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  1. The rise of injecting drug use in east Africa: a case study from Kenya

    PubMed Central

    Beckerleg, Susan; Telfer, Maggie; Hundt, Gillian Lewando

    2005-01-01

    Studies on injecting drug use in East Africa are reviewed. The existingstudies document the spread of heroin injection in Kenya and Tanzania, both countries where HIV rates are high. No data from Uganda on injecting drug use was found by the authors. A case study of the growth of heroin injection in a Kenyan coastal town is presented. The need for needle-exchange programmes and other prevention services is discussed. PMID:16122382

  2. A Call to Learning Focus in East Africa: Uwezo's Measurement of Learning in Kenya, Tanzania and Uganda

    ERIC Educational Resources Information Center

    Mugo, John Kabutha; Ruto, Sara Jerop; Nakabugo, Mary Goretti; Mgalla, Zaida

    2015-01-01

    From the late 1990s, education in East Africa started to be appraised on the basis of enrolment. The universalisation of primary education that started in Uganda in 1997--and peaked in Tanzania in 2002, as well as in Kenya in 2003--was politicised as the epitome of education reform. Yet, alternative voices called for consideration of improving…

  3. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  4. Theatre Safari in East Africa: An Exploration of Theatre in Kenya.

    ERIC Educational Resources Information Center

    Hutchinson, P. William

    Six months of observation--at two universities, at a drama festival, and with several independent theatre companies--form the basis for this evaluation of theatre in Kenya, Africa. While Kenyan dramas deal with a variety of themes, the majority are topical rather than universal in their treatment of issues. In many, the emphasis is on the…

  5. Improving Early-Grade Literacy in East Africa: Experimental Evidence from Kenya and Uganda

    ERIC Educational Resources Information Center

    Lucas, Adrienne M.; McEwan, Patrick J.; Ngware, Moses; Oketch, Moses

    2014-01-01

    Primary school enrollments have increased rapidly in sub-Saharan Africa, spurring concerns about low levels of learning. We analyze field experiments in Kenya and Uganda that assessed whether the Reading to Learn intervention, implemented by the Aga Khan Foundation in both countries, improved early-grade literacy as measured by common assessments.…

  6. The seismicity in Kenya (East Africa) for the period 1906-2010: A review

    NASA Astrophysics Data System (ADS)

    Mulwa, J. K.; Kimata, F.; Suzuki, S.; Kuria, Z. N.

    2014-01-01

    Kenya has had a seismic station since 1963 as part of the World Wide Standardized Seismograph Network (WWSSN). In 1990, the University of Nairobi in collaboration with GeoForschungsZentrum (GFZ) started to build up a local seismological network, the Kenya National Seismic Network (KNSN), which operated for about ten years between 1993-2002. This, however, experienced a myriad of problems ranging from equipment breakdown, vandalism and lack of spares. Kenya is seismically active since the Kenya rift valley traverses through the country from north to south bisecting the country into eastern and western regions. In the central part, the Kenya rift branches to form the NW-SE trending Kavirondo (Nyanza) rift. The Kenya rift valley and the Kavirondo (Nyanza) rift are the most seismically active where earthquakes of local magnitude (Ml) in the order of ⩽2.0-5.0 occur. Furthermore, historical records show that earthquakes of magnitudes of the order of Ml ⩾ 6.0 have occurred in Kenya. Such large magnitude earthquakes include the January 6, 1928 Subukia earthquake (Ml 7.1) and an aftershock (Ml 6.2) four days later, as well as the 1913 Turkana region earthquake (Ml 6.2). Since early 1970's, numerous seismic investigations have been undertaken in Kenya in order to understand the formation and structure of the Kenyan part of the East African rift valley. Earthquake data from these studies is, however, rather disorganized and individual datasets, including that acquired during the period 1993-2002, cannot furnish us with comprehensive information on the seismicity of Kenya for the past ∼100 years. The purpose of this paper is, therefore, to review the seismicity in Kenya for the period 1906-2010 by utilizing data and results from different sources. The general seismicity of Kenya has been evaluated using historical data, data recorded by local seismic networks, the United States Geological Survey catalogue as well as earthquake data from the numerous seismic

  7. East Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows the East African nations of Ethiopia, Eritrea, and Somalia, as well as portions of Kenya, Sudan, Yemen, and Saudi Arabia. Dominating the scene are the green Ethiopian Highlands. With altitudes as high as 4,620 meters (15,157 feet), the highlands pull moisture from the arid air, resulting in relatively lush vegetation. In fact, coffee-one of the world's most prized crops-originated here. To the north (above) the highlands is Eritrea, which became independent in 1993. East (right) of Ethiopia is Somalia, jutting out into the Indian Ocean. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) captured this true-color image on November 29, 2000. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  8. Distribution of Glycerol Diakyl Glycerol Tetraethers in Surface Soil and Crater Lake Sediments from Mount Kenya, East Africa

    NASA Astrophysics Data System (ADS)

    Omuombo, C.; Huguet, A.; Olago, D.; Williamson, D.

    2013-12-01

    Glycerol diakyl glycerol tetraethers (GDGTs), a palaeoclimate proxy based on the relative abundance of lipids produced by archaea and bacteria, is gaining wide acceptance for the determination of past temperature and pH conditions. This study looks at the spatial distribution and abundance of GDGTs in soil and sediment samples along an altitudinal transect from 3 crater lakes of Mt. Kenya (Lake Nkunga, Sacred Lake and Lake Rutundu) ranging in elevation from 1700m - 3080m above sea level. GDGTs were extracted with solvents and then analysed using high performance liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (HPLC/APCI-MS). Mean annual air temperature and pH were estimated based on the relative abundance of the different branched GDGTs, i.e. on the MBT (Methylation index of Branched Tetraethers) and CBT (Cyclization ratio of Branched Tetraethers) indices. Substantial amount of GDGTs were detected in both soil and sediment samples. In addition, branched GDGT distribution was observed to vary with altitude. These results highlight the importance of quantifying the branched GDGTs to understand the environmental parameters controlling the distribution of these lipids. The MBT/CBT proxy is a promising tool to infer palaeotemperatures and characterize the climate events of the past millennia in equatorial east Africa.

  9. Late Neogene Paleosols and Paleoclimate, Mweiga Area, Mount Kenya, East Africa

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Barendregt, R. W.; Villeneuve, M.; Dostal, J.; Hamilton, T.; Milner, M. W.; Kapran, B.

    2009-05-01

    A sequence of lavas, principally trachyandesites and tephrites of Pliocene age, forming the underpinning of the Mt. Kenya Volcanic Series and long considered to have a Pliocene/Miocene age, were recently dated by Ar/Ar, and from oldest to youngest, gave ages of 5.48, 5.38 and 5.19 Ma. All dated lavas are reversely magnetized. Outcrops of two flows, both with interbedded paleosols, and overlain with loess occur near the Amboni River north of Mweiga, Kenya, along the Nyeri/Thompson Falls Road at 0 degrees 18 minutes S; 37 degrees 48 minutes E. Mineralogy of lavas was determined using microprobe and whole rock chemistry, while sediments and paleosols were analyzed using X-ray diffraction and Energy-Dispersive Spectrometry. Sediments and paleosols were studied for lithologic uniformity, weathering characteristics, and clay mineralogy. Ages of lavas and sediments were determined by Ar/Ar dating and paleomagnetism. The compound paleosols of Late Neogene age depict a long and complex weathering history of rock alteration, leading in part to the formation of claystone and later saw the addition of loessic sediments. The paleosols appear to have been episodically deflated, initially in phase with outpourings of lavas, and later with periods of climatic deterioration when wind systems intensified. Such disjunct weathering histories within multi- component paleosol profiles are similar to those documented on nearby Mount Kenya, where well-weathered lower paleosol horizons developed on Matuyama-age till are overlain by much younger, less weathered paleosols developed on Brunhes-age loess. These first-reported Ar/Ar ages, and paleomagnetism of lavas within the very Late Miocene/Early Pliocene, provide maximum ages for initial weathering rates in a xeric tropical highland climate. Clay mineral analyses of both the weathered bedrock and surface loessic sediments indicate an initial prolonged dry climate during the Lower Pliocene, followed by more humid conditions during the Upper

  10. Antibodies to Neospora caninum in wild animals from Kenya, East Africa.

    PubMed

    Ferroglio, E; Wambwa, E; Castiello, M; Trisciuoglio, A; Prouteau, A; Pradere, E; Ndungu, S; De Meneghi, D

    2003-12-01

    The prevalence of antibodies to Neospora caninum was examined in six wild Artiodactyla species, and in five wild Carnivora species from Kenya. Blood sera (104 wild ungulates from Marula Estates (MEs), and 31 wild carnivores from Masai-Mara reserve and from other wildlife areas in northern and Southern Kenya), were screened using a Neospora agglutination test (NAT), with a twofold dilution (1:40-1:320 titres). Presence of NAT antibodies to N. caninun is reported here for the first time in zebra (Equus burchelli), eland (Taurotragus oryx), African buffalo (Syncerus caffer), Thompson gazelle (Gazella thompsoni), impala (Aepyceros melampus), warthog (Phacochoerus aethiopicus), spotted hyena (Crocuta crocuta) and in free-ranging cheetah (Acinonyx jubatus). At 1:80 dilution, prevalence was 61.5% in eland, 58.5% in zebra, 19.2% in Thompson gazelle, 33.3% in warthog, 50% in African buffalo, 30% in lion (Panthera leo), 20% in cheetah, and 33.3% in spotted hyena. Antibodies up to 1:320 titre were detected in eland (38.4%), zebra (19.5%), Thompson gazelle (3.8%) and lion (5%). Amongst herbivores, sero-prevalence was significantly (P<0.05) higher, at all dilutions, in "grazer/digger" species (e.g. eland and zebra) than in non-"grazer/digger" species (e.g. impala and Thompson gazelle). No antibodies to N. caninum were found in two leopards (Panthera pardus) and one serval (Felis serval). Our results indicates a steady presence of N. caninum in wild mammals from Kenya. The hypothesis of a sylvatic cycle of N. caninum could be suggested, but more data are needed to verify the hypothesis, as to evaluate the role of N. caninum infection on the dynamics of wild animals population in the study area. PMID:14651874

  11. The uppermost mantle beneath the Kenya dome and relation to melting, rifting and uplift in East Africa

    NASA Astrophysics Data System (ADS)

    Davis, Paul M.; Slack, Philip D.

    2002-04-01

    We compare new results on S-wave delays and P wave tomography to characterize the rising limb and melt zone of an inferred mantle convection cell beneath the Kenya dome. These results are extended to the Nyiragongo and Ethiopia domes using long wavelength gravity and topography. We suggest that the east African rift results from separation of deeper mantle upwelling into three currents that impinge on and erode the base of the lithosphere. Their thermal buoyancy drives the domal uplift, whereas brittle failure of the upper lithosphere forms the rift grabens.

  12. Smallpox inoculation (variolation) in East Africa with special reference to the practice among the Boran and Gabra of Northern Kenya.

    PubMed

    Imperato, Pascal James; Imperato, Gavin H

    2014-12-01

    Smallpox inoculation (variolation) was widely reported in sub-Sahara Africa before, during, and after the colonial era. The infective smallpox materials and techniques used, as well as the anatomical sites for inoculation, varied widely among different ethnic groups. The practice among the Boran and Gabra pastoralists of northern Kenya resembled that which was prevalent in a number of areas of Ethiopia. This is not surprising as the Boran also live in southern Ethiopia, and Gabra herdsmen frequently cross the border into this region. The Boran and Gabra technique for smallpox inoculation consisted of taking infective material from the vesicles or pustules of those with active smallpox, and scraping it into the skin on the dorsum of the lower forearm. Although the intent was to cause a local reaction and at most a mild form of smallpox, severe cases of the disease not infrequently resulted. Also, variolated individuals were capable of infecting others with smallpox, thereby augmenting outbreaks and sustaining them. The limited known reports of smallpox inoculation among the Boran and Gabra are presented in this communication. The expansion of vaccination with effective heat stable vaccines, the development of medical and public health infrastructures, and educational programs all contributed to the eventual disappearance of the practice among the Boran and Gabra. PMID:25100176

  13. Sediment infill within rift basins: Facies distribution and effects of deformation: Examples from the Kenya and Tanganyika Rifts, East Africa

    SciTech Connect

    Tiercelin, J.J.; Lezzar, K.E. ); Richert, J.P. )

    1994-07-01

    Oil is known from lacustrine basins of the east African rift. The geology of such basins is complex and different depending on location in the eastern and western branches. The western branch has little volcanism, leading to long-lived basins, such as Lake Tanganyika, whereas a large quantity of volcanics results in the eastern branch characterized by ephemeral basins, as the Baringo-Bogoria basin in Kenya. The Baringo-Bogoria basin is a north-south half graben formed in the middle Pleistocene and presently occupied by the hypersaline Lake Bogoria and the freshwater Lake Baringo. Lake Bogoria is fed by hot springs and ephemeral streams controlled by grid faults bounding the basin to the west. The sedimentary fill is formed by cycles of organic oozes having a good petroleum potential and evaporites. On the other hand, and as a consequence of the grid faults, Lake Baringo is fed by permanent streams bringing into the basin large quantities of terrigenous sediments. Lake Tanganyika is a meromictic lake 1470 m deep and 700 km long, of middle Miocene age. It is subdivided into seven asymmetric half grabens separated by transverse ridges. The sedimentary fill is thick and formed by organic oozes having a very good petroleum potential. In contrast to Bogoria, the lateral distribution of organic matter is characterized by considerable heterogeneity due to the existence of structural blocks or to redepositional processes.

  14. Onset of uplift and environmental change in East Africa: paleoaltimetry constraints from a 17 Ma beaked whale fossil from northern Kenya

    NASA Astrophysics Data System (ADS)

    Wichura, H.; Jacobs, L. L.; Strecker, M. R.; Lin, A. S.; Polcyn, M. J.; Manthi, F. K.; Winkler, D. A.; Clemens, M.

    2014-12-01

    Deciphering the timing and magnitude of vertical crustal motions is key to understanding the impact of tectonic uplift on changes in atmospheric circulation, rainfall, and environmental conditions. Uplift of the East African Plateau (EAP) of Kenya has been linked to mantle processes, but paleoaltimetry data are still too scarce to unambiguously constrain plateau evolution and subsequent vertical motions associated with late Cenozoic rifting. Here we assess the fossil remains of a beaked whale (Ziphiidae) from the Turkana region of Kenya, 700 km inland from the present-day coastline of the Indian Ocean. The whale fossil was found at an elevation of 650 m and helps constraining the uplift of the northeastern flanks of the EAP. The Kenyan ziphiid was discovered in fluvio-lacustrine sediments of the extensional Oligo-Miocene Lokichar basin (Mead, 1975) along with terrestrial mammals and freshwater mollusks below a basalt dated at 17.1 ± 1.0 Ma (Boschetto et al., 1992). The unifying characteristics of riverine occurrences of modern marine mammals include sufficient discharge in low-gradient rivers to maintain pathways deep enough to facilitate migration, and the absence of shallow bedrock, rapids and waterfalls. The most likely route, which may have had these characteristics is a fluvial corridor controlled by thermal subsidence of the Cretaceous Anza Rift, which once linked extensional processes in Central and East Africa with the continental margin. The fossil locality and analogies with present-day occurrences of marine mammals in terrestrial realms suggest that the ziphiid stranded slightly above sea level. In combination with 13.5. Ma phonolite flows that utilized eastward-directed drainages away from the EAP the fossil find thus provides the older of only two empirical paleoelevation points that constrain the onset of uplift of the EAP to the interval between approximately 17 and 13 Ma. Topographic uplift of the EAP induced paleoclimatic change from a low

  15. Early- to Mid-Holocene hydroclimate shifts in tropical East Africa: the multi-proxy sediment record from Lake Rutundu, Kenya

    NASA Astrophysics Data System (ADS)

    De Cort, Gijs; Creutz, Mike; Barao, Lucia; Conley, Daniel; Haug, Gerald; Bodé, Samuel; Blaauw, Maarten; Engstrom, Dan; Verschuren, Dirk

    2015-04-01

    Following the generally arid conditions of the Last Glacial Maximum (LGM), a large part of the African continent experienced the Early to Mid-Holocene as a much more humid period than today. This so-called African Humid Period (AHP) coincided with high summertime insolation over the Northern Hemisphere subtropics, causing invigorated monsoons to create moist conditions over the northern parts of the continent. Similarly, equatorial and even low-latitude southeastern Africa experienced a wetter climate due to the post-glacial increase in atmospheric greenhouse gasses ultimately leading to altered Atlantic and Indian Ocean monsoon dynamics. The timing and abruptness of the onset and ending of the AHP in the different regions of the continent have been the subject of major discussion. On the other hand, shorter-lived climate fluctuations within the AHP have received much less attention, due to a scarcity of well-dated, high-resolution African paleoclimate records spanning the entire Holocene. In this study we used the sediment record of Lake Rutundu, a high-altitude crater lake on Mount Kenya, to document multidecadal to millennial-scale hydroclimate variability on the East African equator from the LGM to the present. A multiproxy approach combining core-surface scanning techniques (magnetic susceptibility, X-ray fluorescence) and close-interval bulk-sediment analyses (organic matter and biogenic Si content, grain size, organic δ15N and δ13C) resulted in a high-resolution record firmly anchored in time by an age model based on 210Pb dating and sixteen calibrated radiocarbon ages. This new Lake Rutundu hydroclimate record confirms that moister conditions following the LGM returned to East Africa ca.16 kyr BP, and it contains a perfectly timed Younger Dryas episode (12.8-11.5 kyr BP) of intermittent drought. We find that the Early- to Mid-Holocene period, which in African records is often described as uniformly wet, was in fact punctuated by three distinct, century

  16. A new species of arboreal forest-dwelling gecko (Hemidactylus: Squamata: Gekkonidae) from coastal Kenya, East Africa.

    PubMed

    Malonza, Patrick K; Bauer, Aaron M

    2014-01-01

    A new species of Hemidactylus, H. mrimaensis sp. nov., is described from coastal kaya forests of Kenya. This small-sized, arboreal gecko may be distinguished from its probable close relative, the sympatric H. mabouia, by its more slender habitus, golden color, small adult body length (maximum SVL 50 mm in females) and features of scalation including keeled dorsal tubercles in 11-14 longitudinal rows, pointed tubercles on tail larger than those on the dorsum, and 32-34 precloacal pores in males. This gecko may be endemic to the coastal forests and given the ongoing threats to this habitat, the species is of high conservation concern. PMID:24869535

  17. Late Cenozoic Moisture History of East Africa

    NASA Astrophysics Data System (ADS)

    Trauth, M. H.; Maslin, M. A.; Deino, A.; Strecker, M. R.

    2004-12-01

    Evidence from fluvio-lacustrine sediments in ten separate basins in the Ethiopian and Kenya rifts suggests there were three protracted humid periods during the Late Cenozoic; at 2.7 - 2.5, 1.9 - 1.7, and 1.1 - 0.9 million years before present. These wet periods are coeval with known increases of aridity in parts of North West and North East Africa, indicating significant regional shifts in African climate. These three East African wet periods correspond to major global climatic changes as well as maxima in eccentricity and thus precession, suggesting a combined global and local causation. These climatic changes were important for the speciation and dispersal of mammals and hominids in East Africa as it implies that key steps in human evolution occurred during relatively humid periods in a region containing extensive deep lakes.

  18. Kenya.

    PubMed

    1988-01-01

    Attention in this discussion of Kenya is directed to the following: geography; people; history; government; political conditions; the economy; defense; and relations between Kenya and the US. In 1987, the population was estimated at 21.6 million with an estimated annual growth rate of 4.1%. Traditional herders, Arab Muslims, and cosmopolitan residents of Nairobi all contribute to the culture of Kenya. The standard of living in major cities is among the highest in sub-Saharan Africa. Fossils located in east Africa suggest that protohumans roamed the area more than 20 million years ago. Recent anthropological finds near Kenya's Lake Turkana indicate that the "Homo" genus of humans lived in the area 2.6 million years ago. Kenya's colonial history dates from the Berlin conference of 1885. In 1895, the British government established the East African Protectorate and, soon after, opened the fertile highlands to white settlers. The settlers were allowed a voice in government before it officially was made a British colony in 1920, but Africans were not permitted any direct political participation until 1944. Kenya became independent on December 12, 1963, and in 1964 assumed the status of a republic within the Commonwealth. The president is elected by the National Assembly to serve a 5-year term, but if the president dissolves the assembly, a new presidential election must be held. Since independence, Kenya has maintained remarkable stability during many changes within the democratic system. Kenya's major political challenge is to reinvigorate its economy, which has suffered from a combination of problems such as government deficit spending, a chronic shortage of foreign exchange, and the rising cost of oil imports. Economic growth has declined since 1973, and real gross domestic product (GDP) has grown only by about 2.75% for the 1980-86 period. One of Kenya's basic problems is its population growth rate. With less than 20% of the land classified as potentially arable and

  19. Does Family Background Matter for Learning in East Africa?

    ERIC Educational Resources Information Center

    Jones, Sam; Schipper, Youdi

    2015-01-01

    The extent to which differences in family background characteristics explain differences in learning outcomes between children captures the extent of equality in educational opportunities. This study uses large-scale data on literacy and numeracy outcomes for children of school age across East Africa (Kenya, Tanzania and Uganda) to investigate the…

  20. Cenozoic extension in the Kenya Rift from low-temperature thermochronology: Links to diachronous spatiotemporal evolution of rifting in East Africa

    NASA Astrophysics Data System (ADS)

    Torres Acosta, Verónica; Bande, Alejandro; Sobel, Edward R.; Parra, Mauricio; Schildgen, Taylor F.; Stuart, Finlay; Strecker, Manfred R.

    2015-12-01

    The cooling history of rift shoulders and the subsidence history of rift basins are cornerstones for reconstructing the morphotectonic evolution of extensional geodynamic provinces, assessing their role in paleoenvironmental changes and evaluating the resource potential of their basin fills. Our apatite fission track and zircon (U-Th)/He data from the Samburu Hills and the Elgeyo Escarpment in the northern and central sectors of the Kenya Rift indicate a broadly consistent thermal evolution of both regions. Results of thermal modeling support a three-phased thermal history since the early Paleocene. The first phase (~65-50 Ma) was characterized by rapid cooling of the rift shoulders and may be coeval with faulting and sedimentation in the Anza Rift basin, now located in the subsurface of the Turkana depression and areas to the east in northern Kenya. In the second phase, very slow cooling or slight reheating occurred between ~45 and 15 Ma as a result of either stable surface conditions, very slow exhumation, or subsidence. The third phase comprised renewed rapid cooling starting at ~15 Ma. This final cooling represents the most recent stage of rifting, which followed widespread flood-phonolite emplacement and has shaped the present-day landscape through rift shoulder uplift, faulting, basin filling, protracted volcanism, and erosion. When compared with thermochronologic and geologic data from other sectors of the East African Rift System, extension appears to be diachronous, spatially disparate, and partly overlapping, likely driven by interactions between mantle-driven processes and crustal heterogeneities, rather than the previously suggested north-south migrating influence of a mantle plume.

  1. Paleoenvironmental context of the Middle Stone Age record from Karungu, Lake Victoria Basin, Kenya, and its implications for human and faunal dispersals in East Africa.

    PubMed

    Faith, J Tyler; Tryon, Christian A; Peppe, Daniel J; Beverly, Emily J; Blegen, Nick; Blumenthal, Scott; Chritz, Kendra L; Driese, Steven G; Patterson, David

    2015-06-01

    The opening and closing of the equatorial East African forest belt during the Quaternary is thought to have influenced the biogeographic histories of early modern humans and fauna, although precise details are scarce due to a lack of archaeological and paleontological records associated with paleoenvironmental data. With this in mind, we provide a description and paleoenvironmental reconstruction of the Late Pleistocene Middle Stone Age (MSA) artifact- and fossil-bearing sediments from Karungu, located along the shores of Lake Victoria in western Kenya. Artifacts recovered from surveys and controlled excavations are typologically MSA and include points, blades, and Levallois flakes and cores, as well as obsidian flakes similar in geochemical composition to documented sources near Lake Naivasha (250 km east). A combination of sedimentological, paleontological, and stable isotopic evidence indicates a semi-arid environment characterized by seasonal precipitation and the dominance of C4 grasslands, likely associated with a substantial reduction in Lake Victoria. The well-preserved fossil assemblage indicates that these conditions are associated with the convergence of historically allopatric ungulates from north and south of the equator, in agreement with predictions from genetic observations. Analysis of the East African MSA record reveals previously unrecognized north-south variation in assemblage composition that is consistent with episodes of population fragmentation during phases of limited dispersal potential. The grassland-associated MSA assemblages from Karungu and nearby Rusinga Island are characterized by a combination of artifact types that is more typical of northern sites. This may reflect the dispersal of behavioral repertoires-and perhaps human populations-during a paleoenvironmental phase dominated by grasslands. PMID:25883052

  2. East African and Kuunga Orogenies in Tanzania - South Kenya

    NASA Astrophysics Data System (ADS)

    Fritz, H.; Hauzenberger, C. A.; Tenczer, V.

