, Julia; Hay-Smith, Graham; Kim, Hanna; Tielsch, James

    2012-01-01

    Objective To determine the prevalence, etiologies, and risk factors of blindness and visual impairment among persons age 40 years and older residing in an urban West African location. Design Population-based cross-sectional study. Participants Five thousand six hundred and three participants residing in Tema, Ghana. Methods Proportionate random cluster sampling was used to select participants age 40 and over living in the city of Tema. Presenting distance visual acuity was measured at 4 and 1 meters using a reduced Logarithm of the Minimum Angle of Resolution (logMAR) tumbling E chart and then with trial frame based on autorefraction. A screening examination was performed in the field on all participants. Complete clinical examination by an ophthalmologist was performed on participants with best corrected visual acuity visual acuity in the better eye of visual impairment (visual acuity in the better eye of visual impairment was 17.1% and blindness was 1.2%. After refraction and spectacle correction, the prevalence of visual impairment and blindness decreased to 6.7% and 0.75% respectively, suggesting that refractive error is the major correctable etiology of visual impairment and blindness in this population. Of 65 subjects having visual acuity visual impairment, and one to normal. The remaining 43 (66%) had underlying pathology (19 cataract, 9 glaucoma, 3 non-glaucomatous optic neuropathy, 3 corneal opacities, 3 retinal disease, 5 undetermined) that prevented refractive correction. Increased age was a significant risk factor for blindness and visual impairment. Conclusions There is a high prevalence of blindness and visual impairment among those aged ≥40 years in Tema, Ghana, West Africa. Refractive error is a major cause of blindness and visual impairment in this population, followed by cataract, glaucoma, and corneal disease. PMID:22677425

  1. Pattern of skin infections in black Africans of Sierra Leone (West Africa

    Directory of Open Access Journals (Sweden)

    Bari Arfan ul

    2007-01-01

    Full Text Available Background: Physical differences among human populations may lead to variable prevalence of skin disorders in different ethnicities. Skin infections are one of the important curable and largely preventable categories of skin disorders in the communities. Aim: The purpose of the study was to see the patterns of skin infections in black Africans of Sierra Leone and to compare with other ethnic populations. Materials and Methods: Local blacks of all age groups presenting in Dermatology out patient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone were included (from Nov 2004 to Oct 2005. Relevant clinical history and physical examination was done. Laboratory investigations were carried out when indicated. Skin diseases were broadly classified into two major categories i.e., infective and noninfective. Among infective, sexually transmitted infections were again separated. Nonblack settlers in the area and UN troops were not included in the study. Data was recorded and analyzed by Microsoft Excel program. Results: 3011 patients belonging to different local tribes having a variety of skin disorders were seen. Patients were of all ages and both sexes ranging from one month to 73 years of age. The Infective skin disorders were seen in 61.7% patients and most prevalent were superficial fungal infections (41.2% followed by, sexually transmitted infections (9.9% and parasitic infections (6.5%. Bacterial and viral infections were rare and so was the scabies. More than 90% parasitic infections were onchocerciasis with full spectrum of cutaneous manifestations. Conclusion: Pattern of skin infections in blacks varies considerably from other ethnic races. Environmental factors, geographical location and free existence of vector for onchocerciasis in West African region, possibly have a significant influence in this variable prevalence.

  2. Association between age at antiretroviral therapy initiation and 24-month immune response in West-African HIV-infected children

    DEFF Research Database (Denmark)

    Desmonde, Sophie; Dicko, Fatoumata; Koueta, Fla

    2014-01-01

    OBJECTIVE: We describe the association between age at antiretroviral therapy (ART) initiation and 24-month CD4 cell response in West African HIV-infected children. METHODS: All HIV-infected children from the IeDEA paediatric West African cohort, initiating ART, with at least two CD4 cell count...... measurements, including one at ART initiation (baseline) were included. CD4 cell gain on ART was estimated using a multivariable linear mixed model adjusted for baseline variables: age, CD4 cell count, sex, first-line ART regimen. Kaplan-Meier survival curves and a Cox proportional hazards regression model...... compared immune recovery for age within 24 months post-ART. RESULTS: Of the 4808 children initiated on ART, 3014 were enrolled at a median age of 5.6 years; 61.2% were immunodeficient. After 12 months, children at least 4 years at baseline had significantly lower CD4 cell gains compared with children less...

  3. The first endemic West African vertebrate family – a new anuran family highlighting the uniqueness of the Upper Guinean biodiversity hotspot

    Science.gov (United States)

    2014-01-01

    Background Higher-level systematics in amphibians is relatively stable. However, recent phylogenetic studies of African torrent-frogs have uncovered high divergence in these phenotypically and ecologically similar frogs, in particular between West African torrent-frogs versus Central (Petropedetes) and East African (Arthroleptides and Ericabatrachus) lineages. Because of the considerable molecular divergence, and external morphology of the single West African torrent-frog species a new genus was erected (Odontobatrachus). In this study we aim to clarify the systematic position of West African torrent-frogs (Odontobatrachus). We determine the relationships of torrent-frogs using a multi-locus, nuclear and mitochondrial, dataset and include genera of all African and Asian ranoid families. Using micro-tomographic scanning we examine osteology and external morphological features of West African torrent-frogs to compare them with other ranoids. Results Our analyses reveal Petropedetidae (Arthroleptides, Ericabatrachus, Petropedetes) as the sister taxon of the Pyxicephalidae. The phylogenetic position of Odontobatrachus is clearly outside Petropedetidae, and not closely related to any other ranoid family. According to our time-tree estimation Odontobatrachus has been separated from other frog lineages since the Cretaceous (90.1 Ma; confidence interval: 84.2-97.1 Ma). Along with this molecular evidence, osteological and external diagnostic characters recognize West African torrent-frogs as distinct from other ranoids and provide strong support for the necessity of the recognition of a new family of frogs. This is the only endemic vertebrate family occurring in the Upper Guinea biodiversity hotspot. Conclusion Based on molecular and morphological distinctiveness, the West African torrent-frog Odontobatrachus natator is allocated to a newly described anuran family. The discovery of an endemic vertebrate family in West Africa highlights the Upper Guinean forests as an

  4. Significant Impacts of Radiation Physics in the WRF Model on the Precipitation and Dynamics of the West African Monsoon

    OpenAIRE

    Li, R.; Jin, J.; Wang, Shih-Yu; Gillies, R. R.

    2014-01-01

    Precipitation from the West African Monsoon (WAM) provides food security and supports the economy in the region. As a consequence of the intrinsic complexities of the WAM’s evolution, accurate simulations of the WAM and its precipitation regime, through the application of regional climate models, are challenging. We used the coupled Weather Research and Forecasting (WRF) and Community Land Model (CLM) to explore impacts of radiation physics on the precipitation and dynamics of the WAM. Our re...

  5. Morphological assessment of the Zebu Bororo (Wodaabé cattle of Niger in the West African zebu framework

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    M. M. A. Moussa

    2017-10-01

    Full Text Available A total of 357 adult cows and 29 sires belonging to the long-horned Niger Zebu Bororo cattle population were assessed for 13 body measurements and 11 qualitative traits. Data were jointly analysed with 311 cows and 64 sires belonging to other four West African zebu cattle populations, sampled in Burkina Faso and Benin, representative of both the short-horned and the long-horned West African zebu groups using multivariate statistical methods. Besides the other long-horned zebu breed analysed (Zebu Mbororo of Burkina Faso, Zebu Bororo cattle tended to have the highest mean values for all body measurements. Mahalanobis distance matrices further informed that pairs involving Zebu Bororo cattle had the higher differentiation of the dataset. However, contour plots constructed using eigenvalues computed via principal component analysis (PCA illustrated a lack of differentiation among West African zebu cattle populations at the body measurements level. Correspondence analysis carried out on the 11 qualitative traits recorded allowed for ascertaining a clear differentiation between the Zebu Bororo and the other zebu cattle populations analysed which, in turn, did not show a clear differentiation at the qualitative type traits level. In our data, Zebu Bororo cattle had in high frequency qualitative features such as dropped ears, lyre-shaped horns and red-pied coat colour that are not frequently present in the other West African zebu populations analysed. A directional selection due to a rough consensus of the stock-keepers may be hypothesised. Performance of further analyses to assess the degree in which such breeding differences may be related to genetic or production differences are advised.

  6. The West African Monsoon Dynamics. Part II: The `Preonset' and `Onset' of the Summer Monsoon.

    Science.gov (United States)

    Sultan, Benjamin; Janicot, Serge

    2003-11-01

    meridional circulation intensity is the highest at the beginning of the monsoon onset. This can lead to 1) increased convective inhibition in the ITCZ through intrusion of dry and subsiding air from the north, and 2) increased potential instability through a greater inland moisture advection and a higher monsoon depth induced by a stronger cyclonic circulation in the low levels, through higher vertical wind shear due to westerly monsoon wind and midlevel African easterly jet (AEJ) increases, through enhancement of the instability character of the AEJ, and through increased shortwave radiation received at the surface. During the monsoon onset, once the rainfall minimum occurred due to the convective inhibition, the accumulated potential instability breaks the convective inhibition, the inertial instability of the monsoon circulation is released, and the associated regional-scale circulation increases, leading to the abrupt shift of the ITCZ. Then the ITCZ moves north up to 10°N, where thermodynamical conditions are favorable.It is suggested by the authors that the abrupt shift of the ITCZ, initiated by the amplification of the heat low dynamics, could be due to an interaction with the northern orography of the Atlas-Ahaggar Mountains. Subsidence over and north of this orography, due to both the northern branches of the heat low and of the northern Hadley-type cell, contributes to enhance the high geopotentials north of these mountains and the associated northeasterly winds. This leads to the development of a leeward trough that reinforces the heat low dynamics, maintaining an active convective ITCZ through enhanced moist air advection from the ocean, increasing the northern Hadley circulation, which reinforces the high geopotentials and the interaction with the orography through a positive feedback. The fact that an abrupt shift of the ITCZ is only observed on the western part of West Africa may result from the enhancement of moisture advection, which comes from the west and

  7. Effect of feeding some West African browse foliages on growth and carcass composition in sheep.

    Science.gov (United States)

    Ouédraogo-Koné, Salifou; Kaboré-Zoungrana, Chantal Y; Ledin, Inger

    2009-10-01

    The effect of feeding foliage from Afzelia africana, Pterocarpus erinaceus or Khaya senegalensis on growth performance was evaluated using 32 West African Djallonké rams of about 8 months of age and with a mean initial body weight (BW) of 16.1 kg. The animals were randomly assigned to four groups of 8 animals and the experiment lasted for 13 weeks. All the animals received the same amount of hay from Andropogon gayanus and maize bran (200 g/day each) and dried foliage ad libitum. The control group was fed cottonseed cake in restricted amounts. The animals were able to consume higher amounts of A. africana than of P. erinaceus and K. senegalensis. There was no significant difference in growth rate between sheep offered A. africana or P. erinaceus, 62.9 and 58.8 g/d, respectively, but sheep offered K. senegalensis had a lower average daily gain, 48 g/day (P erinaceus and K. senegalensis had similar carcass characteristics and dressing percentage but lower fasted BW, empty BW, carcass weight and dressing percentage (P < 0.05) than sheep offered A. africana. These tree species can provide valuable feed during periods of feed shortage in the humid and sub-humid zones.

  8. Recruitment success and growth variability of mugilids in a West African estuary impacted by climate change

    Science.gov (United States)

    Trape, S.; Durand, J.-D.; Vigliola, L.; Panfili, J.

    2017-11-01

    With the persistence of a drought since the late 1960s, some West African estuaries became permanently reversed in term of salinity gradient and hypersaline waters are present in their upstream part (salinity >60). To understand the mechanisms regulating fish recruitment intensity in these estuaries and evaluate the consequences of freshwater shortages on juvenile habitat quality, a growth study was conducted in the Saloum hypersaline estuary (Senegal). The Mugilidae fish family, highly representative of estuarine environments, was targeted and several species sampled (Chelon dumerili, Mugil bananensis and M. cf. curema sp. M). Juveniles were sampled monthly all the year round in three areas of the estuary exhibiting strongly contrasted habitat conditions. Otolith sections were used to estimate the ages, reconstruct growth trajectories, estimate the duration of the oceanic larval phase, and evaluate juvenile growth variability along the salinity gradient. Analyses revealed that the temporal recruitment variability of C. dumerili, with 2 annual cohorts, was not mainly induced by growth-selection mechanisms, but probably more by predation pressures. Juveniles exhibited significantly faster growth rates in the lower salinity suggesting that benthic food availability was a strong factor controlling habitat quality of early juveniles. Salinity had also a clear impact when reducing the growth in hypersaline conditions and/or selecting slower growing individuals. Moderate freshwater inputs positively affected the nursery function of the estuary for mugilids by enhancing the productivity of the first trophic levels. In a long term, the global change could have an impact of the mugilid fishery and its management.

  9. Distribution, reproduction, and feeding of West African shrimp Plesionika carinata Holthuis, 1951 (Decapoda, Pandalidae)

    Science.gov (United States)

    Burukovsky, R. N.

    2017-09-01

    Plesionika carinata is endemic in the West African tropical biogeographical realm and is distributed from the western Sahara coast (23°35' N) to southern Namibia (29° S). A total of 263 individuals with a total carapace length of 31 to 71 mm have been studied. P. carinata juveniles are pelagic and occur over depths from 340 to 2000 m or more, mainly over the lower part of the continental slope in summer and over the upper part of the continental slope in autumn. Adults are mainly benthic and occur on the edge of the shelf and the upper part of the continental slope (at depths of 300 to 880 m). Ovigerous females have 750 to 3330 eggs 0.45-0.5 × 0.5-0.65 mm in size on pleopods. Plesionika carinata feeds on abundant micronectonic and macroplanktonic crustaceans (euphausiids and pelagic shrimps) at earlier pelagic stages; it is detritophagous/necrophagous and predatory near the bottom when adult.

  10. On the coupled response of the equatorial Atlantic to West African dust outbreaks

    Science.gov (United States)

    Evan, Amato

    2013-04-01

    The Atlantic Meridional Mode (AMM) is the dominant source of coupled atmosphere-ocean variability in the tropical Atlantic, characterized by a hemispheric sea surface temperature (SST) gradient and cross equatorial surface winds that reinforce SST anomalies in both hemispheres. The AMM provides a theoretical framework for understanding the nature of regional patterns of precipitation and Atlantic hurricane variability. Although the wind-evaporation-SST (WES) feedback reinforces the existing meridional SST gradient when either phase of the AMM is excited the AMM is thermodynamically damped and thus requires external forcing to persist as is observed. However, there is little consensus as to what physical mechanisms may excite the AMM and thus govern regional coupled climate variability. Here I use observations and a physical model to show that the AMM is excited by variability in African dust outbreaks via dust radiatively-forced SST anomalies on interannual to decadal time scales. My analysis suggests that SST anomalies resulting from the aerosol direct effect persist in time via the WES feedback that defines the AMM. I conclude that the AMM and the state of the tropical Atlantic are directly tied to land surface processes over West Africa via dust emission. These results suggest that human activity may already be altering regional climate due to land use change and underscore the importance of resolving uncertainty in modeling land surface processes and dust emissions in order to estimate the regional response to future climate change.

  11. Deglacial Tropical Atlantic subsurface warming links ocean circulation variability to the West African Monsoon.

    Science.gov (United States)

    Schmidt, Matthew W; Chang, Ping; Parker, Andrew O; Ji, Link; He, Feng

    2017-11-13

    Multiple lines of evidence show that cold stadials in the North Atlantic were accompanied by both reductions in Atlantic Meridional Overturning Circulation (AMOC) and collapses of the West African Monsoon (WAM). Although records of terrestrial change identify abrupt WAM variability across the deglaciation, few studies show how ocean temperatures evolved across the deglaciation. To identify the mechanism linking AMOC to the WAM, we generated a new record of subsurface temperature variability over the last 21 kyr based on Mg/Ca ratios in a sub-thermocline dwelling planktonic foraminifera in an Eastern Equatorial Atlantic (EEA) sediment core from the Niger Delta. Our subsurface temperature record shows abrupt subsurface warming during both the Younger Dryas (YD) and Heinrich Event 1. We also conducted a new transient coupled ocean-atmosphere model simulation across the YD that better resolves the western boundary current dynamics and find a strong negative correlation between AMOC strength and EEA subsurface temperatures caused by changes in ocean circulation and rainfall responses that are consistent with the observed WAM change. Our combined proxy and modeling results provide the first evidence that an oceanic teleconnection between AMOC strength and subsurface temperature in the EEA impacted the intensity of the WAM on millennial time scales.

  12. Validity of photographs for food portion estimation in a rural West African setting.

    Science.gov (United States)

    Huybregts, L; Roberfroid, D; Lachat, C; Van Camp, J; Kolsteren, P

    2008-06-01

    To validate food photographs for food portion size estimation of frequently consumed dishes, to be used in a 24-hour recall food consumption study of pregnant women in a rural environment in Burkina Faso. This food intake study is part of an intervention evaluating the efficacy of prenatal micronutrient supplementation on birth outcomes. Women of childbearing age (15-45 years). A food photograph album containing four photographs of food portions per food item was compiled for eight selected food items. Subjects were presented two food items each in the morning and two in the afternoon. These foods were weighed to the exact weight of a food depicted in one of the photographs and were in the same receptacles. The next day another fieldworker presented the food photographs to the subjects to test their ability to choose the correct photograph. The correct photograph out of the four proposed was chosen in 55% of 1028 estimations. For each food, proportions of underestimating and overestimating participants were balanced, except for rice and couscous. On a group level, mean differences between served and estimated portion sizes were between -8.4% and 6.3%. Subjects who attended school were almost twice as likely to choose the correct photograph. The portion size served (small vs. largest sizes) had a significant influence on the portion estimation ability. The results from this study indicate that in a West African rural setting, food photographs can be a valuable tool for the quantification of food portion size on group level.

  13. Analysis of farmers’ adaptation to weather extremes in West African Sudan Savanna

    Directory of Open Access Journals (Sweden)

    David Boansi

    2017-06-01

    Full Text Available There have been recent incidences of weather extremes in the West African Sudan Savanna and farmers have responded through implementation of relevant adaptation strategies. For a deeper insight into farmers’ adaptation to climatic shocks, this study documents farmers’ perception of recent changes in the local climate, and identifies factors that influence the number and choice of strategies implemented. Interdependencies among strategies are explored and joint and marginal probabilities of adoption estimated. Upper East Ghana and Southwest Burkina Faso are used as the case study regions. These regions were selected due to extreme reliance of inhabitants on agriculture for sustenance, and their recent exposure to weather extremes. Through estimation of a Poisson regression and multivariate probit model to identify the major factors that influence the number and choice of strategies adopted, we discover that, limited access to credit, markets, and extension services, smaller cropland area, and low level of mechanization could impede effective adaptation to weather extremes. To enhance farmers’ adaptive capacity, policy makers and various stakeholders need to contribute towards improving farmers’ access to credit, markets, and extension services, and implement measures to promote mechanization.

  14. Cleft lip and palate repair: the experience from two West African sub-regional centres.

    Science.gov (United States)

    Onah, I I; Opara, K O; Olaitan, P B; Ogbonnaya, I S

    2008-08-01

    Compliance with primary surgical treatment in people with cleft lip and palate is a well-known problem, especially in developing countries fraught with poverty and ignorance. Different protocols of treatment exist. In this paper, we retrospectively review a cohort from two centres, with a discussion on the outcome and its implications. The records of all patients with cleft lip and palate seen in the National Orthopaedic Hospital, Enugu, Nigeria, from January 1993 to December 1999, were sought, and all available case notes reviewed retrospectively. This included new cases seen in the period, and also cases operated during this period. Follow up took place until January 2005, when the data were collated. The records of all such patients seen at Ladoke Akintola University Teaching Hospital Osogbo, Nigeria, from September 2004 to June 2006 were also collated and analysed. During this period, 102 patients were seen (93 at Enugu and nine at Osogbo). Fifteen had isolated cleft palate, 42 had isolated cleft lip and 45 had combined cleft lip and palate. Presentation time ranged from 1 day to 43 years. The palate was not repaired in 20 people after lip repair; two patients with cleft lip and palate completely defaulted; and only one person with isolated cleft palate failed to undergo surgery in this period. Two patients in Osogbo absconded. The West African sub-region has a high drop out rate after lip repair.

  15. Exploring child prostitution in a major city in the West African region.

    Science.gov (United States)

    Hounmenou, Charles

    2016-09-01

    The study explored the characteristics of child prostitution in a major city in the West African region. A convenience sample of children in prostitution, specifically girls below age 18 (n=243), were recruited on 83 prostitution sites identified in Ouagadougou, the capital city of Burkina Faso. A survey instrument, consisting of 71 closed-ended question items, was used to explore various variables including profile of children in prostitution, factors of vulnerability to prostitution; prostitution practices, compensations and related issues in child prostitution. The findings show that most children in prostitution in the city were from Burkina Faso (63%) and Nigeria (30%), two countries that do not share borders. Most native respondents practiced prostitution for survival and to support their families. In contrast, all the respondents from Nigeria practiced prostitution as victims of international sex trafficking. An important finding was that 77% of the children in prostitution surveyed were educated. Among the respondents, there were similarities in the major life events that contributed to their situation of prostitution. These life events include early separation with parents, sexual abuse, foster care, and forced marriage. Implications for policy, practice and research are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. UTILIZATION OF MEXICAN SUNFLOWER LEAF MEAL-BASED DIETS BY PRE WEANED WEST AFRICAN DWARF LAMBS

    Directory of Open Access Journals (Sweden)

    Anthony Henry Ekeocha

    2012-06-01

    Full Text Available Studies were conducted using 16 West African Dwarf (WAD lambs selected from 16 ewes brought to heat (Oestrus by synchronization and served by 2 rams. The experimental animals were placed at 6 weeks of age and were fed with Panicum maximum plus concentrate diet mixture of Mexican Sunflower Leaves (MSL and Wheat Bran (WB such that 0, 15, 30 and 45% of wheat bran was replaced by weight with MSL gravimetrically in diets A, B, C and D respectively. The experiment lasted for seven weeks. Feed and water were provided ad libitum and routine vaccination and medication were administered. Parameters measured were weight gain, dry matter intake, weaning weight and Feed Conversion Ratio (FCR. The Dry Matter Intake - DMI (g/day was highest for lambs on diet C (156.94 followed by B (156.53, A (154.29 and D (152.04 g/day respectively. This increase was numerically higher than observed values for animals on treatments A and B but statistically significant (P0.05. Results from this study showed that 30% MSLM-based diet was acceptable to the pre-weaned lambs as it supported dry matter intake, optimum weight gain, weaning weight and feed conversion ratio before diminishing return sets in.

  17. In Vitro Activity of Selected West African Medicinal Plants against Mycobacterium ulcerans Disease

    Directory of Open Access Journals (Sweden)

    Patrick Valere Tsouh Fokou

    2016-04-01

    Full Text Available Buruli ulcer (BU is the third most prevalent mycobacteriosis, after tuberculosis and leprosy. The currently recommended combination of rifampicin-streptomycin suffers from side effects and poor compliance, which leads to reliance on local herbal remedies. The objective of this study was to investigate the antimycobacterial properties and toxicity of selected medicinal plants. Sixty-five extracts from 27 plant species were screened against Mycobacterium ulcerans and Mycobacterium smegmatis, using the Resazurin Microtiter Assay (REMA. The cytotoxicity of promising extracts was assayed on normal Chang liver cells by an MTT assay. Twenty five extracts showed activity with minimal inhibitory concentration (MIC values ranging from 16 µg/mL to 250 µg/mL against M. smegmatis, while 17 showed activity against M. ulcerans with MIC values ranging from 125 µg/mL to 250 µg/mL. In most of the cases, plant extracts with antimycobacterial activity showed no cytotoxicity on normal human liver cells. Exception were Carica papaya, Cleistopholis patens, and Polyalthia suaveolens with 50% cell cytotoxic concentrations (CC50 ranging from 3.8 to 223 µg/mL. These preliminary results support the use of some West African plants in the treatment of Buruli ulcer. Meanwhile, further studies are required to isolate and characterize the active ingredients in the extracts.

  18. West African monsoon decadal variability and surface-related forcings: second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II)

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Yongkang; de Sales, Fernando; Lau, Willliam; Boone, Aaron; Kim, Kyu-Myong; Mechoso, C. R.; Wang , Guiling; Kucharski, Fred; Schiro, Kathleen; Hosaka, Masahiro; Li, Suosuo; Druyan, Leonard M.; Sanda, Ibrah S.; Thiaw, Wassila; Zeng, Ning; Comer, Ruth E.; Lim, Young-Kwon; Mahanama, Sarith; Song, Guoqiong; Gu, Yu; Hagos, Samson M.; Chin, Mian; Schubert, Siefried; Dirmeyer, Paul; Leung, Lai-Yung; Kalnay, Eugenia; Kitoh, Akio; Lu, Cheng-Hsuan; Mahowald, N. M.; Zhang, Zhengqiu J.

    2016-06-13

    The Sahel climate system had experienced one of the strongest interdecadal climate variabilities and the longest drought on the planet in the twentieth century. Most modeling studies on the decadal variability of the Sahel climate so far have focused on the role of anomalies in either sea surface temperature (SST), land surface processes, or aerosols concentration. The Second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedback of SST, land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales. The WAMME II strategy is to apply observationally based anomaly forcing, i.e., “idealized but realistic” forcing, in simulations by general circulation models’ (GCMs) and regional climate models’ (RCMs) to test the relative impacts of such forcings in producing/amplifying the Sahelian seasonal and decadal climate variability, including the 20th century drought. To test individual ocean’s SST effect, a special approach in the experimental design is taken to avoid undermine its effect. This is the first multi-model experiment specifically designed to simultaneously evaluate relative contributions of multiple-external forcings to the Sahel drought. This paper presents the major results and preliminary findings of the WAMME II SST experiment, including each ocean’s contribution to the global SST effect, as well as comparison of the SST effect with the LULCC effect. The common empirical orthogonal functions and other analyses are applied to assess and comprehend the discrepancies among the models. In general, the WAMME II models have reached a consensus on SST’s major contribution to the great Sahel drought and show that with the maximum possible SST forcing, it can produce up to 60% of the absolute amount of precipitation difference between the 1980s and the 1950s. This paper has 3 also delineated the role of SSTs in

  19. Above ground biomass estimation from lidar and hyperspectral airbone data in West African moist forests.

    Science.gov (United States)

    Vaglio Laurin, Gaia; Chen, Qi; Lindsell, Jeremy; Coomes, David; Cazzolla-Gatti, Roberto; Grieco, Elisa; Valentini, Riccardo

    2013-04-01

    The development of sound methods for the estimation of forest parameters such as Above Ground Biomass (AGB) and the need of data for different world regions and ecosystems, are widely recognized issues due to their relevance for both carbon cycle modeling and conservation and policy initiatives, such as the UN REDD+ program (Gibbs et al., 2007). The moist forests of the Upper Guinean Belt are poorly studied ecosystems (Vaglio Laurin et al. 2013) but their role is important due to the drier condition expected along the West African coasts according to future climate change scenarios (Gonzales, 2001). Remote sensing has proven to be an effective tool for AGB retrieval when coupled with field data. Lidar, with its ability to penetrate the canopy provides 3D information and best results. Nevertheless very limited research has been conducted in Africa tropical forests with lidar and none to our knowledge in West Africa. Hyperspectral sensors also offer promising data, being able to evidence very fine radiometric differences in vegetation reflectance. Their usefulness in estimating forest parameters is still under evaluation with contrasting findings (Andersen et al. 2008, Latifi et al. 2012), and additional studies are especially relevant in view of forthcoming satellite hyperspectral missions. In the framework of the EU ERC Africa GHG grant #247349, an airborne campaign collecting lidar and hyperspectral data has been conducted in March 2012 over forests reserves in Sierra Leone and Ghana, characterized by different logging histories and rainfall patterns, and including Gola Rainforest National Park, Ankasa National Park, Bia and Boin Forest Reserves. An Optech Gemini sensor collected the lidar dataset, while an AISA Eagle sensor collected hyperspectral data over 244 VIS-NIR bands. The lidar dataset, with a point density >10 ppm was processed using the TIFFS software (Toolbox for LiDAR Data Filtering and Forest Studies)(Chen 2007). The hyperspectral dataset, geo

  20. Radiative effect of black carbon aerosol on a squall line case in North China

    Science.gov (United States)

    Fu, Shizuo; Deng, Xin; Li, Zhe; Xue, Huiwen

    2017-11-01

    The radiative effect of black carbon aerosol (BC) on a squall line case in north China is studied with the Weather Research and Forecasting model. Before the initiation of the squall line, the surface-emitted BC is mixed only in the boundary layer (BL). BC is then transported from the BL into the free troposphere by the updrafts in the squall line system. Once distributed in the atmosphere, BC absorbs solar radiation and heats the surrounding air. The maximum increase of temperature is 0.05 K for the moderately polluted case bc2 and 0.37 K for the heavily polluted case bc20. In case bc2, where the BC concentration is not very high, the solar flux reaching the surface, the sensible heat flux, and the latent heat flux are not significantly affected by BC. In case bc20, the solar flux reaching the surface, the sensible heat flux, and the latent heat flux are reduced by up to 80, 30, and 21 W m- 2, respectively. The reduced surface evaporation leads to a reduced vapor amount at the early stage. After some time, the heating effect causes a large-scale convergence and brings slightly more vapor into the domain. The effect of BC on the cold pool strength and low-level wind shear is small and hence does not significantly affect the triggering of new convections. In addition, our results show that the effect of BC is negligible on the strength and rain rate of the squall line case.

  1. The history and future of African Rice: food security and survival in a West African war zone

    NARCIS (Netherlands)

    Richards, P.

    2006-01-01

    The paper analyses farmer coping strategies under war-time conditions in Sierra Leone in order to identify why food-insecure farmers continue to value African Rice. African Rice has an important association with 'sokoihun' (forest enclaves). These enclaves - written in the history of the landscape -

  2. 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

    Science.gov (United States)

    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

  3. The taxonomic status of two West African Leptopelis species: L. macrotis Schiøtz, 1967 and L. spiritusnoctis Rödel, 2007 (Amphibia: Anura: Arthroleptidae

    Directory of Open Access Journals (Sweden)

    Mark-Oliver Roedel

    2014-03-01

    Full Text Available We herein examine the taxonomic status of two West African forest-dwelling Leptopelis species. The small L. spiritusnoctis, described from the Upper Guinean forests of West Africa, was recently synonymized with L. aubryi, described from Gabon. The large L. macrotis, known from Ghana to Sierra Leone, was downgraded to a subspecies of L. millsoni, ranging from the Niger Delta to eastern Democratic Republic of Congo. These taxonomic decisions are in contrast to the general biogeographic pattern of African forest anurans and we consequently tested if the morphologically similar taxon pairs are indeed conspecifics by applying acoustic and molecular techniques. Both techniques confirmed that populations from West Africa differ significantly from their Central African morphological equivalents. Consequently, we herein resurrect L. spiritusnoctis as a valid species. The acoustic data indicate that L. aubryi may comprise a complex of cryptic species. We further advocate using the name L. macrotis for West African and L. millsoni for Central African populations of these larger arboreal frogs. However, we had neither genetic nor acoustic data from the type locality of L. millsoni available and could not clarify if these frogs belong to the more western or eastern taxon or even represent a Nigerian endemic. Thus, it is possible that West African populations need to be termed L. millsoni in the future. For populations east of the Cross River, Nigeria, the name L. guineensis would be available.

  4. A historical overview of Moroccan magmatic events along northwest edge of the West African Craton

    Science.gov (United States)

    Ikenne, Moha; Souhassou, Mustapha; Arai, Shoji; Soulaimani, Abderrahmane

    2017-03-01

    Located along the northwestern edge of the West African Craton, Morocco exhibits a wide variety of magmatic events from Archean to Quaternary. The oldest magmatic rocks belong to the Archean Reguibat Shield outcrops in the Moroccan Sahara. Paleoproterozoic magmatism, known as the Anti-Atlas granitoids, is related to the Eburnean orogeny and initial cratonization of the WAC. Mesoproterozoic magmatism is represented by a small number of mafic dykes known henceforth as the Taghdout mafic volcanism. Massive Neoproterozoic magmatic activity, related to the Pan-African cycle, consists of rift-related Tonian magmatism associated with the Rodinia breakup, an Early Cryogenian convergent margin event (760-700 Ma), syn-collisional Bou-Azzer magmatism (680-640 Ma), followed by widespread Ediacaran magmatism (620-555 Ma). Each magmatic episode corresponded to a different geodynamic environment and produced different types of magma. Phanerozoic magmatism began with Early Cambrian basaltic (rift?) volcanism, which persisted during the Middle Cambrian, and into the Early Ordovician. This was succeeded by massive Late Devonian and Carboniferous, pre-Variscan tholeiitic and calc-alkaline (Central Morocco) volcanic flows in basins of the Moroccan Meseta. North of the Atlas Paleozoic Transform Zone, the Late Carboniferous Variscan event was accompanied by the emplacement of 330-300 Ma calc-alkaline granitoids in upper crustal shear zones. Post-Variscan alkaline magmatism was associated with the opening of the Permian basins. Mesozoic magmatism began with the huge volumes of magma emplaced around 200 Ma in the Central Atlantic Magmatic Province (CAMP) which was associated with the fragmentation of Pangea and the subsequent rifting of Central Atlantic. CAMP volcanism occurs in all structural domains of Morocco, from the Anti-Atlas to the External Rif domain with a peak activity around 199 Ma. A second Mesozoic magmatic event is represented by mafic lava flows and gabbroic intrusions in

  5. Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment.

    Science.gov (United States)

    Thorsen, Line; Kando, Christine Kere; Sawadogo, Hagrétou; Larsen, Nadja; Diawara, Bréhima; Ouédraogo, Georges Anicet; Hendriksen, Niels Bohse; Jespersen, Lene

    2015-03-02

    Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus cereus occasionally occurs in Maari. This study characterizes succession patterns and pathogenic potential of B. cereus isolated from the raw materials (ash, water from a drilled well (DW) and potash), seed mash throughout fermentation (0-96h), after steam cooking and sun drying (final product) from two production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 10(5)cfu/ml in DW, and ranged between 6.5×10(3) and 1.2×10(4)cfu/g in potash, 10(9)-10(10)cfu/g in seed mash during fermentation and 10(7) - 10(9) after sun drying. Fifty three out of total 290 AMB isolates were identified as B. cereus sensu lato by use of ITS-PCR and grouped into 3 groups using PCR fingerprinting based on Escherichia coli phage-M13 primer (M13-PCR). As determined by panC gene sequencing, the isolates of B. cereus belonged to PanC types III and IV with potential for high cytotoxicity. Phylogenetic analysis of concatenated sequences of glpF, gmk, ilvD, pta, pur, pycA and tpi revealed that the M13-PCR group 1 isolates were related to B. cereus biovar anthracis CI, while the M13-PCR group 2 isolates were identical to cereulide (emetic toxin) producing B. cereus strains. The M13-PCR group 1 isolates harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were found in potash, DW, cooking water and at 8h fermentation. The "emetic" type B. cereus were present in DW, the seed mash at 48-72h of fermentation and in the final product

  6. Skill, reproducibility and potential predictability of the West African monsoon in coupled GCMs

    Energy Technology Data Exchange (ETDEWEB)

    Philippon, N. [UMR5210 CNRS/Universite de Bourgogne, Centre de Recherches de Climatologie, 6 blvd Gabriel, BP 21877, Dijon Cedex (France); Doblas-Reyes, F.J. [Institut Catala de Ciencies del Clima, Barcelona (Spain); Ruti, P.M. [Ente por le Nuove Tecnologie, l' Energia e l' Ambiante, Rome (Italy)

    2010-07-15

    In the framework of the ENSEMBLES FP6 project, an ensemble prediction system based on five different state-of-the-art European coupled models has been developed. This study evaluates the performance of these models for forecasting the West African monsoon (WAM) at the monthly time scale. From simulations started the 1 May of each year and covering the period 1991-2001, the reproducibility and potential predictability (PP) of key parameters of the WAM - rainfall, zonal and meridional wind at four levels from the surface to 200 hPa, and specific humidity, from July to September - are assessed. The Sahelian rainfall mode of variability is not accurately reproduced contrary to the Guinean rainfall one: the correlation between observations (from CMAP) and the multi-model ensemble mean is 0.17 and 0.55, respectively. For the Sahelian mode, the correlation is consistent with a low PP of about {proportional_to}6%. The PP of the Guinean mode is higher, {proportional_to}44% suggesting a stronger forcing of the sea surface temperature on rainfall variability over this region. Parameters relative to the atmospheric dynamics are on average much more skillful and reproducible than rainfall. Among them, the first mode of variability of the zonal wind at 200 hPa that depicts the Tropical Easterly Jet, is correlated at 0.79 with its ''observed'' counterpart (from the NCEP/DOE2 reanalyses) and has a PP of 39%. Moreover, models reproduce the correlations between all the atmospheric dynamics parameters and the Sahelian rainfall in a satisfactory way. In that context, a statistical adaptation of the atmospheric dynamic forecasts, using a linear regression model with the leading principal components of the atmospheric dynamical parameters studied, leads to moderate receiver operating characteristic area under the curve and correlation skill scores for the Sahelian rainfall. These scores are however much higher than those obtained using the modelled rainfall. (orig.)

  7. Fire Patterns and Drivers of Fires in the West African Tropical Forest

    Science.gov (United States)

    Dwomoh, F. K.; Wimberly, M. C.

    2015-12-01

    The West African tropical forest (referred to as the Upper Guinean forest, UGF), is a global biodiversity hotspot providing vital ecosystem services for the region's socio-economic and environmental wellbeing. It is also one of the most fragmented and human-modified tropical forest ecosystems, with the only remaining large patches of original forests contained in protected areas. However, these remnant forests are susceptible to continued fire-mediated degradation and forest loss due to intense climatic, demographic and land use pressures. We analyzed human and climatic drivers of fire activity in the sub-region to better understand the spatial and temporal patterns of these risks. We utilized MODIS active fire and burned area products to identify fire activity within the sub-region. We measured climatic variability using TRMM rainfall data and derived indicators of human land use from a variety of geospatial datasets. We used a boosted regression trees model to determine the influences of predictor variables on fire activity. Our analyses indicated that the spatial and temporal variability of precipitation is a key driving factor of fire activity in the UGF. Anthropogenic effects on fire activity in the area were evident through the influences of agriculture and low-density populations. These human footprints in the landscape make forests more susceptible to fires through forest fragmentation, degradation, and fire spread from agricultural areas. Forested protected areas within the forest savanna mosaic experienced frequent fires, whereas the more humid forest areas located in the south and south-western portions of the study area had fewer fires as these rainforests tend to offer some buffering against fire encroachment. These results improve characterization of UGF fire regime and expand our understanding of the spatio-temporal dynamics of tropical forest fires in response to human and climatic pressures.

  8. Women School Leaders: Entrepreneurs in Low Fee Private Schools in Three West African Nations

    Directory of Open Access Journals (Sweden)

    Paula A. Cordeiro

    2018-01-01

    Full Text Available This study explores the opportunities and challenges of women who own low-fee private schools in three West African nations. With the implementation of the Millennium Development Goals (MDGs in 2000 and the Sustainable Development Goals in 2016, it has become obvious to policymakers that school leadership needs to be a policy priority around the world. Increased school autonomy and a greater focus on schooling and school results have made it essential to understand and support the role of school leaders. Few countries however have strong and systematic initiatives to professionalize school leadership and to nurture and support current school leaders. This becomes even more complex for governments given the rise of private schooling in low and middle-income countries worldwide; thus, it is crucial for governments to understand the importance of leadership at the school level and how to nurture and professionalize it. In this study, the authors examine the roles of women school leaders in Burkina Faso, Ghana, and Liberia within the context of MDG 3: promote gender equality and empower women. Because of the many challenges in the public sector in education in low and middle-income countries, the private sector has responded by creating thousands of small businesses. Since a large and growing number of women are leading these private schools, this study presents the findings on the nature of the leadership of these women entrepreneurs. Fourteen school proprietors participated in face-to face interviews about their reasons for founding a school as well as the supports and challenges they face. Findings discuss the limited professional learning opportunities for school leaders in these nations. The study describes the school leaders’ desires to help build their nations, and the unique cultural and contextual factors in each country.

