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Sample records for africa southern africa

  1. Southern Africa

    Atmospheric Science Data Center

    2013-04-16

    ... tip of South Africa is at the bottom of the image, and Zambia is at the top. Distinctive features about a third of the way from the ... MISR Team. Aug 25, 2000 - South Africa to Zambia including the Okavango Delta. project:  MISR ...

  2. Astrophysics in Southern Africa

    NASA Astrophysics Data System (ADS)

    Whitelock, Patricia

    2008-03-01

    The government of South Africa has identified astronomy as a field in which their country has a strategic advantage and is consequently investing very significantly in astronomical infrastructure. South Africa now operates a 10-m class optical telescope, the Southern African Large Telescope (SALT), and is one of two countries short listed to host the Square Kilometre Array (SKA), an ambitious international project to construct a radio telescope with a sensitivity one hundred times that of any existing telescope. The challenge now is to produce an indigenous community of users for these facilities, particularly from among the black population which was severely disadvantaged under the apartheid regime. In this paper I briefly describe the observing facilities in Southern Africa before going on to discuss the various collaborations that are allowing us to use astronomy as a tool for development, and at the same time to train a new generation of astronomers who will be well grounded in the science and linked to their colleagues internationally.

  3. Central and southern Africa

    SciTech Connect

    McGrew, H.J.

    1981-10-01

    Exploration in central and southern Africa continued to expand during 1980. The greatest concentration of activity was in Nigeria. However, there was considerable increase in the level of exploratory work in Cameroon and Congo. Significant new finds have been made in Ivory Coast. Geological and geophysical activity was carried out in 18 of the countries, with those in the western part having the largest share. Seismic work involved 225 party months of operation. Most of this time was spent on land, but marine operations accounted for 73,389 km of new control. Gravity and magnetic data were recorded during the marine surveys, and several large aeromagnetic projects were undertaken to obtain a total of 164,498 line km of data. Exploratory and development drilling accounted for a total of 304 wells and 2,605,044 ft (794,212 m) of hole. The 92 exploratory wells that were drilled resulted in 47 oil and gas discoveries. In development drilling 89% of the 212 wells were successful. At the end of the year, 27 exploratory wells were underway, and 34 development wells were being drilled for a total of 61. Oil production from the countries that this review covers was 918,747,009 bbl in 1980, a drop of about 9% from the previous year. Countries showing a decline in production were Nigeria, Gabon, Cabinda, and Zaire. Increases were recorded in Cameroon, Congo, and Ghana. A new country was added to the list of producers when production from the Belier field in Ivory Coast came on stream. 33 figures, 15 tables.

  4. 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…

  5. 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…

  6. 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.

  7. Southern Africa’s Transnational Threats

    DTIC Science & Technology

    2013-04-01

    distribution of Cannabis (also known as marijuana) is prevalent throughout Southern Africa. In most incidences, Cannabis profits dwarfs local income...had its source in Tanzania and Tanzanians have identified markets for their fake US dollars in South Africa. Cannabis South Africa, Lesotho...Swaziland, Mozambique, Tanzania, Malawi, Zimbabwe, Zambia National and International markets Page 23. the listed states are the major cannabis - producing

  8. Atmospheric Chemistry Over Southern Africa

    NASA Technical Reports Server (NTRS)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    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 semi-permanent atmosphere 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 for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  9. Unprecedented Fires in Southern Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The fires that raged across southern Africa this August and September produced a thick 'river of smoke' over the region. NASA-supported studies currently underway on the event will contribute to improved air pollution policies in the region and a better understanding of its impact on climate change. This year the southern African fire season peaked in early September. The region is subject to some of the highest levels of biomass burning in the world. The heaviest burning was in western Zambia, southern Angola, northern Namibia, and northern Botswana. Some of the blazes had fire fronts 20 miles long that lasted for days. In this animation, multiple fires are burning across the southern part of the African continent in September 2000. The fires, indicated in red, were observed by the Advanced Very High Resolution Radiometer (AVHRR) instrument on board the NOAA-14 satellite. The fires generated large amounts of heat-absorbing aerosols (the dark haze), which were observed with the Earth Probe Total Ozone Mapping Spectrometer (TOMS) instrument. These observations were collected as part of a NASA-supported field campaign called SAFARI 2000 (Southern African Regional Science Initiative). The recent six-week 'dry-season' portion of this experiment was planned to coincide with the annual fires. SAFARI 2000 planners tracked the changing location of fires with daily satellite maps provided by researchers at NASA's Goddard Space Flight Center. 'Every year African biomass burning greatly exceeds the scale of the fires seen this year in the western United States,' says Robert Swap of the University of Virginia, one of the campaign organizers. 'But the southern African fire season we just observed may turn out to be an extreme one even by African standards. It was amazing how quickly this region went up in flames.' The thick haze layer from these fires was heavier than campaign participants had seen in previous field studies in the Amazon Basin and during the Kuwati oil fires

  10. Retinitis pigmentosa in southern Africa.

    PubMed

    Greenberg, J; Bartmann, L; Ramesar, R; Beighton, P

    1993-11-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal disorders which are a common cause of genetic blindness. The relative frequencies of the different forms of RP in South Africa, as determined from the register at the DNA banking centre for RP at the Department of Human Genetics, University of Cape Town, are presented and discussed. Of the 125 families analysed, 29 (23%) showed autosomal dominant, 33 (27%) autosomal recessive and 3 (3%) X-linked inheritance. In 10 families the pedigree data were insufficient to allow accurate genetic subtyping and a further 50 patients were sporadic without a family history of RP or other syndromic features which would allow categorization.

  11. The Seismotectonic Model of Southern Africa

    NASA Astrophysics Data System (ADS)

    Midzi, Vunganai; Mulabisana, Thifelimbulu; Manzunzu, Brassnavy

    2013-04-01

    Presented in this report is a summary of the major structures and seismotectonic zones in Southern Africa (Botswana, Lesotho, Namibia, South Africa and Swaziland), which includes available information on fault plane solutions and stress data. Reports published by several experts contributed much to the prepared zones. The work was prepared as part of the requirements for the SIDA/IGCP Project 601 titled "Seismotectonics and Seismic Hazards in Africa" as well as part of the seismic source characterisation of the GEM-Africa Seismic hazard study. The seismic data used are part of the earthquake catalogue being prepared for the GEM-Africa project, which includes historical and instrumental records as collected from various agencies. Seventeen seismic zones/sources were identified and demarcated using all the available information. Two of the identiied sources are faults with reliable evidence of their activity. Though more faults have been identified in unpublished material as being active, more work is being carried out to obtain information that can be used to characterise them before they are included in the seismotectonic model. Explanations for the selected boundaries of the zones are also given in the report. It should be noted that this information is the first draft of the seismic source zones of the region. Futher interpreation of the data is envisaged which might result in more than one version of the zones.

  12. Southern Africa seismic structure and source studies

    NASA Astrophysics Data System (ADS)

    Zhao, Ming

    1998-09-01

    The upper mantle seismic velocity structure beneath southern Africa is investigated using travel time and waveform data. Waveform and travel time data used in this study come mainly from a large mine tremor in South Africa (msb{b} 5.6) recorded on stations of the southern Africa and the Tanzania Broadband Seismic Experiment. Auxiliary data along similar profiles are obtained from other moderate events within eastern and southern Africa. The waveform data from the large tremor show upper mantle triplications for both the 400 and 670-km discontinuities between 18sp° and 27sp° distance. The most notable feature of the data is a large, late P phase that propagates to at least 27sp°. This phase is striking because of its late arrival time (as much as 15 seconds after direct P at 27sp°) and high amplitude relative to the first arrival. Travel times from all available stations are used to invert for the P wave velocity structure down to 800 km depth and S wave velocity structure down to 200 km using the Wiechert-Herglotz (W-H) inversion technique. The P wave velocities from the uppermost mantle down to 300 km are as much as 3% higher than the global average and are slightly slower than the global average between 300 and 400 km depths. The velocity gradient between 300 and 400 km is 0.0015 1/s. The S wave travel time data yield fast velocities above 200-km depth. The S wave velocity structure appears inconsistent with the P wave structure model indicating varying Poisson's ratio in the upper mantle. Little evidence is found for a pronounced upper mantle low velocity zone. Both sharp and gradual-change 400-km discontinuities are favored by the waveform data. The 670-km discontinuity appears as a gradual-change zone. The source mechanism of the mb 5.6 mining tremor itself is important for seismic discrimination and insight into mining tremor sources. Source parameters for this event as well as some other large mining tremors from the South African gold mines are studied

  13. Educational Reform and the Transformation of Southern Africa.

    ERIC Educational Resources Information Center

    Mungazi, Dickson A.; Walker, L. Kay

    The purpose of this study is to furnish evidence supporting the conclusion that the thrust for the transformation of southern Africa, that region of Africa south of the equator, cannot be initiated without responding to the need for fundamental educational reform. In this study, transformation is defined as basic change in the structure of…

  14. Evidence of nutrition transition in Southern Africa.

    PubMed

    Nnyepi, Maria S; Gwisai, Namo; Lekgoa, Malebogo; Seru, Tumelo

    2015-11-01

    Nutrition transition is characterised by shift to highly refined diets high in fat, salt and caloric sweeteners and low in fibre in rapidly growing economies. Dietary shifts occur almost concurrently with demographic and epidemiologic shifts, urbanisation and industrialisation and together contribute to increased prevalence of nutrition related (NR)-non-communicable disease (NCR). The emergence of nutrition transition in Southern Africa countries (SAC) was examined using anthropometric, NCD prevalence, and food consumption data. The findings reveal growing prevalence of overweight and obesity (OWOB) across SAC, with national prevalence estimated between 30 and 60 % in all but two SAC. Overweight prevalence in excess of 60 % has been reported in some sub-population groups. Hypertension prevalence of at least 30 % has also been reported. Further, the prevalence of OWOB and hypertension in many SAC exceeds that of HIV and is often at par with stunting in children. NCD are equally serious public health problems as stunting and HIV. Collectively, NR-NCD explain 20-31 % of mortality for Botswana, South Africa, Swaziland, Mozambique and Zambia. At least 72 % of adults in SAC have fewer servings of fruit and vegetable servings daily than recommended. Additionally, adults in SAC do poorly in physical activity; 31-75 % do not exercise regularly. Not surprisingly, 15-40 % of adults in SAC have at least three risk factors of CVD. SAC are grappling with NR-NCD which threaten to surpass infectious diseases burden. SAC are at various levels in interventions for moving their populations to stage 5, but there is room for much improvement.

  15. Stars and Seasons in Southern Africa

    NASA Astrophysics Data System (ADS)

    Snedegar, K. V.

    Although the indigenous people of Southern Africa traditionally viewed the sky as a place quite apart from the Earth, they believed celestial phenomena to be natural signs united with those of the Earth in a harmonious synchronicity. There is no substantial evidence that the precolonial Africans imagined a casual relationship between celestial bodies and the seasonal patterns of life on Earth. They did, however, recognize a coincidental relationship. The traditional African cosmos, then, worked as a noetic principle unifying the observed motions of celestial bodies, the sequence of seasons, and the behavior of plants and animals. Such a cosmos, with local peculiarities, was widely understood in Southern Africa before the end of the last century. By the early 20th century European colonial paradigms had largely obliterated this African worldview. This paper will offer a partial reconstruction. Pre-colonial South African people viewed time as a sequence of discrete natural events; through annual repetition these events served as a guide for proper human action. The South Africans analyzed the passage of time in terms of the motions of celestial bodies, the maturation of beneficial plants, and the mating patterns of animals. The rightful course of human life was seen to fit within the seasonal context of these natural phenomena. The visibility of conspicuous stars and asterisms marked significant times of year. For instance, the Lovedu people greeted the dawn rising of Canopus with joy: "The boy has come out." The star was a signal for rainmaking and boys' initiation ceremonies to proceed. The Venda constellation Thutlwa, the giraffes, comprises α and β Crucis and α and β Centauri. In October Thutlwa skims the trees of the evening horizon. The Venda Thutlwa literally means 'rising above the trees,' an allusion to the majestic vegetarian creatures and the stars advising the people to be done with their spring planting. This paper will describe stellar associations

  16. Applications of the IRI in Southern Africa

    NASA Astrophysics Data System (ADS)

    Coetzee, P. J.

    2004-01-01

    The IRI forms the basis of the Single Site Location Direction Finding networks of the South African Defence Force as well as theNational Intelligence Agency. It is also used in "Path Analysis" applications where the possible transmitter coverage is calculated. Another application of the IRI is in HF frequency predictions, especially for the South African Defence Force involved in peace keeping duties in Africa. The IRI is either used independently or in conjunction with vertical ionosondes. In the latter case the scaled F2 peak parameters (foF2, hmF2) are used as inputs to the IRI. The IRI thus gets "calibrated" to extend the area covered by the ionosonde(s). The IRI has proved to be a very important tool in South Africa and Africa in the fight against crime, drug trafficking, political instability and maintaining the peace in potentially unstable countries.

  17. Ancient west Eurasian ancestry in southern and eastern Africa

    PubMed Central

    Pickrell, Joseph K.; Patterson, Nick; Loh, Po-Ru; Lipson, Mark; Berger, Bonnie; Stoneking, Mark; Pakendorf, Brigitte; Reich, David

    2014-01-01

    The history of southern Africa involved interactions between indigenous hunter–gatherers and a range of populations that moved into the region. Here we use genome-wide genetic data to show that there are at least two admixture events in the history of Khoisan populations (southern African hunter–gatherers and pastoralists who speak non-Bantu languages with click consonants). One involved populations related to Niger–Congo-speaking African populations, and the other introduced ancestry most closely related to west Eurasian (European or Middle Eastern) populations. We date this latter admixture event to ∼900–1,800 y ago and show that it had the largest demographic impact in Khoisan populations that speak Khoe–Kwadi languages. A similar signal of west Eurasian ancestry is present throughout eastern Africa. In particular, we also find evidence for two admixture events in the history of Kenyan, Tanzanian, and Ethiopian populations, the earlier of which involved populations related to west Eurasians and which we date to ∼2,700–3,300 y ago. We reconstruct the allele frequencies of the putative west Eurasian population in eastern Africa and show that this population is a good proxy for the west Eurasian ancestry in southern Africa. The most parsimonious explanation for these findings is that west Eurasian ancestry entered southern Africa indirectly through eastern Africa. PMID:24550290

  18. Clean Air Slots Amid Dense Atmospheric Pollution in Southern Africa

    NASA Technical Reports Server (NTRS)

    Hobbs, Peter V.

    2003-01-01

    During the flights of the University of Washington's Convair-580 in the Southern African Regional Science Initiative (SAFARI 2000) in southern Africa, a phenomenon was observed that has not been reported previously. This was the occurrence of thin layers of remarkably clean air, sandwiched between heavily polluted air, which persisted for many hours during the day. Photographs are shown of these clean air slots (CAS), and particle concentrations and light scattering coefficients in and around such slot are presented. An explanation is proposed for the propensity of CAS to form in southern Africa during the dry season.

  19. Livestock First Reached Southern Africa in Two Separate Events

    PubMed Central

    Sadr, Karim

    2015-01-01

    After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which ‘infiltrated’ livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa. PMID:26295347

  20. Seismic Hazard Implication of the Seismotectonics of southern Africa

    NASA Astrophysics Data System (ADS)

    Midzi, Vunganai; Mulabisana, Thifelimbilu; Manzunzu, Brassnavy

    2014-05-01

    The work presented in this report / presentation was prepared as part of the requirements for the SIDA/IGCP Project 601 titled "Seismotectonics and Seismic Hazards in Africa" as well as part of the seismic source characterisation of the GEM-Africa Seismic hazard study. An effort was made to compile information necessary to prepare a seismotectonic map of Africa which can then be used in carrying out a seismic hazard assessment of the continent or locations within the continent. Information on major faults, fault plane solutions, geophysical data as well as stress data has so far been collected and included in a database for the southern Africa region. Reports published by several experts contributed much to the collected information. The seismicity data used are part of the earthquake catalogue being prepared for the GEM-Africa project, which includes historical and instrumental records as collected from various sources. An effort has been made to characterise the identified major faults and through further analysis investigate their possible impact on the seismic hazard of southern Africa.

  1. Energy resources in southern Africa: a select bibliography

    SciTech Connect

    Cavan, A.

    1981-01-01

    The aims, progress, and possibilities involved in Southern Africa's energy development are the subject of this 473-item bibliography. The primary items of information described in this document are relatively recent (1975-81), originate from both indigenous and international sources, and are mostly in English, although a few are in French and Portuguese. The presented information focuses on the African continent, the Southern African region, and the nations of Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, Swaziland, South Africa, Tanzania, Zambia, and Zimbabwe. The energy source topics include alcohol, coal, gas, oil, solar, uranium, water, wind, and wood; as well as a general energy-development category.

  2. Canine Rabies Ecology in Southern Africa

    PubMed Central

    2005-01-01

    Rabies is a widespread disease in African domestic dogs and certain wild canine populations. Canine rabies became established in Africa during the 20th century, coinciding with ecologic changes that favored its emergence in canids. I present a conceptual and terminologic framework for understanding rabies ecology in African canids. The framework is underpinned by 2 distinct concepts: maintenance and persistence. Maintenance encompasses the notion of indefinite transmission of infection within a local population and depends on an average transmission ratio >1. Maintenance in all local populations is inherently unstable, and the disease frequently becomes extinct. Persistence, the notion of long-term continuity, depends on the presence of rabies in >1 local population within the canine metapopulation at any time. The implications for understanding rabies ecology and control are reviewed, as are previous studies on rabies ecology in African canids. PMID:16229759

  3. Sublingual immunotherapy in southern Africa: lessons learned.

    PubMed

    Potter, Paul

    2013-07-01

    Sublingual immunotherapy (SLIT) is recommended in South Africa for the treatment of allergic rhinitis (with or without asthma) to house dust mites or grass pollens. Recent local studies have confirmed efficacy and safety but have also shown heterogeneity in clinical responses to the European SLIT vaccines used in the region. It has been found that regular follow-up with standardized rhinitis quality-of-life questionnaires improves compliance and encourages the patients to complete the 3-year SLIT course. Patients who discontinue usually do so in the first year because of logistic and financial reasons rather than adverse side effects. Further studies are in progress at the Allergy Diagnostic & Clinical Research Unit to identify immunologic markers of the SLIT responder phenotype.

  4. Environmental Education Research in Southern Africa: Dilemmas of Interpretation

    ERIC Educational Resources Information Center

    Gough, Annette; Gough, Noel

    2004-01-01

    These multiple framings of our reflections on environmental education research in southern Africa are written as dilemmas of interpretation that aim to disrupt any temptation to generalise or essentialise its qualities and characteristics. Recognising that research is a textual practice, we use J. M. Coetzee's portrayal of the dilemmas faced by…

  5. Educational Strategies for Accelerating Development in Southern Africa.

    ERIC Educational Resources Information Center

    Parker, Franklin

    This paper discusses the following major problems related to the educational crisis in southern Africa: 1) maintaining educational quality while providing for rising enrollment; 2) providing for increased enrollment but with relatively less money for education; 3) counteracting the imbalance between the increasing school output and the number of…

  6. Primary School Literacy in Southern Africa: African Perspectives

    ERIC Educational Resources Information Center

    Perry, Kristen H.

    2008-01-01

    This research review examines trends in recent scholarship concerning primary school literacy instruction in Southern Africa. Past scholarship, particularly that which originated from western researchers, focused on technical or structural issues facing literacy instruction in the region, such as language of instruction, school conditions,…

  7. Literacy for Revitalization in the SADCC Countries of Southern Africa.

    ERIC Educational Resources Information Center

    Bhola, H. S.

    The role of literacy in the revitalization of societies is particularly meaningful in the context of the Southern African Development Coordination Conference (SADCC), a group of nine countries (Angola, Botswana, Lesotho, Malawi, Mozambique, Swaziland, Tanzania, Zambia, and Zimbabwe) surrounding or surrounded by the Republic of South Africa (RSA).…

  8. Creating Cultural Competence: An Outreach Immersion Experience in Southern Africa

    ERIC Educational Resources Information Center

    West-Olatunji, Cirecie; Goodman, Rachael D.; Mehta, Sejal; Templeton, Laura

    2011-01-01

    With disasters on the rise, counselors need to increase their cultural awareness, knowledge, and skills to work with affected communities. This study reports outcomes of a four-week immersion experience in southern Africa with six counselor-trainees. Data sources for this qualitative study were: daily journals and demographic forms. Outcomes…

  9. Communal goat production in Southern Africa: a review.

    PubMed

    Rumosa Gwaze, F; Chimonyo, M; Dzama, K

    2009-10-01

    Despite the fact that about 64% of goats in sub-Saharan Africa (SSA) are located in rural arid (38%) and semi-arid (26%) agro-ecological zones and that more than 90% of goats in these zones are indigenous, information on indigenous breeds is inadequate. This paper reviews the social and economic importance of goats to the communal farmer and assesses the potential of using goats in rural development in Southern Africa. Farmers in Southern Africa largely use the village goat management system. There are various goat breeds in Southern Africa, of which the Mashona, Matabele, Tswana, Nguni and the Landim are the dominant ones. It is, however, not clear if these breeds are distinct. Major constraints to goat production include high disease and parasite prevalence, low levels of management, limited forage availability and poor marketing management. Potential research areas that are required to ensure that goats are vehicles for rural development include evaluation of constraints to goat production, assessing the contribution of goats to household economies and food securities throughout the year, genetic and phenotypic characterisation of the indigenous breeds to identify appropriate strains and sustainable methods of goat improvement through either selection or crossbreeding.

  10. [Male circumcision: hope for HIV infection decrease in southern Africa].

    PubMed

    Legeai, Camille; Auvert, Bertran

    2008-05-01

    Given the magnitude of the HIV pandemic, development of new prevention means is necessary. Male circumcision reduces HIV transmission from female to male by 57 % [95 % Confident Interval (CI): 42-68 %]. Its generalization in sub-Saharan Africa could avert, among men and women, from 1 to 4 millions new HIV infections over the next ten years. Acceptability of this new prevention mean is high in countries which could benefit the most from male circumcision, that means located in southern Africa, a region where in majority men are uncircumcised and where HIV prevalence is high. Male circumcision is a cost-effective prevention strategy. Actual prevention means (condoms, sexual abstinence and fidelity) are not used enough to curb the HIV epidemic. Research is ongoing on other prevention means (vaccine, pre- and post-exposition prophylaxis, microbicides, diaphragm) but their efficiency has not been demonstrated yet. Nevertheless, generalization of circumcision in southern Africa is responsible for contestations in part due to the fact that this prevention mean protects only partially from HIV infection. Moreover, for now, only a few countries integrated circumcision in their HIV prevention program in spite of WHO (World Health Organization) recommendations supporting male circumcision acknowledgement as an additional, important strategy for the prevention of heterosexually acquired HIV infection in men. Significant available funding should allow the situation to evolve quickly. At the same time, research goes on in order to know more about the effects and to facilitate the generalization of this prevention mean which is a great hope for southern Africa.

  11. Transport of Biomass Burning Emissions from Southern Africa

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Jaegle,Lyatt; Hobbs, Peter V.; Liang, Qing

    2004-01-01

    The transport of biomass burning emissions from southern Africa to the neighboring Atlantic and Indian Oceans during the dry season (May-October) of 2000 is characterized using ground, ozonesonde, and aircraft measurements of carbon monoxide (CO) and ozone (O3) in and around southern Africa, together with the GEOS-CHEM global model of tropospheric chemistry. The model shows a positive bias of approximately 20% for CO and a negative bias of approximately 10-25% for O3 at oceanic sites downwind of fire emissions. Near areas of active fire emissions the model shows a negative bias of approximately 60% and approximately 30% for CO and O3, respectively, likely due to the coarse spatial (2 deg. x 2.5 deg.) and temporal (monthly) resolution of the model compared to that of active fires. On average, from 1994 to 2000, approximately 60 Tg of carbon monoxide (CO) from biomass burning in southern Africa was transported eastward to the Indian Ocean across the latitude band 0 deg. -60 S during the 6 months of the dry season. Over the same time period, approximately 40 Tg of CO from southern African biomass burning was transported westward to the Atlantic Ocean over the latitudes 0 deg. -20 S during the 6-month dry season, but most of that amount was transported back eastward over higher latitudes to the south (21 deg. -60 S). Eastward transport of biomass burning emissions from southern Africa enhances CO concentrations by approximately 4- 13 ppbv per month over the southern subtropical Indian Ocean during the dry season, with peak enhancements in September. Carbon monoxide from southern African and South American biomass burning is seen in the model simulations as far away as Australia, contributing approximately 8 ppbv and approximately 12-15 ppbv CO, respectively, and thus explaining the approximately 20- 25 ppbv observed enhancement of CO over Melbourne in mid-September 2000.

  12. Climatology of Aerosol Optical Properties in Southern Africa

    NASA Technical Reports Server (NTRS)

    Queface, Antonio J.; Piketh, Stuart J.; Eck, Thomas F.; Tsay, Si-Chee

    2011-01-01

    A thorough regionally dependent understanding of optical properties of aerosols and their spatial and temporal distribution is required before we can accurately evaluate aerosol effects in the climate system. Long term measurements of aerosol optical depth, Angstrom exponent and retrieved single scattering albedo and size distribution, were analyzed and compiled into an aerosol optical properties climatology for southern Africa. Monitoring of aerosol parameters have been made by the AERONET program since the middle of the last decade in southern Africa. This valuable information provided an opportunity for understanding how aerosols of different types influence the regional radiation budget. Two long term sites, Mongu in Zambia and Skukuza in South Africa formed the core sources of data in this study. Results show that seasonal variation of aerosol optical thicknesses at 500 nm in southern Africa are characterized by low seasonal multi-month mean values (0.11 to 0.17) from December to May, medium values (0.20 to 0.27) between June and August, and high to very high values (0.30 to 0.46) during September to November. The spatial distribution of aerosol loadings shows that the north has high magnitudes than the south in the biomass burning season and the opposite in none biomass burning season. From the present aerosol data, no long term discernable trends are observable in aerosol concentrations in this region. This study also reveals that biomass burning aerosols contribute the bulk of the aerosol loading in August-October. Therefore if biomass burning could be controlled, southern Africa will experience a significant reduction in total atmospheric aerosol loading. In addition to that, aerosol volume size distribution is characterized by low concentrations in the non biomass burning period and well balanced particle size contributions of both coarse and fine modes. In contrast high concentrations are characteristic of biomass burning period, combined with

  13. Complex Patterns of Genomic Admixture within Southern Africa

    PubMed Central

    Petersen, Desiree C.; Libiger, Ondrej; Tindall, Elizabeth A.; Hardie, Rae-Anne; Hannick, Linda I.; Glashoff, Richard H.; Mukerji, Mitali; Fernandez, Pedro; Haacke, Wilfrid; Schork, Nicholas J.; Hayes, Vanessa M.

    2013-01-01

    Within-population genetic diversity is greatest within Africa, while between-population genetic diversity is directly proportional to geographic distance. The most divergent contemporary human populations include the click-speaking forager peoples of southern Africa, broadly defined as Khoesan. Both intra- (Bantu expansion) and inter-continental migration (European-driven colonization) have resulted in complex patterns of admixture between ancient geographically isolated Khoesan and more recently diverged populations. Using gender-specific analysis and almost 1 million autosomal markers, we determine the significance of estimated ancestral contributions that have shaped five contemporary southern African populations in a cohort of 103 individuals. Limited by lack of available data for homogenous Khoesan representation, we identify the Ju/'hoan (n = 19) as a distinct early diverging human lineage with little to no significant non-Khoesan contribution. In contrast to the Ju/'hoan, we identify ancient signatures of Khoesan and Bantu unions resulting in significant Khoesan- and Bantu-derived contributions to the Southern Bantu amaXhosa (n = 15) and Khoesan !Xun (n = 14), respectively. Our data further suggests that contemporary !Xun represent distinct Khoesan prehistories. Khoesan assimilation with European settlement at the most southern tip of Africa resulted in significant ancestral Khoesan contributions to the Coloured (n = 25) and Baster (n = 30) populations. The latter populations were further impacted by 170 years of East Indian slave trade and intra-continental migrations resulting in a complex pattern of genetic variation (admixture). The populations of southern Africa provide a unique opportunity to investigate the genomic variability from some of the oldest human lineages to the implications of complex admixture patterns including ancient and recently diverged human lineages. PMID:23516368

  14. Tracing pastoralist migrations to southern Africa with lactase persistence alleles.

    PubMed

    Macholdt, Enrico; Lede, Vera; Barbieri, Chiara; Mpoloka, Sununguko W; Chen, Hua; Slatkin, Montgomery; Pakendorf, Brigitte; Stoneking, Mark

    2014-04-14

    Although southern African Khoisan populations are often assumed to have remained largely isolated during prehistory, there is growing evidence for a migration of pastoralists from eastern Africa some 2,000 years ago, prior to the arrival of Bantu-speaking populations in southern Africa. Eastern Africa harbors distinctive lactase persistence (LP) alleles, and therefore LP alleles in southern African populations may be derived from this eastern African pastoralist migration. We sequenced the lactase enhancer region in 457 individuals from 18 Khoisan and seven Bantu-speaking groups from Botswana, Namibia, and Zambia and additionally genotyped four short tandem repeat (STR) loci that flank the lactase enhancer region. We found nine single-nucleotide polymorphisms, of which the most frequent is -14010(∗)C, which was previously found to be associated with LP in Kenya and Tanzania and to exhibit a strong signal of positive selection. This allele occurs in significantly higher frequency in pastoralist groups and in Khoe-speaking groups in our study, supporting the hypothesis of a migration of eastern African pastoralists that was primarily associated with Khoe speakers. Moreover, we find a signal of ongoing positive selection in all three pastoralist groups in our study, as well as (surprisingly) in two foraging groups.

  15. Shear Wave Splitting Across Eastern, Western and Southern Africa

    NASA Astrophysics Data System (ADS)

    Nyblade, A.; Ramirez, C.; Bagley, B. C.; Mulibo, G. D.; Tugume, F.; Wysession, M. E.; Wiens, D. A.

    2014-12-01

    The expansion of the AfricaArray network across eastern, western and southern Africa, in conjunction with seismic data from many PASSCAL deployments over the past 20 years, is helping to fill in major gaps in the global coverage of shear wave splitting measurements. New results from stations in Ghana, Nigeria, Mozambique, Botswana, Angola, Namibia and South Africa are presented in this study that when combined with previously published measurements help to map the pattern of seismic anisotropy over much of the African continent. A general pattern of fast polarization directions, characterized by NE orientations, is found, and superimposed on this subcontinental-scale pattern is local and regional variability, most notably around the Archean Tanzania craton in eastern Africa. The subcontinental-scale pattern, as well as local and regional variations in this pattern, are interpreted in terms of large-scale mantle flow from the African Superplume, fossil anisotropy in the lithosphere, and shape anisotropy in magmatic regions of the East African rift system.

  16. 3.5 billion years of reshaped Moho, southern Africa

    NASA Astrophysics Data System (ADS)

    Stankiewicz, Jacek; de Wit, Maarten

    2013-12-01

    According to some previous studies, Archean continental crust is, on global average, apparently thinner than Proterozoic crust. Subsequently, the validity of this statement has been questioned. To provide an additional perspective on this issue, we present analyses of Moho signatures derived from recent seismic data along swaths 2000 km in length across southern Africa and its flanking ocean. The imaged crust has a near continuous age range between ca. 0.1 and 3.7 billion years, and the seismic data allow direct comparison of Moho depths between adjacent Archean, Proterozoic and Phanerozoic crust. We find no simple secular change in depth to Moho over this time period. In contrast, there is significant variation in depth to Moho beneath both Archean and Proterozoic crust; Archean crust of southern Africa displays as much crustal diversity in thickness as the adjacent Proterozoic crust. The Moho beneath all crustal provinces that we have analysed has been severely altered by tectono-metamorphic and igneous processes, in many cases more than once, and cannot provide unequivocal data for geodynamic models dealing with secular changes in continental crust formation. These results and conclusions are similar to those documented along ca. 2000 km swaths across the Canadian Shield recorded by Lithoprobe. Tying the age and character of the Precambrian crust of southern Africa to their depth diversities is clearly related to manifold processes of tectono-thermal ‘surgery’ subsequent to their origin, the details of which are still to be resolved, as they are in most Precambrian terranes. Reconstructing pristine Moho of the early Earth therefore remains a formidable challenge. In South Africa, better knowledge of ‘fossilised’ Archean crustal sections ‘turned-on-edge’, such as at the Vredefort impact crater (for the continental crust), and from the Barberton greenstone belt (for oceanic crust) is needed to characterize potential pristine Archean Moho transitions.

  17. Southern Africa Validation of NASA's Earth Observing System (SAVE EOS)

    NASA Technical Reports Server (NTRS)

    Privette, Jeffrey L.

    2000-01-01

    Southern Africa Validation of EOS (SAVE) is 4-year, multidisciplinary effort to validate operational and experimental products from Terra-the flagship satellite of NASA's Earth Observing System (EOS). At test sites from Zambia to South Africa, we are measuring soil, vegetation and atmospheric parameters over a range of ecosystems for comparison with products from Terra, Landsat 7, AVHRR and SeaWiFS. The data are also employed to parameterize and improve vegetation process models. Fixed-point and mobile "transect" sampling are used to collect the ground data. These are extrapolated over larger areas with fine-resolution multispectral imagery. We describe the sites, infrastructure, and measurement strategies developed underSAVE, as well as initial results from our participation in the first Intensive Field Campaign of SAFARI 2000. We also describe SAVE's role in the Kalahari Transect Campaign (February/March 2000) in Zambia and Botswana.

  18. Education in Southern Africa: Current conditions and future directions

    NASA Astrophysics Data System (ADS)

    Baine, David; Mwamwenda, Tuntufye

    1994-03-01

    This paper provides a concise summary of selected topics of contemporary, primary and secondary education of black students in Southern Africa. The topics reviewed are: a) curricula, b) methods of instructional delivery, c) learning materials and equipment, d) examinations, e) enrollment and class sizes, f) teachers, g) teacher-student ratios, h) drop-out, failure and repeater rates, i) economic considerations, j) rural-urban discrepancies, k) racial and class issues, 1) female education, and m) language of instruction. The discussion begins with an acknowledgement of the enormous improvements that have been made in the field of education in Africa despite vast limitations of resources: economic, personnel, technological and material. In spite of these achievements, given the magnitude and complexity of educational development, a number of problems continue to exist. These problems are reviewed as are various recommendations for change.

  19. Pre-exposure prophylaxis in Southern Africa: feasible or not?

    PubMed Central

    Venter, Willem Daniel François; Cowan, Frances; Black, Vivian; Rebe, Kevin; Bekker, Linda-Gail

    2015-01-01

    Introduction Southern and Eastern Africa bear the brunt of the AIDS epidemic, and current prevention interventions remain inadequate. Antiretroviral-based pre-exposure prophylaxis (PrEP) is gaining momentum as an effective prevention intervention. Discussion Discussions have been started on how this strategy could be employed in Africa such that the populations most in need can be reached urgently for the greatest impact. This requires the selection of specific risk groups and service environments in which PrEP can be distributed safely and cost effectively while being mindful of any ethical issues. Conclusions Given the need for an integrated public health approach to this, a number of potential populations and opportunities for PrEP distribution exist and are discussed in this commentary. PMID:26198344

  20. Climate and southern Africa's water-energy-food nexus

    NASA Astrophysics Data System (ADS)

    Conway, Declan; van Garderen, Emma Archer; Deryng, Delphine; Dorling, Steve; Krueger, Tobias; Landman, Willem; Lankford, Bruce; Lebek, Karen; Osborn, Tim; Ringler, Claudia; Thurlow, James; Zhu, Tingju; Dalin, Carole

    2015-09-01

    In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven, for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and gross domestic product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water.

  1. Climate and Southern Africa's Water-Energy-Food Nexus

    NASA Astrophysics Data System (ADS)

    Conway, D.; Osborn, T.; Dorling, S.; Ringler, C.; Lankford, B.; Dalin, C.; Thurlow, J.; Zhu, T.; Deryng, D.; Landman, W.; Archer van Garderen, E.; Krueger, T.; Lebek, K.

    2014-12-01

    Numerous challenges coalesce to make Southern Africa emblematic of the connections between climate and the water-energy-food nexus. Rainfall and river flows in the region show high levels of variability across a range of spatial and temporal scales. Physical and socioeconomic exposure to climate variability and change is high, for example, the contribution of electricity produced from hydroelectric sources is over 30% in Madagascar and Zimbabwe and almost 100% in the DRC, Lesotho, Malawi, and Zambia. The region's economy is closely linked with that of the rest of the African continent and climate-sensitive food products are an important item of trade. Southern Africa's population is concentrated in regions exposed to high levels of hydro-meteorological variability, and will increase rapidly over the next four decades. The capacity to manage the effects of climate variability tends, however, to be low. Moreover, with climate change annual precipitation levels, soil moisture and runoff are likely to decrease and rising temperatures will increase evaporative demand. Despite high levels of hydro-meteorological variability, the sectoral and cross-sectoral water-energy-food linkages with climate in Southern Africa have not been considered in detail. Lack of data and questionable reliability are compounded by complex dynamic relationships. We review the role of climate in Southern Africa's nexus, complemented by empirical analysis of national level data on climate, water resources, crop and energy production, and economic activity. Our aim is to examine the role of climate variability as a driver of production fluctuations in the nexus, and to improve understanding of the magnitude and temporal dimensions of their interactions. We first consider national level exposure of food, water and energy production to climate in aggregate economic terms and then examine the linkages between interannual and multi-year climate variability and economic activity, focusing on food and

  2. Southern Africa winter temperature shifts and their link to the Southern Annular Mode

    NASA Astrophysics Data System (ADS)

    Manatsa, Desmond; Matarira, Caxton; Mushore, Terrence D.; Mudavanhu, Chipo

    2015-11-01

    The main characteristics of spatial and temporal variability of the winter (June-August) observed surface air minimum temperature (SAMT) of southern Africa (Africa south of the equator) were examined from 1960 to 2011. The empirical orthogonal function (EOF) analysis was used to extract the dominant mode of SAMT variability. Statistically significant shifts were detected in both the index derived from the spatially averaged regional SAMT and its EOF1 time coefficients. These discontinuities displayed a sharp rise followed by an abrupt drop during the periods around 1988 and 2007 respectively. The years corresponded to change points in the Southern Annular Mode index where the 1988 significant alteration to a relatively more positive index polarity was followed by a sudden weakening during the latter shift. The development of the warm phase coincided with the decoupling of SAM from SAMT. This occurred when the strengthening of the western ridge of the Mascarene High appeared to be coupled to the creation of anomalously low pressure systems over Angola and the region pole-ward of South Africa. In this epoch, the meridional wind over southern Africa reversed to become predominantly northerly and hence was symptomatic of warm temperature advection from the lower latitudes. However the post 2007 era, though still of indeterminate length, is characterized by a partial return to the pre-1988 circulation conditions. This implies that the impacts of SAM's epochal alterations have implications not only for the current climate, but also for the interpretation of climate change over southern Africa.

  3. Taxonomy of the water beetle genus Limnebius Leach in southern Africa (Coleoptera:  Hydraenidae).

    PubMed

    Perkins, Philip D

    2015-04-20

    The southern African species of the water beetle genus Limnebius Leach, 1815, are revised. Eleven new species are described, based on the examination and databasing of 6,201 specimens from 96 localities/events. Male genitalia are illustrated, and high resolution habitus images of the holotypes are provided. Distribution maps are provided for the eleven species now known from southern Africa, including Namibia, South Africa, Zambia, Zimbabwe, and the extreme southern part of Angola. New species of Limnebius are: L. capensis (South Africa: Western Cape Province, W. Cape, Hawequas); L. convexus (South Africa: Western Cape Province, Little Karroo, Raubenheimer Dam); L. endroedyi (Namibia: C. Namib desert, Numis Wasser); L. kavango (Namibia: Kavango: Mahango Game Reserve); L. masculinus (South Africa: KwaZulu-Natal Province, Hluhluwe Game Reserve); L. probus (South Africa: KwaZulu-Natal Province, Zululand, Dukuduku Forest Station); L. quantillus (South Africa: Limpopo Province, N. Transvaal, Mmabolela estate); L. retiolus (South Africa: Northern Cape Province, Cape Farm Ezelsfontein); L. speculus (South Africa: KwaZulu-Natal Province, Hluhluwe Game Reserve); L. suaviculus (South Africa: KwaZulu-Natal Province, Tugela River near Olivershoek road); L. transversus (South Africa: KwaZulu-Natal Province, Mtubatuba).

  4. The Lithospheric Structure of Southern Africa from Magnetotelluric Sounding

    NASA Astrophysics Data System (ADS)

    Evans, R. L.; Jones, A. G.; Atekwana, E. A.

    2014-12-01

    Measurements of mantle electrical conductivity, made through the magnetotelluric method, offer considerable insight into the structure of cratonic lithosphere. A particularly expansive data set has been collected in Southern Africa, started through the Southern Africa Magnetotelluric Experiment (SAMTEX) experiment, now continuing north through Zambia as part of the Project for Rift Initiation Development and Evolution (PRIDE) experiment. The combined data set highlights large variability in lithospheric structure that broadly correlates with surface geology: cratonic lithosphere is generally thick and electrically resistive, while much thinner lithosphere is seen beneath mobile belts. In areas of relatively uniform resistivity structure, we have constructed resistivity-depth profiles and use new laboratory data to place constraints on the water content of lithospheric mantle. Uncertainty in our estimates arises from differences between different laboratory results, but our data are generally consistent with a slightly damp upper lithospheric mantle above a dry and strong cratonic root. Other areas show complexity of structure that is difficult to understand using current knowledge of conductivity -the Bushveld complex, where the mantle is highly conductive, is one such example. In southwestern Zambia, the lithosphere is seen to be very thin (around 50km) beneath mobile belt terrain, as was inferred nearly 40 years ago on the basis of high heatflow. The mantle is highly conductive, most likely due to a combination of elevated temperatures, water content and perhaps a trace amount of melting. This anomalous structure may be linked to the southwest propagation of the East African Rift system.

  5. The Southern and Eastern Africa Consortium for Monitoring Educational Quality. Assessment GEMs No. 8

    ERIC Educational Resources Information Center

    Australian Council for Educational Research, 2015

    2015-01-01

    The Southern and Eastern Africa Consortium for Monitoring Educational Quality (SACMEQ) carries out large-scale cross-national research studies in member countries in the Southern and Eastern Africa region. It aims to assess the conditions of schooling and performance levels of learners and teachers in the areas of literacy and numeracy. SACMEQ has…

  6. Gondwana assembly: The view from Southern Africa and East Gondwana

    NASA Astrophysics Data System (ADS)

    Wilson, T. J.; Grunow, A. M.; Hanson, R. E.

    1997-07-01

    Neoproterozoic-Cambrian tectonism in Africa, Antarctica and formerly adjacent parts of East Gondwana records the final assembly of the Gondwana supercontinent. Here we compile recent data regarding the timing and kinematics of tectonism for critical parts of southern Africa and East Gondwana, focusing on the period between ~ 650-500 Ma, and integrate these data into a regional framework in order to investigate aspects of the assembly of this portion of Gondwana. We use this information to address the following questions. What cratons remained coherent continental blocks between Rodinia break-up and Gondwana assembly? What were the configurations of Neoproterozoic-Cambrian oceans that separated these coherent blocks? When did the cratons reassemble into the Gondwana supercontinent? In southern Africa, the apparent continuity of older terranes across the Neoproterozoic Zambezi belt, together with other evidence, suggest that the Congo and Kalahari cratons have been a coherent block since ~ 1.1 Ga. The Khomas/Adamastor ocean did not transect the Congo/ Kalahari block; instead any tectonic connection with the Neoproterozoic-Cambrian collisional plate boundary in the Mozambique belt must have been via shear zones such as the Mwembeshi dislocation, which was active at ~ 550 Ma. Age and structural data from Queen Maud Land in East Antarctica indicate that this area was also linked with the Congo/Kalahari block and remained attached to it during the breakup of Rodinia. A suture must thus separate this block from the main part of the East Antarctic craton and likely represents the southern continuation of the Mozambique Ocean. Accumulating evidence for Neoproterozoic-Cambrian orogenesis (~ 550-520 Ma) in the Lützow-Holm Bay and Queen Maud Land regions of East Antarctica suggest the postulated continuation of the Mozambique suture zone may lie beneath the ice, where it separates the main part of the East Antarctic craton from the Congo-Kalahari block and contiguous sectors

  7. Atmospheric Transport and Photochemistry of Ozone Over Central Southern Africa During the Southern Africa Fire-Atmosphere Research Initiative

    NASA Technical Reports Server (NTRS)

    Tyson, P. D.; Garstang, M.; Thompson, A. M.; DAbreton, P.; Diab, R. D.; Browell, E. V.

    1997-01-01

    Vertically integrated back and forward trajectories for the 300-200, 700-500 and surface-800 hPa levels are calculated using Pretoria as point of origin for the Southern Africa Fire-Atmosphere Research Initiative (SAFARI) period September-October 1992. The transport fields are then combined to show both horizontal and vertical transport of air to and from Pretoria at the different levels. Air transport patterns in the vertical are linked to the occurrence of absolutely stable layers which are also evident in the 16 ozonesonde profiles recorded at Pretoria during SAFARI. The coherence of the stratification based on dynamical and ozone analysis permits the use of mean ozone profiles with air volume fluxes to interpret the ozone in terms of photochemistry and transport within stable layers. Extensive recirculation across the meridional plane at Pretoria implies that advection of ozone is slow and that photochemistry is responsible for the observed vertical structure over central southern Africa in September and October 1992. Requisite ozone formation rates are supported by model analysis of ozone and ozone precursors measured from SAFARI and Transport and Atmospheric Research Chemistry near the Equator-Atlantic aircraft.

  8. El Niño–Southern Oscillation diversity and Southern Africa teleconnections during Austral Summer

    USGS Publications Warehouse

    Hoell, Andrew; Funk, Christopher C.; Magadzire, Tamuka; Zinke, Jens; Husak, Gregory J.

    2014-01-01

    A wide range of sea surface temperature (SST) expressions have been observed during the El Niño–Southern Oscillation events of 1950–2010, which have occurred simultaneously with different global atmospheric circulations. This study examines the atmospheric circulation and precipitation during December–March 1950–2010 over the African Continent south of 15∘S, a region hereafter known as Southern Africa, associated with eight tropical Pacific SST expressions characteristic of El Niño and La Niña events. The self-organizing map method along with a statistical distinguishability test was used to isolate the SST expressions of El Niño and La Niña. The seasonal precipitation forcing over Southern Africa associated with the eight SST expressions was investigated in terms of the horizontal winds, moisture budget and vertical motion. El Niño events, with warm SST across the east and central Pacific Ocean and warmer than average SST over the Indian Ocean, are associated with precipitation reductions over Southern Africa. The regional precipitation reductions are forced primarily by large-scale mid-tropospheric subsidence associated with anticyclonic circulation in the upper troposphere. El Niño events with cooler than average SST over the Indian Ocean are associated with precipitation increases over Southern Africa associated with lower tropospheric cyclonic circulation and mid-tropospheric ascent. La Niña events, with cool SST anomalies over the central Pacific and warm SST over the west Pacific and Indian Ocean, are associated with precipitation increases over Southern Africa. The regional precipitation increases are forced primarily by lower tropospheric cyclonic circulation, resulting in mid-tropospheric ascent and an increased flux of moisture into the region.

  9. Gender, ageing & carework in East and Southern Africa: A review

    PubMed Central

    Seeley, Janet

    2016-01-01

    An estimated 58 million persons aged 60-plus live in sub-Saharan Africa; by 2050 that number will rise sharply to 215 million. Older Africans traditionally get care in their old age from the middle generation. But in East and Southern Africa, HIV has hollowed out that generation, leaving many older persons to provide care for their children’s children without someone to care for him or herself in old age. Simultaneously, the burden of disease among older persons is changing in this region. The result is a growing care deficit. This article examines the existing literature on care for and by older persons in this region, highlighting understudied aspects of older persons’ experiences of ageing and care – including the positive impacts of carework, variation in the region, and the role of resilience and pensions. We advance a conceptual framework of gendered identities – for both men and women – and intergenerational social exchange to help focus and understand the complex interdependent relationships around carework, which are paramount in addressing the needs of older persons in the current care deficit in this region, and the Global South more generally. PMID:25947225

  10. Preliminary estimate of undiscovered petroleum resources of southern Africa

    SciTech Connect

    Kingston, J.

    1986-05-01

    Onshore and offshore southern Africa (Nigeria and southward) are ten major rifted continental margin basis; six include about 100,000 mi/sup 2/ on the Atlantic coast, and five encompass about 300,000 mi/sup 2/ on the south and Indian Ocean side, including Madagascar. A series of four very large (totaling about 575,000 mi/sup 2/) interior sag basins are found between South Africa and the central Congo. The Atlantic margin basins are the most prospective and the only ones presently producing. Of these, the Niger delta is by far the most prolific, having original oil and gas reserves of some 25 billion BOE (barrels of oil equivalent) versus five billion BOE for the rest of the basinal trend. The Indian Ocean marginal basins have more area and some shows, including a 22 billion BOE tar sand in Madagascar, but the lack of exploration success downgrades the prospects of this trend. The interior sags have a large volume of sediment; about one-third is marine or lacustrine and probably thermally mature, but lack of established traps, or in some cases sufficient rock, makes for high-risk prospects. Preliminary most-likely estimates of undiscovered oil and gas resources are 15 billion BOE on the Atlantic margin, about 3 billion BOE on the Indian Ocean side, and about 1 billion BOE in the interior sags, with these latter basins having the highest potential for unknown giant fields.

  11. Multi-scale investigation of shrub encroachment in southern Africa

    NASA Astrophysics Data System (ADS)

    Aplin, Paul; Marston, Christopher; Wilkinson, David; Field, Richard; O'Regan, Hannah

    2016-04-01

    There is growing speculation that savannah environments throughout Africa have been subject to shrub encroachment in recent years, whereby grassland is lost to woody vegetation cover. Changes in the relative proportions of grassland and woodland are important in the context of conservation of savannah systems, with implications for faunal distributions, environmental management and tourism. Here, we focus on southern Kruger National Park, South Africa, and investigate whether or not shrub encroachment has occurred over the last decade and a half. We use a multi-scale approach, examining the complementarity of medium (e.g. Landsat TM and OLI) and fine (e.g. QuickBird and WorldView-2) spatial resolution satellite sensor imagery, supported by intensive field survey in 2002 and 2014. We employ semi-automated land cover classification, involving a hybrid unsupervised clustering approach with manual class grouping and checking, followed by change detection post-classification comparison analysis. The results show that shrub encroachment is indeed occurring, a finding evidenced through three fine resolution replicate images plus medium resolution imagery. The results also demonstrate the complementarity of medium and fine resolution imagery, though some thematic information must be sacrificed to maintain high medium resolution classification accuracy. Finally, the findings have broader implications for issues such as vegetation seasonality, spatial transferability and management practices.

  12. Last interglacial semi-desert expansions in southern Africa

    NASA Astrophysics Data System (ADS)

    Urrego, D. H.; Sanchez Goni, M.; Lechevrel, S.; Daniau, A.

    2013-05-01

    While our understanding of the effects of orbital-scale variability on the vegetation has grown during the past decades, empirical data from some climatically important periods and regions are still lacking. Scarce data exist for instance for deep-time glacial-interglacial cycles that could provide suitable analogs for current climate change. Recent global-scale syntheses of vegetation responses to rapid events during the last glacial have been useful, however, these global compilations clearly show that some regions, namely the southern tropics and subtropics, remain understudied. We use pollen analysis of marine sediments from core MD96-2098 to produce a paleoenvironmental record from southern Africa spanning MIS 6 to 3. Our interpretations are supported by an analysis of present-day pollen-vegetation-climate relationships for the region. We applied canonical correspondence analysis (CCA) and detrended correspondence analysis (DCA) on pollen spectra from terrestrial surface samples to investigate these relationships and to identify pollen taxa that are suitable bioclimatic indicators for the different South African biomes. Semi-desert vegetation dominated southern Africa during the MIS 5 interglacial. Expansion of the semi-desert biome into the Namib desert likely resulted from the reduction of the Benguela upwelling and a relative decrease in aridity. In its eastern boundary, the semi-desert likely expanded at the expense of grasslands as a result of increased subtropical high pressure and reduced summer precipitation. Semi-desert expansion in its southern boundary probably resulted from reduced influence of the southern westerlies and decreased winter precipitation. This atmospheric configuration was probably exacerbated during the three warm substages of MIS 5. During glacial isotopic stages MIS 6, 4 and 3 grasslands gained area over the semi-desert as summer precipitation increased. The area occupied by Fynbos vegetation was particularly large at the

  13. Women's stories of abortion in southern Gabon, Africa.

    PubMed

    Hess, Rosanna F

    2007-01-01

    The purpose of this study was to explore the reasons women in rural, southern Gabon, Africa, chose to terminate their pregnancies, the methods used to induce abortions, and postabortion effects experienced by these women. Abortion is illegal in this country. A descriptive qualitative design guided the methodology for this study. Five women with a history of induced abortion were interviewed in-depth for their abortion story. Reasons cited for an abortion included lack of financial and partner support. Abortion methods included oral, rectal, and vaginal concoctions of leaves, bark, and water and over-the-counter medications, including misoprostol. Affects were physical, spiritual, and relational. Health care professionals need to provide women with guidance for appropriate contraceptive usage. Abortion after-care of women with physical and spiritual needs is important. Future research is suggested on the use of misoprostol in Gabon to understand its affects on women's reproductive health.

  14. Preliminary Exploration of Encounter During Transit Across Southern Africa

    SciTech Connect

    Stroud, Phillip David; Cuellar-Hengartner, Leticia; Kubicek, Deborah Ann; Cleland, Timothy James

    2016-10-28

    Los Alamos National Laboratory (LANL) is utilizing the Probability Effectiveness Methodology (PEM) tools, particularly the Pathway Analysis, Threat Response and Interdiction Options Tool (PATRIOT) to support the DNDO Architecture and Planning Directorate’s (APD) development of a multi-region terrorist risk assessment tool. The effort is divided into three stages. The first stage is an exploration of what can be done with PATRIOT essentially as is, to characterize encounter rate during transit across a single selected region. The second stage is to develop, condition, and implement required modifications to the data and conduct analysis to generate a well-founded assessment of the transit reliability across that selected region, and to identify any issues in the process. The final stage is to extend the work to a full multi-region global model. This document provides the results of the first stage, namely preliminary explorations with PATRIOT to assess the transit reliability across the region of southern Africa.

  15. The quantity of biomass burned in southern Africa

    NASA Astrophysics Data System (ADS)

    Scholes, R. J.; Kendall, J.; Justice, C. O.

    1996-10-01

    A new method is described for calculating the amount of biomass burned, its type and location, and the time of burning. Active fires in 1989 were detected using daily advanced very high resolution radiometer (AVHRR) satellite imagery. The fire count was calibrated to area burned using a stratified sample of multitemporal multispectral scanner (MSS) imagery. The calibration factor is strongly dependent on mean individual fire area, which is in turn strongly related to cumulative normalized difference vegetation index (NDVI). The best available vegetation maps for southern hemisphere Africa were combined and reclassified into functional vegetation types with a similar fire ecology. The fuel load was calculated in each 0.5° × 0.5° grid square using a production model specific for each vegetation type, driven by monthly rainfall data. Multiyear fuel accumulation, herbivory, and decay were accounted for. Combustion completeness was modeled as a function of fuel mass and fuel type, established from field-collected data. The method was compared to the conventional procedure for calculating biomass burned, based on classification. The estimated amount of biomass burned in vegetation fires in southern hemisphere Africa annually is 90-264 Tg dry matter (DM) by the new modeling method and 247-2719 Tg DM by the conventional classification method. The modeling method is conservative since it does not include burning due to forest clearing or the burning of agricultural waste or domestic biomass fuels, but it is believed to be more realistic than the classification method and provides space-and-time-resolved output. The bulk of the burning occurs between June and September, with a peak in August. Half of the burning takes place in the broad-leaved, low-nutrient-status savannas which dominate the zone between 5° and 18°S.

  16. Africana Acquisitions; Report of a Publication Survey Trip to Nigeria, Southern Africa, and Europe, 1972.

    ERIC Educational Resources Information Center

    Witherell, Julian W.

    A publication survey trip to Nigeria, Southern Africa, and Europe was taken by Julian W. Witherell of the African Section of the Library of Congress in 1972. The purpose of the trip was to improve the flow of publications about Africa to the Library of Congress. The trip was successful in that personal contacts helpful in obtaining local materials…

  17. "That Indefinable Something Besides": Southern Africa, British Identity, and the Authorial Informant, 1883-1924

    ERIC Educational Resources Information Center

    Free, Melissa

    2009-01-01

    This project examines the role of southern Africa (from the Cape to the Zambezi) in the constitution of British identity from the rise of the systematic exploitation of the region's mineral deposits through the close of World War One. Reading a wide variety of print culture produced by South Africa's "authorial informants"--British…

  18. Carbon isotope ratios and impurities in diamonds from Southern Africa

    NASA Astrophysics Data System (ADS)

    Kidane, Abiel; Koch-Müller, Monika; Morales, Luiz; Wiedenbeck, Michael; De Wit, Maarten

    2015-04-01

    We are investigating the sources of diamonds from southern Africa by studying both their carbon isotopic composition and chemical impurities. Our samples include macro-sized diamonds from River Ranch kimberlite in Zimbabwe and the Helam and Klipspringer kimberlitic deposits from South Africa, as well as micro-sized diamonds from Klipspringer and Premier kimberlites in South Africa. We have characterized the samples for their structurally bounded nitrogen, hydrogen and platelets defect using a Fourier Transmission Infrared Spectroscopy (FTIR). Using the DiaMap routine, open source software (Howell et al., 2012), IR spectra were deconvulated and quantified for their nitrogen (A, B and D components) and hydrogen contents. High to moderate nitrogen concentrations (1810 to 400 µg/g; 400 to 50 µg/g respectively) were found in diamonds from Klipspringer and Helam. Moderate to low (<50 µg/g) nitrogen concentrations were observed in diamonds from Premier and River Ranch. Type II diamonds, i.e. diamonds with no N impurities, which are presumed to have been derived from ultramafic sources, are found in the River Ranch deposit. The macro- and micro-size diamonds from the Klipspringer deposit display similar nitrogen defects, with higher nitrogen concentration and more frequent D components found in the macro-size diamonds. One of the first steps towards reliable carbon isotope studies is the development of calibration materials for SIMS carbon isotopic analyses. We have investigated candidate materials both from a polycrystalline synthetic diamond sheet and two natural gem quality diamonds from Juina (Brazil). Electron-based images of the synthetic diamond sheet, obtained using GFZ Potsdam's dual beam FIB instrument, show many diamond grains with diameters greater than 35 µm. SIMS testing of the isotopic homogeneity of the back and front sides of the synthetic sheets reveal similar 13C/12C ratio within a RSD of <1 ‰ . SIMS isotopic analyses of the two natural diamond RMs

  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. Next Year Will Be a Good Year--Southern Africa's Dreadful Dryland Farming Disaster.

    ERIC Educational Resources Information Center

    Johns, Maria

    1992-01-01

    Discusses how agricultural productivity in drought stricken southern Africa is diminished by economically and ecologically unsustainable agricultural practices. A vignette provides alternative farming techniques appropriate for dry regions with an emphasis on respect for the land. (MCO)

  1. Individual-Particle Analysis of Aerosols From Southern Africa

    NASA Astrophysics Data System (ADS)

    Li, J.; Posfai, M.; Hobbs, P. V.; Buseck, P. R.

    2001-12-01

    Aerosol samples were collected on the University of Washington Convair-580 research aircraft over southern Africa during the Safari 2000 Experiment. Individual aerosol particles were analyzed using transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FESEM) with energy-dispersive x-ray spectrometry (EDS). The objective of the study is to characterize the major aerosol emissions from biomass burning over southern Africa, with emphasis on the sizes, shapes, compositions, mixing states, and surface coatings of the aerosols. Aging and reaction of smoke aerosols with plume transport were investigated. Particulate emissions from combustion of different vegetation types and at different burning phases were compared. Preliminary results show that aerosols from biomass burning mainly consist of amorphous carbonaceous spherules ("tar balls"); soot; K salts including KCl, K2SO4, and probably KNO3 mixed with organic particles; and Ca-bearing particles including Ca carbonate, phosphate, and sulfate. Minor amounts of sea salt and minerals such as quartz, mica, smectite, and gypsum are also present. The relative concentrations of tar balls increase with distance from the fires. More KCl particles occur in fresh smoke plumes close to fire sources, whereas more K2SO4 and KNO3 particles are present in aged smoke. This change indicates that KCl forming from the fire was converted to K2SO4 and KNO3 through reactions with S- and N-bearing species emitted from biomass burning. The conversion of KCl resembles that of NaCl in sea salt particles, suggesting similar reaction mechanisms with the aging of smoke. More soot is present in smoke from flaming grass fires than bush and wood fires, which is probably related to the high fraction of flaming combustion of grass fires. The high abundance of organic particles and soluble salt may affect the hygroscopic properties of biomass burning aerosols and influence their role as cloud condensation nuclei

  2. Circulation patterns associated with droughts over southern Africa

    NASA Astrophysics Data System (ADS)

    Garanganga, B.

    2002-12-01

    The paper highlights the circulation patterns associated with droughts that have demonstrated the vulnerability of the socioeconomic development of around 200 million people from 14 the Southern African Development Community (SADC) countries to the vagaries of the climate system. The recent, apparently perennial droughts juxtaposed with floods across southern Africa have to be seen against the background of advances made by the scientific community in the understanding of the global ocean-atmosphere system. The paper seeks to contribute to such advances science is making in order to make humankind benefit from the knowledge science has provided. The data used in the analyses include actual rainfall from the SADC countries and those from the United States NOAA (NCEP/NCAR Reanalysis) data banks. The paper briefly looks at the regional climatology of the SADC countries, which shows that rains fall within the period October during one year to March of the following year. Most of the damaging droughts have tended to occur during January to March. Thus, the more detailed analysis of the circulation characteristics has a focus of composite of these months. A few recent drought years are selected for analyzing of the dynamical structures of the regional circulation patterns and the tropical ocean and global atmosphere. These tended to coincide with El Ninos. However, the selected years include the recent drought during the 2001/2002 rainfall season, which occurred in a neutral El Nino-Southern Oscillation (ENSO) phase. There emerged significant similarity between rainfall anomaly variability and the ENSO signals. The many parameters of the atmosphere showed consistent characteristics in different drought years. The regional circulation patterns associated with droughts show similarities in both active and neutral ENSO years. The study also shows how possible generators of the climate anomalies can be grouped together. Thus the diagnosis of the various fields contributes to

  3. Petroleum developments in central and southern Africa in 1979

    SciTech Connect

    Rachwal, C.A.; Destefano, E.R.

    1980-11-01

    This review presents developments in petroleum exploration and production during 1979 in 44 countries of central and southern Africa. Petroleum production from 7 countries increased 16.6% to a new record 1,006,846,691 bbl (2.758 million b/d). Nigeria increased production 21% to 845 million, Congo 11.5% to 19 million, and Cameroon 17.6% to 12.5 million bbl. Gabon continued to show a decline in production, off 7.6% at 70.5 million bbl. Surface exploration work decreased 17.5% to 174.9 party-months, though figures on Nigeria are incomplete. Exploration drilling yielded 43 oil and 10 gas wells out of 111 drilled, a 47.7% success rate. Cameroon had 21 and Congo 8 new-field discovery and appraisal wells, up from 11 and 1 respectively in 1978. Development wells numbered 137 of which 86% were successful completions; 45 rigs were operating at year end.

  4. Globalization and occupational health: a perspective from southern Africa.

    PubMed Central

    Loewenson, R.

    2001-01-01

    Increased world trade has generally benefited industrialized or strong economies and marginalized those that are weak. This paper examines the impact of globalization on employment trends and occupational health, drawing on examples from southern Africa. While the share of world trade to the world's poorest countries has decreased, workers in these countries increasingly find themselves in insecure, poor-quality jobs, sometimes involving technologies which are obsolete or banned in industrialized countries. The occupational illness which results is generally less visible and not adequately recognized as a problem in low-income countries. Those outside the workplace can also be affected through, for example, work-related environmental pollution and poor living conditions. In order to reduce the adverse effects of global trade reforms on occupational health, stronger social protection measures must be built into production and trade activities, including improved recognition, prevention, and management of work-related ill-health. Furthermore, the success of production and trade systems should be judged on how well they satisfy both economic growth and population health. PMID:11584735

  5. Institutional Research in Emerging Countries of Southern Africa, Latin America, and the Middle East and North Africa: Global Frameworks and Local Practices

    ERIC Educational Resources Information Center

    Lange, Lis; Saavedra, F. Mauricio; Romano, Jeanine

    2013-01-01

    This chapter presents a synthesis of the conceptualization and practice of institutional research (IR) in higher education (HE) in emerging countries across Southern Africa, Latin America and the Middle East and North Africa (MENA) regions. The chapter contextualizes the growing need for IR in these regions, identifies problems and challenges…

  6. A Strategy to Protect and Strengthen Development in Southern Africa

    DTIC Science & Technology

    2009-04-01

    and promote lasting development in the future. 1 Erich Wiedemann and Thilo Thielke, “Too Much of a...Quarter (October 2008): 61-66. Wiedemann, Erich and Thilo Thielke. “Too Much of a Good Thing: Choking on Aid Money in Africa.” Spiegel Online

  7. Novel Arenavirus Isolates from Namaqua Rock Mice, Namibia, Southern Africa.

    PubMed

    Witkowski, Peter T; Kallies, René; Hoveka, Julia; Auste, Brita; Ithete, Ndapewa L; Šoltys, Katarína; Szemes, Tomáš; Drosten, Christian; Preiser, Wolfgang; Klempa, Boris; Mfune, John K E; Kruger, Detlev H

    2015-07-01

    Arenaviruses are feared as agents that cause viral hemorrhagic fevers. We report the identification, isolation, and genetic characterization of 2 novel arenaviruses from Namaqua rock mice in Namibia. These findings extend knowledge of the distribution and diversity of arenaviruses in Africa.