    2012-04-01

    ) (Fritz et al., 2009). Majority of data suggest an anticlockwise P-T loop and prolonged, slow cooling at deep crustal levels without significant exhumation. Isobaric cooling is explained by horizontal flow with rates faster than thermal equilibration of the lower crust. Those settings are found in domains of previously thinned lithosphere such as extended passive margins. Such rheolgically weak plate boundaries do not produce self-sustaining one-sided subduction but large areas of magmatic underplating that enable melt enhanced lateral flow of the lower crust. Western Granulites deformed by high-vorticity westwards thrusting at c. 550 Ma (Kuunga orogeny). Rocks exhibit clockwise P-T paths and experienced significant exhumation during isothermal decompression. Overprint between Kuungan structures and 620 Ma East African fabrics resulted in complex interference pattern within the Eastern Granulites. The three orogen portions that converge in Tanzania / Southern Kenya have different orogen styles. The southern ANS formed by transcurrent deformation of an island arc root; the Eastern Granulites by lower crustal channelized flow of a hot inverted passive margin; the Western Granulites by lower to mid crustal stacking of old and cold crustal fragments. Collins, A.S., Pisarevsky, S.A. (2005). Amalgamating eastern Gondwana: The evolution of the Circum-Indian Orogens. Earth-Science Reviews, 71, 229-270. De Waele, B., Kampunzu, A.B., Mapani, B.S.E., Tembo, F. (2006). The Mesoproterozoic Irumide belt of Zambia. Journal of African Earth Sciences, 46, 36-70 Fritz, H., Tenczer, V., Hauzenberger, C., Wallbrecher, E., Muhongo, S. (2009). Hot granulite nappes — Tectonic styles and thermal evolution of the Proterozoic granulite belts in East Africa. Tectonophysics, 477, 160-173.

  3. East Africa continental margins

    SciTech Connect

    Bosellini, A.

    1986-01-01

    New well data from Somalia, together with the history of sea-floor spreading in the Indian Ocean derived from magnetic anomalies, show that the East African margins from latitude 15/sup 0/S into the Gulf of Aden comprise four distinct segments that formed successively by the southward drift of Madagascar from Somalia during the Middle to Late Jurassic and Early Cretaceous, by the northeastward drift of India along the Owen Transform during the Late Cretaceous and Paleocene, and by the opening of the Gulf of Aden during the Neogene.

  4. A Scientific note on Varroa mites found in East Africa; Threat or Opportunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Varroa mites have devastated Apis mellifera L. honeybee populations wherever they co-occur around the world, yet in East Africa these mites may have finally met their match. Varroa destructor Anderson and Truman (Acari:Varroidae) was found in Kenya and Tanzania for the first time in early 2009, but...

  5. Evaluating the Madrasa Preschool Programme in East Africa: A Quasi-Experimental Study

    ERIC Educational Resources Information Center

    Mwaura, Peter A. M.; Sylva, Kathy; Malmberg, Lars-Erik

    2008-01-01

    This study investigated the effect of preschool experience (two types of preschool: Madrasa and non-Madrasa) on the cognitive development of children in East Africa. In the three countries studied (Kenya, Uganda, and Tanzania/Zanzibar) preschool education is burgeoning and government standards are being set. This quasi experimental evaluation used…

  6. Kenya.

    PubMed

    Obura, D O

    2001-12-01

    The Kenya coast is bathed by the northward-flowing warm waters of the East Africa Coastal Current, located between latitudes 1 and 5 degrees S. With a narrow continental shelf, the coastal marine environments are dominated by coral reefs, seagrass beds and mangroves, with large expanses of sandy substrates where river inputs from Kenya's two largest rivers, the Tana and Athi rivers, prevent the growth of coral reefs. The northern part of the coast is seasonally influenced by upwelling waters of the Somali Current, resulting in lower water temperatures for part of the year. The coast is made up of raised Pleistocene reefs on coastal plains and hills of sedimentary origin, which support native habitats dominated by scrub bush and remnant pockets of the forests that used to cover East Africa and the Congo basin. The marine environment is characterized by warm tropical conditions varying at the surface between 25 degrees C and 31 degrees C during the year, stable salinity regimes, and moderately high nutrient levels from terrestrial runoff and groundwater. The semi-diurnal tidal regime varies from 1.5 to 4 m amplitude from neap to spring tides, creating extensive intertidal platform and rocky-shore communities exposed twice-daily during low tides. Fringing reef crests dominate the whole southern coast and parts of the northern coast towards Somalia, forming a natural barrier to the wave energy from the ocean. Coral reefs form the dominant ecosystem along the majority of the Kenya coast, creating habitats for seagrasses and mangroves in the lagoons and creeks protected by the reef crests. Kenya's marine environment faces a number of threats from the growing coastal human population estimated at just under three million in 2000. Extraction of fish and other resources from the narrow continental shelf, coral reef and mangrove ecosystems increases each year with inadequate monitoring and management structures to protect the resource bases. Coastal development in urban and

  7. Development of a Testate Amoebae Calibration Dataset from a freshwater wetland in a semi-arid environment: Loboi Swamp, Kenya, East Africa.

    NASA Astrophysics Data System (ADS)

    Goman, M. F.; Ashley, G. M.; Hover, V. C.; Muasya, A. M.

    2005-12-01

    The East African Rift Valley is characterized as an arid to semi-arid region, with several large, well studied, alkaline lakes; within the region, freshwater wetlands persist. These wetland systems, locally are important sources of freshwater. They also provide overlooked important paleoclimate archives, as the fragile ecology of these wetlands can be affected by even minor changes in hydrology and climate. Loboi Swamp is a 1.5 km2 freshwater wetland located near the equator in the Kenyan Rift Valley. The region receives approximately 700 mm of precipitation per year, while potential evaporation exceeds 2500 mm annually. Analysis of 25-years of precipitation data from local weather stations indicate that significant positive precipitation anomalies occur during El Niño years. Radiocarbon, pollen, and diatom data from Loboi Swamp indicates that the current wetland developed approximately 700 years ago. Sediment surface samples were collected for pollen, seeds and testate amoebae, along with water chemistry and vegetation data from throughout the Loboi Marsh. In this paper we present preliminary data and results in the development of a calibration dataset to test the feasibility of using testate amoebae as a proxy for hydrological and geochemical changes in a semi-arid setting. Initial results indicate significant qualitative differences in testate amoebae taxon distribution within geographic regions of the marsh, which likely correlate with a variety of hydrologic parameters (e.g., alkalinity, PH, DO, and temperature).

  8. Assessing the status of food safety management systems for fresh produce production in East Africa: evidence from certified green bean farms in Kenya and noncertified hot pepper farms in Uganda.

    PubMed

    Nanyunja, J; Jacxsens, L; Kirezieva, K; Kaaya, A N; Uyttendaele, M; Luning, P A

    2015-06-01

    The farms of fresh produce farmers are major sources of food contamination by microbiological organisms and chemical pesticides. In view of their choice for farming practices, producers are influenced by food safety requirements. This study analyzes the role of food safety standard certification toward the maturity of food safety management systems (FSMS) in the primary production of fresh produce. Kenya and Uganda are two East African countries that export green beans and hot peppers, respectively, to the European Union but have contrasting features in terms of agricultural practices and certification status. In the fresh produce chain, a diagnostic instrument for primary production was used to assess context factors, core control and assurance activities, and system output to measure the performance of FSMS for certified green bean farms in Kenya and noncertified hot pepper farms in Uganda. Overall, our findings show that in Uganda, noncertified hot pepper farms revealed only a "basic level of control and assurance" activities in their FSMS, which was not satisfactory, because no insight into potential pesticide microbial contamination was presented by these farmers. On the other hand, certified green bean farms in Kenya had an "average level of control and assurance," providing insight into the delivered food safety and quality by the farmers. Farm size did not impact the maturity level of FSMS. This study confirms the role played by food safety standard certification toward the maturity of FSMS implemented in developing countries and demonstrates the possibility of Ugandan farms to upgrade agricultural practices in the fresh produce sector. PMID:26038896

  9. An age for Kajong, a Miocene fossil site east of Lake Turkana, Kenya

    NASA Astrophysics Data System (ADS)

    Brown, Francis H.; Jicha, Brian R.; Leakey, R. E.

    2016-02-01

    The Kajong Formation in Marsabit District, northern Kenya has yielded a Miocene mammalian fauna consisting of nine taxa. It is capped by a basalt 40Ar/39Ar dated at 19.1 ± 0.1 Ma, and a volcanic clast from a conglomerate within the formation yielded an age of 20.3 Ma, only slightly older. The entire fauna from this site thus lies close to the base of the Miocene Epoch and is older than 19.2 Ma. The site has yielded some of the oldest examples of Archaeobelodon filholi, Prodeinotherium hobleyi, and Gomphotherium sp. in east Africa.

  10. Terrestrial heat flow in east and southern Africa

    NASA Astrophysics Data System (ADS)

    Nyblade, Andrew A.; Pollack, Henry N.; Jones, D. L.; Podmore, Francis; Mushayandebvu, Martin

    1990-10-01

    We report 26 new heat flow and 13 radiogenic heat production measurements from Zimbabwe, Zambia and Tanzania, together with details and some revisions of 18 previous heat flow measurements by other investigators from Kenya and Tanzania. These measurements come from Archean cratons, Proterozoic mobile belts, and Mesozoic and Cenozoic rifts. Heat flow data from eight new sites in the Archean Zimbabwe Craton are consistent with previous measurements in the Archean Kaapvaal-Zimbabwe Craton and Limpopo Belt (Kalahari Craton) and do not change the mean heat flow of 47±2 mW m-2 (standard error of the mean) in the Kalahari Craton based on 53 previous measurements. Eight new sites in the Archean Tanzania Craton give a mean heat flow of 34±4 mW m-2. The mean heat flow from nine sites in the Proterozoic Mozambique Belt to the east of the Tanzania Craton in Kenya and Tanzania is 47±4 mW m-2. Twelve measurements in the Mesozoic rifted continental margin in east Africa give a mean heat flow of 68±4 mW m-2; four measurements in the Mesozoic Luangwa and Zambezi Rifts range from 44 to 110 mW m-2 with a mean of 76±14 mW m-2. In comparing heat flow in east and southern Africa, we observe a common heat flow pattern of increasing heat flow away from the centers of the Archean cratons. This pattern suggests a fundamental difference in lithospheric thermal structure between the Archean cratons and the Proterozoic and early Paleozoic mobile belts which surround them. Superimposed on this common pattern are two regional variations in heat flow. Heat flow in the Tanzania Craton is lower by about 13 mW m-2 than in the Kalahari Craton, and in the Mozambique Belt in east Africa heat flow is somewhat lower than in the southern African mobile belts at similar distances from the Archean cratonic margin. The two regional variations can be explained in several ways, none of which can as yet be elevated to a preferred status: (1) by variations in crustal heat production, (2) by thin

  11. East Africa seminar and workshop of remote sensing of natural resources and environment

    USGS Publications Warehouse

    Deutsch, Morris

    1975-01-01

    Report on total program covering East Africa Seminar and Workshop on remote sensing of natural resources and the environment held in Nairobi, Kenya, March 21 April 3, 1974, attended by participants from 10 English-speaking African nations. Appendices are included for Seminar proceedings, workshop lectures and outlines, field trip reports and critiques by participants, and reports on potential applications of an operational earth resources satellite for the participating countries.

  12. Reduced interannual rainfall variability in East Africa during the last ice age.

    PubMed

    Wolff, Christian; Haug, Gerald H; Timmermann, Axel; Sinninghe Damsté, Jaap S; Brauer, Achim; Sigman, Daniel M; Cane, Mark A; Verschuren, Dirk

    2011-08-01

    Interannual rainfall variations in equatorial East Africa are tightly linked to the El Niño Southern Oscillation (ENSO), with more rain and flooding during El Niño and droughts in La Niña years, both having severe impacts on human habitation and food security. Here we report evidence from an annually laminated lake sediment record from southeastern Kenya for interannual to centennial-scale changes in ENSO-related rainfall variability during the last three millennia and for reductions in both the mean rate and the variability of rainfall in East Africa during the Last Glacial period. Climate model simulations support forward extrapolation from these lake sediment data that future warming will intensify the interannual variability of East Africa's rainfall. PMID:21817050

  13. Study of the genetic heterogeneity of SAT-2 foot-and-mouth disease virus in sub-Saharan Africa with specific focus on East Africa.

    PubMed

    Sahle, M; Dwarka, R M; Venter, E H; Vosloo, W

    2007-12-01

    The epidemiology of serotype SAT-2 foot-and-mouth disease was investigated in sub-Saharan Africa by phylogenetic analysis using the 1D gene encoding the major antigenic determinant. Fourteen genotypes were identified of which three are novel and belong to East Africa, bringing the total number of genotypes for that region to eight. The genotypes clustered into three lineages that demonstrated surprising links between East, southern and south-western Africa. One lineage was unique to West Africa. These results established numerous incursions across country borders in East Africa and long term conservation of sequences for periods up to 41 years. Ethiopia, Kenya and Uganda have all experienced outbreaks from more than one unrelated strain, demonstrating the potential for new introductions. The amount of variation observed within this serotype nearly equalled that which was found between serotypes; this has severe implications for disease control using vaccination. PMID:18453238

  14. Predictability of rainy season onset and cessation in east Africa

    NASA Astrophysics Data System (ADS)

    Joseph, B.-M.

    2012-04-01

    PREDICTABILITY OF RAINY SEASONS ONSET AND CESSATION IN EAST AFRICA Boyard-Micheau Joseph, joseph.boyard-micheau@u-bourgogne.fr Camberlin Pierre, Kenya and northern Tanzania mainly display bimodal rainfall regimes, which are controlled by the annual migration of the Intertropical Convergence Zone on both sides of the equator. In the low-income, semi-arid areas, food security is highly dependent on cereal yields (maize, millet and sorghum). Vulnerability is aggravated by the fact that these crops are mostly rainfed, and rely on the performance of the two, relatively brief rainy seasons. This performance depends on a combination of several rainy season characteristics, or rainfall descriptors, such as the onset and cessation dates of the rains, the frequency of rainy days, their intensity and the occurrence of wet/dry spells. The prediction of these descriptors some time (>15 days) before the real onset of the rainy season can be seen as a useful tool to help in the establishment of agricultural adaptation strategies. The main objective consists to understand linkages between regional variability of these rainfall descriptors and global modes of the climate system, in order to set up efficient predictive tools based on Model Output Statistics (MOS). The rainfall descriptors are computed from daily rainfall data collected for the period 1961-2001 from the Kenya Meteorological Department, the IGAD Climate Prediction and Application Center and the Tanzania Meteorological Agency. An initial spatial coherence analysis assesses the potential predictability of each descriptor, permitting eventually to eliminate those which are not spatially coherent, on the assumption that low spatial coherence denotes low potential predictability. Rainfall in East Africa simulated by a 24-ensemble member of the ECHAM 4.5 atmospheric general circulation model is compared with observations, to test the reproducibility of the rainfall descriptors. Canonical Correlation Analysis is next used to

  15. Late Cenozoic Moisture History of East Africa

    NASA Astrophysics Data System (ADS)

    Trauth, Martin H.; Maslin, Mark A.; Deino, Alan; Strecker, Manfred R.

    2005-09-01

    Lake sediments in 10 Ethiopian, Kenyan, and Tanzanian rift basins suggest that there were three humid periods at 2.7 to 2.5 million years ago (Ma), 1.9 to 1.7 Ma, and 1.1 to 0.9 Ma, superimposed on the longer-term aridification of East Africa. These humid periods correlate with increased aridity in northwest and northeast Africa and with substantial global climate transitions. These episodes could have had important impacts on the speciation and dispersal of mammals and hominins, because a number of key events, such as the origin of the genus Homo and the evolution of the species Homo erectus, took place in this region during that time.

  16. Mesozoic and early Tertiary rift tectonics in East Africa

    NASA Astrophysics Data System (ADS)

    Bosworth, William

    1992-08-01

    A complex history of crustal extension occurred in east and central Africa during the Mesozoic and early Tertiary. Beginning in the Late Jurassic, this resulted in a large system of rifts, the Central African rift system, that spanned from central Sudan to southern Kenya. Late Jurassic rifting is best documented in the White and Blue Nile rifts of the Sudan, and records east-west extension in half-graben that were connected by large-scale shear zones and pull-apart basins. Early Cretaceous rifting re-activated Jurassic basins and spread to the large South Sudan rifts and Anza rift in Kenya. By the Late Cretaceous, the extension direction shifted to the NE-SW, and the presently observed large-scale rift geometry was established. In the early Tertiary, some Mesozoic basins were again reactivated, while other regions underwent wrench faulting and basin inversion. The large number of basins preserved in the Central African rift system can be used to construct an evolutionary model of continental rift tectonics. Early phases of extension at low strains produced alternating half-graben/accommodation zone geometries similar to those observed in most young and active continental rifts. At higher strains, some border faults were abandoned so that through-going, simpler active fault systems could evolve. This is interpreted as representing a switch from complex, oppositely dipping detachment structures, with strike dimensions of 50-150 km, to regional detachment structures that continue for hundreds of kilometers parallel to the rift. This change in the type of detachment was accompanied by a shift in the position of the subsidence away from the breakaway to a position focused further within the regional upper plate. Non-rotational, high angle, normal faulting dominates in the development of these late basin geometries. Deciphering similar rift basin histories from passive continental margins may, in many cases, exceed the limits of available reflection seismic data. East

  17. A biocultural framework for examining maternal cravings and aversions among pastoral women in east Africa.

    PubMed

    Young, Alyson G; Pike, Ivy L

    2012-01-01

    Food preferences during pregnancy result from a complex set of biocultural interactions with important implications for maternal and child health. This article explores the social context of maternal food choice in marginal environments of East Africa. Biocultural data collected among Turkana and Datoga women living in Kenya and Tanzania indicate there is a significant social context to food choice that influences the types of food that women report craving and the food that is consumed. Our framework argues for a deeper understanding of how culture shapes food preferences and how marginalization can constrain access to favored and healthy foods. PMID:22881360

  18. Khat in East Africa: taking women into or out of sex work?

    PubMed

    Beckerleg, Susan

    2008-07-01

    Women's drug use is often associated with sex work as a means of raising money for consumption. Similarly, in Kenya and Uganda, journalists, the general public and aid agencies associate female consumption of the stimulant drug, khat (Catha edulis), as pulling women into prostitution. In contrast to Yemen and Ethiopia, these views are expressed by people living in areas where there are no rituals or traditions of female khat consumption. This paper presents data from a study carried out in Kenya and Uganda in 2004 and 2005 that documents that the majority of women engaging in khat chewing are not sex workers. Frequently, however, women who retail khat are often assumed by men to be sexually immoral. The role of women in the retail and wholesale khat trade is examined. The stigma attached to selling khat is linked to the overall situation of independent women in East Africa and the place of commercial sex in urban life. PMID:18649237

  19. Recent outbreaks of rift valley Fever in East Africa and the middle East.

    PubMed

    Himeidan, Yousif E; Kweka, Eliningaya J; Mahgoub, Mostafa M; El Rayah, El Amin; Ouma, Johnson O

    2014-01-01

    Rift Valley fever (RVF) is an important neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health. Mosquitoes in the Aedes genus have been considered as the reservoir, as well as vectors, since their transovarially infected eggs withstand desiccation and larvae hatch when in contact with water. However, different mosquito species serve as epizootic/epidemic vectors of RVF, creating a complex epidemiologic pattern in East Africa. The recent RVF outbreaks in Somalia (2006-2007), Kenya (2006-2007), Tanzania (2007), and Sudan (2007-2008) showed extension to districts, which were not involved before. These outbreaks also demonstrated the changing epidemiology of the disease from being originally associated with livestock, to a seemingly highly virulent form infecting humans and causing considerably high-fatality rates. The amount of rainfall is considered to be the main factor initiating RVF outbreaks. The interaction between rainfall and local environment, i.e., type of soil, livestock, and human determine the space-time clustering of RVF outbreaks. Contact with animals or their products was the most dominant risk factor to transfer the infection to humans. Uncontrolled movement of livestock during an outbreak is responsible for introducing RVF to new areas. For example, the virus that caused the Saudi Arabia outbreak in 2000 was found to be the same strain that caused the 1997-98 outbreaks in East Africa. A strategy that involves active surveillance with effective case management and diagnosis for humans and identifying target areas for animal vaccination, restriction on animal movements outside the affected areas, identifying breeding sites, and targeted intensive mosquito control programs has been shown to succeed in limiting the effect of RVF outbreak and curb the spread of the disease from the onset. PMID:25340047

  20. Recent Outbreaks of Rift Valley Fever in East Africa and the Middle East

    PubMed Central

    Himeidan, Yousif E.; Kweka, Eliningaya J.; Mahgoub, Mostafa M.; El Rayah, El Amin; Ouma, Johnson O.

    2014-01-01

    Rift Valley fever (RVF) is an important neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health. Mosquitoes in the Aedes genus have been considered as the reservoir, as well as vectors, since their transovarially infected eggs withstand desiccation and larvae hatch when in contact with water. However, different mosquito species serve as epizootic/epidemic vectors of RVF, creating a complex epidemiologic pattern in East Africa. The recent RVF outbreaks in Somalia (2006–2007), Kenya (2006–2007), Tanzania (2007), and Sudan (2007–2008) showed extension to districts, which were not involved before. These outbreaks also demonstrated the changing epidemiology of the disease from being originally associated with livestock, to a seemingly highly virulent form infecting humans and causing considerably high-fatality rates. The amount of rainfall is considered to be the main factor initiating RVF outbreaks. The interaction between rainfall and local environment, i.e., type of soil, livestock, and human determine the space-time clustering of RVF outbreaks. Contact with animals or their products was the most dominant risk factor to transfer the infection to humans. Uncontrolled movement of livestock during an outbreak is responsible for introducing RVF to new areas. For example, the virus that caused the Saudi Arabia outbreak in 2000 was found to be the same strain that caused the 1997–98 outbreaks in East Africa. A strategy that involves active surveillance with effective case management and diagnosis for humans and identifying target areas for animal vaccination, restriction on animal movements outside the affected areas, identifying breeding sites, and targeted intensive mosquito control programs has been shown to succeed in limiting the effect of RVF outbreak and curb the spread of the disease from the onset. PMID:25340047

  1. The Precambrian crustal structure of East Africa

    NASA Astrophysics Data System (ADS)

    Tugume, Fred Alex

    In this thesis, the Precambrian crustal structure of East African is investigated along with the crustal structures of three Cenozoic rift basins located in the western branch of the East African Rift System (EARS). In the first part of the thesis, P-wave receiver functions are modeled using the H-k method to obtain new insights about the bulk composition and thickness of the crust for Precambrian terrains throughout East Africa. The average crustal thickness for all but one of the terrains is between 37 and 39 km. An exception is the Ubendian terrain, which has an average crustal thickness 42 km. In all terrains, the average Poisson's ratio is similar, ranging from 0.25 to 0.26, indicating a bulk crustal composition that is felsic to intermediate. The main finding of this study is that crustal structure is similar across all terrains, which span more than 4.0 Ga of earth history. There is no discernable difference in the crustal thicknesses and Poisson's ratios between the Archean and Proterozoic terrains, or between the Proterozoic terrains, unlike the variability in Precambrian crustal structure found in many other continents. In the second part of the thesis, a joint inversion of Rayleigh wave phase and group velocities and receiver functions was used to investigate the shear wave velocity structure of the crust and uppermost mantle beneath the Precambrian terrains of East Africa. In comparison with other areas of similar age in southern and western Africa where the same joint inversion method has been applied, I find that while there is little difference in the mean shear wave velocities for the entire crust across all of the Precambrian terrains, and also few differences in the thickness of the crust, there exists substantial variability in lower crustal structure. This variability is reflected primarily in the thickness of the lower crustal layers with shear wave velocities ≥ 4.0 km/s. This variability is found both within terrains of the same age (i

  2. The importance of context in delivering effective EIA: Case studies from East Africa

    SciTech Connect

    Marara, Madeleine; Okello, Nick; Kuhanwa, Zainab; Douven, Wim; Beevers, Lindsay Leentvaar, Jan

    2011-04-15

    This paper reviews and compares the condition of the environmental impact assessment (EIA) system in three countries in the East Africa region: Kenya, Rwanda and Tanzania. The criteria used for the evaluation and the comparison of each system are based on the elements of the legal, administrative and procedural frameworks, as well as the context in which they operate. These criteria are adapted from the evaluation and quality control criteria derived from a number of literature sources. The study reveals that the EIA systems of Kenya and Tanzania are at a similar stage in their development. The two countries, the first to introduce the EIA concept into their jurisdiction in this part of Africa, therefore have more experience than Rwanda in the practice of environmental impact assessment, where the legislation and process requires more time to mature both from the governmental and societal perspective. The analysis of the administrative and procedural frameworks highlights the weakness in the autonomy of the competent authority, in all three countries. Finally a major finding of this study is that the contextual set up i.e. the socio-economic and political situation plays an important role in the performance of an EIA system. The context in developing countries is very different from developed countries where the EIA concept originates. Interpreting EIA conditions in countries like Kenya, Rwanda and Tanzania requires that the analysis for determining the effectiveness of their systems should be undertaken within a relevant framework, taking into account the specific requirements of those countries.

