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Sample records for africa region human

  1. Wet phases in the Sahara/Sahel region and human migration patterns in North Africa

    PubMed Central

    Castañeda, Isla S.; Mulitza, Stefan; Schefuß, Enno; Lopes dos Santos, Raquel A.; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2009-01-01

    The carbon isotopic composition of individual plant leaf waxes (a proxy for C3 vs. C4 vegetation) in a marine sediment core collected from beneath the plume of Sahara-derived dust in northwest Africa reveals three periods during the past 192,000 years when the central Sahara/Sahel contained C3 plants (likely trees), indicating substantially wetter conditions than at present. Our data suggest that variability in the strength of Atlantic meridional overturning circulation (AMOC) is a main control on vegetation distribution in central North Africa, and we note expansions of C3 vegetation during the African Humid Period (early Holocene) and within Marine Isotope Stage (MIS) 3 (≈50–45 ka) and MIS 5 (≈120–110 ka). The wet periods within MIS 3 and 5 coincide with major human migration events out of sub-Saharan Africa. Our results thus suggest that changes in AMOC influenced North African climate and, at times, contributed to amenable conditions in the central Sahara/Sahel, allowing humans to cross this otherwise inhospitable region. PMID:19910531

  2. Wet phases in the Sahara/Sahel region and human migration patterns in North Africa.

    PubMed

    Castañeda, Isla S; Mulitza, Stefan; Schefuss, Enno; Lopes dos Santos, Raquel A; Sinninghe Damsté, Jaap S; Schouten, Stefan

    2009-12-01

    The carbon isotopic composition of individual plant leaf waxes (a proxy for C(3) vs. C(4) vegetation) in a marine sediment core collected from beneath the plume of Sahara-derived dust in northwest Africa reveals three periods during the past 192,000 years when the central Sahara/Sahel contained C(3) plants (likely trees), indicating substantially wetter conditions than at present. Our data suggest that variability in the strength of Atlantic meridional overturning circulation (AMOC) is a main control on vegetation distribution in central North Africa, and we note expansions of C(3) vegetation during the African Humid Period (early Holocene) and within Marine Isotope Stage (MIS) 3 ( approximately 50-45 ka) and MIS 5 ( approximately 120-110 ka). The wet periods within MIS 3 and 5 coincide with major human migration events out of sub-Saharan Africa. Our results thus suggest that changes in AMOC influenced North African climate and, at times, contributed to amenable conditions in the central Sahara/Sahel, allowing humans to cross this otherwise inhospitable region. PMID:19910531

  3. Community Support for Basic Education in Sub-Saharan Africa. Africa Region Human Development Working Paper Series.

    ERIC Educational Resources Information Center

    Watt, Patrick

    Currently, Africa stands out as the world's poorest and most educationally deprived region. Where communities are empowered to identify their own needs and priorities, participate in decisions about resource allocation, and hold education providers accountable for ensuring that children receive a minimum acceptable standard of education, schooling…

  4. A Chance to Learn: Knowledge and Finance for Education in Sub-Saharan Africa. Africa Region Human Development Series.

    ERIC Educational Resources Information Center

    Verspoor, Adriaan

    Without rapid and substantial improvements in education access and quality, broader poverty reduction efforts in Sub-Saharan Africa will be thwarted. This book argues that at the cusp of the 21st century, the opportunity to address the often intractable problems of education in Sub-Saharan Africa is perhaps greater than at any time in the past two…

  5. Human Constraints to Sustainable Agriculture in the Arid Regions of South Africa.

    ERIC Educational Resources Information Center

    Duvel, G. H.; Botha, A. J.

    1999-01-01

    Interviews with 79 South African farmers in arid regions showed that their conservation practices were influenced by such human factors as needs, perceptions, and knowledge. Direct influence on adoption behaviors was recommended to encourage sustainable agriculture practices. (SK)

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

    PubMed Central

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

    2014-01-01

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

  7. The Impact of Human Activities in Africa, the North and South Pole Regions on Global Climate Change.

    NASA Astrophysics Data System (ADS)

    Abubakar, B.

    2007-05-01

    a way that goals could be achieved without necessarily causing problems to the world climate. 4. The International Maritime Organization (IMO) should check and control the Ocean Pollutions caused as a result of the degreasing activities of the "QUAY APRONS" currently going on at the various African Sea Ports in order to protect the Ocean pollution with chemicals that can make the World's ice to be melting. 5. The International Meteorological Organization should open its offices within each region of the six continents in order to have a closer monitoring of human activities that can influence the world's climate. Organizing seminars, Conferences and Workshops on a regular basis by the United Nations and other related organizations can help in the areas of public enlightenment and the education of the rural populace who are also great contributors to the situation. The UN should use its capacity to discourage the importation of fairly used refrigerators, Air-conditioners and propellants to Africa and at the same time assist in the subsidy of the newer ones coming to Africa, so that the average African can afford buying them I believe that if the above listed suggestions/recommendations are adopted and implemented it will help in reducing these challenges threatening the entire world. Thanks for listening.

  8. The impact of human activities in africa,the north and south pole regions on global climate change

    NASA Astrophysics Data System (ADS)

    Abubakar, Babagana

    a way that goals could be achieved without necessarily causing problems to the world climate. 4. The International Maritime Organization (IMO) should check and control the Ocean Pollutions caused as a result of the degreasing activities of the "QUAY APRONS" currently going on at the various African Sea Ports in order to protect the Ocean pollution with chemicals that can make the World's ice to be melting. 5. The International Meteorological Organization should open its offices within each region of the six continents in order to have a closer monitoring of human activities that can influence the world's climate. 6. Organizing seminars, Conferences and Workshops on a regular basis by the United Nations and other related organizations can help in the areas of public enlightenment and the education of the rural populace who are also great contributors to the situation. 7. The UN should use its capacity to discourage the importation of fairly used refrigerators, Air-conditioners and propellants to Africa and at the same time assist in the subsidy of the newer ones coming to Africa, so that the average African can afford buying them I believe that if the above listed suggestions/recommendations are adopted and implemented it will help in reducing these challenges threatening the entire world. Thanks for listening.

  9. Nitrogen in West Africa: the regional cycle

    SciTech Connect

    Robertson, G.P.; Rosswall, T.

    1986-03-01

    A nitrogen cycle budget has been calculated for West Africa south of the northern Sahara that quantifies biologically important pools of nitrogen in the region and major fluxes associated with these pools. Major compartments of the model include noncultivated systems broken down by vegetation zone, successional status, and plant components, annual and perennial crops each broken down by crop species and plant and harvest components; wetlands; anthropic systems, and soils and sediments. Base reference year is 1978. Biological nitrogen fixation and precipitation fluxes dominated nitrogen inputs to West Africa in 1978. Approximately 12 x 10/sup 9/ kg were fixed in noncultivated systems; about half of this was fixed in early successional (0-6 yr) rain forests, and much of the rest in grazed or fallow savanna grasslands and woodlands. Less than 0.7 x 10/sup 9/ kg were fixed in cultivated systems; legumes accounted for approx. = 25% of this. Total anthropic sources (fossil fuel combustion, fertilizer production, and agricultural commodity imports) were minor (< 0.3 x 10/sup 9/ kg). Precipitation inputs to the region were approx. = 0.4 x 10/sup 9/ kg. Most nitrogen leaving West Africa did so volatilized by fire (approx. = 8.3 x 10/sup 9/ kg), principally in non-cropped systems. Major losses also occurred via hydrologic export to the Atlantic Ocean (1.5 x 10/sup 9/ kg) and via denitrification (1.1 x 10/sup 9/ kg). Total N losses from West Africa exceeded 11.0 x 10/sup 9/ kg. The overall budget balances within 1%, despite independent calculations of all major fluxes. The balance portrays a nitrogen cycle dominated by pools and fluxes in noncropped systems. Indirect human influences, however, mainly through effects on vegetation cover, appear to be a major determinant of both the rates at which nitrogen is cycled in West Africa and the relative importance of most pools and fluxes.

  10. Human fascioliasis in South Africa.

    PubMed

    Black, J; Ntusi, N; Stead, P; Mayosi, B; Mendelson, M

    2013-09-01

    Human fascioliasis has the widest latitudinal, longitudinal and altitudinal distribution of any vector-borne disease, yet only 3 cases have been reported from South Africa, the last in 1964. We report 2 cases from the same geographic area associated with local consumption of watercress, suggesting an endemic focus.  PMID:24300687

  11. Regional Projections of Extreme Apparent Temperature Days in Africa and the Related Potential Risk to Human Health

    PubMed Central

    Garland, Rebecca M.; Matooane, Mamopeli; Engelbrecht, Francois A.; Bopape, Mary-Jane M.; Landman, Willem A.; Naidoo, Mogesh; van der Merwe, Jacobus; Wright, Caradee Y.

    2015-01-01

    Regional climate modelling was used to produce high resolution climate projections for Africa, under a “business as usual scenario”, that were translated into potential health impacts utilizing a heat index that relates apparent temperature to health impacts. The continent is projected to see increases in the number of days when health may be adversely affected by increasing maximum apparent temperatures (AT) due to climate change. Additionally, climate projections indicate that the increases in AT results in a moving of days from the less severe to the more severe Symptom Bands. The analysis of the rate of increasing temperatures assisted in identifying areas, such as the East African highlands, where health may be at increasing risk due to both large increases in the absolute number of hot days, and due to the high rate of increase. The projections described here can be used by health stakeholders in Africa to assist in the development of appropriate public health interventions to mitigate the potential health impacts from climate change. PMID:26473895

  12. Regional Projections of Extreme Apparent Temperature Days in Africa and the Related Potential Risk to Human Health.

    PubMed

    Garland, Rebecca M; Matooane, Mamopeli; Engelbrecht, Francois A; Bopape, Mary-Jane M; Landman, Willem A; Naidoo, Mogesh; Merwe, Jacobus van der; Wright, Caradee Y

    2015-10-01

    Regional climate modelling was used to produce high resolution climate projections for Africa, under a "business as usual scenario", that were translated into potential health impacts utilizing a heat index that relates apparent temperature to health impacts. The continent is projected to see increases in the number of days when health may be adversely affected by increasing maximum apparent temperatures (AT) due to climate change. Additionally, climate projections indicate that the increases in AT results in a moving of days from the less severe to the more severe Symptom Bands. The analysis of the rate of increasing temperatures assisted in identifying areas, such as the East African highlands, where health may be at increasing risk due to both large increases in the absolute number of hot days, and due to the high rate of increase. The projections described here can be used by health stakeholders in Africa to assist in the development of appropriate public health interventions to mitigate the potential health impacts from climate change. PMID:26473895

  13. The Regionalization of Africa: Delineating Africa's Subregions Using Airline Data

    ERIC Educational Resources Information Center

    Good, Pieter R.; Derudder, Ben; Witlox, Frank J.

    2011-01-01

    Current regionalizations of Africa have limitations in that they are attribute-based and regions are delineated according to national boundaries. Taking the world city network approach as starting point, it is possible to use relational data (i.e., information about the relationships between cities) rather than attribute data, and moreover, it…

  14. Human origins: Out of Africa

    PubMed Central

    Tattersall, Ian

    2009-01-01

    Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent. PMID:19805256

  15. Human pentastomiasis in Sub-Saharan Africa.

    PubMed

    Vanhecke, C; Le-Gall, P; Le Breton, M; Malvy, D

    2016-09-01

    Pentastomiasis is a rare zoonotic infection but it is frequently observed in Africa and Asia. Most human infections are caused by members of the Armillifer armillatus species. They are responsible for visceral pentastomiasis in Western and Central Africa. Humans may be infected by eating infected undercooked snake meat or by direct contact with an infected reptile. An increasing number of infections are being reported in Congo, Nigeria, and Cameroon. Despite an occasionally high number of nymphs observed in human viscera, most infections are asymptomatic and often diagnosed by accident during surgery or autopsy. The clinical presentation of pentastomiasis is quite varied and depends on infected tissues. The liver, lungs, and pleura are most frequently involved. Abdominal emergencies have been reported. Diagnostic delays always occur and diagnosis focuses on the patient's lifestyle and living environment. It is mainly based on the morphological description of the parasite's calcified cuticle, the site of the lesion, and the parasite's region of origin. Most patients do not require any treatment. Personal measures such as avoidance of contact with snake droppings are recommended to prevent transmission. Imported pentastomiasis has been observed in African migrants. PMID:27004769

  16. Human immunodeficiency virus and viral hepatitis among high-risk groups: Understanding the knowledge gap in the Middle East and North Africa Region

    PubMed Central

    Melhem, Nada M; Rahhal, Nour; Charide, Rana; Kreidieh, Khalil; El-Khatib, Rolla

    2015-01-01

    AIM: To identify gaps in the existing knowledge on single, dual and triple infections of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) in the Middle East and North Africa (MENA) region among men who have sex with men (MSMs), female sex workers (FSWs), injecting drug users (IDUs) and prisoners. METHODS: We performed an extensive literature search on articles published on the topic in the 25 countries of the MENA region. PubMed database was used as the main search engine. Case reports, case series, qualitative studies, editorials, commentaries, authors’ replies and animal studies were excluded. Original articles and reviews dealing with the prevalence of HIV, HBV and HCV and their co-infection were included. Data on population type, sample size, age and markers of infections were extracted from the relevant studies. RESULTS: HIV, HBV and HCV are blood-borne viruses with similar modes of transmission. The categories of people at high risk of acquiring HIV-1, HBV and HCV commonly include: MSMs, FSW and IDUs. It is well established that HIV-positive individuals co-infected with HBV or HCV suffer from liver pathology associated with morbidity and mortality. Moreover, HIV-infected individuals do not respond well to treatment for HBV or HCV and hence are at increased risk of hepatic toxicity. Consequently, co-infection of HIV-positive individuals with HBV and/or HCV is a global health problem of significant magnitude. Our review reveals the paucity of epidemiological data for key populations in many countries of the region. Limited number of studies exists in the MENA region on the status of HIV, HBV and HCV and their co-infections among prisoners, MSMs and FSWs. Evidence support the continued increase of the HIV epidemic among MSMs. In addition to the lack of studies on MSMs and FSWs in the MENA region, our review highlights the lack of data on the practices, characteristics, or the status of HIV infection and viral hepatitis

  17. The first modern human dispersals across Africa.

    PubMed

    Rito, Teresa; Richards, Martin B; Fernandes, Verónica; Alshamali, Farida; Cerny, Viktor; Pereira, Luísa; Soares, Pedro

    2013-01-01

    The emergence of more refined chronologies for climate change and archaeology in prehistoric Africa, and for the evolution of human mitochondrial DNA (mtDNA), now make it feasible to test more sophisticated models of early modern human dispersals suggested by mtDNA distributions. Here we have generated 42 novel whole-mtDNA genomes belonging to haplogroup L0, the most divergent clade in the maternal line of descent, and analysed them alongside the growing database of African lineages belonging to L0's sister clade, L1'6. We propose that the last common ancestor of modern human mtDNAs (carried by "mitochondrial Eve") possibly arose in central Africa ~180 ka, at a time of low population size. By ~130 ka two distinct groups of anatomically modern humans co-existed in Africa: broadly, the ancestors of many modern-day Khoe and San populations in the south and a second central/eastern African group that includes the ancestors of most extant worldwide populations. Early modern human dispersals correlate with climate changes, particularly the tropical African "megadroughts" of MIS 5 (marine isotope stage 5, 135-75 ka) which paradoxically may have facilitated expansions in central and eastern Africa, ultimately triggering the dispersal out of Africa of people carrying haplogroup L3 ~60 ka. Two south to east migrations are discernible within haplogroup LO. One, between 120 and 75 ka, represents the first unambiguous long-range modern human dispersal detected by mtDNA and might have allowed the dispersal of several markers of modernity. A second one, within the last 20 ka signalled by L0d, may have been responsible for the spread of southern click-consonant languages to eastern Africa, contrary to the view that these eastern examples constitute relicts of an ancient, much wider distribution. PMID:24236171

  18. Regional Climate Change Hotspots over Africa

    NASA Astrophysics Data System (ADS)

    Anber, U.; Zakey, A.; Abd El Wahab, M.

    2009-04-01

    Regional Climate Change Index (RCCI), is developed based on regional mean precipitation change, mean surface air temperature change, and change in precipitation and temperature interannual variability. The RCCI is a comparative index designed to identify the most responsive regions to climate change, or Hot- Spots. The RCCI is calculated for Seven land regions over North Africa and Arabian region from the latest set of climate change projections by 14 global climates for the A1B, A2 and B1 IPCC emission scenarios. The concept of climate change can be approaches from the viewpoint of vulnerability or from that of climate response. In the former case a Hot-Spot can be defined as a region for which potential climate change impacts on the environment or different activity sectors can be particularly pronounced. In the other case, a Hot-Spot can be defined as a region whose climate is especially responsive to global change. In particular, the characterization of climate change response-based Hot-Spot can provide key information to identify and investigate climate change Hot-Spots based on results from multi-model ensemble of climate change simulations performed by modeling groups from around the world as contributions to the Fourth Assessment Report of Intergovernmental Panel on Climate Change (IPCC). A Regional Climate Change Index (RCCI) is defined based on four variables: change in regional mean surface air temperature relative to the global average temperature change ( or Regional Warming Amplification Factor, RWAF ), change in mean regional precipitation (P % , of present day value ), change in regional surface air temperature interannual variability (T % ,of present day value), change in regional precipitation interannual variability (P % ,of present day value ). In the definition of the RCCI it is important to include quantities other than mean change because often mean changes are not the only important factors for specific impacts. We thus also include inter

  19. Regional Climate Change Hotspots over Africa

    NASA Astrophysics Data System (ADS)

    Anber, U.

    2009-04-01

    Regional Climate Change Index (RCCI), is developed based on regional mean precipitation change, mean surface air temperature change, and change in precipitation and temperature interannual variability. The RCCI is a comparative index designed to identify the most responsive regions to climate change, or Hot- Spots. The RCCI is calculated for Seven land regions over North Africa and Arabian region from the latest set of climate change projections by 14 global climates for the A1B, A2 and B1 IPCC emission scenarios. The concept of climate change can be approaches from the viewpoint of vulnerability or from that of climate response. In the former case a Hot-Spot can be defined as a region for which potential climate change impacts on the environment or different activity sectors can be particularly pronounced. In the other case, a Hot-Spot can be defined as a region whose climate is especially responsive to global change. In particular, the characterization of climate change response-based Hot-Spot can provide key information to identify and investigate climate change Hot-Spots based on results from multi-model ensemble of climate change simulations performed by modeling groups from around the world as contributions to the Assessment Report of Intergovernmental Panel on Climate Change (IPCC). A Regional Climate Change Index (RCCI) is defined based on four variables: change in regional mean surface air temperature relative to the global average temperature change ( or Regional Warming Amplification Factor, RWAF ), change in mean regional precipitation ( , of present day value ), change in regional surface air temperature interannual variability ( ,of present day value), change in regional precipitation interannual variability ( , of present day value ). In the definition of the RCCI it is important to include quantities other than mean change because often mean changes are not the only important factors for specific impacts. We thus also include inter annual

  20. Africa's Famine: The Human Dimension.

    ERIC Educational Resources Information Center

    Raloff, Janet

    1985-01-01

    Human activities are believed to have had major impact on disasters which have previously been called "natural." Overcultivation, overgrazing, and deforestation are used to illustrate how many African nations have become weakened and impoverished. Programs directed toward economic development are essential for overcoming these problems. (DH)

  1. Africa Section. Regional Activities Division. Papers.

    ERIC Educational Resources Information Center

    International Federation of Library Associations, The Hague (Netherlands).

    Papers on the role and services of African libraries and the education of African librarians, which were presented at the 1983 International Federation of Library Associations (IFLA) conference, include: (1) "The Information Sector in the Economic Development of Africa: The Potential Role for Libraries," in which Benzies Y. Boadi (Nigeria)…

  2. Regional paleogeographic evolution of west Africa: Implications for hydrocarbon exploration

    SciTech Connect

    Hempton, M.R.; Rosen, M.A.; Coughlin, R.M.; Scardina, A.D.; Hagen, E.S.; Nordstrom, P.J. )

    1991-03-01

    New paleogeographic reconstructions of west African continental margins provide a regional framework to contrast differences in hydrocarbon habitat and tectonostratigraphic style. Five regional provinces are delineated: (1) Northwest Africa margin from mauritania to Sierra Leone, (2) Transform margin from Liberia to Benin, (3) Niger delta of Nigeria, Cameroon, and Equatorial Guinea, (4) South Atlantic Salt basin margin from Cameroon to Angola, and (5) Southwest Africa margin of Namibia and South Africa. Computer-constrained paleogeographic reconstructions based on exploration data depict the separation of west Africa from South and North America during the Late Triassic to the present along three rift systems. In northwest Africa rifting began in the Late Triassic associated with the opening of the Central Atlantic. In southwest Africa rifting began between the southern tips of Africa and South America in the Early Cretaceous (Valanginian) and propagated northward to the Benue Trough, a broad zone of left-lateral shear and extensional basins that began to open in the Aptian. Between these two rift systems, the Transform margin rift system initiated in the Early Cretaceous (Barremain) as a wrench-fault dominated eastward extension of the Proto-Caribbean ocean that propagated to the Benue Trough by the middle Albian. The most important variables affecting the tectonostratigraphic and hydrocarbon evolution of the west African margins include (1) the geometry, kinematics, and duration of rifting; (2) distribution of rift basins relative to paleoclimate zones (which affects the deposition of lacustrine source rocks and evaporites while influencing the type and quantity of sediment derived from land); (3) sea-level fluctuations; and (4) distribution of deltaic and turbiditic depocenters.

  3. Evaluation of global and regional climate simulations over Africa

    NASA Astrophysics Data System (ADS)

    Nikulin, Grigory; Jones, Colin; Kjellström, Erik; Gbobaniyi, Emiola

    2013-04-01

    Two ensembles of climate simulations, one global and one regional, are evaluated and inter-compared over the Africa-CORDEX domain. The global ensemble includes eight coupled atmosphere ocean general circulation models (AOGCMs) from the CMIP5 project with horizontal resolution varying from about 1° to 3°, namely CanESM2, CNRM-CM5, HadGEM2-ES, NorESM1-M, EC-EARTH, MIROC5, GFDL-ESM2M and MPI-ESM-LR. In the regional ensemble all 8 AOGCMs are downscaled over the Africa-CORDEX domain at the Rossby Centre (SMHI) by a regional climate model - RCA4 at 0.44° resolution. The main focus is on ability of both global and regional ensembles to simulate precipitation in different climate zones of Africa. Precipitation climatology is characterized by seasonal means, inter-annual variability and by various characteristics of the rainy season: onset, cessation, mean intensity and intra-seasonal variability. To see potential benefits of higher resolution in the regional downscaling all precipitation statistics are inter-compared between the individual AOGCM-RCA4(AOGCM) pairs and between the two multi-model ensemble averages. A special attention in the study is on how the AOGCMs simulate teleconnection patterns of large-scale internal variability and how these teleconnection pattern are reproduced in the downscaled regional simulations.

  4. Human ecology and behaviour in malaria control in tropical Africa

    PubMed Central

    MacCormack, C. P.

    1984-01-01

    Since about 250 BC, human modification of African environments has created increasingly favourable breeding conditions for Anopheles gambiae. Subsequent adaptations to the increased malaria risk are briefly described and reference is made to Macdonald's mathematical model for the disease. Since values for the variables in that model are high in tropical Africa, there is little possibility that simple, inexpensive, self-help primary health care initiatives can control malaria in the region. However, in combination with more substantial public health initiatives, simple primary health care activities might be done by communities to (1) prevent mosquitos from feeding on people, (2) prevent or reduce mosquito breeding, (3) destroy adult mosquitos, and (4) eliminate malaria parasites from human hosts. Lay methods of protection and self-care are examined and some topics for further research are indicated. Culturally appropriate health education methods are also suggested. PMID:6335685

  5. Alien phytogeographic regions of southern Africa: numerical classification, possible drivers, and regional threats.

    PubMed

    Hugo, Sanet; Van Rensburg, Berndt J; Van Wyk, Abraham E; Steenkamp, Yolande

    2012-01-01

    The distributions of naturalised alien plant species that have invaded natural or semi-natural habitat are often geographically restricted by the environmental conditions in their new range, implying that alien species with similar environmental requirements and tolerances may form assemblages and characterise particular areas. The aim of this study was to use objective numerical techniques to reveal any possible alien phytogeographic regions (i.e. geographic areas with characteristic alien plant assemblages) in southern Africa. Quarter degree resolution presence records of naturalised alien plant species of South Africa, Lesotho, Swaziland, Namibia and Botswana were analysed through a divisive hierarchical classification technique, and the output was plotted on maps for further interpretation. The analyses revealed two main alien phytogeographic regions that could be subdivided into eight lower level phytogeographic regions. Along with knowledge of the environmental requirements of the characteristic species and supported by further statistical analyses, we hypothesised on the main drivers of alien phytogeographic regions, and suggest that environmental features such as climate and associated biomes were most important, followed by human activities that modify climatic and vegetation features, such as irrigation and agriculture. Most of the characteristic species are not currently well-known as invasive plant species, but many may have potential to become troublesome in the future. Considering the possibility of biotic homogenization, these findings have implications for predicting the characteristics of the plant assemblages of the future. However, the relatively low quality of the dataset necessitates further more in-depth studies with improved data before the findings could be directly beneficial for management. PMID:22574145

  6. Alien Phytogeographic Regions of Southern Africa: Numerical Classification, Possible Drivers, and Regional Threats

    PubMed Central

    Hugo, Sanet; Van Rensburg, Berndt J.; Van Wyk, Abraham E.; Steenkamp, Yolande

    2012-01-01

    The distributions of naturalised alien plant species that have invaded natural or semi-natural habitat are often geographically restricted by the environmental conditions in their new range, implying that alien species with similar environmental requirements and tolerances may form assemblages and characterise particular areas. The aim of this study was to use objective numerical techniques to reveal any possible alien phytogeographic regions (i.e. geographic areas with characteristic alien plant assemblages) in southern Africa. Quarter degree resolution presence records of naturalised alien plant species of South Africa, Lesotho, Swaziland, Namibia and Botswana were analysed through a divisive hierarchical classification technique, and the output was plotted on maps for further interpretation. The analyses revealed two main alien phytogeographic regions that could be subdivided into eight lower level phytogeographic regions. Along with knowledge of the environmental requirements of the characteristic species and supported by further statistical analyses, we hypothesised on the main drivers of alien phytogeographic regions, and suggest that environmental features such as climate and associated biomes were most important, followed by human activities that modify climatic and vegetation features, such as irrigation and agriculture. Most of the characteristic species are not currently well-known as invasive plant species, but many may have potential to become troublesome in the future. Considering the possibility of biotic homogenization, these findings have implications for predicting the characteristics of the plant assemblages of the future. However, the relatively low quality of the dataset necessitates further more in-depth studies with improved data before the findings could be directly beneficial for management. PMID:22574145

  7. Combustion particulate emissions in Africa: regional climate modeling and validation

    NASA Astrophysics Data System (ADS)

    Konare, A.; Liousse, C.; Guillaume, B.; Solmon, F.; Assamoi, P.; Rosset, R.; Gregoire, J. M.; Giorgi, F.

    2008-04-01

    Africa, as a major aerosol source in the world, plays a key role in regional and global geochemical cycles and climate change. Combustion carbonaceous particles, central in this context through their radiative and hygroscopic properties, require ad hoc emission inventories. These inventories must incorporate fossil fuels FF (industries, traffic,...), biofuels BF (charcoal, wood burning,... quite common in Africa for domestic use), and biomass burning BB regularly occurring over vast areas all over the African continent. This latter, subject to rapid massive demographic, migratory, industrial and socio-economic changes, requires continuous emission inventories updating, so as to keep pace with this evolution. Two such different inventories, L96 and L06 with main focus on BB emissions, have been implemented for comparison within the regional climate model RegCM3 endowed with a specialized carbonaceous aerosol module. Resulting modeled black carbon BC and organic carbon OC fields have been compared to past and present composite data set available in Africa. This data set includes measurements from intensive field campaigns (EXPRESSO 1996, SAFARI 2000), from the IDAF/DEBITS surface network and from MODIS, focused on selected west, central and southern African sub-domains. This composite approach has been adopted to take advantage of possible combinations between satellite high-resolution coverage of Africa, regional modeling, use of an established surface network, together with the patchy detailed knowledge issued from past short intensive regional field experiments. Stemming from these particular comparisons, one prominent conclusion is the need for continuous detailed time and spatial updating of combustion emission inventories apt to reflect the rapid transformations of the African continent.

  8. The Evolution of Human Genetic and Phenotypic Variation in Africa

    PubMed Central

    Campbell, Michael C.

    2010-01-01

    Africa is the birthplace of modern humans, and is the source of the geographic expansion of ancestral populations into other regions of the world. Indigenous Africans are characterized by high levels of genetic diversity within and between populations. The pattern of genetic variation in these populations has been shaped by demographic events occurring over the last 200,000 years. The dramatic variation in climate, diet, and exposure to infectious disease across the continent has also resulted in novel genetic and phenotypic adaptations in extant Africans. This review summarizes some recent advances in our understanding of the demographic history and selective pressures that have influenced levels and patterns of diversity in African populations. PMID:20178763

  9. The epidemiology of human immunodeficiency virus in South Africa.

    PubMed Central

    Williams, B G; Gouws, E

    2001-01-01

    We review the epidemiology of human immunodeficiency virus (HIV) in South Africa where the prevalence of HIV infection is among the highest in the world. The epidemic reached South Africa relatively recently but the prevalence of infection has increased rapidly and there are significant differences among provinces. Although few 15-year-old people are infected the prevalence increases rapidly with age thereafter, especially among women. The prevalence of herpes simplex virus type 2 exceeds that of HIV and curable sexually transmitted infections are common. 'Circular migration' may help to explain the high rates and rapid spread of HIV in the region. The incidence of tuberculosis has increased dramatically as a result of the HIV epidemic. Antiretroviral therapy for the prevention of vertical transmission has been shown to be effective in local conditions but transmission through breast-feeding remains problematical. While some epidemiological models have been developed, much more needs to be done in this regard in order to plan, coordinate and evaluate an effective response to the epidemic. We conclude by discussing some of the research that is needed and steps that could be taken to reduce the continued spread of the infection. PMID:11516385

  10. AIDS in Southern Africa: a major factor in planning for the region.

    PubMed

    Place, J L

    1990-01-01

    This article discusses the spread and impact of AIDS in Southern Africa, as well as government responses to the pandemic. A with a total of 14,325 reported AIDS cases as of September 1990, the countries the Southern Africa (Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Zambia, and Zimbabwe) now account for 20% of all AIDS cases in Africa. This represents an eightfold increase in just over 2 years. Because of the young age structure of the population, which in the next few years will become sexually active, experts fear rapid increases in the rate of infection. With the exception of South Africa, AIDS has struck men and women alike. The region has also witnessed a growing number of HIV-infected babies and children orphaned by the disease. Besides its cost in human lives, the spread of AIDs threatens the economic development of the region, as it effects the most productive segment of the population, and as the resources to combat the disease dwindle, while its destructive potential grows. Surveillance of the disease has proven difficult, especially among refugees and returning exiles. Government responses to the pandemic have differed. In Zambia, where President Kaunda's own son died of the disease, the government has adopted an extensive AIDS program. Kaunda has appealed for a compassionate treatment of people with AIDS. The South African response, however, has met great skepticism. Most of the AIDS cases have been among blacks and homosexuals, 2 groups that have been marginalized by society. Nonetheless, the region has seen a bright note with the formation of the Southern Africa Network of AIDS Service Organization, which is designed to promote cooperation in combating the spread of AIDS. PMID:12284198

  11. Lost Horizons: The Humanities in South Africa (Part 1)

    ERIC Educational Resources Information Center

    Vale, Peter

    2008-01-01

    Politics chartered the development of the Humanities in South Africa. Under the apartheid system three separate traditions--English-speaking, Afrikaner and Homeland--co-existed, albeit uneasily, in separate institutional forms. As apartheid crumbled in the 1980s, the Humanities, by drawing the three traditions together, established a growing voice…

  12. Wetlands of South Africa: Hydrology and Human Use

    NASA Astrophysics Data System (ADS)

    Price, J. S.; Grundling, P.; Grundling, A.

    2009-05-01

    South Africa has a relatively dry climate (average 479 mm/y), and consequently wetlands are sparse covering 10-12% of the land surface, but locally extremely important hydrologically, ecologically and as a resource for human use. Given the climate, peatlands occur only where strong and sustained groundwater discharge occurs - either from regional-scale hydrogeological formations or from more localized aquifers such as coastal dunes, etc., and comprise 8-10% of South African wetlands. Elsewhere, the seasonal variation in precipitation typically results in ephemeral wetlands (without peat). In either case the perennial or seasonal availability of fresh-water is a focus of ecological activity and often of human interaction. Human use of wetlands includes water abstraction, grazing and harvesting of materials for building and handicrafts , often done in a sustainable manner. Other activities include totally unsustainable peat extraction and partly sustainable cultivation. Activities adjacent to wetlands including mining, timber plantations and groundwater exploitation for mining, commercial agriculture and urban water needs can also profoundly affect their water supply. Disturbances upstream or within wetlands can cause severe erosion and gullying. From 30 - 50% of wetlands have been lost due to landuse changes in their drainage basins or in the wetland itself. Ecohydrological feedback to even relatively modest disturbance of these systems can elicit a cycle of destructive and ongoing degradation. Wetland management requires a good understanding of the ecohydrological and landscape factors that support wetlands, proactive measures for restoration, and sensitivity to the needs of poverty-stricken users of wetland resources.

  13. The Ebola Virus and Human Rights Concerns in Africa.

    PubMed

    Durojaye, Ebenezer T; Mirugi-Mukundi, Gladys

    2015-09-01

    In the wake of the Ebola virus disease (EVD) that is ravaging parts of Africa certain measures are being taken by governments to prevent the spread of the epidemic within their borders. Some of these measures are drastic and may likely have implications for the fundamental rights of individuals. The EVD outbreaks have brought to the fore again the tension between public health and human rights. This article discusses the origin and mode of transmission of the EVD and then considers the human rights challenges that may arise as a result of states' responses to the disease in Africa. PMID:26897909

  14. Africa and Discovery: Human Rights, Environment, and Development.

    ERIC Educational Resources Information Center

    Hitchcock, Robert K.

    1993-01-01

    Contends that, in the past 30 years, a dramatic upsurge has taken place in activities designed to promote human rights for indigenous peoples around the world. Asserts that, in the case of Africa, attention generally has been concentrated on socioeconomic rights, such as health care, sufficient water, food, and shelter. (CFR)

  15. "Eve" in Africa: Human Evolution Meets Molecular Biology.

    ERIC Educational Resources Information Center

    Seager, Robert D.

    1990-01-01

    Presented is a discussion of recent evidence on the evolution of human forms on earth gathered and evaluated using mitochondrial DNA techniques. Theories regarding the possibility that a common female ancestor existed in Africa about 200,000 years ago are discussed. A list of teaching aids is provided. (CW)

  16. Apartheid medicine. Health and human rights in South Africa.

    PubMed

    Nightingale, E O; Hannibal, K; Geiger, H J; Hartmann, L; Lawrence, R; Spurlock, J

    Human rights and health care under apartheid in South Africa were studied. Human rights violations, such as detention without charge or trial, assault and torture in police custody, and restriction orders, have had devastating effects on the health of persons experiencing them. These violations have occurred in the context of a deliberate policy of discriminatory health care favoring the white minority over the black majority. South Africa's medical societies have had mixed responses to the health problems raised by human rights violations and inequities in the health care system. The amelioration of health care for all and prevention of human rights violations depend on ending apartheid and discrimination and greater government attention to these problems. PMID:2214078

  17. Regional Variation in Travel-related Illness acquired in Africa, March 1997–May 2011

    PubMed Central

    Han, Pauline V.; Vincent, Peter; von Sonnenburg, Frank; Cramer, Jakob P.; Loutan, Louis; Kain, Kevin C.; Parola, Philippe; Hagmann, Stefan; Gkrania-Klotsas, Effrossyni; Sotir, Mark; Schlagenhauf, Patricia

    2014-01-01

    To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism. PMID:24655358

  18. Regional variation in travel-related illness acquired in Africa, March 1997-May 2011.

    PubMed

    Mendelson, Marc; Han, Pauline V; Vincent, Peter; von Sonnenburg, Frank; Cramer, Jakob P; Loutan, Louis; Kain, Kevin C; Parola, Philippe; Hagmann, Stefan; Gkrania-Klotsas, Effrossyni; Sotir, Mark; Schlagenhauf, Patricia

    2014-04-01

    To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism. PMID:24655358

  19. Testing modern human out-of-Africa dispersal models and implications for modern human origins.

    PubMed

    Reyes-Centeno, Hugo; Hubbe, Mark; Hanihara, Tsunehiko; Stringer, Chris; Harvati, Katerina

    2015-10-01

    The modern human expansion process out of Africa has important implications for understanding the genetic and phenotypic structure of extant populations. While intensely debated, the primary hypotheses focus on either a single dispersal or multiple dispersals out of the continent. Here, we use the human fossil record from Africa and the Levant, as well as an exceptionally large dataset of Holocene human crania sampled from Asia, to model ancestor-descendant relationships along hypothetical dispersal routes. We test the spatial and temporal predictions of competing out-of-Africa models by assessing the correlation of geographical distances between populations and measures of population differentiation derived from quantitative cranial phenotype data. Our results support a model in which extant Australo-Melanesians are descendants of an initial dispersal out of Africa by early anatomically modern humans, while all other populations are descendants of a later migration wave. Our results have implications for understanding the complexity of modern human origins and diversity. PMID:26164107

  20. Regional Model Nesting Within GFS Daily Forecasts Over West Africa

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  1. A Regional Model Study of Synoptic Features Over West Africa

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  2. A regional approach to water shortage problems in the Sahel region of Africa

    SciTech Connect

    Isiorho, S.A.

    1995-03-01

    The Sahel region of Africa has repeatedly experienced drought periods, such as those highlighted during the early to mid-eighties. Water, an essential of life, is a scarce commodity in the region. Lake Chad is the major source of water for approximately ten million people across four nations. For proper management of water resources in this persistently drought prone region, the regional hydrology must be understood. Remote sensing, geophysical, and geochemical techniques are currently being used in an attempt to understand the hydrology of the region. Preliminary results indicate that lineament trace analysis from remote sensing can be correlated with faults/fractures of the region, with important implications for its hydrology. Field data indicate groundwater recharge from the lake to the southwest of the Chad Basin. Because of the low annual rainfall (less than 30 cm), a high rate of evaporation (230 cm/yr) and clay-rich surface materials (topsoil) of the region, Lake Chad appears to be its main source of water, either as surface or groundwater, as indicated by preliminary isotopic data. Understanding the hydrology of the region is imperative for the proper management of water resources in this drought-prone part of Africa. The governments of the Sahel need to approach the water shortage problem from a regional point of view.

  3. Human cytomegalovirus (CMV) in Africa: a neglected but important pathogen.

    PubMed

    Bates, Matthew; Brantsaeter, Arne Broch

    2016-01-01

    In Africa, human cytomegalovirus (CMV) is an important pathogen in a diverse range of patient groups. Congenital CMV infection is common, and most children undergo primary infection during the first year of life. Preliminary studies suggest that these early primary CMV infections could have population-wide effects on growth and development. In most studies of adults, CMV seroprevalence is close to 100%, but some studies have found that significant minorities of adults are seronegative. CMV is a common cause of pneumonia and meningitis in hospitalised immunosuppressed patient groups, and CMV DNAemia may be an important marker of rapid progression and poor outcomes of HIV infection, despite roll-out of antiretroviral therapy (ART). Diagnosis and treatment of CMV-related disease is broadly neglected in Africa, and no randomised clinical trials of anti-CMV drugs have been conducted to date. Autopsy is rarely performed in Africa, but identifies CMV as a frequent pathogen when it is carried out. Here we review the available literature on CMV in Africa, primarily in adult patients, and discuss this in the context of contemporary understanding of CMV as a human pathogen. PMID:27482452

  4. Regional, Continental, and Global Mobility to an Emerging Economy: The Case of South Africa

    ERIC Educational Resources Information Center

    Lee, Jenny J.; Sehoole, Chika

    2015-01-01

    This study examined mobility within the understudied region of southern Africa and particularly, the factors that drive and shape educational migration toward South Africa as a regional, continental, and global destination. Based on a survey administered to international students across seven South African universities, the findings revealed…

  5. Late Pleistocene human skull from Hofmeyr, South Africa, and modern human origins.

    PubMed

    Grine, F E; Bailey, R M; Harvati, K; Nathan, R P; Morris, A G; Henderson, G M; Ribot, I; Pike, A W G

    2007-01-12

    The lack of Late Pleistocene human fossils from sub-Saharan Africa has limited paleontological testing of competing models of recent human evolution. We have dated a skull from Hofmeyr, South Africa, to 36.2 +/- 3.3 thousand years ago through a combination of optically stimulated luminescence and uranium-series dating methods. The skull is morphologically modern overall but displays some archaic features. Its strongest morphometric affinities are with Upper Paleolithic (UP) Eurasians rather than recent, geographically proximate people. The Hofmeyr cranium is consistent with the hypothesis that UP Eurasians descended from a population that emigrated from sub-Saharan Africa in the Late Pleistocene. PMID:17218524

  6. Genome-Wide and Paternal Diversity Reveal a Recent Origin of Human Populations in North Africa

    PubMed Central

    Martínez-Cruz, Begoña; Zalloua, Pierre; Benammar Elgaaied, Amel; Comas, David

    2013-01-01

    The geostrategic location of North Africa as a crossroad between three continents and as a stepping-stone outside Africa has evoked anthropological and genetic interest in this region. Numerous studies have described the genetic landscape of the human population in North Africa employing paternal, maternal, and biparental molecular markers. However, information from these markers which have different inheritance patterns has been mostly assessed independently, resulting in an incomplete description of the region. In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations. Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components. Consequently, genome-wide diversity show similar patterns with admixture tests suggesting North Africans are a mixture of ancestral populations related to current Africans and Eurasians with more affinity towards the out-of-Africa populations than to sub-Saharan Africans. We estimate from the paternal lineages that most North Africans emerged ∼15,000 years ago during the last glacial warming and that population splits started after the desiccation of the Sahara. Although most North Africans share a common admixture history, the Tunisian Berbers show long periods of genetic isolation and appear to have diverged from surrounding populations without subsequent mixture. On the other hand, continuous gene flow from the Middle East made Egyptians genetically closer to Eurasians than to other North Africans. We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period. PMID:24312208

  7. Health Human Capital in Sub-Saharan Africa: Conflicting Evidence from Infant Mortality Rates and Adult Heights

    PubMed Central

    Akachi, Yoko; Canning, David

    2011-01-01

    We investigate trends in cohort infant mortality rates and adult heights in 39 developing countries since 1960. In most regions of the world improved nutrition, and reduced childhood exposure to disease, have lead to improvements in both infant mortality and adult stature. In Sub-Saharan Africa, however, despite declining infant mortality rates, adult heights have not increased. We argue that in Sub-Saharan Africa the decline in infant mortality may have been due to interventions that prevent infant deaths rather than improved nutrition and childhood morbidity. Despite declining infant mortality, Sub-Saharan Africa may not be experiencing increases in health human capital. PMID:20634153

  8. Impacts of Climate Change/Variability and Human Activities on Contemporary Vegetation Productivity across Africa

    NASA Astrophysics Data System (ADS)

    Ugbaje, S. U.; Odeh, I. A.; Bishop, T.

    2015-12-01

    Vegetation productivity is increasingly being impacted upon by climate change/variability and anthropogenic activities, especially in developing countries, where many livelihoods depend on the natural resource base. Despite these impacts, the individual and combined roles of climate and anthropogenic factors on vegetation dynamics have rarely been quantified in many ecosystems and regions of the world. This paper analyzes recent trend in vegetation productivity across Africa and quantified the relative roles of climate change/variability and human activities in driving this trend over 2000-2014 using net primary productivity (NPP) as an indicator. The relative roles of these factors to vegetation productivity change were quantified by comparing the trend slope (p<0.1) and total change in interannual actual NPP (NPPA), potential NPP (NPPP), and human appropriated NPP (NPPH). NPP significantly increased across Africa relative to NPP decline, though the extent of NPP decline is also quite appreciable. Whereas estimated NPP declined by 207 Tg C over 140 X 104 km of land area, vegetation productivity was estimated to improve by 1415 Tg C over 786 X 104 km of land area. NPP improvement is largely concentrated in equatorial and northern hemispheric Africa, while subequatorial Africa exhibited the most NPP decline. Generally, anthropogenic activities dominated climate change/variability in improving or degrading vegetation productivity. Of the estimated total NPP gained over the study period, 32.6, 8.8, and 58.6 % were due to individual human, climate and combined impacts respectively. The contributions of the factors to NPP decline in the same order are: 50.7, 16.0 and 33.3 %. The Central Africa region is where human activities had the greatest impact on NPP improvement; whereas the Sahel and the coastlines of west northern Africa are areas associated with the greatest influence of climate-driven NPP gain. Areas with humans dominating NPP degradation include eastern

  9. Private sector, human resources and health franchising in Africa.

    PubMed Central

    Prata, Ndola; Montagu, Dominic; Jefferys, Emma

    2005-01-01

    In much of the developing world, private health care providers and pharmacies are the most important sources of medicine and medical care and yet these providers are frequently not considered in planning for public health. This paper presents the available evidence, by socioeconomic status, on which strata of society benefit from publicly provided care and which strata use private health care. Using data from The World Bank's Health Nutrition and Population Poverty Thematic Reports on 22 countries in Africa, an assessment was made of the use of public and private health services, by asset quintile groups, for treatment of diarrhoea and acute respiratory infections, proxies for publicly subsidized services. The evidence and theory on using franchise networks to supplement government programmes in the delivery of public health services was assessed. Examples from health franchises in Africa and Asia are provided to illustrate the potential for franchise systems to leverage private providers and so increase delivery-point availability for public-benefit services. We argue that based on the established demand for private medical services in Africa, these providers should be included in future planning on human resources for public health. Having explored the range of systems that have been tested for working with private providers, from contracting to vouchers to behavioural change and provider education, we conclude that franchising has the greatest potential for integration into large-scale programmes in Africa to address critical illnesses of public health importance. PMID:15868018

  10. Soil mapping in Africa using satellite remote sensing at regional and continental scales

    NASA Astrophysics Data System (ADS)

    Dewitte, O.; Jones, A.; Horion, S.; Elbelrhiti, H.; Bosco, C.; Montanarella, L.

    2012-04-01

    The protection and the sustainable management of soil resources in Africa are of paramount importance, particularly in the context of the uncertain impact of climate change and the increasing pressures of human activities. From the perspective of a policy maker interested in topics such as food security and land degradation in Africa, up-to-date and relevant soil information at regional and continental scales are required. To provide timely and reliable information on soils at synoptic scales, moderate and coarse spatial resolution satellite data offer many possibilities. Here we review how a range of multispectral, thermal infrared, passive microwave and active microwave spaceborne sensors can be used in the delineation of soil units, as well as in the assessment of some of the key soil properties and threats to soil functions (water and wind erosion, landslides and salinisation). We show that remotely sensed data can be used for mapping soils in Africa but often they need to be combined with ancillary data and field observations in order to be effective. Remote sensing is shown to be a key component of the emerging discipline of digital soil mapping.

  11. The WASCAL regional climate simulations for West Africa - how to add value to existing climate projections

    NASA Astrophysics Data System (ADS)

    Arnault, J.; Heinzeller, D.; Klein, C.; Dieng, D.; Smiatek, G.; Bliefernicht, J.; Sylla, M. B.; Kunstmann, H.

    2015-12-01

    With climate change being one of the most severe challenges to rural Africa in the 21st century, West Africa is facing an urgent need to develop effective adaptation and mitigation measures to protect its constantly growing population. WASCAL (West African Science Service Center on Climate Change and Adapted Land Use) is a large-scale research-focused program designed to enhance the resilience of human and environmental systems to climate change and increased variability. An integral part of its climate services is the provisioning of a new set of high resolution, ensemble-based regional climate change scenarios for the region of West Africa. In this contribution, we present the overall concept of the WASCAL regional climate projections and provide information on the dissemination of the data. We discuss the model performance over the validation period for two of the three regional climate models employed, the Weather Research & Forecasting Tool (WRF) and the Consortium for Small-scale Modeling Model COSMO in Climate Mode (COSMO-CLM), and give details about a novel precipitation database used to verify the models. Particular attention is paid to the representation of the dynamics of the West African Summer Monsoon and to the added value of our high resolution models over existing data sets. We further present results on the climate change signal obtained from the WRF model runs for the periods 2020-2050 and 2070-2100 and compare them to current state-of-the-art projections from the CORDEX project. As an example, the figure shows the different climate change signals obtained for the total annual rainfall with respect to the 1980-2010 mean (WRF-E: WASCAL 12km high-resolution run MPI-ESM + WRFV3.5.1, CORDEX-E: 50km medium-resolution run MPI-ESM + RCA4, CORDEX-G: 50km medium-resolution run GFDL-ESM + RCA4).

  12. Archaeological shellfish size and later human evolution in Africa

    PubMed Central

    Klein, Richard G.; Steele, Teresa E.

    2013-01-01

    Approximately 50 ka, one or more subgroups of modern humans expanded from Africa to populate the rest of the world. Significant behavioral change accompanied this expansion, and archaeologists commonly seek its roots in the African Middle Stone Age (MSA; ∼200 to ∼50 ka). Easily recognizable art objects and “jewelry” become common only in sites that postdate the MSA in Africa and Eurasia, but some MSA sites contain possible precursors, especially including abstractly incised fragments of ocher and perforated shells interpreted as beads. These proposed art objects have convinced most specialists that MSA people were behaviorally (cognitively) modern, and many argue that population growth explains the appearance of art in the MSA and its post-MSA florescence. The average size of rocky intertidal gastropod species in MSA and later coastal middens allows a test of this idea, because smaller size implies more intense collection, and more intense collection is most readily attributed to growth in the number of human collectors. Here we demonstrate that economically important Cape turban shells and limpets from MSA layers along the south and west coasts of South Africa are consistently and significantly larger than turban shells and limpets in succeeding Later Stone Age (LSA) layers that formed under equivalent environmental conditions. We conclude that whatever cognitive capacity precocious MSA artifacts imply, it was not associated with human population growth. MSA populations remained consistently small by LSA standards, and a substantial increase in population size is obvious only near the MSA/LSA transition, when it is dramatically reflected in the Out-of-Africa expansion. PMID:23776248

  13. Impact of human schistosomiasis in sub-Saharan Africa.

    PubMed

    Adenowo, Abiola Fatimah; Oyinloye, Babatunji Emmanuel; Ogunyinka, Bolajoko Idiat; Kappo, Abidemi Paul

    2015-01-01

    Schistosomiasis, a neglected tropical disease of poverty ranks second among the most widespread parasitic disease in various nations in sub-Saharan Africa. Neglected tropical diseases are causes of about 534,000 deaths annually in sub-Saharan Africa and an estimated 57 million disability-adjusted life-years are lost annually due to the neglected tropical diseases. The neglected tropical diseases exert great health, social and financial burden on economies of households and governments. Schistosomiasis has profound negative effects on child development, outcome of pregnancy, and agricultural productivity, thus a key reason why the "bottom 500 million" inhabitants of sub-Saharan Africa continue to live in poverty. In 2008, 17.5 million people were treated globally for schistosomiasis, 11.7 million of those treated were from sub-Saharan Africa. This enervating disease has been successfully eradicated in Japan, as well as in Tunisia. Morocco and some Caribbean Island countries have made significant progress on control and management of this disease. Brazil, China and Egypt are taking steps towards elimination of the disease, while most sub-Saharan countries are still groaning under the burden of the disease. Various factors are responsible for the continuous and persistent transmission of schistosomiasis in sub-Saharan Africa. These include climatic changes and global warming, proximity to water bodies, irrigation and dam construction as well as socio-economic factors such as occupational activities and poverty. The morbidity and mortality caused by this disease cannot be overemphasized. This review is an exposition of human schistosomiasis as it affects the inhabitants of various communities in sub-Sahara African countries. It is hoped this will bring a re-awakening towards efforts to combat this impoverishing disease in terms of vaccines development, alternative drug design, as well as new point-of-care diagnostics. PMID:25636189

  14. Potential source regions of dust accumulated in northern Africa

    NASA Astrophysics Data System (ADS)

    Wasowska, S.; Woronko, B.

    2012-04-01

    Iguidi and Chech-Adrar, although the most probable source area is Erg Occidental. Tunisian dusts come from vast expanses of Erg Oriental and Chott-el-Jerid. The potential source of the dusts accumulated in Alexandria could be Libyan Desert. This does not preclude also much more distant sources of sediment, as for instance ergs from North Sudan. From the other hand the presence of shell parts of diatoms of the Actinoptychus genus may indicate the dispelling of the Nile alluvium. Key words: source region, aeolian accumulation, north Africa, textural features of grains, aeolian dust, meteorological situation, Sahara, SEM analysis

  15. Mortality of children in the Transkei region of South Africa.

    PubMed

    Meel, B L

    2003-06-01

    This study attempted to unfold, perhaps for the first time, the problem of childhood mortality resulting from trauma in the Eastern Cape Province of South Africa. This study was carried out in the Umtata and Ngqeleni magisterial districts, which have a combined population of about 400,000. Most people there have very few resources and have historically relied on money repatriated by migrant workers. In the Transkei region, unemployment is at a very high level: 48.5%. Assault on children is very common in this region, and this may result in death. The aim of this study was to establish the state of deaths resulting from pediatric trauma, and to formulate recommendations that could probably help prevent or reduce these deaths. The objective was to gather epidemiologic information on the victims of pediatric trauma. The study was designed as a descriptive study, using reviews of traumatic deaths in pediatric age groups during the period January 1993 to December 1999. This study was carried out on cases that were brought to the medicolegal laboratory at Umtata General Hospital, Umtata, in the Transkei region of the Eastern Cape Province, South Africa. There were 6181 autopsies conducted from 1993 to 1999. All the medicolegal autopsies were divided into two groups: pediatric (15 years of age or younger) and adult (older than 15 years). Of the autopsies, 89.4% (n = 5587) were in the adult group, and 10.6% (n = 594) were in the pediatric group. Of the pediatric deaths, 64% (n = 383) were related to trauma. The highest numbers were in the 11- to 15-year (n = 146, 38%) and the 6- to 10-year (n = 135, 34%) age groups. Of the children who died of trauma, 112 (28%) were aged 0 to 5 years. Unintentional injuries from motor vehicle accidents were the leading cause of death (59%), whereas intentional injuries (41%) were associated with murder. Nearly a quarter (22%) of pediatric traumatic deaths were due to penetrating injuries: stab (12%) and gunshot (10%) wounds. Most of the

  16. Human Dispersal Out of Africa: A Lasting Debate

    PubMed Central

    López, Saioa; van Dorp, Lucy; Hellenthal, Garrett

    2015-01-01

    Unraveling the first migrations of anatomically modern humans out of Africa has invoked great interest among researchers from a wide range of disciplines. Available fossil, archeological, and climatic data offer many hypotheses, and as such genetics, with the advent of genome-wide genotyping and sequencing techniques and an increase in the availability of ancient samples, offers another important tool for testing theories relating to our own history. In this review, we report the ongoing debates regarding how and when our ancestors left Africa, how many waves of dispersal there were and what geographical routes were taken. We explore the validity of each, using current genetic literature coupled with some of the key archeological findings. PMID:27127403

  17. A highly variable segment of human subterminal 16p reveals a history of population growth for modern humans outside Africa

    PubMed Central

    Alonso, Santos; Armour, John A. L.

    2001-01-01

    We have sequenced a highly polymorphic subterminal noncoding region from human chromosome 16p13.3, flanking the 5′ end of the hypervariable minisatellite MS205, in 100 chromosomes sampled from different African and Euroasiatic populations. Coalescence analysis indicates that the time to the most recent common ancestor (approximately 1 million years) predates the appearance of anatomically modern human forms. The root of the network describing this variability lies in Africa. African populations show a greater level of diversity and deeper branches. Most Euroasiatic variability seems to have been generated after a recent out-of-Africa range expansion. A history of population growth is the most likely scenario for the Euroasiatic populations. This pattern of nuclear variability can be reconciled with inferences based on mitochondrial DNA. PMID:11158547

  18. New Technology Tools for Human Development? Towards Policy and Practice for Knowledge Societies in Southern Africa.

    ERIC Educational Resources Information Center

    Johnson, Phyllis

    2002-01-01

    Explores the interface of technology and education for human development in southern Africa. Uses the case of Mozambique to describe the challenges presented by the global marketplace and local policy. Outlines the vision of the New Partnership for Africa's Development Centre (SARDC) to reduce the digital divide for Africa. (CAJ)

  19. Africa.

    ERIC Educational Resources Information Center

    Happel, Sue; Loeb, Joyce

    Although the activities in this unit are designed primarily for students in the intermediate grades, the document's text, illustrations, and bibliographic references are suitable for anyone interested in learning about Africa. Following a brief introduction and map work, the document is arranged into six sections. Section 1 traces Africa's history…

  20. Africa.

    ERIC Educational Resources Information Center

    Martz, Carlton

    2001-01-01

    This publication explores issues related to Africa. It examines the U.S. response to the Barbary pirate states (Morocco, Algiers, Tunis, Tripoli) in the early 19th century; the current AIDS crisis in Africa; and 14th century Mali and other Islamic lands through the eyes of Ibn Battuta, who traveled throughout the Muslim world. Each article…

  1. Evolution of human-driven fire regimes in Africa

    PubMed Central

    Archibald, Sally; Staver, A. Carla; Levin, Simon A.

    2012-01-01

    Human ability to manipulate fire and the landscape has increased over evolutionary time, but the impact of this on fire regimes and consequences for biodiversity and biogeochemistry are hotly debated. Reconstructing historical changes in human-derived fire regimes empirically is challenging, but information is available on the timing of key human innovations and on current human impacts on fire; here we incorporate this knowledge into a spatially explicit fire propagation model. We explore how changes in population density, the ability to create fire, and the expansion of agropastoralism altered the extent and seasonal distribution of fire as modern humans arose and spread through Africa. Much emphasis has been placed on the positive effect of population density on ignition frequency, but our model suggests this is less important than changes in fire spread and connectivity that would have occurred as humans learned to light fires in the dry season and to transform the landscape through grazing and cultivation. Different landscapes show different limitations; we show that substantial human impacts on burned area would only have started ∼4,000 B.P. in open landscapes, whereas they could have altered fire regimes in closed/dissected landscapes by ∼40,000 B.P. Dry season fires have been the norm for the past 200–300 ky across all landscapes. The annual area burned in Africa probably peaked between 4 and 40 kya. These results agree with recent paleocarbon studies that suggest that the biomass burned today is less than in the recent past in subtropical countries. PMID:22184249

  2. Mosaic maternal ancestry in the Great Lakes region of East Africa.

    PubMed

    Gomes, Verónica; Pala, Maria; Salas, Antonio; Álvarez-Iglesias, Vanesa; Amorim, António; Gómez-Carballa, Alberto; Carracedo, Ángel; Clarke, Douglas J; Hill, Catherine; Mormina, Maru; Shaw, Marie-Anne; Dunne, David W; Pereira, Rui; Pereira, Vânia; Prata, Maria João; Sánchez-Diz, Paula; Rito, Teresa; Soares, Pedro; Gusmão, Leonor; Richards, Martin B

    2015-09-01

    The Great Lakes lie within a region of East Africa with very high human genetic diversity, home of many ethno-linguistic groups usually assumed to be the product of a small number of major dispersals. However, our knowledge of these dispersals relies primarily on the inferences of historical, linguistics and oral traditions, with attempts to match up the archaeological evidence where possible. This is an obvious area to which archaeogenetics can contribute, yet Uganda, at the heart of these developments, has not been studied for mitochondrial DNA (mtDNA) variation. Here, we compare mtDNA lineages at this putative genetic crossroads across 409 representatives of the major language groups: Bantu speakers and Eastern and Western Nilotic speakers. We show that Uganda harbours one of the highest mtDNA diversities within and between linguistic groups, with the various groups significantly differentiated from each other. Despite an inferred linguistic origin in South Sudan, the data from the two Nilotic-speaking groups point to a much more complex history, involving not only possible dispersals from Sudan and the Horn but also large-scale assimilation of autochthonous lineages within East Africa and even Uganda itself. The Eastern Nilotic group also carries signals characteristic of West-Central Africa, primarily due to Bantu influence, whereas a much stronger signal in the Western Nilotic group suggests direct West-Central African ancestry. Bantu speakers share lineages with both Nilotic groups, and also harbour East African lineages not found in Western Nilotic speakers, likely due to assimilating indigenous populations since arriving in the region ~3000 years ago. PMID:26188410

  3. Human Responses to Climate Variability: The Case of South Africa

    NASA Astrophysics Data System (ADS)

    Oppenheimer, M.; Licker, R.; Mastrorillo, M.; Bohra-Mishra, P.; Estes, L. D.; Cai, R.

    2014-12-01

    Climate variability has been associated with a range of societal and individual outcomes including migration, violent conflict, changes in labor productivity, and health impacts. Some of these may be direct responses to changes in mean temperature or precipitation or extreme events, such as displacement of human populations by tropical cyclones. Others may be mediated by a variety of biological, social, or ecological factors such as migration in response to long-term changes in crops yields. Research is beginning to elucidate and distinguish the many channels through which climate variability may influence human behavior (ranging from the individual to the collective, societal level) in order to better understand how to improve resilience in the face of current variability as well as future climate change. Using a variety of data sets from South Africa, we show how climate variability has influenced internal (within country) migration in recent history. We focus on South Africa as it is a country with high levels of internal migration and dramatic temperature and precipitation changes projected for the 21st century. High poverty rates and significant levels of rain-fed, smallholder agriculture leave large portions of South Africa's population base vulnerable to future climate change. In this study, we utilize two complementary statistical models - one micro-level model, driven by individual and household level survey data, and one macro-level model, driven by national census statistics. In both models, we consider the effect of climate on migration both directly (with gridded climate reanalysis data) and indirectly (with agricultural production statistics). With our historical analyses of climate variability, we gain insights into how the migration decisions of South Africans may be influenced by future climate change. We also offer perspective on the utility of micro and macro level approaches in the study of climate change and human migration.

  4. Managing the human component of fire regimes: lessons from Africa.

    PubMed

    Archibald, Sally

    2016-06-01

    Human impacts on fire regimes accumulated slowly with the evolution of modern humans able to ignite fires and manipulate landscapes. Today, myriad voices aim to influence fire in grassy ecosystems to different ends, and this is complicated by a colonial past focused on suppressing fire and preventing human ignitions. Here, I review available evidence on the impacts of people on various fire characteristics such as the number and size of fires, fire intensity, fire frequency and seasonality of fire in African grassy ecosystems, with the intention of focusing the debate and identifying areas of uncertainty. Humans alter seasonal patterns of fire in grassy systems but tend to decrease total fire emissions: livestock have replaced fire as the dominant consumer in many parts of Africa, and fragmented landscapes reduce area burned. Humans alter the season and time of day when fires occur, with important implications for fire intensity, tree-grass dynamics and greenhouse gas (GHG) emissions. Late season fires are more common when fire is banned or illegal: these later fires are far more intense but emit fewer GHGs. The types of fires which preserve human livelihoods and biodiversity are not always aligned with the goal of reducing GHG concentrations. Current fire management challenges therefore involve balancing the needs of a large rural population against national and global perspectives on the desirability of different types of fire, but this cannot happen unless the interests of all parties are equally represented. In the future, Africa is expected to urbanize and land use to intensify, which will imply different trajectories for the continent's fire regimes.This article is part of the themed issue 'The interaction of fire and mankind. PMID:27216516

  5. The Levant versus the Horn of Africa: Evidence for Bidirectional Corridors of Human Migrations

    PubMed Central

    Luis, J. R.; Rowold, D. J.; Regueiro, M.; Caeiro, B.; Cinnioğlu, C.; Roseman, C.; Underhill, P. A.; Cavalli-Sforza, L. L.; Herrera, R. J.

    2004-01-01

    Paleoanthropological evidence indicates that both the Levantine corridor and the Horn of Africa served, repeatedly, as migratory corridors between Africa and Eurasia. We have begun investigating the roles of these passageways in bidirectional migrations of anatomically modern humans, by analyzing 45 informative biallelic markers as well as 10 microsatellite loci on the nonrecombining region of the Y chromosome (NRY) in 121 and 147 extant males from Oman and northern Egypt, respectively. The present study uncovers three important points concerning these demic movements: (1) The E3b1-M78 and E3b3-M123 lineages, as well as the R1*-M173 lineages, mark gene flow between Egypt and the Levant during the Upper Paleolithic and Mesolithic. (2) In contrast, the Horn of Africa appears to be of minor importance in the human migratory movements between Africa and Eurasia represented by these chromosomes, an observation based on the frequency distributions of E3b*-M35 (no known downstream mutations) and M173. (3) The areal diffusion patterns of G-M201, J-12f2, the derivative M173 haplogroups, and M2 suggest more recent genetic associations between the Middle East and Africa, involving the Levantine corridor and/or Arab slave routes. Affinities to African groups were also evaluated by determining the NRY haplogroup composition in 434 samples from seven sub-Saharan African populations. Oman and Egypt’s NRY frequency distributions appear to be much more similar to those of the Middle East than to any sub-Saharan African population, suggesting a much larger Eurasian genetic component. Finally, the overall phylogeographic profile reveals several clinal patterns and genetic partitions that may indicate source, direction, and relative timing of different waves of dispersals and expansions involving these nine populations. PMID:14973781

  6. A Spring Forward for Human Evolution in East Africa?

    NASA Astrophysics Data System (ADS)

    Cuthbert, M. O.; Ashley, G. M.

    2014-12-01

    The current consensus is that humans evolved in Africa and then migrated in waves to other parts of the world starting as early as 2 Ma. The climate was both cooling and drying. One of the major unknowns connected with human survival in this climatically turbulent environment is the availability of resources, particularly water. A growing body of geological evidence shows an association between springs, stone tools and hominin fossils at a number of sites in the East African Rift System (EARS) during a critical period for hominin evolution (from 1.8 Ma). The springs may have been vulnerable to climate variability, thus the role that groundwater availability may have played in human evolution and migration to other continents is not known. Using palaeogeological reconstruction and groundwater modelling of the paleo-catchment of one such EARS site, Olduvai Gorge (3°S), we show how spring discharge was likely linked to climate variability of annual to Milankovitch cycle timescales. Under decadal to centennial timescales, spring flow would have been relatively invariant providing good water resource resilience through long droughts. For multi-millennial periods, modelled spring flows lag groundwater recharge by 100s to 1000 years. Our results show how groundwater would have provided 'drought proof' water supply and habitats during arid phases as potable surface water from rivers or lakes became increasingly scarce. Localized groundwater systems are likely to have been widespread within the EARS providing refugia and intense competition during dry periods. Thus, springs and associated wetlands may have been important factors in natural selection and evolution, as well as a vital resource during dispersal within and out of Africa. While further exploration is needed to test the geographical extent of groundwater use by early humans, we propose that groundwater flow systems produced in the EARS played a significant role in the evolution and dispersal of early humans.