  8. Novel Arenavirus Isolates from Namaqua Rock Mice, Namibia, Southern Africa

    PubMed Central

    Kallies, René; Hoveka, Julia; Auste, Brita; Ithete, Ndapewa L.; Šoltys, Katarína; Szemes, Tomáš; Drosten, Christian; Preiser, Wolfgang; Klempa, Boris; Mfune, John K.E.; Kruger, Detlev H.

    2015-01-01

    Arenaviruses are feared as agents that cause viral hemorrhagic fevers. We report the identification, isolation, and genetic characterization of 2 novel arenaviruses from Namaqua rock mice in Namibia. These findings extend knowledge of the distribution and diversity of arenaviruses in Africa. PMID:26079174

  9. Tamarix (Tamaricaceae) hybrids: most dominant invasive genotype in southern Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybridization can potentially enhance invasiveness. Tamarix (Tamaricaceae) hybrids appear to be the dominant genotypes in their invasions. Exotic Tamarix are declared invasive in South Africa and the exotic T. chinensis and T. ramosissima are known to hybridize between themselves, and with the nativ...

  10. New records of the Cryphonectriaceae from southern Africa including Latruncellus aurorae gen. sp. nov.

    PubMed

    Vermeulen, Marcele; Gryzenhout, Marieka; Wingfield, Michael J; Roux, Jolanda

    2011-01-01

    The Cryphonectriaceae accommodates some of the world's most important tree pathogens, including four genera known from native and introduced Myrtales in Africa. Surveys in the past 3 y in southern Africa have led to the discovery of cankers with fruiting structures resembling those of the Cryphonectriaceae on trees in the Myrtales in Namibia, South Africa, Swaziland and Zambia. These fungi were identified with morphological characteristics and DNA sequence data. For the first time we report Chrysoporthe austroafricana from Namibia and on Syzygium guineense and Holocryphia eucalypti in Swaziland on a Eucalyptus grandis clone. The host and geographic ranges of Celoporthe dispersa are expanded to include S. legatti in South Africa and S. guineense in Zambia. In addition a monotypic genus, Latruncellus aurorae gen. sp. nov., is described from Galpinia transvaalica (Lythraceae, Myrtales) in Swaziland. The present and other recent studies clearly emphasize the limited understanding of the diversity and distribution of fungi in the Cryphonectriaceae in Africa.

  11. SPACES Project ARS AfricaE – Adaptive Resilience of Southern African ecosystems

    NASA Astrophysics Data System (ADS)

    Falge, Eva; Brümmer, Christian; Schmullius, Christiane; Hüttich, Christian; Scholes, Robert John; Midgley, Guy; Hickler, Thomas; Scheiter, Simon; Twine, Wayne; Bradshaw, Karen; Lück, Wolfgang; Thiel-Clemen, Thomas; Lenfers, Ulfia; Mukelabai, Mukufute; Kutsch, Werner

    2015-04-01

    Nowadays, many semi-arid ecosystems are affected by at least two different kinds of disturbances: land use (change) and climate change. Based on this, it can be hypothesized that even very resilient ecosystems may not return to their initial state after disturbance, but will rather adapt to a new steady-state. We name this phenomenon "Adaptive Resilience of Ecosystems" and use it as base for the research concept of ARS AfricaE. This project wants to go beyond older approaches that only describe structural changes in savannas and their drivers. It employs functional aspects, such as the investigation of biogeochemical cycles, but also targets a deeper understanding of the functional consequences of ecosystem changes caused by multiple disturbances, and defines "degradation" as a sustained loss in the broad set of ecosystem services, i.e. a decrease in natural capital. To achieve this goal, the project will • create a network of research clusters (with natural and altered vegetation) along an aridity gradient in the Greater Karoo, Kruger National Park in South Africa, and Kataba Forest Reserve in Zambia • link biogeochemical functions with ecosystem structure, diversity of species and eco-physiological properties • describe ecosystem disturbance (and recovery) in terms of ecosystem function such as carbon balance components and water use efficiency • build an individual-based model to predict ecosystem dynamics under (post) disturbance managements • combine this model with long-term landscape dynamic information derived from remote sensing and aerial photography • develop sustainable management strategies for disturbed ecosystems and land use change

  12. Post Rift Evolution of the Indian Margin of Southern Africa

    NASA Astrophysics Data System (ADS)

    Baby, Guillaume; Guillocheau, François; Robin, Cécile; Dall'asta, Massimo

    2016-04-01

    The objective of this study is to discuss the evolution of the South African Plateau along the Indian margin of Southern Africa. Since the classical works of A. du Toit and L.C. King and the improvement of thermochronological methods and numerical models, the question of the uplift of South African Plateau was highly debated with numerous scenarios: early Cretaceous at time of rifting (Van der Beek et al., J.Geophys.Res., 2002), late Cretaceous (Braun et al., Solid Earth, 2014), late Cenozoic (Burke & Gunnell, Geol.Soc.of America, 2008). Limited attention has been paid on the constraints provided by the offshore stratigraphic record of the surrounding margins. The objective of our study is to integrate onshore and offshore data (seismic profiles and industrial wells) to (1) analyse the infill of the whole margin (21°S to 31°S) from its hinterland to the distal deep water basin, (2) to constrain and quantify the vertical movements. We discuss the impact on accommodation and sediments partitioning, and their significance on South African Plateau uplift history. 1. Sedimentary basins of the Indian margin of Southern Africa are related to the break-up of Gondwana during late Jurassic, resulting in rifts and flexural basins. First marine incursions started during early Cretaceous times (oldest marine outcropping sediments are of Barremian age ~128 Ma). The region developed as a normal continental shelf at the Aptian-Albian transition (~113 Ma). 2. The Cretaceous geological history of the basins is characterized by differential uplift and subsidence of the basement, controlled by structures inherited from break up. As example, major early Cretaceous depocenters of the margin are located on the north of Save-Limpopo uplift (Forster, Paleogography, Paleoclimatology, Paleoecology, 1975) showing an eastward drainage pattern, maybe related to a proto Limpopo drainage. Those observations suggest that the escarpment bordering the Bushveld depression is an old relief inherited

  13. Contracts in the real world: case studies from Southern Africa.

    PubMed

    Palmer, Natasha; Mills, Anne

    2005-06-01

    The desirability of using the private sector to deliver public services is widely debated internationally. Understanding the nature of contracts that initiate and govern such public-private partnerships, and the extent to which they can define the performance of private providers, is key in addressing the questions that underlie this debate. Such understanding has to be gained through better knowledge of all the influences upon contractual relationships. Environmental and institutional factors have been highlighted as one set of influences in need of more attention. This paper presents case studies of three contracts for primary care services in Southern Africa. It reports aspects of the institutional and environmental context in which they operate, and reflects on the nature of publicly financed primary care as a service to be contracted out. An urban-based private sector contract for a sub-set of primary care services was found to operate very differently from rural-based public sector contracts, which attempted to provide broader coverage. The latter contracts were more loosely defined and operated in a more relational manner. Important environmental influences on incomplete contractual relationships explored here are the nature of the market, scope of services, management capacity and involvement of a public purchaser. The paper illustrates some of the practical challenges for low- and middle-income countries in pursuing a policy of contracting with private providers for public primary care services, and particularly highlights the difficulties of deciding how to divide up responsibility between the public and private sectors and yet maintain a comprehensive service delivery system.

  14. Carbon Monoxide Distributions and Atmosphere Transports over Southern Africa. Pt-2

    NASA Technical Reports Server (NTRS)

    Garstang, Michael; Swap, Robert J.; Piketh, Stuart; Mason, Simon; Connors, Vickie

    1999-01-01

    Sources and transports of CO as measured by the Measurement of Air Pollution from Space (MAPS) over a substantial sector of the southern hemisphere between South America and southern Africa are described by air parcel trajectories based upon European Center for Medium Range Weather Forecasts (ECMWF) model data fields. Observations, made by NASA Shuttle astronauts during the October 1994 mission, of vegetation fires suggest a direct relationship between in situ biomass burning, at least over South America and southern Africa, and coincident tropospheric measurements of CO. Results of this paper indicate that the transport of CO from the surface to the levels of maximum MAPS sensitivity (about 450 hPa) over these regions is not of a direct nature due largely to the well stratified atmospheric environment. The atmospheric transport of CO from biomass burning within this region is found to occur over intercontinental scales over numbers of days to more than a week. Three distinct synoptic circulation and transport classes are found to have occurred over southern Africa during the October 1994 MAPS experiment: (1) transport from South America and Africa to southern Africa associated with elevated MAPS measured CO (> 150 ppbv); (2) weakening anticyclonic transport from South America associated with moderate CO (< 150 ppbv and > 105 ppbv); and (3) transport from the high southern latitudes associated with low CO (<105 ppbv).

  15. Cape diversification and repeated out-of-southern-Africa dispersal in paper daisies (Asteraceae-Gnaphalieae).

    PubMed

    Bergh, Nicola G; Linder, H Peter

    2009-04-01

    The large daisy tribe Gnaphalieae occurs in extra-tropical habitats worldwide, but is most diverse in southern Africa and in Australia. We explore the age and evolutionary history of the tribe by means of a phylogenetic hypothesis based on Bayesian analysis of plastid and nuclear DNA sequences, maximum likelihood reconstruction of ancestral areas, and relaxed Bayesian dating. Early diversification occurred in southern Africa in the Eocene-Oligocene, resulting in a grade of mostly Cape-centred lineages which subsequently began speciating in the Miocene, consistent with diversification times for many Cape groups. Gnaphalieae from other geographic regions are embedded within a southern African paraphylum, indicating multiple dispersals out of southern Africa since the Oligocene to Miocene which established the tribe in the rest of the world. Colonisation of Australia via direct long-distance trans-oceanic dispersal in the Miocene resulted in the radiation which produced the Australasian gnaphalioid flora. The similarly diverse regional gnaphalioid floras of Australasia and southern Africa thus exhibit very different temporal species accumulation histories. An examination of the timing and direction of trans-Indian Ocean dispersal events in other angiosperms suggests a role for the West Wind Drift in long-distance dispersal eastwards from southern Africa.

  16. Gene flow from North Africa contributes to differential human genetic diversity in southern Europe

    PubMed Central

    Botigué, Laura R.; Henn, Brenna M.; Gravel, Simon; Maples, Brian K.; Gignoux, Christopher R.; Corona, Erik; Atzmon, Gil; Burns, Edward; Ostrer, Harry; Flores, Carlos; Bertranpetit, Jaume; Comas, David; Bustamante, Carlos D.

    2013-01-01

    Human genetic diversity in southern Europe is higher than in other regions of the continent. This difference has been attributed to postglacial expansions, the demic diffusion of agriculture from the Near East, and gene flow from Africa. Using SNP data from 2,099 individuals in 43 populations, we show that estimates of recent shared ancestry between Europe and Africa are substantially increased when gene flow from North Africans, rather than Sub-Saharan Africans, is considered. The gradient of North African ancestry accounts for previous observations of low levels of sharing with Sub-Saharan Africa and is independent of recent gene flow from the Near East. The source of genetic diversity in southern Europe has important biomedical implications; we find that most disease risk alleles from genome-wide association studies follow expected patterns of divergence between Europe and North Africa, with the principal exception of multiple sclerosis. PMID:23733930

  17. Gene flow from North Africa contributes to differential human genetic diversity in southern Europe.

    PubMed

    Botigué, Laura R; Henn, Brenna M; Gravel, Simon; Maples, Brian K; Gignoux, Christopher R; Corona, Erik; Atzmon, Gil; Burns, Edward; Ostrer, Harry; Flores, Carlos; Bertranpetit, Jaume; Comas, David; Bustamante, Carlos D

    2013-07-16

    Human genetic diversity in southern Europe is higher than in other regions of the continent. This difference has been attributed to postglacial expansions, the demic diffusion of agriculture from the Near East, and gene flow from Africa. Using SNP data from 2,099 individuals in 43 populations, we show that estimates of recent shared ancestry between Europe and Africa are substantially increased when gene flow from North Africans, rather than Sub-Saharan Africans, is considered. The gradient of North African ancestry accounts for previous observations of low levels of sharing with Sub-Saharan Africa and is independent of recent gene flow from the Near East. The source of genetic diversity in southern Europe has important biomedical implications; we find that most disease risk alleles from genome-wide association studies follow expected patterns of divergence between Europe and North Africa, with the principal exception of multiple sclerosis.

  18. HIV/AIDS and disability in Southern Africa: a review of relevant literature.

    PubMed

    Rohleder, Poul; Braathen, Stine Hellum; Swartz, Leslie; Eide, Arne Henning

    2009-01-01

    Purpose. HIV/AIDS has grown to become the biggest epidemic in modern history. Southern Africa is at the epicentre of the global epidemic, with just of a third of the world's HIV-positive population living here. It is known that HIV/AIDS affect vulnerable population groups. It is surprising then, that persons with disabilities, one of the world's most vulnerable population groups, particularly in southern Africa, have been largely overlooked with regards to HIV/AIDS. This review sought to establish the state of the knowledge at present. Method. This article reports on findings of a literature review conducted as an initial step in a research project currently underway in South Africa. This article focuses on HIV/AIDS as it affects persons with disabilities in southern Africa, as it is in this region that the majority of people living with HIV live. However, as fewer studies exist that have as its focus southern Africa (particularly looking at HIV/AIDS and persons with disabilities), relevant articles from the international literature were used as indications of what we may find through future research also in the southern African countries. Given the paucity of published literature dealing with HIV/AIDS and persons with disabilities, the review looked at various risk factors associated with HIV infection, and how it affects persons with disabilities. Results. Findings from the literature review suggest that persons with disabilities, particularly in southern Africa, are at significant risk for HIV infection. Conclusions. There is an urgent need for more research on HIV/AIDs and sexuality among persons with disabilities in Africa.

  19. Drivers and Dynamics of Global Environmental Change in Southern Africa

    NASA Astrophysics Data System (ADS)

    Jewitt, Graham; Munishi, Subira; Kunz, Richard; Viola, Paula

    2010-05-01

    Africa's potential to provide food, fuel, fibre and fodder for future global food and energy security has made it a target for a myriad investors from developed and developing countries alike. In many places, land grants and purchases have led to the establishment of huge monoculture production areas for food, fuel, fibre (maize, sugar cane, jatropha, plantation forestry etc) often preceded by deforestation and large scale utilisation and modification of available water resources. This coupled with the likelihood of rapid urbanisation in Africa over the next forty years and associated impacts linked to the high concentrations of inhabitants utilising and ultimately degrading available natural resources (e.g. wood for charcoal; water quality) have made Africa's ecosystems and people amongst the most vulnerable to global environmental change. Key questions that arise are how available scientific knowledge can best be utilized to reduce this vulnerability, where key gaps in knowledge in understanding the inter-linkages between societal needs and Food- Fibre-Energy-Water supply exist and how to best address the necessary complexity of considering these at different spatial and temporal scales. Drawing on the Ecosystem Goods and Services approach, we present key messages from ongoing research activities in South Africa, Swaziland, Mozambique and Tanzania and report on progress in applying management tools and systems to support decision making in these areas where development needs are critical. We also highlight lessons drawn from situations where unintended consequences have resulted from well meaning or politically expedient initiatives linked to large donor or foreign investment schemes, such as "outgrower" programmes, and where major environmental damage and ultimately the permanent loss of productivity of some landscapes has occurred.

  20. El Niño Southern Oscillation (ENSO) and annual malaria incidence in Southern Africa.

    PubMed

    Mabaso, Musawenkosi L H; Kleinschmidt, Immo; Sharp, Brian; Smith, Thomas

    2007-04-01

    We evaluated the association between annual malaria incidence and El Niño Southern Oscillation (ENSO) as measured by the Southern Oscillation Index (SOI) in five countries in Southern Africa from 1988 to 1999. Below normal incidence of malaria synchronised with a negative SOI (El Niño) and above normal incidence with a positive SOI (La Niña), which lead to dry and wet weather conditions, respectively. In most countries there was a positive relationship between SOI and annual malaria incidence, especially where Anopheles arabiensis is a major vector. This mosquito breeds in temporary rain pools and is highly sensitive to fluctuations in weather conditions. South Africa and Swaziland have the most reliable data and showed the strongest associations, but the picture there may also be compounded by the moderating effect of other oscillatory systems in the Indian Ocean. The impact of ENSO also varies over time within countries, depending on existing malaria control efforts and response capacity. There remains a need for quantitative studies that at the same time consider both ENSO-driven climate anomalies and non-ENSO factors influencing epidemic risk potential to assess their relative importance in order to provide an empirical basis for malaria epidemic forecasting models.

  1. Upper Permian fluviolacustrine deposits of southern Africa and the late Permian climate southern Gondwana

    SciTech Connect

    Yemane, K. . Dept. of Geology Bryn Mawr Coll., PA . Dept. of Geology)

    1993-03-01

    Upper Permian-age fluviolacustrine deposits are widespread throughout southern Africa. In the southern part of the subcontinent, where deposition took place in foreland basin settings, the sequences are thicker and fluvial-dominated whereas, lacustrine-dominated deposits accumulated in settings of low relief, broad warping and mild faulting at the northern end. The geographic extent and lateral correlatability of these deposits suggest the existence of concurrent, perhaps interconnected, giant lakes within major fluvial frameworks throughout the subcontinent, thousands of miles inland from the sea. This period of major lake development within fluvial depositional settings suggests climatic conditions that sustained a uniquely wet continental environment, deep in the heart of the Gondwanan supercontinent. Simulations based on various general circulation and energy balance climate models predict extreme seasonal temperatures and aridity for Gondwana at the palaeolatitudes of southern Africa during the Late Permian. On the other hand, distribution of climate-sensitive rocks, palynologic and palaeobotanic data and vertebrate fossils, coroborate the temperature climate documented by sedimentologic studies. The erroneous modeling results may have arisen from the fact that the models do not employ palaeogeographies that accommodate the existence of the vast lakes and rivers of Gondwana. The Late Permian palaeogeography of series of giant lakes within major fluvial frameworks would have had considerable influences on the regional climate. This suggests that it is imperative that numerical modeling studies incorporate accurate palaeogeographies, constructed based on available geological data, in order to recreate past climates with acceptable degree of accuracy.

  2. 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.

  3. Comparison of Interglacial fire dynamics in Southern Africa

    NASA Astrophysics Data System (ADS)

    Brücher, Tim; Daniau, Anne-Laure

    2016-04-01

    Responses of fire activity to a change in climate are still uncertain and biases exist by integrating this non-linear process into global modeling of the Earth system. Warming and regional drying can force fire activity in two opposite directions: an increase in fire in fuel supported ecosystems or a fire reduction in fuel-limited ecosystems. Therefore, climate variables alone can not be used to estimate the fire risk because vegetation variability is an important determinant of fire dynamics and responds itself to change in climate. Southern Africa (south of 20°S) paleofire history reconstruction obtained from the analysis of microcharcoal preserved in a deep-sea core located off Namibia reveals changes of fire activity on orbital timescales in the precession band. In particular, increase in fire is observed during glacial periods, and reduction of fire during interglacials such as the Eemian and the Holocene. The Holocene was characterized by even lower level of fire activity than Eemian. Those results suggest the alternance of grass-fueled fires during glacials driven by increase in moisture and the development of limited fueled ecosystems during interglacials characterized by dryness. Those results question the simulated increase in the fire risk probability projected for this region under a warming and drying climate obtained by Pechony and Schindell (2010). To explore the validity of the hypotheses we conducted a data-model comparison for both interglacials from 126.000 to 115.000 BP for the Eemian and from 8.000 to 2.000 BP for the Holocene. Data out of a transient, global modeling study with a Vegetation-Fire model of full complexity (JSBACH) is used, driven by a Climate model of intermediate complexity (CLIMBER). Climate data like precipitation and temperature as well as vegetation data like soil moisture, productivity (NPP) on plant functional type level are used to explain trends in fire activity. The comparison of trends in fire activity during the

  4. Moho depth and crustal composition in Southern Africa

    NASA Astrophysics Data System (ADS)

    Youssof, M.; Thybo, H.; Artemieva, I. M.; Levander, A.

    2013-12-01

    We present new results on structure, thickness, and composition of the crust in southern Africa based on 6300 seismic receiver functions at 85 stations. Application of Hk-stacking to the entire SASE dataset and use of multi-frequency bands improve resolution substantially. We observe a highly heterogeneous crustal structure with short wavelength variations in thickness (H), Vp/Vs-ratio (composition), and Moho sharpness, which defines ~ 20 blocks that do not everywhere coincide with surface tectonic features. In the Zimbabwe Craton, the Tokwe block has H = 35-38 km and Vp/Vs = 1.74-1.79 whereas the thicker crust in the Tati block (H = 47-51 km) may be related to deformation of the Archean crust along the cratonic margin. Two distinct crustal blocks with similar crustal thickness (42-46 km) but significantly different Vp/Vs-ratios are recognized in the Limpopo Belt. Extreme values of 1.90-1.94 at the dyke swarms in eastern Limpopo, and 1.84 at the Olifants River Dyke Swarm and easternmost Bushveld Intrusion Complex (BIC) indicate voluminous magmatic intrusions in the whole crust. We find no evidence for magmatic intrusions in the central (inferred) part of BIC, where the crust is thick (45-50 km) and Vp/Vs is low (1.68-1.70). This thick crustal root may have deflected rising magmas to form the two BIC lobes. Most of central Kaapvaal has thin (35-40 km) crust and Vp/Vs ~ 1.74. These characteristics are similar to the Tokwe block in Zimbabwe Craton and may indicate delamination of pre-existing lower crust, which is further supported by a very sharp Moho transition. The exposed cross-section in the Vredefort impact crater is non-representative of cratonic crust due to shallow Moho (34 km) and high Vp/Vs ~ 1.80 attributed to shock metamorphism. High Vp/Vs = 1.76 is typical of the Witwatersrand Basin, and anomalously low Vp/Vs = 1.66-1.67 marks the Kaapvaal-Kheis-Namaqua transition. Highly heterogeneous crust, both in thickness and Vp/Vs-ratio is typical of the Namaqua

  5. Lead Toxicosis in a Southern Ground Hornbill Bucorvus leadbeateri in South Africa.

    PubMed

    Koeppel, Katja N; Kemp, Lucy V

    2015-12-01

    The southern ground hornbill (Bucorvus leadbeateri) has been classified as globally vulnerable and, in South Africa, regionally endangered, with a negative population trend. Factors contributing to the population decline in South Africa are poisoning, electrocution, and illegal capture for trade, coupled with slow reproductive rates and extensive habitat requirements. Lead toxicosis is a previously undescribed threat for the population. An adult southern ground hornbill presented with acute lead toxicosis due to lead particles in the gizzard, which required intensive treatment. Two other hornbills were likely exposed. The source of the lead in these cases was likely a carcass of a porcupine that was killed with lead shot. This report highlights the importance of the use of lead-free ammunition within the habitat of the southern ground hornbill in South Africa.

  6. Time to Consider Moving Beyond Exclusive Breastfeeding in Southern Africa

    PubMed Central

    Wojcicki, Janet M.

    2017-01-01

    While there have been considerable advances in the reduction of mother to child transmission of HIV (MTCT) in sub-Saharan Africa with the advance of anti-retroviral therapies (ART), there remain challenges in the late postpartum period.  Structural issues including food insecurity and stigma make better maternal ART adherence and exclusive breastfeeding unreachable for some women. There are no other scientifically researched feeding options as there have been few studies on different types of mixed feeding practices and risk of HIV infection. Additional studies are warranted to assess detailed feeding practices in HIV exposed infants in relation to clinical outcomes. PMID:28125026

  7. Key Issues in Library and Information Science for Southern Africa: A Handbook for Library and Information Specialists.

    ERIC Educational Resources Information Center

    Mncube, Stephen Sipho

    Designed to provide a conceptual and workable framework for the development of interdisciplinary information systems in Southern Africa, this handbook focuses on Southern Africa's information needs and addresses the problems between theory and practice in information transfer and utilization. The handbook is divided into two major parts. The four…

  8. Identification of widespread pollution in the southern hemisphere deduced from satellite analyses. [AFRICA

    SciTech Connect

    Fishman, J. ); Fakhruzzaman, K. ); Cros, B.; Nganga, D. )

    1991-06-21

    Vertical profiles of ozone obtained from ozonesondes in Brazzaville, Congo (4{degree}S, 15{degree}E), and Ascension Island (98{degree}S, 15{degree}W) show that large quantities of tropospheric ozone are present over southern Africa and the adjacent eastern tropical South Atlantic Ocean. The origin of this pollution is widespread biomass burning in Africa. These measurements support satellite-derived tropospheric ozone data that demonstrate that ozone originating from the region is transported throughout most of the Southern Hemisphere. Seasonally high levels of carbon monoxide and methane observed at middle- and high-latitude stations in Africa, Australia, and Antarctica likely reflect the effects of this distant biomass burning. These data suggest that even the most remote regions on this planet may be significantly more polluted than previously believed.

  9. Ozone maxima over Southern Africa: A mid-latitude link

    NASA Technical Reports Server (NTRS)

    Barsby, Jane; Diab, Roseanne D.

    1994-01-01

    The relationship between patterns of total ozone and day-to-day weather was explored over South Africa for the period 1987 to 1988. Generally, there was a fairly poor relationship (variance less than 20 percent) between total ozone and the heights of the 100, 300 and 500 hPa geopotential heights at 5 South African stations. However, over a shorter period, October to December 1988, fluctuations in the height of the 300 hPa surface accounted for 53 percent of the variance in total ozone at Cape Town. High ozone amounts are associated with the lowering of the 300 hPa surface in the presence of an upper-air trough. The role of the mid-latitude westerly waves in this respect is discussed.

  10. Geological setting and age of Australopithecus sediba from southern Africa.

    PubMed

    Dirks, Paul H G M; Kibii, Job M; Kuhn, Brian F; Steininger, Christine; Churchill, Steven E; Kramers, Jan D; Pickering, Robyn; Farber, Daniel L; Mériaux, Anne-Sophie; Herries, Andy I R; King, Geoffrey C P; Berger, Lee R

    2010-04-09

    We describe the geological, geochronological, geomorphological, and faunal context of the Malapa site and the fossils of Australopithecus sediba. The hominins occur with a macrofauna assemblage that existed in Africa between 2.36 and 1.50 million years ago (Ma). The fossils are encased in water-laid, clastic sediments that were deposited along the lower parts of what is now a deeply eroded cave system, immediately above a flowstone layer with a U-Pb date of 2.026 +/- 0.021 Ma. The flowstone has a reversed paleomagnetic signature and the overlying hominin-bearing sediments are of normal polarity, indicating deposition during the 1.95- to 1.78-Ma Olduvai Subchron. The two hominin specimens were buried together in a single debris flow that lithified soon after deposition in a phreatic environment inaccessible to scavengers.

  11. Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011

    PubMed Central

    Glancey, Margaret M.; Linthicum, Kenneth J.

    2015-01-01

    Abstract Background: Rift Valley fever (RVF) outbreaks have been associated with periods of widespread and above-normal rainfall over several months. Knowledge on the environmental factors influencing disease transmission dynamics has provided the basis for developing models to predict RVF outbreaks in Africa. From 2008 to 2011, South Africa experienced the worst wave of RVF outbreaks in almost 40 years. We investigated rainfall-associated environmental factors in southern Africa preceding these outbreaks. Methods: RVF epizootic records obtained from the World Animal Health Information Database (WAHID), documenting livestock species affected, location, and time, were analyzed. Environmental variables including rainfall and satellite-derived normalized difference vegetation index (NDVI) data were collected and assessed in outbreak regions to understand the underlying drivers of the outbreaks. Results: The predominant domestic vertebrate species affected in 2008 and 2009 were cattle, when outbreaks were concentrated in the eastern provinces of South Africa. In 2010 and 2011, outbreaks occurred in the interior and southern provinces affecting over 16,000 sheep. The highest number of cases occurred between January and April but epidemics occurred in different regions every year, moving from the northeast of South Africa toward the southwest with each progressing year. The outbreaks showed a pattern of increased rainfall preceding epizootics ranging from 9 to 152 days; however, NDVI and rainfall were less correlated with the start of the outbreaks than has been observed in eastern Africa. Conclusions: Analyses of the multiyear RVF outbreaks of 2008 to 2011 in South Africa indicated that rainfall, NDVI, and other environmental and geographical factors, such as land use, drainage, and topography, play a role in disease emergence. Current and future investigations into these factors will be able to contribute to improving spatial accuracy of models to map risk areas

  12. Of Drama, Dreams and Desire: Creative Approaches to Applied Sex Education in Southern Africa

    ERIC Educational Resources Information Center

    Casale, Marisa; Hanass-Hancock, Jill

    2011-01-01

    In the midst of a generalised HIV and AIDS epidemic in southern Africa, the argument for more coordinated and comprehensive youth sexual health interventions is intensifying. Yet the crucial question of "how best" to provide young people with these skills and knowledge remains a key challenge for policy-makers, researchers and…

  13. Universal Basic Education and the Provision of Quality Mathematics in Southern Africa

    ERIC Educational Resources Information Center

    Kazima, Mercy

    2014-01-01

    In this paper, I discuss Universal Basic Education (UBE) in relation to the teaching and learning of mathematics in Southern Africa. I present the status of UBE for all countries in the region and then use 3 selected examples: Botswana, Malawi, and Zambia, to illustrate the provision of mathematics in the general framework of UBE in the countries.…

  14. Can Inclusive Education in South(ern) Africa Survive the HIV and AIDS Pandemic?

    ERIC Educational Resources Information Center

    Beyers, Christa; Hay, Johnnie

    2007-01-01

    Fagan (1986, p. 859) stated many years ago that "school psychology has survived the complex interaction between education and psychology, and will continue to do so in future". Applied and adapted to South(ern) Africa of 2007, one may ask whether inclusive education will survive the complex interaction with the HIV and AIDS pandemic, and…

  15. Delivering Lifelong Learning for Sustainable Development in Southern Africa: Problems and Prospects

    ERIC Educational Resources Information Center

    Maruatona, Tonic L.

    2012-01-01

    Southern African Development Community (SADC) nations in principle endorse lifelong learning (LLL) as a useful framework for sustainable development. However, in spite of the rhetoric, only a few member states such as South Africa, Botswana and Namibia have officially endorsed LLL in their educational policies. The sub-region is plagued by social…

  16. Language Policy and Orthographic Harmonization across Linguistic, Ethnic and National Boundaries in Southern Africa

    ERIC Educational Resources Information Center

    Banda, Felix

    2016-01-01

    Drawing on online and daily newspapers, speakers' language and writing practices, official government documents and prescribed spelling systems in Southern Africa, the paper explores the challenges and possibilities of orthographic reforms allowing for mobility across language clusters, ethnicity, regional and national borders. I argue that this…

  17. Language Choice and Education Quality in Eastern and Southern Africa: A Review

    ERIC Educational Resources Information Center

    Trudell, Barbara

    2016-01-01

    In 2014, UNICEF commissioned a review of language policy and education quality in the 21 countries of UNICEF's Eastern and Southern Africa Region. This paper examines findings from the review, related to the role of English and local languages in current education practice in the region. National language policies and implementation practices are…

  18. Diffusion of the National Qualifications Framework and Outcomes-Based Education in Southern and Eastern Africa

    ERIC Educational Resources Information Center

    Chisholm, Linda

    2007-01-01

    This article explores policy and curriculum diffusion in southern and eastern Africa through an examination of the National Qualifications Framework (NQF) and outcomes-based education. The article argues that the NQF was adopted for different reasons in different contexts, but that discourse coalitions and conferences have been critical in…

  19. Challenges for Children and Women in the 1990s: Eastern and Southern Africa in Profile.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, Nairobi (Kenya). Eastern and Southern Africa Regional Office.

    This report profiles conditions in the lives of children and women in Eastern and Southern Africa (ESA), and attempts to identify and analyze trends and issues which are emerging in ESA and which have particular significance for UNICEF activities. During the 1980s, ESA experienced unprecedented economic decline due to falling commodity prices and…

  20. Steps Forward and New Challenges: Indigenous Communities and Mother-Tongue Education in Southern Africa

    ERIC Educational Resources Information Center

    Hays, Jennifer

    2009-01-01

    Two international conferences held in southern Africa in 2005 gathered education and language experts to discuss practical, theoretical, and political aspects of the development of African languages for education. Despite the diversity of the participants, there was unanimous agreement that the economic and social benefits of providing…

  1. Educating Handicapped Young People in Eastern and Southern Africa in 1981-83.

    ERIC Educational Resources Information Center

    Ross, D. H.

    This publication compiles the findings and conclusions of the 3-year first phase (1980-83) of the Unesco Sub-regional Project for Special Education in Eastern and Southern Africa. It presents the state of the art of special education and prospects for future development in Botswana, Ethiopia, Kenya, Lesotho, Malawi, Mauritius, Seychelles, Somalia,…

  2. Analysis of the Cordex evaluation runs (ERA_Interim) over Southern Africa

    NASA Astrophysics Data System (ADS)

    Lennard, Chris; Kalognoumou, Liana

    2013-04-01

    The CORDEX program was instituted by the World Climate Research Program (WCRP) to develop downscaled regional climate change projections at user-relevant scales for all terrestrial regions of the world. Africa was identified as the priority domain in urgent need of attention. In light of this the Cordex-Africa Analysis campaign was initiated as a co-ordinated effort to analyse the available Era-Interim downscalings. Three regional African groups were formed (West Africa, East Africa and Southern Africa) and experts from each region tasked with the assessment of the available downscaled data. Within Africa, CORDEX has come to be viewed by many in the decision making community as the leading source of new climate change information, and expectations are high. This paper presents the analysis performed by the southern African team in which the ability of ten regional climate models (RCMs) to simulate precipitation over southern Africa within the Cordex framework was evaluated. An ensemble of ten regional climate simulations and the ensemble average is analysed to evaluate the model's ability to reproduce seasonal and interannual rainfall characteristics over regions of the sub-continent. All the RCMs use the Cordex African domain, have a spatial resolution of ~50km and are driven by the ERA-Interim reanalysis (1989- 2008). Results are compared against a number of observational datasets such as the GPCC, CRU, UDEL, TRMM etc. The spatial and temporal nature of rainfall over the Southern African region is captured by all RCMs, however, individual models exhibit wet or dry biases over particular regions of the domain. Models generally produce lower seasonal variability of precipitation compared to observations and the magnitude of the variability varies in space and time. Model biases are related to the positioning of the ITCZ as well as moisture transport. The multi-model ensemble mean generally out-performs individual models, with bias magnitudes similar to differences

  3. The reorganization of mine labor recruitment in Southern Africa: evidence from Botswana.

    PubMed

    Taylor, J

    1990-01-01

    "The past decade has been one of unprecedented change in the pattern and organization of mine labor recruitment in Southern Africa. Using detailed data on recruitment patterns in Botswana, this article supports the view that recent changes have initiated a self-sustaining trend whereby certain flows of foreign labor into South Africa will decline unabated into the foreseeable future. This results from a shift in general recruiting policy from one of encouraging external migrant labor flows--by expanding recruitment networks and employing a variable and transient workforce--to one of retrenchment and labor stabilization biased in favor of internalized labor supplies."

  4. Epizootic ulcerative syndrome affecting fish in the Zambezi river system in southern Africa.

    PubMed

    Andrew, T G; Huchzermeyer, K D A; Mbeha, B C; Nengu, S M

    2008-11-22

    In late 2006, diseased fish of a variety of species began to appear in the Chobe and upper Zambezi rivers in southern Africa. In April 2007, investigations showed that the levels of pesticides and heavy metals in the tissues of the fish were very low, discounting pollution as an underlying cause for the disease. However, histological evidence showed that the disease closely resembled the epizootic ulcerative syndrome caused by the oomycete Aphanomyces invadans, a serious aquatic pathogen that has been isolated from freshwater and estuarine fish in Japan, south-east Asia, Australia and the usa since the 1970s, but not previously recorded in Africa.

  5. A southern Africa harmonic spline core field model derived from CHAMP satellite data

    NASA Astrophysics Data System (ADS)

    Nahayo, E.; Kotzé, P. B.; McCreadie, H.

    2015-02-01

    The monitoring of the Earth's magnetic field time variation requires a continuous recording of geomagnetic data with a good spatial coverage over the area of study. In southern Africa, ground recording stations are limited and the use of satellite data is needed for the studies where high spatial resolution data is required. We show the fast time variation of the geomagnetic field in the southern Africa region by deriving an harmonic spline model from CHAMP satellite measurements recorded between 2001 and 2010. The derived core field model, the Southern Africa Regional Model (SARM), is compared with the global model GRIMM-2 and the ground based data recorded at Hermanus magnetic observatory (HER) in South Africa and Tsumeb magnetic observatory (TSU) in Namibia where the focus is mainly on the long term variation of the geomagnetic field. The results of this study suggest that the regional model derived from the satellite data alone can be used to study the small scale features of the time variation of the geomagnetic field where ground data is not available. In addition, these results also support the earlier findings of the occurrence of a 2007 magnetic jerk and rapid secular variation fluctuations of 2003 and 2004 in the region.

  6. Mantle Flow Implications across Easter and Southern Africa from Shear Wave Splitting Measurements

    NASA Astrophysics Data System (ADS)

    Ramirez, C.; Nyblade, A.; Bagley, B. C.; Mulibo, G. D.; Tugume, F.; Wysession, M. E.; Wiens, D.; van der Meijde, M.

    2015-12-01

    In this study, we present new shear wave splitting results from broadband seismic stations in Botswana and Namibia, and combine them with previous results from stations in Kenya, Uganda, Tanzania, Malawi, Zambia, South Africa, Mozambique, Zimbabwe, and Angola to further examine the pattern of seismic anisotropy across southern Africa. The new results come from stations in northern Namibia and Botswana, which help to fill in large gaps in data coverage. Our preliminary results show that fast polarization directions overall trend in a NE orientation. The most noticeable measurements that deviate from this pattern are located around the Archean Tanzania Craton in eastern Africa. The general NE pattern of fast polarization directions is attributed to mantle flow linked to the African superplume. Smaller scale variations from this general direction can be explained by shape anisotropy in the lithosphere in magmatic regions in the East African rift system and to fossil anisotropy in the Precambrian lithosphere.

  7. A new species of spectacularly coloured flat lizard Platysaurus (Squamata: Cordylidae: Platysaurinae) from southern Africa.

    PubMed

    Whiting, Martin J; Branch, William R; Pepper, Mitzy; Keogh, J Scott

    2015-07-16

    We describe a new species of flat lizard (Platysaurus attenboroughi sp. nov.) from the Richtersveld of the Northern Cape Province of South Africa and the Fish River Canyon region of southern Namibia. This species was formerly confused with P. capensis from the Kamiesberg region of Namaqualand, South Africa. Genetic analysis based on one mtDNA and two nDNA loci found Platysaurus attenboroughi sp. nov. to be genetically divergent from P. capensis and these species can also be differentiated by a number of scalation characters, coloration and their allopatric distributions. To stabilize the taxonomy the type locality of Platysaurus capensis A. Smith 1844 is restricted to the Kamiesberg region, Namaqualand, Northern Cape Province, South Africa.

  8. Age and origin of cold climate landforms from the Eastern Cape Drakensberg, southern Africa: palaeoclimatic implications

    NASA Astrophysics Data System (ADS)

    Mills, Stephanie C.; Barrows, Timothy T.; Fifield, L. Keith

    2014-05-01

    Reliable dating is crucial for resolving the nature and timing of cold events in southern Africa and the associated cold climate landforms produced. Evidence for glaciation has been proposed for the Eastern Cape Drakensberg, based on the identification of moraines that were presumed to be of last glacial maximum age. Temperature depressions of 10-17°C have been proposed for this region, based on the presence of these moraines (Lewis and Illgner, 2001) and the identification of a relict rock glacier. Such large temperature depressions are, however, unsupported by other palaeoclimatic proxies in southern Africa. Debate regarding the occurrence of glaciation in southern Africa has been ongoing for several decades. There is good evidence for small-scale glaciation during the last glacial cycle in Lesotho, at elevations exceeding 3000 m a.s.l., but these sites are more than 1000 m higher in elevation than those identified in the Eastern Cape, and suggest a temperature depression of only ~6°C and a change to a winter dominated precipitation regime during the last glacial cycle. This paper presents preliminary cosmogenic nuclide exposure ages for the Eastern Cape 'moraines' and a periglacial blockstream in this region. We discuss potential alternative interpretations for the formation of the landforms and suggest that glaciers were absent in the Eastern Cape Drakensberg during the last glacial period. However, there is widespread evidence for periglacial activity down to an elevation of ~1700 m a.s.l., as illustrated by extensive blockstreams, stone garlands and solifluction deposits. These periglacial deposits suggest that the climate was much colder (~6ºC) during the last glacial cycle, in keeping with other proxy records, but not cold enough to initiate or sustain glaciers at low elevations. References Lewis C. A., Illgner, P. M., 2001. Late Quaternary glaciation in Southern Africa: moraine ridges and glacial deposits at Mount Enterprise in the Drakensberg of the

  9. Exploring how sand ramps respond to Quaternary environmental change in Southern Africa

    NASA Astrophysics Data System (ADS)

    Rowell, Alex; Thomas, David; Bailey, Richard

    2014-05-01

    The current climate of southern Africa is particularly complex and interesting due to the interaction of several climatic systems. However, reconstructions of how these systems behaved in the past, and how the environment responded, have been hampered by a general paucity of records and poor chronological control. Sand ramps may provide the potential to improve palaeoenvironmental reconstructions of southern Africa (and beyond). Formed against a topographic barrier, sand ramps include a combination of aeolian, fluvial and colluvial deposits in varying proportions. Therefore, they have the potential to record changes in moisture availability, circulation patterns and sediment supply which can be independently dated using luminescence dating. Nevertheless relatively little attention has been paid to these features and thus the environmental controls on their formation are not yet fully understood. In particular, there is debate as to whether they reflect deposition during a 'window of opportunity' in which high-magnitude, low-frequency events are recorded (Bateman et al. 2012) or whether they record more gradual, cyclic climate change (Bertram, 2003) or even if there is a uniform control on their formation. This research aims to investigate how sand ramps respond to environmental change and what they can tell us about the paleoenvironment of southern Africa. This poster displays preliminary results based on initial field investigation. This confirmed sand ramps to be ubiquitous in southern Africa and that they record a complex interaction of aeolian, fluvial and colluvial deposits which appears to differ between sand ramps. Preliminary luminescence dating results and sedimentology are displayed for two sand ramps, one from south west Namibia the other from the Karoo region of South Africa.

  10. Middle to Late Pleistocene vegetation and climate change in subtropical southern East Africa

    NASA Astrophysics Data System (ADS)

    Castañeda, Isla S.; Caley, Thibaut; Dupont, Lydie; Kim, Jung-Hyun; Malaizé, Bruno; Schouten, Stefan

    2016-09-01

    In this study we investigate Pleistocene vegetation and climate change in southern East Africa by examining plant leaf waxes in a marine sediment core that receives terrestrial runoff from the Limpopo River. The plant leaf wax records are compared to a multi-proxy sea surface temperature (SST) record and pollen assemblage data from the same site. We find that Indian Ocean SST variability, driven by high-latitude obliquity, exerted a strong control on the vegetation of southern East Africa during the past 800,000 yr. Interglacial periods were characterized by relatively wetter and warmer conditions, increased contributions of C3 vegetation, and higher SST, whereas glacial periods were marked by cooler and arid conditions, increased contributions of C4 vegetation, and lower SST. We find that Marine Isotope Stages (MIS) 5e, 11c, 15e and 7a-7c are strongly expressed in the plant leaf wax records but MIS 7e is absent while MIS 9 is rather weak. Our plant leaf wax records also record the climate transition associated with the Mid-Brunhes Event (MBE) suggesting that the pre-MBE interval (430-800 ka) was characterized by higher inputs from grasses in comparison to relatively higher inputs from trees in the post-MBE interval (430 to 0 ka). Differences in vegetation and SST of southern East Africa between the pre- and post-MBE intervals appear to be related to shifts in the location of the Subtropical Front. Comparison with vegetation records from tropical East Africa indicates that the vegetation of southern East Africa, while exhibiting glacial-interglacial variability and notable differences between the pre- and post-MBE portions of the record, likely did not experience such dramatic extremes as occurred to the north at Lake Malawi.

  11. An assessment of renewable energy in Southern Africa: Wind, solar, hydro

    NASA Astrophysics Data System (ADS)

    Fant, Charles William, IV

    While electricity demand is rising quickly in the Southern African Power Pool (SAPP), the nations involved struggle to build the necessary infrastructure to meet the demand. In addition, the principal member---the Republic of South Africa---has made ambitious targets to reduce emissions via renewable energy technology. In this dissertation, three stand-alone studies on this subject are presented that address the future reliability of renewable energy in southern Africa, considering climate variability as well as long-term trends caused by climate change. In the first study, a suite of models are used to assess the vulnerability of the countries dependent on resources from the Zambezi River Basin to changes in climate. The study finds that the sectors most vulnerable to climate change are: hydropower in Zambia, irrigation in Zimbabwe and Mozambique, and flooding in Mozambique. In the second study, hourly reanalysis data is used to characterize wind power intermittency and assess the value of interconnection in southern Africa. The study finds that wind potential is high in Kenya, central Tanzania, and southern South Africa. With a closer look, wind power resource in South Africa is unreliable (i.e. intermittent) and is weak when power demand is highest on all relevant time-scales. In the third study, presented in Chapter 4, we develop a risk profile for changes in the long-term mean of wind and solar power sources. To do this, we use a statistical relationship between global mean temperature and each local gridded wind speed and solar radiation from the GCMs. We find that only small changes in wind speed and solar radiation are predicted in the median of the distributions projected to 2050. Furthermore, at the extremes of the distribution, relatively significant changes are predicted in some parts of southern Africa, and are associated with low probability. Finally, in the conclusion chapter, limitations and assumptions are listed for each of the three studies

  12. The Impact of International Teacher Migration on Schooling in Developing Countries--The Case of Southern Africa

    ERIC Educational Resources Information Center

    Appleton, Simon; Sives, Amanda; Morgan, W. John

    2006-01-01

    Whilst the migration of teachers has been a phenomenon for hundreds of years, the advent of "globalisation" has seen such migration return to prominence. This article focuses on the experiences of two developing countries in Southern Africa which have been on different ends of the process: South Africa as a net sender of teachers and…

  13. Childhood Psychological Problems in School Settings in Rural Southern Africa

    PubMed Central

    Cortina, Melissa A.; Fazel, Mina; Hlungwani, Tintswalo Mercy; Kahn, Kathleen; Tollman, Stephen; Cortina-Borja, Mario; Stein, Alan

    2013-01-01

    Background Many children can be exposed to multiple adversities in low and middle-income countries (LMICs) placing them at potential risk of psychological problems. However, there is a paucity of research using large representative cohorts examining the psychological adjustment of children in school settings in these countries. Children’s psychological adjustment has been shown to affect educational progress which is critical for their future. This study, based in a rural, socio-economically disadvantaged area of South Africa, aimed to examine the prevalence of children’s psychological problems as well as possible risk and protective factors. Methods Rates of psychological problems in 10–12 year olds were examined using teacher- and child-report questionnaires. Data on children from 10 rural primary schools, selected by stratified random sampling, were linked to individual and household data from the Agincourt health and socio-demographic surveillance system collected from households over 15 years. Results A total of 1,025 children were assessed. Teachers identified high levels of behavioural and emotional problems (41%). Children reported lower, but substantial rates of anxiety/depression (14%), and significant post-traumatic stress symptoms (24%); almost a quarter felt unsafe in school. Risk factors included being a second-generation former refugee and being from a large household. Protective factors highlight the importance of maternal factors, such as being more educated and in a stable partnership. Conclusion The high levels of psychological problems identified by teachers are a serious public health concern, as they are likely to impact negatively on children’s education, particularly given the large class sizes and limited resources in rural LMIC settings. Despite the high levels of risk, a proportion of children were managing well and research to understand resilience could inform interventions. PMID:23776443

  14. Phylogeography of the widespread African puff adder (Bitis arietans) reveals multiple Pleistocene refugia in southern Africa.

    PubMed

    Barlow, Axel; Baker, Karis; Hendry, Catriona R; Peppin, Lindsay; Phelps, Tony; Tolley, Krystal A; Wüster, Catharine E; Wüster, Wolfgang

    2013-02-01

    Evidence from numerous Pan-African savannah mammals indicates that open-habitat refugia existed in Africa during the Pleistocene, isolated by expanding tropical forests during warm and humid interglacial periods. However, comparative data from other taxonomic groups are currently lacking. We present a phylogeographic investigation of the African puff adder (Bitis arietans), a snake that occurs in open-habitat formations throughout sub-Saharan Africa. Multiple parapatric mitochondrial clades occur across the current distribution of B. arietans, including a widespread southern African clade that is subdivided into four separate clades. We investigated the historical processes responsible for generating these phylogeographic patterns in southern Africa using species distribution modelling and genetic approaches. Our results show that interior regions of South Africa became largely inhospitable for B. arietans during glacial maxima, whereas coastal and more northerly areas remained habitable. This corresponds well with the locations of refugia inferred from mitochondrial data using a continuous phylogeographic diffusion model. Analysis of data from five anonymous nuclear loci revealed broadly similar patterns to mtDNA. Secondary admixture was detected between previously isolated refugial populations. In some cases, this is limited to individuals occurring near mitochondrial clade contact zones, but in other cases, more extensive admixture is evident. Overall, our study reveals a complex history of refugial isolation and secondary expansion for puff adders and a mosaic of isolated refugia in southern Africa. We also identify key differences between the processes that drove isolation in B. arietans and those hypothesized for sympatric savannah mammals.

  15. Evaluation of two GCMs in simulating rainfall inter-annual variability over Southern Africa

    NASA Astrophysics Data System (ADS)

    Klutse, Nana Ama Browne; Abiodun, Babatunde J.; Hewitson, Bruce C.; Gutowski, William J.; Tadross, Mark A.

    2016-02-01

    We evaluate the performance of two global circulation models (GCMs) over Southern Africa, as part of the efforts to improve the skill of seasonal forecast from a multi-model ensemble system over the region. The two GCMs evaluated in the study are the Community Atmosphere Model version 3 (CAM3) and the Hadley Centre Atmospheric Model version 3 (HadAM3). The study analyzed 30-year climate simulations from the models and compared the results with those from Climate Research Unit (CRU) and National Center for Environmental Prediction (NCEP) reanalysis dataset. The evaluation focused on how well the models simulate circulation features, seasonal variation of temperature and rainfall, and the inter-annual rainfall and circulations during El Niño Southern Oscillation (ENSO) years. The study also investigated the relationship between the regional rainfall from the models and global sea surface temperature (SST) during the El Niño and La Niña years. The results show that both GCMs simulate the circulation features and the seasonal cycles of rainfall and temperature fairly well. The location and magnitude of maxima and minima in surface temperature, sea level pressure (SLP), and rainfall fields are well reproduced. The maximum error in the simulated temperature fields is about 2 °, 4 mb in SLP and 8 mm/day in rainfall. However, CAM3 shows a major bias in simulating the summer rainfall; it simulates the maximum rainfall along the western part of Southern Africa, instead of the eastern part. The phase of the seasonal cycles is well reproduced, but the amplitude is underestimated over the Western Cape. Both CAM3 and HadAM3 give reasonable simulations of significant relationship between the regional rainfall and SST over the Nino 3.4 region and show that ENSO strongly drives the climate of Southern Africa. Hence, the model simulations could contribute to understanding the climate of the region and improve seasonal forecasts over Southern Africa.

  16. 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.

  17. 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

  18. Importance of the Indian Ocean for simulating rainfall anomalies over eastern and southern Africa

    NASA Astrophysics Data System (ADS)

    Goddard, Lisa; Graham, Nicholas E.

    1999-08-01

    The relative contributions of the Indian Ocean and Pacific Ocean sea surface temperatures (SSTs) to the rainfall variability over eastern central, and southern Africa during the austral spring-summer are examined. The variability of African rainfall is statistically related to both oceans, but the variability in the two oceans is also related. To separate the effects of the Indian and Pacific Oceans, a suite of numerical model simulations is presented: GOGA, the atmosphere is forced by observed SSTs globally; IOGA, the atmosphere is forced by observed SSTs only in the Indian Ocean basin; and POGA, the atmosphere is forced by observed SSTs only in the tropical Pacific basin. While the SST variability of the tropical Pacific exerts some influence over the African region, it is the atmospheric response to the Indian Ocean variability that is essential for simulating the correct rainfall response over eastern, central, and southern Africa. Analyses of the dynamical response(s) seen in the numerical experiments and in the observations indicate that the Pacific and Indian Oceans have a competing influence over the Indian Ocean/African region. This competition is related to the influence of the two oceans on the Walker circulation and the consequences of that variability on low-level fluxes of moisture over central and southern Africa. Finally, given the high correlation found between SST variability in the Indian and Pacific Oceans with the Pacific leading by ˜3 months, we speculate on an approach to long-lead dynamical climate prediction over central-east and southern Africa.

  19. Mantle discontinuities under southern Africa from precursors to P′ P′df

    USGS Publications Warehouse

    Xu, Fei; Vidale, John E.; Earle, Paul S.; Benz, Harley M.

    1998-01-01

    We investigate the reflection properties of upper-mantle discontinuities beneath southern Africa using precursors to the df branch of PKPPKP (P′ P′). The P′ P′df branch is weaker than the ab and bc branches, but it does not have the complication of a caustic and appears across a wider distance range. Stacks from hundreds of short-period seismograms recorded in California from the March 9, 1994 Tonga earthquake (Mw = 7.6) show an ∼5% reflection (at 3.5 s dominate period) from 660-km depth indicating a sharp “660” under southern Africa. A 3.5 s period reflection from 410-km depth is also visible in these stacks, but only ∼2% the strength of P′ P′df. This result contrasts with the observation of the “410” and the “660” reflecting comparable amounts of high-frequency energy under the Indian Ocean [Benz and Vidale, 1993a], indicating either a diffuse “410” boundary under southern Africa or global variations in the impedance change across the “410”. A 1.5 s period reflection may indicate the existence of fine-scale heterogeneity near 320-km depth. Reflectivity synthetic seismograms also show that a previously claimed reflection from 785-km depth has the more likely explanation as PcPPKP.

  20. Earliest modern humans in southern Africa dated by isoleucine epimerization in ostrich eggshell

    NASA Astrophysics Data System (ADS)

    Miller, G. H.; Beaumont, P. B.; Deacon, H. J.; Brooks, A. S.; Hare, P. E.; Jull, A. J. T.

    1999-11-01

    The oldest anatomically modern human remains are beyond the range of radiocarbon dating, and associated deposits lack material suitable for most other dating methods. Consequently, age estimates for early human skeletal material and correlative stratigraphic horizons in southern Africa are frequently based on paleoclimatic correlations to the deep-sea record and extrapolated sedimentation rates, both of which incorporate a number of untested assumptions. Here we focus on one substage of the Middle Stone Age of southern Africa, the Howiesons Poort industry, a distinctive culture-stratigraphic marker in sequences south of the Zambezi. Anatomically modern human skeletal material has been found associated with, or even older than the Howiesons Poort layer in stratified deposits at Border Cave and Klasies River main site. We have dated or bracketed the Howiesons Poort horizon at Border Cave, Boomplaas Cave and Apollo 11 Cave, three stratified cave sites in southern Africa, based on the extent of isoleucine epimerization in associated ostrich eggshells. We conclude that the Howiesons Poort lithic industry is bracketed by limiting dates of 56 and 80 ka, and is most likely centered on 66±5 ka. Anatomically modern human remains in deeper levels are more than 100 ka old, lending support to the hypothesis of an African origin for Homo sapiens.

  1. Managing conflicts arising from fisheries enhancements based on non-native fishes in southern Africa.

    PubMed

    Ellender, B R; Woodford, D J; Weyl, O L F; Cowx, I G

    2014-12-01

    Southern Africa has a long history of non-native fish introductions for the enhancement of recreational and commercial fisheries, due to a perceived lack of suitable native species. This has resulted in some important inland fisheries being based on non-native fishes. Regionally, these introductions are predominantly not benign, and non-native fishes are considered one of the main threats to aquatic biodiversity because they affect native biota through predation, competition, habitat alteration, disease transfer and hybridization. To achieve national policy objectives of economic development, food security and poverty eradication, countries are increasingly looking towards inland fisheries as vehicles for development. As a result, conflicts have developed between economic and conservation objectives. In South Africa, as is the case for other invasive biota, the control and management of non-native fishes is included in the National Environmental Management: Biodiversity Act. Implementation measures include import and movement controls and, more recently, non-native fish eradication in conservation priority areas. Management actions are, however, complicated because many non-native fishes are important components in recreational and subsistence fisheries that contribute towards regional economies and food security. In other southern African countries, little attention has focussed on issues and management of non-native fishes, and this is cause for concern. This paper provides an overview of introductions, impacts and fisheries in southern Africa with emphasis on existing and evolving legislation, conflicts, implementation strategies and the sometimes innovative approaches that have been used to prioritize conservation areas and manage non-native fishes.

  2. New insights into the history of the C-14010 lactase persistence variant in Eastern and Southern Africa.

    PubMed

    Macholdt, Enrico; Slatkin, Montgomery; Pakendorf, Brigitte; Stoneking, Mark

    2015-04-01

    Lactase persistence (LP), the ability to digest lactose into adulthood, is strongly associated with the cultural traits of pastoralism and milk-drinking among human populations, and several different genetic variants are known that confer LP. Recent studies of LP variants in Southern African populations, with a focus on Khoisan-speaking groups, found high frequencies of an LP variant (the C-14010 allele) that also occurs in Eastern Africa, and concluded that the C-14010 allele was brought to Southern Africa via a migration of pastoralists from Eastern Africa. However, this conclusion was based on indirect evidence; to date no study has jointly analyzed data on the C-14010 allele from both Southern African Khoisan-speaking groups and Eastern Africa. Here, we combine and analyze published data on the C-14010 allele in Southern and Eastern African populations, consisting of haplotypes with the C-14010 allele and four closely-linked short tandem repeat loci. Our results provide direct evidence for the previously-hypothesized Eastern African origin of the C-14010 allele in Southern African Khoisan-speaking groups. In addition, we find evidence for a separate introduction of the C-14010 allele into the Bantu-speaking Xhosa. The estimated selection intensity on the C-14010 allele in Eastern Africa is lower than that in Southern Africa, which suggests that in Eastern Africa the dietary changes conferring the fitness advantage associated with LP occurred some time after the origin of the C-14010 allele. Conversely, in Southern Africa the fitness advantage was present when the allele was introduced, as would be expected if pastoralism was introduced concomitantly.

  3. Mongoose rabies in southern Africa: a re-evaluation based on molecular epidemiology.

    PubMed

    Nel, L H; Sabeta, C T; von Teichman, B; Jaftha, J B; Rupprecht, C E; Bingham, J

    2005-05-01

    Relative to the developed world, rabies has been poorly studied in the vast African continent. The southern African countries of Zimbabwe and South Africa, however, are known to sustain a great diversity of lyssaviruses, with large biological variations amongst genotype 1 (rabies viruses) at present more apparent here than elsewhere on the continent. One recognized biotype of rabies virus in the subcontinent appears to be specifically adapted to a variety of mongooses, belonging to the Viverrinae subfamily (family Herpestidae) and are commonly referred to as viverrid viruses, although the term mongoose rabies would be more correct, considering the taxonomic status of the host species involved. It was our objective to study the genetic relationships of 77 rabies virus isolates of this mongoose biotype, isolated in South Africa and Zimbabwe, towards elucidation of the molecular epidemiology of this interesting group of African viruses. In our study of a 592 nucleotide sequence encompassing the cytoplasmic domain of the glycoprotein and the G-L intergenic region of the viral genomes, we provide the first comprehensive data on the molecular epidemiology of these viruses and indicate a history of extended evolutionary adaptation in this geographical domain. The molecular epidemiological observations reported here are highly unlikely to be limited to the small geographical areas of South Africa and Zimbabwe and illustrate the need for lyssavirus surveillance in the rest of sub-Saharan Africa and throughout the entire continent.

  4. Agricultural nematology in East and Southern Africa: problems, management strategies and stakeholder linkages.

    PubMed

    Talwana, Herbert; Sibanda, Zibusiso; Wanjohi, Waceke; Kimenju, Wangai; Luambano-Nyoni, Nessie; Massawe, Cornel; Manzanilla-López, Rosa H; Davies, Keith G; Hunt, David J; Sikora, Richard A; Coyne, Danny L; Gowen, Simon R; Kerry, Brian R

    2016-02-01

    By 2050, Africa's population is projected to exceed 2 billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of Sub-Saharan Africa, where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant-parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can produce symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe.

  5. Dust from southern Africa: rates of emission and biogeochemical properties

    NASA Astrophysics Data System (ADS)

    Bhattachan, A.; D'Odorico, P.; Zobeck, T. M.; Okin, G. S.; Dintwe, K.

    2012-12-01

    The stabilized linear dunefields in the southern Kalahari show signs of reactivation due to reduced vegetation cover owing to drought and/or overgrazing. It has been demonstrated with a laboratory dust generator that the southern Kalahari soils are good emitters of dust and that large-scale dune reactivation can potentially make the region an important dust source in the relatively low-dust Southern Hemisphere. We show that emergence of the southern Kalahari as a new dust source may affect ocean biogeochemistry as the soils are rich in soluble iron and the dust from the southern Kalahari commonly reaches the Southern Ocean. We investigate the biogeochemical properties of the fine fraction of soil from the Kalahari dunes and compare them to those of currently active dust sources such as the Makgadikgadi and the Etosha pans as well as other smaller pans in the region. Using field measurements of sediment fluxes and satellite images, we calculate the rates of dust emission from the southern Kalahari under different land cover scenarios. To assess the reversibility of dune reactivation in the southern Kalahari, we investigate the resilience of dunefield vegetation by looking at changes in soil nutrients, fine soil fractions, and seed bank in areas affected by intense denudation.

  6. Dust from southern Africa: rate of emission and biogeochemical properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stabilized linear dunefields in the southern Kalahari show signs of reactivation due to reduced vegetation cover owing to drought and/or overgrazing. It has been demonstrated with a laboratory dust generator that the southern Kalahari soils are good emitters of dust and that large-scale dune rea...

  7. Late Quaternary environmental change along the temperate-tropical interface in southern Africa. (Invited)

    NASA Astrophysics Data System (ADS)

    Chase, B. M.