  9. Socioeconomic potential of carbon sequestration through agroforestry in the West African Sahel

    Energy Technology Data Exchange (ETDEWEB)

    Alavalpati, J.R.R. [School of Forest Resources and Conservation, University of Florida, Gainesville, FL (United States); Nair, P.K.R. [School of Forest Resources and Conservation, University of Florida, Gainesville, FL (United States); Takimoto A. [School of Forest Resources and Conservation, University of Florida, Gainesville, FL (United States)

    2008-08-15

    The recognition of agroforestry as a greenhouse-gas mitigation strategy under the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) offers an opportunity to agroforestry practitioners to benefit from the global carbon (C) credit market. Our knowledge on this important topic from the semiarid regions such as the West African Sahel (WAS) is, however, very limited. In order to fill this gap, this study was undertaken in the Segou region of Mali (annual temperature, 29{sup o}C; annual rainfall, 300-700 mm in 60 to 90 days), focusing on two improved agroforestry systems (live fence and fodder bank) along with traditional parkland agroforestry systems of the region. A cost-benefit analysis was conducted to assess the economic profitability and risks associated with the systems considering them as 25-year projects and their potential for participation in C credit market. The traditional systems had high C stock in their biomass and soil, but little potential for sequestering additional C; on the other hand, the improved systems had low C stock, but high sequestration potential. For the standard size live fence (291 m) and fodder bank (0.25 ha) projects, the estimated net present values (NPV) were $96.0 and $158.8 without C credit sale, and $109.9 and $179.3 with C sale, respectively. From the C sale perspective, live fence seemed less risky and more profitable than fodder bank. Carbon credit sale is likely to contribute to economic development of the subsistence farmers in the WAS.

  10. Suicidal ideation among MSM in three West African countries: Associations with stigma and social capital.

    Science.gov (United States)

    Stahlman, Shauna; Grosso, Ashley; Ketende, Sosthenes; Pitche, Vincent; Kouanda, Seni; Ceesay, Nuha; Ouedraogo, Henri G; Ky-Zerbo, Odette; Lougue, Marcel; Diouf, Daouda; Anato, Simplice; Tchalla, Jules; Baral, Stefan

    2016-09-01

    Suicidal ideation is understudied among men who have sex with men (MSM) across Sub-Saharan Africa. This study aimed to explore social capital and sexual behavior stigma associated with suicidal ideation among MSM in the West African nations of The Gambia, Burkina Faso and Togo. Participants were recruited using respondent-driven sampling and snowball sampling across multiple cities (n = 1555) from July 2011 to August 2013. During a single study visit, participants completed a survey. Logistic regression models were used to assess bivariate and multivariable associations with suicidal ideation. The prevalence of lifetime suicidal ideation was 13% overall and ranged 6%-17% across study sites. After adjusting for potential confounders, MSM who reported stigma as a result of having sex with men were more likely to report suicidal ideation. Physical and sexual violence was strongly associated with suicidal ideation, including being physically harmed (adjusted odds ratio (aOR) = 2.94, 95% confidence interval (CI) = 1.91, 4.52), tortured (aOR = 3.86, 95% CI = 2.17, 6.86) and raped (aOR = 3.07, 95% CI = 2.05, 4.60). In contrast, increasing social participation with the broader community was associated with decreased report of suicidal ideation (aOR = 0.91, 95% CI = 0.85, 0.99). Sexual behavior stigma should be addressed to improve mental health among MSM in Western Sub-Saharan Africa. © The Author(s) 2016.

  11. Economic institutions and economic growth: Empirical evidence from the Economic Community of West African States

    Directory of Open Access Journals (Sweden)

    Lazarus Z. Wanjuu

    2017-12-01

    Background: Economic institutions are considered as the fundamental cause of economic growth. Economic institutions affect economic growth through allocation of resources like physical and human capital. Unfortunately, there is dearth of empirical studies showing the impact of economic institutions on growth of the Economic Community of West African States (ECOWAS. Aim: This study investigates the impact of economic institutions on economic growth of the ECOWAS. Setting and method: The study applied cause and effect relationship. The study used econometric research techniques of unit root and co-integration tests to establish the time series properties of the data; the vector error correction and co-integration regression models to estimate the population parameters. The research data comprised data obtained from the United Nations Conference on Trade and Development (UNCTAD, the Transparency International (TI and Heritage Foundation databases. The variables employed were the real gross domestic product (GDP per capita (RGDPPC, corruption perception index (CPI, property rights protection (PROPRGT, private investment per capita (INVESPC, government expenditure per capita (GOEXPPC and trade openness (TRAOPN. Results: The results of the data analysed showed that economic institutions represented by the property rights index engender RGDPPC growth in ECOWAS. The CPI could not stimulate RGDPPC growth in ECOWAS. The results also show that all the other variables stimulated growth except trade openness. Conclusion: The study concludes that good economic institutions, private investments, and government intervention by providing security, economic and social infrastructural facilities are conducive for economic growth in the ECOWAS region. The study recommended that more efforts be made at curbing corruption in the region

  12. Retraction | Simon | African Zoology

    African Journals Online (AJOL)

    Panthera leo) ina. West African national park”. African Zoology is publishing an Editorial Expression of Concern regarding the following article: “New records of a threatened lion population (Panthera leo) in a West African national park” by ...

  13. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling

    Energy Technology Data Exchange (ETDEWEB)

    Auger, P.A., E-mail: pierreamael.auger@gmail.com [Laboratoire de Physique des Océans (LPO), UMR-CNRS 6523/IFREMER/IRD/UBO, BP70, 29280 Plouzané (France); Machu, E.; Gorgues, T.; Grima, N. [Laboratoire de Physique des Océans (LPO), UMR-CNRS 6523/IFREMER/IRD/UBO, BP70, 29280 Plouzané (France); Waeles, M. [Université de Bretagne Occidentale (UBO), Laboratoire de l' Environnement Marin (LEMAR), UMR-CNRS 6539/IRD/UBO, place N. Copernic, 29280 Plouzané (France)

    2015-02-01

    A Lagrangian approach based on a physical–biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural Cd-uptake by plankton communities while anthropogenic Cd-uptake is high. As expected, the situation is reversed in the Senegalo-Mauritanian upwelling where natural Cd-uptake is higher than anthropogenic Cd-uptake. Based upon an estimate of Cd sources, our modeling study shows, unexpectedly, that the anthropogenic signal of potential Cd-bioaccumulation in the Moroccan upwelling is of the same order of magnitude as the natural signal mainly present in the Senegalo-Mauritanian upwelling region. A comparison with observed Cd levels in mollusk and fishes, which shows overall agreement with our simulations, is confirming our estimates. - Highlights: • We model the physical–biogeochemical dynamics in the North-West African upwelling. • We model the transport of cadmium from natural and anthropogenic sources. • We derive proxies of potential cadmium absorption and bioaccumulation in the plankton food chain. • The anthropogenic signal off Morocco at least equals the natural upwelling signal off Mauritania. • We compare our results with observed cadmium levels in mollusks and fishes.

  14. Haemonchotolerance in West African Dwarf goats: contribution to sustainable, anthelmintics-free helminth control in traditionally managed Nigerian dwarf goats

    Science.gov (United States)

    Chiejina, Samuel N.; Behnke, Jerzy M.; Fakae, Barineme B.

    2015-01-01

    West African Dwarf (WAD) goats are extremely important in the rural village economy of West Africa, but still little is known about their biology, ecology and capacity to cope with gastrointestinal nematode (GIN) infections. Here, we summarise the history of this breed and explain its economic importance in rural West Africa. We review recent work showing that Nigerian WAD goats are highly trypanotolerant and resist infections with Haemonchus contortus more effectively than other breeds of domestic goat (haemonchotolerance). We believe that haemonchotolerance is largely responsible for the generally low level GIN infections and absence of clinical haemonchosis in WADs under field conditions, and has contributed to the relatively successful and sustainable, anthelmintics-free, small-scale system of goat husbandry in Nigeria’s humid zone, and is immunologically based and genetically controlled. If haemonchotolerance can be shown to be genetically controlled, it should be possible to exploit the underlying genes to improve GIN resistance among productive fibre and milk producing breeds of goats, most of which are highly susceptible to nematode infections. Genetic resistance to GIN and trypanosome infections would obviate the need for expensive chemotherapy, mostly unaffordable to small-holder farmers in Africa, and a significant cost of goat husbandry in more developed countries. Either introgression of resistance alleles into susceptible breeds by conventional breeding, or transgenesis could be used to develop novel parasite-resistant, but highly productive breeds, or to improve the resistance of existing breeds, benefitting the local West African rural economy as well as global caprine livestock agriculture. PMID:25744655

  15. Analysis and Prediction of West African Moist Events during the Boreal Spring of 2009

    Science.gov (United States)

    Mera, Roberto Javier

    Weather and climate in Sahelian West Africa are dominated by two major wind systems, the southwesterly West African Monsoon (WAM) and the northeasterly (Harmattan) trade winds. In addition to the agricultural benefit of the WAM, the public health sector is affected given the relationship between the onset of moisture and end of meningitis outbreaks. Knowledge and prediction of moisture distribution during the boreal spring is vital to the mitigation of meningitis by providing guidance for vaccine dissemination. The goal of the present study is to (a) develop a climatology and conceptual model of the moisture regime during the boreal spring, (b) investigate the role of extra-tropical and Convectively-coupled Equatorial Waves (CCEWs) on the modulation of westward moving synoptic waves and (c) determine the efficacy of a regional model as a tool for predicting moisture variability. Medical reports during 2009, along with continuous meteorological observations at Kano, Nigeria, showed that the advent of high humidity correlated with cessation of the disease. Further analysis of the 2009 boreal spring elucidated the presence of short-term moist events that modulated surface moisture on temporal scales relevant to the health sector. The May moist event (MME) provided insight into interplays among climate anomalies, extra-tropical systems, equatorially trapped waves and westward-propagating synoptic disturbances. The synoptic disturbance initiated 7 May and traveled westward to the coast by 12 May. There was a marked, semi-stationary moist anomaly in the precipitable water field (kg m-2) east of 10°E through late April and early May, that moved westward at the time of the MME. Further inspection revealed a mid-latitude system may have played a role in increasing the latitudinal amplitude of the MME. CCEWs were also found to have an impact on the MME. A coherent Kelvin wave propagated through the region, providing increased monsoonal flow and heightened convection. A

  16. Allometric models and aboveground biomass stocks of a West African Sudan Savannah watershed in Benin.

    Science.gov (United States)

    Chabi, Adéyèmi; Lautenbach, Sven; Orekan, Vincent Oladokoun Agnila; Kyei-Baffour, Nicholas

    2016-12-01

    The estimation of forest biomass changes due to land-use change is of significant importance for estimates of the global carbon budget. The accuracy of biomass density maps depends on the availability of reliable allometric models used in combination with data derived from satellites images and forest inventory data. To reduce the uncertainty in estimates of carbon emissions resulting from deforestation and forest degradation, better information on allometric equations and the spatial distribution of aboveground biomass stocks in each land use/land cover (LULC) class is needed for the different ecological zones. Such information has been sparse for the West African Sudan Savannah zone. This paper provides new data and results for this important zone. The analysis combines satellite images and locally derived allometric models based on non-destructive measurements to estimate aboveground biomass stocks at the watershed level in the Sudan Savannah zone in Benin. We compared three types of empirically fitted allometric models of varying model complexity with respect to the number of input parameters that are easy to measure at the ground: model type I based only on the diameter at breast height (DBH), type II which used DBH and tree height and model type III which used DBH, tree height and wood density as predictors. While for most LULC classes model III outperformed the other models even the simple model I showed a good performance. The estimated mean dry biomass density values and attached standard error for the different LULC class were 3.28 ± 0.31 (for cropland and fallow), 3.62 ± 0.36 (for Savanna grassland), 4.86 ± 1.03 (for Settlements), 14.05 ± 0.72 (for Shrub savanna), 45.29 ± 2.51 (for Savanna Woodland), 46.06 ± 14.40 (for Agroforestry), 94.58 ± 4.98 (for riparian forest and woodland), 162 ± 64.88 (for Tectona grandis plantations), 179.62 ± 57.61 (for Azadirachta indica plantations), 25.17 ± 7.46 (for Gmelina arborea plantations

  17. Allometric models and aboveground biomass stocks of a West African Sudan Savannah watershed in Benin

    Directory of Open Access Journals (Sweden)

    Adéyèmi Chabi

    2016-08-01

    Full Text Available Abstract Background The estimation of forest biomass changes due to land-use change is of significant importance for estimates of the global carbon budget. The accuracy of biomass density maps depends on the availability of reliable allometric models used in combination with data derived from satellites images and forest inventory data. To reduce the uncertainty in estimates of carbon emissions resulting from deforestation and forest degradation, better information on allometric equations and the spatial distribution of aboveground biomass stocks in each land use/land cover (LULC class is needed for the different ecological zones. Such information has been sparse for the West African Sudan Savannah zone. This paper provides new data and results for this important zone. The analysis combines satellite images and locally derived allometric models based on non-destructive measurements to estimate aboveground biomass stocks at the watershed level in the Sudan Savannah zone in Benin. Results We compared three types of empirically fitted allometric models of varying model complexity with respect to the number of input parameters that are easy to measure at the ground: model type I based only on the diameter at breast height (DBH, type II which used DBH and tree height and model type III which used DBH, tree height and wood density as predictors. While for most LULC classes model III outperformed the other models even the simple model I showed a good performance. The estimated mean dry biomass density values and attached standard error for the different LULC class were 3.28 ± 0.31 (for cropland and fallow, 3.62 ± 0.36 (for Savanna grassland, 4.86 ± 1.03 (for Settlements, 14.05 ± 0.72 (for Shrub savanna, 45.29 ± 2.51 (for Savanna Woodland, 46.06 ± 14.40 (for Agroforestry, 94.58 ± 4.98 (for riparian forest and woodland, 162 ± 64.88 (for Tectona grandis plantations, 179.62 ± 57.61 (for Azadirachta indica plantations, 25.17

  18. Identification, tissue distribution and functional characterization of the ghrelin receptor in West African lungfish, Protopterus annectens.

    Science.gov (United States)

    Kaiya, Hiroyuki; Konno, Norifumi; Kangawa, Kenji; Uchiyama, Minoru; Miyazato, Mikiya

    2014-12-01

    We identified two ghrelin receptor isoforms, the ghrelin receptor type-1a (GHS-R1a) and its alternative splice form (GHS-R1b) for West African lungfish, Protopterus annectens. Lungfish GHS-R1a and 1b comprised 361 and 281 amino acids, respectively. Lungfish GHS-R1a showed the highest identity to coelacanth GHS-R1a (80.4%). The highest expression of GHS-R1a mRNAs was seen in the brain, liver, ovary, heart, intestine, and gills. GHS-R1b mRNAs were also detected in the same tissues with GHS-R1a, but their expression level was 1/20 that of GHS-R1a. In human embryonic kidney 293 cells transiently expressing lungfish GHS-R1a, rat and bullfrog ghrelin, and two GHS-R1a agonists, GHRP-6 and hexarelin, increased intracellular Ca(2+) concentrations. The intensity of the Ca(2+) increases induced by GHS-R1a agonists was twice when compared to that induced by ghrelin, although the median effective doses (ED50) were similar, suggesting a long-lasting effect of GHS-R1a agonists with similar affinity. We also examined changes in the GHS-R gene expression during an eight-week estivation. Body weight was slightly lowered, but plasma sodium and glucose concentrations decreased; plasma urea concentration increased significantly 4weeks after the start of estivation. Overall, expression of GHS-R1a mRNA decreased, but changes in GHS-R1b mRNA expression were inconsistent with those of GHS-R1a during estivation, suggesting an involvement of GHS-R in energy homeostasis, as seen in mammals. Our results suggest that the ghrelin-GHS-R1a system is present in this lungfish although ghrelin has not yet been found. The structure of GHS-R1a is closer to that of tetrapods than Actinopterygian fish, indicating a process of evolution that follows the Crossopterygii such as coelacanth. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Analysis of West African Drug Trafficking: The Dynamics of Interdiction and State Capacity

    Science.gov (United States)

    2011-03-01

    Illegal drug trafficking through West Africa has grown dramatically in the last decade, capturing the attention of U.S., European, and U.N...policymakers. Most countries in West Africa have struggled to adapt to the challenges drug trafficking has presented. A few countries, like Ghana, have made a

  20. Analyzing Seasonal and Interannual Changes in the West African Monsoon with Machine Learning Approaches: Self-Organizing Mapping

    Science.gov (United States)

    Van Gordon, M.; Larsen, L.; Chiang, J. C. H.

    2016-12-01

    Here we present findings on recent interannual and seasonal-scale changes in the West African monsoon system. Using self-organizing mapping (SOM) for inductive pattern discovery, we examine the distribution and characteristics of rainfall over space and time at a finer level of detail than is possible using single or multi-variate spatially constrained indices. Unlike more traditional empirical orthogonal function analysis, SOM produces physically representative patterns that we use to investigate precipitation patterns in this region: spatially, annually, and intra-annually. Existing literature demonstrates an increase in recent years in the variability of annual precipitation in West Africa; projections indicate a possible shift in precipitation toward later in the season. Through self-organizing mapping, we examine the role of the myriad underlying spatio-temporal precipitation patterns in the overall changes in variability and timing of precipitation. We distinguish, at inter- and intra-annual time scales, the contributions of: changes in the timing of shifts between precipitation patterns; changes in the precipitation patterns themselves; large scale precipitation patterns associated with the monsoon; and small scale patterns associated with mesoscale systems. We find that observed changes in rainfall dynamics, regionally and sub-regionally, are associated with both changes in the timing of shifts between rainfall patterns and changes in the rainfall patterns themselves. The spatial-temporal analysis of precipitation dynamics in West Africa points toward monsoon timing as the driving factor behind broader precipitation trends observed in the region. We compare SOM patterns derived from observational data against those derived from model data to evaluate model performance. Comparison of observation- and model-derived SOM patterns is a novel spatially and temporally detailed metric. Examining precipitation in West Africa with the higher-dimensional, more

  1. A literary analysis of the West Africans' reaction to the introduction of ...

    African Journals Online (AJOL)

    This paper analyzes the Francophone and the Anglophone Africans' attitude towards the introduction of Western education in Africa by the British and French colonizers. Camara Laye's The African Child and Cheikh Hamidou Kane' Ambiguous Adventure are used as samples of Francophone writing and John Munonye's ...

  2. a literary analysis of the west africans' reaction to the introduction

    African Journals Online (AJOL)

    mycl

    Abstract. This paper analyzes the Francophone and the Anglophone Africans' attitude towards the introduction of Western education in Africa by the British and French colonizers. Camara Laye's The African Child and Cheikh Hamidou Kane' Ambiguous Adventure are used as samples of Francophone writing and John ...

  3. Neurological morbidity among human T-lymphotropic-virus-type-1-infected individuals in a rural West African population.

    Science.gov (United States)

    Cooper, S; van der Loeff, M Schim; McConkey, S; Cooper, M; Sarge-Njie, R; Kaye, S; Whittle, H

    2009-01-01

    Community-based neurological data about human T lymphotropic virus type 1 (HTLV-1) morbidity in sub-Saharan Africa are scarce. To ascertain the prevalence of neurological morbidity, in particular tropical spastic paraparesis (TSP), among HTLV-1-infected subjects and to compare TSP prevalence in HTLV-1-infected with that in non-infected subjects in a rural West African population. A cross-sectional study of HTLV-1-infected cases and controls (ratio 4:1) from a rural community (population approximately 10 000, HTLV-1 prevalence 7.7%). One neurologist masked to HTLV-1 serological status assessed all subjects. Clinical criteria were employed to diagnose TSP. From 205 eligible cases and controls, 139 were recruited with a mean age of 56 years, and 113 (81%) were HTLV-1-infected. 108/139 (78%) were female, and 8/113 HTLV-1 infected cases (7.1%) had a definite or probable TSP (all females; mean age 67 years) compared with 0/26 controls. Two with TSP were co-infected with HIV-2. Complaints of back pain and leg weakness were more common in HTLV-1-infected individuals (p = 0.03, p = 0.02), but no single symptom distinguished between subjects with and without TSP. We report a prevalence of TSP among HTLV-1-infected persons in this rural West African setting of 7.1%. There are difficulties excluding other potential aetiologies here.

  4. West African languages enrich the frequency code: Multi-functional pitch and multi-dimensional prosody in Ikaan polar questions

    Directory of Open Access Journals (Sweden)

    Sophie Salffner

    2017-06-01

    Full Text Available Cross-linguistically, statements tend to be pronounced with low or falling pitch and questions with high or rising pitch, a form–meaning pairing which has been attributed to the frequency code (Ohala, 1984. In many West African languages, however, questions are marked with a ‘lax’ prosody comprising falling intonation, low tones, lengthening, breathy termination, and open vowels (Rialland, 2007. This paper presents prosody findings from Ikaan (Niger-Congo; ISO 639-3: kcf and proposes a re-analysis of the West African lax question prosody to integrate it with the frequency code model. The paper shows that the pragmatic functions of statement and polar question are expressed prosodically in Ikaan. Audio recordings of statements and morphosyntactically identical polar questions by six speakers were annotated segmentally, tonally, and for the presence of prosodic question markers. Speakers mark questions by using higher onset pitch, wider drops to final low tones, final breathy voice and voicelessness, final vowel lengthening, vowel insertion, and increased intensity. Breathiness may further contrast with creaky voice and glottal stops in statements. Phonation mode, and the accompanying vowel lengthening and insertion, are argued to indicate friendliness and appeals for collaboration, linking phonation mode to similar functions of higher pitch in the frequency code.

  5. The social ecology of resolving family conflict among West African immigrants in New York: a grounded theory approach.

    Science.gov (United States)

    Rasmussen, Andrew; Chu, Tracy; Akinsulure-Smith, Adeyinka M; Keatley, Eva

    2013-09-01

    The current study employs a grounded theory approach to examine West African immigrants' resolution of parent-child conflict and intimate partner conflict. Data from 59 participants present an interactive social ecological framework, where a lack of resolution at one level results in attempts to resolve problems at higher levels. Four levels are identified within West African immigrants' problem solving ecology, each with specific actors in positions of authority: individual/dyadic (parents and spouses), extended family (which includes distant relatives and relatives living in home countries), community leadership (non-family elders and religious leaders), and state authorities. From participants' descriptions of family challenges emerged a picture of a social ecology in flux, with traditional, socially conservative modes of resolving family conflict transposed across migration into the more liberal and state-oriented familial context of the United States. This transposition results in a loss spiral for the traditional social ecology, differentially affecting individual actors within families. Implications for helping professionals working with new immigrant communities include identifying variability in openness to adapting structures that are not working well (e.g., patriarchal protection of abusive husbands) and supporting structures known to be associated with well being (e.g., collective monitoring of youth).

  6. Representation of the West African Monsoon System in the aerosol-climate model ECHAM6-HAM2

    Science.gov (United States)

    Stanelle, Tanja; Lohmann, Ulrike; Bey, Isabelle

    2017-04-01

    The West African Monsoon (WAM) is a major component of the global monsoon system. The temperature contrast between the Saharan land surface in the North and the sea surface temperature in the South dominates the WAM formation. The West African region receives most of its precipitation during the monsoon season between end of June and September. Therefore the existence of the monsoon is of major social and economic importance. We discuss the ability of the climate model ECHAM6 as well as the coupled aerosol climate model ECHAM6-HAM2 to simulate the major features of the WAM system. The north-south temperature gradient is reproduced by both model versions but all model versions fail in reproducing the precipitation amount south of 10° N. A special focus is on the representation of the nocturnal low level jet (NLLJ) and the corresponding enhancement of low level clouds (LLC) at the Guinea Coast, which are a crucial factor for the regional energy budget. Most global climate models have difficulties to represent these features. The pure climate model ECHAM6 is able to simulate the existence of the NLLJ and LLC, but the model does not represent the pronounced diurnal cycle. Overall, the representation of LLC is worse in the coupled model. We discuss the model behaviors on the basis of outputted temperature and humidity tendencies and try to identify potential processes responsible for the model deficiencies.

  7. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling.

    Science.gov (United States)

    Auger, P A; Machu, E; Gorgues, T; Grima, N; Waeles, M

    2015-02-01

    A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural Cd-uptake by plankton communities while anthropogenic Cd-uptake is high. As expected, the situation is reversed in the Senegalo-Mauritanian upwelling where natural Cd-uptake is higher than anthropogenic Cd-uptake. Based upon an estimate of Cd sources, our modeling study shows, unexpectedly, that the anthropogenic signal of potential Cd-bioaccumulation in the Moroccan upwelling is of the same order of magnitude as the natural signal mainly present in the Senegalo-Mauritanian upwelling region. A comparison with observed Cd levels in mollusk and fishes, which shows overall agreement with our simulations, is confirming our estimates. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Agricultural Investments and Farmer-Fulani Pastoralist Conflict in West African Drylands: A Northern Ghanaian Case Study

    Directory of Open Access Journals (Sweden)

    Sebastiaan Soeters

    2017-11-01

    Full Text Available In the Global South, there is a push to drive agricultural modernisation processes through private sector investments. In West African drylands, land concessions are required for such agri-businesses are often negotiated through customary authorities, and inject large amounts of money into localised rural systems with low cash bases. The article argues that such transactions serve to increase area under crop cultivation on an inter-seasonal basis, as financial spill-overs allow for farmers to purchase larger quantities of agricultural inputs and prepare larger tracts of land. Simultaneously, such direct and indirect cash flows also result in larger local herd sizes and an increase in the number of locally-owned cattle, as cash is exchanged for cattle, largely regarded as an interest-accruing, savings buffer. Larger herd sizes, in turn, attract Fulani pastoralists in search of employment as contracted herders for local cattle owners. Taking Integrated Water and Agricultural Development (IWAD, a private sector, large-scale irrigation initiative in northern Ghana as a case study, the article argues that there is an inevitability of the pathway, which leads from large-scale land acquisitions in West-African drylands, to an increase in conflict (and/or the risk thereof between sedentary and Fulani pastoralists.

  9. HLA-DRB1 and -DQB1 loci in three west African ethnic groups: genetic relationship with sub-Saharan African and European populations.

    Science.gov (United States)

    Lulli, Patrizia; Mangano, Valentina D; Onori, Annamaria; Batini, Chiara; Luoni, Gaia; Sirima, Bienvenu S; Nebie, Issa; Chessa, Luciana; Petrarca, Vincenzo; Modiano, David

    2009-11-01

    The Fulani of west Africa have been shown to be less susceptible to malaria and to mount a stronger immune response to malaria than sympatric ethnic groups. The analysis of HLA diversity is useful for the assessment of the genetic distance between the Fulani and sympatric populations, which represents the necessary theoretical background for the investigation of genetic determinants of susceptibility to malaria. We assessed the polymorphism of HLA-DRB1 and -DQB1 loci and analyzed the distribution of alleles/haplotypes in Fulani, Mossi, and Rimaibé from Burkina Faso. We then investigated the genetic relationship of these three ethnic groups with other sub-Saharan African populations as well as with Europeans. We confirmed that the Fulani from Burkina Faso are genetically distinct from sympatric Mossi and Rimaibé. Furthermore the Fulani from Burkina Faso are close to those from The Gambia and, intriguingly, share the distribution of specific alleles with east African populations (Amhara and Oromo). It is noteworthy that the HLA-DRB1*04 and -DQB1*02 alleles, which are implicated in the development of several autoimmune diseases, are present at high frequency in the Fulani, suggesting their potential involvement in the enhanced immune reactivity observed in this population.

  10. Prevalence and time trends in diabetes and physical inactivity among adult West African populations: the epidemic has arrived.

    Science.gov (United States)

    Abubakari, A R; Lauder, W; Jones, M C; Kirk, A; Agyemang, C; Bhopal, R S

    2009-09-01

    To determine the prevalence and distribution of, and trends in, physical inactivity and diabetes in adult West African populations. Systematic review and meta-analysis. Literature searches were conducted using four electronic databases. Journal hand searches and examination of citations of relevant articles were also undertaken. To be included, studies had to be population based, use clearly defined criteria for measuring diabetes and physical inactivity, present data that allowed calculation of the prevalence of diabetes or physical inactivity, and sample adult participants. Studies retrieved were appraised critically. Meta-analysis was performed using the DerSimonian-Laird random effect model. Twenty-one reports were retrieved for diabetes and 15 reports were retrieved for physical in/activity. Most studies (10 for diabetes and six for physical activity) were conducted solely among urban populations. The prevalence of diabetes in West Africa was approximately 4.0% [95% confidence interval (CI) 2.0-9.0] in urban adults and 2.6% (95%CI 1.5-4.4) in rural adults, and was similar in men and women [prevalence ratio (PR) 1.36, 95%CI 0.96-1.92]. Cumulative time trend analyses suggested an increase in the prevalence of diabetes among adults in urban West Africa, from approximately 3.0% (95%CI 1.0-7.0) to 4.0% (95%CI 2.0-9.0) in the past 10 years. The prevalence of inactivity in West Africa was 13% (95%CI 9.0-18.0). An association was found between physical inactivity and being older (> or = 50 years) (PR 1.82, 95%CI 1.36-2.44), female gender (PR 1.62, 95%CI 1.41-1.87) and urban residence (PR 2.04, 95%CI 1.58-2.63). Diabetes and physical inactivity are important public health issues in urban West Africa, with similar prevalences to wealthy industrialized countries. There is an urgent need for policy makers, politicians and health promotion experts to put measures in place to encourage active lifestyles and control diabetes in urban West Africa.

  11. Population structure, biomass and production of the West African lucinid Keletistes rhizoecus (Bivalvia, Mollusca) in Sivibilagbara swamp at Bodo Creek, Niger Delta, Nigeria

    NARCIS (Netherlands)

    Zabbey, N.; Hart, A. I.; Wolff, W. J.

    2010-01-01

    The West African lucinid bivalve Keletistes rhizoecus (Oliver, Basteria 50:47-64, 1986) is only known from the Niger Delta in Nigeria. Due to inaccessibility of its habitat population biology, growth parameters, biomass, and annual secondary production are unknown. The danger of oil pollution

  12. The role of the percentage free PSA in the diagnosis of prostate cancer in Blacks: Findings in indigenous West African men using TRUS guided biopsy

    Directory of Open Access Journals (Sweden)

    K.H. Tijani

    2017-03-01

    Conclusion: The %fPSA is an effective discriminating tool in determining the need for prostate biopsy in indigenous West African men with PSA 4–10 ng/ml. A cut off of 15% was associated with the highest performance.

  13. Clinical profile and containment of the Ebola virus disease outbreak in two large West African cities, Nigeria, July–September 2014

    Directory of Open Access Journals (Sweden)

    Chima Ohuabunwo

    2016-12-01

    Conclusion: The EVD outbreak in Nigeria was characterized by the severe febrile gastroenteritis syndrome typical of the West African outbreak, better outcomes, rapid containment, and no infection among EVD care-providers. Early case detection, an effective incident management system, and prompt case management with on-site mobilization and training of local professionals were key to the outcome.

  14. Breeding performance of the grasshopper buzzard (Butastur rufipennis) in a natural and a human-modified West African savanna

    NARCIS (Netherlands)

    Buij, Ralph; Kortekaas, Kim; van Krimpen, Roderick R. D.; van Wijk, Rien; van der Zanden, Saskia; de Iongh, Hans H.; Heitkonig, Ignas M. A.; de Snoo, Geert R.; Komdeur, Jan; Heitkönig, Ignas M.A.

    Few studies have examined raptor reproduction in response to land-use change in sub-Saharan Africa, hampering conservation efforts to address regional declines. To further our understanding of mechanisms underlying the dramatic declines of West African raptors, we examined the relationship between

  15. Characterization of African Bush Mango trees with emphasis on the differences between sweet and bitter trees in the Dahomey Gap (West Africa)

    NARCIS (Netherlands)

    Vihotogbe, R.

    2012-01-01

     African bush mango trees (ABMTs) are economically the most important species within the family of Irvingiaceae. They are priority trees producing non-timber forest products (NTFPs) and widely distributed in the humid lowland forests of West and Central Africa. To boost their production and

  16. Weakening and Shifting of the Saharan Heat Low Circulation During Wet Years of the West African Monsoon

    CERN Document Server

    Shekhar, Ravi

    2016-01-01

    The correlation between increased West African monsoon rainfall and anomalously low surface pressure over the Sahara is well established in observations and global climate models, and has been interpreted as a strengthening of the Saharan Heat Low (SHL) during wet monsoon years. This study uses two atmospheric reanalysis datasets to examine interannual variability of Sahel rainfall and the shallow Saharan Heat Low circulation, which consists of the near surface SHL and the Saharan High in the lower mid-troposphere. During wet Sahel years, the SHL circulation shifts poleward, producing a drop in low-level geopotential height and surface pressure over the Sahara. Statistically removing the effect of the poleward shift from the low-level geopotential eliminates significant correlations between this geopotential and Sahel precipitation. As the SHL circulation shifts poleward, its mid-tropospheric divergent outflow decreases, indicating a weakening of its overturning mass flux. The poleward shift and weakening of ...

  17. Comparative effects of slow freezing and vitrification on cryosurvival of spermatozoa obtained from west African dwarf goat bucks.

    Science.gov (United States)

    Daramola, J O; Adekunle, E O

    2016-01-01

    Slow freezing and vitrification are used to improve the viability of spermatozoa from various species but comparative effects of these cryoprotocols have never been evaluated for spermatozoa obtained from West African Dwarf (WAD) goat bucks. This study evaluated the comparative effects of slow freezing and vitrification on the viability of spermatozoa of WAD goat bucks. Semen samples collected with the aid of artificial vagina were allocated to slow freezing and vitrification protocols and cryopreserved for 30 days in liquid nitrogen. Consistent higher (Pfreezing compared to vitrification. Abnormal sperm cells and malondialdehyde (MDA) concentrations reduced (Pfreezing compared to vitrification. Higher (Pfreezing compared to vitrification. The findings indicated that spermatozoa obtained from WAD goat bucks were better preserved in slow freezing compared to vitrification.

  18. Extensive nucleotide changes and deletions within the envelope glycoprotein gene of Euro-African West Nile viruses.

    Science.gov (United States)

    Berthet, F X; Zeller, H G; Drouet, M T; Rauzier, J; Digoutte, J P; Deubel, V

    1997-09-01

    We compared the sequence of an envelope protein gene fragment from 21 temporally distinct West Nile (WN) virus strains, isolated in nine African countries and in France. Alignment of nucleotide sequences defined two groups of viruses which diverged by up to 29%. The first group of subtypes is composed of nine WN strains from France and Africa. The Austral-Asian Kunjin virus was classified as a WN subtype in this first group. The second group includes 12 WN strains from Africa and Madagascar. Four strains harboured a 12 nucleotide in-frame deletion. The loss of the corresponding four amino acids resulted in the loss of the potential glycosylation site present in several WN strains. The distribution of virus subtypes into two lineages did not correlate with host preference or geographical origin. The isolation of closely related subtypes in distant countries is consistent with WN viruses being disseminated by migrating birds.

  19. Leukocyte transcript alterations in West-African girls following a booster vaccination with diphtheria-tetanus-pertussis vaccine

    DEFF Research Database (Denmark)

    Orntoft, Nikolaj W; Thorsen, Kasper; Benn, Christine S

    2013-01-01

    identified a group of nine comparable West African girls, from a biobank of 356 children, who were due to receive DTP booster vaccine at age 18 months. As a pilot experiment we extracted RNA from blood samples before, and 6 weeks after, vaccination to analyze the coding transcriptome in leukocytes using......Background. Observational studies from low-income countries have shown that the vaccination against diphtheria, tetanus and pertussis (DTP) is associated with excess female mortality due to infectious diseases. Methods. To investigate possible changes in gene expression after DTP vaccination, we...... expression microarrays, and ended up with information from eight girls. The data was further analyzed using dedicated array pathway and network software. We aimed to study whether DTP vaccination introduced a systematic alteration in the immune system in girls. Results. We found very few transcripts to alter...

  20. Nutrient flows in urban and peri-urban agroecosystems in three West African cities

    NARCIS (Netherlands)

    Abdulkadir, A.

    2012-01-01

    Key words: Sustainability, CATPCA, two-step cluster analysis, farm types, nutrient balances, West Africa, gross margin, NUTMON/MONQI. Urban and peri-urban agriculture (UPA) is defined as the cultivation of crops and keeping livestock within and around cities. In addition to providing the

  1. Biogeographical and anthropogenic determinants of landscape-scale patterns of raptors in West African savannas

    NARCIS (Netherlands)

    Buij, Ralph; Croes, Barbara M.; Komdeur, Jan

    Strong raptor population declines have recently been reported in sub-Saharan West Africa, where the pressure on wildlife and their supporting habitats is particularly high. This makes it imperative to understand the role of land-use on landscape-scale patterns of raptors and to define priority areas

  2. Surface runoff scale effects in West African watersheds: Modeling and management options

    NARCIS (Netherlands)

    Giesen, van de N.C.; Stomph, T.J.; Ridder, de N.

    2005-01-01

    Measurements of surface runoff from uniform slopes of different lengths in West Africa have shown that longer slopes tend to have less runoff per unit of length than short slopes. The main reason for this scale effect is that once the rain stops, water on long slopes has more opportunity time to

  3. Pattern of Ptosis in Kano North-West Nigeria | Lamina | African ...

    African Journals Online (AJOL)

    Objective: Epidemiological data on ptosis are generally lacking in the developing nations. The aim of this study was to assess the seven years pattern of ptosis in a Nigerian Specialist Hospital, Kano North-West Nigeria. Method: The records of patients' diagnosis as ptosis between 2000 and 2006 were scrutinized.

  4. Change and Variation in Family Religious Language Policy in a West African Muslim Community

    Science.gov (United States)

    Moore, Leslie C.

    2016-01-01

    This article examines variation in family religious language policy in a Muslim community in West Africa. Taking an ethnographically grounded case study approach, I situate families' choices with regards to their children's religious (language) education within the larger linguistic, social, and cultural context, focusing on new influences on…

  5. On the West-African species of the subgenus Eupalaemon Ortm

    NARCIS (Netherlands)

    Man, de J.G.

    1911-01-01

    In addition to my description of Palaemon (Eupalaemon) Lenzii de Man (see p. 225 of this volume) I give here a key to the species of the subgenus Eupalaemon Ortm. as yet known to occur in the rivers of West-Africa. Six species are at present known from there, viz.: 1. Pal. (Eupalaemon) macrobrachion

  6. West African Journal of Applied Ecology - Vol 12, No 1 (2008)

    African Journals Online (AJOL)

    Effect of pesticide application rate on yield of vegetables and soil microbial communities · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD ... Linking Biotechnology and Agricultural Biodiversity Resources in Holistic Strategy in West Africa · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD ...

  7. West African Journal of Applied Ecology - Vol 23, No 1 (2015)

    African Journals Online (AJOL)

    Establishing a National Shellfish Sanitation Program in The Gambia, West Africa · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. MA Rice, F Conteh, K Kent, B Crawford, B Banja, F Janha, I Bojang, 1-20 ...

  8. Dyed and Printed Textiles: Javanese Batik [and] Dutch Wax Prints [and] West African Adire. Third Edition.

    Science.gov (United States)

    Burke, Sue

    Three booklets focusing on dyed and printed textile techniques of Java, West Africa, and the Netherlands describe historical and ethnographic materials as well as the development of particular technical traditions. Each section may be used alone or with either or both of the others. When used together, these booklets illustrate the…

  9. Influence of Islamic Traditions on Breastfeeding Beliefs and Practices Among African American Muslims in West Philadelphia: A Mixed-Methods Study.

    Science.gov (United States)

    Kamoun, Camilia; Spatz, Diane

    2018-02-01

    Little is known regarding the influence of religion on breastfeeding in African American communities. In particular, whether Islamic traditions influence breastfeeding beliefs and practices among African American Muslims has not been studied. Research aim: This study sought to gain understanding of breastfeeding attitudes, rates, and education among African American Muslims in West Philadelphia and to examine if engaging Islamic teachings in breastfeeding education can positively influence breastfeeding attitudes. Open-ended, in-person, digitally recorded qualitative interviews were conducted with 10 community leaders and analyzed by conventional content analysis. A study tool distributed to a convenience sample of 44 community members and 11 leaders was used to gather information about education received from community leaders, breastfeeding attitudes and practices, and the potential for Islamic teachings to positively affect breastfeeding attitudes and practices. To obtain further data on this last topic, preliminary data analysis guided the creation of an education pamphlet, about which feedback was gathered through another study tool. Education surrounding Islamic perspectives on breastfeeding was not prevalent. African American Muslims in West Philadelphia view breastfeeding favorably and have higher rates of breastfeeding than African Americans as a whole. Community education about breastfeeding that engaged Islamic teachings improved respondents' breastfeeding attitudes. Increasing education among providers and African American Muslims about Islamic perspectives on breastfeeding may improve breastfeeding exclusivity and duration. Healthcare providers who care for Muslim women should be aware of Islam's tradition of positive attitudes toward breastfeeding and partner with Muslim leaders to improve breastfeeding rates and duration among such women.