  7. Carbon Erosion in the Great Karoo Region of South Africa

    NASA Astrophysics Data System (ADS)

    Krenz, Juliane; Greenwood, Philip; Kuhn, Brigitte; Foster, Ian; Boardman, John; Meadows, Mike; Kuhn, Nikolaus

    2015-04-01

    Work undertaken in the seasonally arid upland areas of the Great Karoo region of South Africa has established a link between land degradation and overgrazing which began in the second half of the 18th century when European farmers first settled the area. Ongoing land use change and shifting rainfall patterns resulted in the development of badlands on foot slopes of upland areas, and gully systems on valley bottoms. As a consequence of agricultural intensification and overgrazing, accompanied by a higher water demand, many small reservoirs were constructed, most of which are now in-filled with sediment. The deposited material serves as an environmental archive by which land use change over the last 100 years can be analysed, but with a particular focus on erosion and deposition of soil-associated carbon (C). It is assumed that erosion caused an initial flush of carbon rich soil which was subsequently buried and stored off-site. Despite this assumption, however the net-effect of erosion on carbon dioxide emissions is still unknown. In this project, preliminary results are presented from an investigation to determine whether land degradation in the Karoo has resulted in a shift from a net sink of C to a net source of C. Firstly, a high resolution digital elevation model was generated and erosion modelling was then employed to create an erosion risk map showing areas most prone to erosion. Information from the model output then served as the basis for ground-truthing and on-site erosion mapping. Secondly, sediment deposits from silted reservoirs were analysed for varying physicochemical parameters, in order to reconstruct spatial patterns of erosion and deposition. Analysis of total carbon (TC) content revealed a sharp decrease with decreasing depth. This provisionally suggests that land degradation during and after post-European settlement probably led to accelerated erosion of the relatively fertile surface soils. This presumably resulted in the rapid in-filling of

  8. Human brucellosis in South Africa: Public health and diagnostic pitfalls.

    PubMed

    Wojno, Justyna Maria; Moodley, Clinton; Pienaar, Jaco; Beylis, Natalie; Jacobsz, Lourens; Nicol, Mark P; Rossouw, Jenny; Bamford, Colleen

    2016-09-01

    Human brucellosis in South Africa (SA) is under-diagnosed and under-reported. This is because many clinicians have little or no experience in managing affected patients, and in part because of the nonspecific and insidious nature of the disease. A case of human brucellosis caused by Brucella melitensis in a patient from the Western Cape Province of SA is described, and the resulting exposure of staff members at two medical microbiology laboratories, as well as the public health investigation that was conducted, are discussed. This article aims to highlight the need for strengthening integration between public health, medical and veterinary services and exposing deficiencies in public health, veterinary and laboratory practices. PMID:27601111

  9. Evidence for henipavirus spillover into human populations in Africa

    PubMed Central

    Pernet, Olivier; Schneider, Bradley S.; Beaty, Shannon M.; LeBreton, Matthew; Yun, Tatyana E.; Park, Arnold; Zachariah, Trevor T.; Bowden, Thomas A.; Hitchens, Peta; Ramirez, Christina M.; Daszak, Peter; Mazet, Jonna; Freiberg, Alexander N.; Wolfe, Nathan D.; Lee, Benhur

    2014-01-01

    Zoonotic transmission of lethal henipaviruses (HNVs) from their natural fruit bat reservoirs to humans has only been reported in Australia and South/Southeast Asia. However, a recent study discovered numerous HNV clades in African bat samples. To determine the potential for HNV spillover events among humans in Africa, here we examine well-curated sets of bat (Eidolon helvum, n=44) and human (n=497) serum samples from Cameroon for Nipah virus (NiV) cross-neutralizing antibodies (NiV-X-Nabs). Using a vesicular stomatitis virus (VSV)-based pseudoparticle seroneutralization assay, we detect NiV-X-Nabs in 48% and 3–4% of the bat and human samples, respectively. Seropositive human samples are found almost exclusively in individuals who reported butchering bats for bushmeat. Seropositive human sera also neutralize Hendra virus and Gh-M74a (an African HNV) pseudoparticles, as well as live NiV. Butchering bat meat and living in areas undergoing deforestation are the most significant risk factors associated with seropositivity. Evidence for HNV spillover events warrants increased surveillance efforts. PMID:25405640

  10. Evidence for henipavirus spillover into human populations in Africa.

    PubMed

    Pernet, Olivier; Schneider, Bradley S; Beaty, Shannon M; LeBreton, Matthew; Yun, Tatyana E; Park, Arnold; Zachariah, Trevor T; Bowden, Thomas A; Hitchens, Peta; Ramirez, Christina M; Daszak, Peter; Mazet, Jonna; Freiberg, Alexander N; Wolfe, Nathan D; Lee, Benhur

    2014-01-01

    Zoonotic transmission of lethal henipaviruses (HNVs) from their natural fruit bat reservoirs to humans has only been reported in Australia and South/Southeast Asia. However, a recent study discovered numerous HNV clades in African bat samples. To determine the potential for HNV spillover events among humans in Africa, here we examine well-curated sets of bat (Eidolon helvum, n = 44) and human (n = 497) serum samples from Cameroon for Nipah virus (NiV) cross-neutralizing antibodies (NiV-X-Nabs). Using a vesicular stomatitis virus (VSV)-based pseudoparticle seroneutralization assay, we detect NiV-X-Nabs in 48% and 3-4% of the bat and human samples, respectively. Seropositive human samples are found almost exclusively in individuals who reported butchering bats for bushmeat. Seropositive human sera also neutralize Hendra virus and Gh-M74a (an African HNV) pseudoparticles, as well as live NiV. Butchering bat meat and living in areas undergoing deforestation are the most significant risk factors associated with seropositivity. Evidence for HNV spillover events warrants increased surveillance efforts. PMID:25405640

  11. Water, plants, and early human habitats in eastern Africa.

    PubMed

    Magill, Clayton R; Ashley, Gail M; Freeman, Katherine H

    2013-01-22

    Water and its influence on plants likely exerted strong adaptive pressures in human evolution. Understanding relationships among water, plants, and early humans is limited both by incomplete terrestrial records of environmental change and by indirect proxy data for water availability. Here we present a continuous record of stable hydrogen-isotope compositions (expressed as δD values) for lipid biomarkers preserved in lake sediments from an early Pleistocene archaeological site in eastern Africa--Olduvai Gorge. We convert sedimentary leaf- and algal-lipid δD values into estimates for ancient source-water δD values by accounting for biochemical, physiological, and environmental influences on isotopic fractionation via published water-lipid enrichment factors for living plants, algae, and recent sediments. Reconstructed precipitation and lake-water δD values, respectively, are consistent with modern isotopic hydrology and reveal that dramatic fluctuations in water availability accompanied ecosystem changes. Drier conditions, indicated by less negative δD values, occur in association with stable carbon-isotopic evidence for open, C(4)-dominated grassland ecosystems. Wetter conditions, indicated by lower δD values, are associated with expanded woody cover across the ancient landscape. Estimates for ancient precipitation amounts, based on reconstructed precipitation δD values, range between approximately 250 and 700 mm · y(-1) and are consistent with modern precipitation data for eastern Africa. We conclude that freshwater availability exerted a substantial influence on eastern African ecosystems and, by extension, was central to early human proliferation during periods of rapid climate change. PMID:23267102

  12. Occurrence of aflatoxins in human foodstuffs in South Africa

    SciTech Connect

    Loetter, L.H.; Kroehm, H.J.

    1988-02-01

    Aflatoxins are toxic metabolites of Aspergillus spp and have been reported as contaminants in a number of foodstuffs, namely corn, rice, peanuts, and cereals. In the Republic of South Africa, aflatoxin levels in human foodstuffs are limited to a maximum of 10 ..mu..g/kg for the total and 5 ..mu..g/kg for aflatoxin B/sub 1/. During 1985 and 1986, samples of sorghum beer, sorghum cereal, peanuts, peanut butter and maize meal were purchased from supermarkets in Johannesburg and analyzed for aflatoxins. A total of 414 samples were analyzed during the survey. In 1985, roughly a third of the samples were contaminated with aflatoxins, with no levels in excess of the legal limit. In 1986 the percentage of contaminated samples rose significantly, but the levels of contamination remained low, with only one sample exceeding the legal maximum.

  13. Human immunodeficiency virus and migrant labor in South Africa.

    PubMed

    Jochelson, K; Mothibeli, M; Leger, J P

    1991-01-01

    The authors investigate the impact of the migrant labor system on heterosexual relationships on South African mines and assess the implications for the future transmission of human immunodeficiency virus (HIV) infection. The migrant labor system has created a market for prostitution in mining towns and geographic networks of relationships within and between urban and rural communities. A section of the migrant workforce and a group of women dependent on prostitution for economic support appear especially vulnerable to contracting HIV infection since they are involved in multiple sexual encounters with different, changing partners, usually without condom protection. Furthermore, sexually transmitted disease morbidity is extensive in the general and mineworker populations. Historically, migration facilitated the transmission of sexually transmitted diseases and may act similarly for HIV. Problems of combating the HIV epidemic in South Africa are discussed. PMID:2004869

  14. Learning about War and Peace in the Great Lakes Region of Africa

    ERIC Educational Resources Information Center

    Bird, Lyndsay

    2007-01-01

    Two-thirds of the world's conflicts are in Africa. In particular, the Great Lakes region (Rwanda, Burundi, Democratic Republic of Congo, Uganda and Tanzania) continues to see conflicts that are complex, extreme and seemingly intractable. By exploring the narrative experiences of those most affected by the conflicts in the region--specifically…

  15. International migration and sustainable human development in eastern and southern Africa.

    PubMed

    Oucho, J O

    1995-01-01

    International migration in eastern and southern Africa (ESA) is rarely addressed in population and development policies or regional organizations, and regional organizations must in the articulation of sustainable shared development identify the role of international migration. Poor quality data on international migration hampers analysis. Sustainable, shared, and human development within the region are subregional issues. Permanent migration is characterized among ESA countries as increasing demographic ethnic pluralism that may result in redrawing of territorial boundaries and further population movement. Portuguese and Arab settlement and integration in eastern areas resulted in coexistence, while European immigration to South Africa resulted in racial segregation. Modern colonial settlement and the aftermath of political conflict resulted in independent countries after the 1960s and outmigration of nonAfrican groups. Much of the labor migration in ESA is unskilled workers moving to South African mining regions. Labor migration to Zimbabwe and Zambia declined after the 1960s. The formation of the Common Market for ESA and the potential merger with the Preferential Trade Area and South African Development Community is a key approach to integration of migration into regional cooperation and shared development. Refugee movements create the most problems. Prior to 1992 ESA countries accounted for 83.4% of refugees, particularly in Mozambique, Ethiopia, and Somalia. Some countries blame poor economic performance on the deluge of refugees. Illegal migration is currently detected because of the required work permits, but the adoption of the Common Market would obscure this phenomenon. Human development is affected most by migrations related to drought, labor migration to strong economic areas, and return migration. The Inter-Governmental Authority on Drought and Development needs to become more active and establish better policies on nomadic and refugee movements and

  16. Ecosystem variability and early human habitats in eastern Africa.

    PubMed

    Magill, Clayton R; Ashley, Gail M; Freeman, Katherine H

    2013-01-22

    The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma--the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ(13)C values) of lipid biomarkers from ancient plants. Within this framework, δ(13)C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C(4) grasslands abruptly transitioned to closed C(3) forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth's orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution. PMID:23267092

  17. Human genetics in Johannesburg, South Africa: past, present and future.

    PubMed

    Kromberg, Jennifer G R; Krause, Amanda

    2013-12-01

    Genetic services were set up in Johannesburg, South Africa, in the late 1960s, but only became widespread and formalised after the first Professor of Human Genetics, Trefor Jenkins, was installed at the University of the Witwatersrand in 1974. The first services involved chromosome studies, and these developed into genetic counselling services. Prenatal diagnosis began to be offered, particularly for older women at risk for chromosome abnormalities in the fetus, and those at risk for neural tube defects. Genetic screening was then initiated for the Jewish community because of their high carrier rate for Tay-Sachs disease. Educational courses in human genetics were offered at Wits Medical School, and medical as well as other health professionals began to be trained. Research, supported by national and international bodies, was integral in the activities of the Department (now Division) of Human Genetics and focused on genetic conditions affecting the generally understudied black community. In the late 1980s the first training programme for genetic counsellors was started at MSc level, and postgraduate scientists at MSc and PhD levels studied in and qualified through the Department. At the same time molecular genetic laboratories were set up. In the late 1990s training for medical geneticists was initiated. Extensive high-quality genetic services developed over the four decades were comparable to those of most other departments in developed countries.  PMID:24300637

  18. Ecosystem variability and early human habitats in eastern Africa

    PubMed Central

    Magill, Clayton R.; Ashley, Gail M.; Freeman, Katherine H.

    2013-01-01

    The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma—the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ13C values) of lipid biomarkers from ancient plants. Within this framework, δ13C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C4 grasslands abruptly transitioned to closed C3 forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth’s orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution. PMID:23267092

  19. AMMA-CATCH studies in the Sahelian region of West-Africa: An overview

    NASA Astrophysics Data System (ADS)

    Lebel, Thierry; Cappelaere, Bernard; Galle, Sylvie; Hanan, Niall; Kergoat, Laurent; Levis, Samuel; Vieux, Baxter; Descroix, Luc; Gosset, Marielle; Mougin, Eric; Peugeot, Christophe; Seguis, Luc

    2009-08-01

    SummaryThe African Monsoon Multidisciplinary Analysis (AMMA) is an international and interdisciplinary experiment designed to investigate the interactions between atmospheric, oceanic and terrestrial systems and their joint controls on tropical monsoon dynamics in West Africa. This special issue reports results from a group of AMMA studies regrouped in the component " Couplage de l'Atmosphère Tropicale et du Cycle Hydrologique" (CATCH). AMMA-CATCH studies focus on measuring and understanding land surface properties and processes in West Africa, the role of terrestrial systems in altering boundary layer dynamics, and thus the potential that surface hydrology and biology, and human land use practices, may directly or indirectly affect monsoon dynamics and rainfall in the region. AMMA-CATCH studies focus on three intensively instrumented mesoscale sites in Mali, Niger and Benin that sample across the 100-1300 mm/annum rainfall gradient of the Sahel, Sudan and North-Guinean bioclimatic zones. Studies report on: (i) surface-boundary layer interactions that may influence atmospheric convergence and convective processes and thus rainfall type, timing and amount; (ii) vegetation dynamics at seasonal to decadal time-scales that may respond to, and alter, atmospheric processes; (iii) surface-atmosphere fluxes of heat, water and carbon dioxide that directly influence the atmosphere; (iv) soil moisture variability in space and time that provide the proximate control on vegetation activity, evapotranspiration and energy balance; and (v) local and mesoscale modeling of hydrology and land surface-atmosphere exchanges to assess their role in the hydrological, atmospheric and rainfall dynamics of West Africa. The AMMA-CATCH research reported in this issue will be extended in future years as measurements and analysis continue and are concluded within the context of both CATCH and the wider AMMA study. This body of research will contribute to an improved understanding of the

  20. Regional Climate Change Impact on Agricultural Land Use in West Africa

    NASA Astrophysics Data System (ADS)

    Ahmed, K. F.; Wang, G.; You, L.

    2014-12-01

    Agriculture is a key element of the human-induced land use land cover change (LULCC) that is influenced by climate and can potentially influence regional climate. Temperature and precipitation directly impact the crop yield (by controlling photosynthesis, respiration and other physiological processes) that then affects agricultural land use pattern. In feedback, the resulting changes in land use and land cover play an important role to determine the direction and magnitude of global, regional and local climate change by altering Earth's radiative equilibrium. The assessment of future agricultural land use is, therefore, of great importance in climate change study. In this study, we develop a prototype land use projection model and, using this model, project the changes to land use pattern and future land cover map accounting for climate-induced yield changes for major crops in West Africa. Among the inputs to the land use projection model are crop yield changes simulated by the crop model DSSAT, driven with the climate forcing data from the regional climate model RegCM4.3.4-CLM4.5, which features a projected decrease of future mean crop yield and increase of inter-annual variability. Another input to the land use projection model is the projected changes of food demand in the future. In a so-called "dumb-farmer scenario" without any adaptation, the combined effect of decrease in crop yield and increase in food demand will lead to a significant increase in agricultural land use in future years accompanied by a decrease in forest and grass area. Human adaptation through land use optimization in an effort to minimize agricultural expansion is found to have little impact on the overall areas of agricultural land use. While the choice of the General Circulation Model (GCM) to derive initial and boundary conditions for the regional climate model can be a source of uncertainty in projecting the future LULCC, results from sensitivity experiments indicate that the changes

  1. Impact of climate change upon vector born diseases in Europe and Africa using ENSEMBLES Regional Climate Models

    NASA Astrophysics Data System (ADS)

    Caminade, Cyril; Morse, Andy

    2010-05-01

    Climate variability is an important component in determining the incidence of a number of diseases with significant human/animal health and socioeconomic impacts. The most important diseases affecting health are vector-borne, such as malaria, Rift Valley Fever and including those that are tick borne, with over 3 billion of the world population at risk. Malaria alone is responsible for at least one million deaths annually, with 80% of malaria deaths occurring in sub-Saharan Africa. The climate has a large impact upon the incidence of vector-borne diseases; directly via the development rates and survival of both the pathogen and the vector, and indirectly through changes in the environmental conditions. A large ensemble of regional climate model simulations has been produced within the ENSEMBLES project framework for both the European and African continent. This work will present recent progress in human and animal disease modelling, based on high resolution climate observations and regional climate simulations. Preliminary results will be given as an illustration, including the impact of climate change upon bluetongue (disease affecting the cattle) over Europe and upon malaria and Rift Valley Fever over Africa. Malaria scenarios based on RCM ensemble simulations have been produced for West Africa. These simulations have been carried out using the Liverpool Malaria Model. Future projections highlight that the malaria incidence decreases at the northern edge of the Sahel and that the epidemic belt is shifted southward in autumn. This could lead to significant public health problems in the future as the demography is expected to dramatically rise over Africa for the 21st century.

  2. Regional-scale climate-variability synchrony of cholera epidemics in West Africa

    PubMed Central

    Constantin de Magny, Guillaume; Guégan, Jean-François; Petit, Michel; Cazelles, Bernard

    2007-01-01

    Background The relationship between cholera and climate was explored in Africa, the continent with the most reported cases, by analyzing monthly 20-year cholera time series for five coastal adjoining West African countries: Côte d'Ivoire, Ghana, Togo, Benin and Nigeria. Methods We used wavelet analyses and derived methods because these are useful mathematical tools to provide information on the evolution of the periodic component over time and allow quantification of non-stationary associations between time series. Results The temporal variability of cholera incidence exhibits an interannual component, and a significant synchrony in cholera epidemics is highlighted at the end of the 1980's. This observed synchrony across countries, even if transient through time, is also coherent with both the local variability of rainfall and the global climate variability quantified by the Indian Oscillation Index. Conclusion Results of this study suggest that large and regional scale climate variability influence both the temporal dynamics and the spatial synchrony of cholera epidemics in human populations in the Gulf of Guinea, as has been described for two other tropical regions of the world, western South America and Bangladesh. PMID:17371602

  3. First Evaluation of the CCAM Aerosol Simulation over Africa: Implications for Regional Climate Modeling

    NASA Astrophysics Data System (ADS)

    Horowitz, H.; Garland, R. M.; Thatcher, M. J.; Naidoo, M.; van der Merwe, J.; Landman, W.; Engelbrecht, F.

    2015-12-01

    An accurate representation of African aerosols in climate models is needed to understand the regional and global radiative forcing and climate impacts of aerosols, at present and under future climate change. However, aerosol simulations in regional climate models for Africa have not been well-tested. Africa contains the largest single source of biomass-burning smoke aerosols and dust globally. Although aerosols are short-lived relative to greenhouse gases, black carbon in particular is estimated to be second only to carbon dioxide in contributing to warming on a global scale. Moreover, Saharan dust is exported great distances over the Atlantic Ocean, affecting nutrient transport to regions like the Amazon rainforest, which can further impact climate. Biomass burning aerosols are also exported from Africa, westward from Angola over the Atlantic Ocean and off the southeastern coast of South Africa to the Indian Ocean. Here, we perform the first extensive quantitative evaluation of the Conformal-Cubic Atmospheric Model (CCAM) aerosol simulation against monitored data, focusing on aerosol optical depth (AOD) observations over Africa. We analyze historical regional simulations for 1999 - 2012 from CCAM consistent with the experimental design of CORDEX at 50 km global horizontal resolution, through the dynamical downscaling of ERA-Interim data reanalysis data, with the CMIP5 emissions inventory (RCP8.5 scenario). CCAM has a prognostic aerosol scheme for organic carbon, black carbon, sulfate, and dust, and non-prognostic sea salt. The CCAM AOD at 550nm was compared to AOD (observed at 440nm, adjusted to 550nm with the Ångström exponent) from long-term AERONET stations across Africa. Sites strongly impacted by dust and biomass burning and with long continuous records were prioritized. In general, the model captures the monthly trends of the AERONET data. This presentation provides a basis for understanding how well aerosol particles are represented over Africa in

  4. Water, plants, and early human habitats in eastern Africa

    PubMed Central

    Magill, Clayton R.; Ashley, Gail M.; Freeman, Katherine H.

    2013-01-01

    Water and its influence on plants likely exerted strong adaptive pressures in human evolution. Understanding relationships among water, plants, and early humans is limited both by incomplete terrestrial records of environmental change and by indirect proxy data for water availability. Here we present a continuous record of stable hydrogen-isotope compositions (expressed as δD values) for lipid biomarkers preserved in lake sediments from an early Pleistocene archaeological site in eastern Africa—Olduvai Gorge. We convert sedimentary leaf- and algal-lipid δD values into estimates for ancient source-water δD values by accounting for biochemical, physiological, and environmental influences on isotopic fractionation via published water–lipid enrichment factors for living plants, algae, and recent sediments. Reconstructed precipitation and lake-water δD values, respectively, are consistent with modern isotopic hydrology and reveal that dramatic fluctuations in water availability accompanied ecosystem changes. Drier conditions, indicated by less negative δD values, occur in association with stable carbon-isotopic evidence for open, C4-dominated grassland ecosystems. Wetter conditions, indicated by lower δD values, are associated with expanded woody cover across the ancient landscape. Estimates for ancient precipitation amounts, based on reconstructed precipitation δD values, range between approximately 250 and 700 mm·y−1 and are consistent with modern precipitation data for eastern Africa. We conclude that freshwater availability exerted a substantial influence on eastern African ecosystems and, by extension, was central to early human proliferation during periods of rapid climate change. PMID:23267102

  5. Desertification, refugees and regional conflict in west Africa.

    PubMed

    Nnoli, O

    1990-06-01

    This article documents the potential for inter-state conflict in the migration of hundreds of thousands of famine refugees across international borders in West Africa. Nigeria and Ghana, for example, have to deal not only with the effects of land degradation in their northern territories but also with the influx of famine victims from Mali, Niger, Chad and Burkino Faso. These migrations put an enormous extra burden on the fragile and already overstretched social and economic infrastructures of the host countries. The construction of dams for irrigation and electricity generation in international river basins, is another cause of inter-state conflict related to land degradation. The capacity of West African states to find peaceful solutions to these problems is being undermined by the increasing impoverishment and marginalisation of their populations. A self-serving neo-colonialist governing elite is caught in the economic stranglehold of the advanced capitalist nations. While there is thus no short term solution to the problem of land degradation, immediate steps should at least be taken to give legal protection to those who are forced to cross international borders because of drought and famine. PMID:20958699

  6. Regional and Global Aspects of Aerosols in Western Africa: From Air Quality to Climate

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Diehl, Thomas; Kucsera, Tom; Spinhime, Jim; Palm, Stephen; Holben, Brent; Ginoux, Paul

    2006-01-01

    Western Africa is one of the most important aerosol source regions in the world. Major aerosol sources include dust from the world's largest desert Sahara, biomass burning from the Sahel, pollution aerosols from local sources and long-range transport from Europe, and biogenic sources from vegetation. Because these sources have large seasonal variations, the aerosol composition over the western Africa changes significantly with time. These aerosols exert large influences on local air quality and regional climate. In this study, we use the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model to analyze satellite lidar data from the GLAS instrument on the ICESat and the sunphotometer data from the ground-based network AERONET taken in both the wet (September - October 2003) and dry (February - March 2004) seasons over western Africa. We will quantify the seasonal variations of aerosol sources and compositions and aerosol spatial (horizontal and vertical) distributions over western Africa. We will also assess the climate impact of western African aerosols. Such studies will be applied to support the international project, Africa Monsoon Multidisciplinary Analysis (AMMA) and to analyze the AMMA data.

  7. Human foot bones from Klasies River main site, South Africa.

    PubMed

    Rightmire, G Philip; Deacon, H J; Schwartz, Jeffrey H; Tattersall, Ian

    2006-01-01

    The caves at Klasies River contain abundant archaeological evidence relating to human evolution in the late Pleistocene of southern Africa. Along with Middle Stone Age artifacts, animal bones, and other food waste, there are hominin cranial fragments, mandibles with teeth, and a few postcranial remains. Three foot bones can now be added to this inventory. An adult first metatarsal is similar in size and discrete anatomical features to those from Holocene burials in the Cape Province. A complete and well-preserved second metatarsal is especially long and heavy at midshaft in comparison to all Holocene and more recent South African homologues. A large fifth metatarsal is highly distinctive in its morphology. In overall size, these pedal elements resemble specimens from late Pleistocene sites in western Asia, but there are some differences in proportions. The fossils support earlier suggestions concerning a relatively high level of sexual dimorphism in the African Middle Stone Age population. Squatting facets on the two lateral metatarsals appear to indicate a high frequency of kneeling among members of this group. The new postcranial material also underlines the fact that the morphology of particular skeletal elements of some of the 100,000-year-old Klasies River individuals falls outside the range of modern variation. PMID:16242755

  8. The burden of human papillomavirus infections and related diseases in sub-saharan Africa.

    PubMed

    De Vuyst, Hugo; Alemany, Laia; Lacey, Charles; Chibwesha, Carla J; Sahasrabuddhe, Vikrant; Banura, Cecily; Denny, Lynette; Parham, Groesbeck P

    2013-12-29

    Despite the scarcity of high quality cancer registries and lack of reliable mortality data, it is clear that human papillomavirus (HPV)-associated diseases, particularly cervical cancer, are major causes of morbidity and mortality in sub-Saharan Africa (SSA). Cervical cancer incidence rates in SSA are the highest in the world and the disease is the most common cause of cancer death among women in the region. The high incidence of cervical cancer is a consequence of the inability of most countries to either initiate or sustain cervical cancer prevention services. In addition, it appears that the prevalence of HPV in women with normal cytology is higher than in more developed areas of the world, at an average of 24%. There is, however, significant regional variation in SSA, with the highest incidence of HPV infection and cervical cancer found in Eastern and Western Africa. It is expected that, due to aging and growth of the population, but also to lack of access to appropriate prevention services and the concomitant human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic, cervical cancer incidence and mortality rates in SSA will rise over the next 20 years. HPV16 and 18 are the most common genotypes in cervical cancer in SSA, although other carcinogenic HPV types, such as HPV45 and 35, are also relatively more frequent compared with other world regions. Data on other HPV-related anogenital cancers including those of the vulva, vagina, anus, and penis, are limited. Genital warts are common and associated with HPV types 6 and 11. HIV infection increases incidence and prevalence of all HPV-associated diseases. Sociocultural determinants of HPV-related disease, as well as the impact of forces that result in social destabilization, demand further study. Strategies to reduce the excessive burden of HPV-related diseases in SSA include age-appropriate prophylactic HPV vaccination, cervical cancer prevention services for women of the reproductive

  9. Three and half million year vegetation history of South West Africa and its implications for human evolution

    NASA Astrophysics Data System (ADS)

    Maslin, M. A.; Pancost, R. D.

    2010-12-01

    Ocean Drilling Program Site 1085 provides a continuous marine sediment record off South West Africa for at least the last three and half million years. The n-alkane carbon isotope record from this site records past vegetation and provides an indication of the moisture availability of SW Africa over this time period. We compared the n-alkane carbon isotope record with the soil carbonate carbon isotope records of East Africa to better understand the vegetation dynamics of Africa over the Plio-Pleistocene. In SW Africa very little variation, and no trend, is observed in the n-alkane carbon isotope record over 3 million years, suggesting stable long-term conditions despite large changes in East African tectonics and global climate. Slightly higher n-alkane carbon isotope values occur between 3.5 and 2.7 Ma suggesting slightly drier conditions than today. Between 2.5 and 2.7 Ma there is a shift to more negative n-alkane carbon isotope values suggesting slightly wetter conditions during a ~0.2 Ma episode that coincides with the intensification of Northern Hemisphere Glaciation (iNHG). From 2.5 to 0.4 Ma the n-alkane carbon isotope values are very consistent, varying by less than ±0.5 per mil and suggesting little or no long-term change in the moisture availability of South West Africa over the last 2.5 million years. This is in marked contrast to the East African long-term drying trend that was punctuated by periodic extreme wet and dry periods. The comparison of the climate history of these two regions suggests that Southern Africa may have been a safe refuge for hominins and other animals during the last 3.5 Myrs and thus important implications for our understand of early human evolution.

  10. Lassa fever in West Africa: evidence for an expanded region of endemicity.

    PubMed

    Sogoba, N; Feldmann, H; Safronetz, D

    2012-09-01

    Lassa virus (LASV) is endemic in Sierra Leone, Guinea and Liberia (known as the Mano River region) and Nigeria and Lassa fever cases from these countries are being reported annually. Recent investigations have found evidence for an expanded endemicity zone between the two known Lassa endemic regions indicating that LASV is more widely distributed throughout the Tropical Wooded Savanna ecozone in West Africa. PMID:22958249

  11. The Burden of Human Papillomavirus Infections and Related Diseases in Sub-Saharan Africa

    PubMed Central

    De Vuyst, Hugo; Alemany, Laia; Lacey, Charles; Chibwesha, Carla J.; Sahasrabuddhe, Vikrant; Banura, Cecily; Denny, Lynette; Parham, Groesbeck P.

    2014-01-01

    Despite the scarcity of high quality cancer registries and lack of reliable mortality data, it is clear that human papillomavirus (HPV)-associated diseases, particularly cervical cancer, are major causes of morbidity and mortality in sub-Saharan Africa (SSA). Cervical cancer incidence rates in SSA are the highest in the world and the disease is the most common cause of cancer death among women in the region. The high incidence of cervical cancer is a consequence of the inability of most countries to either initiate or sustain cervical cancer prevention services. In addition, it appears that the prevalence of HPV in women with normal cytology is higher than in more developed areas of the world, at an average of 24%. There is, however, significant regional variation in SSA, with the highest incidence of HPV infection and cervical cancer found in Eastern and Western Africa. It is expected that, due to aging and growth of the population, but also to lack of access to appropriate prevention services and the concomitant human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic, cervical cancer incidence and mortality rates in SSA will rise over the next 20 years. HPV16 and 18 are the most common genotypes in cervical cancer in SSA, although other carcinogenic HPV types, such as HPV45 and 35, are also relatively more frequent compared with other world regions. Data on other HPV-related anogenital cancers including those of the vulva, vagina, anus, and penis, are limited. Genital warts are common and associated with HPV types 6 and 11. HIV infection increases incidence and prevalence of all HPV-associated diseases. Sociocultural determinants of HPV-related disease, as well as the impact of forces that result in social destabilization, demand further study. Strategies to reduce the excessive burden of HPV-related diseases in SSA include age-appropriate prophylactic HPV vaccination, cervical cancer prevention services for women of the reproductive

  12. Sexual and bodily rights as human rights in the Middle East and North Africa.

    PubMed

    Ercevik Amado, Liz

    2004-05-01

    A regional workshop on sexual and bodily rights as human rights in the Middle East and North Africa was held in Malta in 2003, attended by 22 NGO representatives from Jordan, Egypt, Lebanon, Palestine, Tunisia, Morocco, Algeria, Turkey, Pakistan and USA. The meeting aimed to develop strategies for overcoming human rights violations in the region with reference to law and social and political practices. Session topics included sexuality and gender identity; sexuality and sexual health; sexuality and comparative penal law; sexual rights in international documents; advocacy and lobbying. Sexual rights, sexual health and education, sexual violence and adolescent sexuality were explored in depth, including taboos and emerging trends. Specific areas of concern included marital rape, early marriages, temporary marriages, sexual orientation, premarital and extramarital sexuality, honour crimes, female genital mutilation, unmarried mothers, adolescent sexuality, unwanted pregnancies and safe abortion, sexuality in education and health services. An analysis of civil codes, penal codes and personal status codes indicated a clear imperative for legal reform. Participants heard about efforts to promote the right to sexual orientation which have already been initiated in Lebanon, Turkey and Tunisia. Networking within the region and with counterparts in other regions in comparable situations and conditions was deemed essential. PMID:15242219

  13. Climate Change in Africa: Impacts and Effects on the Inhabitants of the Lake Chad Region.

    NASA Astrophysics Data System (ADS)

    Abubakar, B.; Tahir, S. M.; Olisa, O.

    2009-05-01

    The Department of Energy and Climate Change defined climate as the average weather experienced over a long period. This includes temperature, wind and rainfall patterns. The climate of the Earth is not static, and has changed many times in response to a variety of natural causes. Due to human activities in emmiting green house gases has resulted the Earth to get warmed by 0.74°C over the last hundred years. Around 0.4°C of this warming has occurred since the 1970s. Climate is now one of the major phenomenon threatening lives and humanity in general since the beginning of industrial revolution. Climate exerts a profound influence on the lives of poor populations in the Lake Chad region of Africa who depend on fishing and crop cultivation for livelihood and sustenance, who are unprotected against climate-related diseases, who lacked secure access to water and food and who are vulnerable to hydro meteorological hazard. The effects of climate change on the study area are many and include diminishing resources and conflicts over the available limited water resources. The Lake Chad region is a fragile area with high climate variability and extremes of weather. As this inland water is used for domestic and agricultural purposes, salt mining, as well as transportation by Nigerians, Nigeriens, Chadian and Cameroonians, it is an area of trans-boundary water conflicts. This paper examines the part played by climate change in the decline of fishery resources and livelihood activities in the Lake Chad region. Data from field studies, structured interview and secondary sources show that fish catches and livelihood activities have declined tremendously in recent times due to several factors including overexploitation and increasing demands on the aquatic resources. Findings from the study show that droughty periods have resulted in the reduction of open lake water surface from about 25,000 km2 in 1973 to less than 2,000 km2 in the 1990s. This has led to the diminishing aquatic

  14. Evaluating daily and extreme seasonal precipitations over continental Africa from a Regional Climate Model Simulation

    NASA Astrophysics Data System (ADS)

    Bamba Sylla, Mouhamadou; Mariotti, Laura; Coppola, Erika; Giorgi, Filippo

    2010-05-01

    Spatial and temporal variability of rainfall over Africa offers considerable challenges on climate change over the region. This is because of the complexity of regional climates in Africa and their associated geographic features. Adding to that complexity are deserts, vegetation variations, numerous mountain chains that can alter regional climate and weather patterns, the influence of the land-sea contrast due to the presence of several large lakes and the surrounding Indian and Atlantic Oceans. This leads to strong fluctuations of rainfall that may cause drought and flood in the region. Therefore, being able to simulate the spatial distribution of mean precipitation is quite important but also capturing their occurrences and intensities is critical for Africa whose economy relies on rain-fed agriculture. The International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3), driven by the newly produced ERA-Interim reanalysis, is used to investigate this issue. Several indices, such as the number of wet days and their intensity, maximum dry and wet spells length and the frequency of heavy precipitation days, are used to characterize the spatial variability of seasonal extreme rainfall over continental Africa. Model results are compared to both TRMM and FEWS rainfall data. They indicate that although the model captures the location of longest and shortest wet and dry spells, it tends to extend slightly the wet spell length around mountainous regions and along the ITCZ and the dry spell length over northern and southern Africa during austral and boreal summer respectively. This is mainly visible when compared to FEWS. Extension of the wet spell length may be partly related to the overestimation of the number of wet days. As a result, the intensity due to the wet days only is slightly overpredicted in these regions. This is, in turn, linked to the tendency of the RegCM3 to produce more intense and convective rainfall events in the ITCZ and the ZAB as

  15. The State of Humanities in Post-Apartheid South Africa--A Quantitative Story

    ERIC Educational Resources Information Center

    Pillay, V.; Yu, K.

    2010-01-01

    This article depicts the state of Humanities in post-apartheid South Africa by examining HEMIS enrolment and graduation data from 1999 to 2007. It demonstrates that although the decline in student enrolment and graduation in Humanities has not been severe; read in the context of substantial growth of all other disciplines, Humanities is in a…

  16. Tracking Enrolments and Graduations in Humanities Education in South Africa: Are We in Crisis?

    ERIC Educational Resources Information Center

    Yu, K.; Pillay, V.

    2011-01-01

    In this article we respond to the perceived crisis in humanities education in South Africa which posits firstly that large numbers of students are leaving this field and that secondly, the value of a humanities education has declined. To do this we track the enrolments and graduation rates in humanities at both undergraduate and postgraduate…

  17. Towards malaria elimination in the MOSASWA (Mozambique, South Africa and Swaziland) region.

    PubMed

    Moonasar, Devanand; Maharaj, Rajendra; Kunene, Simon; Candrinho, Baltazar; Saute, Francisco; Ntshalintshali, Nyasatu; Morris, Natashia

    2016-01-01

    The substantial impact of cross-border collaborative control efforts on the burden of malaria in southern Africa has previously been demonstrated through the successes of the Lubombo Spatial Development Initiative. Increases in malaria cases recorded in the three partner countries (Mozambique, South Africa, Swaziland) since termination of that programme in 2011 have provided impetus for the resuscitation of cooperation in the form of the MOSASWA malaria initiative. MOSASWA, launched in 2015, seeks to renew regional efforts to accelerate progress towards malaria elimination goals already established in the region. National malaria programmes, together with developmental partners, academic institutions and the private sector seek to harmonize policy, strengthen capacity, share expertise, expand access to elimination interventions particularly amongst migrant and border population groups, mobilize resources and advocate for long-term funding to ultimately achieve and sustain malaria elimination in the MOSASWA region. PMID:27538990

  18. Revised timeline and distribution of the earliest diverged human maternal lineages in southern Africa.

    PubMed

    Chan, Eva K F; Hardie, Rae-Anne; Petersen, Desiree C; Beeson, Karen; Bornman, Riana M S; Smith, Andrew B; Hayes, Vanessa M

    2015-01-01

    The oldest extant human maternal lineages include mitochondrial haplogroups L0d and L0k found in the southern African click-speaking forager peoples broadly classified as Khoesan. Profiling these early mitochondrial lineages allows for better understanding of modern human evolution. In this study, we profile 77 new early-diverged complete mitochondrial genomes and sub-classify another 105 L0d/L0k individuals from southern Africa. We use this data to refine basal phylogenetic divergence, coalescence times and Khoesan prehistory. Our results confirm L0d as the earliest diverged lineage (∼172 kya, 95%CI: 149-199 kya), followed by L0k (∼159 kya, 95%CI: 136-183 kya) and a new lineage we name L0g (∼94 kya, 95%CI: 72-116 kya). We identify two new L0d1 subclades we name L0d1d and L0d1c4/L0d1e, and estimate L0d2 and L0d1 divergence at ∼93 kya (95%CI:76-112 kya). We concur the earliest emerging L0d1'2 sublineage L0d1b (∼49 kya, 95%CI:37-58 kya) is widely distributed across southern Africa. Concomitantly, we find the most recent sublineage L0d2a (∼17 kya, 95%CI:10-27 kya) to be equally common. While we agree that lineages L0d1c and L0k1a are restricted to contemporary inland Khoesan populations, our observed predominance of L0d2a and L0d1a in non-Khoesan populations suggests a once independent coastal Khoesan prehistory. The distribution of early-diverged human maternal lineages within contemporary southern Africans suggests a rich history of human existence prior to any archaeological evidence of migration into the region. For the first time, we provide a genetic-based evidence for significant modern human evolution in southern Africa at the time of the Last Glacial Maximum at between ∼21-17 kya, coinciding with the emergence of major lineages L0d1a, L0d2b, L0d2d and L0d2a. PMID:25807545

  19. Revised Timeline and Distribution of the Earliest Diverged Human Maternal Lineages in Southern Africa

    PubMed Central

    Chan, Eva K. F.; Hardie, Rae-Anne; Petersen, Desiree C.; Beeson, Karen; Bornman, Riana M. S.; Smith, Andrew B.; Hayes, Vanessa M.

    2015-01-01

    The oldest extant human maternal lineages include mitochondrial haplogroups L0d and L0k found in the southern African click-speaking forager peoples broadly classified as Khoesan. Profiling these early mitochondrial lineages allows for better understanding of modern human evolution. In this study, we profile 77 new early-diverged complete mitochondrial genomes and sub-classify another 105 L0d/L0k individuals from southern Africa. We use this data to refine basal phylogenetic divergence, coalescence times and Khoesan prehistory. Our results confirm L0d as the earliest diverged lineage (∼172 kya, 95%CI: 149–199 kya), followed by L0k (∼159 kya, 95%CI: 136–183 kya) and a new lineage we name L0g (∼94 kya, 95%CI: 72–116 kya). We identify two new L0d1 subclades we name L0d1d and L0d1c4/L0d1e, and estimate L0d2 and L0d1 divergence at ∼93 kya (95%CI:76–112 kya). We concur the earliest emerging L0d1’2 sublineage L0d1b (∼49 kya, 95%CI:37–58 kya) is widely distributed across southern Africa. Concomitantly, we find the most recent sublineage L0d2a (∼17 kya, 95%CI:10–27 kya) to be equally common. While we agree that lineages L0d1c and L0k1a are restricted to contemporary inland Khoesan populations, our observed predominance of L0d2a and L0d1a in non-Khoesan populations suggests a once independent coastal Khoesan prehistory. The distribution of early-diverged human maternal lineages within contemporary southern Africans suggests a rich history of human existence prior to any archaeological evidence of migration into the region. For the first time, we provide a genetic-based evidence for significant modern human evolution in southern Africa at the time of the Last Glacial Maximum at between ∼21–17 kya, coinciding with the emergence of major lineages L0d1a, L0d2b, L0d2d and L0d2a. PMID:25807545

  20. Attributing Climate Conditions for Stable Malaria Transmission to Human Activity in sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Sheldrake, L.; Mitchell, D.; Allen, M. R.

    2015-12-01

    Temperature and precipitation limit areas of stable malaria transmission, but the effects of climate change on the disease remain controversial. Previously, studies have not separated the influence of anthropogenic climate change and natural variability, despite being an essential step in the attribution of climate change impacts. Ensembles of 2900 simulations of regional climate in sub-Saharan Africa for the year 2013, one representing realistic conditions and the other how climate might have been in the absence of human influence, were used to force a P.falciparium climate suitability model developed by the Mapping Malaria Risk in Africa project. Strongest signals were detected in areas of unstable transmission, indicating their heightened sensitivity to climatic factors. Evidently, impacts of human-induced climate change were unevenly distributed: the probability of conditions being suitable for stable malaria transmission were substantially reduced (increased) in the Sahel (Greater Horn of Africa (GHOA), particularly in the Ethiopian and Kenyan highlands). The length of the transmission season was correspondingly shortened in the Sahel and extended in the GHOA, by 1 to 2 months, including in Kericho (Kenya), where the role of climate change in driving recent malaria occurrence is hotly contested. Human-induced warming was primarily responsible for positive anomalies in the GHOA, while reduced rainfall caused negative anomalies in the Sahel. The latter was associated with anthropogenic impacts on the West African Monsoon, but uncertainty in the RCM's ability to reproduce precipitation trends in the region weakens confidence in the result. That said, outputs correspond well with broad-scale changes in observed endemicity, implying a potentially important contribution of anthropogenic climate change to the malaria burden during the past century. Results support the health-framing of climate risk and help indicate hotspots of climate vulnerability, providing

  1. Human immunodeficiency virus and hepatitis C co-infection in sub-Saharan West Africa.

    PubMed

    Mboto, C I; Davies, A; Fielder, M; Jewell, A P

    2006-01-01

    Co-infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is becoming a major global problem, leading to increased morbidity and mortality in developed countries. Co-existence in sub-Saharan West Africa of a high prevalence of HIV and HCV, which share similar behavioural risk factors and modes of transmission, must be seen in the broader context of an emerging third epidemic of HIV and HCV co-infection, as many factors that may affect the spread of HIV and HCV co-infection are endemic in the continent, including host factors such as sexual behaviour, presence of other sexually transmitted diseases, female and male circumcision status, percutaneous and perinatal exposure, and poverty. This review examines the epidemiology, risk factors and transmission of HIV and HCV co-infection and draws attention to the possible emergence of an epidemic of HIV and HCV co-infection in the region. PMID:16613141

  2. [Monitoring human African trypanosomiasis in Central Africa in 2001 and cartography: results and perspectives].

    PubMed

    Lucas, P; Fanchey, G; Mouton, C; Jannin, J

    2001-01-01

    Cases of human African trypanosomiasis are distributed in changing geographical "outbreak areas" that can be visualized over time and space. Because of these variations in distribution, cartography and spatial analysis provide powerful tools for planning surveillance and control strategies. In 1996, the WHO in collaboration with the 15 most endemic countries in Central Africa undertook a program to develop a standardized inter-regional map of trypanosomiasis. This article provides a brief overview of the value of geomatic tools in public health followed by a description of the WHO program and its preliminary results. Also presented in this article is the Trypinfo site being development on the internet to increase the surveillance response-time and improve the feedback system. PMID:11803827

  3. Regional nitrogen budget of the Lake Victoria Basin, East Africa: syntheses, uncertainties and perspectives

    NASA Astrophysics Data System (ADS)

    Zhou, Minghua; Brandt, Patric; Pelster, David; Rufino, Mariana C.; Robinson, Timothy; Butterbach-Bahl, Klaus

    2014-10-01

    Using the net anthropogenic nitrogen input (NANI) approach we estimated the N budget for the Lake Victoria Basin in East Africa. The NANI of the basin ranged from 887 to 3008 kg N km-2 yr-1 (mean: 1827 kg N km-2 yr-1) for the period 1995-2000. The net nitrogen release at basin level is due primarily to livestock and human consumption of feed and foods, contributing between 69% and 85%. Atmospheric oxidized N deposition contributed approximately 14% to the NANI of the Lake Victoria Basin, while either synthetic N fertilizer imports or biological N fixations only contributed less than 6% to the regional NANI. Due to the low N imports of feed and food products (<20 kg N km-2 yr-1), nitrogen release to the watershed must be derived from the mining of soil N stocks. The fraction of riverine N export to Lake Victoria accounted for 16%, which is much lower than for watersheds located in Europe and USA (25%). A significant reduction of the uncertainty of our N budget estimate for Lake Victoria Basin would be possible if better data on livestock systems and riverine N export were available. Our study indicates that at present soil N mining is the main source of nitrogen in the Lake Victoria Basin. Thus, sustainable N management requires increasing agricultural N inputs to guarantee food security and rehabilitation and protection of soils to minimize environmental costs. Moreover, to reduce N pollution of the lake, improving management of human and animal wastes needs to be carefully considered in future.

  4. Seasonal drought forecast system for food-insecure regions of East Africa

    NASA Astrophysics Data System (ADS)

    Shukla, Shraddhanand; McNally, Amy; Husak, Greg; Funk, Chris

    2014-05-01

    In East Africa, agriculture is mostly rainfed and hence sensitive to interannual rainfall variability, and the increasing food and water demands of a growing population place further stresses on the water resources of this region. Skillful seasonal agricultural drought forecasts for this region can inform timely water and agricultural management decisions, support the proper allocation of the region's water resources, and help mitigate socio-economic losses. Here we describe the development and implementation of a seasonal drought forecast system that is being used for providing seasonal outlooks of agricultural drought in East Africa. We present a test case of the evaluation and applicability of this system for March-April-May growing season over equatorial East Africa (latitude 20 south to 80 North and 360 E to 460E) that encompasses one of the most food insecure and climatically and socio-economically vulnerable regions in East Africa. This region experienced famine as recently as in 2011. The system described here combines advanced satellite and re-analysis as well as station-based long term and real-time observations (e.g. NASA's TRMM, Infra-red remote sensing, Climate Forecast System Reanalysis), state-of-the-art dynamical climate forecast system (NCEP's Climate Forecast System Verison-2) and large scale land surface models (e.g. Variable Infiltration Capacity, NASA's Land Information System) to provide forecasts of seasonal rainfall, soil moisture and Water Requirement Satisfaction Index (WRSI) throughout the season - with an emphasis on times when water is the most critical: start of season/planting and the mid-season/crop reproductive phase. Based on the hindcast assessment of this system, we demonstrate the value of this approach to the US Agency for International Development (USAID)'s efforts to mitigate future losses of lives and economic losses by allowing a proactive approach of drought management that includes early warning and timely action.

  5. Analysis and simulation of recent climate variability in the high-mountain regions of East Africa

    NASA Astrophysics Data System (ADS)

    Collier, Emily; Mölg, Thomas

    2016-04-01

    Kilimanjaro is the highest free-standing mountain in the world, and the glaciers at its summit represent regionally unique high-altitude sampling points in the troposphere. The region is influenced by, among other phenomena, the El Niño Southern Oscillation (ENSO), the Indian Ocean Zonal Mode, and the Quasi-Biennial Oscillation. However, the impacts of these phenomena as well as interactions between them on climate conditions in the high-mountain regions of East Africa are poorly constrained. Here we analyze recent high-altitude climate variability in East Africa using a combination of atmospheric reanalysis data, convection permitting (~1 km grid spacing) numerical simulations with the regional atmospheric model WRF, and multi-year in-situ weather station data at the summits of Mount Kenya and Kilimanjaro. We utilize these datasets to elucidate the impact of modes of internal climate variability, with a particular emphasis on ENSO, on both the large- and local-scale atmospheric conditions. Our analysis is compared with a ten-year record of glacier surface-height-change measurements on Kilimanjaro to elucidate the drivers of recent glacier response in East Africa.

  6. Seismotectonic Analysis for the KZN region of South Africa

    NASA Astrophysics Data System (ADS)

    Singh, M.

    2012-04-01

    Recently, devastating earthquakes and tsunamis have shocked the modern world (Japan [April 7 2011, Mw 9.0, loss of life and destruction of infrastructure, 15,457 deaths 5,389 injured, US300billion loss (Japanese National Police Agency 2011)], New Zealand [21 February 2011, Mw 6.3, 148 killed], Haiti [12 January 2010, Mw 7.0, estimated 316 000 killed and 300 000 injured]. These earthquakes have caused large scale damage to the built environment not to mention the high number of fatalities. The KZN coastal region is also fast developing especially towards the north of Durban CBD (Cornubia [New development near Umhlanga, 25 Billion Rands investment], Gateway/Umhlanga Business District, Moses Mabida Stadium (cost of R3.4 billion ), King Shaka International Airport at a cost of R6.8 billion, Dube Tradeport to be developed next to the airport at a cost of R5 billion, as well as the development of the Richards Bay Industrial Development Zone . The KZN is home to 10 million inhabitants with a relatively denser population distribution around the Durban and Pietermaritzburg CBDs. With the increasing amount of investment towards the north coast of Durban, the population distribution will migrate to these areas. These areas now become 'vulnerable' to rare, infrequent and potentially devastating natural disasters like earthquakes. One of the first steps to understand and plan for an earthquake occurrence is through a seismic hazard and risk assessment. The seismic hazard and risk method has well been established since 1968 (see Cornell (1968); Veneziano et al., (1984); Bender and Perkins (1993); McGuire (1993); McGuire and Toro (2008); Kijko and Graham (1998); Kijko and Sellevoll, (1989, 1992)). The components of a seismic risk assessment (SRA) include several building blocks namely: the development of the earthquake catalogue, seismotectonic model, attenuation models, seismic hazard assessment (SHA), vulnerability assessment and seismic risk computations. The seismotectonic

  7. Developing High-resolution Soil Database for Regional Crop Modeling in East Africa

    NASA Astrophysics Data System (ADS)

    Han, E.; Ines, A. V. M.

    2014-12-01

    The most readily available soil data for regional crop modeling in Africa is the World Inventory of Soil Emission potentials (WISE) dataset, which has 1125 soil profiles for the world, but does not extensively cover countries Ethiopia, Kenya, Uganda and Tanzania in East Africa. Another dataset available is the HC27 (Harvest Choice by IFPRI) in a gridded format (10km) but composed of generic soil profiles based on only three criteria (texture, rooting depth, and organic carbon content). In this paper, we present a development and application of a high-resolution (1km), gridded soil database for regional crop modeling in East Africa. Basic soil information is extracted from Africa Soil Information Service (AfSIS), which provides essential soil properties (bulk density, soil organic carbon, soil PH and percentages of sand, silt and clay) for 6 different standardized soil layers (5, 15, 30, 60, 100 and 200 cm) in 1km resolution. Soil hydraulic properties (e.g., field capacity and wilting point) are derived from the AfSIS soil dataset using well-proven pedo-transfer functions and are customized for DSSAT-CSM soil data requirements. The crop model is used to evaluate crop yield forecasts using the new high resolution soil database and compared with WISE and HC27. In this paper we will present also the results of DSSAT loosely coupled with a hydrologic model (VIC) to assimilate root-zone soil moisture. Creating a grid-based soil database, which provides a consistent soil input for two different models (DSSAT and VIC) is a critical part of this work. The created soil database is expected to contribute to future applications of DSSAT crop simulation in East Africa where food security is highly vulnerable.

  8. EDCTP regional networks of excellence: initial merits for planned clinical trials in Africa

    PubMed Central

    2013-01-01

    Background Achieving the Millennium Development Goals (MDGs) and combating hotspots with escalating but preventable communicable diseases remain major challenges in Africa. The European and Developing Countries Clinical Trials Partnership (EDCTP) intervened to combat poverty-related diseases including malaria, tuberculosis and HIV/AIDS, and to conduct multi-centre clinical trials and multi-disciplinary health research through an innovative model of regional Networks of Excellence (NoEs). Methods We participated in a quasi-formative evaluation between October and December 2011 on the 4 regional-led research networks. These included the: Central Africa Network on Tuberculosis, HIV/AIDS and Malaria (CANTAM); East African Consortium for Clinical Research (EACCR); West African Network of Excellence for TB, AIDS and Malaria (WANETAM), and the Trials of Excellence for Southern Africa (TESA) launched between 2009 and 2010. We shared a participatory appraisal of field reports, progress reports and presentations from each network to jointly outline the initial experiences of the merits, outputs and lessons learnt. Results The self-regulating democratic networks, with 64 institutions in 21 African countries, have trained over 1, 000 African scientists, upgraded 36 sites for clinical trials, leveraged additional € 24 million and generated 38 peer-reviewed publications through networking and partnerships. Conclusions The shared initial merits and lessons learnt portray in part the strengthened capacity of these networks for improved research coordination and conduct of planned multi-center clinical trials in Africa. Increased funding by African agencies, governments and international health partners will ensure sustainability of these networks for research capacity development and demonstrate their commitment to achieving the MDGs in Africa. PMID:23517572

  9. In search of a viable IAU-OAD Regional Node: A case for Africa

    NASA Astrophysics Data System (ADS)

    Okere, B. I.; Okoh, D. C.; Obi, I. A.; Okeke, P. N.; Opara, F. E.

    2015-03-01

    The establishment of the IAU Office of Astronomy for Development (OAD) in Cape Town, South Africa, with the aim of using astronomy to stimulate development at all levels including primary, secondary and tertiary education, science research and the public understanding of science is a welcome development to consolidate the gains of IYA2009. To assist the IAU OAD office in achieving its goal of using astronomy as a tool for development, there is need to have OAD regional nodes. In this paper, we present the astronomy activities/programs required of such a Regional Node in Africa and how the Node can play a significant role to realise the vision of Astronomy for a better world!

  10. Multidrug-resistant Salmonella enterica serotype Typhi, Gulf of Guinea Region, Africa.

    PubMed

    Baltazar, Murielle; Ngandjio, Antoinette; Holt, Kathryn Elizabeth; Lepillet, Elodie; Pardos de la Gandara, Maria; Collard, Jean-Marc; Bercion, Raymond; Nzouankeu, Ariane; Le Hello, Simon; Dougan, Gordon; Fonkoua, Marie-Christine; Weill, François-Xavier

    2015-04-01

    We identified 3 lineages among multidrug-resistant (MDR) Salmonella enterica serotype Typhi isolates in the Gulf of Guinea region in Africa during the 2000s. However, the MDR H58 haplotype, which predominates in southern Asia and Kenya, was not identified. MDR quinolone-susceptible isolates contained a 190-kb incHI1 pST2 plasmid or a 50-kb incN pST3 plasmid. PMID:25811307

  11. Multidrug-Resistant Salmonella enterica Serotype Typhi, Gulf of Guinea Region, Africa

    PubMed Central

    Baltazar, Murielle; Ngandjio, Antoinette; Holt, Kathryn Elizabeth; Lepillet, Elodie; Pardos de la Gandara, Maria; Collard, Jean-Marc; Bercion, Raymond; Nzouankeu, Ariane; Le Hello, Simon; Dougan, Gordon; Fonkoua, Marie-Christine

    2015-01-01

    We identified 3 lineages among multidrug-resistant (MDR) Salmonella enterica serotype Typhi isolates in the Gulf of Guinea region in Africa during the 2000s. However, the MDR H58 haplotype, which predominates in southern Asia and Kenya, was not identified. MDR quinolone-susceptible isolates contained a 190-kb incHI1 pST2 plasmid or a 50-kb incN pST3 plasmid. PMID:25811307

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

    NASA Technical Reports Server (NTRS)

    Jemison, Mae C.; Thomas, J. Segun

    1992-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  14. Mitochondrial lineage M1 traces an early human backflow to Africa

    PubMed Central

    González, Ana M; Larruga, José M; Abu-Amero, Khaled K; Shi, Yufei; Pestano, José; Cabrera, Vicente M

    2007-01-01

    Background The out of Africa hypothesis has gained generalized consensus. However, many specific questions remain unsettled. To know whether the two M and N macrohaplogroups that colonized Eurasia were already present in Africa before the exit is puzzling. It has been proposed that the east African clade M1 supports a single origin of haplogroup M in Africa. To test the validity of that hypothesis, the phylogeographic analysis of 13 complete mitochondrial DNA (mtDNA) sequences and 261 partial sequences belonging to haplogroup M1 was carried out. Results The coalescence age of the African haplogroup M1 is younger than those for other M Asiatic clades. In contradiction to the hypothesis of an eastern Africa origin for modern human expansions out of Africa, the most ancestral M1 lineages have been found in Northwest Africa and in the Near East, instead of in East Africa. The M1 geographic distribution and the relative ages of its different subclades clearly correlate with those of haplogroup U6, for which an Eurasian ancestor has been demonstrated. Conclusion This study provides evidence that M1, or its ancestor, had an Asiatic origin. The earliest M1 expansion into Africa occurred in northwestern instead of eastern areas; this early spread reached the Iberian Peninsula even affecting the Basques. The majority of the M1a lineages found outside and inside Africa had a more recent eastern Africa origin. Both western and eastern M1 lineages participated in the Neolithic colonization of the Sahara. The striking parallelism between subclade ages and geographic distribution of M1 and its North African U6 counterpart strongly reinforces this scenario. Finally, a relevant fraction of M1a lineages present today in the European Continent and nearby islands possibly had a Jewish instead of the commonly proposed Arab/Berber maternal ascendance. PMID:17620140

  15. The Interaction between Human Immunodeficiency Virus and Human Papillomaviruses in Heterosexuals in Africa

    PubMed Central

    Williamson, Anna-Lise

    2015-01-01

    Sub-Saharan Africa has the highest incidence of human papillomavirus (HPV) and cervical cancer in the world, which is further aggravated by the burden of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) disease with invasive cervical cancer being an AIDS-defining cancer. The prevalence of HPV infection and associated disease is very high in HIV-infected people and continues to be a problem even after anti-retroviral therapy. In the genital tract, the interaction between HPV and HIV is complex, with infection with multiple HPV types reported to make both women and men more susceptible to HIV infection. Besides the national programmes to vaccinate girls against HPV and screen women for cervical cancer, there should be targeted cervical cancer screening, treatment and prevention programmes introduced into HIV treatment centres. There is evidence that in high HIV prevalence areas, HIV-positive women could cause increases in the prevalence of genital HPV infection in HIV-negative men and so increase the HPV circulating in the community. Condom use and circumcision reduce the acquisition of HIV-1, and also to some extent of HPV. This review will highlight what is known about the interaction of HIV and HPV, with an emphasis on research in Africa. PMID:26239348

  16. Politics and Human Welfare: Retinitis Pigmentosa Patients in South Africa.

    ERIC Educational Resources Information Center

    McKendrick, B. W.; Leketi, M.

    1990-01-01

    The study found that apartheid impacted the sociopsychological and physical circumstances of 12 African and 11 White people with retinitis pigmentosa in South Africa. Findings are discussed in terms of onset of condition, effects on subjects' lives, knowledge of social services, and needs unmet by existing services. (JDD)

  17. Soil carbon and plant diversity distribution at the farm level in the savannah region of Northern Togo (West Africa)

    NASA Astrophysics Data System (ADS)

    Sebastiã, M.-T.; Marks, E.; Poch, R. M.

    2008-10-01

    In western Africa, soil organic matter is a source of fertility for food provision and a tool for climate mitigation. In the Savannah region, strong soil degradation linked to an increase in population threatens organic matter conservation and agricultural yield. Soil degradation is also expected to impact biodiversity and, with it, increase the vulnerability of ecosystem goods and services, including the storage of soil organic carbon. Studies of land use, plant species composition and soil fertility were conducted for a conservation project at a demonstration farm in Northern Togo (West Africa), host to various management regimes. Results showed a low organic matter content of the surface soil horizons, often around 0.5%. The highest values were found in a sacred forest within the farm (2.2%). Among crops, rice had the highest soil organic matter, around 1%. In a survey of grasslands, pastures showed the highest organic matter content, with vegetation composition differing from grazed fallows and abandoned grasslands. Plant species richness showed a positive relationship with soil organic matter (R2adj=41.2%), but only by the end of the wet season, when species richness was also highest. Sampling date had a strong effect on vegetation composition. Results showed a strong influence of human activity on soil formation and distribution, and also on plant diversity. The soil characteristics found under the permanent forest suggest a high potential of the soils of the region for improvement of both agricultural yields and as a potential carbon sink relevant to global change policies.

  18. Simulating the link between ENSO and summer drought in Southern Africa using regional climate models

    NASA Astrophysics Data System (ADS)

    Meque, Arlindo; Abiodun, Babatunde J.

    2015-04-01

    This study evaluates the capability of regional climate models (RCMs) in simulating the link between El Niño Southern Oscillation (ENSO) and Southern African droughts. It uses the Standardized Precipitation-Evapotranspiration Index (SPEI, computed using rainfall and temperature data) to identify 3-month drought over Southern Africa, and compares the observed and simulated correlation between ENSO and SPEI. The observation data are from the Climate Research Unit, while the simulation data are from ten RCMs (ARPEGE, CCLM, HIRHAM, RACMO, REMO, PRECIS, RegCM3, RCA, WRF, and CRCM) that participated in the regional climate downscaling experiment (CORDEX) project. The study analysed the rainy season (December-February) data for 19 years (1989-2008). The results show a strong link between ENSO and droughts (SPEI) over Southern Africa. The link is owing to the influence of ENSO on both rainfall and temperature fields, but the correlation between ENSO and temperature is stronger than the correlation between ENSO and rainfall. Hence, using only rainfall to monitor droughts in Southern Africa may underestimate the influence of ENSO on the droughts. Only few CORDEX RCMs simulate the influence of ENSO on Southern African drought as observed. In this regard, the ARPEGE model shows the best simulation, while CRCM shows the worst. The different in the performance may be due to their lateral boundary conditions. The RCA-simulated link between ENSO and Southern African droughts is sensitive to the global dataset used as the lateral boundary conditions. In some cases, using RCA to downscale global circulation models (GCM) simulations adds value to the simulated link between ENSO and the droughts, but in other cases the downscaling adds no value to the link. The added value of RCA to the simulated link decreases as the capability of the GCM to simulate the link increases. This study suggests that downscaling GCM simulations with RCMs over Southern Africa may improve or depreciate the

  19. Mechanisms Linking Land Use and Regional Climate Changes in West Africa

    NASA Astrophysics Data System (ADS)

    Wang, G.; Ahmed, K. F.; Yu, M.; JI, Z.; Pal, J. S.

    2014-12-01

    Land use land cover change is an important driver for regional climate changes in West Africa due to the strong land-atmosphere coupling. On the other hand, land use is also strongly influenced by climate changes due to the primarily rain-fed agriculture in this region and the relatively low capacity to adapt. It is therefore important that projections for future climate changes or land use changes account for the impact of the feedback between land use and climate. Land use influences regional climate through several different pathways, including changes in surface biogeophysical properties (e.g., surface albedo, Bowen ratio, surface roughness) that have been widely studied, and changes in the dynamic properties of the land surface influencing dust emission. The relative importance of these two pathways is likely to be model dependent and region dependent. In this study the effects of these two pathways will be evaluated and compared, based on results from a modeling framework that includes a regional climate-vegetation model, a crop growth model, an agricultural economics model, and a land use allocation model. This will be conducted in the context of future land use and climate change projections, with the ultimate objective to assess how agricultural land use in West Africa may change driven by climate and socioeconomic changes, and how the resulting land use change may further modify regional climate in the future.

  20. Coal and peat in the sub-Saharan region of Africa: alternative energy options?

    USGS Publications Warehouse

    Weaver, J.N.; Landis, E.R.

    1990-01-01

    Coal and peat are essentially unused and in some cases unknown in sub-Saharan Africa. However, they might comprise valuable alternative energy sources in some or all of the developing nations of the region. The 11 countries considered in this appraisal reportedly contain coal and peat. On the basis of regional geology, another five countries might also contain coal-bearing rocks. If the resource potential is adequate, coal and peat might be utilized in a variety of ways including substituting for fuelwood, generating electricity, supplying process heat for local industry and increasing agricultural productivity. -from Author

  1. Biogeography and climatic change as a context to human dispersal out of Africa and within Eurasia

    NASA Astrophysics Data System (ADS)

    van der Made, Jan

    2011-06-01

    The dispersal of the genus Homo occurred against a background of continuous environmental change. Here, dispersals of large mammals through the Levantine Corridor and into Western Europe and Java are studied and compared to existing records of climatic change and dispersals of early humans and lithic industry. The first human dispersal (with Oldowan lithic industry) out of Africa, around or shortly before 1.8 Ma may have been triggered by biological evolution and increased social organisation, rather than environmental change. After that event, increasing aridity led to decreased faunal exchange between Africa and Eurasia and may have isolated the human populations of Africa and Africa. Southern (Java) and Eastern Asia (China) also seem to have been isolated. Human dispersal into Western Europe may have been limited by closed environments in Central Europe until about 1.2 Ma ago, when faunal dispersal into Europe suggests the cyclic spread of open environments to the west. Acheulean technology originated in Africa, some 1.6-1.5 Ma ago, but its dispersal into Eurasia may have been obstructed by an arid Southwest Asia, until broadly about 0.9 Ma ago, when faunal exchange suggests that the area became temporarily less dry. By 0.6-0.5 Ma ago it reached Europe.

  2. AgMIP: New Results from Sub-Saharan Africa and South Asia Regional Integrated Assessments

    NASA Astrophysics Data System (ADS)

    Rosenzweig, C.

    2014-12-01

    AgMIP conducted the first set of comprehensive regional integrated assessments of climate change impacts on smallholder farmers in Sub-Saharan Africa and South Asia led by researchers from the regions themselves. The project developed new methods integrating climate, crop, livestock and economic models to conduct climate change impact assessments that characterize impacts on smallholder groups. AgMIP projections of climate change impacts on agriculture are more realistic than previous assessments because they take agricultural development into account. Using the best available data and models, the assessments directly evaluated yield, income, and poverty outcomes including the effects of adaptation packages and development pathways. Results show that even with agricultural development, climate change generally will exert negative pressure on yields of smallholder farmers in Sub-Saharan Africa and South Asia. Without adaptation, climate change leads to increased poverty in some locations in Sub-Saharan Africa and South Asia compared to a future in which climate change does not occur. Adaptation can significantly improve smallholder farmer responses to climate change. AgMIP expert teams identified improved varieties, sowing practices, fertilizer application, and irrigation applications as prioritized adaptation strategies. These targeted adaptation packages were able to overcome a portion of detrimental impacts but could not compensate completely in many locations. Even in cases where average impact is near zero, vulnerability (i.e., those at risk of loss) can be substantial even when mean impacts are positive.

  3. Out of Africa: the importance of rivers as human migration corridors

    NASA Astrophysics Data System (ADS)

    Ramirez, J. A.; Coulthard, T. J.; Rogerson, M.; Barton, N.; Bruecher, T.

    2013-12-01

    The route and timing of Homo sapiens exiting Africa remains uncertain. Corridors leading out of Africa through the Sahara, the Nile Valley, and the Red Sea coast have been proposed as migration routes for anatomically modern humans 80,000-130,000 years ago. During this time climate conditions in the Sahara were wetter than present day, and monsoon rainfall fed rivers that flowed across the desert landscape. The location and timing of these rivers may have supported human migration northward from central Africa to the Mediterranean coast, and onwards to Europe or Asia. Here, we use palaeoclimate rainfall and a hydrological model to spatially simulate and quantitatively test the existence of three major rivers crossing the Sahara from south to north during the time of human migration. We provide evidence that, given realistic underlying climatology, the well-known Sahabi and Kufrah rivers very likely flowed across modern day Libya and reached the coast. More unexpectedly an additional river crossed the core of the Sahara through Algeria (Irharhar river) and flowed into the Chotts basin. The Irharhar river is unique, because it links locations in central Africa experiencing monsoon climates with temperate coastal Mediterranean environments where food and resources were likely abundant. From an ecological perspective, this little-known corridor may prove to be the most parsimonious migration route. Support for the Irharar as a viable migration corridor is provided by its geographic proximity to middle Stone Age archaeological artefacts found in North Africa. Our new, highly novel approach provides the first quantitative analysis of the likelihood that rivers occurred during the critical period of human migration out of Africa. Simulated probability of surface water in North Africa during the last interglacial and the location of tools and ornaments from the Middle Stone Age.

  4. Science and Technology Education Newsletter, No. 7, September 1976. A Supplement to the Bulletin of the Regional Office of Science and Technology for Africa. "Special Issue" Environmental Education.

    ERIC Educational Resources Information Center

    Ibukun, Olu, Ed.

    This publication is a collaborative effort between the science and education sections of UNESCO and particularly between UNESCO Regional Office for Science and Technology for Africa (Nairobi) and the UNESCO Regional Office for Education in Africa (Dakar). Articles in this issue focus on Africa: (1) The Belgrade Charter - A Guide to Environmental…

  5. Spread of distinct human immunodeficiency virus type 1 AG recombinant lineages in Africa.

    PubMed

    Cornelissen, M; van Den Burg, R; Zorgdrager, F; Goudsmit, J

    2000-02-01

    To identify new subtype G human immunodeficiency virus type 1 (HIV-1) strains and AG recombinant forms, we collected 28 serum samples from immigrants to the Netherlands from 12 countries throughout Africa. Based on the gag sequences 22 isolates were identified as subtype A or G. Phylogenetic analysis of discontinuous regions of the gag (726 nt), pol (1176 nt) and env (276 nt) genes revealed 13 AG recombinants with the mosaic structure A(gag)/G(pol)/A(env), three with A(gag)/G(pol)/G(env) and one other with A(gag) /G(pol)/G(env), in addition to 'pure' subtypes A(gag)/A(pol)/A(env) (n=1) and G(gag)/G(pol)/G(env) (n=4). To analyse the crossover points in more detail, a new RT-PCR was developed resulting in a large contiguous sequence of 2600 nt from the gag region to half the pol region. All the 13 A(gag)/G(pol)/A(env) recombinants appeared to belong to the circulating recombinant form (CRF) AG (IbNG). The three A(gag)/G(pol) /G(env) recombinants differed from the CRF AG (IbNG) subtype, suggesting the identification of a new CRF subtype. The recovery of AG recombinants from African countries a thousand miles apart indicates the active spread of new recombinants. PMID:10644851

  6. The monetary value of human milk in Francophone west Africa: a PROFILES analysis for nutrition policy communication.

    PubMed

    Aguayo, Víctor M; Ross, Jay

    2002-06-01

    Using a simple and conservative methodology, we estimated the volume and monetary value of the human milk produced by lactating women in Francophone West Africa. In that region, children zero to 35.9 months old consume over 1.1 billion liters of human milk per year. However, suboptimal breastfeeding practices account for the loss of 175 million liters of human milk annually. If the human milk consumed by children zero to 35.9 months old were to be adequately replaced using commercial breastmilk substitutes, an annual expenditure of about 2 billion US dollars would be needed. At the household level, the annual replacement cost of human milk would amount to US$412 per infant. This is beyond the reach of most families in West Africa, where as many as 61% of families in some countries live on less than one US dollar per day. Appropriate policies to foster breastfeeding need to be developed and adequately implemented. Such policy action is more likely to occur if decision makers fully appreciate the monetary value of human milk. PMID:12094665

  7. Periodic isolation of the southern coastal plain of South Africa and the evolution of modern humans over late Quaternary glacial to interglacial cycles

    NASA Astrophysics Data System (ADS)

    Compton, J. S.