    2013-12-01

    As a relatively low-relief landscape stretching from the equator to the mid-latitudes, the African sector of the Southern Hemisphere provides an excellent opportunity to study long-term interactions between tropical, subtropical and temperate climate systems. This potential, however, has remained largely unrealised as funding has generally been focussed on the large lakes of Eastern Africa and the analysis of marine cores from the continental margin. The result is a spatially and temporally disjunct regional dataset, and the dominance of broad conceptual models to contextualise the limited available data and explain palaeoenvironmental dynamics. The dominant hypotheses to explain long-term climate change in southern Africa are: 1) changes in temperate systems result from expansions and contractions of Antarctic sea-ice that vary with trends in polar/global temperatures; 2) tropical change is primarily a function of shifts in the mean position of the Intertropical Convergence Zone (ITCZ) as a result of orbitally-induced changes in direct insolation forcing, and/or as a response to Northern Hemisphere cooling. In both cases, some evidence exists to support these hypotheses, but the proxies and interpretations are not unambiguous, and in some cases the interpretations of the data have been primarily developed to conform to the dominant conceptual paradigm. This paper will discuss the interplay between temperate and tropical systems in southern Africa, and the implications for hemispheric and global climate dynamics. New data, particularly high-resolution records from fossilised rock hyrax middens (Chase et al., 2012, Quaternary Science Reviews; www.hyrax.univ-montp2.fr), is providing a robust framework into which lower resolution or more poorly understood proxies can better understood. Findings from a subcontinental-scale initiative funded by the European Research Council so far indicate that shifts of the Subtropical Front and the westerly storm tracks did bring

  8. Evidence of Unique Genotypes of Beak and Feather Disease Virus in Southern Africa

    PubMed Central

    Heath, Livio; Martin, Darren P.; Warburton, Louise; Perrin, Mike; Horsfield, William; Kingsley, Chris; Rybicki, Edward P.; Williamson, Anna-Lise

    2004-01-01

    Psittacine beak and feather disease (PBFD), caused by Beak and feather disease virus (BFDV), is the most significant infectious disease in psittacines. PBFD is thought to have originated in Australia but is now found worldwide; in Africa, it threatens the survival of the indigenous endangered Cape parrot and the vulnerable black-cheeked lovebird. We investigated the genetic diversity of putative BFDVs from southern Africa. Feathers and heparinized blood samples were collected from 27 birds representing 9 psittacine species, all showing clinical signs of PBFD. DNA extracted from these samples was used for PCR amplification of the putative BFDV coat protein (CP) gene. The nucleotide sequences of the CP genes of 19 unique BFDV isolates were determined and compared with the 24 previously described sequences of BFDV isolates from Australasia and America. Phylogenetic analysis revealed eight BFDV lineages, with the southern African isolates representing at least three distinctly unique genotypes; 10 complete genome sequences were determined, representing at least one of every distinct lineage. The nucleotide diversity of the southern African isolates was calculated to be 6.4% and is comparable to that found in Australia and New Zealand. BFDVs in southern Africa have, however, diverged substantially from viruses found in other parts of the world, as the average distance between the southern African isolates and BFDV isolates from Australia ranged from 8.3 to 10.8%. In addition to point mutations, recombination was found to contribute substantially to the level of genetic variation among BFDVs, with evidence of recombination in all but one of the genomes analyzed. PMID:15308722

  9. Emissions of Trace Gases and Particles from Savanna Fires in Southern Africa

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Bertschi, Isaac T.; Blake, Donald R.; Simpson, Isobel J.; Gao, Song; Kirchstetter, Thomas W.; Novakov, Tica

    2003-01-01

    Airborne measurements made on initial smoke from 10 savanna fires in southern Africa provide quantitative data on emissions of 50 gaseous and particulate species, including carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, methane, ammonia, dimethyl sulfide, nonmethane organic compounds, halocarbons, gaseous organic acids, aerosol ionic components, carbonaceous aerosols, and condensation nuclei (CN). Measurements of several of the gaseous species by gas chromatography and Fourier transform infrared spectroscopy are compared. Emission ratios and emission factors are given for eight species that have not been reported previously for biomass burning of savanna in southern Africa (namely, dimethyl sulfide, methyl nitrate, five hydrocarbons, and particles with diameters from 0.1 to 3 microns). The emission factor that we measured for ammonia is lower by a factor of 4, and the emission factors for formaldehyde, hydrogen cyanide, and CN are greater by factors of about 3, 20, and 3 - 15, respectively, than previously reported values. The new emission factors are used to estimate annual emissions of these species from savanna fires in Africa and worldwide.

  10. Parasites of domestic and wild animals in South Africa. XLIX. Ticks (Acari: Ixodidae) infesting white and black rhinoceroses in southern Africa.

    PubMed

    Horak, Ivan G; Boshoff, Christiaan R; Cooper, David V; Foggin, Christoper M; Govender, Danny; Harrison, Alan; Hausler, Guy; Hofmeyr, Markus; Kilian, J Werner; MacFadyen, Duncan N; Nel, Pierre J; Peinke, Dean; Squarre, David; Zimmermann, David

    2017-01-30

    The objectives of the study were to determine the species composition of ticks infesting white and black rhinoceroses in southern Africa as well as the conservation status of those tick species that prefer rhinos as hosts. Ticks were collected opportunistically from rhinos that had been immobilised for management purposes, and 447 white rhinoceroses (Ceratotherium simum) and 164 black rhinoceroses (Diceros bicornis) were sampled in South Africa, 61 black rhinos in Namibia, 18 white and 12 black rhinos in Zimbabwe, and 24 black rhinos in Zambia. Nineteen tick species were recovered, of which two species, Amblyomma rhinocerotis and Dermacentor rhinocerinus, prefer rhinos as hosts. A. rhinocerotis was collected only in the northeastern KwaZulu-Natal reserves of South Africa and is endangered, while D. rhinocerinus is present in these reserves as well as in the Kruger National Park and surrounding conservancies. Eight of the tick species collected from the rhinos are ornate, and seven species are regularly collected from cattle. The species present on rhinos in the eastern, moister reserves of South Africa were amongst others Amblyomma hebraeum, A. rhinocerotis, D. rhinocerinus, Rhipicephalus maculatus, Rhipicephalus simus and Rhipicephalus zumpti, while those on rhinos in the Karoo and the drier western regions, including Namibia, were the drought-tolerant species, Hyalomma glabrum, Hyalomma rufipes, Hyalomma truncatum and Rhipicephalus gertrudae. The species composition of ticks on rhinoceroses in Zambia differed markedly from those of the other southern African countries in that Amblyomma sparsum, Amblyomma tholloni and Amblyomma variegatum accounted for the majority of infestations.

  11. 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.

  12. First Ground-based Observation of Transient Luminous Events over Southern Africa

    NASA Astrophysics Data System (ADS)

    Nnadih, Ogechukwu; Kosch, Michael; Martinez, Peter

    2016-07-01

    We present the first ground-based observations in southern Africa of Transient Luminous Events (TLEs) in the summer of 2015/16 over convective thunderstorms. For the months of December to February, South Africa has one of the highest lightning stroke rates in the world. This was part of the AfriSprite campaign initiated by the South African National Space Agency. These observations show a variety of fine structures such as tree-like shaped, carrot, angel and jellyfish-shaped sprites. The South African Weather Service array of VLF receivers is used to locate and quantify the magnitude and polarity of the lightning strikes associated with TLEs. We plan to make bi-static as well as multi-wavelength observations in future.

  13. Antiretroviral Therapy and Nutrition in Southern Africa: Citizenship and the Grammar of Hunger.

    PubMed

    Cousins, Thomas

    2016-01-01

    How might we understand and respond to the new forms of hunger that arise with the massive rollout of antiretroviral therapy (ART) for HIV in southern Africa? Rather than 'merely' a technical problem of measurement, medicine or infrastructure, I suggest that a philosophical question arises concerning the relationship between the experience of hunger, the utterances that communicate that experience, and the bodily regimes of well-being and ill-being indexed by such utterances. Taking the gut as a particular kind of mediator of experience, I draw on ethnographic fieldwork conducted in KwaZulu-Natal, South Africa to open up a set of questions on acknowledgment and avoidance. The central question concerns the divergent concepts of 'grammar' that confront the relationship between hunger and ART.

  14. Central southern Africa at the time of the African Humid Period: A new analysis of Holocene palaeoenvironmental and palaeoclimate data.

    NASA Astrophysics Data System (ADS)

    Burrough, Sallie; Thomas, David

    2014-05-01

    The Holocene African Humid Period (c 14.8-5.5 ka) is now recognised in high-resolution records from western Africa as well as in tropical Africa north of the equator. Establishing a clear picture of Holocene environmental changes from palaeodata in central southern Africa is, however, proving both difficult and contentious. This is because in dryland systems in particular it can be difficult to distinguish the effects of sub-millennial scale regional climatic variability from those of major externally-forced global climate changes. We analyse and review existing records for central southern Africa, and neighbouring areas affected by the same climate systems, to attempt to build a clearer spatial picture of regional hydrological system responses during the Holocene. We suggest palaeodata, including new data from Makgadikgadi basin barchan dunes indicate mid-late Holocene aridity following a period of marked hydrological dynamism extending from the early Holocene. We propose that present-day conditions in central southern Africa are relatively stable compared to the early and mid-Holocene and infer that this period of relative stability in the landscape has occurred since ca. 2 ka. We explain Holocene hydrological changes through analysis of changing zonal climatic influences linked to Congo Air Boundary (CAB) and Intertropical Convergence Zone (ITCZ) dynamics, the effects of which filter into the region via complex drainage basin dynamics. It is proposed that, sensu stricto, the AHP was not a spatially uniform feature of early Holocene central southern Africa.

  15. Modelling Bambara Groundnut Yield in Southern Africa: Towards a Climate-Resilient Future

    NASA Technical Reports Server (NTRS)

    Karunaratne, A. S.; Walker, S.; Ruane, A. C.

    2015-01-01

    Current agriculture depends on a few major species grown as monocultures that are supported by global research underpinning current productivity. However, many hundreds of alternative crops have the potential to meet real world challenges by sustaining humanity, diversifying agricultural systems for food and nutritional security, and especially responding to climate change through their resilience to certain climate conditions. Bambara groundnut (Vigna subterranea (L.) Verdc.), an underutilised African legume, is an exemplar crop for climate resilience. Predicted yield performances of Bambara groundnut by AquaCrop (a crop-water productivity model) were evaluated for baseline (1980-2009) and mid-century climates (2040-2069) under 20 downscaled Global Climate Models (CMIP5-RCP8.5), as well as for climate sensitivities (AgMIPC3MP) across 3 locations in Southern Africa (Botswana, South Africa, Namibia). Different land - races of Bambara groundnut originating from various semi-arid African locations showed diverse yield performances with diverse sensitivities to climate. S19 originating from hot-dry conditions in Namibia has greater future yield potential compared to the Swaziland landrace Uniswa Red-UN across study sites. South Africa has the lowest yield under the current climate, indicating positive future yield trends. Namibia reported the highest baseline yield at optimum current temperatures, indicating less yield potential in future climates. Bambara groundnut shows positive yield potential at temperatures of up to 31degC, with further warming pushing yields down. Thus, many regions in Southern Africa can utilize Bambara groundnut successfully in the coming decades. This modelling exercise supports decisions on genotypic suitability for present and future climates at specific locations.

  16. Rainfall variability over southern Africa: an overview of current research using satellite and climate model data

    NASA Astrophysics Data System (ADS)

    Williams, C.; Kniveton, D.; Layberry, R.

    2009-04-01

    It is increasingly accepted that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. In this research, satellite-derived rainfall data are used as a basis for undertaking model experiments using a state-of-the-art climate model, run at both high and low spatial resolution. Once the model's ability to reproduce extremes has been assessed, idealised regions of sea surface temperature (SST) anomalies are used to force the model, with the overall aim of investigating the ways in which SST anomalies influence rainfall extremes over southern Africa. In this paper, a brief overview is given of the authors' research to date, pertaining to southern African rainfall. This covers (i) a description of present-day rainfall variability over southern Africa; (ii) a comparison of model simulated daily rainfall with the satellite-derived dataset; (iii) results from sensitivity testing of the model's domain size; and (iv) results from the idealised SST experiments.

  17. Slow river incision and erosion strongly limit active uplift in southern Africa

    NASA Astrophysics Data System (ADS)

    Erlanger, E. D.; Granger, D. E.; Gibbon, R. J.

    2010-12-01

    The high topography of the southern African passive margin has been attributed to uplift since the 1950’s, when L.C. King associated widespread, deeply weathered surfaces to successive cycles of uplift and erosion. Since the time of King, others have attempted to identify a source for the high topography. Competing hypotheses include 1) uplift is recent and continuing due to mantle-driven dynamic topography, or 2) the high topography has been relict since at least the late Cretaceous, and any ongoing uplift is due solely to erosional isostasy. It has remained difficult to test these hypotheses because estimates of late Neogene uplift rates have been very poorly constrained, ranging from ~10-1000 m/My. To resolve whether uplift is active today, we determined modern erosion rates, paleo-erosion rates, and river incision rates in South Africa. River incision rates and paleo-erosion rates were calculated from a flight of terraces along the Sundays River Valley, located on the southeastern coast. This valley hosts the best preserved flight of strath terraces in southern Africa. We dated the river terraces with cosmogenic 26Al and 10Be in quartz sediment, using an isochron burial dating method. The ages of these terraces range from modern to ~4 Ma and vary in height from ~6-80 m above the present river level, providing an excellent opportunity to evaluate uplift rates over million-year timescales. From the terrace ages and heights, we calculated a long-term incision rate of 16 m/My for the Sundays River. The average paleo-erosion rate for the Sundays River is ~10 m/My, about equal in magnitude to the long-term incision rate. We measured modern erosion rates over a large part of South Africa, including several distinct geographic regions: the southeast coast, the Great escarpment, the Lesotho highlands, and the continental interior. Along the southeast coast, erosion rates vary from 4-10 m/My. The Great Escarpment is eroding the fastest at 30-60 m/My. Erosion rates in

  18. Drought regimes in Southern Africa and how well GCMs simulate them

    NASA Astrophysics Data System (ADS)

    Ujeneza, Eva L.; Abiodun, Babatunde J.

    2014-09-01

    This paper presents the spatial and temporal structures of drought regimes in Southern Africa and evaluates the capability of ten global climate models (GCMs) in simulating the regimes. The study uses a multi-scaled standardized index (called standardized precipitation evapo-transpiration index, SPEI) in characterizing droughts over Southern Africa at 3- and 12-month scales. The spatial patterns of the drought regimes are identified using the rotated principal component analysis (PCA) on the SPEI, while the temporal characteristics of the drought regimes are studied using wavelet analysis. The relationship between each drought regime and global SSTs (and climate indices) is quantified using correlation analysis and wavelet coherence analysis. The study also quantifies the capability of the GCMs in simulating the drought regimes. The PCA results show four main drought regimes that jointly explain about 50 % SPEI variance over South Africa. The drought regimes (hereafter PF1, PF2, PF3 and PF4) centre over the south-western part of Southern Africa (i.e. South Africa, Botswana and Namibia common border), Zimbabwe, Tanzania, and Angola, respectively. PF1, PF2 and PF4 are strongly correlated with SST over the South Atlantic, Tropical Pacific and Indian Oceans, while PF3 is strongly correlated with the SST over the Tropical Pacific, Atlantic and Indian Oceans. The drought regimes (except PF4) have significant coherence with some atmospheric teleconnection, but the strength, duration, and phase of the coherence vary with time. All the GCMs simulate the drought regimes better at a 3-month scale than at a 12-month scale. At a 3-month scale, 70 % of the GCMs simulate all the drought regimes with a high correlation coefficient (r > 0.6), but at a 12-month scale only 60 % of the models simulate at least three of the drought regimes with a high correlation coefficient (r > 0.6). The results of this study have applications in using GCMs to study the underlying atmospheric

  19. Drought regimes in Southern Africa and how well GCMs simulate them

    NASA Astrophysics Data System (ADS)

    Ujeneza, Eva L.; Abiodun, Babatunde J.

    2015-03-01

    This paper presents the spatial and temporal structures of drought regimes in Southern Africa and evaluates the capability of ten global climate models (GCMs) in simulating the regimes. The study uses a multi-scaled standardized index (called standardized precipitation evapo-transpiration index, SPEI) in characterizing droughts over Southern Africa at 3- and 12-month scales. The spatial patterns of the drought regimes are identified using the rotated principal component analysis (PCA) on the SPEI, while the temporal characteristics of the drought regimes are studied using wavelet analysis. The relationship between each drought regime and global SSTs (and climate indices) is quantified using correlation analysis and wavelet coherence analysis. The study also quantifies the capability of the GCMs in simulating the drought regimes. The PCA results show four main drought regimes that jointly explain about 50 % SPEI variance over South Africa. The drought regimes (hereafter PF1, PF2, PF3 and PF4) centre over the south-western part of Southern Africa (i.e. South Africa, Botswana and Namibia common border), Zimbabwe, Tanzania, and Angola, respectively. PF1, PF2 and PF4 are strongly correlated with SST over the South Atlantic, Tropical Pacific and Indian Oceans, while PF3 is strongly correlated with the SST over the Tropical Pacific, Atlantic and Indian Oceans. The drought regimes (except PF4) have significant coherence with some atmospheric teleconnection, but the strength, duration, and phase of the coherence vary with time. All the GCMs simulate the drought regimes better at a 3-month scale than at a 12-month scale. At a 3-month scale, 70 % of the GCMs simulate all the drought regimes with a high correlation coefficient (r > 0.6), but at a 12-month scale only 60 % of the models simulate at least three of the drought regimes with a high correlation coefficient (r > 0.6). The results of this study have applications in using GCMs to study the underlying atmospheric

  20. 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

  1. Electrical lithosphere beneath the Kaapvaal craton, southern Africa

    NASA Astrophysics Data System (ADS)

    Evans, Rob L.; Jones, Alan G.; Garcia, Xavier; Muller, Mark; Hamilton, Mark; Evans, Shane; Fourie, C. J. S.; Spratt, Jessica; Webb, Susan; Jelsma, Hielke; Hutchins, Dave

    2011-04-01

    A regional-scale magnetotelluric (MT) experiment across the southern African Kaapvaal craton and surrounding terranes, called the Southern African Magnetotelluric Experiment (SAMTEX), has revealed complex structure in the lithospheric mantle. Large variations in maximum resistivity at depths to 200-250 km relate directly to age and tectonic provenance of surface structures. Within the central portions of the Kaapvaal craton are regions of resistive lithosphere about 230 km thick, in agreement with estimates from xenolith thermobarometry and seismic surface wave tomography, but thinner than inferred from seismic body wave tomography. The MT data are unable to discriminate between a completely dry or slightly "damp" (a few hundred parts per million of water) structure within the transitional region at the base of the lithosphere. However, the structure of the uppermost ˜150 km of lithosphere is consistent with enhanced, but still low, conductivities reported for hydrous olivine and orthopyroxene at levels of water reported for Kaapvaal xenoliths. The electrical lithosphere around the Kimberley and Premier diamond mines is thinner than the maximum craton thickness found between Kimberley and Johannesburg/Pretoria. The mantle beneath the Bushveld Complex is highly conducting at depths around 60 km. Possible explanations for these high conductivities include graphite or sulphide and/or iron metals associated with the Bushveld magmatic event. We suggest that one of these conductive phases (most likely melt-related sulphides) could electrically connect iron-rich garnets in a garnet-rich eclogitic composition associated with a relict subduction slab.

  2. Political challenges to implementing IWRM in Southern Africa

    NASA Astrophysics Data System (ADS)

    Swatuk, Larry A.

    Southern African states are undertaking comprehensive water sector reforms. While motives for reform are partially local, they are in large part driven by the interests and ideologies of Western states and civil societies. Within the Southern African Development Community (SADC), national (water, sanitation, irrigation) master plans are being written or revised. In several states, new Water Acts are in place and new institutions have been created to improve delivery. The stated goal of these activities is integrated water resources management (IWRM) defined simply as equitable, efficient and sustainable use of the resource. This article summarizes findings of social science-oriented scholarship on water management in the region, in particular that published in three special issues of Physics and Chemistry of the Earth (vol. 27, nos. 11-22; vol. 28, nos. 20-27; vol. 29, nos. 15-18). Evidence shows, among other things, that governments have been reluctant to devolve power to stakeholders; that rural dwellers are suspicious of the motives behind reform; that already empowered actors dominate new institutions touting broad-based participation; that efforts to fully recover costs in urban areas have been met with widespread civil resistance; and that new institutions have undermined existing forms of cooperation and conflict resolution, making matters worse not better. At the same time, these studies show the utility of decision support tools, capacity building exercises and research and knowledge production-all positive outcomes that should not be discounted. The paper argues that difficulties with reform reflect the highly political nature of the undertaking. Specifically, the new water architecture proposes a profound realignment of decision making power in already fragile, underdeveloped states. As a result, what may have started as a project now constitutes a context wherein differently empowered actors negotiate and renegotiate roles and rights to resources. Thus

  3. Macroeconomics, (Adult) Education, and Poverty Eradication in Southern Africa

    NASA Astrophysics Data System (ADS)

    Nhamo, Senia; Nhamo, Godwell

    2006-05-01

    The Millennium Summit held in New York in September 2000 outlined the Millennium Development Goals (MDGs). The first of these involves the eradication of extreme poverty and hunger, setting two targets: halving by 2015 the percentage of the world's populace in 1990 with income less than US-1 a day (i.e., cutting this percentage from 27.9 to 14%); and halving the share of people who suffer from hunger. As for education, the MDGs seek to ensure that all children can complete primary schooling by 2015. Drawing on examples from selected southern African countries, the present study examines the need to strengthen economic support for (adult) education as an instrument of poverty eradication. It argues that human capital is one of the fundamental determinants of economic growth, and that this economic resource is essentially determined in both qualitative and quantitative regards by education.

  4. Stable oxygen and carbon isotope characteristics in speleothems from Southern Africa - how good are they?

    NASA Astrophysics Data System (ADS)

    Holmgren, K.

    2009-04-01

    Much remains to be understood about the interaction between the African climate system, its surrounding ocean-atmosphere climate variability and the global climate system. A better understanding of the regional climate evolution is crucial for understanding global climate dynamics and issues surrounding environmental change throughout Africa and a prerequisite for increasing climate forecasting capabilities for the region. As part of developing this understanding, a longer term perspective that reaches beyond the information available from instrumental records is required. Speleothems are frequently abundant in southern Africa. Quite a few records are now available, reporting significant changes in climate and environmental conditions over longer and shorter time scales. Conclusions are mainly based on the stable isotopic composition of the speleothems. The interpretation of the stable isotope data is, however, not always straight-forward, since many processes contribute to the observed signal in the speleothem and these processes may influence the signal differently at different spatial and temporal scales. For example was the Makapansgat speleothem oxygen isotope record, originally interpreted as being generally determined by shifts in atmospheric circulation pattern (Lee-Thorp et al. 2001, Holmgren et al. 2003), recently challenged and re-interpreted by Partin et al. (2008) to reflect annual rainfall amounts. Historically, less attention has been paid to the stable carbon isotope composition in speleothems. Today, an increasing number of studies demonstrate the potential of stable carbon variations as providing additional information on climate and environment. Measured variations can be a function of the amount of C3 versus C4 vegetation, vegetation cover and soil biological activity, bedrock proportion, rainfall amount and the drip rate. Clearly the multitudes of plausible processes behind the isotopic composition of speleothems in southern Africa (as well as

  5. An archeomagnetic record from southern Africa and its bearing on the history of the South Atlantic Anomaly

    NASA Astrophysics Data System (ADS)

    Tarduno, John; Cottrell, Rory; Huffman, Thomas; Watkeys, Michael; Grigsby, Miriam; Blackman, Eric

    2016-04-01

    The paucity of Southern Hemisphere archeomagnetic data limits the resolution of paleosecular variation models, while at the same time important changes in the modern and historical field, including the recent dipole decay, appear to originate in this region. We have recently presented the first archeomagnetic data from Iron Age sites of southern Africa (˜1000-1650 AD) (Tarduno et al., Nature Communications, 2015). Magnetic data show a sharp intensity drop at ˜1300 AD, at a rate comparable to modern field changes in the South Atlantic Anomaly (SAA), but to lower values. These changes motivated our conceptual model whereby the recurrence of low field values reflects magnetic flux expulsion from the core, promoted by the unusual core-mantle boundary composition and structure beneath southern Africa as defined by seismology (specifically the African Large Low Velocity Seismic Province, or LLVSP). Because the African LLVSP is a longstanding structure, we expect this region to be a steady site of flux expulsion, and perhaps the triggering site for reversals, on time scales of millions of years. Here we discuss our ongoing efforts to extend the archeomagnetic record from southern Africa back in time, and further develop the flux expulsion- African LLVSP hypothesis, through new sampling and paleomagnetic analyses of Iron Age burnt huts, grain bins and kraals from South Africa, Zimbabwe and Botswana. Our preliminary analyses define a loop in the archeomagnetic curve for southern Africa between ca. 400 and 1000 AD, absent in predictions from available paleosecular variation models, that might record another flux expulsion episode.

  6. Southern Mozambique basin: most promising hydrocarbon province offshore eat Africa

    SciTech Connect

    De Buyl, M.; Flores, G.

    1984-09-01

    Recent offshore acquisition of 12,800 km (8,000 mi) of seismic reflection data, with gravity and magnetic profiles encompassing the southern half of the Mozambique basin, reveals new facets of the subsurface geology. Integrated interpretation of these new geophysical data with old well information results in the development of depositional and tectonic models that positively establish the hydrocarbon potential of the basin. The recent comprehensive interpretation affords the following conclusions. (1) Significant oil shows accompany wet gas discoveries suggest that the South Mozambique basin is a mature province, as the hydrocarbon associations imply thermogenic processes. (2) Super-Karoo marine Jurassic sequences have been encountered in Nhamura-1 well onshore from the application of seismic stratigraphy and well correlation. (3) Steeply dipping reflectors truncated by the pre-Cretaceous unconformity testify to significant tectonic activity preceding the breakup of Gondwanaland. Hence, preconceived ideas about the depth of the economic basement and the absence of mature source rocks of pre-Cretaceous age should be revised. (4) Wildcats in the vicinity of ample structural closures have not been, in retrospect, optimally positioned nor drilled to sufficient depth to test the viability of prospects mapped along a major offshore extension of the East African rift system delineated by this new survey.

  7. Novel genotype of Tritrichomonas foetus from cattle in Southern Africa.

    PubMed

    Casteriano, Andrea; Molini, Umberto; Kandjumbwa, Kornelia; Khaiseb, Siegfried; Frey, Caroline F; Šlapeta, Jan

    2016-12-01

    Bovine trichomonosis caused by Tritrichomonas foetus is a significant reproductive disease of cattle. Preputial samples were collected using sheath washing technique in bulls in Namibia. Thirty-six trichomonad cultures were characterized using the TaqMan-probe commercial real-time polymerase chain reaction (PCR) diagnostic assay (VetMAX™-Gold Trich Detection Kit) and CYBR real-time PCR assay based on TFR3/4 primers. Diagnostic real-time PCRs and DNA sequencing of the internal transcribed region confirmed presence of T. foetus in 35 out of 36 samples. Multilocus genotyping using cysteine proteases (CP1, CP2, CP4, CP5, CP6, CP7, CP8, CP9) and malate dehydrogenase (MDH1) gene sequences demonstrate that the T. foetus in Namibia are genetically distinct from those characterized elsewhere. We report the discovery of a novel genotype of T. foetus in Namibian cattle, distinct from other T. foetus genotypes in Europe, South and North America and Australia. We suggest recognition of a 'Southern African' genotype of T. foetus. Identification of the new genotype of T. foetus demonstrates the need for wider global sampling to fully understand the diversity and origin of T. foetus causing disease in cattle or cats.

  8. Ancient substructure in early mtDNA lineages of southern Africa.

    PubMed

    Barbieri, Chiara; Vicente, Mário; Rocha, Jorge; Mpoloka, Sununguko W; Stoneking, Mark; Pakendorf, Brigitte

    2013-02-07

    Among the deepest-rooting clades in the human mitochondrial DNA (mtDNA) phylogeny are the haplogroups defined as L0d and L0k, which are found primarily in southern Africa. These lineages are typically present at high frequency in the so-called Khoisan populations of hunter-gatherers and herders who speak non-Bantu languages, and the early divergence of these lineages led to the hypothesis of ancient genetic substructure in Africa. Here we update the phylogeny of the basal haplogroups L0d and L0k with 500 full mtDNA genome sequences from 45 southern African Khoisan and Bantu-speaking populations. We find previously unreported subhaplogroups and greatly extend the amount of variation and time-depth of most of the known subhaplogroups. Our major finding is the definition of two ancient sublineages of L0k (L0k1b and L0k2) that are present almost exclusively in Bantu-speaking populations from Zambia; the presence of such relic haplogroups in Bantu speakers is most probably due to contact with ancestral pre-Bantu populations that harbored different lineages than those found in extant Khoisan. We suggest that although these populations went extinct after the immigration of the Bantu-speaking populations, some traces of their haplogroup composition survived through incorporation into the gene pool of the immigrants. Our findings thus provide evidence for deep genetic substructure in southern Africa prior to the Bantu expansion that is not represented in extant Khoisan populations.

  9. Rainfall variability and extremes over southern Africa: assessment of a climate model to reproduce daily extremes

    NASA Astrophysics Data System (ADS)

    Williams, C.; Kniveton, D.; Layberry, R.

    2009-04-01

    It is increasingly accepted that that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability and the identification of rainfall extremes is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. The majority of previous climate model verification studies have compared model output with observational data at monthly timescales. In this research, the assessment of ability of a state of the art climate model to simulate climate at daily timescales is carried out using satellite derived rainfall data from the Microwave Infra-Red Algorithm (MIRA). This dataset covers the period from 1993-2002 and the whole of southern Africa at a spatial resolution of 0.1 degree longitude/latitude. The ability of a climate model to simulate current climate provides some indication of how much confidence can be applied to its future predictions. In this paper, simulations of current climate from the UK Meteorological Office Hadley Centre's climate model, in both regional and global mode, are firstly compared to the MIRA dataset at daily timescales. This concentrates primarily on the ability of the model to simulate the spatial and temporal patterns of rainfall variability over southern Africa. Secondly, the ability of the model to reproduce daily rainfall extremes will

  10. Climate change and maize yield in southern Africa: what can farm management do?

    PubMed

    Rurinda, Jairos; van Wijk, Mark T; Mapfumo, Paul; Descheemaeker, Katrien; Supit, Iwan; Giller, Ken E

    2015-12-01

    There is concern that food insecurity will increase in southern Africa due to climate change. We quantified the response of maize yield to projected climate change and to three key management options - planting date, fertilizer use and cultivar choice - using the crop simulation model, agricultural production systems simulator (APSIM), at two contrasting sites in Zimbabwe. Three climate periods up to 2100 were selected to cover both near- and long-term climates. Future climate data under two radiative forcing scenarios were generated from five global circulation models. The temperature is projected to increase significantly in Zimbabwe by 2100 with no significant change in mean annual total rainfall. When planting before mid-December with a high fertilizer rate, the simulated average grain yield for all three maize cultivars declined by 13% for the periods 2010-2039 and 2040-2069 and by 20% for 2070-2099 compared with the baseline climate, under low radiative forcing. Larger declines in yield of up to 32% were predicted for 2070-2099 with high radiative forcing. Despite differences in annual rainfall, similar trends in yield changes were observed for the two sites studied, Hwedza and Makoni. The yield response to delay in planting was nonlinear. Fertilizer increased yield significantly under both baseline and future climates. The response of maize to mineral nitrogen decreased with progressing climate change, implying a decrease in the optimal fertilizer rate in the future. Our results suggest that in the near future, improved crop and soil fertility management will remain important for enhanced maize yield. Towards the end of the 21st century, however, none of the farm management options tested in the study can avoid large yield losses in southern Africa due to climate change. There is a need to transform the current cropping systems of southern Africa to offset the negative impacts of climate change.

  11. Outcomes of infants starting antiretroviral therapy in Southern Africa, 2004-2012

    PubMed Central

    Porter, Mireille; Davies, Mary-Ann; Mapani, Muntanga K.; Rabie, Helena; Phiri, Sam; Nuttall, James; Fairlie, Lee; Technau, Karl-Günter; Stinson, Kathryn; Wood, Robin; Wellington, Maureen; Haas, Andreas D.; Giddy, Janet; Tanser, Frank; Eley, Brian

    2015-01-01

    Background There is limited published data on the outcomes of infants starting antiretroviral therapy (ART) in routine care in Southern Africa. This study aimed to examine the baseline characteristics and outcomes of infants initiating ART. Methods We analysed prospectively collected cohort data from routine ART initiation in infants from 11 cohorts contributing to the International Epidemiologic Database to Evaluate AIDS in Southern Africa. We included ART naïve HIV-infected infants <12 months of age initiating ≥ three antiretroviral drugs between 2004 and 2012. Kaplan-Meier estimates were calculated for mortality, loss to follow-up (LTFU), transfer out and virological suppression. We used Cox Proportional Hazards models stratified by cohort to determine baseline characteristics associated with outcomes mortality and virological suppression. Results The median (interquartile range) age at ART initiation of 4945 infants was 5.9 months (3.7-8.7) with follow-up of 11.2 months (2.8-20.0). At ART initiation 77% had WHO clinical stage 3 or 4 disease and 87% were severely immunosuppressed. Three-year mortality probability was 16% and LTFU 29%. Severe immunosuppression, WHO stage 3 or 4, anaemia, being severely underweight and initiation of treatment before 2010 were associated with higher mortality. At 12 months after ART initiation 17% of infants were severely immunosuppressed and the probability of attaining virological suppression was 56%. Conclusion Most infants initiating ART in Southern Africa had severe disease with high probability of LTFU and mortality on ART. Although the majority of infants remaining in care showed immune recovery and virological suppression, these responses were suboptimal. PMID:26167620

  12. 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.

  13. Biology and genetics of oculocutaneous albinism and vitiligo - common pigmentation disorders in southern Africa.

    PubMed

    Manga, Prashiela; Kerr, Robyn; Ramsay, Michèle; Kromberg, Jennifer G R

    2013-07-29

    Pigmentation disorders span the genetic spectrum from single-gene autosomal recessive disorders such as oculocutaneous albinism (OCA), the autosomal dominant disorder piebaldism to X-linked ocular albinism and multifactorial vitiligo. OCA connotes a group of disorders that result in hypopigmented skin due to decreased melanin production in melanocytes and loss of visual acuity. There are four non-syndromic forms, OCA1-4, which are classified based on the gene that is mutated (tyrosinase, OCA2, tyrosinase-related protein 1 and SLC45A2, respectively). Despite the fact that multiple genes account for the various forms of OCA, the phenotypes of all four forms result from disruption in the maturation and trafficking of the enzyme tyrosinase. OCA2 is the most prevalent autosomal recessive disorder among southern African blacks, affecting 1/3 900 individuals; while OCA3, although rare, is most prevalent in southern Africa. Another common pigmentation disorder in southern Africa is vitiligo, which affects 1 - 2% of people worldwide. Vitiligo is a complex, acquired disorder in which melanocytes are destroyed due to an autoimmune response. The aetiology underlying this disorder is poorly understood, although recent genetic association studies have begun to shed light on the contributing factors. Pigmentation disorders have significant psychosocial implications and co-morbidities, yet therapies are still lacking. Recent progress in our understanding of the pathobiology of both albinism and vitiligo may herald novel treatment strategies for these disorders. 

  14. Cultural Diffusion Was the Main Driving Mechanism of the Neolithic Transition in Southern Africa

    PubMed Central

    Jerardino, Antonieta; Fort, Joaquim; Isern, Neus; Rondelli, Bernardo

    2014-01-01

    It is well known that the Neolithic transition spread across Europe at a speed of about 1 km/yr. This result has been previously interpreted as a range expansion of the Neolithic driven mainly by demic diffusion (whereas cultural diffusion played a secondary role). However, a long-standing problem is whether this value (1 km/yr) and its interpretation (mainly demic diffusion) are characteristic only of Europe or universal (i.e. intrinsic features of Neolithic transitions all over the world). So far Neolithic spread rates outside Europe have been barely measured, and Neolithic spread rates substantially faster than 1 km/yr have not been previously reported. Here we show that the transition from hunting and gathering into herding in southern Africa spread at a rate of about 2.4 km/yr, i.e. about twice faster than the European Neolithic transition. Thus the value 1 km/yr is not a universal feature of Neolithic transitions in the world. Resorting to a recent demic-cultural wave-of-advance model, we also find that the main mechanism at work in the southern African Neolithic spread was cultural diffusion (whereas demic diffusion played a secondary role). This is in sharp contrast to the European Neolithic. Our results further suggest that Neolithic spread rates could be mainly driven by cultural diffusion in cases where the final state of this transition is herding/pastoralism (such as in southern Africa) rather than farming and stockbreeding (as in Europe). PMID:25517968

  15. Cultural diffusion was the main driving mechanism of the Neolithic transition in southern Africa.

    PubMed

    Jerardino, Antonieta; Fort, Joaquim; Isern, Neus; Rondelli, Bernardo

    2014-01-01

    It is well known that the Neolithic transition spread across Europe at a speed of about 1 km/yr. This result has been previously interpreted as a range expansion of the Neolithic driven mainly by demic diffusion (whereas cultural diffusion played a secondary role). However, a long-standing problem is whether this value (1 km/yr) and its interpretation (mainly demic diffusion) are characteristic only of Europe or universal (i.e. intrinsic features of Neolithic transitions all over the world). So far Neolithic spread rates outside Europe have been barely measured, and Neolithic spread rates substantially faster than 1 km/yr have not been previously reported. Here we show that the transition from hunting and gathering into herding in southern Africa spread at a rate of about 2.4 km/yr, i.e. about twice faster than the European Neolithic transition. Thus the value 1 km/yr is not a universal feature of Neolithic transitions in the world. Resorting to a recent demic-cultural wave-of-advance model, we also find that the main mechanism at work in the southern African Neolithic spread was cultural diffusion (whereas demic diffusion played a secondary role). This is in sharp contrast to the European Neolithic. Our results further suggest that Neolithic spread rates could be mainly driven by cultural diffusion in cases where the final state of this transition is herding/pastoralism (such as in southern Africa) rather than farming and stockbreeding (as in Europe).

  16. Socio-epidemiological Aspects of Respiratory Allergic Diseases in Southern Africa

    PubMed Central

    Taborda-Barata, Luís

    2012-01-01

    Abstract The prevalence of respiratory allergic diseases has been increasing in Southern Africa both in urban and in rural environments. Various factors may contribute toward this situation, namely, exposure to aeroallergens, such as grass pollens and house dust mites. However, other irritant environmental triggers, such as exposure to tobacco smoke and certain indoor and outdoor fumes, may also play a relevant part. Furthermore, certain parasitic and mycobacterial infections may act as allergic disease risk modifiers, although such an influence should be confirmed. Finally, certain cultural and socioeconomic factors may also influence accessibility to healthcare and adherence to treatment of these diseases. PMID:23268464

  17. Cantharidin and demethylcantharidin (palasonin) content of blister beetles (Coleoptera: Meloidae) from southern Africa.

    PubMed

    Mebs, Dietrich; Pogoda, Werner; Schneider, Michael; Kauert, Gerold

    2009-03-15

    In two species of meloid beetles, Hycleus oculatus and Hycleus tinctus, from southern Africa, cantharidin and demethylcantharidin (palasonin) were assayed quantitatively. For cantharidin the mean value per specimen was about 1 mg for H. oculatus and 0.2 mg for H. tinctus, the mean palasonin concentration was 20 (H. oculatus) and 12 times (H. tinctus) lower, respectively. However, considerable individual variation in the cantharidin concentration was observed and values of more than 6 mg of this compound per beetle were measured pointing to the high risk of severe and even fatal poisoning when ingesting these insects.

  18. Assessment of a climate model to reproduce rainfall variability and extremes over Southern Africa

    NASA Astrophysics Data System (ADS)

    Williams, C. J. R.; Kniveton, D. R.; Layberry, R.

    2010-01-01

    It is increasingly accepted that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The sub-continent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability and the identification of rainfall extremes is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. The majority of previous climate model verification studies have compared model output with observational data at monthly timescales. In this research, the assessment of ability of a state of the art climate model to simulate climate at daily timescales is carried out using satellite-derived rainfall data from the Microwave Infrared Rainfall Algorithm (MIRA). This dataset covers the period from 1993 to 2002 and the whole of southern Africa at a spatial resolution of 0.1° longitude/latitude. This paper concentrates primarily on the ability of the model to simulate the spatial and temporal patterns of present-day rainfall variability over southern Africa and is not intended to discuss possible future changes in climate as these have been documented elsewhere. Simulations of current climate from the UK Meteorological Office Hadley Centre's climate model, in both regional and global mode, are firstly compared to the MIRA dataset at daily timescales. Secondly, the ability of the model to reproduce daily rainfall extremes is assessed, again by a comparison with

  19. Interpretation of Nimbus-7 37 GHz microwave brightness temperature data in semi-arid southern Africa

    NASA Technical Reports Server (NTRS)

    Prince, S. D.; Choudhury, B. J.

    1989-01-01

    Monthly 37 GHz microwave polarization difference temperatures (MPDT) derived from the Nimbus-7 scanning multichannel microwave radiometer (SMMR) for southern Africa from 1979 to 1985 are compared with rainfall and Advanced Very High Resolution Radiometer (AVHRR) normalized difference vegetation index (NDVI) data. MPDT rose sharply during a drought episode which occurred within the period included in the data. The rise was seen not only in the growing season, but also in the dry season MPDT when no actively photosynthetic, water-containing leaves are present. The results suggest that scattering of the emitted microwave radiation by dead and living vegetation is a more important factor than has previously been recognized.

  20. Theoretical Perspectives on Gender in Education: The Case of Eastern and Southern Africa

    NASA Astrophysics Data System (ADS)

    Mannathoko, Changu

    1999-11-01

    In recent years, throughout Eastern and Southern Africa, there has been a proliferation of research on gender in education. It is possible to point to a wide variety of publications, courses and programmes planned and organized by universities, national governments, international organizations, non-governmental organizations and the private sector relating to this field. This article examines the feminist and gender theories underpinning all these endeavors. The theories are assessed for their potential capacity to assist in elucidating the complex relationship between gender and development within the region.

  1. Big Sugar in southern Africa: rural development and the perverted potential of sugar/ethanol exports.

    PubMed

    Richardson, Ben

    2010-01-01

    This paper asks how investment in large-scale sugar cane production has contributed, and will contribute, to rural development in southern Africa. Taking a case study of the South African company Illovo in Zambia, the argument is made that the potential for greater tax revenue, domestic competition, access to resources and wealth distribution from sugar/ethanol production have all been perverted and with relatively little payoff in wage labour opportunities in return. If the benefits of agro-exports cannot be so easily assumed, then the prospective 'balance sheet' of biofuels needs to be re-examined. In this light, the paper advocates smaller-scale agrarian initiatives.

  2. Oil and gas developments in central and southern Africa in 1981

    SciTech Connect

    McGrew, H.J.

    1982-11-01

    Exploratory activity in central and southern Africa continued to grow during 1981. Geophysical operations reached nearly record levels and the number of wells increased markedly. Oil production suffered from the adverse conditions that existed throughout the world and dropped by a significant amount. New Concession acquisitions occurred in several of the countries in northeast Africa. Elsewhere, the operating companies negotiated new concessions and renewed those that were expiring. In several countries where production has been proven, the operators were assigned exploitation concessions. Seismic crews and marine geophysical vessels were active throughout the countries in this area. A total of 365 party-months of work was done to yield 98,035 km of new lines. A moderate amount of 3-D recording was carried out in connection with field development. Some aeromagnetic work was done, principally in northeast Africa and in Mozambique. Forty-four new fields or pools were discovered by drilling 115 new-field wildcat and exploratory wells. These wells accounted for 1,060,254 ft (323,248 m) of hole. Appraisal and development drilling resulted in 321 wells with a total of 2,533,305 ft (772,349 m) of hole drilled. At year end, 25 exploratory wells were under way or resting, and 49 rigs were active in development drilling. Oil production for the year was 691,995,939 bbl, a decrease of nearly 25% from 1980. Nigeria suffered the greatest drop in production; however, increases were achieved in Cameroon, Congo, and Zaire. The cumulative production from this part of Africa passed the 10 billion bbl mark.

  3. Coexisting shortening and extension along the "Africa-Eurasia" plate boundary in southern Italy

    NASA Astrophysics Data System (ADS)

    Cuffaro, M.; Riguzzi, F.; Scrocca, D.; Doglioni, C.

    2009-04-01

    We performed geodetic strain rate field analyses along the "Africa (Sicily microplate)"-"Eurasia (Tyrrhenian microplate)" plate boundary in Sicily (southern Italy), using new GPS velocities from a data set spanning maximum ten years (1998-2007). Data from GPS permanent stations maintained from different institutions and the recent RING network, settled in Italy in the last five years by the Istituto Nazionale di Geofisica e Vulcanologia, were included into the analysis. Two dimensional strain and rotation rate fields were estimated by the distance weighted approach on a regularly spaced grid (30*30km), estimating the strain using all stations, but data from each station are weighted by their distance from the grid node by a constant a=70km that specifies how the effect of a station decays with distance from the node grid interpolation. Results show that most of the shortening of the Africa-Eurasia relative motion is distributed in the northwestern side offshore Sicily, whereas the extension becomes comparable with shortening on the western border of the Capo d'Orlando basin, and grater in the northeastern side, offshore Sicily, as directly provided by GPS velocities which show a larger E-ward component of sites located in Calabria with respect to those located either in northern Sicily or in the Ustica-Aeolian islands. Moreover, where shortening and extension have mostly a similar order of magnitude, two rotation rate fields can be detected, CCW in the northwestern side of Sicily, and CW in the northeastern one respectively. Also, 2-D dilatation field records a similar pattern, with negative values (shortening) in the northwestern area of Sicily close to the Ustica island, and positive values (extension) in the northeastern and southeastern ones, respectively. Principal shortening and extension rate axes are consistent with long-term geological features: seismic reflection profiles acquired in the southern Tyrrhenian seismogenic belt show active extensional faults

  4. Out of southern Africa: Origin, biogeography and age of the Aizooideae (Aizoaceae).

    PubMed

    Klak, Cornelia; Hanáček, Pavel; Bruyns, Peter V

    2017-04-01

    The Aizooideae is an early-diverging lineage within the Aizoaceae. It is most diverse in southern Africa, but also has endemic species in Australasia, Eurasia and South America. We derived a phylogenetic hypothesis from Bayesian and Maximum Likelihood analyses of plastid DNA-sequences. We find that one of the seven genera, the fynbos-endemic Acrosanthes, does not belong to the Aizooideae, but is an ancient sister-lineage to the subfamilies Mesembryanthemoideae & Ruschioideae. Galenia and Plinthus are embedded inside Aizoon and Aizoanthemum is polyphyletic. The Namibian endemic Tetragonia schenckii is sister to Tribulocarpus of the Sesuvioideae. For the Aizooideae, we explored their possible age by means of relaxed Bayesian dating and used Bayesian Binary MCMC reconstruction of ancestral areas to investigate their area of origin. Early diversification occurred in southern Africa in the Eocene-Oligocene, with a split into a mainly African lineage and an Eurasian-Australasian-African-South American lineage. These subsequently radiated in the early Miocene. For Tetragonia, colonisation of Australasia via long-distance dispersal from Eurasia gave rise to the Australasian lineage from which there were subsequent dispersals to South America and Southern Africa. Despite the relatively old age of the Aizooideae, more than half the species have radiated since the Pleiocene, coinciding with the large and rapid diversification of the Ruschioideae. The lineage made up of Tetragonia schenckii &Tribulocarpus split from the remainder of the Sesuvioideae already in the mid Oligocene and its disjunct distribution between Namibia and north-east Africa may be the result of a previously wider distribution within an early Arid African flora. Our reconstruction of ancestral character-states indicates that the expanding keels giving rise to hygrochastic fruits originated only once, i.e. after the split of the Sesuvioideae from the remainder of the Aizoaceae and that they were subsequently

  5. Distributions of Trace Gases and Aerosols during the Dry Biomass Burning Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Sinha, Parikhit; Hobbs, Peter V.; Yokelson, Robert J.; Blake, Donald R.; Gao, Song; Kirchstetter, Thomas W.

    2003-01-01

    Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO2), ozone (O3), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO2), CO, methane (CH4), O3, black particulate carbon, and total particulate carbon were in the Botswana and Zambia sectors (388 and 392 ppmv, 369 and 453 ppbv, 1753 and 1758 ppbv, 79 and 88 ppbv, 2.6 and 5.5 micrograms /cubic meter and 13.2 and 14.3 micrograms/cubic meter). This was due to intense biomass burning in Zambia and surrounding regions. The South Africa sector had the highest average concentrations of SO2, sulfate particles, and CN (5.1 ppbv, 8.3 micrograms/cubic meter, and per 6400 cubic meter , respectively), which derived from biomass burning and electric generation plants and mining operations within this sector. Air quality in the Mozambique sector was similar to the neighboring South Africa sector. Over the arid Namibia sector there were polluted layers aloft, in which average SO2, O3, and CO mixing ratios (1.2 ppbv, 76 ppbv, and 3 10 ppbv, respectively) were similar to those measured over the other more polluted sectors. This was due to transport of biomass smoke from regions of widespread savanna burning in southern Angola. Average concentrations over all sectors of CO2 (386 +/- 8 ppmv), CO (261 +/- 81 ppbv), SO2 (2.5 +/- 1.6 ppbv), O3 (64 +/- 13 ppbv), black particulate carbon (2.3 +/- 1.9 microgram/cubic meter), organic particulate carbon (6.2 +/- 5.2 microgram/cubic meter), total particle mass (26.0 +/- 4.7 microgram/cubic meter), and potassium particles (0

  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.

  7. Late Quaternary dietary shifts of the Cape grysbok ( Raphicerus melanotis) in southern Africa

    NASA Astrophysics Data System (ADS)

    Faith, J. Tyler

    2011-01-01

    The Cape grysbok is endemic to southern Africa's Cape Floral Region where it selectively browses various species of dicotyledonous vegetation. Fossil evidence indicates that the grysbok persisted under glacial and interglacial conditions throughout the late Quaternary and inhabited a range of environments. This study employs mesowear analysis to reconstruct grysbok diets over time and in response to changing environments at Nelson Bay Cave, Die Kelders Cave 1, Klasies River Mouth, and Swartklip 1. Results indicate that the amount of grasses (monocots) versus leafy vegetation (dicots) included in the diet fluctuated over time and largely in agreement with changes in faunal community structure. The case for dietary flexibility is particularly clear at Nelson Bay Cave, where there is a significant trend from mixed feeding towards increased browsing from the late Pleistocene (~ 18,500 14C yr BP) through the Holocene. Dietary shifts at Nelson Bay Cave are consistent with the hypothesis that declining grassland productivity is responsible for the terminal Pleistocene extinction of several large ungulates in southern Africa. Furthermore, the short-term dietary shifts demonstrated here (100s to 1000s of years) provide an important caution against relying on taxonomic uniformitarianism when reconstructing the dietary preferences of fossil ungulates, both extant and extinct.

  8. The SASSCAL contribution to climate observation, climate data management and data rescue in Southern Africa

    NASA Astrophysics Data System (ADS)

    Kaspar, F.; Helmschrot, J.; Mhanda, A.; Butale, M.; de Clercq, W.; Kanyanga, J. K.; Neto, F. O. S.; Kruger, S.; Castro Matsheka, M.; Muche, G.; Hillmann, T.; Josenhans, K.; Posada, R.; Riede, J.; Seely, M.; Ribeiro, C.; Kenabatho, P.; Vogt, R.; Jürgens, N.

    2015-07-01

    A major task of the newly established "Southern African Science Service Centre for Climate Change and Adaptive Land Management" (SASSCAL; www.sasscal.org) and its partners is to provide science-based environmental information and knowledge which includes the provision of consistent and reliable climate data for Southern Africa. Hence, SASSCAL, in close cooperation with the national weather authorities of Angola, Botswana, Germany and Zambia as well as partner institutions in Namibia and South Africa, supports the extension of the regional meteorological observation network and the improvement of the climate archives at national level. With the ongoing rehabilitation of existing weather stations and the new installation of fully automated weather stations (AWS), altogether 105 AWS currently provide a set of climate variables at 15, 30 and 60 min intervals respectively. These records are made available through the SASSCAL WeatherNet, an online platform providing near-real time data as well as various statistics and graphics, all in open access. This effort is complemented by the harmonization and improvement of climate data management concepts at the national weather authorities, capacity building activities and an extension of the data bases with historical climate data which are still available from different sources. These activities are performed through cooperation between regional and German institutions and will provide important information for climate service related activities.

  9. Density heterogeneity of the cratonic mantle and dynamic topography in southern Africa

    NASA Astrophysics Data System (ADS)

    Artemieva, Irina; Vinnik, Lev

    2016-04-01

    An unusually high topography in southern Africa may be caused by the dynamic support of the mantle below the lithosphere base and/or by a low density (high depletion) of the cratonic lithospheric mantle. We use free-board constraints to examine the relative contributions of the both factors to surface topography and present the model of density structure of the lithospheric mantle in southern Africa. The results indicate that 0.5-1.0 km of topography requires contribution from the sublithospheric mantle because it cannot be explained by the lithosphere structure within the petrologically permitted range of mantle densities. We propose that this additional topography may be associated with the low-density region below the depth of isostatic compensation (LAB). A likely candidate is the low velocity layer between the lithospheric base and the mantle transition zone, where a temperature anomaly of 100-200 deg may produce the required extra contribution to regional topographic uplift. The calculated lithospheric mantle density values are in an overall agreement with xenolith-based data for lithospheric terranes of different ages and show an overall trend in mantle density increase from Archean to younger lithospheric terranes. A significant anomaly in mantle depletion beneath the Limpopo belt and the Bushveld Complex may result from regional melt-metasomatism. Density anomalies in the lithospheric mantle show an overall inverse correlation with seismic Vp, Vs velocities at 100-150 km depth; however, density-velocity relationship is strongly non-unique. Manuscripts in revision, Gondwana Research (2016)

  10. The Arabian cradle: mitochondrial relicts of the first steps along the southern route out of Africa.

    PubMed

    Fernandes, Verónica; Alshamali, Farida; Alves, Marco; Costa, Marta D; Pereira, Joana B; Silva, Nuno M; Cherni, Lotfi; Harich, Nourdin; Cerny, Viktor; Soares, Pedro; Richards, Martin B; Pereira, Luísa

    2012-02-10

    A major unanswered question regarding the dispersal of modern humans around the world concerns the geographical site of the first human steps outside of Africa. The "southern coastal route" model predicts that the early stages of the dispersal took place when people crossed the Red Sea to southern Arabia, but genetic evidence has hitherto been tenuous. We have addressed this question by analyzing the three minor west-Eurasian haplogroups, N1, N2, and X. These lineages branch directly from the first non-African founder node, the root of haplogroup N, and coalesce to the time of the first successful movement of modern humans out of Africa, ∼60 thousand years (ka) ago. We sequenced complete mtDNA genomes from 85 Southwest Asian samples carrying these haplogroups and compared them with a database of 300 European examples. The results show that these minor haplogroups have a relict distribution that suggests an ancient ancestry within the Arabian Peninsula, and they most likely spread from the Gulf Oasis region toward the Near East and Europe during the pluvial period 55-24 ka ago. This pattern suggests that Arabia was indeed the first staging post in the spread of modern humans around the world.

  11. Balancing livestock production and wildlife conservation in and around southern Africa's transfrontier conservation areas.

    PubMed

    Thomson, G R; Penrith, M-L; Atkinson, M W; Atkinson, S J; Cassidy, D; Osofsky, S A

    2013-12-01

    Biodiversity conservation, of which the transfrontier conservation area movement is an integral part, and more effective livestock production/trade are pivotal to future rural development in southern Africa. For that reason, it is imperative to effectively ameliorate the obstacles that have impeded progress towards the coexistence of these two sectors for more than half a century. Transboundary animal diseases, foot and mouth disease in particular, have been and continue to be the most important of these obstacles. Fortunately, new developments in international sanitary standards applicable to trade in commodities and products derived from animals are beginning to make a solution possible. However, while progress in principle has been achieved, practical implementation remains problematic for technical reasons, exacerbated by inconsistent attitudes towards acceptance of non-traditional international trade standards. This paper describes the background to this situation, progress that has been achieved in the recent past and remaining difficulties that need to be overcome to advance towards achievement of balanced rural development in southern Africa.

  12. Epidemiological Trends for HIV in Southern Africa: Implications for Reaching the Elimination Targets.

    PubMed

    Williams, Brian G; Gouws, Eleanor; Somse, Pierre; Mmelesi, Mpho; Lwamba, Chibwe; Chikoko, Trouble; Fazito, Erika; Turay, Mohamed; Kiwango, Eva; Chikukwa, Pepukai; Damisoni, Henry; Gboun, Michael

    2015-06-01

    Southern Africa is the region worst affected by HIV in the world and accounts for one third of the global burden of HIV. Achieving the UNAIDS 90-90-90 target by 2020 and ending the AIDS epidemic by 2030 depend on success in this region. We review epidemiological trends in each country in southern Africa with respect to the prevalence, incidence, mortality, coverage of anti-retroviral therapy (ART) and TB notification rates, to better understand progress in controlling HIV and TB and to determine what needs to be done to reach the UNAIDS targets. Significant progress has been made in controlling HIV. In all countries in the region, the prevalence of HIV in people not on ART, the incidence of HIV, AIDS-related mortality and, in most countries, TB notification rates, are falling. In some countries, the risk of infection began to fall before biomedical interventions such as ART became widely available as a result of effective prevention measures or people's awareness of, and response to, the epidemic but the reasons for these declines remain uncertain. Some countries have achieved better levels of ART coverage than others, but all are in a position to reach the 2020 and 2030 targets if they accelerate the roll-out of ART and of targeted prevention efforts. Achieving the HIV treatment targets will further reduce the incidence of HIV-related TB, but efforts to control TB in HIV-negative people must be improved and strengthened.

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

    NASA Astrophysics Data System (ADS)

    Adler, Bianca; Kalthoff, Norbert; Gantner, Leonhard

    2017-01-01

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

  14. Local biomass burning is a dominant cause of the observed precipitation reduction in southern Africa

    PubMed Central

    Hodnebrog, Øivind; Myhre, Gunnar; Forster, Piers M.; Sillmann, Jana; Samset, Bjørn H.

    2016-01-01

    Observations indicate a precipitation decline over large parts of southern Africa since the 1950s. Concurrently, atmospheric concentrations of greenhouse gases and aerosols have increased due to anthropogenic activities. Here we show that local black carbon and organic carbon aerosol emissions from biomass burning activities are a main cause of the observed decline in southern African dry season precipitation over the last century. Near the main biomass burning regions, global and regional modelling indicates precipitation decreases of 20–30%, with large spatial variability. Increasing global CO2 concentrations further contribute to precipitation reductions, somewhat less in magnitude but covering a larger area. Whereas precipitation changes from increased CO2 are driven by large-scale circulation changes, the increase in biomass burning aerosols causes local drying of the atmosphere. This study illustrates that reducing local biomass burning aerosol emissions may be a useful way to mitigate reduced rainfall in the region. PMID:27068129

  15. 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

  16. History and origin of the HIV-1 subtype C epidemic in South Africa and the greater southern African region.

    PubMed

    Wilkinson, Eduan; Engelbrecht, Susan; de Oliveira, Tulio

    2015-11-17

    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.

  17. Climate co-variability between South America and Southern Africa at interannual, intraseasonal and synoptic scales

    NASA Astrophysics Data System (ADS)

    Puaud, Yohan; Pohl, Benjamin; Fauchereau, Nicolas; Macron, Clémence; Beltrando, Gérard

    2016-08-01

    This paper investigates and quantifies co-variability between large-scale convection in the South American and Southern African sectors at different timescales (interannual, intraseasonal and synoptic), during the austral summer seasons (November-February) from 1979 to 2012. Multivariate analyses (Canonical Correlation Analysis and Principal Component Analysis) are applied to daily outgoing longwave radiation (OLR, used as a proxy for atmospheric convection) anomalies to extract the principal modes of variability and co-variability in each and between both regions, filtered to consider the appropriate time-scales. At the interannual timescale, results confirm the predominant role of El Niño Southern Oscillation (ENSO), favoring enhanced convection over both southeastern Brazil and northern Argentina on the one hand, and tropical Africa and the western Indian Ocean on the other hand. At the intraseasonal timescale, the leading mode of co-variability is related to modulations of large-scale atmospheric convection over most of South America, and 10 days later, tropical Southern Africa. This mode accounts for the impacts of the Madden-Julian-oscillation (MJO) over these regions: identifying robust co-variability at the intraseasonal timescale between both regions require thus to consider a temporal shift between the two sectors. At the synoptic scale, however, co-variability consists mostly of a synchronous modulation of the large-scale atmospheric convection over the South American and Southern African sectors. This results from the development of concomitant Rossby waves forming a continuous wave train over the South Atlantic in the mid-latitudes, affecting both the South Atlantic and South Indian Convergence Zones. Among the days when convection shows significant anomalies (30 % of the total days in each sector), this synchronous mode occurs about 25 % of the time, individual Rossby waves modulating convection over one single region only during the remaining 75

  18. Sustained High HIV Incidence in Young Women in Southern Africa: Social, Behavioral and Structural Factors and Emerging Intervention Approaches

    PubMed Central

    Harrison, Abigail; Colvin, Christopher J.; Kuo, Caroline; Swartz, Alison; Lurie, Mark

    2015-01-01

    Young women in southern Africa experience some of the highest incidence rates of HIV infection in the world. Across southern Africa, HIV prevalence among women increases rapidly between the teenage years and young adulthood. Adult HIV prevalence is 16.8 percent in South Africa, 23 percent in Botswana, 23 percent in Lesotho and 26.5 percent in Swaziland. Existing research has illuminated some of the key social, behavioral and structural factors associated with young women's disproportionate HIV risk, including gendered social norms that advantage male power in sexual relationships, and age disparities in relationships between younger women and older male partners. Important structural factors include the region's history of labor migration and legacy of family disruption, and entrenched social and economic inequalities. New interventions are emerging to address these high levels of HIV risk in the key population of young women, including structural interventions, biomedical prevention such as PrEP, and combined HIV prevention approaches. PMID:25855338

  19. Sustained High HIV Incidence in Young Women in Southern Africa: Social, Behavioral, and Structural Factors and Emerging Intervention Approaches.

    PubMed

    Harrison, Abigail; Colvin, Christopher J; Kuo, Caroline; Swartz, Alison; Lurie, Mark

    2015-06-01

    Young women in southern Africa experience some of the highest incidence rates of HIV infection in the world. Across southern Africa, HIV prevalence among women increases rapidly between the teenage years and young adulthood. Adult HIV prevalence is 16.8 % in South Africa, 23 % in Botswana, 23 % in Lesotho, and 26.5 % in Swaziland. Existing research has illuminated some of the key social, behavioral, and structural factors associated with young women's disproportionate HIV risk, including gendered social norms that advantage male power in sexual relationships and age disparities in relationships between younger women and older male partners. Important structural factors include the region's history of labor migration and legacy of family disruption, and entrenched social and economic inequalities. New interventions are emerging to address these high levels of HIV risk in the key population of young women, including structural interventions, biomedical prevention such as PrEP, and combined HIV prevention approaches.

  20. Vernonieae (Asteraceae) of southern Africa: A generic disposition of the species and a study of their pollen

    PubMed Central

    Robinson, Harold; Skvarla, John J.; Funk, Vicki A.

    2016-01-01

    Abstract Current and previously included members of the Tribe Vernonieae (Asteraceae) of southern Africa are listed in their presently recognized genera with complete synonymies and keys to genera and species. The genus Vernonia, as presently delimited, does not occur in Africa. Genera of the Vernonieae presently recognized from southern Africa are Baccharoides, Bothriocline, Cyanthillium, Distephanus, Erlangea, Ethulia, Gymnanthemum, Hilliardiella, Oocephala, Orbivestus, Parapolydora, Polydora, Vernonella, Vernoniastrum, plus two genera that are named as new: Namibithamnus and Pseudopegolettia. Twelve new combinations are provided and two species, Vernonia potamiphila and Vernonia collinii Klatt., hom. illeg., remain unplaced because of a lack of material. Pollen types are illustrated including previously recognized types: non-lophate, sublophate, tricolporate lophate, and non-colpate triporate lophate. A type previously unknown in the Asteraceae is described here and in a separate paper for Oocephala and Polydora; a non-colpate pantoporate lophate type with pores not strictly equatorial. PMID:27081344

  1. 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.

  2. Diversity and biogeographical patterns of legumes (Leguminosae) indigenous to southern Africa

    PubMed Central

    Trytsman, Marike; Westfall, Robert H.; Breytenbach, Philippus J. J.; Calitz, Frikkie J.; van Wyk, Abraham E.

    2016-01-01

    Abstract The principal aim of this study was to establish biogeographical patterns in the legume flora of southern Africa so as to facilitate the selection of species with agricultural potential. Plant collection data from the National Herbarium, South Africa, were analysed to establish the diversity and areas covered by legumes (Leguminosae/Fabaceae) indigenous to South Africa, Lesotho and Swaziland. A total of 27,322 records from 1,619 quarter degree grid cells, representing 1,580 species, 122 genera and 24 tribes were included in the analyses. Agglomerative hierarchical clustering was applied to the presence or absence of legume species in quarter degree grid cells, the resultant natural biogeographical regions (choria) being referred to as leguminochoria. The description of the 16 uniquely formed leguminochoria focuses on defining the associated bioregions and biomes, as well as on the key climate and soil properties. Legume species with a high occurrence in a leguminochorion are listed as key species. The dominant growth form of key species, species richness and range within each leguminochorion is discussed. Floristic links between the leguminochoria are established, by examining and comparing key species common to clusters, using a vegetation classification program. Soil pH and mean annual minimum temperature were found to be the main drivers for distinguishing among legume assemblages. This is the first time that distribution data for legumes has been used to identify biogeographical areas covered by leguminochoria on the subcontinent. One potential application of the results of this study is to assist in the selection of legumes for pasture breeding and soil conservation programs, especially in arid and semi-arid environments. PMID:27829799

  3. Effects of Humidity on Aerosols in Southern Africa during the Biomass Burning Season

    NASA Technical Reports Server (NTRS)

    Magi, Brian I.; Hobbs, Peter V.