  10. Considerations in Establishing an Economic Community of West African States’ Defense Pact.

    Science.gov (United States)

    1987-03-01

    Development and Security African states spend an enormous amount of money on military equipment with comparatively large armies, instead of directing such...Islamic empire, fuels dissent in the Community under the guise of religon and inship, destabilizes regimes with its immense wealth in the subregion

  11. Seed systems for African food security: linking molecular genetic analysis and cultivator knowledge in West Africa

    NARCIS (Netherlands)

    Richards, P.; Bruin-Hoekzema, de M.; Hughes, S.G.; Kudadjie, C.Y.; Offei, S.K.; Struik, P.C.

    2009-01-01

    A challenge for African countries is how to integrate new sources of knowledge on plant genetics with knowledge from farmer practice to help improve food security. This paper considers the knowledge content of farmer seed systems in the light of a distinction drawn in artificial intelligence

  12. Pattern of Ptosis in Kano North-West Nigeria | Lamina | African ...

    African Journals Online (AJOL)

    African Health Sciences. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 8, No 4 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load here if your Web ...

  13. Management of west African dwarf goats fed value-added cassava ...

    African Journals Online (AJOL)

    for Researchers · for Journals · for Authors · for Policy Makers · about Open Access · Journal Quality. 521 African Journals. Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free To Read Titles This Journal is Open Access. Featuring journals from 32 Countries: Algeria (5); Benin (2); Botswana ...

  14. How to change West-African minds in order to increase general ...

    African Journals Online (AJOL)

    EB

    Medical education in Western African countries is at a very important evolution stage: how to integrate occidental research modalities into traditional beliefs? How to accommodate both? We agree with the opinion expressed by Dr. Kieran Walsh1 saying “insight into beliefs alone is insufficient”; before changing things, things ...

  15. Study on the macrometry of gastrointestinal tract of wild west African ...

    African Journals Online (AJOL)

    Parrots are ornamental birds that are found in the wild and those in domestication end up in animal units of schools and houses of the wealthy individuals. The wild African Senegal parrot population is at risk of extinction due to its high popularity with urban dweller. Despite their high popularity, there is scanty documentation ...

  16. Measuring pesticide ecological and health risks in West African agriculture to establish an enabling environment for sustainable intensification

    Science.gov (United States)

    Jepson, P. C.; Guzy, M.; Blaustein, K.; Sow, M.; Sarr, M.; Mineau, P.; Kegley, S.

    2014-01-01

    We outline an approach to pesticide risk assessment that is based upon surveys of pesticide use throughout West Africa. We have developed and used new risk assessment models to provide, to our knowledge, the first detailed, geographically extensive, scientifically based analysis of pesticide risks for this region. Human health risks from dermal exposure to adults and children are severe enough in many crops to require long periods of up to three weeks when entry to fields should be restricted. This is impractical in terms of crop management, and regulatory action is needed to remove these pesticides from the marketplace. We also found widespread risks to terrestrial and aquatic wildlife throughout the region, and if these results were extrapolated to all similar irrigated perimeters in the Senegal and Niger River Basins, they suggest that pesticides could pose a significant threat to regional biodiversity. Our analyses are presented at the regional, national and village levels to promote regulatory advances but also local risk communication and management. Without progress in pesticide risk management, supported by participatory farmer education, West African agriculture provides a weak context for the sustainable intensification of agricultural production or for the adoption of new crop technologies. PMID:24535399

  17. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

    Science.gov (United States)

    Nuijten, Edwin; van Treuren, Robbert; Struik, Paul C; Mokuwa, Alfred; Okry, Florent; Teeken, Béla; Richards, Paul

    2009-10-06

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo) using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty.

  18. The impact of anthropogenic land cover changes on the West African monsoon: A multi-model study

    Science.gov (United States)

    Boone, A. A.

    2016-12-01

    The population over West Africa has approximately doubled since the mid 1960s and this trend is expected to continue through this century. One effect of this demographic change is a notable anthropogenic imprint on the land use and land cover (LULC), which is mainly characterized as a degradation owing to the loss of natural vegetation (savanna and forest) to agriculture and wood for fuel. The key question which arises is what is the impact of such changes on the regional scale hydrological cycle ? This issue is investigated using an ensemble of state-of-the-art global climate models (GCMs) under the auspices of the West African Monsoon Model Evaluation (WAMME) project. It is advantageous to use multiple models since both the modeled land-atmosphere coupling strength and the representation of the land cover can vary significantly among models. It is found that by imposing strong but realistic changes to the biogeophysical parameters consistent with degradation, the monsoon season rainfall is reduced in the Sahel by 4 to 25 %, depending on the GCM. It is shown that part of the inter-model variability arises because some GCMs are more sensitive to the overall reduction in the surface moist enthalpy flux mainly resulting from albedo changes, while others are most sensitive to changes in the Bowen ratio arising primarily from LAI reductions. The statistical significance of the results is presented, along with a discussion of the difficulty in prescribing a consistent change in the biogeophysical characteristics across models with recommendations for future studies.

  19. Burden of human scabies in sub-Saharan African prisons: Evidence from the west region of Cameroon.

    Science.gov (United States)

    Kouotou, Emmanuel Armand; Nansseu, Jobert Richie N; Sangare, Abdoulaye; Moguieu Bogne, Léonnelle-Lynda; Sieleunou, Isidore; Adegbidi, Hugues; Tameyi Tatsa, Joël; Moyou Somo, Roger

    2018-02-01

    There is little data on the profile and magnitude of scabies in sub-Saharan African prisons. The present study aimed to assess the prevalence and determinants of scabies in prisons of the west region of Cameroon. We conducted a cross-sectional study from March to August 2014, and consecutively recruited volunteer detainees of three randomly selected prisons in the West Region of Cameroon. The diagnosis was based on clinical findings after assessment by two experienced and well-trained dermatologists. We enrolled 755 prisoners, 17 (2%) of whom were women. Their mean age was 32 ± 12 years. There were 242 cases (32%) of scabies, with significantly more cases in the most crowded prison (P 10 (aOR 1.89; P = 0.002), but not age, duration of incarceration, number of baths/week and washing/week, were independent drivers of scabies occurrence. Almost one-third of prisoners suffered from scabies in our prisons. A low educational level, the sharing of clothes/bedding and number of detainees/cell > 10 were independent determinants of the disease. Urgent measures must be undertaken to reduce the burden of scabies in our prisons. © 2017 The Australasian College of Dermatologists.

  20. Measuring pesticide ecological and health risks in West African agriculture to establish an enabling environment for sustainable intensification.

    Science.gov (United States)

    Jepson, P C; Guzy, M; Blaustein, K; Sow, M; Sarr, M; Mineau, P; Kegley, S

    2014-04-05

    We outline an approach to pesticide risk assessment that is based upon surveys of pesticide use throughout West Africa. We have developed and used new risk assessment models to provide, to our knowledge, the first detailed, geographically extensive, scientifically based analysis of pesticide risks for this region. Human health risks from dermal exposure to adults and children are severe enough in many crops to require long periods of up to three weeks when entry to fields should be restricted. This is impractical in terms of crop management, and regulatory action is needed to remove these pesticides from the marketplace. We also found widespread risks to terrestrial and aquatic wildlife throughout the region, and if these results were extrapolated to all similar irrigated perimeters in the Senegal and Niger River Basins, they suggest that pesticides could pose a significant threat to regional biodiversity. Our analyses are presented at the regional, national and village levels to promote regulatory advances but also local risk communication and management. Without progress in pesticide risk management, supported by participatory farmer education, West African agriculture provides a weak context for the sustainable intensification of agricultural production or for the adoption of new crop technologies.

  1. Tobacco use and its determinants in HIV-infected patients on antiretroviral therapy in West African countries

    Science.gov (United States)

    Jaquet, Antoine; Ekouevi, Didier-Koumavi; Aboubakrine, Maiga; Bashi, Jules; Messou, Eugène; Maiga, Moussa; Traore, Hamar-Alassane; Zannou, Marcel; Guehi, Calixte; Ba-Gomis, Franck-Olivier; Minga, Albert; Allou, Gérard; Eholie, Serge-Paul; Dabis, Francois; Bissagnene, Emmanuel; Sasco, Annie-Jeanne

    2009-01-01

    INTRODUCTION Tobacco smoking is common in HIV-infected patients from industrialized countries. In West Africa, few data exist concerning tobacco consumption. METHODS A cross-sectional survey was conducted within the International epidemiological Database to Evaluate AIDS (IeDEA) network in West Africa. Health workers administered to patients receiving antiretroviral treatment a questionnaire assessing tobacco and cannabis consumption. Regular smokers were defined as present smokers who smoked >1 cigarette per day for ≥1 year. RESULTS Overall, 2920 patients were enrolled in three countries. The prevalence of ever smokers and present smokers were 46.2% (95% CI 42.8–49.5) and 15.6% (95% CI 13.2–18.0) in men and 3.7% (95% CI 2.9–4.5) and 0.6% (95% CI 0.3–0.9) in women, respectively. Regular smoking was associated being from Côte d’Ivoire or Mali compared to Benin (OR 4.6; 95% CI 2.9–7.3 and 7.7; 95% CI 4.4–13.6), a severely impaired immunological status at HAART initiation (OR 1.5; 95% CI 1.1–2.2) and a history of tuberculosis (OR 1.8; 95% CI 1.1–3.0). CONCLUSION Marked differences of smoking prevalence exist between these West African countries. This survey approach also provides evidences concerning the association between cigarette smoking and tuberculosis in HIV-infected patients, a major public health issue in this part of the world. PMID:19861019

  2. Analysis of a grid ionospheric vertical delay and its bounding errors over West African sub-Saharan region

    Science.gov (United States)

    Abe, O. E.; Otero Villamide, X.; Paparini, C.; Radicella, S. M.; Nava, B.

    2017-02-01

    Investigating the effects of the Equatorial Ionization Anomaly (EIA) ionosphere and space weather on Global Navigation Satellite Systems (GNSS) is very crucial, and a key to successful implementation of a GNSS augmentation system (SBAS) over the equatorial and low-latitude regions. A possible ionospheric vertical delay (GIVD, Grid Ionospheric Vertical Delay) broadcast at a Ionospheric Grid Point (IGP) and its confidence bounds errors (GIVE, Grid Ionospheric Vertical Error) are analyzed and compared with the ionospheric vertical delay estimated at a nearby user location over the West African Sub-Saharan region. Since African sub-Saharan ionosphere falls within the EIA region, which is always characterized by a disturbance in form of irregularities after sunset, and the disturbance is even more during the geomagnetically quiet conditions unlike middle latitudes, the need to have a reliable ionospheric threat model to cater for the nighttime ionospheric plasma irregularities for the future SBAS user is essential. The study was done during the most quiet and disturbed geomagnetic conditions on October 2013. A specific low latitude EGNOS-like algorithm, based on single thin layer model, was engaged to simulate SBAS message in the study. Our preliminary results indicate that, the estimated GIVE detects and protects a potential SBAS user against sampled ionospheric plasma irregularities over the region with a steep increment in GIVE to non-monitored after local sunset to post midnight. This corresponds to the onset of the usual ionospheric plasma irregularities in the region. The results further confirm that the effects of the geomagnetic storms on the ionosphere are not consistent in affecting GNSS applications over the region. Finally, this paper suggests further work to be investigated in order to improve the threat integrity model activity, and thereby enhance the availability of the future SBAS over African sub-Saharan region.

  3. Intergenerational differences in smoking among West Indian, Haitian, Latin American, and African blacks in the United States

    Directory of Open Access Journals (Sweden)

    Tod G. Hamilton

    2017-12-01

    Full Text Available Due in large part to increased migration from Africa and the Caribbean, black immigrants and their descendants are drastically changing the contours of health disparities among blacks in the United States. While prior studies have examined health variation among black immigrants by region of birth, few have explored the degree of variation in health behaviors, particularly smoking patterns, among first- and second- generation black immigrants by ancestral heritage. Using data from the 1995–2011 waves of the Tobacco Use Supplements of the Current Population Survey (TUS-CPS, we examine variation in current smoking status among first-, second-, and third/higher- generation black immigrants. Specifically, we investigate these differences among all black immigrants and then provide separate analyses for individuals with ancestry from the English-speaking Caribbean (West Indies, Haiti, Latin America, and Africa—the primary sending regions of black immigrants to the United States. We also explore differences in smoking behavior by gender. The results show that, relative to third/higher generation blacks, first-generation black immigrants are less likely to report being current smokers. Within the first-generation, immigrants who migrated after age 13 have a lower probability of smoking relative to those who migrated at or under age 13. Disparities in smoking prevalence among the first-generation by age at migration are largest among black immigrants from Latin America. The results also suggest that second-generation immigrants with two foreign-born parents are generally less likely to smoke than the third/higher generation. We find no statistically significant difference in smoking between second-generation immigrants with mixed nativity parents and the third or higher generation. Among individuals with West Indian, Haitian, Latin American, and African ancestry, the probability of being a current smoker increases with each successive generation

  4. Impacts of Microphysical Scheme on Convective and Stratiform Characteristics in Two High Precipitation Squall Line Events

    Science.gov (United States)

    Wu, Di; Dong, Xiquan; Xi, Baike; Feng, Zhe; Kennedy, Aaron; Mullendore, Gretchen; Gilmore, Matthew; Tao, Wei-Kuo

    2013-01-01

    This study investigates the impact of snow, graupel, and hail processes on simulated squall lines over the Southern Great Plains in the United States. The Weather Research and Forecasting (WRF) model is used to simulate two squall line events in Oklahoma during May 2007, and the simulations are validated against radar and surface observations. Several microphysics schemes are tested in this study, including the WRF 5-Class Microphysics (WSM5), WRF 6-Class Microphysics (WSM6), Goddard Cumulus Ensemble (GCE) Three Ice (3-ice) with graupel, Goddard Two Ice (2-ice), and Goddard 3-ice hail schemes. Simulated surface precipitation is sensitive to the microphysics scheme when the graupel or hail categories are included. All of the 3-ice schemes overestimate the total precipitation with WSM6 having the largest bias. The 2-ice schemes, without a graupel/hail category, produce less total precipitation than the 3-ice schemes. By applying a radar-based convective/stratiform partitioning algorithm, we find that including graupel/hail processes increases the convective areal coverage, precipitation intensity, updraft, and downdraft intensities, and reduces the stratiform areal coverage and precipitation intensity. For vertical structures, simulations have higher reflectivity values distributed aloft than the observed values in both the convective and stratiform regions. Three-ice schemes produce more high reflectivity values in convective regions, while 2-ice schemes produce more high reflectivity values in stratiform regions. In addition, this study has demonstrated that the radar-based convective/stratiform partitioning algorithm can reasonably identify WRF-simulated precipitation, wind, and microphysical fields in both convective and stratiform regions.

  5. Micronutrient density and stability in West African pearl millet – potential for biofortification

    DEFF Research Database (Denmark)

    Bürger, Anna; Jensen, Henning Høgh; Gondah, Jadah

    2014-01-01

    Pearl millet (Cenchrus americanus (L.) Morrone) is one of the most important cereals in West and Central Africa (WCA). Human populations in WCA are strongly affected by micronutrient deficiencies. Biofortification, the development of pearl millet varieties with enhanced micronutrient levels...... among minerals and agro morphological traits. The study included 72 WCA pearl millet genotypes which were grown in three environments in Niger, contrasting in soil fertilization. Significant genotypic effects, moderate estimates of heritability, and genetic variation for mineral densities, especially...

  6. Climatic variations in tropical West African rainfall and the implications for military planners

    OpenAIRE

    Montgomery, Christi S.

    2008-01-01

    We have identified statistical and dynamical relationships between summer rainfall variations in tropical West Africa (TWA) and El NinÌ o/La NinÌ a (ENLN) events in the tropical Pacific. Our primary data sets were the National Centers for Environmental Prediction / National Center for Atmospheric Research reanalysis fields and the Multivariate ENSO Index (MEI) for the period 1970- 2007. Correlations of TWA rainfall and MEI time series showed that high (low) TWA rainfall was significantl...

  7. Factor structure of PTSD symptoms among West and Central African refugees.

    Science.gov (United States)

    Rasmussen, Andrew; Smith, Hawthorne; Keller, Allen S

    2007-06-01

    Although trauma is widespread in Africa, Africans are unrepresented in the literature on posttraumatic stress disorder (PTSD). The authors used confirmatory factor analysis of responses to the Harvard Trauma Questionnaire to model PTSD symptom structure in a sample of African refugees presenting at a U.S. torture treatment clinic. They tested four models that are proposed in the literature and one based on their clinical experience in which some symptoms of hyperarousal were integrated into intrusion. Their findings support a preference for a 4-factor aroused intrusion model. Discussion focuses on interpretation of models, the role of numbing and avoidance, and the limitations of Euro American symptoms in non-Euro American populations.

  8. Solar quiet day ionospheric source current in the West African region

    OpenAIRE

    Theresa N. Obiekezie; Okeke, Francisca N.

    2013-01-01

    The Solar Quiet (Sq) day source current were calculated using the magnetic data obtained from a chain of 10 magnetotelluric stations installed in the African sector during the French participation in the International Equatorial Electrojet Year (IEEY) experiment in Africa. The components of geomagnetic field recorded at the stations from January–December in 1993 during the experiment were separated into the source and (induced) components of Sq using Spherical Harmonics Analysis (SHA) method....

  9. Health-Needs Assessment for West African Immigrants in Greater Providence, RI.

    Science.gov (United States)

    Adu-Boahene, Akosua Boadiwaa; Laws, Michael Barton; Dapaah-Afriyie, Kwame

    2017-01-06

    African immigrants in the United States may experience barriers to health-care access and effectiveness. This mixed-methods study used paper-based surveys of people (N=101) in the target population from Nigeria, Ghana, and Liberia, recruited through convenience and snowball sampling. Semi-structured interviews were conducted with 3 clergy members who pastor churches with large Nigerian, Ghanaian, and Liberian populations, respectively; and five physicians and a clinical pharmacist who serve African immigrants. Length of stay in the United States was associated with the health status of refugee children. Undocumented immigration status was associated with lack of health insurance. Cardiovascular diseases, uterine fibroids and stress-related disorders were the most prevalent reported conditions. Regardless of English fluency, many immigrants are unfamiliar with medical terminology. African immigrants in the state of Rhode Island need more health education and resources to navigate the US health-care system. [Full article available at http://rimed.org/rimedicaljournal-2017-01.asp].

  10. Institutional development: from legal pluralism to institutional bricolage in West African pastoralism.

    Science.gov (United States)

    Fokou, G; Bonfoh, B

    2016-11-01

    Pastoralists in Africa are increasingly vulnerable to the effects of globalisation, climate change and changes in land use. They are confronted with problems related to access to scarce natural resources and their regulation, the management of mobility, and too little investment in health systems, livestock production and social service delivery. However, this paper focuses on positive trends and vital innovations in pastoral societies. These rely on robust institutions and policy frameworks that contribute to economically secure, politically stable, and environmentally sustainable livelihoods for African pastoral societies. The authors analyse ways in which internal and external efforts can improve the economic viability and social aspects of pastoralism. The institutions that manage natural resources and their effects on livelihoods and access to social services must be critically reviewed. The authors suggest that a new model for the economic and social development of African pastoralism should be positioned between donor- or governmentdriven development (in other words, 'seeing like a state') and the autonomous development goals of pastoralists ('seeing like a pastoralist'). Pastoralists are resourceful, entrepreneurial and innovative people, fully able to support new institutional systems and services which recognise their way of life and production systems. It seems evident that African pastoralism will maintain its vitality and creativity through a process of 'bricolage', with institutional and policy innovations based on a constant renegotiation of norms, the reinvention or transformation of tradition, the importance of legitimate authority and the role of the people themselves in shaping such arrangements.

  11. Reviving the African Wolf Canis lupus lupaster in North and West Africa: A Mitochondrial Lineage Ranging More than 6,000 km Wide

    Science.gov (United States)

    Gaubert, Philippe; Bloch, Cécile; Benyacoub, Slim; Abdelhamid, Adnan; Pagani, Paolo; Djagoun, Chabi Adéyèmi Marc Sylvestre; Couloux, Arnaud; Dufour, Sylvain

    2012-01-01

    The recent discovery of a lineage of gray wolf in North-East Africa suggests the presence of a cryptic canid on the continent, the African wolf Canis lupus lupaster. We analyzed the mtDNA diversity (cytochrome b and control region) of a series of African Canis including wolf-like animals from North and West Africa. Our objectives were to assess the actual range of C. l. lupaster, to further estimate the genetic characteristics and demographic history of its lineage, and to question its taxonomic delineation from the golden jackal C. aureus, with which it has been considered synonymous. We confirmed the existence of four distinct lineages within the gray wolf, including C. lupus/familiaris (Holarctic wolves and dogs), C. l. pallipes, C. l. chanco and C. l. lupaster. Taxonomic assignment procedures identified wolf-like individuals from Algeria, Mali and Senegal, as belonging to C. l. lupaster, expanding its known distribution c. 6,000 km to the west. We estimated that the African wolf lineage (i) had the highest level of genetic diversity within C. lupus, (ii) coalesced during the Late Pleistocene, contemporaneously with Holarctic wolves and dogs, and (iii) had an effective population size of c. 80,000 females. Our results suggest that the African wolf is a relatively ancient gray wolf lineage with a fairly large, past effective population size, as also suggested by the Pleistocene fossil record. Unique field observations in Senegal allowed us to provide a morphological and behavioral diagnosis of the African wolf that clearly distinguished it from the sympatric golden jackal. However, the detection of C. l. lupaster mtDNA haplotypes in C. aureus from Senegal brings the delineation between the African wolf and the golden jackal into question. In terms of conservation, it appears urgent to further characterize the status of the African wolf with regard to the African golden jackal. PMID:22900047

  12. Reviving the African wolf Canis lupus lupaster in North and West Africa: a mitochondrial lineage ranging more than 6,000 km wide.

    Directory of Open Access Journals (Sweden)

    Philippe Gaubert

    Full Text Available The recent discovery of a lineage of gray wolf in North-East Africa suggests the presence of a cryptic canid on the continent, the African wolf Canis lupus lupaster. We analyzed the mtDNA diversity (cytochrome b and control region of a series of African Canis including wolf-like animals from North and West Africa. Our objectives were to assess the actual range of C. l. lupaster, to further estimate the genetic characteristics and demographic history of its lineage, and to question its taxonomic delineation from the golden jackal C. aureus, with which it has been considered synonymous. We confirmed the existence of four distinct lineages within the gray wolf, including C. lupus/familiaris (Holarctic wolves and dogs, C. l. pallipes, C. l. chanco and C. l. lupaster. Taxonomic assignment procedures identified wolf-like individuals from Algeria, Mali and Senegal, as belonging to C. l. lupaster, expanding its known distribution c. 6,000 km to the west. We estimated that the African wolf lineage (i had the highest level of genetic diversity within C. lupus, (ii coalesced during the Late Pleistocene, contemporaneously with Holarctic wolves and dogs, and (iii had an effective population size of c. 80,000 females. Our results suggest that the African wolf is a relatively ancient gray wolf lineage with a fairly large, past effective population size, as also suggested by the Pleistocene fossil record. Unique field observations in Senegal allowed us to provide a morphological and behavioral diagnosis of the African wolf that clearly distinguished it from the sympatric golden jackal. However, the detection of C. l. lupaster mtDNA haplotypes in C. aureus from Senegal brings the delineation between the African wolf and the golden jackal into question. In terms of conservation, it appears urgent to further characterize the status of the African wolf with regard to the African golden jackal.

  13. Reviving the African wolf Canis lupus lupaster in North and West Africa: a mitochondrial lineage ranging more than 6,000 km wide.

    Science.gov (United States)

    Gaubert, Philippe; Bloch, Cécile; Benyacoub, Slim; Abdelhamid, Adnan; Pagani, Paolo; Djagoun, Chabi Adéyèmi Marc Sylvestre; Couloux, Arnaud; Dufour, Sylvain

    2012-01-01

    The recent discovery of a lineage of gray wolf in North-East Africa suggests the presence of a cryptic canid on the continent, the African wolf Canis lupus lupaster. We analyzed the mtDNA diversity (cytochrome b and control region) of a series of African Canis including wolf-like animals from North and West Africa. Our objectives were to assess the actual range of C. l. lupaster, to further estimate the genetic characteristics and demographic history of its lineage, and to question its taxonomic delineation from the golden jackal C. aureus, with which it has been considered synonymous. We confirmed the existence of four distinct lineages within the gray wolf, including C. lupus/familiaris (Holarctic wolves and dogs), C. l. pallipes, C. l. chanco and C. l. lupaster. Taxonomic assignment procedures identified wolf-like individuals from Algeria, Mali and Senegal, as belonging to C. l. lupaster, expanding its known distribution c. 6,000 km to the west. We estimated that the African wolf lineage (i) had the highest level of genetic diversity within C. lupus, (ii) coalesced during the Late Pleistocene, contemporaneously with Holarctic wolves and dogs, and (iii) had an effective population size of c. 80,000 females. Our results suggest that the African wolf is a relatively ancient gray wolf lineage with a fairly large, past effective population size, as also suggested by the Pleistocene fossil record. Unique field observations in Senegal allowed us to provide a morphological and behavioral diagnosis of the African wolf that clearly distinguished it from the sympatric golden jackal. However, the detection of C. l. lupaster mtDNA haplotypes in C. aureus from Senegal brings the delineation between the African wolf and the golden jackal into question. In terms of conservation, it appears urgent to further characterize the status of the African wolf with regard to the African golden jackal.

  14. Illegal Chinese Fishing in West African Waters : A study on Chinese IUU Activities and its Consequences to Socio-Ecological Systems

    OpenAIRE

    Dobo, Avital

    2009-01-01

    West African fisheries, considered as one of the most productive in the world, have been subjected to stress by distant fishing fleets since the 1950’s. The introduction of Exclusive Economic Zones by the United Nations in the 1970’s made it possible for these fleets to fish only under fishing agreements signed with a hosting land, provided that they will harvest the surplus left by the local fishing fleet. In the last two decades, China has emerged as an important fishing nation in West Afri...

  15. Statistical modeling of the abundance of vectors of West African Rift Valley fever in Barkedji, Senegal.

    Directory of Open Access Journals (Sweden)

    Cheikh Talla

    Full Text Available Rift Valley fever is an emerging mosquito-borne disease that represents a threat to human and animal health. The exophilic and exophagic behavior of the two main vector in West Africa (Aedes vexans and Culex poicilipes, adverse events post-vaccination, and lack of treatment, render ineffective the disease control. Therefore it is essential to develop an information system that facilitates decision-making and the implementation of adaptation strategies. In East Africa, RVF outbreaks are linked with abnormally high rainfall, and can be predicted up to 5 months in advance by modeling approaches using climatic and environmental parameters. However, the application of these models in West Africa remains unsatisfactory due to a lack of data for animal and human cases and differences in the dynamics of the disease emergence and the vector species involved in transmission. Models have been proposed for West Africa but they were restricted to rainfall impact analysis without a spatial dimension. In this study, we developed a mixed Bayesian statistical model to evaluate the effects of climatic and ecological determinants on the spatiotemporal dynamics of the two main vectors. Adult mosquito abundance data were generated from July to December every fortnight in 2005-2006 at 79 sites, including temporary ponds, bare soils, shrubby savannah, wooded savannah, steppes, and villages in the Barkédji area. The results demonstrate the importance of environmental factors and weather conditions for predicting mosquito abundance. The rainfall and minimum temperature were positively correlated with the abundance of Cx. poicilipes, whereas the maximum temperature had negative effects. The rainfall was negatively correlated with the abundance of Ae. vexans. After combining land cover classes, weather conditions, and vector abundance, our model was used to predict the areas and periods with the highest risks of vector pressure. This information could support decision

  16. Trends and Variability in Pastoral Resources in the West African Sahel

    Science.gov (United States)

    Hanan, N. P.

    2014-12-01

    The geography of water and nutrients in the savannas of West Africa has shaped the development of a system of migratory cattle movements ("transhumance") in which herds travel north during the rainy season to graze the nutritious grasslands of the Sahel and return south in the dry season to graze in fallow lands and on agricultural residue. Cattle in this system gain most of their body mass while grazing in the Sahel and frequently lose mass on their dry season range. The Sahel is, therefore, at the heart of extensive livestock production systems in West Africa. However, there is increasing concern regarding how climate change will impact the region, while human population growth and economic development require increased agricultural and livestock production. The future for pastoral production systems in West Africa is, therefore, uncertain. This presentation combines remote sensing of vegetation structure and phenology with a watershed-scale tree-grass ecohydrology model, to explore how key resources for Sahelian pastoralist communities (forage and surface water for livestock, woody biomass for fuel) respond to climate variability and extreme events, conditioned by human management of grazing, fire and fuel-wood harvest. Mortality of woody species and loss of herbaceous cover during the Sahelian droughts of the 1970's and 1980's significantly perturbed vegetation dynamics and ecohydrological interactions, perturbations from which the region is still recovering. The re-greening and reforestation of the Sahel reported by many authors is, in part, an expression of this recovery. Future trajectories of change in pastoral resources in the Sahel, in particular forage availability and drinking water, are explored using climate change ensembles.

  17. Towards understanding the genetics of tolerance to low soil phosphorus conditions in West African pearl millet

    OpenAIRE

    Gemenet, Dorcus Chepkesis

    2015-01-01

    About two hundred and twenty three million people are undernourished in Sub-Saharan Africa (SSA) with 11 million people being food insecure in the Sahel region of West Africa (WA). A growing global population and climate change are expected to exacerbate this situation and present new challenges on global food production. Phosphate rock, a non-renewable resource is expected to be depleted in about 40-400 years depending on the source of information but a phosphorus (P) peak (where P demand ex...

  18. West African governance of marketplaces - a contemporary heritage of the "Dual-sex Political System"?

    DEFF Research Database (Denmark)

    Prag, Ebbe

    This paper discusses women’s governance of urban marketplaces in the southern West Africa. I investigate changes of women’s citizenship in public marketplaces and female leaders’ authority and influence on the governance of these political spaces focussing on the leader’ ability to produce...... and enforce rules and regulations. Furthermore, I discuss the definition, applicability and the appropriateness of the “hybrid governance” concept framing it with literature on state-formation processes, governance and legal processes. I apply a literature review of historical and recent material on women...

  19. Small businesses performance in West African border regions: Do social networks pay off?

    DEFF Research Database (Denmark)

    Kuepié, Mathias; Tenikué, Michel; Walther, Olivier

    This paper studies the link between economic performance and social networks in West Africa. Using first-hand data collected on 358 small-scale traders in five border markets between Niger, Nigeria and Benin, we are particularly interested in testing whether the most well-connected actors of trade...... networks are also the most successful in terms of monthly sales and profit. The paper shows that the overall economic performance of traders is affected by the socio-professional position of the actors with whom they are connected. While social ties with local religious leaders have no effect...

  20. Solar quiet day ionospheric source current in the West African region

    Directory of Open Access Journals (Sweden)

    Theresa N. Obiekezie

    2013-05-01

    Full Text Available The Solar Quiet (Sq day source current were calculated using the magnetic data obtained from a chain of 10 magnetotelluric stations installed in the African sector during the French participation in the International Equatorial Electrojet Year (IEEY experiment in Africa. The components of geomagnetic field recorded at the stations from January–December in 1993 during the experiment were separated into the source and (induced components of Sq using Spherical Harmonics Analysis (SHA method. The range of the source current was calculated and this enabled the viewing of a full year’s change in the source current system of Sq.

  1. Impact of uncertainties in parameterized cloud-microphysical processes on the simulated development of an idealized 2-D squall line

    Science.gov (United States)

    Michelson, Sara; Bao, Jian-Wen; Grell, Evelyn

    2016-04-01

    In this study, numerical model simulations of an idealized 2-D squall line are investigated using microphysics budget analysis. Four commonly-used microphysics schemes of various complexity are used in the simulations. Diagnoses of the source and sink terms of the hydrometeor budget equations reveal that the differences related to the assumptions of hydrometeor size-distributions between the schemes lead to the differences in the simulations due to the net effect of various microphysical processes on the interaction between latent heating/evaporative cooling and flow dynamics as the squall line develops. Results from this study also highlight the possibility that the advantage of double-moment formulations can be overshadowed by the uncertainties in the spectral definition of individual hydrometeor categories and spectrum-dependent microphysical processes.

  2. Numerical Simulation of Surface Energy and Water Balances over a Semiarid Grassland Ecosystem in the West African Savanna

    Directory of Open Access Journals (Sweden)

    Emmanuel Quansah

    2017-01-01

    Full Text Available To understand surface energy exchange processes over the semiarid regions in West Africa, numerical simulations of surface energy and water balances were carried out using a one-dimensional multilayer atmosphere-SOil-VEGetation (SOLVEG model for selected days of the dry and rainy seasons over a savanna grassland ecosystem in Sumbrungu in the Upper East region of Ghana. The measured Bowen ratio was used to partition the residual energy into the observed sensible heat flux (H and latent heat flux (LE in order to investigate the impact of the surface energy closure on model performance. The results showed that the model overall reproduced the diurnal changes in the observed energy fluxes, especially the net radiation (Rn, compared to half-hourly eddy covariance flux measurements, for the study periods. The performance measure in terms of the correlation coefficient (R, centred root mean square error (RMSE, and normalized standard deviation (σ between the simulated H and LE and their corresponding uncorrected observed values ranged between R = 0.63–0.99 and 0.83–0.94, RMSE = 0.88–1.25 and 0.88–1.92, and σ = 0.95–2.23 and 0.13–2.82 for the dry and rainy periods respectively, indicating a moderate to good model performance. The partitioning of H and LE by SOLVEG was generally in agreement with the observations during the dry period but showed clear discrepancies during the rainy period, particularly after rainfall events. Further sensitivity tests over longer simulation periods (e.g., 1 year are required to improve model performance and to investigate seasonal exchanges of surface energy fluxes over the West African Savanna ecosystems in more details.

  3. Unmet reproductive health needs among women in some West African countries: a systematic review of outcome measures and determinants.

    Science.gov (United States)

    Ayanore, Martin Amogre; Pavlova, Milena; Groot, Wim

    2016-01-16

    Identifying relevant measures of women's reproductive health needs is critical to improve women's chances of service utilization. The study aims to systematically review and analyze the adequacy of outcome measures and determinants applied in previous studies for assessing women reproductive health needs across West Africa. Evidence on outcomes and determinants of unmet reproductive health needs among women of childbearing age in diverse multicultural, religious, and ethnic settings in West African countries was systematically reviewed. The review included recent English language publications (from January 2009 - March 2014). Clinical studies particularly on obstetric care services and reproductive services in relation to HIV/AIDS were excluded. We acknowledge the possibility to have excluded non-English publications and yet-to-be-published articles related to the study aim and objectives. Outcomes and determinants were assessed and defined at three main levels; contraceptive use, obstetric care, and antenatal care utilization. Results show increasing unmet need for women's reproductive health needs. Socio-cultural norms and practices resulting in discontinuation of service use, economic constraints, travel distance to access services and low education levels of women were found to be key predictors of service utilization for contraception, antenatal and obstetric care services. Outcome measures were mainly assessed based on service utilization, satisfaction, cost, and quality of services available as core measures across the three levels assessed in this review. Evidence from this review indicates that currently applied measures of women's reproductive health needs might be inadequate in attaining best maternal outcomes since they appear rather broad. More support and research for developing and advancing context-related measures may help to improve women's maternal health.

  4. The impact of various browse feeds with different tannin content on the fecal shedding of Clostridium perfringens in West African dwarf sheep.

    Science.gov (United States)

    Aschfalk, A; Müller, W; Drochner, W

    2000-01-01

    In 1994 and 1995 leaves from eight browse feeds, containing tannins in different amounts (BF), were fed to West African Dwarf Sheep in Benin to evaluate their impact on Clostridium perfringens in the intestinal tract. An inhibitory impact of various BF on the growth of C. perfringens was assessed in in-vitro assays before, and thus a potential use of these leaves as a preventive diet against C. perfringens enterotoxemia in small ruminants was assumed. Surprisingly, an inhibitory impact of the BF on the shedding of C. perfringens in the feces of West African Dwarf Sheep could not be shown in seven of the eight BF examined. However, the pattern of inhibition of unlike C. perfringens toxovars may differ and a selective inhibitory impact of the BF Dialium guineense on C. perfringens toxovar D may be assumed.

  5. Baited camera survey of deep-sea demersal fishes of the West African oil provinces off Angola: 1200-2500m depth, East Atlantic Ocean.

    Science.gov (United States)

    Jamieson, Alan J; Linley, Thomas D; Craig, Jessica

    2017-08-01

    Deep-sea demersal fish surveys using baited cameras were undertaken in the West African oil provinces between 1297 m and 2453 m depth in 2002, 2005 and 2008. A total of 29 deployments amounting to 16,175 images encountered 31 species of bait attending deep-sea fish from 17 families. The extrapolated species richness was 34, indicating that the survey encountered over 90% of bait attending fish species in this area. The dominant species in the area were the morid Antimora rostrata, the synaphobranchids Synaphobranchus cf. kaupii and Simenchelys parasitica, the somniosid Centroscymnus coelolepis and the zoarcid Pachycara crassiceps. An unusually high diversity of bait attending macrourids was observed in addition to patchy aggregations of zoarcids. This study serves as baseline survey data on which to base future long-term environmental monitoring of fish populations in the vicinity of the West African oil provinces. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Statistical ensemble postprocessing for precipitation forecasting during the West African Monsoon

    Science.gov (United States)

    Vogel, Peter; Gneiting, Tilmann; Knippertz, Peter; Fink, Andreas H.; Schlüter, Andreas

    2017-04-01

    Precipitation forecasts for one up to several days are of high socioeconomic importance for agriculturally dominated societies in West Africa. In this contribution, we evaluate the performance of operational European Centre for Medium-Range Weather Forecasts (ECWMF) raw ensemble and statistically postprocessed against climatological precipitation forecasts for accumulation periods of 1 to 5 days for the monsoon periods (May to mid-October) from 2007 to 2014. We use Bayesian Model Averaging (BMA) and Ensemble Model Output Statistics (EMOS) as state-of-the-art postprocessing methods and verify against station and gridded Tropical Rainfall Measuring Mission (TRMM) observations. Based on a subset of past forecast—observation-pairs, statistical postprocessing corrects ensemble forecasts for biases and dispersion errors. For the midlatitudes, statistical postprocessing has demonstrated its added value for a wide range of meteorological quantities and this contribution is the first to apply it to precipitation forecasts over West Africa, where the high degree of convective organization at the mesoscale makes precipitation forecasts particularly challenging. The raw ECMWF ensemble predictions of accumulated precipitation are poor compared to climatological forecasts and exhibit strong dispersion errors and biases. For the Guinea Coast, we find a substantial wet bias of the ECMWF ensemble and more than every second ensemble forecast fails to capture the verifying observation within its forecast range. Postprocessed forecasts clearly outperform ECMWF raw ensemble forecasts by correcting for biases and dispersion errors, but disappointingly reveal only slight, if any, improvements compared to climatological forecasts. These results hold across verification regions and years, for 1 to 5-day accumulated precipitation forecasts, and for station and gridded observations. We investigate different spatial accumulation sizes from 0.25 x 0.25° to 5 x 2° longitude

  7. The hopes of West African refugees during resettlement in northern Sweden: a 6-year prospective qualitative study of pathways and agency thoughts

    OpenAIRE

    Anjum Tanvir M; Nordqvist Cecilia; Timpka Toomas

    2012-01-01

    Abstract Background Little is known about how positive phenomena can support resettlement of refugees in a new country. The aim of this study was to examine the hopeful thinking in a group of West African quota refugees at arrival and after 6 years in Sweden and compare these thoughts to the views of resettlement support professionals. Method The primary study population comprised 56 adult refugees and 13 resettlement professionals. Qualitative data were collected from the refugees by questio...