    2012-04-01

    Humans evolved in Africa, but where in Africa and by what mechanisms remain unclear. The evolution of modern humans over the last million years is associated with the onset of major global climate fluctuations, glacial to interglacial cycles, related to the build up and melting of large ice sheets in the Northern Hemisphere. During interglacial periods, such as today, warm and wet climates favored human expansion but during cold and dry glacial periods conditions were harsh and habitats fragmented. These large climate fluctuations periodically expanded and contracted African ecosystems and led to human migrations to more hospitable glacial refugia. Periodic isolation of relatively small numbers of humans may have allowed for their rapid evolutionary divergence from the rest of Africa. During climate transitions these divergent groups may have then dispersed and interbred with other groups (hybridization). Two areas at the opposite ends of Africa stand out as regions that were periodically isolated from the rest of Africa: North Africa (the Maghreb) and the southern coastal plain (SCP) of South Africa. The Maghreb is isolated by the Sahara Desert which periodically greens and is reconnected to the rest of Africa during the transition from glacial to interglacial periods. The SCP of South Africa is isolated from the rest of Africa by the rugged mountains of the Cape Fold Belt associated with inedible vegetation and dry climates to the north. The SCP is periodically opened when sea level falls by up to 130 m during glacial maxima to expose the present day submerged inner continental shelf. A five-fold expansion of the SCP receiving more rainfall in glacial periods may have served as a refuge to humans and large migratory herds. The expansive glacial SCP habitat abruptly contracts, by as much as one-third in 300 yr, during the rapid rise in sea level associated with glacial terminations. Rapid flooding may have increased population density and competition on the SCP to

  8. Choir singing in Subsaharan Africa: Acoustic factors of a regional style in southern Mozambique

    NASA Astrophysics Data System (ADS)

    Soeiro de Carvalho, Joao

    2005-09-01

    Choir singing is a most prominent form of expressive behavior in Subsaharan Africa. A vast majority of expressive modes involves multipart singing, both within the framework of European tonal system as well as other structured ways of combining vocal sounds of different frequencies. Vocal improvisation stands as an important process for the course of performance; individual voice ranges, as well as issues of social status and musical competence, determine the ways musicians participate in performance. Aesthetic validation is often expressed by the use of a nonverbal expressive mode, ``kulungwani,'' a vocal technique involving the action of the lower maxillae and tongue in order to produce a low-frequency interruption of sound emission. Choral singing intonation processes seem to rely on harmonic results, rather than melodic. A regional choral style in southern Africa seems to have developed, where a particular distribution of formant frequencies and an emphasis on low-frequency energy play a significant role.

  9. Transcribed ultraconserved region in human cancers

    PubMed Central

    Peng, Jiang Chen; Shen, Jun; Ran, Zhi Hua

    2013-01-01

    Long non-coding RNAs (lncRNAs) are transcripts longer than ~200 nucleotides with little or no protein-coding capacity. Growing evidence shows that lncRNAs present important function in development and are associated with many human diseases such as cancers, Alzheimer disease, and heart diseases. Transcribed ultraconserved region (T-UCR) transcripts are a novel class of lncRNAs transcribed from ultraconserved regions (UCRs). UCRs are absolutely conserved (100%) between the orthologous regions of the human, rat, and mouse genomes. The UCRs are frequently located at fragile sites and at genomic regions involved in cancers. Recent data suggest that T-UCRs are altered at the transcriptional level in human tumorigenesis and the aberrant T-UCRs expression profiles can be used to differentiate human cancer types. The profound understanding of T-UCRs can throw new light on the pathogenesis of human cancers. PMID:24384562

  10. Continental and sea surface temperature variability in southeast Africa (Zambezi River region) since MIS 3

    NASA Astrophysics Data System (ADS)

    Castañeda, I. S.; Tjallingii, R.; Wang, Y. V.; Mets, A.; van der Lubbe, J.; Brummer, G.; Sinninghe Damste, J. S.; Schneider, R. R.; Schouten, S.

    2010-12-01

    At present, few paleoclimate records exist from the region of southeast Africa. The continental climate history of southeast Africa is of much interest since this region falls under the influence of both the Intertropical Convergence Zone (ITCZ) and Congo Air Boundary (CAB) and likely experienced considerably different hydrological conditions when glacial conditions prevailed. Likewise, the paleoceanographic history of the Mozambique Channel of the coast of southeast Africa is of much interest since mesoscale eddies (Agulhas rings) formed in this region transport and release warm and saline Indian Ocean waters into the South Atlantic influencing the buoyancy of Atlantic thermocline waters, deep-water formation, and Atlantic Meridional Overturning Circulation. Sea surface temperatures (SST) of the southern Indian Ocean are additionally important for modulating precipitation in southeast Africa. Here, we utilize multiple organic (TEX86, BIT Index, MBT, CBT) and inorganic (XRF core scanning) geochemical proxies on a sediment core collected from near the Zambezi River (core 64PE304-80; -18.24 °S, 37.87 °E) to examine continental conditions within the Zambezi River catchment as well as the SST history of the Mozambique Channel. Throughout the ~38 kyr record of 64PE304-80, variations in the BIT Index, a proxy for marine vs. soil organic matter input, closely track changes in the log (Ca/Ti) ratio, a proxy for marine vs. lithogenic input. These records indicate increased lithogenic/soil OM contributions in the Late Pleistocene portion of the record whereas the Holocene is characterized by increased marine contributions. This pattern likely reflects closer proximity of the Zambezi river mouth and transport of terrestrial material to the coring site during the last glacial sea-level lowstand. A particularly interesting feature of these records is pronounced millennial-scale fluctuations occurring within Marine Isotope Stages (MIS) 2 and 3, which posses a similar structure

  11. Early modern human diversity suggests subdivided population structure and a complex out-of-Africa scenario

    PubMed Central

    Gunz, Philipp; Bookstein, Fred L.; Mitteroecker, Philipp; Stadlmayr, Andrea; Seidler, Horst; Weber, Gerhard W.

    2009-01-01

    The interpretation of genetic evidence regarding modern human origins depends, among other things, on assessments of the structure and the variation of ancient populations. Because we lack genetic data from the time when the first anatomically modern humans appeared, between 200,000 and 60,000 years ago, instead we exploit the phenotype of neurocranial geometry to compare the variation in early modern human fossils with that in other groups of fossil Homo and recent modern humans. Variation is assessed as the mean-squared Procrustes distance from the group average shape in a representation based on several hundred neurocranial landmarks and semilandmarks. We find that the early modern group has more shape variation than any other group in our sample, which covers 1.8 million years, and that they are morphologically similar to recent modern humans of diverse geographically dispersed populations but not to archaic groups. Of the currently competing models of modern human origins, some are inconsistent with these findings. Rather than a single out-of-Africa dispersal scenario, we suggest that early modern humans were already divided into different populations in Pleistocene Africa, after which there followed a complex migration pattern. Our conclusions bear implications for the inference of ancient human demography from genetic models and emphasize the importance of focusing research on those early modern humans, in particular, in Africa. PMID:19307568

  12. Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate.

    PubMed

    Beyin, Amanuel

    2011-01-01

    Although there is a general consensus on African origin of early modern humans, there is disagreement about how and when they dispersed to Eurasia. This paper reviews genetic and Middle Stone Age/Middle Paleolithic archaeological literature from northeast Africa, Arabia, and the Levant to assess the timing and geographic backgrounds of Upper Pleistocene human colonization of Eurasia. At the center of the discussion lies the question of whether eastern Africa alone was the source of Upper Pleistocene human dispersals into Eurasia or were there other loci of human expansions outside of Africa? The reviewed literature hints at two modes of early modern human colonization of Eurasia in the Upper Pleistocene: (i) from multiple Homo sapiens source populations that had entered Arabia, South Asia, and the Levant prior to and soon after the onset of the Last Interglacial (MIS-5), (ii) from a rapid dispersal out of East Africa via the Southern Route (across the Red Sea basin), dating to ~74-60 kya. PMID:21716744

  13. Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate

    PubMed Central

    Beyin, Amanuel

    2011-01-01

    Although there is a general consensus on African origin of early modern humans, there is disagreement about how and when they dispersed to Eurasia. This paper reviews genetic and Middle Stone Age/Middle Paleolithic archaeological literature from northeast Africa, Arabia, and the Levant to assess the timing and geographic backgrounds of Upper Pleistocene human colonization of Eurasia. At the center of the discussion lies the question of whether eastern Africa alone was the source of Upper Pleistocene human dispersals into Eurasia or were there other loci of human expansions outside of Africa? The reviewed literature hints at two modes of early modern human colonization of Eurasia in the Upper Pleistocene: (i) from multiple Homo sapiens source populations that had entered Arabia, South Asia, and the Levant prior to and soon after the onset of the Last Interglacial (MIS-5), (ii) from a rapid dispersal out of East Africa via the Southern Route (across the Red Sea basin), dating to ~74–60 kya. PMID:21716744

  14. Control of Invasive Salmonella Disease in Africa: Is There a Role for Human Challenge Models?

    PubMed Central

    Gibani, Malick M.; Jin, Celina; Darton, Thomas C.; Pollard, Andrew J.

    2015-01-01

    Invasive Salmonella disease in Africa is a major public health concern. With evidence of the transcontinental spread of the Salmonella Typhi H58 haplotype, improved estimates of the burden of infection and understanding of the complex interplay of factors affecting disease transmission are needed to assist with efforts aimed at disease control. In addition to Salmonella Typhi, invasive nontyphoidal Salmonella are increasingly recognized as an important cause of febrile illness and mortality in sub-Saharan Africa. Human experimental oral challenge studies with Salmonella can be used as a model to offer unique insights into host–pathogen interactions as well as a platform to efficiently test new diagnostic and vaccine candidates. In this article, we review the background and use of human challenge studies to date and discuss how findings from these studies may lead to progress in the control of invasive Salmonella disease in Africa. PMID:26449941

  15. Human-caused fires limit convection in tropical Africa: First temporal observations and attribution

    NASA Astrophysics Data System (ADS)

    Tosca, M. G.; Diner, D. J.; Garay, M. J.; Kalashnikova, O. V.

    2015-08-01

    It is well established that smoke particles modify clouds, which in turn affects climate. However, no study has quantified the temporal dynamics of aerosol-cloud interactions with direct observations. Here for the first time, we use temporally offset satellite observations from northern Africa between 2006 and 2010 to quantitatively measure the effect of fire aerosols on convective cloud dynamics. We attribute a reduction in cloud fraction during periods of high aerosol optical depths to a smoke-driven inhibition of convection. We find that higher smoke burdens limit upward vertical motion, increase surface pressure, and increase low-level divergence—meteorological indicators of convective suppression. These results are corroborated by climate simulations that show a smoke-driven increase in regionally averaged shortwave tropospheric heating and decrease in convective precipitation during the fire season. Our results suggest that in tropical regions, anthropogenic fire initiates a positive feedback loop where increased aerosol emissions limit convection, dry the surface, and enable increased fire activity via human ignition.

  16. Were Rivers Flowing across the Sahara During the Last Interglacial? Implications for Human Migration through Africa

    PubMed Central

    Coulthard, Tom J.; Ramirez, Jorge A.; Barton, Nick; Rogerson, Mike; Brücher, Tim

    2013-01-01

    Human migration north through Africa is contentious. This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant. The findings have major implications for our understanding of how humans migrated north through Africa, for the first time providing a quantitative perspective on the probabilities that these routes were viable for human habitation at these times. PMID:24040347

  17. Potential Risk of Regional Disease Spread in West Africa through Cross-Border Cattle Trade

    PubMed Central

    Dean, Anna S.; Fournié, Guillaume; Kulo, Abalo E.; Boukaya, G. Aboudou; Schelling, Esther; Bonfoh, Bassirou

    2013-01-01

    Background Transboundary animal movements facilitate the spread of pathogens across large distances. Cross-border cattle trade is of economic and cultural importance in West Africa. This study explores the potential disease risk resulting from large-scale, cross-border cattle trade between Togo, Burkina Faso, Ghana, Benin, and Nigeria for the first time. Methods and Principal Findings A questionnaire-based survey of livestock movements of 226 cattle traders was conducted in the 9 biggest cattle markets of northern Togo in February-March 2012. More than half of the traders (53.5%) operated in at least one other country. Animal flows were stochastically simulated based on reported movements and the risk of regional disease spread assessed. More than three quarters (79.2%, range: 78.1–80.0%) of cattle flowing into the market system originated from other countries. Through the cattle market system of northern Togo, non-neighbouring countries were connected via potential routes for disease spread. Even for diseases with low transmissibility and low prevalence in a given country, there was a high risk of disease introduction into other countries. Conclusions By stochastically simulating data collected by interviewing cattle traders in northern Togo, this study identifies potential risks for regional disease spread in West Africa through cross-border cattle trade. The findings highlight that surveillance for emerging infectious diseases as well as control activities targeting endemic diseases in West Africa are likely to be ineffective if only conducted at a national level. A regional approach to disease surveillance, prevention and control is essential. PMID:24130721

  18. MENA 1.1 - An Updated Geophysical Regionalization of the Middle East and North Africa

    SciTech Connect

    Walters, B.; Pasyanos, M.E.; Bhattacharyya, J.; O'Boyle, J.

    2000-03-01

    This short report provides an update to the earlier LLNL paper entitled ''Preliminary Definition of Geophysical Regions for the Middle East and North Africa'' (Sweeney and Walter, 1998). This report is designed to be used in combination with that earlier paper. The reader is referred to Sweeney and Walter (1998) for all details, including definitions, references, uses, shortcomings, etc., of the regionalization process. In this report we will discuss only those regions in which we have changed the boundaries or velocity structure from that given by the original paper. The paper by Sweeney and Walter (1998) drew on a variety of sources to estimate a preliminary, first-order regionalization of the Middle East and North Africa (MENA), providing regional boundaries and velocity models within each region. The model attempts to properly account for major structural discontinuities and significant crustal thickness and velocity variations on a gross scale. The model can be used to extrapolate sparse calibration data within a distinct geophysical region. This model can also serve as a background model in the process of forming station calibration maps using intelligent interpolation techniques such as kriging, extending the calibration into aseismic areas. Such station maps can greatly improve the ability to locate and identify seismic events, which in turn improves the ability to seismically monitor for underground nuclear testing. The original model from Sweeney and Walter (1998) was digitized to a 1{sup o} resolution, for simplicity we will hereafter refer to this model as MENA 1.0. The new model described here has also been digitized to a 1{sup o} resolution and will be referred to as MENA1.1 throughout this report.

  19. Taking forward the World TB Day 2016 theme 'Unite to End Tuberculosis' for the WHO Africa Region.

    PubMed

    Ntoumi, Francine; Kaleebu, Pontiano; Macete, Eusebio; Mfinanga, Sayoki; Chakaya, Jeremiah; Yeboah-Manu, Dorothy; Bates, Matthew; Mwaba, Peter; Maeurer, Markus; Petersen, Eskild; Zumla, Alimuddin

    2016-05-01

    Tuberculosis (TB) remains a global emergency, with an estimated 9.6 million new TB cases worldwide reported in 2014. Twenty-eight percent of these cases were in the World Health Organization (WHO) Africa Region, where the annual case detection rate was 281 per 100000 population-more than double the global average of 133 per 100000. Of the 9.6 million people who developed TB, an estimated 1.2 million (12%) were HIV-positive, and the Africa Region accounted for 74% of these cases. Three million people with TB remain undiagnosed and untreated. Globally, an estimated 480000 had multidrug-resistant TB (MDR-TB). Whilst of the African countries, only South Africa has reported a high prevalence of MDR-TB, it is likely that all of Sub-Saharan Africa has an unreported high load of drug-resistant TB. Tragically, in 2014, only 48% of individuals diagnosed with MDR-TB had successful treatment and an estimated 190000 people died of MDR-TB. Of the global TB funding gap of US$ 0.8 billion, the largest funding gap was in the Africa Region, amounting to US$ 0.4 billion in 2015. The MDR-TB pandemic in particular now threatens to devastate entire regions and may fundamentally alter the life-expectancy and demographic profile of many countries in Sub-Saharan Africa. The theme designated for this year's World TB Day, March 24, 2016, is 'Unite to End TB'. From the Africa Region, there is an urgent need to seriously address the political, economic, and social factors that influence host-Mycobacterium tuberculosis interactions and result in disease. Recent political and funder initiatives that provide renewed hope for the alleviation of Africa's TB and TB/HIV problems are discussed. PMID:26969406

  20. The environmental context of human evolutionary history in Eurasia and Africa.

    PubMed

    Elton, Sarah

    2008-04-01

    negotiate, but their exploitation was accomplished by archaic and/or anatomically modern humans independently in Africa and south-east Asia. Complex social behaviour and material culture also allowed modern humans to reach some of the most hostile regions of the globe, above the Arctic Circle, by the late Pleistocene. This, with colonization of the Americas and Australasia, established Homo sapiens as a truly cosmopolitan species. PMID:18380862

  1. The environmental context of human evolutionary history in Eurasia and Africa

    PubMed Central

    Elton, Sarah

    2008-01-01

    to negotiate, but their exploitation was accomplished by archaic and/or anatomically modern humans independently in Africa and south-east Asia. Complex social behaviour and material culture also allowed modern humans to reach some of the most hostile regions of the globe, above the Arctic Circle, by the late Pleistocene. This, with colonization of the Americas and Australasia, established Homo sapiens as a truly cosmopolitan species. PMID:18380862

  2. Quantification of uncertainties related to the regional application of a conceptual hydrological model in Benin (West Africa)

    NASA Astrophysics Data System (ADS)

    Bormann, H.; Diekkrüger, B.

    2003-04-01

    A conceptual model is presented to simulate the water fluxes of regional catchments in Benin (West Africa). The model is applied in the framework of the IMPETUS project (an integrated approach to the efficient management of scarce water resources in West Africa) which aims to assess the effects of environmental and anthropogenic changes on the regional hydrological processes and on the water availability in Benin. In order to assess the effects of decreasing precipitation and increasing human activities on the hydrological processes in the upper Ouémé valley, a scenario analysis is performed to predict possible changes. Therefore a regional hydrological model is proposed which reproduces the recent hydrological processes, and which is able to consider the changes of landscape properties.The study presented aims to check the validity of the conceptual and lumped model under the conditions of the subhumid tree savannah and therefore analyses the importance of possible sources of uncertainty. Main focus is set on the uncertainties caused by input data, model parameters and model structure. As the model simulates the water fluxes at the catchment outlet of the Térou river (3133 km2) in a sufficient quality, first results of a scenario analysis are presented. Changes of interest are the expected future decrease in amount and temporal structure of the precipitation (e.g. minus X percent precipitation during the whole season versus minus X percent precipitation in the end of the rainy season, alternatively), the decrease in soil water storage capacity which is caused by erosion, and the increasing consumption of ground water for drinking water and agricultural purposes. Resuming from the results obtained, the perspectives of lumped and conceptual models are discussed with special regard to available management options of this kind of models. Advantages and disadvantages compared to alternative model approaches (process based, physics based) are discussed.

  3. Silent Epidemic of Depression in Women in the Middle East and North Africa Region

    PubMed Central

    Eloul, Liyam; Ambusaidi, Aamal; Al-Adawi, Samir

    2009-01-01

    Background: As the world is being gripped by economic depression, international psychological epidemiologists have amassed evidence to suggest that psychological depression and its variants are becoming leading contributors to the global burden of disease with the Middle East and North Africa (MENA) region being no exception. Aim: The main aim of the present discourse, based on a review of the available literature, is to discuss critically whether women in the MENA region have a higher rate of psychological depression than those in other parts of the globe. Result: From the present synthesis, it emerges that the rate of depression may not be necessarily unique to the region. Conclusion: Although no society has totally overcome the marginalisation and lack of empowerment of women, in order to come to grips to this complex issue more vigorously designed epidemiological studies, using taxonomies that are standardised for cross-cultural populations, are needed to quantify the psychological functioning of women. PMID:21509269

  4. MERS-CoV Antibodies in Humans, Africa, 2013-2014.

    PubMed

    Liljander, Anne; Meyer, Benjamin; Jores, Joerg; Müller, Marcel A; Lattwein, Erik; Njeru, Ian; Bett, Bernard; Drosten, Christian; Corman, Victor Max

    2016-06-01

    Dromedaries in Africa and elsewhere carry the Middle East respiratory syndrome coronavirus (MERS-CoV). To search for evidence of autochthonous MERS-CoV infection in humans, we tested archived serum from livestock handlers in Kenya for MERS-CoV antibodies. Serologic evidence of infection was confirmed for 2 persons sampled in 2013 and 2014. PMID:27071076

  5. Language: The Gatekeeper of Humanity. Implications of South Africa's Language in Education Policies

    ERIC Educational Resources Information Center

    May, Judy J.

    2007-01-01

    English is perceived as the language of the powerful elite as well as a tool of oppression and dehumanization. English, as the medium of instruction in South Africa, functions as the barrier to full societal participation of native speakers (Webb, 2003, p.1) and the gatekeeper of humanity. This study combines historical and qualitative methods to…

  6. MERS-CoV Antibodies in Humans, Africa, 2013–2014

    PubMed Central

    Liljander, Anne; Meyer, Benjamin; Jores, Joerg; Müller, Marcel A.; Lattwein, Erik; Njeru, Ian; Bett, Bernard; Corman, Victor Max

    2016-01-01

    Dromedaries in Africa and elsewhere carry the Middle East respiratory syndrome coronavirus (MERS-CoV). To search for evidence of autochthonous MERS-CoV infection in humans, we tested archived serum from livestock handlers in Kenya for MERS-CoV antibodies. Serologic evidence of infection was confirmed for 2 persons sampled in 2013 and 2014. PMID:27071076

  7. Educational Development and Knowledge Flow: Local and Global Forces in Human Development in Africa

    ERIC Educational Resources Information Center

    Nsamenang, A. Bame

    2005-01-01

    Both local and global forces impact on educational and human development. This disrupts Africa's capacity to own, generate, and share knowledge. A disorganizing hybridism between African, Eastern and Western heritages exacerbates the difficulty. A social Darwinian perspective disparages but exploits Africanity. Furthermore, no extant theory…

  8. Frameworks for Africa-UK Research Collaboration in the Social Sciences and Humanities: African University Perspectives

    ERIC Educational Resources Information Center

    Harle, Jonathan

    2007-01-01

    This report was commissioned by the British Academy's Africa Panel to examine the challenges facing African universities when undertaking collaborative research with UK and other international partners, particularly in the social sciences and humanities. It draws principally on a consultation undertaken by the Association of Commonwealth…

  9. Adult Literacy Programs in Uganda. Africa Region Human Development Series.

    ERIC Educational Resources Information Center

    Okech, Anthony; Carr-Hill, Roy A.; Katahoire, Anne R.; Kakooza, Teresa; Ndidde, Alice N.; Oxenham, John

    This report evaluates the outcomes and cost effectiveness of adult literacy programs in Ugandan villages and compares government programs with those provided by nongovernmental organizations (NGOs). Part 1 describes evaluation objectives, government and NGO literacy programs and the rural socioeconomic context, and evaluation design. About 100…

  10. Trials and projects on cervical cancer and human papillomavirus prevention in sub-Saharan Africa.

    PubMed

    Adefuye, Peter O; Broutet, Nathalie J; de Sanjosé, Silvia; Denny, Lynette A

    2013-12-29

    Cervical cancer is the leading cause of cancer morbidity and mortality in women in sub-Saharan Africa (SSA), accounting for about 50,000 deaths annually. Until recently, cytology was the gold standard for screening and prevention of cervical cancer. This method of screening has not been successful in SSA due to a lack of human, financial and material resources and poor health care infrastructure. It is estimated that less than 5% of at risk women have ever being screened. In the past two decades alternative approaches to cytology for cervical cancer screening have been evaluated in low- and medium-income countries. Visual inspection with acetic acid (VIA) and/or Lugol's iodine (VILI) have been shown to have adequate sensitivity, although low specificity, in a number of cross-sectional research and demonstration projects. Visual inspection methods require minimal resources, are technologically accessible, and are feasible for screening for precancerous lesions. Linking screening with VIA/VILI to treatment with cryotherapy may enable screening and treatment to take place in one visit, but this is likely to result in large numbers of women being subjected to unnecessary treatment. A number of studies have shown that cryotherapy is not associated with significant side effects or complications and is well tolerated. Creating the infrastructure for screening of older women is considered desirable, despite the limitations of visual inspection methods as screening tests. Understanding the role of human papillomavirus (HPV) infection in the etiology of cervical cancer and the discovery of HPV rapid test kits, as well as the development of vaccines against the HPV oncogenic types, have created new opportunities for prevention of cervical cancer. Trials and projects have established (and are still ongoing) the feasibility of using these molecular tests for screening. The ultimate in prevention method is primary prevention, offered by the advent of prophylactic vaccines

  11. Infrastructure requirements for human papillomavirus vaccination and cervical cancer screening in sub-Saharan Africa.

    PubMed

    Sankaranarayanan, Rengaswamy; Anorlu, Rose; Sangwa-Lugoma, Ghislain; Denny, Lynette A

    2013-12-29

    The availability of both human papillomavirus (HPV) vaccination and alternative screening tests has greatly improved the prospects of cervical cancer prevention in sub-Saharan African (SSA) countries. The inclusion of HPV vaccine in the portfolio of new vaccines offered by the Gobal Alliance for Vaccines and Immunization (GAVI) to GAVI-eligible countries has vastly improved the chances of introducing HPV vaccination. Further investments to improve vaccine storage, distribution and delivery infrastructure and human resources of the Extended Programme of Immunization will substantially contribute to the faster introduction of HPV vaccination in SSA countries through both school- and campaign-based approaches. Alternative methods to cytology for the prevention of cervical cancer through the early detection and treatment of cervical cancer precursors have been extensively evaluated in the past 15 years, in Africa as well as in other low-resource settings. Visual inspection with 3-5% dilute acetic acid (VIA) and HPV testing are the two alternative screening methods that have been most studied, in both cross-sectional and randomised clinical trials. VIA is particularly suitable to low-resource settings; however, its efficacy in reducing cervical cancer is likely to be significantly lower than HPV testing. The introduction of VIA screening programmes will help develop the infrastructure that will, in turn, facilitate the introduction of affordable HPV testing in future. Links with the existing HIV/AIDS control programmes is another strategy to improve the infrastructure and screening services in SSA. Infrastructural requirements for an integrated approach aiming to vaccinate single-year cohorts of girls in the 9-13 years age-range and to screen women over 30 years of age using VIA or affordable rapid HPV tests are outlined in this manuscript. This article forms part of a regional report entitled "Comprehensive Control of HPV Infections and Related Diseases in the Sub

  12. Addressing Challenges of regional climate modeling over the Greater Horn of Africa: Africa Regional Climate Model Inter-comparison Project (AFRMIP)

    NASA Astrophysics Data System (ADS)

    Anyah, R.

    2009-04-01

    The Greater Horn of Africa (GHA) has distinct climate characteristics compared to the rest of the continent. The GHA is replete with complex terrain comprising of some of the known tropical glacier covered high mountains of Kilimanjaro, Kenya and Rwenzori as well as the Great Rift Valley System (GRVS). The region also has several freshwater lakes that include Lake Victoria (second largest freshwater lake), and Lake Tanganyika (the second largest deepest freshwater lake). As a whole the complex GHA terrain presents an enabling environment where local and large scale climate systems frequently interact to create highly variable climate in both space and time. At the same time, inter-annual variability of the GHA climate is linked to perturbations in the global SSTs, especially over the equatorial Pacific and Indian Ocean basins, and to some extent, the Atlantic Ocean. These three global oceans, all at the same time or each at different times, intriguingly influence the interannual variability of the GHA climate. Interactions and feedbacks among these multiple climate drivers over the region present challenges in quantitative understanding of regional climate variability and changes based on typical empirical techniques. Therefore, there is need to also employ physically-based, regional climate models (RCMs) that can offer scope and capability to unveil cause-effect relationships between regional climate variability and individual or combination of processes. However, representation of the multiple sources of forcing to the GHA climate also poses a great challenge to RCMs as well. This presentation will give an overview of the AFRMIP project, whose primary objective is to undertake a systematic and comprehensive audit of the deficiencies and uncertainties in regional model simulations of the GHA climate. The project specifically seeks to build a coalition of a regional climate modeling community to address the following issues; (i) representation of the GHA

  13. 21st Century African Philosophy of Adult and Human Resource Education in Southern Africa

    ERIC Educational Resources Information Center

    Mutamba, Charlene

    2012-01-01

    This paper will attempt to define a philosophy of adult education for the purpose of workforce development in Southern Africa. The different influences such as Ubuntu and communalism, indigenous education, diversity western philosophy, globalization and technology are explored in the context of the Southern African region.

  14. Has Rift Valley fever virus evolved with increasing severity in human populations in East Africa?

    PubMed Central

    Baba, Marycelin; Masiga, Daniel K; Sang, Rosemary; Villinger, Jandouwe

    2016-01-01

    Rift Valley fever (RVF) outbreaks have occurred across eastern Africa from 1912 to 2010 approximately every 4–15 years, most of which have not been accompanied by significant epidemics in human populations. However, human epidemics during RVF outbreaks in eastern Africa have involved 478 deaths in 1998, 1107 reported cases with 350 deaths from 2006 to 2007 and 1174 cases with 241 deaths in 2008. We review the history of RVF outbreaks in eastern Africa to identify the epidemiological factors that could have influenced its increasing severity in humans. Diverse ecological factors influence outbreak frequency, whereas virus evolution has a greater impact on its virulence in hosts. Several factors could have influenced the lack of information on RVF in humans during earlier outbreaks, but the explosive nature of human RVF epidemics in recent years mirrors the evolutionary trend of the virus. Comparisons between isolates from different outbreaks have revealed an accumulation of genetic mutations and genomic reassortments that have diversified RVF virus genomes over several decades. The threat to humans posed by the diversified RVF virus strains increases the potential public health and socioeconomic impacts of future outbreaks. Understanding the shifting RVF epidemiology as determined by its evolution is key to developing new strategies for outbreak mitigation and prevention of future human RVF casualties. PMID:27329846

  15. Has Rift Valley fever virus evolved with increasing severity in human populations in East Africa?

    PubMed

    Baba, Marycelin; Masiga, Daniel K; Sang, Rosemary; Villinger, Jandouwe

    2016-01-01

    Rift Valley fever (RVF) outbreaks have occurred across eastern Africa from 1912 to 2010 approximately every 4-15 years, most of which have not been accompanied by significant epidemics in human populations. However, human epidemics during RVF outbreaks in eastern Africa have involved 478 deaths in 1998, 1107 reported cases with 350 deaths from 2006 to 2007 and 1174 cases with 241 deaths in 2008. We review the history of RVF outbreaks in eastern Africa to identify the epidemiological factors that could have influenced its increasing severity in humans. Diverse ecological factors influence outbreak frequency, whereas virus evolution has a greater impact on its virulence in hosts. Several factors could have influenced the lack of information on RVF in humans during earlier outbreaks, but the explosive nature of human RVF epidemics in recent years mirrors the evolutionary trend of the virus. Comparisons between isolates from different outbreaks have revealed an accumulation of genetic mutations and genomic reassortments that have diversified RVF virus genomes over several decades. The threat to humans posed by the diversified RVF virus strains increases the potential public health and socioeconomic impacts of future outbreaks. Understanding the shifting RVF epidemiology as determined by its evolution is key to developing new strategies for outbreak mitigation and prevention of future human RVF casualties. PMID:27329846

  16. Sexual minorities, human rights and public health strategies in Africa.

    PubMed

    Epprecht, Marc

    2012-01-01

    Remarkable progress has been made towards the recognition of sexual minority rights in Africa. At the same time, a marked increase in attacks, rhetorical abuse, and restrictive legislation against sexual minorities or ‘homosexuality’ makes activism for sexual rights a risky endeavour in many African countries. Campaigns for sexual rights and ‘coming out’ are frequently perceived as a form of Western cultural imperialism, leading to an exportation of Western gay identities and provoking a patriotic defensiveness. Cultures of quiet acceptance of same-sex relationships or secretive bisexuality are meanwhile also problematic given the high rate of HIV prevalence on much of the continent. This article examines specific initiatives that are using subtle, somewhat covert means to negotiate a path between rights activism and secretive bisexuality. It argues that strategies primarily focused on health concerns that simultaneously yet discreetly promote sexual rights are having some success in challenging prevalent homophobic or ‘silencing’ cultures and discourses. PMID:22826897

  17. Downscaling Reanalysis over Continental Africa with a Regional Model: NCEP Versus ERA Interim Forcing

    NASA Technical Reports Server (NTRS)

    Druyan, Leonard M.; Fulakeza, Matthew B.

    2013-01-01

    Five annual climate cycles (1998-2002) are simulated for continental Africa and adjacent oceans by a regional atmospheric model (RM3). RM3 horizontal grid spacing is 0.44deg at 28 vertical levels. Each of 2 simulation ensembles is driven by lateral boundary conditions from each of 2 alternative reanalysis data sets. One simulation downs cales National Center for Environmental Prediction reanalysis 2 (NCPR2) and the other the European Centre for Medium Range Weather Forecasts Interim reanalysis (ERA-I). NCPR2 data are archived at 2.5deg grid spacing, while a recent version of ERA-I provides data at 0.75deg spacing. ERA-I-forced simulations are recomrp. ended by the Coordinated Regional Downscaling Experiment (CORDEX). Comparisons of the 2 sets of simulations with each other and with observational evidence assess the relative performance of each downscaling system. A third simulation also uses ERA-I forcing, but degraded to the same horizontal resolution as NCPR2. RM3-simulated pentad and monthly mean precipitation data are compared to Tropical Rainfall Measuring Mission (TRMM) data, gridded at 0.5deg, and RM3-simulated circulation is compared to both reanalyses. Results suggest that each downscaling system provides advantages and disadvantages relative to the other. The RM3/NCPR2 achieves a more realistic northward advance of summer monsoon rains over West Africa, but RM3/ERA-I creates the more realistic monsoon circulation. Both systems recreate some features of JulySeptember 1999 minus 2002 precipitation differences. Degrading the resolution of ERA-I driving data unrealistically slows the monsoon circulation and considerably diminishes summer rainfall rates over West Africa. The high resolution of ERA-I data, therefore, contributes to the quality of the downscaling, but NCPR2laterai boundary conditions nevertheless produce better simulations of some features.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  19. Trends in floods in West Africa: analysis based on 11 catchments in the region

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    After the drought of the 1970s in West Africa, the variability in rainfall and land use changes mostly affected flow, and recently flooding has been said to be an increasingly common occurrence throughout the whole of West Africa. These changes have raised many questions about the impact of climate change on the flood regimes in West African countries. This paper investigates whether floods are becoming more frequent or more severe and to what extent climate patterns have been responsible for these changes. We analyzed the trends in the floods occurring in 11 catchments within West Africa's main climate zones. The methodology includes two methods for sampling flood events, namely the AM (annual maximum) method and the POT (peak over threshold), and two perspectives of analysis are presented: long-term analysis based on two long flood time series and a regional perspective involving 11 catchments with shorter series. The Mann-Kendall trend test and the Pettitt break test were used to detect nonstationarities in the time series. The trends detected in flood time series were compared to the rainfall index trends and vegetation indices using contingency tables in order to identify the main driver of change in flood magnitude and flood frequency. The relation between the flood index and the physiographic index was evaluated through a success criterion and the Cramer criterion calculated from the contingency tables. The results show the existence of trends in flood magnitude and flood frequency time series, with two main patterns. Sahelian floods show increasing flood trends and one Sudanian. catchment presents decreasing flood trends. For the overall catchments studied, trends in the maximum 5-day consecutive rainfall index (R5d) show good coherence with trends in flood, while the trends in normalized difference vegetation indices (NDVIs) do not show a significant agreement with flood trends, meaning that this index has possibly no impact on the behavior of floods in

  20. Origin of Clothing Lice Indicates Early Clothing Use by Anatomically Modern Humans in Africa

    PubMed Central

    Toups, Melissa A.; Kitchen, Andrew; Light, Jessica E.; Reed, David L.

    2011-01-01

    Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene. PMID:20823373

  1. Distal tephras of the eastern Lake Victoria basin, equatorial East Africa: correlations, chronology and a context for early modern humans

    NASA Astrophysics Data System (ADS)

    Blegen, Nick; Tryon, Christian A.; Faith, J. Tyler; Peppe, Daniel J.; Beverly, Emily J.; Li, Bo; Jacobs, Zenobia

    2015-08-01

    The tephrostratigraphic framework for Pliocene and Early Pleistocene paleoanthropological sites in East Africa has been well established through nearly 50 years of research, but a similarly comprehensive framework is lacking for the Middle and particularly the Late Pleistocene. We provide the first detailed regional record of Late Pleistocene tephra deposits associated with artifacts or fossils from the Lake Victoria basin of western Kenya. Correlations of Late Pleistocene distal tephra deposits from the Wasiriya beds on Rusinga Island, the Waware beds on Mfangano Island and deposits near Karungu, mainland Kenya, are based on field stratigraphy coupled with 916 electron microprobe analyses of eleven major and minor element oxides from 50 samples. At least eight distinct distal tephra deposits are distinguished, four of which are found at multiple localities spanning >60 km over an approximately north to south transect. New optically stimulated luminescence dates help to constrain the Late Pleistocene depositional ages of these deposits. Our correlation and characterization of volcaniclastic deposits expand and refine the current stratigraphy of the eastern Lake Victoria basin. This provides the basis for relating fossil- and artifact-bearing sediments and a framework for ongoing geological, archaeological and paleontological studies of Late Pleistocene East Africa, a crucial time period for human evolution and dispersal within and out of Africa.

  2. Internationalization "vs" Regionalization of Higher Education in East Africa and the Challenges of Quality Assurance and Knowledge Production

    ERIC Educational Resources Information Center

    Ogachi, Oanda

    2009-01-01

    Internationalization of higher education in East Africa raises various questions related to its magnitude and intensity, its capacity to address issues of access, equity and regional research and developmental needs. Internationalization and regionalization as processes in higher education can synergize each other but can also limit the success of…

  3. Monitoring vegetation dynamics with medium resolution MODIS-EVI time series at sub-regional scale in southern Africa

    NASA Astrophysics Data System (ADS)

    Dubovyk, Olena; Landmann, Tobias; Erasmus, Barend F. N.; Tewes, Andreas; Schellberg, Jürgen

    2015-06-01

    Currently there is a lack of knowledge on spatio-temporal patterns of land surface dynamics at medium spatial scale in southern Africa, even though this information is essential for better understanding of ecosystem response to climatic variability and human-induced land transformations. In this study, we analysed vegetation dynamics across a large area in southern Africa using the 14-years (2000-2013) of medium spatial resolution (250 m) MODIS-EVI time-series data. Specifically, we investigated temporal changes in the time series of key phenometrics including overall greenness, peak and timing of annual greenness over the monitoring period and study region. In order to specifically capture spatial and per pixel vegetation changes over time, we calculated trends in these phenometrics using a robust trend analysis method. The results showed that interannual vegetation dynamics followed precipitation patterns with clearly differentiated seasonality. The earliest peak greenness during 2000-2013 occurred at the end of January in the year 2000 and the latest peak greenness was observed at the mid of March in 2012. Specifically spatial patterns of long-term vegetation trends allowed mapping areas of (i) decrease or increase in overall greenness, (ii) decrease or increase of peak greenness, and (iii) shifts in timing of occurrence of peak greenness over the 14-year monitoring period. The observed vegetation decline in the study area was mainly attributed to human-induced factors. The obtained information is useful to guide selection of field sites for detailed vegetation studies and land rehabilitation interventions and serve as an input for a range of land surface models.

  4. Many human accelerated regions are developmental enhancers

    PubMed Central

    Capra, John A.; Erwin, Genevieve D.; McKinsey, Gabriel; Rubenstein, John L. R.; Pollard, Katherine S.

    2013-01-01

    The genetic changes underlying the dramatic differences in form and function between humans and other primates are largely unknown, although it is clear that gene regulatory changes play an important role. To identify regulatory sequences with potentially human-specific functions, we and others used comparative genomics to find non-coding regions conserved across mammals that have acquired many sequence changes in humans since divergence from chimpanzees. These regions are good candidates for performing human-specific regulatory functions. Here, we analysed the DNA sequence, evolutionary history, histone modifications, chromatin state and transcription factor (TF) binding sites of a combined set of 2649 non-coding human accelerated regions (ncHARs) and predicted that at least 30% of them function as developmental enhancers. We prioritized the predicted ncHAR enhancers using analysis of TF binding site gain and loss, along with the functional annotations and expression patterns of nearby genes. We then tested both the human and chimpanzee sequence for 29 ncHARs in transgenic mice, and found 24 novel developmental enhancers active in both species, 17 of which had very consistent patterns of activity in specific embryonic tissues. Of these ncHAR enhancers, five drove expression patterns suggestive of different activity for the human and chimpanzee sequence at embryonic day 11.5. The changes to human non-coding DNA in these ncHAR enhancers may modify the complex patterns of gene expression necessary for proper development in a human-specific manner and are thus promising candidates for understanding the genetic basis of human-specific biology. PMID:24218637

  5. Southern Africa Regional Office of Astronomy for Development: A New Hub for Astronomy for Development

    NASA Astrophysics Data System (ADS)

    Siseho Mutondo, Moola

    2015-08-01

    A new Astronomy for Development hub needs innovative tools and programs. SAROAD is developing exciting tools integrating Raspberry Pi® technology to bring cost-effective astronomy content to learning centres. SAROAD would also like to report achievements in realising the IAU's strategic plan. In order to manage, evaluate and coordinate regional IAU capacity building programmes, including the recruitment and mobilisation of volunteers, SAROAD has built an intranet that is accessible to regional members upon request. Using this resource, regional members can see and participate in regional activities. This resource also forms the foundation for closer collaboration between SAROAD member countries. SAROAD has commenced with projects in the three Task Force areas of Universities and Research, Children and Schools and Public Outreach. Under the three Task Force areas, a total of seven projects have commenced in Zambia. A further two projects involve the collaboration of Zambia and other regional member countries in order to foster engagement with important regional astronomy facilities (e.g. SKA). SAROAD has identified the IAU’s International Year of Light and a starting point for offering regional support for IAU-endorsed global activities. SAROAD has set up a hub dedicated to regional events and activities about the International Year of Light. SAROAD has a database of regional authorities to enable contact with the region's decision makers and experts. SAROAD will hold an annual event which brings forum for astronomy for development. The creation of the database and the SAROAD Road show is a first step towards this goal. The SAROAD website has helped to advertise upcoming events for astronomy development and education; it is used to provide advice, guidance and information for astronomers in all countries in the Southern Africa. Fundraising is the primary goal for SAROAD in 2015 towards financial self-sufficiency by 2020. We report on the methods that work best

  6. Chromosomal radiosensitivity of human immunodeficiency virus positive/negative cervical cancer patients in South Africa

    PubMed Central

    HERD, OLIVIA; FRANCIES, FLAVIA; KOTZEN, JEFFREY; SMITH, TRUDY; NXUMALO, ZWIDE; MULLER, XANTHENE; SLABBERT, JACOBUS; VRAL, ANNE; BAEYENS, ANS

    2016-01-01

    Cervical cancer is the second most common cancer amongst South African women and is the leading cause of cancer-associated mortality in this region. Several international studies on radiation-induced DNA damage in lymphocytes of cervical cancer patients have remained inconclusive. Despite the high incidence of cervical cancer in South Africa, and the extensive use of radiotherapy to treat it, the chromosomal radiosensitivity of South African cervical cancer patients has not been studied to date. Since a high number of these patients are human immunodeficiency virus (HIV)-positive, the effect of HIV infection on chromosomal radiosensitivity was also investigated. Blood samples from 35 cervical cancer patients (20 HIV-negative and 15 HIV-positive) and 20 healthy controls were exposed to X-rays at doses of 6 MV of 2 and 4 Gy in vitro. Chromosomal radiosensitivity was assessed using the micronucleus (MN) assay. MN scores were obtained using the Metafer 4 platform, an automated microscopic system. Three scoring methods of the MNScore module of Metafer were applied and compared. Cervical cancer patients had higher MN values than healthy controls, with HIV-positive patients having the highest MN values. Differences between groups were significant when using a scoring method that corrects for false positive and false negative MN. The present study suggested increased chromosomal radiosensitivity in HIV-positive South African cervical cancer patients. PMID:26549042

  7. The 'Out of Africa' Hypothesis, Human Genetic Diversity, and Comparative Economic Development

    PubMed Central

    Ashraf, Quamrul; Galor, Oded

    2013-01-01

    This research argues that deep-rooted factors, determined tens of thousands of years ago, had a significant effect on the course of economic development from the dawn of human civilization to the contemporary era. It advances and empirically establishes the hypothesis that, in the course of the exodus of Homo sapiens out of Africa, variation in migratory distance from the cradle of humankind to various settlements across the globe affected genetic diversity and has had a long-lasting effect on the pattern of comparative economic development that is not captured by geographical, institutional, and cultural factors. In particular, the level of genetic diversity within a society is found to have a hump-shaped effect on development outcomes in both the pre-colonial and the modern era, reflecting the trade-off between the beneficial and the detrimental effects of diversity on productivity. While the intermediate level of genetic diversity prevalent among Asian and European populations has been conducive for development, the high degree of diversity among African populations and the low degree of diversity among Native American populations have been a detrimental force in the development of these regions. PMID:25506083

  8. Human-Bat Interactions in Rural West Africa.

    PubMed

    Anti, Priscilla; Owusu, Michael; Agbenyega, Olivia; Annan, Augustina; Badu, Ebenezer Kofi; Nkrumah, Evans Ewald; Tschapka, Marco; Oppong, Samuel; Adu-Sarkodie, Yaw; Drosten, Christian

    2015-08-01

    Because some bats host viruses with zoonotic potential, we investigated human-bat interactions in rural Ghana during 2011-2012. Nearly half (46.6%) of respondents regularly visited bat caves; 37.4% had been bitten, scratched, or exposed to bat urine; and 45.6% ate bat meat. Human-bat interactions in rural Ghana are frequent and diverse. PMID:26177344

  9. Study of Regional Volcanic Impact on the Middle East and North Africa using high-resolution global and regional models

    NASA Astrophysics Data System (ADS)

    Osipov, Sergey; Dogar, Mohammad; Stenchikov, Georgiy

    2016-04-01

    High-latitude winter warming after strong equatorial volcanic eruptions caused by circulation changes associated with the anomalously positive phase of Arctic Oscillation is a subject of active research during recent decade. But severe winter cooling in the Middle East observed after the Mt. Pinatubo eruption of 1991, although recognized, was not thoroughly investigated. These severe regional climate perturbations in the Middle East cannot be explained by solely radiative volcanic cooling, which suggests that a contribution of forced circulation changes could be important and significant. To better understand the mechanisms of the Middle East climate response and evaluate the contributions of dynamic and radiative effects we conducted a comparative study using Geophysical Fluid Dynamics Laboratory global High Resolution Atmospheric Model (HiRAM) with the effectively "regional-model-resolution" of 25-km and the regional Weather Research and Forecasting (WRF) model focusing on the eruption of Mount Pinatubo on June 15, 1991 followed by a pronounced positive phase of the Arctic Oscillation. The WRF model has been configured over the Middle East and North Africa (MENA) region. The WRF code has been modified to interactively account for the radiative effect of volcanic aerosols. Both HiRAM and WRF capture the main features of the MENA climate response and show that in winter the dynamic effects in the Middle East prevail the direct radiative cooling from volcanic aerosols.

  10. Simulation of the annual and diurnal cycles of rainfall over South Africa by a regional climate model

    NASA Astrophysics Data System (ADS)

    Pohl, Benjamin; Rouault, Mathieu; Roy, Shouraseni Sen

    2014-10-01

    The capability of a current state-of-the-art regional climate model for simulating the diurnal and annual cycles of rainfall over a complex subtropical region is documented here. Hourly rainfall is simulated over Southern Africa for 1998-2006 by the non-hydrostatic model weather research and forecasting (WRF), and compared to a network of 103 stations covering South Africa. We used five simulations, four of which consist of different parameterizations for atmospheric convection at a 0.5 × 0.5° resolution, performed to test the physic-dependency of the results. The fifth experiment uses explicit convection over tropical South Africa at a 1/30° resolution. WRF simulates realistic mean rainfall fields, albeit wet biases over tropical Africa. The model mean biases are strongly modulated by the convective scheme used for the simulations. The annual cycle of rainfall is well simulated over South Africa, mostly influenced by tropical summer rainfall except in the Western Cape region experiencing winter rainfall. The diurnal cycle shows a timing bias, with atmospheric convection occurring too early in the afternoon, and causing too abundant rainfall. This result, particularly true in summer over the northeastern part of the country, is weakly physic-dependent. Cloud-resolving simulations do not clearly reduce the diurnal cycle biases. In the end, the rainfall overestimations appear to be mostly imputable to the afternoon hours of the austral summer rainy season, i.e., the periods during which convective activity is intense over the region.

  11. Africa-U.S. Higher Education Collaboration Initiative: Empowering African Higher Education for Africa's Transformation. A Discussion Paper for the Africa Region Post-Summit Workshop. Working Paper

    ERIC Educational Resources Information Center

    National Association of State Universities and Land-Grant Colleges, 2008

    2008-01-01

    This paper examines how higher education can contribute to Africa's transformation, reviews the challenges and priorities for higher education institution building, and introduces a proposed partnership program among African and U.S. higher education institutions to strengthen African higher education. In July of 2007 the National Association of…

  12. An Integrated Land Use - Land Cover Change Model for the Southern Africa Region

    NASA Astrophysics Data System (ADS)

    Desanker, P. V.

    2001-12-01

    A land use change model covering the Miombo region of Southern Africa region is presented. The model includes a structure that recognizes the scales at which land use change decisions are made in the region, namely the traditional authority for subsistence agricultural land use, and includes social-economic and biophysical constraints to land use at multiple levels. Land cover information for the 1990's based on maps derived from Landsat Thematic Mapper data are used to initiative the model. The model, called MELT, can be used to examine impacts of land use change on carbon pools, emissions from land use change (slash and burn agriculture or as a result of soil carbon changes), and spatial patterning of land cover. MELT provides a suitable representation of the process of land use in this region, and will be essential in providing the correct context for observed fire and emissions across the region of the SAFARI 2000 initiative. MELT is implemented using an object-oriented approach, and allows easy linkage with impacts models.

  13. African leaders’ views on critical human resource issues for the implementation of family medicine in Africa

    PubMed Central

    2014-01-01

    Background The World Health Organisation has advocated for comprehensive primary care teams, which include family physicians. However, despite (or because of) severe doctor shortages in Africa, there is insufficient clarity on the role of the family physician in the primary health care team. Instead there is a trend towards task shifting without thought for teamwork, which runs the risk of dangerous oversimplification. It is not clear how African leaders understand the challenges of implementing family medicine, especially in human resource terms. This study, therefore, sought to explore the views of academic and government leaders on critical human resource issues for implementation of family medicine in Africa. Method In this qualitative study, key academic and government leaders were purposively selected from sixteen African countries. In-depth interviews were conducted using an interview guide. All interviews were audio-recorded, transcribed and thematically analysed. Results There were 27 interviews conducted with 16 government and 11 academic leaders in nine Sub-Saharan African countries: Botswana, Democratic Republic of Congo, Ghana, Kenya, Malawi, Nigeria, Rwanda, South Africa and Uganda. Respondents spoke about: educating doctors in family medicine suited to Africa, including procedural skills and holistic care, to address the difficulty of recruiting and retaining doctors in rural and underserved areas; planning for primary health care teams, including family physicians; new supervisory models in primary health care; and general human resource management issues. Conclusions Important milestones in African health care fail to specifically address the human resource issues of integrated primary health care teamwork that includes family physicians. Leaders interviewed in this study, however, proposed organising the district health system with a strong embrace of family medicine in Africa, especially with regard to providing clinical leadership in team

  14. Statistical and dynamical downscaling in CORDEX-Africa: differing views on the regional climate

    NASA Astrophysics Data System (ADS)

    Hewitson, Bruce; Lennard, Christopher; Jack, Christopher; Coop, Lisa

    2013-04-01

    The need for credible regional climate change projections for use in adaptation actions and decision making is well recognised. The CORDEX activity has evolved in large part as a response to this need. For the most part, CORDEX has so far been dominated by regional climate modelling (RCM) activities. However, implicit in CORDEX is the use of statistical downscaling (SD) as a complement to RCMs, although the SD activities lag that of the RCMs. For Africa, the CORDEX RCM work is well advanced with the control climate simulations completed, and a number of RCM-based projections also available. The early results indicate the RCMs produce a credible representation of the regional climate when aggregated in time and/or space, and provide an initial multimodal suite of regional climate change projections for Africa. The SD activities are catching up with this process and the emerging challenge is how to integrate and compare the results from the two downscaling methods. The two approaches, SD and RCMs, have respective strengths and weaknesses, but are considered in the literature to be of comparable overall skill. Where climate change stationarity is not considered a major issue, such as on timescales out to perhaps 2050, it is arguable that SD (comprehensively undertaken) may possibly be more skillful. From the perspective of users of regional scale projections, decision makers and policy developers, it is critical to compare, and assess the relative strengths of the methods on a regional basis. To avoid confusion the contradictions and/or robust messages emerging from the two methods needs to be clearly understood and articulated. The inter-comparison between the RCMs is already the subject of a number of papers, and here we present an initial comparison of early results between the SD and the envelope of RCM downscaling for CORDEX-Africa. Using the available SD results, we consider where the overlap and/or marked differences lie between the two methods. The focus is

  15. Utilization of the Primary Health Care Services in the Tshwane Region of Gauteng Province, South Africa

    PubMed Central

    Nteta, Thembi P.; Mokgatle-Nthabu, Matilda; Oguntibeju, Oluwafemi O.

    2010-01-01

    Background In South Africa, the provision of primary health care is a basic service designed to be cost effective and bring healthcare as close as possible to the population, particularly to those people of low economic status. It is a service which is provided free of charge by the South African government and as part of the millennium health goals, it is intended that the service should be accessible to the populace and be effectively utilized. Objective This study was designed to investigate the accessibility and utilization of the primary health care services in three community health care centres in the Tshwane of the Gauteng Province, South Africa. Methodology Data were obtained from participants attending three Community Health Care Centres in the Tshwane Region using self-administered structured questionnaires. A document review of the Community Health Care Centres records was conducted to investigate the utilization trends of the services provided and descriptive statistics were used to analyze the data obtained. Results The results showed that the Community Health Care Centres in the Tshwane Region are accessible to most participants who lived within 5 km of such centres and who traveled 30 minutes or less to the clinic. Using a taxi or walking were found to be the most common means of transport used to gain access to such a clinic. The findings showed that generally, participants were satisfied with the services provided. Conclusion Participants of this study have access to the community health care centres in the Tshwane Region and there seems to be effective utilization by patients attending them. PMID:21085475

  16. Regional assessment of the hydropower potential of rivers in West Africa

    NASA Astrophysics Data System (ADS)

    Kling, Harald; Stanzel, Philipp; Fuchs, Martin

    2016-04-01

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

  17. Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa)

    NASA Astrophysics Data System (ADS)

    Grimaud, Jean-Louis; Chardon, Dominique; Metelka, Václav; Beauvais, Anicet; Bamba, Ousmane

    2015-07-01

    The regionally correlated and dated regolith-paleolandform sequence of Sub-Saharan West Africa offers a unique opportunity to constrain continental-scale regolith dynamics as the key part of the sediment routing system. In this study, a regolith mapping protocol is developed and applied at the scale of Southwestern Burkina Faso. Mapping combines field survey and remote sensing data to reconstruct the topography of the last pediplain that formed over West Africa in the Early and Mid-Miocene (24-11 Ma). The nature and preservation pattern of the pediplain are controlled by the spatial variation of bedrock lithology and are partitioned among large drainage basins. Quantification of pediplain dissection and drainage growth allows definition of a cratonic background denudation rate of 2 m/My and a minimum characteristic timescale of 20 Ma for shield resurfacing. These results may be used to simulate minimum export fluxes of drainage basins of constrained size over geological timescales. Background cratonic denudation results in a clastic export flux of ~ 4 t/km2/year, which is limited by low denudation efficiency of slope processes and correlatively high regolith storage capacity of tropical shields. These salient characteristics of shields' surface dynamics would tend to smooth the riverine export fluxes of shields through geological time.

  18. A seasonal agricultural drought forecast system for food-insecure regions of East Africa

    USGS Publications Warehouse

    Shukla, Shraddhanand; McNally, Amy; Husak, Gregory; Funk, Christopher C.

    2014-01-01

     The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. More accurate seasonal agricultural drought forecasts for this region can inform better water and agricultural management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses incurred by droughts and floods. Here we describe the development and implementation of a seasonal agricultural drought forecast system for East Africa (EA) that provides decision support for the Famine Early Warning Systems Network's science team. We evaluate this forecast system for a region of equatorial EA (2° S to 8° N, and 36° to 46° E) for the March-April-May growing season. This domain encompasses one of the most food insecure, climatically variable and socio-economically vulnerable regions in EA, and potentially the world: this region has experienced famine as recently as 2011. To assess the agricultural outlook for the upcoming season our forecast system simulates soil moisture (SM) scenarios using the Variable Infiltration Capacity (VIC) hydrologic model forced with climate scenarios for the upcoming season. First, to show that the VIC model is appropriate for this application we forced the model with high quality atmospheric observations and found that the resulting SM values were consistent with the Food and Agriculture Organization's (FAO's) Water Requirement Satisfaction Index (WRSI), an index used by FEWS NET to estimate crop yields. Next we tested our forecasting system with hindcast runs (1993–2012). We found that initializing SM forecasts with start-of-season (5 March) SM conditions resulted in useful SM forecast skill (> 0.5 correlation) at 1-month, and in some cases at 3 month lead times. Similarly, when the forecast was initialized with mid-season (i.e. 5 April) SM conditions the skill until the end-of-season improved. This shows that early-season rainfall

  19. A seasonal agricultural drought forecast system for food-insecure regions of East Africa

    NASA Astrophysics Data System (ADS)

    Shukla, S.; McNally, A.; Husak, G.; Funk, C.

    2014-03-01

    The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. More accurate seasonal agricultural drought forecasts for this region can inform better water and agricultural management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses incurred by droughts and floods. Here we describe the development and implementation of a seasonal agricultural drought forecast system for East Africa (EA) that provides decision support for the Famine Early Warning Systems Network's science team. We evaluate this forecast system for a region of equatorial EA (2° S to 8° N, and 36° to 46° E) for the March-April-May growing season. This domain encompasses one of the most food insecure, climatically variable and socio-economically vulnerable regions in EA, and potentially the world: this region has experienced famine as recently as 2011. To assess the agricultural outlook for the upcoming season our forecast system simulates soil moisture (SM) scenarios using the Variable Infiltration Capacity (VIC) hydrologic model forced with climate scenarios for the upcoming season. First, to show that the VIC model is appropriate for this application we forced the model with high quality atmospheric observations and found that the resulting SM values were consistent with the Food and Agriculture Organization's (FAO's) Water Requirement Satisfaction Index (WRSI), an index used by FEWS NET to estimate crop yields. Next we tested our forecasting system with hindcast runs (1993-2012). We found that initializing SM forecasts with start-of-season (5 March) SM conditions resulted in useful SM forecast skill (> 0.5 correlation) at 1-month, and in some cases at 3 month lead times. Similarly, when the forecast was initialized with mid-season (i.e. 5 April) SM conditions the skill until the end-of-season improved. This shows that early-season rainfall is

  20. A seasonal agricultural drought forecast system for food-insecure regions of East Africa

    NASA Astrophysics Data System (ADS)

    Shukla, S.; McNally, A.; Husak, G.; Funk, C.

    2014-10-01

    The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. More accurate seasonal agricultural drought forecasts for this region can inform better water and agropastoral management decisions, support optimal allocation of the region's water resources, and mitigate socioeconomic losses incurred by droughts and floods. Here we describe the development and implementation of a seasonal agricultural drought forecast system for East Africa (EA) that provides decision support for the Famine Early Warning Systems Network's (FEWS NET) science team. We evaluate this forecast system for a region of equatorial EA (2° S-8° N, 36-46° E) for the March-April-May (MAM) growing season. This domain encompasses one of the most food-insecure, climatically variable, and socioeconomically vulnerable regions in EA, and potentially the world; this region has experienced famine as recently as 2011. To produce an "agricultural outlook", our forecast system simulates soil moisture (SM) scenarios using the Variable Infiltration Capacity (VIC) hydrologic model forced with climate scenarios describing the upcoming season. First, we forced the VIC model with high-quality atmospheric observations to produce baseline soil moisture (SM) estimates (here after referred as SM a posteriori estimates). These compared favorably (correlation = 0.75) with the water requirement satisfaction index (WRSI), an index that the FEWS NET uses to estimate crop yields. Next, we evaluated the SM forecasts generated by this system on 5 March and 5 April of each year between 1993 and 2012 by comparing them with the corresponding SM a posteriori estimates. We found that initializing SM forecasts with start-of-season (SOS) (5 March) SM conditions resulted in useful SM forecast skill (> 0.5 correlation) at 1-month and, in some cases, 3-month lead times. Similarly, when the forecast was initialized with midseason (i.e., 5

  1. Impact of regional climate change on human health.

    PubMed

    Patz, Jonathan A; Campbell-Lendrum, Diarmid; Holloway, Tracey; Foley, Jonathan A

    2005-11-17

    The World Health Organisation estimates that the warming and precipitation trends due to anthropogenic climate change of the past 30 years already claim over 150,000 lives annually. Many prevalent human diseases are linked to climate fluctuations, from cardiovascular mortality and respiratory illnesses due to heatwaves, to altered transmission of infectious diseases and malnutrition from crop failures. Uncertainty remains in attributing the expansion or resurgence of diseases to climate change, owing to lack of long-term, high-quality data sets as well as the large influence of socio-economic factors and changes in immunity and drug resistance. Here we review the growing evidence that climate-health relationships pose increasing health risks under future projections of climate change and that the warming trend over recent decades has already contributed to increased morbidity and mortality in many regions of the world. Potentially vulnerable regions include the temperate latitudes, which are projected to warm disproportionately, the regions around the Pacific and Indian oceans that are currently subjected to large rainfall variability due to the El Niño/Southern Oscillation sub-Saharan Africa and sprawling cities where the urban heat island effect could intensify extreme climatic events. PMID:16292302

  2. Impact of regional climate change on human health

    NASA Astrophysics Data System (ADS)

    Patz, Jonathan A.; Campbell-Lendrum, Diarmid; Holloway, Tracey; Foley, Jonathan A.

    2005-11-01

    The World Health Organisation estimates that the warming and precipitation trends due to anthropogenic climate change of the past 30years already claim over 150,000 lives annually. Many prevalent human diseases are linked to climate fluctuations, from cardiovascular mortality and respiratory illnesses due to heatwaves, to altered transmission of infectious diseases and malnutrition from crop failures. Uncertainty remains in attributing the expansion or resurgence of diseases to climate change, owing to lack of long-term, high-quality data sets as well as the large influence of socio-economic factors and changes in immunity and drug resistance. Here we review the growing evidence that climate-health relationships pose increasing health risks under future projections of climate change and that the warming trend over recent decades has already contributed to increased morbidity and mortality in many regions of the world. Potentially vulnerable regions include the temperate latitudes, which are projected to warm disproportionately, the regions around the Pacific and Indian oceans that are currently subjected to large rainfall variability due to the El Niño/Southern Oscillation sub-Saharan Africa and sprawling cities where the urban heat island effect could intensify extreme climatic events.

  3. Ancient Human Migration after Out-of-Africa.

    PubMed

    Shriner, Daniel; Tekola-Ayele, Fasil; Adeyemo, Adebowale; Rotimi, Charles N

    2016-01-01

    The serial founder model of modern human origins predicts that the phylogeny of ancestries exhibits bifurcating, tree-like behavior. Here, we tested this prediction using three methods designed to investigate gene flow in autosome-wide genotype data from 3,528 unrelated individuals from 163 global samples. Specifically, we investigated whether Cushitic ancestry has an East African or Middle Eastern origin. We found evidence for non-tree-like behavior in the form of four migration events. First, we found that Cushitic ancestry is a mixture of ancestries closely related to Arabian ancestry and Nilo-Saharan or Omotic ancestry. We found evidence for additional migration events in the histories of: 1) Indian and Arabian ancestries, 2) Kalash ancestry, and 3) Native American and Northern European ancestries. These findings, based on analysis of ancestry of present-day humans, reveal migration in the distant past and provide new insights into human history. PMID:27212471

  4. Ancient Human Migration after Out-of-Africa

    PubMed Central

    Shriner, Daniel; Tekola-Ayele, Fasil; Adeyemo, Adebowale; Rotimi, Charles N.

    2016-01-01

    The serial founder model of modern human origins predicts that the phylogeny of ancestries exhibits bifurcating, tree-like behavior. Here, we tested this prediction using three methods designed to investigate gene flow in autosome-wide genotype data from 3,528 unrelated individuals from 163 global samples. Specifically, we investigated whether Cushitic ancestry has an East African or Middle Eastern origin. We found evidence for non-tree-like behavior in the form of four migration events. First, we found that Cushitic ancestry is a mixture of ancestries closely related to Arabian ancestry and Nilo-Saharan or Omotic ancestry. We found evidence for additional migration events in the histories of: 1) Indian and Arabian ancestries, 2) Kalash ancestry, and 3) Native American and Northern European ancestries. These findings, based on analysis of ancestry of present-day humans, reveal migration in the distant past and provide new insights into human history. PMID:27212471

  5. A new look at human immunodeficiency virus infection and stroke in Sub-Saharan Africa.

    PubMed

    Luchuo, Engelbert Bain; Nkoke, Clovis

    2016-06-01

    Stroke and human immunodeficiency virus (HIV) infection are major causes of morbidity and mortality in Sub-Saharan Africa (SSA), with disease burdens being amongst the highest worldwide. HIV infection has emerged as an important risk factor for stroke. The remarkable development in the treatment of HIV infection which occurred in recent decades has allowed the survival of a large number of patients. This therapeutic success which allows patients to live longer has facilitated the emergence of a new population of adults with increased risk for cardiovascular disease including stroke due to aging, the direct effects of HIV infection and combined anti-retroviral therapy (cART). Preventive strategies to decrease the burden of stroke amongst this specific patient population remain understudied in this region of the world. Lack of early diagnosis (CT scans) and poor record keeping make appreciation of the burden difficult. There is indisputable evidence that early diagnosis and early placement on cART therapy reduce HIV associated morbidity and mortality in this region of the world. However, the emergence of a new population of patients at risk for developing stroke (HIV patients) who fortunately live longer deserves a keener attention. Long term effects of cART regimens on cardiovascular and metabolic profiles remain uncertain, and specific cohort studies to properly ascertain its consequences are needed. The evidence and specific guidelines with regards to anti-platelet therapies and statin use, though potentially beneficial, in this patient sub group remains scarce. African specific cohort studies including HIV positive patients in our opinion should constitute a top research priority, to properly ascertain the potential roles of anti-platelet therapies and statins with regards to primary and secondary prevention of stroke, as well as long term effects of cART on their cardiovascular and metabolic profiles. PMID:27429969

  6. A new look at human immunodeficiency virus infection and stroke in Sub-Saharan Africa

    PubMed Central

    Luchuo, Engelbert Bain

    2016-01-01

    Stroke and human immunodeficiency virus (HIV) infection are major causes of morbidity and mortality in Sub-Saharan Africa (SSA), with disease burdens being amongst the highest worldwide. HIV infection has emerged as an important risk factor for stroke. The remarkable development in the treatment of HIV infection which occurred in recent decades has allowed the survival of a large number of patients. This therapeutic success which allows patients to live longer has facilitated the emergence of a new population of adults with increased risk for cardiovascular disease including stroke due to aging, the direct effects of HIV infection and combined anti-retroviral therapy (cART). Preventive strategies to decrease the burden of stroke amongst this specific patient population remain understudied in this region of the world. Lack of early diagnosis (CT scans) and poor record keeping make appreciation of the burden difficult. There is indisputable evidence that early diagnosis and early placement on cART therapy reduce HIV associated morbidity and mortality in this region of the world. However, the emergence of a new population of patients at risk for developing stroke (HIV patients) who fortunately live longer deserves a keener attention. Long term effects of cART regimens on cardiovascular and metabolic profiles remain uncertain, and specific cohort studies to properly ascertain its consequences are needed. The evidence and specific guidelines with regards to anti-platelet therapies and statin use, though potentially beneficial, in this patient sub group remains scarce. African specific cohort studies including HIV positive patients in our opinion should constitute a top research priority, to properly ascertain the potential roles of anti-platelet therapies and statins with regards to primary and secondary prevention of stroke, as well as long term effects of cART on their cardiovascular and metabolic profiles. PMID:27429969

  7. Ground-based Instrumentations in Africa and its Scientific and Societal Benefits to the region

    NASA Astrophysics Data System (ADS)

    Yizengaw, Endawoke

    2012-07-01

    Much of what we know about equatorial physics is based on Jicamarca Incoherent Scattering Radar (ISR) observations. However, Jicamarca is in the American sector where the geomagnetic equator dips with a fairly large excursion between the geomagnetic and geodetic equator. On the other hand, in the African sector the geomagnetic equator is fairly well aligned with the geodetic equator. Satellites (e.g. ROCSAT, DMSP, C/NOFS) observations have also indicated that the equatorial ionosphere in the African sector responds differently than other sectors. However, these satellite observations have not been confirmed, validated or studied in detail by observations from the ground due to lack of suitable ground-based instrumentation in the region. Thus, the question of what causes or drives these unique density irregularities in the region is still not yet fully understood, leading the investigation of the physics behind each effect into speculative dead ends. During the past couple of years very few (compared to the land-mass that Africa covers) small instruments, like GPS receivers, magnetometers, VHF, and VLF have been either deployed in the region or in process. However, to understand the most dynamic region in terms of ionospheric irregularities, those few instruments are far from enough. Recently, significant progress has been emerging in securing more ground-based instrument into the region, and thus three ionosondes are either deployed or in process. In this paper, results from AMBER magnetometer network, ionosonde, and GPS receivers will be presented. By combining the multi instrument independent observations, this paper will show a cause and effect of space weather impact in the region for the first time. While the magnetometer network, such as those operated under the umbrella of AMBER project, estimates the fundamental electrodynamics that governs equatorial ionospheric motion, the GPS receivers will track the structure and dynamics of the ionosphere. In addition

  8. A vectorial capacity product to monitor changing malaria transmission potential in epidemic regions of Africa

    USGS Publications Warehouse

    Ceccato, Pietro; Vancutsem, Christelle; Klaver, Robert; Rowland, James; Connor, Stephen J.