  3. Rainfall and drought in equatorial east Africa during the past 1,100 years.

    PubMed

    Verschuren, D; Laird, K R; Cumming, B F

    2000-01-27

    Knowledge of natural long-term rainfall variability is essential for water-resource and land-use management in sub-humid regions of the world. In tropical Africa, data relevant to determining this variability are scarce because of the lack of long instrumental climate records and the limited potential of standard high-resolution proxy records such as tree rings and ice cores. Here we present a decade-scale reconstruction of rainfall and drought in equatorial east Africa over the past 1,100 years, based on lake-level and salinity fluctuations of Lake Naivasha (Kenya) inferred from three different palaeolimnological proxies: sediment stratigraphy and the species compositions of fossil diatom and midge assemblages. Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the 'Medieval Warm Period' (approximately AD 1000-1270) and a relatively wet climate during the 'Little Ice Age' (approximately AD 1270-1850) which was interrupted by three prolonged dry episodes. We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development. PMID:10667789

  4. Somalian Earthquakes of May, 1980, East Africa

    SciTech Connect

    Ruegg, J.C.; Lepine, J.C.; Tarantola, A.; Leveque, J.J.

    1981-04-01

    A seismic crisis, with a m/sub b/ = 5.3 main shock, occured in the Somali Republic East Africa (10 /sup 0/N, 43 /sup 0/E) from April to November 1980. Up to 2000 earthquakes with M/sub L/>2 have been recorded during this period. This earthquake sequence is of particular interest because it occurred in a seismically inactive zone and include a rather long aftershock sequence. Two groups of epicenters were identified using a relative location procedure. Aftershocks observed during the first two weeks fall very close to the Borama City, while latter shocks are situated 10km west. This may suggest that the second group of earthquakes has been induced continental margin between the Somalian Plateau shield and the quasi-oceanic crust of the Afar-Gulf of Aden region, remains active to day and is relevant to intraplate seismicity.

  5. Pastoral and environmental security in East Africa.

    PubMed

    Ornas, A H

    1990-06-01

    The most vulnerable people in Third World countries are often accused of destroying forests and fragile ecosystems and of practising destructive forms of agriculture and animal husbandry. The key to environmental sustainability, however, lies in more reliable production and food security at the local level. This article focuses on individual and household security amongst dryland herders in East Africa. The most crucial aspect of pastoral viability is the maintenance of a balance between family herd and size of household. Risk-spreading, through dependence on relatives, the borrowing of animals, redistribution through marriage etc. is a general principle of social behaviour amongst these peoples. Consideration of local-level security, furthermore, reveals the connection between ecological stress and political conflict. Only by establishing secure access to food for individuals and families can sustainable development and political security, not only at the local but also at the national and international levels, be achieved. PMID:20958697

  6. Linguistic Human Rights in Africa: Challenges and Prospects for Indigenous Languages in Kenya

    ERIC Educational Resources Information Center

    Musau, Paul M.

    2003-01-01

    With reference to Kenya, the paper shows that although linguistic rights have been eloquently articulated in various charters and declarations, their implementation has been problematic. In Africa this has led to an imbalance of status between the former colonial languages and the indigenous ones. This imbalance is evident in the educational…

  7. Learning To Compete: Education, Training & Enterprise in Ghana, Kenya & South Africa. Education Research Paper.

    ERIC Educational Resources Information Center

    Afenyadu, Dela; King, Kenneth; McGrath, Simon; Oketch, Henry; Rogerson, Christian; Visser, Kobus

    A multinational, multidisciplinary team examined the impact of globalization on education, training, and small and medium sized enterprise development in Ghana, Kenya, and South Africa. The study focused on the following issues: developing a learner-led competitiveness approach; building learning enterprises; education for microenterprises and…

  8. Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya.

    PubMed

    Spoor, F; Leakey, M G; Gathogo, P N; Brown, F H; Antón, S C; McDougall, I; Kiarie, C; Manthi, F K; Leakey, L N

    2007-08-01

    Sites in eastern Africa have shed light on the emergence and early evolution of the genus Homo. The best known early hominin species, H. habilis and H. erectus, have often been interpreted as time-successive segments of a single anagenetic evolutionary lineage. The case for this was strengthened by the discovery of small early Pleistocene hominin crania from Dmanisi in Georgia that apparently provide evidence of morphological continuity between the two taxa. Here we describe two new cranial fossils from the Koobi Fora Formation, east of Lake Turkana in Kenya, that have bearing on the relationship between species of early Homo. A partial maxilla assigned to H. habilis reliably demonstrates that this species survived until later than previously recognized, making an anagenetic relationship with H. erectus unlikely. The discovery of a particularly small calvaria of H. erectus indicates that this taxon overlapped in size with H. habilis, and may have shown marked sexual dimorphism. The new fossils confirm the distinctiveness of H. habilis and H. erectus, independently of overall cranial size, and suggest that these two early taxa were living broadly sympatrically in the same lake basin for almost half a million years. PMID:17687323

  9. Hydrocarbon potential of the Lamu basin of south-east Kenya

    SciTech Connect

    Nyagah, K.; Cloeter, J.J.; Maende, A. )

    1996-01-01

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

  10. Hydrocarbon potential of the Lamu basin of south-east Kenya

    SciTech Connect

    Nyagah, K.; Cloeter, J.J.; Maende, A.

    1996-12-31

    The Lamu basin occupies the coastal onshore and offshore areas of south-east Kenya. This fault bounded basin formed as a result of the Paleozoic-early Mesozoic phase of rifting that developed at the onset of Gondwana dismemberment. The resultant graben was filled by Karroo (Permian-Early Jurassic) continental siliciclastic sediments. Carbonate deposits associated with the Tethyan sea invasion, dominate the Middle to Late Jurassic basin fill. Cessation of the relative motion between Madagascar and Africa in the Early Cretaceous, heralded passive margin development and deltaic sediment progradation until the Paleogene. Shallow seas transgressed the basin in the Miocene when another carbonate regime prevailed. The basin depositional history is characterized by pulses of transgressive and regressive cycles, bounded by tectonically enhanced unconformities dividing the total sedimentary succession into discrete megasequences. Source rock strata occur within Megasequence III (Paleogene) depositional cycle and were lowered into the oil window in Miocene time, when the coastal parts of the basin experienced the greatest amount of subsidence. The tectono-eustatic pulses of the Tertiary brought about source and reservoir strata into a spatial relationship in which hydrocarbons could be entrapped. A basement high on the continental shelf has potential for Karroo sandstone and Jurassic limestone reservoirs. Halokinesis of Middle Jurassic salt in Miocene time provides additional prospects in the offshore area. Paleogene deltaic sands occur in rotated listric fault blacks. A Miocene reef Play coincides with an Eocene source rock kitchen.

  11. Modelling malaria risk in East Africa at high-spatial resolution

    PubMed Central

    Omumbo, J. A.; Hay, S. I.; Snow, R. W.; Tatem, A. J.; Rogers, D. J.

    2011-01-01

    Summary OBJECTIVES Malaria risk maps have re-emerged as an important tool for appropriately targeting the limited resources available for malaria control. In Sub-Saharan Africa empirically derived maps using standardized criteria are few and this paper considers the development of a model of malaria risk for East Africa. METHODS Statistical techniques were applied to high spatial resolution remotely sensed, human settlement and land-use data to predict the intensity of malaria transmission as defined according to the childhood parasite ratio (PR) in East Africa. Discriminant analysis was used to train environmental and human settlement predictor variables to distinguish between four classes of PR risk shown to relate to disease outcomes in the region. RESULTS Independent empirical estimates of the PR were identified from Kenya, Tanzania and Uganda (n = 330). Surrogate markers of climate recorded on-board earth orbiting satellites, population settlement, elevation and water bodies all contributed significantly to the predictive models of malaria transmission intensity in the sub-region. The accuracy of the model was increased by stratifying East Africa into two ecological zones. In addition, the inclusion of urbanization as a predictor of malaria prevalence, whilst reducing formal accuracy statistics, nevertheless improved the consistency of the predictive map with expert opinion malaria maps. The overall accuracy achieved with ecological zone and urban stratification was 62% with surrogates of precipitation and temperature being among the most discriminating predictors of the PR. CONCLUSIONS It is possible to achieve a high degree of predictive accuracy for Plasmodium falciparum parasite prevalence in East Africa using high-spatial resolution environmental data. However, discrepancies were evident from mapped outputs from the models which were largely due to poor coverage of malaria training data and the comparable spatial resolution of predictor data. These

  12. Evolutionary analysis of foot-and-mouth disease virus serotype SAT 1 isolates from east africa suggests two independent introductions from southern africa

    PubMed Central

    2010-01-01

    Background In East Africa, foot-and-mouth disease virus serotype SAT 1 is responsible for occasional severe outbreaks in livestock and is known to be maintained within the buffalo populations. Little is known about the evolutionary forces underlying its epidemiology in the region. To enhance our appreciation of the epidemiological status of serotype SAT 1 virus in the region, we inferred its evolutionary and phylogeographic history by means of genealogy-based coalescent methods using 53 VP1 coding sequences covering a sampling period from 1948-2007. Results The VP1 coding sequence of 11 serotype SAT 1 FMD viruses from East Africa has been determined and compared with known sequences derived from other SAT 1 viruses from sub-Saharan Africa. Purifying (negative) selection and low substitution rates characterized the SAT 1 virus isolates in East Africa. Two virus groups with probable independent introductions from southern Africa were identified from a maximum clade credibility tree. One group was exclusive to Uganda while the other was present within Kenya and Tanzania. Conclusions Our results provide a baseline characterization of the inter-regional spread of SAT 1 in sub-Saharan Africa and highlight the importance of a regional approach to trans-boundary animal disease control in order to monitor circulating strains and apply appropriate vaccines. PMID:21118525

  13. Agriculture and development in Africa: the case of Kenya.

    PubMed

    Hyden, G

    1987-01-01

    The Government of Kenya has successfully developed macroeconomic policies that overcome constraints in the domestic and international environments and have a relatively well-functioning public sector. At present, the major challenge facing Kenya concerns the ability of the government to improve agricultural productivity given the weakness of its research services and peasant resistance to development. The response to the 1984 drought indicates that the Government of Kenya has the formal structures in place to deal with emergencies, yet the absence of reliable statistics on grain production, marketing, and on-farm storage led to serious miscalculations of the severity of the drought. Government of Kenya has been reluctant to experiment with institutional forms that reduce the opportunity for direct political control, especially over agricultural marketing. Privatization of the grain trade or the establishment of cooperatively owned local dairies has been proposed but rejected as too risky. New policies and concerted action, at both the government and community levels, tend to be in response to threat or hardship rather than a result of a dynamic strategy. Given this tendency to avoid experimentation with alternative political forms, socioeconomic development in Kenya may be limited in the years ahead. PMID:12341775

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

    NASA Astrophysics Data System (ADS)

    Collier, Emily; Mölg, Thomas

    2016-04-01

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

  15. A Heated Debate: Evidence for Two Thermal Upwellings in East Africa

    NASA Astrophysics Data System (ADS)

    Rooney, T.; Herzberg, C.; Bastow, I.

    2008-12-01

    East African Cenozoic magmatism records the thermal influence of one or more long-lived mantle plumes. We present primary magma compositions, mantle potential temperatures (Tp), and mantle melt fractions using PRIMELT2 in order to examine the geographic and historical distribution of upper mantle thermal anomalies in East Africa. Regional magmatism can be divided into an early flood basalt phase in Ethiopia/Yemen (~30 Ma), a longer-lived episode of basaltic magmatism in Kenya and Southern Ethiopia (~45 to 23 Ma), and a more recent phase (~23 Ma to Present) that is coincidental with the development of the East African Rift (EAR). We have carefully selected a total of 54 samples from these time periods, excluding erroneous results derived from lavas with evidence of clinopyroxene fractionation or volatile rich and pyroxenitic sources. Our results show that elevated Tp in the Ethiopian/Yemen flood basalt province (Tp max =1520°C) and in the early Kenya/S. Ethiopia magmatism (Tp max = 1510°C) are virtually identical. Our results indicate that the existing geochemical division between high and low Ti Ethiopia/Yemen flood basalts has a thermal basis: low-Ti lavas are hotter than the high-Ti lavas. Magmatism in the region subsequent to 23 Ma exhibits only minor cooling (Tp max = 1490°C), though more substantial cooling is observed in Turkana, Kenya (60°C) and Yemen (80°C). Rift lavas from Ethiopia exhibit a clear decrease in Tp away from Afar southwestward along the EAR before progressively rising again in Southern Ethiopia towards Turkana. South of Turkana, elevated Tp is observed in the western and eastern branches of the EAR surrounding the Tanzania Craton. The modern spatial distribution of Tp in EAR magmatism indicate two distinct heat sources, one in Afar and another under the Tanzania craton. We suggest that hot mantle plume material from Afar and Turkana (which may or may not merge at depth) is channeled beneath the thinned rift lithosphere and provides a

  16. Night Pass over Central Africa and the Middle East

    NASA Video Gallery

    This video over Central Africa and the Middle East was taken by the crew of Expedition 29 aboard the International Space Station. This sequence of shots was taken on Oct. 1, 2011, from 21:20:24 to ...

  17. Mshindi Kablanketi Dry Bean for East Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mshindi’ was derived from the single cross ‘Rojo’ x ‘Kablanketi’ made in Dec-Jan 1992-93. Mshindi was previously tested under the experimental number EG 21. Mshindi is Swahili for “Winner”. Mshindi out-yielded the check Kenya in 10 of 12 trials and had an overall yield advantage of 117%. Mshindi ha...

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  19. East African mid-Holocene wet-dry transition recorded in palaeo-shorelines of Lake Turkana, northern Kenya Rift

    NASA Astrophysics Data System (ADS)

    Garcin, Yannick; Melnick, Daniel; Strecker, Manfred R.; Olago, Daniel; Tiercelin, Jean-Jacques

    2012-05-01

    The 'wet' early to mid-Holocene of tropical Africa, with its enhanced monsoon, ended with an abrupt shift toward drier conditions and was ultimately replaced by a drier climate that has persisted until the present day. The forcing mechanisms, the timing, and the spatial extent of this major climatic transition are not well understood and remain the subject of ongoing research. We have used a detailed palaeo-shoreline record from Lake Turkana (Kenya) to decipher and characterise this marked climatic transition in East Africa. We present a high-precision survey of well-preserved palaeo-shorelines, new radiocarbon ages from shoreline deposits, and oxygen-isotope measurements on freshwater mollusk shells to elucidate the Holocene moisture history from former lake water-levels in this climatically sensitive region. In combination with previously published data our study shows that during the early Holocene the water-level in Lake Turkana was high and the lake overflowed temporarily into the White Nile drainage system. During the mid-Holocene (~ 5270 ± 300 cal. yr BP), however, the lake water-level fell by ~ 50 m, coeval with major episodes of aridity on the African continent. A comparison between palaeo-hydrological and archaeological data from the Turkana Basin suggests that the mid-Holocene climatic transition was associated with fundamental changes in prehistoric cultures, highlighting the significance of natural climate variability and associated periods of protracted drought as major environmental stress factors affecting human occupation in the East African Rift System.

  20. East African Soil Erosion Recorded in a 300 Year old Coral Colony From Kenya

    NASA Astrophysics Data System (ADS)

    Dunbar, R. B.; Fleitmann, D.; McCulloch, M.; Mudelsee, M.; Vuille, M.; McClanahan, T.; Cole, J.; Eggins, S.

    2006-12-01

    Soil erosion threatens the food security of 2.6 billion people worldwide. The situation is particularly dire in East and Sub-Saharan Africa where per capita food production has declined over the past 45 years. Erosion and the resultant loss of fertile soil is a key socio-economic and ecological problem in Kenya, affecting all sectors of its economy and damaging marine and terrestrial ecosystems. The temporal pattern of soil erosion is almost unknown and currently only sparse and rather anecdotal information exists. To aid in filling this gap of knowledge, we present a 300-year long Barium record from two Kenyan coral colonies (Porites sp., 3°15'S, 40°9' E; Malindi Marine National Park) that documents a dynamic history of soil erosion in the Sabaki river drainage basin. To reconstruct Sabaki River sediment flux to the Malindi coral reef Ba/Ca ratios were measured in the skeleton of two Porites colonies (Mal 96-1 and Mal 95-3). Well-developed annual bands allow us to develop annually precise chronologies. Ba/Ca ratios were measured in core Mal 96-1 at continuous 40 μm intervals (~400 to 500 samples yr-1) using laser-ablation inductively coupled plasma mass spectrometry (LA- ICP-MS). To test for reproducibility and accuracy of the Mal 96-1 Ba/Ca profile, coral core Mal 95-3 was analyzed at lower resolution (1 to 12 samples yr-1) using discrete micro-drill sampling and isotope dilution ICP-MS. The close similarity between both coral Ba/Ca profiles, in absolute values as well as general pattern, underscores the accuracy of the LA-ICP-MS technique and adds confidence to our interpretation of the 300 year long Mal 96-1 Ba/Ca profile. The Ba/Ca coral proxy record shows that while the sediment flux from the Sabaki River is nearly constant between 1700 and 1900, a continuous rise in sediment flux is observed since 1900, reflecting steadily increasing demographic pressure on land use. The peak in suspended sediment load and hence soil erosion recorded at the Malindi reef

  1. Reconstructing the origin and dispersal patterns of village chickens across East Africa: insights from autosomal markers

    PubMed Central

    Mwacharo, J M; Nomura, K; Hanada, H; Han, J L; Amano, T; Hanotte, O

    2013-01-01

    Unravelling the genetic history of any livestock species is central to understanding the origin, development and expansion of agricultural societies and economies. Domestic village chickens are widespread in Africa. Their close association with, and reliance on, humans for long-range dispersal makes the species an important biological marker in tracking cultural and trading contacts between human societies and civilizations across time. Archaezoological and linguistic evidence suggest a complex history of arrival and dispersion of the species on the continent, with mitochondrial DNA (mtDNA) D-loop analysis revealing the presence of five distinct haplogroups in East African village chickens. It supports the importance of the region in understanding the history of the species and indirectly of human interactions. Here, through a detailed analysis of 30 autosomal microsatellite markers genotyped in 657 village chickens from four East African countries (Kenya, Uganda, Ethiopia and Sudan), we identify three distinct autosomal gene pools (I, II and III). Gene pool I is predominantly found in Ethiopia and Sudan, while II and III occur in both Kenya and Uganda. A gradient of admixture for gene pools II and III between the Kenyan coast and Uganda's hinterland (P = 0.001) is observed, while gene pool I is clearly separated from the other two. We propose that these three gene pools represent genetic signatures of separate events in the history of the continent that relate to the arrival and dispersal of village chickens and humans across the region. Our results provide new insights on the history of chicken husbandry which has been shaped by terrestrial and maritime contacts between ancient and modern civilizations in Asia and East Africa. PMID:23611649

  2. Epidemiology and genetic diversity of multidrug-resistant tuberculosis in East Africa

    PubMed Central

    Kidenya, Benson R.; Webster, Lauren E.; Behan, Sehan; Kabangila, Rodrick; Peck, Robert N.; Mshana, Stephen E.; Ocheretina, Oksana; Fitzgerald, Daniel W.

    2013-01-01

    SUMMARY Multidrug-resistant tuberculosis (MDR-TB) is an emerging problem in many parts of the world, and levels of MDR-TB among new TB patients are increasing in sub-Saharan Africa. We reviewed the prevalence and molecular epidemiology of MDR-TB in East Africa, including Burundi, Kenya, Rwanda, Tanzania, and Uganda. In 16 epidemiologic surveys, the prevalence of MDR among new cases ranges from 0.4% in Tanzania to 4.4% in Uganda, and among recurrent cases ranges from 3.9% in Tanzania to 17.7% in Uganda. There is a gap of 5,948 cases between the estimated number of MDR-TB cases in East Africa and the number actually diagnosed. The only confirmed risk factors for MDR-TB are prior treatment for TB and refugee status. HIV has not been reported as a risk factor, and there are no reports of statistical association between spoligotype and drug resistance pattern. Increased capacity for diagnosis and treatment of MDR-TB is needed, with an emphasis on recurrent TB cases and refugees. PMID:24215798

  3. Connecting Science and Stakeholders for Improved Drought and Crop Productivity Assessments in East Africa: Early Lessons

    NASA Astrophysics Data System (ADS)

    Granger, S. L.; Macharia, D.; Andreadis, K.; Das, N. N.

    2014-12-01

    Agriculture is the 'backbone' of the economies in East Africa and is dominated by smallholder farms that are mainly rain-fed and highly vulnerable to climate change, variability, and drought. However the region lacks access to developed, reliable, and effective data and analysis to guide planning for agriculture and drought mitigation. Advances in remote sensing technologies and associated tools enable the collection and quantitative analysis of observations over large geographic regions. As such, data from remote sensing platforms have become a critical tool in developed countries for climate adaptation, water resources management, drought planning and mitigation, and agriculture. Yet barriers remain in Africa due to cost (even as costs decline), issues of sustainability, and lack of capacity and expertise. A shift must be facilitated at the policy maker and practitioner level to adopt or incorporate remote sensing observations and analysis to make better, more informed decisions for drought and agricultural management and planning. Based on an on-going NASA-USAID SERVIR East Africa Drought and Crop Productivity project, recent experience is presented to illustrate best practices and lessons learned in transitioning NASA Earth Science research results to decision making in Kenya through capacity building.

  4. HIV/AIDS among pastoralists and refugees in north-east Africa: a neglected problem.

    PubMed

    Serbessa, Mirgissa Kaba; Mariam, Damen Haile; Kassa, Afework; Alwan, Fathia; Kloos, Helmut

    2016-03-01

    The eight member states (Djibouti, Eritrea, Ethiopia, Kenya, Somalia, South Sudan, Sudan and Uganda) of the Intergovernmental Authority for Development (IGAD) have the largest proportions of cross-border mobile pastoralists and refugees in Africa. Although all IGAD countries have had national HIV/AIDS prevention, care and treatment programmes since the late 1980s, the IGAD Regional HIV & AIDS Partnership Program was (IRAPP) established in 2007 to mitigate the challenges of HIV among neglected pastoral and refugee communities. This article assesses vulnerability of pastoralists and refugee communities to HIV and interventions targeting these groups in the IGAD countries. Outcomes from this study may serve as a baseline for further research and to improve interventions. Published articles were accessed through web searches using PubMed and Google Scholar engines and unpublished documents were collected manually. The search terms were HIV risk behaviour, vulnerability, HIV prevalence and interventions, under the headings pastoralists, refugees, IGAD and north-east Africa for the period 2001-2014. Of the 214 documents reviewed, 78 met the inclusion criteria and were included. Most HIV/AIDS related studies focusing of pastoral communities in IGAD countries were found to be limited in scope and coverage but reveal precarious situations. Sero-prevalence among various pastoral populations ranged from 1% to 21% in Ethiopia, Kenya, Somalia and Uganda and from 1% to 5% among refugees in Sudan, Kenya and Uganda. Socioeconomic, cultural, logistic, infrastructure and programmatic factors were found to contribute to continuing vulnerability to HIV. Interventions need to be further contextualised to the needs of those impoverished populations and integrated into national HIV/AIDS programmes. HIV/AIDS remains a major public health concern among the pastoral and refugee communities of IGAD countries. This calls for IGAD to collaborate with national and international partners in

  5. 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. PMID:26299755

  6. Phylogenetic Variants of Rickettsia africae, and Incidental Identification of "Candidatus Rickettsia Moyalensis" in Kenya

    PubMed Central

    Kimita, Gathii; Mutai, Beth; Nyanjom, Steven Ger; Wamunyokoli, Fred; Waitumbi, John

    2016-01-01

    Background Rickettsia africae, the etiological agent of African tick bite fever, is widely distributed in sub-Saharan Africa. Contrary to reports of its homogeneity, a localized study in Asembo, Kenya recently reported high genetic diversity. The present study aims to elucidate the extent of this heterogeneity by examining archived Rickettsia africae DNA samples collected from different eco-regions of Kenya. Methods To evaluate their phylogenetic relationships, archived genomic DNA obtained from 57 ticks a priori identified to contain R. africae by comparison to ompA, ompB and gltA genes was used to amplify five rickettsial genes i.e. gltA, ompA, ompB, 17kDa and sca4. The resulting amplicons were sequenced. Translated amino acid alignments were used to guide the nucleotide alignments. Single gene and concatenated alignments were used to infer phylogenetic relationships. Results Out of the 57 DNA samples, three were determined to be R. aeschlimanii and not R. africae. One sample turned out to be a novel rickettsiae and an interim name of “Candidatus Rickettsia moyalensis” is proposed. The bonafide R. africae formed two distinct clades. Clade I contained 9% of the samples and branched with the validated R. africae str ESF-5, while clade II (two samples) formed a distinct sub-lineage. Conclusions This data supports the use of multiple genes for phylogenetic inferences. It is determined that, despite its recent emergence, the R. africae lineage is diverse. This data also provides evidence of a novel Rickettsia species, Candidatus Rickettsia moyalensis. PMID:27387337

  7. Multiproxy Evidence for a Positive Hydrological Budget during the Little Ice Age in the East African Rift, Kenya

    NASA Astrophysics Data System (ADS)

    Goman, M.; Ashley, G. M.; Hover, V. C.; Owen, R.