    2003-01-01

    Measurements of the aerosol total light scattering coefficient, asp, and the aerosol hemispheric backscatter ratio, p(1), as functions of relative humidity (RH in %) (so-called humidographs) at three wavelengths (450,550, and 700 nm) were obtained in the dry season in southern Africa (1) in ambient air in South Africa, Botswana, Mozambique and Zambia, (2) at various distances downwind in identifiable smoke plumes from biomass fires, and (3) along the southwest coast of Africa. The ratio of sigma(sub sp) at an RH of 80% to that at 30% provides a measure of the effects of RH on sigma(sub sp), and similarly for Beta(1). For the three broad sampling categories given above, and at a wavelength of 550 nm, these ratios varied from 1.42 +/- 0.05 to 2.07 +/- 0.03 for sigma(sub sp), and from 0.69 +/- 0.05 to 0.99 +/- 0.14 for Beta(1). In general, humidographs for the ambient air samples showed a greater dependence on RH than those for smoke from identifiable biomass fires. During a period when dense, aged smoke was transported to the region from the north, the humidographs for sigma(sub sp) for ambient air samples were similar to those for identifiable smoke plume samples just approximately 10- to 50-min old. This suggests that as far as the effects of RH on sigma(sub sp) are concerned the effects of aging of smoke and its mixing with ambient air are realized within less than about an hour.

  4. Diversity and biogeographical patterns of legumes (Leguminosae) indigenous to southern Africa.

    PubMed

    Trytsman, Marike; Westfall, Robert H; Breytenbach, Philippus J J; Calitz, Frikkie J; van Wyk, Abraham E

    2016-01-01

    The principal aim of this study was to establish biogeographical patterns in the legume flora of southern Africa so as to facilitate the selection of species with agricultural potential. Plant collection data from the National Herbarium, South Africa, were analysed to establish the diversity and areas covered by legumes (Leguminosae/Fabaceae) indigenous to South Africa, Lesotho and Swaziland. A total of 27,322 records from 1,619 quarter degree grid cells, representing 1,580 species, 122 genera and 24 tribes were included in the analyses. Agglomerative hierarchical clustering was applied to the presence or absence of legume species in quarter degree grid cells, the resultant natural biogeographical regions (choria) being referred to as leguminochoria. The description of the 16 uniquely formed leguminochoria focuses on defining the associated bioregions and biomes, as well as on the key climate and soil properties. Legume species with a high occurrence in a leguminochorion are listed as key species. The dominant growth form of key species, species richness and range within each leguminochorion is discussed. Floristic links between the leguminochoria are established, by examining and comparing key species common to clusters, using a vegetation classification program. Soil pH and mean annual minimum temperature were found to be the main drivers for distinguishing among legume assemblages. This is the first time that distribution data for legumes has been used to identify biogeographical areas covered by leguminochoria on the subcontinent. One potential application of the results of this study is to assist in the selection of legumes for pasture breeding and soil conservation programs, especially in arid and semi-arid environments.

  5. Transitioning HIV care and treatment programs in southern Africa to full local management.

    PubMed

    Vermund, Sten H; Sidat, Mohsin; Weil, Lori F; Tique, José A; Moon, Troy D; Ciampa, Philip J

    2012-06-19

    Global AIDS programs such as the US President's Emergency Plan for AIDS Relief (PEPFAR) face a challenging health care management transition. HIV care must evolve from vertically-organized, externally-supported efforts to sustainable, locally controlled components that are integrated into the horizontal primary health care systems of host nations. We compared four southern African nations in AIDS care, financial, literacy, and health worker capacity parameters (2005 to 2009) to contrast in their capacities to absorb the huge HIV care and prevention endeavors that are now managed with international technical and fiscal support. Botswana has a relatively high national income, a small population, and an advanced HIV/AIDS care program; it is well poised to take on management of its HIV/AIDS programs. South Africa has had a slower start, given HIV denialism philosophies of the previous government leadership. Nonetheless, South Africa has the national income, health care management, and health worker capacity to succeed in fully local management. The sheer magnitude of the burden is daunting, however, and South Africa will need continuing fiscal assistance. In contrast, Zambia and Mozambique have comparatively lower per capita incomes, many fewer health care workers per capita, and lower national literacy rates. It is improbable that fully independent management of their HIV programs is feasible on the timetable being contemplated by donors, nor is locally sustainable financing conceivable at present. A tailored nation-by-nation approach is needed for the transition to full local capacitation; donor nation policymakers must ensure that global resources and technical support are not removed prematurely.

  6. Central southern Africa at the time of the African Humid Period: a new analysis of Holocene palaeoenvironmental and palaeoclimate data

    NASA Astrophysics Data System (ADS)

    Burrough, S. L.; Thomas, D. S. G.

    2013-11-01

    The Holocene African Humid Period (c 14.8-5.5 ka) is now recognised in high-resolution records from western Africa as well as in tropical Africa north of the equator. Establishing a clear picture of Late Quaternary, including Holocene, environmental changes in central southern Africa is proving both difficult and contentious. This is because in dryland systems in particular it can be difficult to distinguish the effects of sub-millennial scale regional climatic variability from those of major externally-forced global climate changes, and because it is essential to distinguish records of environmental drivers from those of environmental responses. We analyse and review existing records for central southern Africa, and neighbouring areas affected by the same climate systems, to understand the primary controls of regional hydrological systems during the Holocene. We then present new data from Makgadikgadi basin barchan dunes that indicate mid-late Holocene aridity following a period of marked hydrological dynamism extending from the early Holocene. We suggest that present-day conditions in central southern Africa are relatively stable compared to the early and mid-Holocene and infer that this period of relative stability in the landscape has occurred since ca 2 ka. We explain Holocene hydrological changes through analysis of changing zonal climatic influences linked to Congo Air Boundary (CAB) and Intertropical Convergence Zone (ITCZ) dynamics, the effects of which filter into the region via complex drainage basin dynamics. It is proposed that, sensu stricto, the AHP was not a spatially uniform feature of early Holocene central southern Africa.

  7. Maritime and Underwater Cultural Heritage in South Africa: The Development of Relevant Management Strategies in the Historical Maritime Context of the Southern Tip of Africa

    NASA Astrophysics Data System (ADS)

    Sharfman, Jonathan; Boshoff, Jaco; Parthesius, Robert

    2012-10-01

    South Africans have a long association with water. It has provided a source of food, a medium for trade and a catalyst for migration and development. The country's geographical position as a crossroads of maritime trade between Europe and the East means that its history is inextricably linked to the history of the rest of the world. The result is a multi-faceted representation of sites, objects and mythologies related to water and maritime heritage that reflect not only local historical and social development, but global cultural change as well. Given the importance of South Africa's underwater cultural heritage (UCH), managers have grappled with management principles, ethics and theoretical models in an effort to produce and enforce heritage legislation that is relevant and effective. This paper outlines South Africa's maritime context from 1.5 million years ago until the present, summarises legislative and mitigation developments over the past half century and provides details of current trends in maritime archaeology and UCH management at the southern tip of Africa. Training programmes and public awareness are keys to this strategy to bring UCH and maritime archaeology into the mainstream and counter treasure hunting and looting of this rich, friable resource.

  8. Lithospheric geometries revealed through electromagnetic imaging: SAMTEX (Southern Africa MagnetoTelluric Experiment) observations and results

    NASA Astrophysics Data System (ADS)

    Jones, A. G.; Muller, M. R.; Evans, R. L.; Miensopust, M. P.; Khoza, D. T.; Samtex Team

    2011-12-01

    The Southern African Magnetotelluric Experiment (SAMTEX) is imaging the properties and geometries of the lithosphere below southern Africa to depths of 200+ km. Electrical conductivity is highly sensitive to ambient temperature, and to the presence of an interconnected conducting phase, such as a solid phase like graphite or sulphides, a fluid phase like partial melt, or bound water through hydrogen diffusion. Thus, primary geometrical information can be readily obtained from lithospheric-scale MT experiments about the three-dimensional variation in conductivity that can be related to formation and deformation processes. One important piece of information easily obtained from MT data is the depth to the lithosphere-asthenosphere boundary (LAB), due to the sensitivity of conductivity to small fractions (<1%) of partial melt and/or of some hundreds of ppm of bound water. SAMTEX measurements have been made at a total of more than 750 MT sites over an area in excess of a million square kilometres, making it by far the largest-ever regional MT project undertaken. One of the most significant results from SAMTEX is the mapping of the LAB beneath the Archean cratons and bounding mobile belts of Southern Africa, particularly of the previously unknown regions of Namibia and Botswana. The LAB is shallow (150 km) beneath the mobile belts, deep (250 km) in the centres of the cratons, and transitional at the edges. Diamondiferous kimberlites are located primarily where lithosphere is transitional in thickness, or where there is a change in its anisotropy properties, both of which are craton edge effects. The electrical properties of the continental mantle derived from SAMTEX data can be compared with seismic ones derived from data from the South African Seismic Experiment (SASE) of the Kaapvaal Project. Generally there is very good predictive linear agreement between seismic velocity and log(conductivity), indicative of both being influenced by the same bulk property factors

  9. Rainfall variability and extremes over southern Africa: Assessment of a climate model to reproduce daily extremes

    NASA Astrophysics Data System (ADS)

    Williams, C. J. R.; Kniveton, D. R.; Layberry, R.

    2009-04-01

    It is increasingly accepted that that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability and the identification of rainfall extremes is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. The majority of previous climate model verification studies have compared model output with observational data at monthly timescales. In this research, the assessment of ability of a state of the art climate model to simulate climate at daily timescales is carried out using satellite derived rainfall data from the Microwave Infra-Red Algorithm (MIRA). This dataset covers the period from 1993-2002 and the whole of southern Africa at a spatial resolution of 0.1 degree longitude/latitude. The ability of a climate model to simulate current climate provides some indication of how much confidence can be applied to its future predictions. In this paper, simulations of current climate from the UK Meteorological Office Hadley Centre's climate model, in both regional and global mode, are firstly compared to the MIRA dataset at daily timescales. This concentrates primarily on the ability of the model to simulate the spatial and temporal patterns of rainfall variability over southern Africa. Secondly, the ability of the model to reproduce daily rainfall extremes will

  10. Dental microwear of sympatric rodent species sampled across habitats in southern Africa: Implications for environmental influence.

    PubMed

    Burgman, Jenny H E; Leichliter, Jennifer; Avenant, Nico L; Ungar, Peter S

    2016-03-01

    Dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil vertebrates. Nevertheless, some studies have recently questioned the efficacy of this approach, suggesting that aspects of habitat unrelated to food preference, especially environmental grit load, might have a confounding effect on microwear patterning that obscures the diet signal. Here we evaluate this hypothesis by examining microwear textures of 3 extant sympatric rodent species that vary in diet breadth and are found in a variety of habitat types: Mastomys coucha, Micaelamys namaquensis and Rhabdomys pumilio. We sample each of these species from 3 distinct environmental settings in southern Africa that differ in rainfall and vegetative cover: Nama-Karoo shrublands (semi-desert) and Dry Highveld grasslands in the Free State Province of South Africa, and Afromontane (wet) grasslands in the highlands of Lesotho. While differences between habitat types are evident for some of the species, inconsistency in the pattern suggests that the microwear signal is driven by variation in foods eaten rather than grit-level per se. It is clear that, at least for species and habitats sampled in the current study, environmental grit load does not swamp diet-related microwear signatures.

  11. The evolutionary dynamics of canid and mongoose rabies virus in Southern Africa.

    PubMed

    Davis, P L; Rambaut, A; Bourhy, H; Holmes, E C

    2007-01-01

    Two variants of rabies virus (RABV) currently circulate in southern Africa: canid RABV, mainly associated with dogs, jackals, and bat-eared foxes, and mongoose RABV. To investigate the evolutionary dynamics of these variants, we performed coalescent-based analyses of the G-L inter-genic region, allowing for rate variation among viral lineages through the use of a relaxed molecular clock. This revealed that mongoose RABV is evolving more slowly than canid RABV, with mean evolutionary rates of 0.826 and 1.676 x 10(-3) nucleotide substitutions per site, per year, respectively. Additionally, mongoose RABV exhibits older genetic diversity than canid RABV, with common ancestors dating to 73 and 30 years, respectively, and while mongoose RABV has experienced exponential population growth over its evolutionary history in Africa, populations of canid RABV have maintained a constant size. Hence, despite circulating in the same geographic region, these two variants of RABV exhibit striking differences in evolutionary dynamics which are likely to reflect differences in their underlying ecology.

  12. Oil and gas developments in central and southern Africa in 1987

    SciTech Connect

    Hartman, J.B.; Walker, T.L.

    1988-10-01

    Significant rightholding changes took place in central and southern Africa during 1987. Angola, Benin, Congo, Gabon, Ghana, Guinea, Guinea Bissau, Mauritania, Seychelles, Somali Republic, Tanzania, Zaire, and Zambia announced awards or acreage open for bidding. Decreases in exploratory rightholdings occurred in Cameroon, Congo, Cote d'Ivoire, Equatorial Guinea, Gabon, Kenya, Namibia, South Africa, and Tanzania. More wells and greater footage were drilled in 1987 than in 1986. Total wells increased by 18% as 254 wells were completed compared to 217 in 1986. Footage drilled during the year increased by 46% as about 1.9 million ft were drilled compared to about 1.3 million ft in 1986. The success rate for exploration wells in 1987 improved slightly to 36% compared to 34% in 1986. Significant discoveries were made in Nigeria, Angola, Congo, and Gabon. Seismic acquisition in 1987 was the major geophysical activity during the year. Total oil production in 1987 was 773 million bbl (about 2.1 million b/d), a decrease of 7%. The decrease is mostly due to a 14% drop in Nigerian production, which comprises 60% of total regional production. The production share of OPEC countries (Nigeria and Gabon) versus non-OPEC countries of 67% remained unchanged from 1986. 24 figs., 5 tabs.

  13. Sperm head structure of a murid rodent from southern Africa: the red veld rat Aethomys chrysophilus.

    PubMed

    Breed, W G; Cox, G A; Leigh, C M; Hawkins, P

    1988-02-01

    The morphology of spermatozoa from the red veld rat, Aethomys chrysophilus, of Southern Africa is described; two very different types were found, which came from animals from two separate, as-yet-undescribed, species. In individuals from South Africa the sperm head had a somewhat disc-shaped nucleus and a large acrosome with a huge apical segment that, during epididymal transit, changed in form from initially projecting anteriorly to a highly complex structure that was flexed caudad and lay alongside part of the rest of the sperm head. In addition, the chromatin generally appeared to be not fully condensed. Spermatozoa from animals collected in Malawi were very different in morphology and had a head with a typical apical hook, a perforatorium, fully condensed chromatin, and a 4-micron-long ventral spur. Its sperm tail was also significantly longer. The time of divergence of these two groups of animals from a common ancestor is not known, but the present results show that a considerable morphological change in the sperm nucleus, acrosome, and subacrosomal space can evolve even between two, presumably closely related, species.

  14. Age and growth and maturity of southern Africa's largest cyprinid fish, the largemouth yellowfish Labeobarbus kimberleyensis.

    PubMed

    Ellender, B R; Weyl, O L F; Winker, H

    2012-09-01

    The aim of this study was to use specimens of the largemouth yellowfish Labeobarbus kimberleyensis, southern Africa's largest cyprinid [IUCN red-listed as Near Threatened (NT)], obtained from gillnet by-catch to describe aspects of its biology in order to assist future conservation and management decisions. Ninety three L. kimberleyensis were collected between March 2007 and May 2008 from Lake Gariep, South Africa. Labeobarbus kimberleyensis was present in 38% of all gillnet catches, but in low numbers (2% of the catch) and it contributed 8% to the catch by mass. Age was estimated using astericus otoliths. Growth increment formation on these otoliths was validated as annual using edge analysis and the mark-recapture of chemically tagged captive fish. Resultant analysis showed that the species is slow growing and the oldest aged fish was a 17 year, 690 mm fork length (L(F)) male. The smallest ripe female fish measured 394 mm L(F) and was 7+ years old and the smallest mature male was 337 mm L(F) and 5+ years old. Slow growth and late maturity make this species vulnerable to exploitation emphasizing the need for continued high conservation priority.

  15. 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

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

    PubMed

    Will, Manuel; Mackay, Alex; 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.

  17. Risk factors of Toxoplasma gondii infection in hunting, pet and watchdogs from Southern Spain and Northern Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dogs can act as reservoirs of Toxoplasma gondii infections for humans and other hosts. Here we determined seroprevalence and risk factors of T. gondii infection in dogs from Andalusia (Southern Spain) and Ceuta (Northern Africa). Antibodies to T. gondii were detected in 235 out of 769 dogs (30.6%; C...

  18. Working with Cultural-Historical Activity Theory and Critical Realism to Investigate and Expand Farmer Learning in Southern Africa

    ERIC Educational Resources Information Center

    Mukute, Mutizwa; Lotz-Sisitka, Heila

    2012-01-01

    This article uses the theoretical and methodological tools of cultural historical activity theory and critical realism to examine three case studies of the introduction and expansion of sustainable agricultural practices in southern Africa. The article addresses relevant issues in the field of agricultural extension, which lacks a theoretical…

  19. Prediction, Assessment of the Rift Valley fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Nino/Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and ...

  20. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historical episodic outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns (El Niño and La Niña) of El Niño Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite ...

  1. Eco-climatic Conditions Associated with Rift Valley fever Activity in Southern Africa in 2008-2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The time period 2008-2011 has been marked by a series of Rift Valley fever (RVF) outbreaks in Southern Africa. These multi-year episodes of RVF have not occurred in the region since the mid-1970s. We examine climatic and ecological conditions associated with the outbreaks and present results of our ...

  2. Social and Economic Change in Southern Africa. Fulbright-Hays Summer Seminars Abroad Program, Summer 1991. [Curriculum Projects and Papers.

    ERIC Educational Resources Information Center

    Institute of International Education, New York, NY.

    This document presents curriculum projects and papers written by U.S. teachers who traveled to countries in Southern Africa in the summer of 1991 as part of the Fulbright-Hays Summer Seminars Abroad Program. The included projects and papers are: "Through a Glass Darkly: The Enigmatic Educational System of Botswana" (Alan C. Howard);…

  3. Review of SISA Student Dissertations on Library and Information Systems and Services in Eastern and Southern Africa.

    ERIC Educational Resources Information Center

    Chowdhury, G. G.; Tadesse, Taye T.

    1995-01-01

    Analyzes student dissertations at the School of Information Studies for Africa (SISA) at Addis Ababa University (Ethiopia) in order to present an overview of the library and information systems and services available in seven eastern and southern African countries: Ethiopia, Kenya, Malawi, Sudan, Tanzania, Uganda, and Zambia. (Author/LRW)

  4. A Progressively Wetter Climate in Southern East Africa Over the Past 1.3 Million Years

    NASA Astrophysics Data System (ADS)

    Berke, M. A.; Johnson, T. C.; Werne, J. P.; Contreras, S.; Brown, E. T.

    2015-12-01

    We present a 1.3 million year record of hydroclimate in the basin of Lake Malawi, the second deepest lake in Africa, located at ~10 - 15ºS latitude in the East African Rift Valley. The lake is ~550 km long, has a maximum depth of 706 m, and is presently anoxic below ~200 m. While the lake is an open basin today with outflow through the Shire River at its southern end, the surface of Lake Malawi has dropped well below the elevation of its outlet on several occasions in its past. We examined a 380 m sediment sequence taken from a water depth of 590 m, from Cores MAL05-1B and MAL05-1C of the Lake Malawi Drilling Project. Sediment samples were analyzed for the carbon isotopic composition of the C29 - C33 n-alkanes derived from fossil leaf waxes, which primarily reflect the relative abundance of C3 (mostly trees and shrubs) and C4 (mostly grass) vegetation, i.e., relatively humid or arid conditions, respectively, in the lake basin. The δ13Cwax record portrays a transition from a highly variable and predominantly arid climate prior to 900 ka to a progressively more humid environment after the Mid-Pleistocene Transition, dominated by 100 ky cycles consisting of warm, wet interglacial periods alternating with relatively cool, dry glacial periods. This shift towards more humid conditions in the Lake Malawi basin contrasts with the well-documented progression towards a more arid environment in North Africa over the same period, as reflected in the carbon isotopic record of soil carbonates and in dust records from marine sediment recovered from the Atlantic Ocean and Gulf of Aden. Aridification in the Horn of Africa has been attributed to a cooling of the Indian Ocean. Model results suggest that this would be accompanied by a weakening of a localized Walker circulation over the Indian Ocean, less ascending air over the western Indian Ocean and coastal Africa, and more precipitation in the Rift Valley.

  5. South Africa/Time Running Out.

    ERIC Educational Resources Information Center

    Clark, Todd, Ed.

    1984-01-01

    Based on the book, "South Africa: Time Running Out," a report of the Study Commission on U.S. Policy Toward Southern Africa, this 10-20 day unit of study is designed to help high school students learn about the history, geography, and present situation in South Africa and its relationship to the United States. The first of four sections…

  6. Astronomy Across Africa

    NASA Astrophysics Data System (ADS)

    Williams, Ted

    2014-01-01

    African astronomy is growing rapidly. The Southern African Large Telescope is the largest optical telescope in the southern hemisphere, MeerKat and the Square Kilometer Array will revolutionize radio astronomy in the coming decade, and Namibia hosts HESS II, the world’s largest gamma-ray telescope. A growing community of observational and theoretical astronomers utilizes these multi-wavelength observational facilities. The largest concentrations of researchers are in southern Africa, but the community is now expanding across the continent. Substantial resources are being invested in developing the next generation of African astronomers. The African Astronomical Society was formed in 2011 to foster and coordinate the growth of the science in Africa. The IAU has located its global Office of Astronomy for Development in South Africa, with the mandate to find innovative ways of using astronomy to promote social and educational development around the world. African astronomy offers abundant opportunities for collaborative research with colleagues from across the globe. This special session will introduce many of the aspects of African astronomy to the US community, with the aim of engendering new partnerships and strengthening existing ones.

  7. North Africa

    SciTech Connect

    Nicod, M.A.

    1981-10-01

    The total area covered by petroleum rights in the six countries described in this paper increased by more than 17% in 1980 compared to 1979. Joint venture agreements were finalized for 19 blocks over 94,000 km/sup 2/ in the Algerian venture. Although official information is scarce for Algeria and Libya, seismic activity probably increased in 1980 compared to 1979. Exploration drilling activity increased with 121 wildcats drilled compared to 93 during the previous year. This effort led to 40 discoveries, a 34.5% success ratio. Chevron was especially successful in wildcatting, with 6 oil discoveries for 8 wells drilled in the interior basins of Sudan. One Moroccan discovery can be considered as a highlight: the BRPM Meskala 101 well in the Essaouira basin found an apparently large amount of gas in Triassic sandstones. This discovery deserves special attention, since the gas has been found in Triassic pays rather than in the usual Jurassic pays in the Essaouira basin. Oil production in North Africa decreased from about 13.5% in 1980, with about 3,405,000 barrels of oil per day compared to 3,939,500 barrels of oil per day in 1979. When oil output strongly decreased in Algeria (-16.4%) and Libya (-15.6%), Tunisian production peaked at 116,287 barrels of oil per day and Egypt production also peaked at 584,148 barrels of oil per day. Total gas production in 1980 strongly declined from 44%, mostly due to the decline of the Algerian gas production. 8 figures, 40 tables.

  8. Slope Deposits and (Paleo)Soils as Geoarchives to Reconstruct Late Quaternary Environments of Southern Africa

    NASA Astrophysics Data System (ADS)

    Huerkamp, K.; Voelkel, J.; Heine, K.; Bens, O.

    2009-04-01

    Although it is clear that large, rapid temperature changes have occurred during the last glacial-interglacial cycle and the Holocene in southern Africa, we have only limited, and often imprecise, knowledge of how the major moisture-bearing atmospheric circulation systems have reacted to these changes. Using slope deposits and soils as palaeoclimatic geoarchives we will overcome these constraints. The role of many geoarchives in the reconstruction of the Quaternary climate in southern Africa remains controversial, since the paleoclimate data are based on evidence from marine cores, lake sediments, speleothems and spring sinter, fluvial sediments, aeolian sands and dust, colluvium, and coastal sediments. To elucidate climate controls on Quaternary landscape evolution and to use these data for palaeoclimatic reconstructions, thus far slope deposits and soils have been investigated. Climatic controls on these cycles are incompletely known. The availability of results from earlier fieldwork, micromorphology, Optical Stimulated Luminescence (OSL), 14C dating and stable carbon isotope analysis will permit a thorough assessment of slope deposits and soils in terms of their palaeoenvironmental potential. The knowledge of suitable areas and sites in different climatic zones of southern Africa where slope deposits and soils have already been found document the late Quaternary climatic history and even climatic anomalies (e.g. Younger Dryas period at Eksteenfontein, 8.2 ka event at Tsumkwe, 4 ka event in the Auob valley, Little Ice Age in the Namib Desert). The findings will show the late Quaternary history of precipitation fluctuations, of the shifting of the ITCZ (and the ABF - Agulhas-Benguela Front), of wind intensities and directions, and of extreme precipitation events. The project will employ state-of-the-art geoscience methodology to interpret the record of precipitation changes of the late Quaternary, including the shifting of the summer and winter rain belts, the

  9. Oil and gas developments in central and southern Africa in 1984

    SciTech Connect

    Armstrong, A.C.

    1985-10-01

    Key indications are that the industry decline that began in 1982 has bottomed out in central and southern Africa. Seismic in 1984 was up more than 10% from 1983. Wildcatting and total drilling were down slightly, but production posted a 13% increase. The total number of wildcats decreased from 86 in 1983 to 83 in 1984; however, if Nigerian activity is excluded, wildcats actually increased to 71 from 62. Production is up principally because existing fields were expanded and new ones came on stream. It increased from 1.85 million BOPD in 1983 to 2.1 million BOPD in 1984. The increase in development drilling led by Cameroon and Nigeria should result in a continuation of this rise unless world conditions override.

  10. Oil and gas developments in central and southern Africa in 1984

    SciTech Connect

    Armstrong, A.C.

    1985-10-01

    Key indications are that the industry decline that began in 1982 has bottomed out in central and southern Africa. Seismic in 1984 was up more than 10% from 1983. Wildcatting and total drilling were down slightly, but production posted a 13% increase. The total number of wildcats decreased from 86 in 1983 to 83 in 1984; however, if Nigerian activity is excluded, wildcats actually increased to 71 from 62. Production is up principally because existing fields were expanded and new ones came on stream. It increased from 1.85 million BOPD in 1983 to 2.1 million BOPD in 1984. The increase in development drilling led by Cameroon and Nigeria should result in a continuation of this rise unless world conditions override. 31 figures, 7 tables.

  11. Late Quaternary climate and landscape changes in Southern Africa based on integrative analyses of geoarchives

    NASA Astrophysics Data System (ADS)

    Huerkamp, K.; Voelkel, J.; Heine, K.; Bens, O.; Winkelbauer, J.

    2009-12-01

    Although it is clear that large, rapid temperature changes have occurred during the last glacial-interglacial cycle and the Holocene in Southern Africa, we have only limited, and often imprecise, knowledge of how the major moisture-bearing atmospheric circulation systems have reacted to these changes. Using slope deposits, soils and sediments as palaeoclimatic geoarchives we will overcome these constraints. The role of many geoarchives in the reconstruction of the Quaternary climate in Southern Africa remains controversial, since the palaeoclimate data are based on evidence from marine cores, lake sediments, speleothems and spring sinter, fluvial sediments, aeolian sands and dust, colluvium, and coastal sediments. To elucidate climate controls on Quaternary landscape evolution and to use these data for palaeoclimatic reconstructions, slope deposits, soils and sediments have been investigated. The project will employ state-of-the-art geoscience methodology to interpret the record of precipitation changes of the Late Quaternary, including the shifting of the summer and winter rain belts, the chronology of catastrophic floods, the wind intensity and direction, and the role climatic factors may have played for prehistoric cultures. High resolution Late Quaternary records are provided by analysing the interstratification of slope deposits and soils with fluvial, lacustrine and aeolian sediment sequences. Earlier research has shown that aeolian and fluvial processes were active at the same time in the southwestern Kalahari during the LGM, documented by sequences of alternate bedding of aeolian, colluvial and fluvial sediments. The interfingering of slope deposits with fluvial flood sediments (slackwater deposits) in Namib Desert valleys document extreme precipitation events in the upper highland catchments and rains at the same time in the desert itself.

  12. Impacts of climate change on water resources in southern Africa: A review

    NASA Astrophysics Data System (ADS)

    Kusangaya, Samuel; Warburton, Michele L.; Archer van Garderen, Emma; Jewitt, Graham P. W.

    The Intergovernmental Panel on Climate Change concluded that there is consensus that the increase of atmospheric greenhouse gases will result in climate change which will cause the sea level to rise, increased frequency of extreme climatic events including intense storms, heavy rainfall events and droughts. This will increase the frequency of climate-related hazards, causing loss of life, social disruption and economic hardships. There is less consensus on the magnitude of change of climatic variables, but several studies have shown that climate change will impact on the availability and demand for water resources. In southern Africa, climate change is likely to affect nearly every aspect of human well-being, from agricultural productivity and energy use to flood control, municipal and industrial water supply to wildlife management, since the region is characterised by highly spatial and temporally variable rainfall and, in some cases, scarce water resources. Vulnerability is exacerbated by the region's low adaptive capacity, widespread poverty and low technology uptake. This paper reviews the potential impacts of climate change on water resources in southern Africa. The outcomes of this review include highlighting studies on detected climate changes particularly focusing on temperature and rainfall. Additionally, the impacts of climate change are highlighted, and respective studies on hydrological responses to climate change are examined. The review also discusses the challenges in climate change impact analysis, which inevitably represents existing research and knowledge gaps. Finally the paper concludes by outlining possible research areas in the realm of climate change impacts on water resources, particularly knowledge gaps in uncertainty analysis for both climate change and hydrological modelling.

  13. Estimating probabilistic rainfall and food security outcomes for eastern and southern Africa

    NASA Astrophysics Data System (ADS)

    Verdin, J.; Funk, C.; Dettinger, M.; Brown, M.

    2009-05-01

    Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains high, and declining per-capita agricultural capacity retards development. In September of 2008, Ethiopia, Kenya, Djibouti, and Somalia faced high or extreme conditions of food insecurity caused by repeated droughts and rapid food price inflation. In this talk we present research, performed for the US Agency for International Development on probabilistic projections of rainfall and food security trends for eastern and southern Africa. Analyses of station data and satellite-based estimates of precipitation have identified another problematic trend: main growing- season rainfall has diminished by ~15% in food-insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain-fed agriculture, these declines constitute a long term danger to subsistence agricultural and pastoral livelihoods. Tracing moisture deficits upstream to an anthropogenically-induced warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus, late 20th century Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling millions of undernourished people as a function of rainfall, population, cultivated area, and seed and fertilizer use. Persistence of current trends may result in a 50% increase in undernourished people. On the other hand, modest increases in per-capita agricultural productivity could more than offset the

  14. Resourcing resilience: social protection for HIV prevention amongst children and adolescents in Eastern and Southern Africa.

    PubMed

    Toska, Elona; Gittings, Lesley; Hodes, Rebecca; Cluver, Lucie D; Govender, Kaymarlin; Chademana, K Emma; Gutiérrez, Vincent Evans

    2016-07-01

    Adolescents are the only age group with growing AIDS-related morbidity and mortality in Eastern and Southern Africa, making HIV prevention research among this population an urgent priority. Structural deprivations are key drivers of adolescent HIV infection in this region. Biomedical interventions must be combined with behavioural and social interventions to alleviate the socio-structural determinants of HIV infection. There is growing evidence that social protection has the potential to reduce the risk of HIV infection among children and adolescents. This research combined expert consultations with a rigorous review of academic and policy literature on the effectiveness of social protection for HIV prevention among children and adolescents, including prevention for those already HIV-positive. The study had three goals: (i) assess the evidence on the effectiveness of social protection for HIV prevention, (ii) consider key challenges to implementing social protection programmes that promote HIV prevention, and (iii) identify critical research gaps in social protection and HIV prevention, in Eastern and Southern Africa. Causal pathways of inequality, poverty, gender and HIV risk require flexible and responsive social protection mechanisms. Results confirmed that HIV-inclusive child-and adolescent-sensitive social protection has the potential to interrupt risk pathways to HIV infection and foster resilience. In particular, empirical evidence (literature and expert feedback) detailed the effectiveness of combination social protection particularly cash/in-kind components combined with "care" and "capability" among children and adolescents. Social protection programmes should be dynamic and flexible, and consider age, gender, HIV-related stigma, and context, including cultural norms, which offer opportunities to improve programmatic coverage, reach and uptake. Effective HIV prevention also requires integrated social protection policies, developed through strong national

  15. Regulating the for-profit private health sector: lessons from East and Southern Africa.

    PubMed

    Doherty, Jane E

    2015-03-01

    International evidence shows that, if poorly regulated, the private health sector may lead to distortions in the type, quantity, distribution, quality and price of health services, as well as anti-competitive behaviour. This article provides an overview of legislation governing the for-profit private health sector in East and Southern Africa. It identifies major implementation problems and suggests strategies Ministries of Health could adopt to regulate the private sector more effectively and in line with key public health objectives. This qualitative study was based on a document review of existing legislation in the region, and seven semi-structured interviews with individuals selected purposively on the basis of their experience in policymaking and legislation. Legislation was categorized according to its objectives and the level at which it operates. A thematic content analysis was conducted on interview transcripts. Most legislation focuses on controlling the entry of health professionals and organizations into the market. Most countries have not developed adequate legislation around behaviour following entry. Generally the type and quality of services provided by private practitioners and facilities are not well-regulated or monitored. Even where there is specific health insurance regulation, provisions seldom address open enrolment, community rating and comprehensive benefit packages (except in South Africa). There is minimal control of prices. Several countries are updating and improving legislation although, in most cases, this is without the benefit of an overarching policy on the private sector, or reference to wider public health objectives. Policymakers in the East and Southern African region need to embark on a programme of action to strengthen regulatory frameworks and instruments in relation to private health care provision and insurance. They should not underestimate the power of the private health sector to undermine efforts for increased

  16. Improved predictability of droughts over southern Africa using the standardized precipitation evapotranspiration index and ENSO

    NASA Astrophysics Data System (ADS)

    Manatsa, Desmond; Mushore, Terrence; Lenouo, Andre

    2017-01-01

    The provision of timely and reliable climate information on which to base management decisions remains a critical component in drought planning for southern Africa. In this observational study, we have not only proposed a forecasting scheme which caters for timeliness and reliability but improved relevance of the climate information by using a novel drought index called the standardised precipitation evapotranspiration index (SPEI), instead of the traditional precipitation only based index, the standardised precipitation index (SPI). The SPEI which includes temperature and other climatic factors in its construction has a more robust connection to ENSO than the SPI. Consequently, the developed ENSO-SPEI prediction scheme can provide quantitative information about the spatial extent and severity of predicted drought conditions in a way that reflects more closely the level of risk in the global warming context of the sub region. However, it is established that the ENSO significant regional impact is restricted only to the period December-March, implying a revisit to the traditional ENSO-based forecast scheme which essentially divides the rainfall season into the two periods, October to December and January to March. Although the prediction of ENSO events has increased with the refinement of numerical models, this work has demonstrated that the prediction of drought impacts related to ENSO is also a reality based only on observations. A large temporal lag is observed between the development of ENSO phenomena (typically in May of the previous year) and the identification of regional SPEI defined drought conditions. It has been shown that using the Southern Africa Regional Climate Outlook Forum's (SARCOF) traditional 3-month averaged Nino 3.4 SST index (June to August) as a predictor does not have an added advantage over using only the May SST index values. In this regard, the extended lead time and improved skill demonstrated in this study could immensely benefit

  17. Development of a locally sustainable functional food based on mutandabota, a traditional food in southern Africa.

    PubMed

    Mpofu, Augustine; Linnemann, Anita R; Sybesma, Wilbert; Kort, Remco; Nout, M J R; Smid, Eddy J

    2014-05-01

    A probiotic dairy product was developed on the basis of a traditional dish called mutandabota to enable resource-poor populations in southern Africa to benefit from a functional food. Mutandabota is widely consumed in rural southern Africa, making it an ideal food matrix to carry probiotics. First, a process to produce probiotic mutandabota was designed. Raw cow milk was boiled and subsequently cooled to ambient temperature (25°C). Next, dry pulp from the fruit of the baobab tree (Adansonia digitata L.) was added to the milk at a concentration of 4% (wt/vol). This mixture was inoculated with the probiotic Lactobacillus rhamnosus yoba and left to ferment for 24h, while the growth of the bacterial culture was monitored. Final ingredients were then added to produce probiotic mutandabota that had 14% (wt/vol) baobab fruit pulp and 7% (wt/vol) sugar in cow milk. The pH of probiotic mutandabota was pH 3.5, which ensures that the product is microbiologically safe. The viable plate count of L. rhamnosus yoba increased from 5.8 ± 0.3 log cfu/mL at the point of inoculation to 8.8 ± 0.4 log cfu/mL at the moment of consumption, thereby meeting the criterion to have a viable count of the probiotic bacterium in excess of 6 log cfu/mL of a product. Baobab fruit pulp at 4% promoted growth of L. rhamnosus yoba with a maximal specific growth rate (μmax) of 0.6 ± 0.2/h at 30°C. The developed technology, though specific for this particular product, has potential to be applied for the delivery of probiotics through a variety of indigenous foods in different regions of the world. Upon consumption, probiotic mutandabota is expected to improve the population's intestinal health, which is especially relevant for vulnerable target groups such as children and elderly people.

  18. Seasonal Trend of Aerosol Single Scattering Albedo at Biomass Burning Sites in Southern Africa

    NASA Astrophysics Data System (ADS)

    Eck, T. F.; Holben, B. N.; Reid, J. S.; Ward, D.; Mukelabai, M. M.; Piketh, S.; Hyer, E. J.; Dubovik, O.; Sinyuk, A.; Schafer, J. S.; Giles, D. M.; Smirnov, A.; Slutsker, I.

    2011-12-01

    A database of the optical properties of primarily biomass burning aerosols in Mongu, Zambia from multi-year monitoring at an AERONET sun-sky radiometer site was examined. For the biomass burning season months (July-November), we investigate the aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals utilizing the algorithm of Dubovik and King (2000). The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from ~0.84 in July to ~0.93 in November (from 0.78 to 0.90 at 675 nm in these same months). There was no significant change in particle size, in either the dominant accumulation or secondary coarse modes during these months, nor any significant trend in the Angstrom Exponent (440-870 nm; r2=0.02). A significant downward seasonal trend in imaginary refractive index (r2=0.43) suggests a trend of decreasing black carbon content in the aerosol composition as the burning season progresses. Similarly, seasonal SSA retrievals for both the Etosha Pan, Namibia and Skukuza, South Africa AERONET sites also show increasing single scattering albedo values through the burning season. We show maps of satellite detected fire counts, which indicate that the regions of primary biomass burning in southern Africa shift significantly from July to October. Possible reasons for the seasonal changes in observed SSA include differences in biomass fuel types in different regions and seasons (fraction of woody biomass versus grasses), agricultural practices (Chitemene: in which woody fuels are burned at the end of the dry season), differences in fuel moisture content (as mid-October is the typical beginning of the rainy season) and differences in aging due to transport speed and distance from varying source regions. We also analyze the seasonality of SSA for sites in biomass burning regions of southern Amazonia, where no significant seasonal trend in SSA was detected.

  19. Hemorrhagic fevers, with special reference to recent outbreaks in southern Africa.

    PubMed

    Gear, J H

    1979-01-01

    In considering the diagnosis of a patient admitted to the Johannesburg Hospital, suffering from an illness characterized by high fever and complicated by a hemorrhagic state from which he died, a list of possible causes of his illness was drawn up. This list included the arthropodborne viral infections prevalent in southern Africa, namely, chikungunya fever, Sindbis fever, West Nile fever, yellow fever, and Rift Valley fever; viral infections associated with rodents, such as Lassa fever; the viral infection associated with monkeys, Marburg virus disease; the rickettsial infections; tick-bite fever (the variety of spotted fever of tick typhus occurring in southern Africa) and Q fever; the bacterial infections, especially the coccal infections, plague septicemia, and meningococcal, staphylococcal, and streptococcal septicemia; and the blood protozoal infections malaria and trypanosomiasis. In addition, rubella, Gasser's syndrome, Henoch-Schönlein purpura, and viperine snakebite were briefly described in this review. All of these conditions may be complicated by the development of a hemorrhagic state. The circulation of large numbers of infecting organisms, by they viruses, rickettsiae, bacteria, or protozoa, may initiate the coagulation cascade, the formation of fibrin and its deposition in the finer blood vessels, and the aggregation and entanglement of platelets resulting in marked thrombocytopenia and bleeding. This bleeding tendency is greatly aggravated when the infection specifically involves the parenchymal cells of the liver; such a condition results in defective formation of coagulation factors such as prothrombin. The proper care of patients in whom a hemorrhagic state has developed requires urgent and accurate diagnosis followed by immediate and appropriate treatment that will combat the infection and alleviate the hemorrhagic state and liver disorder. If the hemorrhagic state is due to one of the dangerous infectious fevers, adequate protection of the

  20. Risks and benefits of genetically modified maize donations to southern Africa: views from Malawi.

    PubMed

    Muula, Adamson S; Mfutso-Bengo, Joseph M

    2003-02-01

    In 2001 and 2002, many countries in the Southern African Development Community (SADC) have suffered from severe food shortages resulting in an estimated 14 million people facing starvation due to inadequate quantities of the staple maize. The international community's response has been the donation of foodstuffs, including genetically modified maize. Reactions of the recipient countries of Zambia, Zimbabwe, and Malawi have been different. Zambia appealed to the donors not to send genetically modified maize, whereas Malawi accepted the maize donations. Malawi is currently facing many public health challenges because 10% of its 10-million population is HIV-positive, maternal mortality rate has almost doubled between 1992 and 2000, and there are also an estimated 1 million orphans due to HIV/AIDS. In the European Union, genetically modified maize falls under "Novel Foods" and its marketing and distribution are strictly regulated by law. This has never been the case in the southern African countries. In this article, we discuss the ethical challenges associated with genetically modified maize donations to southern Africa. Although genetically modified food offers a way to avoid many adverse effects of food shortages, we believe that some of the ethical questions of genetically modified food donations should be solved first, under the leadership of the donor countries and partnership of the developing countries. There are fears that consummation of genetically modified maize could have adverse health effects. These fears must be addressed if the confidence of developing countries in the donor community is to be maintained.

  1. Increasing behavioral flexibility? New archaeological and ecological approaches to understanding the Howieson's Poort in Southern Africa

    NASA Astrophysics Data System (ADS)

    Kandel, A. W.; Bolus, M.; Bruch, A. A.; Haidle, M. N.; Hertler, C.; Märker, M.

    2012-04-01

    The Howieson's Poort (HP) of Southern Africa peaked between 60 and 65 ka and represents a distinct phase of cultural innovation adopted by modern humans during the Middle Stone Age. While researchers generally attribute the rise and fall of the HP to social and environmental causes, neither provides a complete explanation. As patterns at the site level come into focus, large-scale trends explaining the HP expansion remain uncertain. Comparisons with earlier and later cultural phases may provide ways to view the HP phenomenon. The most notable artifacts of the HP lithic industry are standardized, crescent-shaped, backed stone tools called segments that were mounted on wooden shafts in several orientations using mixtures of ground pigment and plant resin to create composite tools such as stone-tipped arrows and spears. The use of ocher, often faceted or striated from grinding and sometimes engraved with geometric patterns, attests to functional and possibly symbolic behavior. Other attributes of the HP include the use of laminar lithic technology to produce blades and a preference for finer grained raw materials. While rare bone tools hint at advanced hunting strategies, other organic finds include geometrically engraved and perforated ostrich eggshell containers and perhaps shell beads, artifacts that serve as markers conveying individual and group status. Analyses of faunal remains supports the possible use of snares and traps, in addition to diverse hunting strategies. Even the sediments testify to changes in behavior that involved the increasing maintenance of living areas. Micromorphological evidence for the construction of bedding layers that were regularly cleaned by burning appears towards the end of the HP. While this combination of behaviors indicates a cultural complexity that did not exist before or after the HP, the reasons for its appearance and the causes of its demise remain unclear. To test the hypotheses of cultural and environmental causality and

  2. 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.

  3. Historical Notes on Three Exceptional Iron Meteorites of Southern Africa: The Cape of Good Hope, Gibeon, and Hoba

    NASA Astrophysics Data System (ADS)

    Marvin, Ursula B.

    2000-01-01

    Africa, is among the richest of continents in meteorites from hot deserts. Namibia is the site of the world's largest individual meteorite, the 60-ton Hoba Ni-rich ataxite, and the largest known meteorite strewn field, that of the Gibeon fine octahedrite. In Egypt, history goes back at least as far as approx. 1340 B.C when an iron dagger with a small content of nickel was placed in the tomb of King Tutankhamen. History also comes up-to-date in northern Africa with recoveries in recent years of thousands of meteorites in the reaches of the Sahara from Libya to Mauretania. This paper will review the histories of three exceptional meteorites from southern Africa.

  4. History and development of research on wildlife parasites in southern Africa, with emphasis on terrestrial mammals, especially ungulates

    PubMed Central

    Junker, Kerstin; Horak, Ivan G.; Penzhorn, Banie

    2014-01-01

    The history of wildlife parasitology in South Africa, and to some extent southern Africa, is reviewed, giving a brief overview of the early years and following its development from the founding of the Onderstepoort Veterinary Institute in 1908 until the turn of the century. An emphasis is placed on game species. The main findings on protozoan parasites, including those of carnivores, are presented, starting in the 1890s and leading up to the first decade of the 21st century. Important developments with regard to the studies of arthropod and helminth parasites took place during a period of three decades, starting from the 1970s. Because of the sheer volume of work done by parasitologists during this time, this particular part of the overview concentrates on South African authors or authors working in South Africa at the time, and is limited to hosts that are members of the order Perissodactyla and the superorder Cetartiodactyla. PMID:25830101

  5. Community engagement practices in Southern Africa: Review and thematic synthesis of studies done in Botswana, Zimbabwe and South Africa.

    PubMed

    Musesengwa, Rosemary; Chimbari, Moses J

    2016-03-19

    Community Engagement (CE) is intended to enhance the participation of community stakeholders in research. CE is usually mentioned in publications as researchers discuss how they carried out community entry, consent and retained study participants but the actual CE activities are not always well documented. This paper reviews CE strategies employed in health research in Botswana, South Africa and Zimbabwe with reference to the development of a CE strategy for a multi-centre study to be conducted in these countries. The search was conducted using JANE (Journal/Author Name Estimator), Google Scholar and PubMed with known institutions and researchers providing context-specific material. The final synthesis includes 35 publications, 2 reports and 2 abstracts. There is evidence of CE being practiced in health research and eight closely related CE strategies were revealed. We conclude that since communities are heterogeneous and unique, CE activities will not have similar results in different settings. Even though there was insufficient evidence to determine which CE strategy is most effective, the review provides sufficient information to develop a CE strategy for a multi-centre study using the various strategies and activities described.

  6. How the transport sector drives HIV / AIDS and how HIV/ AIDS drives transport. Economic impact: Southern Africa.

    PubMed

    Whiteside, A

    1998-04-01

    A close connection exists between mobility and the spread of HIV infection. Being away from home and traditional social networks and constraints makes people more likely to have sex partners other than their spouses or regular partners. The transport sector has an important role in facilitating the movement of people. Indeed, improving transport is a developmental goal worldwide, with an efficient transport system seen to be a necessary precondition to economic growth. The role of the transport sector in facilitating the spread of HIV needs to be considered. South Africa has the greatest length of roads, railways, and the most registered vehicles in southern Africa. In 1997, Johannesburg International Airport became Africa's most busy airport. South Africa also has a considerable maritime transport sector. In 1994, an estimated more than 500,000 people were employed in the country's transport sector. The following risk groups must be targeted in order to control the spread of HIV in South Africa: people working in building and maintaining infrastructure; people who work in the railways, roads, airlines, and shipping services; transport sector managers; and passengers.

  7. Organic-rich mud on the western margin of southern Africa: Nutrient source to the Southern Ocean?

    NASA Astrophysics Data System (ADS)

    Compton, John; Herbert, Caren; Schneider, Ralph

    2009-12-01

    The biological pump plays a major role in the transfer of CO2 from the atmosphere to the deep Southern Ocean, a transfer which is largely controlled by the supply of iron and which may partially explain glacial to interglacial variations in pCO2. Analogous to the well-documented, smaller-scale "island mass effect," we propose that the lateral advection of iron by south flowing intermediate waters along the southern African margin may sustain high-productivity blooms of the Subtropical Convergence Zone (SCZ) between 10 and 70°E. We assess the present-day interglacial (Holocene) reservoirs and fluxes of organic carbon (OC) and terrigenous mud on the western margin of southern Africa in order to estimate the potential supply of Fe to the Southern Ocean. The highly productive Benguela Upwelling System (BUS) appears to be a relatively inefficient coastal biological pump. Repeated sediment resuspension by wave and tidal energy dissipation limits OC burial to <0.2% of net primary production (NPP) in the southern BUS and to between 0.2 to 2.4% in the northern BUS. Productivity and OC-rich mud accumulation are focused on the inner portion of the 100-200 km wide shelf which, combined with south flowing bottom currents, limits the export of OC beyond the shelf break to 1.2-8.4% of NPP. However, winnowing of 1 million tons yr-1 of clay particles and the potential early diagenetic benthic (dissolved) Fe flux may supply 10 times more Fe than is transported by dust to the open ocean biological pump of the SCZ. Lowering sea level during glacial periods disperses interglacial mud deposits off the shelf and increases particulate Fe export by as much as a factor of 4. Glacial pulses of margin export may enhance the efficiency of the subantarctic Southern Ocean biological pump and contribute to the initial as well as glacial maximum drawdown in pCO2.

  8. Teacher Migration Impact: A Review in the Context of Quality Education Provision and Teacher Training in Higher Education in Southern Africa

    ERIC Educational Resources Information Center

    Brown, B.

    2008-01-01

    Teacher mobility has become a common feature of the cross-border flows and transnational networks that constitute globalisation. International and intraregional migration of teachers is an important factor in education provision and management in countries in the Southern Africa region, for example Botswana and South Africa. In an increasingly…

  9. Attributing the Risk of Late Onset of the Rainy Season in Southern Africa to Climate Change

    NASA Astrophysics Data System (ADS)

    Wolski, P.; Stone, D. A.; Tadross, M. A.; Hewitson, B.; Wehner, M. F.

    2015-12-01

    Rainfed subsistence agriculture in Sub-Saharan Africa accounts for approximately 96% of all cropland. This, combined with strong intra-seasonal and interannual variability of rains makes food production sensitive to climate variations, and increases the potential and frequent occurrence of climate-triggered famines. Farmers often identify the timing of the onset of the growing season (in many areas dependent predominantly on rainfall) as a key climate characteristic which influences crop yields, influences planting activities, and can be used to adapt to changing seasonal conditions without requiring additional resources. It is thus important to understand factors affecting the timing of the onset of rains, particularly how anthropogenic climate change may increase the risk of later onsets. Here, we present a study designed to assess the level of influence of anthropogenic CO2 emissions on the risk of late onset in southern Africa. Considering numerous definitions of rainy season onset, we use one that describes onset related to the growing of maize, as it is the most wide-ranging and consumed staple in the region. Attribution is done using a risk-based event attribution methodology in which we use dedicated simulations by AGCMs (HadAM3p-N96 and CAM5.1-1degree) performed in the framework of the Climate of the 20th Century Plus (C20C+) Detection and Attribution Project. These simulations enable comparison of event (in our case the timing of the onset of a particular rainy season) probabilities under real world climates with those under a climate that might have been had human activities not emitted greenhouse gases. The fraction of risk of later onsets, attributable to an increase in greenhouse gases, is done in a spatially-explicit way for onset events derived from observed and reanalysis data for the 2007-2014 period.

  10. Lessons from implementation of ecohealth projects in Southern Africa: A principal investigator's perspective.

    PubMed

    Chimbari, Moses John

    2016-09-28

    Ecohealth projects are designed to garner ownership among all stakeholders, such as researchers, communities, local leadership and policy makers. Ideally, designs should ensure that implementation goes smoothly and that findings from studies benefit the stakeholders, particularly bringing changes to the communities researched. Paradoxically, the process is fraught with challenges associated with implementation. Notwithstanding these challenges, evidence from projects implemented in southern Africa justify the need to invest in the subject of ecohealth. This paper describes and discusses a principal investigator's experience of leading ecohealth projects in Zimbabwe between 2002 and 2005, in Botswana between 2010 and 2014 and in South Africa (ongoing). The discourse is centred on issues of project management and leadership, transdisciplinarity, students' involvement, data management, community engagement, dissemination of research findings and the role of institutions in project management and implementation. The paper concludes that the ecohealth approach is valuable and should be encouraged making the following recommendations; 1) principal investigators must have a good understanding of socio-ecological systems, have excellent project management and writing skills, 2) more than one PI should be involved in the day-to-day running of the project in order to avoid disruption of project activities in the event that the PI leaves the project before it ends, 3) researchers should be trained in ecohealth principles and methodologies at the time of building the research teams, 4) full proposals should be developed with active participation of communities and stakeholders in order to develop a shared vision, 5) involvement of postdoctoral fellows and dedicated researchers with postgraduate students should be encouraged to avoid situations where some objectives are not fully addressed because of the narrow nature of students' work; and 6) citizen science should be

  11. 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.

  12. 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

  13. Aeolian dust emissions in Southern Africa: field measurements of dynamics and drivers

    NASA Astrophysics Data System (ADS)

    Wiggs, Giles; Thomas, David; Washington, Richard; King, James; Eckardt, Frank; Bryant, Robert; Nield, Joanna; Dansie, Andrew; Baddock, Matthew; Haustein, Karsten; Engelstaedter, Sebastian; von Holdt, Johannah; Hipondoka, Martin; Seely, Mary

    2016-04-01

    Airborne dust derived from the world's deserts is a critical component of Earth System behaviour, affecting atmospheric, oceanic, biological, and terrestrial processes as well as human health and activities. However, very few data have been collected on the factors that control dust emission from major source areas, or on the characteristics of the dust that is emitted. Such a paucity of data limits the ability of climate models to properly account for the radiative and dynamical impacts triggered by atmospheric dust. This paper presents field data from the DO4 Models (Dust Observations for Models) project that aims to understand the drivers of variability in dust emission processes from major source areas in southern Africa. Data are presented from three field campaigns undertaken between 2011 and 2015. We analysed remote sensing data to identify the key geomorphological units in southern Africa which are responsible for emission of atmospheric dust. These are the Makgadikgadi pans complex in northern Botswana, the ephemeral river valleys of western Namibia, and Etosha Pan in northern Namibia. Etosha Pan is widely recognised as perhaps the most significant source of atmospheric dust in the southern hemisphere. We deployed an array of field equipment within each source region to measure the variability in and dynamics of aeolian erosivity, as well as dust concentration and flux characteristics. This equipment included up to 11 meteorological stations measuring wind shear stress and other standard climatic parameters, Cimel sun photometers, a LiDAR, sediment transport detectors, high-frequency dust concentration monitors, and dust flux samplers. Further data were gathered at each site on the dynamics of surface characteristics and erodibility parameters that impact upon erosion thresholds. These data were augmented by use of a Pi-Swerl portable wind tunnel. Our data represent the first collected at source for these key dust emission areas and highlight the

  14. Cowpea and peanut in southern Africa are nodulated by diverse Bradyrhizobium strains harboring nodulation genes that belong to the large pantropical clade common in Africa.

    PubMed

    Steenkamp, Emma T; Stepkowski, Tomasz; Przymusiak, Anna; Botha, Wilhelm J; Law, Ian J

    2008-09-01

    Cowpea (Vigna unguiculata) and peanut (Arachis hypogaea) in southern Africa are nodulated by a genetically diverse group of Bradyrhizobium strains. To determine the identity of these bacteria, a collection of 22 isolates originating from the root nodules of both hosts in Botswana and South Africa was investigated using the combined sequences for the core genome genes rrs, recA, and glnII. These data separated the majority of the isolates into one of three unique lineages that most likely represent novel Bradyrhizobium species. Some isolates were also conspecific with B. yuanmingense and with B. elkanii, although none grouped with B. japonicum, B. canariense or B. liaoningense. To study the evolution of nodulation genes in these bacteria, the common nodulation gene, nodA, and host-specific nodulation genes, nodZ, noeE, and noeI, were analyzed. The nodA phylogeny showed that the cowpea and peanut Bradyrhizobium isolates represent various locally adapted groups or ecotypes that form part of Clade III of the seven known BradyrhizobiumnodA clades. This large and highly diverse clade comprises all strains from sub-Saharan Africa, as well as some originating from the Americas, Australia, Indonesia, China and Japan. Some similar groupings were supported by the other nodulation genes, although the overall phylogenies for the nodulation genes were incongruent with that inferred from the core genome genes, suggesting that horizontal gene transfer significantly influences the evolution of cowpea and peanut root-nodule bacteria. Furthermore, identification of the nodZ, noeI, and noeE genes in the isolates tested indicates that African Bradyrhizobium species may produce highly decorated nodulation factors, which potentially represent an important adaptation enabling nodulation of a great variety of legumes inhabiting the African continent.

  15. Multispecimen and temper archeomagnetic studies: Application to Iron Age sites from southern Africa

    NASA Astrophysics Data System (ADS)

    Cottrell, R. D.; Tarduno, J. A.; Watkeys, M. K.; Huffman, T. N.

    2008-12-01

    Here we compare methods of paleointensity analysis as applied to pottery shards. We prefer the Thellier technique because of its foundation in basic rock physics and its associated reliability checks. Nevertheless, we recognize that additional techniques may be useful on problematic samples. We start with multiple specimen techniques. These are attractive because they can potentially address the presence of multidomain magnetic carriers. In addition, pottery shards can often be cut into multiple samples with nearly identical physical properties, and the magnetic component structure is often simple. Nevertheless, grain size effects appear to be present in synthetic samples used to test multi-specimen methods, and selection/rejection criteria are not fully developed. Irrespective of these issues, we find that results from multi- specimen experiments which yield linear results over a broad range of applied fields tend to agree well with results from Thellier runs. The results of other samples are more difficult to interpret, with apparent non- linear behavior at high and low-field values. We also introduce a new paleointensity approach: analysis of temper from pottery shards. This method is an extension of single crystal techniques, and relies on the addition of grains to the pot matrix prior to firing. As is the case in the analysis of lavas, careful separation and selection of grains is needed as temper is diverse between archeological areas. We apply these methods to a new collection of pottery shards from southern Africa, in hopes of constructing a Southern Hemisphere paleointensity record.

  16. Crustal structure of Nigeria and Southern Ghana, West Africa from P-wave receiver functions

    NASA Astrophysics Data System (ADS)

    Akpan, Ofonime; Nyblade, Andrew; Okereke, Chiedu; Oden, Michael; Emry, Erica; Julià, Jordi

    2016-04-01

    We report new estimates of crustal thickness (Moho depth), Poisson's ratio and shear-wave velocities for eleven broadband seismological stations in Nigeria and Ghana. Data used for this study came from teleseismic earthquakes recorded at epicentral distances between 30° and 95° and with moment magnitudes greater than or equal to 5.5. P-wave receiver functions were modeled using the Moho Ps arrival times, H-k stacking, and joint inversion of receiver functions and Rayleigh wave group velocities. The average crustal thickness of the stations in the Neoproterozoic basement complex of Nigeria is 36 km, and 23 km for the stations in the Cretaceous Benue Trough. The crustal structure of the Paleoproterozoic Birimian Terrain, and Neoproterozoic Dahomeyan Terrain and Togo Structural Unit in southern Ghana is similar, with an average Moho depth of 44 km. Poisson's ratios for all the stations range from 0.24 to 0.26, indicating a bulk felsic to intermediate crustal composition. The crustal structure of the basement complex in Nigeria is similar to the average crustal structure of Neoproterozoic terrains in other parts of Africa, but the two Neoproterozoic terrains in southern Ghana have a thicker crust with a thick mafic lower crust, ranging in thickness from 12 to 17 km. Both the thicker crust and thick mafic lower crustal section are consistent with many Precambrian suture zones, and thus we suggest that both features are relict from the collisional event during the formation of Gondwana.

  17. Rayleigh wave group velocity dispersion across Northern Africa, Southern Europe and the Middle East

    SciTech Connect

    McNamara, D.E.; Walter, W.R.

    1997-07-15

    THis report presents preliminary results from a large scale study of surface wave group velocity dispersion throughout Northern Africa, the Mediterranean, Southern Europe and the Middle East. Our goal is to better define the 3D lithospheric shear-wave velocity structure within this region by improving the resolution of global surface wave tomographic studies. We hope to accomplish this goal by incorporating regional data at relatively short periods (less than 40 sec), into the regionalization of lateral velocity variation. Due to the sparse distributions of stations and earthquakes throughout the region (Figure 1) we have relied on data recorded at both teleseismic and regions; distances. Also, to date we have concentrated on Rayleigh wave group velocity measurements since valuable measurements can be made without knowledge of the source. In order to obtain Rayleigh wave group velocity throughout the region, vertical component teleseismic and regional seismograms were gathered from broadband, 3-component, digital MEDNET, GEOSCOPE and IRIS stations plus the portable PASSCAL deployment in Saudi Arabia. Figure 1 shows the distribution of earthquakes (black circles) and broadband digital seismic stations (white triangles) throughout southern Europe, the middle east and northern Africa used in this study. The most seismicly active regions of northern Africa are the Atlas mountains of Morocco and Algeria as well as the Red Sea region to the east. Significant seismicity also occurs in the Mediterranean, southern Europe and throughout the high mountains and plateaus of the middle-east. To date, over 1300 seismograms have been analyzed to determine the individual group velocities of 10-150 second Rayleigh waves. Travel times, for each period, are then inverted in a back projection tomographic method in order to determine the lateral group velocity variation throughout the region. These results are preliminary, however, Rayleigh wave group velocity maps for a range of

  18. Shifts in Köppen-Geiger climate zones over southern Africa in relation to key global temperature goals

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Christien J.; Engelbrecht, Francois A.

    2016-01-01

    Potential changes in Köppen-Geiger climate zones over southern Africa (Africa south of 22 °S) under future climate change are investigated using an ensemble of high-resolution projections of a regional climate model. The projections are performed under the A2 scenario of the Special Report on Emission Scenarios (SRES), and changes are presented for those times in the future when the increase in global average surface temperature reaches thresholds of 1, 2, and 3 °C, relative to the present-day baseline climatology. Widespread shifts in climate regimes are projected, of which the southern and eastern expansion of the hot desert and hot steppe zones is the most prominent. From occupying 33.1 and 19.4 % of southern Africa under present-day climate, these regions are projected to occupy between 47.3 and 59.7 % (hot desert zone) and 24.9 and 29.9 % (hot steppe zone) of the region in a future world where the global temperature has increased by 3 °C. The cold desert and cold steppe zones are projected to decrease correspondingly. The temperate regions of eastern South Africa, the Cape south coast, and winter rainfall region of the southwestern Cape are also projected to contract. An expansion of the hot steppe zone into the cold steppe and temperate zones may favor the intrusion of trees (and therefore the savanna biome) into the most pristine grasslands of southern Africa. However, the correlative climate-vegetation approach of using projected changes in Köppen-Geiger zones to infer future vegetation patterns is of limited value in the savanna complex of southern Africa, where complex feedbacks occur between carbon dioxide (CO2) concentrations, trees, C4 grasses, fire, and climate. The present-day temperate Cape Fynbos regime may come under increasing pressure as the encompassing temperate zone is invaded mainly from the east by the hot steppe climate regime under climate change, with the incidence of Fynbos fires also becoming more likely in a generally warmer and

  19. The potential value of seasonal forecasts in a changing climate in southern Africa

    NASA Astrophysics Data System (ADS)

    Winsemius, H. C.; Dutra, E.; Engelbrecht, F. A.; Archer Van Garderen, E.; Wetterhall, F.; Pappenberger, F.; Werner, M. G. F.

    2014-04-01

    Subsistence farming in southern Africa is vulnerable to extreme weather conditions. The yield of rain-fed agriculture depends largely on rainfall-related factors such as total seasonal rainfall, anomalous onsets and lengths of the rainy season and the frequency of occurrence of dry spells. Livestock, in turn, may be seriously impacted by climatic stress with, for example, exceptionally hot days, affecting condition, reproduction, vulnerability to pests and pathogens and, ultimately, morbidity and mortality. Climate change may affect the frequency and severity of extreme weather conditions, impacting on the success of subsistence farming. A potentially interesting adaptation measure comprises the timely forecasting and warning of such extreme events, combined with mitigation measures that allow farmers to prepare for the event occurring. This paper investigates how the frequency of extreme events may change in the future due to climate change over southern Africa and, in more detail, the Limpopo Basin using a set of climate change projections from several regional climate model downscalings based on an extreme climate scenario. Furthermore, the paper assesses the predictability of these indicators by seasonal meteorological forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasting system. The focus is on the frequency of dry spells as well as the frequency of heat stress conditions expressed in the temperature heat index. In areas where their frequency of occurrence increases in the future and predictability is found, seasonal forecasts will gain importance in the future, as they can more often lead to informed decision-making to implement mitigation measures. The multi-model climate projections suggest that the frequency of dry spells is not likely to increase substantially, whereas there is a clear and coherent signal among the models of an increase in the frequency of heat stress conditions by the end of the century. The

  20. Responses to satellite remote sensing opportunities in East and Southern Africa

    NASA Astrophysics Data System (ADS)

    Falconer, Allan; Odenyo, Victor A. O.