    2012-01-01

    Rainfall and temperature are two of the major factors triggering malaria epidemics in warm semi-arid (desert-fringe) and high altitude (highland-fringe) epidemic risk areas. The ability of the mosquitoes to transmit Plasmodium spp. is dependent upon a series of biological features generally referred to as vectorial capacity. In this study, the vectorial capacity model (VCAP) was expanded to include the influence of rainfall and temperature variables on malaria transmission potential. Data from two remote sensing products were used to monitor rainfall and temperature and were integrated into the VCAP model. The expanded model was tested in Eritrea and Madagascar to check the viability of the approach. The analysis of VCAP in relation to rainfall, temperature and malaria incidence data in these regions shows that the expanded VCAP correctly tracks the risk of malaria both in regions where rainfall is the limiting factor and in regions where temperature is the limiting factor. The VCAP maps are currently offered as an experimental resource for testing within Malaria Early Warning applications in epidemic prone regions of sub-Saharan Africa. User feedback is currently being collected in preparation for further evaluation and refinement of the VCAP model.

  9. Preliminary maps of crustal thickness and regional seismic phases for the Middle East and North Africa

    SciTech Connect

    Sweeney, J.J.

    1995-09-06

    As part of the development of regional seismic discrimination methods for the Middle East and North Africa (MENA) the author is building a database of information related to seismic propagation and crustal structure as well as associated geologic-tectonic and geophysical data. He hopes to use these data to construct and test models of regional seismic propagation and evaluate various detection/discrimination scenarios. To date, the database has been developed by building on a list of references for MENA provided by the Institute for the Study of the Continents (INSTOC) at Cornell University. To this list the author has added an equal number of references resulting from his own literature search which has emphasized papers dealing with seismicity and regional and teleseismic phase data. This paper represents an initial attempt to consolidate some of the information from the database into a form useful to researchers modeling regional seismic waveforms. The information compiled in this report is supplemental to the INSTOC database and has not been compiled anywhere else. What follows is a series of maps which illustrate the spatial variation of seismic phase velocities and crustal thickness. The text identifies the sources of information used in the map preparation. Data for the compilation of these maps has come from an initial search of the database as it presently exists and is not intended to be exhaustive. The author hopes that this initial exercise will help to identify areas and types of data that are deficient and help to focus future data gathering activities.

  10. The Out of Africa hypothesis and the ancestry of recent humans: Cherchez la femme (et l'homme).

    PubMed

    Árnason, Úlfur

    2016-07-01

    The Out of Africa hypothesis (OOAH) has been a mainstay in the discussion of human evolution since its presentation in the 1980's. However, recent advances in palaeontology and molecular genetics have made it possible to examine the hypothesis in a manner that was inconceivable at the time of its proposal. The palaeontological progress relates to early Homo finds in the Caucasus, Denisova finds in the Altai Mountains and Neanderthal finds in a wide range of localities from the Altai Mountains, the Caucasus, the Levant, Asia Minor, southern and Central Europe and the Iberian Peninsula. The Eurasian location of these finds and recognition of the principle of Last common ancestor (LCA) lend no support to OOAH. The same conclusion is drawn from genomic findings, which (a) have revealed the presence of Denisovan and Neanderthal nuclear DNA, primarily in the genomes of recent Eurasians and (b) have shown genomic introgression from early modern humans into Neanderthals in the Altai Mountains. Similarly, archaeological finds in Sulawesi and the discovery of ≈100,000years old human teeth in southern China constitute strong independent challenges to OOAH. The genomic and palaeogenomic results and the new palaeontological and archaeological discoveries suggest (a) that the ancestors of modern humans had their origin in a Eurasian (largely Asian) biogeographic region which may also have extended into NE Africa, and (b) that the founders of basal African lineages became separated, geographically and genetically, in the westernmost part of this region and spread from there to different parts of the African continent. PMID:26995655

  11. A Variable-resolution Surface Wave Dispersion Study of Eurasia, North Africa, and Surrounding Regions

    SciTech Connect

    Pasyanos, M E

    2005-03-21

    This paper presents the results of a large-scale study of surface wave dispersion performed across Eurasia and North Africa. Improvements were made to previous surface wave work by enlarging the study region, increasing path density, improving spatial resolution, and expanding the period range. This study expands the coverage area northwards and eastwards relative to a previous dispersion analysis, which covered only North Africa and the Middle East. We have significantly increased the number of seismograms examined and group velocity measurements made. We have now made good quality dispersion measurements for about 30,000 Rayleigh wave and 20,000 Love wave paths, and have incorporated measurements from several other researchers into the study. A conjugate gradient method was employed for the group velocity tomography, which improved the inversion from the previous study by adopting a variable smoothness. This technique allows us to go to higher resolution where the data allow without producing artifacts. The current results include both Love and Rayleigh wave inversions across the region for periods from 7 to 100 seconds at 1{sup o} resolution. Short period group velocities are sensitive to slow velocities associated with large sedimentary features such as the Caspian Sea, West Siberian Platform, Mediterranean Sea, Bay of Bengal, Tarim Basin, and Persian Gulf. Intermediate periods are sensitive to differences in crustal thickness, such as those between oceanic and continental crust or along orogenic zones and continental plateaus. At longer periods, fast velocities are consistently found beneath cratons while slow upper mantle velocities occur along rift systems, subduction zones, and collision zones such as the Tethys Belt. We have compared the group velocities at various periods with features such as sediment thickness, topographic height, crustal thickness, proximity to plate boundaries, lithospheric age and lithospheric thickness, and find significant

  12. Unnatural deaths among children in the Transkei region of South Africa.

    PubMed

    Meel, B L

    2008-07-01

    Nearly 99% of the 10.9 million children worldwide under the age of five years who died in 2000 were from developing countries. This amounts to at least 29,000 deaths per day (UNICEF, 2005). This study aims to trace the pattern of unnatural deaths in the Transkei region of South Africa. It is a records review of the medico-legal autopsies carried out between 1996 and 2004 at Umtata General Hospital (UGH). All subjects aged 18 years or below were considered as children. Between 1996-2004, 7,303 unnatural deaths were recorded. Of these, 1,449 (19.8%) were children. Trauma accounted for 1,028 (70.9%) child deaths and 421 (29.1%) were deaths related to other causes such as hanging, burns, lightning strike, drowning, gas suffocation, falls from a height and poisoning. Motor vehicle accidents accounted for 469 (45.6%) deaths and homicides for 553 (54.4%) deaths. The homicides were firearms injuries, 196 (19%), stab wounds, 185 (18%), and blunt trauma, 178 (17.3%). Non-traumatic deaths were hanging, 81 (19.2%), drowning, 166 (39.4%), lightning strike, 38 (9%), burns, 51 (12.1%), gas suffocation, 24 (5.7%), poisoning, 33 (8.4%) and falls from a height 28 (6.7%). There is a high risk of unnatural death among children in the area of Mthatha. It threatens the survival of young children in this region of South Africa. Poverty is an underlying cause for these preventable deaths. PMID:18754210

  13. Analysis of human infectious avian influenza virus: hemagglutinin genetic characteristics in Asia and Africa from 2004 to 2009.

    PubMed

    Zhang, Jirong; Lei, Fumin

    2010-09-01

    In the present study, we used nucleotide and protein sequences of avian influenza virus H5N1, which were obtained in Asia and Africa, analyzed HA proteins using ClustalX1.83 and MEGA4.0, and built a genetic evolutionary tree of HA nucleotides. The analysis revealed that the receptor specificity amino acid of A/HK/213/2003, A/Turkey/65596/2006 and etc mutated into QNG, which could bind with á-2, 3 galactose and á-2, 6 galactose. A mutation might thus take place and lead to an outbreak of human infections of avian influenza virus. The mutations of HA protein amino acids from 2004 to 2009 coincided with human infections provided by the World Health Organization, indicating a "low-high-highest-high-low" pattern. We also found out that virus strains in Asia are from different origins: strains from Southeast Asia and East Asia are of the same origin, whereas those from West Asia, South Asia and Africa descend from one ancestor. The composition of the phylogenetic tree and mutations of key site amino acids in HA proteins reflected the fact that the majority of strains are regional and long term, and virus diffusions exist between China, Laos, Malaysia, Indonesia, Azerbaijan, Turkey and Iraq. We would advise that pertinent vaccines be developed and due attention be paid to the spread of viruses between neighboring countries and the dangers of virus mutation and evolution. PMID:21392344

  14. The Impact of Human Conflict on the Genetics of Mastomys natalensis and Lassa Virus in West Africa

    PubMed Central

    Denys, Christiane; ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease. PMID:22615894

  15. The impact of human conflict on the genetics of Mastomys natalensis and Lassa virus in West Africa.

    PubMed

    Lalis, Aude; Leblois, Raphaël; Lecompte, Emilie; Denys, Christiane; Ter Meulen, Jan; Wirth, Thierry

    2012-01-01

    Environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. The contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. Here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of Lassa virus and its natural reservoir, the rodent Mastomys natalensis, in Guinea, West Africa. Analysis of nucleoprotein gene sequences enabled us to reconstruct the evolutionary history of Lassa virus, which appeared 750 to 900 years ago in Nigeria and only recently spread across western Africa (170 years ago). Bayesian demographic inferences revealed that both the host and the virus populations have gone recently through severe genetic bottlenecks. The timing of these events matches civil war-related mass movements of refugees and accompanying environmental degradation. Forest and habitat destruction and human predation of the natural reservoir are likely explanations for the sharp decline observed in the rodent populations, the consequent virus population decline, and the coincident increased incidence of Lassa fever in these regions. Interestingly, we were also able to detect a similar pattern in Nigeria coinciding with the Biafra war. Our findings show that anthropogenic factors may profoundly impact the population genetics of a virus and its reservoir within the context of an emerging infectious disease. PMID:22615894

  16. Managing Human Tissue Transfer Across National Boundaries - An Approach from an Institution in South Africa.

    PubMed

    Mahomed, Safia; Behrens, Kevin; Slabbert, Melodie; Sanne, Ian

    2016-04-01

    With biobank research on the increase and the history of exploitation in Africa, it has become necessary to manage the transfer of human tissues across national boundaries. There are many accepted templates of Material Transfer Agreements (MTAs) that currently exist internationally. However, these templates do not address the specific concerns of South Africa and even of Africa as a continent. This article will examine three significantly important ethico-legal concepts that were deliberated and carefully adapted by a South African Institution to suit the transfer of Human Biological Materials (HBMs) and associated data for biobank research, namely: informed consent; benefit sharing arrangements; and ownership together with intellectual property rights in human tissues. The discussion includes an analysis of current practice; the ethico-legal challenges in the South African/African context; the decisions made with regard to how the related ethico-legal challenges were addressed in the MTA; and justifications for implementing these decisions. The processes considered could be of benefit to other developing world countries who consider it necessary to manage the transfer of HBMs across national boundaries. PMID:25688848

  17. Population genetic structure of Plasmodium falciparum across a region of diverse endemicity in West Africa

    PubMed Central

    2012-01-01

    Background Malaria parasite population genetic structure varies among areas of differing endemicity, but this has not been systematically studied across Plasmodium falciparum populations in Africa where most infections occur. Methods Ten polymorphic P. falciparum microsatellite loci were genotyped in 268 infections from eight locations in four West African countries (Republic of Guinea, Guinea Bissau, The Gambia and Senegal), spanning a highly endemic forested region in the south to a low endemic Sahelian region in the north. Analysis was performed on proportions of mixed genotype infections, genotypic diversity among isolates, multilocus standardized index of association, and inter-population differentiation. Results Each location had similar levels of pairwise genotypic diversity among isolates, although there were many more mixed parasite genotype infections in the south. Apart from a few isolates that were virtually identical, the multilocus index of association was not significant in any population. Genetic differentiation between populations was low (most pairwise FST values < 0.03), and an overall test for isolation by distance was not significant. Conclusions Although proportions of mixed genotype infections varied with endemicity as expected, population genetic structure was similar across the diverse sites. Very substantial reduction in transmission would be needed to cause fragmented or epidemic sub-structure in this region. PMID:22759447

  18. The regional and diurnal variability of the vertical structure of precipitation systems in Africa, based on TRMM precipitation radar data

    NASA Astrophysics Data System (ADS)

    Demissie, Yonas; Dejene Demissie, Teferi; D'Odorico, Paolo; Sharma, Rishi

    2013-04-01

    Five years of the Tropical Rainfall Measuring Mission (TRMM) 2A25 radar reflectivity profiles and derived surface rain rates are used to describe the vertical structure of precipitation systems in boreal and austral summer rainy seasons in Africa. The continent is divided into several climatologically rather homogenous regions and those regions are characterized and contrasted. To place the composite reflectivity profiles in context, they are also contrasted against TRMM 2A25 observations over the Amazon. Precipitation systems tend to be deeper and more intense in all of tropical Africa than in the Amazon, and shallow warm-rain events are less common. Storms, in all African regions, are characterized by high echo tops, high hydro-meteor loading aloft, little indication of a radar bright band maximum at the freezing level, and evidence for low-level evaporation. The diurnal modulation is regionally variable. The amplitude of the diurnal cycle of the mean echo top height decreases from the arid margins of the zenithal rain region toward the equatorial region, and is smallest in the Amazon. A secondary predawn (0000-0600 LT) maximum occurs in the Congo, in terms of rainfall frequency, rainfall intensity, and echo tops. The difference between all African regions and the Amazon, and the relatively smaller differences between regions in Africa, can be understood in terms of the climatological humidity, CAPE, and low-level shear values.

  19. A Revised Root for the Human Y Chromosomal Phylogenetic Tree: The Origin of Patrilineal Diversity in Africa

    PubMed Central

    Cruciani, Fulvio; Trombetta, Beniamino; Massaia, Andrea; Destro-Bisol, Giovanni; Sellitto, Daniele; Scozzari, Rosaria

    2011-01-01

    To shed light on the structure of the basal backbone of the human Y chromosome phylogeny, we sequenced about 200 kb of the male-specific region of the human Y chromosome (MSY) from each of seven Y chromosomes belonging to clades A1, A2, A3, and BT. We detected 146 biallelic variant sites through this analysis. We used these variants to construct a patrilineal tree, without taking into account any previously reported information regarding the phylogenetic relationships among the seven Y chromosomes here analyzed. There are several key changes at the basal nodes as compared with the most recent reference Y chromosome tree. A different position of the root was determined, with important implications for the origin of human Y chromosome diversity. An estimate of 142 KY was obtained for the coalescence time of the revised MSY tree, which is earlier than that obtained in previous studies and easier to reconcile with plausible scenarios of modern human origin. The number of deep branchings leading to African-specific clades has doubled, further strengthening the MSY-based evidence for a modern human origin in the African continent. An analysis of 2204 African DNA samples showed that the deepest clades of the revised MSY phylogeny are currently found in central and northwest Africa, opening new perspectives on early human presence in the continent. PMID:21601174

  20. Voluntary Medical Male Circumcision: Strategies for Meeting the Human Resource Needs of Scale-Up in Southern and Eastern Africa

    PubMed Central

    Curran, Kelly; Njeuhmeli, Emmanuel; Mirelman, Andrew; Dickson, Kim; Adamu, Tigistu; Cherutich, Peter; Mahler, Hally; Fimbo, Bennett; Mavuso, Thembisile Khumalo; Albertini, Jennifer; Fitzgerald, Laura; Bock, Naomi; Reed, Jason; Castor, Delivette; Stanton, David

    2011-01-01

    Voluntary medical male circumcision (VMMC) reduces female-to-male HIV transmission by approximately 60%; modeling suggests that scaling up VMMC to 80% of men 15- to 49-years-old within five years would avert over 3.3 million new HIV infections in 14 high priority countries/regions in southern and eastern Africa by 2025 and would require 20.33 million circumcisions. However, the shortage of health professionals in these countries must be addressed to reach these proposed coverage levels. To identify human resource approaches that are being used to improve VMMC volume and efficiency, we looked at previous literature and conducted a program review. We identified surgical efficiencies, non-surgical efficiencies, task shifting, task sharing, temporary redeployment of public sector staff during VMMC campaign periods, expansion of the health workforce through recruitment of unemployed, recently retired, newly graduating, or on-leave health care workers, and the use of volunteer medical staff from other countries as approaches that address human resource constraints. Case studies from Kenya, Tanzania, and Swaziland illustrate several innovative responses to human resource challenges. Although the shortage of skilled personnel remains a major challenge to the rapid scale-up of VMMC in the 14 African priority countries/regions, health programs throughout the region may be able to replicate or adapt these approaches to scale up VMMC for public health impact. PMID:22140364

  1. The New Regionalism in Sub-Saharan Africa: More Than Meets the Eye? Policy Brief No. 20

    ERIC Educational Resources Information Center

    Goldstein, Andrea

    2002-01-01

    Following independence in sub-Saharan Africa in the 1960s, traditional integration strategies produced disappointing results in most instances, as they started with very modest levels of intra-regional trade, marked differences in income and industrialisation levels and diffuse fiscal weakness. They also had a strong protectionist bias, trying to…

  2. High-temperature environments of human evolution in East Africa based on bond ordering in paleosol carbonates.

    PubMed

    Passey, Benjamin H; Levin, Naomi E; Cerling, Thure E; Brown, Francis H; Eiler, John M

    2010-06-22

    Many important hominid-bearing fossil localities in East Africa are in regions that are extremely hot and dry. Although humans are well adapted to such conditions, it has been inferred that East African environments were cooler or more wooded during the Pliocene and Pleistocene when this region was a central stage of human evolution. Here we show that the Turkana Basin, Kenya--today one of the hottest places on Earth--has been continually hot during the past 4 million years. The distribution of (13)C-(18)O bonds in paleosol carbonates indicates that soil temperatures during periods of carbonate formation were typically above 30 degrees C and often in excess of 35 degrees C. Similar soil temperatures are observed today in the Turkana Basin and reflect high air temperatures combined with solar heating of the soil surface. These results are specific to periods of soil carbonate formation, and we suggest that such periods composed a large fraction of integrated time in the Turkana Basin. If correct, this interpretation has implications for human thermophysiology and implies a long-standing human association with marginal environments. PMID:20534500

  3. Scientists Spot 15 Regions of Human DNA Linked to Depression

    MedlinePlus

    ... 160189.html Scientists Spot 15 Regions of Human DNA Linked to Depression Many are located near genes ... say they've identified 15 regions of human DNA associated with depression. These regions may contain genes ...

  4. Regional climate change projections over southern Africa: Benefits of a high resolution climate change simulation

    NASA Astrophysics Data System (ADS)

    Haensler, A.; Hagemann, S.; Jacob, D.

    2009-12-01

    The southern African region is known to be a biodiversity hotspot but future climate change is likely to have a major influence on the biodiversity. To estimate the impacts of climate change on the biosphere high resolution climate information is needed for both current and future conditions. In the framework of the BIOTA South project we are therefore applying the regional climate model (RCM) REMO of the Max-Planck-Institute for Meteorology (MPI-M) over the southern African region. The model is integrated for a transient climate change simulation for the time period 1960 to 2100 at 1/2 degree and 1/6 degree horizontal resolution using a double-nesting approach. The 1/6 degree simulation is the first long-term climate projection for southern Africa on such a high horizontal resolution. The boundary forcing for the 1/2 degree projection is taken from a global ECHAM5/MPIOM IPCC A1B scenario simulation. In the current study we will analyse projected changes on the hydrological cycle, thereby focusing on the Orange river catchment and on the main BIOTA research transect, which spans from the north-east corner of Namibia to the Cape region in the South. In order to quantify the impact of model resolution on the projected changes we will intercompare the two REMO simulations and the ECHAM5/MPIOM forcing data. A comparison for the high resolution REMO validation simulation and its forcing ERA40 data already revealed an added value in the representation of the seasonal rainfall characteristics for the region. The benefits of using high resolution RCM data for climate change studies will be highlighted and uncertainties introduced by the application of an RCM will be discussed.

  5. Towards an automated monitoring of human settlements in South Africa using high resolution SPOT satellite imagery

    NASA Astrophysics Data System (ADS)

    Kemper, T.; Mudau, N.; Mangara, P.; Pesaresi, M.

    2015-04-01

    Urban areas in sub-Saharan Africa are growing at an unprecedented pace. Much of this growth is taking place in informal settlements. In South Africa more than 10% of the population live in urban informal settlements. South Africa has established a National Informal Settlement Development Programme (NUSP) to respond to these challenges. This programme is designed to support the National Department of Human Settlement (NDHS) in its implementation of the Upgrading Informal Settlements Programme (UISP) with the objective of eventually upgrading all informal settlements in the country. Currently, the NDHS does not have access to an updated national dataset captured at the same scale using source data that can be used to understand the status of informal settlements in the country. This pilot study is developing a fully automated workflow for the wall-to-wall processing of SPOT-5 satellite imagery of South Africa. The workflow includes an automatic image information extraction based on multiscale textural and morphological image features extraction. The advanced image feature compression and optimization together with innovative learning and classification techniques allow a processing of the SPOT-5 images using the Landsat-based National Land Cover (NLC) of South Africa from the year 2000 as low-resolution thematic reference layers as. The workflow was tested on 42 SPOT scenes based on a stratified sampling. The derived building information was validated against a visually interpreted building point data set and produced an accuracy of 97 per cent. Given this positive result, is planned to process the most recent wall-to-wall coverage as well as the archived imagery available since 2007 in the near future.

  6. Distance from sub-Saharan Africa predicts mutational load in diverse human genomes.

    PubMed

    Henn, Brenna M; Botigué, Laura R; Peischl, Stephan; Dupanloup, Isabelle; Lipatov, Mikhail; Maples, Brian K; Martin, Alicia R; Musharoff, Shaila; Cann, Howard; Snyder, Michael P; Excoffier, Laurent; Kidd, Jeffrey M; Bustamante, Carlos D

    2016-01-26

    The Out-of-Africa (OOA) dispersal ∼ 50,000 y ago is characterized by a series of founder events as modern humans expanded into multiple continents. Population genetics theory predicts an increase of mutational load in populations undergoing serial founder effects during range expansions. To test this hypothesis, we have sequenced full genomes and high-coverage exomes from seven geographically divergent human populations from Namibia, Congo, Algeria, Pakistan, Cambodia, Siberia, and Mexico. We find that individual genomes vary modestly in the overall number of predicted deleterious alleles. We show via spatially explicit simulations that the observed distribution of deleterious allele frequencies is consistent with the OOA dispersal, particularly under a model where deleterious mutations are recessive. We conclude that there is a strong signal of purifying selection at conserved genomic positions within Africa, but that many predicted deleterious mutations have evolved as if they were neutral during the expansion out of Africa. Under a model where selection is inversely related to dominance, we show that OOA populations are likely to have a higher mutation load due to increased allele frequencies of nearly neutral variants that are recessive or partially recessive. PMID:26712023

  7. Distance from sub-Saharan Africa predicts mutational load in diverse human genomes

    PubMed Central

    Henn, Brenna M.; Botigué, Laura R.; Peischl, Stephan; Dupanloup, Isabelle; Lipatov, Mikhail; Maples, Brian K.; Martin, Alicia R.; Musharoff, Shaila; Cann, Howard; Snyder, Michael P.; Excoffier, Laurent; Kidd, Jeffrey M.; Bustamante, Carlos D.

    2016-01-01

    The Out-of-Africa (OOA) dispersal ∼50,000 y ago is characterized by a series of founder events as modern humans expanded into multiple continents. Population genetics theory predicts an increase of mutational load in populations undergoing serial founder effects during range expansions. To test this hypothesis, we have sequenced full genomes and high-coverage exomes from seven geographically divergent human populations from Namibia, Congo, Algeria, Pakistan, Cambodia, Siberia, and Mexico. We find that individual genomes vary modestly in the overall number of predicted deleterious alleles. We show via spatially explicit simulations that the observed distribution of deleterious allele frequencies is consistent with the OOA dispersal, particularly under a model where deleterious mutations are recessive. We conclude that there is a strong signal of purifying selection at conserved genomic positions within Africa, but that many predicted deleterious mutations have evolved as if they were neutral during the expansion out of Africa. Under a model where selection is inversely related to dominance, we show that OOA populations are likely to have a higher mutation load due to increased allele frequencies of nearly neutral variants that are recessive or partially recessive. PMID:26712023

  8. Comparing the regional epidemiology of the cassava mosaic and cassava brown streak virus pandemics in Africa.

    PubMed

    Legg, J P; Jeremiah, S C; Obiero, H M; Maruthi, M N; Ndyetabula, I; Okao-Okuja, G; Bouwmeester, H; Bigirimana, S; Tata-Hangy, W; Gashaka, G; Mkamilo, G; Alicai, T; Lava Kumar, P

    2011-08-01

    The rapid geographical expansion of the cassava mosaic disease (CMD) pandemic, caused by cassava mosaic geminiviruses, has devastated cassava crops in 12 countries of East and Central Africa since the late 1980s. Region-level surveys have revealed a continuing pattern of annual spread westward and southward along a contiguous 'front'. More recently, outbreaks of cassava brown streak disease (CBSD) were reported from Uganda and other parts of East Africa that had been hitherto unaffected by the disease. Recent survey data reveal several significant contrasts between the regional epidemiology of these two pandemics: (i) severe CMD radiates out from an initial centre of origin, whilst CBSD seems to be spreading from independent 'hot-spots'; (ii) the severe CMD pandemic has arisen from recombination and synergy between virus species, whilst the CBSD pandemic seems to be a 'new encounter' situation between host and pathogen; (iii) CMD pandemic spread has been tightly linked with the appearance of super-abundant Bemisia tabaci whitefly vector populations, in contrast to CBSD, where outbreaks have occurred 3-12 years after whitefly population increases; (iv) the CMGs causing CMD are transmitted in a persistent manner, whilst the two cassava brown streak viruses appear to be semi-persistently transmitted; and (v) different patterns of symptom expression mean that phytosanitary measures could be implemented easily for CMD but have limited effectiveness, whereas similar measures are difficult to apply for CBSD but are potentially very effective. An important similarity between the pandemics is that the viruses occurring in pandemic-affected areas are also found elsewhere, indicating that contrary to earlier published conclusions, the viruses per se are unlikely to be the key factors driving the two pandemics. A diagrammatic representation illustrates the temporal relationship between B. tabaci abundance and changing incidences of both CMD and CBSD in the Great Lakes region

  9. Evaluating Spatial Interaction Models for Regional Mobility in Sub-Saharan Africa

    PubMed Central

    Wesolowski, Amy; O’Meara, Wendy Prudhomme; Eagle, Nathan; Tatem, Andrew J.; Buckee, Caroline O.

    2015-01-01

    Simple spatial interaction models of human mobility based on physical laws have been used extensively in the social, biological, and physical sciences, and in the study of the human dynamics underlying the spread of disease. Recent analyses of commuting patterns and travel behavior in high-income countries have led to the suggestion that these models are highly generalizable, and as a result, gravity and radiation models have become standard tools for describing population mobility dynamics for infectious disease epidemiology. Communities in Sub-Saharan Africa may not conform to these models, however; physical accessibility, availability of transport, and cost of travel between locations may be variable and severely constrained compared to high-income settings, informal labor movements rather than regular commuting patterns are often the norm, and the rise of mega-cities across the continent has important implications for travel between rural and urban areas. Here, we first review how infectious disease frameworks incorporate human mobility on different spatial scales and use anonymous mobile phone data from nearly 15 million individuals to analyze the spatiotemporal dynamics of the Kenyan population. We find that gravity and radiation models fail in systematic ways to capture human mobility measured by mobile phones; both severely overestimate the spatial spread of travel and perform poorly in rural areas, but each exhibits different characteristic patterns of failure with respect to routes and volumes of travel. Thus, infectious disease frameworks that rely on spatial interaction models are likely to misrepresent population dynamics important for the spread of disease in many African populations. PMID:26158274

  10. Evaluating Spatial Interaction Models for Regional Mobility in Sub-Saharan Africa.

    PubMed

    Wesolowski, Amy; O'Meara, Wendy Prudhomme; Eagle, Nathan; Tatem, Andrew J; Buckee, Caroline O

    2015-07-01

    Simple spatial interaction models of human mobility based on physical laws have been used extensively in the social, biological, and physical sciences, and in the study of the human dynamics underlying the spread of disease. Recent analyses of commuting patterns and travel behavior in high-income countries have led to the suggestion that these models are highly generalizable, and as a result, gravity and radiation models have become standard tools for describing population mobility dynamics for infectious disease epidemiology. Communities in Sub-Saharan Africa may not conform to these models, however; physical accessibility, availability of transport, and cost of travel between locations may be variable and severely constrained compared to high-income settings, informal labor movements rather than regular commuting patterns are often the norm, and the rise of mega-cities across the continent has important implications for travel between rural and urban areas. Here, we first review how infectious disease frameworks incorporate human mobility on different spatial scales and use anonymous mobile phone data from nearly 15 million individuals to analyze the spatiotemporal dynamics of the Kenyan population. We find that gravity and radiation models fail in systematic ways to capture human mobility measured by mobile phones; both severely overestimate the spatial spread of travel and perform poorly in rural areas, but each exhibits different characteristic patterns of failure with respect to routes and volumes of travel. Thus, infectious disease frameworks that rely on spatial interaction models are likely to misrepresent population dynamics important for the spread of disease in many African populations. PMID:26158274

  11. Convergent adaptation of human lactase persistence in Africa and Europe

    PubMed Central

    Tishkoff, Sarah A; Reed, Floyd A; Ranciaro, Alessia; Voight, Benjamin F; Babbitt, Courtney C; Silverman, Jesse S; Powell, Kweli; Mortensen, Holly M; Hirbo, Jibril B; Osman, Maha; Ibrahim, Muntaser; Omar, Sabah A; Lema, Godfrey; Nyambo, Thomas B; Ghori, Jilur; Bumpstead, Suzannah; Pritchard, Jonathan K; Wray, Gregory A; Deloukas, Panos

    2009-01-01

    A SNP in the gene encoding lactase (LCT) (C/T-13910) is associated with the ability to digest milk as adults (lactase persistence) in Europeans, but the genetic basis of lactase persistence in Africans was previously unknown. We conducted a genotype-phenotype association study in 470 Tanzanians, Kenyans and Sudanese and identified three SNPs (G/C-14010, T/G-13915 and C/G-13907) that are associated with lactase persistence and that have derived alleles that significantly enhance transcription from the LCT promoter in vitro. These SNPs originated on different haplotype backgrounds from the European C/T-13910 SNP and from each other. Genotyping across a 3-Mb region demonstrated haplotype homozygosity extending >2.0 Mb on chromosomes carrying C-14010, consistent with a selective sweep over the past ~7,000 years. These data provide a marked example of convergent evolution due to strong selective pressure resulting from shared cultural traits—animal domestication and adult milk consumption. PMID:17159977

  12. Pleistocene sea-level fluctuations and human evolution on the southern coastal plain of South Africa

    NASA Astrophysics Data System (ADS)

    Compton, John S.

    2011-03-01

    Humans evolved in Africa, but where and how remain unclear. Here it is proposed that the southern coastal plain (SCP) of South Africa may have served as a geographical point of origin through periodic expansion and contraction (isolation) in response to glacial/interglacial changes in sea level and climate. During Pleistocene interglacial highstands when sea level was above -75 m human populations were isolated for periods of 360-3400 25-yr generations on the SCP by the rugged mountains of the Cape Fold Belt, climate and vegetation barriers. The SCP expands five-fold as sea level falls from -75 to -120 m during glacial maxima to form a continuous, unobstructed coastal plain accessible to the interior. An expanded and wet glacial SCP may have served as a refuge to humans and large migratory herds and resulted in the mixing of previously isolated groups. The expansive glacial SCP habitat abruptly contracts, by as much as one-third in 300 yr, during the rapid rise in sea level associated with glacial terminations. Rapid flooding may have increased population density and competition on the SCP to select for humans who expanded their diet to include marine resources or hunted large animals. Successful adaptations developed on an isolated SCP are predicted to widely disperse during glacial terminations when the SCP rapidly contracts or during the initial opening of the SCP in the transition to glacial maxima. The hypothesis that periodic expansion and contraction of the SCP, as well as the coastal plain of North Africa, contributed to the stepwise origin of our species over the last 800 thousand years (kyr) is evaluated by comparing the archeological, DNA and sea-level records. These records generally support the hypothesis, but more complete and well dated records are required to resolve the extent to which sea-level fluctuations influenced the complex history of human evolution.

  13. Lightning fatalities in the Transkei sub-region of South Africa.

    PubMed

    Meel, B L

    2007-04-01

    Lightning is a particularly unsettling product of bad weather. It kills more people than other natural disasters such as floods, hurricanes, and tornadoes, but, because lightning usually kills people one at a time, it tends to be an underrated hazard. High risk groups are uneducated, unsheltered and rural people. This study was carried out to determine the incidence of lightning fatalities in the Transkei sub-region. It is a review of records between 1993 and 2004 from the medico-legal autopsies at Umtata General Hospital (UGH). During the study period there were 10,860 autopsies performed on those who died of trauma and other unnatural circumstances which included 151 (1.4%) lightning fatalities. This represents 0.31 deaths per million per year. The highest (0.5/million) was in 1999, and the lowest (0.13/million) in 1997. The age of the victims ranged from 1 to 82 years, with a mean of 22 years. Males and females were almost equally represented (50%). The highest number of deaths (26.5%) was in the age group of 11 to 20 years, and the lowest number (2.7%) in the age group of 70+ years. There is a high incidence of lightning fatalities in the Transkei sub-region of South Africa. People need to be educated to disregard the myths of lightning strike. PMID:17520962

  14. Capacity Building for Disaster Management in Vulnerable Regions of Africa: Implementing an Operational Flood Warming System in Lake Victoria

    NASA Astrophysics Data System (ADS)

    Hong, Y.; Li, L.; Adler, R.; Policelli, F.

    2008-12-01

    NASA Applied Science program has partnered with USAID and The Regional Centre for Mapping of Resources for Development (RCMRD) in Africa to implement an operational flood warning system for East Africa, SERVIR-Africa project. The project seeks to take advantage of remote sensing information as an alternative and supplemental to ground-based observation in order to preserve the spatial extent of flood hazards. The recently available and virtually uninterrupted supply of satellite-based rainfall estimates is increasingly becoming a cost-effective data source for flood prediction in many under-gauged regions around the world. Our initial focus aims to provide an operational flood warning system for Lake Victoria, a flood-prone region home to 30 million people. The key datasets enabling the development of a distributed hydrological model in Africa include TRMM-based Multi-satellite Precipitation Analysis (TMPA), digital elevation data from the Shuttle Radar Topography Mission (SRTM) mission, HydroSHEDS hydrological products, MODIS Land cover, and soil parameters provided by FAO. This research focuses on evaluation and integration the TMPA Real- Time product into an online operational flood prediction system. We will also identify the optimal calibration strategy for satellite rainfall data into real-time hydrological modeling, one current knowledge gap that has remained relatively unexplored. Early results demonstrate this flood modeling system is useful decision- support tool for governmental officials and international aid organizations to better quantify flood impacts and extent of hazard risk, as well as more expediently respond to flood emergencies.

  15. Impact of land cover characterization on regional climate modeling over West Africa

    NASA Astrophysics Data System (ADS)

    Sylla, Mouhamadou Bamba; Pal, Jeremy S.; Wang, Guiling L.; Lawrence, Peter J.

    2016-01-01

    The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998-2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features.

  16. Geopotential field anomalies and regional tectonic features - two case studies: southern Africa and Germany

    NASA Astrophysics Data System (ADS)

    Korte, Monika; Mandea, Mioara

    2016-05-01

    Maps of magnetic and gravity field anomalies provide information about physical properties of the Earth's crust and upper mantle, helpful in understanding geological conditions and tectonic structures. Depending on data availability, whether from the ground, airborne, or from satellites, potential field anomaly maps contain information on different ranges of spatial wavelengths, roughly corresponding to sources at different depths. Focussing on magnetic data, we compare amplitudes and characteristics of anomalies from maps based on various available data and as measured at geomagnetic repeat stations. Two cases are investigated: southern Africa, characterized by geologically old cratons and strong magnetic anomalies, and the smaller region of Germany with much younger crust and weaker anomalies. Estimating lithospheric magnetic anomaly values from the ground stations' time series (repeat station crustal biases) reveals magnetospheric field contributions causing time-varying offsets of several nT in the results. Similar influences might be one source of discrepancy when merging anomaly maps from different epochs. Moreover, we take advantage of recently developed satellite potential field models and compare magnetic and gravity gradient anomalies of ˜ 200 km resolution. Density and magnetization represent independent rock properties and thus provide complementary information on compositional and structural changes. Comparing short- and long-wavelength anomalies and the correlation of rather large-scale magnetic and gravity anomalies, and relating them to known lithospheric structures, we generally find a better agreement in the southern African region than the German region. This probably indicates stronger concordance between near-surface (down to at most a few km) and deeper (several kilometres down to Curie depth) structures in the former area, which can be seen to agree with a thicker lithosphere and a lower heat flux reported in the literature for the southern

  17. Human evolution out of Africa: the role of refugia and climate change.

    PubMed

    Stewart, J R; Stringer, C B

    2012-03-16

    Although an African origin of the modern human species is generally accepted, the evolutionary processes involved in the speciation, geographical spread, and eventual extinction of archaic humans outside of Africa are much debated. An additional complexity has been the recent evidence of limited interbreeding between modern humans and the Neandertals and Denisovans. Modern human migrations and interactions began during the buildup to the Last Glacial Maximum, starting about 100,000 years ago. By examining the history of other organisms through glacial cycles, valuable models for evolutionary biogeography can be formulated. According to one such model, the adoption of a new refugium by a subgroup of a species may lead to important evolutionary changes. PMID:22422974

  18. Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease

    PubMed Central

    Gomez, Felicia; Hirbo, Jibril; Tishkoff, Sarah A.

    2014-01-01

    Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent. PMID:24984772

  19. A human economy: A ``third way'' for the future of young people in the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Zaalouk, Malak

    2014-06-01

    This paper looks at the vulnerability of today's youth worldwide, with a particular focus on the Middle East and North Africa (MENA), where the proportion of citizens aged 12-24 is particularly high at one-third of the total population. Cursed with poor education and few work opportunities, the youth unemployment rate has risen to 50 per cent in this region. There is a consequent lack of participation at all levels, and a large number of youth are showing symptoms of low self-esteem, frustration, anger and unrest. After discussing the outcomes of years of an inhuman economic system on a global level, this article points to a more humane and empowering path. The author argues that, instead of continuing with profit-oriented capitalism or relying on the informal sector, the co-operative way represents a third alternative to existing economic sectors within the dominant contemporary economic system. The article analyses the many benefits of this path for the realisation of a humane economy. In so doing, it touches on issues of equity and social protection. Finally, the article outlines what needs to be done if this is to be a viable solution for a human economy. While giving many examples of successful co-operative enterprises worldwide, the author singles out the MENA region as one which could also benefit from the new trends outlined.

  20. H3ABioNet, a sustainable pan-African bioinformatics network for human heredity and health in Africa

    PubMed Central

    Mulder, Nicola J.; Adebiyi, Ezekiel; Alami, Raouf; Benkahla, Alia; Brandful, James; Doumbia, Seydou; Everett, Dean; Fadlelmola, Faisal M.; Gaboun, Fatima; Gaseitsiwe, Simani; Ghazal, Hassan; Hazelhurst, Scott; Hide, Winston; Ibrahimi, Azeddine; Jaufeerally Fakim, Yasmina; Jongeneel, C. Victor; Joubert, Fourie; Kassim, Samar; Kayondo, Jonathan; Kumuthini, Judit; Lyantagaye, Sylvester; Makani, Julie; Mansour Alzohairy, Ahmed; Masiga, Daniel; Moussa, Ahmed; Nash, Oyekanmi; Ouwe Missi Oukem-Boyer, Odile; Owusu-Dabo, Ellis; Panji, Sumir; Patterton, Hugh; Radouani, Fouzia; Sadki, Khalid; Seghrouchni, Fouad; Tastan Bishop, Özlem; Tiffin, Nicki; Ulenga, Nzovu

    2016-01-01

    The application of genomics technologies to medicine and biomedical research is increasing in popularity, made possible by new high-throughput genotyping and sequencing technologies and improved data analysis capabilities. Some of the greatest genetic diversity among humans, animals, plants, and microbiota occurs in Africa, yet genomic research outputs from the continent are limited. The Human Heredity and Health in Africa (H3Africa) initiative was established to drive the development of genomic research for human health in Africa, and through recognition of the critical role of bioinformatics in this process, spurred the establishment of H3ABioNet, a pan-African bioinformatics network for H3Africa. The limitations in bioinformatics capacity on the continent have been a major contributory factor to the lack of notable outputs in high-throughput biology research. Although pockets of high-quality bioinformatics teams have existed previously, the majority of research institutions lack experienced faculty who can train and supervise bioinformatics students. H3ABioNet aims to address this dire need, specifically in the area of human genetics and genomics, but knock-on effects are ensuring this extends to other areas of bioinformatics. Here, we describe the emergence of genomics research and the development of bioinformatics in Africa through H3ABioNet. PMID:26627985

  1. H3ABioNet, a sustainable pan-African bioinformatics network for human heredity and health in Africa.

    PubMed

    Mulder, Nicola J; Adebiyi, Ezekiel; Alami, Raouf; Benkahla, Alia; Brandful, James; Doumbia, Seydou; Everett, Dean; Fadlelmola, Faisal M; Gaboun, Fatima; Gaseitsiwe, Simani; Ghazal, Hassan; Hazelhurst, Scott; Hide, Winston; Ibrahimi, Azeddine; Jaufeerally Fakim, Yasmina; Jongeneel, C Victor; Joubert, Fourie; Kassim, Samar; Kayondo, Jonathan; Kumuthini, Judit; Lyantagaye, Sylvester; Makani, Julie; Mansour Alzohairy, Ahmed; Masiga, Daniel; Moussa, Ahmed; Nash, Oyekanmi; Ouwe Missi Oukem-Boyer, Odile; Owusu-Dabo, Ellis; Panji, Sumir; Patterton, Hugh; Radouani, Fouzia; Sadki, Khalid; Seghrouchni, Fouad; Tastan Bishop, Özlem; Tiffin, Nicki; Ulenga, Nzovu

    2016-02-01

    The application of genomics technologies to medicine and biomedical research is increasing in popularity, made possible by new high-throughput genotyping and sequencing technologies and improved data analysis capabilities. Some of the greatest genetic diversity among humans, animals, plants, and microbiota occurs in Africa, yet genomic research outputs from the continent are limited. The Human Heredity and Health in Africa (H3Africa) initiative was established to drive the development of genomic research for human health in Africa, and through recognition of the critical role of bioinformatics in this process, spurred the establishment of H3ABioNet, a pan-African bioinformatics network for H3Africa. The limitations in bioinformatics capacity on the continent have been a major contributory factor to the lack of notable outputs in high-throughput biology research. Although pockets of high-quality bioinformatics teams have existed previously, the majority of research institutions lack experienced faculty who can train and supervise bioinformatics students. H3ABioNet aims to address this dire need, specifically in the area of human genetics and genomics, but knock-on effects are ensuring this extends to other areas of bioinformatics. Here, we describe the emergence of genomics research and the development of bioinformatics in Africa through H3ABioNet. PMID:26627985

  2. Education and language: A human right for sustainable development in Africa

    NASA Astrophysics Data System (ADS)

    Babaci-Wilhite, Zehlia; Geo-JaJa, Macleans A.; Lou, Shizhou

    2012-10-01

    Pre-colonial Africa was neither an educationally nor a technologically unsophisticated continent. While education was an integral part of the culture, issues of language identification and standardisation which are subject to contentious debate today were insignificant. Children learned community knowledge and history by asking questions instead of being taught in a hegemonic alien language. This article argues that education and development should take place in a broader context of human rights, and explores the links between three areas often dealt with separately, namely: language, education and development. The authors of this paper demonstrate that changing the face of the multi-dimensionalities of poverty within societies is possible only when education is constructed in a rights perspective over the favoured colonial languages, which are not an integral part of the culture and resources of a community. The authors make a distinction between the right to education and rights in education, the latter of which are found to be more significant for the challenges Africa faces. It is argued here that the elements of Amartya Sen's "threshold" conditions for inclusion in human rights and self-development in education are essential, and that a more promising architecture of education would include what the authors term meta-narrative frameworks, i.e. interrelated policies. The authors contend that the neoliberal commodification of the knowledge sector has only exacerbated human rights and capabilities deprivation - which encompasses both human and income poverty.

  3. Climatic controls on ecosystem resilience: Postfire regeneration in the Cape Floristic Region of South Africa

    PubMed Central

    Wilson, Adam M.; Latimer, Andrew M.; Silander, John A.

    2015-01-01

    Conservation of biodiversity and natural resources in a changing climate requires understanding what controls ecosystem resilience to disturbance. This understanding is especially important in the fire-prone Mediterranean systems of the world. The fire frequency in these systems is sensitive to climate, and recent climate change has resulted in more frequent fires over the last few decades. However, the sensitivity of postfire recovery and biomass/fuel load accumulation to climate is less well understood than fire frequency despite its importance in driving the fire regime. In this study, we develop a hierarchical statistical framework to model postfire ecosystem recovery using satellite-derived observations of vegetation as a function of stand age, topography, and climate. In the Cape Floristic Region (CFR) of South Africa, a fire-prone biodiversity hotspot, we found strong postfire recovery gradients associated with climate resulting in faster recovery in regions with higher soil fertility, minimum July (winter) temperature, and mean January (summer) precipitation. Projections using an ensemble of 11 downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs) suggest that warmer winter temperatures in 2080–2100 will encourage faster postfire recovery across the region, which could further increase fire frequency due to faster fuel accumulation. However, some models project decreasing precipitation in the western CFR, which would slow recovery rates there, likely reducing fire frequency through lack of fuel and potentially driving local biome shifts from fynbos shrubland to nonburning semidesert vegetation. This simple yet powerful approach to making inferences from large, remotely sensed datasets has potential for wide application to modeling ecosystem resilience in disturbance-prone ecosystems globally. PMID:26150521

  4. Climatic controls on ecosystem resilience: Postfire regeneration in the Cape Floristic Region of South Africa.

    PubMed

    Wilson, Adam M; Latimer, Andrew M; Silander, John A

    2015-07-21

    Conservation of biodiversity and natural resources in a changing climate requires understanding what controls ecosystem resilience to disturbance. This understanding is especially important in the fire-prone Mediterranean systems of the world. The fire frequency in these systems is sensitive to climate, and recent climate change has resulted in more frequent fires over the last few decades. However, the sensitivity of postfire recovery and biomass/fuel load accumulation to climate is less well understood than fire frequency despite its importance in driving the fire regime. In this study, we develop a hierarchical statistical framework to model postfire ecosystem recovery using satellite-derived observations of vegetation as a function of stand age, topography, and climate. In the Cape Floristic Region (CFR) of South Africa, a fire-prone biodiversity hotspot, we found strong postfire recovery gradients associated with climate resulting in faster recovery in regions with higher soil fertility, minimum July (winter) temperature, and mean January (summer) precipitation. Projections using an ensemble of 11 downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs) suggest that warmer winter temperatures in 2080-2100 will encourage faster postfire recovery across the region, which could further increase fire frequency due to faster fuel accumulation. However, some models project decreasing precipitation in the western CFR, which would slow recovery rates there, likely reducing fire frequency through lack of fuel and potentially driving local biome shifts from fynbos shrubland to nonburning semidesert vegetation. This simple yet powerful approach to making inferences from large, remotely sensed datasets has potential for wide application to modeling ecosystem resilience in disturbance-prone ecosystems globally. PMID:26150521

  5. The transatlantic dust transport from North Africa to the Americas—Its characteristics and source regions

    NASA Astrophysics Data System (ADS)

    Gläser, Gregor; Wernli, Heini; Kerkweg, Astrid; Teubler, Franziska

    2015-11-01

    Transport of Saharan dust over the Atlantic to the Americas is a relevant process since dust is a nutrient for marine and terrestrial ecosystems. It is therefore important to better quantify the frequency and amount of transatlantic dust transport, its preferred altitude and duration, and the regions of dust origin. This study uses a novel combination of Eulerian and Lagrangian diagnostics, applied to a previously validated 5 year simulation of the fifth generation European Centre for Medium Range Weather Forecast-Hamburg-model (ECHAM5)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry model, to quantify these dust transport characteristics and their seasonal variations. Results confirm the previously found preferred transatlantic dust pathways: in boreal winter and spring, African dust is mainly transported below 800 hPa toward South America, whereas in summer and autumn the preferred pathway is to the Caribbean and occurs in a layer up to 500 hPa. The averaged transport duration from dust emission to deposition is 10 days in winter for deposition in the Amazon region and almost 12 days in summer for deposition in the Caribbean. These estimates were obtained by combining correlation analyses of Eulerian dust fluxes and trajectory calculations. The latter were also essential to identify the main source regions of transatlantic dust transport, which were found in all seasons in northwestern Africa (Algeria, Mali, and Mauritania) but not farther east, e.g., in the Bodélé Depression. A specific Lagrangian analysis for this dust emission hot spot suggests that wet deposition associated with the Intertropical Convergence Zone in winter and the African monsoon in summer inhibits Bodélé dust to leave the African continent.

  6. Hantaviruses in Africa.

    PubMed

    Witkowski, Peter T; Klempa, Boris; Ithete, Ndapewa L; Auste, Brita; Mfune, John K E; Hoveka, Julia; Matthee, Sonja; Preiser, Wolfgang; Kruger, Detlev H

    2014-07-17

    This paper summarizes the progress in the search for hantaviruses and hantavirus infections in Africa. After having collected molecular evidence of an indigenous African hantavirus in 2006, an intensive investigation for new hantaviruses has been started in small mammals. Various novel hantaviruses have been molecularly identified not only in rodents but also in shrews and bats. In addition, the first African hantavirus, Sangassou virus, has been isolated and functionally characterized in cell culture. Less is known about the ability of these hantaviruses to infect humans and to cause diseases. To date, no hantavirus genetic material could be amplified from patients' specimens collected in Africa. Serological studies in West Africa, based on a battery of screening and confirmatory assays, led to the detection of hantavirus antibodies in the human population and in patients with putative hantavirus disease. In addition to this overview, we present original data from seroepidemiological and field studies conducted in the Southern part of Africa. A human seroprevalence rate of 1.0% (n=1442) was detected in the South African Cape Region whereas no molecular evidence for the presence of hantavirus was found in 2500 small animals trapped in South Africa and Namibia. PMID:24406800

  7. Mapping human dispersals into the Horn of Africa from Arabian Ice Age refugia using mitogenomes

    PubMed Central

    Gandini, Francesca; Achilli, Alessandro; Pala, Maria; Bodner, Martin; Brandini, Stefania; Huber, Gabriela; Egyed, Balazs; Ferretti, Luca; Gómez-Carballa, Alberto; Salas, Antonio; Scozzari, Rosaria; Cruciani, Fulvio; Coppa, Alfredo; Parson, Walther; Semino, Ornella; Soares, Pedro; Torroni, Antonio; Richards, Martin B.; Olivieri, Anna

    2016-01-01

    Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium; and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene flow even further afield, into Iran, Pakistan and India. PMID:27146119

  8. Mapping human dispersals into the Horn of Africa from Arabian Ice Age refugia using mitogenomes.

    PubMed

    Gandini, Francesca; Achilli, Alessandro; Pala, Maria; Bodner, Martin; Brandini, Stefania; Huber, Gabriela; Egyed, Balazs; Ferretti, Luca; Gómez-Carballa, Alberto; Salas, Antonio; Scozzari, Rosaria; Cruciani, Fulvio; Coppa, Alfredo; Parson, Walther; Semino, Ornella; Soares, Pedro; Torroni, Antonio; Richards, Martin B; Olivieri, Anna

    2016-01-01

    Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium; and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene flow even further afield, into Iran, Pakistan and India. PMID:27146119

  9. Adherence To Malaria Prophylaxis Among Peace Corps Volunteers in the Africa Region, 2013

    PubMed Central

    Landman, Keren Z.; Tan, Kathrine R.; Arguin, Paul M.

    2016-01-01

    Background Although malaria can be prevented with prophylaxis, it is diagnosed in over 100 Africa-region Peace Corps Volunteers annually. This suggests that prophylaxis non-adherence is a problem in these non-immune travelers. Methods We investigated Volunteers’ knowledge, attitudes, and practices regarding prophylaxis using an internet-based survey during August 19–September 30, 2013. Adherence was defined as taking doxycycline or atovaquone-proguanil daily, or taking mefloquine doses no more than 8 days apart. Results The survey was sent to 3,248 Volunteers. Of 781 whose responses were analyzed, 514 (73%) reported adherence to prophylaxis. The most common reasons for non-adherence were forgetting (n=530, 90%); fear of long-term adverse effects (LTAEs; n=316, 54%); and experiencing adverse events that Volunteers attributed to prophylaxis (n=297, 51%). Two hundred fourteen (27%) Volunteers reported not worrying about malaria. On multivariate analysis controlling for sex and experiencing adverse events Volunteers attributed to prophylaxis, the factor most strongly associated with non-adherence was being prescribed mefloquine (OR 5.4, 95% confidence interval 3.2–9.0). Conclusions We found moderate adherence and a prevailing fear of LTAEs among Volunteers. Strategies to improve prophylaxis adherence may include medication reminders, increasing education about prophylaxis safety and malaria risk, and promoting prompt management of prophylaxis side effects. PMID:25534297

  10. IASI-derived Surface Temperature Under Dusty Conditions: Application to the West Africa Region.

    NASA Astrophysics Data System (ADS)

    Mechri, Rihab; Capelle, Virginie; Chedin, Alain

    2016-04-01

    Giving access to energy and water budgets, Surface Temperature (ST) is considered as a key variable for a wide range of applications in particular for meteorology and climatology. An accurate knowledge of this variable should significantly improve the monitoring of numerous atmospheric and surface processes as well as their interactions. Even-though satellite sensors bring ST global fields at different spatial and temporal scales, the accuracy of these products is still questionable especially over land or for complex atmospheric conditions (presence of clouds, of aerosols, etc.). At LMD, the ST is determined through the simultaneous "Look-up-Table" inversion of satellite METOP/IASI radiances in terms of Aerosol Optical Depth (AOD), dust layer mean altitude and surface temperature . The main aim of this work is to validate IASI ST product and to analyze its spatial and temporal variability, in particular in the presence of dust aerosols. This approach has been first applied to the West Africa region. The accuracy of this ST product will be assessed in terms of bias and standard deviation against ST products from ECMWF forecast, from other satellite products (MODIS AQUA/TERRA, AATSR,…) and from in-situ measurements for different periods ranging from July 2007 to today according to the availability of these validation data.

  11. Buried black soils surrounding the white roof of Africa as regional carbon storage hotspot

    NASA Astrophysics Data System (ADS)

    Zech, M.; Hörold, C.; Leiber-Sauheitl, K.; Hemp, A.; Zech, W.

    2012-04-01

    Mt. Kilimanjaro, the at least still "white roof" of Africa, attracts much attention because of its dramatically shrinking ice caps. By contrast, it was discovered only recently that intriguing paleosol sequences with buried and often strikingly black soils developed along the slopes of Mt. Kilimanjaro during the Late Quaternary. In our study we investigated in detail the soil organic carbon (SOC) contents and SOC stocks of soil profiles which are situated along two altitudinal transects; one along the humid southern slopes and the other one along the more arid northern slopes. We found up to 3 m thick paleosol sequences occurring almost area-wide particularly in the montane forest zone. SOC contents are remarkable high with values of up to more than 10%, indicating high preservation of soil organic matter (SOM). We suggest that the SOM preservation is favoured by several factors, such as (i) the burial by aeolian deposition, (ii) lower temperatures and (iii) more resistant Erica litter during glacial periods, (iv) formation of stable organo-mineral complexes and (v) high black carbon (BC) contents. The SOC-rich buried black soils account for mean SOC stocks of ~82 kg m-2 in the montane rainforest. Extrapolating this SOC storage and comparing it with the SOC storage achieved by the surrounding savannah soils of the Maasai Steppe highlights that the buried black soils are a prominent regional carbon storage hotspot.

  12. Spatial distribution of precipitation annual cycles over South Africa in 10 CORDEX regional climate model present-day simulations

    NASA Astrophysics Data System (ADS)

    Favre, Alice; Philippon, Nathalie; Pohl, Benjamin; Kalognomou, Evangelia-Anna; Lennard, Christopher; Hewitson, Bruce; Nikulin, Grigori; Dosio, Alessandro; Panitz, Hans-Juergen; Cerezo-Mota, Ruth

    2016-03-01

    This study presents an evaluation of the ability of 10 regional climate models (RCMs) participating in the COordinated Regional climate Downscaling Experiment-Africa to reproduce the present-day spatial distribution of annual cycles of precipitation over the South African region and its borders. As found in previous studies, annual mean precipitation is quasi-systematically overestimated by the RCMs over a large part of southern Africa south of about 20°S and more strongly over South Africa. The spatial analysis of precipitation over the studied region shows that in most models the distribution of biases appears to be linked to orography. Wet biases are quasi-systematic in regions with higher elevation with inversely neutral to dry biases particularly in the coastal fringes. This spatial pattern of biases is particularly obvious during summer and specifically at the beginning of the rainy season (November and December) when the wet biases are found to be the strongest across all models. Applying a k-means algorithm, a classification of annual cycles is performed using observed precipitation data, and is compared with those derived from modeled data. It is found that the in-homogeneity of the spatial and temporal distribution of biases tends to impact the modeled seasonality of precipitation. Generally, the pattern of rainfall seasonality in the ensemble mean of the 10 RCMs tends to be shifted to the southwest. This spatial shift is mainly linked to a strong overestimation of convective precipitation at the beginning of the rainy season over the plateau inducing an early annual peak and to an underestimation of stratiform rainfall in winter and spring over southwestern South Africa.

  13. Mycobacterium africanum—Review of an Important Cause of Human Tuberculosis in West Africa

    PubMed Central

    de Jong, Bouke C.; Antonio, Martin; Gagneux, Sebastien

    2010-01-01

    Mycobacterium africanum consists of two phylogenetically distinct lineages within the Mycobacterium tuberculosis complex, known as M. africanum West African 1 and M. africanum West African 2. These lineages are restricted to West Africa, where they cause up to half of human pulmonary tuberculosis. In this review we discuss the definition of M. africanum, describe the prevalence and restricted geographical distribution of M. africanum West African 1 and 2, review the occurrence of M. africanum in animals, and summarize the phenotypic differences described thus far between M. africanum and M. tuberculosis sensu stricto. PMID:20927191

  14. Orphans and Vulnerable Children Affected by Human Immunodeficiency Virus in Sub-Saharan Africa.

    PubMed

    Bryant, Malcolm; Beard, Jennifer

    2016-02-01

    In Sub-Saharan Africa, 15.1 million children have been orphaned because of human immunodeficiency virus (HIV). They face significant vulnerabilities, including stigma and discrimination, trauma and stress, illness, food insecurity, poverty, and difficulty accessing education. Millions of additional children who have living parents are vulnerable because their parents or other relatives are infected. This article reviews the current situation of orphans and vulnerable children, explores the underlying determinants of vulnerability and resilience, describes the response by the global community, and highlights the challenges as the HIV pandemic progresses through its fourth decade. PMID:26613693

  15. Solar variability effects in equatorial F-region vertical plasma drifts over Africa ionosphere

    NASA Astrophysics Data System (ADS)

    Oyekola, Oyedemi

    . F-region vertical drifts were made using ionosonde for the Africa equatorial station Ouagadougou (12o N, 1.5o W; 5.9o N dip) from 3 years of data during January 1987 to December 1989 for solar cycle minimum, medium, and maximum conditions (F10.7 = 85, 141, and 214, respectively) under geomagnetic quiet-time. The variations are found to be dominated by the characteristics morning peak and evening prereversal enhancement (PRE) velocities. Seasonal and solar cycle effects are prominent near the dusk sector with an increase of PRE from solar minimum to maximum. The average equinoctial evening prereversal enhancement increases by almost a factor of three from low to high flux. On the average, the values of daytime and nighttime ionosonde-derived vertical drifts are smaller by about a factor of four than the magnitude often mentioned in publication for equatorial regions from other experimental techniques. In addition, the morning peak velocities maximize between about 0830-0930 LT with typical values of 12-18 m/s. In contrast, PRE have largest amplitude between about 1700-2200 LT with typical values of 5-10 m/s. The morning reversal times do not reveal any dependence on season and solar cycle; but the most probable time of occurrence is around 0530 LT. The evening reversal times are in excellent agreements for the three levels of solar activity periods apart from June solstice that exhibit considerable variations. The most likely time of occurrence is near 2000 LT. Of significance importance, the link between the onset / inhibition parameters of postsunset irregularities over Ouagadougou indicate anti-correlations with solar variability.

  16. The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

    NASA Astrophysics Data System (ADS)

    Abbate, Ernesto; Bruni, Piero; Ferretti, Marco Peter; Delmer, Cyrille; Laurenzi, Marinella Ada; Hagos, Miruts; Bedri, Omar; Rook, Lorenzo; Sagri, Mario; Libsekal, Yosief

    2014-11-01

    exceed thousands of square kilometers in only a single case (Mendefera), but were quite restricted in most cases. Their most likely endorheic and local character, together with a regional ill-defined fluvial network, was the effect of a water-course rerouting caused by the progressive rising of the eastern African and Arabian plateaux. Chronological constraints for the intertrappean beds can be inferred from the age of the hosting Trap succession and by the stratigraphical position that they occupy. Intervolcanic sedimentary episodes are typically found in the basaltic and subordinately rhyolitic successions that followed the 31-29 Ma old basaltic widespread paroxysm. With due caveats deriving from the discontinuous availability of datings specifically dedicated to this issue, we regard the age of the intertrappean beds as mostly encompassed in the interval from 29 to 27 Ma at the transition between the Early and Late Oligocene in the Ethiopia/Yemen Trap core. In marginal areas, such as SW Arabia, Eritrea and Kenya, the volcanic activity above the intertrappean beds resumed later, and its quiescence allowed a more prolonged period of sedimentation. The intertrappean beds fall in the second cooling event of the Oligocene climatic deterioration. During the contemporaneous apparent drop in the global sea-level and closure of the Tethyan Ocean between Arabia and southwestern Asia, connections were established between the African and the Eurasian continents. At that time, southwestern Asia was experiencing severe aridity with faunal exchanges toward the luxuriously vegetated eastern Africa.

  17. The Hydroclimate of East Africa: Seasonal cycle, Decadal Variability, and Human-induced Climate Change

    NASA Astrophysics Data System (ADS)

    Yang, Wenchang

    cold east SST bias over the Indian Ocean contributes to the wet OND rainfall bias in East Africa. Finally, to understand the East African regional climate in the context of the broader tropical climate and circulation, zonal momentum balance of the tropical atmospheric circulation during the global monsoon mature months (January and July) are analyzed in three dimensions based on the ERA-Interim Re-Analysis. It is found that the dominant terms in the balance of the atmospheric boundary layer (ABL) in both months are the pressure gradient force, the Coriolis force and friction. The nonlinear advection term plays a significant role only in the Asian summer monsoon regions including off East Africa. In the upper troposphere, the pressure gradient force, the Coriolis force and nonlinear advection are the dominant terms. The transient eddy force and the residual force (which can be explained as convective momentum transfer over open oceans) are secondary yet can not be neglected near the equator. Zonal mean equatorial upper troposphere easterlies are maintained by the absolute angular momentum advection associated with the cross-equatorial Hadley circulation. Equatorial upper troposphere easterlies over the Asian monsoon regions are also controllled by the absolute angular momentum advection but are mainly maintained by the pressure gradient force in January. The equivalent linear Rayleigh friction, which is widely applied in simple tropical models, is calculated and the corresponding spatial distribution of local coefficient and damping time scale are estimated from the linear regression. It is found that the linear momentum model is in general capable of crudely describing the tropical atmospheric circulation dynamics yet the caveat should be kept in mind that the friction coefficient is not uniformly distributed and is even negative in some regions.

  18. Regional aerosol deposition in human upper airways

    SciTech Connect

    Swift, D.L.

    1989-11-01

    During the report period significant progress on the quantitative understanding of regional upper airway deposition of airborne particle has been realized. Replicate models of the human upper airways obtained from post-mortem casting of the nasal, oral, pharyngeal, laryngeal and upper tracheal regions and in vivo magnetic resonance imaging (MRI) of the same regions of adults and children have been employed to determine the overall and local deposition characteristics of aerosols in the ultrafine (1--100 {mu}m diameter) and fine (0.8--12 {mu}m diameter) region. Studies have been carried out for both nasal and oral breathing during inspiratory and expiratory flow at constant flow rates representative of rest and states of exercise. The results of these investigations indicate that particles in the size range of unattached'' radon progeny (1--3 nm) are deposited in both the nasal and oral passages with high efficiency (60--80%) for both inspiration and expiration, with the nasal deposition being somewhat greater (5--10%) than oral deposition. The effect of flow rate on upper airway deposition for both pathways is not great; data analysis indicates that the deposition for all flow rates from 4--50 liters/minute can be grouped by plotting deposition vs Q-{sup 1/8}, where Q is flow rate, a far weaker dependency than observed for inertial deposition. Diffusional transport is the primary mechanism of deposition, and size dependence can be accounted for by plotting, deposition percent vs D{sup n} where D is particle diffusion coefficient and n ranges from 0.5--0.66. 2 refs.

  19. Implications of Nubian-Like Core Reduction Systems in Southern Africa for the Identification of Early Modern Human Dispersals

    PubMed Central

    Phillips, Natasha

    2015-01-01

    Lithic technologies have been used to trace dispersals of early human populations within and beyond Africa. Convergence in lithic systems has the potential to confound such interpretations, implying connections between unrelated groups. Due to their reductive nature, stone artefacts are unusually prone to this chance appearance of similar forms in unrelated populations. Here we present data from the South African Middle Stone Age sites Uitpanskraal 7 and Mertenhof suggesting that Nubian core reduction systems associated with Late Pleistocene populations in North Africa and potentially with early human migrations out of Africa in MIS 5 also occur in southern Africa during early MIS 3 and with no clear connection to the North African occurrence. The timing and spatial distribution of their appearance in southern and northern Africa implies technological convergence, rather than diffusion or dispersal. While lithic technologies can be a critical guide to human population flux, their utility in tracing early human dispersals at large spatial and temporal scales with stone artefact types remains questionable. PMID:26125972

  20. Precipitation recycling in West Africa - regional modeling, evaporation tagging and atmospheric water budget analysis

    NASA Astrophysics Data System (ADS)

    Arnault, Joel; Kunstmann, Harald; Knoche, Hans-Richard

    2015-04-01

    Many numerical studies have shown that the West African monsoon is highly sensitive to the state of the land surface. It is however questionable to which extend a local change of land surface properties would affect the local climate, especially with respect to precipitation. This issue is traditionally addressed with the concept of precipitation recycling, defined as the contribution of local surface evaporation to local precipitation. For this study the West African monsoon has been simulated with the Weather Research and Forecasting (WRF) model using explicit convection, for the domain (1°S-21°N, 18°W-14°E) at a spatial resolution of 10 km, for the period January-October 2013, and using ERA-Interim reanalyses as driving data. This WRF configuration has been selected for its ability to simulate monthly precipitation amounts and daily histograms close to TRMM (Tropical Rainfall Measuring Mission) data. In order to investigate precipitation recycling in this WRF simulation, surface evaporation tagging has been implemented in the WRF source code as well as the budget of total and tagged atmospheric water. Surface evaporation tagging consists in duplicating all water species and the respective prognostic equations in the source code. Then, tagged water species are set to zero at the lateral boundaries of the simulated domain (no inflow of tagged water vapor), and tagged surface evaporation is considered only in a specified region. All the source terms of the prognostic equations of total and tagged water species are finally saved in the outputs for the budget analysis. This allows quantifying the respective contribution of total and tagged atmospheric water to atmospheric precipitation processes. The WRF simulation with surface evaporation tagging and budgets has been conducted two times, first with a 100 km2 tagged region (11-12°N, 1-2°W), and second with a 1000 km2 tagged region (7-16°N, 6°W -3°E). In this presentation we will investigate hydro

  1. Validation of the regional climate model MAR over the CORDEX Africa domain and comparison with other regional models using unpublished data set

    NASA Astrophysics Data System (ADS)

    Prignon, Maxime; Agosta, Cécile; Kittel, Christoph; Fettweis, Xavier; Michel, Erpicum

    2016-04-01

    In the framework of the CORDEX project, we have applied the regional model MAR over the Africa domain at a resolution of 50 km. ERA-Interim and NCEP-NCAR reanalysis have been used as 6 hourly forcing at the MAR boundaries over 1950-2015. While MAR was already been validated over the West Africa, it is the first time that MAR simulations are carried out at the scale of the whole continent. Unpublished daily measurements, covering the Sahel and more areas up South, with a large set of variables, are used as validation of MAR, other CORDEX-Africa RCMs and both reanalyses. Comparisons with the CRU and the ECA&D databases are also performed. The unpublished daily data set covers the period 1884-2006 and comes from 1460 stations. The measured variables are wind, evapotranspiration, relative humidity, insolation, rain, surface pressure, temperature, vapour pressure and visibility. It covers 23 countries: Algeria, Benin, Burkina, Canary Islands, Cap Verde, Central Africa, Chad, Congo, Ivory Coast, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Mali, Mauritania, Morocco, Niger, Nigeria, Senegal, Sudan and Togo.