    2011-12-01

    Hominin evolution took place in Africa during the Plio-Pleistocene and climate change is thought to be a factor, with Africa experiencing a general cooling and increasing aridification over the last several million years. Today, the climate of the East African Rift Valley of Kenya is characterized as semi-arid with evapotranspiration four times precipitation. Water resources are a valuable commodity for the many millions of inhabitants of the Valley. The short instrumental record shows precipitation fluctuates at sub-decadal timeframes as a result of the ENSO cycle; while during prehistory variations in monsoonal precipitation occurred on Milankovitch timescales (i.e. African Humid Period). Both timescales exhibit significant impacts on the distribution of surface water. However, little is known regarding precipitation variability over sub-millennial timescales. Emerging paleoclimate data indicates that the near surface presence of water has also varied over century length timescales. We present paleoclimate data from multiple sites along a north-south 600 km transect of the Gregory Rift Valley (Kenya) that indicate the region experienced wetter conditions during the Little Ice Age (A.D. 1400-1850). Our reconstructions of landscape and climate during this time frame rely upon a multiproxy and interdisciplinary approach. We discuss data from a variety of environmental settings (e.g. lakes, wetlands, and springs) that indicate an overall increase in hydrologic balance. Evidence is derived from biologic microfossils such as pollen, diatom and testate amoebae assemblages as well as inorganic components of the sedimentary record and geomorphic changes. The data differs significantly from studies undertaken to the west in Uganda and the Congo, where negative hydrologic balances occurred during the Little Ice Age. While the atmospheric dynamics causing this disparity are not yet recognized, interactions between the Intertropical Convergence Zone and the Congo Air Boundary

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  9. A new species of Alhajarmyia Stuckenberg (Diptera: Vermileonidae), the first wormlion fly described from East Africa and its biogeographical implications.

    PubMed

    Swart, Vaughn R; Kirk-Spriggs, Ashley H; Copeland, Robert S

    2015-01-01

    A second species of the genus Alhajarmyia Stuckenberg (A. stuckenbergi Swart, Kirk-Spriggs & Copeland, sp. n.), is described and figured, from the Eastern Arc Mountains of Kenya (Kasigau Mountain and Taita Hills), being the first vermileonid recorded from East Africa. The species is shown to differ from its congener, A. umbraticola (Stuckenberg & Fisher), described from Oman in the Arabian Peninsula, based on external characters including male and female terminalia. An identification key is provided together with distribution maps for the two species, and biogeographical aspects are discussed. PMID:26624725

  10. Evaluation of the Distribution and Impacts of Parasites, Pathogens, and Pesticides on Honey Bee (Apis mellifera) Populations in East Africa

    PubMed Central

    Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

    2014-01-01

    In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations. PMID:24740399

  11. Evaluation of the distribution and impacts of parasites, pathogens, and pesticides on honey bee (Apis mellifera) populations in East Africa.

    PubMed

    Muli, Elliud; Patch, Harland; Frazier, Maryann; Frazier, James; Torto, Baldwyn; Baumgarten, Tracey; Kilonzo, Joseph; Kimani, James Ng'ang'a; Mumoki, Fiona; Masiga, Daniel; Tumlinson, James; Grozinger, Christina

    2014-01-01

    In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations. PMID:24740399

  12. Solar electricity for Africa: The case of Kenya

    SciTech Connect

    Plas, R.J. van der

    1997-12-01

    This paper presents results of two recent World Bank efforts made in Kenya, Niger, and Cameroon to study the impact of two different renewable projects, one a Micro-Lights program involving about 500 lanterns and the second a survey of 410 households using solar electricity systems. The Micro-Lights program showed that users have distinct preferences in the style of the lamps, that they are willing to spend cash, and that they demand good quality. They may be initially satisfied, but rapidly want more from their purchases. The photoelectric system survey touched less than 1% of such households, and looked at user education, system size, satisfaction, expectations, age of system, appliances, and expectations.

  13. Aspects of Education in the Middle East and North Africa

    ERIC Educational Resources Information Center

    Brock, Colin, Ed.; Levers, Lila Zia

    2007-01-01

    The chapters in this volume do not represent the whole of the Middle East and North Africa, as such a collection would have been too large for one volume. Rather, the selection here is intended to present different perspectives on a range of educational issues, relevant to a particular focus or country, or common to a number of countries in the…

  14. Reducing the Burden of Cancer in East Africa

    Cancer.gov

    The mission of CGH is to advance global cancer research, build expertise, and leverage resources across nations to reduce cancer deaths worldwide. To carry out that mission, we facilitate the sharing of knowledge and expertise. CGH's latest effort, the East Africa Cancer Control Leadership Forum, carried out this mission by helping African partners develop their own individual cancer control programs.

  15. A solar box cooker for mass production in East Africa

    SciTech Connect

    Funk, P.A.; Wilcke, W.F.

    1992-12-31

    A solar box cooker produced in Tanzania, East Africa with indigenous materials is described. When compared to a commercially produced glass and cardboard one, it was found to perform as well. Heat transfer through each major component of the cooker is presented. The smallest losses were through the walls of the box. The greatest losses were observed in the cover system.

  16. Towards an integrated soil moisture drought monitor for East Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought in East Africa is a recurring phenomenon with significant humanitarian impacts. Given the steep climatic gradients, topographic contrasts, general data scarcity, and, in places, political instability that characterize the region, there is a need for spatially distributed, remotely derived mo...

  17. Women of the World: Near East and North Africa.

    ERIC Educational Resources Information Center

    Chamie, Mary

    The third in a series of five handbooks designed to present and analyze statistical data on women in various regions of the world, this handbook focuses on women in 14 countries in the Near East and North Africa. Beginning with an overview of population distribution and changes in the region, the analysis continues with a description of women's…

  18. Genetic diversity and geographic distribution of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) genotypes associated with cassava in East Africa

    PubMed Central

    Mugerwa, Habibu; Rey, Marie E C; Alicai, Titus; Ateka, Elijah; Atuncha, Hellen; Ndunguru, Joseph; Sseruwagi, Peter

    2012-01-01

    The genetic variability of whitefly (Bemisia tabaci) species, the vectors of cassava mosaic begomoviruses (CMBs) in cassava growing areas of Kenya, Tanzania, and Uganda, was investigated through comparison of partial sequences of the mitochondria cytochrome oxidase I (mtCOI) DNA in 2010/11. Two distinct species were obtained including sub-Saharan Africa 1 (SSA1), comprising of two sub-clades (I and II), and a South West Indian Ocean Islands (SWIO) species. Among the SSA1, sub-clade I sequences shared a similarity of 97.8–99.7% with the published Uganda 1 genotypes, and diverged by 0.3–2.2%. A pairwise comparison of SSA1 sub-clade II sequences revealed a similarity of 97.2–99.5% with reference southern Africa genotypes, and diverged by 0.5–2.8%. The SSA1 sub-clade I whiteflies were widely distributed in East Africa (EA). In comparison, the SSA1 sub-clade II whiteflies were detected for the first time in the EA region, and occurred predominantly in the coast regions of Kenya, southern and coast Tanzania. They occurred in low abundance in the Lake Victoria Basin of Tanzania and were widespread in all four regions in Uganda. The SWIO species had a sequence similarity of 97.2–97.7% with the published Reunion sequence and diverged by 2.3–2.8%. The SWIO whiteflies occurred in coast Kenya only. The sub-Saharan Africa 2 whitefly species (Ug2) that was associated with the severe CMD pandemic in Uganda was not detected in our study. PMID:23170210

  19. Chemical ecology: studies from East Africa.

    PubMed

    Meinwald, J; Prestwich, G D; Nakanishi, K; Kubo, I

    1978-03-17

    The International Centre of Insect Physiology and Ecology (ICIPE), in Nairobi, provides a laboratory at which a multinational group of scientists pursues interdisciplinary research. In collaboration with their colleagues in biology, ICIPE chemists have characterized the sex pheromones of the tick which serves as a vector of East Coast fever and have identified a termite queen-cell-building pheromone. The structure of many anthropod defensive chemicals have been determined; most interesting of these are the trinervitenes, structurally novel diterpenoids from nasute termites. Several highly active insect antifeedants were discovered using a simple bioassay to screen selected East African plants. These antifeedants may provide leads for the development of new insect-control techniques. PMID:17745589

  20. Concentrations, distribution, sources and risk assessment of organohalogenated contaminants in soils from Kenya, Eastern Africa.

    PubMed

    Sun, Hongwei; Qi, Yueling; Zhang, Di; Li, Qing X; Wang, Jun

    2016-02-01

    The organohalogenated contaminants (OCs) including 12 organochlorine pesticides (OCPs), 7 indicator polychlorinated biphenyls (PCBs) and 7 polybrominated diphenyl ethers (PBDEs) were determined in soils collected from Kenya, Eastern Africa. The total OCPs fell in the range of n.d-49.74 μg kg(-1) dry weight (dw), which was dominated by DDTs and endosulfan. Identification of pollution sources indicated new input of DDTs for malaria control in Kenya. The total PCBs ranged from n.d. to 55.49 μg kg(-1) dw, dominated by penta- and hexa-PCBs, probably associated with the leakage of obsolete transformer oil. The soils were less contaminated by PBDEs, ranging from 0.19 to 35.64 μg kg(-1) dw. The predominant PBDE congeners were penta-, tri- or tetra-BDEs, varying among different sampling sites. Risk assessment indicated potential human health risks posed by OCs in soils from Kenya, with PCBs as the most contributing pollutants. The local authorities are recommended to make best efforts on management of OC pollution, particularly from DDTs and PCBs to meet the requirement of Stockholm Convention. PMID:26686059

  1. Sexual behavior of female sex workers and access to condoms in Kenya and Uganda on the Trans-Africa highway.

    PubMed

    Morris, Chester N; Morris, Sheldon R; Ferguson, Alan G

    2009-10-01

    Female sex workers and their clients remain a high risk core group for HIV in Africa. We measured sexual behavior of a snowball sample of female sex workers (FSW) along the Trans Africa highway from Mombasa, Kenya to Kampala, Uganda and surveyed the availability of male condoms at 1,007 bars and lodgings in Kenya along the highway trucking stops where transactional sex occurs. There were 578 FSW one month sex diaries analyzed, 403 from Kenya and 175 from Uganda. Kenyan FSW had a median of 45 sexual acts per 28 days compared to 39 sex acts per 28 days by Ugandan FSW (P < 0.05). Condom use by FSW for all sexual liaisons was 79% in Kenya compared to 74% in Uganda. In multivariate analysis, adjusting for repeated measures, Kenyan FSW were more likely to use a condom by an adjusted odds ratio of 2.54 (95% confidence interval 1.89-3.41) compared to Ugandan FSW. Condom use with regular clients was 50.8% in Uganda compared with 68.7% in Kenya (P < 0.01). The number of sex workers reporting 100% condom use was 26.8% in Kenya and 18.9% in Uganda (P < 0.01). Bars and lodges in Kenya compared to Uganda were more likely to: have condom dispensers, 25% versus 1%, respectively (P < 0.01); distribute or sell condoms, 73.9% versus 47.6% (P < 0.01); and have more weekly condom distribution, 4.92 versus 1.27 condoms per seating capacity (P < 0.01). Our data indicate that in both countries condom use for FSW is suboptimal, particularly with regular partners, and greater condom use by Trans African highway FSW in Kenya compared to Uganda may be related to availability. Targeted interventions are warranted for FSW and truck drivers to prevent transmission in this important core group. PMID:18665445

  2. One Health: Lessons Learned from East Africa.

    PubMed

    Travis, Dominic A; Chapman, David W; Craft, Meggan E; Deen, John; Farnham, MacDonald W; Garcia, Carolyn; Hueston, William D; Kock, Richard; Mahero, Michael; Mugisha, Lawrence; Nzietchueng, Serge; Nutter, Felicia B; Olson, Debra; Pekol, Amy; Pelican, Katharine M; Robertson, Cheryl; Rwego, Innocent B

    2014-02-01

    Africa is faced with many of the most daunting challenges of our time. It comprises roughly 15% of the world's human population, and most of its countries are perpetually ranked "Low" on the United Nations' Human Development Index. On the other hand, Africa has arguably the largest proportion of intact natural ecosystems, biodiversity, and sociocultural capital and the lowest impact on global warming of any continent. Thus, African leaders are faced with competing demands and values among a multitude of complex issues, such as high human population growth, extreme poverty, food insecurity, land use policy, climate change, and biodiversity conservation. In this context, building sustainable national systems for human and/or animal health is one of the grand challenges of this generation. Today's complex global health and development challenges require long-term commitment and a range of approaches that are too broad for any one discipline, institution, or country to implement on its own. The One Health concept recognizes the interconnectedness of global health issues and, as such, promotes the importance of and need for international, interdisciplinary, and cross-sectoral communication and collaboration at local, national, and international levels. By taking advantage of natural cultural tendencies for shared leadership, resource allocation, and community values, African leaders are currently proactively demonstrating the principles of One Health, and thus becoming a model for this global vision. And by focusing on partnerships rather than donor-recipient relationships, they are fostering the development of shared priorities and are increasingly driving their own health agenda to fulfill their own needs. PMID:26082115

  3. Protected areas: mixed success in conserving East Africa's evergreen forests.

    PubMed

    Pfeifer, Marion; Burgess, Neil D; Swetnam, Ruth D; Platts, Philip J; Willcock, Simon; Marchant, Robert

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at -9.3% (17,167 km(2)), but varied between countries (range: -0.9% to -85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa's forest conservation efforts. PMID:22768074

  4. A 17-My-old whale constrains onset of uplift and climate change in east Africa

    NASA Astrophysics Data System (ADS)

    Wichura, Henry; Jacobs, Louis L.; Lin, Andrew; Polcyn, Michael J.; Manthi, Fredrick K.; Winkler, Dale A.; Strecker, Manfred R.; Clemens, Matthew

    2015-03-01

    Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates.

  5. A 17-My-old whale constrains onset of uplift and climate change in east Africa

    PubMed Central

    Wichura, Henry; Lin, Andrew; Polcyn, Michael J.; Manthi, Fredrick K.; Winkler, Dale A.; Strecker, Manfred R.; Clemens, Matthew

    2015-01-01

    Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates. PMID:25775586

  6. A 17-My-old whale constrains onset of uplift and climate change in east Africa.

    PubMed

    Wichura, Henry; Jacobs, Louis L; Lin, Andrew; Polcyn, Michael J; Manthi, Fredrick K; Winkler, Dale A; Strecker, Manfred R; Clemens, Matthew

    2015-03-31

    Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼ 17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates. PMID:25775586

  7. Coping With Lake Kivu, East Africa

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas C.; Scholz, Christopher A.

    2010-07-01

    Workshop on Tropical Rift Lake Systems: Integrated Volcanogenic, Tectonic, Biogeochemical, and Geohazard Assessment of Lake Kivu; Gisenyi, Rwanda, 13-15 January 2010; Situated in the volcanic highlands of the East African Rift Valley's western branch, Lake Kivu contains one of the most unusual and fascinating aquatic ecosystems on the planet. Bottom waters in the 480-meter-deep lake are warmer and saltier than its surface waters. The concentrations of dissolved carbon dioxide and methane are so high in the deep water that catastrophic overturn, an abrupt upwelling of deep water and gas driven by the buoyancy of expanding gas bubbles as they rise from the depths, could well happen in the coming century. Were this to occur, human fatalities would likely number in the hundreds of thousands—a disaster similar to what occurred when Lake Nyos (Cameroon) in 1986 emitted a large amount of carbon dioxide, causing hundreds of local residents to suffocate—but with orders-of-magnitude more gas release.

  8. Our University: Ethnicity, Higher Education and the Quest for State Legitimacy in Kenya

    ERIC Educational Resources Information Center

    Munene, Ishmael I.

    2012-01-01

    In East Africa, no other country has witnessed as great a surge in university institutions as Kenya. The intent of this paper is to explore the persistence of the ethnic configurations in the surge of higher education in Kenya, within the context of the country's history. Outlining the major flashpoints in the country's history will be…

  9. The development of the East African Rift system in north-central Kenya

    NASA Astrophysics Data System (ADS)

    Hackman, B. D.; Charsley, T. J.; Key, R. M.; Wilkinson, A. F.

    1990-11-01

    Between 1980 and 1986 geological surveying to produce maps on a scale of 1:250,000 was completed over an area of over 100,000 km 2 in north-central Kenya, bounded by the Equator, the Ethiopian border and longitudes 36° and 38 °E. The Gregory Rift, much of which has the structure of an asymmetric half-graben, is the most prominent component of the Cenozoic multiple rift system which extends up to 200 km to the east and for about 100 km to the west, forming the Kenya dome. On the eastern shoulder and fringes two en echelon arrays of late Tertiary to Quaternary multicentre shields can be recognized: to the south is the Aberdares-Mount Kenya-Nyambeni Range chain and, to the north the clusters of Mount Kulal, Asie, Huri Hills and Marsabit, with plateau lavas and fissure vents south of Marsabit in the Laisamis area. The Gregory Rift terminates at the southern end of Lake Turkana. Further north the rift system splays: the arcuate Kinu Sogo fault zone forms an offset link with the central Ethiopian Rift system. In the rifts of north-central Kenya volcanism, sedimentation and extensional tectonics commenced and have been continuous since the late Oligocene. Throughout this period the Elgeyo Fault acted as a major bounding fault. A comparative study of the northern and eastern fringes of the Kenya dome with the axial graben reinforces the impression of regional E-W asymmetry. Deviations from the essential N-trend of the Gregory Rift reflect structural weaknesses in the underlying Proterozoic basement, the Mozambique Orogenic Belt: thus south of Lake Baringo the swing to the southeast parallels the axes of the ca. 620 Ma phase folds. Secondary faults associated with this flexure have created a "shark tooth" array, an expression of en echelon offsets of the eastern margin of the Gregory Rift in a transtensional stress regime: hinge zones where major faults intersect on the eastern shoulder feature intense box faulting and ramp structures which have counterparts in the rift

  10. Probabilistic maize yield simulation over East Africa using ensemble seasonal climate forecasts

    NASA Astrophysics Data System (ADS)

    Ogutu, Geoffrey; Supit, Iwan; Hutjes, Ronald

    2016-04-01

    Seasonal climate variability influences crop yields, especially in areas where rain fed agriculture is widely practiced such as in the East African region. Assuming that seasonal climate prediction skill would translate to similarly skillful prediction of impacts, an ensemble seasonal climate hindcast (ECMWF system4 EPS) for the period 1981 to 2010 at different initialization dates (lead months) before sowing is used to drive a crop simulation model: the World Food Studies (WOFOST) model, implemented for a single season Maize crop. The water-limited yield predictions were assessed against reference yields produced by the same crop model forced by the WATCH Forcing Data ERA-Interim (WFDEI) at grid point level. We focus on the main sowing dates of June/July (Northern region), March (Equatorial East Africa) and November (Southern region). Deviation of yields from the mean over the study period is used to indicate regions in which probabilistic yield forecasts would be useful while the Relative Operating Curve Skill Score (ROCSS) indicates prediction skill of above normal, near normal and below normal yield prediction. Equatorial regions of East Africa and coastal Kenya with sowing date in March show a mean deviation of ≥ 500 Kg/ha. Here probabilistic yield forecasts can potentially be useful as opposed to the northern and southern regions with less deviation. The high deviation in this region may also be due to the existence of more than one cropping season corresponding to the bi-modal rainfall regime since the model only simulates a single season. A positive ROCSS over a large extent of the equatorial region show predictability skill of all the tercile forecasts simulated by forecasts initialized at the start of sowing date (March i.e. lead 0 forecasts) and no predictability at longer lead months. Over Ethiopia in the northern region of East Africa, November harvests with a sowing date of June show predictability of the upper, lower and middle terciles at lead-0

  11. What are the constraints and opportunities for HIVST scale-up in Africa? Evidence from Kenya, Malawi and South Africa

    PubMed Central

    van Rooyen, Heidi; Tulloch, Olivia; Mukoma, Wanjiru; Makusha, Tawanda; Chepuka, Lignet; Knight, Lucia C; Peck, Roger B; Lim, Jeanette M; Muturi, Nelly; Chirwa, Ellen; Taegtmeyer, Miriam

    2015-01-01

    Introduction HIV self-testing (HIVST) has the potential to increase uptake of HIV testing among untested populations in sub-Saharan Africa and is on the brink of scale-up. However, it is unclear to what extent HIVST would be supported by stakeholders, what policy frameworks are in place and how variations between contexts might influence country-preparedness for scale-up. This qualitative study assessed the perceptions of HIVST among stakeholders in three sub-Saharan countries. Methods Fifty-four key informant interviews were conducted in Kenya (n=16), Malawi (n=26) and South Africa (n=12) with government policy makers, academics, activists, donors, procurement specialists, laboratory practitioners and health providers. A thematic analysis was conducted in each country and a common coding framework allowed for inter-country analysis to identify common and divergent themes across contexts. Results Respondents welcomed the idea of an accurate, easy-to-use, rapid HIV self-test which could increase testing across all populations. High-risk groups, such as men, Men who have sex with men (MSM), couples and young people in particular, could be targeted through a range of health facility and community-based distribution points. HIVST is already endorsed in Kenya, and political support for scale-up exists in South Africa and Malawi. However, several caveats remain. Further research, policy and ensuing guidelines should consider how to regulate, market and distribute HIVST, ensure quality assurance of tests and human rights, and critically, link testing to appropriate support and treatment services. Low literacy levels in some target groups would also need context-specific consideration before scale up. World Health Organization (WHO) policy and regulatory frameworks are needed to guide the process in those areas which are new or specific to self-testing. Conclusions Stakeholders in three HIV endemic sub-Saharan countries felt that HIVST will be an important complement to

  12. International energy outlook. Volume 1. Mideast, Far East, and Africa

    SciTech Connect

    Jablonski, D.M.

    1982-01-01

    The developing nations of the Mideast, Far East, and Africa face a bleaker - and more-complicated - energy picture than that of the West. Rapid industrial and agricultural expansion in the region severely drains already-inadequate energy systems. Energy-importing countries find they must diversify and develop indigenous resources, but often lack the technical known-how to do so. Volume 1 is a compilation of official US government intelligence reports examining the way 22 countries in the Mideast, Far East, and Africa are responding to the energy problems. The countries covered are: Algeria, Australia, Burma, China, Egypt, Gabon, India, Indonesia, Ivory Coast, Japan, Korea, Kuwait, Lebanon, Morocco, Mozambique, Pakistan, Saudi Arabia, South Africa, Sudan, Taiwan, Tunisia and Turkey. The range and detail of country reports vary, due to availability of reports. Although the book details current energy situations, its main emphasis is on the future, including estimates of future production and consumption, and descriptions of energy development plans. Some of the countries in this region are fortunate to have petrochemical resources, while electric energy expansion is crucial to national development in all. Coal will be filling the gap left by diminishing oil supplies. 61 tables.

  13. [Gestational diabetes in East Africa: a mostly disregarded disease?].

    PubMed

    Zeck, W; Lang, U; Panzitt, T; Oneko, O; Obure, J; McIntyre, H D

    2009-01-01

    The majority of all deliveries worldwide take place in the so-called developing world. Most recent epidemiological data have shown that the number of cases of type 2 diabetes mellitus and diabetes in pregnancy is steadily increasing worldwide. However, little is known about the prevalence of gestational diabetes in East Africa. Intrauterine exposure to the metabolic environment of maternal diabetes increases the risk of altered glucose homeostasis in the offspring, producing a higher prevalence of gestational diabetes mellitus in the next generation. Our preliminary results from an East African tertiary referral center show that in the year 2007 3.1% of all newborns had a birth weight of more than 4,000 g (mean 4,300 g, range 4,000- 5,600 g). During the same time period, the mean birth weight in the general population was only 3,046 g (range 600-3,200 g). Hence, personal experience in East Africa has convinced the authors that diabetes in pregnancy is grossly neglected. Besides infectious diseases like HIV/AIDS, the African continent is increasingly facing metabolic diseases such as type 2 diabetes mellitus and diabetes in pregnancy. PMID:20530939

  14. Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future.