  8. "911" Among West African immigrants in New York City: a qualitative study of parents' disciplinary practices and their perceptions of child welfare authorities.

    Science.gov (United States)

    Rasmussen, Andrew; Akinsulure-Smith, Adeyinka; Chu, Tracy; Keatley, Eva

    2012-08-01

    Immigrant parents' perceptions of child protective services may have important implications for their engagement in public institutions that are central to their children's well being. The current study examined West African immigrants' perceptions of child welfare authorities and the role of disciplining and monitoring in these communities' meaning making. A multiethnic group of 59 West African immigrants (32 parents and 27 adolescent children) living in the United States were interviewed in 18 focus groups and eight individual interviews between December 2009 and July 2010. Data were analyzed using a grounded theory approach; strategies for rigor included triangulation (multiple interview formats, varied composition of groups, multiple coders for each transcript), verification (follow-up interviewing, feedback to community-based organizations), and auditability. Primary among parents' concerns were "911" (used to refer to the police and child protective authorities), the loss of collective child monitoring networks, and threats to their children posed by "American" values and neighborhood violence. Children were concerned with parents' close monitoring that resulted in boredom and a sense that parents did not recognize them for adhering to their families' values. Feedback from CBOs suggested that parents got their information about child protective policies from children but that although misinformed they were accurate in their negative assessment of contact. Not unlike in other urban populations, West African immigrants' disciplinary tactics are instrumental, oriented toward protecting their children from the multiple dangers perceived in their surroundings, but may also put them at risk for contact with child protective services. Results suggest that "911" results from a "loss spiral" (Hobfoll, 1989) that begins as West Africans resettle without collective child monitoring networks, leading to increased concern for their children's safety, and interacting with

  9. Compositional analysis and projected biofuel potentials from common West African agricultural residues

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe; Kádár, Zsófia; Schmidt, Jens Ejbye

    2014-01-01

    In recent years the focus on sustainable biofuel production from agricultural residues has increased considerably. However, the scientific work within this field has predominantly been concentrated upon bioresources from industrialised and newly industrialised countries, while analyses of the res......In recent years the focus on sustainable biofuel production from agricultural residues has increased considerably. However, the scientific work within this field has predominantly been concentrated upon bioresources from industrialised and newly industrialised countries, while analyses...... bioethanol (kg TS)−1 based on starch and cellulose alone due to their high starch content and low content of un-biodegradable lignin and ash. A complete biomass balance was done for each of the 13 residues, providing a basis for further research into the production of biofuels or biorefining from West...

  10. Long-term spatio-temporal changes in a West African bushmeat trade system.

    Science.gov (United States)

    McNamara, J; Kusimi, J M; Rowcliffe, J M; Cowlishaw, G; Brenyah, A; Milner-Gulland, E J

    2015-10-01

    Landscapes in many developing countries consist of a heterogeneous matrix of mixed agriculture and forest. Many of the generalist species in this matrix are increasingly traded in the bushmeat markets of West and Central Africa. However, to date there has been little quantification of how the spatial configuration of the landscape influences the urban bushmeat trade over time. As anthropogenic landscapes become the face of rural West Africa, understanding the dynamics of these systems has important implications for conservation and landscape management. The bushmeat production of an area is likely to be defined by landscape characteristics such as habitat disturbance, hunting pressure, level of protection, and distance to market. We explored (SSG, tense) the role of these four characteristics in the spatio-temporal dynamics of the commercial bushmeat trade around the city of Kumasi, Ghana, over 27 years (1978 to 2004). We used geographic information system methods to generate maps delineating the spatial characteristics of the landscapes. These data were combined with spatially explicit market data collected in the main fresh bushmeat market in Kumasi to explore the relationship between trade volume (measured in terms of number of carcasses) and landscape characteristics. Over time, rodents, specifically cane rats (Thryonomys swinderianus), became more abundant in the trade relative to ungulates and the catchment area of the bushmeat market expanded. Areas of intermediate disturbance supplied more bushmeat, but protected areas had no effect. Heavily hunted areas showed significant declines in bushmeat supply over time. Our results highlight the role that low intensity, heterogeneous agricultural landscapes can play in providing ecosystem services, such as bushmeat, and therefore the importance of incorporating bushmeat into ecosystem service mapping exercises. Our results also indicate that even where high bushmeat production is possible, current harvest levels may

  11. The p.Arg86Gln change in GARP2 (glutamic acid-rich protein-2) is a common West African-related polymorphism.

    Science.gov (United States)

    Gibriel, Abdullah A Y; Tate, Rothwelle J; Yu, Yongbin; Rawson-Lax, Emma; Hammer, Harold M; Tettey, Justice N A; Pyne, Nigel J; Converse, Carolyn A

    2013-02-15

    The aim of the present study is to probe the potential association between previously-reported GARP2 mutations and retinitis pigmentosa (RP) using Scottish RP patients and controls. Exons 4, 5 and 8 in DNA from blood or buccal samples (130 autosomal recessive and simplex RP patients, 31 controls) were amplified and analysed for single-strand conformational polymorphism by capillary electrophoresis (CE-SSCP) and confirmed by sequencing. The p.Arg86Gln mutation in exon 4 was found in just one patient (out of 130), and in 10 of the 31 unaffected subjects. All of these occurrences were in people of West African origin (patient and controls). Two polymorphisms in exon 5, p.His100Arg and p.Gly109Gly, and a c.534+20A>G change in the intronic region flanking the 3' end of exon 8 were also found not to be associated with RP. The Scottish population examined here had no mutations in the GARP2 exons surveyed that could be associated with RP. The p.Arg86Gln mutation actually appears to be a polymorphism common in ethnic West Africans and not associated with RP. This change may provide a useful marker for West African ancestry. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Dietary intake in Black British adults; an observational assessment of nutritional composition and the role of traditional foods in UK Caribbean and West African diets.

    Science.gov (United States)

    Goff, Louise M; Timbers, Louise; Style, Hannah; Knight, Annemarie

    2015-08-01

    Acculturation to the UK diet may contribute to the increased burden of non-communicable diseases in Black British communities. The present study aimed to assess nutritional composition and the contribution that traditional foods make to dietary intake in a group of UK-residing Caribbean and West African adults and to explore differences according to ethnicity and duration of residence. Observational study. Dietary intake was assessed using multiple, standardised triple-pass 24 h recalls and analysed using a nutritional composition database. Associations between sociodemographic variables and duration of residence with dietary intake were assessed using ANCOVA. London, UK, October 2011-December 2012. UK adults of Caribbean (n 50) or West African (n 83) ancestry, aged 18-75 years. The Caribbean participants were older and more likely to be born in the UK. After adjusting for age, sex and ethnicity, those who had been resident in the UK for the longest duration had significantly higher intakes of energy (Ptraditional cultural foods compared with the Caribbean diet, which was more reliant on 'Westernised' foods such as sugar-sweetened beverages. These results are novel in demonstrating dietary acculturation in UK adults of Caribbean and West African ancestry. We have provided detailed data regarding the role of traditional foods, presenting dietary information that may guide in individualising care for patients from these communities and improve the cultural sensitivity of public health strategies.

  13. Mesoscale Analysis of AN Intense Mid-Latitude Squall-Line System

    Science.gov (United States)

    Biggerstaff, Michael Irwin

    The kinematic structure of the mature phase of a mid-latitude squall-line system with a leading-line trailing stratiform-percipitation structure was examined using a unique set of composite data analyses. The broad-scale aspects of the storm system was determined from a composite of high-frequency rawinsonde, profiler, and surface mesonetwork data combined with several dual-Doppler analyses in a common framework attached to the moving storm. A higher-resolution, but spatially more limited, composite was constructed using eleven dual-Doppler analyses which provided detailed wind and precipitation information over the entire breadth of the northern half of the storm. Analysis from these two data sets revealed several aspects of the structure of squall-line systems that have not been documented previously. A deep layer of subsidence consisting of two separate, but vertically aligned, downdrafts driven by different mechanisms was found over the mid-to -low level radar-reflectivity minimum in the transition zone. Based on an analysis of the individual downdrafts observed in the near-instantaneous dual-Doppler syntheses, the upper-level and lower-level transition-zone downdrafts were found be the averaged effect of convective drafts in dissipating convective cells that were moving rearward relative to the front edge of the storm. The structure of the individual upper-level downdrafts suggested that they were a combination of dynamically forced gravity waves excited by the interaction of the penetrative updrafts with the stable ambient flow and other pressure forces associated with the rearward moving dissipating convective cells. Hydrometeor trajectories through the transition zone revealed that the hydrometeors in the reflectivity minimum were likely unaffected by the upper-level transition -zone downdraft. However, the mid-to-low level subsidence was important in the development of the reflectivity minimum through the sublimation of small ice crystals in the transition

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

    National Research Council Canada - National Science Library

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

    2017-01-01

    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...

  15. The impact of IMF conditionality on government health expenditure: A cross-national analysis of 16 West African nations.

    Science.gov (United States)

    Stubbs, Thomas; Kentikelenis, Alexander; Stuckler, David; McKee, Martin; King, Lawrence

    2017-02-01

    How do International Monetary Fund (IMF) policy reforms-so-called 'conditionalities'-affect government health expenditures? We collected archival documents on IMF programmes from 1995 to 2014 to identify the pathways and impact of conditionality on government health spending in 16 West African countries. Based on a qualitative analysis of the data, we find that IMF policy reforms reduce fiscal space for investment in health, limit staff expansion of doctors and nurses, and lead to budget execution challenges in health systems. Further, we use cross-national fixed effects models to evaluate the relationship between IMF-mandated policy reforms and government health spending, adjusting for confounding economic and demographic factors and for selection bias. Each additional binding IMF policy reform reduces government health expenditure per capita by 0.248 percent (95% CI -0.435 to -0.060). Overall, our findings suggest that IMF conditionality impedes progress toward the attainment of universal health coverage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Dust emissions in the West African heat trough. The role of the diurnal cycle and of extratropical disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Knippertz, P. [Inst. fuer Physik der Atmosphaere, Johannes Gutenberg-Univ. Mainz (Germany)

    2008-10-15

    The summertime West African heat trough (HT) is one of the most active dust sources in the world. A detailed case study during May/June 2006 based upon analyses from the European Centre for Medium-Range Weather Forecasts and a new Meteosat dust product illustrates two important mechanisms of dust emissions in this region: (1) The dry continental-scale HT circulation exhibits a strong diurnal cycle characterized by nocturnal low-level jets and downward mixing of momentum to the surface during the build-up of the planetary boundary layer in the morning. This leads to strong gusty surface winds and dust emission, mostly along the northern side of the HT, but also within the southerly monsoon flow. Transports lead to an accumulation of dust near the axis of the HT. (2) Triggered by a lee cyclogenesis south of the Atlas Mountains, the Intertropical Discontinuity that separates dry Saharan and moist monsoonal air shifts northward and allows deep moist convection to penetrate into the Sahara. The evaporation of precipitation in the dry desert air also generates strong gusty winds and dust emissions. This study helps to clarify the physical mechanisms for a previously discovered relation between the annual cycles of dustiness on one hand and near-surface convergence and gustiness on the other hand. (orig.)

  17. The impact of handpump corrosion on water quality in rural areas of West African sub-region.

    Science.gov (United States)

    Ibe, K M; Egereonu, U U; Sowa, A H O

    2002-08-01

    Water, even in its natural environment, contains some level of impurities. Water is nearly a universal solvent. It contains dissolved solids and gases, and hosts a number of micro-organisms. The exploitation of groundwater by means of boreholes for supplying small user groups and rural communities with water has been widely applied in certain parts of the world for several decades. In recent years this practice has spread all over the globe, and hundred of thousands of boreholes have been drilled to tap low-yield aquifers. It is evident that such boreholes require pumps for lifting the water. In developing countries these are usually handpumps, but solar as well as other systems with submersible pumps are also used, depending upon the energy sources available and the financial means of the beneficiaries. This article gives a general overview of groundwater quality with regard to its physico-chemical composition. The results presented originate from the experience gained from handpump equipped boreholes within the UNICEF through German Centre for Technical Education Transfer executed inter-regional UNDP-Handpumps Project in West African Regions. Particular attention is paid to presenting corrosion on the water quality of wells in terms of iron concentration and other parameters. Furthermore, the corrosion attack on galvanised iron, the effect of biofilms on the corrosion rate, and the difference between internal and external corrosion of rising mains are shown.

  18. Acculturation, economics and food insecurity among refugees resettled in the USA: a case study of West African refugees.

    Science.gov (United States)

    Hadley, Craig; Zodhiates, Ariel; Sellen, Daniel W

    2007-04-01

    To assess the occurrence and severity of food insecurity, and examine associations between food insecurity and measures of socio-economic status and indicators of acculturation. Structured interviews among a non-probability sample of West African refugees at baseline and 6 months' follow-up. Setting Mid-sized city in north-eastern USA. One hundred and one caregivers with children under the age of 5 years and who have been living the USA for fewer than 4 years. Food insecurity was indicated in approximately half of households (53%). The occurrence of food insecurity was associated with measures of socio-economic status such as income, employment status and participation in the Food Stamp Program (P Refugees are a potentially vulnerable group and our results echo others in suggesting a need for more thorough monitoring of the health and well-being of recently resettled refugees. These results also suggest that reliance on employment as the sole indicator of success in the resettlement process may be too narrow an indicator. Future research should focus on a wider range of measures of health and well-being.

  19. Preliminary investigation of haemoglobin polymorphism and association with morphometric traits in West African Dwarf goats in north central Nigeria

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    Abdulmojeed Yakubu

    2014-03-01

    Full Text Available The aim of this study was to characterize the genetic pool of the West African Dwarf (WAD goats using haemoglobin (Hb polymorphism, as well as the association of some morphological traits with the Hb variants. Blood samples were collected from a total of 104 mature goats of both sexes belonging to the WAD breed in north central Nigeria. The red cell lysates were subjected to cellulose acetate electrophoresis and specific staining procedure to reveal the band patterns of haemoglobin. Three co-dominant alleles, causing the presence of three genotypes (AA, AB and AC were detected among individual goats. The frequencies of the A, B and C alleles were 0.69, 0.30 and 0.01, respectively. The corresponding genotype frequencies for AA, AB and AC in the goat population were 0.37, 0.61 and 0.02, respectively. The discrepancy between the observed and the expected genotype number was significant (P0.05 by Hb variants. There is a need for further study encompassing more number of goats covering larger areas, use of DNA markers and their relationship with economic traits as well as performance study for detailed understanding of breed characteristics, conservation and genetic improvement of WAD goats in north central Nigeria.

  20. Semen characteristics and sperm morphological studies of the West African Dwarf Buck treated with Aloe vera gel extract

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    Oyeyemi Matthew Olugbenga

    2011-01-01

    Full Text Available Background: Aloe vera (Aloe barbadensis miller is an evergreen perennial plant widely used in modern herbal practice and is often available in proprietary herbal preparations.Objective: This study was designed to investigate the semen picture and spermatozoa morphology of West African Dwarf (WAD bucks treated with Aloe vera extract.Materials and Methods: Twelve sexually matured WAD bucks, weighing between 11 and 15 kg, were used for the study. The bucks were first used as control (pre-treatment and later as two groups of six animals each. The first six bucks received 10 mls of the 3% extract while the other six received 10 mls of the 4% of the extract for a 7 day period. Semen was collected from both the 3 and 4% extract treated bucks for the control (pre-treatment, on days eight (first week post-treatment and fifteen (second week post-treatment in each case using the electroejaculation method. The spermiogram of the bucks were investigated using standard procedures. Data obtained were analyzed using two way ANOVA and significance reported at p<0.05.Results: The continuous administration of Aloe vera extract significantly (p<0.05 reduced sperm concentration, motility and percentage livability and resulted in increased sperm abnormalities in the WAD buck.Conclusion: Aloe vera adversely affected the spermiogram of bucks. The plant can reduce fertility in male animals and is therefore not recommended for medicinal purpose in male animals especially those used for breeding.

  1. Comparison of West African and Congo Basin monkeypox viruses in BALB/c and C57BL/6 mice.

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    Christina L Hutson

    2010-01-01

    Full Text Available Although monkeypox virus (MPXV studies in wild rodents and non-human primates have generated important knowledge regarding MPXV pathogenesis and inferences about disease transmission, it might be easier to dissect the importance of virulence factors and correlates of protection to MPXV in an inbred mouse model. Herein, we compared the two clades of MPXV via two routes of infection in the BALB/c and C57BL/6 inbred mice strains. Our studies show that similar to previous animal studies, the Congo Basin strain of MPXV was more virulent than West African MPXV in both mouse strains as evidenced by clinical signs. Although animals did not develop lesions as seen in human MPX infections, localized signs were apparent with the foot pad route of inoculation, primarily in the form of edema at the site of inoculation; while the Congo Basin intranasal route of infection led to generalized symptoms, primarily weight loss. We have determined that future studies with MPXV and laboratory mice would be very beneficial in understanding the pathogenesis of MPXV, in particular if used in in vivo imaging studies. Although this mouse model may not suffice as a model of human MPX disease, with an appropriate inbred mouse model, we can unravel many unknown aspects of MPX pathogenesis, including virulence factors, disease progression in rodent hosts, and viral shedding from infected animals. In addition, such a model can be utilized to test antivirals and the next generation of orthopoxvirus vaccines for their ability to alter the course of disease.

  2. Semen characteristics and sperm morphological studies of the West African Dwarf Buck treated with Aloe vera gel extract

    Science.gov (United States)

    Olugbenga, Oyeyemi Matthew; Olukole, Samuel Gbadebo; Adeoye, Ajayi Tolulope; Adejoke, Adeniji Deborah

    2011-01-01

    Background: Aloe vera (Aloe barbadensis miller) is an evergreen perennial plant widely used in modern herbal practice and is often available in proprietary herbal preparations. Objective: This study was designed to investigate the semen picture and spermatozoa morphology of West African Dwarf (WAD) bucks treated with Aloe vera extract. Materials and Methods: Twelve sexually matured WAD bucks, weighing between 11 and 15 kg, were used for the study. The bucks were first used as control (pre-treatment) and later as two groups of six animals each. The first six bucks received 10 mls of the 3% extract while the other six received 10 mls of the 4% of the extract for a 7 day period. Semen was collected from both the 3 and 4% extract treated bucks for the control (pre-treatment), on days eight (first week post-treatment) and fifteen (second week post-treatment) in each case using the electroejaculation method. The spermiogram of the bucks were investigated using standard procedures. Data obtained were analyzed using two way ANOVA and significance reported at p<0.05. Results: The continuous administration of Aloe vera extract significantly (p<0.05) reduced sperm concentration, motility and percentage livability and resulted in increased sperm abnormalities in the WAD buck. Conclusion: Aloe vera adversely affected the spermiogram of bucks. The plant can reduce fertility in male animals and is therefore not recommended for medicinal purpose in male animals especially those used for breeding. PMID:25587252

  3. Epidemiology of pertussis in a West African community before and after introduction of a widespread vaccination program.

    Science.gov (United States)

    Préziosi, Marie-Pierre; Yam, Abdoulaye; Wassilak, Steven G F; Chabirand, Laurence; Simaga, Aminata; Ndiaye, Malick; Dia, Marème; Dabis, François; Simondon, François

    2002-05-15

    The control of pertussis remains a worldwide concern. Little has been documented about its epidemiology in Africa. The authors have studied pertussis in a prospective cohort of children in a rural West African community over a 13-year period comprising time before and after introduction of a vaccination program. Children under age 15 years who were residents of the Niakhar study area in Senegal were followed prospectively between January 1984 and December 1996 for the occurrence of pertussis. Morbidity and mortality rates were extremely high before the launch of immunization. Crude incidence was 183 per 1,000 child-years at risk under age 5 years, with a 2.8% case-fatality rate. After the introduction of the vaccination program, overall incidence dropped rapidly and dramatically-by 27% after 3 years and 46% after 6 years. The decline in incidence involved all age groups but was most substantial in the group under age 5 years and was particularly pronounced in unvaccinated infants. The median age of acquisition of the disease rose steadily with population vaccine coverage. This study shows the tremendous magnitude of the disease burden in children and the rapid decline after vaccination, and it suggests a strong herd-immunity effect.

  4. Distribution of Porcine Haemal Nodes and Morphological Variations in the Haemal Nodes of Cattle and West African Dwarf Goats

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    Anietie Francis UDOUMOH

    2016-12-01

    Full Text Available Apparently healthy, non-lactating, non-gravid adult large white pigs (15, adult cattle (10 and adult West African Dwarf (WAD goats of either genders were used to investigate the morphology of haemal nodes using gross anatomical and histological techniques. The results demonstrated that the haemal nodes of pigs occurred in the thoracic, abdominal and pelvic regions along the course of blood vessels. The ranges of the longest diameters of the dark brown organs were 6.1 – 30.3 cm in pigs, 4.1 – 18.7 cm in cattle and 2.7 – 8.2 cm in WAD goats. Bovine haemal nodes showed cortical and medullary parenchymal areas, with the cortex demonstrating primary and secondary lymphoid follicles in a circumferential fashion. The medulla showed blood filled medullary sinusoids and medullary cords. In WAD goat, the reticular cells and smooth muscle cells of the capsule were oriented in different directions and the subcapsular, cortical and medullary sinusoids exhibited erythrocytes in pockets. In conclusion, the present study has provided information on the distribution of haemal nodes in pigs as well as other unique morphological features of cattle and WAD goat haemal nodes that could aid their identification and suggest their roles in the body.

  5. Large scale prediction of soil properties in the West African yam belt based on mid-infrared soil spectroscopy

    Science.gov (United States)

    Baumann, Philipp; Lee, Juhwan; Paule Schönholzer, Laurie; Six, Johan; Frossard, Emmanuel

    2016-04-01

    Yam (Dioscorea sp.) is an important staple food in West Africa. Fertilizer applications have variable effects on yam tuber yields, and a management option solely based on application of mineral NPK fertilizers may bear the risk of increased organic matter mineralization. Therefore, innovative and sustainable nutrient management strategies need to be developed and evaluated for yam cultivation. The goal of this study was to establish a mid-infrared soil spectroscopic library and models to predict soil properties relevant to yam growth. Soils from yam fields at four different locations in Côte d'Ivoire and Burkina Faso that were representative of the West African yam belt were sampled. The project locations ranged from the humid forest zone (5.88 degrees N) to the northern Guinean savannah (11.07 degrees N). At each location, soils of 20 yam fields were sampled (0-30 cm). For the location in the humid forest zone additional 14 topsoil samples from positions that had been analyzed in the Land Degradation Surveillance Framework developed by ICRAF were included. In total, 94 soil samples were analyzed using established reference analysis protocols. Besides soils were milled and then scanned by fourier transform mid-infrared spectroscopy in the range between 400 and 4000 reciprocal cm. Using partial least squares (PLS) regression, PLS1 calibration models that included soils from the four locations were built using two thirds of the samples selected by Kennard-Stones sampling algorithm in the spectral principal component space. Models were independently validated with the remaining data set. Spectral models for total carbon, total nitrogen, total iron, total aluminum, total potassium, exchangeable calcium, and effective cation exchange capacity performed very well, which was indicated by R-squared values between 0.8 and 1.0 on both calibration and validation. For these soil properties, spectral models can be used for cost-effective, rapid, and accurate predictions

  6. Analysis of ten year return period floods in west african rivers

    Science.gov (United States)

    Nka Nnomo, Bernadette; Oudin, Ludovic; Paturel, Jean Emmanuel; Karambiri, Harouna; Ribstein, Pierre

    2014-05-01

    In West Africa, flood and flow are usually determined by using methods advocated by the FAO (1996) and developed by ORSTOM and CIEH researchers in the 1960s. However, the 1970s, 1980s, 1990s decades were 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 led to a substantial increase of floods in some catchments. More recently, studies pointed out an increase in the frequency of intense rainfall events and an increase of flood events. Consequently, the reliability of conventional methods for flood estimation is questionable. In this work, we analyzed the trends of the ten-year return period rainfall and stream flow events for several catchments in the Sahelian and Sudanian regions. We used eleven tributaries of large river basins (Niger, Nakambe, Senegal, Gambia) for which daily rainfall and flow data were collected from national hydrological services of four countries over West Africa (Burkina Faso, Mali, Niger, Senegal). The conjoint use of rainfall and flow data allowed us to analyze the possible causality link between the two variables. Mann-Kendall, Pettitt and Hubert tests were used to detect trends and abrupt change points in the annual maximum time series.The quantification of change was assessed by computing 10-year return period rain and flow values on sliding sub periods in the long-term maxima time series with the GEV distribution. Trend tests on annual maximum flows time series showed mixed results depending on the location of the catchments: generally speaking, a decrease is observed for Sudanian catchments and an increase is observed for Sahelian catchments. On a period of 50 years (1950 - 2010) we pointed out an increase of 72% of the mean value of flood 10-year return period for a station like Kakassi in the sahelian region, with respect to the period before the detected disruption; while for a soudanian catchment like Fadougou, the average

  7. A Record of Early to Middle Holocene Hydroclimate Variability from the West African Sahel

    Science.gov (United States)

    McIntosh, R.; Douglas, P. M.; Warren, C.; Meyers, S. R.; Coutros, P.; Park, D. P.

    2011-12-01

    The African Humid Period (ca. 14.8 to 5.5 ka) is an interval of wet climates across northwest Africa, with evidence for widespread lake basins and savannah vegetation in areas that are now desert. There are few high-resolution continental records of hydrologic variability during the African humid period however. In particular, it remains uncertain how periods of north Atlantic climate variability were expressed in northwest Africa. We present results from a 5.4 meter sediment core from Lake Fati in northern Mali (16.29° N, 3.71° W), which represents the first lake sediment core from the western Sahel. The Lake Fati core contains a continuous record of lake mud from 10.43 to 4.66 kyr BP. Centimeter scale XRF scanning indicates strong covariation between iron, calcium, manganese and phosphorous abundance due to enrichment of these elements during periods of enhanced deposition of authigenic siderite. Preliminary oxygen isotope measurements indicate that authigenic siderite δ18O values are positively correlated with Fe counts, suggesting that siderite deposition increased during drier periods with greater evaporation of lake waters. These drying events occurred on decadal to centennial time scales, with higher-frequency variability during the early Holocene. Peaks in zirconium and titanium abundance coincide with some of the inferred dry periods, suggesting that deposition of aeolian silt coincided with periods of increased evaporation of lake water. A roughly 30 year interval of sand deposition at ~8.33 kyr BP suggests major drying and activation of aeolian sand deposition. This abrupt climate change could be related to the 8.2 ka event in the North Atlantic; further efforts to refine the sediment core age model will constrain the relationship of this rapid drying to abrupt climate change in the North Atlantic. Aluminum and silicon counts co-vary for much of the lake Fati record, and are related to input of terrigenous sediment, primarily during seasonal flooding

  8. Lightning and Electric Field Structure of a Squall Line During TELEX

    Science.gov (United States)

    Macgorman, D.; Rust, D.; Bruning, E.; Ramig, N.; Apostolakopoulos, I.; Schuur, T.; Biggerstaff, M.; Straka, J.; Krehbiel, P.; Rison, B.; Hamlin, T.

    2004-12-01

    During the 2004 field program for the Thunderstorm Electrification and Lightning Experiment (TELEX), simultaneous electric field soundings, three-dimensional lightning mapping observations, high-resolution Doppler radar data, polarimetric radar data, and environmental soundings were acquired for several mesoscale convective systems, supercell storms, and non-severe thunderstorms. The overall data set was of particularly high quality for a squall line that produced frequent lightning in southern and central Oklahoma on the morning of 19 June 2004. A total of five balloon-borne electric field soundings were launched into the leading line of convection and into the trailing stratiform region. Two 5-cm wavelength mobile Doppler radars (SMART-R's) provided coordinated volume scans every 3 min throughout the period of operations. Furthermore, all operations were well within range of the 10-cm wavelength polarimetric radar and the three-dimensional lightning mapping array. This presentation will emphasize lightning mapping and electric field observations to characterize the electrical behavior of the convective line and the stratiform region.

  9. Changes in viral hepatitis B screening practices over time in West African HIV clinics.

    Science.gov (United States)

    Coffie, P A; Patassi, A; Doumbia, A; Bado, G; Messou, E; Minga, A; Allah-Kouadio, E; Zannou, D M; Seydi, M; Kakou, A R; Dabis, F; Wandeler, G

    2017-10-01

    We aimed to describe changes in hepatitis B screening practices over a 3-year period among HIV-infected patients in West Africa. A medical chart review was conducted in urban HIV treatment centers in Ivory Coast (3 sites), Benin, Burkina Faso, Senegal, and Togo (1 site each). Among patients who started antiretroviral treatment between 2010 and 2012, 100 per year were randomly selected from each clinic. Demographic, clinical, and laboratory data was collected using a standardized questionnaire. We assessed changes in the proportion of patients screened over time and identified predictors of screening in a multivariable logistic regression. A total of 2097 patients were included (median age: 37 years, 65.4% of women). Overall, 313 (14.9%) patients had been screened for hepatitis B, with an increase from 10.6% in 2010 to 18.9% in 2012 (P<0.001) and substantial differences across countries. In multivariable analysis, being aged over 45 years (adjusted odds ratio: 1.34 [1.01-1.77]) and having an income-generating activity (adjusted odds ratio: 1.82 [1.09-3.03]) were associated with screening for hepatitis B infection. Overall, 62 HIV-infected patients (19.8%, 95% confidence interval: 15.5-24.7) were HBsAg-positive and 82.3% of them received a tenofovir-containing drug regimen. Hepatitis B screening among HIV-infected patients was low between 2010 and 2012. The increasing availability of HBsAg rapid tests and tenofovir in first-line antiretroviral regimen should improve the rates of hepatitis B screening. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Development and validation of risk profiles of West African rural communities facing multiple natural hazards.

    Science.gov (United States)

    Asare-Kyei, Daniel; Renaud, Fabrice G; Kloos, Julia; Walz, Yvonne; Rhyner, Jakob

    2017-01-01

    West Africa has been described as a hotspot of climate change. The reliance on rain-fed agriculture by over 65% of the population means that vulnerability to climatic hazards such as droughts, rainstorms and floods will continue. Yet, the vulnerability and risk levels faced by different rural social-ecological systems (SES) affected by multiple hazards are poorly understood. To fill this gap, this study quantifies risk and vulnerability of rural communities to drought and floods. Risk is assessed using an indicator-based approach. A stepwise methodology is followed that combines participatory approaches with statistical, remote sensing and Geographic Information System techniques to develop community level vulnerability indices in three watersheds (Dano, Burkina Faso; Dassari, Benin; Vea, Ghana). The results show varying levels of risk profiles across the three watersheds. Statistically significant high levels of mean risk in the Dano area of Burkina Faso are found whilst communities in the Dassari area of Benin show low mean risk. The high risk in the Dano area results from, among other factors, underlying high exposure to droughts and rainstorms, longer dry season duration, low caloric intake per capita, and poor local institutions. The study introduces the concept of community impact score (CIS) to validate the indicator-based risk and vulnerability modelling. The CIS measures the cumulative impact of the occurrence of multiple hazards over five years. 65.3% of the variance in observed impact of hazards/CIS was explained by the risk models and communities with high simulated disaster risk generally follow areas with high observed disaster impacts. Results from this study will help disaster managers to better understand disaster risk and develop appropriate, inclusive and well integrated mitigation and adaptation plans at the local level. It fulfills the increasing need to balance global/regional assessments with community level assessments where major decisions

  11. Standardising visual control devices for tsetse flies: Central and West African species Glossina palpalis palpalis.

    Science.gov (United States)

    Kaba, Dramane; Zacarie, Tusevo; M'pondi, Alexis Makumyaviri; Njiokou, Flobert; Bosson-Vanga, Henriette; Kröber, Thomas; McMullin, Andrew; Mihok, Steve; Guerin, Patrick M

    2014-01-01

    Glossina palpalis palpalis (G. p. palpalis) is one of the principal vectors of sleeping sickness and nagana in Africa with a geographical range stretching from Liberia in West Africa to Angola in Central Africa. It inhabits tropical rain forest but has also adapted to urban settlements. We set out to standardize a long-lasting, practical and cost-effective visually attractive device that would induce the strongest landing response by G. p. palpalis for future use as an insecticide-impregnated tool in area-wide population suppression of this fly across its range. Trials were conducted in wet and dry seasons in the Ivory Coast, Cameroon, the Democratic Republic of Congo and Angola to measure the performance of traps (biconical, monoconical and pyramidal) and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a practical enumerator at these remote locations to compare landing efficiencies of devices. Independent of season and country, both phthalogen blue-black and blue-black-blue 1 m(2) targets covered with adhesive film proved to be as good as traps in phthalogen blue or turquoise blue for capturing G. p. palpalis. Trap efficiency varied (8-51%). There was no difference between the performance of blue-black and blue-black-blue 1 m(2) targets. Baiting with chemicals augmented the overall performance of targets relative to traps. Landings on smaller phthalogen blue-black 0.25 m(2) square targets were not significantly different from either 1 m(2) blue-black-blue or blue-black square targets. Three times more flies were captured per unit area on the smaller device. Blue-black 0.25 m(2) cloth targets show promise as simple cost effective devices for management of G. p. palpalis as they can be used for both control when impregnated with insecticide and for population sampling when covered with adhesive film.

  12. The socio-economic drivers of bushmeat consumption during the West African Ebola crisis

    Science.gov (United States)

    Arandjelovic, Mimi; Boesch, Lukas; Gatiso, Tsegaye; Grimes, Trokon; Kuehl, Hjalmar S.; Lormie, Menladi; Stephens, Colleen; Tweh, Clement; Junker, Jessica

    2017-01-01

    Bushmeat represents an important source of animal protein for humans in tropical Africa. Unsustainable bushmeat hunting is a major threat to wildlife and its consumption is associated with an increased risk of acquiring zoonotic diseases, such as Ebola virus disease (EVD). During the recent EVD outbreak in West Africa, it is likely that human dietary behavior and local attitudes toward bushmeat consumption changed in response to the crisis, and that the rate of change depended on prevailing socio-economic conditions, including wealth and education. In this study, we therefore investigated the effects of income, education, and literacy on changes in bushmeat consumption during the crisis, as well as complementary changes in daily meal frequency, food diversity and bushmeat preference. More specifically, we tested whether wealthier households with more educated household heads decreased their consumption of bushmeat during the EVD crisis, and whether their daily meal frequency and food diversity remained constant. We used Generalized Linear Mixed Models to analyze interview data from two nationwide household surveys across Liberia. We found an overall decrease in bushmeat consumption during the crisis across all income levels. However, the rate of bushmeat consumption in high-income households decreased less than in low-income households. Daily meal frequency decreased during the crisis, and the diversity of food items and preferences for bushmeat species remained constant. Our multidisciplinary approach to study the impact of EVD can be applied to assess how other disasters affect social-ecological systems and improve our understanding and the management of future crises. PMID:28282378

  13. The socio-economic drivers of bushmeat consumption during the West African Ebola crisis.

    Directory of Open Access Journals (Sweden)

    Isabel Ordaz-Németh

    2017-03-01

    Full Text Available Bushmeat represents an important source of animal protein for humans in tropical Africa. Unsustainable bushmeat hunting is a major threat to wildlife and its consumption is associated with an increased risk of acquiring zoonotic diseases, such as Ebola virus disease (EVD. During the recent EVD outbreak in West Africa, it is likely that human dietary behavior and local attitudes toward bushmeat consumption changed in response to the crisis, and that the rate of change depended on prevailing socio-economic conditions, including wealth and education. In this study, we therefore investigated the effects of income, education, and literacy on changes in bushmeat consumption during the crisis, as well as complementary changes in daily meal frequency, food diversity and bushmeat preference. More specifically, we tested whether wealthier households with more educated household heads decreased their consumption of bushmeat during the EVD crisis, and whether their daily meal frequency and food diversity remained constant. We used Generalized Linear Mixed Models to analyze interview data from two nationwide household surveys across Liberia. We found an overall decrease in bushmeat consumption during the crisis across all income levels. However, the rate of bushmeat consumption in high-income households decreased less than in low-income households. Daily meal frequency decreased during the crisis, and the diversity of food items and preferences for bushmeat species remained constant. Our multidisciplinary approach to study the impact of EVD can be applied to assess how other disasters affect social-ecological systems and improve our understanding and the management of future crises.

  14. Towards improved uptake of malaria chemoprophylaxis among West African travellers: identification of behavioural determinants

    Science.gov (United States)

    2013-01-01

    Background Malaria is a potentially lethal illness for which preventive measures are not optimally used among all travellers. Travellers visiting friends and relatives in their country of origin (VFRs) are known to use chemoprophylaxis less consistently compared to tourist travellers. In this study, factors explaining the low use of chemoprophylaxis were pursued to contribute to improving uptake of preventive measures among VFRs. Methods Following in-depth interviews with Ghanaians living in Amsterdam, a questionnaire was developed to assess which behavioural determinants were related to taking preventive measures. The questionnaire was administered at gates of departing flights from Schiphol International Airport, Amsterdam (the Netherlands) to Kotoka International Airport, Accra (Ghana). Results In total, 154 questionnaires were eligible for analysis. Chemoprophylaxis had been started by 83 (53.9%) and bought by 93 (60.4%) travellers. Pre-travel advice had been obtained by 104 (67.5%) travellers. Those who attended the pre-travel clinic and those who incorrectly thought they had been vaccinated against malaria were more likely to use preventive measures. Young-, business- and long-term travellers, those who had experienced malaria, and those who thought curing malaria was easier than taking preventive tablets were less likely to use preventive measures. Conclusion Almost half of the VFRs travelling to West Africa had not started chemoprophylaxis; therefore, there is room for improvement. Risk reduction strategies could aim at improving attendance to travel clinics and focus on young-, business and long term travellers and VFRs who have experienced malaria during consultation. Risk reduction strategies should focus on improving self-efficacy and conceptions of response efficacy, including social environment to aim at creating the positive social context needed. PMID:24107150

  15. A comparison of model ensembles for attributing 2012 West African rainfall

    Science.gov (United States)

    Parker, Hannah R.; Lott, Fraser C.; Cornforth, Rosalind J.; Mitchell, Daniel M.; Sparrow, Sarah; Wallom, David

    2017-01-01

    In 2012, heavy rainfall resulted in flooding and devastating impacts across West Africa. With many people highly vulnerable to such events in this region, this study investigates whether anthropogenic climate change has influenced such heavy precipitation events. We use a probabilistic event attribution approach to assess the contribution of anthropogenic greenhouse gas emissions, by comparing the probability of such an event occurring in climate model simulations with all known climate forcings to those where natural forcings only are simulated. An ensemble of simulations from 10 models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) is compared to two much larger ensembles of atmosphere-only simulations, from the Met Office model HadGEM3-A and from weather@home with a regional version of HadAM3P. These are used to assess whether the choice of model ensemble influences the attribution statement that can be made. Results show that anthropogenic greenhouse gas emissions have decreased the probability of high precipitation across most of the model ensembles. However, the magnitude and confidence intervals of the decrease depend on the ensemble used, with more certainty in the magnitude in the atmosphere-only model ensembles due to larger ensemble sizes from single models with more constrained simulations. Certainty is greatly decreased when considering a CMIP5 ensemble that can represent the relevant teleconnections due to a decrease in ensemble members. An increase in probability of high precipitation in HadGEM3-A using the observed trend in sea surface temperatures (SSTs) for natural simulations highlights the need to ensure that estimates of natural SSTs are consistent with observed trends in order for results to be robust. Further work is needed to establish how anthropogenic forcings are affecting the rainfall processes in these simulations in order to better understand the differences in the overall effect.