    Since 1978 the U.S. Agency for International Development (USAID) has funded a regional remote sensing project for East and Southern Africa. The project, hosted by the Regional Centre for Services in Surveying Mapping and Remote Sensing, has provided a programme of training courses, user services and project support. This included the equipping and establishment of a photo-laboratory complex for processing Landsat images and the provision of advice and support for agencies undertaking natural resources analysis. Response to the training programme has been very good. Courses are usually over subscribed and there is a continued demand for training. Assessments of the courses by participants are highly positive and the courses have featured consultants of international calibre. Requests for follow-up courses, and for specialist group training indicate a strong response to this training activity. User services are active, consultations with staff, use of the browse file and interpretation equipment and the purchase of data for project work all produce an average demand of 12 active enquiries per working week. The photo-laboratory is particularly active and demand for products exceeds available capacity. Project work is now being supported but limited resources restrict the range and amount of project activity. Response to the opportunities offered for projects has been favourable and this activity is ripe for expansion. The difficulty in expanding to meet the expressed demand is primarily financial. The east and southern Africa region is not economically strong and has a great need for natural resources data for development work and planning. The responses to satellite remote sensing opportunities will be limited by these financial constraints which effectively means by the level of international aid directed to this activity. For such aid to be effective it must be coordinated and firmly attached to the region. Such coordinated aid programmes would avoid fragmentation

  1. Foraging potential of underground storage organ plants in the southern Cape, South Africa.

    PubMed

    Singels, Elzanne; Potts, Alastair J; Cowling, Richard M; Marean, Curtis W; De Vynck, Jan; Esler, Karen J

    2016-12-01

    Underground storage organs (USOs) serve as a staple source of carbohydrates for many hunter-gatherer societies and they feature prominently in discussions of diets of early modern humans. While the way of life of hunter-gatherers in South Africa's Cape no longer exists, there is extensive ethnographic, historical, and archaeological evidence of hunter-gatherers' use of USOs. This is to be expected, given that the Cape supports the largest concentration of plant species with USOs globally. The southern Cape is the location of several Middle Stone Age sites that are highly significant to research on the origins of behaviourally modern humans, and this provided the context for our research. Here, we evaluate the foraging potential of USOs by identifying how abundant edible biomass is in the southern Cape, how easily it is gathered, and how nutritious it is. One hundred 5 × 5 m plots were assessed in terms of USO species and abundance. Nearly all of the sites sampled (83%) contained edible USOs and some had high concentrations of edible biomass. Extrapolating from these sites suggests that the edible USO biomass falls within the range of biomass observed in areas supporting extant hunter-gatherer communities. The nutritional content for six USO species was assessed; these contained between 40 and 228 calories/100 g. Furthermore, foraging events were staged to provide an indication of the potential return rates for the same six USOs. The target species grow near the soil surface, mostly in sandy soils, and were gathered with minimal effort. Some 50% of the foraging events conducted yielded enough calories to meet the daily requirements of a hunter-gatherer within two hours. In conclusion, we demonstrate that USOs are a readily available source of carbohydrates in the southern Cape landscape and, therefore, there is a strong possibility that USOs played a critical role in providing food for early humans.

  2. 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

  3. [Epidemic typhus in Africa].

    PubMed

    Ndihokubwayo, J B; Raoult, D

    1999-01-01

    Epidemic typhus is caused by a small strictly intracellular virus named Rickettsia prowazekii, a member of the Rickettsial family. It is transmitted to man by the body louse, Pediculus humanus. Although now rare in Western countries, exanthematic typhus remains common in the Southern hemisphere due to poverty, inadequate clothing hygiene, and poor socioeconomic conditions. In Africa, outbreaks have historically occurred in Burundi, Rwanda, southwest Ouganda, and Ethiopia. The largest outbreak of epidemic typhus since the World War II was reported in Burundi where ongoing civil war since October 1993 has forced 10 p. 100 of the population of Burundi to live in cold, promiscuity, and malnutrition of makeshift refugee camps. The purpose of this report based on our two-year experience working with this unfortunate population is to describe the characteristics of this disease in Africa where the epidemic form had become rare until recently. Indeed political unrest as well as numerous civil wars are now epidmiological factors favorizing outbreaks of epidemic typhus at any time. This overview also provides an opportunity to recall epidemiological, bacteriological, and clinical aspects of typhus as well as diagnosis and treatment of the disease in the context of Africa.

  4. Using Tournament Angler Data to Rapidly Assess the Invasion Status of Alien Sport Fishes (Micropterus spp.) in Southern Africa

    PubMed Central

    Hargrove, John S.; Weyl, Olaf L. F.; Allen, Micheal S.; Deacon, Neil R.

    2015-01-01

    Fishes are one of the most commonly introduced aquatic taxa worldwide, and invasive fish species pose threats to biodiversity and ecosystem function in recipient waters. Considerable research efforts have focused on predicting the invasibility of different fish taxa; however, accurate records detailing the establishment and spread of invasive fishes are lacking for large numbers of fish around the globe. In response to these data limitations, a low-cost method of cataloging and quantifying the temporal and spatial status of fish invasions was explored. Specifically, angler catch data derived from competitive bass angling tournaments was used to document the distribution of 66 non-native populations of black bass (Micropterus spp.) in southern Africa. Additionally, catch data from standardized tournament events were used to assess the abundance and growth of non-native bass populations in southern Africa relative to their native distribution (southern and eastern United States). Differences in metrics of catch per unit effort (average number of fish retained per angler per day), daily bag weights (the average weight of fish retained per angler), and average fish weight were assessed using catch data from 14,890 angler days of tournament fishing (11,045 days from South Africa and Zimbabwe; 3,845 days from the United States). No significant differences were found between catch rates, average daily bag weight, or the average fish weight between countries, suggesting that bass populations in southern Africa reach comparable sizes and numbers relative to waters in their native distribution. Given the minimal cost associated with data collection (i.e. records are collected by tournament organizers), the standardized nature of the events, and consistent bias (i.e. selection for the biggest fish in a population), the use of angler catch data represents a novel approach to infer the status and distribution of invasive sport fish. PMID:26047487

  5. Using Tournament Angler Data to Rapidly Assess the Invasion Status of Alien Sport Fishes (Micropterus spp.) in Southern Africa.

    PubMed

    Hargrove, John S; Weyl, Olaf L F; Allen, Micheal S; Deacon, Neil R

    2015-01-01

    Fishes are one of the most commonly introduced aquatic taxa worldwide, and invasive fish species pose threats to biodiversity and ecosystem function in recipient waters. Considerable research efforts have focused on predicting the invasibility of different fish taxa; however, accurate records detailing the establishment and spread of invasive fishes are lacking for large numbers of fish around the globe. In response to these data limitations, a low-cost method of cataloging and quantifying the temporal and spatial status of fish invasions was explored. Specifically, angler catch data derived from competitive bass angling tournaments was used to document the distribution of 66 non-native populations of black bass (Micropterus spp.) in southern Africa. Additionally, catch data from standardized tournament events were used to assess the abundance and growth of non-native bass populations in southern Africa relative to their native distribution (southern and eastern United States). Differences in metrics of catch per unit effort (average number of fish retained per angler per day), daily bag weights (the average weight of fish retained per angler), and average fish weight were assessed using catch data from 14,890 angler days of tournament fishing (11,045 days from South Africa and Zimbabwe; 3,845 days from the United States). No significant differences were found between catch rates, average daily bag weight, or the average fish weight between countries, suggesting that bass populations in southern Africa reach comparable sizes and numbers relative to waters in their native distribution. Given the minimal cost associated with data collection (i.e. records are collected by tournament organizers), the standardized nature of the events, and consistent bias (i.e. selection for the biggest fish in a population), the use of angler catch data represents a novel approach to infer the status and distribution of invasive sport fish.

  6. Terrorism in South Africa.

    PubMed

    MacFarlane, Campbell

    2003-01-01

    The Republic of South Africa lies at the southern tip of the African continent. The population encompasses a variety of races, ethnic groups, religions, and cultural identities. The country has had a turbulent history from early tribal conflicts, colonialisation, the apartheid period, and post-apartheid readjustment. Modern terrorism developed mainly during the apartheid period, both by activities of the state and by the liberation movements that continued to the time of the first democratic elections in 1994, which saw South Africa evolve into a fully representative democratic state with equal rights for all. Since 1994, terrorist acts have been criminal-based, evolving in the Cape Town area to political acts, largely laid at the feet of a predominantly Muslim organisation, People against Gangsterism and Drugs, a vigilant organisation allegedly infiltrated by Muslim fundamentalists. Along with this, has been terrorist activities, mainly bombings by disaffected members of white, right-wing groups. In the apartheid era, a Draconian series of laws was enacted to suppress liberation activities. After 1994, most of these were repealed and new legislation was enacted, particularly after the events of 11 September 2001; this legislation allows the government to act against terrorism within the constraints of a democratic system. Disaster management in South Africa has been largely local authority-based, with input from provincial authorities and Civil Defence. After 1994, attempts were made to improve this situation, and national direction was provided. After 11 September 2001, activity was increased and the Disaster Management Act 2002 was brought into effect. This standardized disaster management system at national, provincial, and local levels, also facilites risk assessment and limitation as well as disaster mitigation. The potential still exists for terrorism, mainly from right-wing and Muslim fundamentalist groups, but the new legislation should stimulate disaster

  7. Rock weathering on the eastern mountains of southern Africa: Review and insights from case studies

    NASA Astrophysics Data System (ADS)

    Sumner, P. D.; Hall, K. J.; van Rooy, J. L.; Meiklejohn, K. I.

    2009-12-01

    The mountains in the eastern region of southern Africa are of significant regional importance, providing for a diverse range of land use including conservation, tourism and subsistence agriculture. The higher regions are comprised of flood basalts and are immediately underlain by predominantly aeolian-origin sandstones. Our understanding of the weathering of these basalts and sandstones is reviewed here, with particular focus on the insights gained from the Lesotho Highlands Water Project and an ongoing study into the deterioration of rock art. While the chemical weathering attributes of the basalts have been substantially investigated, it is evident that the environmental surface conditions of rock moisture and temperature, as affecting weathering processes, remain largely unknown. Within the sandstones, studies pertaining to rock art deterioration present insights into the potential surface weathering processes and highlight the need for detailed field monitoring. Outside of these site-specific studies, however, little is understood of how weathering impacts on landscape development; notably absent, are detail on weathering rates, and potential effects of biological weathering. Some palaeoenvironmental inferences have also been made from weathering products, both within the basalts and the sandstones, but aspects of these remain controversial and further detailed research can still be undertaken.

  8. Particle and Gas Emissions From a Savanna Fire From Biomass Burning in Southern Africa

    NASA Astrophysics Data System (ADS)

    Hobbs, P. V.; Sinha, P.; Jilek, B.; Yokelson, R. J.; Blake, D. R.

    2001-12-01

    Airborne measurements of the emissions of particles and gases from a 1000 ha prescribed savanna fire in the Timbavati Game Park, South Africa, were obtained on September 7, 2000, during the Southern African Fire-Atmosphere Research Initiative 2000 (SAFARI-2000) field study. These measurements provide enhancement ratios and emission factors at various points downwind of the fire for a number of gaseous and particulate species, including CO2, CO, SO2, NOx, methane, non-methane hydrocarbons, halocarbons, organic acids, ionic aerosol, organic aerosols, and condensation nuclei (CN). The structure of the plume is revealed by profiles of CN concentrations and light scattering along the length of the plume. The decay of reactive hydrocarbons and the complementary formation of formaldehyde, ozone, and acetic acid are shown downwind of the fire. Aerosol size distributions show increases in concentrations of particles greater than 0.1 μ m in diameter with increasing distance from the fire. As the fire aged, emission factors of CO2 decreased while those of CO increased, indicating a shift from flaming to smoldering combustion. Vertical profiles of trace gases show peaks in water vapor, SO2, O3, and CN beneath strong temperature inversions above the fire. >http://cargsun2.atmos.washington.edu/sys/research/safari/

  9. Individual aerosol particles from biomass burning in southern Africa: 2, Compositions and aging of inorganic particles

    NASA Astrophysics Data System (ADS)

    Li, Jia; Pósfai, MiháLy; Hobbs, Peter V.; Buseck, Peter R.

    2003-07-01

    Individual aerosol particles collected over southern Africa during the SAFARI 2000 field study were studied using transmission electron microscopy and field-emission scanning electron microscopy. The sizes, shapes, compositions, mixing states, surface coatings, and relative abundances of aerosol particles from biomass burning, in boundary layer hazes, and in the free troposphere were compared, with emphasis on aging and reactions of inorganic smoke particles. Potassium salts and organic particles were the predominant species in the smoke, and most were internally mixed. More KCl particles occur in young smoke, whereas more K2SO4 and KNO3 particles were present in aged smoke. This change indicates that with the aging of the smoke, KCl particles from the fires were converted to K2SO4 and KNO3 through reactions with sulfur- and nitrogen-bearing species from biomass burning as well as other sources. More soot was present in smoke from flaming grass fires than bush and wood fires, probably due to the predominance of flaming combustion in grass fires. The high abundance of organic particles and soluble salts can affect the hygroscopic properties of biomass-burning aerosols and therefore influence their role as cloud condensation nuclei. Particles from biomass burning were important constituents of the regional hazes.

  10. Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season

    SciTech Connect

    Kirchstetter, Thomas W.; Novakov, T.; Hobbs, Peter V.; Magi, Brian

    2002-06-17

    Particulate matter collected aboard the University of Washington's Convair-580 research aircraft over southern Africa during the dry, biomass burning season was analyzed for total carbon, organic carbon, and black carbon contents using thermal and optical methods. Samples were collected in smoke plumes of burning savanna and in regional haze. A known artifact, produced by the adsorption of organic gases on the quartz filter substrates used to collect the particulate matter samples, comprised a significant portion of the total carbon collected. Consequently, conclusions derived from the data are greatly dependent on whether or not organic carbon concentrations are corrected for this artifact. For example, the estimated aerosol co-albedo (1 - single scattering albedo), which is a measure of aerosol absorption, of the biomass smoke samples is 60 percent larger using corrected organic carbon concentrations. Thus, the corrected data imply that the biomass smoke is 60 percent more absorbing than do the uncorrected data. The black carbon to (corrected) organic carbon mass ratio (BC/OC) of smoke plume samples (0.18/2610.06) is lower than that of samples collected in the regional haze (0.25/2610.08). The difference may be due to mixing of biomass smoke with background air characterized by a higher BC/OC ratio. A simple source apportionment indicates that biomass smoke contributes about three-quarters of the aerosol burden in the regional haze, while other sources (e.g., fossil fuel burning) contribute the remainder.

  11. Sustainability of NGO capacity building in southern Africa: successes and opportunities.

    PubMed

    Humphries, Debbie; Gomez, Ligia; Hartwig, Kari

    2011-01-01

    Despite an increase in organizational capacity building efforts by external organizations in low and middle income countries, the documentation of these efforts and their effects on health programs and systems remains limited. This paper reviews key frameworks for considering sustainability of capacity building and applies these frameworks to an evaluation of the sustainability of an AIDS non-governmental organization (NGO) capacity building initiative. From 2004-2007 Bristol-Myers Squibb Foundation's Secure the Future(TM) initiative in southern Africa funded a five country program, the NGO Training Institute (NGOTI), to build capacity of NGOs working to address HIV/AIDS. Lessons learned from this project include issues of ownership, the importance of integrating planning for sustainability within capacity-building projects, and the value of identifying primary capacity-building objectives in order to select sustainability strategies that are focused on maintaining program benefits. Sustainability for capacity building projects can be developed by discussing key issues early in the planning process with all primary stakeholders.

  12. Dynamic Locomotor Capabilities Revealed by Early Dinosaur Trackmakers from Southern Africa

    PubMed Central

    Wilson, Jeffrey A.; Marsicano, Claudia A.; Smith, Roger M. H.

    2009-01-01

    Background A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs. Methodology/Principal Findings The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently. Whereas the theropod trackmaker accommodated sloping and slippery surfaces by gripping the substrate with its pedal claws, the basal ornithischian trackmakers adjusted to the terrain by changing between quadrupedal and bipedal stance, wide and narrow gauge limb support (abduction range = 31°), and plantigrade and digitigrade foot posture. Conclusions/Significance The locomotor adjustments coincide with changes in substrate consistency along the trackway and appear to reflect ‘real time’ responses to a complex terrain. It is proposed that these responses foreshadow important locomotor transformations characterizing the later evolution of the two main dinosaur lineages. Ornithischians, which shifted from bipedal to quadrupedal posture at least three times in their evolutionary history, are shown to have been capable of adopting both postures early in their evolutionary history. The substrate-gripping behavior demonstrated by the early theropod, in turn, is consistent with the hypothesized function of pedal claws in bird ancestors. PMID:19806213

  13. Groundwater supply and demand from southern Africa's crystalline basement aquifer: evidence from Malawi

    NASA Astrophysics Data System (ADS)

    Robins, Nick; Davies, Jeffrey; Farr, John

    2013-06-01

    Failure of borehole sources in weathered and fractured crystalline basement aquifers in Malawi in southern Africa has been linked with poor borehole design, mechanical failure and badly sited boreholes. However, recent work in Malawi indicates that demand may now exceed long-term resource potential in some places and that this is also a cause of water point failure. An 11-year climate cycle (including a wet and dry period) necessitates overdraft from groundwater storage during the dry-cycle years before episodic rainfall events in the wetter part of the cycle again recharge the aquifers. Data, particularly groundwater hydrograph data, are sparse, but sufficient to evaluate the long-term renewable groundwater potential for both fractured and weathered basement-aquifer types in each of the 15 management areas in Malawi. The groundwater potential or long-term renewable resource (recharge) is given by the sum of Darcian throughflow and dry-season depletion of storage. Estimated rural demand exceeds the renewable resource in the fractured-rock aquifer in two management units and in the weathered-rock aquifer in two other units. Although there is inherent uncertainty in the water-balance estimates, the likelihood that rural demand is exceeding long-term average recharge in some areas is cause for concern.

  14. An Overview of SASSCAL Activities Supporting Interdisciplinary Water Research in Southern Africa

    NASA Astrophysics Data System (ADS)

    Helmschrot, J.; Jürgens, N.

    2013-12-01

    Climate change will affect current water resources in sub-Saharan Africa. Considering projected climate scenarios, the overall challenge in the southern African region is to secure water at sufficient quality and quantity for both, the stability of ecosystems with their functions and services as well as for human well-being (potable water, irrigation water, and water for industrial use). Thus, improved understanding of the linkages between hydrological (including hydro-geological) components of ecosystems and society is needed as a precondition to develop sustainable management strategies for integrated water resources management in this data scarce region. Funded by the German Ministry of Education and Research (BMBF), 87 research projects of the SASSCAL Initiative (Southern African Science Service Centre for Climate Change and Adaptive Land Management) focus on providing information and services allowing for a better understanding and assessment of the impact of climate and land management changes in five thematic areas, namely climate, water, agriculture, forestry and biodiversity. Water-related research activities in SASSCAL aim to improve our knowledge on the complex interactions and feedbacks between surface and groundwater dynamics and resources as well as land surface processes in selected regions of the participating countries (Angola, Botswana, Namibia, South Africa and Zambia). The main objective of this joint and integrated research effort is to develop reliable hydrological and hydro-geological baseline data along with a set of analytical methods to strengthen the research capacity of the water sector of the Southern African region. Thereby, SASSCAL contributes to the implemention of integrated water resources management strategies for improved trans-boundary river management and resources usage in the perspective of global climate and land management changes. Here, we present an overview and first results of ongoing studies conducted by various

  15. The nexus between integrated natural resources management and integrated water resources management in southern Africa

    NASA Astrophysics Data System (ADS)

    Twomlow, Stephen; Love, David; Walker, Sue

    The low productivity of smallholder farming systems and enterprises in the drier areas of the developing world can be attributed mainly to the limited resources of farming households and the application of inappropriate skills and practices that can lead to the degradation of the natural resource base. This lack of development, particularly in southern Africa, is of growing concern from both an agricultural and environmental perspective. To address this lack of progress, two development paradigms that improve land and water productivity have evolved, somewhat independently, from different scientific constituencies. One championed by the International Agricultural Research constituency is Integrated Natural Resource Management (INRM), whilst the second championed predominantly by Environmental and Civil Engineering constituencies is Integrated Water Resources Management (IWRM). As a result of similar objectives of working towards the millennium development goals of improved food security and environmental sustainability, there exists a nexus between the constituencies of the two paradigms, particularly in terms of appreciating the lessons learned. In this paper lessons are drawn from past INRM research that may have particular relevance to IWRM scientists as they re-direct their focus from blue water issues to green water issues, and vice-versa. Case studies are drawn from the management of water quality for irrigation, green water productivity and a convergence of INRM and IWRM in the management of gold panning in southern Zimbabwe. One point that is abundantly clear from both constituencies is that ‘one-size-fits-all’ or silver bullet solutions that are generally applicable for the enhancement of blue water management/formal irrigation simply do not exist for the smallholder rainfed systems.

  16. Spatial and seasonal variations in CCN distribution and the aerosol-CCN relationship over southern Africa

    NASA Astrophysics Data System (ADS)

    Ross, K. E.; Piketh, S. J.; Bruintjes, R. T.; Burger, R. P.; Swap, R. J.; Annegarn, H. J.

    2003-07-01

    The sources and transport of cloud condensation nuclei (CCN) over southern Africa have been investigated using in situ measurements collected during the Aerosol Recirculation and Rainfall Experiment (ARREX) wet season projects and during the Southern African Regional Science Initiative (SAFARI-2000) intensive dry season campaign. CCN concentrations over the subcontinent are generally higher in the dry season than in the wet season and exceed 2000 cm-3 in highly polluted air masses. In the late dry season, CCN concentrations are highest in the northern regions of the subcontinent due to the burning of savanna biomass. Emissions from industries and power plants on the South African Highveld are a prolific year-round source of CCN and are sufficient to account for CCN levels south of 20°S throughout the year. Most CCN are contained within the mixing layer, which extends to an altitude of 3000-4000 m over the plateau and is capped by a temperature inversion. Multiple inversions and absolutely stable layers control the stratification of aerosols and CCN. Biomass burning particles are efficient CCN, and the median diameter of the accumulation mode is large (up to 0.19 μm). Recently emitted industrial aerosols are less soluble and have a smaller median diameter (0.11 μm). Twice as many aerosols act as CCN in the dry season (68%) than in the wet season (34%). The fraction is highest in the dry season over the tropical regions (>80%), where smoke aerosol predominates. Elevated aerosol and CCN concentrations are expected to have implications for direct radiative forcing, especially in the dry season, and for indirect forcing in the wet season.

  17. Documentary evidence of climate variability during cold seasons in Lesotho, southern Africa, 1833-1900

    NASA Astrophysics Data System (ADS)

    Grab, Stefan W.; Nash, David J.

    2010-03-01

    This study presents the first 19th century cold season climate chronology for the Kingdom of Lesotho in southern Africa. The chronology is constructed using a variety of documentary sources including letters, diaries, reports, monographs and newspaper articles obtained from southern African and British archives. Information relating to cold season weather phenomena during the austral autumn, winter and early spring months were recorded verbatim. Each of the cold seasons from 1833 to 1900 was then classified as “very severe”, “severe” or “normal/mild”, with a confidence rating ranging from low (1) to high (3) awarded against each annual classification. The accuracy of the document-derived chronology was verified against temperature data for Maseru for the period 1893-1900. Excellent correspondence of the document-derived chronology with the Maseru instrumental data and also with other global proxy temperature records for the 19th century is achieved. The results indicate 12 (18% of the total) very severe, 16 (23%) severe and 40 (59%) normal/mild cold seasons between 1833 and 1900. The overall trend is for more severe and snow-rich cold seasons during the early part of the study period (1833-1854) compared with the latter half of the 19th century (with the exception of the 1880s). A reduction in the duration of the frost season by over 20 days during the 19th century is also tentatively identified. Several severe to very severe cold seasons in Lesotho follow after major tropical and SH volcanic eruptions; such years are usually characterized by early frosts, and frequent and heavy snowfalls. The blocking of solar radiation and the enhanced northward displacement of polar fronts that are directly or indirectly associated with volcanic events, may account for many of the most severe Lesotho winters during the 19th century.

  18. Documentary evidence of climate variability during cold seasons in Lesotho, southern Africa, 1833-1900

    NASA Astrophysics Data System (ADS)

    Grab, S. W.; Nash, D. J.

    2009-04-01

    This study presents the first 19th century cold season climate chronology for the Kingdom of Lesotho in southern Africa. The chronology is constructed using a variety of documentary sources including letters, diaries, reports, monographs and newspaper articles obtained from southern African and British archives. Information relating to cold season weather phenomena during the austral autumn, winter and early spring months were recorded verbatim. Each of the cold seasons from 1833 to 1900 was then classified as ‘very severe', ‘severe' or ‘normal/mild', with a confidence rating ranging from low (1) to high (3) awarded against each annual classification. The accuracy of the document-derived chronology was verified against temperature data for Maseru for the period 1893-1900. Excellent correspondence of the document-derived chronology with the Maseru instrumental data and also with other global proxy temperature records for the 19th century is achieved. The results indicate 12 (18% of the total) very severe, 16 (23%) severe and 40 (59%) normal/mild cold seasons between 1833 and 1900. The overall trend is for more severe and snow-rich cold seasons during the early part of the study period (1833-1854) compared with the latter half of the 19th century (with the exception of the 1880s). A reduction in the duration of the frost season by over 20 days during the 19th century is also tentatively identified. Several severe to very severe cold seasons in Lesotho follow after major tropical and SH volcanic eruptions; such years are usually characterized by early frosts, and frequent and heavy snowfalls. The blocking of solar radiation and the enhanced northward displacement of polar fronts that are directly or indirectly associated with volcanic events, may account for many of the most severe Lesotho winters during the 19th century. Keywords: Cold season chronology, 19th century, Lesotho, volcanic forcing

  19. Emplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa

    NASA Astrophysics Data System (ADS)

    Fontana, Giovanni; Mac Niocaill, Conall; Brown, Richard J.; Sparks, R. Stephen J.; Field, Matthew

    2011-10-01

    Palaeomagnetic techniques for estimating the emplacement temperatures of volcanic deposits have been applied to pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa. Lithic clasts were sampled from a variety of lithofacies from three pipes for which the internal geology is well constrained (the Cretaceous A/K1 pipe, Orapa Mine, Botswana, and the Cambrian K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions, layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Basalt lithic clasts in the layered and massive vent-filling pyroclastic deposits in the A/K1 pipe at Orapa were emplaced at >570°C, in the pyroclastic crater-filling deposits at 200-440°C and in crater-filling talus breccias and volcaniclastic breccias at <180°C. The results from the K1 and K2 pipes at Venetia suggest emplacement temperatures for the vent-filling breccias of 260°C to >560°C, although the interpretation of these results is hampered by the presence of Mesozoic magnetic overprints. These temperatures are comparable to the estimated emplacement temperatures of other kimberlite deposits and fall within the proposed stability field for common interstitial matrix mineral assemblages within vent-filling volcaniclastic kimberlites. The temperatures are also comparable to those obtained for pyroclastic deposits in other, silicic, volcanic systems. Because the lithic content of the studied deposits is 10-30%, the initial bulk temperature of the pyroclastic mixture of cold lithic clasts and juvenile kimberlite magma could have been 300-400°C hotter than the palaeomagnetic estimates. Together with the discovery of welded and agglutinated juvenile pyroclasts in some pyroclastic kimberlites, the palaeomagnetic results indicate that there are examples of kimberlites where phreatomagmatism did not play a major role in the generation

  20. Migration and interaction in a contact zone: mtDNA variation among Bantu-speakers in Southern Africa.

    PubMed

    Barbieri, Chiara; Vicente, Mário; Oliveira, Sandra; Bostoen, Koen; Rocha, Jorge; Stoneking, Mark; Pakendorf, Brigitte

    2014-01-01

    Bantu speech communities expanded over large parts of sub-Saharan Africa within the last 4000-5000 years, reaching different parts of southern Africa 1200-2000 years ago. The Bantu languages subdivide in several major branches, with languages belonging to the Eastern and Western Bantu branches spreading over large parts of Central, Eastern, and Southern Africa. There is still debate whether this linguistic divide is correlated with a genetic distinction between Eastern and Western Bantu speakers. During their expansion, Bantu speakers would have come into contact with diverse local populations, such as the Khoisan hunter-gatherers and pastoralists of southern Africa, with whom they may have intermarried. In this study, we analyze complete mtDNA genome sequences from over 900 Bantu-speaking individuals from Angola, Zambia, Namibia, and Botswana to investigate the demographic processes at play during the last stages of the Bantu expansion. Our results show that most of these Bantu-speaking populations are genetically very homogenous, with no genetic division between speakers of Eastern and Western Bantu languages. Most of the mtDNA diversity in our dataset is due to different degrees of admixture with autochthonous populations. Only the pastoralist Himba and Herero stand out due to high frequencies of particular L3f and L3d lineages; the latter are also found in the neighboring Damara, who speak a Khoisan language and were foragers and small-stock herders. In contrast, the close cultural and linguistic relatives of the Herero and Himba, the Kuvale, are genetically similar to other Bantu-speakers. Nevertheless, as demonstrated by resampling tests, the genetic divergence of Herero, Himba, and Kuvale is compatible with a common shared ancestry with high levels of drift, while the similarity of the Herero, Himba, and Damara probably reflects admixture, as also suggested by linguistic analyses.

  1. Extra Tuition in Southern and Eastern Africa: Coverage, Growth, and Linkages with Pupil Achievement

    ERIC Educational Resources Information Center

    Paviot, Laura; Heinsohn, Nina; Korkman, Julia

    2008-01-01

    The phenomenon of extra tuition is witnessed in many countries and some educationalists have described it as a parallel education system. However, the incidence and impact of extra tuition have often not been studied systematically, especially in Africa. In this article cross-national data for six African education systems (Kenya, Malawi,…

  2. Distance Education in Southern Africa Conference, 1987. Papers 7: Late Submissions.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Ten papers and four abstracts of papers from the University of South Africa's Conference on Distance Education are presented. They include: "Access to Higher Education and Training in the South Pacific: The Role of Telecommunications and Distance Education" (Som Naidu); "Distance Education in Japan" (Takashi Sakamoto);…

  3. The Efficacy of Prevention: Improving the Status of Children in Southern Africa.

    ERIC Educational Resources Information Center

    Norward, Josephine Norma

    1994-01-01

    Assesses a range of recent atrocities and apparently resultant problems experienced by children in areas of Namibia, Mozambique, and South Africa. Includes data from the literature and personal impressions from visits and extended periods of stay. Recommends expansion of birth control programs and awareness. (RAH)

  4. Going to the Bush: Language, Power and the Conserved Environment in Southern Africa

    ERIC Educational Resources Information Center

    Cloete, Elsie L.

    2011-01-01

    English, in the words of Bill Bryson, "is one of the world's great growth industries". Like some kind of metalanguage with its own Europe-based meaning systems, it has constructed its own discourses in relation to Africa's conserved natural environment, nature documentaries, tourism and environmental education--at the expense of…

  5. A progressively wetter climate in southern East Africa over the past 1.3 million years.

    PubMed

    Johnson, T C; Werne, J P; Brown, E T; Abbott, A; Berke, M; Steinman, B A; Halbur, J; Contreras, S; Grosshuesch, S; Deino, A; Scholz, C A; Lyons, R P; Schouten, S; Damsté, J S Sinninghe

    2016-09-08

    African climate is generally considered to have evolved towards progressively drier conditions over the past few million years, with increased variability as glacial-interglacial change intensified worldwide. Palaeoclimate records derived mainly from northern Africa exhibit a 100,000-year (eccentricity) cycle overprinted on a pronounced 20,000-year (precession) beat, driven by orbital forcing of summer insolation, global ice volume and long-lived atmospheric greenhouse gases. Here we present a 1.3-million-year-long climate history from the Lake Malawi basin (10°-14° S in eastern Africa), which displays strong 100,000-year (eccentricity) cycles of temperature and rainfall following the Mid-Pleistocene Transition around 900,000 years ago. Interglacial periods were relatively warm and moist, while ice ages were cool and dry. The Malawi record shows limited evidence for precessional variability, which we attribute to the opposing effects of austral summer insolation and the temporal/spatial pattern of sea surface temperature in the Indian Ocean. The temperature history of the Malawi basin, at least for the past 500,000 years, strongly resembles past changes in atmospheric carbon dioxide and terrigenous dust flux in the tropical Pacific Ocean, but not in global ice volume. Climate in this sector of eastern Africa (unlike northern Africa) evolved from a predominantly arid environment with high-frequency variability to generally wetter conditions with more prolonged wet and dry intervals.

  6. South[ern] Africa's "Dar ul-'Ulums": Institutions of Social Change for the Common Good?

    ERIC Educational Resources Information Center

    Haron, Muhammed

    2014-01-01

    Muslim communities in principally non-Muslim nation states (e.g. South Africa, United States of America, the United Kingdom and the Netherlands) established a plethora of Muslim theological institutions. They have done so with the purpose of educating and reinforcing their Muslim identity. These educational structures have given rise to numerous…

  7. African Buffalo Movement and Zoonotic Disease Risk across Transfrontier Conservation Areas, Southern Africa.

    PubMed

    Caron, Alexandre; Cornelis, Daniel; Foggin, Chris; Hofmeyr, Markus; de Garine-Wichatitsky, Michel

    2016-02-01

    We report on the long-distance movements of subadult female buffalo within a Transfrontier Conservation Area in Africa. Our observations confirm that bovine tuberculosis and other diseases can spread between buffalo populations across national parks, community land, and countries, thus posing a risk to animal and human health in surrounding wildlife areas.

  8. Tertiary Education Curricula Internationalisation in Southern Africa: Its Impact on Global Employment Opportunities

    ERIC Educational Resources Information Center

    Gwakwa, Milton

    2016-01-01

    While education systems in Africa share common backgrounds historically (educationally, socially, politically, economically and culturally), they are deep variations in the approaches and contexts resulting in many questions than answers. The purpose of this study was to interrogate the current tertiary education curriculum, provide a rationale…

  9. A progressively wetter climate in southern East Africa over the past 1.3 million years

    NASA Astrophysics Data System (ADS)

    Johnson, T. C.; Werne, J. P.; Brown, E. T.; Abbott, A.; Berke, M.; Steinman, B. A.; Halbur, J.; Contreras, S.; Grosshuesch, S.; Deino, A.; Scholz, C. A.; Lyons, R. P.; Schouten, S.; Damsté, J. S. Sinninghe

    2016-09-01

    African climate is generally considered to have evolved towards progressively drier conditions over the past few million years, with increased variability as glacial-interglacial change intensified worldwide. Palaeoclimate records derived mainly from northern Africa exhibit a 100,000-year (eccentricity) cycle overprinted on a pronounced 20,000-year (precession) beat, driven by orbital forcing of summer insolation, global ice volume and long-lived atmospheric greenhouse gases. Here we present a 1.3-million-year-long climate history from the Lake Malawi basin (10°-14° S in eastern Africa), which displays strong 100,000-year (eccentricity) cycles of temperature and rainfall following the Mid-Pleistocene Transition around 900,000 years ago. Interglacial periods were relatively warm and moist, while ice ages were cool and dry. The Malawi record shows limited evidence for precessional variability, which we attribute to the opposing effects of austral summer insolation and the temporal/spatial pattern of sea surface temperature in the Indian Ocean. The temperature history of the Malawi basin, at least for the past 500,000 years, strongly resembles past changes in atmospheric carbon dioxide and terrigenous dust flux in the tropical Pacific Ocean, but not in global ice volume. Climate in this sector of eastern Africa (unlike northern Africa) evolved from a predominantly arid environment with high-frequency variability to generally wetter conditions with more prolonged wet and dry intervals.

  10. Distance Education in Southern Africa Conference, 1987. Papers 5: Administration and Student Support in Distance Education.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Seventeen papers from the University of South Africa's Conference on Distance Education are presented. They include: "Establishing a Formal Student Support System--Time Is of the Essence" (Karen Hinrichs); "A Student Services Unit in a Distance Education Institution" (Hendrik Gous); "Distance Education and the Community:…

  11. Distance Education in Southern Africa Conference, 1987. Papers 1: The Theory and Practice of Distance Education.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Fifteen papers from the University of South Africa's Conference on Distance Education are presented on the theory and practice of distance education. Titles and authors include: "Evaluation at a Distance" (Margalit Ganor); "Can the Tables Be Turned? Likelihood That Distance Teaching at University Can Be More Effective Than…

  12. South-South medical tourism and the quest for health in Southern Africa.

    PubMed

    Crush, Jonathan; Chikanda, Abel

    2015-01-01

    Intra-regional South-South medical tourism is a vastly understudied subject despite its significance in many parts of the Global South. This paper takes issue with the conventional notion of South Africa purely as a high-end "surgeon and safari" destination for medical tourists from the Global North. It argues that South-South movement to South Africa for medical treatment is far more significant, numerically and financially, than North-South movement. The general lack of access to medical diagnosis and treatment in SADC countries has led to a growing temporary movement of people across borders to seek help at South African institutions in border towns and in the major cities. These movements are both formal (institutional) and informal (individual) in nature. In some cases, patients go to South Africa for procedures that are not offered in their own countries. In others, patients are referred by doctors and hospitals to South African facilities. But the majority of the movement is motivated by lack of access to basic healthcare at home. The high demand and large informal flow of patients from countries neighbouring South Africa has prompted the South African government to try and formalise arrangements for medical travel to its public hospitals and clinics through inter-country agreements in order to recover the cost of treating non-residents. The danger, for 'disenfranchised' medical tourists who fall outside these agreements, is that medical xenophobia in South Africa may lead to increasing exclusion and denial of treatment. Medical tourism in this region and South-South medical tourism in general are areas that require much additional research.

  13. Foraging ranges of immature African white-backed vultures (Gyps africanus) and their use of protected areas in southern Africa.

    PubMed

    Phipps, W Louis; Willis, Stephen G; Wolter, Kerri; Naidoo, Vinny

    2013-01-01

    Vultures in the Gyps genus are declining globally. Multiple threats related to human activity have caused widespread declines of vulture populations in Africa, especially outside protected areas. Addressing such threats requires the estimation of foraging ranges yet such estimates are lacking, even for widespread (but declining) species such as the African white-backed vulture (Gyps africanus). We tracked six immature African white-backed vultures in South Africa using GPS-GSM units to study their movement patterns, their use of protected areas and the time they spent in the vicinity of supplementary feeding sites. All individuals foraged widely; their combined foraging ranges extended into six countries in southern Africa (mean (± SE) minimum convex polygon area =269,103±197,187 km(2)) and three of the vultures travelled more than 900 km from the capture site. All six vultures spent the majority of their tracking periods outside protected areas. South African protected areas were very rarely visited whereas protected areas in northern Botswana and Zimbabwe were used more frequently. Two of the vultures visited supplementary feeding sites regularly, with consequent reduced ranging behaviour, suggesting that individuals could alter their foraging behaviour in response to such sites. We show that immature African white-backed vultures are capable of travelling throughout southern Africa, yet use protected areas to only a limited extent, making them susceptible to the full range of threats in the region. The standard approach of designating protected areas to conserve species is unlikely to ensure the protection of such wide-ranging species against threats in the wider landscape.

  14. Generation 2030/Africa

    ERIC Educational Resources Information Center

    You, Danzhen; Hug, Lucia; Anthony, David

    2014-01-01

    Until relatively recently, much of Africa has been among the economically least developed and least densely populated places on earth, replete with villages and rural communities. Africa is changing rapidly, in its economy, trade and investment; in climate change; in conflict and stability; in urbanization, migration patterns, and most of all in…

  15. Islam in Africa

    DTIC Science & Technology

    2008-05-09

    orders as well as followers in West Africa and Sudan, and, like other orders, strives to know God through meditation and emotion. Sufis may be Sunni or...Shi’ite, and their ceremonies may involve chanting, music, dancing, and meditation . West Africa and Sudan have various Sufi orders regarded

  16. Language in South Africa.

    ERIC Educational Resources Information Center

    Mesthrie, Rajend, Ed.

    This collection of 24 papers focuses on language and society in South Africa. Part 1, "The Main Language Groupings," includes (1) "South Africa: A Sociolinguistic Overview" (R. Mesthrie); (2) "The Khoesan Languages" (A. Traill); (3) "The Bantu Languages: Sociohistorical Perspectives" (Robert K. Herbert and…

  17. Teaching about Francophone Africa.

    ERIC Educational Resources Information Center

    Merryfield, Mary; Timbo, Adama

    Lessons and resources for Social Studies and French courses are included in this document. The major goals of these materials are to help students (1) explore the history and geography of Francophone Africa, (2) examine French influences in contemporary Africa, (3) recognize and appreciate cultural differences and similarities in values and…

  18. Airborne studies of aerosol emissions from savanna fires in southern Africa: 2. Aerosol chemical composition

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.; Andreae, T. W.; Annegarn, H.; Beer, J.; Cachier, H.; Le Canut, P.; Elbert, W.; Maenhaut, W.; Salma, I.; Wienhold, F. G.; Zenker, T.

    1998-12-01

    We investigated smoke emissions from fires in savanna, forest, and agricultural ecosystems by airborne sampling of plumes close to prescribed burns and incidental fires in southern Africa. Aerosol samples were collected on glass fiber filters and on stacked filter units, consisting of a Nuclepore prefilter for particles larger than ˜1-2 μm and a Teflon second filter stage for the submicron fraction. The samples were analyzed for soluble ionic components, organic carbon, and black carbon. Onboard the research aircraft, particle number and volume distributions as a function of size were determined with a laser-optical particle counter and the black carbon content of the aerosol with an aethalometer. We determined the emission ratios (relative to CO2 and CO) and emission factors (relative to the amount of biomass burnt) for the various aerosol constituents. The smoke aerosols were rich in organic and black carbon, the latter representing 10-30% of the aerosol mass. K+ and NH4+ were the dominant cationic species in the smoke of most fires, while Cl- and SO42- were the most important anions. The aerosols were unusually rich in Cl-, probably due to the high Cl content of the semiarid vegetation. Comparison of the element budget of the fuel before and after the fires shows that the fraction of the elements released during combustion is highly variable between elements. In the case of the halogen elements, almost the entire amount released during the fire is present in the aerosol phase, while in the case of C, N, and S, only a small proportion ends up as particulate matter. This suggests that the latter elements are present predominantly as gaseous species in the fresh fire plumes studied here.

  19. "Candidatus Borrelia kalaharica" Detected from a Febrile Traveller Returning to Germany from Vacation in Southern Africa

    PubMed Central

    Wächtler, Martin; Margos, Gabriele; Ruske, Sabine; Jung, Jette; Löscher, Thomas; Wendtner, Clemens; Wieser, Andreas

    2016-01-01

    A 26 year-old female patient presented to the Tropical Medicine outpatient unit of the Ludwig Maximilians-University in Munich with febrile illness after returning from Southern Africa, where she contracted a bite by a large mite-like arthropod, most likely a soft-tick. Spirochetes were detected in Giemsa stained blood smears and treatment was started with doxycycline for suspected tick-borne relapsing fever. The patient eventually recovered after developing a slight Jarisch-Herxheimer reaction during therapy. PCR reactions performed from EDTA-blood revealed a 16S rRNA sequence with 99.4% similarity to both, Borrelia duttonii, and B. parkeri. Further sequences obtained from the flagellin gene (flaB) demonstrated genetic distances of 0.066 and 0.097 to B. parkeri and B. duttonii, respectively. Fragments of the uvrA gene revealed genetic distance of 0.086 to B. hermsii in genetic analysis and only distant relations with classic Old World relapsing fever species. This revealed the presence of a novel species of tick-borne relapsing fever spirochetes that we propose to name “Candidatus Borrelia kalaharica”, as it was contracted from an arthropod bite in the Kalahari Desert belonging to both, Botswana and Namibia, a region where to our knowledge no relapsing fever has been described so far. Interestingly, the novel species shows more homology to New World relapsing fever Borrelia such as B. parkeri or B. hermsii than to known Old World species such as B. duttonii or B. crocidurae. PMID:27031729

  20. Metal Enrichment and Toxicity Levels in Sediments from the Tourist Beaches of Southern Durban, South Africa

    NASA Astrophysics Data System (ADS)

    Chari, S. V.; Vetrimurugan, E.; Jonathan, M. P.; Rodriguez-Espinosa, P. F.

    2014-12-01

    Durban city in South Africa is developing in a fast pace in the field of tourism and thereby needs to be reviewed for the enrichment of metals in tourist beaches. Geochemical studies have been done on nearly 65 beach sediments collected from inter-tidal regions of Amanzi Toti, Isipingo, Bluff, Cutting and southern part of Durban beaches. The study was done in order to unravel the anthropogenic and natural geochemical signals. Total (TTMs) and partially extracted trace metals (PETMs) (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, Zn) in sediments were evaluated along with organic carbon and carbonates. Evaluation of enrichment of geochemical elements were done using contamination factor (CF), pollution load index (PLI), ecological risk index (RI) and geoaccumulation index (Igeo) to understand the pollution status of the study area and it indicates that As, Cd, Cu, Fe, Mn, Ni, Pb, V and Zn are enriched by two to three folds from the natural background values. Uncontrolled tourism activities have led to increase of certain elements in the Durban beaches. Textural analysis provides the information regarding the dominance of sediments either in sand fraction, mud fraction or gravel. The results indicated that they are dominantly coarse grained except in regions where local river input is observed. Industrial development as well as the mining activities in few locations near the coast has led to increase in the elemental concentrations. Regular monitoring of enrichment levels of trace metals in the sediments is mandatory to assess the beach quality in order to restore them from further enrichment so that the biological system in this region is also preserved. Keywords: Tourism, Beach sediments, Trace metals, contamination indices.

  1. 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

  2. "Candidatus Borrelia kalaharica" Detected from a Febrile Traveller Returning to Germany from Vacation in Southern Africa.

    PubMed

    Fingerle, Volker; Pritsch, Michael; Wächtler, Martin; Margos, Gabriele; Ruske, Sabine; Jung, Jette; Löscher, Thomas; Wendtner, Clemens; Wieser, Andreas

    2016-03-01

    A 26 year-old female patient presented to the Tropical Medicine outpatient unit of the Ludwig Maximilians-University in Munich with febrile illness after returning from Southern Africa, where she contracted a bite by a large mite-like arthropod, most likely a soft-tick. Spirochetes were detected in Giemsa stained blood smears and treatment was started with doxycycline for suspected tick-borne relapsing fever. The patient eventually recovered after developing a slight Jarisch-Herxheimer reaction during therapy. PCR reactions performed from EDTA-blood revealed a 16S rRNA sequence with 99.4% similarity to both, Borrelia duttonii, and B. parkeri. Further sequences obtained from the flagellin gene (flaB) demonstrated genetic distances of 0.066 and 0.097 to B. parkeri and B. duttonii, respectively. Fragments of the uvrA gene revealed genetic distance of 0.086 to B. hermsii in genetic analysis and only distant relations with classic Old World relapsing fever species. This revealed the presence of a novel species of tick-borne relapsing fever spirochetes that we propose to name "Candidatus Borrelia kalaharica", as it was contracted from an arthropod bite in the Kalahari Desert belonging to both, Botswana and Namibia, a region where to our knowledge no relapsing fever has been described so far. Interestingly, the novel species shows more homology to New World relapsing fever Borrelia such as B. parkeri or B. hermsii than to known Old World species such as B. duttonii or B. crocidurae.

  3. Genotypic Diversity Is Associated with Clinical Outcome and Phenotype in Cryptococcal Meningitis across Southern Africa

    PubMed Central

    Beale, Mathew A.; Sabiiti, Wilber; Robertson, Emma J.; Fuentes-Cabrejo, Karen M.; O’Hanlon, Simon J.; Jarvis, Joseph N.; Loyse, Angela; Meintjes, Graeme; Harrison, Thomas S.; May, Robin C.; Fisher, Matthew C.; Bicanic, Tihana

    2015-01-01

    Cryptococcal meningitis is a major cause of mortality throughout the developing world, yet little is known about the genetic markers underlying Cryptococcal virulence and patient outcome. We studied a cohort of 230 Cryptococcus neoformans (Cn) isolates from HIV-positive South African clinical trial patients with detailed clinical follow-up using multi-locus sequence typing and in vitro phenotypic virulence assays, correlating these data with clinical and fungal markers of disease in the patient. South African Cn displayed high levels of genetic diversity and locus variability compared to globally distributed types, and we identified 50 sequence types grouped within the main molecular types VNI, VNII and VNB, with 72% of isolates typed into one of seven 'high frequency' sequence types. Spatial analysis of patients’ cryptococcal genotype was not shown to be clustered geographically, which might argue against recent local acquisition and in favour of reactivation of latent infection. Through comparison of MLST genotyping data with clinical parameters, we found a relationship between genetic lineage and clinical outcome, with patients infected with the VNB lineage having significantly worse survival (n=8, HR 3.35, CI 1.51-7.20, p=0.003), and this was maintained even after adjustment for known prognostic indicators and treatment regimen. Comparison of fungal genotype with in vitro phenotype (phagocytosis, laccase activity and CSF survival) performed on a subset of 89 isolates revealed evidence of lineage-associated virulence phenotype, with the VNII lineage displaying increased laccase activity (p=0.001) and ex vivo CSF survival (p=0.0001). These findings show that Cryptococcus neoformans is a phenotypically heterogeneous pathogen, and that lineage plays an important role in cryptococcal virulence during human infection. Furthermore, a detailed understanding of the genetic diversity in Southern Africa will support further investigation into how genetic diversity is

  4. Oil and gas developments in central and southern Africa in 1983

    SciTech Connect

    McGrew, H.J.

    1984-10-01

    All exploratory activity in central and southern Africa decreased in 1983, reflecting world economic conditions and excess productive capacity. Seismic activity has declined sharply from its peak year of 1981. Land operations suffered the greatest drop in 1983, whereas party-months of marine work increased slightly. 3-D recording continued to be used but at a reduced rate compared with 1982. Large aeromagnetic surveys were made in several countries; however, the coverage was less than in 1982. Gravity continues to be used to supplement other geophysical work, but other exploratory techniques are being used infrequently. Total wells drilled dropped from 464 in 1982 to 387 in 1983. Most of the decline was in exploratory drilling, which dropped from 132 to 86 wells. This was reflected in the number of discoveries, which decreased from 48 to 27 while the success rate continued about the same. Development drilling continued at a high level in Cameroon and Congo, whereas in Nigeria the emphasis shifted to the drilling of appraisal wells. In all, 2,937,708 ft (895,643 m) of hole was drilled, a decrease of about 20% from 1982. Oil production of 673,075,667 bbl in 1983 was an increase of 1.7% over 1982's production, bringing cumulative production to over 12 billion bbl. Marked increases in production were recorded in Cabinda, Ivory Coast, and Congo. Production from Nigerian fields continued to dominate this part of the world as they contributed about 67% of the annual production and 75% of the cumulative production. 44 figures, 15 tables.

  5. Participatory planning in river catchments, an innovative toolkit tested in Southern Africa and North West England.

    PubMed

    Tippett, J

    2005-01-01

    The European Union Water Framework Directive (WFD) offers an unparalleled opportunity for improving river basin management. Active participation is essential for its delivery. "End-of-pipe" solutions will not deliver the improvements needed to achieve its ambitious goals. This research tested DesignWays, a toolkit for participatory planning, as a mechanism for maximizing the long-term social and environmental benefits of such stakeholder and community participation. It examined the emerging role of "planning for sustainability" in the context of river catchments. Sustainable management of water requires integration, and recognition of interconnections between systems at different levels of scale. This is an endeavour in which systems thinking provides useful tools. The development of DesignWays was a conscious attempt to embed 'new paradigm' living systems metaphors into a practical planning tool. This paper begins with a description of DesignWays and its development in Southern Africa. An outline of the context of the action research in North-West England is followed by a description of the stages of the process, with highlights of the outcomes. This research had two major outcomes: a contribution to theory through an in-depth exploration of the theoretical basis of participatory, ecologically informed design; and a contribution to practice through investigating DesignWays' potential to meet key challenges of the WFD. This research points to the importance of understanding participatory planning as a societal process, aiming to make the process engaging and meaningful. It has pointed to the need to see participatory planning and education for sustainability as an integrated process. It demonstrated the benefits of an iterative process in which planning at the landscape level of scale informs, and is informed by, work at the site level. It has shown that an approach consistent with a living systems paradigm can contribute to the development of more integrated

  6. Genotypic Diversity Is Associated with Clinical Outcome and Phenotype in Cryptococcal Meningitis across Southern Africa.

    PubMed

    Beale, Mathew A; Sabiiti, Wilber; Robertson, Emma J; Fuentes-Cabrejo, Karen M; O'Hanlon, Simon J; Jarvis, Joseph N; Loyse, Angela; Meintjes, Graeme; Harrison, Thomas S; May, Robin C; Fisher, Matthew C; Bicanic, Tihana

    2015-01-01

    Cryptococcal meningitis is a major cause of mortality throughout the developing world, yet little is known about the genetic markers underlying Cryptococcal virulence and patient outcome. We studied a cohort of 230 Cryptococcus neoformans (Cn) isolates from HIV-positive South African clinical trial patients with detailed clinical follow-up using multi-locus sequence typing and in vitro phenotypic virulence assays, correlating these data with clinical and fungal markers of disease in the patient. South African Cn displayed high levels of genetic diversity and locus variability compared to globally distributed types, and we identified 50 sequence types grouped within the main molecular types VNI, VNII and VNB, with 72% of isolates typed into one of seven 'high frequency' sequence types. Spatial analysis of patients' cryptococcal genotype was not shown to be clustered geographically, which might argue against recent local acquisition and in favour of reactivation of latent infection. Through comparison of MLST genotyping data with clinical parameters, we found a relationship between genetic lineage and clinical outcome, with patients infected with the VNB lineage having significantly worse survival (n=8, HR 3.35, CI 1.51-7.20, p=0.003), and this was maintained even after adjustment for known prognostic indicators and treatment regimen. Comparison of fungal genotype with in vitro phenotype (phagocytosis, laccase activity and CSF survival) performed on a subset of 89 isolates revealed evidence of lineage-associated virulence phenotype, with the VNII lineage displaying increased laccase activity (p=0.001) and ex vivo CSF survival (p=0.0001). These findings show that Cryptococcus neoformans is a phenotypically heterogeneous pathogen, and that lineage plays an important role in cryptococcal virulence during human infection. Furthermore, a detailed understanding of the genetic diversity in Southern Africa will support further investigation into how genetic diversity is

  7. A review of the stratigraphy and sedimentary environments of the Karoo-aged basins of Southern Africa

    NASA Astrophysics Data System (ADS)

    Smith, R. M. H.; Eriksson, P. G.; Botha, W. J.

    1993-02-01

    The Karoo Basin of South Africa was one of several contemporaneous intracratonic basins in southwestern Gondwana that became active in the Permo-Carboniferous (280 Ma) and continued to accumulate sediments until the earliest Jurassic, 100 million years later. At their maximum areal extent, during the early Permian, these basins covered some 4.5 million km 2. The present outcrop area of Karoo rocks in southern Africa is about 300 000 km 2 with a maximum thickness of some 8000 m. The economic importance of these sediments lies in the vast reserves of coal within the Ecca Group rocks of northern and eastern Transvaal and Natal, South Africa. Large reserves of sandstone-hosted uranium and molybdenum have been proven within the Beaufort Group rocks of the southern Karoo trough, although they are not mineable in the present market conditions. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo succession in South Africa demonstrates the changes in depositional style caused by regional and localized tectonism within the basin. These depocentres were influenced by a progressive aridification of climate which was primarily caused by the northward drift of southwestern Gondwana out of a polar climate and accentuated by the meteoric drying effect of the surrounding land masses. Changing palaeoenvironments clearly influenced the rate and direction of vertebrate evolution in southern Gondwana as evidenced by the numerous reptile fossils, including dinosaurs, which are found in the Karoo strata of South Africa, Lesotho, Namibia and Zimbabwe. During the Late Carboniferous the southern part of Gondwana migrated over the South Pole resulting in a major ice sheet over the early Karoo basin and surrounding highlands. Glacial sedimentation in upland valleys and on the lowland shelf resulted in the Dwyka Formation at the base of the Karoo Sequence. After glaciation, an extensive shallow sea covered the gently subsiding shelf, fed by large volumes of meltwater

  8. Africa's present and future needs in toxicology education: Southern African perspective

    SciTech Connect

    Gulumian, Mary . E-mail: mary.gulumian@nioh.nhls.co.za; Ginsburg, Carren; Stewart, Michael J.

    2005-09-01

    Degrees and diplomas as well as certificates that are granted by universities and technikons in South Africa in scientific disciplines, such as forensic medicine, pharmacology, marine and veterinary sciences, environmental health, and occupational hygiene, include toxicology as one of the subjects in their overall syllabus. However, aspects of toxicology included in each of these courses are biased towards that particular subdiscipline and basic level of toxicology may be taught. Educational needs in toxicology in South Africa can be summarized as follows: (a) recognition of toxicology as a discipline in its own right at these tertiary education institutions and (b) creation of opportunities to study and obtain higher degrees in one or more of the many subdisciplines of toxicology. The results from a survey conducted on the toxicology syllabi offered at these tertiary education institutions are used to substantiate these needs.

  9. A first calibration of nonmarine ostracod species for the quantitative estimation of Pleistocene climate change in southern Africa

    NASA Astrophysics Data System (ADS)

    Horne, D. J.; Martens, K.

    2009-04-01

    Although qualitative statements have been made about general climatic conditions in southern Africa during the Pleistocene, there are few quantifiable palaeoclimatic data based on field evidence, especially regarding whether the area was wetter or drier during the Last Glacial Maximum. Such information is critical in validating models of climate change, both in spatial and temporal dimensions. As an essential preliminary step towards palaeoclimate reconstructions using fossil ostracods from cored lake sediment sequences, we have calibrated a training set of living ostracod species' distributions against a modern climate dataset and other available environmental data. The modern ostracod dataset is based on the collections in the Royal Belgian Institute of Natural Sciences in Brussels, which constitutes the most diverse and comprehensive collection of southern African nonmarine ostracods available anywhere in the world. To date, c. 150 nominal species have been described from southern Africa (Martens, 2001) out of c. 450 species in the total Afrotropical area (Martens et al., 2008). Here we discuss the potential value and limitations of the training set for the estimation of past climatic parameters including air temperature (July and January means, maxima and minima, Mean Annual Air Temperature), precipitation, water conductivity and pH. The next step will be to apply the Mutual Ostracod Temperature Range method (Horne, 2007; Horne & Mezquita, 2008) to the palaeoclimatic analysis of fossil ostracod assemblages from sequences recording the Last Glacial Maximum in southern Africa. Ultimately this work will contribute to the development of a glacier-climate modelling project based on evidence of former niche glaciation of the Drakensberg Escarpment. Horne, D. J. 2007. A Mutual Temperature Range method for Quaternary palaeoclimatic analysis using European nonmarine Ostracoda. Quaternary Science Reviews, 26, 1398-1415. Horne, D. J. & Mezquita, F. 2008. Palaeoclimatic

  10. Calibrating a new proxy for Pleistocene climate change in southern Africa: the Mutual Ostracod Temperature Range method

    NASA Astrophysics Data System (ADS)

    Horne, David; Martens, Koen

    2010-05-01

    The Mutual Ostracod Temperature Range (MOTR) method has so far been applied only in the European Pleistocene, where it is proving effective in producing past air temperature range estimates that compare well with those obtained by other proxy methods (Horne, 2007; Horne & Mezquita, 2008; Holmes et al., in press). As an essential preliminary step towards applying the method in southern Africa, we have calibrated a training set of living ostracod species' distributions against a modern climate dataset and other available environmental data. The modern ostracod dataset is based on material held by the Royal Belgian Institute of Natural Sciences in Brussels, which constitutes the most diverse and comprehensive collection of southern African nonmarine ostracods available anywhere in the world. To date, c. 150 nominal species have been described from southern Africa (Martens, 2001) out of c. 450 species in the total Afrotropical area (Martens et al., 2008). We used an edited dataset comprising a total of 2,118 records of ostracod species from 748 localities in southern Africa, ranging in latitude from approximately 17 degrees S to 35 degrees S. We have explored the potential value and limitations of this training set for the estimation of past climatic parameters including mean July, January and annual air temperatures, precipitation, water conductivity and pH. Holmes, J. A., Atkinson, T., Darbyshire, D. P. F., Horne, D. J., Joordens, J., Roberts, M. B., Sinka, K. J. & Whittaker, J. E. (accepted, in press). Middle Pleistocene climate and hydrological environment at the Boxgrove hominin site (West Sussex, UK) from ostracod records. Quaternary Science Reviews, doi:10.1016/j.quascirev.2009.02.024, 1-13. Horne, D. J. 2007. A Mutual Temperature Range method for Quaternary palaeoclimatic analysis using European nonmarine Ostracoda. Quaternary Science Reviews, 26, 1398-1415. Horne, D. J. & Mezquita, F. 2008. Palaeoclimatic applications of large databases: developing and testing

  11. Overcoming constraints to the implementation of water demand management in southern Africa

    NASA Astrophysics Data System (ADS)

    Mwendera, E. J.; Hazelton, D.; Nkhuwa, D.; Robinson, P.; Tjijenda, K.; Chavula, G.

    This paper presents results of a study on water demand management status and overcoming constraints to implementation of water demand management in the southern African region, as part of Phase II of water demand management (WDM) programme implemented by the IUCN (The World Conservation Union). The study was conducted in Malawi, Namibia, South Africa, Swaziland, Zambia and Zimbabwe. The study methodology consisted of a survey of literature, and interviewing and communicating with stakeholders in order to learn from stakeholders on the critical constraints to WDM implementation and strategies to overcome them. The study has shown that, despite the potential savings that would accrue from implementation of WDM, the water sector across the southern African region continues to focus on water supply augmentation. There are inadequate financial and human resources for rehabilitation, operation and maintenance of water conveyance systems resulting in system leaks, which contribute to high levels of unaccounted-for water, a situation that masks the potential benefits of WDM. In most countries, the water sector operates on ad-hoc sub-sector water user objectives, which provided guidelines only for development and management purposes. Most of the institutional frameworks have remained diffuse, resulting into poor performance in the sector, and into crisis management in the water resources development. Though the WDM policy in most countries is already accessible through guidelines for catchment management institutions and water supply institutions; there is a lack of broad commitment to implementing them. In other countries the instruments are relatively new and have not been applied widely. Similarly, the effectiveness of instruments has not been well evaluated in most countries. In countries where policy is weak there is often a lack of clarity as to who is responsible for WDM implementation, and even less clarity on who is responsible for facilitating and monitoring

  12. Nitrogen deposition in a southern hemisphere biodiversity hotspot within and surrounding Cape Town, South Africa

    NASA Astrophysics Data System (ADS)

    Angstmann, J. L.; Hall, S.; February, E.; West, A. G.; Allsopp, N.; Bond, W.

    2011-12-01

    Anthropogenic nitrogen (N) emissions have increased dramatically since the agricultural and industrial revolutions leading to N deposition in the northern hemisphere that is estimated to be an order of magnitude greater than preindustrial fluxes. N deposition rates of 5-15 kg N ha-1 yr-1 in Europe and N. America decrease plant species diversity, increase invasive species, and lead to eutrophication of surface waters. The southern hemisphere is home to over 50% of the world's biodiversity hotspots, including the 90,000 km2 Cape Floristic Region which houses 9,030 vascular plant species, 69% of which are endemic. However, to date, N deposition rates in the southern hemisphere are highly uncertain, with global models of N deposition based upon sparse datasets at best. Many terrestrial systems, such as fynbos shrublands, are adapted to low N availability and exhibit high species diversity and endemism, rendering them susceptible to ecological changes from N deposition. In this research, we quantified the spatial and temporal distribution of wet and dry N deposition across 30 protected fynbos ecosystems within the urban airshed of Cape Town, South Africa. We predicted that 1) total inorganic N deposition varies predictably along the urban-rural gradient (highest near the city centre), 2) N deposition varies seasonally, with higher fluxes in the winter months when atmospheric stability causes a build-up of N gases in and around the city, and 3) total inorganic N deposition will exceed the critical load of 10-15 kg N ha-1 yr-1 for Mediterranean shrublands, past which negative ecosystem effects have been shown to occur. Estimates of N deposition based on NO2 concentrations within the city suggest that total N deposition ranges from 8-13 kg N ha-1 yr-1 . However, we show that N deposition measured by ion-exchange resin collectors is far less than expected, averaging less than 2 kg N ha-1 yr-1 (range 0.5 - 5.5 kg N ha-1 yr-1 ), and is is dominated by NO3-, suggesting

  13. Hydrological drought forecasting and skill assessment for the Limpopo River basin, southern Africa

    NASA Astrophysics Data System (ADS)

    Trambauer, P.; Werner, M.; Winsemius, H. C.; Maskey, S.; Dutra, E.; Uhlenbrook, S.