  2. WMO SDS-WAS NAMEE Regional Center: Towards continuous evaluation of dust models in Northern Africa

    NASA Astrophysics Data System (ADS)

    Basart, Sara; García-Castillo, Gerardo; Cuevas, Emilio; Terradellas, Enric

    2016-04-01

    One of the most important activities of the Regional Center for Northern Africa, Middle East and Europe of the World Meteorological Organization's Sand and Dust Storm Warning Advisory and Assessment System (WMO SDS-WAS, http://sds-was.aemet.es) is the dust model intercomparison and forecast evaluation, which is deemed an indispensable service to the users and an invaluable tool to assess model skills. Currently, the Regional Center collects daily dust forecasts from models run by nine partners (BSC, ECMWF, NASA, NCEP, SEEVCCC, EMA, CNR-ISAC, NOA and UK Met Office). A multi-model ensemble has also been set up in an effort to provide added-value products to the users. The first problem to address the dust model evaluation is the scarcity of suitable routine observations near the Sahara, the world's largest source of mineral dust. The present contribution presents preliminary results of dust model evaluation using new observational datasets. The current routine evaluation of dust predictions is focused on total-column dust optical depth (DOD) and uses remote-sensing retrievals from sun-photometric (AERONET) and satellite (MODIS) measurements. However, most users of dust forecasts are interested in the concentration near the surface (in the air we breathe) rather than in the total column content. Therefore, evaluation of the predicted surface concentration is also necessary. In this context, the initiative of the African Monsoon Interdisciplinary Analysis (AMMA) International Program to establish permanent measuring stations in the Sahel is extremely important. Tapered Element Oscillating Microbalance (TEOM) monitors continuously record PM10 in M'Bour (Senegal); Cinzana (Mali) and Banizoumbou (Niger). This surface model evaluation is complemented with the PM10 observation from the Air Quality Control and Monitoring Network (AQCMN) of the Canary Islands (Spain). The region, located in the sub-tropical Eastern Atlantic (roughly 100 km west of the Moroccan coast), is

  3. Pathogen-Host Associations and Predicted Range Shifts of Human Monkeypox in Response to Climate Change in Central Africa

    PubMed Central

    Thomassen, Henri A.; Fuller, Trevon; Asefi-Najafabady, Salvi; Shiplacoff, Julia A. G.; Mulembakani, Prime M.; Blumberg, Seth; Johnston, Sara C.; Kisalu, Neville K.; Kinkela, Timothée L.; Fair, Joseph N.; Wolfe, Nathan D.; Shongo, Robert L.; LeBreton, Matthew; Meyer, Hermann; Wright, Linda L.; Muyembe, Jean-Jacques; Buermann, Wolfgang; Okitolonda, Emile; Hensley, Lisa E.; Lloyd-Smith, James O.; Smith, Thomas B.; Rimoin, Anne W.

    2013-01-01

    Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX). Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC), and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4th Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts. PMID:23935820

  4. Analysis of adequacy levels for human resources improvement within primary health care framework in Africa.

    PubMed

    Parent, Florence; Fromageot, Audrey; Coppieters, Yves; Lejeune, Colette; Lemenu, Dominique; Garant, Michèle; Piette, Danielle; Levêque, Alain; De Ketele, Jean-Marie

    2005-12-01

    Human resources in health care system in sub-Saharan Africa are generally picturing a lack of adequacy between expected skills from the professionals and health care needs expressed by the populations. It is, however, possible to analyse these various lacks of adequacy related to human resource management and their determinants to enhance the effectiveness of the health care system. From two projects focused on nurse professionals within the health care system in Central Africa, we present an analytic grid for adequacy levels looking into the following aspects:- adequacy between skills-based profiles for health system professionals, quality of care and service delivery (health care system /medical standards), needs and expectations from the populations,- adequacy between allocation of health system professionals, quality of care and services delivered (health care system /medical standards), needs and expectations from the populations,- adequacy between human resource management within health care system and medical standards,- adequacy between human resource management within education/teaching/training and needs from health care system and education sectors,- adequacy between basic and on-going education and realities of tasks expected and implemented by different categories of professionals within the health care system body,- adequacy between intentions for initial and on-going trainings and teaching programs in health sciences for trainers (teachers/supervisors/health care system professionals/ directors (teaching managers) of schools...). This tool is necessary for decision-makers as well as for health care system professionals who share common objectives for changes at each level of intervention within the health system. Setting this adequacy implies interdisciplinary and participative approaches for concerned actors in order to provide an overall vision of a more broaden system than health district, small island with self-rationality, and in which they

  5. Late Stone Age human remains from Ishango (Democratic Republic of Congo): New insights on Late Pleistocene modern human diversity in Africa.

    PubMed

    Crevecoeur, I; Brooks, A; Ribot, I; Cornelissen, E; Semal, P

    2016-07-01

    Although questions of modern human origins and dispersal are subject to intense research within and outside Africa, the processes of modern human diversification during the Late Pleistocene are most often discussed within the context of recent human genetic data. This situation is due largely to the dearth of human fossil remains dating to the final Pleistocene in Africa and their almost total absence from West and Central Africa, thus limiting our perception of modern human diversification within Africa before the Holocene. Here, we present a morphometric comparative analysis of the earliest Late Pleistocene modern human remains from the Central African site of Ishango in the Democratic Republic of Congo. The early Late Stone Age layer (eLSA) of this site, dated to the Last Glacial Maximum (25-20 Ky), contains more than one hundred fragmentary human remains. The exceptional associated archaeological context suggests these remains derived from a community of hunter-fisher-gatherers exhibiting complex social and cognitive behaviors including substantial reliance on aquatic resources, development of fishing technology, possible mathematical notations and repetitive use of space, likely on a seasonal basis. Comparisons with large samples of Late Pleistocene and early Holocene modern human fossils from Africa and Eurasia show that the Ishango human remains exhibit distinctive characteristics and a higher phenotypic diversity in contrast to recent African populations. In many aspects, as is true for the inner ear conformation, these eLSA human remains have more affinities with Middle to early Late Pleistocene fossils worldwide than with extant local African populations. In addition, cross-sectional geometric properties of the long bones are consistent with archaeological evidence suggesting reduced terrestrial mobility resulting from greater investment in and use of aquatic resources. Our results on the Ishango human remains provide insights into past African modern

  6. Human Monkeypox in the Kivus, a Conflict Region of the Democratic Republic of the Congo.

    PubMed

    McCollum, Andrea M; Nakazawa, Yoshinori; Ndongala, Guy Mutombo; Pukuta, Elisabeth; Karhemere, Stomy; Lushima, Robert Shongo; Ilunga, Benoit Kebela; Kabamba, Joelle; Wilkins, Kimberly; Gao, Jinxin; Li, Yu; Emerson, Ginny; Damon, Inger K; Carroll, Darin S; Reynolds, Mary G; Malekani, Jean; Tamfum, Jean-Jacques Muyembe

    2015-10-01

    Monkeypox (MPX) is a zoonotic Orthopoxvirus infection endemic in central and western Africa. Human MPX cases occur in the central and northern regions of the Democratic Republic of the Congo (DRC), and this is the first report of confirmed MPX cases in the forested areas of North and South Kivu Provinces, with a detailed epidemiological investigation for one case. The location of each case is within areas predicted to be suitable for MPX virus transmission based on an ecological niche model. Phylogenetic analysis places these viruses in the Congo Basin clade. PMID:26283752

  7. Disentangling the relative effects of bushmeat availability on human nutrition in central Africa.

    PubMed

    Fa, John E; Olivero, Jesús; Real, Raimundo; Farfán, Miguel A; Márquez, Ana L; Vargas, J Mario; Ziegler, Stefan; Wegmann, Martin; Brown, David; Margetts, Barrie; Nasi, Robert

    2015-01-01

    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met. PMID:25639588

  8. Disentangling the relative effects of bushmeat availability on human nutrition in central Africa

    NASA Astrophysics Data System (ADS)

    Fa, John E.; Olivero, Jesús; Real, Raimundo; Farfán, Miguel A.; Márquez, Ana L.; Vargas, J. Mario; Ziegler, Stefan; Wegmann, Martin; Brown, David; Margetts, Barrie; Nasi, Robert

    2015-02-01

    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met.

  9. Disentangling the relative effects of bushmeat availability on human nutrition in central Africa

    PubMed Central

    Fa, John E.; Olivero, Jesús; Real, Raimundo; Farfán, Miguel A.; Márquez, Ana L.; Vargas, J. Mario; Ziegler, Stefan; Wegmann, Martin; Brown, David; Margetts, Barrie; Nasi, Robert

    2015-01-01

    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met. PMID:25639588

  10. Tracing the Route of Modern Humans out of Africa by Using 225 Human Genome Sequences from Ethiopians and Egyptians

    PubMed Central

    Pagani, Luca; Schiffels, Stephan; Gurdasani, Deepti; Danecek, Petr; Scally, Aylwyn; Chen, Yuan; Xue, Yali; Haber, Marc; Ekong, Rosemary; Oljira, Tamiru; Mekonnen, Ephrem; Luiselli, Donata; Bradman, Neil; Bekele, Endashaw; Zalloua, Pierre; Durbin, Richard; Kivisild, Toomas; Tyler-Smith, Chris

    2015-01-01

    The predominantly African origin of all modern human populations is well established, but the route taken out of Africa is still unclear. Two alternative routes, via Egypt and Sinai or across the Bab el Mandeb strait into Arabia, have traditionally been proposed as feasible gateways in light of geographic, paleoclimatic, archaeological, and genetic evidence. Distinguishing among these alternatives has been difficult. We generated 225 whole-genome sequences (225 at 8× depth, of which 8 were increased to 30×; Illumina HiSeq 2000) from six modern Northeast African populations (100 Egyptians and five Ethiopian populations each represented by 25 individuals). West Eurasian components were masked out, and the remaining African haplotypes were compared with a panel of sub-Saharan African and non-African genomes. We showed that masked Northeast African haplotypes overall were more similar to non-African haplotypes and more frequently present outside Africa than were any sets of haplotypes derived from a West African population. Furthermore, the masked Egyptian haplotypes showed these properties more markedly than the masked Ethiopian haplotypes, pointing to Egypt as the more likely gateway in the exodus to the rest of the world. Using five Ethiopian and three Egyptian high-coverage masked genomes and the multiple sequentially Markovian coalescent (MSMC) approach, we estimated the genetic split times of Egyptians and Ethiopians from non-African populations at 55,000 and 65,000 years ago, respectively, whereas that of West Africans was estimated to be 75,000 years ago. Both the haplotype and MSMC analyses thus suggest a predominant northern route out of Africa via Egypt. PMID:26027499

  11. Tracing the route of modern humans out of Africa by using 225 human genome sequences from Ethiopians and Egyptians.

    PubMed

    Pagani, Luca; Schiffels, Stephan; Gurdasani, Deepti; Danecek, Petr; Scally, Aylwyn; Chen, Yuan; Xue, Yali; Haber, Marc; Ekong, Rosemary; Oljira, Tamiru; Mekonnen, Ephrem; Luiselli, Donata; Bradman, Neil; Bekele, Endashaw; Zalloua, Pierre; Durbin, Richard; Kivisild, Toomas; Tyler-Smith, Chris

    2015-06-01

    The predominantly African origin of all modern human populations is well established, but the route taken out of Africa is still unclear. Two alternative routes, via Egypt and Sinai or across the Bab el Mandeb strait into Arabia, have traditionally been proposed as feasible gateways in light of geographic, paleoclimatic, archaeological, and genetic evidence. Distinguishing among these alternatives has been difficult. We generated 225 whole-genome sequences (225 at 8× depth, of which 8 were increased to 30×; Illumina HiSeq 2000) from six modern Northeast African populations (100 Egyptians and five Ethiopian populations each represented by 25 individuals). West Eurasian components were masked out, and the remaining African haplotypes were compared with a panel of sub-Saharan African and non-African genomes. We showed that masked Northeast African haplotypes overall were more similar to non-African haplotypes and more frequently present outside Africa than were any sets of haplotypes derived from a West African population. Furthermore, the masked Egyptian haplotypes showed these properties more markedly than the masked Ethiopian haplotypes, pointing to Egypt as the more likely gateway in the exodus to the rest of the world. Using five Ethiopian and three Egyptian high-coverage masked genomes and the multiple sequentially Markovian coalescent (MSMC) approach, we estimated the genetic split times of Egyptians and Ethiopians from non-African populations at 55,000 and 65,000 years ago, respectively, whereas that of West Africans was estimated to be 75,000 years ago. Both the haplotype and MSMC analyses thus suggest a predominant northern route out of Africa via Egypt. PMID:26027499

  12. From the Cover: Feature Article: Water, plants, and early human habitats in eastern Africa

    NASA Astrophysics Data System (ADS)

    Magill, Clayton R.; Ashley, Gail M.; Freeman, Katherine H.

    2013-01-01

    Water and its influence on plants likely exerted strong adaptive pressures in human evolution. Understanding relationships among water, plants, and early humans is limited both by incomplete terrestrial records of environmental change and by indirect proxy data for water availability. Here we present a continuous record of stable hydrogen-isotope compositions (expressed as δD values) for lipid biomarkers preserved in lake sediments from an early Pleistocene archaeological site in eastern Africa-Olduvai Gorge. We convert sedimentary leaf- and algal-lipid δD values into estimates for ancient source-water δD values by accounting for biochemical, physiological, and environmental influences on isotopic fractionation via published water-lipid enrichment factors for living plants, algae, and recent sediments. Reconstructed precipitation and lake-water δD values, respectively, are consistent with modern isotopic hydrology and reveal that dramatic fluctuations in water availability accompanied ecosystem changes. Drier conditions, indicated by less negative δD values, occur in association with stable carbon-isotopic evidence for open, C4-dominated grassland ecosystems. Wetter conditions, indicated by lower δD values, are associated with expanded woody cover across the ancient landscape. Estimates for ancient precipitation amounts, based on reconstructed precipitation δD values, range between approximately 250 and 700 mm.y-1 and are consistent with modern precipitation data for eastern Africa. We conclude that freshwater availability exerted a substantial influence on eastern African ecosystems and, by extension, was central to early human proliferation during periods of rapid climate change.

  13. Molecular Epidemiology of Human Rhinoviruses and Enteroviruses Highlights Their Diversity in Sub-Saharan Africa

    PubMed Central

    L’Huillier, Arnaud G.; Kaiser, Laurent; Petty, Tom J.; Kilowoko, Mary; Kyungu, Esther; Hongoa, Philipina; Vieille, Gaël; Turin, Lara; Genton, Blaise; D’Acremont, Valérie; Tapparel, Caroline

    2015-01-01

    Human rhinoviruses (HRVs) and enteroviruses (HEVs) belong to the Enterovirus genus and are the most frequent cause of infection worldwide, but data on their molecular epidemiology in Africa are scarce. To understand HRV and HEV molecular epidemiology in this setting, we enrolled febrile pediatric patients participating in a large prospective cohort assessing the causes of fever in Tanzanian children. Naso/oropharyngeal swabs were systematically collected and tested by real-time RT-PCR for HRV and HEV. Viruses from positive samples were sequenced and phylogenetic analyses were then applied to highlight the HRV and HEV types as well as recombinant or divergent strains. Thirty-eight percent (378/1005) of the enrolled children harboured an HRV or HEV infection. Although some types were predominant, many distinct types were co-circulating, including a vaccinal poliovirus, HEV-A71 and HEV-D68. Three HRV-A recombinants were identified: HRV-A36/HRV-A67, HRV-A12/HRV-A67 and HRV-A96/HRV-A61. Four divergent HRV strains were also identified: one HRV-B strain and three HRV-C strains. This is the first prospective study focused on HRV and HEV molecular epidemiology in sub-Saharan Africa. This systematic and thorough large screening with careful clinical data management confirms the wide genomic diversity of these viruses, brings new insights about their evolution and provides data about associated symptoms. PMID:26670243

  14. Fine-Scale Human Population Structure in Southern Africa Reflects Ecogeographic Boundaries.

    PubMed

    Uren, Caitlin; Kim, Minju; Martin, Alicia R; Bobo, Dean; Gignoux, Christopher R; van Helden, Paul D; Möller, Marlo; Hoal, Eileen G; Henn, Brenna M

    2016-09-01

    Recent genetic studies have established that the KhoeSan populations of southern Africa are distinct from all other African populations and have remained largely isolated during human prehistory until ∼2000 years ago. Dozens of different KhoeSan groups exist, belonging to three different language families, but very little is known about their population history. We examine new genome-wide polymorphism data and whole mitochondrial genomes for >100 South Africans from the ≠Khomani San and Nama populations of the Northern Cape, analyzed in conjunction with 19 additional southern African populations. Our analyses reveal fine-scale population structure in and around the Kalahari Desert. Surprisingly, this structure does not always correspond to linguistic or subsistence categories as previously suggested, but rather reflects the role of geographic barriers and the ecology of the greater Kalahari Basin. Regardless of subsistence strategy, the indigenous Khoe-speaking Nama pastoralists and the N|u-speaking ≠Khomani (formerly hunter-gatherers) share ancestry with other Khoe-speaking forager populations that form a rim around the Kalahari Desert. We reconstruct earlier migration patterns and estimate that the southern Kalahari populations were among the last to experience gene flow from Bantu speakers, ∼14 generations ago. We conclude that local adoption of pastoralism, at least by the Nama, appears to have been primarily a cultural process with limited genetic impact from eastern Africa. PMID:27474727

  15. Human evolution in a variable environment: the amplifier lakes of Eastern Africa

    NASA Astrophysics Data System (ADS)

    Trauth, Martin H.; Maslin, Mark A.; Deino, Alan L.; Junginger, Annett; Lesoloyia, Moses; Odada, Eric O.; Olago, Daniel O.; Olaka, Lydia A.; Strecker, Manfred R.; Tiedemann, Ralph

    2010-11-01

    The development of the Cenozoic East African Rift System (EARS) profoundly re-shaped the landscape and significantly increased the amplitude of short-term environmental response to climate variation. In particular, the development of amplifier lakes in rift basins after three million years ago significantly contributed to the exceptional sensitivity of East Africa to climate change compared to elsewhere on the African continent. Amplifier lakes are characterized by tectonically-formed graben morphologies in combination with an extreme contrast between high precipitation in the elevated parts of the catchment and high evaporation in the lake area. Such amplifier lakes respond rapidly to moderate, precessional-forced climate shifts, and as they do so apply dramatic environmental pressure to the biosphere. Rift basins, when either extremely dry or lake-filled, form important barriers for migration, mixing and competition of different populations of animals and hominins. Amplifier lakes link long-term, high-amplitude tectonic processes and short-term environmental fluctuations. East Africa may have become the place where early humans evolved as a consequence of this strong link between different time scales.

  16. Intra-continental spread of human invasive Salmonella Typhimurium pathovariants in sub-Saharan Africa

    PubMed Central

    Okoro, Chinyere K.; Kingsley, Robert A.; Connor, Thomas R.; Harris, Simon R.; Parry, Christopher M.; Al-Mashhadani, Manar N; Kariuki, Samuel; Msefula, Chisomo L.; Gordon, Melita A.; de Pinna, Elizabeth; Wain, John; Heyderman, Robert S.; Obaro, Stephen; Alonso, Pedro L.; Mandomando, Inacio; MacLennan, Calman A.; Tapia, Milagritos D.; Levine, Myron M.; Tennant, Sharon M; Parkhill, Julian; Dougan, Gordon

    2012-01-01

    A highly invasive form of non-typhoidal Salmonella (iNTS) disease has been recently documented in many countries in sub-Saharan Africa. The most common Salmonella enterica serovar causing this disease is Typhimurium. We applied whole-genome sequence-based phylogenetic methods to define the population structure of sub-Saharan African invasive Salmonella Typhimurium and compared these to global Salmonella Typhimurium isolates. Notably, the vast majority of sub-Saharan invasive Salmonella Typhimurium fell within two closely-related, highly-clustered phylogenetic lineages that we estimate emerged independently ~52 and ~35 years ago, in close temporal association with the current HIV pandemic. Clonal replacement of isolates of lineage I by lineage II was potentially influenced by the use of chloramphenicol for the treatment of iNTS disease. Our analysis suggests that iNTS disease is in part an epidemic in sub-Saharan Africa caused by highly related Salmonella Typhimurium lineages that may have occupied new niches associated with a compromised human population and antibiotic treatment. PMID:23023330

  17. The financial cost of doctors emigrating from sub-Saharan Africa: human capital analysis

    PubMed Central

    Kanters, Steve; Hagopian, Amy; Bansback, Nick; Nachega, Jean; Alberton, Mark; Au-Yeung, Christopher G; Mtambo, Andy; Bourgeault, Ivy L; Luboga, Samuel; Hogg, Robert S; Ford, Nathan

    2011-01-01

    Objective To estimate the lost investment of domestically educated doctors migrating from sub-Saharan African countries to Australia, Canada, the United Kingdom, and the United States. Design Human capital cost analysis using publicly accessible data. Settings Sub-Saharan African countries. Participants Nine sub-Saharan African countries with an HIV prevalence of 5% or greater or with more than one million people with HIV/AIDS and with at least one medical school (Ethiopia, Kenya, Malawi, Nigeria, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe), and data available on the number of doctors practising in destination countries. Main outcome measures The financial cost of educating a doctor (through primary, secondary, and medical school), assuming that migration occurred after graduation, using current country specific interest rates for savings converted to US dollars; cost according to the number of source country doctors currently working in the destination countries; and savings to destination countries of receiving trained doctors. Results In the nine source countries the estimated government subsidised cost of a doctor’s education ranged from $21 000 (£13 000; €15 000) in Uganda to $58 700 in South Africa. The overall estimated loss of returns from investment for all doctors currently working in the destination countries was $2.17bn (95% confidence interval 2.13bn to 2.21bn), with costs for each country ranging from $2.16m (1.55m to 2.78m) for Malawi to $1.41bn (1.38bn to 1.44bn) for South Africa. The ratio of the estimated compounded lost investment over gross domestic product showed that Zimbabwe and South Africa had the largest losses. The benefit to destination countries of recruiting trained doctors was largest for the United Kingdom ($2.7bn) and United States ($846m). Conclusions Among sub-Saharan African countries most affected by HIV/AIDS, lost investment from the emigration of doctors is considerable. Destination countries should

  18. Field Epidemiology and Laboratory Training Programs in West Africa as a model for sustainable partnerships in animal and human health.

    PubMed

    Becker, Karen M; Ohuabunwo, Chima; Ndjakani, Yassa; Nguku, Patrick; Nsubuga, Peter; Mukanga, David; Wurapa, Frederick

    2012-09-01

    The concept of animal and human health experts working together toward a healthier world has been endorsed, but challenges remain in identifying concrete actions to move this one health concept from vision to action. In 2008, as a result of avian influenza outbreaks in West Africa, international donor support led to a unique opportunity to invest in Field Epidemiology and Laboratory Training Programs (FELTPs) in the region that engaged the animal and human health sectors to strengthen the capacity for prevention and control of zoonotic diseases. The FELTPs mixed 25% to 35% classroom and 65% to 75% field-based training and service for cohorts of physicians, veterinarians, and laboratory scientists. They typically consisted of a 2-year course leading to a master's degree in field epidemiology and public health laboratory management for midlevel public health leaders and competency-based short courses for frontline public health surveillance workers. Trainees and graduates work in multidisciplinary teams to conduct surveillance, outbreak investigations, and epidemiological studies for disease control locally and across borders. Critical outcomes of these programs include development of a cadre of public health leaders with core skills in integrated disease surveillance, outbreak investigation, vaccination campaigns, laboratory diagnostic testing, and epidemiological studies that address priority public health problems. A key challenge exists in identifying ways to successfully scale up and transform this innovative donor-driven program into a sustainable multisectoral one health workforce capacity development model. PMID:22916854

  19. The Great Karoo region of South Africa: A carbon source or sink?

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus; Greenwood, Philip; Kuhn, Brigitte; Boardman, John; Foster, Ian; Meadows, Mike

    2014-05-01

    Work undertaken in the seasonally arid upland areas of the Great Karoo region of South Africa has established a link between land degradation and overgrazing that began approximately 200 years ago when European farmers first settled the area. In response to changing land use, coupled with shifting rainfall patterns, parts of the landscape are now characterised by badlands on footslopes of valley-sides and complex gully systems on valley floors. Limited precipitation and agricultural intensification, particularly from around the 1920s onwards, resulted in a growing demand for water, and led to the construction of many small reservoirs, most of which are now in-filled with sediment. Whilst the deposited material has provided a means of linking catchment-scale responses to land use changes over the last ca. 100 years, the influence of land degradation on erosion and deposition of soil-associated carbon (C) has received only limited attention. Despite a reversion to extensive agriculture and reduced livestock densities in certain areas, limited vegetation regrowth suggests that soil rehabilitation will be a long-term process. This communication presents preliminary results from an investigation to determine whether land degradation in the Karoo has resulted in a shift from a net sink of C to a net source of C. Sediment deposits from a silted-up reservoir in a small dry valley system was analysed for varying physicochemical parameters. Total Carbon (TC) content was recorded and the sharp decrease in total C content with decreasing depth suggests that land degradation during and after post-European settlement probably led to accelerated erosion of the relatively fertile surface soils, and this presumably resulted in the rapid in-filling of reservoirs with carbon-rich surface material. Overall, the results indicate a sharp decline in soil organic matter (SOM) of eroded material, presumably as a consequence of land degradation. This suggests that in landscapes such as the

  20. Explaining the Ordinary Magic of Stable African Multilingualism in the Vaal Triangle Region in South Africa

    ERIC Educational Resources Information Center

    Coetzee-Van Rooy, Susan

    2014-01-01

    The academic and public debates about language maintenance and language shift in the post-1994 South Africa distract attention from the more productive and important endeavour of explaining the nature of the multilingualism observed among users of African languages in urban contexts. An explanation for this phenomenon is offered here, based on…

  1. Future changes in African temperature and precipitation in an ensemble of Africa-CORDEX regional climate model simulations

    NASA Astrophysics Data System (ADS)

    Kjellström, Erik; Nikulin, Grigory; Gbobaniyi, Emiola; Jones, Colin

    2013-04-01

    In this study we investigate possible changes in temperature and precipitation on a regional scale over Africa from 1961 to 2100. We use data from two ensembles of climate simulations, one global and one regional, over the Africa-CORDEX domain. The global ensemble includes eight coupled atmosphere ocean general circulation models (AOGCMs) from the CMIP5 project with horizontal resolution varying from about 1° to 3°, namely CanESM2, CNRM-CM5, HadGEM2-ES, NorESM1-M, EC-EARTH, MIROC5, GFDL-ESM2M and MPI-ESM-LR. In the regional ensemble all 8 AOGCMs are downscaled at the Rossby Centre (SMHI) by a regional climate model - RCA4 at 0.44° resolution. Two forcing scenarios are considered, RCP 4.5 and 8.5. The experimental setup allows us to illustrate how uncertainties in future climate change are related to forcing scenario and to forcing AOGCM at different time periods. Further, we investigate the benefit of the higher horizontal resolution in RCA4 by comparing the results to the coarser driving AOGCM data. The significance of the results is investigated by comparing to i) the model simulated natural variability, and, ii) the biases in the control period. Results dealing with changes in the seasonal cycle of temperature and precipitation are presented. We also address higher-order variability by showing results for changes in temperature extremes and for changes in intensity and frequency of extreme precipitation.

  2. Human-associated Staphylococcus aureus strains within great ape populations in Central Africa (Gabon).

    PubMed

    Nagel, M; Dischinger, J; Türck, M; Verrier, D; Oedenkoven, M; Ngoubangoye, B; Le Flohic, G; Drexler, J F; Bierbaum, G; Gonzalez, J-P

    2013-11-01

    The risk of serious infections caused by Staphylococcus aureus is well-known. However, most studies regarding the distribution of (clinically relevant) S. aureus among humans and animals took place in the western hemisphere and only limited data are available from (Central) Africa. In this context, recent studies focused on S. aureus strains in humans and primates, but the question of whether humans and monkeys share related S. aureus strains or may interchange strains remained largely unsolved. In this study we aimed to evaluate the distribution and spread of human-like S. aureus strains among great apes living in captivity. Therefore, a primate facility at the International Centre for Medical Research of Franceville (Gabon) was screened. We detected among the primates a common human S. aureus strain, belonging to the spa-type t148. It was isolated from three different individuals of the western lowland gorilla (Gorilla gorilla gorilla), of which one individual showed a large necrotizing wound. This animal died, most probably of a staphylococcal sepsis. Additionally, we discovered the t148 type among chimpanzees (Pan troglodytes) that were settled in the immediate neighbourhood of the infected gorillas. A detailed analysis by pulsed field gel electrophoresis showed that the gorilla and chimpanzee isolates represented two closely related strains. To our knowledge, this is the first report of a human-associated S. aureus strain causing disease in great apes. The simultaneous detection in gorillas and chimpanzees indicated an interspecies transmission of this S. aureus strain. Our results recommend that protection of wild animals must not only be based on habitat conservation, but also on the assessment of the risk of contact with human pathogens. PMID:23398468

  3. The relationship between human security, demand for arms and disarmament in the horn of Africa.

    PubMed

    Gebrewold, Kiflemariam

    2002-01-01

    The drive to find security through possession of weapons is linked to the history and culture of a social group. Amongst pastoralists in the Horn of Africa there is a failure of security through state systems such as police and the recent replacement of less-lethal traditional weapons by small arms and other light weapons. A warrior or vendetta culture with these arms leads to violent inter-clan clashes with many casualties, although traditional methods of weapons control still seem operational within clans. Understanding the drive to seek weapons is essential in finding ways to control their use. Improving the capacities of the police must come hand in hand with human rights training and an end to corruption. Further work is required on how traditional methods of arms control can be co-operatively linked with state controls. PMID:12498403

  4. Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa

    PubMed Central

    Okoro, Chinyere K.; Barquist, Lars; Connor, Thomas R.; Harris, Simon R.; Clare, Simon; Stevens, Mark P.; Arends, Mark J.; Hale, Christine; Kane, Leanne; Pickard, Derek J.; Hill, Jennifer; Harcourt, Katherine; Parkhill, Julian; Dougan, Gordon; Kingsley, Robert A.

    2015-01-01

    Two lineages of Salmonella enterica serovar Typhimurium (S. Typhimurium) of multi-locus sequence type ST313 have been linked with the emergence of invasive Salmonella disease across sub-Saharan Africa. The expansion of these lineages has a temporal association with the HIV pandemic and antibiotic usage. We analysed the whole genome sequence of 129 ST313 isolates representative of the two lineages and found evidence of lineage-specific genome degradation, with some similarities to that observed in S. Typhi. Individual ST313 S. Typhimurium isolates exhibit a distinct metabolic signature and modified enteropathogenesis in both a murine and cattle model of colitis, compared to S. Typhimurium outside of the ST313 lineages. These data define phenotypes that distinguish ST313 isolates from other S. Typhimurium and may represent adaptation to a distinct pathogenesis and lifestyle linked to an-immuno-compromised human population. PMID:25803844

  5. Spatial epidemiology of human schistosomiasis in Africa: risk models, transmission dynamics and control☆

    PubMed Central

    Brooker, Simon

    2007-01-01

    Summary This paper reviews recent studies on the spatial epidemiology of human schistosomiasis in Africa. The integrated use of geographical information systems, remote sensing and geostatistics has provided new insights into the ecology and epidemiology of schistosomiasis at a variety of spatial scales. Because large-scale patterns of transmission are influenced by climatic conditions, an increasing number of studies have used remotely sensed environmental data to predict spatial distributions, most recently using Bayesian methods of inference. Such data-driven approaches allow for a more rational implementation of intervention strategies across the continent. It is suggested that improved incorporation of transmission dynamics into spatial models and assessment of uncertainties inherent in data and modelling approaches represent important future research directions. PMID:17055547

  6. Recruitment and Selection Strategies in Optometric Education towards Addressing Human Resource Disparities in Sub-Saharan Africa

    ERIC Educational Resources Information Center

    Moodley, V. R.; Loughman, James; Naidoo, K. S.

    2015-01-01

    The dire need for eye care services and a dearth of human resources (HR) in sub-Saharan Africa motivated the setting up of new optometry programmes. However, to make a meaningful impact, geographical, gender, economic and educational disparities must additionally be addressed. A qualitative study utilizing purposive sampling to select academic…

  7. Human Resources Development and the Skills Crisis in South Africa: The Need for a Multi-Pronged Strategy

    ERIC Educational Resources Information Center

    Kraak, Andre

    2005-01-01

    This article presents a critique of the 'high skills' argument which, in the international literature, presents a high skill strategy as an adjunct and necessary condition for the successful expansion of human resources development (HRD) alongside social market institutions and 'joined up' policy. For a developing country such as South Africa,…

  8. Genome Sequences for a Cluster of Human Isolates of Listeria monocytogenes Identified in South Africa in 2015

    PubMed Central

    Naicker, Preneshni; Bamford, Colleen; Shuping, Liliwe; McCarthy, Kerrigan M.; Sooka, Arvinda; Smouse, Shannon L.; Tau, Nomsa; Keddy, Karen H.

    2016-01-01

    Listeria monocytogenes is a Gram-positive bacterium with a ubiquitous presence in the environment. There is growing concern about the increasing prevalence of L. monocytogenes associated with food-borne outbreaks. Here we report genome sequences for a cluster of human isolates of L. monocytogenes identified in South Africa in 2015. PMID:27056221

  9. Variability and trends of local/regional scale surface climate in northern Africa during the twentieth century

    NASA Astrophysics Data System (ADS)

    Djomou, Zéphirin Yepdo; Monkam, David; Woafo, Paul

    2014-08-01

    Four regions are detected in northern Africa (20° W-40° E, 0-30° N) by applying the cluster analysis method on the annual rainfall anomalies of the period 1901-2000. The first region (R1), an arid land, covers essentially the north of 17.75° N from west to east of the study zone. The second region (R2), a semiarid land with a Sahelian climate, less warm than the dry climate of R1, is centred on Chad, with almost regular extension to the west towards Mauritania, and to the east, including the north of the Central African Republic and the Sudan. The region 3 (R3), a wet land, is centred on the Ivory Coast and covers totally Liberia, the south part of Ghana, Togo, Benin and the southwest of Nigeria. The fourth region (R4), corresponding to the wet equatorial forest, covers a part of Senegal, the Central Africa, the south of Sudan and a part of Ethiopia. An analysis of observed temperature and precipitation variability and trends throughout the twentieth century over these regions is presented. Summer, winter and annual data are examined using a range of variability measures. Statistically, significant warming trends are found over the majority of regions. The trends have a magnitude of up to 1.5 K per century. Only a few precipitation trends are statistically significant. Regional temperature and precipitation show pronounced variability at scales from interannual to multi-decadal. The interannual variability shows significant variations and trends throughout the century, the latter being mostly negative for precipitation and both positive and negative for temperature. Temperature and precipitation anomalies show a chaotic-type behaviour in which the regional conditions oscillate around the long-term mean trend and occasionally fall into long-lasting (up to 10 years or more) anomaly regimes. A generally modest temporal correlation is found between anomalies of different regions and between temperature and precipitation anomalies for the same region. This

  10. The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis

    PubMed Central

    2010-01-01

    Background This is the second in a series of three articles documenting the geographical distribution of 41 dominant vector species (DVS) of human malaria. The first paper addressed the DVS of the Americas and the third will consider those of the Asian Pacific Region. Here, the DVS of Africa, Europe and the Middle East are discussed. The continent of Africa experiences the bulk of the global malaria burden due in part to the presence of the An. gambiae complex. Anopheles gambiae is one of four DVS within the An. gambiae complex, the others being An. arabiensis and the coastal An. merus and An. melas. There are a further three, highly anthropophilic DVS in Africa, An. funestus, An. moucheti and An. nili. Conversely, across Europe and the Middle East, malaria transmission is low and frequently absent, despite the presence of six DVS. To help control malaria in Africa and the Middle East, or to identify the risk of its re-emergence in Europe, the contemporary distribution and bionomics of the relevant DVS are needed. Results A contemporary database of occurrence data, compiled from the formal literature and other relevant resources, resulted in the collation of information for seven DVS from 44 countries in Africa containing 4234 geo-referenced, independent sites. In Europe and the Middle East, six DVS were identified from 2784 geo-referenced sites across 49 countries. These occurrence data were combined with expert opinion ranges and a suite of environmental and climatic variables of relevance to anopheline ecology to produce predictive distribution maps using the Boosted Regression Tree (BRT) method. Conclusions The predicted geographic extent for the following DVS (or species/suspected species complex*) is provided for Africa: Anopheles (Cellia) arabiensis, An. (Cel.) funestus*, An. (Cel.) gambiae, An. (Cel.) melas, An. (Cel.) merus, An. (Cel.) moucheti and An. (Cel.) nili*, and in the European and Middle Eastern Region: An. (Anopheles) atroparvus, An. (Ano

  11. Seasonal Scale Water Deficit Forecasting in East Africa and the Middle East Region Using the NMME Models Forecasts

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Funk, C. C.; Zaitchik, B. F.; Narapusetty, B.; Arsenault, K. R.; Peters-Lidard, C. D.

    2015-12-01

    In this presentation we report on our ongoing efforts to provide seasonal scale water deficit forecasts in East Africa and the Middle East regions. First, we report on the skill of the seasonal climate forecasts from the North American Multimodel Ensemble (NMME) models over this region. We evaluated deterministic (anomaly correlation), categorical (the equitable threat score) and probabilistic (the ranked probabilistic skill score) skill of the NMME models forecasts over the hindcast period of 1982-2010, focusing on the primary rainy seasons of March-May (MAM), July-September (JAS) and October-December (OND). We also examined the potential predictability of the NMME models using the anomaly correlation between the ensemble mean forecasts from a given model against a single ensemble member of the same model (homogenous predictability) and rest of the models (heterogeneous predictability), and observations (forecast skill). Overall, we found precipitation forecast skill in this region to be sparse and limited (up to three month of lead) to some locations and seasons, and temperature forecast skill to be much more skillful than the precipitation forecast skill. Highest level of skill exists over equatorial East Africa (OND season) and over parts of northern Ethiopia and southern Sudan (JAS season). Categorical and probabilistic forecast skills are also higher in those regions. We found the homogeneous predictability to be greater than the forecast skill indicating potential for forecast skill improvement. In the rest of the presentation we describe implementation and evaluation of a hybrid approach (that combines statistical and dynamical approaches) of downscaling climate forecasts to improve the precipitation forecast skill in this region. For this part of the analysis we mainly focus on two of the NMME models (NASA's GMAO and NCEP's CFSv2). Past research on a hybrid approach focusing only over equatorial East Africa has shown promising results. We found that MAM

  12. The Ysterfontein 1 Middle Stone Age site, South Africa, and early human exploitation of coastal resources.

    PubMed

    Klein, Richard G; Avery, Graham; Cruz-Uribe, Kathryn; Halkett, David; Parkington, John E; Steele, Teresa; Volman, Thomas P; Yates, Royden

    2004-04-20

    Human fossils and the genetics of extant human populations indicate that living people derive primarily from an African population that lived within the last 200,000 years. Yet it was only approximately 50,000 years ago that the descendants of this population spread to Eurasia, where they swamped or replaced the Neanderthals and other nonmodern Eurasians. Based on archaeological observations, the most plausible hypothesis for the delay is that Africans and Eurasians were behaviorally similar until 50,000 years ago, and it was only at this time that Africans developed a behavioral advantage. The archaeological findings come primarily from South Africa, where they suggest that the advantage involved much more effective use of coastal resources. Until now, the evidence has come mostly from deeply stratified caves on the south (Indian Ocean) coast. Here, we summarize results from recent excavations at Ysterfontein 1, a deeply stratified shelter in a contrasting environment on the west (Atlantic) coast. The Ysterfontein 1 samples of human food debris must be enlarged for a full comparison to samples from other relevant sites, but they already corroborate two inferences drawn from south coast sites: (i) coastal foragers before 50,000 years ago did not fish routinely, probably for lack of appropriate technology, and (ii) they collected tortoises and shellfish less intensively than later people, probably because their populations were smaller. PMID:15007171

  13. From the Cover: Feature Article: Ecosystem variability and early human habitats in eastern Africa

    NASA Astrophysics Data System (ADS)

    Magill, Clayton R.; Ashley, Gail M.; Freeman, Katherine H.

    2013-01-01

    The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma-the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ13C values) of lipid biomarkers from ancient plants. Within this framework, δ13C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C4 grasslands abruptly transitioned to closed C3 forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth's orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution.

  14. The Ysterfontein 1 Middle Stone Age site, South Africa, and early human exploitation of coastal resources

    PubMed Central

    Klein, Richard G.; Avery, Graham; Cruz-Uribe, Kathryn; Halkett, David; Parkington, John E.; Steele, Teresa; Volman, Thomas P.; Yates, Royden

    2004-01-01

    Human fossils and the genetics of extant human populations indicate that living people derive primarily from an African population that lived within the last 200,000 years. Yet it was only ≈50,000 years ago that the descendants of this population spread to Eurasia, where they swamped or replaced the Neanderthals and other nonmodern Eurasians. Based on archaeological observations, the most plausible hypothesis for the delay is that Africans and Eurasians were behaviorally similar until 50,000 years ago, and it was only at this time that Africans developed a behavioral advantage. The archaeological findings come primarily from South Africa, where they suggest that the advantage involved much more effective use of coastal resources. Until now, the evidence has come mostly from deeply stratified caves on the south (Indian Ocean) coast. Here, we summarize results from recent excavations at Ysterfontein 1, a deeply stratified shelter in a contrasting environment on the west (Atlantic) coast. The Ysterfontein 1 samples of human food debris must be enlarged for a full comparison to samples from other relevant sites, but they already corroborate two inferences drawn from south coast sites: (i) coastal foragers before 50,000 years ago did not fish routinely, probably for lack of appropriate technology, and (ii) they collected tortoises and shellfish less intensively than later people, probably because their populations were smaller. PMID:15007171

  15. Can differences in heat flow between east and southern Africa be easily interpreted?: Implications for understanding regional variability in continental heat flow

    NASA Astrophysics Data System (ADS)

    Nyblade, Andrew A.; Pollack, Henry N.

    1993-03-01

    We address the extent to which regional variations in continental heat flow can be interpreted, making use of a heat flow data set from east and southern Africa. The first-order observation deriving from these heat flow measurements is a common pattern characterized in both regions by low heat flow in Archean cratons and higher heat flow in younger mobile belts. Two regional differences between east and southern Africa are superimposed on this common heat flow pattern: (1) heat flow in the Tanzania Craton is about 13 mW m -2 lower than in the Kalahari Craton, and (2) heat flow in the Mozambique Belt in east Africa is about 9 mW m -2 lower than in the southern African mobile belts, within about 250 km of the respective Archean cratons. The differences in heat flow between east and southern Africa suggest that the thermal structure of the lithosphere beneath these regions differs somewhat, and we attempt to resolve these differences in lithospheric thermal structure by examining four explanations that could account for the heat flow observations: (1) diminished heat flow in shallow boreholes in east Africa; (2) less crustal heat production in the regions of lower heat flow; (3) thicker lithosphere beneath the regions of lower heat flow; (4) cooler mantle beneath the areas of lower heat flow. We find it difficult to interpret uniquely the heat flow differences between east and southern Africa because available constraints on crustal heat production, crustal structure, lithospheric thickness and mantle temperatures are insufficient to discriminate among the possible explanations. Hence, extracting significant information about lithospheric thermal structure from regional heat flow variations requires more ancillary geochemical and geophysical information than Africa presently offers.

  16. Adiposity and human regional body temperature123

    PubMed Central

    Savastano, David M; Gorbach, Alexander M; Eden, Henry S; Brady, Sheila M; Reynolds, James C

    2009-01-01

    Background: Human obesity is associated with increased heat production; however, subcutaneous adipose tissue provides an insulating layer that impedes heat loss. To maintain normothermia, therefore, obese individuals must increase their heat dissipation. Objective: The objective was to test the hypothesis that temperature in a heat-dissipating region of the hand is elevated in obese adults. Design: Obese [body mass index (in kg/m2) ≥ 30] and normal-weight (NW; body mass index = 18–25) adults were studied under thermoneutral conditions at rest. Core body temperature was measured by using ingested telemetric capsules. The temperatures of the third fingernail bed of the right hand and of abdominal skin from an area 1.5 cm inferior to the umbilicus were determined by using infrared thermography. Abdominal skin temperatures were also measured via adhesive thermistors that were placed over a prominent skin-surface blood vessel and over an adjacent nonvessel location. The groups were compared by analysis of covariance with age, sex, race, and room temperature as covariates. Results: Core temperature did not differ significantly between the 23 obese and 13 NW participants (P = 0.74). However, infrared thermography–measured fingernail-bed temperature was significantly higher in obese subjects than in NW subjects (33.9 ± 0.7°C compared with 28.6 ± 0.9°C; P < 0.001). Conversely, infrared thermography–measured abdominal skin temperature was significantly lower in obese subjects than in NW subjects (31.8 ± 0.2°C compared with 32.8 ± 0.3°C; P = 0.02). Nonvessel abdominal skin temperatures measured by thermistors were also lower in obese subjects (P = 0.04). Conclusions: Greater subcutaneous abdominal adipose tissue in obese adults may provide a significant insulating layer that blunts abdominal heat transfer. Augmented heat release from the hands may offset heat retention in areas of the body with greater adiposity, thereby helping to maintain normothermia in

  17. Malaria control in the African Region: perceptions and viewspoints on proceedings of the Africa Leaders Malaria Alliance (ALMA)

    PubMed Central

    2011-01-01

    Union and regional economic communities to address the cross-border dimension of malaria control. It was agreed that countries needed to secure adequate domestic and external funding for sustained commitment to malaria elimination; strengthen national malaria control programmes in the context of broader health system strengthening; ensure free access to long-lasting insecticide treated nets and malaria diagnosis and treatment for vulnerable groups; strengthen human resource capacity at central, district and community levels; and establish strong logistics, information and surveillance systems. Conclusion It is critically important for countries to have a clear vision and strategy for malaria elimination; effective leadership of national malaria control programmes; draw lessons from other African countries that have succeeded to dramatically reduce the burden of malaria; and sustain funding and ongoing interventions. PMID:21810213

  18. A humid corridor across the Sahara for the migration of early modern humans out of Africa 120,000 years ago

    PubMed Central

    Osborne, Anne H.; Vance, Derek; Rohling, Eelco J.; Barton, Nick; Rogerson, Mike; Fello, Nuri

    2008-01-01

    It is widely accepted that modern humans originated in sub-Saharan Africa ≈150–200 thousand years ago (ka), but their route of dispersal across the currently hyperarid Sahara remains controversial. Given that the first modern humans north of the Sahara are found in the Levant ≈120–90 ka, northward dispersal likely occurred during a humid episode in the Sahara within Marine Isotope Stage (MIS) 5e (130–117 ka). The obvious dispersal route, the Nile, may be ruled out by notable differences between archaeological finds in the Nile Valley and the Levant at the critical time. Further west, space-born radar images reveal networks of—now buried—fossil river channels that extend across the desert to the Mediterranean coast, which represent alternative dispersal corridors. These corridors would explain scattered findings at desert oases of Middle Stone Age Aterian lithic industries with bifacial and tanged points that can be linked with industries further to the east and as far north as the Mediterranean coast. Here we present geochemical data that demonstrate that water in these fossil systems derived from the south during wet episodes in general, and penetrated all of the way to the Mediterranean during MIS 5e in particular. This proves the existence of an uninterrupted freshwater corridor across a currently hyperarid region of the Sahara at a key time for early modern human migrations to the north and out of Africa. PMID:18936490

  19. Mapping human resources for eye health in 21 countries of sub-Saharan Africa: current progress towards VISION 2020

    PubMed Central

    2014-01-01

    Background Development of human resources for eye health (HReH) is a major focus of the Global Action Plan 2014 to 2019 to reduce the prevalence of avoidable visual impairment by 25% by the year 2019. The eye health workforce is thought to be much smaller in sub-Saharan Africa than in other regions of the world but data to support this for policy-making is scarce. We collected HReH and cataract surgeries data from 21 countries in sub-Sahara to estimate progress towards key suggested population-based VISION 2020 HReH indicators and cataract surgery rates (CSR) in 2011. Methods Routinely collected data on practitioner and surgery numbers in 2011 was requested from national eye care coordinators via electronic questionnaires. Telephone and e-mail discussions were used to determine data collection strategies that fit the national context and to verify reported data quality. Information was collected on six practitioner cadres: ophthalmologists, cataract surgeons, ophthalmic clinical officers, ophthalmic nurses, optometrists and ‘mid-level refractionists’ and combined with publicly available population data to calculate practitioner to population ratios and CSRs. Associations with development characteristics were conducted using Wilcoxon rank sum tests and Spearman rank correlations. Results HReH data was not easily available. A minority of countries had achieved the suggested VISION 2020 targets in 2011; five countries for ophthalmologists/cataract surgeons, four for ophthalmic nurses/clinical officers and two for CSR. All countries were below target for optometrists, even when other cadres who perform refractions as a primary duty were considered. The regional (sample) ratio for surgeons (ophthalmologists and cataract surgeons) was 2.9 per million population, 5.5 for ophthalmic clinical officers and nurses, 3.7 for optometrists and other refractionists, and 515 for CSR. A positive correlation between GDP and CSR as well as many practitioner ratios was observed

  20. The Impact of Human Activities on Microbial Quality of Rivers in the Vhembe District, South Africa

    PubMed Central

    Traoré, Afsatou N.; Mulaudzi, Khodani; Chari, Gamuchirai J.E.; Foord, Stefan H.; Mudau, Lutendo S.; Barnard, Tobias G.; Potgieter, Natasha

    2016-01-01

    Background: Water quality testing is dictated by microbial agents found at the time of sampling in reference to their acceptable risk levels. Human activities might contaminate valuable water resources and add to the microbial load present in water bodies. Therefore, the effects of human activities on the microbial quality of rivers collected from twelve catchments in the Vhembe District in South Africa were investigated, with samples analyzed for total coliform (TC) and Eschericha coli (E. coli) contents. Methods: Physical parameters and various human activities were recorded for each sampling site. The Quanti-Tray® method was adopted for the assessment of TC and E. coli contents in the rivers over a two-year period. A multiplex polymerase chain (PCR) method was used to characterize the strains of E. coli found. Results: The microbial quality of the rivers was poor with both TC and E. coli contents found to be over acceptable limits set by the South African Department of Water and Sanitation (DWS). No significant difference (p > 0.05) was detected between TC and E. coli risks in dry and wet seasons. All six pathogenic E. coli strains were identified and Enteroaggregative E. coli (EAEC), atypical Enteropathogenic E. coli (a-EPEC) and Enterotoxigenic E. coli (ETEC) were the most prevalent E. coli strains detected (respectively, 87%, 86% and 83%). Conclusions: The study indicated that contamination in the majority of sampling sites, due to human activities such as car wash, animal grazing and farming, poses health risks to communities using the rivers for various domestic chores. It is therefore recommended that more education by the respective departments is done to avert pollution of rivers and prevent health risks to the communities in the Vhembe District. PMID:27529265

  1. Out of Africa: modern human origins special feature: the spread of modern humans in Europe.

    PubMed

    Hoffecker, John F

    2009-09-22

    The earliest credible evidence of Homo sapiens in Europe is an archaeological proxy in the form of several artifact assemblages (Bohunician) found in South-Central and possibly Eastern Europe, dating to < or =48,000 calibrated radiocarbon years before present (cal BP). They are similar to assemblages probably made by modern humans in the Levant (Emiran) at an earlier date and apparently represent a population movement into the Balkans during a warm climate interval [Greenland Interstadial 12 (GI 12)]. A second population movement may be represented by a diverse set of artifact assemblages (sometimes termed Proto-Aurignacian) found in the Balkans, parts of Southwest Europe, and probably in Eastern Europe, and dating to several brief interstadials (GI 11-GI 9) that preceded the beginning of cold Heinrich Event 4 (HE4) (approximately 40,000 cal BP). They are similar to contemporaneous assemblages made by modern humans in the Levant (Ahmarian). The earliest known human skeletal remains in Europe that may be unequivocally assigned to H. sapiens (Peçstera cu Oase, Romania) date to this time period (approximately 42,000 cal BP) but are not associated with artifacts. After the Campanian Ignimbrite volcanic eruption (40,000 cal BP) and the beginning of HE4, artifact assemblages assigned to the classic Aurignacian, an industry associated with modern human skeletal remains that seems to have developed in Europe, spread throughout the continent. PMID:19571003

  2. Vegetation-climate feedback causes reduced precipitation in CMIP5 regional Earth system model simulation over Africa

    NASA Astrophysics Data System (ADS)

    Wu, Minchao; Smith, Benjamin; Schurgers, Guy; Lindström, Joe; Rummukainen, Markku; Samuelsson, Patrick

    2013-04-01

    Terrestrial ecosystems have been demonstrated to play a significant role within the climate system, amplifying or dampening climate change via biogeophysical and biogeochemical exchange with the atmosphere and vice versa (Cox et al. 2000; Betts et al. 2004). Africa is particularly vulnerable to climate change and studies of vegetation-climate feedback mechanisms on Africa are still limited. Our study is the first application of A coupled Earth system model at regional scale and resolution over Africa. We applied a coupled regional climate-vegetation model, RCA-GUESS (Smith et al. 2011), over the CORDEX Africa domain, forced by boundary conditions from a CanESM2 CMIP5 simulation under the RCP8.5 future climate scenario. The simulations were from 1961 to 2100 and covered the African continent at a horizontal grid spacing of 0.44°. RCA-GUESS simulates changes in the phenology, productivity, relative cover and population structure of up to eight plant function types (PFTs) in response to forcing from the climate part of the model. These vegetation changes feedback to simulated climate through dynamic adjustments in surface energy fluxes and surface properties. Changes in the net ecosystem-atmosphere carbon flux and its components net primary production (NPP), heterotrophic respiration and emissions from biomass burning were also simulated but do not feedback to climate in our model. Constant land cover was assumed. We compared simulations with and without vegetation feedback switched "on" to assess the influence of vegetation-climate feedback on simulated climate, vegetation and ecosystem carbon cycling. Both positive and negative warming feedbacks were identified in different parts of Africa. In the Sahel savannah zone near 15°N, reduced vegetation cover and productivity, and mortality caused by a deterioration of soil water conditions led to a positive warming feedback mediated by decreased evapotranspiration and increased sensible heat flux between vegetation and

  3. Regional generalisations about the relationships between the environment and foraminifera along the SW Cape coast, South Africa.

    PubMed

    Toefy, R; Gibbons, M J

    2014-03-15

    Factors influencing the composition of shallow water benthic foraminifera along the SW coast of South Africa at two locations (Table Bay, TB; St Helena Bay, SHB) ∼200km from each other were examined. Small taxa dominated in both locations; living assemblages from SHB (28 species, Ammonia parkinsoniana dominant) differed from TB (34 species, Elphidium articulatum dominant). Environmental parameters were similar in both areas. Patchiness in assemblage structure was pronounced, differences between pipeline and non-pipeline sites within locations were evident in environmental parameters. Diversity was significantly correlated with grain size, the nitrogen and heavy metal content (especially Cd). These data represent the first for extant benthic Foraminifera from the southern Benguela upwelling area and is the first attempt at using foraminifera as indicators of pollution in this region. The data stressed the need for more than one sampling location to better understand the factors influencing foraminiferal assemblages in any regional context. PMID:24393379

  4. Consistent rainy season changes predicted from Regional Climate Models ensembles indicate threats to crop production in West Africa

    NASA Astrophysics Data System (ADS)

    Wisser, D.; Sylla, M. B.; Ibrahim, B.

    2014-12-01

    Agricultural production in West Africa is extremely vulnerable to precipitation change and variability. Designing adaptation options to anticipate these changes in precipitation requires robust predicting future climate conditions. Output from Global Circulation Models (GCMs) is too coarse to be used directly to assess regional and high order statistics changes. We use output from a set of Regional Climate Models that dynamically downscale CMIP5 GCMs and analyze mid-century changes in the characteristics of precipitation in West Africa over cropland areas. For each RCM/GCM combinations, we compared predicted precipitation for the period 2035-2065 under the RCP 8.5 scenario with its historical reconstruction of 1975-2005. The mean changes emerging from an analysis of the ensemble of 15 RCM/GCM combinations suggest moderate (~3%) increases in annual precipitation,a very consistent delay in the onset of the rainy season (1 to 4 days from South to North) and no consistent change in the ending of the rainy season. This illustrates a general shortening of the rainy season. An analysis of dry spells (periods of consecutive days with less than 5 mm) for a durations of between 5 and 15 days revealed an increased probability of experiencing longer dry spells during the rainy season in the future climate, coupled with a general intensification of precipitation. This finding was consistent across all models. Our analysis promotes regional prioritization of adaptation measures to the changes in precipitation characteristics that could potentially have detrimental effects on crop yields while also affecting water resources management, species distribution, and others sectors. Increased storage of water, in combination with supplemental irrigation can be an important mechanism for adapting to the effects for regional precipitation changes on crop yield.

  5. The hydrological cycle of the Niger River basin simulated by the CORDEX-Africa regional climate models

    NASA Astrophysics Data System (ADS)

    Mascaro, G.; White, D. D.; Westerhoff, P.; Bliss, N.

    2015-12-01

    The Niger River Basin (NRB) is a large transnational watershed of ~1.5 million km2, whose water resources sustain more than 100 million people of nine countries in West Africa. Evaluating the reliability of climate simulations in the region is essential to support water sustainability and food security under possible future climatic changes and population growth. Here, we assess the ability of a set of state-of-the-art regional climate models (RCMs) of the COordinated Regional climate Downscaling EXperiment (CORDEX)-Africa to reproduce the hydrologic cycle of the NRB. For this aim, we adopt a verification framework based on the mass conservation principle that assumes that the mean annual difference between precipitation and evaporation equals the long-term mean discharge. We focus on four nested sub-basins encompassing different climatic zones with available discharge observations. We found that most RCMs overestimate the mean annual runoff (from +10% to +400%), because of a positive bias in the simulation of precipitation and a weak hydrologic cycle in the evaporation channel. Some exceptions are found in the more humid sub-basin upstream where a few climate simulations are not able to capture the intensity of the West African monsoon. Analyses of the water balance components also revealed that the signature of the RCMs is more significant than that of the driving General Circulation Model, likely due to the specific schemes adopted in the RCMs to parameterize the land-surface processes. This work is useful to increase the utility of regional climate simulations in impact studies supporting the development of water management polices and
planning of hydraulic infrastructures in the basin.

  6. Ground Truth, Magnitude Calibration and Regional Phase Propagation and Detection in the Middle East and Horn of Africa

    SciTech Connect

    Nyblade, A; Brazier, R; Adams, A; Park, Y; Rodgers, A; Al-Amri, A

    2007-07-08

    In this project, we are exploiting several seismic data sets to improve U.S. operational capabilities to monitor for low yield nuclear tests across the Middle East (including the Iranian Plateau, Zagros Mountains, Arabian Peninsula, Turkish Plateau, Gulf of Aqaba, Dead Sea Rift) and the Horn of Africa (including the northern part of the East African Rift, Afar Depression, southern Red Sea and Gulf of Aden). The data sets are being used to perform three related tasks. (1) We are determining moment tensors, moment magnitudes and source depths for regional events in the magnitude 3.0 to 6.0 range. (2) These events are being used to characterize high-frequency (0.5-16 Hz) regional phase attenuation and detection thresholds, especially from events in Iran recorded at stations across the Arabian Peninsula. (3) We are collecting location ground truth at GT5 (local) and GT20 (regional) levels for seismic events with M > 2.5, including source geometry information and source depths. Towards meeting these objectives, seismograms from earthquakes in the Zagros Mountains recorded at regional distances have been inverted for moment tensors, which have then been used to create synthetic seismograms to determine the source depths of the earthquakes via waveform matching. The source depths have been confirmed by modeling teleseismic depth phases recorded on GSN and IMS stations. Early studies of the distribution of seismicity in the Zagros region found evidence for earthquakes in the upper mantle. But subsequent relocations of teleseismic earthquakes suggest that source depths are generally much shallower, lying mainly within the upper crust. All of the regional events studied so far nucleated within the upper crust, and most of the events have thrust mechanisms. The source mechanisms for these events are being used to characterize high-frequency (0.5-16 Hz) regional phase attenuation and detection thresholds for broadband seismic stations in the Arabian Peninsula, including IMS

  7. Land Cover Mapping for the Development of Green House Gas (GHG) Inventories in the Eastern and Southern Africa Region

    NASA Astrophysics Data System (ADS)

    Wakhayanga, J. A.; Oduor, P.; Korme, T.; Farah, H.; Limaye, A. S.; Irwin, D.; Artis, G.

    2014-12-01

    Anthropogenic activities are responsible for the largest share of green house gas (GHG) emissions. Research has shown that greenhouse gases cause radioactive forcing in the stratosphere, leading to ozone depletion. Different land cover types act as sources or sinks of carbon dioxide (CO2), the most dominant GHG.Under the oversight of the United Nations Framework Convention on Climate Change (UNFCCC) the Eastern and Southern Africa (ESA) region countries are developing Sustainable National GHG Inventory Management Systems. While the countries in the ESA region are making substantial progress in setting up GHG inventories, there remains significant constraints in the development of quality and sustainable National GHG Inventory Systems. For instance, there are fundamental challenges in capacity building and technology transfer, which can affect timely and consistent reporting on the land use, land-use change and forestry (LULUCF) component of the GHG inventory development. SERVIR Eastern and Southern Africa is a partnership project between the National Aeronautics and Space Administration (NASA) and the Regional Center for Mapping of Resources for Development (RCMRD), an intergovernmental organization in Africa, with 21 member states in the ESA region. With support from the United States Agency for International Development (USAID), SERVIR ESA is implementing the GHG Project in 9 countries. The main deliverables of the project are land cover maps for the years 2000 and 2010 (also 1990 for Malawi and Rwanda), and related technical reports, as well as technical training in land cover mapping using replicable methodologies. Landsat imagery which is freely available forms the main component of earth observation input data, in addition to ancillary data collected from each country. Supervised classification using maximum likelihood algorithm is applied to the Landsat images. The work is completed for the initial 6 countries (Malawi, Zambia, Rwanda, Tanzania, Botswana, and

  8. LIMA U-Pb ages link lithospheric mantle metasomatism to Karoo magmatism beneath the Kimberley region, South Africa

    NASA Astrophysics Data System (ADS)

    Giuliani, Andrea; Phillips, David; Maas, Roland; Woodhead, Jon D.; Kendrick, Mark A.; Greig, Alan; Armstrong, Richard A.; Chew, David; Kamenetsky, Vadim S.; Fiorentini, Marco L.

    2014-09-01

    The Karoo igneous rocks (174-185 Ma) of southern Africa represent one of the largest continental flood basalt provinces on Earth. Available evidence indicates that Karoo magmas either originated in the asthenosphere and were extensively modified by interaction with the lithospheric mantle prior to emplacement in the upper crust; or were produced by partial melting of enriched mantle lithosphere. However, no direct evidence of interaction by Karoo melts (or their precursors) with lithospheric mantle rocks has yet been identified in the suites of mantle xenoliths sampled by post-Karoo kimberlites in southern Africa. Here we report U-Pb ages for lindsleyite-mathiasite (LIMA) titanate minerals (crichtonite series) from three metasomatised, phlogopite and clinopyroxene-rich peridotite xenoliths from the ∼84 Ma Bultfontein kimberlite (Kimberley, South Africa), located in the southern part of the Karoo magmatic province. The LIMA minerals appear to have formed during metasomatism of the lithospheric mantle by fluids enriched in HFSE (Ti, Zr, Hf, Nb), LILE (K, Ba, Ca, Sr) and LREE. LIMA U-Pb elemental and isotopic compositions were measured in situ by LA-ICP-MS methods, and potential matrix effects were evaluated by solution-mode analysis of mineral separates. LIMA minerals from the three samples yielded apparent U-Pb ages of 177±12 Ma, 178±29 Ma and 190±24 Ma (±2σ). A single zircon grain extracted from the ∼190 Ma LIMA-bearing sample produced a similar U-Pb age of 184±6 Ma, within uncertainty of the LIMA ages. These data provide the first robust evidence of fluid enrichment in the lithospheric mantle beneath the Kimberley region at ∼180-190 Ma, and suggest causation of mantle metasomatism by Karoo melts or their precursor(s). The results further indicate that U-Pb dating of LIMA minerals provides a new, accurate tool for dating metasomatic events in the lithospheric mantle.

  9. The relationship between African easterly waves and daily rainfall over West Africa: observations and regional climate simulations

    NASA Astrophysics Data System (ADS)

    Crétat, Julien; Vizy, Edward K.; Cook, Kerry H.

    2015-01-01

    The relationship between summer African easterly waves (AEWs) and daily rainfall is assessed in West Africa for 1998-2008 using various reanalyses, satellite-derived rainfall products, and a regional climate model (RCM) run at 90- and 30-km resolutions. 3-5 and 6-9 day AEWs are extracted by filtering daily 700 hPa meridional wind time series at 1°W and 11.5°N, and 1°W and 17.5°N, respectively. Both observed and simulated rainfall anomalies are of larger magnitude over West Africa during 3-5-d than 6-9-d AEWs. The RCM simulates larger rainfall rates in phase with the 3-5-d wave trough instead of ahead, unlike the observations, and overestimates the intensity and spatial coverage of rainfall associated with 6-9-d AEWs. The observed and simulated co-variability between 3-5-d (6-9-d) AEW activity and daily rainfall is strong (weak) and mostly located south (north) of 15°N. However, the RCM overestimates the spatial coverage of the AEW-rainfall relationship in the longitudinal (latitudinal) direction in the case of 3-5-d (6-9-d) AEWs. Observed and simulated daily intense rainfall events, extracted using a percentile threshold approach, are mostly located south of 15°N during summer. The observed relationship between their frequency of occurrence and active 3-5-d AEWs is maximal west of 8°E, while extends up to southern Chad in both RCM simulations. Their magnitude is also largely overestimated by the RCM, indicating an exaggerated coupling between the wave activity and the convection. Finally, observed and simulated 3-5-d AEWs establish the most favorable synoptic conditions for the development of intense rainfall events over West Africa.

  10. Insights from Earth Sciences into Human Evolution studies: The example of prehistoric landscape use in Africa and the Levant

    NASA Astrophysics Data System (ADS)

    Devès, Maud H.; Reynolds, Sally; King, Geoffrey C. P.; Kuebler, Simon; Sturdy, Derek; Godet, Nan

    2015-07-01

    Fossil remains are embedded in a continually evolving landscape. Earth scientists have the methods and approaches to study the processes that shape the landscape at various temporal and spatial scales. Some of these methods can generate insights that are of potential use for researchers in other fields, such as archaeology and palaeoanthropology. Here we present two case studies to illustrate how a broader landscape perspective can provide new insights into the land use by Pliocene hominins in southern Africa, and more recently, by Palaeolithic hominins in the southern Levant. Key landscape attributes can help explain why humans, hominins and the wider animal community exploit certain types of landscapes in predictable ways. Our first case study examines how active tectonics or volcanism appears to be important in creating fertile regions with reliable water sources and complex topography. While relatively easy for agile primates such as hominins to negotiate, zones of complex topography are harder for certain predators and prey animals to traverse. In the second case study, we consider that differences in soil edaphics can exert a major control on animals by supplying or failing to supply necessary trace elements, such as selenium, copper, phosphate and potassium (Henkin et al., 1995). We show that the pattern of trace element distribution can accurately map animal movements between areas of suitable grazing. This predictability could have enabled Levantine humans to ambush megafauna during these seasonal migrations. By studying the landscape attributes around fossil site locations, Earth scientists can offer new insights and perspectives into the past, particularly on the ways in which the inhabitants would have used their landscapes.