  16. Harmattan, Saharan heat low, and West African monsoon circulation: modulations on the Saharan dust outflow towards the North Atlantic

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    K. Schepanski

    2017-09-01

    Full Text Available The outflow of dust from the northern African continent towards the North Atlantic is stimulated by the atmospheric circulation over North Africa, which modulates the spatio-temporal distribution of dust source activation and consequently the entrainment of mineral dust into the boundary layer, as well as the transport of dust out of the source regions. The atmospheric circulation over the North African dust source regions, predominantly the Sahara and the Sahel, is characterized by three major circulation regimes: (1 the harmattan (trade winds, (2 the Saharan heat low (SHL, and (3 the West African monsoon circulation. The strength of the individual regimes controls the Saharan dust outflow by affecting the spatio-temporal distribution of dust emission, transport pathways, and deposition fluxes.This study aims at investigating the atmospheric circulation pattern over North Africa with regard to its role favouring dust emission and dust export towards the tropical North Atlantic. The focus of the study is on summer 2013 (June to August, during which the SALTRACE (Saharan Aerosol Long-range TRansport and Aerosol-Cloud interaction Experiment field campaign also took place. It involves satellite observations by the Spinning Enhanced Visible and InfraRed Imager (SEVIRI flying on board the geostationary Meteosat Second Generation (MSG satellite, which are analysed and used to infer a data set of active dust sources. The spatio-temporal distribution of dust source activation frequencies (DSAFs allows for linking the diurnal cycle of dust source activations to dominant meteorological controls on dust emission. In summer, Saharan dust source activations clearly differ from dust source activations over the Sahel regarding the time of day when dust emission begins. The Sahara is dominated by morning dust source activations predominantly driven by the breakdown of the nocturnal low-level jet. In contrast, dust source activations in the Sahel are

  17. Agricultural Production, Land-use/cover Change and the Desertification Debate in the West African Savannah: An Adapted Political Ecology Approach

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    Peter Kojo Boateng

    2013-10-01

    Full Text Available In the semi-arid tropics of West Africa where farming is the major livelihood source, it is claimed that African farmers are degrading their land: first because of shifting cultivation, later because population growth brought about “over-cultivation” or farm expansion and the scattering of more farms on the landscape.  In response to these issues, West African governments have emphasised the need and rolled out programmes for modernisation of smallholder agriculture through promotion of capital-intensive and market-driven strategies. Implicit in this modernisation policy orientation is the idea that the way production is organised by peasants in the semi-arid environments have to change; meaning poor peasants, regarded as perpetuators of land degradation, who may not produce for the market need to be modernised in line with the state’s vision of agricultural development and environmental management. However, new perspectives being generated from several local level studies of agricultural production and land-use/cover change in the semi-arid savannah regions of West Africa offer departure points from those dominant narratives of increasing degradation and desertification. This paper discusses this emerging paradigmatic revolution by reviewing the literature on 3 highly polarised issues around land-use/cover change in the West African savannah – (a discourses of environmental degradation; (b human-environment interactions and agricultural production; and (c mapping of land cover changes in drylands. Within these reviews, the paper highlights ways it move beyond currently contrasting views, before advancing an adapted political ecology framework deemed suited for exploring the complex relationships between agricultural production and land-use/cover change.

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

    Science.gov (United States)

    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

  19. New Seep Sites along the West-African Passive Margin Identified from Seismo-Acoustic Data

    Science.gov (United States)

    Fekete, N.; Spiess, V.; Caparachin, C.; Ding, F.; Gehrmann, R.; Riepshoff, H.; Trampe, A.; Foucher, J.-P.

    2009-04-01

    Recent and ongoing venting activity is documented offshore West Africa by large pockmarks, as has been observed by previous marine expeditions along the continental margin (e.g. Meteor Cruises M47/3 and M56). In summer 2008, an interdisciplinary campaign was carried out in cooperation between the MARUM Center for Marine Environmental Sciences in Bremen and IFREMER, Brest. The main scientific goal of the cruise was to assess the influence of different geological settings on the nature of venting and related features. Multi-frequency seismo-acoustic tools including swath bathymetry, sediment echosounder, flare imagery, and high-resolution multichannel seismics were utilized within the scope of geophysical studies for investigating the distribution of seep structures and associated subsurface feeder systems. Observations confirm a widespread occurrence of pockmarks along the continental margins of Gabon, Congo and Angola in deep water. Spatial surveys have further shown that venting-related features are present on different scales, particularly with sizes of tens of meters in diameter and topographical expressions on the meter scale. While these structures seem to be related to relatively shallow gas reservoirs, larger ones reveal roots to gas reservoirs in several hundred meters below the seafloor. At some sites, gas flares of a few hundred to over a thousand meters height could be identified within the water column. Comparing target areas north and south of the Congo Canyon, it has become evident that different driving forces and sedimentary and tectonic boundary conditions may be responsible for fluid venting and its distribution. While in the north, a thick sediment cover restricts seepage to selected zones of weakness and higher permeability, salt diapirism in the south is massively fracturing overlying sediments, creating numerous promising morphological features at the seafloor. However, only a few active vents could be found in the area of salt diapirism

  20. Standardising visual control devices for tsetse flies: Central and West African species Glossina palpalis palpalis.

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    Dramane Kaba

    Full Text Available BACKGROUND: Glossina palpalis palpalis (G. p. palpalis is one of the principal vectors of sleeping sickness and nagana in Africa with a geographical range stretching from Liberia in West Africa to Angola in Central Africa. It inhabits tropical rain forest but has also adapted to urban settlements. We set out to standardize a long-lasting, practical and cost-effective visually attractive device that would induce the strongest landing response by G. p. palpalis for future use as an insecticide-impregnated tool in area-wide population suppression of this fly across its range. METHODOLOGY/PRINCIPAL FINDINGS: Trials were conducted in wet and dry seasons in the Ivory Coast, Cameroon, the Democratic Republic of Congo and Angola to measure the performance of traps (biconical, monoconical and pyramidal and targets of different sizes and colours, with and without chemical baits, at different population densities and under different environmental conditions. Adhesive film was used as a practical enumerator at these remote locations to compare landing efficiencies of devices. Independent of season and country, both phthalogen blue-black and blue-black-blue 1 m(2 targets covered with adhesive film proved to be as good as traps in phthalogen blue or turquoise blue for capturing G. p. palpalis. Trap efficiency varied (8-51%. There was no difference between the performance of blue-black and blue-black-blue 1 m(2 targets. Baiting with chemicals augmented the overall performance of targets relative to traps. Landings on smaller phthalogen blue-black 0.25 m(2 square targets were not significantly different from either 1 m(2 blue-black-blue or blue-black square targets. Three times more flies were captured per unit area on the smaller device. CONCLUSIONS/SIGNIFICANCE: Blue-black 0.25 m(2 cloth targets show promise as simple cost effective devices for management of G. p. palpalis as they can be used for both control when impregnated with insecticide and for

  1. Late Cretaceous Turbidite Reservoirs Along the Equatorial West African Margin: An Industry Perspective on Source-to-Sink Relationships

    Science.gov (United States)

    Wilson, Jonathan; Kohlmann, Fabian; Nicoll, Graeme

    2017-04-01

    The source-to-sink mindset provides an important framework for the exploration geologist. It enables an integrated understanding of hinterland and basin, and can lead to subsurface risk mitigation, particularly with respect to predicting reservoir location and quality. Despite the numerous benefits associated with source-to-sink analysis, such studies are time-consuming to generate, encompassing a large array of disciplines and data, and are not routinely performed within the hydrocarbon industry. The discovery of several significant hydrocarbon fields along the equatorial West African margin has been followed by a series of expensive failures throughout the last decade associated with reservoir quality/presence. This paper discusses a case study focused on the equatorial West African margin, demonstrating how three well-known but effective approaches can be integrated to reconstruct source-to-sink relationships in an ancient sedimentary system, helping de-risk exploration efforts. The first step is to characterize the hinterland. To do this, detailed information was collected for two separate but interlinked datasets—mineral deposits and hard rock geochronology. Combined, these two datasets allow an understanding of the timing and nature of an areas tectonic evolution to be easily developed. The data can be used alongside stratigraphic data and geodynamic information from a plate tectonic model to reconstruct topography and bathymetry of the earth at different episodes of geological time. Paleo digital elevation models (PDEMs) give a first-order approximation of hinterland topography and therefore allow possible sediment source areas to be identified and potential sediment transport pathways to be visualized by means of the digital reconstruction of paleo-drainage networks and their attendant watersheds. This integrated global dataset of hinterland geochronology provides useful "source" information complemented by "sink" information contained within a detrital

  2. West African equatorial ionospheric parameters climatology based on Ouagadougou ionosonde station data from June 1966 to February 1998

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    F. Ouattara

    2009-06-01

    Full Text Available This study is the first which gives the climatology of West African equatorial ionosphere by using Ouagadougou station through three solar cycles. It has permitted to show the complete morphology of ionosphere parameters by analyzing yearly variation, solar cycle and geomagnetic activity, seasonal evolution and diurnal development. This work shows that almost all ionospheric parameters have 11-year solar cycle evolution. Seasonal variation shows that only foF2 exhibits annual, winter and semiannual anomaly. foF2 seasonal variation has permitted us to identify and characterize solar events effects on F2 layer in this area. In fact (1 during quiet geomagnetic condition foF2 presents winter and semiannual anomalies asymmetric peaks in March/April and October. (2 The absence of winter anomaly and the presence of equinoctial peaks are the most visible effects of fluctuating activity in foF2 seasonal time profiles. (3 Solar wind shock activity does not modify the profile of foF2 but increases ionization. (4 The absence of asymmetry peaks, the location of the peaks in March and October and the increase of ionization characterize recurrent storm activity. F1 layers shows increasing trend from cycle 20 to cycle 21. Moreover, E layer parameters seasonal variations exhibit complex structure. It seems impossible to detect fluctuating activity effect in E layer parameters seasonal variations but shock activity and wind stream activity act to decrease E layer ionization. It can be seen from Es layer parameters seasonal variations that wind stream activity effect is fairly independent of solar cycle. E and Es layers critical frequencies and virtual heights diurnal variations let us see the effects of the greenhouse gases in these layers.

  3. Studies on Zinc and Copper Ion in Relation to Wound Healing in Male and Female West African Dwarf Goats.

    Science.gov (United States)

    Olaifa, A K; Fadason, S T

    2017-03-06

    Wound healing remains a challenging clinical problem for which precise and efficient management is essential in order to curtail morbidity and mortality. Wound healing has been shown to depend upon the availability of appropriate trace elements like copper and zinc which serve as enzyme cofactors and structural components in tissue repair. This study aims at evaluating the distribution of zinc and copper found in the hair as well as skin during epidermal wound healing. Adult and healthy West African dwarf (WAD) goats of both sexes fed with concentrate, grass, cassava peel and water ad libitum were used. The animals were housed for three weeks before commencement of the experiments. Epidermal wounds were created on the trunks of all the goats using cardboard template of 1cm². Progressive changes in wound contraction were monitored grossly by placing clean and sterile venier calliper on the wound margin. Hair and skin elemental (copper and zinc) analyses were done using atomic absorption spectroscopy (AAS). Significant increases in Cu level were observed in the female hair compared with that of males. There were significant increases in the Zn levels of the females' hair compared with the males. The wound healed faster in female goat compared with the males. The ratio of copper to zinc is clinically more important than the concentration of either of these trace metals. The pattern of distribution between zinc and copper concentration in the skin and hair of the male and female goats observed in this study could be added factor responsible for early wound healing in female. Therefore, our findings suggest that the distribution in the Cu and Zinc level in skin and hair of both male and female goats could also be a factor for wound healing in the animals.

  4. Variability and Predictability of West African Droughts. A Review in the Role of Sea Surface Temperature Anomalies

    Science.gov (United States)

    Rodriguez-Fonseca, Belen; Mohino, Elsa; Mechoso, Carlos R.; Caminade, Cyril; Biasutti, Michela; Gaetani, Marco; Garcia-Serrano, J.; Vizy, Edward K.; Cook, Kerry; Xue, Yongkang; hide

    2015-01-01

    The Sahel experienced a severe drought during the 1970s and 1980s after wet periods in the 1950s and 1960s. Although rainfall partially recovered since the 1990s, the drought had devastating impacts on society. Most studies agree that this dry period resulted primarily from remote effects of sea surface temperature (SST) anomalies amplified by local land surface-atmosphere interactions. This paper reviews advances made during the last decade to better understand the impact of global SST variability on West African rainfall at interannual to decadal time scales. At interannual time scales, a warming of the equatorial Atlantic and Pacific/Indian Oceans results in rainfall reduction over the Sahel, and positive SST anomalies over the Mediterranean Sea tend to be associated with increased rainfall. At decadal time scales, warming over the tropics leads to drought over the Sahel, whereas warming over the North Atlantic promotes increased rainfall. Prediction systems have evolved from seasonal to decadal forecasting. The agreement among future projections has improved from CMIP3 to CMIP5, with a general tendency for slightly wetter conditions over the central part of the Sahel, drier conditions over the western part, and a delay in the monsoon onset. The role of the Indian Ocean, the stationarity of teleconnections, the determination of the leader ocean basin in driving decadal variability, the anthropogenic role, the reduction of the model rainfall spread, and the improvement of some model components are among the most important remaining questions that continue to be the focus of current international projects.

  5. Lower Cambrian-Ediacaran Paleogeography and True Polar Wander with New Paleomagnetic Constraints from West African Craton

    Science.gov (United States)

    Robert, B.; Besse, J.; Blein, O.; Greff-Lefftz, M.; Baudin, T.; Fernando, L.; Meslouh, S.; Belbadaoui, M.

    2014-12-01

    Paleomagnetic data from Laurentia and Baltica continents suggest fast large oscillations of the virtual geomagnetic poles (VGP) from high to low latitudes during the Ediacaran (635-542 Ma). These data are interpreted in the literature either as oscillations of the Earth magnetic dipole between polar and equatorial positions, or as True Polar Wander (TPW), implying a very fast tumbling of continents and perhaps, of whole Earth. In this study, we try to test these hypotheses by bringing new paleomagnetic data on volcanic series from another continent, the West African Craton (WAC). We have sampled well dated pyroclastic and lava flows from the Ouarzazate and Taroudant groups in the Anti-Atlas, (Morocco). 480 samples from 105 sites were thermally demagnetized in our laboratory. Our preliminary results highlight two major groups of directions, mainly carried by hematite, magnetite also contributing sometimes to the magnetization. The first group consists of a dual polarity high inclination direction that may represent the original magnetization. The observed paleolatitude is compatible with that predicted by the lower Cambrian-Ediacaran apparent polar wander path (APWP) of Gondwana, assuming that the WAC was already accreted to Gondwana at this age. Nevertheless, a complete agreement between our pole and the APWP needs a local rotation of around 80° on a vertical axis. The second group displays a single polarity direction, with a shallow inclination and a south-east declination. This direction is close to the expected direction derived from the Permo-Carboniferous segment of the Gondwana APWP, and may represent a remagnetization acquired during the Kiaman reversed polarity superchron. Our preliminary paleomagnetic results thus display large changes in the VGP position, as also evidenced by others on Baltica and Laurentia. However, their interpretation does not favor TPW episodes or equatorial Earth magnetic dipole during the lower Cambrian-Ediacaran periods, but

  6. Synergy in efficacy of fungal entomopathogens and permethrin against West African insecticide-resistant Anopheles gambiae mosquitoes.

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    Marit Farenhorst

    Full Text Available BACKGROUND: Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, against a laboratory colony and field population of West African insecticide-resistant Anopheles gambiae s.s. mosquitoes. METHODOLOGY/FINDINGS: A range of fungus-insecticide combinations was used to test effects of timing and sequence of exposure. Both the laboratory-reared and field-collected mosquitoes were highly resistant to permethrin but susceptible to B. bassiana and M. anisopliae infection, inducing 100% mortality within nine days. Combinations of insecticide and fungus showed synergistic effects on mosquito survival. Fungal infection increased permethrin-induced mortality rates in wild An. gambiae s.s. mosquitoes and reciprocally, exposure to permethrin increased subsequent fungal-induced mortality rates in both colonies. Simultaneous co-exposure induced the highest mortality; up to 70.3+/-2% for a combined Beauveria and permethrin exposure within a time range of one gonotrophic cycle (4 days. CONCLUSIONS/SIGNIFICANCE: Combining fungi and permethrin induced a higher impact on mosquito survival than the use of these control agents alone. The observed synergism in efficacy shows the potential for integrated fungus-insecticide control measures to dramatically reduce malaria transmission and enable control at more moderate levels of coverage even in areas where insecticide resistance has rendered pyrethroids essentially ineffective.

  7. Synergy in Efficacy of Fungal Entomopathogens and Permethrin against West African Insecticide-Resistant Anopheles gambiae Mosquitoes

    Science.gov (United States)

    Farenhorst, Marit; Knols, Bart G. J.; Thomas, Matthew B.; Howard, Annabel F. V.; Takken, Willem; Rowland, Mark; N’Guessan, Raphael

    2010-01-01

    Background Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, against a laboratory colony and field population of West African insecticide-resistant Anopheles gambiae s.s. mosquitoes. Methodology/Findings A range of fungus-insecticide combinations was used to test effects of timing and sequence of exposure. Both the laboratory-reared and field-collected mosquitoes were highly resistant to permethrin but susceptible to B. bassiana and M. anisopliae infection, inducing 100% mortality within nine days. Combinations of insecticide and fungus showed synergistic effects on mosquito survival. Fungal infection increased permethrin-induced mortality rates in wild An. gambiae s.s. mosquitoes and reciprocally, exposure to permethrin increased subsequent fungal-induced mortality rates in both colonies. Simultaneous co-exposure induced the highest mortality; up to 70.3±2% for a combined Beauveria and permethrin exposure within a time range of one gonotrophic cycle (4 days). Conclusions/Significance Combining fungi and permethrin induced a higher impact on mosquito survival than the use of these control agents alone. The observed synergism in efficacy shows the potential for integrated fungus-insecticide control measures to dramatically reduce malaria transmission and enable control at more moderate levels of coverage even in areas where insecticide resistance has rendered pyrethroids essentially ineffective. PMID:20711409

  8. Hierarchical multi-species modeling of carnivore responses to hunting, habitat and prey in a West African protected area.

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    A Cole Burton

    Full Text Available Protected areas (PAs are a cornerstone of global efforts to shield wildlife from anthropogenic impacts, yet their effectiveness at protecting wide-ranging species prone to human conflict--notably mammalian carnivores--is increasingly in question. An understanding of carnivore responses to human-induced and natural changes in and around PAs is critical not only to the conservation of threatened carnivore populations, but also to the effective protection of ecosystems in which they play key functional roles. However, an important challenge to assessing carnivore communities is the often infrequent and imperfect nature of survey detections. We applied a novel hierarchical multi-species occupancy model that accounted for detectability and spatial autocorrelation to data from 224 camera trap stations (sampled between October 2006 and January 2009 in order to test hypotheses about extrinsic influences on carnivore community dynamics in a West African protected area (Mole National Park, Ghana. We developed spatially explicit indices of illegal hunting activity, law enforcement patrol effort, prey biomass, and habitat productivity across the park, and used a Bayesian model selection framework to identify predictors of site occurrence for individual species and the entire carnivore community. Contrary to our expectation, hunting pressure and edge proximity did not have consistent, negative effects on occurrence across the nine carnivore species detected. Occurrence patterns for most species were positively associated with small prey biomass, and several species had either positive or negative associations with riverine forest (but not with other habitat descriptors. Influences of sampling design on carnivore detectability were also identified and addressed within our modeling framework (e.g., road and observer effects, and the multi-species approach facilitated inference on even the rarest carnivore species in the park. Our study provides insight for the

  9. Hierarchical multi-species modeling of carnivore responses to hunting, habitat and prey in a West African protected area.

    Science.gov (United States)

    Burton, A Cole; Sam, Moses K; Balangtaa, Cletus; Brashares, Justin S

    2012-01-01

    Protected areas (PAs) are a cornerstone of global efforts to shield wildlife from anthropogenic impacts, yet their effectiveness at protecting wide-ranging species prone to human conflict--notably mammalian carnivores--is increasingly in question. An understanding of carnivore responses to human-induced and natural changes in and around PAs is critical not only to the conservation of threatened carnivore populations, but also to the effective protection of ecosystems in which they play key functional roles. However, an important challenge to assessing carnivore communities is the often infrequent and imperfect nature of survey detections. We applied a novel hierarchical multi-species occupancy model that accounted for detectability and spatial autocorrelation to data from 224 camera trap stations (sampled between October 2006 and January 2009) in order to test hypotheses about extrinsic influences on carnivore community dynamics in a West African protected area (Mole National Park, Ghana). We developed spatially explicit indices of illegal hunting activity, law enforcement patrol effort, prey biomass, and habitat productivity across the park, and used a Bayesian model selection framework to identify predictors of site occurrence for individual species and the entire carnivore community. Contrary to our expectation, hunting pressure and edge proximity did not have consistent, negative effects on occurrence across the nine carnivore species detected. Occurrence patterns for most species were positively associated with small prey biomass, and several species had either positive or negative associations with riverine forest (but not with other habitat descriptors). Influences of sampling design on carnivore detectability were also identified and addressed within our modeling framework (e.g., road and observer effects), and the multi-species approach facilitated inference on even the rarest carnivore species in the park. Our study provides insight for the conservation

  10. Comparison of a flow assay for brucellosis antibodies with the reference cELISA test in West African Bos indicus.

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    Barend M deC Bronsvoort

    Full Text Available Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (approximately 87% and highly specific (approximately 97%. The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities.

  11. Comparison of a Flow Assay for Brucellosis Antibodies with the Reference cELISA Test in West African Bos indicus

    Science.gov (United States)

    Bronsvoort, Barend M. deC.; Koterwas, Bronwyn; Land, Fiona; Handel, Ian G.; Tucker, James; Morgan, Kenton L.; Tanya, Vincent N.; Abdoel, Theresia H.; Smits, Henk L.

    2009-01-01

    Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA) for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (∼87%) and highly specific (∼97%). The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities. PMID:19381332

  12. Human activities and microbial geographies. An anthropological approach to the risk of infections in West African hospitals.

    Science.gov (United States)

    d'Alessandro, Eugénie

    2015-07-01

    In hospital care, management of the risk of infection represents a crucial issue. Nevertheless, this question remains a neglected area in anthropological research, especially in African countries. To shed new light on this question, we conducted an anthropological investigation in the infectious disease department of a hospital in Niger. Daily observation of the work of the hospital staff for a total period of 6 months was spread out over 2008 and 2009. During our prolonged stay, we also collected 64 in-depth interviews of health care workers and attendants in the department. This study method made it possible to describe many of the practices and discourses related to the issues of medical and personal care and hospital hygiene and to compare the practices observed to standard principles for preventing hospital-acquired infections. Our ethnographic attention to the behavior of the actors showed the absence of formal spatial segmentations between different activities. The care provided by the untrained relatives serving as personal attendants introduced territorial enclaves governed by home hygiene standards into the interior of technical spaces. At the same time, privatizing equipment and space for their diverse activities, the medical staff disrupted technical chains and generated the recurrent crossing of microbial geographies. These results allow us to offer two principal guidelines for improving the quality of care and the management of risks of infection in hospitals in West Africa: (1) the essential role of the attendants in the care provided to hospital inpatients must be officially taken into account, especially by including them in the organization of medical hygiene procedures; (2) the different overlapping technical activities and social activities in the work space must be limited by their geographic and architectural segmentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Geology of the world-class Kiaka polyphase gold deposit, West African Craton, Burkina Faso

    Science.gov (United States)

    Fontaine, Arnaud; Eglinger, Aurélien; Ada, Koumangdiwè; André-Mayer, Anne-Sylvie; Reisberg, Laurie; Siebenaller, Luc; Le Mignot, Elodie; Ganne, Jérôme; Poujol, Marc

    2017-02-01

    The Kiaka gold deposit is a major resource in West Africa, with measured and indicated resources of 124 Mt at 1.09 g/t Au (3.9 Moz) and inferred resources of 27 Mt at 0.83 g/t Au (0.8 Moz). Located within the Manga-Fada N'Gourma greenstone and plutonic belt in south of the Burkina Faso, the deposit is hosted by a metamorphosed volcano-sedimentary sequence of lithic-, quartz-biotite metagreywackes, aluminosilicate-bearing metapelites and garnet-orthopyroxene-bearing schists and volcanic units. Structural observations indicate four local deformation events: DK1, DK2 and DK3 and DK4. Respectively, these events are linked to regional D1 E-W compression, D2 NW-SE compression and lastly, D3- and D4-related reactivations along D2 shear zones. The S2 foliation and D2 shear zones are developed during lower amphibolite facies metamorphism whereas retrogression occurs during D3-4 reactivations along these shear zones at upper greenschist facies conditions. The emplacement of a dioritic intrusion, dated at 2140 ± 7 Ma (Concordia U-Pb age on magmatic zircon), is interpreted to be contemporaneous with sinistral displacement along mineralized, NE-trending D2 shear zones. The intersection of these shears zones and the Markoye shear zone (dextral-reverse D1 and sinistral-reverse D2 reactivations) controlled the final geometry of the host rocks and the ore zones. Four subparallel elongated ore bodies are mainly hosted within D2-related shear zones and some are developed in an apparent axial plane of a F2 isoclinal fold. Detailed petrographic studies have identified two main types of hydrothermal alteration associated with two stages of gold mineralization. The stage (1) corresponds to replacement zones with biotite and clinozoisite during the D2 event associated with pyrrhotite ± pyrite, chalcopyrite (disseminated gold stage). The stage (2) occurs during reactivations of the D2-related auriferous shear zones (vein stage) and is characterized by diopside ± actinolite D3 veins and

  14. Why do global climate models struggle to represent low-level clouds in the West African summer monsoon?

    Science.gov (United States)

    Knippertz, Peter; Hannak, Lisa; Fink, Andreas H.; Kniffka, Anke; Pante, Gregor

    2017-04-01

    Climate models struggle to realistically represent the West African monsoon (WAM), which hinders reliable future projections and the development of adequate adaption measures. Low-level clouds over southern West Africa (5-10°N, 8°W-8°E) during July-September are an integral part of the WAM through their effect on the surface energy balance and precipitation, but their representation in climate models has so far received little attention. These clouds usually form during the night near the level of the nocturnal low-level jet ( 950 hPa), thicken and spread until the mid-morning ( 09 UTC), and then break up and rise in the course of the day, typically to about 850 hPa. The low thermal contrast to the surface and the frequent presence of obscuring higher-level clouds make detection of the low-level clouds from space rather challenging. Here we use 30 years of output from 18 models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) as well as 20 years of output from 8 models participating in the Year of Tropical Convection (YoTC) experiments to identify cloud biases and their causes. A great advantage of the YoTC dataset is the 6-hourly output frequency, which allows an analysis of the diurnal cycle, and the availability of temperature and moisture tendencies from parameterized processes such as convection, radiation and boundary-layer turbulence. A comparison to earlier analyses based on CMIP3 output reveals rather limited improvements with regard to the represenation of low-level cloud and winds. Compared to ERA-Interim re-analyses, which shows satisfactory agreement with surface observations, many of the CMIP5 and YoTC models still have large biases in low-level cloudiness of both signs and a tendency to too high elevation and too weak diurnal cycles. At the same time, these models tend to have too strong low-level jets, the impact of which is unclear due to concomitant effects on temperature and moisture advection as well as turbulent

  15. Very high CO2 exchange fluxes at the peak of the rainy season in a West African grazed semi-arid savanna ecosystem

    DEFF Research Database (Denmark)

    Tagesson, Håkan Torbern; Ardoe, Jonas; Guiro, Idrissa

    2016-01-01

    Africa is a sink of carbon, but there are large gaps in our knowledge regarding the CO2 exchange fluxes for many African ecosystems. Here, we analyse multi-annual eddy covariance data of CO2 exchange fluxes for a grazed Sahelian semi-arid savanna ecosystem in Senegal, West Africa. The aim...... to that of other semi-arid savanna sites due the short length of the rainy season. An inter-comparison between the open-path and a closed-path infrared sensor indicated no systematic errors related to the instrumentation. An uncertainty analysis of long-term NEE budgets indicated that corrections for air density...... response to climate change....

  16. Assessment of the petroleum, coal, and geothermal resources of the Economic Community of West African States (ECOWAS) region

    Science.gov (United States)

    Mattick, R. E.

    1982-01-01

    Approximately 85 percent of the land area of the ECOWAS (Economic Community of West African States) region is covered by basement rocks (igneous and highly metamorphosed rocks) or relatively thin layers of Paleozoic, Upper Precambrian, and 'Continental Intercalaire? sedimentary rocks. These areas have little or no petroleum potential. Areas of the ECOWAS region that have potential for petroleum production or potential for increased petroleum production include the narrow belt of sedimentary rocks that stretches along the continental margin from Mauritania to Nigeria and the Niger Delta and the Benue depression. The Senegal Basin, located on the continental margin of Mauritania, Senegal, Gambia, Guinea Bissau, and Guinea, has been intensely explored by the oil industry and most of the larger structures onshore and on the shelf probably have been tested by drilling with little or no resulting commercial production. Unless basic ideas pertaining to the petroleum geology of the Senegal Basin are revised, future discoveries are expected to be limited to small fields overlooked by industry at a time when petroleum prices were low. On the continental shelf of Sierra Leone and the continental shelf of northeast and central Liberia, the sedimentary rocks are relatively thin, and industry has shown little interest in the area. On the continental rise of these countries, however, the sedimentary section, deposited in a complex fault-block system, increases in thickness. A renewal of industry interest in this deep-water area will probably follow further development of deep-water production technology. A recent oil discovery on the continental slope off the Ivory Coast is expected to spur further exploration offshore of southeastern Liberia, Ivory Coast, Ghana, Togo, and Benin. This relatively unexplored area in the Gulf of Guinea has good possibilities .for the discovery of giant oil fields. Nigeria's oil development from the Niger Delta may have peaked, as 13 of 14 giant oil

  17. High-resolution measurements of atmospheric molecular hydrogen and its isotopic composition at the West African coast of Mauritania

    Directory of Open Access Journals (Sweden)

    S. Walter

    2013-05-01

    Full Text Available Oceans are a net source of molecular hydrogen (H2 to the atmosphere, where nitrogen (N2 fixation is assumed to be the main biological production pathway followed by photochemical production from organic material. The sources can be distinguished using isotope measurements because of clearly differing isotopic signatures of the produced hydrogen. Here we present the first ship-borne measurements of atmospheric molecular H2 mixing ratio and isotopic composition at the West African coast of Mauritania (16–25° W, 17–24° N. This area is one of the biologically most active regions of the world's oceans with seasonal upwelling events and characterized by strongly differing hydrographical/biological properties and phytoplankton community structures. The aim of this study was to identify areas of H2 production and distinguish H2 sources by isotopic signatures of atmospheric H2. For this more than 100 air samples were taken during two cruises in February 2007 and 2008. During both cruises a transect from the Cape Verde Islands towards the Mauritanian Coast was sampled to cover differing oceanic regions such as upwelling and oligotrophic regimes. In 2007, additionally, four days were sampled at high resolution of one sample per hour to investigate a possible diurnal cycle of atmospheric H2. Our results indicate the influence of local sources and suggest the Banc d'Arguin as a pool for precursors for photochemical H2 production, whereas oceanic N2 fixation could not be identified as a source for atmospheric H2 during these two cruises. The variability in diurnal cycles is probably influenced by released precursors for photochemical H2 production and also affected by a varying origin of air masses. This means for future investigations that only measuring the mixing ratio of H2 is insufficient to explain the variability of an atmospheric diurnal cycle and support is needed, e.g. by isotopic measurements. Nevertheless, measurements of atmospheric H2

  18. The link between the West African Ebola outbreak and health systems in Guinea, Liberia and Sierra Leone: a systematic review.

    Science.gov (United States)

    Shoman, Haitham; Karafillakis, Emilie; Rawaf, Salman

    2017-01-04

    An Ebola outbreak started in December 2013 in Guinea and spread to Liberia and Sierra Leone in 2014. The health systems in place in the three countries lacked the infrastructure and the preparation to respond to the outbreak quickly and the World Health Organisation (WHO) declared a public health emergency of international concern on August 8 2014. The aim of this study was to determine the effects of health systems' organisation and performance on the West African Ebola outbreak in Guinea, Liberia and Sierra Leone and lessons learned. The WHO health system building blocks were used to evaluate the performance of the health systems in these countries. A systematic review of articles published from inception until July 2015 was conducted following the PRISMA guidelines. Electronic databases including Medline, Embase, Global Health, and the Cochrane library were searched for relevant literature. Grey literature was also searched through Google Scholar and Scopus. Articles were exported and selected based on a set of inclusion and exclusion criteria. Data was then extracted into a spreadsheet and a descriptive analysis was performed. Each study was critically appraised using the Crowe Critical Appraisal Tool. The review was supplemented with expert interviews where participants were identified from reference lists and using the snowball method. Thirteen articles were included in the study and six experts from different organisations were interviewed. Findings were analysed based on the WHO health system building blocks. Shortage of health workforce had an important effect on the control of Ebola but also suffered the most from the outbreak. This was followed by information and research, medical products and technologies, health financing and leadership and governance. Poor surveillance and lack of proper communication also contributed to the outbreak. Lack of available funds jeopardised payments and purchase of essential resources and medicines. Leadership and

  19. Impact of climate change on hydrological conditions in a tropical West African catchment using an ensemble of climate simulations

    Science.gov (United States)

    Yira, Yacouba; Diekkrüger, Bernd; Steup, Gero; Yaovi Bossa, Aymar

    2017-04-01

    This study evaluates climate change impacts on water resources using an ensemble of six regional climate models (RCMs)-global climate models (GCMs) in the Dano catchment (Burkina Faso). The applied climate datasets were performed in the framework of the COordinated Regional climate Downscaling Experiment (CORDEX-Africa) project.After evaluation of the historical runs of the climate models' ensemble, a statistical bias correction (empirical quantile mapping) was applied to daily precipitation. Temperature and bias corrected precipitation data from the ensemble of RCMs-GCMs was then used as input for the Water flow and balance Simulation Model (WaSiM) to simulate water balance components.The mean hydrological and climate variables for two periods (1971-2000 and 2021-2050) were compared to assess the potential impact of climate change on water resources up to the middle of the 21st century under two greenhouse gas concentration scenarios, the Representative Concentration Pathways (RCPs) 4.5 and 8.5. The results indicate (i) a clear signal of temperature increase of about 0.1 to 2.6 °C for all members of the RCM-GCM ensemble; (ii) high uncertainty about how the catchment precipitation will evolve over the period 2021-2050; (iii) the applied bias correction method only affected the magnitude of the climate change signal; (iv) individual climate models results lead to opposite discharge change signals; and (v) the results for the RCM-GCM ensemble are too uncertain to give any clear direction for future hydrological development. Therefore, potential increase and decrease in future discharge have to be considered in climate change adaptation strategies in the catchment. The results further underline on the one hand the need for a larger ensemble of projections to properly estimate the impacts of climate change on water resources in the catchment and on the other hand the high uncertainty associated with climate projections for the West African region. A water

  20. Sensitivity of the southern West African mean atmospheric state to variations in low-level cloud cover as simulated by ICON

    Science.gov (United States)

    Kniffka, Anke; Knippertz, Peter; Fink, Andreas

    2017-04-01

    This contribution presents first results of numerical sensitivity experiments that are carried out in the framework of the project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa). DACCIWA aims to investigate the impact of the drastic increase in anthropogenic emissions in West Africa on the local weather and climate, for example through cloud-aerosol interactions or impacts on radiation and stability. DACCIWA organised a major international field campaign in West Africa in June-July 2016 and involves a wide range of modelling activities. Several studies have shown - and first results of the DACCIWA campaign confirm - that extensive ultra-low stratus clouds form in the southern parts of West Africa (8°W-8°E, 5-10°N) at night in connection with strong nocturnal low-level jets. The clouds persist long after sunrise and have therefore a substantial impact on the surface radiation budget and consequently on the diurnal evolution of the daytime, convectively mixed boundary layer. The objective of this study is to investigate the sensitivity of the West African monsoon system and its diurnal cycle to the radiative effects of these low clouds. The study is based on a series of daily 5-day sensitivity simulations using ICON, the operational numerical weather prediction model of the German Weather Service during the months July - September 2006. In these simulations, low clouds are made transparent, by artificially lowering the optical thickness information passed on to the model's radiation scheme. Results reveal a noticeable influence of the low-level cloud cover on the atmospheric mean state of our region of interest and beyond. Also the diurnal development of the convective boundary layer is influenced by the cloud modification. In the transparent-cloud experiments, the cloud deck tends to break up later in the day and is shifted to a higher altitude, thereby causing a short-lived intensification around 11 LT. The average rainfall patterns are

  1. A Cloud-Resolving Modeling Intercomparison Study on Properties of Cloud Microphysics, Convection, and Precipitation for a Squall Line Cas

    Science.gov (United States)

    Fan, J.; Han, B.; Morrison, H.; Varble, A.; Mansell, E.; Milbrandt, J.; Wang, Y.; Lin, Y.; Dong, X.; Giangrande, S. E.; Jensen, M. P.; Collis, S. M.; North, K.; Kollias, P.

    2015-12-01

    The large spread in CRM model simulations of deep convection and aerosol effects on deep convective clouds (DCCs) makes it difficult (1) to further our understanding of deep convection and (2) to define "benchmarks" and recommendations for their use in parameterization developments. Past model intercomparison studies used different models with different complexities of dynamic-microphysics interactions, making it hard to isolate the causes of differences between simulations. In this intercomparison study, we employed a much more constrained approach - with the same model and same experiment setups for simulations with different cloud microphysics schemes (one-moment, two-moment, and bin models). Both the piggybacking and interactive approaches are employed to explore the major microphysical processes that control the model differences and the significance of their feedback to dynamics through latent heating/cooling and cold pool characteristics. Real-case simulations are conducted for the squall line case 20 May 2011 from the MC3E field campaign. Results from the piggybacking approach show substantially different responses of the microphysics schemes to the same dynamical fields. Although the interactive microphysics-dynamics simulations buffer some differences compared with those from the piggyback runs, large differences still exist and are mainly contributed by ice microphysical processes parameterizations. The presentation will include in-depth analyses of the major microphysical processes for the squall line case, the significance of the feedback of the processes to dynamics, and how those results differ in different cloud microphysics schemes.

  2. West African Antislavery Movements

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi; Pelckmans, Lotte

    2011-01-01

    the penal code of Mali. Anti-slavery activists not only address their claims to their national governments but also intend to initiate change at local level. In that respect the democratic decentralization reforms were significant because they allowed educated anti-slavery activists to appeal their brethren...... to unite, mobilize and struggle. Members of anti-slavery movements with slave origins accessed power positions through peaceful electoral processes in Benin, mali, Niger and Mauritania. People of slave origins gained ground in local politics of a number of municipalities. In localities where anti...

  3. Prostate cancer disparities in Black men of African descent: a comparative literature review of prostate cancer burden among Black men in the United States, Caribbean, United Kingdom, and West Africa

    Directory of Open Access Journals (Sweden)

    Reams R Renee

    2009-02-01

    Full Text Available Abstract Background African American men have the highest prostate cancer morbidity and mortality rates than any other racial or ethnic group in the US. Although the overall incidence of and mortality from prostate cancer has been declining in White men since 1991, the decline in African American men lags behind White men. Of particular concern is the growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry in the Caribbean Islands, United Kingdom and West Africa. This higher incidence of prostate cancer observed in populations of African descent may be attributed to the fact that these populations share ancestral genetic factors. To better understand the burden of prostate cancer among men of West African Ancestry, we conducted a review of the literature on prostate cancer incidence, prevalence, and mortality in the countries connected by the Transatlantic Slave Trade. Results Several published studies indicate high prostate cancer burden in Nigeria and Ghana. There was no published literature for the countries Benin, Gambia and Senegal that met our review criteria. Prostate cancer morbidity and/or mortality data from the Caribbean Islands and the United Kingdom also provided comparable or worse prostate cancer burden to that of US Blacks. Conclusion The growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry follows the path of the Transatlantic Slave Trade. To better understand and address the global prostate cancer disparities seen in Black men of West African ancestry, future studies should explore the genetic and environmental risk factors for prostate cancer among this group.

  4. Endangered West African Chimpanzees Pan troglodytes verus (Schwarz, 1934 (Primates: Hominidae in Senegal prefer Pterocarpus erinaceus, a threatened tree species, to build their nests: implications for their conservation

    Directory of Open Access Journals (Sweden)

    P.I. Ndiaye

    2013-12-01

    Full Text Available The West African Chimpanzee Pan troglodytes verus is Endangered (A4cd ver 3.1 in Senegal (Humle et al. 2008, mainly due to habitat fragmentation and destruction. We gathered qualitative and quantitative data on the tree species preferences of the West African Chimpanzee for nest building in order to gain insight into habitat dependence. Between March 1998 and Febrary 2000 we identified tree species in which a sample of 1790 chimpanzee nests had been built, and ranked species in preference order. We compared this sample to the relative abundance of tree species in the chimpanzee habitat to determine whether particular species were chosen for nesting. We observed that about a quarter (25.42% of nests were built in Pterocarpus erinaceus, which is considerably greater than would be expected from the abundance of this species in the habitat (6.35%, indicating a strong preference by chimpanzees. We examined the physical traits of the most-used tree species and concluded that height and wood hardness may be key choice features. P. erinaceus is threatened in Senegal due to extensive cutting, which may endanger chimpanzees living outside the boundaries of protected areas. In the current anthropogenic setting our results provide conservation managers with information on how to protect a key aspect of the chimpanzee natural environment.