    PubMed

    Gachohi, John; Skilton, Rob; Hansen, Frank; Ngumi, Priscilla; Kitala, Philip

    2012-01-01

    In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the

  15. Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future

    PubMed Central

    2012-01-01

    In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the

  16. The small east african shorthorn zebu cows in Kenya. I: linear body measurements.

    PubMed

    Mwacharo, J M; Okeyo, A M; Kamande, G K; Rege, J E O

    2006-01-01

    Assessment of genetic diversity is a prerequisite for the management and conservation of animal genetic resources. Appropriate design of breeding programmes is therefore impossible for breeds that have not been adequately characterized either phenotypically and/or genetically. Phenotypic characteristics are important in breed identification and classification in ways that farming communities can relate with. This study phenotypically characterized two breeds of zebu cattle in Kenya. A total of 12 measurements (face length, ear length, horn length, heart girth, height at withers, chest depth, body length, height at rump, pelvis width, corpus length, pin bone width and tail length) were collected on 373 Maasai and 277 Kamba zebu kept by traditional farmers in south-east Kenya. The data were classified on the basis of breed group, age group, sex and coat colour pattern. Breed group, age group and sex significantly influenced all measurements. Coat colour pattern significantly influenced only height at withers, corpus length, ear length and tail length. Except for horn and ear length, all the other measurements were significantly higher for the Maasai zebu. Additionally, the Maasai zebu was taller than it was long. The opposite was true for the Kamba zebu. The Maasai and Kamba zebus can be classified as medium-sized breeds; however, great variations exist in their body sizes within and between the breeds. PMID:17405630

  17. The Importance of Magmatic Fluids in Continental Rifting in East Africa

    NASA Astrophysics Data System (ADS)

    Muirhead, J.; Kattenhorn, S. A.; Ebinger, C. J.; Lee, H.; Fischer, T. P.; Roecker, S. W.; Kianji, G.

    2015-12-01

    The breakup of strong continental lithosphere requires more than far-field tectonic forces. Growing evidence for early-stage cratonic rift zones points to the importance of heat, magma and volatile transfer in driving lithospheric strength reduction. The relative contributions of these processes are fundamental to our understanding of continental rifting. We present a synthesis of results from geological, geochemical and geophysical studies in one of the most seismically and volcanically active sectors of the East African Rift (Kenya-Tanzania border) to investigate the role of fluids during early-stage rifting (<10 Ma). Xenolith data indicate that rifting initiated in initially thick lithosphere. Diffuse soil CO2 flux maxima occur in the vicinity of faults, with carbon isotope values exhibiting a mantle-derived signature. These faults feed aligned sets of hydrothermal springs, which have N2-He-Ar relative abundances also indicating a mantle-derived source. Geochemical and surface faulting information are integrated with subsurface imaging and fault kinematic data derived from the 38-station CRAFTI broadband seismic array. Teleseismic and abundant local earthquakes enable assessment of the state-of-stress and b-values as a function of depth. High Vp/Vs ratios and tomographic imaging suggest the presence of fluids in the crust, with high pore fluid pressures driving failure at lower tectonic stress. Together, these cross-disciplinary data provide compelling evidence that early-stage rifting in East Africa is assisted by fluids exsolved from deep magma bodies, some of which are imaged in the lower crust. We assert that the flux of deep magmatic fluids during rift initiation plays a key role in weakening lithosphere and localizing strain. High surface gas fluxes, fault-fed hydrothermal springs and persistent seismicity highlight the East African Rift as the ideal natural laboratory for investigating fluid-driven faulting processes in extensional tectonic environments.

  18. Landscape feedbacks, Climate Change, and Food Production Risk in East Africa

    NASA Astrophysics Data System (ADS)

    Moore, N.; Pijanowski, B.; Lofgren, B.; Alagarswamy, G.

    2008-12-01

    Land Cover/ Land Use Change (LCLUC) and climate change due to elevated levels of greenhouse gases (GHG) both exert strong influence over agricultural production in developing countries. In addition, LCLUC is a first-order climate forcing capable of mitigating or exacerbating GHG effects on climate. LCLUC and GHG forcings that alter climate may then in turn influence agricultural systems, thereby creating a feedback to LCLUC. These human-land-climate interactions are complex- particularly in heterogeneous landscapes like East Africa- where subsistence farming and highly variable growing season conditions are excellent for investigating the nature and magnitude of these interactions. Here we present results of a sensitivity test exploring these feedbacks in Kenya, Tanzania, Uganda, Rwanda, and Burundi. First, we assess the impacts of "aggressive" agricultural expansion and generally warmer, wetter boundary conditions due to large increases in GHG for 2050-2059 using the Regional Atmospheric Modeling System (RAMS). These results are contrasted to simulations conducted for 2000- 2009 conditions. Second, we examine simulated changes in agricultural yield using the process-based crop model CERES-Maize; we use maize as a proxy for all East African agricultural productivity. These simulated yields are imported into the Land Transformation Model (LTM), which, informed by socioeconomic constraints, develops a new projection of land cover under the new yield conditions. Third, by comparing the original "aggressive" landscape with the new yield-feedback landscape, we show areas exhibiting sensitivity to LCLUC under elevated GHG conditions. Although this is a mere sensitivity test, we can identify areas prone to potential food production disturbances. These sensitive areas, while unlikely to see climate and landscape changes this dramatic, can serve as "canaries in the coal mine" for predicting larger changes in East African food production. Additionally, we discuss key

  19. 2H/1H composition of soil n-alkanes along two altitudinal transects in East Africa

    NASA Astrophysics Data System (ADS)

    Coffinet, Sarah; Huguet, Arnaud; Pedentchouk, Nikolai; Omuombo, Christine; Williamson, David; Bergonzini, Laurent; Wagner, Thomas; Derenne, Sylvie

    2015-04-01

    Long chains n-alkanes are components of terrestrial plant leaf waxes that are ubiquitously found in geological archives. They have been extensively used to track environmental and ecological variations in the past, notably changes in vegetation communities. Recent analytical developments led to the possibility of measuring their deuterium to hydrogen isotopic ratio (δ2Hwax). This parameter is suggested to be linked to hydrogen isotope ratio of precipitations (δ2Hp). In 2008, Jia et al. proposed to use soil derived δ2 Hwax as a paleoelevation proxy since precipitations are known to get more depleted in deuterium with altitude. They found a linear correlation (R2 0.73) between δ2Hwax in surface soils and altitude along Mt. Gongga (China). Since then, the correlation between δ2Hwax and δ2Hp was shown for several other altitudinal transects. Contrary to these previous observations, however, no trend with altitude was observed in East Africa along an altitudinal gradient in Mt. Kilimanjaro (North eastern, Tanzania, Peterse et al., 2009 and Zech et al., 2014). What is the reason for this absence of trend? Is it because of a difference between African and Asian soils? Or is it specific to Mt. Kilimanjaro? To get an insight into this problem, we determined δ2Hwax in 41 surface soils sampled along two altitudinal transects: from 500 to 2800 m in Mt. Rungwe (South-western Tanzania) and from 1897 to 3268 m in Mt. Kenya (Central Kenya). The goal of the study was to further investigate the conditions of applicability of this proxy in East Africa. A correlation between soil derived δ2Hwax and altitude was observed along Mt. Kenya (δ2Hwax=20.2*ALT-88.0, R2=0.51) but not along Mt. Rungwe - similarly to Mt. Kilimanjaro (Peterse et al., 2009; Zech et al., 2014). This contrast between Mt. Kenya on one hand and Mts. Rungwe and Kilimanjaro on the other hand may be explained by differences in topography. These results highlight the complexity of the signal recorded by δ2H, and

  20. Fission-track dating of pumice from the KBS Tuff, East Rudolf, Kenya

    USGS Publications Warehouse

    Hurford, A.J.; Gleadow, A.J.W.; Naeser, C.W.

    1976-01-01

    Fission-track dating of zircon separated from two pumice samples from the KBS Tuff in the Koobi Fora Formation, in Area 131, East Rudolf, Kenya, gives an age of 2.44??0.08 Myr for the eruption of the pumice. This result is compatible with the previously published K-Ar and 40Ar/ 39Ar age spectrum estimate of 2.61??0.26 Myr for the KBS Tuff in Area 105, but differs from the more recently published K-Ar date of 1.82??0.04 Myr for the KBS Tuff in Area 131. This study does not support the suggestion that pumice cobbles of different ages occur in the KBS Tuff. ?? 1976 Nature Publishing Group.

  1. Reconstruction of the East Africa and Antarctica continental margins

    NASA Astrophysics Data System (ADS)

    Nguyen, L. C.; Hall, S. A.; Ball, P.; Bird, D. E.

    2015-12-01

    The Early Jurassic separation of Antarctica from Africa plays an important role in our understanding of the dispersal of Gondwana. Previously proposed reconstruction models often contain overlaps and gaps in the restored margins that reflect difficulties in accurately delineating the continent-ocean boundary (COB) and determining the amount and distribution of extended continental crust. This study focuses on the evolution of the African margin adjacent to the Mozambique Basin and the conjugate margin of Antarctica near the Riiser Larsen Sea. New satellite-derived gravity data have been used to trace the orientations and landward limits of fracture zones in the study area. A 3-D gravity inversion has produced a crustal thickness model that reliably quantifies the extent and amount of stretched crust. Information on crustal thickness along with the identification of fracture zones reveal the COBs that are located significantly closer to the coasts of Africa and Antarctica than previously recognized. Correlation of both fracture zone azimuths and the identified COBs over the conjugate margins suggest Antarctica began drifting away from Africa at approximately 171 Ma in a roughly SSE direction. Of several scenarios examined, the Beira High is most likely oceanic and may be a conjugate feature of the southern Astrid Ridge. An areal-balancing method that involves restoring the crust to a uniform pre-rift thickness has been used to perform the non-rigid reconstruction for both non-volcanic and volcanic margin with magmatic underplating. Based on the results, Africa underwent extension of 65-105 km while Antarctic crust was stretched by 90-190 km. Both margins reveal a trend of increasing extension from east to west. Various models tested to determine the direction of extension during rifting suggest that Antarctica underwent a counter-clockwise rotation with respect to Africa between 186-171 Ma prior to the onset of seafloor spreading.

  2. Plasmodium–Helminth Coinfection and Its Sources of Heterogeneity Across East Africa

    PubMed Central

    Pullan, Rachel L.; Gitonga, Caroline W.; Ashton, Ruth A.; Kolaczinski, Jan H.; Kabatereine, Narcis B.; Snow, Robert W.

    2012-01-01

    Background. Plasmodium–helminth coinfection can have a number of consequences for infected hosts, yet our knowledge of the epidemiology of coinfection across multiple settings is limited. This study investigates the distribution and heterogeneity of coinfection with Plasmodium falciparum and 3 major helminth species across East Africa. Methods. Cross-sectional parasite surveys were conducted among 28 050 children in 299 schools across a range of environmental settings in Kenya, Uganda, and Ethiopia. Data on individual, household, and environmental risk factors were collected and a spatially explicit Bayesian modeling framework was used to investigate heterogeneities of species infection and coinfection and their risk factors as well as school- and individual-level associations between species. Results. Broad-scale geographical patterns of Plasmodium–helminth coinfection are strongly influenced by the least common infection and by species-specific environmental factors. At the individual level, there is an enduring positive association between P. falciparum and hookworm but no association between P. falciparum and Schistosoma species. However, the relative importance of such within-individual associations is less than the role of spatial factors in influencing coinfection risks. Conclusions. Patterns of coinfection seem to be influenced more by the distribution of the least common species and its environmental risk factors, rather than any enduring within-individual associations. PMID:22262792

  3. Components of rainy seasons' variability in Equatorial East Africa: onset, cessation, rainfall frequency and intensity

    NASA Astrophysics Data System (ADS)

    Camberlin, Pierre; Moron, Vincent; Okoola, Raphael; Philippon, Nathalie; Gitau, Wilson

    2009-10-01

    The inter-annual and spatial variability of different rainfall variables is analysed over Equatorial East Africa (Kenya and northeastern Tanzania). At the station level, three variables are considered: the total precipitation amount (P), the number of rain days (NRD) and the daily rainfall intensity (INT). Using a network of 34 stations, inter-station correlations (1958-1987) are computed for each of these variables. The spatial coherence of monthly or seasonal P and NRD is always much higher than that of rainfall intensity. However, large variations in spatial coherence are found in the course of the seasonal cycle. Coherence is highest at the peak of the short rains (October-December) and low during the long rains (March-May), except at its beginning. The inter-annual variability of the onset and cessation of the rains is next considered, at the regional scale, and the study extended to 2001. In the long rains, the onset and cessation dates are independent of NRD and INT during the rainy season. Hence, the long rains seasonal rainfall total depends on a combination of virtually unrelated factors, which may account for the difficulty in its prediction. However, the onset, which exhibits a large inter-annual variability and a strong spatial coherence, has a prime role. Conversely, in the short rains, though the onset is again more decisive than the cessation, the different intra-seasonal descriptors of the rains are more strongly inter-related.

  4. Hepatitis B epidemiology in Asia, the Middle East and Africa.

    PubMed

    André, F

    2000-02-18

    Asia and Africa have previously been classified as areas of high endemicity for hepatitis B virus (HBV), but in some countries highly effective vaccination programmes have shifted this pattern towards intermediate or low endemicity. Thus, China is now the only country in Asia where HBV endemicity is high. Countries with intermediate endemicity include India, Korea, the Philippines, Taiwan and Thailand, and those with low endemicity include Japan, Pakistan, Bangladesh, Singapore, Sri Lanka and Malaysia. Most countries in Africa have high HBV endemicity, with the exceptions of Tunisia and Morocco, which have intermediate endemicity. Zambia has borderline intermediate/high endemicity. In the Middle East, Bahrain, Iran, Israel and Kuwait are areas of low endemicity, Cyprus, Iraq and the United Arab Emirates have intermediate endemicity, and Egypt, Jordan, Oman, Palestine, Yemen and Saudi Arabia have high endemicity. All of these Middle East countries reach a large proportion of their population with hepatitis B vaccination, which is reducing the infection rate, particularly in Saudi Arabia. The vaccination programme in Taiwan has also greatly reduced the HBV infection rate. Future vaccination programmes must take into account the mode of transmission of HBV, the healthcare infrastructure to deliver vaccination, and the socioeconomic and political factors in each individual country, to determine the most cost-effective way of infection control. PMID:10683538

  5. Evaluating Downscaling Methods for Seasonal Climate Forecasts over East Africa

    NASA Technical Reports Server (NTRS)

    Roberts, J. Brent; Robertson, Franklin R.; Bosilovich, Michael; Lyon, Bradfield; Funk, Chris

    2013-01-01

    The U.S. National Multi-Model Ensemble seasonal forecasting system is providing hindcast and real-time data streams to be used in assessing and improving seasonal predictive capacity. The NASA / USAID SERVIR project, which leverages satellite and modeling-based resources for environmental decision making in developing nations, is focusing on the evaluation of NMME forecasts specifically for use in impact modeling within hub regions including East Africa, the Hindu Kush-Himalayan (HKH) region and Mesoamerica. One of the participating models in NMME is the NASA Goddard Earth Observing System (GEOS5). This work will present an intercomparison of downscaling methods using the GEOS5 seasonal forecasts of temperature and precipitation over East Africa. The current seasonal forecasting system provides monthly averaged forecast anomalies. These anomalies must be spatially downscaled and temporally disaggregated for use in application modeling (e.g. hydrology, agriculture). There are several available downscaling methodologies that can be implemented to accomplish this goal. Selected methods include both a non-homogenous hidden Markov model and an analogue based approach. A particular emphasis will be placed on quantifying the ability of different methods to capture the intermittency of precipitation within both the short and long rain seasons. Further, the ability to capture spatial covariances will be assessed. Both probabilistic and deterministic skill measures will be evaluated over the hindcast period

  6. Evaluating Downscaling Methods for Seasonal Climate Forecasts over East Africa

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Roberts, J. Brent; Bosilovich, Michael; Lyon, Bradfield

    2013-01-01

    The U.S. National Multi-Model Ensemble seasonal forecasting system is providing hindcast and real-time data streams to be used in assessing and improving seasonal predictive capacity. The NASA / USAID SERVIR project, which leverages satellite and modeling-based resources for environmental decision making in developing nations, is focusing on the evaluation of NMME forecasts specifically for use in impact modeling within hub regions including East Africa, the Hindu Kush-Himalayan (HKH) region and Mesoamerica. One of the participating models in NMME is the NASA Goddard Earth Observing System (GEOS5). This work will present an intercomparison of downscaling methods using the GEOS5 seasonal forecasts of temperature and precipitation over East Africa. The current seasonal forecasting system provides monthly averaged forecast anomalies. These anomalies must be spatially downscaled and temporally disaggregated for use in application modeling (e.g. hydrology, agriculture). There are several available downscaling methodologies that can be implemented to accomplish this goal. Selected methods include both a non-homogenous hidden Markov model and an analogue based approach. A particular emphasis will be placed on quantifying the ability of different methods to capture the intermittency of precipitation within both the short and long rain seasons. Further, the ability to capture spatial covariances will be assessed. Both probabilistic and deterministic skill measures will be evaluated over the hindcast period.

  7. An evaluation of GRACE groundwater estimates over East Africa

    NASA Astrophysics Data System (ADS)

    Nanteza, J.; Thomas, B. F.; de Linage, C.; Famiglietti, J. S.

    2013-12-01

    The East African (EA) region, comprised of five countries (Uganda, Kenya, Tanzania, Rwanda and Burundi), is among those regions characterized as vulnerable to water stress. The region's freshwater resources, both surface and groundwater, are impacted due to increased pressure from changes in climate and human activities. Better management approaches are required to ensure that these pressures do not significantly impact water availability and accessibility. However, the lack of adequate ground-based observation networks to monitor freshwater resources - especially groundwater (the major source of freshwater in EA), limits effective management of the available water resources. In this study, we explore the potential of using remotely sensed data to monitor freshwater resources over EA. The study uses data from the Gravity Recovery and Climate Experiment (GRACE) satellite to estimate groundwater storage variations over EA during the last decade. The satellite's performance in accurately observing changes in groundwater storage is examined by evaluating the GRACE groundwater estimates against spatially interpolated in-situ groundwater observations using goodness of fit criteria including linear regression coefficient, coefficient of determination and root mean square errors. The results demonstrate that GRACE performs well in observing the behavior of groundwater storage. These results can be useful in improving land surface model simulations - a basis for better decision making in water resources management in the region.

  8. The 17 Ma old Turkana beaked whale fossil: new paleoaltimetry constraints for uplift and environmental change in East Africa

    NASA Astrophysics Data System (ADS)

    Wichura, Henry; Jacobs, Louis L.; Strecker, Manfred R.; Lin, Andrew; Polcyn, Michael J.; Manthi, Fredrick K.; Winkler, Dale A.; Matthew, Clemens

    2015-04-01

    Timing and magnitude of vertical motions of the Earth's crust is key to evaluate the impact of tectonic processes on changes in atmospheric circulation patterns, rainfall, and environmental conditions. The East African Plateau (EAP) is a major topographic feature that fundamentally impacts the patterns of the Indian-African Monsoon and the eastward transport of air masses from the Congo Basin. Uplift of the EAP in Kenya has been linked to mantle processes, but due to the lack of reliable palaeoaltimetric data it has been challenging to unambiguously constrain plateau evolution, vertical motions associated with late Cenozoic rifting of the East African Rift System, and ensuing environmental change. We explored the fossil remains of a beaked whale (Ziphiidae) from the Turkana region in the northern Kenya Rift, 700 km inland from the present-day coastline of the Indian Ocean. The whale fossil, preserved near sea level, was discovered at an elevation of 620 m and thus constrains the uplift of the northeastern flanks of the EAP. The Kenyan ziphiid was discovered in fluvio-lacustrine sediments of the extensional Oligo-Miocene Lokichar basin (Mead, 1975) along with terrestrial mammals and freshwater molluscs below a basalt dated at 17.1 ± 1.0 Ma (Boschetto et al., 1992). The unifying characteristics of riverine occurrences of modern marine mammals include sufficient discharge in low-gradient rivers to maintain pathways deep enough to facilitate migration, and the absence of shallow bedrock, rapids, and waterfalls. The most likely route, which may have had these characteristics is a fluvial corridor controlled by protracted thermal subsidence of the Cretaceous Anza Rift, which once linked extensional processes in Central and East Africa with the continental margin of northeastern Africa. The fossil locality and analogies with present-day occurrences of marine mammals in terrestrial realms suggest that the ziphiid stranded slightly above sea level. In combination with

  9. Reconstruction of the East Africa and Antarctica continental margins

    NASA Astrophysics Data System (ADS)

    Nguyen, Luan C.; Hall, Stuart A.; Bird, Dale E.; Ball, Philip J.

    2016-06-01

    The Early Jurassic separation of Antarctica from Africa plays an important role in our understanding of the dispersal of Gondwana and Pangea. Previous reconstruction models contain overlaps and gaps in the restored margins that reflect difficulties in accurately delineating the continent-ocean-boundary (COB) and determining the amount and distribution of extended continental crust. This study focuses on the evolution of the African margin adjacent to the Mozambique Basin and the conjugate Antarctic margin near the Riiser-Larsen Sea. Satellite-derived gravity data have been used to trace the orientations and landward limits of fracture zones. A 3-D gravity inversion has produced a crustal thickness model that reliably quantifies the extent and amount of stretched crust. Crustal thicknesses together with fracture zone terminations reveal COBs that are significantly closer to the African and Antarctic coasts than previously recognized. Correlation of fracture zone azimuths and identified COBs suggests Antarctica began drifting away from Africa at approximately 171 Ma in a roughly SSE direction. An areal-balancing method has been used to restore the crust to a uniform prerift thickness so as to perform a nonrigid reconstruction for both nonvolcanic and volcanic margins. Both margins reveal a trend of increasing extension from east to west. Our results suggest Africa underwent extension of 60-120 km, while Antarctic crust was stretched by 105-180 km. Various models tested to determine the direction of extension during rifting suggest that Antarctica moved away from Africa in a WNW-ESE direction during the period between 184 and 171 Ma prior to the onset of seafloor spreading.

  10. Accuracy of Clinical Suspicion and Pathologic Diagnosis of Kaposi Sarcoma in East Africa

    PubMed Central

    Woodruff, Carina Martin; Forrestel, Amy; Wenger, Megan; McCalmont, Timothy; LeBoit, Philip; Maurer, Toby; Laker-Oketta, Miriam; Muyindike, Winnie; Bwana, Mwebesa; Buziba, Nathan; Busakhala, Naftali; Wools-Kaloustian, Kara; Martin, Jeffrey

    2016-01-01

    Background: HIV-associated Kaposi sarcoma (KS) is one of the most common malignancies in sub-Saharan Africa. The diagnosis is often based on clinical suspicion, without histopathologic confirmation. When biopsies are performed, the accuracy of interpretation by local pathologists is poorly understood. We assessed the accuracy of clinical suspicion and pathologic diagnosis of KS in 2 East African countries. Methods: At 2 large HIV care sites in Uganda and Kenya, we evaluated consecutive biopsies performed from October 2008 to January 2013 on HIV-infected adults with clinically suspected KS. Biopsies were interpreted by both local African pathologists and a group of US-based dermatopathologists from a high volume medical center. For the purpose of this analysis, the US-based dermatopathologist interpretation was used as the gold standard. Positive predictive value was used to characterize accuracy of local African clinical suspicion of KS, and concordance, sensitivity, and specificity were used to characterize accuracy of local pathologic diagnosis. Results: Among 1106 biopsies, the positive predictive value of clinical suspicion of KS was 77% (95% confidence interval: 74% to 79%). When KS was not histopathologically diagnosed, clinically banal conditions were found in 35%, medically significant disorders which required different therapy in 59% and life-threatening diseases in 6%. Concordance between African pathologists and US-based dermatopathologists was 69% (95% confidence interval: 66% to 72%). Sensitivity and specificity of African pathologic diagnoses were 68% and 89%, respectively. Conclusions: Among East African HIV-infected patients, we found suboptimal positive predictive value of clinical suspicion of KS and specific, but not sensitive, histopathologic interpretation. The findings call for abandonment of isolated clinical diagnosis of KS in the region and augmentation of local dermatopathologic services. PMID:26452066

  11. Astronomy in the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Athem Alsabti, Abdul

    2015-08-01

    Recent turbulent events in the Middle East and North Africa have influenced all aspects of life. Education in general, including astronomy, teaching and research has all been greatly affected. In this presentation, the current situation regarding astronomy in this region is reviewed in detail. This is based on visits made to Tunisia and Algeria recently on behalf of the IAU and other visits to Iraq, Qatar, Egypt and Jordan in recent years, as well as on discussions and communications with astronomers, officials and astronomical and educational institutes in the region. Discussions have also been established with astronomers from Iran, Oman and Morocco. Ideas and proposals will be presented on the best ways for the IAU and the international academic community to help under these circumstances.