    2015-04-01

    Ensemble hydrological predictions are normally obtained by forcing hydrological models with ensembles of atmospheric forecasts produced by numerical weather prediction models. To be of practical value to water users, such forecasts should not only be sufficiently skilful, they should also provide information that is relevant to the decisions end users make. The semi-arid Limpopo Basin in southern Africa has experienced severe droughts in the past, resulting in crop failure, economic losses and the need for humanitarian aid. In this paper we address the seasonal prediction of hydrological drought in the Limpopo River basin by testing three proposed forecasting systems (FS) that can provide operational guidance to reservoir operators and water managers at the seasonal timescale. All three FS include a distributed hydrological model of the basin, which is forced with either (i) a global atmospheric model forecast (ECMWF seasonal forecast system - S4), (ii) the commonly applied ensemble streamflow prediction approach (ESP) using resampled historical data, or (iii) a conditional ESP approach (ESPcond) that is conditional on the ENSO (El Niño-Southern Oscillation) signal. We determine the skill of the three systems in predicting streamflow and commonly used drought indices. We also assess the skill in predicting indicators that are meaningful to local end users in the basin. FS_S4 shows moderate skill for all lead times (3, 4, and 5 months) and aggregation periods. FS_ESP also performs better than climatology for the shorter lead times, but with lower skill than FS_S4. FS_ESPcond shows intermediate skill compared to the other two FS, though its skill is shown to be more robust. The skill of FS_ESP and FS_ESPcond is found to decrease rapidly with increasing lead time when compared to FS_S4. The results show that both FS_S4 and FS_ESPcond have good potential for seasonal hydrological drought forecasting in the Limpopo River basin, which is encouraging in the context of

  14. U.S. Security Assistance Programs in Southern Africa: Are They Supporting National Objectives?

    DTIC Science & Technology

    1985-04-01

    AFRICA: ARE THEY SUPPORTING NATIONAL OBJECTIVES? MAJOR ROBIERT D. GRISWELL 85-0985 "insights into tomorrow" LA- DOMMMONSTATEMEi Appmed Am pua Woo 1D~ utut ~s...name and complete title of the study . This document may be reproduced for use in other research reports or educational pursuits contingent upon the...national ~objocti𔃾es, This study reviews the national objectives, examines U.S. interests in tereiod compares UJS. and U.S.S.R. security assistance

  15. Sustainability of Strategic Minerals in Southern Africa and Potential Conflicts and Partnerships

    DTIC Science & Technology

    2010-01-01

    strategic minerals, including rare earth minerals, fluorspar, and titanium sands.22 South Africa poses a growing challenge to the United States and...DRC, which may lead to the eventual interruption of the supply of strategic minerals to the United States and its allies. State weakness and...east of the country.69 State weakness and corruption and put U.S. and Western companies at a disadvantage and could eventually affect the supply of

  16. AIDS Infects Education Systems in Africa

    ERIC Educational Resources Information Center

    Keller, Bess

    2005-01-01

    The AIDS pandemic raging across sub-Saharan Africa does not stop with personal carnage. It also threatens whole systems, including what is arguably the most critical for the region's future--education. Where rates of HIV infection are high, as they are in much of southern and eastern Africa, experts warn, the effects on social stability and…

  17. A chronological perspective on the acheulian and its transition to the middle stone age in southern Africa: the question of the fauresmith.

    PubMed

    Herries, Andy I R

    2011-01-01

    An understanding of the age of the Acheulian and the transition to the Middle Stone Age in southern Africa has been hampered by a lack of reliable dates for key sequences in the region. A number of researchers have hypothesised that the Acheulian first occurred simultaneously in southern and eastern Africa at around 1.7-1.6 Ma. A chronological evaluation of the southern African sites suggests that there is currently little firm evidence for the Acheulian occurring before 1.4 Ma in southern Africa. Many researchers have also suggested the occurrence of a transitional industry, the Fauresmith, covering the transition from the Early to Middle Stone Age, but again, the Fauresmith has been poorly defined, documented, and dated. Despite the occurrence of large cutting tools in these Fauresmith assemblages, they appear to include all the technological components characteristic of the MSA. New data from stratified Fauresmith bearing sites in southern Africa suggest this transitional industry maybe as old as 511-435 ka and should represent the beginning of the MSA as a broad entity rather than the terminal phase of the Acheulian. The MSA in this form is a technology associated with archaic H. sapiens and early modern humans in Africa with a trend of greater complexity through time.

  18. A Chronological Perspective on the Acheulian and Its Transition to the Middle Stone Age in Southern Africa: The Question of the Fauresmith

    PubMed Central

    Herries, Andy I. R.

    2011-01-01

    An understanding of the age of the Acheulian and the transition to the Middle Stone Age in southern Africa has been hampered by a lack of reliable dates for key sequences in the region. A number of researchers have hypothesised that the Acheulian first occurred simultaneously in southern and eastern Africa at around 1.7-1.6 Ma. A chronological evaluation of the southern African sites suggests that there is currently little firm evidence for the Acheulian occurring before 1.4 Ma in southern Africa. Many researchers have also suggested the occurrence of a transitional industry, the Fauresmith, covering the transition from the Early to Middle Stone Age, but again, the Fauresmith has been poorly defined, documented, and dated. Despite the occurrence of large cutting tools in these Fauresmith assemblages, they appear to include all the technological components characteristic of the MSA. New data from stratified Fauresmith bearing sites in southern Africa suggest this transitional industry maybe as old as 511–435 ka and should represent the beginning of the MSA as a broad entity rather than the terminal phase of the Acheulian. The MSA in this form is a technology associated with archaic H. sapiens and early modern humans in Africa with a trend of greater complexity through time. PMID:21785711

  19. Shear wave velocity structure of the lower crust in southern Africa: Evidence for compositional heterogeneity within Archaean and Proterozoic terrains

    NASA Astrophysics Data System (ADS)

    Kgaswane, Eldridge M.; Nyblade, Andrew A.; Juliã, Jordi; Dirks, Paul H. G. M.; Durrheim, Raymond J.; Pasyanos, Michael E.

    2009-12-01

    The nature of the lower crust across the southern African shield has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations located in Botswana, South Africa and Zimbabwe. For large parts of both Archaean and Proterozoic terrains, the velocity models obtained from the inversions show shear wave velocities ≥4.0 km/s below ˜20-30 km depth, indicating a predominantly mafic lower crust. However, for much of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain in South Africa, as well as for the western part of the Tokwe terrain in Zimbabwe, shear wave velocities of ≤3.9 km/s are found below ˜20-30 km depth, indicating an intermediate-to-felsic lower crust. The areas of intermediate-to-felsic lower crust in South Africa coincide with regions where Ventersdorp rocks have been preserved, suggesting that the more evolved composition of the lower crust may have resulted from crustal reworking and extension during the Ventersdorp tectonomagmatic event at c. 2.7 Ga.

  20. CDRD and PNPR passive microwave precipitation retrieval algorithms: verification study over Africa and Southern Atlantic

    NASA Astrophysics Data System (ADS)

    Panegrossi, Giulia; Casella, Daniele; Cinzia Marra, Anna; Petracca, Marco; Sanò, Paolo; Dietrich, Stefano

    2015-04-01

    The ongoing NASA/JAXA Global Precipitation Measurement mission (GPM) requires the full exploitation of the complete constellation of passive microwave (PMW) radiometers orbiting around the globe for global precipitation monitoring. In this context the coherence of the estimates of precipitation using different passive microwave radiometers is a crucial need. We have developed two different passive microwave precipitation retrieval algorithms: one is the Cloud Dynamics Radiation Database algorithm (CDRD), a physically ¬based Bayesian algorithm for conically scanning radiometers (i.e., DMSP SSMIS); the other one is the Passive microwave Neural network Precipitation Retrieval (PNPR) algorithm for cross¬-track scanning radiometers (i.e., NOAA and MetOp¬A/B AMSU-¬A/MHS, and NPP Suomi ATMS). The algorithms, originally created for application over Europe and the Mediterranean basin, and used operationally within the EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF, http://hsaf.meteoam.it), have been recently modified and extended to Africa and Southern Atlantic for application to the MSG full disk area. The two algorithms are based on the same physical foundation, i.e., the same cloud-radiation model simulations as a priori information in the Bayesian solver and as training dataset in the neural network approach, and they also use similar procedures for identification of frozen background surface, detection of snowfall, and determination of a pixel based quality index of the surface precipitation retrievals. In addition, similar procedures for the screening of not ¬precipitating pixels are used. A novel algorithm for the detection of precipitation in tropical/sub-tropical areas has been developed. The precipitation detection algorithm shows a small rate of false alarms (also over arid/desert regions), a superior detection capability in comparison with other widely used screening algorithms, and it is applicable

  1. Coastal lake sediments from the southern Cape, South Africa - Implications for sea level and climate variations during the Holocene

    NASA Astrophysics Data System (ADS)

    Wündsch, M.; Haberzettl, T.; Kirsten, K. L.; Meschner, S.; Frenzel, P.; Baade, J.; Daut, G.; Mäusbacher, R.; Kasper, T.; Quick, L. J.; Meadows, M. E.; Zabel, M.

    2015-12-01

    Within the RAIN project (Regional Archives for Integrated iNvestigations) interdisciplinary investigations on climate evolution and environmental change in southern Africa during the Late Quaternary are being conducted. For this purpose, spatial and temporal variations of the three major rainfall zones covering South Africa (winter-, summer- and year-round rainfall zone) are studied using both marine and terrestrial archives. Here we present results inferred from sediment records from lakes Groenvlei and Eilandvlei located on the southern Cape coast within the year-round rainfall zone. From Eilandvlei, a brackish lake that is connected to the Indian Ocean via an estuary, a 30.5 m sediment core was recovered. Reservoir-corrected radiocarbon ages reveal a continuous sedimentation and a maximum age of about 8,900 cal BP. This ultra-high-resolution record of environmental change during the Holocene represents a unique discovery for entire southern Africa. Geochemical data reveal different phases of marine and terrestrial sediment deposition throughout the covered time span. Hence, this record reflects changes in sea level, but also variations in terrestrial sediment transport and thus changing climatic conditions. The sediment core from Groenvlei, which today is isolated from the Indian Ocean, covers the past 4,200 cal BP. Sediments from this lake are predominantly composed of autochthonous carbonates. Mineralogical investigations reveal alternating deposition of calcite and aragonite/dolomite, pointing to variable Mg/Ca ratios and thus variations in lake water salinity. These changes can be linked to sea level variations as well as to changes in the precipitation/evaporation balance, and hence climate. Based on these results, the Groenvlei record reveals a decreasing marine influence and a trend from generally drier to wetter conditions within the last 4,200 yrs. Moreover, several layers of enhanced allochtonous input were detected in this record, which can be

  2. Changes in Holocene to LGM water mass stratification near Southern Africa inferred from Nd isotopes

    NASA Astrophysics Data System (ADS)

    Jones, K. M.; Goldstein, S. L.; Hemming, S. R.; Hall, I. R.; Zahn, R.

    2009-12-01

    Global thermohaline circulation (THC) is an important component of the climate system that initiates or amplifies abrupt climate change. A major driver of THC is the formation of North Atlantic Deep Water (NADW), which is sandwiched by northward flowing Southern Ocean water masses as it is advected southward. An important exit route of NADW out of the South Atlantic is through flow around the southern tip of Africa, which makes the South African Margin an excellent location to investigate changes in THC and water mass stratification through time. We measured the Nd isotopes of modern seawater from three depth profiles collected along the South African Margin, which were collected on RSS Charles Darwin Cruise 154. All seawater profiles show a similar pattern with higher ɛNd values at intermediate depths (ɛNd ~ -9.5 at 600-1200m), lower values for the core of NADW (ɛNd ~ -11.5 at 2000-3500m), and higher values in the deepest waters sampled (ɛNd -9.8 at 4150m). This pattern is consistent with conservative mixing of major North Atlantic and Southern Ocean end-member water masses and is not consistent with inputs from, or exchange with margin sediments, for most depths. We also measured the Nd isotopes of multiple sedimentary archives in proximal Holocene coretop sediments collected from depths spanning intermediate to deep/bottom waters. The Nd isotopes of a fish tooth, several foram coating leachates, and multiple bulk sediment Fe-Mn leachates display the same pattern as the local seawater. We had no seawater for comparison with our deepest core (VM19-224; depth ~ 4600m), but the eNd value from it (ɛNd = -8.4) is consistent with Antarctic Bottom Water (ɛNd ~ -8.5). These results suggest: (1) that Nd isotopes of seawater in the region behave conservatively; (2) that the local margin sediments faithfully record the Nd isotope composition of the waters they are bathed in and (3) this “ground-truthing” implies that it is valid to use Nd isotopes as a circulation

  3. Palaeoclimatic conditions in the Late Triassic-Early Jurassic of southern Africa: A geochemical assessment of the Elliot Formation

    NASA Astrophysics Data System (ADS)

    Sciscio, Lara; Bordy, Emese M.

    2016-07-01

    The Triassic-Jurassic boundary marks a global faunal turnover event that is generally considered as the third largest of five major biological crises in the Phanerozoic geological record of Earth. Determining the controlling factors of this event and their relative contributions to the biotic turnover associated with it is on-going globally. The Upper Triassic and Lower Jurassic rock record of southern Africa presents a unique opportunity for better constraining how and why the biosphere was affected at this time not only because the succession is richly fossiliferous, but also because it contains important palaeoenvironmental clues. Using mainly sedimentary geochemical proxies (i.e., major, trace and rare earth elements), our study is the first quantitative assessment of the palaeoclimatic conditions during the deposition of the Elliot Formation, a continental red bed succession that straddles the Triassic-Jurassic boundary in southern Africa. Employing clay mineralogy as well as the indices of chemical alteration and compositional variability, our results confirm earlier qualitative sedimentological studies and indicate that the deposition of the Upper Triassic and Lower Jurassic Elliot Formation occurred under increasingly dry environmental conditions that inhibited chemical weathering in this southern part of Pangea. Moreover, the study questions the universal validity of those studies that suggest a sudden increase in humidity for the Lower Jurassic record and supports predictions of long-term global warming after continental flood basalt emplacement.

  4. “Of Sheep and Men”: Earliest Direct Evidence of Caprine Domestication in Southern Africa at Leopard Cave (Erongo, Namibia)

    PubMed Central

    Pleurdeau, David; Imalwa, Emma; Détroit, Florent; Lesur, Joséphine; Veldman, Anzel; Bahain, Jean-Jacques; Marais, Eugène

    2012-01-01

    The origins of herding practices in southern Africa remain controversial. The first appearance of domesticated caprines in the subcontinent is thought to be c. 2000 years BP; however, the origin of this cultural development is still widely debated. Recent genetic analyses support the long-standing hypothesis of herder migration from the north, while other researchers have argued for a cultural diffusion hypothesis where the spread of herding practices took place without necessarily implicating simultaneous and large population movements. Here we document the Later Stone Age (LSA) site of Leopard Cave (Erongo, Namibia), which contains confirmed caprine remains, from which we infer that domesticates were present in the southern African region as early as the end of the first millennium BC. These remains predate the first evidence of domesticates previously recorded for the subcontinent. This discovery sheds new light on the emergence of herding practices in southern Africa, and also on the possible southward routes used by caprines along the western Atlantic coast. PMID:22808138

  5. Exploring the correlation between Southern Africa NDVI and Pacific sea surface temperatures: Results for the 1998 maize growing season

    USGS Publications Warehouse

    Verdin, J.; Funk, C.; Klaver, R.; Roberts, D.

    1999-01-01

    Several studies have identified statistically significant correlations between Pacific sea surface temperature anomalies and NDVI anomalies in Southern Africa. The potential predictive value of the relationship was explored for the 1998 maize growing season. Cross-validation techniques suggested a more useful relationship for regions of wet anomaly than for regions of dry anomaly. Observed 1998 NDVI anomaly patterns were consistent with this result. Wet anomalies were observed as expected, but wide areas of expected dry anomalies exhibited average or above-average greeness.

  6. Poverty reduction in Africa

    PubMed Central

    Collier, Paul

    2007-01-01

    Poverty in Africa has been rising for the last quarter-century, while it has been falling in the rest of the developing world. Africa's distinctive problem is that its economies have not been growing. This article attempts to synthesize a range of recent research to account for this failure of the growth process. I argue that the reasons lie not in African peculiarities but rather in geographic features that globally cause problems but that are disproportionately pronounced in Africa. These features interact to create three distinct challenges that are likely to require international interventions beyond the conventional reliance on aid. PMID:17942702

  7. Poverty reduction in Africa.

    PubMed

    Collier, Paul

    2007-10-23

    Poverty in Africa has been rising for the last quarter-century, while it has been falling in the rest of the developing world. Africa's distinctive problem is that its economies have not been growing. This article attempts to synthesize a range of recent research to account for this failure of the growth process. I argue that the reasons lie not in African peculiarities but rather in geographic features that globally cause problems but that are disproportionately pronounced in Africa. These features interact to create three distinct challenges that are likely to require international interventions beyond the conventional reliance on aid.

  8. Country reports on five key asylum countries in eastern and southern Africa.

    PubMed

    Clark, L

    1987-01-01

    This is the 2nd in a series of 3 papers concerning refugees in Eastern and Southern Africa. It contains in-depth information on the refugee situations in Djibouti, Somalia, Tanzania, Zambia, and Zimbabwe. In Djibouti, political and material constraints have made all 3 durable solutions--voluntary repatriation, local integration, and resettlement to a 3rd country--problematic. Djibouti may be a harbinger for a danger that could face refugees in many other countries of the world, the danger that the inability to find durable solutions for the refugees, or even any viable self-sufficiency programs, may lead to frustration with their presence, which could turn into erosion of support for the provision of asylum itself. If only to avoid the creation of such extreme solutions as "humane deterrence," there is a need for increased attention to problems created in the care-and-maintenance phase of refugee operations rather than just to the difficulties of relief assistance and attaining durable solutions. Because Somalia contains 1 of the world's largest care-and-maintenance populations, there has been considerable discussion of how to help the refugees attain self-sufficiency. What successes there have been so far have been in agriculture; other income-generating projects have been unsuccessful, often producing inferior goods of higher price. A possible rapprochement between Somalia and Ethiopia may lead to changed circumstances which could draw refugees back home to Ethiopia or it may merely lead to their chilly reception by the Somali government. Tanzania has long been looked to for positive models concerning how to promote local integration of refugees through rural settlements. The approaches taken in Tanzania have been much more successful in dealing with economic viability than they have been in dealing with integration. It is rare to hear an assistance official in a settlement mention any concrete steps that are being taken to promote integration, as opposed to not

  9. Density as an explanatory variable of movements and calf survival in savanna elephants across southern Africa.

    PubMed

    Young, K D; Van Aarde, R J

    2010-05-01

    1. Southern Africa's 'elephant problem' is often attributed to an overabundance of elephants (Loxodonta africana) in conservation areas. Paradoxically, the African elephant is listed as 'vulnerable' (IUCN Redlist) despite occupying a large geographical range and numbering about 600 000. How densities influence elephant populations is therefore important for conservation management decisions, particularly because a move towards non-equilibrium management of savannas implies a need for elephant populations to fluctuate in response to variation in intrinsic (demographic) and extrinsic (resource) factors. 2. A study on one of the world's largest elephant populations demonstrated that population regulation is driven by a spatial response to water availability, environmental stochasticity and density. The challenge remains to identify the demographic and behavioural variables that drive density dependence. 3. We evaluated whether the movements of elephant family groups from 13 populations across a wide resource gradient were explained by variability in primary productivity, rainfall and population density. We then assessed whether density-related movements explained variability in juvenile survival, hence inferring a spatially driven behavioural mechanism that may explain density-dependent population growth. We also analysed whether management actions modified this mechanism. 4. In the dry season, daily-displacement distances (DDDs) increased non-linearly with density, and declined with increased vegetation productivity and previous wet season rainfall. In the wet season, DDDs were primarily explained by vegetation productivity. 5. The survival of weaned calves (4-7 years) decreased with increasing dry season DDDs, but this did not hold for suckling calves (1-3 years) or sub-adults (8-11 years). 6. Fences and supplementary water modified the shape and strength of relationships between DDDs and densities, vegetation productivity and rainfall and negated the relationships

  10. Present and past microbial life in continental salt pan sediments in Southern Africa

    NASA Astrophysics Data System (ADS)

    Genderjahn, Steffi; Mangelsdorf, Kai; Alawi, Mashal; Kallmeyer, Jens; Wagner, Dirk

    2015-04-01

    The southwestern African region is characterized by strong climate variability. To get a better understanding on the climate evolution and environmental condition in Namibia and South Africa, terrestrial climate archives are investigated. Since there are almost no lakes, continental salt pans represent the only terrestrial geoarchives with the potential to preserve climate signals during sediment deposition. Climate has a strong impact on the salt pan ecosystem, causing adaptation of salt pan microorganisms to varying temperature, precipitation and salinity conditions. To reconstruct climate variability during the Holocene, the composition, diversity and abundance of indigenous microbial communities with depth and related to different soil parameters are investigated. We are using a combined approach of microbiological and lipid biomarker analyses to demonstrate the response of the microbial communities due to environmental changes. For microbiological analyses outcrops were conducted or short cores (0-100 cm) were drilled at four different salt pans in Aminuis, Koes and Witpan region having rather different geochemical properties. The current work focused on changes within the microbial communities due to the impact of long-term climate variation and the associated environmental changes and is part of the project 'Signals of climate and landscape change preserved in southern African GeoArchives' in the scope of the SPACES program, which is funded by the German Federal Ministry of Education and Research (BMBF). For a quantitative characterization of microbial communities molecular techniques such as polymerase chain reaction (PCR) and real-time quantitative PCR (qPCR) based on the 16S rRNA genes are used. Moreover, 454 sequencing technique is utilized to describe the diversity and abundance of microorganisms in detail. Soil parameters are described by standard soil scientific methods. Furthermore, microbial lipid biomarker analyses were done to characterize living

  11. Mechanisms of seismic attenuation in the crust: Scattering and anelasticity in New York state, South Africa, and southern California

    NASA Astrophysics Data System (ADS)

    Frankel, Arthur

    1991-04-01

    The envelopes of high-frequency seismograms from earthquakes in New York State, South Africa, and southern California are analyzed to determine how much of the observed attenuation of shear waves in the crust is caused by anelasticity and how much is produced by scattering from small-scale heterogeneities. For seismograms from New York and South Africa, there is a systematic enrichment of high-frequency energy that develops in the coda relative to the direct S or Lg waves. This enrichment of high frequencies in the coda grows larger with increasing source-receiver distance. This implies that high-frequency energy is scattered from the direct wave into the coda as the shear wave propagates in the crust. I use the growth with source-receiver distance of the high-frequency energy in the coda relative to the direct wave to estimate the scattering attenuation of the crust. For seismograms from New York, it is consistently observed that the time decay of high-frequency energy in the coda, when compared to the low-frequency coda decay, is less than the relative decay of high-frequency energy with travel time in the Lg wave. This observations supports the idea that the time decay of the coda is controlled mainly by the anelastic attenuation and is insensitive to the scattering attenuation, as suggested by coda models incorporating conservation of energy such as the energy flux model. I use the relative time decay of high-frequency energy in the coda to determine the anelastic attenuation. This analysis indicates that the observed attenuation of 15-Hz Lg waves in New York State (Δ = 100-400 km) is caused about equally by scattering and anelasticity. Using the estimate of Lg wave Q as a constraint, I find that the scattering Q in the crust of New York is either independent of frequency or increases with frequency ƒ slower than ƒ0.3. This implies that the one-dimensional power spectrum of spatial velocity variations in the crust of New York decays with increasing

  12. Contemporary Problems in Africa.

    ERIC Educational Resources Information Center

    O'Meara, Patrick; Winchester, N. Brian

    1987-01-01

    Provides a brief overview of political and economic developments of the past 25 years in Africa. Maintains this was a period of experimentation with vast differences in the ways in which governments dealt with human and natural problems. (JDH)

  13. Child Labour in Africa.

    ERIC Educational Resources Information Center

    Bonnet, Michel

    1993-01-01

    The question of child labor in Africa is complicated by the failures of the educational system, family relations, traditional forms of apprenticeship, proliferation of the informal economic sector, and continuing existence of a rural economy. Hazardous working conditions prevail. (SK)

  14. AIDS in Africa

    DTIC Science & Technology

    2006-03-09

    have recommended that Africans infected with HIV be treated with an antibiotic/ sulfa drug combination known as cotrimoxazole in order to prevent...response is the subject of much debate. An estimated 500,000 Africa AIDS patients were being treated with antiretroviral drugs in mid-2005, up from 150,000...whether drugs can be made widely accessible without costly health infrastructure improvements. U.S. concern over AIDS in Africa grew in the 1980s, as the

  15. Profile of South Africa

    SciTech Connect

    Fox, G.J.; Tonneson, L.C.

    1996-08-01

    A broad overview of the Republic of South Africa`s nuclear energy program is presented. Economic aspects are the main focus of the article, and numerical data is provided for electricity generation and use and uranium production. The role of the molecular laser isotope process for enrichment is discussed. The research reactor program, waste disposal and decommissioning, mining history, uranium production, and nonproliferation policy are other highlighted topics.

  16. Framework for monitoring equity in access and health systems issues in antiretroviral therapy Programmes in southern Africa.

    PubMed

    Kalanda, Boniface; Makwiza, Ireen; Kemp, Julia

    2007-03-01

    Universal provision of antiretroviral therapy (ART), while feasible, is expensive. In light of this limitation, the World Health Organisation (WHO) has launched the 3 × 5 initiative, to provide ART to 3 million people by the end of the year 2005. In Southern Africa, large-scale provision of ART will likely be achieved through fragile public health systems. ART programmes should therefore be developed and expanded in ways that will not aggravate inequities or result in the inappropriate withdrawal of resources from other health interventions or from other parts of the health system. This paper, proposes a framework for monitoring equity in access and health systems issues in ART programmes in Southern Africa. It proposes that an equity monitoring system should comprise seven thematic areas. These thematic areas encompass a national monitoring system which extends beyond one agency or single data collection method. Together with monitoring of targets in terms of numbers treated, there should also be monitoring of health systems impacts and issues in ART expansion, with reporting both nationally and to a regional body.

  17. Non-Hodgkin lymphoma in Southern Africa: review of 487 cases from The International Non-Hodgkin Lymphoma Classification Project.

    PubMed

    Perry, Anamarija M; Perner, Yvonne; Diebold, Jacques; Nathwani, Bharat N; MacLennan, Kenneth A; Müller-Hermelink, Hans K; Bast, Martin; Boilesen, Eugene; Armitage, James O; Weisenburger, Dennis D

    2016-03-01

    Comparative data on the distribution of non-Hodgkin lymphoma (NHL) subtypes in Southern Africa (SAF) is scarce. In this study, five expert haematopathologists classified 487 consecutive cases of NHL from SAF using the World Health Organization classification, and compared the results to North America (NA) and Western Europe (WEU). Southern Africa had a significantly lower proportion of low-grade (LG) B-NHL (34·3%) and a higher proportion of high-grade (HG) B-NHL (51·5%) compared to WEU (54·5% and 36·4%) and NA (56·1% and 34·3%). High-grade Burkitt-like lymphoma was significantly more common in SAF (8·2%) than in WEU (2·4%) and NA (2·5%), most likely due to human immunodeficiency virus infection. When SAF patients were divided by race, whites had a significantly higher frequency of LG B-NHL (60·4%) and a lower frequency of HG B-NHL (32·7%) compared to blacks (22·5% and 62·6%), whereas the other races were intermediate. Whites and other races had a significantly higher frequency of follicular lymphoma and a lower frequency of Burkitt-like lymphoma compared to blacks. The median ages of whites with LG B-NHL, HG B-NHL and T-NHL (64, 56 and 67 years) were significantly higher than those of blacks (55, 41 and 34 years). Epidemiological studies are needed to better understand these differences.

  18. Towards a gender perspective in qualitative research on voluntary medical male circumcision in east and southern Africa

    PubMed Central

    Pérez, Guillermo Martínez; Durán, Laura Triviño; Gasch, Angel; Desmond, Nicole

    2016-01-01

    The World Health Organization endorsed voluntary medical male circumcision (VMMC) in 2007 as an effective method to provide partial protection against heterosexual female-to-male transmission of HIV in regions with high rates of such transmission, and where uptake of VMMC is low. Qualitative research conducted in east and southern Africa has focused on assessing acceptability, barriers to uptake of VMMC and the likelihood of VMMC increasing men’s adoption of risky sexual behaviours. Less researched, however, have been the perceptions of women and sexual minorities towards VMMC, even though they are more vulnerable to HIV/AIDS transmission than are heterosexual men. The purpose of this paper is to identify core areas in which a gendered perspective in qualitative research might improve the understanding and framing of VMMC in east and southern Africa. Issues explored in this analysis are risk compensation, the post-circumcision appearance of the penis, inclusion of men who have sex with men as study respondents and the antagonistic relation between VMMC and female genital cutting. If biomedical and social science researchers explore these issues in future qualitative inquiry utilising a gendered perspective, a more thorough understanding of VMMC can be achieved, which could ultimately inform policy and implementation. PMID:25727455

  19. Seeds of hope, seeds of despair: towards a political economy of the seed industry in southern Africa.

    PubMed

    Zerbe, N

    2001-01-01

    The seed industry in Southern Africa has been radically transformed by a policy of liberalisation and privatisation started under structural adjustment. Traditionally under the domain of parastatals, seed research, production and distribution has been criticised for failing to provide modern variety seed to smallholder farmers. However, the private companies which have stepped in to replace seed parastatals in southern Africa have proven no more effective in meeting the demands of smallholders. The Trade Related Intellectual Property Rights (TRIPs) Agreement, concluded in 1994 as part of the Uruguay Rounds of GATT negotiations, as well as certain biotechnological innovations such as Terminator or Traitor technologies, threaten to further undermine local seed production and consumption by destroying the informal seed sector so central to agricultural production in the region. What alternatives exist? The success of Zimbabwe's maize seed network offers some insight. Resting on a unique relationship between government and nationally based producer co-operatives, Zimbabwe's maize programme was able to provide nearly every farmer in the country with hybrid maize suited for local growing conditions.

  20. Towards a gender perspective in qualitative research on voluntary medical male circumcision in east and southern Africa.

    PubMed

    Martínez Pérez, Guillermo; Triviño Durán, Laura; Gasch, Angel; Desmond, Nicole

    2015-01-01

    The World Health Organization endorsed voluntary medical male circumcision (VMMC) in 2007 as an effective method to provide partial protection against heterosexual female-to-male transmission of HIV in regions with high rates of such transmission, and where uptake of VMMC is low. Qualitative research conducted in east and southern Africa has focused on assessing acceptability, barriers to uptake of VMMC and the likelihood of VMMC increasing men's adoption of risky sexual behaviours. Less researched, however, have been the perceptions of women and sexual minorities towards VMMC, even though they are more vulnerable to HIV/AIDS transmission than are heterosexual men. The purpose of this paper is to identify core areas in which a gendered perspective in qualitative research might improve the understanding and framing of VMMC in east and southern Africa. Issues explored in this analysis are risk compensation, the post-circumcision appearance of the penis, inclusion of men who have sex with men as study respondents and the antagonistic relation between VMMC and female genital cutting. If biomedical and social science researchers explore these issues in future qualitative inquiry utilising a gendered perspective, a more thorough understanding of VMMC can be achieved, which could ultimately inform policy and implementation.

  1. Decolonizing Bioethics in Africa

    PubMed Central

    Macaulay-Adeyelure, O.C.

    2017-01-01

    The global spread of bioethics from its North-American and European provenance to non-Western societies is currently raising some concerns. Part of the concern has to do with whether or not the exportation of bioethics in its full Western sense to developing non-Western states is an instance of ethical imperialism or bioethical neocolonialism. This paper attempts an exploration of this debate in the context of bioethics in sub-Saharan Africa. Rather than conceding that bioethics has a colonial agenda in Africa, this paper defends the position that the current bioethics trend in sub-Saharan Africa is an unintended imperialistic project. It argues that its colonizing character is not entirely a product of the Western programmed goals of training and institution building; rather, it is a structural consequence of many receptive African minds and institutions. Though bioethics in Africa is turning out as a colonizing project, one serious implication of such trend, if unchecked urgently, is that bioethics’ invaluable relevance to Africa is being incapacitated. This paper, therefore, attempts a decolonizing trajectory of bioethics in Africa. Contrary to the pretense of ‘African bioethics,’ which some African scholars are now defending, this paper through the logic of decolonization makes case for ‘bioethics in Africa’. In such logic, the principle of existential needs is prioritized over the principle of identity and authenticity that define African voice in bioethics. PMID:28344985

  2. Changing styles of crustal growth in Southern Africa: Constraints from geochemical and Sr-Nd isotope studies in Archaean to Pan African terrains

    NASA Technical Reports Server (NTRS)

    Mcdermott, F.; Hawkesworth, C. J.; Harris, N. B. W.

    1988-01-01

    Nd isotopic data was presented for southern Africa in support of episodic crustal growth. Over 50 percent of the continental crust there had formed before 2.5 Ga, and less than 10 percent was produced after about 1.0 Ga. The data imply a mean crustal age of about 2.4 Ga for southern Africa, and a higher rate of crustal growth than that derived from Australian shale data, particularly during the Proterozoic. Isotopic data from Damara metasediments imply that there is no need to invoke decoupling of the Rb-Sr and Sm-Nd systems in the continental crust.

  3. 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

  4. Human trafficking, labor brokering, and mining in southern Africa: responding to a decentralized and hidden public health disaster.

    PubMed

    Steele, Sarah

    2013-01-01

    Many southern African economies are dependent on the extractive industries. These industries rely on low-cost labor, often supplied by migrants, typically acquired through labor brokers. Very little attention has so far been paid to trafficking of men into extractive industries or its connection with trafficked women in the region's mining hubs. Recent reports suggest that labor-brokering practices foster human trafficking, both by exposing migrant men to lack of pay and exploitative conditions and by creating male migratory patterns that generate demand for sex workers and associated trafficking of women and girls. While trafficking in persons violates human rights, and thus remains a priority issue globally, there is little or no evidence of an effective political response to mine-related trafficking in southern Africa. This article concludes with recommendations for legal and policy interventions, as well as an enhanced public health response, which if implemented would help reduce human trafficking toward mining sites.

  5. The African buffalo: a villain for inter-species spread of infectious diseases in southern Africa.

    PubMed

    Michel, Anita L; Bengis, Roy G

    2012-06-20

    The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after 'Big Five' in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population's survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.

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

    PubMed

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

    2009-06-01

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

  7. Ectoparasite Burdens of the Damaraland Mole-Rat (Fukomys damarensis) from Southern Africa.

    PubMed

    Lutermann, Heike; Carpenter-Kling, Tegan; Ueckermann, Edward A; Gutjahr, Gundula; Bennett, Nigel C

    2015-12-01

    Damaraland mole-rats (Fukomys damarensis) of the family Bathyergidae are widely distributed subterranean rodents in sub-Saharan Africa. No parasites have ever been reported for this species and only 1 ectoparasite is described for the entire genus. In the current study ectoparasites were collected from individuals captured at 3 localities in South Africa and Namibia to document the ectoparasite community of F. damarensis, investigate their aggregation patterns, and evaluate the influence of season on ectoparasite burden. A total of 2,071 arthropods from 9 mite taxa and 1 louse species (Eulinognathus hilli) were collected from 293 hosts sampled. Of these, 5 mite species (Androlaelaps scapularis, Androlaelaps capensis, Androlaelaps tauffliebi, Radfordia sp., and unidentified chiggers) and the louse were parasites while the remainder was soil mites. All ectoparasites were highly aggregated and the species richness as well as the prevalence and abundance of 4 of them were significantly greater in summer compared to winter, possibly as a result of seasonal changes in rainfall patterns affecting the ectoparasites, host behavior, or both.

  8. Modelled rainfall skill assessment against a 1000-year time/space isotope dendro-climatology for southern Africa

    NASA Astrophysics Data System (ADS)

    Woodborne, Stephan; Hall, Grant; Zhang, Qiong

    2016-04-01

    Palaeoclimate reconstruction using isotopic analysis of tree growth increments has yielded a 1000-year record of rainfall variability in southern Africa. Isotope dendro-climatology reconstructions from baobab trees (Adansonia digitata) provide evidence for rainfall variability from the arid Namib Desert and the Limpopo River Valley. Isotopic analysis of a museum specimen of a yellowwood tree (Podocarps falcatus) yields another record from the southwestern part of the subcontinent. Combined with the limited classic denro-climatologies available in the region these records yield palaeo-rainfall variability in the summer and winter rainfall zones as well as the hyper-arid zone over the last 1000 years. Coherent shifts in all of the records indicate synoptic changes in the westerlies, the inter-tropical convergence zone, and the Congo air boundary. The most substantial rainfall shift takes place at about 1600 CE at the onset of the Little Ice Age. Another distinctive feature of the record is a widespread phenomenon that occurs shortly after 1810 CE that in southern Africa corresponds with a widespread social upheaval known as the Difequane or Mfekane. Large scale forcing of the system includes sea-surface temperatures in the Agulhas Current, the El Nino Southern Oscillation and the Southern Annular Mode. The Little Ice Age and Mfekane climate shifts result from different forcing mechanisms, and the rainfall response in the different regions at these times do not have a fixed phase relationship. This complexity provides a good scenario to test climate models. A first order (wetter versus drier) comparison between each of the tree records and a 1000-year palaeoclimate model simulation for the Little Ice Age and Mfekane transitions demonstrates a generally good correspondence.

  9. Hydrological projections under climate change in the near future by RegCM4 in Southern Africa using a large-scale hydrological model

    NASA Astrophysics Data System (ADS)

    Li, Lu; Diallo, Ismaïla; Xu, Chong-Yu; Stordal, Frode

    2015-09-01

    This study aims to provide model estimates of changes in hydrological elements, such as EvapoTranspiration (ET) and runoff, in Southern Africa in the near future until 2029. The climate change scenarios are projected by a high-resolution Regional Climate Model (RCM), RegCM4, which is the latest version of this model developed by the Abdus Salam International Centre for Theoretical Physics (ICTP). The hydrological projections are performed by using a large-scale hydrological model (WASMOD-D), which has been tested and customized on this region prior to this study. The results reveal that (1) the projected temperature shows an increasing tendency over Southern Africa in the near future, especially eastward of 25°E, while the precipitation changes are varying between different months and sub-regions; (2) an increase in runoff (and ET) was found in eastern part of Southern Africa, i.e. Southern Mozambique and Malawi, while a decrease was estimated across the driest region in a wide area encompassing Kalahari Desert, Namibia, southwest of South Africa and Angola; (3) the strongest climate change signals are found over humid tropical areas, i.e. north of Angola and Malawi and south of Dem Rep of Congo; and (4) large spatial and temporal variability of climate change signals is found in the near future over Southern Africa. This study presents the main results of work-package 2 (WP2) of the 'Socioeconomic Consequences of Climate Change in Sub-equatorial Africa (SoCoCA)' project, which is funded by the Research Council of Norway.

  10. Debates in the late Quaternary of central southern Africa: climate change, environmental variability or just plain poor data?

    NASA Astrophysics Data System (ADS)

    Thomas, D. S.; Burrough, S. L.

    2012-12-01

    Quaternary palaeoclimatic/environmental analyses in dryland regions are well-known for the limited range of proxy data sets available, resulting in debates about achieving robust reconstructions (e.g. Butzer 1984, Thomas 1986, Maslin and Christiansen 2007). In some regions, e.g. central southern Africa, this has resulted in reliance on geoproxies: the analysis and dating of depositional landforms and associated sediments. Despite significant advances in geoproxy interpretation and chronometric control, their efficacy remains contentious, not least because of apparent temporal contradictions in reconstructions of past drier and past more humid conditions. Consequently their use has been eschewed in favour of spatially extensive extrapolations from higher-resolution, but geographically-distant, data sets (e.g. Chase and Meadows 2008); an approach not without its own limitations (e.g. Gasse et al. 2008, Thomas and Burrough 2012, Thomas et al. 2012), given the variability in modern terrestrial conditions in dryland regions today. It is therefore highly appropriate to revisit the debates of Butzer (1984) and Thomas (1986) regarding data quality and data extrapolation, but to add in the very relevant characteristic of temporal and spatial environmental variability. Environmental and climatic variability at a range of temporal and spatial scales are significant traits of drylands in southern Africa and worldwide, impacting on ecosystem and geomorphic processes, and human behaviour. It can be hypothesised that while environmental variability has been an important trait of Late Quaternary environments and climate in southern Africa. It has rarely been considered as a viable environmental 'state' when proxy records are analysed and integrated, particularly in the case of spatially extensive geoproxies and in contexts where palaeoenvironment and palaeoclimate are used interchangeably. We present examples where debates over the nature of past changes and quality of datasets

  11. The emergence of Taenia solium cysticercosis in Eastern and Southern Africa as a serious agricultural problem and public health risk.

    PubMed

    Phiri, Isaac K; Ngowi, Helena; Afonso, Sonia; Matenga, Elizabeth; Boa, Mathias; Mukaratirwa, Samson; Githigia, Samuel; Saimo, Margaret; Sikasunge, Chummy; Maingi, Ndichu; Lubega, George W; Kassuku, Ayub; Michael, Lynne; Siziya, Seter; Krecek, Rosina C; Noormahomed, Emilia; Vilhena, Manuela; Dorny, Pierre; Willingham, A Lee

    2003-06-01

    Pig production has increased significantly in the Eastern and Southern Africa (ESA) region during the past decade, especially in rural, resource-poor, smallholder communities. Concurrent with the increase in smallholder pig keeping and pork consumption, there have been increasing reports of porcine cysticercosis in the ESA region. This article reviews the findings concerning the presence and impact of porcine cysticercosis in seven of the ESA countries. Most of the reported findings are based on surveys utilising lingual palpation and post-mortem examination, however, some also used serological assays. In Tanzania, community-based studies on porcine cysticercosis indicate a prevalence of 17.4% in the northern highlands district of Mbulu and a prevalence range of 5.1-16.9% in the southern highlands. In Kenya recent surveys in the southwestern part of the country where smallholder pig keeping is popular indicate that 10-14% of pigs are positive for cysticercosis by lingual examination. Uganda has the most pigs in Eastern Africa, most of which are kept under smallholder conditions. Preliminary surveys in 1998 and 1999 at slaughterhouses in Kampala indicated a prevalence of porcine cysticercosis between 0.12 and 1.2%, however, a rural survey in northern Uganda in 1999 indicated 34-45% of pigs slaughtered in selected villages were infected. Additionally, a new survey of 297 pigs slaughtered in Kampala in 2002 indicated that pigs from the central region of the country were negative for cysticercosis while 33.7% of the pigs coming from the rural Lira district in the north were positive. Interestingly 8 piglet foetuses removed from an infected slaughtered sow coming from Lira district were all found to harbour cysts of T. solium providing evidence of congenital transmission of porcine cysticercosis. In Mozambique, abattoir records indicate that porcine cysticercosis is present in all provinces of the country. A serological survey on pigs in rural Tete Province found 15% of

  12. The Wordy Worlds of Popular Music in Eastern and Southern Africa: Possible Implications for Language-in-Education Policy

    ERIC Educational Resources Information Center

    Makoni, Sinfree; Makoni, Busi; Rosenberg, Aaron

    2010-01-01

    Language-in-education policy in Africa is replete with debate regarding the use of standard African languages as part of mother-tongue education. An issue inadequately addressed within this debate is the role and function of urban vernaculars which have become "the" mother tongue of the greater part of Africa's population. Using data…

  13. Sub-Saharan Africa Report

    DTIC Science & Technology

    1987-03-23

    Farms Over Peasant Farming (SOUTHERN AFRICA FOCUS, Feb 87) 69 SAO TOME AND PRINCIPE Pinto da Costa Reshuffles Cabinet, Creates New Ministries...Voting Slated 134 ECONOMIC Statistics Reveal Shortage of Engineering Graduates (Mandy Jean Woods; BUSINESS DAY, 10 Feb 87) 135 Self-Help Projects...Ocean Newsletter. It is not certain that Jacques Chirac’s government is excessively worried, satisfied as it is at having secured a modus vivendi

  14. Prediction, assessment of the Rift Valley fever activity in East and Southern Africa 2006-2008 and possible vector control strategies.

    PubMed

    Anyamba, Assaf; Linthicum, Kenneth J; Small, Jennifer; Britch, Seth C; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W; Breiman, Robert F; Chretien, Jean-Paul; Tucker, Compton J; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M; Reynes, Jean-Marc; Swanepoel, Robert

    2010-08-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2-4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future.

  15. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006–2008 and Possible Vector Control Strategies

    PubMed Central

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, Seth C.; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W.; Breiman, Robert F.; Chretien, Jean-Paul; Tucker, Compton J.; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B.; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M.; Reynes, Jean-Marc; Swanepoel, Robert

    2010-01-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2–4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future. PMID:20682905

  16. Identifying needs for streamflow forecasting in the Incomati basin, Southern Africa

    NASA Astrophysics Data System (ADS)

    Sunday, Robert; Werner, Micha; Masih, Ilyas; van der Zaag, Pieter

    2013-04-01

    Despite being widely recognised as an efficient tool in the operational management of water resources, rainfall and streamflow forecasts are currently not utilised in water management practice in the Incomati Basin in Southern Africa. Although, there have been initiatives for forecasting streamflow in the Sabie and Crocodile sub-basins, the outputs of these have found little use because of scepticism on the accuracy and reliability of the information, or the relevance of the information provided to the needs of the water managers. The process of improving these forecasts is underway, but as yet the actual needs of the forecasts are unclear and scope of the ongoing initiatives remains very limited. In this study questionnaires and focused group interviews were used to establish the need, potential use, benefit and required accuracy of rainfall and streamflow forecasts in the Incomati Basin. Thirty five interviews were conducted with professionals engaged in water sector and detailed discussions were held with water institutions, including the Inkomati Catchment Management Agency (ICMA), Komati Basin Water Authority (KOBWA), South African Weather Service (SAWS), water managers, dam operators, water experts, farmers and other water users in the Basin. Survey results show that about 97% of the respondents receive weather forecasts. In contrast to expectations, only 5% have access to the streamflow forecast. In the weather forecast, the most important variables were considered to be rainfall and temperature at daily and weekly time scales. Moreover, forecasts of global climatic indices such as El Niño or La Niña were neither received nor demanded. There was limited demand and/or awareness of flood and drought forecasts including the information on their linkages with global climatic indices. While the majority of respondents indicate the need and indeed use the weather forecast, the provision, communication and interpretation were in general found to be with too

  17. The Late Pleistocene and Holocene palaeoenvironmental context of Wonderwerk Cave in the southern Kalahari, South Africa

    NASA Astrophysics Data System (ADS)

    Scott, Louis; Avery, Margaret; Bamford, Marion; Berna, Francesco; Brink, James; Brook, George; Chazan, Michael; Ecker, Michaela; Fernandez-Jalvo, Yolanda; Goldberg, Paul; Lee-Thorp, Julia; Rossouw, Lloyd; Thackeray, Francis; Horwitz, Liora

    2014-05-01

    Wonderwerk Cave, located in the arid southern Kalahari in South Africa, is an exceptional site, since it preserves a two million year long record of human occupation. While research on older levels in various excavation sections of the cave deposits is ongoing, we focus here on the younger levels that span the last 35,000 years. We present the results of past and recent work on zooarchaeology, macrobotany, palynology, phytoliths, stable isotopes, micromorphology and speleothem growth, which track marked diachronic environmental fluctuations. Except for a hiatus of ~33-23 ka, growth and isotope data for a speleothem near the cave entrance suggests moist conditions from ~35-33, and ~22-14 ka with brief, dry episodes at ~34, ~22 and ~15 ka. Temperatures were cool except for an increase ~16-14 ka after which cold conditions equivalent to the Younger Dryas event occurred. In Stratum 5 (>12.5 ka in Excavation 1), relatively low carbon isotope (δ13C) values, pollen in the speleothem, and pollen in dung deposits indicate that the vegetation included a large C3 component during this phase. While the climate experienced sharp fluctuations in moisture when stalagmite growth was interrupted, more severe drying occurred by ~12 ka as indicated by dung pollen. Pollen in Stratum 4d (undifferentiated by stratum sub-phases) suggest that warmer grassy conditions developed before 11 ka, which is supported by δ13C values in OES that suggest a greater C4plant component in Stratum 4dII associated with the Oakhurst-like archaeological industry. Undifferentiated Stratum 4d indicates moderate moisture availability (pollen) but sub-phase 4dII suggest drying (OES δ18O). C3-presence (OES δ13C) in the vegetation became stronger again in Stratum 4dI (Oakhurst) and Stratum 4cII (Wilton). This is supported by Asteraceae pollen especially ~8.5 ka. Except for a fluctuation in OES δ18O values in Stratum 4cII, δ18O and pollen and micromammal composition suggest progressive aridity until ~6 ka

  18. The anthropogenic contribution to atmospheric black carbon concentrations in southern Africa: a WRF-Chem modeling study

    NASA Astrophysics Data System (ADS)

    Kuik, F.; Lauer, A.; Beukes, J. P.; Van Zyl, P. G.; Josipovic, M.; Vakkari, V.; Laakso, L.; Feig, G. T.

    2015-08-01

    South Africa has one of the largest industrialized economies in Africa. Emissions of air pollutants are particularly high in the Johannesburg-Pretoria metropolitan area, the Mpumalanga Highveld and the Vaal Triangle, resulting in local air pollution. This study presents and evaluates a setup for conducting modeling experiments over southern Africa with the Weather Research and Forecasting model including chemistry and aerosols (WRF-Chem), and analyzes the contribution of anthropogenic emissions to the total black carbon (BC) concentrations from September to December 2010. The modeled BC concentrations are compared with measurements obtained at the Welgegund station situated ca. 100 km southwest of Johannesburg. An evaluation of WRF-Chem with observational data from ground-based measurement stations, radiosondes, and satellites shows that the meteorology is modeled mostly reasonably well, but precipitation amounts are widely overestimated and the onset of the wet season is modeled approximately 1 month too early in 2010. Modeled daily mean BC concentrations show a temporal correlation of 0.66 with measurements, but the total BC concentration is underestimated in the model by up to 50 %. Sensitivity studies with anthropogenic emissions of BC and co-emitted species turned off show that anthropogenic sources can contribute up to 100 % to BC concentrations in the industrialized and urban areas, and anthropogenic BC and co-emitted species together can contribute up to 60 % to PM1 levels. Particularly the co-emitted species contribute significantly to the aerosol optical depth (AOD). Furthermore, in areas of large-scale biomass-burning atmospheric heating rates are increased through absorption by BC up to an altitude of about 600hPa.

  19. Social support as a protective factor for children impacted by HIV/AIDS across varying living environments in southern Africa

    PubMed Central

    Barenbaum, Edna; Smith, Tamarah

    2016-01-01

    ABSTRACT The literature on the psychological well-being of children impacted by HIV/AIDS in Africa highlights increased vulnerability due to loss of parents and environmental stressors (e.g., hunger). Research shows that the lack of attachment and social support due to loss limits the grieving process in children. Access to trusting adults and social support through caregivers can be an important protective factor to allow for coping and better emotional adjustment in the future. This study examined social support systems across varying living environments to determine if social support promoted higher levels of well-being in children orphaned and made vulnerable by HIV/AIDS. The participants included 100 children from a small targeted population in southern Africa who receive varying levels of support from a private not-for-profit organization. Children’s well-being was assessed through the Psycho-Social Adjustment Scale-Adolescents developed specifically for vulnerable child populations in Africa. Children were individually interviewed either on their homestead, school or hostel. Data demonstrated that children who do not share their feelings had significantly lower measures of positive well-being (M = 2.61 (0.87) vs. M = 3.10 (0.57), d = 0.60). Children with trusted adults were significantly more likely to share their feelings and had lower incidence of hunger (49.1% vs. 62.5%), suicide ideation (15.1% vs. 62.5%) and witnessing violence (69.8% vs. 87.5%). Sharing feelings with caregivers was more pronounced among children who had greater access to trusted adults and correlated with stronger attachment scores (r = .30, p < .01). An important component to decrease levels of anxiety and depression in this vulnerable population is providing access to trusted individuals. Social support interventions are discussed. PMID:27392004

  20. Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa.

    PubMed

    Van Bressem, Marie-Françoise; Simões-Lopes, Paulo C; Félix, Fernando; Kiszka, Jeremy J; Daura-Jorge, Fabio G; Avila, Isabel C; Secchi, Eduardo R; Flach, Leonardo; Fruet, Pedro F; du Toit, Kate; Ott, Paulo H; Elwen, Simon; Di Giacomo, Amanda B; Wagner, Jeanne; Banks, Aaron; Van Waerebeek, Koen

    2015-11-17

    We report on the epidemiology of lobomycosis-like disease (LLD), a cutaneous disorder evoking lobomycosis, in 658 common bottlenose dolphins Tursiops truncatus from South America and 94 Indo-Pacific bottlenose dolphins T. aduncus from southern Africa. Photographs and stranding records of 387 inshore residents, 60 inshore non-residents and 305 specimens of undetermined origin (inshore and offshore) were examined for the presence of LLD lesions from 2004 to 2015. Seventeen residents, 3 non-residents and 1 inshore dolphin of unknown residence status were positive. LLD lesions appeared as single or multiple, light grey to whitish nodules and plaques that may ulcerate and increase in size over time. Among resident dolphins, prevalence varied significantly among 4 communities, being low in Posorja (2.35%, n = 85), Ecuador, and high in Salinas, Ecuador (16.7%, n = 18), and Laguna, Brazil (14.3%, n = 42). LLD prevalence increased in 36 T. truncatus from Laguna from 5.6% in 2007-2009 to 13.9% in 2013-2014, albeit not significantly. The disease has persisted for years in dolphins from Mayotte, Laguna, Salinas, the Sanquianga National Park and Bahía Málaga (Colombia) but vanished from the Tramandaí Estuary and the Mampituba River (Brazil). The geographical range of LLD has expanded in Brazil, South Africa and Ecuador, in areas that have been regularly surveyed for 10 to 35 yr. Two of the 21 LLD-affected dolphins were found dead with extensive lesions in southern Brazil, and 2 others disappeared, and presumably died, in Ecuador. These observations stress the need for targeted epidemiological, histological and molecular studies of LLD in dolphins, especially in the Southern Hemisphere.

  1. Neogene desertification of Africa

    NASA Astrophysics Data System (ADS)

    Senut, Brigitte; Pickford, Martin; Ségalen, Loïc

    2009-08-01

    Throughout the Neogene, the faunas and floras in Africa recorded global climatic changes. We present an overview of Neogene desertification in Africa by tracing stable isotopes in eggshells and mammalian enamel, by faunal (changes in hypsodonty, etc.) and floral changes in sequences at the latitudinal extremities of the continent and the equator. This work reveals that desertification started in the southwest ca 17-16 Ma, much earlier than the region of the present-day Sahara (ca 8-7 Ma) and long before the deserts in East Africa (Plio-Pleistocene). A consequence of this history is that animals and plants inhabiting the South of the continent had a long period of time in which to adapt to arid, unstable climatic conditions. When parts of East Africa became arid during the Late Miocene and Plio-Pleistocene, several of these lineages expanded northwards and occupied developing arid niches before local lineages could adapt. Several of the latter became extinct, while others withdrew westwards as the tropical forest diminished in extent. It is proposed that the history of desertification in Africa was related to that of the polar ice caps (Antarctic, Arctic).

  2. Accretionary history of the Archean Barberton Greenstone Belt (3.55-3.22 Ga), southern Africa.

    PubMed

    Lowe, D R

    1994-12-01

    The 3.55-3.22 Ga Barberton Greenstone Belt, South Africa and Swaziland, and surrounding coeval plutons can be divided into four tectono-stratigraphic blocks that become younger toward the northwest. Each block formed through early mafic to ultramafic volcanism (Onverwacht Group), probably in oceanic extensional, island, or plateau settings. Volcanism was followed by magmatic quiescence and deposition of fine-grained sediments, possibly in an intraplate setting. Late evolution involved underplating of the mafic crust by tonalitic intrusions along a subduction-related magmatic arc, yielding a thickened, buoyant protocontinental block. The growth of larger continental domains occurred both through magmatic accretion, as new protocontinental blocks developed along the margins of older blocks, and when previously separate blocks were amalgamated through tectonic accretion. Evolution of the Barberton Belt may reflect an Early Archean plate tectonic cycle that characterized a world with few or no large, stabilized blocks of sialic crust.

  3. Naturally acquired antibodies to Bacillus anthracis protective antigen in vultures of southern Africa.

    PubMed

    Turnbull, P C B; Diekmann, M; Kilian, J W; Versfeld, W; De Vos, V; Arntzen, L; Wolter, K; Bartels, P; Kotze, A

    2008-06-01

    Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63%) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a whole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheres, six out of ten White-backed Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypius tracheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. It is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.

  4. Secondary prevention of stroke--results from the Southern Africa Stroke Prevention Initiative (SASPI) study.

    PubMed Central

    Thorogood, M.; Connor, M. D.; Lewando-Hundt, G.; Tollman, S.; Ngoma, B.

    2004-01-01

    OBJECTIVE: To describe the prevalence of risk factors and experience of preventive interventions in stroke survivors, and identilfy barriers to secondary prevention in rural South Africa. METHODS: A clinician visited individuals in the Agincourt field site (in South Africa's rural north east) who were identified in a census as possible stroke victims to confirm the diagnosis of stroke. We explored the impact of stroke on the individual's family, and health-seeking behaviour following stroke by conducting in-depth interviews in the households of 35 stroke survivors. We held two workshops to understand the knowledge, experience, and views of primary care nurses, who provide the bulk of professional health care. FINDINGS :We identified 103 stroke survivors (37 men), 73 (71%) of whom had hypertension, but only 8 (8%) were taking anti-hypertensive treatment. Smoking was uncommon; 8 men and 1 woman smoked a maximum of ten cigarettes daily. 94 (91%) stroke survivors had sought help, which involved allopathic health care for most of them (81; 79%). 42 had also sought help from traditional healers and churches, while another 13 people had sought help only from those sources. Of the 35 survivors who were interviewed, 29 reported having been prescribed anti-hypertensive pills after their stroke. Barriers to secondary prevention included cost of treatment, reluctance to use pills, difficulties with access to drugs, and lack of equipment to measure blood pressure. A negative attitude to allopathic care was not an important factor. CONCLUSION: In this rural area hypertension is the most important modifiable risk factor in stroke survivors. Effective secondary prevention may reduce the incidence of recurrent strokes, but there is no system to deliver such care. New strategies for care are needed involving both allopathic and non-allopathic-health care providers. PMID:15500283

  5. Growth of early archaean crust in the ancient Gneiss complex of Swaziland and adjacent Barberton Greenstone Belt, Southern Africa

    NASA Technical Reports Server (NTRS)

    Kroener, A.; Compston, W.; Tegtmeyer, A.; Milisenda, C.; Liew, T. C.

    1988-01-01

    The relationship between early Archean greenstones and high grade gneisses in the Ancient Gneiss Complex of Swaziland and the neighboring Barberton greenstone belt in Southern Africa is discussed. New high precision zircon analyses reveal a complex history in individual zircons from tonalitic orthogneisses, with ages as old as 3644 + 4 Ma. This suggests the presence of continental crust prior to the formation of the supracrustal rocks of the Barberton greenstone belt, which have been previously considered the earliest rocks in the area. The author suggested that these data are incompatible with the intraoceanic settings that have been widely accepted for this terrane, and favors either a marginal basin or rift environment. By using the detailed age information obtained from zircons in combination with Ar-40 and Ar-39 and paleomagnetic measurements, the author estimated that plate velocities for this part of Africa craton were about 10 to 70 mm/yr, during the period 3.4 to 2.5 Ga. This is not incompatible with the idea that Archean plate velocities may have been similiar to those of today.

  6. Impact of HIV treatment scale-up on women's reproductive health care and reproductive rights in Southern Africa.

    PubMed

    Myer, Landon; Akugizibwe, Paula

    2009-11-01

    The HIV epidemic has changed the face of women's reproductive health across southern Africa. In some circles, there have been calls for restrictions on women's reproductive rights, focusing particularly on the spread of HIV between sexual partners and from mother to child. However, during the past decade, public health attention and resources for the clinical care of HIV-infected individuals living in Africa have led to advances in women's reproductive health services. As many programs have recognized that effective HIV care and treatment services must link to other areas of primary care, key reproductive health services such as those providing contraception and barrier methods are commonly integrated into antiretroviral therapy services. In much of the region, this programmatic focus has helped increase attention on the ground to women's reproductive rights. However, in many settings, policies explicitly supporting the reproductive rights of HIV-infected women have lagged. Important gaps remain both in policy development and in the design, evaluation, and implementation of interventions promoting women's reproductive health and rights at the service delivery level.

  7. Parents as partners in adolescent HIV prevention in Eastern and Southern Africa: an evaluation of the current United Nations' approach.

    PubMed

    Wathuta, Jane

    2016-11-10

    The United Nations's (UN) sustainable development goals (SDGs) include the target (3.3) of ending the HIV/AIDS epidemic by 2030. A major challenge in this regard is to curb the incidence of HIV among adolescents, the number two cause of their death in Africa. In Eastern and Southern Africa, they are mainly infected through heterosexual transmission. Research findings about parental influence on the sexual behavior of their adolescent children are reviewed and findings indicate that parental communication, monitoring and connectedness contribute to the avoidance of risky sexual behavior in adolescents. This article evaluates the extent to which these three dimensions of parenting have been factored in to current HIV prevention recommendations relating to adolescent boys and girls. Four pertinent UN reports are analyzed and the results used to demonstrate that the positive role of parents or primary caregivers vis-à-vis risky sexual behavior has tendentially been back-grounded or even potentially undermined. A more explicit inclusion of parents in adolescent HIV prevention policy and practice is essential - obstacles notwithstanding - enabling their indispensable partnership towards ending an epidemic mostly driven by sexual risk behavior. Evidence from successful or promising projects is included to illustrate the practical feasibility and fruitfulness of this approach.

  8. Moisture source and diet affect development and reproduction of Orius thripoborus and Orius naivashae, two predatory anthocorids from Southern Africa.

    PubMed

    Bonte, Jochem; Vangansbeke, Dominiek; Maes, Sara; Bonte, Maarten; Conlong, Des; De Clercq, Patrick

    2012-01-01

    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed.

  9. Crustal structure beneath southern Africa: insight into how tectonic events affect the Mohorovičić discontinuity

    NASA Astrophysics Data System (ADS)

    Delph, Jonathan R.; Porter, Ryan C.

    2015-01-01

    The long and complex history of southern Africa makes it a geological nexus for understanding how crust forms, evolves and survives plate tectonic processes over billions of years. The goal of this study is to characterize the crustal thickness, composition, and Moho impedance contrasts across the Kaapvaal and Zimbabwe Cratons and surrounding mobile belts, which range in age from Archean to Palaeozoic. We use data gathered from the 1997-1999 Southern Africa Seismic Experiment, the Africa Array (2006-2007) and the Global Seismographic Network (1993-2009) to generate P-wave receiver function Gaussian-weighted common conversion point stacks across the region in order to provide a continuous 3-D image of crustal variations throughout southern Africa. We observe thickened crust associated with mobile belts and the intrusion of the Bushveld Complex relative to the less-deformed cratons. The southern Kaapvaal and eastern Zimbabwe Cratons have a well-defined Moho with an average depth of ˜34 km and Vp/Vs of ˜1.73, indicative of felsic average crustal composition. We explain the felsic composition observed in the Kaapvaal Craton in the context of significant crustal modification related to the deposition of the Ventersdorp lavas. We find that the Bushveld Province, the site of the world's largest layered mafic intrusion, has a thick (>40 km) crust with a Vp/Vs > 1.8, indicative of a mafic average crustal composition. The magnitude of Moho conversions beneath the Bushveld Province is variable, with the lowest amplitude conversion appearing between the eastern and western limbs of the Bushveld Complex, indicative of mafic underplating beneath the region. In the Limpopo Belt and western Zimbabwe Craton, we observe low amplitude Moho conversions beneath the Okavango Dyke Swarm, and attribute this to the reworking of the crust by mafic underplating and intrusion during the Jurassic rifting of Gondwanaland. The Namaqua-Natal event thickened the crust and created a gradational

  10. Key Factors in the Rise of Mass Popular Education and Their Relevance for Education in Southern Africa in the Twenty-First Century.

    ERIC Educational Resources Information Center

    van Niekerk, E. J.

    This paper identifies the historical factors that played a key role in the rise of mass popular education and describes how these factors relate to education in Southern Africa in the 21st century. The broad overview of developments since the Renaissance begins with the Protestant Reformation, which established a theoretical basis for elementary…

  11. Conference on Resource Sharing in Southern and Central Africa (Dar-es-Salaam, Tanzania, December 16-19, 1985). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific and Cultural Organization, Paris (France). General Information Programme.

    This document summarizes the activities of a conference held at the Institute of Finance Management in Tanzania on information resource sharing in Southern and Central Africa. Delegates and observers from Lesotho, Swaziland, Mozambique, Botswana, Zimbabwe, Malawi, Zambia, and Tanzania attended the conference. The 15 participants, 8 sponsored by…

  12. Vocational Education--Priorities and Strategies. Report of the WCOTP Southern Africa Regional Conference (5th, Lilongwe and Mangochi, Malawi, September 22-26, 1985).

    ERIC Educational Resources Information Center

    World Confederation of Organizations of the Teaching Profession, Morges (Switzerland).

    This document reports the proceedings of a conference in Southern Africa that addressed two themes: (1) priorities and strategies for the reform of vocational education; and (2) the functions of teacher organizations. The following presentations are included: "Opening Address" (Frank A. P. Mkomawanthu); "Keynote Address: Priorities…

  13. Empowering biotechnology in southern Africa: establishment of a robust transformation platform for the production of transgenic industry-preferred cassava.