  5. The hopes of West African refugees during resettlement in northern Sweden: a 6-year prospective qualitative study of pathways and agency thoughts.

    Science.gov (United States)

    Anjum, Tanvir M; Nordqvist, Cecilia; Timpka, Toomas

    2012-01-24

    Little is known about how positive phenomena can support resettlement of refugees in a new country. The aim of this study was to examine the hopeful thinking in a group of West African quota refugees at arrival and after 6 years in Sweden and compare these thoughts to the views of resettlement support professionals. The primary study population comprised 56 adult refugees and 13 resettlement professionals. Qualitative data were collected from the refugees by questionnaires on arrival and 6 years later. Data were collected from the resettlement professionals by interview about 3 years after arrival of the refugees. Snyder's cognitive model of hope was used to inform the comparative data analyses. Hopes regarding education were in focus for the refugees shortly after arrival, but thoughts on family reunion were central later in the resettlement process. During the later stages of the resettlement process, the unresponsiveness of the support organization to the family reunion problem became as issue for the refugees. The professionals reported a complex mix of "silent agency thoughts" underlying the local resettlement process as a contributing reason for this unresponsiveness. Hopes regarding education and family reunion were central in the resettlement of West African refugees in Sweden. These thoughts were not systematically followed up by the support organization; possibly the resources for refugees were not fully released. More studies are needed to further investigate the motivational factors underpinning host community support of refugees' hopes and plans.

  6. Determinants of Early Introduction of Solid, Semi-Solid or Soft Foods among Infants Aged 3–5 Months in Four Anglophone West African Countries

    Directory of Open Access Journals (Sweden)

    Abukari I. Issaka

    2014-07-01

    Full Text Available This study was conducted to explore and identify factors associated with the practice of early introduction of solid, semi-solid or soft foods among infants aged 3–5 months in four Anglophone West African countries. Data sources for the analyses were the latest Demographic and Health Survey datasets of the 4 countries, namely Ghana (GDHS, 2008, Liberia (LDHS, 2007, Nigeria (NDHS, 2013 and Sierra Leone (SLDHS, 2008. Multiple logistic regression methods were used to analyze the factors associated with early introduction of solid, semi-solid or soft foods among infants aged 3–5 months, using individual-, household- and community-level determinants. The sample consisted of 2447 infants aged 3–5 months from four Anglophone West African countries: 166 in Ghana, 263 in Liberia, 1658 in Nigeria and 360 in Sierra Leone. Multivariable analyses revealed the individual factors associated with early introduction of solid, semi-solid or soft foods in these countries. These included increased infant’s age, diarrhea, acute respiratory infection and newborns perceived to be small by their mothers. Other predictors of early introduction of solid, semi-solid or soft foods were: mothers with no schooling, young mothers and fathers who worked in an agricultural industry. Public health interventions to improve exclusive breastfeeding practices by discouraging early introduction of solid, semi-solid or soft foods are needed in all 4 countries, targeting especially mothers at risk of introducing solid foods to their infants early.

  7. Growth performance, carcass characteristics and meat sensory evaluation of West African dwarf sheep fed varying levels of maize and cassava hay.

    Science.gov (United States)

    Fasae, O A; Adu, I F; Aina, A B J; Dipeolu, M A

    2011-02-01

    A study was conducted to determine the growth performance and meat yield and quality of West African dwarf sheep. Twenty rams weighing an average of 15.3 ± 0.79 kg live weight and with an average age of 18 months were allotted at random to five dietary treatments of 0%, 25%, 50%, 75% and 100% maize hay (MH) for a period of 105 days. Dry matter (DM) intake and growth rate of the rams were improved as the level of cassava hay (CH) increased in the diets. Live weight gain varied significantly (P 0.05) difference observed across the treatments, while the distribution of the slaughtered parts was similar (P > 0.05) regardless of the dietary treatment. Proximate composition of the meat from the loin indicated that the DM, crude protein, fat and ash contents were not influenced (P > 0.05) by the dietary treatments. Panellists rated the meat to be similar (P > 0.05) in flavour, juiciness, tenderness and overall acceptability while colour and texture varied significantly (P < 0.05) across the treatments. In conclusion, this study indicated that better growth performance and meat production in West African dwarf sheep can be improved in form of body weight and carcass production when fed 25%MH and 75% CH diet.

  8. Effect of dietary monensin inclusion on performance, nutrient utilisation, rumen volatile fatty acid concentration and blood status of West African dwarf bucks fed with basal diets of forages.

    Science.gov (United States)

    Aderinboye, Ronke Yemisi; Onwuka, Chryss Friday Ijeoma; Arigbede, Oluwasanmi Moses; Oduguwa, Oluseyi Olutosin; Aina, Ayobami Bukola Joseph

    2012-06-01

    This experiment investigated the effect of dietary monensin on performance, nutrient utilisation, rumen volatile fatty acid and blood status in West African dwarf (WAD) goats fed with basal diets of forages. Four concentrate supplements were formulated to include 0 (MO), 15 (M15), 30 (M30) and 45 (M45) mg monensin/kg dry matter. Twenty-four WAD bucks (7.3 ± 1.20 kg initial body weight, aged 9-12 months) were randomly allotted to four experimental diets in a completely randomised design for 90 days, six animals per diet. Results indicated that animals fed M15, M30 and M45 diets had lower (P 0.05) while monensin decreased (P < 0.001) acetate/propionate ratio. Blood glucose increased (P < 0.001) from 59.1 mg/dl in animals on M0 diet to 67.8, 66.0 and 66.3 mg/dl in animals on M15, M30 and M45 diets. Overall, there were no variations among animals on M15, M30 and M45 diets. It is concluded that feeding monensin at 15 to 45 mg/kg DM of supplemental concentrate diets to West African dwarf bucks could be effective in improving feed and protein efficiency, manipulating the rumen for increased propionate production and increasing blood glucose levels.

  9. The hopes of West African refugees during resettlement in northern Sweden: a 6-year prospective qualitative study of pathways and agency thoughts

    Directory of Open Access Journals (Sweden)

    Anjum Tanvir M

    2012-01-01

    Full Text Available Abstract Background Little is known about how positive phenomena can support resettlement of refugees in a new country. The aim of this study was to examine the hopeful thinking in a group of West African quota refugees at arrival and after 6 years in Sweden and compare these thoughts to the views of resettlement support professionals. Method The primary study population comprised 56 adult refugees and 13 resettlement professionals. Qualitative data were collected from the refugees by questionnaires on arrival and 6 years later. Data were collected from the resettlement professionals by interview about 3 years after arrival of the refugees. Snyder's cognitive model of hope was used to inform the comparative data analyses. Results Hopes regarding education were in focus for the refugees shortly after arrival, but thoughts on family reunion were central later in the resettlement process. During the later stages of the resettlement process, the unresponsiveness of the support organization to the family reunion problem became as issue for the refugees. The professionals reported a complex mix of "silent agency thoughts" underlying the local resettlement process as a contributing reason for this unresponsiveness. Conclusion Hopes regarding education and family reunion were central in the resettlement of West African refugees in Sweden. These thoughts were not systematically followed up by the support organization; possibly the resources for refugees were not fully released. More studies are needed to further investigate the motivational factors underpinning host community support of refugees' hopes and plans.

  10. The first phylogeographic population structure and analysis of transmission dynamics of M. africanum West African 1--combining molecular data from Benin, Nigeria and Sierra Leone.

    Directory of Open Access Journals (Sweden)

    Florian Gehre

    Full Text Available Mycobacterium africanum is an important cause of tuberculosis (TB in West Africa. So far, two lineages called M. africanum West African 1 (MAF1 and M. africanum West African 2 (MAF2 have been defined. Although several molecular studies on MAF2 have been conducted to date, little is known about MAF1. As MAF1 is mainly present in countries around the Gulf of Guinea we aimed to estimate its prevalence in Cotonou, the biggest city in Benin. Between 2005-06 we collected strains in Cotonou/Benin and genotyped them using spoligo- and 12-loci-MIRU-VNTR-typing. Analyzing 194 isolates, we found that 31% and 6% were MAF1 and MAF2, respectively. Therefore Benin is one of the countries with the highest prevalence (37% of M. africanum in general and MAF1 in particular. Moreover, we combined our data from Benin with publicly available genotyping information from Nigeria and Sierra Leone, and determined the phylogeographic population structure and genotypic clustering of MAF1. Within the MAF1 lineage, we identified an unexpected great genetic variability with the presence of at least 10 sub-lineages. Interestingly, 8 out of 10 of the discovered sub-lineages not only clustered genetically but also geographically. Besides showing a remarkable local restriction to certain regions in Benin and Nigeria, the sub-lineages differed dramatically in their capacity to transmit within the human host population. While identifying Benin as one of the countries with the highest overall prevalence of M. africanum, this study also contains the first detailed description of the transmission dynamics and phylogenetic composition of the MAF1 lineage.

  11. Large-scale mitochondrial DNA analysis of native honey bee Apis mellifera populations reveals a new African subgroup private to the South West Indian Ocean islands.

    Science.gov (United States)

    Techer, Maéva Angélique; Clémencet, Johanna; Simiand, Christophe; Preeaduth, Sookar; Azali, Hamza Abdou; Reynaud, Bernard; Hélène, Delatte

    2017-06-02

    The South West Indian Ocean (SWIO) archipelagos and Madagascar constitute a hotspot of biodiversity with a high rate of endemism. In this area, the endemic subspecies A. m. unicolor has been described in Madagascar. It belongs to the African lineage, one of the four described evolutionary lineages in honey bees. Despite a long beekeeping tradition and several recorded European introductions, few studies have been carried out on the diversity and proportion of honey bee subspecies. In order to identify and define which evolutionary lineages and potential sub-lineages are present in the SWIO, the COI-COII intergenic region and the ND2 gene of the mtDNA were sequenced in honey bee colonies from three archipelagos. An extensive sampling (n = 1184 colonies) was done in the Mascarene (La Réunion, Mauritius, Rodrigues), Seychelles (Mahé, Praslin, La Digue) and Comoros (Grande Comore, Mohéli, Anjouan, Mayotte) archipelagos. Islands genetic diversity was compared to newly sampled populations from Madagascar, continental African and European populations. African lineage haplotypes were found in all islands (except for Rodrigues). Madagascar, Comoros and Seychelles had 100% of A lineage, 95.5% in La Réunion and 56.1% in Mauritius. Among all African colonies detected in the SWIO, 98.1% (n = 633) of COI-COII haplotypes described the presence of the subspecies A. M. unicolor. Both genetic markers revealed i) a new private A I mitochondrial group shared by the SWIO archipelagos and Madagascar distant from continental populations; ii) the private African haplotypes for each island suggested diversity radiation in the archipelagos; iii) the detection of the Comoros archipelago as a possible contact area between insular and continental African populations. The exotic European C and M lineages were only detected in the Mascarene archipelago, but striking differences of proportion were observed among islands. Merely 4.6% of European colonies were found in La Réunion whereas

  12. African civil society initiatives to drive a biobanking, biosecurity and infrastructure development agenda in the wake of the West African Ebola outbreak.

    Science.gov (United States)

    Abayomi, Akin; Gevao, Sahr; Conton, Brian; Deblasio, Pasquale; Katz, Rebecca

    2016-01-01

    This paper describes the formation of a civil society consortium, spurred to action by frustration over the Ebola crises, to facilitate the development of infrastructure and frameworks including policy development to support a harmonized, African approach to health crises on the continent. The Global Emerging Pathogens Treatment Consortium, or GET, is an important example of how African academics, scientists, clinicians and civil society have come together to initiate policy research, multilevel advocacy and implementation of initiatives aimed at building African capacity for timely and effective mitigations strategies against emerging infectious and neglected pathogens, with a focus on biobanking and biosecurity. The consortium has been able to establish it self as a leading voice, drawing attention to scientific infrastructure gaps, the importance of cultural sensitivities, and the power of community engagement. The GET consortium demonstrates how civil society can work together, encourage government engagement and strengthen national and regional efforts to build capacity.

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. ... Featured Country: Nigeria, Featured Journal: West African Journal of Industrial and Academic Research. Most recent issues on AJOL: Vol 6, No 1 (2015). Nigeria Journal of Pure and Applied Physics.

  14. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. ... Featured Country: South Africa, Featured Journal: Southern African Linguistics and Applied Language Studies ...

  15. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics.

  16. Contrasting conditions of surface water balance in wet years and dry years as a possible land surface-atmosphere feedback mechanism in the West African Sahel

    Science.gov (United States)

    Lare, A. R.; Nicholson, S. E.

    1994-01-01

    The climate of West Africa, in particular the Sahel, is characterized by multiyear persistence of anomalously wet or dry conditions. Its Southern Hemisphere counterpart, the Kalahari, lacks the persistence that is evident in the Sahel even though both regions are subject to similar large-scale forcing. It has been suggested that land surface-atmosphere feedback contributes to this persistence and to the severity of drought. In this study, surface energy and water balance are quantified for nine stations along a latitudinal transect that extends from the Sahara to the Guinea coast. In the wetter regions of West Africa, the difference between wet and dry years is primarily reflected in the magnitude of runoff. For the Sahel and drier locations, evapotranspiration and soil moisture are more sensitive to rainfall anomalies. The increase in evapotranspiration, and hence latent heating, over the Sahel in wet years alters the thermal structure and gradients of the overlying atmosphere and thus the strength of the African easterly jet (AEJ) at 700 mb. The difference between dry and wet Augusts corresponds to a decrease in magnitude of the AEJ at 15 deg N on the order of 2.6 m/s, which is consistent with previous studies of observed winds. Spatial patterns were also developed for surface water balance parameters for both West Africa and southern Africa. Over southern Africa, the patterns are not as spatially homogeneous as those over West Africa and are lower in magnitude, thus supporting the suggestion that the persistence of rainfall anomalies in the Sahel might be due, at least in part, to land-atmosphere feedback, and that the absence of such persistence in the Kalahari is a consequence of less significant changes in surface water and energy balance.

  17. "If We Can't Do It, Our Children Will Do It One Day": A Qualitative Study of West African Immigrant Parents' Losses and Educational Aspirations for Their Children

    Science.gov (United States)

    Roubeni, Sonia; De Haene, Lucia; Keatley, Eva; Shah, Nira; Rasmussen, Andrew

    2015-01-01

    This study examined migration narratives of West African immigrants for the connections between experiences of loss and educational aspirations for their children. The qualitative design consisted of three interviews per family in which parents (N = 20, 12 families) were asked to narrate their families' migration histories. Transcripts were…

  18. Impacts of the diversity of traditional uses and potential economic value on food tree species conservation status: case study of African bush mango trees (Irvingiaceae) in the Dahomey Gap (West Africa).

    NARCIS (Netherlands)

    Vihotogbé, R.; Kakai, R.G.; Bongers, F.; Andel, van T.; Berg, van den R.G.; Sinsin, B.; Sosef, M.S.M.

    2014-01-01

    Background and aims – Bitter and sweet African bush mango trees belong to the family Irvingiaceae and produce valuable non-timber forest products in humid lowland areas of West and Central Africa. The bitter and sweet types are treated as distinct taxa at the variety or species level. They have not

  19. Mesoscale spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical model simulations

    Science.gov (United States)

    Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.

    1988-01-01

    It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation mesoscale model with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex.

  20. Dosage comparison of Congo Basin and West African strains of monkeypox virus using a prairie dog animal model of systemic orthopoxvirus disease.

    Science.gov (United States)

    Hutson, Christina L; Carroll, Darin S; Self, Joshua; Weiss, Sonja; Hughes, Christine M; Braden, Zachary; Olson, Victoria A; Smith, Scott K; Karem, Kevin L; Regnery, Russell L; Damon, Inger K

    2010-06-20

    The prairie dog is valuable for the study of monkeypox virus (MPXV) virulence and closely resembles human systemic orthopoxvirus disease. Herein, we utilize a variable dose intranasal challenge with approximately 10(3), 10(4), 10(5), and 10(6)PFU for each clade to further characterize virulence differences between the two MPXV clades. A trend of increased morbidity and mortality as well as greater viral shedding was observed with increasing viral challenge dose. Additionally, there appeared to be a delay in onset of disease for animals challenged with lower dosages of virus. Mathematical calculations were used to determine LD(50) values and based on these calculations, Congo Basin MPXV had approximately a hundred times lower LD(50) value than the West African clade (5.9x10(3) and 1.29x10(5) respectively); reinforcing previous findings that Congo Basin MPXV is more virulent. Published by Elsevier Inc.

  1. DC-SIGN (CD209), pentraxin 3 and vitamin D receptor gene variants associate with pulmonary tuberculosis risk in West Africans

    DEFF Research Database (Denmark)

    Olesen, R; Wejse, C; Velez, D R

    2007-01-01

    We investigated the role of DC-SIGN (CD209), long pentraxin 3 (PTX3) and vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in susceptibility to pulmonary tuberculosis (TB) in 321 TB cases and 347 healthy controls from Guinea-Bissau. Five additional, functionally relevant SNPs...... in a nonadditive model with disease risk when analyzed in combination with ethnicity (P=0.03 for DC-SIGN and P=0.003 for VDR). In addition, PTX3 haplotype frequencies significantly differed in cases compared to controls and a protective effect was found in association with a specific haplotype (OR 0.78, 95% CI 0.......63-0.98). Our findings support previous data showing that VDR SNPs modulate the risk for TB in West Africans and suggest that variation within DC-SIGN and PTX3 also affect the disease outcome. Udgivelsesdato: 2007-Sep...

  2. Petrochemical and petrophysical characterization of the lower crust and the Moho beneath the West African Craton, based on Xenoliths from Kimberlites

    Science.gov (United States)

    Haggerty, Stephen E.; Toft, Paul B.

    1988-01-01

    Additional evidence to the composition of the lower crust and uppermost mantle was presented in the form of xenolith data. Xenoliths from the 2.7-Ga West African Craton indicate that the Moho beneath this shield is a chemically and physically gradational boundary, with intercalations of garnet granulite and garnet eclogite. Inclusions in diamonds indicate a depleted upper mantle source, and zenolith barometry and thermometry data suggest a high mantle geotherm with a kink near the Moho. Metallic iron in the xenoliths indicates that the uppermost mantle has a significant magnetization, and that the depth to the Curie isotherm, which is usually considered to be at or above the Moho, may be deeper than the Moho.

  3. Evidence for the Emergence of New Rice Types of Interspecific Hybrid Origin in West African Farmers' Fields

    NARCIS (Netherlands)

    Nuijten, H.A.C.P.; Treuren, van R.; Struik, P.C.; Mokuwa, G.A.; Okry, F.; Teeken, B.W.E.; Richards, P.

    2009-01-01

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess

  4. Episode-specific risk factors for progression of acute diarrhoea to persistent diarrhoea in west African children

    DEFF Research Database (Denmark)

    Sodemann, Morten; Jakobsen, M S; Mølbak, Kare

    2013-01-01

    The aim of the present study, carried out in Guinea-Bissau, West Africa, was to identify episode-specific risk factors for persistent diarrhoea (PD) related to clinical observations and management efforts. We followed 319 episodes of childhood diarrhoea by repeated household interviews until the ...

  5. Addressing diarrhea prevalence in the West African Middle Belt: social and geographic dimensions in a case study for Benin

    NARCIS (Netherlands)

    Pande, S.; Keyzer, M.A.; Arouna, A.; Sonneveld, B.G.J.S.

    2008-01-01

    Background: In West Africa, the Northern Sahelian zone and the coastal areas are densely populated but the Middle Belt in between is in general sparsely settled. Predictions of climate change foresee more frequent drought in the north and more frequent flooding in the coastal areas, while conditions

  6. Regional level risk factors associated with the occurrence of African swine fever in West and East Africa

    NARCIS (Netherlands)

    Huang, Zheng Y.X.; Langevelde, van Frank; Honer, Karanina J.; Naguib, Marc; Boer, de Willem F.

    2017-01-01

    Background: African swine fever (ASF) causes severe socio-economic impacts due to high mortality and trade restrictions. Many risk factors of ASF have been identified at farm level. However, understanding the risk factors, especially wild suid hosts, determining ASF transmission at regional level

  7. Depths to major density contrats beneath the West African rift system in Nigeria and Cameroon based on the spectral analysis of gravity data

    Science.gov (United States)

    Fairhead, J. D.; Okereke, C. S.

    Estimates of depth to major density contrats within the lithosphere have been made, over the West African Rift System and adjacent basement areas in Nigeria and Cameroon, based on the spectral analysis of the Bouguer gravity field. The study reveals that three main density discontinuities occur in the depth ranges 7 to 12 km, 19 to 30 km and 80 to 93 km. The shallow crustal density discontinuities reflect a range of geological structures associated with the rift zones, shear zones and cratonic margins. The 19 to 30 km depth range is in good agreement with the Moho' depths determined by seismic refraction studies beneath and to the south of the Yola Rift in Cameroon and by East-West gravity modelling profiles across the Benue Trough in Nigeria. The deepest density discontinuities observed at 80 to 93 km depth are compatible with the presence of an anomalous low velocity upper mantle structure at these depths deduced from the inversion of teleseismic travel time residuals. The spectral analysis of gravity data can thus provide reliable first order estimates of depth to density discontinuities within the lithosphere beneath a rifted continental plate where such density variations would be expected.

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

    Science.gov (United States)

    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

  9. Linking the sub-Saharan and West Eurasian gene pools: maternal and paternal heritage of the Tuareg nomads from the African Sahel.

    Science.gov (United States)

    Pereira, Luísa; Cerný, Viktor; Cerezo, María; Silva, Nuno M; Hájek, Martin; Vasíková, Alzbeta; Kujanová, Martina; Brdicka, Radim; Salas, Antonio

    2010-08-01

    The Tuareg presently live in the Sahara and the Sahel. Their ancestors are commonly believed to be the Garamantes of the Libyan Fezzan, ever since it was suggested by authors of antiquity. Biological evidence, based on classical genetic markers, however, indicates kinship with the Beja of Eastern Sudan. Our study of mitochondrial DNA (mtDNA) sequences and Y chromosome SNPs of three different southern Tuareg groups from Mali, Burkina Faso and the Republic of Niger reveals a West Eurasian-North African composition of their gene pool. The data show that certain genetic lineages could not have been introduced into this population earlier than approximately 9000 years ago whereas local expansions establish a minimal date at around 3000 years ago. Some of the mtDNA haplogroups observed in the Tuareg population were involved in the post-Last Glacial Maximum human expansion from Iberian refugia towards both Europe and North Africa. Interestingly, no Near Eastern mtDNA lineages connected with the Neolithic expansion have been observed in our population sample. On the other hand, the Y chromosome SNPs data show that the paternal lineages can very probably be traced to the Near Eastern Neolithic demic expansion towards North Africa, a period that is otherwise concordant with the above-mentioned mtDNA expansion. The time frame for the migration of the Tuareg towards the African Sahel belt overlaps that of early Holocene climatic changes across the Sahara (from the optimal greening approximately 10 000 YBP to the extant aridity beginning at approximately 6000 YBP) and the migrations of other African nomadic peoples in the area.

  10. The role of risk perception in willingness to respond to the 2014-2016 West African Ebola outbreak

    DEFF Research Database (Denmark)

    Gee, Stephanie; Skovdal, Morten

    2017-01-01

    Background: The 2014–2016 West Africa Ebola Virus Disease (EVD) outbreak was an unprecedented public health event, and in addition to claiming over 11,000 lives, it resulted in the deaths of more healthcare workers than any outbreak in recent history. While a cadre of willing and able health...... workers is essential for an effective epidemic response, health workforce capacity in times of crisis may be significantly impacted by how risks are perceived by health staff. This study aimed to explore how risk perceptions influenced healthcare workers’ willingness to respond during this outbreak....... Methods: Through in-depth interviews with 11 front-line international health care workers who chose to respond to the West Africa outbreak, this qualitative study explores how perceptions of risk developed and subsequently mediated the decision to respond to the outbreak. Data was thematically organized...

  11. Challenges of Regional Collective Security: Economic Community of West African States (ECOWAS) Standby Force: A Case Study

    Science.gov (United States)

    2008-06-13

    trouble spots in the sub-region (Audu, 2006, 22). Erskine examines the experiences of the Organization of African Unity (OAU) in Chad and ECOWAS in...international assistance, the dream of a peaceful Africa will never come true. For this reason, the G8 (Canada, France , Germany, Italy, Japan, Russia, the...Strategic Studies (ACSS). France has followed the United States initiative through a program called Renforcement des Capacités Africaines de Maintien de la

  12. A Parameter-Free Dynamic Alternative to Hyper-Viscosity for Coupled Transport Equations: Application to the Simulation of 3D Squall Lines Using Spectral Elements

    Science.gov (United States)

    2015-06-04

    Viscosity for Coupled Transport Equations: Application to the Simulation of 3D Squall Lines Using Spectral Elements 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...the results against those obtained with a fourth-order hyper- viscosity programmed in the same code. The main conclusion that arises is that tuning...second order operator which means that fewer communications are required by VMS+DC than by a hyper- viscosity method fewer communications translate into

  13. Thriving public-private partnership to fortify cooking oil in the West African Economic and Monetary Union (UEMOA) to control vitamin A deficiency: Faire Tache d'Huile en Afrique de l'Ouest.

    Science.gov (United States)

    Sablah, Mawuli; Klopp, Jennifer; Steinberg, Douglas; Touaoro, Zaoro; Laillou, Arnaud; Baker, Shawn

    2012-12-01

    In sub-Saharan Africa, more than 42% of children are at risk for vitamin A deficiency, and control of vitamin A deficiency will prevent more than 600,000 child deaths annually. In the West African Economic and Monetary Union (UEMOA), an estimated 54.3% of preschool-age children are vitamin A deficient and 13% of pregnant women have night blindness. To project the achievements of this West African coalition. This article documents the achievements, challenges, and lessons learned associated with the development of a public-private partnership to fortify vegetable oil in West Africa through project reports and industry assessments. National-level food consumption surveys identified cooking oil as a key vehicle for vitamin A. Stakeholders therefore advocated for the production of fortified vegetable oil at large scale, supported industrial assessments, and reinforced the capacity of cooking oil industries to implement vitamin A fortification through effective coordination of public and private partnerships tied with standards, regulations, and social marketing. Strong alliances for food fortification were established at the regional and national levels. Stakeholders also developed policies, adopted directives, built capacity, implemented social marketing, and monitored quality enforcement systems to sustain fortification for maximum public health impact. The synergy created resulted from the unique and complementary core competencies of all the partners under effective coordination. The initiative began with the 8 UEMOA member countries and now includes all 15 countries of the Economic Community of West African States (ECOWAS), plus Cameroon, Tanzania, and Mozambique, forming a sub-Saharan Africa-wide initiative on food fortification. All members of the Professional Association of Cooking Oil Industries of the West African Economic and Monetary Union (AIFO-UEMOA) now fortify edible oil with vitamin A. Through multisector cooperation, an estimated 70% of the population

  14. Analyzing the impact of land cover changes on water, energy and CO2 fluxes in the West African Sudanian Savannah using Eddy Covariance stations

    Science.gov (United States)

    Berger, Sina; Bliefernicht, Jan; Mauder, Matthias; Heinzeller, Dominikus; Guug, Samuel; Quansah, Emmanuel; Hingerl, Luitpold; Aduna, Aaron; Salack, Seyni; Kunstmann, Harald

    2017-04-01

    An investigation of the impacts of land surface changes in West Africa, one of the most vulnerable regions of the world with respect to climate changes, require a sound understanding of the land-atmosphere exchange processes and their feedback mechanisms. An investigation of the impacts of land surface changes in West Africa require a sound understanding of the land-atmosphere exchange processes and their feedback mechanisms. To improve our process understanding regarding land-atmosphere interactions in the West African Sudanian Savannah, three micro-meteorological stations based on the Eddy Covariance (EC) technique have been installed in northern Ghana and in southern Burkina Faso during two field campaigns in October 2012 and January 2013. The EC stations are located along a transect of changing land cover to investigate how land surface changes influence energy, water and CO2 fluxes between the land surface and the overlying atmosphere. The measurement sites are characterized by different vegetation cover due to different land use practices (near-natural versus intensively used grassland versus a mixture of fallow and cropland). Further site characteristics such as climate, soil and relief are similar. The analysis of the EC measurements was done for a period from January 2013 to August 2016 for four typical seasons in West Africa with different wind, moisture and radiation characteristics. Firstly, monsoonal winds from the southwest blowing over moist soils and lush vegetation between June and August during the monsoon peak, secondly, Harmattan winds from the northeast blowing over desiccated soils between December and February during the dry season, as well as transition periods with winds from various directions either over decaying vegetation and increasingly dry soils between September and November, or over growing vegetation and increasingly wet soils between March and May. Energy balance closures were best during the rainy season, however, we observed

  15. The Paternal Landscape along the Bight of Benin - Testing Regional Representativeness of West-African Population Samples Using Y-Chromosomal Markers.

    Directory of Open Access Journals (Sweden)

    Maarten H D Larmuseau

    Full Text Available Patterns of genetic variation in human populations across the African continent are still not well studied in comparison with Eurasia and America, despite the high genetic and cultural diversity among African populations. In population and forensic genetic studies a single sample is often used to represent a complete African region. In such a scenario, inappropriate sampling strategies and/or the use of local, isolated populations may bias interpretations and pose questions of representativeness at a macrogeographic-scale. The non-recombining region of the Y-chromosome (NRY has great potential to reveal the regional representation of a sample due to its powerful phylogeographic information content. An area poorly characterized for Y-chromosomal data is the West-African region along the Bight of Benin, despite its important history in the trans-Atlantic slave trade and its large number of ethnic groups, languages and lifestyles. In this study, Y-chromosomal haplotypes from four Beninese populations were determined and a global meta-analysis with available Y-SNP and Y-STR data from populations along the Bight of Benin and surrounding areas was performed. A thorough methodology was developed allowing comparison of population samples using Y-chromosomal lineage data based on different Y-SNP panels and phylogenies. Geographic proximity turned out to be the best predictor of genetic affinity between populations along the Bight of Benin. Nevertheless, based on Y-chromosomal data from the literature two population samples differed strongly from others from the same or neighbouring areas and are not regionally representative within large-scale studies. Furthermore, the analysis of the HapMap sample YRI of a Yoruban population from South-western Nigeria based on Y-SNPs and Y-STR data showed for the first time its regional representativeness, a result which is important for standard population and forensic genetic applications using the YRI sample

  16. Mitigation of Disasters Due to Severe Climate Events: from Policy to Practice,the West African Coastal Region Experience

    Science.gov (United States)

    Ediang, Okuku

    2016-07-01

    The distributive pattern of disaster due to severe climate events over the coast of West Africa especially Nigeria was examined using yearly mean disaster due to severe climatic events for the period of 30 years (1981-2010) from the marine stations in the coastal region of Nigeria. Graphical and isohyetal analyses were used to look into the patter of severe weather events over the area considered and to see if the severe weather events is increasing or not in the coast of West Africa especially the Nigerian coast and how to mitigate ,were policy relating to severe weather events are discussed. The paper conclude that due to the nature of coast of West Africa and Nigeria in particular, it enjoys longer severe weather events season than dry during the wet season, it is common to observe periods of enhanced or suppressed convective activity to persist over the wide areas for somedays. This paper also contributes to the wealth of knowledge already existing on Indigenous people play major roles in preserving the ecosystem especially during severe weather events . This has resulted in the recent calls for the integration of indigenous knowledge systems into global knowledge system strategies. Until now, integrating local knowledge systems into severe weather events and climate change concerns is not a completely new idea. A comprehensive review of literature using electronic and non-electronic databases formed the methodology. The paper conclude also by drawing the attention that by targeting Promoting indigenous people's participation in severe weather events and climate change issues is an important initiative towards adaptation and sustainable development in Africa and around the world. It is increasingly realized that the global knowledge system has dominated research, policies and programmes that address current severe weather events and climate change's challenges,mitigation and adaptation strategies.

  17. Linking regional stakeholder scenarios and shared socioeconomic pathways: Quantified West African food and climate futures in a global context.

    Science.gov (United States)

    Palazzo, Amanda; Vervoort, Joost M; Mason-D'Croz, Daniel; Rutting, Lucas; Havlík, Petr; Islam, Shahnila; Bayala, Jules; Valin, Hugo; Kadi Kadi, Hamé Abdou; Thornton, Philip; Zougmore, Robert

    2017-07-01

    The climate change research community's shared socioeconomic pathways (SSPs) are a set of alternative global development scenarios focused on mitigation of and adaptation to climate change. To use these scenarios as a global context that is relevant for policy guidance at regional and national levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise. In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate change. In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population coupled with rising incomes leads to increases in the region's imports. For West Africa, climate change is projected to have negative effects on both crop yields and grassland productivity, and a lack of investment may exacerbate these effects. Linking multi-stakeholder regional scenarios to the global SSPs ensures scenarios that are regionally appropriate and useful for policy development as evidenced in the case study, while allowing for a critical link to global contexts.

  18. The West African monsoon onset in 2006: sensitivity to surface albedo, orography, SST and synoptic scale dry-air intrusions using WRF

    Energy Technology Data Exchange (ETDEWEB)

    Flaounas, Emmanouil [Universite Pierre et Marie Curie (UPMC), LATMOS/IPSL, Paris cedex 05 (France); Janicot, Serge [UPMC, LOCEAN/IPSL, IRD, Paris (France); Bastin, Sophie [UPMC, LATMOS/IPSL, CNRS, Paris (France); Roca, Remy [UPMC, LMD/IPSL, CNRS, Paris (France)

    2012-02-15

    In order to test the sensitivity of the transitional phase of the 2006 West African monsoon (WAM) onset to different mechanisms, weather research and forecasting (WRF) model simulations have been carried out addressing the role of the Saharan heat low (SHL) and its sensitivity to the albedo field and to the northern Africa orography, and the role of the sea surface temperature (SST) in the eastern tropical Atlantic and Mediterranean. Lowering albedo over the desert region induces a northward location of the inter-tropical convergence zone (ITCZ), while removing mountains in North Africa reduces rainfall over West Africa. Shifting SST forward by 15 days leads to a northward location of the ITCZ before the WAM onset. However none of these factors modifies the timing of the WAM onset in 2006. The transitional phase of the 2006 WAM onset has been examined in more detail. The enhancement of SHL intensity, combined with the development of the oceanic cold tongue in the Guinea gulf, leads to low-level moisture flux divergence in the ITCZ reducing rainfall and increasing low-level humidity over the Sahel. However, weakening of convection can be clearly attributed to dry-air intrusions in mid-levels, originating from the subtropical westerly jet and associated with Rossby wave pattern over North Africa. Sensitivity tests on the synoptic scale forcing outside of the WRF model domain confirm the dominating role of large-scale dynamics to control the transitional phase of the WAM onset and its timing. However it is shown that the regional factors can modulate this larger scale forcing. (orig.)

  19. Views of West African surgeons on how well their educational and professional backgrounds may have prepared them for health leadership roles.

    Science.gov (United States)

    Mahmoud, Abdulraheem O; Nkanga, Dennis; Onakoya, Adeola

    2010-12-01

    Because of the appalling health indices in West Africa, Physicians there need to be at the forefront of the organizational challenge in managing and improving health systems. To collate the views of West African surgeons on how well their educational and professional backgrounds may have prepared them for leadership and managerial roles in health care, and draw appropriate policy implications. Filled structured questionnaires from 110 surgeons that were attending an annual conference were analyzed. The respondents' bio data, professional, educational, health administrative backgrounds were probed. Their views on justifications for physicians' involvement in health managerial roles, probable influence of some physicians' characteristic traits and professional attributes on health leadership roles, and suggestions for improvement were also collated. 71.8% of the respondents had held or were then holding health-related administrative posts; 90% had attended different varieties of management courses; 95.4% identified physicians as the inherent leaders of the health care team; but only 28.4% adjudged their health management role "strongly important" (28.4%) among their multi-faceted roles; and they largely agreed that some stated professional and characteristic traits of physicians tend to make them poor leaders and managers. Our findings suggest that the preparations that the respondents got from their formal and professional education for leadership and managerial roles in health care were not optimal. We recommend for a paradigm shift for physicians on health leadership issue which is to be facilitated by a well-focused short time duration health management course for all physicians, particularly specialists.

  20. Duffy Negative Antigen Is No Longer a Barrier to Plasmodium vivax – Molecular Evidences from the African West Coast (Angola and Equatorial Guinea)

    Science.gov (United States)

    Mendes, Cristina; Dias, Fernanda; Figueiredo, Joana; Mora, Vicenta Gonzalez; Cano, Jorge; de Sousa, Bruno; do Rosário, Virgílio E.; Benito, Agustin; Berzosa, Pedro; Arez, Ana Paula

    2011-01-01

    Background Plasmodium vivax shows a small prevalence in West and Central Africa due to the high prevalence of Duffy negative people. However, Duffy negative individuals infected with P. vivax have been reported in areas of high prevalence of Duffy positive people who may serve as supply of P. vivax strains able to invade Duffy negative erythrocytes. We investigated the presence of P. vivax in two West African countries, using blood samples and mosquitoes collected during two on-going studies. Methodology/Findings Blood samples from a total of 995 individuals were collected in seven villages in Angola and Equatorial Guinea, and 820 Anopheles mosquitoes were collected in Equatorial Guinea. Identification of the Plasmodium species was achieved by nested PCR amplification of the small-subunit rRNA genes; P. vivax was further characterized by csp gene analysis. Positive P. vivax-human isolates were genotyped for the Duffy blood group through the analysis of the DARC gene. Fifteen Duffy-negative individuals, 8 from Equatorial Guinea (out of 97) and 7 from Angola (out of 898), were infected with two different strains of P. vivax (VK210 and VK247). Conclusions In this study we demonstrated that P. vivax infections were found both in humans and mosquitoes, which means that active transmission is occurring. Given the high prevalence of infection in mosquitoes, we may speculate that this hypnozoite-forming species at liver may not be detected by the peripheral blood samples analysis. Also, this is the first report of Duffy negative individuals infected with two different strains of P. vivax (VK247 and classic strains) in Angola and Equatorial Guinea. This finding reinforces the idea that this parasite is able to use receptors other than Duffy to invade erythrocytes, which may have an enormous impact in P. vivax current distribution. PMID:21713024

  1. Views of West African surgeons on how well their educational and professional backgrounds may have prepared them for health leadership roles

    Science.gov (United States)

    Mahmoud, Abdulraheem O.; Nkanga, Dennis; Onakoya, Adeola

    2010-01-01

    Background: Because of the appalling health indices in West Africa, Physicians there need to be at the forefront of the organizational challenge in managing and improving health systems. Aim: To collate the views of West African surgeons on how well their educational and professional backgrounds may have prepared them for leadership and managerial roles in health care, and draw appropriate policy implications. Material and Methods: Filled structured questionnaires from 110 surgeons that were attending an annual conference were analyzed. The respondents’ bio data, professional, educational, health administrative backgrounds were probed. Their views on justifications for physicians’ involvement in health managerial roles, probable influence of some physicians’ characteristic traits and professional attributes on health leadership roles, and suggestions for improvement were also collated. Results: 71.8% of the respondents had held or were then holding health-related administrative posts; 90% had attended different varieties of management courses; 95.4% identified physicians as the inherent leaders of the health care team; but only 28.4% adjudged their health management role “strongly important” (28.4%) among their multi-faceted roles; and they largely agreed that some stated professional and characteristic traits of physicians tend to make them poor leaders and managers. Conclusions: Our findings suggest that the preparations that the respondents got from their formal and professional education for leadership and managerial roles in health care were not optimal. We recommend for a paradigm shift for physicians on health leadership issue which is to be facilitated by a well-focused short time duration health management course for all physicians, particularly specialists. PMID:22558571

  2. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics. In partnership with ...