  12. Remote sensing of geobotanical trends in East Africa

    NASA Technical Reports Server (NTRS)

    Warner, Timothy A.; Evans, Carla S.; Heirtzler, James R.

    1989-01-01

    The spatial and phenological distribution of vegetation was examined in a remote sensing geobotanical study of the East Africa Rift region. Six normalized difference vegetation index (NDVI) AVHRR (advanced very high resolution radiometer) scenes (February, June, and September of both 1984 and 1987) were used as a measure of vegetation presence. NOAA ETOPO-5 elevation and geographic coordinate data were coregistered with the multitemporal NDVI images. Univariate and multivariate statistics indicate that the NDVI values are significantly associated with elevation, latitude, and longitude. This supports the concept of quantifiable, regional gradients that affect large-scale geobotanical studies. A quadratic regression line was fitted to the NDVI, elevation, latitude, and longitudinal data. In this way a regional trend, as affected by elevation, was determined. The deviation of the actual data from this regional trend was displayed as an image, and shows the local climatic and geological influences.

  13. 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

  14. A Spring Forward for Hominin Evolution in East Africa

    PubMed Central

    Cuthbert, Mark O.; Ashley, Gail M.

    2014-01-01

    Groundwater is essential to modern human survival during drought periods. There is also growing geological evidence of springs associated with stone tools and hominin fossils in the East African Rift System (EARS) during a critical period for hominin evolution (from 1.8 Ma). However it is not known how vulnerable these springs may have been to climate variability and whether groundwater availability may have played a part in human evolution. Recent interdisciplinary research at Olduvai Gorge, Tanzania, has documented climate fluctuations attributable to astronomic forcing and the presence of paleosprings directly associated with archaeological sites. Using palaeogeological reconstruction and groundwater modelling of the Olduvai Gorge paleo-catchment, we show how spring discharge was likely linked to East African climate variability of annual to Milankovitch cycle timescales. Under decadal to centennial timescales, spring flow would have been relatively invariant providing good water resource resilience through long droughts. For multi-millennial periods, modelled spring flows lag groundwater recharge by 100 s to 1000 years. The lag creates long buffer periods allowing hominins to adapt to new habitats as potable surface water from rivers or lakes became increasingly scarce. Localised groundwater systems are likely to have been widespread within the EARS providing refugia and intense competition during dry periods, thus being an important factor in natural selection and evolution, as well as a vital resource during hominin dispersal within and out of Africa. PMID:25207544

  15. Gestational diabetes in rural East Africa: a call to action.

    PubMed

    Zeck, Willibald; McIntyre, H David

    2008-04-01

    The number of cases of diabetes worldwide has increased significantly in the last decade. Characteristically, the incidence of gestational diabetes (GDM) reflects the incidence of type 2 diabetes mellitus (T2DM) in the background population, which is a warning that a rapid increase in the incidence is to be expected concomitant with the already observed increase in the incidence of T2DM. Although the majority of all deliveries worldwide take place in the so-called developing world, little is known about the prevalence of diabetes in pregnancy in rural areas of East Africa. Diabetes in pregnancy has effects on prospects for marriage, motherhood, and the role of women in East African society. Furthermore, intrauterine exposure to the metabolic environment of maternal diabetes, or GDM, is associated with increased risk of altered glucose homeostasis in the offspring, beginning in childhood and producing a higher prevalence of GDM in the next generation with all burdens and complications being associated with this disease. It is reasonable to conclude that more newborn infants each year are being exposed to the metabolic environment of diabetes during intrauterine development as a result of changing incidence and demographics of diabetes and pregnancy. We believe that programs and policies have to be established, including organization of the health system to provide care, medicines, and other tools necessary for diabetes in pregnancy management, consideration of accessibility and affordability of care, education for healthcare workers, and education of pregnant and nonpregnant women of reproductive age. PMID:18328010

  16. Occurrence, composition and risk assessment of antibiotics in soils from Kenya, Africa.

    PubMed

    Yang, Yuyi; Owino, Anita Awino; Gao, Yan; Yan, Xue; Xu, Chen; Wang, Jun

    2016-08-01

    Antibiotics can accumulate in soils via different ways, which may pose serious threat to ecological environment of soil and quality of agricultural products. In this study, the occurrence of 12 antibiotics including four sulfonamides (SAs), four tetracyclines (TETs) and four fluoroquinolones (FQs) was investigated in soils from four sampling sites of Kenya (Mai Mahiu, Narok, Mount Suswa Conservancy, and Juja), Africa. The soils in suburban area of Narok had the highest average concentrations of total 12 antibiotics with an average value of 43.64 μg kg(-1) dw (dry weight), followed by Mai Mahiu (26.70 μg kg(-1) dw), Juja (24.41 μg kg(-1) dw) and Mount Suswa Conservancy (12.21 μg kg(-1) dw). Sulfamethoxazole, sulfamethazine, oxytetracycline, and enrofloxacin were identified as the main antibiotics polluted in soils. Total organic carbon may influence the distribution of SAs in Narok and FQs in Juja. Ecological risk analysis based on the risk quotient showed that SAs detected in soils have higher risk compared to TETs and FQs. PMID:27189612

  17. Noncommunicable Diseases In East Africa: Assessing The Gaps In Care And Identifying Opportunities For Improvement

    PubMed Central

    Siddharthan, Trishul; Ramaiya, Kaushik; Yonga, Gerald; Mutungi, Gerald N.; Rabin, Tracy L.; List, Justin M.; Kishore, Sandeep P.; Schwartz, Jeremy I.

    2015-01-01

    The prevalence of some noncommunicable diseases (NCDs) in East Africa is beginning to match that in high-income countries. Though the epidemiologic, demographic, and nutritional transitions are well under way in low-income countries, investment and attention in these countries remain focused largely on communicable diseases. We discuss existing infrastructure in communicable disease management as well as linkages between noncommunicable and communicable diseases in East Africa. We describe gaps in NCD management within the health systems in East Africa. We also discuss deficiencies in addressing NCDs from basic science research and medical training to health service delivery, public health initiatives and access to essential medications in East Africa. Finally, we highlight the role of collaboration among East African governments and civil society in addressing NCDs and advocate for a robust primary healthcare system that focuses on the social determinants of health. PMID:26355052

  18. Contrasting long-term records of biomass burning in wet and dry savannas of equatorial East Africa.

    PubMed

    Colombaroli, Daniele; Ssemmanda, Immaculate; Gelorini, Vanessa; Verschuren, Dirk

    2014-09-01

    Rainfall controls fire in tropical savanna ecosystems through impacting both the amount and flammability of plant biomass, and consequently, predicted changes in tropical precipitation over the next century are likely to have contrasting effects on the fire regimes of wet and dry savannas. We reconstructed the long-term dynamics of biomass burning in equatorial East Africa, using fossil charcoal particles from two well-dated lake-sediment records in western Uganda and central Kenya. We compared these high-resolution (5 years/sample) time series of biomass burning, spanning the last 3800 and 1200 years, with independent data on past hydroclimatic variability and vegetation dynamics. In western Uganda, a rapid (<100 years) and permanent increase in burning occurred around 2170 years ago, when climatic drying replaced semideciduous forest by wooded grassland. At the century time scale, biomass burning was inversely related to moisture balance for much of the next two millennia until ca. 1750 ad, when burning increased strongly despite regional climate becoming wetter. A sustained decrease in burning since the mid20th century reflects the intensified modern-day landscape conversion into cropland and plantations. In contrast, in semiarid central Kenya, biomass burning peaked at intermediate moisture-balance levels, whereas it was lower both during the wettest and driest multidecadal periods of the last 1200 years. Here, burning steadily increased since the mid20th century, presumably due to more frequent deliberate ignitions for bush clearing and cattle ranching. Both the observed historical trends and regional contrasts in biomass burning are consistent with spatial variability in fire regimes across the African savanna biome today. They demonstrate the strong dependence of East African fire regimes on both climatic moisture balance and vegetation, and the extent to which this dependence is now being overridden by anthropogenic activity. PMID:24677504

  19. LLNL Middle East and North Africa research database

    SciTech Connect

    Dodge, D; Hauk, T; Moore, R M; O'Boyle, J; Ruppert, S

    1999-07-23

    The Lawrence Livermore National Laboratory (LLNL) Comprehensive Nuclear-Test-Ban Treaty Research and Development (CTBT R and D) program has made significant progress populating a comprehensive seismic research database (RDB) for seismic events and derived research products in the Middle East and North Africa (MENA). Our original ME/NA study region has enlarged and is now defined as an area including the Middle East, Africa, Europe, Southwest Asia, the Former Soviet Union and the Scandinavian/Arctic region. The LLNL RDB will facilitate calibration of all International Monitoring System (IMS) stations (primary and auxiliary) or their surrogates (if not yet installed) as well as a variety of gamma stations. The RDB provides not only a coherent framework in which to store and organize large volumes of collected seismic waveforms and associated event parameter information, but also provides an efficient data processing/research environment for deriving location and discrimination correction sur faces and capabilities. In order to accommodate large volumes of data from many sources with diverse formats the RDB is designed to be flexible and extensible in addition to maintaining detailed quality control information and associated metadata. Station parameters, instrument responses, phase pick information, and event bulletins were compiled and made available through the RDB. For seismic events in the MENA region occurring between 1976 and 1999, we have systematically assembled, quality checked and organized event waveforms; continuous seismic data from 1990 to present are archived for many stations. Currently, over 11,400 seismic events and 1.2 million waveforms are maintained in the RDB and made readily available to researchers. In addition to open sources of seismic data, we have established collaborative relationships with several ME/NA countries that have yielded additional ground truth and broadband waveform data essential for regional calibration and capability

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  1. Molecular detection and genetic characterization of kobuviruses and astroviruses in asymptomatic local pigs in East Africa

    PubMed Central

    Okoth, Edward; Junga, Joseph O.; Ogara, William O.; Njahira, Moses N.; Wang, Qiuhong; Vlasova, Anastasia N.; Djikeng, Appolinaire

    2014-01-01

    In this study, swine fecal specimens (n = 251) collected from nursing and weaned piglets raised under smallholder production systems were screened for the presence of kobuviruses by RT-PCR. Porcine kobuviruses were detected in 13.1 % (33/251) of the samples. We demonstrated that porcine kobuvirus infections exist in indigenous pigs in Kenya and Uganda and that the prevalence was higher in young piglets than older pigs: nursing piglets (15 %), post-weaning (3-month-old) pigs (17 %), 4-month-old pigs (10 %). Genetic analysis of the partial RNA-dependent RNA polymerase (RdRp) region (690 nt) revealed that kobuviruses circulating in East Africa are diverse, sharing nucleotide sequence identities ranging from 89.7 to 99.1 % and 88 to 92.3 % among them and with known porcine kobuviruses, respectively. The nucleotide sequence identities between our kobuvirus strains and those of human, bovine and canine kobuviruses were 69.4-70.7 %, 73.1-74.4 % and 67-70.7 %, respectively. Additionally, upon sequencing selected samples that showed consistent 720-bp RT-PCR bands while using the same primer set, we detected porcine astroviruses in our samples belonging to type 2 and type 3 mamastroviruses. To our knowledge, this study reports the first detection and molecular analysis of both porcine kobuviruses and astroviruses in an African region. Further studies are required to determine the role of these viruses in gastrointestinal infections of pigs in this region and to determine the genetic diversity of the circulating strains to develop accurate diagnostic tools and implement appropriate control strategies. PMID:24327095

  2. Holocene TEX86 temperature reconstructions from Lake Turkana, East Africa

    NASA Astrophysics Data System (ADS)

    Berke, M. A.; Johnson, T. C.; Werne, J. P.; Schouten, S.; Sinninghe Damsté, J. S.

    2009-12-01

    We present new high resolution Holocene lake surface temperature records from Lake Turkana, East Africa. These two TEX86 reconstructions, from the northern and southern basins of the lake, capture ~90 year resolution of climate patterns seen in this closed-basin system, as well as the thermal water dynamics between the two basins. The modern lake experiences surface temperatures in the northern basin ~1-3 °C warmer than the southern basin, due to upwelling in the southern basin induced by the predominant southerly winds. The paleotemperature records show parallel trends to this modern basinal temperature gradient, averaging ~1.5 °C warmer in the northern basin than the southern during the ~2000 years of record overlap (~450-2500 ybp). Some temperature intervals with coverage in both basins show strong agreement (i.e. ~2600-2000 Cal ybp), whereas increased wind-generated upwelling events may be responsible for periods that appear strongly antiphased (i.e. 2000-1600 Cal ybp) between basins. There does not appear to be any evidence of warming into the Medieval Warm Period (MWP, ~800-1200AD) or cooling at the start of the Little Ice Age (LIA, ~600 ybp). The southern basin temperature record indicates a substantial ~5 °C warming culminating in a thermal maximum ~5ka, immediately followed by ~3 °C cooling. This supports previous observations of an anomalously warm interval ~5ka documented in lake surface temperature records from Lakes Malawi and Tanganyika. A similar Holocene thermal maximum ~5ka has also been described from the Indian Ocean off the coast of Somalia (3°11’N, 50°26’E) (Bard et al., 1997). The abundance of these records now point to this being the warmest or one of the warmest intervals in the Holocene in tropical East Africa and indicates this may be a widespread regional climate response. Although these temperature trends appear reasonable, overall TEX86 temperatures for Lake Turkana are considerably lower than modern surface water temperatures

  3. Can leaf wax n-alkane δ²H and GDGTs be used conjointly to reconstruct past environmental changes along altitudinal transects in East Africa?

    NASA Astrophysics Data System (ADS)

    Coffinet, Sarah; Huguet, Arnaud; Pedentchouk, Nikolai; Omuombo, Christine; Williamson, David; Bergonzini, Laurent; Wagner, Thomas; Derenne, Sylvie

    2016-04-01

    Leaf wax n-alkanes (C27-C31) and branched glycerol dialkyl glycerol tetraethers (br GDGTs) are increasingly being used as molecular proxies to investigate past environmental conditions. Indices were previously developed to relate the br GDGT distribution to temperature and pH in soils. Furthermore, the δ²Hwax of leaf wax n-alkanes in soils was shown to track the 'altitude effect', suggesting it could be used to reconstruct paleoelevation. Combination of these two proxies could bring information on both past uplift elevation and past temperature changes, as illustrated by the pioneer paleostudy of Hren et al. (2010) in the Sierra Nevada. In the present study, δ²Hwax and br GDGTs were analysed in ca. 60 surface soils collected along Mt. Rungwe (Southwest Tanzania) and Mt. Kenya (Central Kenya). A weak link was identified between δ²Hwax and altitude (R² = 0.33) along Mt. Kenya, whereas no trend was observed along Mt. Rungwe, as also previously shown by Peterse et al. (2009) for Mt. Kilimanjaro. This shows that the strength of the relationship between soil δ²Hwax and elevation depends on which mountain is considered in East Africa and can be overprinted by numerous poorly understood environmental and/or physiological parameters. In contrast, br GDGT-derived mean annual air temperature (MAAT) and temperature lapse rate (5 °C/1000 m) were in agreement with values recorded along both Mt. Rungwe and Mt. Kenya, highlighting the robustness of this proxy for paleotemperature reconstruction in East Africa. Moreover, the combination of these br GDGT data with previous results obtained from East African surface soils (along Mts. Kilimanjaro (Tanzania), Sinninghe Damsté et al., 2008; Rwenzori (Uganda), Loomis et al., 2011; Rungwe (Tanzania), Coffinet et al., 2014), allowed the establishment of a regional soil calibration between br GDGT distribution and MAAT. This new East African calibration, based on 105 samples, leads to a substantial improvement of both the R2 (0

  4. Event location in the Middle East and North Africa

    SciTech Connect

    Schultz, C.A.; Myers, S.C.; Ruppert, S.D.

    1997-07-01

    The Lawrence Livermore National Laboratory (LLNL) CTBT R{ampersand}D program has made significant progress towards improving the ability of the IMS seismic network to locate small-magnitude events in the Middle East and North Africa (MIYNA). Given that high-grade ground truth (such as known explosions) has been difficult to obtain in these regions, we have placed a significant effort towards the development of a teleseismically constrained seismic database that provides event locations good to within 20m km. This data set is used to make an initial evaluation of the effectiveness of calibration on the proposed seismic IMS network in the MWNA. Utilizing a surrogate IMS regional network in the Middle East we find that when a seismic event lies within the footprint of the recording network the uncalibrated event locations are good to within about 25 km of the teleseismically constrained (TC) location. Using region-specific static station corrections further reduces this difference to about 20 km. To obtain further improvement in location accuracy we have used the modified kriging technique developed by SNL to interpolate new travel-time corrections. We compare this technique withe other robust linear interpolation techniques with the goal of enhancing the estimation of travel-time corrections. This is important to TC events which we find can have large uncorrelated uncertainties. Finally, we are making a large effort to incorporate LLNL analyst picks on primary and secondary phases and develop azimuth and slownsess estimates horn current IMS arrays to improve/supplement the NEIC picks.

  5. Evaluating ESA CCI soil moisture in East Africa

    NASA Astrophysics Data System (ADS)

    McNally, Amy; Shukla, Shraddhanand; Arsenault, Kristi R.; Wang, Shugong; Peters-Lidard, Christa D.; Verdin, James P.

    2016-06-01

    To assess growing season conditions where ground based observations are limited or unavailable, food security and agricultural drought monitoring analysts rely on publicly available remotely sensed rainfall and vegetation greenness. There are also remotely sensed soil moisture observations from missions like the European Space Agency (ESA), Soil Moisture and Ocean Salinity (SMOS) and NASA's Soil Moisture Active Passive (SMAP); however, these time series are still too short to conduct studies that demonstrate the utility of these data for operational applications, or to provide historical context for extreme wet or dry events. To promote the use of remotely sensed soil moisture in agricultural drought and food security monitoring, we evaluate the quality of a 30+ year time series of merged active-passive microwave soil moisture from the ESA Climate Change Initiative (CCI-SM) over East Africa. Compared to the Normalized Difference Vegetation index (NDVI) and modeled soil moisture products, we find substantial spatial and temporal gaps in the early part of the CCI-SM record, with adequate data coverage beginning in 1992. From this point forward, growing season CCI-SM anomalies are well correlated (R > 0.5) with modeled soil moisture, and in some regions, NDVI. We use pixel-wise correlation analysis and qualitative comparisons of seasonal maps and time series to show that remotely sensed soil moisture can inform remote drought monitoring that has traditionally relied on rainfall and NDVI in moderately vegetated regions.

  6. LLNL Middle East and North Africa research database

    SciTech Connect

    Ruppert, S.D.; Hauk, T.F.; Leach, R.

    1997-07-15

    The Lawrence Livermore National Laboratory (LLNL) CTBT R{ampersand}D program has made significant progress assembling a comprehensive seismic database (DB) for events and derived parameters in the Middle East and North Africa (ME/NA). The LLNL research DB provides not only a coherent framework in which store and organize large volumes of collected seismic waveforms and associated event parameter information but also provides an efficient data processing/research environment. The DB is designed to be flexible and extensible in order to accommodate the large volumes of data in diverse formats from many sources in addition to maintaining detailed quality control and metadata. Researchers can make use of the relational nature of the DB and interactive analysis tools to quickly and efficiently process large volumes of data. Seismic waveforms have been systematically collected form a wide range of local and regional networks using numerous earthquake bulletins and converted a common format based on CSS3.O while undergoing quality control and corrections of errors. By combining traveltime observations, event characterization studies, and regional wave-propagation studies of the LLNL CTBT team, we are assembling a library of ground truth information and event location correction surfaces required to support the ME/NA regionalization program. Corrections and parameters distilled from the LLNL research DB will provide needed contributions to the DOE knowledge base for the ME/NA region and enable the USNDC and IDC to effectively verify CTBT compliance.

  7. Reporting AIDS in Kenya: a personal report. Guidelines for journalists have been issued in the UK. What about Africa?

    PubMed

    Hanssen, N

    1993-01-01

    A Norwegian journalist reports on his experiences covering the acquired immunodeficiency syndrome (AIDS) epidemic in Kenya. Denial by the government has resulted in reduced figures. President Daniel Arap Moi refuses to admit that the epidemic has become national in scope. The public broadcasting services carry little information about the epidemic. A study indicating that 25/1700 prostitutes in Nairobi were positive for human immunodeficiency virus (HIV) has been met with skepticism by the public, who question the survey (what was the relationship between researchers and prostitutes, were the prostitutes paid to risk their lives, why was the study carried out in Africa). Some believe the 25 positive women are 'immune' because of a similar gene pattern. There are 750,000 HIV positive adults and 30,000 AIDS cases in Kenya, including a large number of cases among street urchins. Most AIDS cases are sent home to die because of the short supply of hospital beds (45,000). One of these was Ruth Kasuki, a 36-year-old mother of three and AIDS educator and counselor in Kenya, who is now deceased. In an interview conducted shortly before her death, she criticizes the government for its denial and predicts disastrous results. Ms. Kasuki also blamed the extramarital affairs of men for the spread of AIDS among Kenyan women. 8% of women receiving antenatal care are estimated to have HIV; in Nyanza Coast and Nairobi the estimate reaches 12%. Ms. Kasuki also cited the negative attitude of the clergy. PMID:12287718

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

    PubMed

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

    2010-06-22

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

  9. Potential of Gdgts as Temperature Proxies Along Altitudinal Transects in East Africa

    NASA Astrophysics Data System (ADS)

    Coffinet, Sarah; Huguet, Arnaud; Omuombo, Christine; Williamson, David; Fosse, Céline; Anquetil, Christine; Derenne, Sylvie

    2014-05-01

    Glycerol dialkyl glycerol tetraethers (GDGTs) are lipids of high molecular weight and include the isoprenoid GDGTs (iGDGTs) produced by Archaea and the branched GDGTs (brGDGTs) produced by unknown bacteria. Several indices were developed to describe the relationship between GDGT distribution and environmental parameters: the TEX86 (tetraether index of tetraethers consisting of 86 carbons), based on the relative abundances of iGDGTs in sediments, and the MBT (methylation index of branched tetraethers) and CBT (cyclisation ratio of branched tetraethers), based on the relative abundance of brGDGTs in soils. The TEX86 was shown to correlate well with water surface temperature, and the MBT and CBT with mean annual air temperature (MAAT) and soil pH. The GDGTs are increasingly used as temperature proxies. In this study, 41 surface soils were sampled along two altitudinal transects, from 500 to 2800 meters in Mount Rungwe (South western, Tanzania) and from 1897 to 3268 meters in Mount Kenya (Central Kenya). MAAT was reconstructed along the two transects using the MBT/CBT proxies. A linear correlation between the MBT/CBT-derived temperatures and the altitude (R2=0.83) was obtained by combining results of the two transects. The reconstructed temperature lapse rate (0.5 ° C/100 m) was consistent with the one determined from temperature measurements at six altitudes. These results show that the MBT/CBT is a suitable and robust temperature proxy in East Africa. In Mt. Rungwe soil samples, the TEX86 index, which was mainly used to reconstruct water surface temperatures until now, was found to vary linearly with altitude (R2=0.50). Such a relationship between TEX86 and altitude in organic soils has also been recently noticed in Mt. Xiangpi, China (Liu et al., 2013; R2=0.68). The adiabatic cooling of air with altitude could explain the TEX86 variation with altitude. If such a relationship is confirmed, the use of the TEX86 as a temperature proxy could be extended to soil

  10. Rural Development in Africa: A Bibliography. (Part I: General, Central, East). Training & Methods Series Number 16.

    ERIC Educational Resources Information Center

    Anderson, Teresa, Comp.; And Others

    Compiled in July, 1971, this bibliography lists approximately 1,950 books, journal articles, and unpublished manuscripts dealing with rural development in Africa generally and in central and east Africa specifically. General entries appear under the following headings: agriculture; economic affairs; bibliography; law; economic and technical…

  11. Design and descriptive epidemiology of the Infectious Diseases of East African Livestock (IDEAL) project, a longitudinal calf cohort study in western Kenya

    PubMed Central

    2013-01-01

    Background There is a widely recognised lack of baseline epidemiological data on the dynamics and impacts of infectious cattle diseases in east Africa. The Infectious Diseases of East African Livestock (IDEAL) project is an epidemiological study of cattle health in western Kenya with the aim of providing baseline epidemiological data, investigating the impact of different infections on key responses such as growth, mortality and morbidity, the additive and/or multiplicative effects of co-infections, and the influence of management and genetic factors. A longitudinal cohort study of newborn calves was conducted in western Kenya between 2007-2009. Calves were randomly selected from all those reported in a 2 stage clustered sampling strategy. Calves were recruited between 3 and 7 days old. A team of veterinarians and animal health assistants carried out 5-weekly, clinical and postmortem visits. Blood and tissue samples were collected in association with all visits and screened using a range of laboratory based diagnostic methods for over 100 different pathogens or infectious exposures. Results The study followed the 548 calves over the first 51 weeks of life or until death and when they were reported clinically ill. The cohort experienced a high all cause mortality rate of 16% with at least 13% of these due to infectious diseases. Only 307 (6%) of routine visits were classified as clinical episodes, with a further 216 reported by farmers. 54% of calves reached one year without a reported clinical episode. Mortality was mainly to east coast fever, haemonchosis, and heartwater. Over 50 pathogens were detected in this population with exposure to a further 6 viruses and bacteria. Conclusion The IDEAL study has demonstrated that it is possible to mount population based longitudinal animal studies. The results quantify for the first time in an animal population the high diversity of pathogens a population may have to deal with and the levels of co-infections with key