    PubMed

    Chetty, C C; Rossin, C B; Gruissem, W; Vanderschuren, H; Rey, M E C

    2013-01-25

    improvement in South Africa (SA), which can potentially be extended to other countries in southern Africa. The successful establishment of a robust cassava transformation and regeneration system in SA demonstrates the relevance of technology transfer to sub-Saharan Africa and highlights the importance of developing suitable and reliable techniques before their transfer to laboratories offering less optimal conditions.

  14. Metal levels in feathers of cormorants, flamingos and gulls from the coast of Namibia in southern Africa.

    PubMed

    Burger, J; Gochfeld, M

    2001-06-01

    Arsenic, cadmium, chromium, lead, manganese, mercury, selemium, and tin concentrations were measured in the feathers of Cape cormorant (Phalacrocorax capensis), Hartlaub's gull (Larus hartlaubii), kelp gull (Larus dominicanus), and lesser flamingo (Phoeniconaias minor) from the coast of Namibia in southern Africa. Metal concentrations in feathers represent the concentrations in the blood supply at the time of feather formation. Cape Cormorants are piscivores; kelp gulls are primarily piscivores; Hartlaub's gull is an omnivore; and lesser flamingos eat primarily blue-green algae and invertebrates filtered from the water and sediment of hypersaline lagoons. We predicted that metal concentrations would reflect these trophic level differences. There were significant species differences in the concentrations of all metals, with flamingos having the lowest levels, and cormorants having the highest levels of 4 metals but not mercury. The gulls had the highest levels of mercury, perhaps reflecting their more scavenging behavior.

  15. Country Energy Profile, South Africa

    SciTech Connect

    1995-08-01

    This country energy profile provides energy and economic information about South Africa. Areas covered include: Economics, demographics, and environment; Energy situation; Energy structure; Energy investment opportunities; Department of Energy (DOE) programs in South Africa; and a listing of International aid to South Africa.

  16. Family Planning Programmes in Africa.

    ERIC Educational Resources Information Center

    Pradervand, Pierre

    The countries discussed in this paper are the francophone countries of West Africa and the Republic of Congo, with comparative references made to North Africa (mainly Morocco, Algeria, and Tunisia). Obstacles to the adoption of family planning in the countries of tropical Africa are a very high mortality rate among children; a socioeconomic…

  17. Emergency nursing in South Africa.

    PubMed

    Brysiewicz, Petra; Bruce, Judy

    2008-04-01

    The role of the emergency nurse in South Africa is a challenging one due to a variety of reasons. This article describes the healthcare system of South Africa with particular attention to the emergency medical system as well as the reason why most emergency clients present to the emergency departments. The actual experience of working as an emergency nurse in South Africa is highlighted.

  18. An Approach for Including Uncertainty in Integrated Water Resources Assessments within Large River Basins of Southern Africa.

    NASA Astrophysics Data System (ADS)

    Hughes, D.

    2015-12-01

    There are many large basins in southern Africa that are mostly ungauged but may have some streamflow observations either on the main river or on tributaries. Many of the streamflow records are, however, of poor quality or impacted by largely unquantified and non-stationary development impacts. All water resources assessments are therefore uncertain and model setups are difficult to validate in traditional ways. The paper presents a method for practical uncertainty assessment using a semi-distributed (sub-basin) model. The method uses a 2-stage approach where the first stage involves obtaining 'behavioural' parameter sets to represent the incremental natural streamflow for each sub-basin. The criteria for 'behavioural' are based on a series of constraints on model output that can be developed from the available gauged data or from regional assessments of natural hydrological functioning. The second stage simulates the whole basin based on sampling the 'behavioural' incremental flow parameter sets, as well as samples of additional individual parameter values representing downstream routing parts of the model and development impacts. One of the perceived advantage of the method is that all the ensembles at the total basin outlet are made up of behavioural inputs for all sub-basins. The method is also flexible in terms of the uncertainty range of the constraints, which might be expected to be narrow (low uncertainty) in well gauged sub-basins, or areas where our understanding of flow regime characteristics is good, but much wider (higher uncertainty) in other parts of the basin. The paper briefly explains the approach and discusses some of the issues associated with its application using examples from southern Africa.

  19. Models of public-private engagement for health services delivery and financing in Southern Africa: a systematic review.

    PubMed

    Whyle, Eleanor Beth; Olivier, Jill

    2016-12-01

    In low- and middle-income countries (LMICs), the private sector-including international donors, non-governmental organizations, for-profit providers and traditional healers-plays a significant role in health financing and delivery. The use of the private sector in furthering public health goals is increasingly common. By working with the private sector through public -: private engagement (PPE), states can harness private sector resources to further public health goals. PPE initiatives can take a variety of forms and understanding of these models is limited. This paper presents the results of a Campbell systematic literature review conducted to establish the types and the prevalence of PPE projects for health service delivery and financing in Southern Africa. PPE initiatives identified through the review were categorized according to a PPE typology. The review reveals that the full range of PPE models, eight distinct models, are utilized in the Southern African context. The distribution of the available evidence-including significant gaps in the literature-is discussed, and key considerations for researchers, implementers, and current and potential PPE partners are presented. It was found that the literature is disproportionately representative of PPE initiatives located in South Africa, and of those that involve for-profit partners and international donors. A significant gap in the literature identified through the study is the scarcity of information regarding the relationship between international donors and national governments. This information is key to strengthening these partnerships, improving partnership outcomes and capacitating recipient countries. The need for research that disaggregates PPE models and investigates PPE functioning in context is demonstrated.

  20. MODIS Observation of Aerosols over Southern Africa During SAFARI 2000: Data, Validation, and Estimation of Aerosol Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Kaufman, Yoram; Remer, Lorraine; Chu, D. Allen; Mattoo, Shana; Tanre, Didier; Levy, Robert; Li, Rong-Rong; Kleidman, Richard; Lau, William K. M. (Technical Monitor)

    2001-01-01

    Aerosol properties, including optical thickness and size parameters, are retrieved operationally from the MODIS sensor onboard the Terra satellite launched on 18 December 1999. The predominant aerosol type over the Southern African region is smoke, which is generated from biomass burning on land and transported over the southern Atlantic Ocean. The SAFARI-2000 period experienced smoke aerosol emissions from the regular biomass burning activities as well as from the prescribed burns administered on the auspices of the experiment. The MODIS Aerosol Science Team (MAST) formulates and implements strategies for the retrieval of aerosol products from MODIS, as well as for validating and analyzing them in order to estimate aerosol effects in the radiative forcing of climate as accurately as possible. These activities are carried out not only from a global perspective, but also with a focus on specific regions identified as having interesting characteristics, such as the biomass burning phenomenon in southern Africa and the associated smoke aerosol, particulate, and trace gas emissions. Indeed, the SAFARI-2000 aerosol measurements from the ground and from aircraft, along with MODIS, provide excellent data sources for a more intensive validation and a closer study of the aerosol characteristics over Southern Africa. The SAFARI-2000 ground-based measurements of aerosol optical thickness (AOT) from both the automatic Aerosol Robotic Network (AERONET) and handheld Sun photometers have been used to validate MODIS retrievals, based on a sophisticated spatio-temporal technique. The average global monthly distribution of aerosol from MODIS has been combined with other data to calculate the southern African aerosol daily averaged (24 hr) radiative forcing over the ocean for September 2000. It is estimated that on the average, for cloud free conditions over an area of 9 million square kin, this predominantly smoke aerosol exerts a forcing of -30 W/square m C lose to the terrestrial

  1. Socioeconomic status as a risk factor for HIV infection in women in East, Central and Southern Africa: a systematic review.

    PubMed

    Wojcicki, Janet Maia

    2005-01-01

    This is a critical, systematic review of the relationship between socioeconomic status (SES) and HIV infection in women in Southern, Central and Eastern Africa. In light of the interest in micro-credit programmes and other HIV prevention interventions structured to empower women through increasing women's access to funds and education, this review examines the epidemiological and public health literature, which ascertains the association between low SES using different measurements of SES and risk of HIV infection in women. Also, given the focus on structural violence and poverty as factors driving the HIV epidemic at a structural/ecological level, as advocated by Paul Farmer and others, this study examines the extent to which differences in SES between individuals in areas with generalized poverty affect risk for SES. Out of 71 studies retrieved, 36 studies met the inclusion criteria including 30 cross-sectional, one case-control and five prospective cohort or nested case-control studies. Thirty-five studies used at least one measurement of female's SES and fourteen also included a measurement of partner's SES. Studies used variables measuring educational level, household income and occupation or employment status at the individual and neighbourhood level to ascertain SES. Of the 36 studies, fifteen found no association between SES and HIV infection, twelve found an association between high SES and HIV infection, eight found an association between low SES and HIV infection and one was mixed. In interpreting these results, this review examines the role of potential confounders and effect modifiers such as history of STDs, number of partners, living in urban or rural areas and time and location of study in sub-Saharan Africa. It is argued that STDs and number of partners are on the causal pathway under investigation between HIV and SES and should not be adjusted as confounders in any analysis. In conclusion, it is argued that in low-income sub-Saharan Africans

  2. 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

  3. Out of Africa

    ERIC Educational Resources Information Center

    Wilbert, Nancy Corrigan

    2009-01-01

    Karen Blixen (Isak Dinesen), author of "Out of Africa," said, "God made the world round so people would never be able to see too far down the road." The author embraced this wonderful thought by venturing on a three-week journey to Kenya and Tanzania in search of grand adventure. In this article, the author shares her adventure…

  4. Anglicising Postapartheid South Africa

    ERIC Educational Resources Information Center

    Louw, P. Eric

    2004-01-01

    The apartheid state deliberately encouraged linguistic diversity and actively built cultural infrastructures which impeded Anglicisation. With the end of apartheid has come "de facto" Anglicisation. So although South Africa has, since 1994, had 11 official languages, in reality, English is swamping the other 10 languages. Afrikaans has,…

  5. Who Speaks for Africa?

    ERIC Educational Resources Information Center

    Nealy, Michelle

    2005-01-01

    Judging by the press coverage, it would seem that Europeans are the only ones concerned about conditions in Africa, but perhaps the media is not telling the whole story. According to Mark P. Fancher, chair of the National Conference of Black Lawyers' Section on International Affairs & World Peace and the author of "The Splintering of…

  6. South Africa's Constitutional Change.

    ERIC Educational Resources Information Center

    Getman, Thomas

    1987-01-01

    Describes the striking dichotomy of South Africa's beauty and the squalor resulting from the apartheid policies of the government. Reviews reactions of black South Africans to recent constitutional changes and details efforts to secure more sweeping reform. Includes stories of several individuals who have taken actions which oppose the system of…

  7. West and Central Africa.

    PubMed

    Lydie, N; Robinson, N J

    1998-01-01

    This article reviews scientific and other literature during the 1990s that links migration and mobility with the spread of sexually transmitted diseases (STDs), including HIV/AIDS. The focus is on key population groups linked to the spread of HIV and STDs in West and Central Africa: migrant laborers, truck drivers, itinerant traders, commercial sex workers (CSWs), and refugees. Countries with high emigration and immigration tend to have high levels of HIV infection, with the exception of Senegal. The main destination of immigrants are Senegal, Nigeria, and Cote d'Ivoire in West Africa and Cameroon, Congo, Gabon, and Congo in Central Africa. The risk of infection and the spread of HIV is variable among migrants. There is little in the literature that substantiates hypotheses about the strong association between migration and HIV-positive status. Information is needed on the duration, frequency of return visits, living conditions, sexual activities with multiple partners, and information before departure, along the routes, at final destination, and at the time of returns. Action-based research in five West African countries (Burkina Faso, Cote d'Ivoire, Mali, Niger, and Senegal) should produce results in late 1998. Comparable studies in Central Africa are unknown. Regional studies should be complemented by local studies. Prevention would benefit from studies on the relative size of these five population groups by geographic location.

  8. AED in Africa

    ERIC Educational Resources Information Center

    Academy for Educational Development, 2004

    2004-01-01

    Founded in 1961, the Academy for Educational Development (AED) is an independent, nonprofit, charitable organization that operates development programs in the United States and throughout the world. This directory presents an overview of the AED programs in Africa since 1975. Current AED Programs include: (1) HIV/AIDS Prevention and Impact…

  9. AED in Africa.

    ERIC Educational Resources Information Center

    Academy for Educational Development, Washington, DC.

    For 30 years, the Academy for Educational Development (AED) has worked to support African development. In Uganda, Tanzania, and Botswana AED promoted some of Africa's first AIDS prevention programs. AED is funding research in Ethiopia, Tanzania, and perhaps Zambia that will target stigma and its role in AIDS prevention. Working with governments…

  10. Africa: Myth and Reality.

    ERIC Educational Resources Information Center

    Brown, Barbara B.

    1994-01-01

    Reports on the Third International Social Studies Conference held in Nairobi, Kenya, in 1994. Discusses democracy, educational reform efforts, and the importance of tourism to the Kenyan economy. Asserts that U.S. teachers must use accurate and nonstereotypical instructional materials in teaching about Africa. (CFR)

  11. Topical Research: Africa.

    ERIC Educational Resources Information Center

    Lynn, Karen

    This lesson plan can be used in social studies, language arts, or library research. The instructional objective is for students to select a topic of study relating to Africa, write a thesis statement, collect information from media sources, and develop a conclusion. The teacher may assign the lesson for written or oral evaluation. The teacher…

  12. Africa and Applied Linguistics.

    ERIC Educational Resources Information Center

    Makoni, Sinfree, Ed.; Meinhof, Ulrike H., Ed.

    2003-01-01

    This collection of articles includes: "Introducing Applied Linguistics in Africa" (Sinfree Makoni and Ulrike H. Meinhof); "Language Ideology and Politics: A Critical Appraisal of French as Second Official Language in Nigeria" (Tope Omoniyi); "The Democratisation of Indigenous Languages: The Case of Malawi" (Themba…

  13. Trends Abroad: South Africa

    ERIC Educational Resources Information Center

    Varley, Douglas H.

    1970-01-01

    In South Africa today there is a complex structure of laws and regulations which impose a variety of restrictions on individual liberties including the freedom to publish and read literary material. The successive steps by which this state of affairs has been reached are briefly described. (NH)

  14. Anatomy: Spotlight on Africa

    ERIC Educational Resources Information Center

    Kramer, Beverley; Pather, Nalini; Ihunwo, Amadi O.

    2008-01-01

    Anatomy departments across Africa were surveyed regarding the type of curriculum and method of delivery of their medical courses. While the response rate was low, African anatomy departments appear to be in line with the rest of the world in that many have introduced problem based learning, have hours that are within the range of western medical…

  15. Towards a GPS-based TEC prediction model for Southern Africa with feed forward networks

    NASA Astrophysics Data System (ADS)

    Habarulema, John Bosco; McKinnell, Lee-Anne; Opperman, Ben D. L.

    2009-07-01

    In this paper, first results from a national Global Positioning System (GPS) based total electron content (TEC) prediction model over South Africa are presented. Data for 10 GPS receiver stations distributed through out the country were used to train a feed forward neural network (NN) over an interval of at most five years. In the NN training, validating and testing processes, five factors which are well known to influence TEC variability namely diurnal variation, seasonal variation, magnetic activity, solar activity and the geographic position of the GPS receivers were included in the NN model. The database consisted of 1-min data and therefore the NN model developed can be used to forecast TEC values 1 min in advance. Results from the NN national model (NM) were compared with hourly TEC values generated by the earlier developed NN single station models (SSMs) at Sutherland (32.38°S, 20.81°E) and Springbok (29.67°S, 17.88°E), to predict TEC variations over the Cape Town (33.95°S, 18.47°E) and Upington (28.41°S, 21.26°E) stations, respectively, during equinoxes and solstices. This revealed that, on average, the NM led to an improvement in TEC prediction accuracy compared to the SSMs for the considered testing periods.

  16. A comparison of the intestinal helminth communities of Equidae in Southern Africa.

    PubMed

    Matthee, Sonja; Krecek, Rosina C; McGeoch, Melodie A

    2004-12-01

    The intestinal helminth communities of 8 horses, 12 donkeys, 21 Hartmann's mountain zebras, and 44 Burchell's zebras were compared using the original data from 6 studies in South Africa and Namibia. Necropsy and worm recovery techniques were comparable between the studies. Sixty helminth species (58 nematode, 1 cestode, and 1 trematode species) were recorded. There were significant differences in the helminth community structures of the 4 Equus species. The helminth communities of the 2 closely related zebra subspecies were most similar, and they jointly shared 7 helminth species with donkeys and only 1 with horses. Geographic variation and host-mixing contributed to the helminth species composition. Multiple confamilial species infections were the norm in the donkeys and zebra subspecies, and no single-species infection was recorded for the Strongylidae. Congeneric species were commonly recorded in 3 genera (Cyathostomum, Cylicocyclus, and Cylicostephanus). The shape of the occupancy frequency distributions for the donkeys and zebra subspecies was multimodal, with no clear satellite or core modes. Despite the presence of environmental variability and comparatively low parasite-host specificity, the phylogenetic signal within Equus helminth communities remains strong.

  17. The morama bean (Tylosema esculentum): a potential crop for southern Africa.

    PubMed

    Jackson, Jose C; Duodu, Kwaku G; Holse, Mette; Lima de Faria, Margarida D; Jordaan, Danie; Chingwaru, Walter; Hansen, Aase; Cencic, Avrelija; Kandawa-Schultz, Martha; Mpotokwane, Selalelo M; Chimwamurombe, Percy; de Kock, Henrietta L; Minnaar, Amanda

    2010-01-01

    The morama bean is an underutilized leguminous oilseed native to the Kalahari Desert and neighboring sandy regions of Botswana, Namibia, and South Africa (Limpopo, North-West, Gauteng, and Northern Cape provinces), and forms part of the diet of the indigenous population in these countries. It is also known as gemsbok bean, moramaboontjie, elandboontjie, braaiboonjie, marama, marumana, tsi, tsin, gami, and ombanui. It is reported as an excellent source of good quality protein (29-39%); its oil (24-48%) is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Morama is a good source of micronutrients such as calcium, iron, zinc, phosphate, magnesium, and B vitamins including folate. It is also reported to be a potential source of phytonutrients including phenolic compounds (e.g., tannins), trypsin inhibitors, phytates, and oligosaccharides, components which have been shown in other foods to contribute to health in particular, prevention of noncommunicable diseases such as cardiovascular diseases, diabetes, and some cancers. From a nutritional and health perspective, the morama bean has potential commercial value as a cash crop and value-added products, particularly in the communities where it is found.

  18. Comparative ethnoentomology of edible stinkbugs in southern Africa and sustainable management considerations.

    PubMed

    Dzerefos, Catherine Maria; Witkowski, Ed Tadeusz Fernando; Toms, Rob

    2013-03-25

    Insects, such as stinkbugs, are able to produce noxious defence chemicals to ward off predators, nevertheless, some ethnic groups have recipes to render them delicious. We provide an example of edible stinkbugs (Encosternum delegorguei) used by two locally separate ethnic groups in South Africa, the Vhavenda and Mapulana, with a third group, the Bolobedu using them for commercial purposes. Structured interview schedules and observations with 106 harvesters were conducted to determine differences in use, nomenclature and oral history, methods of collection and preparation as well as perceptions pertaining to availability. The stinkbugs’ foul defence chemical and flight response necessitates nocturnal harvesting when the insect is immobilised by cold. The defence chemical stains the skin and affects vision yet protective gear is not worn. Damage to host trees was recorded when harvesters poached from plantations or private land, whereas, in communal-lands, sustainable methods were preferred. The legitimisation of stinkbug harvesting and introduction of a collection funnel could reduce conflicts with managers of plantations and private land. Two methods to remove the defence chemical for increased palatability were used. Preparation methods differed in whether or not water was used and also whether the head was left intact or removed. Stinkbugs have numerous medicinal uses, in particular as a hangover cure. Awareness and optimal use of beneficial insects, such as stinkbugs, in rural areas could lead to a reconsideration of current environmental management strategies, where harvesters act as habitat stewards and clearing, grazing or burning indigenous vegetation is kept to a minimum.

  19. Comparative ethnoentomology of edible stinkbugs in southern Africa and sustainable management considerations

    PubMed Central

    2013-01-01

    Insects, such as stinkbugs, are able to produce noxious defence chemicals to ward off predators, nevertheless, some ethnic groups have recipes to render them delicious. We provide an example of edible stinkbugs (Encosternum delegorguei) used by two locally separate ethnic groups in South Africa, the Vhavenda and Mapulana, with a third group, the Bolobedu using them for commercial purposes. Structured interview schedules and observations with 106 harvesters were conducted to determine differences in use, nomenclature and oral history, methods of collection and preparation as well as perceptions pertaining to availability. The stinkbugs’ foul defence chemical and flight response necessitates nocturnal harvesting when the insect is immobilised by cold. The defence chemical stains the skin and affects vision yet protective gear is not worn. Damage to host trees was recorded when harvesters poached from plantations or private land, whereas, in communal-lands, sustainable methods were preferred. The legitimisation of stinkbug harvesting and introduction of a collection funnel could reduce conflicts with managers of plantations and private land. Two methods to remove the defence chemical for increased palatability were used. Preparation methods differed in whether or not water was used and also whether the head was left intact or removed. Stinkbugs have numerous medicinal uses, in particular as a hangover cure. Awareness and optimal use of beneficial insects, such as stinkbugs, in rural areas could lead to a reconsideration of current environmental management strategies, where harvesters act as habitat stewards and clearing, grazing or burning indigenous vegetation is kept to a minimum. PMID:23531129

  20. Health evaluation of African penguins (Spheniscus demersus) in southern Africa.

    PubMed

    Parsons, Nola J; Gous, Tertius A; Schaefer, Adam M; Vanstreels, Ralph E T

    2016-09-20

    The African penguin (Spheniscus demersus) is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology) was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.

  1. Government-NGO collaboration and sustainability of orphans and vulnerable children projects in southern Africa.

    PubMed

    Rosenberg, Alana; Hartwig, Kari; Merson, Michael

    2008-02-01

    Given current donor attention to orphans and children made vulnerable by HIV/AIDS, and the need for a new framework that recognizes the complementary roles of nations and non-governmental organizations (NGOs), this analysis reviews NGO-operated community-based orphans and vulnerable children (OVC) projects in Botswana, Lesotho, Namibia, South Africa, and Swaziland. There has been a lack of attention within the field of evaluation to inter-organizational relationships, specifically those with government agencies, as a factor in sustainability. We analyzed evaluations of nine OVC projects funded by the Bristol-Myers Squibb Foundation for the influence of government-NGO collaboration on project sustainability. For eight of the nine projects, evaluations provided evidence of the importance of the government partnership for sustainability. Government collaboration was important in projects designed to help families access government grants, initiate community-based solutions, and advocate for OVC rights through legislation. Government partnerships were also critical to the sustainability of two projects involved in placing children in foster care, but these showed signs of tension with government partners. In addition to the more common factors associated with sustainability, such as organizational characteristics, donors and NGOs should concentrate on developing strong partnerships with local and national government agencies for the sustainability of their projects.

  2. Population genetic structure, linkage disequilibrium and effective population size of conserved and extensively raised village chicken populations of Southern Africa.

    PubMed

    Khanyile, Khulekani S; Dzomba, Edgar F; Muchadeyi, Farai C

    2015-01-01

    Extensively raised village chickens are considered a valuable source of biodiversity, with genetic variability developed over thousands of years that ought to be characterized and utilized. Surveys that can reveal a population's genetic structure and provide an insight into its demographic history will give valuable information that can be used to manage and conserve important indigenous animal genetic resources. This study reports population diversity and structure, linkage disequilibrium and effective population sizes of Southern African village chickens and conservation flocks from South Africa. DNA samples from 312 chickens from South African village and conservation flocks (n = 146), Malawi (n = 30) and Zimbabwe (n = 136) were genotyped using the Illumina iSelect chicken SNP60K BeadChip. Population genetic structure analysis distinguished the four conservation flocks from the village chicken populations. Of the four flocks, the Ovambo clustered closer to the village chickens particularly those sampled from South Africa. Clustering of the village chickens followed a geographic gradient whereby South African chickens were closer to those from Zimbabwe than to chickens from Malawi. Different conservation flocks seemed to have maintained different components of the ancestral genomes with a higher proportion of village chicken diversity found in the Ovambo population. Overall population LD averaged over chromosomes ranged from 0.03 ± 0.07 to 0.58 ± 0.41 and averaged 0.15 ± 0.16. Higher LD, ranging from 0.29 to 0.36, was observed between SNP markers that were less than 10 kb apart in the conservation flocks. LD in the conservation flocks steadily decreased to 0.15 (PK) and 0.24 (VD) at SNP marker interval of 500 kb. Genomewide LD decay in the village chickens from Malawi, Zimbabwe and South Africa followed a similar trend as the conservation flocks although the mean LD values for the investigated SNP intervals were lower. The results suggest low effective

  3. Population genetic structure, linkage disequilibrium and effective population size of conserved and extensively raised village chicken populations of Southern Africa

    PubMed Central

    Khanyile, Khulekani S.; Dzomba, Edgar F.; Muchadeyi, Farai C.

    2015-01-01

    Extensively raised village chickens are considered a valuable source of biodiversity, with genetic variability developed over thousands of years that ought to be characterized and utilized. Surveys that can reveal a population's genetic structure and provide an insight into its demographic history will give valuable information that can be used to manage and conserve important indigenous animal genetic resources. This study reports population diversity and structure, linkage disequilibrium and effective population sizes of Southern African village chickens and conservation flocks from South Africa. DNA samples from 312 chickens from South African village and conservation flocks (n = 146), Malawi (n = 30) and Zimbabwe (n = 136) were genotyped using the Illumina iSelect chicken SNP60K BeadChip. Population genetic structure analysis distinguished the four conservation flocks from the village chicken populations. Of the four flocks, the Ovambo clustered closer to the village chickens particularly those sampled from South Africa. Clustering of the village chickens followed a geographic gradient whereby South African chickens were closer to those from Zimbabwe than to chickens from Malawi. Different conservation flocks seemed to have maintained different components of the ancestral genomes with a higher proportion of village chicken diversity found in the Ovambo population. Overall population LD averaged over chromosomes ranged from 0.03 ± 0.07 to 0.58 ± 0.41 and averaged 0.15 ± 0.16. Higher LD, ranging from 0.29 to 0.36, was observed between SNP markers that were less than 10 kb apart in the conservation flocks. LD in the conservation flocks steadily decreased to 0.15 (PK) and 0.24 (VD) at SNP marker interval of 500 kb. Genomewide LD decay in the village chickens from Malawi, Zimbabwe and South Africa followed a similar trend as the conservation flocks although the mean LD values for the investigated SNP intervals were lower. The results suggest low effective

  4. 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

  5. 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

  6. Progress and Challenges for Implementation of the Common Market for Eastern and Southern Africa Policy on Biotechnology and Biosafety

    PubMed Central

    Waithaka, Michael; Belay, Getachew; Kyotalimye, Miriam; Karembu, Margaret

    2015-01-01

    In 2001, the Meeting of the COMESA Ministers of Agriculture raised concerns that proliferation of genetically modified organisms (GMOs) could impact significantly on trade and food security in the region. This triggered studies on a regional approach to biotechnology and biosafety policy in Eastern and Southern Africa. The studies and stakeholder consultations revealed that farm incomes would increase if they switched from conventional varieties of cotton and maize to genetically modified (GM) counterparts. Commercial risks associated with exports to GM sensitive destinations, e.g., EU were negligible. Intra-regional trade would be affected since exports of GM sensitive commodities, such as maize, cotton, and soya bean, mainly go to other African countries. These findings justified the need to consider a regional approach to biosafety and led to the drafting of a regional policy in 2009. The draft policies were discussed in regional and national workshops between 2010 and 2012 for wider ownership. The workshops involved key stakeholders including ministries of agriculture, trade, environment, national biosafety focal points, biosafety competent authorities, academia, seed traders, millers, the media, food relief agencies, the industry, civil society, competent authorities, and political opinion leaders. The COMESA Council of Ministers in February 2014 adopted the COMESA policy on biotechnology and biosafety that takes into account the sovereign right of each member state. Key provisions of the policy include recognition of the benefits and risks associated with GMOs; establishment of a regional-level biosafety risk-assessment system; national-level final decision, and capacity building assistance to member states. The policies are the first regional effort in Africa to develop a coordinated mechanism for handling biosafety issues related to GMO use. A regional approach to biotechnology and biosafety is expected to foster inter-country cooperation through the

  7. Expanding the neutralization scope of the EchiTAb-plus-ICP antivenom to include venoms of elapids from Southern Africa.

    PubMed

    Sánchez, Andrés; Segura, Álvaro; Vargas, Mariángela; Herrera, María; Villalta, Mauren; Estrada, Ricardo; Wu, Francisco; Litschka-Koen, Thea; Perry, Michael Alfred; Alape-Girón, Alberto; León, Guillermo

    2017-01-01

    EchiTAb-plus-ICP is an antivenom prepared from plasma of horses hyperimmunized with the venoms of the carpet viper (Echis ocellatus), the puff adder (Bitis arietans) and the black-necked spitting cobra (Naja nigricollis). Therefore, the use of this antivenom has been limited to Western Africa. In order to expand the neutralization scope of EchiTAb-plus-ICP, we supplemented the immunogenic mixture with the venoms of B. arietans, the black mamba (Dendroaspis polylepis), the Mozambique spitting cobra (Naja mossambica), the snouted cobra (N. annulifera), and the rinkhals (Hemachatus haemachatus) from Swaziland. The ability of the expanded-scope antivenom, hereby named EchiTAb + ICP, to neutralize the venoms of B. arietans, D. polylepis, N. mossambica and H. haemachatus was similar to those of FAV Afrique and the SVA African antivenoms. In comparison to the SAIMR antivenom, the expanded-scope EchiTAb + ICP had lower ability to neutralize the venom of B. arietans, but similar ability to neutralize the venoms of D. polylepis, N. mossambica and H. haemachatus. Owing to its low protein concentration, the expanded-scope EchiTAb + ICP had lower ability to neutralize the venom of N. annulifera than FAV Afrique and the SAIMR antivenoms. However, when formulated at a protein concentration as high as FAV Afrique and SAIMR antivenoms, the expanded-scope EchiTAb + ICP showed similar capacity to neutralize this poorly immunogenic venom. Our results encourage the transition to the new EchiTAb + ICP antivenom, with an expanded neutralization scope that includes venoms of some of the most medically important elapids from Southern Africa. Clinical trials are required to determine the minimum effective-safe dose of the new EchiTAb + ICP for each type of envenomation.

  8. Progress and Challenges for Implementation of the Common Market for Eastern and Southern Africa Policy on Biotechnology and Biosafety.

    PubMed

    Waithaka, Michael; Belay, Getachew; Kyotalimye, Miriam; Karembu, Margaret

    2015-01-01

    In 2001, the Meeting of the COMESA Ministers of Agriculture raised concerns that proliferation of genetically modified organisms (GMOs) could impact significantly on trade and food security in the region. This triggered studies on a regional approach to biotechnology and biosafety policy in Eastern and Southern Africa. The studies and stakeholder consultations revealed that farm incomes would increase if they switched from conventional varieties of cotton and maize to genetically modified (GM) counterparts. Commercial risks associated with exports to GM sensitive destinations, e.g., EU were negligible. Intra-regional trade would be affected since exports of GM sensitive commodities, such as maize, cotton, and soya bean, mainly go to other African countries. These findings justified the need to consider a regional approach to biosafety and led to the drafting of a regional policy in 2009. The draft policies were discussed in regional and national workshops between 2010 and 2012 for wider ownership. The workshops involved key stakeholders including ministries of agriculture, trade, environment, national biosafety focal points, biosafety competent authorities, academia, seed traders, millers, the media, food relief agencies, the industry, civil society, competent authorities, and political opinion leaders. The COMESA Council of Ministers in February 2014 adopted the COMESA policy on biotechnology and biosafety that takes into account the sovereign right of each member state. Key provisions of the policy include recognition of the benefits and risks associated with GMOs; establishment of a regional-level biosafety risk-assessment system; national-level final decision, and capacity building assistance to member states. The policies are the first regional effort in Africa to develop a coordinated mechanism for handling biosafety issues related to GMO use. A regional approach to biotechnology and biosafety is expected to foster inter-country cooperation through the

  9. Tetronarce cowleyi, sp. nov., a new species of electric ray from southern Africa (Chondrichthyes: Torpediniformes: Torpedinidae).

    PubMed

    Ebert, David A; Haas, Diane L; De Carvalho, Marcelo R

    2015-03-19

    A new species of torpedo ray, Tetronarce cowleyi, sp. nov., is described from specimens collected from the southeastern Atlantic Ocean. The new species is placed in the genus Tetronarce based on a uniform dorsal coloration and absence of papillae around the spiracles. The new species is distinguished from its closest congeners, the North Atlantic Tetronarce nobiliana Bonnaparte, 1835, and southwestern Atlantic Tetronarce puelcha Lahille, 1926, by a combination of morphological characteristics including a shorter spiracular length, a proportionally greater head length as measured between snout margin and fifth gill openings, a proportionally greater preoral snout length, a uniform shiny black or dark gray dorsal surface, lacking any prominent markings, and a creamy white ventral color with dark edges in juveniles but fading with growth. Teteronarce cowleyi, sp. nov., is further distinguished from T. nobiliana by its more circular anterior disc shape (vs. relatively straight in T. nobiliana), fewer tooth rows (32/28 vs. 38-53/38-52 in T. nobiliana), greater mouth width (1.5-1.7 times as great as interorbital width vs. 0.5-0.6 times interorbital width in T. nobiliana), smaller distance between second dorsal and caudal fins (3.5-4.9% vs. 6.6-6.8% in T. nobiliana), and a clasper length extending nearly to lower caudal fin origin (claspers in T. nobiliana that extend only two-thirds distance between second dorsal and caudal fins). Teteronarce cowleyi, sp. nov., is known from Walvis Bay, Namibia to Algoa Bay, Eastern Cape, South Africa, at depths of 110 to 457 m.

  10. Chemical transfers along slowly eroding catenas developed on granitic cratons in southern Africa

    USGS Publications Warehouse

    Khomo, Lesego; Bern, Carleton R.; Hartshorn, Anthony S.; Rogers, Kevin H.; Chadwick, Oliver A.

    2013-01-01

    A catena is a series of distinct but co-evolving soils arrayed along a slope. On low-slope, slowly eroding catenas the redistribution of mass occurs predominantly as plasma, the dissolved and suspended constituents in soil water. We applied mass balance methods to track how redistribution via plasma contributed to physical and geochemical differentiation of nine slowly eroding (~ 5 mm ky− 1) granitic catenas. The catenas were arrayed in a 3 × 3 climate by relief matrix and located in Kruger National Park, South Africa. Most of the catenas contained at least one illuviated soil profile that had undergone more volumetric expansion and less mass loss, and these soils were located in the lower halves of the slopes. By comparison, the majority of slope positions were eluviated. Soils from the wetter climates (550 and 730 mm precipitation yr− 1) generally had undergone greater collapse and lost more mass, while soils in the drier climate (470 mm yr− 1) had undergone expansion and lost less mass. Effects of differences in catena relief were less clear. Within each climate zone, soil horizon mass loss and strain were correlated, as were losses of most major elements, illustrating the predominant influence of primary mineral weathering. Nevertheless, mass loss and volumetric collapse did not become extreme because of the skeleton of resistant primary mineral grains inherited from the granite. Colloidal clay redistribution, as traced by the ratio of Ti to Zr in soil, suggested clay losses via suspension from catena eluvial zones. Thus illuviation of colloidal clays into downslope soils may be crucial to catena development by restricting subsurface flow there. Our analysis provides quantitative support for the conceptual understanding of catenas in cratonic landscapes and provides an endmember reference point in understanding the development of slowly eroding soil landscapes.

  11. Parasites of domestic and wild animals in South Africa. XLVIII. Ticks (Acari: Ixodidae) infesting domestic cats and wild felids in southern Africa.

    PubMed

    Horak, Ivan G; Heyne, Heloise; Donkin, Edward F

    2010-11-24

    Ticks collected from domestic cats (Felis catus), cheetahs (Acinonyx jubatus),caracals (Caracal caracal), African wild cats (Felis lybica), black-footed cats (Felis nigripes), a serval (Leptailurus serval), lions(Panthera leo), and leopards (Panthera pardus) were identified and counted. Thirteen species of ixodid ticks and one argasid tick were identified from domestic cats and 17 species of ixodid ticks from wild felids. The domestic cats and wild felids harboured 11 ixodid species in common. The adults of Haemaphysalis elliptica, the most abundant tick species infesting cats and wild felids, were most numerous on a domestic cat in late winter and in mid-summer, during 2 consecutive years. The recorded geographic distribution of the recently described Haemaphysalis colesbergensis, a parasite of cats and caracals, was extended by 2 new locality records in the Northern Cape Province, South Africa.

  12. Internet Performance to Africa

    SciTech Connect

    Cottrell, L

    2003-10-01

    We report the first results ever for real-time Internet performance to Africa using the PingER methodology. Multiple monitoring hosts were used to enable comparisons with performance from different parts of the world. From these preliminary measurements, we have found that Internet packet losses to some African sites in recent months range from very poor to bad (> 12%), some getting better, others are holding steady or getting worse. This, together with the average monthly Round Trip Times, imply end-to-end maximum TCP throughputs that are order of magnitudes different between countries in the region. Africa is shown to be far from the Internet performance in industrialized nations due to the poor infrastructure in place today. These monitoring efforts can provide valuable information to analyze the relative rates of future improvement and today they help us to quantify the digital divide and can provide quantitative information to policy makers.

  13. Tuberculosis in tropical Africa

    PubMed Central

    Roelsgaard, E.; Iversen, E.; Bløcher, C.

    1964-01-01

    Up to the end of the nineteenth century the tubercle bacillus apparently had little opportunity of disseminating among the rather isolated tribes of tropical Africa. With the creation of large centres of trade and industry in the wake of European colonization, tuberculosis seems to have spread rapidly over the continent and is today found everywhere. In a number of tuberculosis prevalence surveys conducted by WHO during 1955-60, randomly selected population groups were tuberculin tested, X-rayed and had sputa examined by direct microscopy. The three methods of examination were applied independently of one another. Data collected during the surveys have been analysed with a view to discovering common epidemiological features of tuberculosis in tropical Africa, assessing the reliability of the diagnostic methods employed and discussing their usefulness in future tuberculosis control programmes. PMID:14178027

  14. Mozambique Coast, Africa

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The serene coastline of Mozambique (17.0S, 39.5E) Africa and the Indian Ocean offer some of the best beaches and recreational diving water in the world. Offshore reefs provide interesting coral formations that host a wide variety of marine life. Inland, the coastal savannas of this tropical nation are filled with a wide range of wildlife in some of the last animal refuges on the African continent.

  15. The Dragon Enters Africa

    DTIC Science & Technology

    2011-05-04

    1950s. China’s establishment of modern relations with Africa started with the 1955 Bandung Conference where 29 developing nations, including China and a...few Af1ican nations, met to show solidarity by denouncing neocolonialism and pledging to stand up to the western powers. 2 The Bandung Conference ...problems; The report caused western banks and loan agencies to bail on a donor’s conference scheduled for July of 2002. The collapse of the donor’s

  16. Islamic Militancy in Africa

    DTIC Science & Technology

    2012-11-01

    has also actively resisted Western influences—seen as negatively affecting Muslims ’ religiosity .3 Both al Shabaab and Boko Haram have their roots in...focused on local concerns. u Islamic militant organizations in Africa generally only command the support of small minorities within Muslim communities...educated activist, inspired by the Islamist Muslim Students’ Society of Nigeria1 (MSSN), formed in 1954, and in particular Ibrahim al Zakzaki, as

  17. Lake Chad, Chad, Africa

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The fluctuating water levels of Lake Chad, (13.0N, 15.0E) at the intersection of the borders of Chad, Niger and Cameroon in the Sahara Desert, is an index of the drought in Africa. The lake level continues to decrease as indicated by the growing number and extent of emerging islands as previously submerged ancient sand dunes become visible. The water impounded between the dunes is probably because of local rainfall rather than a reversal of desertification.

  18. France in Black Africa,

    DTIC Science & Technology

    1989-01-01

    disease and the lack of support from the metropole (mother 4 France Acquires and Adninisters an Empire country), French rule over the small...as socially 9 France in Black Africa undesirable in an officer corps still dominated by the aristocracy; they were apt to be republicans, anticler- ics ...the interior. Endemic tropical diseases like yellow fever and malaria claimed a high proportion of Europeans who attempted to live in this region up to

  19. Epilepsy: Asia versus Africa.

    PubMed

    Bhalla, Devender; Tchalla, Achille Edem; Marin, Benoît; Ngoungou, Edgard Brice; Tan, Chong Tin; Preux, Pierre-Marie

    2014-09-01

    Is epilepsy truly an "African ailment"? We aimed to determine this, since international health agencies often refer to epilepsy as an African disease and the scientific literature has spoken the same tone. Various published materials, mainly reports, articles, were used to gather Asian and African evidence on various aspects of epilepsy and many of its risk and associated factors. Our results suggest that in no way can epilepsy be considered as an African ailment and such characterization is most likely based on popular beliefs rather than scientific evidence. In comparison to Africa, Asia has a 5.0% greater burden from all diseases, and is 17.0% more affected from neuropsychiatric disorders (that include epilepsy). Given that more countries in Asia are transitioning, there may be large demographic and lifestyle changes in the near future. However these changes are nowhere close to those expected in Africa. Moreover, 23 million Asians have epilepsy in comparison to 3.3 million Africans and 1.2 million sub-Saharan Africans. In comparison to Africa, Asia has more untreated patients, 55.0% more additional epilepsy cases every year, because of its larger population, with greater treatment cost and possibly higher premature mortality. Of several associated factors discussed herein, many have more importance for Asia than Africa. The current state of epilepsy in Asia is far less than ideal and there is an urgent need to recognize and accept the importance of epilepsy in Asia. In no way can epilepsy be considered as an African ailment. This is most likely based on popular beliefs rather than scientific evidence. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

  20. Mapping crustal heterogeneity using Lg propagation efficiency throughout the Middle East, Mediterranean, Southern Europe and Northern Africa

    USGS Publications Warehouse

    McNamara, D.E.; Walter, W.R.

    2001-01-01

    In this paper we describe a technique for mapping the lateral variation of Lg characteristics such as Lg blockage, efficient Lg propagation, and regions of very high attenuation in the Middle East, North Africa, Europe and the Mediterranean regions. Lg is used in a variety of seismological applications from magnitude estimation to identification of nuclear explosions for monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These applications can give significantly biased results if the Lg phase is reduced or blocked by discontinuous structure or thin crust. Mapping these structures using quantitative techniques for determining Lg amplitude attenuation can break down when the phase is below background noise. In such cases Lg blockage and inefficient propagation zones are often mapped out by hand. With our approach, we attempt to visually simplify this information by imaging crustal structure anomalies that significantly diminish the amplitude of Lg. The visualization of such anomalies is achieved by defining a grid of cells that covers the entire region of interest. We trace Lg rays for each event/ station pair, which is simply the great circle path, and attribute to each cell a value equal to the maximum value of the Lg/P-coda amplitude ratio for all paths traversing that particular cell. The resulting map, from this empirical approach, is easily interpreted in terms of crustal structure and can successfully image small blockage features often missed by analysis of raypaths alone. This map can then be used to screen out events with blocked Lg prior to performing Q tomography, and to avoid using Lg-based methods of event identification for the CTBT in regions where they cannot work. For this study we applied our technique to one of the most tectonically complex regions on the earth. Nearly 9000 earthquake/station raypaths, traversing the vast region comprised of the Middle East, Mediterranean, Southern Europe and Northern Africa, have been

  1. Dermatophytosis in northern Africa.

    PubMed

    Nweze, E I; Eke, I

    2016-03-01

    Infections caused by dermatophytes are a global problem and a major public health burden in the world today. In Africa, especially in the northern geographical zone, dermatophytic infections are being reported at an alarming rate. This is mostly because of some local but unique cultural practices, socioeconomic and environmental conditions, lack of reliable diagnostic personnel and facilities and ineffective treatment. Interestingly, the pathogen spectrum and the clinical manifestation are most times different from what is seen in other continents. Several epidemiological studies have been performed on the incidence and aetiology of dermatophytoses in northern Africa. However, there is currently no review article with up-to-date information on the relevant findings reported so far in this region. This information is necessary for clinicians who treat dermatophytic infections all over the world since agents of dermatophytes are no longer restricted because of the rapid mobility of humans from one part of the world to another. Moreover, the epidemiology of dermatophytoses is known to change over time, thus requiring the update of information from time to time. A review of relevant studies published on dermatophytoses in northern Africa is presented. This covers all of old Sudan, Algeria, Egypt, Libya, Tunisia and Morocco.

  2. Drought in West Africa

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Drought settled over West Africa's Ivory Coast region when wet season rains came late in 2007. Instead of beginning in February, the rainy season didn't start until March, and steady rains didn't start until late March, said the Famine Early Warning System Network. Though the rain had started to alleviate the drought, vegetation was still depressed in parts of Cote d'Ivoire (Ivory Coast) between March 22 and April 6, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured the data used to make this image. The image shows current vegetation conditions compared to average conditions recorded since 2000. Areas where plants are growing more slowly or more sparsely than average are brown, while areas where vegetation is denser than average are green. The brown tint that dominates the image indicates that plants through most of the country are more sparse than normal. Among the crops affected by the lack of rain was West Africa's cocoa crop. About 70 percent of the world's cocoa comes from West Africa, and Cote d'Ivoire is a top grower, said Reuters. Cocoa prices climbed as the crop fell short. Farmers called the drought the worst in living memory, Reuters said. The delay in rainfall also led to water shortages in parts of Cote d'Ivoire, according to the United Nations Office for the Coordination of Humanitarian Affairs.

  3. The impact of livestock grazing on plant diversity: an analysis across dryland ecosystems and scales in southern Africa.

    PubMed

    Hanke, Wiebke; Böhner, Jürgen; Dreber, Niels; Jürgens, Norbert; Schmiedel, Ute; Wesuls, Dirk; Dengler, Jürgen

    2014-07-01

    A general understanding of grazing effects on plant diversity in drylands is still missing, despite an extensive theoretical background. Cross-biome syntheses are hindered by the fact that the outcomes of disturbance studies are strongly affected by the choice of diversity measures, and the spatial and temporal scales of measurements. The aim of this study is to overcome these weaknesses by applying a wide range of diversity measures to a data set derived from identical sampling in three distinct ecosystems. We analyzed three fence-line contrasts (heavier vs. lighter grazing intensity), representing different degrees of aridity (from arid to semiarid) and precipitation regimes (summer rain vs. winter rain) in southern Africa. We tested the impact of grazing intensity on multiple aspects of plant diversity (species and functional group level, richness and evenness components, alpha and beta diversity, and composition) at two spatial scales, and for both 5-yr means and interannual variability. Heavier grazing reduced total plant cover and substantially altered the species and functional composition at all sites. However, a significant decrease in species alpha diversity was detected at only one of the three sites. By contrast, alpha diversity of plant functional groups responded consistently across ecosystems and scales, with a significant decrease at heavier grazing intensity. The cover-based measures of functional group diversity responded more sensitively and more consistently than functional group richness. Beta diversity of species and functional types increased under heavier grazing, showing that at larger scales, the heterogeneity of the community composition and the functional structure were increased. Heavier grazing mostly increased interannual variability of alpha diversity, while effects on beta diversity and cover were inconsistent. Our results suggest that species diversity alone may not adequately reflect the shifts in vegetation structure that occur

  4. Geographic and taxonomic distribution of a positive interaction: ant-tended homopterans indirectly benefit figs across southern Africa.

    PubMed

    Cushman, J Hall; Compton, Stephen G; Zachariades, Costas; Ware, Anthony B; Nefdt, Rory J C; Rashbrook, Vanessa K

    1998-09-01

    Although species pairs and assemblages often occur across geographic regions, ecologists know very little about the outcome of their interactions on such large spatial scales. Here, we assess the geographic distribution and taxonomic diversity of a positive interaction involving ant-tended homopterans and fig trees in the genus Ficus. Previous experimental studies at a few locations in South Africa indicated that Ficus sur indirectly benefited from the presence of a homopteran (Hilda patruelis) because it attracted ants (primarily Pheidole megacephala) that reduced the effects of both pre-dispersal ovule gallers and parasitoids of pollinating wasps. Based on this work, we evaluated three conditions that must be met in order to support the hypothesis that this indirect interaction involves many fig species and occurs throughout much of southern Africa and Madagascar. Data on 429 trees distributed among five countries indicated that 20 of 38 Ficus species, and 46% of all trees sampled, had ants on their figs. Members of the Sycomorus subgenus were significantly more likely to attract ants than those in the Urostigma subgenus, and ant-colonization levels on these species were significantly greater than for Urostigma species. On average, each ant-occupied F.sur tree had 37% of its fig crop colonized by ants, whereas the value was 24% for other Ficus species. H. patruelis was the most common source for attracting ants, although figs were also attacked by a range of other ant-tended homopterans. P. megacephala was significantly more common on figs than other ant species, being present on 58% of sampled trees. Ant densities commonly exceeded 4.5 per fig, which a field experiment indicated was sufficient to provide protection from ovule gallers and parasitoids of pollinators. Forty-nine percent of all colonized F. sur trees sampled had ant densities equal to or greater than 4.5 per fig, whereas this value was 23% for other Ficus species. We conclude that there is

  5. Climate and CO2 effects on the vegetation of southern tropical Africa over the last 37,000 years

    NASA Astrophysics Data System (ADS)

    Khon, V. C.; Wang, Y. V.; Krebs-Kanzow, U.; Kaplan, J. O.; Schneider, R. R.; Schneider, B.

    2014-10-01

    The savanna vegetation of southern tropical Africa is characterized by co-dominance of C4 grasslands and C3 woodlands. Long-term variations in the tropical savanna vegetation in arid and semi-arid climates are commonly considered to be primarily sensitive to precipitation and atmospheric CO2 concentrations. The sensitivity of tropical vegetation to temperature, however, is often considered as secondary or negligible, particularly in paleostudies due to difficulties of reconstructing terrestrial temperature in the tropics. In this study, we use the terrestrial vegetation model BIOME4, which was forced by climate simulations from the Kiel Climate Model (KCM) for the Holocene and by climate reconstructions for the most recent glacial period to understand reconstructed vegetation changes in southern tropical Africa of the past 37,000 yr. We focus on these two periods because vegetation reconstructions from a marine sediment core near the Zambezi River mouth cannot be explained by precipitation changes and changes of atmospheric CO2 alone. For the Holocene, we force BIOME4 simulations with reconstructed atmospheric CO2 concentrations, and spatial and seasonal climate patterns from the early- and mid-Holocene (9.5 and 6 ka BP) simulations with the KCM. For the glacial period, we analyze idealized experiments based upon reconstructed temperature, precipitation and CO2 at 31, 28 and 21 ka BP. Our study shows that both Holocene and glacial simulations of vegetation cover exhibit good agreement with reconstructed C4:C3 ratios when temperature changes are taken into account. While both precipitation and temperature control the C4:C3 ratio during the Holocene atmospheric CO2 and temperature variations are major factors controlling vegetation changes during the glacial period. In our simulations, variations in temperature along with precipitation and atmospheric CO2 reconcile the evolution of vegetation observed in the Zambezi catchment during the last 37,000 yr. In consequence

  6. Uptake contexts and perceived impacts of HIV testing and counselling among adults in East and Southern Africa: A meta-ethnographic review

    PubMed Central

    Witzel, T. Charles; Lora, Wezzie; Lees, Shelley; Desmond, Nicola

    2017-01-01

    Introduction HIV testing and counselling (HTC) interventions are key to controlling the HIV epidemic in East and Southern Africa where HTC is primarily delivered through voluntary counselling and testing (VCT), provider initiated testing and counselling (PITC), and home-based counselling and testing (HBVCT). Decision making processes around uptake of HTC models must be taken into account when designing new interventions. Counselling in HTC aims to reduce post-test risk taking behaviour and to link individuals to care but its efficacy is unclear. This meta-ethnography aims to understand the contexts of HTC uptake in East and Southern Africa and to analyse the perceived impacts of counselling-based interventions in relation to sexual behaviour and linkage to care. Methods We conducted a systematic literature review of studies investigating HTC in East and Southern Africa from 2003 –April 2014. The search and additional snowballing identified 20 studies that fit our selection criteria. These studies were synthesised through a thematic framework analysis. Results Twenty qualitative and mixed-methods studies examining impacts of HTC models in East and Southern Africa were meta-synthesised. VCT decisions were made individually while HBVCT decisions were located in family and community units. PITC was associated with coercion from healthcare providers. Low quality counselling components and multiple-intersecting barriers faced by individuals mean that counselling in HTC was not perceived to be effective in reducing post-test risk behaviour and had limited perceived effect in facilitating linkage to care. Conclusion HBVCT is associated with minimal stigma and should be considered as an area of priority. Counselling components in HTC interventions were effective in transmitting information about HIV and sexual risk, but were perceived as ineffective in addressing the broader personal circumstances preventing sexual behaviour change and modulating access to care. PMID

  7. Plague in Africa from 1935 to 1949

    PubMed Central

    Davis, D. H. S.

    1953-01-01

    The history of plague in Africa during the period 1935-49 is reviewed. Much of the information derives from a questionnaire sent to all African territories in 1950. The annual incidence of plague in Africa declined, particularly from 1946 onwards. In 1949, under 400 cases were reported, as compared with over 6,000 in 1935. By the end of 1949, plague was still active in the Belgian Congo, Kenya and Tanganyika, Madagascar, and southern Africa. No cases were reported from Egypt, Tunisia, Algeria, Morocco, Senegal, or Uganda during 1949. A comparison of the seasonal incidence of plague with prevailing atmospheric conditions (temperature and rainfall) in African territories shows that human plague is more frequent in warm moist weather—60°-80°F (15°-27°C)—than in hot dry, or cold, weather—over 80°F (27°C) or under 60°F (15°C). The highlands of equatorial Africa and of Madagascar appear to provide the optimum environment for the persistence of plague on the domestic (murine) plane and the high-veld and Kalahari of southern Africa on the sylvatic plane. The rat (Rattus rattus) and the multimammate mouse (R. (Mastomys) natalensis) and their fleas Xenopsylla brasiliensis and X. cheopis appear to be mainly responsible for the persistence of the reservoir in the East African highlands; R. rattus and X. cheopis play this role in Madagascar. The gerbils (Tatera and Desmodillus) and their burrow fleas X. philoxera and X. piriei are the main reservoirs of plague in southern Africa. Within these areas, Pasteurella pestis finds an environment suitable for its continued survival; the conditions seem to be comparable to those defined as obtaining in endemic centres in India. Elsewhere in Africa such endemic centres do not appear to exist. PMID:13115987

  8. How do national strategic plans for HIV and AIDS in southern and eastern Africa address gender-based violence? A women's rights perspective.

    PubMed

    Gibbs, Andrew; Mushinga, Mildred; Crone, E Tyler; Willan, Samantha; Mannell, Jenevieve

    2012-12-15

    Gender-based violence (GBV) is a significant human rights violation and a key driver of the HIV epidemic in southern and eastern Africa. We frame GBV from a broad human rights approach that includes intimate partner violence and structural violence. We use this broader definition to review how National Strategic Plans for HIV and AIDS (NSPs) in southern and eastern Africa address GBV. NSPs for HIV and AIDS provide the national-level framework that shapes government, business, donor, and non-governmental responses to HIV within a country. Our review of these plans for HIV and AIDS suggests that attention to GBV is poorly integrated; few recognize GBV and program around GBV. The programming, policies, and interventions that do exist privilege responses that support survivors of violence, rather than seeking to prevent it. Furthermore, the subject who is targeted is narrowly constructed as a heterosexual woman in a monogamous relationship. There is little consideration of GBV targeting women who have non-conforming sexual or gender identities, or of the need to tackle structural violence in the response to HIV and AIDS. We suggest that NSPs are not sufficiently addressing the human rights challenge of tackling GBV in the response to HIV and AIDS in southern and eastern Africa. It is critical that they do so.

  9. Gender equity and sexual and reproductive health in Eastern and Southern Africa: a critical overview of the literature

    PubMed Central

    MacPherson, Eleanor E.; Richards, Esther; Namakhoma, Ireen; Theobald, Sally

    2014-01-01

    Background Gender inequalities are important social determinants of health. We set out to critically review the literature relating to gender equity and sexual and reproductive health (SRH) in Eastern and Southern Africa with the aim of identifying priorities for action. Design During November 2011, we identified studies relating to SRH and gender equity through a comprehensive literature search. Results We found gender inequalities to be common across a range of health issues relating to SRH with women being particularly disadvantaged. Social and biological determinants combined to increase women's vulnerability to maternal mortality, HIV, and gender-based violence. Health systems significantly disadvantaged women in terms of access to care. Men fared worse in relation to HIV testing and care with social norms leading to men presenting later for treatment. Conclusions Gender inequity in SRH requires multiple complementary approaches to address the structural drivers of unequal health outcomes. These could include interventions that alter the structural environment in which ill-health is created. Interventions are required both within and beyond the health system. PMID:24972916

  10. Temporal and spatial patterns of Cenozoic and Late Mesozoic erosion and deposition along the western margin of southern Africa

    SciTech Connect

    Brown, R.W.; Gleadow, A.J.W. ); Rust, D.J.; Summerfield, M.A. )

    1990-05-01

    Compared with subsidence history and eustatic sea level change, sediment supply has been a neglected component of studies of passive margin stratigraphy. The spatial and temporal pattern of sediment supply to continental margin, however, is a critical factor in determining the architecture of offshore sedimentary sequences. Sediment routing across passive margins is controlled primarily by their tectonic development and the consequent morphological evolution of the subaerial part of the margin. By combining offshore sediment volume and sedimentation rate data based on isopach maps and borehole records with apatite fission-track analysis and denudational modeling onland, the depositional history of the western margin of southern Africa has been related to its geomorphic response to continental rifting. The sediment volume data indicate a declining rate of sedimentation after rifting in the Early Cretaceous despite a probable enlargement of the sediment source area through time. Similarly, apatite fission-track ages and confined track length distributions indicate an Early Cretaceous episode of relatively high erosion rates which affected areas both inland and oceanward of the major topographic discontinuity along the margin represented by the Great Escarpment. Late Cenozoic rates of erosion and sediment supply have been low, although much of the sediment source area is still at a significant elevation. Although aridity may have contributed to this reduction in sediment supply, the morphological response to the tectonic evolution of the margin has also been crucial.

  11. Phylogenetic analyses of Podaxis specimens from Southern Africa reveal hidden diversity and new insights into associations with termites.

    PubMed

    Conlon, Benjamin H; de Beer, Z Wilhelm; De Fine Licht, Henrik H; Aanen, Duur K; Poulsen, Michael

    2016-09-01

    Although frequently found on mounds of the grass-cutting termite genus Trinervitermes, virtually nothing is known about the natural history of the fungal genus Podaxis (Agaricaceae) nor why it associates with termite mounds. More than 40 species of this secotioid genus have been described since Linnaeus characterised the first species in 1771. However, taxonomic confusion arose when most of these species were reduced to synonymy with Podaxis pistillaris in 1933. Although a few more species have since been described, the vast majority of specimens worldwide are still treated as P. pistillaris. Using 45 fresh and herbarium specimens from Southern Africa, four from North America and one each from Ethiopia, and Kenya, we constructed the first comprehensive phylogeny of the genus. Four of the genotyped specimens were more than 100 y old. With the exception of the type specimen of Podaxis rugospora, all herbarium specimens were labelled as P. pistillaris or Podaxis sp. However, our data shows that the genus contains at least five well-supported clades with significant inter-clade differences in spore length, width and wall thickness, and fruiting body length, supporting that clades likely represent distinct Podaxis species. Certain clades consistently associate with termites while others appear entirely free-living.

  12. Warming of the Indian Ocean Threatens Eastern and Southern Africa, but could be Mitigated by Agricultural Development

    NASA Technical Reports Server (NTRS)

    Funk, Chris; Dettinger, Michael D.; Brown, Molly E.; Michaelsen, Joel C.; Verdin, James P.; Barlow, Mathew; Howell, Andrew

    2008-01-01

    Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains very high and declining per capita agricultural capacity retards progress towards Millennium Development goals. Analyses of in situ station data and satellite observations of precipitation identify another problematic trend. Main growing season rainfall receipts have diminished by approximately 15% in food insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain fed agriculture, these declines are societally dangerous. Will they persist or intensify? Tracing moisture deficits upstream to an anthropogenically warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus late 20th century anthropogenic Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling millions of undernourished people as a function of rainfall, population, cultivated area, seed and fertilizer use. Persistence of current tendencies may result in a 50% increase in undernourished people. On the other hand, modest increases in per capita agricultural productivity could more than offset the observed precipitation declines. Investing in agricultural development can help mitigate climate change while decreasing rural poverty and vulnerability.

  13. The sexual and economic politics of (re)integration: HIV / AIDS and the question of stability in Southern Africa.

    PubMed

    Webb, D

    1997-12-01

    In sub-Saharan Africa, the reintegration process being implemented presents a host of opportunities to establish political and economic stability. Particularly, a macro perspective is made possible, with the focus on the new Southern African Development Community. However, the HIV/AIDS pandemic represents one of the principal threats to the realization of such stability. This is because the reintegration process have provided ideal conditions for the spread of HIV, namely: chronic widespread of poverty, a high prevalence of other sexually transmitted diseases, poorly developed health systems, high levels of circulatory migration, rapid urbanization creating gender biases, and chronic levels of violence. In addition, it is emphasized that the impact of AIDS in the region will create negative forces that will counteract the process of regionalization. Existing stresses, being addressed at a regional level, are likely to be exacerbated to unmanageable levels by the cumulative impact of AIDS-related mortality. To this effect, recommendations for policymakers, planners, company managers and program implementors as part of the overall movement towards AIDS impact mitigation are cited.

  14. Pre-rain green-up is ubiquitous across southern tropical Africa: implications for temporal niche separation and model representation.

    PubMed

    Ryan, Casey M; Williams, Mathew; Grace, John; Woollen, Emily; Lehmann, Caroline E R

    2017-01-01

    Tree phenology mediates land-atmosphere mass and energy exchange and is a determinant of ecosystem structure and function. In the dry tropics, including African savannas, many trees grow new leaves during the dry season - weeks or months before the rains typically start. This syndrome of pre-rain green-up has long been recognized at small scales, but the high spatial and interspecific variability in leaf phenology has precluded regional generalizations. We used remote sensing data to show that this precocious phenology is ubiquitous across the woodlands and savannas of southern tropical Africa. In 70% of the study area, green-up preceded rain onset by > 20 d (42% > 40 d). All the main vegetation formations exhibited pre-rain green-up, by as much as 53 ± 18 d (in the wet miombo). Green-up showed low interannual variability (SD between years = 11 d), and high spatial variability (> 100 d). These results are consistent with a high degree of local phenological adaptation, and an insolation trigger of green-up. Tree-tree competition and niche separation may explain the ubiquity of this precocious phenology. The ubiquity of pre-rain green-up described here challenges existing model representations and suggests resistance (but not necessarily resilience) to the delay in rain onset predicted under climate change.

  15. Risk factors of Toxoplasma gondii infection in hunting, pet and watchdogs from southern Spain and northern Africa.

    PubMed

    Cano-Terriza, David; Puig-Ribas, María; Jiménez-Ruiz, Saúl; Cabezón, Óscar; Almería, Sonia; Galán-Relaño, Ángela; Dubey, Jitender P; García-Bocanegra, Ignacio

    2016-10-01

    Dogs can act as reservoirs of Toxoplasma gondii infections for humans and other hosts. Here we determined seroprevalence and risk factors of T. gondii infection in dogs from Andalusia (Southern Spain) and Ceuta (Northern Africa). Antibodies to T. gondii were detected in 235 out of 769 dogs (30.6%; CI95%: 27.3-33.8) by the modified agglutination test (MAT, cut-off of 1:25) with titers of 1:25 in 91, 1:50 in 43, 1:100 in 84, and ≥1:500 in 17 dogs. The main risk factors associated with T. gondii infection in dogs were age (higher seroprevalence in older dogs), hunter activity and size (higher seroprevalence in larger and medium dogs). This is the first study on T. gondii infection in pet dogs from Spain and Ceuta. The results indicate that T. gondii is widespread in dogs in mainland Spain and Ceuta, which might have important implications for public health.