  3. Cloud-Resolving Modeling Intercomparison Study of a Squall Line Case from MC3E - Properties of Convective Core

    Science.gov (United States)

    Fan, J.; Han, B.; Varble, A.; Morrison, H.; North, K.; Kollias, P.; Chen, B.; Dong, X.; Giangrande, S. E.; Khain, A.; Lin, Y.; Mansell, E.; Milbrandt, J.; Stenz, R.; Thompson, G.; Wang, Y.

    2016-12-01

    The large spread in CRM model simulations of deep convection and aerosol effects on deep convective clouds (DCCs) makes it difficult to (1) further our understanding of deep convection and (2) define "benchmarks" and then limit their use in parameterization developments. A constrained model intercomparsion study on a mid-latitude mesoscale squall line is performed using the Weather Research & Forecasting (WRF) model at 1-km horizontal grid spacing with eight cloud microphysics schemes to understand specific processes that lead to the large spreads of simulated convection and precipitation. Various observational data are employed to evaluate the baseline simulations. All simulations tend to produce a wider convective area but a much narrower stratiform area. The magnitudes of virtual potential temperature drop, pressure rise, and wind speed peak associated with the passage of the gust front are significantly smaller compared with the observations, suggesting simulated cool pools are weaker. Simulations generally overestimate the vertical velocity and radar reflectivity in convective cores compared with the retrievals. The modeled updraft velocity and precipitation have a significant spread across eight schemes. The spread of updraft velocity is the combination of both low-level pressure perturbation gradient (PPG) and buoyancy. Both PPG and thermal buoyancy are small for simulations of weak convection but both are large for those of strong convection. Ice-related parameterizations contribute majorly to the spread of updraft velocity, while they are not the reason for the large spread of precipitation. The understandings gained in this study can help to focus future observations and parameterization development.

  4. Cloud-resolving model intercomparison of an MC3E squall line case: Part I—Convective updrafts

    Science.gov (United States)

    Fan, Jiwen; Han, Bin; Varble, Adam; Morrison, Hugh; North, Kirk; Kollias, Pavlos; Chen, Baojun; Dong, Xiquan; Giangrande, Scott E.; Khain, Alexander; Lin, Yun; Mansell, Edward; Milbrandt, Jason A.; Stenz, Ronald; Thompson, Gregory; Wang, Yuan

    2017-09-01

    An intercomparison study of a midlatitude mesoscale squall line is performed using the Weather Research and Forecasting (WRF) model at 1 km horizontal grid spacing with eight different cloud microphysics schemes to investigate processes that contribute to the large variability in simulated cloud and precipitation properties. All simulations tend to produce a wider area of high radar reflectivity (Ze > 45 dBZ) than observed but a much narrower stratiform area. The magnitude of the virtual potential temperature drop associated with the gust front passage is similar in simulations and observations, while the pressure rise and peak wind speed are smaller than observed, possibly suggesting that simulated cold pools are shallower than observed. Most of the microphysics schemes overestimate vertical velocity and Ze in convective updrafts as compared with observational retrievals. Simulated precipitation rates and updraft velocities have significant variability across the eight schemes, even in this strongly dynamically driven system. Differences in simulated updraft velocity correlate well with differences in simulated buoyancy and low-level vertical perturbation pressure gradient, which appears related to cold pool intensity that is controlled by the evaporation rate. Simulations with stronger updrafts have a more optimal convective state, with stronger cold pools, ambient low-level vertical wind shear, and rear-inflow jets. Updraft velocity variability between schemes is mainly controlled by differences in simulated ice-related processes, which impact the overall latent heating rate, whereas surface rainfall variability increases in no-ice simulations mainly because of scheme differences in collision-coalescence parameterizations.

  5. Rainfall monitoring based on microwave links from cellular telecommunication networks: First results from a West African test bed

    Science.gov (United States)

    Doumounia, Ali; Gosset, Marielle; Cazenave, Frederic; Kacou, Modeste; Zougmore, François

    2014-08-01

    Rainfall monitoring based on commercial terrestrial microwave links is tested for the first time in Burkina Faso, in Sahelian West Africa. In collaboration with one national cellular phone operator, Telecel Faso, the attenuation on a 29 km long microwave link operating at 7 GHz was monitored at 1 s time rate for the monsoon season 2012. The time series of attenuation is transformed into rain rates and compared with rain gauge data. The method is successful in quantifying rainfall: 95% of the rainy days are detected. The correlation with the daily rain gauge series is 0.8, and the season bias is 6%. The correlation at the 5 min time step within each event is also high. These results demonstrate the potential interest of exploiting national and regional wireless telecommunication networks for monitoring rainfall in Africa, where operational rain gauge networks are degrading and the hydrometeorological risk increasing.

  6. The role of risk perception in willingness to respond to the 2014-2016 West African Ebola outbreak

    DEFF Research Database (Denmark)

    Gee, Stephanie; Skovdal, Morten

    2017-01-01

    workers is essential for an effective epidemic response, health workforce capacity in times of crisis may be significantly impacted by how risks are perceived by health staff. This study aimed to explore how risk perceptions influenced healthcare workers’ willingness to respond during this outbreak....... Methods: Through in-depth interviews with 11 front-line international health care workers who chose to respond to the West Africa outbreak, this qualitative study explores how perceptions of risk developed and subsequently mediated the decision to respond to the outbreak. Data was thematically organized...... using NVivo 10. Results: We found that numerous individual and social-level factors played a role in modifying risk perception in health workers. Institutional trust emerged as a key risk attenuator, as did past experience, self-efficacy, duty of care, humanitarian ethos, and cognitive heuristics...

  7. Specific and generic stem biomass and volume models of tree species in a West African tropical semi-deciduous forest

    DEFF Research Database (Denmark)

    Goussanou, Cédric A.; Guendehou, Sabin; Assogbadjo, Achille E.

    2016-01-01

    The quantification of the contribution of tropical forests to global carbon stocks and climate change mitigation requires availability of data and tools such as allometric equations. This study made available volume and biomass models for eighteen tree species in a semi-deciduous tropical forest...... in West Africa. Generic models were also developed for the forest ecosystem, and basic wood density determined for the tree species. Non-destructive sampling approach was carried out on five hundred and one sample trees to analyse stem volume and biomass. From the modelling of volume and biomass...... predictive ability for biomass. Given tree species richness of tropical forests, the study demonstrated the hypothesis that species-specific models are preferred to generic models, and concluded that further research should be oriented towards development of specific models to cover the full range...

  8. Two new species, including one representing a new genus, of the West African millipede family Campodesmidae (Diplopoda: Polydesmida

    Directory of Open Access Journals (Sweden)

    Didier VandenSpiegel

    2015-09-01

    Full Text Available A new genus, Campodesmoides gen. nov., is described to only encompass C. corniger sp. nov., from Cameroon. This genus and species is distinguished from the few known species of the small western African family Campodesmidae, all currently in Campodesmus, by the much longer antennae and legs, the normal pore formula with ozopores borne on porosteles, and the suberect and distally twisted gonopod, coupled with peculiar horns on a few anterior postcollum segments. A new Campodesmus is also described, C. alobatus sp. nov., from Ivory Coast, which differs from congeners primarily in the lack of a dorsal/lateral lobe on the otherwise usual and strongly subcircular gonopod telopodite, albeit the latter is not directed mesad, but held subparallel to the main body axis.

  9. Have abrupt climate variations of the last glacial possibly been muted in the south-west African tropics by counteracting mechanisms?

    Science.gov (United States)

    Hessler, I.; Dupont, L.; Handiani, D.; Steinke, S.; Groeneveld, J.; Merkel, U.; Paul, A.

    2012-04-01

    The last glacial period including the last deglaciation (73.5-10 ka BP) is characterised by abrupt shifts between extreme climatic conditions. Millennial-scale climate variations associated with North Atlantic Heinrich Stadials (HSs) are thought to be transmitted by both the atmospheric and oceanic circulation resulting in a near-global footprint. It is further thought that HSs are closely related to a reduction or shut-down of the Atlantic Meridional Overturning Circulation, which, according to the bipolar-seesaw hypothesis, leads to the accumulation of heat in the South Atlantic. In addition, it is hypothesised that HSs result in a southward shift of the Intertropical Convergence Zone which then would likely influence the vegetation composition in the African tropics. To investigate the impact of HSs on the terrestrial African realm and the south-east Atlantic we reconstructed the vegetation development in Angola and the southern Congo Basin as well as the sea surface temperatures (SST) of the south-east Atlantic using marine sediments of ODP Site 1078 (11° 55'S, 13° 24'E, 427 m water depth). Two species of planktonic foraminifera were selected to reconstruct variations in surface water conditions in the south-east Atlantic. Due the ecological and seasonal preferences of Globigerinoides ruber (pink) this species provides a good tool to estimate SST variations during the southern hemisphere summer. In contrast, Globigerina bulloides is representing the Benguela Upwelling System during the southern hemisphere winter. While Mg/Ca-based SSTs of G. ruber (pink) were significantly higher by 1° -2° C during periods of abrupt climate change, the impact of HSs during southern hemisphere winter is less obvious. However, although there are several vegetation records that show an impact of HSs in the African tropics, our high-resolution pollen record from ODP Site 1078 reflects no vegetation changes during periods of HSs. Model simulations conducted with an Earth System

  10. Performance and Parasitology of Semi-intensively Managed West African Dwarf Sheep Exposed to Gastrointestinal Helminth Infected Paddocks and Varied Protein-energy Feeds.

    Science.gov (United States)

    Sonibare, Adekayode Olarinwaju; Sowande, Olusiji Sunday; Iposu, Shamusideen Oladeinde; Luka, Joshua; Ayankosoi, Michael; Egbetade, Adeniyi Olugbega

    2016-01-01

    The performance and parasitology of semi-intensively managed West African dwarf (WAD) lambs were evaluated following exposure to gastrointestinal helminth infected paddock and varied protein-energy feeds. Twenty four lambs obtained from the Department of Animal Breeding and Genetics and brought to Directorate of University farm (DUFARM) of Federal University of Agriculture Abeokuta, Ogun state, Nigeria, where the research was carried out in 2014, were grouped into four each containing six animals based on different energy-protein feed combination thus; group 1(G1) low energy low protein, group 2 (G2) low energy high protein, group 3 (G3) high energy low protein and group 4 (G4) high energy high protein. Experimental animals were supplemented with concentrate feed after grazing on daily in a nematode infected paddock. Clinical signs of infection were monitored. Live weight, faecal egg count (FEC), worm counts, packed cell volume (PCV), haemoglobin concentration (Hb) and red blood cell count (RBC) were determined using standard methods. Anorexia and intermittent diarrhea were the observed signs. Worm counts did not differ significantly (P=0.309) among the groups. The weight and FEC differed significantly (Psuperior performance when compared to the other groups. It is therefore recommended that feed high in protein content is capable of mitigating deleterious effect of gastrointestinal helminth parasitism.

  11. Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa.

    Science.gov (United States)

    Evans, Ben J; Carter, Timothy F; Greenbaum, Eli; Gvoždík, Václav; Kelley, Darcy B; McLaughlin, Patrick J; Pauwels, Olivier S G; Portik, Daniel M; Stanley, Edward L; Tinsley, Richard C; Tobias, Martha L; Blackburn, David C

    2015-01-01

    African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon) to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana) and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups).

  12. Community-based reports of morbidity, mortality, and health-seeking behaviours in four Monrovia communities during the West African Ebola epidemic.

    Science.gov (United States)

    McLean, Kristen E; Abramowitz, Sharon Alane; Ball, Jacob D; Monger, Josephine; Tehoungue, Kodjo; McKune, Sarah Lindley; Fallah, Mosoka; Omidian, Patricia A

    2016-07-27

    The goal of this study was to assess morbidity, mortality, and health-seeking behaviours during the 2014 Ebola outbreak in Monrovia, Liberia. This study examined commonly reported symptoms of illness, pre-clinical diagnostic practices, typical healthcare-seeking strategies, and health resources available to populations, in order to identify salient needs and gaps in healthcare that would inform local emergency response efforts. Semi-structured interviews were conducted with household members in four Monrovia neighbourhoods. Researchers used a multi-stage cluster approach to recruit participants. Within 555 households sampled, 505 individuals were reported sick (69%) or recently sick (38%) or deceased (7%). Common self-diagnoses included malaria, hypertension, influenza, typhoid, and Ebola. The most cited health-seeking strategy was to purchase medications from the private sector. Respondents also obtained healthcare from community members known to have medical experience. Findings suggest that non-formal healthcare systems played an important role in managing morbidity during the West African Ebola virus disease (EVD) outbreak. Lay community members engaged in complex assessments of health symptoms and sought biomedical care at rates perhaps higher than anticipated during the response. This study highlights how informal networks of healthcare providers can play an important role in preventing and curbing future emerging disease outbreaks.

  13. Undetectable plasma viral load predicts normal survival in HIV-2-infected people in a West African village

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    Ricard Dominique

    2010-05-01

    Full Text Available Abstract Background There have been no previous studies of the long-term survival and temporal changes in plasma viral load among HIV-2 infected subjects. Methods 133 HIV-2 infected and 158 HIV-uninfected subjects from a rural area in North-west Guinea-Bissau, West Africa were enrolled into a prospective cohort study in 1991 and followed-up to mid-2009. Data were collected on four occasions during that period on HIV antibodies, CD4% and HIV-2 plasma viral load. Results Median age (interquartile range [IQR] of HIV-2 infected subjects at time of enrollment was 47 (36, 60 years, similar to that of HIV-uninfected control subjects, 49 (38, 62 (p = 0.4. Median (IQR plasma viral load and CD4 percentage were 347 (50, 4,300 copies/ml and 29 (22, 35 respectively. Overall loss to follow-up to assess vital status was small, at 6.7% and 6.3% for HIV-2 infected and uninfected subjects respectively. An additional 17 (12.8% and 16 (10.1% of HIV-2 infected and uninfected subjects respectively were censored during follow-up due to infection with HIV-1. The mortality rate per 100 person-years (95% CI was 4.5 (3.6, 5.8 among HIV-2 infected subjects compared to 2.1 (1.6, 2.9 among HIV-uninfected (age-sex adjusted rate ratio 1.9 (1.3, 2.8, p Viral load measurements were available for 98%, 78%, 77% and 61% HIV-2 infected subjects who were alive and had not become super-infected with HIV-1, in 1991, 1996, 2003 and 2006 respectively. Median plasma viral load (RNA copies per ml (IQR did not change significantly over time, being 150 (50, 1,554; n = 77 in 1996, 203 (50, 2,837; n = 47 in 2003 and 171 (50, 497; n = 31 in 2006. Thirty seven percent of HIV-2 subjects had undetectable viraemia ( Conclusions A substantial proportion of HIV-2 infected subjects in this cohort have stable plasma viral load, and those with an undetectable viral load (37% at study entry had a normal survival rate. However, the sequential laboratory findings need to be interpreted with caution given

  14. Multilateral Machinations: The Strategic Utility of African International Organizations in the Pursuit of National Security Interests in West Africa and the Greater Horn

    OpenAIRE

    Warner, Jason

    2016-01-01

    Since the end of decolonization, African states have created a series of dense and overlapping international organizations (IOs) at both the continental (Organization of African Unity/African Union) and sub-regional (regional economic community, REC) levels of analysis, both of which broadly claim to fulfill similar mandates on a range of issues, including the provision of collective security. Given that every African state is embedded within at least two African IOs with similar mandates – w...

  15. Nutritional status of HIV-infected patients during the first year HAART in two West African cohorts.

    Science.gov (United States)

    Sicotte, Maryline; Bemeur, Chantal; Diouf, Assane; Zunzunegui, Maria Victoria; Nguyen, Vinh-Kim

    2015-05-01

    To examine the association between nutritional markers at initiation and during follow up in two different cohorts of HIV-infected adults initiating highly active antiretroviral therapy (HAART) in West Africa. The ATARAO study was a one year prospective study carried in Mali. It consisted of a sample of consecutive patients initiating HAART in one of four participating centers during that period. Data were collected at time of treatment initiation (baseline) and every 3 months thereafter. The ANRS 1290 study followed Senegalese patients recruited in similar conditions. Bivariate analyses were used to identify nutritional and immunological covariates of malnutrition at baseline. Longitudinal trajectories of body mass index, hemoglobin and albumin, and their associated factors, were evaluated using mixed linear models. In ATARAO, 250 participants were retained for analyses; of which, 36% had a BMI nutritional and immunological status at baseline, as well as during treatment. In spite of therapy, malnutrition is associated with negative clinical and treatment outcomes which suggests that HAART may not be sufficient to address co-existing nutritional deficiencies.

  16. Adaptation of soil nitrifiers to very low nitrogen level jeopardizes the efficiency of chemical fertilization in west african moist savannas.

    Science.gov (United States)

    Assémien, Féline L; Pommier, Thomas; Gonnety, Jean T; Gervaix, Jonathan; Le Roux, Xavier

    2017-08-31

    The moist savanna zone covers 0.5 × 10 6 km 2 in West Africa and is characterized by very low soil N levels limiting primary production, but the ecology of nitrifiers in these (agro)ecosystems is largely unknown. We compared the effects of six agricultural practices on nitrifier activity, abundance and diversity at nine sites in central Ivory Coast. Treatments, including repeated fertilization with ammonium and urea, had no effect on nitrification and crop N status after 3 to 5 crop cycles. Nitrification was actually higher at low than medium ammonium level. The nitrifying community was always dominated by ammonia oxidizing archaea and Nitrospira. However, the abundances of ammonia oxidizing bacteria, AOB, and Nitrobacter increased with fertilization after 5 crop cycles. Several AOB populations, some affiliated to Nitrosospira strains with urease activity or adapted to fluctuating ammonium levels, emerged in fertilized plots, which was correlated to nitrifying community ability to benefit from fertilization. In these soils, dominant nitrifiers adapted to very low ammonium levels have to be replaced by high-N nitrifiers before fertilization can stimulate nitrification. Our results show that the delay required for this replacement is much longer than ever observed for other terrestrial ecosystems, i.e. > 5 crop cycles, and demonstrate for the first time that nitrifier characteristics jeopardize the efficiency of fertilization in moist savanna soils.

  17. Patterning and predicting aquatic insect richness in four West-African coastal rivers using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Edia E.O.

    2010-10-01

    Full Text Available Despite their importance in stream management, the aquatic insect assemblages are still little known in West Africa. This is particularly true in South-Eastern Ivory Coast, where aquatic insect assemblages were hardly studied. We therefore aimed at characterising aquatic insect assemblages on four coastal rivers in South-Eastern Ivory Coast. Patterning aquatic insect assemblages was achieved using a Self-Organizing Map (SOM, an unsupervised Artificial Neural Networks (ANN method. This method was applied to pattern the samples based on the richness of five major orders of aquatic insects (Diptera, Ephemeroptera, Coleoptera, Trichoptera and Odonata. This permitted to identify three clusters that were mainly related to the local environmental status of sampling sites. Then, we used the environmental characteristics of the sites to predict, using a multilayer perceptron neural network (MLP, trained by BackPropagation algorithm (BP, a supervised ANN, the richness of the five insect orders. The BP showed high predictability (0.90 for both Diptera and Trichoptera, 0.84 for both Coleoptera and Odonata, 0.69 for Ephemeroptera. The most contributing variables in predicting the five insect order richness were pH, conductivity, total dissolved solids, water temperature, percentage of rock and the canopy. This underlines the crucial influence of both instream characteristics and riparian context.

  18. Epidemiology and Characteristics of Kikuchi-Fujimoto Disease in the African-Descent Population of Martinique, French West Indies.

    Science.gov (United States)

    Moinet, Florence; Molinié, Vincent; Béraud, Guillaume; Polomat, Katlyne; Cordel, Nadège; Sainte-Marie, Dominique; Duffas, Olivier; Duflo, Suzy; Bomahou, Charlène; Arfi, Serge; Deligny, Christophe

    2016-12-01

    To provide an epidemiologic description of Kikuchi-Fujimoto disease (KFD), and to describe its relationship with systemic lupus erythematosus (SLE) in a population of sub-Saharan origin. Patients were retrospectively included on the basis of lymph node histology compatible with KFD reported in Martinique from 1991 until 2013. In order to describe the characteristics of the disease in a larger cohort, we subsequently included more patients of Afro-Caribbean origin from Guadeloupe and French Guiana. In Martinique, mean annual incidence between 1991 and 2013 was 2.78 cases for 1 million inhabitants (95% confidence interval 1.73-3.93). A total of 36 Afro-Caribbean patients from the 3 French American regions were included. Mean age was 30.5 years (range 5-59 years) and the female:male ratio was 3:1. The main characteristics were cervical adenopathies (88.8%), fever (83.3%), asthenia (73.0%), weight loss (64.4%), and recurrence in 33.3%. KFD was associated with lupus (n = 9 for SLE, n = 2 for cutaneous lupus) in 36.6% (11 of 30). We report the first epidemiologic description of KFD in a population of sub-Saharan origin. According to our data, this disease is present in the black African diaspora and is strongly associated with autoimmune diseases, particularly lupus. © 2016, American College of Rheumatology.

  19. Standardizing visual control devices for tsetse flies: West African species Glossina tachinoides, G. palpalis gambiensis and G. morsitans submorsitans.

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Rayaisse

    Full Text Available Here we describe field trials designed to standardize tools for the control of Glossina tachinoides, G. palpalis gambiensis and G.morsitans submorsitans in West Africa based on existing trap/target/bait technology. Blue and black biconical and monoconical traps and 1 m(2 targets were made in either phthalogen blue cotton, phthalogen blue cotton/polyester or turquoise blue polyester/viscose (all with a peak reflectance between 450-480 nm and a black polyester. Because targets were covered in adhesive film, they proved to be significantly better trapping devices than either of the two trap types for all three species (up to 14 times more for G. tachinoides, 10 times more for G. palpalis gambiensis, and 6.5 times for G. morsitans submorsitans. The relative performance of the devices in the three blue cloths tested was the same when unbaited or baited with a mixture of phenols, 1-octen-3-ol and acetone. Since insecticide-impregnated devices act via contact with flies, we enumerated which device (traps or targets served as the best object for flies to land on by also covering the cloth parts of traps with adhesive film. Despite the fact that the biconical trap proved to be the best landing device for the three species, the difference over the target (20-30% was not significant. This experiment also allowed an estimation of trap efficiency, i.e. the proportion of flies landing on a trap that are caught in its cage. A low overall efficiency of the biconical or monoconical traps of between 11-24% was recorded for all three species. These results show that targets can be used as practical devices for population suppression of the three species studied. Biconical traps can be used for population monitoring, but a correction factor of 5-10 fold needs to be applied to captures to compensate for the poor trapping efficiency of this device for the three species.

  20. Standardizing visual control devices for tsetse flies: West African species Glossina tachinoides, G. palpalis gambiensis and G. morsitans submorsitans.

    Science.gov (United States)

    Rayaisse, Jean-Baptiste; Kröber, Thomas; McMullin, Andrew; Solano, Philippe; Mihok, Steve; Guerin, Patrick M

    2012-01-01

    Here we describe field trials designed to standardize tools for the control of Glossina tachinoides, G. palpalis gambiensis and G.morsitans submorsitans in West Africa based on existing trap/target/bait technology. Blue and black biconical and monoconical traps and 1 m(2) targets were made in either phthalogen blue cotton, phthalogen blue cotton/polyester or turquoise blue polyester/viscose (all with a peak reflectance between 450-480 nm) and a black polyester. Because targets were covered in adhesive film, they proved to be significantly better trapping devices than either of the two trap types for all three species (up to 14 times more for G. tachinoides, 10 times more for G. palpalis gambiensis, and 6.5 times for G. morsitans submorsitans). The relative performance of the devices in the three blue cloths tested was the same when unbaited or baited with a mixture of phenols, 1-octen-3-ol and acetone. Since insecticide-impregnated devices act via contact with flies, we enumerated which device (traps or targets) served as the best object for flies to land on by also covering the cloth parts of traps with adhesive film. Despite the fact that the biconical trap proved to be the best landing device for the three species, the difference over the target (20-30%) was not significant. This experiment also allowed an estimation of trap efficiency, i.e. the proportion of flies landing on a trap that are caught in its cage. A low overall efficiency of the biconical or monoconical traps of between 11-24% was recorded for all three species. These results show that targets can be used as practical devices for population suppression of the three species studied. Biconical traps can be used for population monitoring, but a correction factor of 5-10 fold needs to be applied to captures to compensate for the poor trapping efficiency of this device for the three species.

  1. Ethno-botanical study of the African star apple (Chrysophyllum albidum G. Don in the Southern Benin (West Africa

    Directory of Open Access Journals (Sweden)

    Houessou Laurent G

    2012-10-01

    Full Text Available Abstract Background In addition to plant species biology and ecology, understanding the folk knowledge systems related to the use of plant species and how this knowledge system influences the conservation of plant species is an important issue in the implementation of sustainable strategies of biodiversity conservation programs. This study aimed at providing information on the use and local knowledge variation on Chrysophyllum albidum G. Don a multipurpose tree species widely used in southern Benin. Methods Data was collected through 210 structured interviews. Informants were randomly selected from ten villages. The fidelity level and use value of different plant parts of C. albidum were estimated. The variation in ethnobotanical knowledge was assessed by comparing the use value between ethnic, gender and age groups. In order to assess the use pattern of the different plant parts in folk medicine, a correspondence analysis was carried out on the frequency citation of plant parts. Results Four categories of use (food, medicine, firewood and timber were recorded for C. albidum. With respect to the different plant parts, the fleshy pulp of the African star apple fruit showed high consensus degree as food among the informants. Fifteen diseases were reported to be treated by the different parts of C. albidum in the region. Correspondence analysis revealed the specificity of each part in disease treatment. There was no significant difference among ethnic groups regarding the ethno-botanical use value of C. albidum. However, significant difference existed between genders and among age groups regarding the knowledge of the medical properties of this species. Conclusions C. albidum is well integrated in the traditional agroforestry system of the southern Benin. Despite its multipurpose character, this species remains underutilized in the region. Considering the current threat of habitat degradation, action is needed in order to ensure the long term

  2. Evaluating LSM-Based Water Budgets Over a West African Basin Assisted with a River Routing Scheme

    Science.gov (United States)

    Getirana, Augusto C. V.; Boone, Aaron; Peugeot, Christophe

    2014-01-01

    Within the framework of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project phase 2 (ALMIP-2), this study evaluates the water balance simulated by the Interactions between Soil, Biosphere, and Atmosphere (ISBA) over the upper Oum River basin, in Benin, using a mesoscale river routing scheme (RRS). The RRS is based on the nonlinear Muskingum Cunge method coupled with two linear reservoirs that simulate the time delay of both surface runoff and base flow that are produced by land surface models. On the basis of the evidence of a deep water-table recharge in that region,a reservoir representing the deep-water infiltration (DWI) is introduced. The hydrological processes of the basin are simulated for the 2005-08 AMMA field campaign period during which rainfall and stream flow data were intensively collected over the study area. Optimal RRS parameter sets were determined for three optimization experiments that were performed using daily stream flow at five gauges within the basin. Results demonstrate that the RRS simulates stream flow at all gauges with relative errors varying from -22% to 3% and Nash-Sutcliffe coefficients varying from 0.62 to 0.90. DWI varies from 24% to 67% of the base flow as a function of the sub-basin. The relatively simple reservoir DWI approach is quite robust, and further improvements would likely necessitate more complex solutions (e.g., considering seasonality and soil type in ISBA); thus, such modifications are recommended for future studies. Although the evaluation shows that the simulated stream flows are generally satisfactory, further field investigations are necessary to confirm some of the model assumptions.

  3. Photochemical ozone production in tropical squall line convection during NASA Global Tropospheric Experiment/Amazon Boundary Layer Experiment 2A

    Science.gov (United States)

    Pickering, Kenneth E.; Thompson, Anne M.; Tao, Wei-Kuo; Simpson, Joanne; Scala, John R.

    1991-01-01

    The role of convection was examined in trace gas transport and ozone production in a tropical dry season squall line sampled on August 3, 1985, during NASA Global Tropospheric Experiment/Amazon Boundary Layer Experiment 2A (NASA GTE/ABLE 2A) in Amazonia, Brazil. Two types of analyses were performed. Transient effects within the cloud are examined with a combination of two-dimensional cloud and one-dimensional photochemical modeling. Tracer analyses using the cloud model wind fields yield a series of cross sections of NO(x), CO, and O3 distribution during the lifetime of the cloud; these fields are used in the photochemical model to compute the net rate of O3 production. At noon, when the cloud was mature, the instantaneous ozone production potential in the cloud is between 50 and 60 percent less than in no-cloud conditions due to reduced photolysis and cloud scavenging of radicals. Analysis of cloud inflows and outflows is used to differentiate between air that is undisturbed and air that has been modified by the storm. These profiles are used in the photochemical model to examine the aftereffects of convective redistribution in the 24-hour period following the storm. Total tropospheric column O3 production changed little due to convection because so little NO(x) was available in the lower troposphere. However, the integrated O3 production potential in the 5- to 13-km layer changed from net destruction to net production as a result of the convection. The conditions of the August 3, 1985, event may be typical of the early part of the dry season in Amazonia, when only minimal amounts of pollution from biomass burning have been transported into the region.

  4. Biogenic nitrogen oxide emissions from soils: impact on NOx and ozone over west Africa during AMMA (African Monsoon Multidisciplinary Analysis: observational study

    Directory of Open Access Journals (Sweden)

    J. B. McQuaid

    2008-04-01

    Full Text Available Chemical and meteorological parameters measured on board the Facility for Airborne Atmospheric Measurements (FAAM BAe 146 Atmospheric Research Aircraft during the African Monsoon Multidisciplinary Analysis (AMMA campaign are presented to show the impact of NOx emissions from recently wetted soils in West Africa. NO emissions from soils have been previously observed in many geographical areas with different types of soil/vegetation cover during small scale studies and have been inferred at large scales from satellite measurements of NOx. This study is the first dedicated to showing the emissions of NOx at an intermediate scale between local surface sites and continental satellite measurements. The measurements reveal pronounced mesoscale variations in NOx concentrations closely linked to spatial patterns of antecedent rainfall. Fluxes required to maintain the NOx concentrations observed by the BAe-146 in a number of cases studies and for a range of assumed OH concentrations (1×106 to 1×107 molecules cm−3 are calculated to be in the range 8.4 to 36.1 ng N m−2 s−1. These values are comparable to the range of fluxes from 0.5 to 28 ng N m−2 s−1 reported from small scale field studies in a variety of non-nutrient rich tropical and sub-tropical locations reported in the review of Davidson and Kingerlee (1997. The fluxes calculated in the present study have been scaled up to cover the area of the Sahel bounded by 10 to 20 N and 10 E to 20 W giving an estimated emission of 0.03 to 0.30 Tg N from this area for July and August 2006. The observed chemical data also suggest that the NOx emitted from soils is taking part in ozone formation as ozone concentrations exhibit similar fine scale structure to the NOx, with enhancements over the wet soils. Such variability can not be explained on the basis of transport from other areas. Delon et al. (2008 is a companion paper to this one which models the impact of soil NOx emissions on the NOx and ozone

  5. Anaemia and zidovudine-containing antiretroviral therapy in paediatric antiretroviral programmes in the IeDEA Paediatric West African Database to evaluate AIDS

    Directory of Open Access Journals (Sweden)

    Lorna A Renner

    2013-09-01

    Full Text Available Introduction: There is a risk of anaemia among HIV-infected children on antiretroviral therapy (ART containing zidovudine (ZDV recommended in first-line regimens in the WHO guidelines. We estimated the risk of severe anaemia after initiation of a ZDV-containing regimen in HIV-infected children included in the IeDEA West African database. Methods: Standardized collection of data from HIV-infected children (positive PCR<18 months or positive serology ≥18 months followed up in HIV programmes was included in the regional IeDEA West Africa collaboration. Ten clinical centres from seven countries contributed (Benin, Burkina Faso, Côte d'Ivoire, Gambia, Ghana, Mali and Senegal to this collection. Inclusion criteria were age <16 years and starting ART. We explored the data quality of haemoglobin documentation over time and the incidence and predictors of severe anaemia (Hb<7g/dL per 100 child-years of follow-up over the duration of first-line antiretroviral therapy. Results: As of December 2009, among the 2933 children included in the collaboration, 45% were girls, median age was five years; median CD4 cell percentage was 13%; median weight-for-age z-score was−2.7; and 1772 (60.4% had a first-line ZDV-containing regimen. At baseline, 70% of the children with a first-line ZDV-containing regimen had a haemoglobin measure available versus 76% in those not on ZDV (p≤0.01: the prevalence of severe anaemia was 3.0% (n=38 in the ZDV group versus 10.2% (n=89 in those without (p<0. 01. Over the first-line follow-up, 58.9% of the children had ≥1 measure of haemoglobin available in those exposed to ZDV versus 60.4% of those not (p=0.45. Severe anaemia occurred in 92 children with an incidence of 2.47 per 100 child-years of follow-up in those on a ZDV-containing regimen versus 4.25 in those not (p≤0.01. Adjusted for age at ART initiation and first-line regimen, a weight-for-age z-score ≤−3 was a strong predictor associated with a 5.59 times risk of

  6. How many species and under what names? Using DNA barcoding and GenBank data for west Central African amphibian conservation.

    Science.gov (United States)

    Deichmann, Jessica L; Mulcahy, Daniel G; Vanthomme, Hadrien; Tobi, Elie; Wynn, Addison H; Zimkus, Breda M; McDiarmid, Roy W

    2017-01-01

    Development projects in west Central Africa are proceeding at an unprecedented rate, often with little concern for their effects on biodiversity. In an attempt to better understand potential impacts of a road development project on the anuran amphibian community, we conducted a biodiversity assessment employing multiple methodologies (visual encounter transects, auditory surveys, leaf litter plots and pitfall traps) to inventory species prior to construction of a new road within the buffer zone of Moukalaba-Doudou National Park, Gabon. Because of difficulties in morphological identification and taxonomic uncertainty of amphibian species observed in the area, we integrated a DNA barcoding analysis into the project to improve the overall quality and accuracy of the species inventory. Based on morphology alone, 48 species were recognized in the field and voucher specimens of each were collected. We used tissue samples from specimens collected at our field site, material available from amphibians collected in other parts of Gabon and the Republic of Congo to initiate a DNA barcode library for west Central African amphibians. We then compared our sequences with material in GenBank for the genera recorded at the study site to assist in identifications. The resulting COI and 16S barcode library allowed us to update the number of species documented at the study site to 28, thereby providing a more accurate assessment of diversity and distributions. We caution that because sequence data maintained in GenBank are often poorly curated by the original submitters and cannot be amended by third-parties, these data have limited utility for identification purposes. Nevertheless, the use of DNA barcoding is likely to benefit biodiversity inventories and long-term monitoring, particularly for taxa that can be difficult to identify based on morphology alone; likewise, inventory and monitoring programs can contribute invaluable data to the DNA barcode library and the taxonomy of

  7. How many species and under what names? Using DNA barcoding and GenBank data for west Central African amphibian conservation.

    Directory of Open Access Journals (Sweden)

    Jessica L Deichmann

    Full Text Available Development projects in west Central Africa are proceeding at an unprecedented rate, often with little concern for their effects on biodiversity. In an attempt to better understand potential impacts of a road development project on the anuran amphibian community, we conducted a biodiversity assessment employing multiple methodologies (visual encounter transects, auditory surveys, leaf litter plots and pitfall traps to inventory species prior to construction of a new road within the buffer zone of Moukalaba-Doudou National Park, Gabon. Because of difficulties in morphological identification and taxonomic uncertainty of amphibian species observed in the area, we integrated a DNA barcoding analysis into the project to improve the overall quality and accuracy of the species inventory. Based on morphology alone, 48 species were recognized in the field and voucher specimens of each were collected. We used tissue samples from specimens collected at our field site, material available from amphibians collected in other parts of Gabon and the Republic of Congo to initiate a DNA barcode library for west Central African amphibians. We then compared our sequences with material in GenBank for the genera recorded at the study site to assist in identifications. The resulting COI and 16S barcode library allowed us to update the number of species documented at the study site to 28, thereby providing a more accurate assessment of diversity and distributions. We caution that because sequence data maintained in GenBank are often poorly curated by the original submitters and cannot be amended by third-parties, these data have limited utility for identification purposes. Nevertheless, the use of DNA barcoding is likely to benefit biodiversity inventories and long-term monitoring, particularly for taxa that can be difficult to identify based on morphology alone; likewise, inventory and monitoring programs can contribute invaluable data to the DNA barcode library and

  8. Overcoming Phosphorus Deficiency in West African Pearl Millet and Sorghum Production Systems: Promising Options for Crop Improvement.

    Science.gov (United States)

    Gemenet, Dorcus C; Leiser, Willmar L; Beggi, Francesca; Herrmann, Ludger H; Vadez, Vincent; Rattunde, Henry F W; Weltzien, Eva; Hash, Charles T; Buerkert, Andreas; Haussmann, Bettina I G

    2016-01-01

    West Africa (WA) is among the most food insecure regions. Rapid human population growth and stagnating crop yields greatly contribute to this fact. Poor soil fertility, especially low plant available phosphorus (P) is constraining food production in the region. P-fertilizer use in WA is among the lowest in the world due to inaccessibility and high prices, often unaffordable to resource-poor subsistence farmers. This article provides an overview of soil P-deficiency in WA and opportunities to overcome it by exploiting sorghum and pearl millet genetic diversity. The topic is examined from the perspectives of plant breeding, soil science, plant physiology, plant nutrition, and agronomy, thereby referring to recent results obtained in a joint interdisciplinary research project, and reported literature. Specific objectives are to summarize: (1) The global problem of P scarcity and how it will affect WA farmers; (2) Soil P dynamics in WA soils; (3) Plant responses to P deficiency; (4) Opportunities to breed for improved crop adaptation to P-limited conditions; (5) Challenges and trade-offs for improving sorghum and pearl millet adaptation to low-P conditions in WA; and (6) Systems approaches to address soil P-deficiency in WA. Sorghum and pearl millet in WA exhibit highly significant genetic variation for P-uptake efficiency, P-utilization efficiency, and grain yield under P-limited conditions indicating the possibility of breeding P-efficient varieties. Direct selection under P-limited conditions was more efficient than indirect selection under high-P conditions. Combining P-uptake and P-utilization efficiency is recommendable for WA to avoid further soil mining. Genomic regions responsible for P-uptake, P-utilization efficiency, and grain yield under low-P have been identified in WA sorghum and pearl millet, and marker-assisted selection could be possible once these genomic regions are validated. Developing P-efficient genotypes may not, however, be a sustainable

  9. Overcoming Phosphorus Deficiency in West African Pearl Millet and Sorghum Production Systems: Promising Options for Crop Improvement

    Directory of Open Access Journals (Sweden)

    Dorcus C. GEMENET

    2016-09-01

    Full Text Available West Africa (WA is among the most food insecure regions. Rapid human population growth and stagnating crop yields greatly contribute to this fact. Poor soil fertility, especially low plant available phosphorus (P is constraining food production in the region. P-fertilizer use in WA is among the lowest in the world due to inaccessibility and high prices, unaffordable to resource-poor farmers. This article provides an overview of soil P-deficiency in WA and opportunities to overcome it by exploiting sorghum and pearl millet genetic diversity. The topic is examined from the perspectives of plant breeding, soil science, plant physiology, plant nutrition, and agronomy, thereby referring to recent results obtained in a joint interdisciplinary research project, and reported literature. Specific objectives are to summarize: (1 The global problem of P scarcity and how it will affect WA farmers; (2 Soil P dynamics in WA soils; (3 Plant responses to P deficiency; (4 Opportunities to breed for improved crop adaptation to P-limited conditions; (5 Challenges and trade-offs for improving sorghum and pearl millet adaptation to low-P conditions in WA; and (6 Systems approaches to addressing soil P-deficiency in WA.Sorghum and pearl millet in WA exhibit highly significant genetic variation for P-uptake efficiency, P-utilization efficiency, and grain yield under P-limited conditions indicating the possibility of breeding P-efficient varieties. Direct selection under P-limited conditions was more efficient than indirect selection under high-P conditions. Combining P-uptake and P-utilization efficiency is recommendable for WA to avoid further soil mining. Genomic regions responsible for P-uptake, P-utilization efficiency, and grain yield under low-P have been identified in WA sorghum and pearl millet, and marker-assisted selection could be possible once these genomic regions are validated. Developing P-efficient genotypes may not however be a sustainable solution in

  10. Performance and Parasitology of Semi-intensively Managed West African Dwarf Sheep Exposed to Gastrointestinal Helminth Infect-ed Paddocks and Varied Protein-energy Feeds

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    Adekayode Olarinwaju SONIBARE

    2016-12-01

    Full Text Available Background: The performance and parasitology of semi-intensively managed West African dwarf (WAD lambs were evaluated following exposure to gastrointestinal helminth infected paddock and varied protein-energy feeds.Methods: Twenty four lambs obtained from the Department of Animal Breeding and Genetics and brought to Directorate of University farm (DUFARM of Federal University of Agriculture Abeokuta, Ogun state, Nigeria, where the research was carried out in 2014, were grouped into four each containing six animals based on different energy-protein feed combination thus; group 1(G1 low energy low protein, group 2 (G2 low energy high protein, group 3 (G3 high energy low protein and group 4 (G4 high energy high protein. Experimental animals were supplemented with concentrate feed after grazing on daily in a nematode infected paddock. Clinical signs of infection were monitored. Live weight, faecal egg count (FEC, worm counts, packed cell volume (PCV, haemoglobin concentration (Hb and red blood cell count (RBC were determined using standard methods.Results: Anorexia and intermittent diarrhea were the observed signs. Worm counts did not differ significantly (P=0.309 among the groups. The weight and FEC differed significantly (P˂0.05 across the days and among the groups, while haematological parameters increased significantly (P˂0.05 across the days and among the groups.Conclusion: Lambs in G2 followed by G4 showed improved parameters and superior performance when compared to the other groups. It is therefore recommended that feed high in protein content is capable of mitigating deleterious effect of gastrointestinal helminth parasitism.