  11. Sensitivity of Boreal-Summer Circulation and Precipitation to Atmospheric Aerosols in Selected Regions: Part I Africa and India

    SciTech Connect

    Sud, Yogesh C.; Wilcox, Eric; Lau, William K.; Walker, Greg K.; Liu, Xiaohong; Nenes, Athanasios; Lee , Dongmin; Kim, K. - M.; Zhou, Yaping; Bhattacharjee, P. S.

    2009-10-23

    Version-4 of the Goddard Earth Observing System (GEOS-4) General Circulation Model (GCM) was employed to assess the influence of potential changes in aerosols on the regional circulation, ambient temperatures, and precipitation in four selected regions: India and Africa (current paper), as well as North and South America (companion paper). Ensemble-simulations were carried out with the GCM to assess the aerosol direct and indirect effects, hereafter ADE and AIE. Each simulation was started from the NCEP-analyzed initial conditions for May 1 and was integrated through May-June-July-August of each year: 1982-1987 to provide an ensemble set of six simulations. In the first set, called the baseline experiment (#1), climatological aerosols were prescribed. The next two experiments (#2 and #3) had two sets of simulations each: one with 2X and another with 1/2X the climatological aerosols over each of the four selected regions. In experiment#2, the anomaly regions were advectively restricted (AR), i.e., the large-scale prognostic fields outside the aerosol anomaly regions were prescribed while in experiment#3, the anomaly regions were advectively Interactive (AI) as is the case in a normal GCM integrations, but with the same aerosols anomalies as in experiment #2. Intercomparisons of circulation, diabatic heating, and precipitation difference fields showed large disparities among the AR and AI simulations, which raised serious questions about the AR assumption, commonly invoked in regional climate simulation studies. Consequently AI simulation mode was chosen for the subsequent studies. Two more experiments (#4 and #5) were performed in the AI mode in which ADE and AIE were activated one at a time. The results showed that ADE and AIE work in concert to make the joint influences larger than sum of each acting alone. Moreover, the ADE and AIE influences were vastly different for the Indian and Africa regions, which suggest an imperative need to include them rationally in

  12. Sensitivity of boreal-summer circulation and precipitation to atmospheric aerosols in selected regions - Part 1: Africa and India

    NASA Astrophysics Data System (ADS)

    Sud, Y. C.; Wilcox, E.; Lau, W. K.-M.; Walker, G. K.; Liu, X.-H.; Nenes, A.; Lee, D.; Kim, K.-M.; Zhou, Y.; Bhattacharjee, P. S.

    2009-10-01

    Version-4 of the Goddard Earth Observing System (GEOS-4) General Circulation Model (GCM) was employed to assess the influence of potential changes in aerosols on the regional circulation, ambient temperatures, and precipitation in four selected regions: India and Africa (current paper), as well as North and South America (companion paper). Ensemble-simulations were carried out with the GCM to assess the aerosol direct and indirect effects, hereafter ADE and AIE. Each simulation was started from the NCEP-analyzed initial conditions for 1 May and was integrated through May-June-July-August of each year: 1982-1987 to provide an ensemble set of six simulations. In the first set, called experiment (#1), climatological aerosols were prescribed. The next two experiments (#2 and #3) had two sets of simulations each: one with 2X and other with 1/2X the climatological aerosols over each of the four selected regions. In experiment #2, the anomaly regions were advectively restricted (AR), i.e., the large-scale prognostic fields outside the aerosol anomaly regions were prescribed while in experiment #3, the anomaly regions were advectively Interactive (AI) as is the case in a normal GCM integrations, but with the same aerosols anomalies as in experiment #2. Intercomparisons of circulation, diabatic heating, and precipitation difference fields showed large disparities among the AR and AI simulations, which raised serious questions about the proverbial AR assumption, commonly invoked in regional climate simulation studies. Consequently AI simulation mode was chosen for the subsequent studies. Two more experiments (#4 and #5) were performed in the AI mode in which ADE and AIE were activated one at a time. The results showed that ADE and AIE work in concert to make the joint influences larger than sum of each acting alone. Moreover, the ADE and AIE influences were vastly different for the Indian and Africa regions, which suggest an imperative need to include them rationally in

  13. A humid corridor across the Sahara for the migration "Out of Africa" of early modern humans 120,000 years ago

    NASA Astrophysics Data System (ADS)

    Osborne, A. H.; Vance, D.; Rohling, E. J.; Barton, N.; Rogerson, M.; Fello, N.

    2008-12-01

    a currently hyperarid region of the Sahara at a key time for early modern human migrations to the north and out of Africa. 1Scrivner, A.E. et al. (2004) Geology 32, 565-568.

  14. Africa: Prosperous times

    SciTech Connect

    1996-08-01

    Political instability and corruption is the rule, rather than the exception, in Africa`s main producing regions, but exploration and production prospects there are bright and attractive to foreign operators. The paper discusses exploration, drilling, resource development, and production in Nigeria, Libya, Algeria, Egypt, Angola, Congo, Gabon, and Tunisia. The other countries of Africa are briefly mentioned, i.e., Cameroon, Cote D`Ivoire, South Africa, Sudan, Namibia, Equatorial Guinea, Eritrea, Zaire, Mozambique, Ghana, Niger, and Seychelles.

  15. Assessment of simulated rainfall and temperature from the regional climate model REMO and future changes over Central Africa

    NASA Astrophysics Data System (ADS)

    Fotso-Nguemo, Thierry C.; Vondou, Derbetini A.; Tchawoua, Clément; Haensler, Andreas

    2016-07-01

    This work investigates spatial and temporal changes in rainfall and temperature over Central Africa, using historical and representative concentration pathways (RCP2.6, RCP4.5 and RCP8.5) of the regional climate model REMO forced by two general climate models: the Europe-wide Consortium Earth System Model (EC-Earth) and the Max Planck Institute-Earth System Model (MPI-ESM). We found that in the present period (1980-2005), the spatial distribution of rainfall is simulated with an annual spatial pattern correlation coefficient (PCC) of 0.76 for REMO driven by EC-Earth and 0.74 for REMO driven by MPI-ESM respectively when compared to CRU data. In terms of temperature, the annual PCC is 0.93 for the two REMO outputs. According to the climatology of Central Africa, we subdivided the study area into five sub-regions, we also noticed that the annual and seasonal PCC depend on the considered sub-region. For the future period (2070-2095), temperature is projected to increase following all the three scenarios. The rainfall amount is projected to decrease by up to 5 mm/day towards the end of the twenty first century under RCP8.5 scenario, and by 1-2 mm/day under RCP4.5 and RCP2.6 scenarios over Equatorial Guinea, Gabon, Congo, north-western Democratic Republic of Congo (DRC) and the Lake Victoria. Significant decrease is predicted to occur mostly in the northern part of the domain under RCP8.5 scenario. However, future rainfall over High Lands of Cameroon, Adamawa Plateau, north-eastern DRC and Atlantic Ocean is projected to increase.

  16. The cost implications of participatory research. Experience of a health services review in a rural region in South Africa

    PubMed

    Doherty; Price

    1998-03-01

    OBJECTIVES: The study objectives were to estimate the total costs incurred by a comprehensive review of primary health care services in a rural region in South Africa, and to determine which of these costs were incurred because of the participatory research techniques employed by the review. DESIGN: The costing study estimated the direct and indirect costs of each component of the review in order to determine total costs. Costs that were linked to participatory research activities were aggregated separately. SETTING: The review that was costed was conducted in an area that included the former 'homeland' KaNgwane and the adjacent areas of 'white' South Africa, in part of what is now known as Mpumalanga Province. SUBJECTS: Not relevant. OUTCOME MEASURES: Direct, indirect, total, research and participation costs were used as outcome measures. RESULTS: Expenditure generated by participatory research techniques was estimated to be almost 14% of the total (direct and indirect) costs. CONCLUSIONS: Despite these costs, participatory research techniques are invaluable in terms of the many benefits they have for a research project. However, because of these costs, it is important that the financing of participatory research should be carefully planned. Projects must budget for the direct costs of participatory techniques, participating organisations and individuals must be committed to bearing the indirect costs of participation, and, increasingly, funders must consider funding these indirect costs. This is important in the South African situation, where public health research relies increasingly on the participation of relevant stakeholders. PMID:9608312

  17. Assessment of Regional Climate Models over Côte d'Ivoire and Analysis of Future Projections over West Africa

    NASA Astrophysics Data System (ADS)

    Kouadio, K.; Konare, A.; Diawara, A.; Dje, B. K.; Ajayi, V. O.; Diedhiou, A.

    2015-12-01

    The ability of six Regional Climate Models (RCMs) used in AMMA-ENSEMBLES project is assessed over six meteorological stations in Côte d'Ivoire. The ensemble mean of the models is also used for the prediction of climate change over West Africa. The study focused on two periods: the period 1995-2005, the present-day simulations, is used to evaluate the skills of the models over the country and the years 2010-2013, for assessment of the future climate change scenario used. The results show that the skills of the models vary from one station to another and from one season to another. None of the models considered, presents an excellent performance over the entire country and in all the seasons. Generally, the ensemble mean of all the models presents better results when compared with the observation. These results suggest that the choice of any model for study over the country may depend on the focus of interest: intensity or variability of the rain and also on area of interest. The projection for 2020-2040, future climate change over West Africa shows that the Sahel exhibits a tendency to be drier while wetter Guinean coast is observed

  18. The negative impacts of human activities in the eastern African region: an international waters perspective.

    PubMed

    Payet, Rolph; Obura, David

    2004-02-01

    The complex interactions between human activities and the environment at the interface of land and water is analyzed with a focus on the Somali Current (East Africa), and Indian Ocean Island States, subregions of the Global International Waters Assessment (GIWA). These 2 subregions contain some of the world's richest ecosystems, including the high biodiversity forests of Madagascar and the diverse coastal habitats of the eastern African coast. These ecosystems support local communities and national and regional economies. Current and future degradation of these systems, from water basins to continental shelves, affects the livelihoods and sustainability of the countries in the region, and long-term efforts to reduce poverty. The assessments determined that pollution and climate change are the primary environmental and social concerns in the Islands of the Indian Ocean, while freshwater shortage and unsustainable exploitation of fisheries and other living resources are the primary environmental and social concerns in East Africa. The GIWA approach, through assessing root causes of environmental concerns, enables the development of policy approaches for mitigating environmental degradation. This paper explores policy frameworks for mitigating the impacts, and reducing the drivers, of 3 environmental concerns--freshwater shortage; solid waste pollution; and climate change--addressing social and institutional causes and effects, and linking the subregions to broad international frameworks. The common theme in all 3 case studies is the need to develop integrated ecosystem and international waters policies, and mechanisms to manage conflicting interests and to limit threats to natural processes. PMID:15083647

  19. Regional aerosol deposition in human upper airways

    SciTech Connect

    Swift, D.L.

    1992-11-01

    Laboratory experimental studies were carried out to investigate the factors influencing the deposition of aerosols ranging in size from 1 nm to 10 [mu]m in the human nasal, oral, pharyngeal and laryngeal airways. These experimental studies were performed in replicate upper airway physical models and in human volunteer subjects. New replicate models of the oral passage of an infant, the oral passage of an adult at two openings and the combined nasal and oral airways of an adult were constructed during the period, adding to the existing models of adult, child and infant nasal and oral airways models. Deposition studies in the adult oral and adult nasal models were performed under simulated cyclic flow conditions with 1 nm particles to compare with previously measured constant flow studies. Similar studies with inertial particles (1--10 [mu]m diameter) were performed with the adult nasal model; in both instances, results with cyclic flow were similar to constant flow results using a simple average flow rate based on inspiratory volume and time of inspiration. Human subject studies were performed with particle sizes 5--20 nm for nasal inspiration; preliminary analysis shows good agreement with model studies at several representative flow rates. Nasal inspiratory inertial deposition of 1--4 [mu]m diameter particles was measured in several adults as a function of airway dimensions; dimensional changes of the valve area by decongestion did not produce concomitant deposition changes.

  20. Human Carnivore Coexistence on Communal Land Bordering the Greater Kruger Area, South Africa

    NASA Astrophysics Data System (ADS)

    Lagendijk, D. D. Georgette; Gusset, Markus

    2008-12-01

    The aim of this study was to assess the potential for coexistence between rural people (living adjacent to a protected area) and predators (from the same area) ranging onto communal land. Ninety members of local communities bordering Manyeleti Game Reserve, which is contiguous with Kruger National Park, South Africa were interviewed. Respondents expressed diverging attitudes toward predators, which were more favorable among participants with higher education. Negative views were particularly due to fear of human and livestock losses, especially to lions, Panthera leo. Lions were thought to be the most abundant predator both within and outside the reserve. Lions were also the best known predator and were most often held responsible for killing livestock. Despite these livestock losses and a lack of conservation education, most participants voiced favorable opinions about large carnivore conservation, as predators were considered an integral part of the respondents’ natural heritage. Thanks to this cultural tolerance and also because of a largely accepted management policy regarding predator control, large carnivores and people can coexist in the vicinity of Kruger National Park.

  1. A review of mercury in Lake Victoria, East Africa: implications for human and ecosystem health.

    PubMed

    Campbell, Linda; Dixon, D G; Hecky, R E

    2003-01-01

    Lake Victoria, East Africa, has been the site of many recent studies measuring mercury (Hg) concentrations in water, fish, sediment, soil, and humans. Most of these studies were motivated by concerns about Hg contamination from processing of gold ore on the southern shores. Total Hg (THg) concentrations in fish were usually below permissible World Health Organization (WHO) concentrations and international marketing limits and do not threaten the lucrative export industry. Nile perch 3-10 kg and most >10 kg had THg concentrations above the WHO threshold concentrations for at-risk groups (200 ng/g). Elevated THg concentrations in large Nile perch are not of major concern because Nile perch are rarely consumed by the people living on Lake Victoria and very large Nile perch are becoming increasingly rare in catches. Water THg concentrations were below Canadian drinking water guidelines but were elevated relative to those in the northern Great Lakes. Sediment and soil THg concentrations were within inter-national guidelines and are comparable to those in northern latitudes but are lower than those in the Amazon basin. Biomass burning and soil erosion are estimated to be the major sources of THg for the lake and probably constitute a larger source of THg than gold mining in Tanzania.THg concentrations in urine and hair from human volunteers indicate that while gold miners and frequent skin-bleaching cream users are at risk of inorganic mercury poisoning, the rest of the population, including fishermen, is not. Human exposure assessments demonstrated that fish consumption and soil geophagy constitute major sources of THg for humans, but the total estimated daily intake of THg was below the Health Canada tolerable daily intake (TDI) limits. The use of beauty creams containing high inorganic Hg concentrations, however, caused the estimated THg exposure to exceed the TDI. The high THg content in the hair of regular cream users supports this assessment. The nutritional

  2. The East Africa Oligocene intertrappean beds: Regional distribution, depositional environments and Afro/Arabian mammal dispersals

    NASA Astrophysics Data System (ADS)

    Abbate, Ernesto; Bruni, Piero; Ferretti, Marco Peter; Delmer, Cyrille; Laurenzi, Marinella Ada; Hagos, Miruts; Bedri, Omar; Rook, Lorenzo; Sagri, Mario; Libsekal, Yosief

    2014-11-01

    The extensive outpouring of the Oligocene Trap basalts over eastern Africa and western Arabia was interrupted by a period of quiescence marked by the deposition of terrestrial sediments. These so-called intertrappean beds are often lignitiferous and yield recurrent floras and faunas, sometimes represented by endemic mammals. We intended to highlight the peculiar features of these sedimentary intercalations using a large-scale approach including eastern Africa and the western Arabian peninsula. Starting from a new mapping in the Eritrean highland, the intertrappean beds resulted a continuous level that was a few tens of meters thick and traceable for some tens of kilometers. They consist of fluvial red, green and gray mudstones and siltstones with subordinate channelized pebbly sandstones, and lignite seams. Two new 40Ar-39Ar datings constraint the age of the intertrappean beds between 29.0 Ma and 23.6 Ma. The outcrops near Mendefera have yielded the remains of two proboscidean families, the Deinotheriidae and the Gomphoteriidae. The morphological grade of the two Mendefera proboscideans would suggest a more derived stage than that of representatives of the same families from other Oligocene African sites (e.g., Chilga, Ethiopia). An Oligocene age could be inferred for them. The occurrence of the genus Prodeinotherium at Mai Gobro possibly represents the first occurrence of this taxon, while the Gomphotheirum sp. might represent the oldest occurrence of this taxon in Africa before its dispersal towards Asia and Europe. Proboscideans have also been found in the lowland intertrappean beds of Dogali near Massawa. These sediments were contiguous with the Eritrean highland intertrappean beds during the Oligocene, but are now tectonically displaced from them by two thousand meters of vertical topographical distance. Dogali is also known for the occurrence of possible Deinotheriidae remains and the primitive elephantoid Eritreum. Entering the Ethiopian highland, an

  3. Regional aerosol deposition in human upper airways

    SciTech Connect

    Swift, D.L.

    1990-11-01

    During the current reporting period experimental studies of aerosol deposition in replicate NOPL airways have carried out. A replicate model of a 4 week old infant nasal passage was constructed from MR scans. The model completes the age range from newborn'' to 4 years, there now being one child model for 4 different ages. Deposition studies have been performed with unattached radon progeny aerosols in collaboration with ITRI, Albuquerque, NM and NRPB, Chilton, UK. Overall measurements have been performed in adult and child nasal airways indicating that the child nasal passage was slightly more efficient than the adult in removing 1 nm particles at corresponding flow rates. A similar weak dependence on flow rate was observed. Local deposition studies in an adult nasal model indicated predominant deposition in the anterior region during inspiratory flow, but measurable deposition was found throughout the model. The deposition pattern during expiration was reverse, greater deposition being observed in the posterior region. Local deposition studies of attached progeny aerosol size (100--200 nm) were performed in adult and child nasal models using technigas'' and a gamma scintillation camera. Similar to the unattached size, deposition occurred throughout the models, but was greater in the anterior region.

  4. Human health improvement in Sub-Saharan Africa through integrated management of arthropod transmitted diseases and natural resources.

    PubMed

    Baumgärtner, J; Bieri, M; Buffoni, G; Gilioli, G; Gopalan, H; Greiling, J; Tikubet, G; Van Schayk, I

    2001-01-01

    A concept of an ecosystem approach to human health improvement in Sub-Saharan Africa is presented here. Three factors mainly affect the physical condition of the human body: the abiotic environment, vector-transmitted diseases, and natural resources. Our concept relies on ecological principles embedded in a social context and identifies three sets of subsystems for study and management: human disease subsystems, natural resource subsystems, and decision-support subsystems. To control human diseases and to secure food from resource subsystems including livestock or crops, integrated preventive approaches are preferred over exclusively curative and sectorial approaches. Environmental sustainability - the basis for managing matter and water flows - contributes to a healthy human environment and constitutes the basis for social sustainability. For planning and implementation of the human health improvement scheme, participatory decision-support subsystems adapted to the local conditions need to be designed through institutional arrangements. The applicability of this scheme is demonstrated in urban and rural Ethiopia. PMID:11426264

  5. Regional aerosol deposition in human upper airways

    SciTech Connect

    Swift, D.L.

    1991-11-01

    During the current report experimental studies of upper respiratory deposition of radon progeny aerosols and stimulant aerosols were carried out in replicate casts of nasal and oral passages of adults and children. Additionally, preliminary studies of nasal passage deposition of unattached Po{sup 218} particles was carried out in four human subjects. Data on nasal inspiratory deposition in replicate models of adults and infants from three collaborating laboratories were compared and a best-fit curve of deposition efficiency for both attached and unattached particles was obtained, showing excellent inter-laboratory agreement. This curve demonstrates that nasal inspiratory deposition of radon progeny is weakly dependent upon flow rate over physiologically realistic ranges of flow, does not show a significant age effect, and is relatively independent of nasal passage dimensions for a given age range. Improved replicate models of the human adult oral passage extending to the mid-trachea were constructed for medium and higher flow mouth breathing states; these models were used to assess the deposition of unattached Po{sup 218} particles during oronasal breathing in the oral passage and demonstrated lower deposition efficiency than the nasal passage. Measurements of both Po{sup 218} particle and attached fraction particle size deposition were performed in replicate nasal passage of a four week old infant. 5 refs., 1 fig.

  6. Predicting human age using regional morphometry and inter-regional morphological similarity

    NASA Astrophysics Data System (ADS)

    Wang, Xun-Heng; Li, Lihua

    2016-03-01

    The goal of this study is predicting human age using neuro-metrics derived from structural MRI, as well as investigating the relationships between age and predictive neuro-metrics. To this end, a cohort of healthy subjects were recruited from 1000 Functional Connectomes Project. The ages of the participations were ranging from 7 to 83 (36.17+/-20.46). The structural MRI for each subject was preprocessed using FreeSurfer, resulting in regional cortical thickness, mean curvature, regional volume and regional surface area for 148 anatomical parcellations. The individual age was predicted from the combination of regional and inter-regional neuro-metrics. The prediction accuracy is r = 0.835, p < 0.00001, evaluated by Pearson correlation coefficient between predicted ages and actual ages. Moreover, the LASSO linear regression also found certain predictive features, most of which were inter-regional features. The turning-point of the developmental trajectories in human brain was around 40 years old based on regional cortical thickness. In conclusion, structural MRI could be potential biomarkers for the aging in human brain. The human age could be successfully predicted from the combination of regional morphometry and inter-regional morphological similarity. The inter-regional measures could be beneficial to investigating human brain connectome.

  7. Tropospheric Ozone Increases over the Southern Africa Region: Bellwether for Rapid Growth in Southern Hemisphere Pollution?

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Balashov, Nikolay V.; Witte, J. C.; Coetzee, J. G. R.; Thouret, V.; Posny, F.

    2014-01-01

    Increases in free-tropospheric (FT) ozone based on ozonesonde records from the early 1990s through 2008 over two subtropical stations, Irene (near Pretoria, South Africa) and Réunion (21 deg. S, 55 deg. E; approx. 2800 km NE of Irene in the Indian Ocean), have been reported. Over Irene a large increase in the urban-influenced boundary layer (BL, 1.5-4 km) was also observed during the 18-year period, equivalent to 30%decade-1. Here we show that the Irene BL trend is at least partly due to a gradual change in the sonde launch times from early morning to the midday period. The FT ozone profiles over Irene in 1990-2007 are re-examined, filling in a 1995-1999 gap with ozone profiles taken during the Measurements of Ozone by Airbus In-service Aircraft (MOZAIC) project over nearby Johannesburg. A multivariate regression model that accounts for the annual ozone cycle, El Niño-Southern Oscillation (ENSO) and possible tropopause changes was applied to monthly averaged Irene data from 4 to 11 km and to 1992-2011 Réunion sonde data from 4 to 15 km. Statistically significant trends appear predominantly in the middle and upper troposphere (UT; 4-11 km over Irene, 4-15 km over Réunion) in winter (June-August), with increases 1 ppbv yr(exp. -1) over Irene and approx. 2 ppbv yr(exp. -1) over Réunion. These changes are equivalent to approx. 25 and 35-45%decade( exp. -1), respectively. Both stations also display smaller positive trends in summer, with a 45%decade(exp. -1) ozone increase near the tropopause over Réunion in December. To explain the ozone increases, we investigated a time series of dynamical markers, e.g., potential vorticity (PV) at 330-350 K. PV affects UT ozone over Irene in November-December but displays little relationship with ozone over Réunion. A more likely reason for wintertime FT ozone increases over Irene and Réunion appears to be long-range transport of growing pollution in the Southern Hemisphere. The ozone increases are consistent with trajectory

  8. Tropospheric ozone increases over the southern Africa region: bellwether for rapid growth in Southern Hemisphere pollution?

    NASA Astrophysics Data System (ADS)

    Thompson, A. M.; Balashov, N. V.; Witte, J. C.; Coetzee, J. G. R.; Thouret, V.; Posny, F.

    2014-09-01

    Increases in free-tropospheric (FT) ozone based on ozonesonde records from the early 1990s through 2008 over two subtropical stations, Irene (near Pretoria, South Africa) and Réunion (21° S, 55° E; ~2800 km NE of Irene in the Indian Ocean), have been reported. Over Irene a large increase in the urban-influenced boundary layer (BL, 1.5-4 km) was also observed during the 18-year period, equivalent to 30% decade-1. Here we show that the Irene BL trend is at least partly due to a gradual change in the sonde launch times from early morning to the midday period. The FT ozone profiles over Irene in 1990-2007 are re-examined, filling in a 1995-1999 gap with ozone profiles taken during the Measurements of Ozone by Airbus In-service Aircraft (MOZAIC) project over nearby Johannesburg. A multivariate regression model that accounts for the annual ozone cycle, El Niño-Southern Oscillation (ENSO) and possible tropopause changes was applied to monthly averaged Irene data from 4 to 11 km and to 1992-2011 Réunion sonde data from 4 to 15 km. Statistically significant trends appear predominantly in the middle and upper troposphere (UT; 4-11 km over Irene, 4-15 km over Réunion) in winter (June-August), with increases ~1 ppbv yr-1 over Irene and ~2 ppbv yr-1 over Réunion. These changes are equivalent to ~25 and 35-45% decade-1, respectively. Both stations also display smaller positive trends in summer, with a 45% decade-1 ozone increase near the tropopause over Réunion in December. To explain the ozone increases, we investigated a time series of dynamical markers, e.g., potential vorticity (PV) at 330-350 K. PV affects UT ozone over Irene in November-December but displays little relationship with ozone over Réunion. A more likely reason for wintertime FT ozone increases over Irene and Réunion appears to be long-range transport of growing pollution in the Southern Hemisphere. The ozone increases are consistent with trajectory origins of air parcels sampled by the sondes and

  9. A GCM investigation of dust aerosol impact on the regional climate of North Africa and South/East Asia

    NASA Astrophysics Data System (ADS)

    Gu, Y.; Xue, Y.; De Sales, F.; Liou, K. N.

    2016-04-01

    The climatic effects of dust aerosols in North Africa and South/East Asia have been investigated using an atmospheric general circulation model, NCEP/GCM/SSiB (Simplified Simple Biosphere Model) and the three-dimensional aerosol data simulated by the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. GCM simulations show that due to the scattering and absorption of solar radiation by dust particles, surface temperature decreases over both regions, accompanied by a reduced sensible heat flux. However, precipitation responses are different in these two regions. Due to differences in dust location and the associated heating with respect to the rainfall band and circulation, the effect of dust could either enhance or suppress precipitation. Over the North Africa region where dust particles are mainly located to the north of rainfall band, heating of the air column by dust particles forces a stronger ascent motion over dust layers, which induces an anomalous subsidence (or a weakened upward motion) and suppressed cyclonic circulation to its south where precipitation reduces. Furthermore, both humidity and cloud decrease due to the heating in the middle troposphere (semi-direct effect). In South/East Asia, dust particles are located in the upper troposphere over the major rainfall band during the monsoon season, especially Southwest India and the coastal area of Bay of Bengal. Heating of the air column increases upward motion and strengthens cyclonic circulation. Humidity also increases due to the draw-in of the low level moist air. Therefore, cloud and precipitation increase over South/East Asia associated with dust effect. During the pre-monsoon season, when dust particles are located to the north of the monsoon rainfall band, the heating effect results in shifting precipitation northward. The heating of air column due to dust particles, not surface cooling, plays the major role in precipitation changes. The anomalous upward motion over dust regions will

  10. Water Use and Management in Semiarid Regions - A Distributed Modelling Approach in the Verlorenvlei Catchment, South Africa

    NASA Astrophysics Data System (ADS)

    Fleischer, Melanie; Kralisch, Sven; Fink, Manfred; Pfennig, Björn; Butchart-Kuhlmann, Daniel; Meinhardt, Markus; de Clercq, Willem

    2016-04-01

    Hydrological modelling is a useful method to predict water availability and environmental impacts in a range of climate and land use change scenarios. One of the major challenges to accurate predictions using hydrological modelling in semi-arid areas is the high temporal and spatial variability of rainfall events and the associated uncertainty of related process parameters. Limited and often unreliable climate observations can cause additional problems. These particular circumstances are well documented for many catchments in the world, including semi-arid parts of South Africa. An accurate assessment of water quality and quantity is however crucial for sustainable water resource management, which is often difficult under changing environmental conditions such as climate and land use change. This situation can be found in the Verlorenvlei catchment, a part of the Sandveld area located in the Western Cape region of South Africa. Extensive dry periods in combination with an increasing domestic water demand, expanding irrigation agriculture and expected reducing rainfall due to climate change present a challenging setup for water management in this region. The catchment is a highly sensitive area with one of the most important estuary systems in the Western Cape region, containing significant natural wetlands with high biodiversity and numerous endemic species. With very limited surface water resources, most settlements and irrigation systems in the region are mainly dependent on groundwater. As a result of the particular conditions, the use of improved management techniques, such as centre pivot irrigation and contour-bank farming, are necessary. The distributed, process-oriented hydrological modelling system JAMS/J2000 is used and evaluated to assess water availability within the catchment under different climate and land-use change scenarios. The first phase has involved configuring the model to accurately represent the specific natural conditions of the

  11. Climate Predictors of the Spatial Distribution of Human Plague Cases in the West Nile Region of Uganda

    PubMed Central

    MacMillan, Katherine; Monaghan, Andrew J.; Apangu, Titus; Griffith, Kevin S.; Mead, Paul S.; Acayo, Sarah; Acidri, Rogers; Moore, Sean M.; Mpanga, Joseph Tendo; Enscore, Russel E.; Gage, Kenneth L.; Eisen, Rebecca J.

    2012-01-01

    East Africa has been identified as a region where vector-borne and zoonotic diseases are most likely to emerge or re-emerge and where morbidity and mortality from these diseases is significant. Understanding when and where humans are most likely to be exposed to vector-borne and zoonotic disease agents in this region can aid in targeting limited prevention and control resources. Often, spatial and temporal distributions of vectors and vector-borne disease agents are predictable based on climatic variables. However, because of coarse meteorological observation networks, appropriately scaled and accurate climate data are often lacking for Africa. Here, we use a recently developed 10-year gridded meteorological dataset from the Advanced Weather Research and Forecasting Model to identify climatic variables predictive of the spatial distribution of human plague cases in the West Nile region of Uganda. Our logistic regression model revealed that within high elevation sites (above 1,300 m), plague risk was positively associated with rainfall during the months of February, October, and November and negatively associated with rainfall during the month of June. These findings suggest that areas that receive increased but not continuous rainfall provide ecologically conducive conditions for Yersinia pestis transmission in this region. This study serves as a foundation for similar modeling efforts of other vector-borne and zoonotic disease in regions with sparse observational meteorologic networks. PMID:22403328

  12. Two Distinct Yersinia pestis Populations Causing Plague among Humans in the West Nile Region of Uganda

    PubMed Central

    Respicio-Kingry, Laurel B.; Yockey, Brook M.; Acayo, Sarah; Kaggwa, John; Apangu, Titus; Kugeler, Kiersten J.; Eisen, Rebecca J.; Griffith, Kevin S.; Mead, Paul S.; Schriefer, Martin E.; Petersen, Jeannine M.

    2016-01-01

    Background Plague is a life-threatening disease caused by the bacterium, Yersinia pestis. Since the 1990s, Africa has accounted for the majority of reported human cases. In Uganda, plague cases occur in the West Nile region, near the border with Democratic Republic of Congo. Despite the ongoing risk of contracting plague in this region, little is known about Y. pestis genotypes causing human disease. Methodology/Principal Findings During January 2004–December 2012, 1,092 suspect human plague cases were recorded in the West Nile region of Uganda. Sixty-one cases were culture-confirmed. Recovered Y. pestis isolates were analyzed using three typing methods, single nucleotide polymorphisms (SNPs), pulsed field gel electrophoresis (PFGE), and multiple variable number of tandem repeat analysis (MLVA) and subpopulations analyzed in the context of associated geographic, temporal, and clinical data for source patients. All three methods separated the 61 isolates into two distinct 1.ANT lineages, which persisted throughout the 9 year period and were associated with differences in elevation and geographic distribution. Conclusions/Significance We demonstrate that human cases of plague in the West Nile region of Uganda are caused by two distinct 1.ANT genetic subpopulations. Notably, all three typing methods used, SNPs, PFGE, and MLVA, identified the two genetic subpopulations, despite recognizing different mutation types in the Y. pestis genome. The geographic and elevation differences between the two subpopulations is suggestive of their maintenance in highly localized enzootic cycles, potentially with differing vector-host community composition. This improved understanding of Y. pestis subpopulations in the West Nile region will be useful for identifying ecologic and environmental factors associated with elevated plague risk. PMID:26866815

  13. Downscaling large-scale climate variability using a regional climate model: the case of ENSO over Southern Africa

    NASA Astrophysics Data System (ADS)

    Boulard, Damien; Pohl, Benjamin; Crétat, Julien; Vigaud, Nicolas; Pham-Xuan, Thanh

    2013-03-01

    This study documents methodological issues arising when downscaling modes of large-scale atmospheric variability with a regional climate model, over a remote region that is yet under their influence. The retained case study is El Niño Southern Oscillation and its impacts on Southern Africa and the South West Indian Ocean. Regional simulations are performed with WRF model, driven laterally by ERA40 reanalyses over the 1971-1998 period. We document the sensitivity of simulated climate variability to the model physics, the constraint of relaxing the model solutions towards reanalyses, the size of the relaxation buffer zone towards the lateral forcings and the forcing fields through ERA-Interim driven simulations. The model's internal variability is quantified using 15-member ensemble simulations for seasons of interest, single 30-year integrations appearing as inappropriate to investigate the simulated interannual variability properly. The incidence of SST prescription is also assessed through additional integrations using a simple ocean mixed-layer model. Results show a limited skill of the model to reproduce the seasonal droughts associated with El Niño conditions. The model deficiencies are found to result from biased atmospheric forcings and/or biased response to these forcings, whatever the physical package retained. In contrast, regional SST forcing over adjacent oceans favor realistic rainfall anomalies over the continent, although their amplitude remains too weak. These results confirm the significant contribution of nearby ocean SST to the regional effects of ENSO, but also illustrate that regionalizing large-scale climate variability can be a demanding exercise.

  14. New and interesting species of the genus Muelleria (Bacillariophyta) from the Antarctic region and South Africa

    USGS Publications Warehouse

    Van De Vijver, B.; Mataloni, G.; Stanish, L.; Spaulding, S.A.

    2010-01-01

    During a survey of the terrestrial diatom flora of some sub-Antarctic islands in the southern Indian and Atlantic Oceans and of the Antarctic continent, more than 15 taxa belonging to the genus Muelleria were observed. Nine of these taxa are described as new species using light and scanning electron microscopy. Comments are made on their systematic position and how they are distinguished from other species in the genus. Additionally, two previously unrecognized taxa within the genus were discovered in samples from South Africa. One of these, Muelleria taylorii Van de Vijver & Cocquyt sp. nov., is new to science; the other, Muelleria vandermerwei (Cholnoky) Van de Vijver & Cocquyt nov. comb., had been included in the genus Diploneis. The large number of new Muelleria taxa on the (sub)-Antarctic locations is not surprising. Species in Muelleria occur rarely in collections; in many habitats, it is unusual to find more than 1-2 valves in any slide preparation. As a result, records are scarce. The practice of "force-fitting" (shoehorning) specimens into descriptions from common taxonomic keys (and species drift) results in European species, such as M. gibbula and M. linearis, being applied to Antarctic forms in ecological studies. Finally, the typical terrestrial habitats of soils, mosses and ephemeral water bodies of most of these taxa have been poorly studied in the past.

  15. Regional Higher Education Reform Initiatives in Africa: A Comparative Analysis with the Bologna Process

    ERIC Educational Resources Information Center

    Woldegiorgis, Emnet Tadesse; Jonck, Petronella; Goujon, Anne

    2015-01-01

    Europe's Bologna Process has been identified as a pioneering approach in regional cooperation with respect to the area of higher education. To address the challenges of African higher education, policymakers are recommending regional cooperation that uses the Bologna Process as a model. Based on these recommendations, the African Union Commission…

  16. High Seroprevalence of Human Herpesviruses in HIV-Infected Individuals Attending Primary Healthcare Facilities in Rural South Africa

    PubMed Central

    Schaftenaar, Erik; Verjans, Georges M. G. M.; Getu, Sarah; McIntyre, James A.; Struthers, Helen E.; Osterhaus, Albert D. M. E.; Peters, Remco P. H.

    2014-01-01

    Seroprevalence data of human herpesviruses (HHVs) are limited for sub-Saharan Africa. These are important to provide an indication of potential burden of HHV-related disease, in particular in human immunodeficiency virus (HIV)-infected individuals who are known to be at increased risk of these conditions in the Western world. In this cross-sectional study among 405 HIV-infected and antiretroviral therapy naïve individuals in rural South Africa the seroprevalence of HHVs was: herpes simplex virus type 1 (HSV-1) (98%), herpes simplex virus type 2 (HSV-2) (87%), varicella zoster virus (VZV) (89%), and 100% for both Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Independent factors associated with VZV seropositivity were low educational status and having children. Lack of in-house access to drinking water was independently associated with positive HSV-1 serostatus, whereas Shangaan ethnicity was associated with HSV-2 seropositivity. Increasing age was associated with higher IgG titres to both EBV and CMV, whereas CD4 cell count was negatively associated with EBV and CMV IgG titres. Moreover, IgG titres of HSV-1 and 2, VZV and CMV, and CMV and EBV were positively correlated. The high HHV seroprevalence emphasises the importance of awareness of these viral infections in HIV-infected individuals in South Africa. PMID:24914671

  17. Modeling the distribution of the West Nile and Rift Valley Fever vector Culex pipiens in arid and semi-arid regions of the Middle East and North Africa

    PubMed Central

    2014-01-01

    Background The Middle East North Africa (MENA) region is under continuous threat of the re-emergence of West Nile virus (WNV) and Rift Valley Fever virus (RVF), two pathogens transmitted by the vector species Culex pipiens. Predicting areas at high risk for disease transmission requires an accurate model of vector distribution, however, most Cx. pipiens distribution modeling has been confined to temperate, forested habitats. Modeling species distributions across a heterogeneous landscape structure requires a flexible modeling method to capture variation in mosquito response to predictors as well as occurrence data points taken from a sufficient range of habitat types. Methods We used presence-only data from Egypt and Lebanon to model the population distribution of Cx. pipiens across a portion of the MENA that also encompasses Jordan, Syria, and Israel. Models were created with a set of environmental predictors including bioclimatic data, human population density, hydrological data, and vegetation indices, and built using maximum entropy (Maxent) and boosted regression tree (BRT) methods. Models were created with and without the inclusion of human population density. Results Predictions of Maxent and BRT models were strongly correlated in habitats with high probability of occurrence (Pearson’s r = 0.774, r = 0.734), and more moderately correlated when predicting into regions that exceeded the range of the training data (r = 0.666,r = 0.558). All models agreed in predicting high probability of occupancy around major urban areas, along the banks of the Nile, the valleys of Israel, Lebanon, and Jordan, and southwestern Saudi Arabia. The most powerful predictors of Cx. pipiens habitat were human population density (60.6% Maxent models, 34.9% BRT models) and the seasonality of the enhanced vegetation index (EVI) (44.7% Maxent, 16.3% BRT). Maxent models tended to be dominated by a single predictor. Areas of high probability corresponded with sites of

  18. Regional Meeting of Experts on Environmental Education in Africa, Brazzaville, People's Republic of the Congo, 11-16 September 1976. Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Environmental Education Section.

    This is the final report on the background and proceedings of the Regional Meeting of Experts on Environmental Education in Africa, convened by UNESCO with the collaboration of the University of Brazzaville. This meeting was one of five similar ones held throughout the world as a follow-up to the UNESCO Conference held in Belgrade, Yugoslavia.…

  19. IFLA General Conference, 1992. Division of Regional Activities: Section on Africa; Section on Asia/Oceania; Section on Latin America and the Caribbean. Papers.

    ERIC Educational Resources Information Center

    International Federation of Library Associations and Institutions, London (England).

    Seven papers delivered at the 1992 International Federation of Library Associations and Institutions annual meeting relating to regional activities are presented. These papers deal with library issues in Africa, Asia and Oceania, Latin America, and the Caribbean. The papers are: (1) "Designing National Information Policies in African: Process and…

  20. Effect of cropping system on composition of the Rhizoctonia populations recovered from canola and lupin in a winter rainfall region of South Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia spp. are important pathogens of a broad range of crop plants that are economically important to the farm economy of the Western Cape region of South Africa. However, there is little information concerning the identity and relative importance of these fungal pathogens, and the effect of ...

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  2. MtDNA control region variation affirms diversity and deep sub-structure in populations from southern Africa

    PubMed Central

    2013-01-01

    Background The current San and Khoe populations are remnant groups of a much larger and widely dispersed population of hunter-gatherers and pastoralists, who had exclusive occupation of southern Africa before the influx of Bantu-speakers from 2 ka (ka = kilo annum [thousand years] old/ago) and sea-borne immigrants within the last 350 years. Here we use mitochondrial DNA (mtDNA) to examine the population structure of various San and Khoe groups, including seven different Khoe-San groups (Ju/’hoansi, !Xun, /Gui+//Gana, Khwe, ≠Khomani, Nama and Karretjie People), three different Coloured groups and seven other comparative groups. MtDNA hyper variable segments I and II (HVS I and HVS II) together with selected mtDNA coding region SNPs were used to assign 538 individuals to 18 haplogroups encompassing 245 unique haplotypes. Data were further analyzed to assess haplogroup histories and the genetic affinities of the various San, Khoe and Coloured populations. Where possible, we tentatively contextualize the genetic trends through time against key trends known from the archaeological record. Results The most striking observation from this study was the high frequencies of the oldest mtDNA haplogroups (L0d and L0k) that can be traced back in time to ~100 ka, found at high frequencies in Khoe-San and sampled Coloured groups. Furthermore, the L0d/k sub-haplogroups were differentially distributed in the different Khoe-San and Coloured groups and had different signals of expansion, which suggested different associated demographic histories. When populations were compared to each other, San groups from the northern parts of southern Africa (Ju speaking: !Xun, Ju/’hoansi and Khoe-speaking: /Gui+//Gana) grouped together and southern groups (historically Tuu speaking: ≠Khomani and Karretjie People and some Coloured groups) grouped together. The Khoe group (Nama) clustered with the southern Khoe-San and Coloured groups. The Khwe mtDNA profile was very different from other

  3. Earthquake Hazard and Risk in Sub-Saharan Africa: current status of the Global Earthquake model (GEM) initiative in the region

    NASA Astrophysics Data System (ADS)

    Ayele, Atalay; Midzi, Vunganai; Ateba, Bekoa; Mulabisana, Thifhelimbilu; Marimira, Kwangwari; Hlatywayo, Dumisani J.; Akpan, Ofonime; Amponsah, Paulina; Georges, Tuluka M.; Durrheim, Ray

    2013-04-01

    Large magnitude earthquakes have been observed in Sub-Saharan Africa in the recent past, such as the Machaze event of 2006 (Mw, 7.0) in Mozambique and the 2009 Karonga earthquake (Mw 6.2) in Malawi. The December 13, 1910 earthquake (Ms = 7.3) in the Rukwa rift (Tanzania) is the largest of all instrumentally recorded events known to have occurred in East Africa. The overall earthquake hazard in the region is on the lower side compared to other earthquake prone areas in the globe. However, the risk level is high enough for it to receive attention of the African governments and the donor community. The latest earthquake hazard map for the sub-Saharan Africa was done in 1999 and updating is long overdue as several development activities in the construction industry is booming allover sub-Saharan Africa. To this effect, regional seismologists are working together under the GEM (Global Earthquake Model) framework to improve incomplete, inhomogeneous and uncertain catalogues. The working group is also contributing to the UNESCO-IGCP (SIDA) 601 project and assessing all possible sources of data for the catalogue as well as for the seismotectonic characteristics that will help to develop a reasonable hazard model in the region. In the current progress, it is noted that the region is more seismically active than we thought. This demands the coordinated effort of the regional experts to systematically compile all available information for a better output so as to mitigate earthquake risk in the sub-Saharan Africa.

  4. Regional Climate Simulations with COSMO-CLM for West Africa using three different soil-vegetation-atmosphere-transfer (SVAT) module

    NASA Astrophysics Data System (ADS)

    Breil, Marcus; Panitz, Hans-Jürgen

    2014-05-01

    Climate predictions on decadal timescales constitute a new field of research, closing the gap between short-term and seasonal weather predictions and long-term climate projections. Therefore, the Federal Ministry of Education and Research in Germany (BMBF) has recently funded the research program MiKlip (Mittelfristige Klimaprognosen), which aims to create a model system that can provide reliable decadal climate forecasts. Recent studies have suggested that one region with high potential decadal predictability is West Africa. Therefore, the project DEPARTURE (DEcadal Prediction of African Rainfall and ATlantic HURricanE Activity) was established within the MiKlip program to assess the feasibility and the potential added value of regional decadal climate predictions for West Africa. To quantify the potential decadal climate predictability, a multi-model approach with the three different regional climate models REMO, WRF and COSMO-CLM (CCLM) will be realized. The presented research will contribute to DEPARTURE by performing hindcast ensemble simulations with CCLM, driven by global decadal MPI-ESM-LR simulations. Thereby, one focus is on the dynamic soil-vegetation-climate interaction on decadal timescales. Recent studies indicate that there are significant feedbacks between the land-surface and the atmosphere, which might influence the decadal climate variability substantially. To investigate this connection, two different SVATs (Community Land Model (CLM), and VEG3D) will be coupled with the CCLM, replacing TERRA_ML, the standard SVAT implemented in CCLM. Thus, sensitive model parameters shall be identified, whereby the understanding of important processes might be improved. As a first step, TERRA_ML is substituted by VEG3D, a SVAT developed at the IMK-TRO, Karlsruhe, Germany. Compared to TERRA_ML, VEG3D includes an explicit vegetation layer by using a big leaf approach, inducing higher correlations with observations as it has been shown in previous studies. The

  5. Regional Climate Simulations with COSMO-CLM for West Africa using different soil-vegetation-atmosphere-transfer module's (SVAT's)

    NASA Astrophysics Data System (ADS)

    Breil, Marcus; Panitz, Hans-Jürgen

    2013-04-01

    Climate predictions on decadal timescales constitute a new field of research, closing the gap between short-term and seasonal weather predictions and long-term climate projections. Therefore, the Federal Ministry of Education and Research in Germany (BMBF) has recently funded the research program MiKlip (Mittelfristige Klimaprognosen), which aims to create a model system that can provide reliable decadal climate forecasts. Recent studies have suggested that one region with high potential decadal predictability is West Africa. Therefore, the DEPARTURE project (DEcadal Prediction of African Rainfall and ATlantic HURricanE Activity) was established within the MiKlip program to assess the feasibility and the potential added value of regional decadal climate predictions for West Africa. To quantify the potential decadal climate predictability, a multi-model approach with the three different regional climate models REMO, WRF and COSMO-CLM (CCLM) will be realized. The presented research will contribute to DEPARTURE by performing hindcast ensemble simulations with CCLM, based on SST-driven global MPI-ESM-LR simulations. Thereby, one focus is on the dynamic soil-vegetation-climate interaction on decadal timescales. Recent studies indicate that there are significant feedbacks between the land-surface and the atmosphere, which might influence the decadal climate variability substantially. To investigate this connection, three different SVAT's (TERRA_ML, Community Land Model (CLM), and VEG3D) will be coupled with the CCLM. Thus, sensitive model parameters shall be identified, whereby the understanding of important processes might be improved. As a first step, the influence of the model domain on the CCLM results was examined. For this purpose, recent CCLM results from simulations for the official CORDEX domain were compared with CCLM results achieved by using an extended DEPARTURE model domain to about 60°W. This sensitivity analysis was performed with a horizontal resolution

  6. A survey of the Cape Floristic Region of South Africa for the presence of cyst nematodes (Nematoda: Heteroderidae).

    PubMed

    Knoetze, Rinus; Swart, Antoinette

    2014-01-01

    A survey was performed to detect the presence of cyst nematodes in the Cape Floristic Region of South Africa. Soil was collected in the rhizosphere of the dominant plant species within blocks of indigenous vegetation and cysts were extracted from them. A total of 81 blocks of indigenous vegetation were sampled as described. Cysts were detected in 7 of these samples, representing 6 different vegetation types. One set of primers was used to amplify the ITS regions from these cysts, including the 5.8S ribosomal gene, as well as short parts of the 18S and 28S ribosomal genes. ITS-rDNA sequences from the indigenous isolates were aligned with selected sequences of other species from the Heteroderidae. Phylogenetic analyses to resolve the relationships between indigenous isolates and selected representatives of the Heteroderidae were conducted using the Maximum Parsimony method. The consensus tree resulting from alignment of the circumfenestrate cysts revealed that isolates SK18, WK1 and WK26 are included in a clade of Globodera species that parasitise non-solanaceous plants, forming a monophyletic group with G. millefolii, G. artemisiae, and an unidentified Globodera sp. from Portugal. In a tree resulting from the alignment of the Heterodera spp., isolates OK14 and WK2 are included in the Afenestrata group, forming a monophyletic group with H. orientalis.This survey unearthed at least four potentially new species of cyst nematodes, which may prove invaluable for the study of the evolution and biogeography of the group. PMID:25544531

  7. Evaluation of a regional mineral dust model over Northern Africa, Southern Europe and Middle East with AERONET data

    NASA Astrophysics Data System (ADS)

    Basart, S.; Pérez, C.; Cuevas, E.; Baldasano, J. M.

    2009-04-01

    A variety of regional and global models of the dust aerosol cycle have been developed since early 1990s. Dust models are essential to complement dust-related observations, understand the dust processes and predict the impact of dust on surface level PM concentrations. Dust generation and the parameterization of its deposition processes shows a high variability on spatial and temporal scales. It responds, in a non-linear way, to a variety of environmental factors, such as soil moisture content, the type of surface cover or surface atmospheric turbulence. Thus the modelling of this very complex process is a challenge. DREAM (Dust Regional Atmospheric Model; Nickovic et al., 2001) provides operational dust forecasts for Northern Africa, Europe and Middle East, as well as for the East-Asia regions. DREAM is operated and further developed in the Barcelona Supercomputing Center. DREAM is fully inserted as one of the governing equations in the NCEP/Eta atmospheric model and simulates all major processes of the atmospheric dust cycle. In order to implement new model versions for operational applications there is a need for extensive checking and validation against real observations. The present study focuses on the evaluation of forecasting capacity of the new version of DREAM by means of a model-to-observation comparison of the Aerosol Optical Depth (AOD) over Northern Africa, Southern Europe and Middle East for one year. The model provides 72h forecasts initialized at 12UTC of each day with outputs every 1 hour at horizontal resolution of about 1/3° and 24 z-vertical layers in the troposphere. Comparisons against 47 selected AERONET sites are used. Eight size bins between 0.1 and 10 µm are considered, and dust-radiation interactions are included (Pérez et al., 2006). Wet deposition scheme has been also improved. The simulation has been performed over one year (2004); statistics and time series for the model outputs and AERONET data are used to evaluate the ability of

  8. Toward a Sustainable Society in the Mena (Middle East and North Africa) Region: Roadmap and Priorities

    ERIC Educational Resources Information Center

    El-Bassiouny, Noha

    2012-01-01

    The Business and Society Research Cluster (BSRC) at the German University in Cairo, the El-Khazindar Business Research and Case Center at the American University in Cairo and Misr El-Kheir (MEK) Foundation, Egypt, hosted the region's first sustainability and corporate social responsibility (CSR) case studies conference, entitled "Toward a…

  9. Preliminary definition of geophysical regions for the Middle East and North Africa

    SciTech Connect

    Sweeney, J J; Walter, B

    1998-12-01

    The ability to calibrate seismic stations to improve the monitoring of the Comprehensive Test Ban Treaty is partially limited by the availability of seismic events with known locations and source properties. To confidently extrapolate from these events to aseismic regions, and to properly account for discontinuities in seismic properties requires accurate geophysical models. This paper lays out a preliminary, first-order, regionalization of the Middle East and North African (MENA) region. The model specifies boundaries and velocity structures based on the geology and tectonics of the region, previously published studies, and empirical data observations by the LLNL group. This model is a starting point and is expected to be improved and refined by comparisons with ongoing tomography efforts and the collection of new data. We anticipate that this model and its successors will prove useful as a background model in the process of forming station calibration maps based on intelligent interpolation techniques such as kriging. We also hope the model, as it improves and demonstrates some predictive power, will provide a reference model for broader CTBT research efforts in detection, location and discrimination as well as other aspects of earth science.

  10. Roles of Spatial Scale and Rarity on the Relationship between Butterfly Species Richness and Human Density in South Africa

    PubMed Central

    Mecenero, Silvia; Altwegg, Res; Colville, Jonathan F.; Beale, Colin M.

    2015-01-01

    Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2' to 60' across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation. PMID:25915899

  11. The demographics of human and malaria movement and migration patterns in East Africa

    PubMed Central

    2013-01-01

    Introduction The quantification of parasite movements can provide valuable information for control strategy planning across all transmission intensities. Mobile parasite carrying individuals can instigate transmission in receptive areas, spread drug resistant strains and reduce the effectiveness of control strategies. The identification of mobile demographic groups, their routes of travel and how these movements connect differing transmission zones, potentially enables limited resources for interventions to be efficiently targeted over space, time and populations. Methods National population censuses and household surveys provide individual-level migration, travel, and other data relevant for understanding malaria movement patterns. Together with existing spatially referenced malaria data and mathematical models, network analysis techniques were used to quantify the demographics of human and malaria movement patterns in Kenya, Uganda and Tanzania. Movement networks were developed based on connectivity and magnitudes of flow within each country and compared to assess relative differences between regions and demographic groups. Additional malaria-relevant characteristics, such as short-term travel and bed net use, were also examined. Results Patterns of human and malaria movements varied between demographic groups, within country regions and between countries. Migration rates were highest in 20–30 year olds in all three countries, but when accounting for malaria prevalence, movements in the 10–20 year age group became more important. Different age and sex groups also exhibited substantial variations in terms of the most likely sources, sinks and routes of migration and malaria movement, as well as risk factors for infection, such as short-term travel and bed net use. Conclusion Census and survey data, together with spatially referenced malaria data, GIS and network analysis tools, can be valuable for identifying, mapping and quantifying regional connectivities

  12. Delineating Geographical Regions with Networks of Human Interactions in an Extensive Set of Countries

    PubMed Central

    Sobolevsky, Stanislav; Szell, Michael; Campari, Riccardo; Couronné, Thomas; Smoreda, Zbigniew; Ratti, Carlo

    2013-01-01

    Large-scale networks of human interaction, in particular country-wide telephone call networks, can be used to redraw geographical maps by applying algorithms of topological community detection. The geographic projections of the emerging areas in a few recent studies on single regions have been suggested to share two distinct properties: first, they are cohesive, and second, they tend to closely follow socio-economic boundaries and are similar to existing political regions in size and number. Here we use an extended set of countries and clustering indices to quantify overlaps, providing ample additional evidence for these observations using phone data from countries of various scales across Europe, Asia, and Africa: France, the UK, Italy, Belgium, Portugal, Saudi Arabia, and Ivory Coast. In our analysis we use the known approach of partitioning country-wide networks, and an additional iterative partitioning of each of the first level communities into sub-communities, revealing that cohesiveness and matching of official regions can also be observed on a second level if spatial resolution of the data is high enough. The method has possible policy implications on the definition of the borderlines and sizes of administrative regions. PMID:24367490

  13. Human rights violations and smoking status among South African adults enrolled in the South Africa Stress and Health (SASH) study.

    PubMed

    Dutra, Lauren M; Williams, David R; Gupta, Jhumka; Kawachi, Ichiro; Okechukwu, Cassandra A

    2014-03-01

    Despite South Africa's history of violent political conflict, and the link between stressful experiences and smoking in the literature, no public health study has examined South Africans' experiences of human rights violations and smoking. Using data from participants in the nationally representative cross-sectional South Africa Stress and Health study (SASH), this analysis examined the association between respondent smoking status and both human rights violations experienced by the respondent and violations experienced by the respondents' close friends and family members. SAS-Callable SUDAAN was used to construct separate log-binomial models by political affiliation during apartheid (government or liberation supporters). In comparison to those who reported no violations, in adjusted analyses, government supporters who reported violations of themselves but not others (RR = 1.76, 95% CI: 1.25-2.46) had a significantly higher smoking prevalence. In comparison to liberation supporters who reported no violations, those who reported violations of self only (RR = 1.56, 95%CI: 1.07-2.29), close others only (RR = 1.97, 95%CI: 1.12-3.47), or violations of self and close others due to close others' political beliefs and the respondent's political beliefs (RR = 2.86, 95%CI: 1.70-4.82) had a significantly higher prevalence of smoking. The results of this analysis suggest that a relationship may exist between human rights violations and smoking among South Africa adults. Future research should use longitudinal data to assess causality, test the generalizability of these findings, and consider how to apply these findings to smoking cessation interventions. PMID:24509050

  14. Ethnomycological studies of edible and medicinal mushrooms in the Mount Cameroon region (Cameroon, Africa).

    PubMed

    Kinge, Tonjock R; Tabi, Ebai M; Mih, Afui M; Enow, Egbe A; Njouonkou, L; Nji, T M

    2011-01-01

    Inhabitants of the Mount Cameroon region depend on the forest resources of the region for their livelihood, including the diverse use of macrofungi. With the increasing loss of forest due to exploitation and urbanization, they are liable to rapidly lose their indigenous knowledge of the forest resources, especially of mushrooms. An ethnomycological survey was conducted with the aim of documenting the indigenous knowledge of mushrooms as a prelude to conservation efforts. We also sought to assess the mycophilic and mycophobic tendencies of the inhabitants. It was revealed that traditionally, mushrooms were used as food, medicine, for mythological purposes, for aesthetics, and some poisonous species were also recorded. At least 15 different species were identified to be edible among the Bakweri people. Species used for ethnomedicine among the Bakweris belonged to several genera, including Termitomyces, Auricularia, Agaricus, Daldinia, Dictyophora, Pleurotus, Russula, Trametes, Chlorophyllum, and Ganoderma. Mushrooms were used as love charms, for dispelling evil spirits, and as part of cultural festivals. PMID:22135882

  15. Surface Wave Analysis of Regional Earthquakes in the Eastern Rift System (Africa)

    NASA Astrophysics Data System (ADS)

    Oliva, S. J. C.; Guidarelli, M.; Ebinger, C. J.; Roecker, S. W.; Tiberi, C.

    2015-12-01

    The Northern Tanzania Divergence (NTD), the youngest part of the East African Rift System, presents the opportunity to obtain insights about the birth and early stages of rifting before it progresses to mature rifting and seafloor spreading. This region is particularly interesting because the Eastern rift splits into three arms in this area and develops in a region of thick and cold lithosphere, amid the Archaean Tanzanian craton and the Proterozoic orogenic belt (the Masai block). We analyzed about two thousand seismic events recorded by the 39 broadband stations of the CRAFTI network during its two-year deployment in the NTD area in 2013 to 2014. We present the results of surface wave tomographic inversion obtained from fundamental-mode Rayleigh waves for short periods (between 4 to 14 seconds). Group velocity dispersion curves obtained via multiple filter analysis are path-averaged and inverted to produce 0.1º x 0.1º nodal grid tomographic maps for discrete periods using a 2D generalization of the Backus and Gilbert method. To quantify our results in terms of S-wave velocity structure the average group velocity dispersion curves are then inverted, using a linearized least-squares inversion scheme, in order to obtain the shear wave velocity structure for the upper 20 km of the crust. Low velocity anomalies are observed in the region 50 km south of Lake Natron, as well as in the area of the Ngorongoro crater. The implications of our results for the local tectonics and the development of the rifting system will be discussed in light of the growing geophysical database from this region.

  16. Twentieth century seismicity of the Koffiefontein region (Free State, South Africa): consistent determination of earthquake catalogue parameters from mixed data types

    NASA Astrophysics Data System (ADS)

    Strasser, F. O.; Albini, P.; Flint, N. S.; Beauval, C.

    2015-10-01

    The preparation of earthquake catalogues for seismic hazard analysis requires the use of uniform parameters, in particular for magnitudes, although the original data include a variety of formats, such as macroseismic intensities and various instrumental magnitude scales. In regions of low seismicity, such as South Africa, data are generally sparse and not always sufficient to develop locally calibrated conversion relations. They can nevertheless be used to test the applicability of imported conversion relations, as well as their consistency. The Koffiefontein region of South Africa provides a good test case in view of its somewhat higher level of seismicity, and central geographic location within the country. This paper reviews determinations of location and magnitude parameters for a suite of moderate-to-large earthquakes that have occurred in this region between 1903 and 1985.

  17. Performance of the CORDEX-Africa regional climate simulations in representing the hydrological cycle of the Niger River basin

    NASA Astrophysics Data System (ADS)

    Mascaro, Giuseppe; White, Dave D.; Westerhoff, Paul; Bliss, Nadya

    2015-12-01

    The water resources of the Niger River basin (NRB) in West Africa are crucial to support the socioeconomic development of nine countries. In this study, we compared and evaluated performances of simulations at 0.44° resolution of several regional climate models (RCMs) of the Coordinated Regional climate Downscaling Experiment (CORDEX) in reproducing the statistical properties of the hydrological cycle of the NRB in the current climate. To capture the large range of climatic zones in the region, analyses were conducted by spatially averaging the water balance components in four nested subbasins. Most RCMs overestimate (order of +10% to +400%, depending on model and subbasin) the mean annual difference between precipitation (P) and evaporation (E), whose observed value was assumed equal to the long-term discharge based on the mass conservation principle. This is due to a tendency to simulate larger mean annual P and a weak hydrological cycle in the E channel. Some exceptions appear in the humid most-upstream subbasin, where a few RCMs underestimate P. Overall, the representation of the water balance is mostly sensitive to the parameterized land surface and atmospheric processes of the nested RCMs, with less influence of the driving general circulation model. This finding is supported by further analyses on seasonal cycle and spatial variability of the water balance components and on model performances in reproducing observed climatology. Results of this work should be considered when RCMs are used directly or in impact studies to develop policies and plan investments aimed at ensuring water sustainability in the NRB.

  18. Cholera outbreaks in Africa.

    PubMed

    Mengel, Martin A; Delrieu, Isabelle; Heyerdahl, Leonard; Gessner, Bradford D

    2014-01-01

    During the current seventh cholera pandemic, Africa bore the major brunt of global disease burden. More than 40 years after its resurgence in Africa in 1970, cholera remains a grave public health problem, characterized by large disease burden, frequent outbreaks, persistent endemicity, and high CFRs, particularly in the region of the central African Great Lakes which might act as reservoirs for cholera. There, cases occur year round with a rise in incidence during the rainy season. Elsewhere in sub-Saharan Africa, cholera occurs mostly in outbreaks of varying size with a constant threat of widespread epidemics. Between 1970 and 2011, African countries reported 3,221,050 suspected cholera cases to the World Health Organization, representing 46 % of all cases reported globally. Excluding the Haitian epidemic, sub-Saharan Africa accounted for 86 % of reported cases and 99 % of deaths worldwide in 2011. The number of cholera cases is possibly much higher than what is reported to the WHO due to the variation in modalities, completeness, and case definition of national cholera data. One source on country specific incidence rates for Africa, adjusting for underreporting, estimates 1,341,080 cases and 160,930 deaths (52.6 % of 2,548,227 estimated cases and 79.6 % of 209,216 estimated deaths worldwide). Another estimates 1,411,453 cases and 53,632 deaths per year, respectively (50 % of 2,836,669 estimated cases and 58.6 % of 91,490 estimated deaths worldwide). Within Africa, half of all cases between 1970 and 2011 were notified from only seven countries: Angola, Democratic Republic of the Congo, Mozambique, Nigeria, Somalia, Tanzania, and South Africa. In contrast to a global trend of decreasing case fatality ratios (CFRs), CFRs have remained stable in Africa at approximately 2 %. Early propagation of cholera outbreaks depends largely on the extent of individual bacterial shedding, host and organism characteristics, the likelihood of people coming into contact with

  19. South Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  20. GROUND TRUTH, MAGNITUDE CALIBRATION AND REGIONAL PHASE PROPAGATION AND DETECTION IN THE MIDDLE EAST AND HORN OF AFRICA

    SciTech Connect

    Nyblade, A; Adams, A; Brazier, R; Park, Y; Rodgers, A

    2006-07-10

    In this project, we are exploiting unique and open source seismic data sets to improve seismic monitoring across the Middle East (including the Iranian Plateau, Zagros Mountains, Arabian Peninsula, Turkish Plateau, Gulf of Aqaba, Dead Sea Rift) and the Horn of Africa (including the northern part of the East African Rift, Afar Depression, southern Red Sea and Gulf of Aden). The data sets are being used to perform three related tasks. (1) We are determining moment tensors, moment magnitudes and source depths for regional events in the magnitude 3.0 to 6.0 range. (2) These events are being used to characterize high-frequency (0.5-16 Hz) regional phase attenuation and detection thresholds, especially from events in Iran recorded at stations across the Arabian Peninsula. (3) We are collecting location ground truth at GT5 (local) and GT20 (regional) levels for seismic events with M > 2.5, including source geometry information and source depths. In the first phase of this project, seismograms from earthquakes in the Zagros Mountains recorded at regional distances have been inverted for moment tensors, and source depths for the earthquakes have been determined via waveform matching. Early studies of the distribution of seismicity in the Zagros region found evidence for earthquakes in the upper mantle. But subsequent relocations of teleseismic earthquakes suggest that source depths are generally much shallower, lying mainly within the upper crust. Nine events with magnitudes between 5 and 6 have been studied so far. Source depths for six of the events are within the upper crust, and three are located within the lower crust. The uncertainty in the source depths of the lower crustal events allows for the possibility that some of them may have even nucleated within the upper mantle. Eight events have thrust mechanisms and one has a strike-slip mechanism. We also report estimates of three-dimensional P- and S-wave velocity structure of the upper mantle beneath the Arabian

  1. Spatiotemporal analysis of droughts using self-calibrating Palmer's Drought Severity Index in the central region of South Africa

    NASA Astrophysics Data System (ADS)

    Edossa, Desalegn C.; Woyessa, Yali E.; Welderufael, Worku A.

    2015-08-01

    The loss of life and property from drought events has forced society to focus on the development of reliable early warning systems which may enable farmers and other stakeholders to correctly and timely adapt to the expected impacts of climatic hazard. However, a scientific approach to a reliable early warning system for a region requires, among others, characterisation of drought events in the region in terms of duration, magnitude, intensity and frequency using standard drought indices. Therefore, the objective of this study was to identify and characterise drought events in the Modder River basin, central region of South Africa, using a self-calibrated Palmer's Drought Severity Index (sc-PDSI). Attempts were also made to establish a relationship between meteorological and hydrological drought events in the region. During the period of analysis, the total number of drought episodes identified in the study area ranged between eight and sixteen. It was found that the most severe drought episodes occurred during the period 1992-1995 followed by the period 1982-1987. Results of analysis of seasonal drought events in one of the quaternary catchments (C52A) revealed that peak drought events during the three summer months (November, December and January) occurred in the area in 1993. However, in terms of event magnitude and intensity, the worst drought events were recorded during the period December 1982-July 1987, followed by the event that ensued during December 1989-September 1995. Results of analysis of decadal variation of drought events showed that the number of extreme and moderate drought events recorded in the catchment showed statistically significant increasing trends during the five decades at 5 % significance level. Moreover, spectral analysis of sc-PDSI time series in the region identified periodicities in the time series ranging from 6 years (C52E) to 16 years (C52K). In terms of the spatial extent of extreme drought events, the maximum areal coverage (91

  2. Linguistic Human Rights in Africa: Challenges and Prospects for Indigenous Languages in Kenya

    ERIC Educational Resources Information Center

    Musau, Paul M.