  12. Effects of urban wastewater on crab and mollusc assemblages in equatorial and subtropical mangroves of East Africa

    NASA Astrophysics Data System (ADS)

    Cannicci, Stefano; Bartolini, Fabrizio; Dahdouh-Guebas, Farid; Fratini, Sara; Litulo, Carlos; Macia, Adriano; Mrabu, Elisha J.; Penha-Lopes, Gil; Paula, José

    2009-09-01

    Mangrove forests are known to accomplish crucial ecosystem functions and services. They are nursery areas for fish, prawns and crabs, which provide coastal communities with a variety of food, timber and chemicals, and protect coasts from catastrophic events, such as tsunamis. Recently, a novel ecological service has been proposed for mangrove systems, namely natural wastewater treatment wetlands. This hypothesis was based on experimental data collected mainly in Chinese mangrove systems, which proved that mangrove soils were efficient in absorbing nutrients. Moreover, sewage loading seemed harmless to both plants and benthic communities in these systems. However, before promoting the use of natural mangroves as pollution buffers, or constructed mangrove wetlands as sewage treatment facilities, more data are needed on their overall tolerance to organic loading. Differences in macrobenthos patterns were thus investigated between peri-urban mangroves and sites not affected by sewage disposal in East Africa. We assessed differences in epifaunal assemblages, comprising crabs and molluscs, employing multivariate ACI unbalanced analyses to compare peri-urban mangrove swamps with those characteristic of non-urban mangroves with similar ecological traits. The sampling design was spatially nested, replicates being assessed at equatorial (southern Kenya) and subtropical (southern Mozambique) sites. The results manifested a consistent increase in crab biomass at the peri-urban sites in both Kenya and Mozambique. Moreover, the peri-urban systems were richer than the non-urban mangroves, both in terms of fiddler crabs ( Uca spp.) which feed on benthic microalgae and bacteria, and sesarmids, such as Perisesarma guttatum and Neosarmatium meinerti, which feed on both substratum and leaf litter. The abundance of gastropods, in contrast, decreased significantly, especially in Kenya, mainly due to the disappearance of the mud whelk Terebralia palustris. The results thus indicate that

  13. Complete Genome Sequences of Lineage III Peste des Petits Ruminants Viruses from the Middle East and East Africa.

    PubMed

    Muniraju, Murali; Munir, Muhammad; Banyard, Ashley C; Ayebazibwe, Chrisostom; Wensman, Jonas; Zohari, Siamak; Berg, Mikael; Parthiban, AravindhBabu R; Mahapatra, Mana; Libeau, Geneviève; Batten, Carrie; Parida, Satya

    2014-01-01

    For the first time, complete genome sequences of four lineage III peste des petits ruminants (PPR) viruses (Oman 1983, United Arab Emirates 1986, Ethiopia 1994, and Uganda 2012) originated from the Middle East and East Africa are reported here. The availability of complete genome sequences from all four lineages (I to IV) of the PPR virus (PPRV) would greatly help in a comprehensive understanding of the molecular evolution and emergence of PPRV. PMID:25342675

  14. Food, Aid, and Education in East Africa: Repackaging the Conversation

    ERIC Educational Resources Information Center

    Stambach, Amy

    2016-01-01

    This paper examines students' food perspectives in three rapidly diversifying contemporary contexts: a university setting in Kigali, Rwanda where students help to prepare Chinese dumplings; a school garden and canteen in Nairobi, Kenya where students jostle for bowls of beans and rice; and a fast-food restaurant in Dar es Salaam, Tanzania, where…

  15. Drought-associated chikungunya emergence along coastal East Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Epidemics of chikungunya fever, an Aedes spp.-borne viral disease, affected hundreds of thousands of people in western Indian Ocean islands and India during 2005--2006. The initial outbreaks occurred in coastal Kenya (Lamu, then Mombasa) in 2004. We investigated ecoclimatic conditions associated wit...

  16. Forecast and Validation of the Rift Valley fever outbreak in East Africa: 2006-2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background The instantaneous occurrence of El Nino / Southern Oscillation (ENSO) warm events and anomalous warming of the equatorial western Indian Ocean (WIO) are associated with elevated and widespread rainfall over East Africa. Such, sustained, heavy rainfall in East is associated with the emerg...

  17. Smart Boards to Chalkboards: Professional Development for Early Childhood Teachers in Rural East Africa

    ERIC Educational Resources Information Center

    Williams, Jeanne

    2012-01-01

    The purpose of this study was to examine the teaching strategies of early childhood development teachers in rural East Africa. Teams of early childhood educators from the United States presented professional development conferences for East African Early Childhood Development teachers during the summers of 2007 and 2008. The conferences introduced…

  18. Unlocking the potential of tropical root crop biotechnology in east Africa by establishing a genetic transformation platform for local farmer-preferred cassava cultivars

    PubMed Central

    Nyaboga, Evans; Njiru, Joshua; Nguu, Edward; Gruissem, Wilhelm; Vanderschuren, Herve; Tripathi, Leena

    2013-01-01

    Cassava genetic transformation capacity is still mostly restricted to advanced laboratories in the USA, Europe and China; and its implementation and maintenance in African laboratories has remained scarce. The impact of transgenic technologies for genetic improvement of cassava will depend largely on the transfer of such capabilities to researchers in Africa, where cassava has an important socioeconomic niche. A major constraint to the development of genetic transformation technologies for cassava improvement has been the lack of an efficient and robust transformation and regeneration system. Despite the success achieved in genetic modification of few cassava cultivars, including the model cultivar 60444, transgenic cassava production remains difficult for farmer-preferred cultivars. In this study, a protocol for cultivar 60444 developed at ETH Zurich was successfully implemented and optimized to establish transformation of farmer-preferred cassava cultivars popular in east Africa. The conditions for production and proliferation of friable embryogenic calli (FEC) and Agrobacterium-mediated transformation were optimized for three east African farmer-preferred cultivars (Ebwanatereka, Kibandameno and Serere). Our results demonstrated transformation efficiencies of about 14–22 independent transgenic lines per 100 mg of FEC for farmer-preferred cultivars in comparison to 28 lines per 100 mg of the model cultivar 60444. The presence, integration and expression of the transgenes were confirmed by PCR, Southern blot analysis and histochemical GUS assay. This study reports the establishment of a cassava transformation platform at International Institute of Tropical Agriculture (IITA) hosted by Biosciences eastern and central Africa (BecA) hub in Kenya and provides the basis for transferring important traits such as virus resistance and prolonged shelf-life to farmer-preferred cultivars in east Africa. We anticipate that such platform will also be instrumental to transfer

  19. Development of grasslands and savannas in East Africa during the Neogene

    NASA Astrophysics Data System (ADS)

    Serling, T. E.

    1992-03-01

    The development of savanna-type grasslands is a relatively recent phenomena in East Africa. The stable carbon isotopic composition of paleosol carbonates from fossil localities in East Africa show that C 4 vegetation was present by amout 8-9 Ma but made up only a relatively small proportion of the total biomass. Although the proportion of C 4 vegetation increased in the Pliocene and Pleistocene there is no evidence for the development of virtually pure C 4 grasslands, as is characterized by tropical grasslands today, until Middle Pleistocene times. This has important implications concerning the evolution of mammals in Africa, including hominids.

  20. Diagnostic tests for kala-azar: a multi-centre study of the freeze-dried DAT, rK39 strip test and KAtex in East Africa and the Indian subcontinent.

    PubMed

    Boelaert, M; El-Safi, S; Hailu, A; Mukhtar, M; Rijal, S; Sundar, S; Wasunna, M; Aseffa, A; Mbui, J; Menten, J; Desjeux, P; Peeling, R W

    2008-01-01

    Three diagnostic tests for visceral leishmaniasis (VL), the freeze-dried direct agglutination test (FD-DAT), the rK39 dipstick and a urine latex antigen test (KAtex), were evaluated for use in primary care in East Africa and the Indian subcontinent. Clinical suspects were prospectively recruited and tissue, blood and urine samples were taken. Direct microscopic examination of tissue smear, and FD-DAT, rK39 and KAtex were performed. Sensitivity and specificity with 95% credible intervals were estimated using Bayesian latent class analysis. On the Indian subcontinent both the FD-DAT and the rK39 strip test exceeded the 95% sensitivity and 90% specificity target, but not so in East Africa. Sensitivity of the FD-DAT was high in Ethiopia and Kenya but lower in Sudan, while its specificity was below 90% in Kenya. Sensitivity of the rK39 was below 80% in the three countries, and its specificity was only 70% in Ethiopia. KAtex showed moderate to very low sensitivity in all countries. FD-DAT and rK39 can be recommended for clinical practice on the Indian subcontinent. In East Africa, their clinical use should be carefully monitored. More work is needed to improve existing formats, and to develop better VL diagnostics. PMID:17942129

  1. Reconciling Past and Future Rainfall Trends over East Africa

    NASA Astrophysics Data System (ADS)

    Rowell, Dave; Booth, Ben; Nicholson, Sharon; Good, Peter

    2016-04-01

    droughts, and that the response to CO2 forcing over East Africa is not substantially non-linear (Hypotheses E and F). Further work should therefore focus on improving the modelling of aerosol impacts on regional rainfall changes, on providing a well-considered 'expert judgement' of the reliability of the model's projections for the coming century, and better understanding the relevant natural variability.

  2. Understanding the nature of mantle upwelling beneath East-Africa

    NASA Astrophysics Data System (ADS)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2014-05-01

    The concept of hot upwelling material - otherwise known as mantle plumes - has long been accepted as a possible mechanism to explain hotspots occurring at Earth's surface and it is recognized as a way of removing heat from the deep Earth. Nevertheless, this theory remains controversial since no one has definitively imaged a plume and over the last decades several other potential mechanisms that do not require a deep mantle source have been invoked to explain this phenomenon, for example small-scale convection at rifted margins, meteorite impacts or lithospheric delamination. One of the best locations to study the potential connection between hotspot volcanism at the surface and deep mantle plumes on land is the East African Rift (EAR). We image seismic velocity structure of the mantle below EAR with higher resolution than has been available to date by including seismic data recorded by stations from many regional networks ranging from Saudi Arabia to Tanzania. We use relative travel-time tomography to produce P- velocity models from the surface down into the lower mantle incorporating 9250 ray-paths in our model from 495 events and 402 stations. We add smaller earthquakes (4.5 < mb < 5.5) from poorly sampled regions in order to have a more uniform data coverage. The tomographic results allow us to image structures of ~ 100-km length scales to ~ 1000 km depth beneath the northern East-Africa rift (Ethiopia, Eritrea, Djibouti, Yemen) with good resolution also in the transition zone and uppermost lower mantle. Our observations provide evidence that the shallow mantle slow seismic velocities continue trough the transition zone and into the lower mantle. In particular, the relatively slow velocity anomaly beneath the Afar Depression extends up to depths of at least 1000 km depth while another low-velocity anomaly beneath the Main Ethiopian Rift seems to be present in the upper mantle only. These features in the lower mantle are isolated with a diameter of about 400 km

  3. Analysis of satellite precipitation over East Africa during last decades

    NASA Astrophysics Data System (ADS)

    Cattani, Elsa; Wenhaji Ndomeni, Claudine; Merino, Andrés; Levizzani, Vincenzo

    2016-04-01

    Daily accumulated precipitation time series from satellite retrieval algorithms (e.g., ARC2 and TAMSAT) are exploited to extract the spatial and temporal variability of East Africa (EA - 5°S-20°N, 28°E-52°E) precipitation during last decades (1983-2013). The Empirical Orthogonal Function (EOF) analysis is applied to precipitation time series to investigate the spatial and temporal variability in particular for October-November-December referred to as the short rain season. Moreover, the connection among EA's precipitation, sea surface temperature, and soil moisture is analyzed through the correlation with the dominant EOF modes of variability. Preliminary results concern the first two EOF's modes for the ARC2 data set. EOF1 is characterized by an inter-annual variability and a positive correlation between precipitation and El Niño, positive Indian Ocean Dipole mode, and soil moisture, while EOF2 shows a dipole structure of spatial variability associated with a longer scale temporal variability. This second dominant mode is mostly linked to sea surface temperature variations in the North Atlantic Ocean. Further analyses are carried out by computing the time series of the joint CCI/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI, http://etccdi.pacificclimate.org/index.shtml), i.e. RX1day, RX5day, CDD, CDD, CWD, SDII, PRCPTOT, R10, R20. The purpose is to identify the occurrenes of extreme events (droughts and floods) and extract precipitation temporal variation by trend analysis (Mann-Kendall technique). Results for the ARC2 data set demonstrate the existence of a dipole spatial pattern in the linear trend of the time series of PRCPTOT (annual precipitation considering days with a rain rate > 1 mm) and SDII (average precipitation on wet days over a year). A negative trend is mainly present over West Ethiopia and Sudan, whereas a positive trend is exhibited over East Ethiopia and Somalia. CDD (maximum number of consecutive dry days) and

  4. Responding to the Gender and Education Millennium Development Goals in South Africa and Kenya: Reflections on Education Rights, Gender Equality, Capabilities and Global Justice

    ERIC Educational Resources Information Center

    Unterhalter, Elaine; North, Amy

    2011-01-01

    This paper explores understandings of gender equality and education and the nature of global goal and target setting, drawing on empirical data collected in central and local government departments in Kenya and South Africa reflecting on their implementation of Millennium Development Goal (MDG) 1, concerned with poverty, MDG 2, concerned with…

  5. The Elusive Access to Education for Muslim Women in Kenya from the Late Nineteenth Century to the "Winds of Change" in Africa (1890s to 1960s)

    ERIC Educational Resources Information Center

    Keshavjee, Rashida

    2010-01-01

    This article discusses the denial of access to education to Ismaili Muslim women in colonial Kenya during the 1890s and the 1960s. The Ismailis were part of the "Asians" in Africa, a working class, religious, Muslim immigrant group from India, circumscribed by poverty and a traditional culture, the orthodox elements of which, with regard to their…

  6. Hypovitaminosis D in the Middle East and North Africa

    PubMed Central

    Bassil, Darina; Rahme, Maya; Hoteit, Maha; Fuleihan, Ghada El-Hajj

    2013-01-01

    Background: The Middle East and North Africa (MENA) region registers some of the highest rates of hypovitaminosis D worldwide.   Aim: We systematically reviewed the prevalence of hypovitaminosis D, rickets and osteomalacia, their predictors and impact on major outcomes, in the region. Methods: Medline, Pubmed and Embase search engines, entering keywords and concepts, combined with individual countries of interest, were used. Search was limited years 2000–2012; and review articles were used for the period preceding year 2000. Results: Rickets and osteomalacia still occur in this sunny region. Hypovitaminosis D prevails, with rates varying 30–90%, considering a desirable serum 25 hydroxy-vitamin D [25(OH)D] of 20 ng/ml. Advancing age, female gender, multi-parity, clothing style, season, socio-economic status and urban living are recognized predictors of hypovitaminosis D in adults. Prolonged breastfeeding without vitamin D supplementation and low dietary calcium intake are the recognized risk factors for rickets and hypovitaminosis D in children.. Associations with pain score and disease activity in rheumatologic disorders, viral load and interleukins in hepatitis C, BMI, lipids and insulin sensitivity, blood pressure, heart failure and mortality are described. Sun exposure in adults decreased prevalence of metabolic syndrome in one study. Few randomized vitamin D trials revealed that the majority of mothers or children failed to achieve a desirable 25(OH)D level, even with doses by far exceeding current recommendations. A trial in adolescent girls reveals substantial bone and lean mass increments. Conclusion: Hypovitaminosis D is prevalent in MENA. The lack of populations based studies, gaps in studies in infants, pre-pubertal children and pregnant women, hinder the development of region specific guidelines and constitute a major obstacle to impact this chronic and most often subclinical disease. PMID:24194968

  7. Public health in pre-colonial east-central Africa.

    PubMed

    Waite, G

    1987-01-01

    This study is the first of its kind to suggest that a rich public health tradition existed in east-central Africa before the twentieth century, and that the tradition can be reconstructed historically. It breaks with earlier studies of public health history for the region in that it does not define public health on the basis of western institutions and activities. The definition of public health that is used in this study makes a simple equation between politics and medicine. It includes all activities that ruling authorities undertake to promote the well-being of the societies over which they have charge. Thus rainmaking and sorcery control, the principal services in traditional African societies, are the focus of this study. Evidence is presented here of the control exercised by kings, chiefs, priests over these services in various societies located in southeastern Zaire, southern Tanzania, Zambia, Malawi, northern Mozambique, and Zimbabwe. The cases are all set in the pre-colonial period, before the twentieth century and the beginning of most written records. The evidence is derived primarily, though not exclusively, from non-written sources, such as archaeology, linguistic, and ethnographic records. The best data are those that come from cultural exchanges between people, for historical records are created in this way. Therefore, the cases discussed here all involve contacts between immigrant and autochthonous groups. The political histories of these contacts are already known. What this study does is link up those traditions with independently-acquired evidence of change in medical traditions. Political change often, but not always, led to change in public health institutions. The control of ruling elites over health services is thus made apparent by the manner in which new medical institutions were implanted when new political authorities arose. PMID:3547688

  8. Size variation in Tachyoryctes splendens (East African mole-rat) and its implications for late Quaternary temperature change in equatorial East Africa

    NASA Astrophysics Data System (ADS)

    Faith, J. Tyler; Patterson, David B.; Blegen, Nick; O'Neill, Chris J.; Marean, Curtis W.; Peppe, Daniel J.; Tryon, Christian A.

    2016-05-01

    This study develops a new proxy for Quaternary temperature change in tropical Africa through analysis of size variation in East African mole-rat (Tachyoryctes splendens). In modern mole-rats, mandibular alveolar length is unrelated to annual precipitation, precipitation seasonality, temperature seasonality, or primary productivity. However, it is inversely correlated with mean annual temperature, in agreement with Bergmann's rule. This relationship is observed at temperatures below ∼17.3 °C, but not at higher temperatures. We apply these observations to late Quaternary mole-rats from Wakondo (∼100 ka) and Kisaaka (∼50 ka) in the Lake Victoria region and Enkapune ya Muto (EYM; ∼7.2-3.2 ka) in Kenya's central rift. The Lake Victoria mole-rats are larger than expected for populations from warm climates typical of the area today, implying cooler temperatures in the past. The magnitude of temperature decline needed to drive the size shift is substantial (∼4-6 °C), similar in magnitude to the degree of change between the Last Glacial Maximum and Holocene, but is consistent with regional temperature records and with scenarios linking equatorial African temperature to northern hemisphere summer insolation. Size changes through time at EYM indicate that rising temperatures during the middle Holocene accompanied and potentially contributed to a decline in Lake Naivasha and expansion of grassland vegetation.

  9. Noncommunicable Diseases In East Africa: Assessing The Gaps In Care And Identifying Opportunities For Improvement.

    PubMed

    Siddharthan, Trishul; Ramaiya, Kaushik; Yonga, Gerald; Mutungi, Gerald N; Rabin, Tracy L; List, Justin M; Kishore, Sandeep P; Schwartz, Jeremy I

    2015-09-01

    The prevalence of noncommunicable diseases in East Africa is rising rapidly. Although the epidemiologic, demographic, and nutritional transitions are well under way in low-income countries, investment and attention in these countries remain focused largely on communicable diseases. We discuss existing infrastructure in communicable disease management as well as linkages between noncommunicable and communicable diseases in East Africa. We describe gaps in noncommunicable disease management within the health systems in this region. We also discuss deficiencies in addressing noncommunicable diseases from basic science research and medical training to health services delivery, public health initiatives, and access to essential medications in East Africa. Finally, we highlight the role of collaboration among East African governments and civil society in addressing noncommunicable diseases, and we advocate for a robust primary health care system that focuses on the social determinants of health. PMID:26355052

  10. What are the emerging features of community health insurance schemes in East Africa?

    PubMed Central

    Basaza, Robert; Pariyo, George; Criel, Bart

    2009-01-01

    Background The three East African countries of Uganda, Tanzania, and Kenya are characterized by high poverty levels, population growth rates, prevalence of HIV/AIDS, under-funding of the health sector, poor access to quality health care, and small health insurance coverage. Tanzania and Kenya have user-fees whereas Uganda abolished user-fees in public-owned health units. Objective To provide comparative description of community health insurance (CHI) schemes in three East African countries of Uganda, Tanzania, and Kenya and thereafter provide a basis for future policy research for development of CHI schemes. Methods An analytical grid of 10 distinctive items pertaining to the nature of CHI schemes was developed so as to have a uniform lens of comparing country situations of CHI. Results and conclusions The majority of the schemes have been in existence for a relatively short time of less than 10 years and their number remains small. There is need for further research to identify what is the mix and weight of factors that cause people to refrain from joining schemes. Specific issues that could also be addressed in subsequent studies are whether the current schemes provide financial protection, increase access to quality of care and impact on the equity of health services financing and delivery. On the basis of this knowledge, rational policy decisions can be taken. The governments thereafter could consider an option of playing more roles in advocacy, paying for the poorest, and developing an enabling policy and legal framework. PMID:22312207

  11. Cardiovascular Risk Factor Burden in Africa and the Middle East: The Africa Middle East Cardiovascular Epidemiological (ACE) Study

    PubMed Central

    Alsheikh-Ali, Alawi A.; Omar, Mohamed I.; Raal, Frederick J.; Rashed, Wafa; Hamoui, Omar; Kane, Abdoul; Alami, Mohamed; Abreu, Paula; Mashhoud, Walid M.

    2014-01-01

    Background Increased urbanization in the developing world parallels a rising burden of chronic diseases. Developing countries account for ∼80% of global cardiovascular (CV) deaths, but contribute a paucity of systematic epidemiological data on CV risk factors. Objective To estimate the prevalence of CV risk factors in rural and urban cohorts attending general practice clinics in the Africa and Middle East (AfME) region. Methods In a cross-sectional epidemiological study, the presence of CV risk factors (hypertension, diabetes mellitus (diabetes), dyslipidemia, obesity, smoking and abdominal obesity) were evaluated in stable adult outpatients attending general practice primary care clinics. A rural population was defined as isolated (>50 km or lack of easy access to commuter transportation) from urban centers. Results 4,378 outpatients were systematically recruited from 94 clinics across 14 AfME countries. Mean age was 46±14 years and 52% of outpatients were female. A high prevalence of dyslipidemia (70%) and abdominal obesity (68%) were observed, followed by hypertension (43%) and diabetes (25%). The vast majority of outpatients (92%) had at least one modifiable CV risk factor, many (74%) had more than one, and half (53%) had 3 or more. These findings were observed in both genders and across urban and rural centers. Among outpatients with pre-existing hypertension or dyslipidemia, many were not at their target blood pressure or LDL-cholesterol goals. Conclusion Cardiovascular risk factors are highly prevalent among relatively young, stable outpatients attending general practice clinics across AfME. The findings support opportunistic screening for CV risk factors whenever outpatients visit a general practitioner and provide an opportunity for early identification and management of CV risk factors, including lifestyle interventions. PMID:25090638

  12. The Influence of European Pollution on Ozone in the Near East and Northern Africa

    NASA Technical Reports Server (NTRS)

    Duncan, B. N.; West, J. J.; Yoshida, Y.; Fiore, A. M.; Ziemke, J. R.

    2008-01-01

    We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50-150 additional violations per year (i.e. above those that would occur without European pollution) of the European health standard for ozone (8-h average greater than 120 micrograms per cubic meters or approximately 60 ppbv) in northern Africa and the Near East. We estimate that European ozone pollution is responsible for 50 000 premature mortalities globally each year, of which the majority occurs outside of Europe itself, including 37% (19 000) in northern Africa and the Near East. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions.