  11. Factors Associated with Early Introduction of Formula and/or Solid, Semi-Solid or Soft Foods in Seven Francophone West African Countries

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    Abukari I. Issaka

    2015-01-01

    Full Text Available The aim of this study was to identify factors associated with early introduction of formula and/or solid, semi-solid or soft foods to infants aged three to five months in seven Francophone West African countries. The sources of data for the analyses were the most recent Demographic and Health Survey datasets of the seven countries, namely Benin (BDHS, 2012, Burkina Faso (BFDHS, 2010, Cote d’Ivoire (CIDHS, 2011–2012, Guinea (GDHS, 2012, Mali (MDHS, 2012–2013, Niger (NDHS, 2012 and Senegal (SDHS, 2010. The study used multiple logistic regression methods to analyse the factors associated with early introduction of complementary feeding using individual-, household- and community-level determinants. The sample was composed of 4158 infants aged between three and five months with: 671 from Benin, 811 from Burkina Faso, 362 from Cote d’Ivoire, 398 from Guinea, 519 from Mali, 767 from Niger and 630 from Senegal. Multiple analyses indicated that in three of the seven countries (Benin, Guinea and Senegal, infants who suffered illnesses, such as diarrhoea and acute respiratory infection, were significantly more likely to be introduced to formula and/or solid, semi-solid or soft foods between the age of three and five months. Other significant factors included infants who: were born in second to fourth position (Benin, whose mothers did not attend any antenatal clinics (Burkina Faso and Niger, were male (Cote d’Ivoire and Senegal, lived in an urban areas (Senegal, or were delivered by traditional birth attendants (Guinea, Niger and Senegal. Programmes to discourage early introduction of formula and/or solid, semi-solid or soft foods in these countries should target the most vulnerable segments of the population in order to improve exclusive breastfeeding practices and reduce infant mortality.

  12. The West African experience in establishing steering committees for better collaboration between researchers and decision-makers to increase the use of health research findings.

    Science.gov (United States)

    Keita, Namoudou; Lokossou, Virgil; Berthe, Abdramane; Sombie, Issiaka; Johnson, Ermel; Busia, Kofi

    2017-07-12

    Aware of the advantages of a project steering committee (SC) in terms of influencing the development of evidence-based health policies, the West African Health Organisation (WAHO) encouraged and supported the creation of such SCs around four research projects in four countries (Burkina Faso, Nigeria, Senegal and Sierra Leone). This study was conducted to describe the process that was used to establish these committees and its findings aim to assist other stakeholders in initiating this type of process. This is a cross-sectional, qualitative study of the initiative's four projects. In addition to a literature review and a review of the project documents, an interview guide was used to collect data from 14 members of the SCs, research teams, WAHO and the International Development Research Center. The respondents were selected with a view to reaching data saturation. The technique of thematic analysis by simple categorisation was used. To set up the SCs, a research team in each country worked with health authorities to identify potential members, organise meetings with these members and sought the authorities' approval to formalise the SCs. The SCs' mission was to provide technical assistance to the researchers during the implementation phase and to facilitate the transfer and use of the findings. The 'doing by learning' approach used by each research team, combined with WAHO's catalytic role with each country's Ministry of Health, helped each SC manage its contextual difficulties and function effectively. The involvement of technical and financial partners motivated the researchers and ministries of health, who, in turn, motivated other actors to volunteer on the SCs. The 'doing by learning' approach made it possible to develop strategies adapted to each context to create, facilitate and operate each SC and manage its difficulties. To reproduce such an experience, a strong understanding of the local context and the involvement of strong partners are required.

  13. No evidence for transmission of SIVwrc from western red colobus monkeys (piliocolobus badius badius) to wild west african chimpanzees (pan troglodytes verus) despite high exposure through hunting

    Science.gov (United States)

    2011-01-01

    Background Simian Immunodeficiency Viruses (SIVs) are the precursors of Human Immunodeficiency Viruses (HIVs) which have lead to the worldwide HIV/AIDS pandemic. By studying SIVs in wild primates we can better understand the circulation of these viruses in their natural hosts and habitat, and perhaps identify factors that influence susceptibility and transmission within and between various host species. We investigated the SIV status of wild West African chimpanzees (Pan troglodytes verus) which frequently hunt and consume the western red colobus monkey (Piliocolobus badius badius), a species known to be infected to a high percentage with its specific SIV strain (SIVwrc). Results Blood and plasma samples from 32 wild chimpanzees were tested with INNO-LIA HIV I/II Score kit to detect cross-reactive antibodies to HIV antigens. Twenty-three of the samples were also tested for antibodies to 43 specific SIV and HIV lineages, including SIVwrc. Tissue samples from all but two chimpanzees were tested for SIV by PCRs using generic SIV primers that detect all known primate lentiviruses as well as primers designed to specifically detect SIVwrc. Seventeen of the chimpanzees showed varying degrees of cross-reactivity to the HIV specific antigens in the INNO-LIA test; however no sample had antibodies to SIV or HIV strain - and lineage specific antigens in the Luminex test. No SIV DNA was found in any of the samples. Conclusions We could not detect any conclusive trace of SIV infection from the red colobus monkeys in the chimpanzees, despite high exposure to this virus through frequent hunting. The results of our study raise interesting questions regarding the host-parasite relationship of SIVwrc and wild chimpanzees in their natural habitat. PMID:21284842

  14. Feeding potential of cassava (Manihot esculenta Crantz) peels ensiled with Leucaena leucocephala and Gliricidia sepium assessed with West African dwarf goats.

    Science.gov (United States)

    Oduguwa, Bamidele Omonuwa; Oni, Adebayo Olusoji; Arigbede, Oluwasanmi Moses; Adesunbola, Julius Olukunle; Sudekum, Karl Heinz

    2013-08-01

    Cassava peels (CaPe) were ensiled in mixtures with Gliricidia sepium and Leucaena leucocephala, and the utilization of the mixed silages by West African dwarf (WAD) goats was assessed. Five silages were composed, comprising of 100% ensiled CaPe (control), CaPe + G. sepium 2:1 (w/w; 2CGS), CaPe + G. sepium 1:1 (w/w; CGS), CaPe + L. leucocephala 2:1 (w/w; 2CLL) and CaPe + L. leucocephala 1:1 (w/w; CLL). All diets were supplemented with molasses (40 g/kg) before ensiling which lasted 3 months. Fifteen WAD goats (8.01 ± 0.12 kg body weight) were fed one of the experimental diets (50 g/kg body weight) for 8 weeks. The control had the lowest hydrocyanic acid content (0.05 mg/kg DM), while others ranged from 6.2 to 81.3 mg/kg. Condensed tannin concentration ranged from 1.7 to 8.4 mg/kg DM, while mimosine levels were 11.6 and 12.4 mg/kg DM in 2CLL and CLL, respectively. After fermentation, all silages showed low pH (<4.5) and were different (P < 0.05) in the lactic, acetic and butyric acid concentrations. Ratio of foliage supplementation influenced DM intake (P < 0.05). Daily weight gains ranged from 17 (CLL) to 24 g/day in control. The digestibility coefficients of nutrients and fibre fractions differed (P < 0.05) among diets. The values for packed cell volume, haemoglobin, red blood cells, neutrophils, lymphocytes and monocytes were also different (P < 0.05) across the dietary treatments. Ensiling CaPe with foliages of G. sepium and L. leucocephala can be recommended for feeding WAD goats especially during the dry spells when there is little or no available forage for the animals.

  15. Genetic Diversity of the Hepatitis B Virus Strains in Cuba: Absence of West-African Genotypes despite the Transatlantic Slave Trade

    Science.gov (United States)

    Rodríguez Lay, Licel A.; Corredor, Marité B.; Villalba, Maria C.; Frómeta, Susel S.; Wong, Meilin S.; Valdes, Lidunka; Samada, Marcia; Sausy, Aurélie; Hübschen, Judith M.; Muller, Claude P.

    2015-01-01

    Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV) strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutations of 172 Cuban HBsAg and HBV-DNA positive patients were determined by direct sequencing and phylogenetic analysis. Phylogenetic analysis of HBV S gene sequences showed a predominance of genotype A (92.4%), subgenotype A2 (84.9%) and A1 (7.6%). Genotype D (7.0%) and subgenotype C1 (0.6%) were also detected but typical (sub)genotypes of contemporary West-Africa (E, A3) were conspicuously absent. All genotype A, D, and C strains exhibited sequence characteristics of the adw2, ayw2, and adrq serotypes, respectively. Thirty-three (19.1%) patients showed single, double, or multiple point mutations inside the Major Hydrophilic domain associated with vaccine escape; eighteen (10.5%) patients had mutations in the T-cell epitope (amino acids 28-51), and there were another 111 point mutations downstream of the S gene. One patient had an HBV A1/A2 mixed infection. This first genetic study of Cuban HBV viruses revealed only strains that were interspersed with strains from particularly Europe, America, and Asia. The absence of genotype E supports previous hypotheses about an only recent introduction of this genotype into the general population in Africa. The presence of well-known vaccine escape (3.5%) and viral resistance mutants (2.9%) warrants strain surveillance to guide vaccination and treatment strategies. PMID:25978398

  16. Comparison of the key aroma compounds in organically grown, raw West-African peanuts (Arachis hypogaea) and in ground, pan-roasted meal produced thereof.

    Science.gov (United States)

    Chetschik, Irene; Granvogl, Michael; Schieberle, Peter

    2008-11-12

    Application of an aroma extract dilution analysis on an aroma distillate prepared from organically grown, raw West-African peanuts (Cameroon) revealed 36 odor-active areas in the flavor dilution (FD) factor range of 1 to 2048. The identification experiments, which were all performed by using the respective reference chemicals, revealed 2-isopropyl-3-methoxypyrazine (earthy, pea-like), 2-isobutyl-3-methoxypyrazine (bell pepper-like, earthy), and trans-4,5-epoxy-(E)-2-decenal (metallic) with the highest FD factors among the 36 aroma compounds identified. The two last mentioned odorants and another set of 22 further odorants were identified for the first time in raw peanuts. A comparative aroma extract dilution analysis applied on distillates prepared from either the raw peanuts or ground peanut meal roasted in a pan showed 52 odor-active areas in the FD factor range of 8 to 2048 in the roasted nut material. The identification experiments in combination with the FD factors revealed that among them, 2-acetyl-1-pyrroline and 4-hydroxy-2,5-dimethyl-3-(2H)-furanone showed the most significant contribution to the overall aroma, followed by 1-octen-3-one, 2-isopropyl-3-methoxypyrazine, (E, E)-2,4-decadienal, and trans-4,5-epoxy-(E)-2-decenal. As a further result, 20 aroma compounds were newly identified in roasted peanuts, such as 2-propionyl-1-pyrroline and 2-acetyltetrahydropyridine (both popcorn-like). In particular, 2-acetyl-1-pyrroline and 4-hydroxy-2,5-dimethyl-3(2 H)-furanone showed the most pronounced increase after roasting.

  17. Calorific value of Prosopis africana and Balanites aegyptiaca wood: Relationships with tree growth, wood density and rainfall gradients in the West African Sahel

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Carmen Sotelo; Weber, John C. [World Agroforestry Centre (ICRAF), Sahel Office, B.P. E 5118 Bamako (Mali); Silva, Dimas Agostinho da; Bolzon de Muniz, Graciela Ines [Universidade Federal do Parana (UFPR), Av. Lothario Meissner, 900, CEP.: 80270-170-Curitiba (Brazil); Garcia, Rosilei A. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Instituto de Florestas, Departamento de Produtos Florestais, BR 465, km 07, 23890-000, Seropedica, Rio de Janeiro (Brazil)

    2011-01-15

    Prosopis africana and Balanites aegyptiaca are native tree species in the West African Sahel and provide wood for fuel, construction and other essential products. A provenance/progeny test of each species was established at one relatively dry site in Niger, and evaluated at 13 years. Gross calorific value of the wood was determined for a random sample of trees in each test: gross CV and CVm{sup 3} = gross calorific value in MJ kg{sup -1} and MJ m{sup -3}, respectively. The major objectives were to determine if gross CV was positively correlated with wood density and tree growth, and if gross CV and/or CVm{sup 3} varied with rainfall gradients in the sample region. Provenances were grouped into a drier and more humid zone, and correlations were computed among all trees and separately in each zone. Results indicated that gross CV was not significantly correlated with density in either species. Gross CV was positively correlated with growth of P. africana (but not B. aegyptiaca) only in the drier zone. Gross CVm{sup 3} was positively correlated with growth of both species, and the correlations were stronger in the drier zone. Multiple regressions with provenance latitude, longitude and elevation indicated that provenance means for gross CV increased, in general, from the drier to the more humid zones. Regressions with gross CVm{sup 3} were not significant. Results are compared with earlier research reports from the provenance/progeny tests and with other tropical hardwood species; and practical implications are presented for tree improvement and conservation programs in the region. (author)

  18. West African monsoon dynamics and precipitation: the competition between global SST warming and CO2 increase in CMIP5 idealized simulations

    Science.gov (United States)

    Gaetani, Marco; Flamant, Cyrille; Bastin, Sophie; Janicot, Serge; Lavaysse, Christophe; Hourdin, Frederic; Braconnot, Pascale; Bony, Sandrine

    2017-02-01

    Climate variability associated with the West African monsoon (WAM) has important environmental and socio-economic impacts in the region. However, state-of-the-art climate models still struggle in producing reliable climate predictions. An important cause of this low predictive skill is the sensitivity of climate models to different forcings. In this study, the mechanisms linking the WAM dynamics to the CO2 forcing are investigated, by comparing the effect of the CO2 direct radiative effect with its indirect effect mediated by the global sea surface warming. The July-to-September WAM variability is studied in climate simulations extracted from the Coupled Model Intercomparison Project Phase 5 archive, driven by prescribed sea surface temperature (SST). The individual roles of global SST warming and CO2 atmospheric concentration increase are investigated through idealized experiments simulating a 4 K warmer SST and a quadrupled CO2 concentration, respectively. Results show opposite and competing responses in the WAM dynamics and precipitation. A dry response (-0.6 mm/day) to the SST warming is simulated in the Sahel, with dryer conditions over western Sahel (-0.8 mm/day). Conversely, the CO2 increase produces wet conditions (+0.5 mm/day) in the Sahel, with the strongest response over central-eastern Sahel (+0.7 mm/day). The associated responses in the atmospheric dynamics are also analysed, showing that the SST warming affects the Sahelian precipitation through modifications in the global tropical atmospheric dynamics, reducing the importance of the regional drivers, while the CO2 increase reinforces the coupling between precipitation and regional dynamics. A general agreement in model responses demonstrates the robustness of the identified mechanisms linking the WAM dynamics to the CO2 direct and indirect forcing, and indicates that these primary mechanisms are captured by climate models. Results also suggest that the spread in future projections may be caused by

  19. Geophysical evidence of Cretaceous volcanics in Logone Birni Basin (Northern Cameroon), Central Africa, and consequences for the West and Central African Rift System

    Science.gov (United States)

    Loule, Jean-Pierre; Pospisil, Lubomil

    2013-01-01

    Detailed analyses and interpretation realized by combining existing 2D reflection seismic and Gravity/Magnetic data of the Logone Birni Basin (LBB) in the West and Central African Rift System (WCAS) have revealed the distribution of the main buried volcanic bodies as well as their relationships with the structural and tectonic evolution of this basin. The volcanic activity in the LBB is restricted to the Cretaceous period. Three main volcanic episodes are identified and are associated to the Neocomian, Late Albian and Cenomanian-Turonian rifting phases respectively. The volcanic bodies within the Lower Cretaceous are either lying directly on basement or are mainly interbedded with the contemporaneous sediments whereas the Upper Cretaceous bodies are morphologically expressed in the forms of dykes and sills. The volcanic activity was more intense in the western region of the central LBB (Zina sub-basin) along the Cameroon-Nigeria border whereas it was scanty and scattered in the other parts of the basin. The main volcanic dykes are found on the flanks of the major faults bounding basement horsts or in crestal positions in association with syndepositional faults. Although WCAS is associated with large amount of crustal extension and minor volcanism, the intense volcanic activity observed in LBB during the Cretaceous suggests that the intrusive zone during this period was confined to the basement beneath the study area flanked respectively to the north, south and southwest by the Lake Chad, Poli and Chum triple junctions. Tensional stresses generated by this localized domal uplift accounts for most of the observed tectonic structures where major faults transected the entire lithosphere, thus providing conduits for magma migration.

  20. Effects of waste water irrigation on soil properties and soil fauna of spinach fields in a West African urban vegetable production system.

    Science.gov (United States)

    Stenchly, Kathrin; Dao, Juliane; Lompo, Désiré Jean-Pascal; Buerkert, Andreas

    2017-03-01

    The usage of inadequately processed industrial waste water (WW) can lead to strong soil alkalinity and soil salinization of agricultural fields with negative consequences on soil properties and biota. Gypsum as a soil amendment to saline-sodic soils is widely used in agricultural fields to improve their soil physical, chemical and hence biological properties. This study aimed at analysing the effects of intensive WW irrigation on the structure and composition of soil-dwelling arthropods on spinach fields (Spinacia oleracea L.) in a West African urban vegetable production system. We used gypsum as a soil amendment with the potential to alleviate soil chemical stress resulting in a potentially positive impact on soil arthropods. A total of 32 plots were established that showed a gradient in soil pH ranging from slight to strong soil alkalinity and that were irrigated with WW (n = 12) or clean water (CW; n = 20), including eight plots into which gypsum was incorporated. Our study revealed a high tolerance of soil-dwelling arthropods for alkaline soils, but spinach fields with increased soil electrical conductivity (EC) showed a reduced abundance of Hymenoptera, Diptera and Auchenorrhyncha. Arthropod abundance was positively related to a dense spinach cover that in turn was not affected by WW irrigation or soil properties. Gypsum application reduced soil pH but increased soil EC. WW irrigation and related soil pH affected arthropod composition in the investigated spinach fields which may lead to negative effects on agronomical important arthropod groups such as pollinators and predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Addressing diarrhea prevalence in the West African Middle Belt: social and geographic dimensions in a case study for Benin

    Directory of Open Access Journals (Sweden)

    Arouna Aminou

    2008-04-01

    Full Text Available Abstract Background In West Africa, the Northern Sahelian zone and the coastal areas are densely populated but the Middle Belt in between is in general sparsely settled. Predictions of climate change foresee more frequent drought in the north and more frequent flooding in the coastal areas, while conditions in the Middle Belt will remain moderate. Consequently, the Middle Belt might become a major area for immigration but there may be constraining factors as well, particularly with respect to water availability. As a case study, the paper looks into the capacity of the Middle Belt zone of Benin, known as the Oueme River Basin (ORB, to reduce diarrhea prevalence. In Benin it links to the Millennium Development Goals on child mortality and environmental sustainability that are currently farthest from realization. However, diarrhea prevalence is only in part due to lack of availability of drinking water from a safe source. Social factors such as hygienic practices and poor sanitation are also at play. Furthermore, we consider these factors to possess the properties of a local public good that suffers from under provision and requires collective action, as individual actions to prevent illness are bound to fail as long as others free ride. Methods Combining data from the Demographic Health Survey with various spatial data sets for Benin, we apply mixed effect logit regression to arrive at a spatially explicit assessment of geographical and social determinants of diarrhea prevalence. Starting from an analysis of these factors separately at national level, we identify relevant proxies at household level, estimate a function with geo-referenced independent variables and apply it to evaluate the costs and impacts of improving access to good water in the basin. Results First, the study confirms the well established stylized fact on the causes of diarrhea that a household with access to clean water and with good hygienic practices will, irrespective of

  2. Addressing diarrhea prevalence in the West African Middle Belt: social and geographic dimensions in a case study for Benin.

    Science.gov (United States)

    Pande, Saket; Keyzer, Michiel A; Arouna, Aminou; Sonneveld, Ben G J S

    2008-04-23

    In West Africa, the Northern Sahelian zone and the coastal areas are densely populated but the Middle Belt in between is in general sparsely settled. Predictions of climate change foresee more frequent drought in the north and more frequent flooding in the coastal areas, while conditions in the Middle Belt will remain moderate. Consequently, the Middle Belt might become a major area for immigration but there may be constraining factors as well, particularly with respect to water availability. As a case study, the paper looks into the capacity of the Middle Belt zone of Benin, known as the Oueme River Basin (ORB), to reduce diarrhea prevalence. In Benin it links to the Millennium Development Goals on child mortality and environmental sustainability that are currently farthest from realization. However, diarrhea prevalence is only in part due to lack of availability of drinking water from a safe source. Social factors such as hygienic practices and poor sanitation are also at play. Furthermore, we consider these factors to possess the properties of a local public good that suffers from under provision and requires collective action, as individual actions to prevent illness are bound to fail as long as others free ride. Combining data from the Demographic Health Survey with various spatial data sets for Benin, we apply mixed effect logit regression to arrive at a spatially explicit assessment of geographical and social determinants of diarrhea prevalence. Starting from an analysis of these factors separately at national level, we identify relevant proxies at household level, estimate a function with geo-referenced independent variables and apply it to evaluate the costs and impacts of improving access to good water in the basin. First, the study confirms the well established stylized fact on the causes of diarrhea that a household with access to clean water and with good hygienic practices will, irrespective of other conditions, not suffer diarrhea very often. Second

  3. Briefing : West Africa and its oil

    NARCIS (Netherlands)

    Ellis, S.

    2003-01-01

    The US war on terrorism and preparations for war against Iraq have enormously increased the strategic value of West African oil reserves. This comes at a time when there have been massive new discoveries in offshore waters. This article focuses on the increased US interests in West African oil. It

  4. Ebola exposure, illness experience, and Ebola antibody prevalence in international responders to the West African Ebola epidemic 2014-2016: A cross-sectional study.

    Science.gov (United States)

    Houlihan, Catherine F; McGowan, Catherine R; Dicks, Steve; Baguelin, Marc; Moore, David A J; Mabey, David; Roberts, Chrissy H; Kumar, Alex; Samuel, Dhan; Tedder, Richard; Glynn, Judith R

    2017-05-01

    Healthcare and other front-line workers are at particular risk of infection with Ebola virus (EBOV). Despite the large-scale deployment of international responders, few cases of Ebola virus disease have been diagnosed in this group. Since asymptomatic or pauci-symptomatic infection has been described, it is plausible that infections have occurred in healthcare workers but have escaped being diagnosed. We aimed to assess the prevalence of asymptomatic or pauci-symptomatic infection, and of exposure events, among returned responders to the West African Ebola epidemic 2014-2016. We used snowball sampling to identify responders who had returned to the UK or Ireland, and used an online consent and questionnaire to determine their exposure to EBOV and their experience of illness. Oral fluid collection devices were sent and returned by post, and samples were tested using an EBOV IgG capture assay that detects IgG to Ebola glycoprotein. Blood was collected from returnees with reactive samples for further testing. Unexposed UK controls were also recruited. In all, 300 individuals consented, of whom 268 (89.3%) returned an oral fluid sample (OFS). The majority had worked in Sierra Leone in clinical, laboratory, research, and other roles. Fifty-three UK controls consented and provided samples using the same method. Of the returnees, 47 (17.5%) reported that they had had a possible EBOV exposure. Based on their free-text descriptions, using a published risk assessment method, we classified 43 (16%) as having had incidents with risk of Ebola transmission, including five intermediate-risk and one high-risk exposure. Of the returnees, 57 (21%) reported a febrile or diarrhoeal illness in West Africa or within 1 mo of return, of whom 40 (70%) were not tested at the time for EBOV infection. Of the 268 OFSs, 266 were unreactive. Two returnees, who did not experience an illness in West Africa or on return, had OFSs that were reactive on the EBOV IgG capture assay, with similar results

  5. Ebola exposure, illness experience, and Ebola antibody prevalence in international responders to the West African Ebola epidemic 2014-2016: A cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Catherine F Houlihan

    2017-05-01

    Full Text Available Healthcare and other front-line workers are at particular risk of infection with Ebola virus (EBOV. Despite the large-scale deployment of international responders, few cases of Ebola virus disease have been diagnosed in this group. Since asymptomatic or pauci-symptomatic infection has been described, it is plausible that infections have occurred in healthcare workers but have escaped being diagnosed. We aimed to assess the prevalence of asymptomatic or pauci-symptomatic infection, and of exposure events, among returned responders to the West African Ebola epidemic 2014-2016.We used snowball sampling to identify responders who had returned to the UK or Ireland, and used an online consent and questionnaire to determine their exposure to EBOV and their experience of illness. Oral fluid collection devices were sent and returned by post, and samples were tested using an EBOV IgG capture assay that detects IgG to Ebola glycoprotein. Blood was collected from returnees with reactive samples for further testing. Unexposed UK controls were also recruited. In all, 300 individuals consented, of whom 268 (89.3% returned an oral fluid sample (OFS. The majority had worked in Sierra Leone in clinical, laboratory, research, and other roles. Fifty-three UK controls consented and provided samples using the same method. Of the returnees, 47 (17.5% reported that they had had a possible EBOV exposure. Based on their free-text descriptions, using a published risk assessment method, we classified 43 (16% as having had incidents with risk of Ebola transmission, including five intermediate-risk and one high-risk exposure. Of the returnees, 57 (21% reported a febrile or diarrhoeal illness in West Africa or within 1 mo of return, of whom 40 (70% were not tested at the time for EBOV infection. Of the 268 OFSs, 266 were unreactive. Two returnees, who did not experience an illness in West Africa or on return, had OFSs that were reactive on the EBOV IgG capture assay, with

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been ... Featured Country: Nigeria, Featured Journal: Nigeria Journal of Pure and Applied Physics ...

  7. The Boussinesq-BO equation for algebraic gravity solitary waves in baroclinic atmosphere and the research of squall lines formation mechanism

    Science.gov (United States)

    Guo, Min; Chen, Xin; Chen, Yaodeng; Yang, Hongwei

    2017-12-01

    The gravity solitary waves are a kind of waves which are caused by the disturbance of static equilibrium. The nonlinearity concentration of the gravity solitary waves makes the energy assemble together and forms disastrous weather phenomena, such as squall lines. By the calculation condition and theoretical method limit, previous studies tried hard to reduce the variable numbers and discussed the gravity solitary waves in barotropic atmosphere, but the baroclinic problem of atmosphere is inevitable topic. In this paper, from the basic kinetic equations in baroclinic non-static equilibrium atmosphere, by using multi-scale analysis and perturbation method, a new model is derived to describe the algebraic gravity solitary waves, we call it Boussinesq-BO equation. Comparing with the former models, the Boussinesq-BO model can describe the propagation process of waves in two directions and is more suitable for the real atmosphere condition. With the help of the trial function method, an exact solution of Boussinesq-BO equation is obtained and the fission property of algebraic gravity solitary waves is discussed. Finally, we can find that the fission of algebraic gravity solitary waves is also a possible formation mechanism of squall lines.

  8. Genotypic characterization directly applied to sputum improves the detection of Mycobacterium africanum West African 1, under-represented in positive cultures.

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    C N'Dira Sanoussi

    2017-09-01

    Full Text Available This study aimed to compare the prevalence of Mycobacterium tuberculosis complex (MTBc lineages between direct genotyping (on sputum and indirect genotyping (on culture, to characterize potential culture bias against difficult growers.Smear-positive sputa from consecutive new tuberculosis patients diagnosed in Cotonou, (Benin were included, before patients had started treatment. An aliquot of decontaminated sputum was used for direct spoligotyping, and another aliquot was cultured on Löwenstein Jensen (LJ medium (90 days, for indirect spoligotyping. After DNA extraction, spoligotyping was done according to the standard method for all specimens, and patterns obtained from sputa were compared versus those from the derived culture isolates. From 199 patient's sputa, 146 (73.4% yielded a positive culture. In total, direct spoligotyping yielded a pattern in 98.5% (196/199 of the specimens, versus 73.4% (146/199 for indirect spoligotyping on cultures. There was good agreement between sputum- and isolate derived patterns: 94.4% (135/143 at spoligotype level and 96.5% (138/143 at (sublineage level. Two of the 8 pairs with discrepant pattern were suggestive of mixed infection in sputum. Ancestral lineages (Lineage 1, and M. africanum Lineages 5 and 6 were less likely to grow in culture (OR = 0.30, 95%CI (0.14 to 0.64, p = 0.0016; especially Lineage 5 (OR = 0.37 95%CI (0.17 to 0.79, p = 0.010. Among modern lineages, Lineage 4 was over-represented in positive-culture specimens (OR = 3.01, 95%CI (1.4 to 6.51, p = 0.005.Ancestral lineages, especially M. africanum West African 1 (Lineage 5, are less likely to grow in culture relative to modern lineages, especially M. tuberculosis Euro-American (Lineage 4. Direct spoligotyping on smear positive sputum is effective and efficient compared to indirect spoligotyping of cultures. It allows for a more accurate unbiased determination of the population structure of the M. tuberculosis complex.ClinicalTrials.gov NCT

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

    Science.gov (United States)

    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

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all over the ... Featured Country: Ghana, Featured Journal: Ghana Journal of Linguistics ...

  11. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all over ... Featured Country: South Africa, Featured Journal: Stellenbosch Papers in Linguistics ...

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all ... Featured Country: South Africa, Featured Journal: Stellenbosch Papers in Linguistics Plus ...

  13. WEST AFRICAN JOURNAL OF MEDICINE

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    ABSTRACT _. BACKGROUND: Pericoronitis is an infectious disease of the operculum overlying an erupting or semi—impacted tooth particularly the lower third molars. It is a painful, sometimes debilitating and common periodontal emergency commonly found in young adults. OBJECTIVE: The purpose of this study was to ...

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    Abbreviations: CD4, Cluster of Differentiation 4; HAART, Highly Active Antiretroviral Therapy; HBV, Hepatitis B Virus; HCV, Hepatitis C. Virus; HIV ..... Mortality and Morbidity from HCC and Chronic Liver Disease in a. Prospective Study. The American. Journal of Gastroenterology2006; 101: 1797–1803. 4. Antipa C, Ruta S, ...

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    user1

    Harcourt Teaching Hospital (UPTH) de Janvier 2001 Décembre. 2005 ont été récupérées. Informations sur les caractéristiques socio-démographiques, les raisons de la contraception, et leurs méthodes préférées a été extraite. Les données ont été analysées à l'aide du logiciel SPSS version 11.0 du logiciel informatique.

  16. West African Journal of Medicine

    African Journals Online (AJOL)

    Case—control study of anthropométric measures and prostate cancer risk. IntJ. Cancer. 2004; 110: 278 — 83. Hubbard JS, Rohrmann S, Landis PK,. Metter EJ, Mullèr DC, Andres R, Carter. HB, Platz EA. Association of prostate cancer risk with insulin, glucose, and anthropometry in the Baltimore longitudinal study of aging.

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    ABSTRACT. BACKGROUND:Uncomplicated dyspepsia has a low predictive value in diagnosing upper gastrointestinal organic disease making early endoscopy essential. OBJECTIVE: To assess the reliability of clinical information in the diagnosis of organic disease in patients referred for upper gastrointestinal endoscopy.

  18. WEST AFRICAN JOURNAL OF MEDICINE

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    Dix complications associées à l'ablation de la. SNG ont été retrouvées dont 6 dans le Groupe 1 et 4 .... 0. 2. Laparotomy for acute mesenteric lymphadenitis. 0. 2. 2. Adhesiolysis for postoperative intestinal obstruction. 1. 1. 2. Cholecystectomy. 1. 1. 2. Choledochojejunostomy. 0. 1. 1. Splenectomy. 1. 0. 1. Pyloromyotomy. 1. 0.

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    Late presentation was a common feature and surgical excision was the treatment of choice. CONCLUSION: Odontogenic myxoma is un-common among. Nigerians when compared with ameloblastoma. Clinicopathological characteristics in this series are similar to information in the scientific literature. WAJM 2011; 30(4):.

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    user1

    to marked delay in diagnosis. Hey et al compared the survival rates of colorectal carcinoma in young patients and older patients, and they found a comparable prognosis state for stage.16 Also, Chung et al17 observed no significant difference in tumor characteristics and survival in patients with colorectal cancer aged less.

  1. WEST AFRICAN JOURNAL OF MEDICINE

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    patients vers les structures de soins pour une prise en charge appropriée. WAJM 2012 ... health facility but function as general and referral hospital. .... causes were respiratory tract infections, septicaemia, osteomyelitis and urinary tract infections. The high frequency of vaso-oclusive crisis (VOC) observed in this review has ...

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    Microbiology, Abia State University, Abia State, Eastern. Nigeria, ††Medicine, University of Sheffield, UK, ‡‡Public Administration, Imo State University, Imo State, Eastern Nigeria, §§Ogun. State University Teaching Hospital, Ogun State, Nigeria, ...

  3. WEST AFRICAN JOURNAL OF MEDICINE

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    diagnosis of cancer of the prostate (CaP) amongst unscreened patients. PATIENTS, MATERIALS AND METHODS: A prospective study168 unscreened men who were referred for evaluation for. CaP. They all had a 10-core extended transrectal prostatic needle biopsy using size 16 Tru Cut needle for either an elevated.

  4. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    born annually with sickle-cell anaemia in. Nigeria.2. Sickle cell disease is characterized by chronic haemolytic anaemia and the clinical course of affected children is typically associated with intermittent episodic acute events, often referred to as “crises”.3 However, persons suffering from sickle cell disease are not ill most of.

  5. West African Journal of Medicine

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    Aetiology, Clinical Features and Treatment Outcome of Intrauterine. Adhesion in Ilorin, Central ... treatment. CONCLUSION: The incidence of intrauterine adhesion among gynaecological patients in this study is lower than those from previous reviews elsewhere in the country. However ..... the volume of evidences supporting.

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    African Journals Online (AJOL)

    elevated PTH hormone, ischemia and deficiencies of proteins C and S that accompanied heavy proteinuria. ... Calcium based Phosphate binders. Diabetes Mellitus. Heavy Proteinuria with loss of Protein C. & Protein S. Obesity .... Semin Dial 20: 150–157. 22. Vassa N, Twardowski ZJ, Campbell J. (1994) Hyperbaric oxygen ...

  7. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    ocular irritation in contrast to the intense discomfort caused by corneal crystals of cystinosis.“35 The corneal crystals have been identified as consisting of immunoglobulins, primarily IgG, but the pathophysiology of crystal formation remains enigmatic.“*“*37 Some data suggest that elevated immunoglobulin levels in tears or ...

  8. WEST AFRICAN JOURNAL OF MEDICINE

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    clinical interview and both groups completed the AIDS Risk. Behaviour Assessment (ARBAQ) and Knowledge (ARBKQ) ... Both groups also admitted participation in various high risk sexual behaviours. CONCLUSION: Our results ..... “Only gay (homosexual) men get AIDS”. 67.4% vs 97.7%; “You can get the AIDS virus after ...

  9. WEST AFRICAN JOURNAL OF MEDICINE

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    user1

    2012-07-04

    Jul 4, 2012 ... duct injury was recorded in one patient who had cholecystectomy and superficial port site wound infections were noticed in two patients who had appendectomy. No mortality was recorded. CONCLUSION:Our results show the feasibility of laparoscopic surgery in Nigeria. We advocate local adaptation and.

  10. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    2 April–June, 2012. Department of †Surgery, University College Hospital, Ibadan, Nigeria ‡Bowen University Iwo, Nigeria. *Correspondence: O. O. Afuwape, Department of Surgery, University College Hospital, Ibadan, Nigeria. E-mail: dolafpe@yahoo.co.uk. Preliminary Experience with Laparoscopic Cholecystectomy in a.

  11. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    of sudden death were documented and echocardiography done. RESULTS: Two such cases which were never encountered in over 20 years of echocardiography in our unit are reported. One was a ruptured sinus of Valsalva aneurysm dissecting the interventricular septum and the other ventricular septal defect aneurysm ...

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    the study as were those with diabetes mellitus, primary respiratory disease and ... patients died. Intra-hospital mortality from progressive pump failure accounted for five of the deaths that occurred while the last case was reported by relatives as a case of sudden death. We followed up. 89 patients in all. Demographic and ...

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    user1

    Les prévalences de l'insuffisance pondérale GLOBALES, le rabougrissement et. Minceur étaient de 260 (25, 5%), 144 (14, 2%) et 226 (22, 2%), respectivement. Obésité et de surpoids présent dans 31 (3, 0%) et 5 (0, 5%) de la population étudiée respectivement. Les garçons étaient significativement plus souvent insuffisant ...

  14. WEST AFRICAN JOURNAL OF MEDICINE

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    La divulgation du statut des personnes vivant avec le VIH / SIDA à Ilorin, Nigeria. A. K. Salami*†, A. Fadeyi‡, J. A. Ogunmodede†, O. O. Desalu†. ABSTRACT. BACKGROUND: HIV/AIDS is a disease that is characterised by discrimination and stigmatisation particularly in Africa. OBJECTIVE: To determine rate of disclosure of ...

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    Lymphadénite Tuberculeuse: Peau Réaction d'hypersensibilité Retardée de Type et les Réponses ... increasing IFN-γ levels and decreasing IL-10 levels mark ..... In this work we demonstrated that .... Turner J, Gonzalez-Juarrero M, Ellis.

  16. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    1997-02-01

    Feb 1, 1997 ... Africians au sud du Sahara. Toutefois, elle est à présent de plus en plus reconnue chez les originaires d'Afrique. OBJECTIF: Une évaluation comparative des particularités de la MII à Accra de 1997 à 2011. MÉTHODES: Une étude rétrospectivea évalué les données cliniques et du suivi des patients de ...

  17. WEST AFRICAN JOURNAL OF MEDICINE

    African Journals Online (AJOL)

    agit de faire la revue des activités ... pour auditer le système et faire des recommandations visant une amélioration du service. Patients, Matériels et ..... Also important is the fact that the cardiac emergencies might not have been recognized ...

  18. WEST AFRICAN JOURNAL OF MEDICINE

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    OBJECTIVE: To determine the effectiveness of coronary heart disease risk reduction interventions. METHODS: The effects of lipid lowering interventions as well as dietary and lifestyle modifications on some risk factors of. CHD were studied retrospectively in 47 males and 53 female patients [aged 33 to 61 years; mean age ...

  19. WEST AFRICAN JOURNAL OF MEDICINE

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    user1

    2012-07-04

    Jul 4, 2012 ... Karayalcin F, Rosner F, Kim KY,. Chandra P, Aballi AJ. Sickle cell anaemia. – clinical manifestations in 100 patients and review of the literature. Am J Med. Sci 1975; 269: 51–68. 8. Elbashier AM, Badu GA. Pattern of bacteriuria in patients with sickle cell disease in Qatif Central Hospital. Saudi. Med J. 1991 ...

  20. WEST AFRICAN JOURNAL OF MEDICINE

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    Recommendation: We recommend that preventive dentistry topics in oral health promotion and prevention of dental caries be part of their postgraduate curriculum, continued dental health education programme for paediatricians, referral of related cases to paediatric dentists and oral health related topics be published in ...