    2003-01-01

    With reference to Kenya, the paper shows that although linguistic rights have been eloquently articulated in various charters and declarations, their implementation has been problematic. In Africa this has led to an imbalance of status between the former colonial languages and the indigenous ones. This imbalance is evident in the educational…

  3. HIV/AIDS and debt crises: threat to human survival in sub-Saharan Africa.

    PubMed

    Odhiambo, Walter

    2003-01-01

    Whether originating from the African primates in the Central African forest, or from polio vaccine trials by some western scientists, there is no doubt that HIV/AIDS poses the greatest single challenge to the marginalized poor of Africa, where it has found a malnourished, vulnerable, defenceless host. Collective response is necessary by physicians and health professionals who must be at the forefront of restoring hope and a dignified quality of life. In sub-Saharan Africa, HIV/AIDS is not a security threat but a painful slow death which forces victims into exhausting their lifetime savings on expensive medicines and massive hospital bills. It leaves helpless orphans to struggle for survival in countries where government subsidy on education and healthcare has been long withdrawn so as to channel the meagre state resources into debt servicing. A combination of the HIV/AIDS pandemic and Third World debt is subjecting millions of children to the worst form of violence. This article reviews the situation in sub-Saharan Africa, with special reference to Kenya and South Africa as examples of countries devastated by the HIV/AIDS pandemic. Changes elsewhere are noted and the global response is critically examined. PMID:12868516

  4. Education and Language: A Human Right for Sustainable Development in Africa

    ERIC Educational Resources Information Center

    Babaci-Wilhite, Zehlia; Geo-JaJa, Macleans A.; Lou, Shizhou

    2012-01-01

    Pre-colonial Africa was neither an educationally nor a technologically unsophisticated continent. While education was an integral part of the culture, issues of language identification and standardisation which are subject to contentious debate today were insignificant. Children learned community knowledge and history by asking questions instead…

  5. Analysis of human accelerated DNA regions using archaic hominin genomes.

    PubMed

    Burbano, Hernán A; Green, Richard E; Maricic, Tomislav; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Kelso, Janet; Pollard, Katherine S; Lachmann, Michael; Pääbo, Svante

    2012-01-01

    Several previous comparisons of the human genome with other primate and vertebrate genomes identified genomic regions that are highly conserved in vertebrate evolution but fast-evolving on the human lineage. These human accelerated regions (HARs) may be regions of past adaptive evolution in humans. Alternatively, they may be the result of non-adaptive processes, such as biased gene conversion. We captured and sequenced DNA from a collection of previously published HARs using DNA from an Iberian Neandertal. Combining these new data with shotgun sequence from the Neandertal and Denisova draft genomes, we determine at least one archaic hominin allele for 84% of all positions within HARs. We find that 8% of HAR substitutions are not observed in the archaic hominins and are thus recent in the sense that the derived allele had not come to fixation in the common ancestor of modern humans and archaic hominins. Further, we find that recent substitutions in HARs tend to have come to fixation faster than substitutions elsewhere in the genome and that substitutions in HARs tend to cluster in time, consistent with an episodic rather than a clock-like process underlying HAR evolution. Our catalog of sequence changes in HARs will help prioritize them for functional studies of genomic elements potentially responsible for modern human adaptations. PMID:22412940

  6. Analysis of Human Accelerated DNA Regions Using Archaic Hominin Genomes

    PubMed Central

    Burbano, Hernán A.; Green, Richard E.; Maricic, Tomislav; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Kelso, Janet; Pollard, Katherine S.; Lachmann, Michael; Pääbo, Svante

    2012-01-01

    Several previous comparisons of the human genome with other primate and vertebrate genomes identified genomic regions that are highly conserved in vertebrate evolution but fast-evolving on the human lineage. These human accelerated regions (HARs) may be regions of past adaptive evolution in humans. Alternatively, they may be the result of non-adaptive processes, such as biased gene conversion. We captured and sequenced DNA from a collection of previously published HARs using DNA from an Iberian Neandertal. Combining these new data with shotgun sequence from the Neandertal and Denisova draft genomes, we determine at least one archaic hominin allele for 84% of all positions within HARs. We find that 8% of HAR substitutions are not observed in the archaic hominins and are thus recent in the sense that the derived allele had not come to fixation in the common ancestor of modern humans and archaic hominins. Further, we find that recent substitutions in HARs tend to have come to fixation faster than substitutions elsewhere in the genome and that substitutions in HARs tend to cluster in time, consistent with an episodic rather than a clock-like process underlying HAR evolution. Our catalog of sequence changes in HARs will help prioritize them for functional studies of genomic elements potentially responsible for modern human adaptations. PMID:22412940

  7. The Impact of Regional Climate Change on Malaria Risk due to Greenhouse Forcing and Land-Use Changes in Tropical Africa

    PubMed Central

    Fink, Andreas H.; Morse, Andrew P.; Paeth, Heiko

    2011-01-01

    Background: Climate change will probably alter the spread and transmission intensity of malaria in Africa. Objectives: In this study, we assessed potential changes in the malaria transmission via an integrated weather–disease model. Methods: We simulated mosquito biting rates using the Liverpool Malaria Model (LMM). The input data for the LMM were bias-corrected temperature and precipitation data from the regional model (REMO) on a 0.5° latitude–longitude grid. A Plasmodium falciparum infection model expands the LMM simulations to incorporate information on the infection rate among children. Malaria projections were carried out with this integrated weather–disease model for 2001 to 2050 according to two climate scenarios that include the effect of anthropogenic land-use and land-cover changes on climate. Results: Model-based estimates for the present climate (1960 to 2000) are consistent with observed data for the spread of malaria in Africa. In the model domain, the regions where malaria is epidemic are located in the Sahel as well as in various highland territories. A decreased spread of malaria over most parts of tropical Africa is projected because of simulated increased surface temperatures and a significant reduction in annual rainfall. However, the likelihood of malaria epidemics is projected to increase in the southern part of the Sahel. In most of East Africa, the intensity of malaria transmission is expected to increase. Projections indicate that highland areas that were formerly unsuitable for malaria will become epidemic, whereas in the lower-altitude regions of the East African highlands, epidemic risk will decrease. Conclusions: We project that climate changes driven by greenhouse-gas and land-use changes will significantly affect the spread of malaria in tropical Africa well before 2050. The geographic distribution of areas where malaria is epidemic might have to be significantly altered in the coming decades. PMID:21900078

  8. An overview of regional and local characteristics of aerosols in South Africa using satellite, ground, and modeling data

    NASA Astrophysics Data System (ADS)

    Hersey, S. P.; Garland, R. M.; Crosbie, E.; Shingler, T.; Sorooshian, A.; Piketh, S.; Burger, R.

    2014-09-01

    domestic burning influence, (2) urban and suburban residential sites with no domestic burning in the immediate vicinity, (3) industrial sites, and (4) one traffic site situated at a major freeway interchange. PM10 concentrations in township areas are 56% higher than in developed residential areas and 78% higher than in industrial areas as an annual average, with PM10 in townships 63 and 136% higher than developed residential and industrial areas, respectively, in winter (June, July, August). Monthly PM10 and PM2.5 concentrations reach annual maxima during winter at all sites except in industrial areas. At industrial sites, maxima in PM10 and PM2.5 tend to occur during summer (December-February), when photochemical generation of secondary aerosol is expected and when deep and unstable boundary layers allow high stack emissions (emitted above the boundary layer during winter) to reach the ground in close proximity to point sources. Diurnal profiles of PM10 and PM2.5 display maxima during morning (06:00-09:00 LT) and evening (17:00-22:00 LT) at nearly every site - especially during winter - and underscore the importance of domestic burning as a major source of primary particles. Multi-year averages indicate that evening maxima at some township sites average in excess of 400 μg m-3. These results from the urban/industrial Gauteng area quantitatively confirm previous studies suggesting that the lowest-income populations of South Africa experience the poorest air quality, and demonstrate that domestic burning results in frequent exposure to high concentrations of particulate pollution in the region comprising the cities of Johannesburg and Tshwane. While remotely-sensed data are frequently used as a proxy for ground air quality, we report poor correlations between PM concentrations and satellite parameters and suggest that this practice is not appropriate in metropolitan South Africa. Disagreement between satellite and ground data may be attributed to a number of factors: (1

  9. Ape malaria transmission and potential for ape-to-human transfers in Africa.

    PubMed

    Makanga, Boris; Yangari, Patrick; Rahola, Nil; Rougeron, Virginie; Elguero, Eric; Boundenga, Larson; Moukodoum, Nancy Diamella; Okouga, Alain Prince; Arnathau, Céline; Durand, Patrick; Willaume, Eric; Ayala, Diego; Fontenille, Didier; Ayala, Francisco J; Renaud, François; Ollomo, Benjamin; Prugnolle, Franck; Paupy, Christophe

    2016-05-10

    Recent studies have highlighted the large diversity of malaria parasites infecting African great apes (subgenus Laverania) and their strong host specificity. Although the existence of genetic incompatibilities preventing the cross-species transfer may explain host specificity, the existence of vectors with a high preference for a determined host represents another possibility. To test this hypothesis, we undertook a 15-mo-long longitudinal entomological survey in two forest regions of Gabon, where wild apes live, at different heights under the canopy. More than 2,400 anopheline mosquitoes belonging to 18 species were collected. Among them, only three species of Anopheles were found infected with ape Plasmodium: Anopheles vinckei, Anopheles moucheti, and Anopheles marshallii Their role in transmission was confirmed by the detection of the parasites in their salivary glands. Among these species, An. vinckei showed significantly the highest prevalence of infection and was shown to be able to transmit parasites of both chimpanzees and gorillas. Transmission was also shown to be conditioned by seasonal factors and by the heights of capture under the canopy. Moreover, human landing catches of sylvan Anopheles demonstrated the propensity of these three vector species to feed on humans when available. Our results suggest therefore that the strong host specificity observed in the Laveranias is not linked to a specific association between the vertebrate host and the vector species and highlight the potential role of these vectors as bridge between apes and humans. PMID:27071123

  10. An Exploration of Public Attitudes Toward LGBTI Rights in the Gauteng City-Region of South Africa.

    PubMed

    Mahomed, Faraaz; Trangoš, Guy

    2016-10-01

    South Africa's legal framework on the rights of sexual minorities is one of the most progressive in the world. Despite this, discrimination and violence against gay and lesbian people continues to be a challenge. Using large-scale survey data gathered in the Gauteng City-Region, this study examines public attitudes related to homosexuality. Most respondents to the survey felt that sexual minorities should have equal rights. However, a considerable proportion of respondents also held negative views toward gay and lesbian individuals, with close to two fifths of respondents believing that homosexuality is against the values of their community, and over 12% of participants holding the view that it is acceptable to be violent toward gays and lesbians. Further analysis also consists of an examination of responses cross-tabulated with the variables of race, gender, age, and education, revealing that younger, well-educated South Africans tend to be the most tolerant, but also exhibiting large variances in attitudes within groups. PMID:26914610

  11. Functional Traits in Parallel Evolutionary Radiations and Trait-Environment Associations in the Cape Floristic Region of South Africa.

    PubMed

    Mitchell, Nora; Moore, Timothy E; Mollmann, Hayley Kilroy; Carlson, Jane E; Mocko, Kerri; Martinez-Cabrera, Hugo; Adams, Christopher; Silander, John A; Jones, Cynthia S; Schlichting, Carl D; Holsinger, Kent E

    2015-04-01

    Evolutionary radiations with extreme levels of diversity present a unique opportunity to study the role of the environment in plant evolution. If environmental adaptation played an important role in such radiations, we expect to find associations between functional traits and key climatic variables. Similar trait-environment associations across clades may reflect common responses, while contradictory associations may suggest lineage-specific adaptations. Here, we explore trait-environment relationships in two evolutionary radiations in the fynbos biome of the highly biodiverse Cape Floristic Region (CFR) of South Africa. Protea and Pelargonium are morphologically and evolutionarily diverse genera that typify the CFR yet are substantially different in growth form and morphology. Our analytical approach employs a Bayesian multiple-response generalized linear mixed-effects model, taking into account covariation among traits and controlling for phylogenetic relationships. Of the pairwise trait-environment associations tested, 6 out of 24 were in the same direction and 2 out of 24 were in opposite directions, with the latter apparently reflecting alternative life-history strategies. These findings demonstrate that trait diversity within two plant lineages may reflect both parallel and idiosyncratic responses to the environment, rather than all taxa conforming to a global-scale pattern. Such insights are essential for understanding how trait-environment associations arise and how they influence species diversification. PMID:25811086

  12. Polybrominated diphenyl ethers and alternative flame retardants in air and precipitation samples from the northern Lake Victoria region, East Africa.

    PubMed

    Arinaitwe, Kenneth; Muir, Derek C G; Kiremire, Bernard T; Fellin, Phil; Li, Henrik; Teixeira, Camilla

    2014-01-01

    High volume air and precipitation samples were collected close to the shore of Lake Victoria at Entebbe, Uganda, between October 2008 and July 2010 inclusive. Polybrominated diphenyl ethers (PBDEs) and alternative flame retardants (AFRs) were analyzed by GC-MS. BDEs 47, 99, and 209 were the predominant PBDEs with mean concentrations (in air) of 9.84, 4.38, 8.27 pg m(-3) and mean fluxes in precipitation of 3.40, 6.23, and 7.82 ng m(-2) sample(-1), respectively. 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and hexabromocyclododecane (HBCDD), anti- and syn-Dechlorane plus were detected at levels comparable with those of PBDEs. Both PBDEs and AFRs in air generally increased from 2008 to 2010. Elevated PBDE concentrations in air were associated with slow moving low altitude air masses from the region immediately adjacent to the lake, while low concentrations were mostly associated with fast moving westerly and southwesterly air masses. Analysis of the octa- and nona-BDE profiles suggested photolysis and pyrolytic debromination of BDE-209 in the air samples. The highly halogenated and most abundant PBDEs and AFRs in air also predominated in precipitation samples. This is the first study to report flame retardants in high volume air samples and precipitation in Equatorial Africa. PMID:24400732

  13. Recombination in the Human Pseudoautosomal Region PAR1

    PubMed Central

    Hinch, Anjali G.; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R.

    2014-01-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  14. Recombination in the human Pseudoautosomal region PAR1.

    PubMed

    Hinch, Anjali G; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R

    2014-07-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  15. Climate, Environment and Early Human Innovation: Stable Isotope and Faunal Proxy Evidence from Archaeological Sites (98-59ka) in the Southern Cape, South Africa.

    PubMed

    Roberts, Patrick; Henshilwood, Christopher S; van Niekerk, Karen L; Keene, Petro; Gledhill, Andrew; Reynard, Jerome; Badenhorst, Shaw; Lee-Thorp, Julia

    2016-01-01

    The Middle Stone Age (MSA) of southern Africa, and in particular its Still Bay and Howiesons Poort lithic traditions, represents a period of dramatic subsistence, cultural, and technological innovation by our species, Homo sapiens. Climate change has frequently been postulated as a primary driver of the appearance of these innovative behaviours, with researchers invoking either climate instability as a reason for the development of buffering mechanisms, or environmentally stable refugia as providing a stable setting for experimentation. Testing these alternative models has proved intractable, however, as existing regional palaeoclimatic and palaeoenvironmental records remain spatially, stratigraphically, and chronologically disconnected from the archaeological record. Here we report high-resolution records of environmental shifts based on stable carbon and oxygen isotopes in ostrich eggshell (OES) fragments, faunal remains, and shellfish assemblages excavated from two key MSA archaeological sequences, Blombos Cave and Klipdrift Shelter. We compare these records with archaeological material remains in the same strata. The results from both sites, spanning the periods 98-73 ka and 72-59 ka, respectively, show significant changes in vegetation, aridity, rainfall seasonality, and sea temperature in the vicinity of the sites during periods of human occupation. While these changes clearly influenced human subsistence strategies, we find that the remarkable cultural and technological innovations seen in the sites cannot be linked directly to climate shifts. Our results demonstrate the need for scale-appropriate, on-site testing of behavioural-environmental links, rather than broader, regional comparisons. PMID:27383620

  16. Climate, Environment and Early Human Innovation: Stable Isotope and Faunal Proxy Evidence from Archaeological Sites (98-59ka) in the Southern Cape, South Africa

    PubMed Central

    Keene, Petro; Gledhill, Andrew; Reynard, Jerome; Badenhorst, Shaw

    2016-01-01

    The Middle Stone Age (MSA) of southern Africa, and in particular its Still Bay and Howiesons Poort lithic traditions, represents a period of dramatic subsistence, cultural, and technological innovation by our species, Homo sapiens. Climate change has frequently been postulated as a primary driver of the appearance of these innovative behaviours, with researchers invoking either climate instability as a reason for the development of buffering mechanisms, or environmentally stable refugia as providing a stable setting for experimentation. Testing these alternative models has proved intractable, however, as existing regional palaeoclimatic and palaeoenvironmental records remain spatially, stratigraphically, and chronologically disconnected from the archaeological record. Here we report high-resolution records of environmental shifts based on stable carbon and oxygen isotopes in ostrich eggshell (OES) fragments, faunal remains, and shellfish assemblages excavated from two key MSA archaeological sequences, Blombos Cave and Klipdrift Shelter. We compare these records with archaeological material remains in the same strata. The results from both sites, spanning the periods 98–73 ka and 72–59 ka, respectively, show significant changes in vegetation, aridity, rainfall seasonality, and sea temperature in the vicinity of the sites during periods of human occupation. While these changes clearly influenced human subsistence strategies, we find that the remarkable cultural and technological innovations seen in the sites cannot be linked directly to climate shifts. Our results demonstrate the need for scale-appropriate, on-site testing of behavioural-environmental links, rather than broader, regional comparisons. PMID:27383620

  17. Public health considerations for mass gatherings in the Middle East and North Africa (MENA) region.

    PubMed

    AlNsour, M; Fleischauer, A

    2013-01-01

    This review describes major mass gatherings in the MENA region and the public health implications of these events, and provides recommendations for public health officials of the host country. Through our search of the literature for peer-reviewed publications, we identified relevant 77 papers; all were related to the annual Hajj. Using the information obtained from the literature review, the Eastern Mediterranean Public Health Network (EMPHNET) and the Centers for Disease Control and Prevention (CDC) developed and conducted 2 workshops on Public Health Surveillance during Mass Gatherings for field epidemiology training programmes and ministry of health focal points from 10 countries. The main potential public health concerns associated with mass gatherings include: infectious diseases (e.g. respiratory disease, gastro-intestinal tract disease, foodborne disease), injuries, traffic accidents, heat-related illnesses, insect stings, non-communicable diseases and terrorism. PMID:24673098

  18. Structural analysis of the 5 prime flanking region of the. beta. -globin gene in African sickle cell anemia patients: Further evidence for three origins of the sickle cell mutation in Africa

    SciTech Connect

    Chebloune, Y.; Pagnier, J.; Trabuchet, G.; Faure, C.; Verdier, G.; Labie, D.; Nigon, V. )

    1988-06-01

    Haplotype analysis of the {beta}-globin gene cluster shows two regions of DNA characterized by nonrandom association of restriction site polymorphisms. These regions are separated by a variable segment containing the repeated sequences (ATTTT){sub n} and (AT){sub x}T{sub y}, which might be involved in recombinational events. Studies of haplotypes linked to the sickle cell gene in Africa provide strong argument for three origins of the mutation: Benin, Senegal, and the Central African Republic. The structure of the variable segment in the three African populations was studied by S1 nuclease mapping of genomic DNA, which allows a comparison of several samples. A 1080-base-pair DNA segment was sequenced for one sample from each population. S1 nuclease mapping confirmed the homogeneity of each population with regard to both (ATTTT){sub n} and (AT){sub x}T{sub y} repeats. The authors found three additional structures for (AT){sub x}T{sub y} correlating with the geographic origin of the patients. Ten other nucleotide positions, 5{prime} and 3{prime} to the (AT){sub x}T{sub y} copies, were found to be variable when compared to homologous sequences from human and monkey DNAs. These results allow us to propose an evolutionary scheme for the polymorphisms in the 5{prime} flanking region of the {beta}-globin gene. The results strongly support the hypothesis of three origins for the sickle mutation in Africa.

  19. NMMB/BSC-DUST: model validation at regional scale in Northern Africa

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Pérez, Carlos; Jorba, Oriol; María Baldasano, José; Janjic, Zavisa; Black, Tom; Slobodan, Nickovic; Prigent, Catherine; Laurent, Benoit

    2010-05-01

    While mineral dust distribution and effects are important at global scales, they strongly depend on dust emissions that are controlled on small spatial and temporal scales. Indeed, the accuracy of surface wind speed used in dust models is crucial. Due to the cubic higher-order power dependency on wind friction velocity and the threshold behaviour of dust emissions, small errors on surface wind speed lead to large dust emission errors. Most global dust models use prescribed wind fields provided by meteorological centres (e.g., NCEP and ECMWF) and their spatial resolution is currently never better than about 1°×1°. Such wind speeds tend to be strongly underestimated over large arid and semi-arid areas and do not account for reflect mesoscale character of systems responsible for a significant fraction of dust emissions regionally and globally. Other Another strong uncertainties in dust emissions from such approaches are related to the missrepresentation originates from of coarse representation of high subgrid-scale spatial heterogeneity in soil and vegetation boundary conditions, mainly in semi-arid areas. With the development of the new model NMMB-BSC/DUST [Pérez et al., 2008], we are now focusing on the evalution of the model sensitivity to several processes related to dust emissions. The results presented here are an intermediate step to provide global dust forecasts up to 7 days at sub-synoptic resolutions in the near future. NMMB-BSC/DUST is coupled online with the NOAA/NCEP/EMC global/regional NMMB atmospheric model [Janjic, 2005] extending from meso to global scales an being fully embedded into the Earth System Modeling Framework (ESMF). We performed regional simulations for the Northern African domain, including the Arabian peninsula and southern/central Europe (0 to 65°N and 25°W to 55°E) at 1/3°x1/3° and 1/6x1/6° horizontal resolution with 64 vertical layers. The model is initialized with 6-hourly updated NCEP 1x1° analysis data with a dust spin

  20. On Expression Patterns and Developmental Origin of Human Brain Regions

    PubMed Central

    Kirsch, Lior; Chechik, Gal

    2016-01-01

    Anatomical substructures of the human brain have characteristic cell-types, connectivity and local circuitry, which are reflected in area-specific transcriptome signatures, but the principles governing area-specific transcription and their relation to brain development are still being studied. In adult rodents, areal transcriptome patterns agree with the embryonic origin of brain regions, but the processes and genes that preserve an embryonic signature in regional expression profiles were not quantified. Furthermore, it is not clear how embryonic-origin signatures of adult-brain expression interplay with changes in expression patterns during development. Here we first quantify which genes have regional expression-patterns related to the developmental origin of brain regions, using genome-wide mRNA expression from post-mortem adult human brains. We find that almost all human genes (92%) exhibit an expression pattern that agrees with developmental brain-region ontology, but that this agreement changes at multiple phases during development. Agreement is particularly strong in neuron-specific genes, but also in genes that are not spatially correlated with neuron-specific or glia-specific markers. Surprisingly, agreement is also stronger in early-evolved genes. We further find that pairs of similar genes having high agreement to developmental region ontology tend to be more strongly correlated or anti-correlated, and that the strength of spatial correlation changes more strongly in gene pairs with stronger embryonic signatures. These results suggest that transcription regulation of most genes in the adult human brain is spatially tuned in a way that changes through life, but in agreement with development-determined brain regions. PMID:27564987

  1. Demographic Inference Using Spectral Methods on SNP Data, with an Analysis of the Human Out-of-Africa Expansion

    PubMed Central

    Lukić, Sergio; Hey, Jody

    2012-01-01

    We present an implementation of a recently introduced method for estimating the allele-frequency spectrum under the diffusion approximation. For single-nucleotide polymorphism (SNP) frequency data from multiple populations, the method computes numerical solutions to the allele-frequency spectrum (AFS) under a complex model that includes population splitting events, migration, population expansion, and admixture. The solution to the diffusion partial differential equation (PDE) that mimics the evolutionary process is found by means of truncated polynomial expansions. In the absence of gene flow, our computation of frequency spectra yields exact results. The results are compared to those that use a finite-difference method and to forward diffusion simulations. In general, all the methods yield comparable results, although the polynomial-based approach is the most accurate in the weak-migration limit. Also, the economical use of memory attained by the polynomial expansions makes the study of models with four populations possible for the first time. The method was applied to a four-population model of the human expansion out of Africa and the peopling of the Americas, using the Environmental Genome Project (EGP) SNP database. Although our confidence intervals largely overlapped previous analyses of these data, some were significantly different. In particular, estimates of migration among African, European, and Asian populations were considerably lower than those in a previous study and the estimated time of migration out of Africa was earlier. The estimated time of founding of a human population outside of Africa was 52,000 years (95% confidence interval: 36,000–80,800 years). PMID:22865734

  2. Implications of Special Regions to Conducting Human Activities on Mars

    NASA Astrophysics Data System (ADS)

    Rummel, J. D.; Barlow, N. G.; Beaty, D. W.; Jones, M. A.; Hipkin, V.

    2014-12-01

    A MEPAG Science Analysis Group (SAG) has undertaken an analysis of Special Regions (SR) on Mars—regions where indigenous martian life could exist or where Earth microbes, if introduced, could survive and reproduce. The SR-SAG has considered the impact of SR on future human activities on the martian surface. Human exploration requires access to in-situ resources, some of which may be found in SR. Water and oxygen for ISRU are found in the atmosphere, surface/near-surface ice, hydrated minerals, and perchlorates. Water ice is most abundant at latitudes poleward of ~60 degrees, but polar darkness, cold temperatures, and CO2 degassing present hazards to human operations in these regions. Accessible water is more limited toward the equator, though temperature and solar energy conditions become more favorable. The possible presence of liquid water in Recurring Slope Lineae and active gullies leads to their treatment as SR. Fuel for surface operations and propellants for crew ascent could be manufactured from the martian atmosphere and surface materials, but dust in the atmosphere may clog ISRU equipment and perchlorate is toxic to humans. Power may be produced from solar or nuclear energy. Reliance on solar energy limits operations to the equatorial zone where easily accessible ice resources are limited. Nuclear power allows surface operations at a range of latitudes, but waste heat could convert some non-SR into SR. Radiation shielding is necessary for long-term human operations on Mars and could be obtained by deposition of regolith or by water storage in tanks or as ice around habitats, or the use of underground habitats. SR-SAG recognizes that it will be impossible for all human-associated processes and operations to be conducted within entirely closed systems. Protocols need to be established so (1) human missions to Mars will not contaminate SR nor be contaminated by materials from them, and (2) human activities on Mars will avoid converting areas into SR.

  3. Habitat type and nursery function for coastal marine fish species, with emphasis on the Eastern Cape region, South Africa

    NASA Astrophysics Data System (ADS)

    Whitfield, Alan K.; Pattrick, Paula

    2015-07-01

    A considerable amount of research has been undertaken to document and assess the nursery function of a variety of coastal habitats for marine fish species around the world. Most of these studies have focused on particular habitats and have generally been confined to a limited range of fish species associated with specific nursery areas. In this review we conduct a general assessment of the state of knowledge of coastal habitats in fulfilling the nursery-role concept for marine fishes, with particular emphasis on biotic and abiotic factors that influence nursery value. A primary aim was to synthesize information that can be used to drive sound conservation planning and provide a conceptual framework so that new marine protected areas (MPAs) incorporate the full range of nursery areas that are present within the coastal zone. We also use published data from a coastal section in the Eastern Cape Province, South Africa, to highlight the differential use of shallow aquatic habitats by a range of juvenile marine fish species within this region. Although the Eastern Cape case study does not assess the relative growth, food availability or predation in nursery and non-nursery areas within the coastal zone, it does document which habitats are important to the juveniles of dominant marine species within each area. These habitats, which range from intertidal pools, subtidal gulleys and surf zones to estuaries, do appear to perform a key role in the biological success of species assemblages, with the juveniles of particular marine fishes tending to favour specific nursery areas. According to a multivariate analysis of nursery habitat use within this region, marine species using estuaries tend to differ considerably from those using nearshore coastal waters, with a similar pattern likely to occur elsewhere in the world.

  4. The shared genomic architecture of human nucleolar organizer regions

    PubMed Central

    Floutsakou, Ioanna; Agrawal, Saumya; Nguyen, Thong T.; Seoighe, Cathal; Ganley, Austen R.D.; McStay, Brian

    2013-01-01

    The short arms of the five acrocentric human chromosomes harbor sequences that direct the assembly and function of the nucleolus, one of the key functional domains of the nucleus, yet they are absent from the current human genome assembly. Here we describe the genomic architecture of these human nucleolar organizers. Sequences distal and proximal to ribosomal gene arrays are conserved among the acrocentric chromosomes, suggesting they are sites of frequent recombination. Although previously believed to be heterochromatic, characterization of these two flanking regions reveals that they share a complex genomic architecture similar to other euchromatic regions of the genome, but they have distinct genomic characteristics. Proximal sequences are almost entirely segmentally duplicated, similar to the regions bordering centromeres. In contrast, the distal sequence is predominantly unique to the acrocentric short arms and is dominated by a very large inverted repeat. We show that the distal element is localized to the periphery of the nucleolus, where it appears to anchor the ribosomal gene repeats. This, combined with its complex chromatin structure and transcriptional activity, suggests that this region is involved in nucleolar organization. Our results provide a platform for investigating the role of NORs in nucleolar formation and function, and open the door for determining the role of these regions in the well-known empirical association of nucleoli with pathology. PMID:23990606

  5. Paleoenvironmental and Human Behavioral Implications of the Boegoeberg 1 Late Pleistocene Hyena Den, Northern Cape Province, South Africa

    NASA Astrophysics Data System (ADS)

    Klein, Richard G.; Cruz-Uribe, Kathryn; Halkett, David; Hart, Tim; Parkington, John E.

    1999-11-01

    Boegoeberg 1 (BOG1) is located on the Atlantic coast of South Africa, 850 km north of Cape Town. The site is a shallow rock shelter in the side of a sand-choked gully that was emptied by diamond miners. Abundant coprolites, chewed bones, and partially digested bones implicate hyenas as the bone accumulators. The location of the site, quantity of bones, and composition of the fauna imply it was a brown hyena nursery den. The abundance of Cape fur seal bones shows that the hyenas had ready access to the coast. Radiocarbon dates place the site before 37,000 14C yr ago, while the large average size of the black-backed jackals and the presence of extralimital ungulates imply cool, moist conditions, probably during the early part of the last glaciation (isotope stage 4 or stage 3 before 37,000 14C yr ago) or perhaps during one of the cooler phases (isotope substages 5d or 5b) within the last interglaciation. Comparisons of the BOG1 seal bones to those from regional Middle Stone Age (MSA) and Later Stone Age (LSA) archeological sites suggest (1) that hyena and human seal accumulations can be distinguished by a tendency for vertebrae to be much more common in a hyena accumulation and (2) that hyena and LSA accumulations can be distinguished by a tendency for hyena-accumulated seals to represent a much wider range of individual seal ages. Differences in the way hyenas and people dismember, transport, and consume seal carcasses probably explain the contrast in skeletal part representation, while differences in season of occupation explain the contrast in seal age representation. Like modern brown hyenas, the BOG1 hyenas probably occupied the coast year-round, while the LSA people focused their coastal visits on the August-October interval when nine-to-eleven-month-old seals were abundant. The MSA sample from Klasies River Mouth Cave 1 resembles BOG1 in seal age composition, suggesting that unlike LSA people, MSA people obtained seals more or less throughout the year.

  6. Early human settlements in Northern Africa: paleomagnetic evidence from the Ain Hanech Formation (northeastern Algeria)

    NASA Astrophysics Data System (ADS)

    Parés, J. M.; Sahnouni, M.; Van der Made, J.; Pérez-González, A.; Harichane, Z.; Derradji, A.; Medig, M.

    2014-09-01

    The question of the earliest hominid settlements in northern Africa has been under debate for a number of years due to the lack of precise chronologies. Here we present new paleomagnetic data that supports an Olduvai Subchron age for the archaeological sites at Ain Hanech and El-Kherba, in northern Algeria. Our study is based on a 22 m-thick magnetostratigraphy of the Ain Hanech Formation, which includes contextualized Oldowan and Acheulian lithic tools. Characteristic remanent magnetization directions were obtained from both thermal and alternating field demagnetization procedures of specimens from twenty five sampled horizons. Our results reveal the presence of the Olduvai Subchron in the upper part of the stratigraphic section, constraining the age of these important archaeological sites in northern Africa.

  7. The Hidden Costs of a Free Caesarean Section Policy in West Africa (Kayes Region, Mali).

    PubMed

    Ravit, Marion; Philibert, Aline; Tourigny, Caroline; Traore, Mamadou; Coulibaly, Aliou; Dumont, Alexandre; Fournier, Pierre

    2015-08-01

    The fee exemption policy for EmONC in Mali aims to lower the financial barrier to care. The objective of the study was to evaluate the direct and indirect expenses associated with caesarean interventions performed in EmONC and the factors associated with these expenses. Data sampling followed the case control approach used in the large project (deceased and near-miss women). Our sample consisted of a total of 190 women who underwent caesarean interventions. Data were collected from the health workers and with a social approach by administering questionnaires to the persons who accompanied the woman. Household socioeconomic status was assessed using a wealth index constructed with a principal component analysis. The factors significantly associated with expenses were determined using multivariate linear regression analyses. Women in the Kayes region spent on average 77,017 FCFA (163 USD) for a caesarean episode in EmONC, of which 70 % was for treatment. Despite the caesarean fee exemption, 91 % of the women still paid for their treatment. The largest treatment-related direct expenses were for prescriptions, transfusion, antibiotics, and antihypertensive medication. Near-misses, women who presented a hemorrhage or an infection, and/or women living in rural areas spent significantly more than the others. Although abolishing fees of EmONC in Mali plays an important role in reducing maternal death by increasing access to caesarean sections, this paper shows that the fee policy did not benefit to all women. There are still barriers to EmONC access for women of the lowest socio-economic group. These included direct expenses for drugs prescription, treatment and indirect expenses for transport and food. PMID:25874875

  8. Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity

    PubMed Central

    Grönemeyer, Jann L.; Kulkarni, Ajinkya; Berkelmann, Dirk; Hurek, Thomas

    2014-01-01

    The rhizobial community indigenous to the Okavango region has not yet been characterized. The isolation of indigenous rhizobia can provide a basis for the formulation of a rhizobial inoculant. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Isolates were obtained from nodules of local varieties of the pulses cowpea, Bambara groundnut, peanut, hyacinth bean, and common bean. Ninety-one of them were identified by BOX repetitive element PCR (BOX-PCR) and sequence analyses of the 16S-23S rRNA internally transcribed spacer (ITS) and the recA, glnII, rpoB, and nifH genes. A striking geographical distribution was observed. Bradyrhizobium pachyrhizi dominated at sampling sites in Angola which were characterized by acid soils and a semihumid climate. Isolates from the semiarid sampling sites in Namibia were more diverse, with most of them being related to Bradyrhizobium yuanmingense and Bradyrhizobium daqingense. Host plant specificity was observed only for hyacinth bean, which was nodulated by rhizobia presumably representing yet-undescribed species. Furthermore, the isolates were characterized with respect to their adaptation to high temperatures, drought, and local host plants. The adaptation experiments revealed that the Namibian isolates shared an exceptionally high temperature tolerance, but none of the isolates showed considerable adaptation to drought. Moreover, the isolates' performance on different local hosts showed variable results, with most Namibian isolates inducing better nodulation on peanut and hyacinth bean than the Angolan strains. The local predominance of distinct genotypes implies that indigenous strains may exhibit a better performance in inoculant formulations. PMID:25239908

  9. Fire and Emission Characterization in the Northern Sub-Saharan Africa (NSSA) Region and their Potential Effects on the Regional Climate System

    NASA Astrophysics Data System (ADS)

    Ellison, L.; Ichoku, C. M.

    2013-12-01

    Northern Sub-Saharan Africa (NSSA) is known for its consistent vast amounts of seasonal biomass burning each year. These mostly anthropogenic slash-and-burn fires typically used for farming and grazing purposes contributes to a significant proportion of the total global emissions of particulate matter (PM). The consequences of such severe burning could potentially have a noticeable influence on local climate patterns, such as the frequent severe droughts over the past century or the drying of Lake Chad, through both direct and indirect causes. This research therefore focuses on: 1) characterizing the burning patterns and extent within NSSA, 2) accurately quantifying PM emissions that have a direct impact on climate, and 3) exploring potential indirect impacts of burning on climate through evaluation of correlations with various environmental and meteorological parameters. In this study, the NSSA region was first split into nine distinct sub-regions to better analyze the burning patters and climatological changes. The diurnal cycle of fire radiative power (FRP, a quantifiable way of measuring fire radiant heat output) within these different regions differ in amplitude and shape, though the basic shape is the same with months of maximum FRP being between November and January and with practically no fires during the rainy season. Corresponding changes in other climatological variables were studied against changes seen in FRP on a monthly scale, including precipitation, soil moisture, surface evaporation, evapotranspiration (ET), normalized difference vegetation index (NDVI) and aerosol optical depth (AOD). This study includes an analysis of the distinct change in FRP signal that occurred in 2006 for the middle of the NSSA region, which is the area with the highest concentration of fires. A decrease in maximum monthly FRP has been observed since 2006 in this region. Regional changes in PM emissions have also been observed since then, including a large region of

  10. Atmospheric chemistry over southern Africa

    NASA Astrophysics Data System (ADS)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2012-03-01

    Changing Chemistry in a Changing Climate: Human and Natural Impacts Over Southern Africa (C4-SAR); Midrand, South Africa, 31 May to 3 June 2011 During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semipermanent atmospheric gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite- derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission on Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from Eskom, the South African power utility; and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa.

  11. Towards a Comprehensive Seismic Velocity Model for the Broader Africa-Eurasia Collision Region, to Improve Nuclear Explosion Monitoring

    SciTech Connect

    der Lee, S v; Flanagan, M P; Rodgers, A J; Pasyanos, M E; Marone, F; Romanowicz, B

    2005-07-13

    We report on progress towards a new, comprehensive three-dimensional model of seismic velocity in a broad region encompassing the Middle East, northern Africa, the Mediterranean Sea, the Levant, the Arabian Peninsula, the Turkish-Iranian Plateau, Indus Valley, and the Hindu Kush. Our model will be based on regional waveform fits, surface wave group velocity measurements, teleseismic arrival times of S and P waves, receiver functions, and published results from active source experiments. We are in the process of assembling each of these data sets and testing the joint inversion for subsets of the data. Seismograms come from a variety of permanent and temporary seismic stations in the region. Some of the data is easily accessible through, for example, IRIS, while collection of other data is more involved. This work builds on ongoing work by Schmid et al. (GJI, 2004, and manuscript in preparation). In these proceedings we highlight our data sets and their inferences, demonstrate the proposed new data-inversion modeling methodology, discuss results from preliminary inversions of subsets of the data, and demonstrate the prediction of arrival times with three-dimensional velocity models. We compare our preliminary inversion results to the results of Schmid et al., and the predicted arrival times to ground-truth data from the NNSA Knowledge Base. Our data sets are simultaneously redundant and highly complementary. The combined data coverage will ensure that our three-dimensional model comprises the crust, the upper mantle, including the transition zone, and the top of the lower mantle, with spatially varying, but useful resolution. The region of interest is one of the most structurally heterogeneous in the world. Continental collision, rifting and sea-floor spreading, back-arc spreading, oceanic subduction, rotating micro plates, continental shelf, and stable platforms, are just some of the region's characteristics. Seismicity and the distribution of seismic stations are

  12. Chromosome region-specific libraries for human genome analysis

    SciTech Connect

    Kao, Fa-Ten.

    1992-08-01

    During the grant period progress has been made in the successful demonstration of regional mapping of microclones derived from microdissection libraries; successful demonstration of the feasibility of converting microclones with short inserts into yeast artificial chromosome clones with very large inserts for high resolution physical mapping of the dissected region; Successful demonstration of the usefulness of region-specific microclones to isolate region-specific cDNA clones as candidate genes to facilitate search for the crucial genes underlying genetic diseases assigned to the dissected region; and the successful construction of four region-specific microdissection libraries for human chromosome 2, including 2q35-q37, 2q33-q35, 2p23-p25 and 2p2l-p23. The 2q35-q37 library has been characterized in detail. The characterization of the other three libraries is in progress. These region-specific microdissection libraries and the unique sequence microclones derived from the libraries will be valuable resources for investigators engaged in high resolution physical mapping and isolation of disease-related genes residing in these chromosomal regions.

  13. Phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the "Out of Africa" hypothesis of Taenia in humans.

    PubMed

    Terefe, Yitagele; Hailemariam, Zerihun; Menkir, Sissay; Nakao, Minoru; Lavikainen, Antti; Haukisalmi, Voitto; Iwaki, Takashi; Okamoto, Munehiro; Ito, Akira

    2014-07-01

    The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010-2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I-IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I+IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the "Out of Africa" hypothesis of Taenia in humans. PMID:24815426

  14. Regional specialization within the human striatum for diverse psychological functions

    PubMed Central

    Pauli, Wolfgang M.; O’Reilly, Randall C.; Wager, Tor D.

    2016-01-01

    Decades of animal and human neuroimaging research have identified distinct, but overlapping, striatal zones, which are interconnected with separable corticostriatal circuits, and are crucial for the organization of functional systems. Despite continuous efforts to subdivide the human striatum based on anatomical and resting-state functional connectivity, characterizing the different psychological processes related to each zone remains a work in progress. Using an unbiased, data-driven approach, we analyzed large-scale coactivation data from 5,809 human imaging studies. We (i) identified five distinct striatal zones that exhibited discrete patterns of coactivation with cortical brain regions across distinct psychological processes and (ii) identified the different psychological processes associated with each zone. We found that the reported pattern of cortical activation reliably predicted which striatal zone was most strongly activated. Critically, activation in each functional zone could be associated with distinct psychological processes directly, rather than inferred indirectly from psychological functions attributed to associated cortices. Consistent with well-established findings, we found an association of the ventral striatum (VS) with reward processing. Confirming less well-established findings, the VS and adjacent anterior caudate were associated with evaluating the value of rewards and actions, respectively. Furthermore, our results confirmed a sometimes overlooked specialization of the posterior caudate nucleus for executive functions, often considered the exclusive domain of frontoparietal cortical circuits. Our findings provide a precise functional map of regional specialization within the human striatum, both in terms of the differential cortical regions and psychological functions associated with each striatal zone. PMID:26831091

  15. Regional specialization within the human striatum for diverse psychological functions.

    PubMed

    Pauli, Wolfgang M; O'Reilly, Randall C; Yarkoni, Tal; Wager, Tor D

    2016-02-16

    Decades of animal and human neuroimaging research have identified distinct, but overlapping, striatal zones, which are interconnected with separable corticostriatal circuits, and are crucial for the organization of functional systems. Despite continuous efforts to subdivide the human striatum based on anatomical and resting-state functional connectivity, characterizing the different psychological processes related to each zone remains a work in progress. Using an unbiased, data-driven approach, we analyzed large-scale coactivation data from 5,809 human imaging studies. We (i) identified five distinct striatal zones that exhibited discrete patterns of coactivation with cortical brain regions across distinct psychological processes and (ii) identified the different psychological processes associated with each zone. We found that the reported pattern of cortical activation reliably predicted which striatal zone was most strongly activated. Critically, activation in each functional zone could be associated with distinct psychological processes directly, rather than inferred indirectly from psychological functions attributed to associated cortices. Consistent with well-established findings, we found an association of the ventral striatum (VS) with reward processing. Confirming less well-established findings, the VS and adjacent anterior caudate were associated with evaluating the value of rewards and actions, respectively. Furthermore, our results confirmed a sometimes overlooked specialization of the posterior caudate nucleus for executive functions, often considered the exclusive domain of frontoparietal cortical circuits. Our findings provide a precise functional map of regional specialization within the human striatum, both in terms of the differential cortical regions and psychological functions associated with each striatal zone. PMID:26831091

  16. The distribution of SNPs in human gene regulatory regions

    PubMed Central

    Guo, Yongjian; Jamison, D Curtis

    2005-01-01

    Background As a result of high-throughput genotyping methods, millions of human genetic variants have been reported in recent years. To efficiently identify those with significant biological functions, a practical strategy is to concentrate on variants located in important sequence regions such as gene regulatory regions. Results Analysis of the most common type of variant, single nucleotide polymorphisms (SNPs), shows that in gene promoter regions more SNPs occur in close proximity to transcriptional start sites than in regions further upstream, and a disproportionate number of those SNPs represent nucleotide transversions. Additionally, the number of SNPs found in the predicted transcription factor binding sites is higher than in non-binding site sequences. Conclusion Current information about transcription factor binding site sequence patterns may not be exhaustive, and SNPs may be actively involved in influencing gene expression by affecting the transcription factor binding sites. PMID:16209714

  17. Taste development: differential growth rates of tongue regions in humans.

    PubMed

    Temple, Elizabeth C; Hutchinson, Ian; Laing, David G; Jinks, Anthony L

    2002-04-30

    There is a paucity of information about the anatomical and functional development of the human gustatory system. Although the anatomical development of the taste-sensitive fungiform, circumvallate and foliate papillae in the respective anterior, posterior and latero-posterior regions of the dorsal surface of the tongue has been well documented in the fetus, there is limited information about how these regions grow and when they exhibit adult function. The present study is concerned with determining when the growth of one of these taste-sensitive regions becomes adult in size, namely, the anterior region, and how this growth compares with that of the remaining posterior region. Two-hundred and thirty-two living subjects aged between 4 and 32 years participated. Following the identification and marking of a series of landmarks on the dorsal surface of the tongue with blue food dye, five measurements of the width and length of various parts of the tongue allowed calculation of the growth of the anterior and posterior regions. The results indicate that the fungiform papillae-rich anterior region attains adult-size by 8-10 years of age whilst the posterior region continues to grow until 15-16 years. Interestingly, this early development is not matched by achievement of adult function [Dev. Brain Res. 82 (1994) 286] or adult size papillae or taste pores [Dev. Brain Res., submitted]. Finally, the findings of the present study will allow studies of the development of taste function in humans to be conducted using equivalent tongue areas in subjects of different ages. PMID:11978394

  18. Predictors of Non-Uptake of Human Immunodeficiency Virus Testing by Tuberculosis Public Primary Patients in Three Districts, South Africa

    PubMed Central

    Peltzer, K; Mchunu, G; Tutshana, B; Naidoo, P; Matseke, G; Louw, J

    2012-01-01

    Background The acceptance of HIV testing among patients with tuberculosis (TB) is low in South Africa. The aim of this study was to assess the prevalence, associated factors and reasons of non-uptake of human immunodeficiency virus (HIV) testing by tuberculosis public primary care patients in three districts, South Africa. Methods: In May–October 2011, this cross-sectional survey was conducted amongst 4726 TB patients across 42 primary health care facilities in three districts in South Africa. All new TB and new retreatment patients (N=4726) were consecutively interviewed within one month of anti-tuberculosis treatment. The outcome was self-reported HIV testing after TB diagnosis, validated using clinic registers. Results: Almost one in ten (9.6%) of the 4726 participants had not undergone HIV testing, with the most often offered explanation being that they were not knowing where to get tested (21.3%), followed by believing not to have or at risk for HIV (24.3%), emotional concerns (not ready for test: 13.2%; afraid to get to know: 12.1%; concerns over confidentiality: 6.3%) and concerns about stigma (3.3%) and losing the job (2.0%). In multivariable analysis being male, severe psychological distress, having sex with someone HIV negative or unknown and frequency of sex without a condom were associated with not having been tested for HIV. Conclusions: The level of HIV testing among TB public primary care patients was suboptimal, as per policy all patients should be tested. The South African Department of Health should continue to scale-up HIV testing and other collaborative TB-HIV services at health facilities. PMID:23304672

  19. Mobile Gis: a Tool for Informal Settlement Occupancy Audit to Improve Integrated Human Settlement Implementation in Ekurhuleni, South Africa

    NASA Astrophysics Data System (ADS)

    Mokoena, B. T.; Musakwa, W.

    2016-06-01

    Upgrading and relocating people in informal settlements requires consistent commitment, good strategies and systems so as to improve the lives of those who live in them. In South Africa, in order to allocate subsidised housing to beneficiaries of an informal settlement, beneficiary administration needs to be completed to determine the number of people who qualify for a subsidised house. Conventional methods of occupancy audits are often unreliable, cumbersome and non-spatial. Accordingly, this study proposes the use of mobile GIS to conduct these audits to provide up-to-date, accurate, comprehensive and real-time data so as to facilitate the development of integrated human settlements. An occupancy audit was subsequently completed for one of the communities in the Ekurhuleni municipality, Gauteng province, using web-based mobile GIS as a solution to providing smart information through evidence based decision making. Fieldworkers accessed the off-line capturing module on a mobile device recording GPS coordinates, socio-economic information and photographs. The results of this audit indicated that only 56.86% of the households residing within the community could potentially benefit from receiving a subsidised house. Integrated residential development, which includes fully and partially subsidised housing, serviced stands and some fully bonded housing opportunities, would then be key to adequately providing access to suitable housing options within a project in a post-colonial South Africa, creating new post-1994 neighbourhoods, in line with policy. The use of mobile GIS therefore needs to be extended to other informal settlement upgrading projects in South Africa.

  20. Social networks and mental health among people living with human immunodeficiency virus (HIV) in Johannesburg, South Africa.

    PubMed

    Odek, Willis Omondi

    2014-01-01

    People living with human immunodeficiency virus (PLHIV) in developing countries can live longer due to improved treatment access, and a deeper understanding of determinants of their quality of life is critical. This study assessed the link between social capital, operationally defined in terms of social networks (group-based and personal social networks) and access to network resources (access to material and non-material resources and social support) and health-related quality of life (HRQoL) among 554 (55% female) adults on HIV treatment through South Africa's public health system. Female study participants were involved with more group-based social networks but had fewer personal social networks in comparison to males. Access to network resources was higher among females and those from larger households but lower among older study participants. Experience of social support significantly increased with household economic status and duration at current residence. Social capital indicators were unrelated to HIV disease status indicators, including duration since diagnosis, CD4 count and viral load. Only a minority (13%) of study participants took part in groups formed by and for predominantly PLHIV (HIV support groups), and participation in such groups was unrelated to their mental or physical health. Personal rather than group-linked social networks and access to network resources were significantly associated with mental but not physical health, after controlling for sociodemographic characteristics. The findings of limited participation in HIV support groups and that the participation in such groups was not significantly associated with physical or mental health may suggest efforts among PLHIV in South Africa to normalise HIV as a chronic illness through broad-based rather than HIV-status bounded social participation, as a strategy for deflecting stigma. Further research is required to examine the effects of HIV treatment on social networking and participation

  1. Capacity building and predictors of success for HIV-1 drug resistance testing in the Asia-Pacific region and Africa

    PubMed Central

    Land, Sally; Zhou, Julian; Cunningham, Philip; Sohn, Annette H; Singtoroj, Thida; Katzenstein, David; Mann, Marita; Sayer, David; Kantor, Rami

    2013-01-01

    Background The TREAT Asia Quality Assessment Scheme (TAQAS) was developed as a quality assessment programme through expert education and training, for laboratories in the Asia-Pacific and Africa that perform HIV drug-resistance (HIVDR) genotyping. We evaluated the programme performance and factors associated with high-quality HIVDR genotyping. Methods Laboratories used their standard protocols to test panels of human immunodeficiency virus (HIV)-positive plasma samples or electropherograms. Protocols were documented and performance was evaluated according to a newly developed scoring system, agreement with panel-specific consensus sequence, and detection of drug-resistance mutations (DRMs) and mixtures of wild-type and resistant virus (mixtures). High-quality performance was defined as detection of ≥95% DRMs. Results Over 4.5 years, 23 participating laboratories in 13 countries tested 45 samples (30 HIV-1 subtype B; 15 non-B subtypes) in nine panels. Median detection of DRMs was 88–98% in plasma panels and 90–97% in electropherogram panels. Laboratories were supported to amend and improve their test outcomes as appropriate. Three laboratories that detected <80% DRMs in early panels demonstrated subsequent improvement. Sample complexity factors – number of DRMs (p<0.001) and number of DRMs as mixtures (p<0.001); and laboratory performance factors – detection of mixtures (p<0.001) and agreement with consensus sequence (p<0.001), were associated with high performance; sample format (plasma or electropherogram), subtype and genotyping protocol were not. Conclusion High-quality HIVDR genotyping was achieved in the TAQAS collaborative laboratory network. Sample complexity and detection of mixtures were associated with performance quality. Laboratories conducting HIVDR genotyping are encouraged to participate in quality assessment programmes. PMID:23845227

  2. Molecular epidemiology of 58 new African human T-cell leukemia virus type 1 (HTLV-1) strains: identification of a new and distinct HTLV-1 molecular subtype in Central Africa and in Pygmies.

    PubMed Central

    Mahieux, R; Ibrahim, F; Mauclere, P; Herve, V; Michel, P; Tekaia, F; Chappey, C; Garin, B; Van Der Ryst, E; Guillemain, B; Ledru, E; Delaporte, E; de The, G; Gessain, A

    1997-01-01

    To gain new insights on the origin, evolution, and modes of dissemination of human T-cell leukemia virus type I (HTLV-1), we performed a molecular analysis of 58 new African HTLV-1 strains (18 from West Africa, 36 from Central Africa, and 4 from South Africa) originating from 13 countries. Of particular interest were eight strains from Pygmies of remote areas of Cameroon and the Central African Republic (CAR), considered to be the oldest inhabitants of these regions. Eight long-term activated T-cell lines producing HTLV-1 gag and env antigens were established from peripheral blood mononuclear cell cultures of HTLV-1 seropositive individuals, including three from Pygmies. A fragment of the env gene encompassing most of the gp21 transmembrane region was sequenced for the 58 new strains, while the complete long terminal repeat (LTR) region was sequenced for 9 strains, including 4 from Pygmies. Comparative sequence analyses and phylogenetic studies performed on both the env and LTR regions by the neighbor-joining and DNA parsimony methods demonstrated that all 22 strains from West and South Africa belong to the widespread cosmopolitan subtype (also called HTLV-1 subtype A). Within or alongside the previously described Zairian cluster (HTLV-1 subtype B), we discovered a number of new HTLV-1 variants forming different subgroups corresponding mainly to the geographical origins of the infected persons, Cameroon, Gabon, and Zaire. Six of the eight Pygmy strains clustered together within this Central African subtype, suggesting a common origin. Furthermore, three new strains (two originating from Pygmies from Cameroon and the CAR, respectively, and one from a Gabonese individual) were particularly divergent and formed a distinct new phylogenetic cluster, characterized by specific mutations and occupying in most analyses a unique phylogenetic position between the large Central African genotype (HTLV-1 subtype B) and the Melanesian subtype (HTLV-1 subtype C). We have

  3. Regional Collaborative Approach for Biotechnological Human Resource Development

    NASA Astrophysics Data System (ADS)

    Iwahara, Masayoshi

    Since more than 20 years ago, we had been discussed and researched between regional collaboration how to use the biomass generated by food industries (and how to promote the reuse) and the value addition of food recyclable resources. Accordingly, we collaborated mainly with Biotechnological Research Development Association and promoted the project for biotechnological human resource development. In order to realize such project, the followings were proposed : the human resource development programs, skill standards, curricula, practices, and estimations. As a result, it is recognized that our trials and practices brought educational effects for not only graduate school students but also working engineers, and that these programs must be conducted for continuing development.

  4. Environmental pollutants and diseases of sexual development in humans and wildlife in South Africa: harbingers of impact on overall health?

    PubMed

    Riana Bornman, M S; Bouwman, Hindrik

    2012-08-01

    This study deals with disorders of sexual development in humans, wildlife and animals in an urban nature reserve (RNR) and a currently DDT-sprayed malarial area. High levels of oestrogenic chemical residues in water, sediment and tissue; skewed sex ratios; reduced biodiversity; gonadal malformations in sharptooth catfish and freshwater snails; intersex in catfish; and impaired spermatogenesis in catfish and striped mouse are of serious concern in the RNR. Persistent eggshell thinning in African darter eggs, intersex in male Mozambican tilapia, follicular atresia in females and impaired spermatogenesis in males following laboratory exposure of parent fish to environmentally relevant DDT and DDE concentrations, and abnormalities in freshwater snails were found in the DDT-sprayed area. Human studies related to DDT exposure indicated impaired semen quality, a weak association with sperm chromatin defects and higher risks for external urogenital birth defects in those who were born to mothers whose houses were sprayed and those who were homemakers (stay at home mother) instead of being employed. These findings indicate that diseases of sexual development occurred in both human and wildlife populations exposed to environmental endocrine disruptor chemicals in South Africa. The chemical mixtures, possibly related to disorders of sexual differentiation (DSD), were very different between the two. However, DSD occurred concurrently in the malarial area, possibly indicating that humans and wildlife shared exposures. Moreover, it emphasizes the importance of suspecting disease in the other when disease is found in either human or wildlife populations. PMID:22827388

  5. Human rights violations and smoking status among South African adults enrolled in the South Africa Stress and Health (SASH) study

    PubMed Central

    Dutra, Lauren M; Williams, David R; Gupta, Jhumka; Kawachi, Ichiro; Okechukwu, Cassandra A

    2014-01-01

    Despite South Africa’s history of violent political conflict, and the link between stressful experiences and smoking in the literature, no public health study has examined South Africans’ experiences of human rights violations and smoking. Using data from participants in the nationally representative cross-sectional South Africa Stress and Health study (SASH), this analysis examined the association between respondent smoking status and both human rights violations experienced by the respondent and violations experienced by the respondents’ close friends and family members. SAS-Callable SUDAAN was used to construct separate log-binomial models by political affiliation during apartheid (government or liberation supporters). In comparison to those who reported no violations, in adjusted analyses, government supporters who reported violations of themselves but not others (RR=1.76, 95%CI: 1.25–2.46) had a significantly higher smoking prevalence. In comparison to liberation supporters who reported no violations, those who reported violations of self only (RR=1.56, 95%CI: 1.07–2.29), close others only (RR=1.97, 95%CI: 1.12–3.47), or violations of self and close others due to close others’ political beliefs and the respondent’s political beliefs (RR=2.86, 95%CI: 1.70–4.82) had a significantly higher prevalence of smoking. The results of this analysis suggest that a relationship may exist between human rights violations and smoking among South Africa adults. Future research should use longitudinal data to assess causality, test the generalizability of these findings, and consider how to apply these findings to smoking cessation interventions. PMID:24509050

  6. Regional boreal biodiversity peaks at intermediate human disturbance.

    PubMed

    Mayor, S J; Cahill, J F; He, F; Sólymos, P; Boutin, S

    2012-01-01

    The worldwide biodiversity crisis has intensified the need to better understand how biodiversity and human disturbance are related. The 'intermediate disturbance hypothesis' suggests that disturbance regimes generate predictable non-linear patterns in species richness. Evidence often contradicts intermediate disturbance hypothesis at small scales, and is generally lacking at large regional scales. Here, we present the largest extent study of human impacts on boreal plant biodiversity to date. Disturbance extent ranged from 0 to 100% disturbed in vascular plant communities, varying from intact forest to agricultural fields, forestry cut blocks and oil sands. We show for the first time that across a broad region species richness peaked in communities with intermediate anthropogenic disturbance, as predicted by intermediate disturbance hypothesis, even when accounting for many environmental covariates. Intermediate disturbance hypothesis was consistently supported across trees, shrubs, forbs and grasses, with temporary and perpetual disturbances. However, only native species fit this pattern; exotic species richness increased linearly with disturbance. PMID:23072810

  7. Synchronization of regional contractions of human labor; direct effects of region size and tissue excitability.

    PubMed

    Young, Roger C

    2015-06-25

    The mechanisms used to coordinate organ-level contractions of human labor are not universally accepted. We previously proposed a dual mechanism, where electrical activity coordinates cellular contractions into tissue-level regional contractions, and mechanotransduction synchronizes the regional contractions into organ-level contractions. The simulation of this model successfully recapitulates the phasic pressure rises typical of human labor. In this work we extend the simulation to probe the effects of three critical parameters: electrical coupling (which defines functional regions within the uterine wall), enhancement of contractile responses during action potential bursts (action potential multiplier), and the threshold for mechanical recruitment of regional myometrial contractions (threshold). We test how changing the values of these parameters modulates the ability of the uterus to generate synchronized organ-level contractions. Simulations are performed using Mathematica and a non-classical cellular automaton program we recently published. At least 15 regions are necessary to generate physiologically relevant, synchronized contractions. Organ-level synchronization was improved using higher values for the action potential multiplier. At lower values of the action potential multiplier, synchronized contractions were inhibited when the number of regions was between 32 and 44, suggesting a critical level of electrical coupling is necessary at the onset of labor. Large numbers of low threshold regions resulted in contraction patterns suggestive of hyperstimulation. This work furthers support for the electrical-mechanotransduction mechanism for organ-level synchronization of uterine contractions. The mathematical simulation provides insight regarding how cellular- and tissue-level physiology converge to express synchronized contractions of human labor. PMID:25698238

  8. The Heritage of Pathogen Pressures and Ancient Demography in the Human Innate-Immunity CD209/CD209L Region

    PubMed Central

    Barreiro, Luis B. ; Patin, Etienne ; Neyrolles, Olivier ; Cann, Howard M. ; Gicquel, Brigitte ; Quintana-Murci, Lluís 

    2005-01-01

    The innate immunity system constitutes the first line of host defense against pathogens. Two closely related innate immunity genes, CD209 and CD209L, are particularly interesting because they directly recognize a plethora of pathogens, including bacteria, viruses, and parasites. Both genes, which result from an ancient duplication, possess a neck region, made up of seven repeats of 23 amino acids each, known to play a major role in the pathogen-binding properties of these proteins. To explore the extent to which pathogens have exerted selective pressures on these innate immunity genes, we resequenced them in a group of samples from sub-Saharan Africa, Europe, and East Asia. Moreover, variation in the number of repeats of the neck region was defined in the entire Human Genome Diversity Panel for both genes. Our results, which are based on diversity levels, neutrality tests, population genetic distances, and neck-region length variation, provide genetic evidence that CD209 has been under a strong selective constraint that prevents accumulation of any amino acid changes, whereas CD209L variability has most likely been shaped by the action of balancing selection in non-African populations. In addition, our data point to the neck region as the functional target of such selective pressures: CD209 presents a constant size in the neck region populationwide, whereas CD209L presents an excess of length variation, particularly in non-African populations. An additional interesting observation came from the coalescent-based CD209 gene tree, whose binary topology and time depth (∼2.8 million years ago) are compatible with an ancestral population structure in Africa. Altogether, our study has revealed that even a short segment of the human genome can uncover an extraordinarily complex evolutionary history, including different pathogen pressures on host genes as well as traces of admixture among archaic hominid populations. PMID:16252244

  9. Out of Africa and into an ice age: on the role of global climate change in the late Pleistocene migration of early modern humans out of Africa.

    PubMed

    Carto, Shannon L; Weaver, Andrew J; Hetherington, Renée; Lam, Yin; Wiebe, Edward C

    2009-02-01

    The results from two climate model simulations are used to explore the relationship between North Atlantic sea surface temperatures and the development of African aridity around 100,000 years ago. Through the use of illustrative simulations with an Earth System Climate Model, it is shown that freshwater fluxes associated with ice sheet surges into the North Atlantic, known as Heinrich events, lead to the southward shift of the intertropical convergence zone over Africa. This, combined with the overall increased aridity in the cooler mean climate, leads to substantial changes in simulated African vegetation cover, particularly in the Sahel. We suggest that Heinrich events, which occurred episodically throughout the last glacial cycle, led to abrupt changes in climate that may have rendered large parts of North, East, and West Africa unsuitable for hominin occupation, thus compelling early Homo sapiens to migrate out of Africa. PMID:19019409

  10. History and origin of the HIV-1 subtype C epidemic in South Africa and the greater southern African region

    PubMed Central

    Wilkinson, Eduan; Engelbrecht, Susan; de Oliveira, Tulio

    2015-01-01

    HIV has spread at an alarming rate in South Africa, making it the country with the highest number of HIV infections. Several studies have investigated the histories of HIV-1 subtype C epidemics but none have done so in the context of social and political transformation in southern Africa. There is a need to understand how these processes affects epidemics, as socio-political transformation is a common and on-going process in Africa. Here, we genotyped strains from the start of the epidemic and applied phylodynamic techniques to determine the history of the southern Africa and South African epidemic from longitudinal sampled data. The southern African epidemic’s estimated dates of origin was placed around 1960 (95% HPD 1956–64), while dynamic reconstruction revealed strong growth during the 1970s and 80s. The South African epidemic has a similar origin, caused by multiple introductions from neighbouring countries, and grew exponentially during the 1980s and 90s, coinciding with socio-political changes in South Africa. These findings provide an indication as to when the epidemic started and how it has grown, while the inclusion of sequence data from the start of the epidemic provided better estimates. The epidemic have stabilized in recent years with the expansion of antiretroviral therapy. PMID:26574165

  11. Potential for human immunodeficiency virus parenteral transmission in the Middle East and North Africa: An analysis using hepatitis C virus as a proxy biomarker

    PubMed Central

    Mohamoud, Yousra A; Miller, F DeWolfe; Abu-Raddad, Laith J

    2014-01-01

    The Middle East and North Africa (MENA) region has endured several major events of infection parenteral transmission. Recent work has established the utility of using hepatitis C virus (HCV) as a proxy biomarker for assessing the epidemic potential for human immunodeficiency virus (HIV) parenteral transmission. In this review, we use data on the prevalence of HCV infection antibody (seroprevalence) among general population and high risk population groups to assess the potential for HIV parenteral transmission in MENA. Relatively low prevalence of HCV infection in the general population groups was reported in most MENA countries indicating that parenteral HIV transmission at endemic levels does not appear to be a cause for concern. Nonetheless, there could be opportunities for localized HIV outbreaks and transmission of other blood-borne infections in some settings such as healthcare facilities. Though there have been steady improvements in safety measures related to parenteral modes of transmission in the region, these improvements have not been uniform across all countries. More precautions, including infection control training programs, surveillance systems for nosocomial infections and wider coverage and evaluation of hepatitis B virus immunization programs need to be implemented to avoid the unnecessary spread of HIV, HCV, and other blood-borne pathogens along the parenteral modes of transmission. PMID:25278675

  12. Human Factors Predicting Failure and Success in Hospital Information System Implementations in Sub-Saharan Africa.

    PubMed

    Verbeke, Frank; Karara, Gustave; Nyssen, Marc

    2015-01-01

    From 2007 through 2014, the authors participated in the implementation of open source hospital information systems (HIS) in 19 hospitals in Rwanda, Burundi, DR Congo, Congo-Brazzaville, Gabon, and Mali. Most of these implementations were successful, but some failed. At the end of a seven-year implementation effort, a number of risk factors, facilitators, and pragmatic approaches related to the deployment of HIS in Sub-Saharan health facilities have been identified. Many of the problems encountered during the HIS implementation process were not related to technical issues but human, cultural, and environmental factors. This study retrospectively evaluates the predictive value of 14 project failure factors and 15 success factors in HIS implementation in the Sub-Saharan region. Nine of the failure factors were strongly correlated with project failure, three were moderately correlated, and one weakly correlated. Regression analysis also confirms that eight factors were strongly correlated with project success, four moderately correlated, and two weakly correlated. The study results may help estimate the expedience of future HIS projects. PMID:26262097

  13. Present concerns of survivors of human rights violations in South Africa.

    PubMed

    Kagee, Ashraf

    2004-08-01

    Most research on persons subjected to physical torture for political reasons has framed this experience as traumatic, with the sequelae approximating the diagnostic criteria of posttraumatic stress disorder (PTSD). However, responses to checklists, questionnaires, and structured interview schedules may reflect the effect of demand characteristics more than the actual concerns of respondents. Thus semi-structured qualitative interviews were conducted with 20 South Africans who were detained for political reasons during the apartheid era. The interviews were transcribed and analyzed with the assistance of the Atlas.ti 4.5 programme. Results showed that the major concerns expressed by the sample were somatic problems, economic marginalization, non-clinical emotional distress, and dissatisfaction with the present political dispensation in South Africa. Respondents also expressed concerns that reflected symptoms of traumatization, but these were not salient in comparison with the other themes that emerged. These data suggest that a model of trauma and the diagnostic category of PTSD may be less appropriate than suggested by most of the literature in accounting for the concerns of many South African former political detainees. This paper critiques the hegemony of the psychiatric model of traumatization in conceptualizing the needs of this population, and suggests an alternate perspective that is broader and more inclusive than a psychiatric paradigm. It also discusses the research and possible clinical implications of the results in terms of addressing the needs of former detainees in South Africa. PMID:15144770

  14. What motivates use of community-based human immunodeficiency virus testing in rural South Africa?

    PubMed

    Upadhya, Devesh; Moll, Anthony P; Brooks, Ralph P; Friedland, Gerald; Shenoi, Sheela V

    2016-07-01

    Despite substantial progress in implementing HIV testing, challenges remain in achieving widespread uptake particularly in rural resource-limited settings. We sought to understand motivations for HIV testing in a community-based HIV testing programme in rural South Africa. We conducted a questionnaire survey in participants undergoing voluntary HIV testing within an ongoing community-based integrated HIV/tuberculosis intensive case finding programme at congregate rural settings. Participants responded to a six-item non-mutually exclusive motivations survey which included the topics of feeling ill, recent HIV exposure, risky lifestyle, illness in a family member, and pregnancy. Among 2068 respondents completing the survey, 1393 (67.4%) were women, median age was 40 years (IQR 19-56), and 1235 (59.7%) were first-time testers. Among all testers, 142 (6.9%) were HIV-positive with median CD4 count was 346 cells/mm(3) (IQR 218-542). Community-based testing for HIV is acceptable and meets the needs of community members in rural South Africa. Motivations for HIV testing at the community level are complex and differ according to gender, age, site of community testing, and HIV status. These differences can be utilised to improve the focus and yield of community-based HIV screening. PMID:26134323

  15. Vegetation-climate feedback causes reduced precipitation and tropical rainforest cover in CMIP5 regional Earth system model simulation over Africa

    NASA Astrophysics Data System (ADS)

    Wu, M.; Smith, B.; Samuelsson, P.; Rummukainen, M.; Schurgers, G.

    2012-12-01

    We applied a coupled regional climate-vegetation model, RCA-GUESS (Smith et al. 2011), over the CORDEX Africa domain, forced by boundary conditions from a CanESM2 CMIP5 simulation under the RCP8.5 future climate scenario. The simulations were from 1961 to 2100 and covered the African continent at a horizontal grid spacing of 0.44°. RCA-GUESS simulates changes in the phenology, productivity, relative cover and population structure of up to eight plant function types (PFTs) in response to forcing from the climate part of the model. These vegetation changes feed back to simulated climate through dynamic adjustments in surface energy fluxes and surface properties. Changes in the net ecosystem-atmosphere carbon flux and its components net primary production (NPP), heterotrophic respiration and emissions from biomass burning were also simulated but do not feed back to climate in our model. Constant land cover was assumed. We compared simulations with and without vegetation feedback switched "on" to assess the influence of vegetation-climate feedback on simulated climate, vegetation and ecosystem carbon cycling. Both positive and negative warming feedbacks were identified in different parts of Africa. In the Sahel savannah zone near 15°N, reduced vegetation cover and productivity, and mortality caused by a deterioration of soil water conditions led to a positive warming feedback mediated by decreased evapotranspiration and increased sensible heat flux between vegetation and the atmosphere. In the equatorial rainforest stronghold region of central Africa, a feedback syndrome characterised by reduced plant production and LAI, a dominance shift from tropical trees to grasses, reduced soil water and reduced rainfall was identified. The likely underlying mechanism was a decline in evaporative water recycling associated with sparser vegetation cover, reminiscent of Earth system model studies in which a similar feedback mechanism was simulated to force dieback of tropical

  16. Endemic Foci of the Tick-Borne Relapsing Fever Spirochete Borrelia crocidurae in Mali, West Africa, and the Potential for Human Infection

    PubMed Central

    Schwan, Tom G.; Anderson, Jennifer M.; Lopez, Job E.; Fischer, Robert J.; Raffel, Sandra J.; McCoy, Brandi N.; Safronetz, David; Sogoba, Nafomon; Maïga, Ousmane; Traoré, Sékou F.