  16. Water-soluble Organic Components in Aerosols Associated with Savanna Fires in Southern Africa: Identification, Evolution and Distribution

    NASA Technical Reports Server (NTRS)

    Gao, Song; Hegg, Dean A.; Hobbs, Peter V.; Kirchstetter, Thomas W.; Magi, Brian I.; Sadilek, Martin

    2003-01-01

    During the SAFARI 2000 field campaign, both smoke aerosols from savanna fires and haze aerosols in the boundary layer and in the free troposphere were collected from an aircraft in southern Africa. These aerosol samples were analyzed for their water-soluble chemical components, particularly the organic species. A novel technique, electrospray ionization-ion trap mass spectrometry, was used concurrently with an ion chromatography system to analyze for carbohydrate species. Seven carbohydrates, seven organic acids, five metallic elements, and three inorganic anions were identified and quantified. On the average, these 22 species comprised 36% and 27% of the total aerosol mass in haze and smoke aerosols, respectively. For the smoke aerosols, levoglucosan was the most abundant carbohydrate species, while gluconic acid was tentatively identified as the most abundant organic acid. The mass abundance and possible source of each class of identified species are discussed, along with their possible formation pathways. The combustion phase of a fire had an impact on the chemical composition of the emitted aerosols. Secondary formation of sulfate, nitrate, levoglucosan, and several organic acids occurred during the initial aging of smoke aerosols. It is likely that under certain conditions, some carbohydrate species in smoke aerosols, such as levoglucosan, were converted to organic acids during upward transport.

  17. Mosquito fauna and perspectives for integrated control of urban vector-mosquito populations in Southern Benin (West Africa).

    PubMed

    Lingenfelser, Andre; Rydzanicz, Katarzyna; Kaiser, Achim; Becker, Norbert

    2010-01-01

    This study aims at an integrated vector management (IVM) concept of implementing biological control agents against vector mosquito larvae as a cost-effective and scalable control strategy. In the first step, the mosquito species composition fauna of southern Benin was studied using standard entomological procedures in natural and man-made habitats. Altogether, 24 species belonging to 6 genera of mosquitoes Aedes, Anopheles, Culex, Mansonia, Uranotaenia, Ficalbia were recorded. Five species, Cx. thalassius, Cx. nebulosus, Cx. perfuscus, Cx. pocilipes and Fi. mediolineata are described the first time for Benin. The local mosquito species showed high susceptibility to a Bacillus sphaericus formulation (VectoLex(R) WDG ) in a standardized field test. A dosage of 1 g/m(2) was effective to achieve 100 percent mortality rate for Cx. quinquefasciatus late instar larvae in a sewage habitat, with a residual effect of up to 7 days. After more than 1 year of baseline data collection, operational larviciding with B. thuringiensis var. israelensis and B. sphaericus was commenced in 2006 in selected areas. Microbial insecticides products for larval control show great potential within IVM programmes and may augment control efforts against adult insects, such as the use of insecticide-treated bed nets or indoor wall spraying in many parts of Africa.

  18. Testing the applicability of morphometric characterisation in discordant catchments to ancient landscapes: A case study from southern Africa

    NASA Astrophysics Data System (ADS)

    Richardson, J. C.; Hodgson, D. M.; Wilson, A.; Carrivick, J. L.; Lang, A.

    2016-05-01

    The ancient landscapes south of the Great Escarpment in southern Africa preserve large-scale geomorphological features despite their antiquity. This study applies and evaluates morphometric indices (such as hypsometry, long profile analysis, stream gradient index, and linear/areal catchment characteristics) to the Gouritz catchment, a large discordant catchment in the Western Cape. Spatial variation of morphometric indices were assessed across catchment (trunk rivers) and subcatchment scales. The hypsometric curve of the catchment is sinusoidal, and a range of curve profiles are evident at subcatchment scale. Hypsometric integrals do not correlate to catchment properties such as area, circularity, relief, and dissection; and stream length gradients do not follow expected patterns, with the highest values seen in the mid-catchment areas. Rock type variation is interpreted to be the key control on morphometric indices within the Gouritz catchment, especially hypsometry and stream length gradient. External controls, such as tectonics and climate, were likely diminished because of the long duration of catchment development in this location. While morphometric indices can be a useful procedure in the evaluation of landscape evolution, this study shows that care must be taken in the application of morphometric indices to constrain tectonic or climatic variation in ancient landscapes because of inherited tectonic structures and signal shredding. More widely, we consider that ancient landscapes offer a valuable insight into long-term environmental change, but refinements to geomorphometric approaches are needed.

  19. The impact of education and globalization on sexual and reproductive health: retrospective evidence from eastern and southern Africa.

    PubMed

    Van Stam, Marie-Anne; Michielsen, Kristien; Stroeken, Koen; Zijlstra, Bonne J H

    2014-01-01

    The objective of this study is to qualify the relationship between sexual and reproductive health (SRH) and educational attainment in eastern and southern Africa (ESA). We hypothesize that the regional level of globalization is a moderating factor in the relationship between SRH and educational attainment. Using retrospective data from Kenya, Malawi, Tanzania, and Zambia, the associations between SRH (eight indicators), educational attainment, and globalization were examined using multilevel logistic regression analysis. It was found that the model fit for every SRH outcome indicator increased significantly after including the interaction between globalization and educational attainment, supporting the hypothesis. Depending on the level of globalization, three types of relationships between education and SRH were found: (1) for the indicators "more than four children," "intercourse before 17 years," "first child before 20 years," and "one or more child died" education is risk-decreasing, and the reduction is stronger in more globalized regions; (2) for the indicators "condom use at last intercourse" and "current contraceptive use" education is risk-decreasing, and the reduction is stronger in less globalized regions; (3) for the indicators "HIV positive" and "more than four lifetime sexual partners" education is risk increasing, but only in less globalized regions. In conclusion, these effects are related to three types of access: (1) access to services, (2) access to information, and (3) access to sexual networks. The findings highlight the relevance of globalization when analyzing the association between SRH and education, and the importance of structural factors in the development of effective SRH promotion interventions.

  20. Massive Open Online Courses for Africa by Africa

    ERIC Educational Resources Information Center

    Oyo, Benedict; Kalema, Billy Mathias

    2014-01-01

    Africa is known for inadequate access to all sorts of human needs including health, education, food, shelter, transport, security, and energy. Before the emergence of massive open online courses (MOOCs), open access to higher education (HE) was exclusive of Africa. However, as a generally affordable method of post-secondary education delivery,…

  1. AIDS in South Africa.

    PubMed

    Ijsselmuiden, C; Evian, C; Matjilla, J; Steinberg, M; Schneider, H

    1993-01-01

    The National AIDS Convention in South Africa (NACOSA) in October 1992 was the first real attempt to address HIV/AIDS. In Soweto, government, the African National Congress, nongovernmental organizations, and organized industry and labor representatives worked for 2 days to develop a national plan of action, but it did not result in a united effort to fight AIDS. The highest HIV infection rates in South Africa are among the KwaZulu in Natal, yet the Inkatha Freedom Party did not attend NACOSA. This episode exemplifies the key obstacles for South Africa to prevent and control AIDS. Inequality of access to health care may explain why health workers did not diagnose the first AIDS case in blacks until 1985. Migrant labor, Bantu education, and uprooted communities affect the epidemiology of HIV infection. Further, political and social polarization between blacks and whites contributes to a mindset that AIDS is limited to the other race which only diminishes the personal and collective sense of susceptibility and the volition and aptitude to act. The Department of National Health and Population Development's voluntary register of anonymously reported cases of AIDS specifies 1517 cumulative AIDS cases (October 1992), but this number is low. Seroprevalence studies show between 400,000-450,000 HIV positive cases. Public hospitals cannot give AIDS patients AZT and DDI. Few communities provided community-based care. Not all hospitals honor confidentiality and patients' need for autonomy. Even though HIV testing is not mandatory, it is required sometimes, e.g., HIV testing of immigrants. AIDS Training, Information and Counselling Centers are in urban areas, but not in poor areas where the need is most acute. The government just recently developed in AIDS education package for schools, but too many people consider it improper, so it is not being used. The poor quality education provided blacks would make it useless anyhow. Lifting of the academic boycott will allow South African

  2. Regions. [Africa, Middle East].

    PubMed

    1985-03-01

    This discussion of population focuses on the regions of Africa and the Middle East. In South Africa more white women are working but fewer black women work. The overall result is that the percentage of women who work is declining. Marita de Beer, research liaison executive at the South African Advertising Research Foundation, reports that the female population grew by 31% in the past 10 years while the number of working women has grown by only 11%. Among blacks the female population rose by 36%, but the number of workers among them declined by about 1%. Married women are among the fastest growing groups of working women in South Africa. The most recent estimate of the population of Nigeria is 92 million. According to Professor Vremudia Diejomaoh, Nigeria's population will probably reach 155 million by 2000 with 33% living in urban areas. In Saudi Arabia the Pan Arab Research Center recently completed a census of retail outlets in 3 metropolitan areas: Jeddah, Riyadh, and Dammam. The types of outlets surveyed include large supermarkets, small supermarkets, groceries with and without deep freeze, tobacco shops, meat shop/delis, small cafeterias, large restaurants/hotels, cosmetics shops or perfumeries, camera stores, toy shops, pharmacies, watch and gift shop, newsstands, department store, and appliance outlets. Using the Census of Retail Outlets as a base, Pan Arab Research Center also has a new distribution audit system that will cover 500 outlets. By plotting Arab countries according to their population policies and their current growth rates, it is possible to project where the middle class will grow fastest in the Arab world. The countries that have declining growth rates and strong population programs designed to encourage lower fertility rates among women are Egypt, Tunisia, Morocco, Algeria, and Lebanon. The countries most likely to have a better per capita distribution of resources within this decade are those where governments encourage reductions in

  3. Nutrition in Africa.

    PubMed

    Murray-lee, M

    1989-07-01

    Village women have adopted techniques set down by UNICEF in achieving higher food production and, ultimately, self sufficiency. Women's cooperatives integrate kitchen gardening and irrigated agriculture in an effort to combat the complex nutritional problems in Africa. Projects also offered training in a variety of areas including management of plots, labor-saving technology--diesel-driven grinding mills, rice husking, machines, wells with hand pumps, motor pumps for irrigation, all geared towards women benefitting themselves by growing their own food and furthering their children's health and development. Projects such as the one in Senegal were undertaken in other regions of Africa, like the Sahel and the Wadis--low-lying areas. From these projects, aid agencies and governments have suggested a number of recommendations in seeking a solution to Africa's nutritional problems. 1st, a balance between production of cash crops and food for consumption is called for. 2nd, research is necessary to improve the quality of locally grown food as much as livestock. 3rd, governments should extend surface area cultivation, 4th, more research on the advantage of indigenous food plants, 5th, women should be in on all levels of decision making in food production, 6th, governments should increase women farmer's efficiency, and further women's access to land and credit and 7th, women should be provided with increased educational opportunities. Nutrition in developing countries cannot be viewed as an isolated phenomenon--solutions to nutritional development should include all aspects of the problem including health and nutrition education, growth monitoring, water supply, literacy, technological know-how, and agricultural and plant and soil conservation.

  4. Zika virus outside Africa.

    PubMed

    Hayes, Edward B

    2009-09-01

    Zika virus (ZIKV) is a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis viruses. In 2007 ZIKV caused an outbreak of relatively mild disease characterized by rash, arthralgia, and conjunctivitis on Yap Island in the southwestern Pacific Ocean. This was the first time that ZIKV was detected outside of Africa and Asia. The history, transmission dynamics, virology, and clinical manifestations of ZIKV disease are discussed, along with the possibility for diagnostic confusion between ZIKV illness and dengue.The emergence of ZIKV outside of its previously known geographic range should prompt awareness of the potential for ZIKV to spread to other Pacific islands and the Americas.

  5. Fires in Central Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hundreds of fires are set every year during the dry season in Central Africa. This true color image from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) shows dozens of smoke plumes in the Democratic Republic of the Congo on June 29, 2000. Residents burn away scrub and brush annually in the woody savanna to clear land for farming and grazing. For more information, visit the SeaWiFS Home Page, Global Fire Monitoring Fact Sheet, and 4km2 Fire Data Image Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  6. Distance Education in Southern Africa Conference, 1987. Papers 4.1: Professional Education and Practical Training at a Distance.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Fifteen papers from the University of South Africa's Conference on Distance Education are presented on professional education and practical training. They include: "Essential and Professional Education of Physics Teachers in Poland" (Kazimierz A. Badziag); "Vocational Teaching at a Distance: The New Zealand Perspective" (Dave…

  7. Distance Education in Southern Africa Conference, 1987. Papers 3.2: Media and Technology in Distance Education.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Thirteen papers from the University of South Africa's Conference on Distance Education are presented on media and technology. They include: "Making the Abstract Concrete: A Slide/Sound Programme to Illustrate Abstract Concepts on the Concrete Level" (Grace Reeler); "The Microcomputer and Distance Education" (Johanna S.…

  8. Genetic relationships and structure among open pollinated maize varieties adapted to eastern and southern Africa using microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Maize and Wheat Improvement Center (CIMMYT), in collaboration with the national agricultural systems (NARS) in sub-Saharan Africa (SSA), have developed various stress-tolerant and more nutritious open-pollinated varieties (OPVs) of maize that are suitable for smallholder farmers’ g...

  9. Managing the wetlands. People and rivers: Africa.

    PubMed

    Dugan, P

    1993-01-01

    At the current population growth rate in Africa, the population will reach 1 billion by 2010. Water is needed to sustain these people, yet rainfall in Africa is erratic. Africans are already confronting a shortage of freshwater. Agriculture supports 66% of the population of sub-Saharan Africa. Sound agricultural development is needed to curb rural-urban migration, but a constant supply of freshwater is essential. Major rivers (the Limpopo in southern Africa and the Save/Sabi in Zimbabwe and Mozambique) now flow only seasonally. The flows of the Chari-Logona, the Nile, and the Zambezi are falling. Continual mismanagement of Africa's river basins coupled with current projections of global climate change will expand desiccation. All but the White Nile and the Zaire rivers flood seasonally every year, thereby expanding Africa's wetlands. Wetlands have been targeted for development projects (e.g., hydroelectric projects and large dams), largely to meet urban-industrial demands. Development planners tend to ignore the economic value of the wetlands. For example, the Niger Inland Delta sustains 550,000 people, 1 million cattle, and 1 million sheep. Wetlands replenish ground water and serve as natural irrigation. River basin planning often results in environmentally disastrous schemes which do not understand local management practices. Hydrologists, engineers, geologists, and economics design these schemes, but sociologists, anthropologists, and development experts should be included. The unfinished Jonglei Canal in southern Sudan would have adversely affected 400,000 pastoralists. The Volta River Authority's Akosombo Dam displaced 84,000 people and flooded the most productive agricultural land in Ghana. A sustainable future in Africa depends on understanding the interactions of human uses and the ways in which they relate to the natural variations in river flow. The IUCN Wetlands Programme, based on the principles of the World Conservation Strategy, is working with

  10. Climate Change and Development in Africa

    DTIC Science & Technology

    2013-01-01

    development, health indicators, deforestation , population growth, or poverty.35 Malawi’s domestic stability and development trajectory are threatened...accessible targets. The main driver for deforestation is the practice of turning charcoal into cooking fuel. The extraction of charcoal from... deforestation rates, 2.8 percent, in Southern Africa.38 Measures put in place to protect forest preserves have further destabilized the communities

  11. Guayule rubber for South Africa

    SciTech Connect

    Not Available

    1981-06-17

    It is reported that Agtec together with South Africa's Council for Scientific and Industrial Research, is investigating the possibility of large-scale production of guayule. The rubber-yielding shrub grows in semi-arid climates and may be the source of a $35-million natural rubber industry in South Africa.

  12. Africa in World Cultures Texts.

    ERIC Educational Resources Information Center

    Sullivan, Jo

    1980-01-01

    Maintains that many world geography and culture textbooks that deal with Africa present misinformation and misleading generalities. Reviews three recent textbooks--"Insights: Sub-Saharan Africa," by Ella C. Leppert, "People and Progress: A Global History," by Milton Finkelstein, and "World Cultures," by Clarence L.…

  13. Theory Meets Theatre Practice: Making a Difference to Public Health Programmes in Southern Africa. Professor Lynn Dalrymple--South African Scholar, Activist, Educator

    ERIC Educational Resources Information Center

    Durden, Emma; Tomaselli, Keyan

    2012-01-01

    Lynn Dalrymple is a pioneer in the field of communication about HIV and AIDS in South Africa. Her work has influenced practitioners, researchers and thinkers in South Africa and beyond. This review explores Dalrymple's background as a teacher in the rural areas of Zululand in South Africa, and how she came to apply theatre theory for one of the…

  14. Reconstructing the History of Maize Streak Virus Strain A Dispersal To Reveal Diversification Hot Spots and Its Origin in Southern Africa ▿ †

    PubMed Central

    Monjane, Adérito L.; Harkins, Gordon W.; Martin, Darren P.; Lemey, Philippe; Lefeuvre, Pierre; Shepherd, Dionne N.; Oluwafemi, Sunday; Simuyandi, Michelo; Zinga, Innocent; Komba, Ephrem K.; Lakoutene, Didier P.; Mandakombo, Noella; Mboukoulida, Joseph; Semballa, Silla; Tagne, Appolinaire; Tiendrébéogo, Fidèle; Erdmann, Julia B.; van Antwerpen, Tania; Owor, Betty E.; Flett, Bradley; Ramusi, Moses; Windram, Oliver P.; Syed, Rizwan; Lett, Jean-Michel; Briddon, Rob W.; Markham, Peter G.; Rybicki, Edward P.; Varsani, Arvind

    2011-01-01

    Maize streak virus strain A (MSV-A), the causal agent of maize streak disease, is today one of the most serious biotic threats to African food security. Determining where MSV-A originated and how it spread transcontinentally could yield valuable insights into its historical emergence as a crop pathogen. Similarly, determining where the major extant MSV-A lineages arose could identify geographical hot spots of MSV evolution. Here, we use model-based phylogeographic analyses of 353 fully sequenced MSV-A isolates to reconstruct a plausible history of MSV-A movements over the past 150 years. We show that since the probable emergence of MSV-A in southern Africa around 1863, the virus spread transcontinentally at an average rate of 32.5 km/year (95% highest probability density interval, 15.6 to 51.6 km/year). Using distinctive patterns of nucleotide variation caused by 20 unique intra-MSV-A recombination events, we tentatively classified the MSV-A isolates into 24 easily discernible lineages. Despite many of these lineages displaying distinct geographical distributions, it is apparent that almost all have emerged within the past 4 decades from either southern or east-central Africa. Collectively, our results suggest that regular analysis of MSV-A genomes within these diversification hot spots could be used to monitor the emergence of future MSV-A lineages that could affect maize cultivation in Africa. PMID:21715477

  15. Relapsing Fever Borreliae in Africa

    PubMed Central

    Elbir, Haitham; Raoult, Didier; Drancourt, Michel

    2013-01-01

    The study of relapsing fever borreliae in Africa has long suffered from the use of non-specific laboratory tools for the direct detection of these spirochetes in clinical and vector specimens. Accordingly, Borrelia hispanica, Borrelia crocidurae, Borrelia duttonii, and Borrelia recurrentis have traditionally been distinguished on the basis of geography and vector and the unproven hypothesis that each species was exclusive to one vector. The recent sequencing of three relapsing fever Borrelia genomes in our laboratory prompted the development of more specific tools and a reappraisal of the epidemiology in Africa. Five additional potential species still need to be cultured from clinical and vector sources in East Africa to further assess their uniqueness. Here, we review the molecular evidence of relapsing fever borreliae in hosts and ectoparasites in Africa and explore the diversity, geographical distribution, and vector association of these pathogens for Africans and travelers to Africa. PMID:23926141

  16. AIDS in Africa.

    PubMed

    Mokhobo, D

    1989-03-01

    Numerous cultural practices and attitudes in Africa represent formidable obstacles to the prevention of the further spread of acquired immunodeficiency syndrome (AIDS). Polygamy and concubinage are still widely practiced throughout Africa. In fact, sexual promiscuity on the part of males is traditionally viewed as positive--a reflection of male supremacy and male sexual prowess. The disintegration of the rural African family, brought about by urbanization, the migrant labor system, and poverty, has resulted in widespread premarital promiscuity. Contraceptive practices are perceived by many as a white conspiracy aimed at limiting the growth of the black population and thereby diminishing its political power. Condom use is particularly in disfavor. Thus, AIDS prevention campaigns urging Africans to restrict the number of sexual partners and to use condoms are unlikely to be successful. Another problem is that most Africans cannot believe that AIDS is sexually linked in that the disease does not affect the sex organs as is the case with other sexually transmitted diseases. The degree to which African governments are able to allocate resources to AIDS education will determine whether the epidemic can be controlled. Even with a massive outpouring of resources, it may be difficult to arouse public alarm about AIDS since Africans are so acclimated to living with calamities of every kind.

  17. Continuity and Change: The Teaching and Research of Islam in South(ern) Africa

    ERIC Educational Resources Information Center

    Haron, M.

    2012-01-01

    Despite being minority religious communities in the Southern African region, Muslims have carved out for themselves a unique identity within a multi-ethnic, multi-linguistic, and a multi-religious region. As a result of the variety of Muslim education programs and institutions that the community had set up over the past few decades its…

  18. Adult Literacy Policies and Performance in the SADCC Region (Southern Africa).

    ERIC Educational Resources Information Center

    Bhola, H. S.

    While the implementation of adult literacy promotion can best be handled at the national level, some important things can be done at the Southern African Development Co-ordination Conference (SADCC) level. A persuasive argument can be made on behalf of adult literacy in the SADCC development strategy. The people need to be educated in the…

  19. Discipline in the Context of Development: A Case of the Social Sciences in Malawi, Southern Africa

    ERIC Educational Resources Information Center

    Holland, Dana G.

    2008-01-01

    Changes in research production precipitated by the globalization have generally been theorized as applying across nations and disciplinary projects. This article examines the relation of discipline to research production from the situational vantage point of the developing world, specifically the Southern African country of Malawi, and from the…

  20. (Re)creating Spaces for "uMunthu": Postcolonial Theory and Environmental Education in Southern Africa

    ERIC Educational Resources Information Center

    Kayira, Jean

    2015-01-01

    Colonialism goes beyond territorial conquest: it affects one's epistemological stance, worldviews and perceptions. Although most African countries gained independence in the 1960s, the impacts of colonialism continue to be present through modern-day globalization as a form of neocolonialism. Education systems in many countries in southern Africa…

  1. Interdisciplinary Environmental Summer Study Abroad in Southern Africa as a Mechanism for the Development of an International Research and Education Consortium

    NASA Astrophysics Data System (ADS)

    Swap, R. J.; Sabea, H.; Annegarn, H.; Ford, C.; Netshandama-Funyufunyu, V.; Omara-Ojungu, P.; Vaz, K.; Ribeiro, N.; Twine, W.; Terni, C.; Estes, L.

    2005-12-01

    We describe an interdisciplinary course for non-specialist undergraduates in which the students experience firsthand issues of regional environmental complexity and have the unique opportunity to gain insight into the role the environment plays in shaping the people and culture of southern Africa. Undergraduates receive 3 hours of credit both in Environmental Science and Anthropology for the ``People, Culture and Environment of Southern Africa" study abroad program. The program is an intensive introduction to the physical geography, history and culture of the region and involves an intensive blend of in-class lectures and field trips with daily debriefing discussions. Over the duration of the 30 day program, students are exposed to elements of geology, ecology, hydrology and atmospheric science and how the interconnectedness of these different aspects of the physical environment help shape the history of the people and their culture in the region. Information about logistics and course development as well as to how this summer study abroad program has contributed to the development and expansion of the Southern Africa Virginia Networks and Associations (SAVANA) consortium will be detailed. The program builds upon more than 12 years of relationships between UVA faculty and their southern African colleagues developed during the course of several regional scale research programs with the most recent being the Southern African Regional Science Initiative - SAFARI 2000. Students enrolled with the UVA program are joined by their counterparts and interact with faculty from institutional partners both in the classroom and in the field. Participants operate out of four major locations: Johannesburg, RSA (Univ. of the Witwatersrand); Thohoyondou, RSA (Univ. of Venda); Maputo, MOZ (Univ. of Eduardo Mondlane); and Acornhoek, RSA (Univ. of the Witwatersrand - Rural Facility). Class size is limited to 15 students from UVA and about 6 SAVANA consortium students. This pairing with

  2. Salt deformation history and postsalt structural trends, offshore southern Gabon, West Africa

    SciTech Connect

    Liro, L.M.; Coen, R.

    1996-12-31

    Salt deformation in offshore southern Gabon is represented by mobilization of an Aptian salt layer in reaction to Tertiary clastic progradation. Seismic mapping of salt bodies and associated faulting has resulted in increased understanding of the types and distribution of these salt bodies, their associated faulting patterns, and some aspects of their origin. Away from the Tertiary depocenter, the growth history of salt swells or pillows can be determined by examining onlapping and draping seismic reflectors. Significant Tertiary clastic progradation into the area mobilized the salt and resulted in a series of linear, deep salt walls and asymmetric, basinward-dipping salt rollers, commonly associated with significant up-to-basin faulting dominates the southern Gabon subbasin. The expansion history of associated sediments suggests that these faults expanded episodically throughout the Tertiary, continuing to present-day bathymetric fault scarps. The bias toward up-to-basin faults, to the apparent exclusion of down-to-basin expansion faults, remains enigmatic.

  3. Book Review: Quaternary Environmental Change in Southern Africa: Physical and Human Dimensions

    NASA Astrophysics Data System (ADS)

    Murray-Wallace, Colin V.

    2017-02-01

    This attractively presented book examines the legacy of a diverse range of Quaternary environmental processes in the fashioning of Southern African landscapes and their ultimate interconnection with human evolution, technological developments and subsistence in dynamically changing environments. In its 25 chapters the book reviews different elements of Southern African landscapes and emphasizes their diversity, from classical desert dune environments to glacial, periglacial, fluvial, karst, wetlands, estuaries and sandy coastal landscapes. In addition, the soils and duricrusts that are so distinctive to these landscapes (Runge) and colluvial deposits and slope instability (Botha et al.) are also reviewed. Evidence for Quaternary environmental change is also examined in terms of pollen, charcoal and plant macrofossil records (Bamford et al.), minerogenic microfossil records (Fitchett et al.) and terrestrial ecosystem changes in the late Quaternary (Meadows and Quick). The archaeological records of the Earlier Stone Age (Kuman), Middle Stone Age, and Later Stone Age (Mitchell) are also comprehensively reviewed.

  4. Reproductive biology knowledge, and behaviour of teenagers in East, Central and Southern Africa: the Zimbabwe case study.

    PubMed

    Mbizvo, M T; Kasule, J; Gupta, V; Rusakaniko, S; Gumbo, J; Kinoti, S N; Mpanju-Shumbusho, W; Sebina-Zziwa; Mwateba, R; Padayachy, J

    1995-11-01

    Sexuality in the teenager is often complicated by unplanned/unwanted pregnancy, abortion and the risks of STDs including AIDS. There is therefore a need for improved understanding of factors affecting adolescent sexuality and the implementation of programmes designed to improve their knowledge, risk awareness and subsequent behavioural outcomes. A multicentre study of reproductive health knowledge and behaviour followed by a health education intervention was undertaken amongst teenagers in selected countries of East, Central and Southern Africa. Reported here are findings at baseline derived from the Zimbabwe component on reproductive biology knowledge and behavior. A self-administered questionnaire was used among 1 689 adolescent pupils drawn from rural, urban, co-education, single sex, boarding and day secondary schools in Zimbabwe. Correct knowledge on reproductive biology as measured by the meaning and interpretation of menstruation and wet dreams varied by school from 68 pc to 86 pc, with a significant trend (p < 0,01) based on level of education at baseline. The reported mean age at which menarche took place was 13,5 years +/- 1,3 (mean +/- SD). First coitus was reported to have taken place at the mean age of 12 years for boys and 13,6 years for girls. Seventeen pc of the adolescent pupils reported that they were sexually experienced and 33,2 had relationships. There were misconceptions reported on menstruation with 23 pc reporting that it was an illness. Peers, followed by magazines were the first sources of information on various aspects of reproductive biology, both of which might not provide the correct first information. Among pupils reporting that they were sexually experienced, the largest proportion (56 pc) had unprotected sex. The findings point to the need for targeting the adolescent pupils for information on reproductive biology and increased awareness on the risks of pregnancy, STDs and HIV.

  5. Assessing participatory practices in community-based natural resource management: experiences in community engagement from southern Africa.

    PubMed

    Dyer, J; Stringer, L C; Dougill, A J; Leventon, J; Nshimbi, M; Chama, F; Kafwifwi, A; Muledi, J I; Kaumbu, J-M K; Falcao, M; Muhorro, S; Munyemba, F; Kalaba, G M; Syampungani, S

    2014-05-01

    The emphasis on participatory environmental management within international development has started to overcome critiques of traditional exclusionary environmental policy, aligning with shifts towards decentralisation and community empowerment. However, questions are raised regarding the extent to which participation in project design and implementation is meaningful and really engages communities in the process. Calls have been made for further local-level (project and community-scale) research to identify practices that can increase the likelihood of meaningful community engagement within externally initiated projects. This paper presents data from three community-based natural resource management (CBNRM) project case studies from southern Africa, which promote Joint Forest Management (JFM), tree planting for carbon and conservation agriculture. Data collection was carried out through semi-structured interviews with key stakeholders, community-level meetings, focus groups and interviews. We find that an important first step for a meaningful community engagement process is to define 'community' in an open and participatory manner. Two-way communication at all stages of the community engagement process is shown to be critical, and charismatic leadership based on mutual respect and clarity of roles and responsibilities is vital to improve the likelihood of participants developing understanding of project aims and philosophy. This can lead to successful project outcomes through community ownership of the project goals and empowerment in project implementation. Specific engagement methods are found to be less important than the contextual and environmental factors associated with each project, but consideration should be given to identifying appropriate methods to ensure community representation. Our findings extend current thinking on the evaluation of participation by making explicit links between the community engagement process and project outcomes, and by

  6. Satellite-based climatology of low-level continental clouds in southern West Africa during the summer monsoon season

    NASA Astrophysics Data System (ADS)

    Linden, Roderick; Fink, Andreas H.; Redl, Robert

    2015-02-01

    Synoptic observations and various satellite products have been utilized for computing climatologies of low-level stratus over southern West Africa for the wet monsoon seasons July-September of 2006-2011. Previous studies found inconsistencies between satellite cloud products; climate models often fail to reproduce the extensive stratus decks. Therefore, a better observational reference and an understanding of its limitations are urgently needed to better validate models. Most detailed information of the spatiotemporal characteristics of low-level clouds was obtained from two Meteosat Second Generation (MSG) satellite-based data sets. However, CALIPSO and CloudSat cross sections of cloud occurrence frequency suggest that both MSG products underestimate the low-level cloudiness over Nigeria due to shielding by abundant upper level and midlevel clouds and reveal that the stratus is lower over the continent than over the ocean. The Terra Multiangle Imaging Spectroradiometer product appears to overestimate the morning extent of low-level clouds. The climatology presented here shows that the zone of abundant low-level stratiform clouds is at its diurnal minimum south of 6-7°N around sunset (~1800 UTC). Thereafter, it starts to spread inland and reaches its maximum northward extent of 10-11°N between 0900 and 1000 UTC. The maximum affected area is approximately 800,000 km2. After about 1000 UTC, the northern boundary gets fragmented due to the breakup of stratus decks into fair-weather cumuli. The stratus is most frequent around Cape Palmas, over Ivory Coast, and at the windward sides of the Mampong Range (Ghana) and Oshogbo Hills (Nigeria).

  7. A multisatellite climatology of clouds, radiation, and precipitation in southern West Africa and comparison to climate models

    NASA Astrophysics Data System (ADS)

    Hill, Peter G.; Allan, Richard P.; Chiu, J. Christine; Stein, Thorwald H. M.

    2016-09-01

    Southern West Africa (SWA) has a large population that relies on highly variable monsoon rainfall, yet climate models show little consensus over projected precipitation in this region. Understanding of the current and future climate of SWA is further complicated by rapidly increasing anthropogenic emissions and a lack of surface observations. Using multiple satellite observations, the ERA-Interim reanalysis, and four climate models, we document the climatology of cloud, precipitation, and radiation over SWA in June-July, highlight discrepancies among satellite products, and identify shortcomings in climate models and ERA-Interim. Large differences exist between monthly mean cloud cover estimates from satellites, which range from 68 to 94%. In contrast, differences among satellite observations in top of atmosphere outgoing radiation and surface precipitation are smaller, with monthly means of about 230 W m-2 of longwave radiation, 145 W m-2 of shortwave radiation, and 5.87 mm d-1 of precipitation. Both ERA-Interim and the climate models show less total cloud cover than observations, mainly due to underestimating low cloud cover. Errors in cloud cover, along with uncertainty in surface albedo, lead to a large spread of outgoing shortwave radiation. Both ERA-Interim and the climate models also show signs of convection developing too early in the diurnal cycle, with associated errors in the diurnal cycles of precipitation and outgoing longwave radiation. Clouds, radiation, and precipitation are linked in an analysis of the regional energy budget, which shows that interannual variability of precipitation and dry static energy divergence are strongly linked.

  8. Individual Aerosol Particles from Biomass Burning in Southern Africa. 1; Compositions and Size Distributions of Carbonaceous Particles

    NASA Technical Reports Server (NTRS)

    Posfai, Mihaly; Simonics, Renata; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

    2003-01-01

    Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, tar ball particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged (1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloud-nucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.

  9. Individual aerosol particles from biomass burning in southern Africa: 1. Compositions and size distributions of carbonaceous particles

    NASA Astrophysics Data System (ADS)

    Pósfai, MiháLy; Simonics, RenáTa; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

    2003-07-01

    Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, "tar ball" particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged (˜1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloud-nucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.

  10. 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.

  11. A Comparison of the Antimicrobial Activity and Toxicity of Six Combretum and Two Terminalia Species from Southern Africa

    PubMed Central

    Cock, I. E.; Van Vuuren, S.F.

    2015-01-01

    Background: Plants of the family Combretaceae are amongst the most widely used plants for traditional medicinal purposes in southern Africa. In particular, many species of Combretum and Terminalia are used for their antibacterial, antifungal, antiprotozoal, antiviral, antidiarrhoeal, analgesic, antimalarial, antioxidant, anti-inflammatory and anticancer activities, yet their antimicrobial potential has not been rigorously studied and compared. Materials and Methods: A survey of antimicrobial activity was undertaken on selected South African Combretum and Terminalia species. Sixteen extracts from 6 Combretum and 2 Terminalia plant species with a history of medicinal usage were investigated by disc diffusion assay against a panel of bacteria and fungi and their MIC values were determined. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: All extracts tested displayed broad spectrum antibacterial activity, inhibiting the growth of 12-16 (75-100%) of the bacteria tested, with Gram-positive and Gram-negative bacteria being approximately equally susceptible. Potent antibacterial activities (generally in the range 200-5000 μg/ml) were evident for all Combretaceae extracts against both Gram-positive and Gram-negative bacteria. Similarly, the extracts also displayed good antifungal activity, inhibiting the growth of 2-3 (66.7-100%) of the fungal species tested, with fungal growth inhibition activities generally in the range 200–4000 μg/ml. In general, the Terminalia extracts had better efficacies than the Combretum extracts. Furthermore, the methanol extracts were generally better antimicrobial agents than the water extracts. All extracts were also shown to be non-toxic in the Artemia nauplii bioassay. Conclusion: The lack of toxicity of these extracts and their inhibitory bioactivity against a panel of bacteria and fungi indicate their potential as medicinal agents and partially validate their usage in multiple South African traditional

  12. Model Validation Through SOM-based Pattern Analysis: Evaluating HadAM3 GCM Hindcasts Over Southern Africa

    NASA Astrophysics Data System (ADS)

    Hewitson, B.; Collins, D.

    2001-05-01

    The decomposition of the time-space structure in atmospheric data has long been a core analysis technique for feature identification and interpretation. Most common of these methods has been EOF analysis and cluster analysis. However, the linear and orthogonal nature of these methods inherently imposes some restrictions on the results. Nonlinear Primary Component Analysis may be used to extend EOF techniques, while Self Organizing Maps (SOMs) may be used to extend clustering techniques. Such technique developments are of particular importance for improving seasonal forecasting by evaluating the shorter time frame of model performance (as opposed to the more common temporal means and anomalies). In this analysis SOMs are applied to time series of spatial fields from the NCEP reanalysis and the HadAM3 GCM forced with observed SSTs. Using 6-hourly data the SOM finds reference vectors that span the high-dimensional input data space, and forms a mapping of this high-dimensional space to a 2-dimensional lattice. In effect the procedure identifies arch-types in the data. The original data fields may then be associated with the reference vectors, in effect performing a clustering of the data against the reference vectors identified. The 2-dimensional mapping may then be used to effectively visualize the ordered relations of the input data. In this manner the relative frequency of occurrence of synoptic events may be determined, as well as the temporal evolution of synoptic events, and the velocity of the synoptic evolution. Using this approach the GCM data for the summer season over southern Africa (DJF) is evaluated against the NCEP reanalysis for the same period. This allows bias and error in the model to be identified in terms of circulation modes and evolution.

  13. 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

  14. Linking the SASSCAL WeatherNet and data management/rescue activities to provide consistent information for climate change assessments in Southern Africa

    NASA Astrophysics Data System (ADS)

    Helmschrot, J.; Kaspar, F.; Muche, G.; Hillmann, T.; Kanyanga, J.; Butale, M.; Nascimento, D.; Josenhans, K.; Falanga, E.; Neto, F. O. S.; Kruger, S.; Juergens, N.

    2014-12-01

    Many countries of Southern Africa face inadequate weather monitoring networks to provide reliable and consistent information for the development of efficient management strategies for sustainable water and land resources management, drought and flood risk analysis and forecasts as well as climate change impacts assessments. In addition, some existing networks are characterized by station data showing notable gaps in long-term observations. On the other hand, useful climate information is saved in historical documents and archives, but only barely explored up to now. Such documents are also available in archives of European meteorological services, partly also not yet in digital format. A main aim of the SASSCAL Initiative (Southern African Science Service Centre for Climate Change and Adaptive Land Management; www.sasscal.org) is to improve the availability of reliable meteorological baseline data along with a set of analytical methods to strengthen the research capacities in the SASSCAL region including Angola, Botswana, Namibia, South Africa and Zambia, and therewith to support and integrate information of existing national monitoring networks of the Southern African region. In close cooperation with the national weather authorities and various research institutions of the SASSCAL region, the above mentioned deficits are specifically addressed by i) extending the existing national monitoring networks through additional automatic weather stations and their integration in the SASSCAL WeatherNet which in near future hosts about 130 stations, ii) contributing to the development of Climate Data Management Systems (CDMS) at the national weather authorities in Angola, Botswana and Zambia and iii) the provision of additional time series of climate data based on the historic documents from various archives in all countries. The paper presents first results and shows how these efforts are linked to provide consistent climate information for Southern Africa in order to

  15. The YES Africa 2011 Symposium: A Key to Developing the Future Geoscience Workforce in Africa

    NASA Astrophysics Data System (ADS)

    Nkhonjera, E.

    2011-12-01

    Africa is facing serious challenges in geoscience education. This has been as a result of absence of or very young/small Earth Science Departments in some universities (e.g., Mauritius, Namibia, Botswana, Swaziland, Malawi): Limited capacity (staff and equipment needed for practicals) to cope with the growing number of students, compounded by brain drain of academic staffs and the fact that current tertiary programmes do not seem to produce graduates suitable for the industry are some of the contributing factors to the challenges, (UNESCO-AEON Report, 2009). As such Earth Science studies in Africa have been one of the career paths that has not been promoted or highly preferred by many students. In January 2011, the YES Network African chapter was launched through the YES Africa 2011 Symposium that took place at the University of Johannesburg South Africa in Conjunction with the 23rd Colloquium of Africa Geology from the 08-14th January 2011. The YES Africa 2011 Symposium was organized by five YES African National networks from Southern, Central, Eastern and Northern Africa to bring young geoscientists from all regions of Africa together to present their research about African geoscience topics. The symposium also included roundtable discussions about increasing the involvement of youth's participation in geoscience issues in Africa, about how to increase the number of youths in African geosciences education university programs, and about how to promote geoscience careers to university students in Africa c. Roundtable discussions revealed that many African colleges and universities do not provide adequate infrastructure and resources to support the students studying in the department. As such, most students graduate with poor preparation for geoscience careers, having gained a theoretical understanding of geology, but not the practical application of the discipline. The recommendations from the YES Africa 2011 Symposium also highlighted on the best ways of

  16. Swampy area transformations by exploitation of Raphia hookeri (Arecaceae) in southern Benin (West Africa)

    SciTech Connect

    Profizi, J.

    1988-03-01

    The Raphia palms in the southern part of Benin are confined to freshwater swamps, where the natural vegetation consists of a forest rich in Dicotyledons. Human activity has transformed this forest into a raphiale where Raphia hookeri has become the main arborescent species. The influence of this transformation on the vegetation results in a more regular distribution of Raphis hookeri trunks and a gradual disappearing of clumps of ramets. By now, the future of Raphis hookeri species is almost ensured except in situations of over-exploitation.

  17. Re-energizing South Africa

    SciTech Connect

    Scholand, M.

    1996-09-01

    Bringing modern energy services to South Africa`s deprived majority doesn`t have to mean simply expanding the now obsolete coal-based system built for the nation`s white minority. A partheid still haunts South Africa`s energy economy. The country`s fledgling democracy has inherited two energy systems, as different from each other as California`s is from that of Bangladesh-but less efficient and more polluting than either of those. For the country`s white minority, cheap electricity is available at the flip of a switch. But even though South Africa has 30 percent more generating capacity than it uses, two-thirds of its black citizens have no electricity at all. Dealing with this legacy is essential for the survival of the two-year-old government. Mandela has made ambitious promises to transform the nation`s energy system-providing such basic amenities as lighting and heating to millions of blacks, while reducing pollution. However, conventional development will never reach those goals - the country`s energy system has huge fundamental inefficiencies. To keep its promises, the government will need an array of cutting-edge technologies, including lowcost super-efficient housing, solar electric systems, gas fired cogeneration. South Africa is well positioned with huge solar and wind energy potential, a well capitalized industrial base and millions of aid dollars. This article examines the emerging energy needs/demands of South Africa in light of these factors.

  18. Occurrences and Effects of Drought across Africa

    NASA Astrophysics Data System (ADS)

    Mwangi, M. N.

    2009-12-01

    Drought is a common occurrence in Africa and its effects vary temporally and spatially across the continent. The objective of this paper is to synthesize available information on droughts in Africa in order to discern emerging trends vis-à-vis spatiotemporal occurrences, impacts and adaptation. Drought forcings in the Sahelian region and southern Africa are predominately related to the passage of mid-latitude air masses while in locations near the equator is strongly linked to the position of ITCZ, except perhaps in the deserts where albedo may predominate. The review shows that drought occurrences have increased both temporally and spatially; its effects on the society vary across scales, and are influenced by political, economic, social, cultural, and ecological factors. The drought occurrence and its impacts varied spatially and temporally. The effect of drought also varied with socioeconomic sector; agriculture and pastoralism were the widely reported. The greater horn of Africa, specifically Kenya, has the most continuous record of droughts. The synthesis also reveals that a suite of drought adaptation strategies exists at the local scale; in contrasts, at the aggregate scale, coping strategies are scarce. Drought management tailored for specific livelihood system or societies are non-existent. The study found that occurrence of drought alongside issues related to the multiscale political economy affect the viability of most adaptation strategies used by societies across Africa. Drought management has been silent on the social, political, and economic dimensions that reasonably aggravate the vulnerability of lives and livelihood systems to this climatic hazard. The effect of drought and social pressures is relational and simultaneous to such a degree that differential vulnerability among communities across Africa is to be expected. Although scenarios about rainfall and drought vis-à-vis Africa are largely contested there is a general indication that most

  19. Satellite Remote Sensing of Atmospheric Pollution: the Far-Reaching Impact of Burning in Southern Africa

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Al-Saadi, Jassim A.; Neil, Doreen O.; Creilson, John K.; Severance, Kurt; Thomason, Larry W.; Edwards, David R.

    2008-01-01

    When the first observations of a tropospheric trace gas were obtained in the 1980s, carbon monoxide enhancements from tropical biomass burning dominated the observed features. In 2005, an active remote-sensing system to provide detailed information on the vertical distribution of aerosols and clouds was launched, and again, one of the most imposing features observed was the presence of emissions from tropical biomass burning. This paper presents a brief overview of space-borne observations of the distribution of trace gases and aerosols and how tropical biomass burning, primarily in the Southern Hemisphere, has provided an initially surprising picture of the distribution of these species and how they have evolved from prevailing transport patterns in that hemisphere. We also show how interpretation of these observations has improved significantly as a result of the improved capability of trajectory modeling in recent years and how information from this capability has provided additional insight into previous measurements form satellites. Key words: pollution; biomass burning; aerosols; tropical trace gas emissions; Southern Hemisphere; carbon monoxide.

  20. A survey of Simulium control in Africa.

    PubMed

    BROWN, A W

    1962-01-01

    It has become possible to control or even eradicate the Simulium fly vectors of Onchocerca volvulus, the causative organism of onchocerciasis. There are two vectors in Africa-namely, S. damnosum, characteristic of the rivers of West Africa, and S. neavei, which breeds on the carapaces of crabs in the streams of East Africa. The use of DDT applied to the water at a concentration as low as 0.1 p.p.m. for 30 minutes eliminates the larvae of Simulium. Such larvicidal methods have eradicated S. neavei from western Kenya and virtually eradicated S. damnosum from the Victoria Nile in Uganda. Excellent control sufficient to render the transmission of onchocerciasis almost negligible has been obtained at Léopoldville (Republic of the Congo) and in circumscribed areas in southern Chad, Northern Nigeria, and Sierra Leone. The following survey describes operational research on Simulium control carried out in Kenya, Uganda, the Congo, Chad, Nigeria, Ghana, Upper Volta and Sierra Leone.

  1. Ebola in West Africa

    PubMed Central

    Raka, Lul; Guardo, Monica

    2015-01-01

    Ebola viral disease (EVD) is a severe and life-threatening disease. The current Ebola outbreak in West Africa entered its second year and is unprecedented because it is the largest one in history, involved urban centers and affected a large number of health care workers. It quickly escalated from medical into a humanitarian, social, economic, and security crisis. The primary pillars to prevent EVD are: early diagnosis, isolation of patients, contact tracing and monitoring, safe burials, infection prevention and control and social mobilization. The implementation of all these components was challenged in the field. Key lessons from this Ebola outbreak are that countries with weak health care systems can’t withstand the major outbreaks; preparedness to treat the first confirmed cases is a national emergency; all control measures must be coordinated together and community engagement is the great factor to combat this disease. PMID:27275217

  2. Ebola in West Africa.

    PubMed

    Raka, Lul; Guardo, Monica

    2015-03-15

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

  3. Advances in the study of Anopheles funestus, a major vector of malaria in Africa.

    PubMed

    Coetzee, M; Fontenille, D

    2004-07-01

    The recent literature on cytogenetic and molecular studies of Anopheles funestus, a major vector of malaria in Africa, is reviewed. Molecular data from West and Central Africa suggest a new species in the group closely allied to Anopheles rivulorum. Cytogenetic and molecular studies of populations from West, Central, East and southern Africa indicate considerable genetic structuring within An. funestus itself, which may well restrict the spread of pyrethroid resistance that has been demonstrated in southern Africa.

  4. Modeling Gross Primary Production of Savanna Woodlands in Southern Africa Using MODIS Imagery and CO2 Flux Tower Data

    NASA Astrophysics Data System (ADS)

    Jin, C.; Xiao, X.; Merbold, L.; Arneth, A.; Veenendaal, E.; Kutsch, W.

    2012-12-01

    Accurate estimation of gross primary production (GPP) of savanna ecosystem is valuable for evaluating the role of Africa in the global carbon cycle. An eddy flux observation network has been established to continuously measure the net CO2 fluxes (NEE) across various savanna vegetation types in Africa (CarboAfrica). Several publications have reported the seasonal dynamics and interannual variation of GPP for the savanna vegetation through partitioning of the measured NEE data. The satellite-based Production Efficiency Models (PEM), which calculate GPP as the product of absorbed photosynthetically active radiation (PAR) and light use efficiency (LUE), have been developed to scale up in situ GPP estimation from the eddy flux towers to regional scale. In this study, the Vegetation Photosynthesis Model (VPM) and the Moderate Resolution Imaging Spectroradiometer (MODIS) data were evaluated for their capacity to model GPP for savanna woodlands at two eddy flux towers in Botswana and Zambia, respectively. These two sites have different woodland types and precipitation pattern (Mopane woodlands vs. Miombo woodlands, semi-arid vs. semi-humid). In the VPM model, GPP is simulated as the product of photosynthetically active radiation (PAR), air temperature, Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI). The results show that the simulated GPP by the VPM track well the temporal dynamic of GPP estimated from the eddy covariance measurements at these two sites. In addition, the land surface phenology of savanna woodlands, described by the satellite vegetation indices, especially the water-sensitive satellite indices-LSWI, are proved to match the phenology based on vegetation physiology activity measured by eddy covariance towers. The information of the timing and duration of vegetation growing season is useful for assisting the VPM modeling. Further evaluation of VPM simulations for and other savanna ecosystems is necessary before the VPM model is applied to

  5. Phophoglucomutase first locus polymorphism as revealed by isoelectric focusing in Southern Africa.

    PubMed

    Tipler, T D; Dunn, D S; Jenkins, T

    1982-01-01

    Eleven Southern African populations (representing European, Asian and Negroid populations) have been typed for the first locus phosphoglucomutase (PGM1) using isoelectric focusing (pH range 5.0-8.0) in acrylamide gels. The gene frequencies of the four common alleles at this locus in these populations were compared to those found previously in European and Negroid populations. Marked differences in gene frequencies were observed: Negroes have a lower PGM1(2-) compared with Caucasoids due to a lower PGM1(2-) frequency, Indians a relatively high PGM1(2) due to a higher frequency of the PGM1(2+) allele. The Afrikaans and Ashkenazim do not differ appreciably from their European counterparts. The appearances of the rarer PGM1(6) and PGM1(7) alleles on isoelectric focusing are described and some kinetic properties examined. The PGM2(2-1), or 'Atkinson' phenotype, can also be detected with this technique.

  6. The African Crane Database (1978-2014): Records of three threatened crane species (Family: Gruidae) from southern and eastern Africa

    PubMed Central

    Smith, Tanya; Page-Nicholson, Samantha; Gibbons, Bradley; Jones, M. Genevieve W.; van Niekerk, Mark; Botha, Bronwyn; Oliver, Kirsten; McCann, Kevin

    2016-01-01

    Abstract Background The International Crane Foundation (ICF) / Endangered Wildlife Trust’s (EWT) African Crane Conservation Programme has recorded 26 403 crane sightings in its database from 1978 to 2014. This sightings collection is currently ongoing and records are continuously added to the database by the EWT field staff, ICF/EWT Partnership staff, various partner organizations and private individuals. The dataset has two peak collection periods: 1994-1996 and 2008-2012. The dataset collection spans five African countries: Kenya, Rwanda, South Africa, Uganda and Zambia; 98% of the data were collected in South Africa. Georeferencing of the dataset was verified before publication of the data. The dataset contains data on three African crane species: Blue Crane Anthropoides paradiseus, Grey Crowned Crane Balearica regulorum and Wattled Crane Bugeranus carunculatus. The Blue and Wattled Cranes are classified by the IUCN Red List of Threatened Species as Vulnerable and the Grey Crowned Crane as Endangered. New information This is the single most comprehensive dataset published on African Crane species that adds new information about the distribution of these three threatened species. We hope this will further aid conservation authorities to monitor and protect these species. The dataset continues to grow and especially to expand in geographic coverage into new countries in Africa and new sites within countries. The dataset can be freely accessed through the Global Biodiversity Information Facility data portal. PMID:27956850

  7. Diversity of Dicotyledenous-Infecting Geminiviruses and Their Associated DNA Molecules in Southern Africa, Including the South-West Indian Ocean Islands

    PubMed Central

    Rey, Marie E. C.; Ndunguru, Joseph; Berrie, Leigh C.; Paximadis, Maria; Berry, Shaun; Cossa, Nurbibi; Nuaila, Valter N.; Mabasa, Ken G.; Abraham, Natasha; Rybicki, Edward P.; Martin, Darren; Pietersen, Gerhard; Esterhuizen, Lindy L.

    2012-01-01

    The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component) or bipartite (two circular ssDNA components called DNA-A and DNA-B), many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-αs) or betasatellites (DNA-βs). Additionally, subgenomic molecules, also known as defective interfering (DIs) DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world. PMID:23170182

  8. Diversity of dicotyledenous-infecting geminiviruses and their associated DNA molecules in southern Africa, including the South-west Indian ocean islands.

    PubMed

    Rey, Marie E C; Ndunguru, Joseph; Berrie, Leigh C; Paximadis, Maria; Berry, Shaun; Cossa, Nurbibi; Nuaila, Valter N; Mabasa, Ken G; Abraham, Natasha; Rybicki, Edward P; Martin, Darren; Pietersen, Gerhard; Esterhuizen, Lindy L

    2012-09-01

    The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component) or bipartite (two circular ssDNA components called DNA-A and DNA-B), many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-αs) or betasatellites (DNA-βs). Additionally, subgenomic molecules, also known as defective interfering (DIs) DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world.

  9. Characteristics of Men Who Have Sex With Men in Southern Africa Who Seek Sex Online: A Cross-Sectional Study

    PubMed Central

    Grosso, Ashley; Ketende, Sosthenes; Mothopeng, Tampose; Taruberekera, Noah; Nkonyana, John; Mabuza, Xolile; Sithole, Bhekie; Mnisi, Zandile; Baral, Stefan

    2015-01-01

    Background Use of the Internet for finding sexual partners is increasing, particularly among men who have sex with men (MSM). In particular, MSM who seek sex online are an important group to target for human immunodeficiency virus (HIV)/sexually transmitted infection (STI) interventions because they tend to have elevated levels of sexual risk behavior and because the Internet itself may serve as a promising intervention delivery mechanism. However, few studies have examined the correlates of online sexual partner seeking among MSM in sub-Saharan Africa. Objective These analyses aim to describe the prevalence of using the Internet to find new male sexual partners among MSM in two southern African countries. In addition, these analyses examine the sociodemographic characteristics, experiences of discrimination and stigma, mental health and substance use characteristics, and HIV-related knowledge, attitudes, and behaviors among MSM associated with meeting sex partners online. Methods MSM were enrolled into a cross-sectional study across two sites in Lesotho (N=530), and one in Swaziland (N=322) using respondent-driven sampling. Participants completed a survey and HIV testing. Data were analyzed using bivariate and multivariable logistic regression models to determine which factors were associated with using the Internet to meet sex partners among MSM. Results The prevalence of online sex-seeking was high, with 39.4% (209/530) of MSM in Lesotho and 43.8% (141/322) of MSM in Swaziland reporting meeting a new male sexual partner online. In the multivariable analysis, younger age (adjusted odds ratio [aOR] 0.37, 95% confidence interval [CI] 0.27-0.50 per 5 years in Lesotho; aOR 0.68, 95% CI 0.49-0.93 in Swaziland), having more than a high school education (aOR 18.2, 95% CI 7.09-46.62 in Lesotho; aOR 4.23, 95% CI 2.07-8.63 in Swaziland), feeling scared to walk around in public places (aOR 1.89, 95% CI 1.00-3.56 in Lesotho; aOR 2.06, 95% CI 1.23-3.46 in Swaziland), and

  10. Challenges of Sanitary Compliance Related to Trade in Products of Animal Origin in Southern Africa.

    PubMed

    Magwedere, Kudakwashe; Songabe, Tembile; Dziva, Francis

    2015-06-30

    Irrespective of the existence of potentially pathogenic organisms carried by animals, foods of animal origin remain the prime nutrition of humans world-wide. As such, food safety continues to be a global concern primarily to safeguard public health and to promote international trade. Application of integrated risk-based quality assurance procedures on-farm and at slaughterhouses plays a crucial role in controlling hazards associated with foods of animal origin. In the present paper we examine safety assurance systems and associated value chains for foods of animal origin based on historical audit results of some Southern African countries with thriving export trade in animal products, mainly to identify areas for improvement. Among the key deficiencies identified were: i) failure to keep pace with scientific advances related to the ever-changing food supply chain; ii) lack of effective national and regional intervention strategies to curtail pathogen transmission and evolution, notably the zoonotic Shiga toxin-producing Escherichia coli; and iii) a lack of effective methods to reduce contamination of foods of wildlife origin. The introduction of foods of wildlife origin for domestic consumption and export markets seriously compounds already existing conflicts in legislation governing food supply and safety. This analysis identifies gaps required to improve the safety of foods of wildlife origin.

  11. Challenges of Sanitary Compliance Related to Trade in Products of Animal Origin in Southern Africa

    PubMed Central

    Magwedere, Kudakwashe; Songabe, Tembile

    2015-01-01

    Irrespective of the existence of potentially pathogenic organisms carried by animals, foods of animal origin remain the prime nutrition of humans world-wide. As such, food safety continues to be a global concern primarily to safeguard public health and to promote international trade. Application of integrated risk-based quality assurance procedures on-farm and at slaughterhouses plays a crucial role in controlling hazards associated with foods of animal origin. In the present paper we examine safety assurance systems and associated value chains for foods of animal origin based on historical audit results of some Southern African countries with thriving export trade in animal products, mainly to identify areas for improvement. Among the key deficiencies identified were: i) failure to keep pace with scientific advances related to the ever-changing food supply chain; ii) lack of effective national and regional intervention strategies to curtail pathogen transmission and evolution, notably the zoonotic Shiga toxin-producing Escherichia coli; and iii) a lack of effective methods to reduce contamination of foods of wildlife origin. The introduction of foods of wildlife origin for domestic consumption and export markets seriously compounds already existing conflicts in legislation governing food supply and safety. This analysis identifies gaps required to improve the safety of foods of wildlife origin. PMID:27800409

  12. Pollen analysis of hyena coprolites and sediments from Equus Cave, Taung, southern Kalahari (South Africa)

    NASA Astrophysics Data System (ADS)

    Scott, Louis

    1987-07-01

    Equus Cave, in Quaternary tufa near Taung in the semiarid woodland of the southern Kalahari, yielded 2.5 m of sediment in which a rich assemblage of bones and coprolites was preserved. The fossils were accumulated mainly by hyenas during the late Pleistocene and Holocene. Pollen from coprolites reflects diet as well as vegetation over relatively large areas visited by hyenas, while pollen from sediments represents more local sources. The pollen sequence derived from coprolites and sediments demonstrates how the vegetation evolved from open grassland with small shrubs and occasional trees during the late Pleistocene, to open savanna with more small shurbs, then, during the last 7500 yr, to modern savanna. Temperatures were not more than 4°C cooler and it was slightly moister than today during the late Pleistocene phase; it became gradually warmer but relatively dry before optimal temperature and moisture conditions developed around 7500 yr B.P. Climatic conditions slightly less favorable for woodland occurred during part of the late Holocene.

  13. Escherichia coli Population Structure and Antibiotic Resistance at a Buffalo/Cattle Interface in Southern Africa

    PubMed Central

    Mercat, Mathilde; Clermont, Olivier; Massot, Méril; Ruppe, Etienne; de Garine-Wichatitsky, Michel; Miguel, Eve; Valls Fox, Hugo; Cornelis, Daniel; Andremont, Antoine; Denamur, Erick

    2015-01-01

    At a human/livestock/wildlife interface, Escherichia coli populations were used to assess the risk of bacterial and antibiotic resistance dissemination between hosts. We used phenotypic and genotypic characterization techniques to describe the structure and the level of antibiotic resistance of E. coli commensal populations and the resistant Enterobacteriaceae carriage of sympatric African buffalo (Syncerus caffer caffer) and cattle populations characterized by their contact patterns in the southern part of Hwange ecosystem in Zimbabwe. Our results (i) confirmed our assumption that buffalo and cattle share similar phylogroup profiles, dominated by B1 (44.5%) and E (29.0%) phylogroups, with some variability in A phylogroup presence (from 1.9 to 12%); (ii) identified a significant gradient of antibiotic resistance from isolated buffalo to buffalo in contact with cattle and cattle populations expressed as the Murray score among Enterobacteriaceae (0.146, 0.258, and 0.340, respectively) and as the presence of tetracycline-, trimethoprim-, and amoxicillin-resistant subdominant E. coli strains (0, 5.7, and 38%, respectively); (iii) evidenced the dissemination of tetracycline, trimethoprim, and amoxicillin resistance genes (tet, dfrA, and blaTEM-1) in 26 isolated subdominant E. coli strains between nearby buffalo and cattle populations, that led us (iv) to hypothesize the role of the human/animal interface in the dissemination of genetic material from human to cattle and toward wildlife. The study of antibiotic resistance dissemination in multihost systems and at anthropized/natural interface is necessary to better understand and mitigate its multiple threats. These results also contribute to attempts aiming at using E. coli as a tool for the identification of pathogen transmission pathway in multihost systems. PMID:26712551

  14. Escherichia coli Population Structure and Antibiotic Resistance at a Buffalo/Cattle Interface in Southern Africa.

    PubMed

    Mercat, Mathilde; Clermont, Olivier; Massot, Méril; Ruppe, Etienne; de Garine-Wichatitsky, Michel; Miguel, Eve; Valls Fox, Hugo; Cornelis, Daniel; Andremont, Antoine; Denamur, Erick; Caron, Alexandre

    2015-12-28

    At a human/livestock/wildlife interface, Escherichia coli populations were used to assess the risk of bacterial and antibiotic resistance dissemination between hosts. We used phenotypic and genotypic characterization techniques to describe the structure and the level of antibiotic resistance of E. coli commensal populations and the resistant Enterobacteriaceae carriage of sympatric African buffalo (Syncerus caffer caffer) and cattle populations characterized by their contact patterns in the southern part of Hwange ecosystem in Zimbabwe. Our results (i) confirmed our assumption that buffalo and cattle share similar phylogroup profiles, dominated by B1 (44.5%) and E (29.0%) phylogroups, with some variability in A phylogroup presence (from 1.9 to 12%); (ii) identified a significant gradient of antibiotic resistance from isolated buffalo to buffalo in contact with cattle and cattle populations expressed as the Murray score among Enterobacteriaceae (0.146, 0.258, and 0.340, respectively) and as the presence of tetracycline-, trimethoprim-, and amoxicillin-resistant subdominant E. coli strains (0, 5.7, and 38%, respectively); (iii) evidenced the dissemination of tetracycline, trimethoprim, and amoxicillin resistance genes (tet, dfrA, and blaTEM-1) in 26 isolated subdominant E. coli strains between nearby buffalo and cattle populations, that led us (iv) to hypothesize the role of the human/animal interface in the dissemination of genetic material from human to cattle and toward wildlife. The study of antibiotic resistance dissemination in multihost systems and at anthropized/natural interface is necessary to better understand and mitigate its multiple threats. These results also contribute to attempts aiming at using E. coli as a tool for the identification of pathogen transmission pathway in multihost systems.

  15. The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa

    NASA Astrophysics Data System (ADS)

    Mills, S. C.; Barrows, T. T.; Telfer, M. W.; Fifield, L. K.

    2017-02-01

    Southern Africa is located in a unique setting for investigating past cold climate geomorphology over glacial-interglacial timescales. It lies at the junction of three of the world's major oceans and is affected by subtropical and temperate circulation systems, therefore recording changes in Southern Hemisphere circulation patterns. Cold climate landforms are very sensitive to changes in climate and thus provide an opportunity to investigate past changes in this region. The proposed existence of glaciers in the high Eastern Cape Drakensberg mountains, together with possible rock glaciers, has led to the suggestion that temperatures in this region were as much as 10-17 °C lower than present. Such large temperature depressions are inconsistent with many other palaeoclimatic proxies in Southern Africa. This paper presents new field observations and cosmogenic nuclide exposure ages from putative cold climate landforms. We discuss alternative interpretations for the formation of the landforms and confirm that glaciers were absent in the Eastern Cape Drakensberg during the last glaciation. However, we find widespread evidence for periglacial activity down to an elevation of 1700 m asl, as illustrated by extensive solifluction deposits, blockstreams, and stone garlands. These periglacial deposits suggest that the climate was significantly colder ( 6 °C) during the Last Glacial Maximum, in keeping with other climate proxy records from the region, but not cold enough to initiate or sustain glaciers or rock glaciers.

  16. Africa: sexual minorities at risk.

    PubMed

    Kazatchkine, Cécile

    2011-04-01

    Violence against homosexuality is growing in Africa, where most of the countries on the continent continue to criminalize same-sex relations, fostering a climate of hate that, in some cases, is abetted by politicians.

  17. Lightning medicine in South Africa.

    PubMed

    Blumenthal, Ryan; Trengrove, Estelle; Jandrell, Ian R; Saayman, Gert

    2012-06-06

    South Africa has a rich history of lightning research; however, research on the clinical and pathological effects and features of lightning-related injury (keraunomedicine or lightning medicine) remains neglected locally. By providing an overview of keraunomedicine and focussing on South African perspectives, we hope to raise awareness and propose that a concerted and co-ordinated attempt be made to report and collate data regarding lightning strike victims in South Africa.

  18. Sub-Saharan Africa Report

    DTIC Science & Technology

    1987-02-19

    quotes Trevor Howard, a former member of the 23d Battalion, an elite unit led by South African officers and white mercenaries recruited by the puppet...intervene only to raise their flag," claims Trevor Howard. AFRICA CONCORD says that it is crucial for South Africa to maintain the UNITA terrorist...racist army had.to mobilize its best land and air facilities to preclude the seizure of Mavinga by the Angolan Armed Forces. Trevor Howard documented the