    2012-01-01

    Background Tick-borne relapsing fever spirochetes are maintained in endemic foci that involve a diversity of small mammals and argasid ticks in the genus Ornithodoros. Most epidemiological studies of tick-borne relapsing fever in West Africa caused by Borrelia crocidurae have been conducted in Senegal. The risk for humans to acquire relapsing fever in Mali is uncertain, as only a few human cases have been identified. Given the high incidence of malaria in Mali, and the potential to confuse the clinical diagnosis of these two diseases, we initiated studies to determine if there were endemic foci of relapsing fever spirochetes that could pose a risk for human infection. Methodology/Principal Findings We investigated 20 villages across southern Mali for the presence of relapsing fever spirochetes. Small mammals were captured, thin blood smears were examined microscopically for spirochetes, and serum samples were tested for antibodies to relapsing fever spirochetes. Ornithodoros sonrai ticks were collected and examined for spirochetal infection. In total, 11.0% of the 663 rodents and 14.3% of the 63 shrews tested were seropositive and 2.2% of the animals had active spirochete infections when captured. In the Bandiagara region, the prevalence of infection was higher with 35% of the animals seropositive and 10% infected. Here also Ornithodoros sonrai were abundant and 17.3% of 278 individual ticks tested were infected with Borrelia crocidurae. Fifteen isolates of B. crocidurae were established and characterized by multi-locus sequence typing. Conclusions/Significance The potential for human tick-borne relapsing fever exists in many areas of southern Mali. PMID:23209863

  17. Advancing human rights through constitutional protection for gays and lesbians in South Africa.

    PubMed

    Louw, Ronald

    2005-01-01

    As a consequence of the 1994 adoption of a justiciable Bill of Rights in South Africa, with an equality provision prohibiting discrimination on the ground of sexual orientation, a coalition of gay and lesbian organisations set about implementing a progressive agenda of gay and lesbian rights litigation. In striking down the offence of sodomy, the Constitutional Court established a jurisprudence of gay and lesbian rights to equality, dignity and privacy that proved to be the foundation for significant litigation around family law issues. Subsequent to the sodomy judgement, the Court has ruled that same-sex couples who are in permanent life partnerships should be entitled to the same rights as married couples to immigration, employment benefits, custody and adoption of children. Despite the extensive equality jurisprudence of the Court, it is still uncertain whether it will rule in the future in favour of same-sex marriage or in favour of a civil union/domestic partnership model. PMID:15814504

  18. Consistently high estimates for the proportion of human exposure to malaria vector populations occurring indoors in rural Africa

    PubMed Central

    Huho, Bernadette; Briët, Olivier; Seyoum, Aklilu; Sikaala, Chadwick; Bayoh, Nabie; Gimnig, John; Okumu, Fredros; Diallo, Diadier; Abdulla, Salim; Smith, Thomas; Killeen, Gerry

    2013-01-01

    Background Insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are highly effective tools for controlling malaria transmission in Africa because the most important vectors, from the Anopheles gambiae complex and the A. funestus group, usually prefer biting humans indoors at night. Methods Matched surveys of mosquito and human behaviour from six rural sites in Burkina Faso, Tanzania, Zambia, and Kenya, with ITN use ranging from 0.2% to 82.5%, were used to calculate the proportion of human exposure to An. gambiae sensu lato and An. funestus s.l. that occurs indoors (πi), as an indicator of the upper limit of personal protection that indoor vector control measures can provide. This quantity was also estimated through use of a simplified binary analysis (πiB) so that the proportions of mosquitoes caught indoors (Pi), and between the first and last hours at which most people are indoors (Pfl) could also be calculated as underlying indicators of feeding by mosquitoes indoors or at night, respectively. Results The vast majority of human exposure to Anopheles bites occurred indoors (πiB = 0.79–1.00). Neither An. gambiae s.l. nor An. funestus s.l. strongly preferred feeding indoors (Pi = 0.40–0.63 and 0.22–0.69, respectively), but they overwhelmingly preferred feeding at times when most humans were indoors (Pfl = 0.78–1.00 and 0.86–1.00, respectively). Conclusions These quantitative summaries of behavioural interactions between humans and mosquitoes constitute a remarkably consistent benchmark with which future observations of vector behaviour can be compared. Longitudinal monitoring of these quantities is vital to evaluate the effectiveness of ITNs and IRS and the need for complementary measures that target vectors outdoors. PMID:23396849

  19. Chromosome region-specific libraries for human genome analysis

    SciTech Connect

    Kao, Fa-Ten.

    1991-01-01

    We have made important progress since the beginning of the current grant year. We have further developed the microdissection and PCR- assisted microcloning techniques using the linker-adaptor method. We have critically evaluated the microdissection libraries constructed by this microtechnology and proved that they are of high quality. We further demonstrated that these microdissection clones are useful in identifying corresponding YAC clones for a thousand-fold expansion of the genomic coverage and for contig construction. We are also improving the technique of cloning the dissected fragments in test tube by the TDT method. We are applying both of these PCR cloning technique to human chromosomes 2 and 5 to construct region-specific libraries for physical mapping purposes of LLNL and LANL. Finally, we are exploring efficient procedures to use unique sequence microclones to isolate cDNA clones from defined chromosomal regions as valuable resources for identifying expressed gene sequences in the human genome. We believe that we are making important progress under the auspices of this DOE human genome program grant and we will continue to make significant contributions in the coming year. 4 refs., 4 figs.

  20. Genetic Effects on Fine-Grained Human Cortical Regionalization.

    PubMed

    Cui, Yue; Liu, Bing; Zhou, Yuan; Fan, Lingzhong; Li, Jin; Zhang, Yun; Wu, Huawang; Hou, Bing; Wang, Chao; Zheng, Fanfan; Qiu, Chengxiang; Rao, Li-Lin; Ning, Yuping; Li, Shu; Jiang, Tianzi

    2016-09-01

    Various brain structural and functional features such as cytoarchitecture, topographic mapping, gyral/sulcal anatomy, and anatomical and functional connectivity have been used in human brain parcellation. However, the fine-grained intrinsic genetic architecture of the cortex remains unknown. In the present study, we parcellated specific regions of the cortex into subregions based on genetic correlations (i.e., shared genetic influences) between the surface area of each pair of cortical locations within the seed region. The genetic correlations were estimated by comparing the correlations of the surface area between monozygotic and dizygotic twins using bivariate twin models. Our genetic subdivisions of diverse brain regions were reproducible across 2 independent datasets and corresponded closely to fine-grained functional specializations. Furthermore, subregional genetic correlation profiles were generally consistent with functional connectivity patterns. Our findings indicate that the magnitude of the genetic covariance in brain anatomy could be used to delineate the boundaries of functional subregions of the brain and may be of value in the next generation human brain atlas. PMID:26250778

  1. Abrupt shifts in Horn of Africa hydroclimate since the Last Glacial Maximum.

    PubMed

    Tierney, Jessica E; deMenocal, Peter B

    2013-11-15

    The timing and abruptness of the initiation and termination of the Early Holocene African Humid Period are subjects of ongoing debate, with direct consequences for our understanding of abrupt climate change, paleoenvironments, and early human cultural development. Here, we provide proxy evidence from the Horn of Africa region that documents abrupt transitions into and out of the African Humid Period in northeast Africa. Similar and generally synchronous abrupt transitions at other East African sites suggest that rapid shifts in hydroclimate are a regionally coherent feature. Our analysis suggests that the termination of the African Humid Period in the Horn of Africa occurred within centuries, underscoring the nonlinearity of the region's hydroclimate. PMID:24114782

  2. Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

    PubMed

    Mgode, Georgies F; Machang'u, Robert S; Mhamphi, Ginethon G; Katakweba, Abdul; Mulungu, Loth S; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A; Belmain, Steven R

    2015-12-01

    The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries. PMID:26624890

  3. Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

    PubMed Central

    Mgode, Georgies F.; Machang’u, Robert S.; Mhamphi, Ginethon G.; Katakweba, Abdul; Mulungu, Loth S.; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A.; Belmain, Steven R.

    2015-01-01

    The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries. PMID:26624890

  4. West Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    With its vast expanses of sand, framed by mountain ranges and exposed rock, northwestern Africa makes a pretty picture when viewed from above. This image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The Canary Islands can be seen on the left side of the image just off Africa's Atlantic shore. The light brown expanse running through the northern two thirds of the image is the Sahara Desert. The desert runs up against the dark brown Haut Atlas mountain range of Morocco in the northwest, the Atlantic Ocean to the west and the semi-arid (light brown pixels) Sahelian region in the South. The Sahara, however, isn't staying put. Since the 1960s, the desert has been expanding into the Sahelian region at a rate of up to 6 kilometers per year. In the 1980s this desert expansion, combined with over cultivation of the Sahel, caused a major famine across west Africa. Over the summer months, strong winds pick up sands from the Sahara and blow them across the Atlantic as far west as North America, causing air pollution in Miami and damaging coral reefs in the Bahamas and the Florida Keys. The white outlines on the map represent country borders. Starting at the top-most portion of the map and working clockwise, the countries shown are Morocco, Western Sahara, Mauritania, Senegal, Mali, Burkina Fasso, Nigeria, Mali (again), and Algeria. Image by Reto Stockli, Robert Simmon, and Brian Montgomery, NASA Earth Observatory, based on data from MODIS

  5. Climate change projections for CORDEX-Africa with COSMO-CLM regional climate model and differences with the driving global climate models

    NASA Astrophysics Data System (ADS)

    Dosio, Alessandro; Panitz, Hans-Jürgen

    2016-03-01

    In the framework of the coordinated regional climate downscaling experiment (CORDEX), an ensemble of climate change projections for Africa has been created by downscaling the simulations of four global climate models (GCMs) by means of the consortium for small-scale modeling (COSMO) regional climate model (RCM) (COSMO-CLM, hereafter, CCLM). Differences between the projected temperature and precipitation simulated by CCLM and the driving GCMs are analyzed and discussed. The projected increase of seasonal temperature is found to be relatively similar between GCMs and RCM, although large differences (more than 1 °C) exist locally. Differences are also found for extreme-event related quantities, such as the spread of the upper end of the maximum temperature probability distribution function and, in turn, the duration of heat waves. Larger uncertainties are found in the future precipitation changes; this is partly a consequence of the inter-model (GCMs) variability over some areas (e.g. Sahel). However, over other regions (e.g. Central Africa) the rainfall trends simulated by CCLM and the GCMs show opposite signs, with CCLM showing a significant reduction in precipitation at the end of the century. This uncertain and sometimes contrasting behaviour is further investigated by analyzing the different models' response to the land-atmosphere interaction and feedback. Given the large uncertainty associated with inter-model variability across GCMs and the reduced spread in the results when a single RCM is used for downscaling, we strongly emphasize the importance of exploiting fully the CORDEX-Africa multi-GCM/multi-RCM ensemble in order to assess the robustness of the climate change signal and, possibly, to identify and quantify the many sources of uncertainty that still remain.

  6. Nodule Worm Infection in Humans and Wild Primates in Uganda: Cryptic Species in a Newly Identified Region of Human Transmission

    PubMed Central

    Ghai, Ria R.; Chapman, Colin A.; Omeja, Patrick A.; Davies, T. Jonathan; Goldberg, Tony L.

    2014-01-01

    Introduction Soil-transmitted helminths (STHs) are a major health concern in tropical and sub-tropical countries. Oesophagostomum infection is considered endemic to West Africa but has also been identified in Uganda, East Africa, among primates (including humans). However, the taxonomy and ecology of Oesophagostomum in Uganda have not been studied, except for in chimpanzees (Pan troglodytes), which are infected by both O. bifurcum and O. stephanostomum. Methods and Findings We studied Oesophagostomum in Uganda in a community of non-human primates that live in close proximity to humans. Prevalence estimates based on microscopy were lower than those based on polymerase chain reaction (PCR), indicating greater sensitivity of PCR. Prevalence varied among host species, with humans and red colobus (Procolobus rufomitratus) infected at lowest prevalence (25% and 41% by PCR, respectively), and chimpanzees, olive baboons (Papio anubis), and l'hoest monkeys (Cercopithecus lhoesti) infected at highest prevalence (100% by PCR in all three species). Phylogenetic regression showed that primates travelling further and in smaller groups are at greatest risk of infection. Molecular phylogenetic analyses revealed three cryptic clades of Oesophagostomum that were not distinguishable based on morphological characteristics of their eggs. Of these, the clade with the greatest host range had not previously been described genetically. This novel clade infects humans, as well as five other species of primates. Conclusions Multiple cryptic forms of Oesophagostomum circulate in the people and primates of western Uganda, and parasite clades differ in host range and cross-species transmission potential. Our results expand knowledge about human Oesophagostomum infection beyond the West African countries of Togo and Ghana, where the parasite is a known public health concern. Oesophagostomum infection in humans may be common throughout Sub-Saharan Africa, and the transmission of this neglected

  7. [Human intestinal parasites in Subsaharan Africa. II. Sao Tomé and Principe].

    PubMed

    Pampiglione, S; Visconti, S; Pezzino, G

    1987-04-01

    In 1983 the authors carried out a survey in the Democratic Republic of São Tomé and Principe, analysing 1050 specimens of stools collected among the population from apparently healthy subjects chosen at random and in a number proportional to the distribution of the population in the regions of the country (about 1% of the population was examined). The examined subjects were divided into 3 age groups (0-3, 4-12, more than 12 years old), to have homogeneous groups in relation principally to modalities of life and nutritional patterns. There were 488 male subjects and 562 females. The survey was preceded by a sensitization of the people to the problem of intestinal parasites and by two preliminary surveys about the number of existing latrines and about people's believes and attitudes in relation to helmintiasis. The tests were made according to the modified Ritchie technique on fecal specimens preserved with 10% formol solution. The following results were found: a) Protozoa: Entamoeba coli, 43.0%; Iodamoeba buetschlii, 9.0%; Giardia intestinalis, 8.8%; Endolimax nana, 7.0%; E. histolytica, 5.5%; E. hartmanni, 2.5%; Chilomastix mesnili, 2.3%; Trichomonas intestinalis, 0.2%; Balantidium coli, 0.1%. b) Helminths: Trichuris trichiura, 87.7%; Ascaris lumbricoides, 64.3%; Ancylostomatidae, 40.5%; Strongyloides stercoralis, 6.8%; Hymenolepis diminuta, 0.3%; H. nana, 0.2%; Schistosoma haematobium, 0.2%. In 28.2% of the specimens (with more than 50% of subjects in some villages) eggs of Heterophyidae were found, very similar to Metagonimus yokogawai, but not yet identified by us, with the following characteristics: elliptical shape, average size 25 mu (22.2-27.7) X 18.5 mu (17-21), thick wall, operculum difficult to see, not sticking out from the outline but visible by focusing being in a different refractiveness, presence of a small polar knob, colour slightly brownish, asymmetric miracidium. Further investigations are necessary to identify the species of this trematode and

  8. Human mucin gene MUC5AC: organization of its 5'-region and central repetitive region.

    PubMed Central

    Escande, F; Aubert, J P; Porchet, N; Buisine, M P

    2001-01-01

    Human mucin gene MUC5AC is clustered with MUC2, MUC5B and MUC6 on chromosome 11p15.5. We report here the full length cDNA sequence upstream of the repetitive region of human MUC5AC. We have also determined the sequence of its large central tandem repeat array. The 5'-region reveals high degree of sequence similarity with MUC2 and MUC5B and codes for 1336 amino acids organized into a signal peptide, four pro-von Willebrand factor-like D domains (D1, D2, D' and D3) and a short domain which connects to the central repetitive region. In the central region, 17 major domains have been identified. Nine code for cysteine-rich domains (Cys-domains 1-9) and exhibit high sequence similarity to the cysteine-rich domains described in the central region of MUC2 and MUC5B. Cys-domains 1-5 are interspersed by domains enriched with serine, threonine, and proline residues. Cys-domains 1-9 are interspersed by four domains (TR1-TR4) composed of various numbers of MUC5AC-type repeats. Southern-blot analyses reveal allelic variations both in length and nucleotide sequence. The length polymorphism which is due to variable numbers of tandem repeats is located in TR1 and TR4, whereas a mutation polymorphism detected with TaqI is located in Cys-domain 6. In this study, the organization of MUC5AC has been entirely elucidated showing extensive similarity to the other chromosome 11p15 MUC genes, particularly MUC5B, and providing additional arguments for common evolution from a single ancestral gene. PMID:11535137

  9. Effects of human presence on chimpanzee nest location in the Lebialem-Mone forest landscape, Southwest Region, Cameroon.

    PubMed

    Last, Cadell; Muh, Bernice

    2013-01-01

    In several areas of Africa, great apes experience increasing predation pressure as a result of human activities. In this study, terrestrial and arboreal nest construction among chimpanzee (Pan troglodytes ellioti) populations was investigated in the Lebialem-Mone Forest Landscape (LMFL), Southwest Region, Cameroon, to examine the anthropogenic effects on nest location. Data on the height, distribution and approximate age of chimpanzee night nests were collected during two 4-week primate field surveys (July to August 2010; July 2011) at two field sites (Bechati and Andu) within the LMFL. Data were collected using the line transect method. Chimpanzee night nests were categorized by their location: arboreal versus terrestrial. During the two field surveys, arboreal night nests were the most frequently constructed nest type at both sites, and the only type of night nest constructed at Bechati. Terrestrial night nests were also constructed at Andu. The main difference between these two sites is the level of human predation and agricultural development. At Bechati chimpanzees inhabit forest regions around dense, expanding villages and are regularly hunted by humans. However, at Andu the chimpanzee populations are not under the same threat. Therefore, terrestrial night nest construction in the LMFL appears to be a behavior exhibited where there is less human presence. PMID:23406888

  10. Identification of fibrillogenic regions in human triosephosphate isomerase

    PubMed Central

    Carcamo-Noriega, Edson N.

    2016-01-01

    Background. Amyloid secondary structure relies on the intermolecular assembly of polypeptide chains through main-chain interaction. According to this, all proteins have the potential to form amyloid structure, nevertheless, in nature only few proteins aggregate into toxic or functional amyloids. Structural characteristics differ greatly among amyloid proteins reported, so it has been difficult to link the fibrillogenic propensity with structural topology. However, there are ubiquitous topologies not represented in the amyloidome that could be considered as amyloid-resistant attributable to structural features, such is the case of TIM barrel topology. Methods. This work was aimed to study the fibrillogenic propensity of human triosephosphate isomerase (HsTPI) as a model of TIM barrels. In order to do so, aggregation of HsTPI was evaluated under native-like and destabilizing conditions. Fibrillogenic regions were identified by bioinformatics approaches, protein fragmentation and peptide aggregation. Results. We identified four fibrillogenic regions in the HsTPI corresponding to the β3, β6, β7 y α8 of the TIM barrel. From these, the β3-strand region (residues 59–66) was highly fibrillogenic. In aggregation assays, HsTPI under native-like conditions led to amorphous assemblies while under partially denaturing conditions (urea 3.2 M) formed more structured aggregates. This slightly structured aggregates exhibited residual cross-β structure, as demonstrated by the recognition of the WO1 antibody and ATR-FTIR analysis. Discussion. Despite the fibrillogenic regions present in HsTPI, the enzyme maintained under native-favoring conditions displayed low fibrillogenic propensity. This amyloid-resistance can be attributed to the three-dimensional arrangement of the protein, where β-strands, susceptible to aggregation, are protected in the core of the molecule. Destabilization of the protein structure may expose inner regions promoting β-aggregation, as well as the

  11. Identification of fibrillogenic regions in human triosephosphate isomerase.

    PubMed

    Carcamo-Noriega, Edson N; Saab-Rincon, Gloria

    2016-01-01

    Background. Amyloid secondary structure relies on the intermolecular assembly of polypeptide chains through main-chain interaction. According to this, all proteins have the potential to form amyloid structure, nevertheless, in nature only few proteins aggregate into toxic or functional amyloids. Structural characteristics differ greatly among amyloid proteins reported, so it has been difficult to link the fibrillogenic propensity with structural topology. However, there are ubiquitous topologies not represented in the amyloidome that could be considered as amyloid-resistant attributable to structural features, such is the case of TIM barrel topology. Methods. This work was aimed to study the fibrillogenic propensity of human triosephosphate isomerase (HsTPI) as a model of TIM barrels. In order to do so, aggregation of HsTPI was evaluated under native-like and destabilizing conditions. Fibrillogenic regions were identified by bioinformatics approaches, protein fragmentation and peptide aggregation. Results. We identified four fibrillogenic regions in the HsTPI corresponding to the β3, β6, β7 y α8 of the TIM barrel. From these, the β3-strand region (residues 59-66) was highly fibrillogenic. In aggregation assays, HsTPI under native-like conditions led to amorphous assemblies while under partially denaturing conditions (urea 3.2 M) formed more structured aggregates. This slightly structured aggregates exhibited residual cross-β structure, as demonstrated by the recognition of the WO1 antibody and ATR-FTIR analysis. Discussion. Despite the fibrillogenic regions present in HsTPI, the enzyme maintained under native-favoring conditions displayed low fibrillogenic propensity. This amyloid-resistance can be attributed to the three-dimensional arrangement of the protein, where β-strands, susceptible to aggregation, are protected in the core of the molecule. Destabilization of the protein structure may expose inner regions promoting β-aggregation, as well as the

  12. Secondary Education in Africa: Strategies for Renewal. World Bank Presentations at the UNESCO/BREDA-World Bank Regional Workshop on the Renewal of Secondary Education in Africa (Mauritius, Africa, December 2001). Africa Region Human Development Working Paper Series.

    ERIC Educational Resources Information Center

    Mastri, Lawrence, Ed.

    During the last 3 decades secondary education has become universal in most industrialized countries. Sub-Saharan African countries face special challenges to benefit from this international trend. The gap between these countries and the rest of the world in coverage, quality, and relevance of secondary education is widening. To address these…

  13. Health systems and access to antiretroviral drugs for HIV in Southern Africa: service delivery and human resources challenges.

    PubMed

    Schneider, Helen; Blaauw, Duane; Gilson, Lucy; Chabikuli, Nzapfurundi; Goudge, Jane

    2006-05-01

    Without strengthened health systems, significant access to antiretroviral (ARV) therapy in many developing countries is unlikely to be achieved. This paper reflects on systemic challenges to scaling up ARV access in countries with both massive epidemics and weak health systems. It draws on the authors' experience in southern Africa and the World Health Organization's framework on health system performance. Whilst acknowledging the still significant gap in financing, the paper focuses on the challenges of reorienting service delivery towards chronic disease care and the human resource crisis in health systems. Inadequate supply, poor distribution, low remuneration and accelerated migration of skilled health workers are increasingly regarded as key systems constraints to scaling up of HIV treatment. Problems, however, go beyond the issue of numbers to include productivity and cultures of service delivery. As more countries receive funds for antiretroviral access programmes, strong national stewardship of these programmes becomes increasingly necessary. The paper proposes a set of short- and long-term stewardship tasks, which include resisting the verticalisation of HIV treatment, the evaluation of community health workers and their potential role in HIV treatment access, international action on the brain drain, and greater investment in national human resource functions of planning, production, remuneration and management. PMID:16713875

  14. Human Rights Violations among Men Who Have Sex with Men in Southern Africa: Comparisons between Legal Contexts

    PubMed Central

    Zahn, Ryan; Grosso, Ashley; Scheibe, Andrew; Bekker, Linda-Gail; Ketende, Sosthenes; Dausab, Friedel; Iipinge, Scholastica; Beyrer, Chris; Trapance, Gift; Baral, Stefan

    2016-01-01

    In 1994, South Africa approved a constitution providing freedom from discrimination based on sexual orientation. Other Southern African countries, including Botswana, Malawi, and Namibia, criminalize same-sex behavior. Men who have sex with men (MSM) have been shown to experience high levels of stigma and discrimination, increasing their vulnerability to negative health and other outcomes. This paper examines the relationship between criminalization of same-sex behavior and experiences of human rights abuses by MSM. It compares the extent to which MSM in peri-urban Cape Town experience human rights abuses with that of MSM in Gaborone, Botswana; Blantyre and Lilongwe, Malawi; and Windhoek, Namibia. In 2008, 737 MSM participated in a cross-sectional study using a structured survey collecting data regarding demographics, human rights, HIV status, and risk behavior. Participants accrued in each site were compared using bivariate and multivariate logistic regression. Encouragingly, the results indicate MSM in Cape Town were more likely to disclose their sexual orientation to family or healthcare workers and less likely to be blackmailed or feel afraid in their communities than MSM in Botswana, Malawi, or Namibia. However, South African MSM were not statistically significantly less likely experience a human rights abuse than their peers in cities in other study countries, showing that while legal protections may reduce experiences of certain abuses, legislative changes alone are insufficient for protecting MSM. A comprehensive approach with interventions at multiple levels in multiple sectors is needed to create the legal and social change necessary to address attitudes, discrimination, and violence affecting MSM. PMID:26764467

  15. Distribution of a community of mammals in relation to roads and other human disturbances in Gabon, central Africa.

    PubMed

    Vanthomme, Hadrien; Kolowski, Joseph; Korte, Lisa; Alonso, Alfonso

    2013-04-01

    We present the first community-level study of the associations of both roads and other human disturbances with the distribution of mammals in Gabon (central Africa). Our study site was in an oil concession within a littoral mosaic landscape. We conducted surveys along 199 line transects and installed camera traps on 99 of these transects to document mammal presence and abundance. We used generalized linear mixed-effect models to document associations between variables related to the ecosystem (land cover, topography, and hydrology), roads (coating, width of rights of way, condition, type of vehicle used on the road, traffic level, affiliation of users, and general type of road), and other human disturbances (urbanization, agriculture, hunting, logging, gathering, and industrial activities) and the abundance or presence of 17 species or groups of mammals including elephant (Loxodonta cyclotis), buffalo (Syncerus caffer), sitatunga (Tragelaphus spekei), red river hog (Potamochoerus porcus), smaller ungulates, gorilla (Gorilla gorilla), chimpanzee (Pan troglodytes), side-striped jackal (Canis adustus), carnivores, monkeys, and large rodents. Some types of roads and other human disturbances were negatively associated with the abundance or presence of elephants, buffalos, gorillas, sitatungas, some monkeys, and duikers. The pattern of associations of mammals with roads and other human disturbances was diverse and included positive associations with road presence (red river hog, some monkeys, and duikers), agriculture (sitatunga, small carnivores, and large rodents) and industrial activities (sitatunga, red river hog, red duikers, and side-striped jackal). Our results suggest that the community of mammals we studied was mostly affected by hunting, agriculture, and urbanization, which are facilitated by road presence. We recommend increased regulation of agriculture, hunting, and road building in the area. PMID:23410077

  16. Human Rights Violations among Men Who Have Sex with Men in Southern Africa: Comparisons between Legal Contexts.

    PubMed

    Zahn, Ryan; Grosso, Ashley; Scheibe, Andrew; Bekker, Linda-Gail; Ketende, Sosthenes; Dausab, Friedel; Iipinge, Scholastica; Beyrer, Chris; Trapance, Gift; Baral, Stefan

    2016-01-01

    In 1994, South Africa approved a constitution providing freedom from discrimination based on sexual orientation. Other Southern African countries, including Botswana, Malawi, and Namibia, criminalize same-sex behavior. Men who have sex with men (MSM) have been shown to experience high levels of stigma and discrimination, increasing their vulnerability to negative health and other outcomes. This paper examines the relationship between criminalization of same-sex behavior and experiences of human rights abuses by MSM. It compares the extent to which MSM in peri-urban Cape Town experience human rights abuses with that of MSM in Gaborone, Botswana; Blantyre and Lilongwe, Malawi; and Windhoek, Namibia. In 2008, 737 MSM participated in a cross-sectional study using a structured survey collecting data regarding demographics, human rights, HIV status, and risk behavior. Participants accrued in each site were compared using bivariate and multivariate logistic regression. Encouragingly, the results indicate MSM in Cape Town were more likely to disclose their sexual orientation to family or healthcare workers and less likely to be blackmailed or feel afraid in their communities than MSM in Botswana, Malawi, or Namibia. However, South African MSM were not statistically significantly less likely experience a human rights abuse than their peers in cities in other study countries, showing that while legal protections may reduce experiences of certain abuses, legislative changes alone are insufficient for protecting MSM. A comprehensive approach with interventions at multiple levels in multiple sectors is needed to create the legal and social change necessary to address attitudes, discrimination, and violence affecting MSM. PMID:26764467

  17. Estimation of human heat loss in five Mediterranean regions.

    PubMed

    Bilgili, M; Simsek, E; Sahin, B; Yasar, A; Ozbek, A

    2015-10-01

    This study investigates the effects of seasonal weather differences on the human body's heat losses in the Mediterranean region of Turkey. The provinces of Adana, Antakya, Osmaniye, Mersin and Antalya were chosen for the research, and monthly atmospheric temperatures, relative humidity, wind speed and atmospheric pressure data from 2007 were used. In all these provinces, radiative, convective and evaporative heat losses from the human body based on skin surface and respiration were analyzed from meteorological data by using the heat balance equation. According to the results, the rate of radiative, convective and evaporative heat losses from the human body varies considerably from season to season. In all the provinces, 90% of heat loss was caused by heat transfer from the skin, with the remaining 10% taking place through respiration. Furthermore, radiative and convective heat loss through the skin reached the highest values in the winter months at approximately between 110 and 140W/m(2), with the lowest values coming in the summer months at roughly 30-50W/m(2). PMID:26025784

  18. High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural western Kenya: implications for human health.

    PubMed

    Maina, Alice N; Jiang, Ju; Omulo, Sylvia A; Cutler, Sally J; Ade, Fredrick; Ogola, Eric; Feikin, Daniel R; Njenga, M Kariuki; Cleaveland, Sarah; Mpoke, Solomon; Ng'ang'a, Zipporah; Breiman, Robert F; Knobel, Darryn L; Richards, Allen L

    2014-10-01

    Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae-genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya. PMID:25325312

  19. Regional atmospheric aerosol composition and sources in the eastern Transvaal, South Africa, and impact of biomass burning

    NASA Astrophysics Data System (ADS)

    Maenhaut, Willy; Salma, Imre; Cafmeyer, Jan; Annegarn, Harold J.; Andreae, Meinrat O.

    1996-10-01

    As part of the Southern Africa Fire-Atmosphere Research Initiative (SAFARI-92), size-fractionated aerosol samples were collected during September-October 1992 at three fixed ground-based sites in the eastern Transvaal, i.e., at two sites within the Kruger National Park (KNP) and at a third site on the Transvaal highveld (about 150 km WSW of the KNP sites), and near a number of prescribed fires in the KNP. The collection devices consisted of stacked filter units, which separate the aerosol into a coarse (2-10 μm equivalent aerodynamic diameter (EAD)) and a fine (<2 μm EAD) size fraction, and of eight-stage cascade impactors, which provide more detailed size fractionation. The samples were analyzed for particulate mass (PM), black carbon (BC), and up to 47 elements. The prescribed fires gave rise to high levels of airborne soil dust, but several species (elements) were particularly enriched in the pyrogenic emissions. This was the case for BC, P, K, Ca, Mn, Zn, Sr, and I in the coarse fraction, and for BC, the halogens (Cl, Br, I), K, Cu, Zn, Rb, Sb, Cs, and Pb (and in the flaming phase also Na and S) in the fine fraction. The aerosol concentrations, compositions, and time trends at the two KNP sites were quite similar, suggesting that regionally representative samples were collected. Receptor modeling calculations, using both absolute principal component analysis and chemical mass balance, indicated that the KNP coarse PM was essentially attributable to mineral dust and sea salt, with average relative apportionments of 75% and 25%, respectively. At the highveld site, mineral dust and sea salt contributed in a 99-to-1 ratio to the coarse PM. In the fine size fraction at all three fixed sites, four components were identified, i.e., mineral dust, sea salt, biomass burning products, and sulfate. The pyrogenic component was the dominant contributor to the atmospheric concentrations of BC, K, Zn, and I, a major source for PM, Cl, Cu, Br, and Cs, but only a minor source

  20. How Changing Human Lifestyles are Shaping Europe's Regional Seas

    NASA Astrophysics Data System (ADS)

    Mee, L. D.; Lowe, C. D.; Langmead, O.; McQuatters-Gollop, A.; Attrill, M.; Cooper, P.; Gilbert, A.; Knudsen, S.; Garnacho, E.

    2007-05-01

    European society is experiencing unprecedented changes triggered by expansion of the European Union, the fall of Communism, economic growth and the onset of globalisation. Europe's regional seas, the Baltic, Black Sea, Mediterranean and North-East Atlantic (including the North Sea), provide key goods and services to the human population but have suffered from severe degradation in past decades. Their integrity as coupled social and ecological systems depends on how humanity will anticipate potential problems and deal with its ecological footprint in the future. We report the outcome of an EU-funded 15-country, 28 institution project entitled European Lifestyles and Marine Ecosystems (ELME). Our studies were designed to inform new EU policy and legislation that incorporates Ecosystem-Based Management. ELME has modelled the key relationships between economic and social drivers (D), environmental pressures (P) and changes in the state of the environment (S) in Europe's regional seas. We examined four key issues in each sea: habitat change, eutrophication, chemical pollution and fisheries. We developed conceptual models for each regional sea and employed a novel stochastic modelling technique to examine the interrelationship between key components of the conceptual models. We used the models to examine 2-3 decade projections of current trends in D, P and S and how a number of alternative development scenarios might modify these trends. These simulations demonstrate the vulnerability of Europe's seas to human pressure. As affluence increases in countries acceding to the EU, so does the demand for marine goods and services. There are `winners' and `losers' amongst marine species; the winners are often species that are opportunistic invaders or those with low economic value. In the case of eutrophication, semi-enclosed seas such as the Baltic or Black Sea are already affected by the `legacy of the past'; nutrients that have accumulated in soils, ground waters and

  1. West Africa

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Hazy and Dusty Skies over Western Africa     View Larger Image ... of agricultural fires that were burning throughout western Africa during December and early January, and was likely to have been ...

  2. The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.

    PubMed

    Elhassan, Nuha; Gebremeskel, Eyoab Iyasu; Elnour, Mohamed Ali; Isabirye, Dan; Okello, John; Hussien, Ayman; Kwiatksowski, Dominic; Hirbo, Jibril; Tishkoff, Sara; Ibrahim, Muntaser E

    2014-01-01

    Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount. PMID:24845801

  3. Filling the gap: a learning network for health an human rights in the Western Cape, South Africa.

    PubMed

    London, Leslie; Fick, Nicole; Tram, Khai Hoan; Stuttaford, Maria

    2012-01-01

    We draw on the experience of a Learning Network for Health and Human Rights (LN) involving collaboration between academic institutions and civil society organizations in the Western Cape, South Africa, aimed at identifying and disseminating best practice related to the right to health. The LN's work in materials development, participatory research, training and capacity-building for action, and advocacy for intervention illustrates important lessons for human rights practice. These include (i) the importance of active translation of knowledge and awareness into action for rights to be made real; (ii) the potential tension arising from civil society action, which might relieve the state of its obligations by delivering services that should be the state's responsibility-and hence the importance of emphasizing civil society's role in holding services accountable in terms of the right to health; (iii) the role of civil society organizations in filling a gap related to obligations to promote rights; (iv) the critical importance of networking and solidarity for building civil society capacity to act for health rights. Evidence from evaluation of the LN is presented to support the argument that civil society can play a key role in bridging a gap between formal state commitment to creating a human rights culture and realizing services and policies that enable the most vulnerable members of society to advance their health. Through access to information and the creation of spaces, both for participation and as a safe environment in which learning can be turned into practice, the agency of those most affected by rights violations can be redressed. We argue that civil society agency is critical to such action. PMID:22773101

  4. A physical map of the human pseudoautosomal region.

    PubMed Central

    Brown, W R

    1988-01-01

    A physical map of the human pseudoautosomal region has been constructed using pulsed field gel electrophoresis and the infrequently cutting restriction enzymes BssHIII, EagI, SstII, NotI, MluI and NruI. This map extends 2.3 Mbp from the telomere to sex-chromosome-specific DNA, includes at least seven CpG islands and locates four genetically mapped loci. Five of the CpG islands are organized into two clusters. One cluster is adjacent to the telomere, the other extends into sex-chromosome-specific DNA. There is congruence between the genetic and physical maps which implies that the frequency of recombination is approximately uniform throughout the DNA. Images PMID:2847916

  5. Balancing Human Rights and Civil Liberties in an Emerging Democracy: Education Law, Policy and Practice in South Africa.

    ERIC Educational Resources Information Center

    Beckmann, Johan; Maile, Simeon; van Vollenhoven, Willie; Joubert Rika

    This outline is part of a collection of 54 papers from the 48th annual conference of the Education Law Association held in November 2002. It covers a presentation on changes in the law and social structure of South Africa. As an outline, it briefly touches upon a number of topics, but focuses mainly on South Africa's emerging "final" Constitution,…

  6. Southern Africa

    Atmospheric Science Data Center

    2013-04-16

    article title:  Southern Africa     View larger JPEG image ... These Multi-angle Imaging SpectroRadiometer (MISR) images of Africa were acquired on August 25, 2000, during Terra orbit 3655. The left ... of smoke plumes and haze. The southern tip of South Africa is at the bottom of the image, and Zambia is at the top. Distinctive ...

  7. An overview of regional and local characteristics of aerosols in South Africa using satellite, ground, and modeling data

    PubMed Central

    Hersey, S. P.; Garland, R. M.; Crosbie, E.; Shingler, T.; Sorooshian, A.; Piketh, S.; Burger, R.

    2015-01-01

    We present a comprehensive overview of particulate air quality across the five major metropolitan areas of South Africa (Cape Town, Bloemfontein, Johannesburg and Tshwane (Gauteng Province), the Industrial Highveld Air Quality Priority Area (HVAPA), and Durban), based on a decadal (1 January 2000 to 31 December 2009) aerosol climatology from multiple satellite platforms and detailed analysis of ground-based data from 19 sites throughout Gauteng Province. Satellite analysis was based on aerosol optical depth (AOD) from MODIS Aqua and Terra (550 nm) and MISR (555 nm) platforms, Ångström Exponent (α) from MODIS Aqua (550/865 nm) and Terra (470/660 nm), ultraviolet aerosol index (UVAI) from TOMS, and results from the Goddard Ozone Chemistry Aerosol Radiation and Transport (GOCART) model. At continentally influenced sites, AOD, α, and UVAI reach maxima (0.12–0.20, 1.0–1.8, and 1.0–1.2, respectively) during austral spring (September–October), coinciding with a period of enhanced dust generation and the maximum integrated intensity of close-proximity and subtropical fires identified by MODIS Fire Information for Resource Management System (FIRMS). Minima in AOD, α, and UVAI occur during winter. Results from ground monitoring indicate that low-income township sites experience by far the worst particulate air quality in South Africa, with seasonally averaged PM10 concentrations as much as 136 % higher in townships that in industrial areas. We report poor agreement between satellite and ground aerosol measurements, with maximum surface aerosol concentrations coinciding with minima in AOD, α, and UVAI. This result suggests that remotely sensed data are not an appropriate surrogate for ground air quality in metropolitan South Africa. PMID:26312061

  8. An overview of regional and local characteristics of aerosols in South Africa using satellite, ground, and modeling data

    NASA Astrophysics Data System (ADS)

    Hersey, S. P.; Garland, R. M.; Crosbie, E.; Shingler, T.; Sorooshian, A.; Piketh, S.; Burger, R.

    2015-04-01

    We present a comprehensive overview of particulate air quality across the five major metropolitan areas of South Africa (Cape Town, Bloemfontein, Johannesburg and Tshwane (Gauteng Province), the Industrial Highveld Air Quality Priority Area (HVAPA), and Durban), based on a decadal (1 January 2000 to 31 December 2009) aerosol climatology from multiple satellite platforms and detailed analysis of ground-based data from 19 sites throughout Gauteng Province. Satellite analysis was based on aerosol optical depth (AOD) from MODIS Aqua and Terra (550 nm) and MISR (555 nm) platforms, Ångström Exponent (α) from MODIS Aqua (550/865 nm) and Terra (470/660 nm), ultraviolet aerosol index (UVAI) from TOMS, and results from the Goddard Ozone Chemistry Aerosol Radiation and Transport (GOCART) model. At continentally influenced sites, AOD, α, and UVAI reach maxima (0.12-0.20, 1.0-1.8, and 1.0-1.2, respectively) during austral spring (September-October), coinciding with a period of enhanced dust generation and the maximum integrated intensity of close-proximity and subtropical fires identified by MODIS Fire Information for Resource Management System (FIRMS). Minima in AOD, α, and UVAI occur during winter. Results from ground monitoring indicate that low-income township sites experience by far the worst particulate air quality in South Africa, with seasonally averaged PM10 concentrations as much as 136% higher in townships that in industrial areas. We report poor agreement between satellite and ground aerosol measurements, with maximum surface aerosol concentrations coinciding with minima in AOD, α, and UVAI. This result suggests that remotely sensed data are not an appropriate surrogate for ground air quality in metropolitan South Africa.

  9. Human impacts on fluvial systems in the Mediterranean region

    NASA Astrophysics Data System (ADS)

    Hooke, J. M.

    2006-09-01

    The long history of substantial human impacts on the landscape of the Mediterranean region, and their effects on fluvial systems, is documented. These effects have included impacts of deforestation and other land use changes, agricultural terracing on a wide scale, water transfers, and irrigation schemes. During the 20th century, major changes were made directly to channels through channelisation, construction of dams of various sizes, and extraction of gravel, and indirectly by reforestation. These changes have caused a major phase of incision on some rivers. Runoff and soil erosion have been affected by types of crops and agricultural practices as well as by the varying extent of cultivation and grazing. Some recent agricultural practices involve wholescale relandscaping of the topography and alteration of surface properties of material. The importance of analysing the connectivity within different land units and of the spatial position of human activity within a catchment is illustrated. The analysis of connectivity is the key to understanding the variability of impact and the extent of propagation of effects.

  10. Differential regional effects of octreotide on human gastrointestinal motor function.

    PubMed Central

    von der Ohe, M R; Camilleri, M; Thomforde, G M; Klee, G G

    1995-01-01

    The effects of octreotide on regional motor function in the human gut are unclear. In a randomised, blinded study the effects of octreotide (50 micrograms, subcutaneously, three times daily) and placebo on gastric, small bowel, and colonic transit, and colonic motility and tone were assessed in 12 healthy volunteers whose colon had been cleansed. Octreotide accelerated initial gastric emptying (p = 0.05), inhibited small bowel transit (p < 0.01), and reduced ileocolonic bolus transfers (p < 0.05). Colonic transit was unaltered by octreotide; the postprandial colonic tonic response was inhibited (p < 0.05 v placebo), whereas colonic phasic pressure activity was increased by octreotide (p < 0.05 v placebo). These data support the use of octreotide in diarrhoeal states but not in diseases that cause small bowel stasis and bacterial overgrowth. Simultaneous measurements of colonic transit, tone, and phasic contractility are valid in studying the effects of pharmacological changes and may be applicable to the study of the human colon in health and disease. PMID:7797125

  11. The hydrological consequences of human impact in the Lublin Region

    NASA Astrophysics Data System (ADS)

    Michalczyk, Zdzisław; Mięsiak-Wójcik, Katarzyna; Sposób, Joanna; Turczyński, Marek

    2012-01-01

    The Lublin Region is an area where local transformations in the natural environment, including the hydrosphere, occur. They result from the impact of agriculture, industry as well as water supply and sewage disposal. These activities lead to changes in the water network resulting from land improvement works, channel straightening and water runoff acceleration, as well as to the formation of local, both point and diffuse sources, of water pollution. The consequences of human impact are manifested in local transformations of the quality or quantity of water resources. As a result of intense groundwater draw-off, hydrogeological conditions are transformed, which is reflected in the persistence of depression cones of varied size and depth, noticeable in the vicinity of water intakes for Lublin, Chełm, Zamość and Kraśnik. The lowering of the first-level groundwater table also occurs as a consequence of the drainage of chalk and marl mine workings in Chełm and Rejowiec, whereas in the area of the hard coal mine both shallow and deep groundwater was transformed. It is important to indicate the consequences of human impact changes of water conditions as the hydrosphere resources should be used according to the principles of sustainable development.

  12. Regional aerosol deposition in human upper airways. Final report

    SciTech Connect

    Swift, D.L.

    1997-11-01

    During the award period, a number of studies have been carried out related to the overall objective of the project which is to elucidate important factors which influence the upper airway deposition and dose of particles in the size range 0.5 nm - 10 {mu}m, such as particle size, breathing conditions, age, airway geometry, and mode of breathing. These studies are listed below. (1) A high voltage electrospray system was constructed to generate polydispersed 1-10 {mu}m diameter di-ethylhexyl sebacate aerosol for particle deposition studies in nasal casts and in human subjects. (2) The effect of nostril dimensions, nasal passage geometry, and nasal resistance on particle deposition efficiency in forty healthy, nonsmoking adults at a constant flowrate were studied. (3) The effect of nostril dimensions, nasal passage dimensions and nasal resistance on the percentage of particle deposition in the anterior 3 cm of the nasal passage of spontaneously breathing humans were studied. (4) The region of deposition of monodispersed aerosols were studied using replicate casts. (5) Ultrafine aerosol deposition using simulated breath holding path and natural path was compared. (6) An experimental technique was proposed and tested to measure the oral deposition of inhaled ultrafine particles. (7) We have calculated the total deposition fraction of ultrafine aerosols from 5 to 200 n in the extrathoracic airways and in the lung. (8) The deposition fraction of radon progeny in the head airways was studied using several head airway models.

  13. Feasible Stability Region in the Frontal Plane During Human Gait

    PubMed Central

    Yang, Feng; Espy, Debbie; Pai, Yi-Chung

    2010-01-01

    The inability to adequately control the motion of the center of mass (COM) in the frontal plane may result in a loss of balance causing a sideways fall during human gait. The primary purposes of this study were (1) to derive the feasible stability region (FSR) in the mediolateral direction, and (2) to compare the FSR with the COM motion state taken from 193 trials among 39 young subjects at liftoff during walking at different speeds. The lower boundary of the FSR was derived, at a given initial COM location, as the minimum rightward COM velocity, at liftoff of the left foot, required to bring the COM into the base of support (BOS), i.e. the right (stance) foot, as the COM velocity diminishes. The upper boundary was derived as the maximum rightward COM velocity, beyond which the left foot must land to the right of the right foot (BOS) in order to prevent a fall. We established a 2-link human model and employed dynamic optimization to estimate these threshold values for velocity. For a range of initial COM positions, simulated annealing algorithm was used to search for the threshold velocity values. Our study quantified the extent to which mediolateral balance can still be maintained without resorting to a crossover step (the left foot lands to the right of the BOS) for balance recovery The derived FSR is in good agreement with our gait experimental results. PMID:19760504

  14. Directory of Human Sciences Research Organizations and Professional Associations in South Africa. Second Edition.

    ERIC Educational Resources Information Center

    van der Berg, Henda, Ed.; Prinsloo, Roelf, Ed.; Pienaar, Drienie, Ed.

    This directory is intended to be a comprehensive reference source for identifying research organizations and institutions, and for promoting research cooperation and facilitating networking. This second edition provides a broad background to the development of the human sciences as well as an overview of existing and emerging science and…

  15. Scaling Up Child and Adolescent Mental Health Services in South Africa: Human Resource Requirements and Costs

    ERIC Educational Resources Information Center

    Lund, Crick; Boyce, Gerard; Flisher, Alan J.; Kafaar, Zuhayr; Dawes, Andrew

    2009-01-01

    Background: Children and adolescents with mental health problems have poor service cover in low- and middle-income countries. Little is known about the resources that would be required to provide child and adolescent mental health services (CAMHS) in these countries. The purpose of this study was to calculate the human resources and associated…

  16. World Bank Education Policy and Human Resource Development in Sub-Saharan Africa

    ERIC Educational Resources Information Center

    Mutamba, Charlene

    2014-01-01

    There is increasing interest in the intersection of education and training through societal development in the developing world, a concept linked to national human resource development (NHRD). In addition, education and training is known to correlate strongly with employment outcomes that are connected to economic success, health and family…

  17. Identification of Reliable Sulcal Patterns of the Human Rolandic Region.

    PubMed

    Mellerio, Charles; Lapointe, Marie-Noël; Roca, Pauline; Charron, Sylvain; Legrand, Laurence; Meder, Jean-François; Oppenheim, Catherine; Cachia, Arnaud

    2016-01-01

    A major feature of the human cortex is its huge morphological variability. Although a comprehensive literature about the sulco-gyral pattern of the central region is available from post-mortem data, a reliable and reproducible characterization from in vivo data is still lacking. The aim of this study is to test the reliability of morphological criteria of the central region sulci used in post-mortem data, when applied to in vivo magnetic resonance imaging (MRI) data. Thirty right-handed healthy individuals were included in the study. Automated segmentation and three dimensional (3D) surface-based rendering were obtained from clinical 3D T1-weighted MRI. Two senior radiologists labeled the three sulci composing the central region (precentral [PreCS], central [CS] and postcentral [PostCS]) and analyzed their morphological variations using 47 standard criteria derived from Ono's atlas based on post-mortem data. For each criterion, inter-rater concordance and comparison with the occurrence frequency provided in Ono's atlas were estimated. Overall, the sulcal pattern criteria derived from MRI data were highly reproducible between the raters with a high mean inter-rater concordance in the three sulci (CS: κ = 0.92 in left hemisphere/κ = 0.91 in right hemisphere; PreCS: κ = 0.91/κ = 0.93; PostCS: κ = 0.84/0.79). Only a very limited number of sulcal criteria significantly differed between the in vivo and the post-mortem data (CS: 2 criteria in the left hemisphere/3 criteria in the right hemisphere; PreCS: 3 in the left and right hemispheres; PostCS: 3 in the left hemisphere and 5 in the right hemisphere). Our study provides a comprehensive description of qualitative sulcal patterns in the central region from in vivo clinical MRI with high agreement with previous post-mortem data. Such identification of reliable sulcal patterns of the central region visible with standard clinical MRI data paves the way for the detection of subtle variations of the central sulcation

  18. Identification of Reliable Sulcal Patterns of the Human Rolandic Region

    PubMed Central

    Mellerio, Charles; Lapointe, Marie-Noël; Roca, Pauline; Charron, Sylvain; Legrand, Laurence; Meder, Jean-François; Oppenheim, Catherine; Cachia, Arnaud

    2016-01-01

    A major feature of the human cortex is its huge morphological variability. Although a comprehensive literature about the sulco-gyral pattern of the central region is available from post-mortem data, a reliable and reproducible characterization from in vivo data is still lacking. The aim of this study is to test the reliability of morphological criteria of the central region sulci used in post-mortem data, when applied to in vivo magnetic resonance imaging (MRI) data. Thirty right-handed healthy individuals were included in the study. Automated segmentation and three dimensional (3D) surface-based rendering were obtained from clinical 3D T1-weighted MRI. Two senior radiologists labeled the three sulci composing the central region (precentral [PreCS], central [CS] and postcentral [PostCS]) and analyzed their morphological variations using 47 standard criteria derived from Ono’s atlas based on post-mortem data. For each criterion, inter-rater concordance and comparison with the occurrence frequency provided in Ono’s atlas were estimated. Overall, the sulcal pattern criteria derived from MRI data were highly reproducible between the raters with a high mean inter-rater concordance in the three sulci (CS: κ = 0.92 in left hemisphere/κ = 0.91 in right hemisphere; PreCS: κ = 0.91/κ = 0.93; PostCS: κ = 0.84/0.79). Only a very limited number of sulcal criteria significantly differed between the in vivo and the post-mortem data (CS: 2 criteria in the left hemisphere/3 criteria in the right hemisphere; PreCS: 3 in the left and right hemispheres; PostCS: 3 in the left hemisphere and 5 in the right hemisphere). Our study provides a comprehensive description of qualitative sulcal patterns in the central region from in vivo clinical MRI with high agreement with previous post-mortem data. Such identification of reliable sulcal patterns of the central region visible with standard clinical MRI data paves the way for the detection of subtle variations of the central sulcation

  19. Subclustering of human immunoglobulin kappa light chain variable region genes

    SciTech Connect

    Kurth, J.H.; Mountain, J.L.; Cavalli-Sforza, L.L. )

    1993-04-01

    The human immunoglobulin kappa light chain (IgK) locus includes multiple variable region gene segments (V[sub k]) that can be divided into four subgroups. Oligonucleotide primers were designed to amplify specifically gene segments of the V[sub k]I, V[sub k]II, and V[sub k]III subgroups using the polymerase chain reaction (PCR). Product sequences were subcloned, sequenced, and compared. Phylogenetic analyses of sequences within each subgroup indicate that some subgroups can be subdivided further into [open quotes]sub-subgroups.[close quotes] The history of V[sub k] segment duplications apparently includes at least two separate periods, the first giving rise to the subgroups and the second generating further complexity within each subgroup. Duplications of large pieces of DNA (demonstrated by others through pulsed-field gel electrophoresis) also played a role. Rates of synonymous and nonsynonymous base changes between pairs of sequences suggest that natural selection has played a major role in the evolution of the V[sub k] variable gene segments, leading to sequence conservation in some regions and to increased diversity in others. 34 refs., 4 figs., 3 tabs.

  20. mRNAs from human adenovirus 2 early region 4.

    PubMed Central

    Virtanen, A; Gilardi, P; Näslund, A; LeMoullec, J M; Pettersson, U; Perricaudet, M

    1984-01-01

    The molecular structure of the mRNAs from early region 4 of human adenovirus 2 has been studied by Northern blot analysis, S1 nuclease analysis, and sequence analysis of cDNA clones. The results make it possible to identify four different splice donor sites and six different splice acceptor sites. The structure of 12 different mRNAs can be deduced from the analysis. The mRNAs have identical 5' and 3' ends and are thus likely to be processed from a common mRNA precursor by differential splicing. The different mRNA species are formed by the removal of one to three introns, and they all carry a short 5' leader segment. The introns appear to serve two functions; they either place a 5' leader segment in juxtaposition with an open reading frame or fuse two open translational reading frames. The early region 4 mRNAs can encode at least seven unique polypeptides. Images PMID:6088804

  1. Usutu virus in Africa.

    PubMed

    Nikolay, Birgit; Diallo, Mawlouth; Boye, Cheikh Saad Bouh; Sall, Amadou Alpha

    2011-11-01

    Usutu virus (USUV) was discovered in South Africa in 1959. Since then, it has been reported in several African countries including Senegal, Central African Republic, Nigeria, Uganda, Burkina Faso, Cote d'Ivoire, and Morocco. In 2001, USUV has been identified for the first time outside of Africa, namely in Europe, where it caused a significant mortality among blackbirds in Vienna, Austria. In 2009, the first two human cases of USUV infection in Europe have been reported in Italy, causing encephalitis in immunocompromised patients. The host range in Africa includes mainly Culex mosquitoes, birds, and also humans with one benign and one severe case. Given its role as a potential human pathogen and the similar appearance compared with other emerging arboviruses, it is essential to investigate the natural history and ecology of USUV in Africa. In this regard, we review the emergence of USUV in Africa, summarizing data about isolations, host range, and potential vectors, which should help to improve our understanding of the factors underlying the circulation of USUV in Europe and Africa. PMID:21767160

  2. Potential forcing of climate changes in crops yields: Brazil and Africa perspectives

    NASA Astrophysics Data System (ADS)

    Justino, F.; Stordal, F.

    2012-12-01

    This presentation will focus on the impact of human induced climate changes on crop yields in Brazil and sub-Saharan Africa. Crop modeling simulations have been run based on regional climate models (RegCM4 and PRECIS) to serve as initial conditions to DSSAT for both current and future climate conditions. The preliminary results indicate that substantial change may be expected in the interannual variability of crop yields in Brazil but not essentially in Africa. This is attributed to substantial changes in precipitation in Brazil which are not predicted to occur in Africa. It might be noted moreover that changes in future crop productivity exhibit for both regions high spatial heterogeneity.

  3. Education and Primitive Accumulation in Sub-Saharan Africa.

    ERIC Educational Resources Information Center

    Emoungu, Paul-Albert N.

    1992-01-01

    The 1988 World Bank report on education in sub-Saharan Africa overstates the regional "crisis" in educational quality and recommends unrealistic strategies, ignoring the fact that basic human needs such as education are unmet because political elites corruptly privatize much of the wealth generated by their nations' economies. (SV)

  4. On the development of a coupled regional climate-vegetation model RCM-CLM-CN-DV and its validation in Tropical Africa

    NASA Astrophysics Data System (ADS)

    Wang, Guiling; Yu, Miao; Pal, Jeremy S.; Mei, Rui; Bonan, Gordon B.; Levis, Samuel; Thornton, Peter E.

    2016-01-01

    This paper presents a regional climate system model RCM-CLM-CN-DV and its validation over Tropical Africa. The model development involves the initial coupling between the ICTP regional climate model RegCM4.3.4 (RCM) and the Community Land Model version 4 (CLM4) including models of carbon-nitrogen dynamics (CN) and vegetation dynamics (DV), and further improvements of the models. Model improvements derive from the new parameterization from CLM4.5 that addresses the well documented overestimation of gross primary production (GPP), a refinement of stress deciduous phenology scheme in CN that addresses a spurious LAI fluctuation for drought-deciduous plants, and the incorporation of a survival rule into the DV model to prevent tropical broadleaf evergreens trees from growing in areas with a prolonged drought season. The impact of the modifications on model results is documented based on numerical experiments using various subcomponents of the model. The performance of the coupled model is then validated against observational data based on three configurations with increasing capacity: RCM-CLM with prescribed leaf area index and fractional coverage of different plant functional types (PFTs); RCM-CLM-CN with prescribed PFTs coverage but prognostic plant phenology; RCM-CLM-CN-DV in which both the plant phenology and PFTs coverage are simulated by the model. Results from these three models are compared against the FLUXNET up-scaled GPP and ET data, LAI and PFT coverages from remote sensing data including MODIS and GIMMS, University of Delaware precipitation and temperature data, and surface radiation data from MVIRI and SRB. Our results indicate that the models perform well in reproducing the physical climate and surface radiative budgets in the domain of interest. However, PFTs coverage is significantly underestimated by the model over arid and semi-arid regions of Tropical Africa, caused by an underestimation of LAI in these regions by the CN model that gets exacerbated

  5. Multilocus phylogeography of a widespread savanna-woodland-adapted rodent reveals the influence of Pleistocene geomorphology and climate change in Africa's Zambezi region.

    PubMed

    McDonough, Molly M; Šumbera, Radim; Mazoch, Vladimír; Ferguson, Adam W; Phillips, Caleb D; Bryja, Josef

    2015-10-01

    Understanding historical influences of climate and physiographic barriers in shaping patterns of biodiversity remains limited for many regions of the world. For mammals of continental Africa, phylogeographic studies, particularly for West African lineages, implicate both geographic barriers and climate oscillations in shaping small mammal diversity. In contrast, studies for southern African species have revealed conflicting phylogenetic patterns for how mammalian lineages respond to both climate change and geologic events such as river formation, especially during the Pleistocene. However, these studies were often biased by limited geographic sampling or exclusively focused on large-bodied taxa. We exploited the broad southern African distribution of a savanna-woodland-adapted African rodent, Gerbilliscus leucogaster (bushveld gerbil) and generated mitochondrial, autosomal and sex chromosome data to quantify regional signatures of climatic and vicariant biogeographic phenomena. Results indicate the most recent common ancestor for all G. leucogaster lineages occurred during the early Pleistocene. We documented six divergent mitochondrial lineages that diverged ~0.270-0.100 mya, each of which was geographically isolated during periods characterized by alterations to the course of the Zambezi River and its tributaries as well as regional 'megadroughts'. Results demonstrate the presence of a widespread lineage exhibiting demographic expansion ~0.065-0.035 mya, a time that coincides with savanna-woodland expansion across southern Africa. A multilocus autosomal perspective revealed the influence of the Kafue River as a current barrier to gene flow and regions of secondary contact among divergent mitochondrial lineages. Our results demonstrate the importance of both climatic fluctuations and physiographic vicariance in shaping the distribution of southern African biodiversity. PMID:26340076

  6. Determination and human exposure assessment of polybrominated diphenyl ethers and tetrabromobisphenol A in indoor dust in South Africa.

    PubMed

    Abafe, Ovokeroye A; Martincigh, Bice S

    2016-04-01

    The concentration of TBBPA in dust samples from automobiles (n = 14), computer laboratories (n = 8), homes (n = 7), and offices (n = 7), and, also, PBDE concentrations in the indoor dust of 19 personal and previously owned automobiles in Durban, South Africa, were determined. Gas chromatography coupled with mass spectrometry was applied for the separation, identification, and quantitation of TBBPA and PBDEs. The median concentrations of TBBPA were 1156, 269, 120, and 492 ng g(-1) in automobiles, computer laboratories, homes, and offices, respectively. The ∑ n = 8 PBDE in 19 automobile samples ranged from 573 to 11,833 ng g(-1). BDE-209 accounted for approximately 42% of ∑ n = 8 PBDE in the samples. Household characteristics influenced the distribution of TBBPA in the various microenvironments. By assuming an average dust ingestion rate, and a median TBBPA concentration, the ∑DED (in ng kg(-1) bw day(-1)) of TBBPA is 0.08, 0.08, and 0.60, for an adult, teenager, and toddler, respectively. These doses are similar to dust ingestion intakes reported for Asian countries where there is a high demand for TBBPA as a flame retardant. Similarly, automobiles provide ample opportunity for human exposure to PBDEs via dust ingestion, particularly for toddlers and occupationally exposed adults. PMID:26743646

  7. Setting targets for human resources for eye health in sub-Saharan Africa: what evidence should be used?

    PubMed

    Courtright, Paul; Mathenge, Wanjiku; Kello, Amir Bedri; Cook, Colin; Kalua, Khumbo; Lewallen, Susan

    2016-01-01

    With a global target set at reducing vision loss by 25% by the year 2019, sub-Saharan Africa with an estimated 4.8 million blind persons will require human resources for eye health (HReH) that need to be available, appropriately skilled, supported, and productive. Targets for HReH are useful for planning, monitoring, and resource mobilization, but they need to be updated and informed by evidence of effectiveness and efficiency. Supporting evidence should take into consideration (1) ever-changing disease-specific issues including the epidemiology, the complexity of diagnosis and treatment, and the technology needed for diagnosis and treatment of each condition; (2) the changing demands for vision-related services of an increasingly urbanized population; and (3) interconnected health system issues that affect productivity and quality. The existing targets for HReH and some of the existing strategies such as task shifting of cataract surgery and trichiasis surgery, as well as the scope of eye care interventions for primary eye care workers, will need to be re-evaluated and re-defined against such evidence or supported by new evidence. PMID:26984773

  8. The case for developing publicly-accessible datasets for health services research in the Middle East and North Africa (MENA) region

    PubMed Central

    Saleh, Shadi S; Alameddine, Mohamad S; El-Jardali, Fadi

    2009-01-01

    Background The existence of publicly-accessible datasets comprised a significant opportunity for health services research to evolve into a science that supports health policy making and evaluation, proper inter- and intra-organizational decisions and optimal clinical interventions. This paper investigated the role of publicly-accessible datasets in the enhancement of health care systems in the developed world and highlighted the importance of their wide existence and use in the Middle East and North Africa (MENA) region. Discussion A search was conducted to explore the availability of publicly-accessible datasets in the MENA region. Although datasets were found in most countries in the region, those were limited in terms of their relevance, quality and public-accessibility. With rare exceptions, publicly-accessible datasets - as present in the developed world - were absent. Based on this, we proposed a gradual approach and a set of recommendations to promote the development and use of publicly-accessible datasets in the region. These recommendations target potential actions by governments, researchers, policy makers and international organizations. Summary We argue that the limited number of publicly-accessible datasets in the MENA region represents a lost opportunity for the evidence-based advancement of health systems in the region. The availability and use of publicly-accessible datasets would encourage policy makers in this region to base their decisions on solid representative data and not on estimates or small-scale studies; researchers would be able to exercise their expertise in a meaningful manner to both, policy makers and the public. The population of the MENA countries would exercise the right to benefit from locally- or regionally-based studies, versus imported and in 'best cases' customized ones. Furthermore, on a macro scale, the availability of regionally comparable publicly-accessible datasets would allow for the exploration of regional variations

  9. Economic Adjustment, Education and Human Resource Development in Africa: The Case of Nigeria

    NASA Astrophysics Data System (ADS)

    Geo-Jaja, Macleans A.; Mangum, Garth

    2003-07-01

    On the basis of the Nigerian experience, this article argues that the structural adjustment programs of the World Bank and the International Monetary Fund, when misapplied, can have a devastating effect on the educational systems that are essential to human resource development. The paper considers how the objectives of structural adjustment might have been accomplished without harming education, and recommends an outcomes-based educational policy for Nigeria which could serve equally well in other developing nations. The key message of the paper is that the ongoing austerity programs have been secured at excessively high human cost, and that it is time for a policy redirection that reaffirms education as the essential tool of all development.

  10. Cross-Species Transmission of Simian Foamy Virus to Humans in Rural Gabon, Central Africa

    PubMed Central

    Mouinga-Ondémé, Augustin; Caron, Mélanie; Nkoghé, Dieudonné; Telfer, Paul; Marx, Preston; Saïb, Ali; Leroy, Eric; Gonzalez, Jean-Paul; Gessain, Antoine

    2012-01-01

    In order to characterize simian foamy retroviruses (SFVs) in wild-born nonhuman primates (NHPs) in Gabon and to investigate cross-species transmission to humans, we obtained 497 NHP samples, composed of 286 blood and 211 tissue (bush meat) samples. Anti-SFV antibodies were found in 31 of 286 plasma samples (10.5%). The integrase gene sequence was found in 38/497 samples, including both blood and tissue samples, with novel SFVs in several Cercopithecus species. Of the 78 humans, mostly hunters, who had been bitten or scratched by NHPs, 19 were SFV seropositive, with 15 cases confirmed by PCR. All but one were infected with ape SFV. We thus found novel SFV strains in NHPs in Gabon and high cross-species transmission of SFVs from gorilla bites. PMID:22072747

  11. Combining Hydrology and Mosquito Population Models to Identify the Drivers of Rift Valley Fever Emergence in Semi-Arid Regions of West Africa

    PubMed Central

    Soti, Valérie; Tran, Annelise; Degenne, Pascal; Chevalier, Véronique; Lo Seen, Danny; Thiongane, Yaya; Diallo, Mawlouth; Guégan, Jean-François; Fontenille, Didier

    2012-01-01

    Background Rift Valley fever (RVF) is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated. Methodology/Principal Findings A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes) involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites. The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961–2003). We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species. Conclusion/Significance Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends the

  12. Formulating a Historical and Demographic Model of Recent Human Evolution Based on Resequencing Data from Noncoding Regions

    PubMed Central

    Laval, Guillaume; Patin, Etienne; Barreiro, Luis B.; Quintana-Murci, Lluís

    2010-01-01

    Background Estimating the historical and demographic parameters that characterize modern human populations is a fundamental part of reconstructing the recent history of our species. In addition, the development of a model of human evolution that can best explain neutral genetic diversity is required to identify confidently regions of the human genome that have been targeted by natural selection. Methodology/Principal Findings We have resequenced 20 independent noncoding autosomal regions dispersed throughout the genome in 213 individuals from different continental populations, corresponding to a total of ∼6 Mb of diploid resequencing data. We used these data to explore and co-estimate an extensive range of historical and demographic parameters with a statistical framework that combines the evaluation of multiple models of human evolution via a best-fit approach, followed by an Approximate Bayesian Computation (ABC) analysis. From a methodological standpoint, evaluating the accuracy of the parameter co-estimation allowed us to identify the most accurate set of statistics to be used for the estimation of each of the different historical and demographic parameters characterizing recent human evolution. Conclusions/Significance Our results support a model in which modern humans left Africa through a single major dispersal event occurring ∼60,000 years ago, corresponding to a drastic reduction of ∼5 times the effective population size of the ancestral African population of ∼13,800 individuals. Subsequently, the ancestors of modern Europeans and East Asians diverged much later, ∼22,500 years ago, from the population of ancestral migrants. This late diversification of Eurasians after the African exodus points to the occurrence of a long maturation phase in which the ancestral Eurasian population was not yet diversified. PMID:20421973

  13. Astronomy Landscape in Africa

    NASA Astrophysics Data System (ADS)

    Nemaungani, Takalani

    2015-01-01

    The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

  14. Climate change and early human land-use in a biodiversity hotspot, the Afromontane region

    NASA Astrophysics Data System (ADS)

    Ivory, S.; Russell, J. M.; Sax, D. F.; Early, R.

    2015-12-01

    African ecosystems are at great risk due to climate and land-use change. Paleo-records illustrate that changes in precipitation and temperature have led to dramatic alterations of African vegetation distribution over the Quaternary; however, despite the fact that the link between mankind and the environment has a longer history in the African tropics than anywhere else on earth, very little is known about pre-colonial land-use. Disentangling the influence of each is particularly critical in areas of exceptional biodiversity and endemism, such as the Afromontane forest region. This region is generally considered to be highly sensitive to temperature and thus at risk to future climate change. However, new evidence suggests that some high elevation species may have occupied warmer areas in the past and thus are not strongly limited by temperature and may be at greater risk from intensifying land-use. First, we use species distrib