  13. LLNL Middle East, North Africa and Western Eurasia Knowledge Base

    SciTech Connect

    O'Boyle, J; Ruppert, S D; Hauk, T F; Dodge, D A; Ryall, F; Firpo, M A

    2001-07-12

    The Lawrence Livermore National Laboratory (LLNL) Ground-Based Nuclear Event Monitoring (GNEM) program has made significant progress populating a comprehensive Seismic Research Knowledge Base (SRKB) and deriving calibration parameters for the Middle East, North Africa and Western Eurasia (ME/NA/WE) regions. The LLNL SRKB provides not only a coherent framework in which to store and organize very large volumes of collected seismic waveforms, associated event parameter information, and spatial contextual data, but also provides an efficient data processing/research environment for deriving location and discrimination correction surfaces. The SRKB is a flexible and extensible framework consisting of a relational database (RDB), Geographical Information System (GIS), and associated product/data visualization and data management tools. This SRKB framework is designed to accommodate large volumes of data (almost 3 million waveforms from 57,000 events) in diverse formats from many sources (both LLNL derived research and integrated contractor products), in addition to maintaining detailed quality control and metadata. We have developed expanded look-up tables for critical station parameter information (including location and response) and an integrated and reconciled event catalog data set (including specification of preferred origin solutions and associated phase arrivals) for the PDE, CMT, ISC, REB and selected regional catalogs. Using the SRKB framework, we are combining traveltime observations, event characterization studies, and regional tectonic models to assemble a library of ground truth information and phenomenology (e.g. travel-time and amplitude) correction surfaces required for support of the ME/NA/WE regionalization program. We also use the SRKB to integrate data and research products from a variety of sources, such as contractors and universities, to merge and maintain quality control of the data sets. Corrections and parameters distilled from the LLNL SRKB

  14. A Revised Holocene History of Lake Kivu, East Africa

    NASA Astrophysics Data System (ADS)

    Votava, J. E.; Johnson, T. C.; Hecky, R. E.

    2013-12-01

    The great lakes of the East African Rift valley are a vast chain of lakes formed in a region of active tectonics. These large, deep lakes are relatively old and many (e.g. Tanganyika, Malawi, and Turkana) have greatly influenced our understanding of terrestrial, tropical East African paleoclimate. Lake Kivu (max depth, 485m) sits at the heart of these rift lakes, north of Lake Tanganyika between the Democratic Republic of the Congo and Rwanda (roughly 250 km west of Lake Victoria). At over 1,400 meters in elevation, this 2,060 km2 mesotrophic lake has a complex stratification regime imposed by hydrothermal springs and deep waters supersaturated at STP in CO2 and CH4 gasses. The active Virunga Volcanoes to the north of the lake supply heated, high-salinity waters below 280 meters water depth maintaining the modern crenogenic meromixis. Based on detailed studies of diatom assemblages and bulk sedimentology, previous workers have suggested this hydrothermal activity began roughly 5,000 years BP. Unfortunately, dating and stratigraphic correlations of these original cores from the 1970 Woods Hole Oceanographic Institution's expedition have been problematic. Here we offer an improved chronology and new carbonate analyses from cores recovered in 2012 and 2013. Our AMS radiocarbon ages come from six terrigeneous macrofossils spanning the last 9,100 years (cal BP). These ages suggest a rather high sedimentation rate on the order of 70cm/kyr, and hence, our 8 m-long core provides us with a high-resolution lake history for the past 10,000 years. Most notable over the past 5,000 years in the lake history is the repeated onset and cessation of carbonate deposition, punctuated by organic-rich intervals. Earlier studies of the Woods Hole cores placed the onset of carbonate deposition at ca. 11,000 years BP suggesting changes in lake hydrology (i.e. closed to open), while the abrupt cessation of carbonate was dated at ca. 5,000 years BP and attributed to the beginning of

  15. Short communication: Genomic selection in a crossbred cattle population using data from the Dairy Genetics East Africa Project.

    PubMed

    Brown, A; Ojango, J; Gibson, J; Coffey, M; Okeyo, M; Mrode, R

    2016-09-01

    Due to the absence of accurate pedigree information, it has not been possible to implement genetic evaluations for crossbred cattle in African small-holder systems. Genomic selection techniques that do not rely on pedigree information could, therefore, be a useful alternative. The objective of this study was to examine the feasibility of using genomic selection techniques in a crossbred cattle population using data from Kenya provided by the Dairy Genetics East Africa Project. Genomic estimated breeding values for milk yield were estimated using 2 prediction methods, GBLUP and BayesC, and accuracies were calculated as the correlation between yield deviations and genomic breeding values included in the estimation process, mimicking the situation for young bulls. The accuracy of evaluation ranged from 0.28 to 0.41, depending on the validation population and prediction method used. No significant differences were found in accuracy between the 2 prediction methods. The results suggest that there is potential for implementing genomic selection for young bulls in crossbred small-holder cattle populations, and targeted genotyping and phenotyping should be pursued to facilitate this. PMID:27423951

  16. Anomalously wet and dry rainy seasons in Equatorial East Africa and associated differences in intra-seasonal characteristics

    NASA Astrophysics Data System (ADS)

    Philippon, N.; Camberlin, P.; Moron, V.; Boyard-Micheau, J.

    2015-10-01

    Differences between anomalously wet and dry rainy seasons over the period 1961-2001 in Equatorial East Africa (Kenya, northern Tanzania) are studied at local scale using a 53 rain-gauge network and analysing six intra-seasonal characteristics (ISCs): the onset and end dates, the wet spells number and length, daily mean rainfall amount and the dry spells length. As compared to anomalously dry Long Rains, anomalously wet ones record earlier onsets, more wet spells with higher daily mean rainfall amounts (above 14 mm/day). For the Short Rains, the end date is also widely modulated across the rain gauge network, and daily mean rainfall amounts above (below) 10 mm/day are more (less) frequent during anomalously wet (dry) seasons. The differences in the number, length and daily mean rainfall amount of wet spells between anomalously wet and anomalously dry rainy seasons is also analysed in an ensemble of 24 sea surface temperature-forced runs of the ECHAM4.5 Atmospheric General Circulation Model. For the Long Rains, results are inconsistent between runs which suggests a lack of reproducibility of the ISCs in the model. For the Short Rains, the ISCs distributions between anomalously wet and anomalously dry years are significantly different in most of the runs/locations. In particular, daily mean rainfall amounts above 8 mm/day are more (less) frequent in the model during anomalously wet (dry) years.

  17. Lithospheric thinning associated with rifting in East Africa

    NASA Technical Reports Server (NTRS)

    Wendlandt, R. F.; Morgan, R.

    1982-01-01

    The rate of ascent of the thermal perturbation of eruptive rock types in the Kenya Dome region can be calculated for depths of origin ranging from greater than 170 km to the lower crust (25-30 km) as combined with dated occurrences. An equation is derived and solved iteratively for ascent velocity at 10 km depth intervals from 150-30 km, assuming a thermal diffusivity of 1 sq mm/sec. For radii of 50 and 100 km and constant gradient increases within the range 55-60 C/km over the lithosphere-asthenosphere boundary (LAB) ascent depth range, the calculated rate of upwelling corresponds well with the results of a simple thermal model of lithospheric thinning. A 1 C/km change in gradient results approximately in a 0.55 Myr change in ascent time from 150 to 30 km, due to the increasing differential between the geotherm and the solidus with decreasing depths and the increasing rate of heat loss to the surface. It is suggested by the temporal-spatial-compositional relations of eruptives in the Kenya Dome region that there is a shallowing of magma source regions with time, implying encroachment of a thermal anomaly.

  18. High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural western Kenya: implications for human health.

    PubMed

    Maina, Alice N; Jiang, Ju; Omulo, Sylvia A; Cutler, Sally J; Ade, Fredrick; Ogola, Eric; Feikin, Daniel R; Njenga, M Kariuki; Cleaveland, Sarah; Mpoke, Solomon; Ng'ang'a, Zipporah; Breiman, Robert F; Knobel, Darryn L; Richards, Allen L

    2014-10-01

    Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae-genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya. PMID:25325312

  19. Middle East, North Africa and Western Eurasia Seismic Research Database

    SciTech Connect

    O'Boyle, J L; Ruppert, S D; Hauk, T F; Dodge, D A; Ganzberger, M D; Ryall, F

    2003-07-14

    The National Nuclear Security Administration (NNSA) Ground-Based Nuclear Explosion Monitoring Research and Engineering (GNEM R&E) Program at Lawrence Livermore National Laboratory (LLNL) has made significant progress populating a comprehensive Seismic Research Database (SRDB) used for deriving seismic calibration parameters for the Middle East, North Africa and Western Eurasia (ME/NA/WE) regions. In addition to an overview of select individual information products, we present an overview of our visualization, integration, validation, and organizational processes. Development of these processes and the LLNL SRDB was necessitated by both the very large amount of data and information involved (over 15 terabytes) and the varied data and research result formats utilized. The LLNL SRDB allows for the collection of raw and contextual seismic data used in research, provides an interface for researchers to access data, provides a framework to store research results and integrate datasets, and supports assembly, integration and dissemination of datasets to the NNSA Knowledge Base (KB). The LLNL SRDB is a flexible and extensible framework consisting of a relational database (RDB), Geographical Information System (GIS), and associated product/data visualization and data management tools. This framework is designed to accommodate large volumes of data in diverse formats from many sources (both in-house-derived research and integrated contractor products), in addition to maintaining detailed quality control and metadata. In order to efficiently organize information within the LLNL SRDB, it was necessary to automate procedures needed to create and update database tables, but a large effort is still required by technicians and scientists to load special datasets, review results of automated processing and resolve quality issues. The LLNL SRDB currently has 3 million reconciled event origins and arrivals from several global, regional and local seismic bulletins and 30 million

  20. Maternal Death Surveillance and Response in East and Southern Africa.

    PubMed

    Scott, Heather; Dairo, Akinyele

    2015-10-01

    Maternal death surveillance and response (MDSR) is one of several low cost, high impact strategies to reduce maternal mortality. This initiative is supported in eastern and southern Africa by the United Nations Population Fund (UNFPA) and other partners. Currently, South Africa is the leading country in the institutionalization of MDSR through the Confidential Enquiry into Maternal Deaths (CEMD). With the support of UNFPA and other partners, at least 15 countries in the region have introduced MDSR into maternal and newborn health care programs. The report from the knowledge-sharing meeting and the findings of the evaluation of the South African MDSR show that MDSR is still not at an optimal level in most countries in sub-Saharan Africa, despite the efforts of national authorities and support from a number of development partners. Additional work is required on the part of national authorities, communities, and development organizations, and the challenges being faced were highlighted at the knowledge-sharing meeting. PMID:26606709

  1. Some Like It Hot: The Influence and Implications of Climate Change on Coffee Berry Borer (Hypothenemus hampei) and Coffee Production in East Africa

    PubMed Central

    Vega, Fernando E.; Davis, Aaron; Borgemeister, Christian; Chabi-Olaye, Adenirin

    2011-01-01

    The negative effects of climate change are already evident for many of the 25 million coffee farmers across the tropics and the 90 billion dollar (US) coffee industry. The coffee berry borer (Hypothenemus hampei), the most important pest of coffee worldwide, has already benefited from the temperature rise in East Africa: increased damage to coffee crops and expansion in its distribution range have been reported. In order to anticipate threats and prioritize management actions for H. hampei we present here, maps on future distributions of H. hampei in coffee producing areas of East Africa. Using the CLIMEX model we relate present-day insect distributions to current climate and then project the fitted climatic envelopes under future scenarios A2A and B2B (for HADCM3 model). In both scenarios, the situation with H. hampei is forecasted to worsen in the current Coffea arabica producing areas of Ethiopia, the Ugandan part of the Lake Victoria and Mt. Elgon regions, Mt. Kenya and the Kenyan side of Mt. Elgon, and most of Rwanda and Burundi. The calculated hypothetical number of generations per year of H. hampei is predicted to increase in all C. arabica-producing areas from five to ten. These outcomes will have serious implications for C. arabica production and livelihoods in East Africa. We suggest that the best way to adapt to a rise of temperatures in coffee plantations could be via the introduction of shade trees in sun grown plantations. The aims of this study are to fill knowledge gaps existing in the coffee industry, and to draft an outline for the development of an adaptation strategy package for climate change on coffee production. An abstract in Spanish is provided as Abstract S1. PMID:21935419

  2. Traditional Music of East Africa: Experiencing "Ngoma" in Tanzania

    ERIC Educational Resources Information Center

    Howard, Karen

    2014-01-01

    The concept of ngoma is present throughout Eastern and Southern Africa. Ngoma refers to the tradition of expression via music, drumming, dance, and storytelling. History, values, education, and even identity can be transmitted between generations. This article traces the experiences of a music teacher from the United States traveling and studying…

  3. Investigating Students' Behavioural Intention to Adopt and Use Mobile Learning in Higher Education in East Africa

    ERIC Educational Resources Information Center

    Mtebe, Joel S.; Raisamo, Roope

    2014-01-01

    Recent penetration of mobile technologies and its services in East Africa has provided a new platform for institutions to widen access to education through mobile learning. Mobile technologies provide learners with flexibility and ubiquity to learn anytime and anywhere via wireless Internet. However, far too little research has been conducted to…

  4. Lessons from Mount Kilimanjaro: Schooling, Community, and Gender in East Africa.

    ERIC Educational Resources Information Center

    Stambach, Amy

    This book presents an ethnographic study of a school and community in East Africa. It focuses on the role school plays in the development of the children's identity and relationships to their parents and community, and in the development of the region. At issue here are the competing influences of Western modernity and the cultural traditions of…

  5. Near East and North Africa: A Question Syllabus. Center for Area and Country Studies.

    ERIC Educational Resources Information Center

    Howard, Harry N.

    This study syllabus on the Near East and North Africa is divided into twelve units. Designed to familiarize government personnel assigned to the area with the region and people, each unit consists of a statement of the main objectives to be studied, questions for consideration, and a list of suggested readings from books and periodicals. Units…

  6. Education, Employment and Rural Development; Proceedings of a Conference (Kericho, Kenya, September, 1966).

    ERIC Educational Resources Information Center

    Sheffield, James R., Ed.

    This document, which contains the discussion papers and the conclusions of The Kericho Conference held in September, 1966, focuses on rural problems in Kenya, including the related issues of education and employment. Papers dealing with general issues are: "Education, Employment, and Rural Development: The Problem in East Africa"; "Projected…

  7. 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.

  8. Plate tectonics of the Red Sea and East Africa.

    PubMed

    McKenzie, D P; Davies, D; Molnar, P

    1970-04-18

    The relative motion between the plates on each side of the East African Rift Valley can be obtained from the opening of the Red Sea and the Gulf of Aden. The calculated direction of relative motion agrees well with fault plane solutions for earthquakes north of the equator. PMID:16057189

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

    NASA Astrophysics Data System (ADS)

    Yang, Wenchang

    The hydroclimate of East Africa shows distinctive variabilities on seasonal to decadal time scales and poses a great challenge to climatologists attempting to project its response to anthropogenic emissions of greenhouse gases (GHGs). Increased frequency and intensity of droughts over East Africa in recent decades raise the question of whether the drying trend will continue into the future. To address this question, we first examine the decadal variability of the East African rainfall during March--May (MAM, the major rainy season in East Africa) and assess how well a series of models simulate the observed features. Observational results show that the drying trend during MAM is associated with decadal natural variability of sea surface temperature (SST) variations over the Pacific Ocean. The multimodel mean of the SST-forced, Coupled Model Intercomparison Project Phase 5 (CMIP5) AMIP experiment models reproduces both the climatological annual cycle and the drying trend in recent decades. The fully coupled models from the CMIP5 historical experiment, however, have systematic errors in simulating the East African rainfall annual cycle by underestimating the MAM rainfall while overestimating the October--December (OND, the second rainy season in East Africa) rainfall. The multimodel mean of the historical coupled runs of the MAM rainfall anomalies, which is the best estimate of the radiatively-forced change, shows a weak wetting trend associated with anthropogenic forcing. However, the SST anomaly pattern associated with the MAM rainfall has large discrepancies with the observations. The errors in simulating the East African hydroclimate with coupled models raise questions about how reliable model projections of future East African climate are. This motivates a fundamental study of why East African climate is the way it is and why coupled models get it wrong. East African hydroclimate is characterized by a dry annual mean climatology compared to other deep tropical

  10. Production objectives and management strategies of livestock keepers in south-east Kenya: implications for a breeding programme.

    PubMed

    Mwacharo, J M; Drucker, A G

    2005-11-01

    A survey of pastoralist and agropastoralist households in south-east Kenya was conducted to determine their production objectives and management strategies in order to optimize and extend a breeding programme for indigenous small East African Shorthorn Zebu cattle. The reasons for keeping cattle and the breed/trait preferences identified reflect the multiple objectives of the livestock keepers, with both adaptive traits and productive/reproductive traits rated as important. Although the Maasai and Kamba zebu (M&KZ) breeds were ranked highly with regard to adaptive traits, the population is considered to have been in decline over recent years. In order to promote the conservation and sustainable use of the M&KZ cattle, the formation of an open nucleus breeding scheme is recommended. In particular, such a scheme would be able to address several existing constraints (e.g. individual herds are very small and communal use of pastures/water makes controlled mating difficult). Such interventions would require the full participation of the livestock keepers, as well as ensuring that a holistic approach to species and breed attributes is taken into account in setting breeding goals, such that the full array of contributions that livestock make to livelihoods and the genetic characteristics related to these contributions are fully incorporated into the programme. PMID:16619880

  11. High-elevation amplification of warming since the Last Glacial Maximum in East Africa: New perspectives from biomarker paleotemperature reconstructions

    NASA Astrophysics Data System (ADS)

    Loomis, S. E.; Russell, J. M.; Kelly, M. A.; Eggermont, H.; Verschuren, D.

    2013-12-01

    Tropical lapse rate variability on glacial/interglacial time scales has been hotly debated since the publication of CLIMAP in 1976. Low-elevation paleotemperature reconstructions from the tropics have repeatedly shown less warming from the Last Glacial Maximum (LGM) to present than reconstructions from high elevations, leading to widespread difficulty in estimating the true LGM-present temperature change in the tropics. This debate is further complicated by the fact that most paleotemperature estimates from high elevations in the tropics are derived from pollen- and moraine-based reconstructions of altitudinal shifts in vegetation belts and glacial equilibrium line altitudes (ELAs). These traditional approaches rely on the assumption that lapse rates have remained constant through time. However, this assumption is problematic in the case of the LGM, when pervasive tropical aridity most likely led to substantial changes in lapse rates. Glycerol dialkyl glycerol tetraethers (GDGTs) can be used to reconstruct paleotemperatures independent of hydrological changes, making them the ideal proxy to reconstruct high elevation temperature change and assess lapse rate variability through time. Here we present two new equatorial paleotemperature records from high elevations in East Africa (Lake Rutundu, Mt. Kenya and Lake Mahoma, Rwenzori Mountains, Uganda) based on branched GDGTs. Our record from Lake Rutundu shows deglacial warming starting near 17 ka and a mid-Holocene thermal maximum near 5 ka. The overall amplitude of warming in the Lake Rutundu record is 6.8×1.0°C from the LGM to the present, with mid-Holocene temperatures 1.6×0.9°C warmer than modern. Our record from Lake Mahoma extends back to 7 ka and shows similar temperature trends to our record from Lake Rutundu, indicating similar temporal resolution of high-elevation temperature change throughout the region. Combining these new records with three previously published GDGT temperature records from different

  12. 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…

  13. Using the SPEI to Estimate Food Production in East Africa

    NASA Astrophysics Data System (ADS)

    Husak, G. J.; Hobbins, M.; Verdin, J. P.; Peterson, P.; Funk, C. C.

    2015-12-01

    The Famine Early Warning Systems Network (FEWS NET) monitors critical environmental variables that impact food production in developing countries. Due to a sparse network of observations in the developing world, many of these variables are estimated using remotely sensed data. As scientists develop new techniques to leverage available observations and remotely sensed information there are opportunities to create products that identify the environmental conditions that stress agriculture and reduce food production. FEWS NET pioneered the development of the Climate Hazards Group InfraRed Precipitation with stations (CHIRPS) dataset, to estimate precipitation and monitor growing conditions throughout the world. These data are used to drive land surface models, hydrologic models and basic crop models among others. A new dataset estimating the reference evapotranspiration (ET0) has been developed using inputs from the ERA-Interim GCM. This ET0 dataset stretches back to 1981, allowing for a long-term record, stretching many seasons and drought events. Combining the CHIRPS data to estimate water availability and the ET0 data to estimate evaporative demand, one can estimate the approximate water gap (surplus or deficit) over a specific time period. Normalizing this difference creates the Standardized Precipitation Evapotranspiration Index (SPEI), which presents these gaps in comparison to the historical record for a specific location and accumulation period. In this study we evaluate the SPEI as a tool to estimate crop yields for different regions of Kenya. Identifying the critical time of analysis for the SPEI is the first step in building a relationship between the water gap and food production. Once this critical period is identified, we look at the predictability of food production using the SPEI, and assess the utility of it for monitoring food security, with the goal of incorporating the SPEI in the standard monitoring suite of FEWS NET tools.

  14. Trace element and Sr-Nd-Pb isotope geochemistry of Rungwe Volcanic Province, Tanzania: Implications for a superplume source for East Africa Rift magmatism

    NASA Astrophysics Data System (ADS)

    Castillo, Paterno; Hilton, David; Halldórsson, Sæmundur

    2014-09-01

    The recently discovered high, plume-like 3He/4He ratios at Rungwe Volcanic Province (RVP) in southern Tanzania, similar to those at the Main Ethiopian Rift in Ethiopia, strongly suggest that magmatism associated with continental rifting along the entire East African Rift System (EARS) has a deep mantle contribution (Hilton et al., 2011). New trace element and Sr-Nd-Pb isotopic data for high 3He/4He lavas and tephras from RVP can be explained by binary mixing relationships involving Early Proterozoic (+/- Archaean) lithospheric mantle, present beneath the southern EARS, and a volatile-rich carbonatitic plume with a limited range of compositions and best represented by recent Nyiragongo lavas from the Virunga Volcanic Province also in the Western Rift. Other lavas from the Western Rift and from the southern Kenya Rift can also be explained through mixing between the same endmember components. In contrast, lavas from the northern Kenya and Main Ethiopian rifts can be explained through variable mixing between the same mantle plume material and the Middle to Late Proterozoic lithospheric mantle, present beneath the northern EARS. Thus, we propose that the bulk of EARS magmatism is sourced from mixing among three endmember sources: Early Proterozoic (+/- Archaean) lithospheric mantle, Middle to Late Proterozoic lithospheric mantle and a volatile-rich carbonatitic plume with a limited range of compositions. We propose further that the African Superplume, a large, seismically anomalous feature originating in the lower mantle beneath southern Africa, influences magmatism throughout eastern Africa with magmatism at RVP and Main Ethiopian Rift representing two different heads of a single mantle plume source. This is consistent with a single mantle plume origin of the coupled He-Ne isotopic signatures of mantle-derived xenoliths and/or lavas from all segments of the EARS (Halldorsson et al., 2014).

  15. Chemistry and chronology of magmatic processes, Central Kenya Peralkaline province, East African Rift

    NASA Astrophysics Data System (ADS)

    Anthony, E.; Deino, A. L.; White, J. C.; Omenda, P. A.

    2014-12-01

    We report here a synthesis of the geochemistry of magma evolution correlated with 40Ar/39Ar, 14 C, and U-series chronology for volcanoes in the Central Kenya Peralkaline Province (CKPP). The volcanic centers - Menengai, Eburru, Olkaria, Longonot, and Suswa - are at the apex of the Kenya Dome, and consist of trachyte, phonolite, comendite, and pantellerite. These volcanic centers are within the graben of the EARS and are characterized by a shield-building phase followed by caldera collapse and subsequent post-caldera eruptions. Geochemical modeling demonstrates that the magmas are the result of fractional crystallization of alkali basaltic magmas and magma mixing. Longonot and Suswa have the most chronologic data -14 C, Ar/Ar and U-series - and they show that the youngest eruptions have 230 Th/232Th of 0.8, which was inherited from the magma system prior to eruption. Subsequent changes in 230 Th/232 Th are due to post-eruptive decay of 230 Th and correlate well with 14 C and Ar/Ar.

  16. How well do CORDEX models simulate extreme rainfall events over the East Coast of South Africa?

    NASA Astrophysics Data System (ADS)

    Abba Omar, Sabina; Abiodun, Babatunde J.

    2016-01-01

    This study assesses the capability of regional climate models (RCMs) in simulating the characteristics of widespread extreme rainfall events over the East Coast of South Africa. Simulations of nine RCMs from the Coordinated Regional Downscaling Experiment (CORDEX) were analyzed for the study. All the simulations cover 12 years (1996-2008). Using the 95th percentile of daily rainfall as the threshold of extreme events and the simultaneous occurrence of extreme events over 50 % of the East Coast as widespread extreme events (WERE), we compared the characteristics of simulated WERE with observations (GPCP and TRMM) and with the reanalysis (ERAINT) that forced the simulations. Most RCMs perform well in simulating the seasonal variation of WEREs over the East Coast but perform poorly in simulating the interannual variability. Based on their rainfall synoptic patterns over Southern Africa, the WEREs in the East Coast can be generally classified into four groups. The first group connects the WEREs with tropical rainfall activities over the subcontinent. The second group links WEREs with frontal rainfall south of the subcontinent. The third group links the WEREs with both tropical and temperate rainfall activities while the fourth group represents isolated WEREs. The RCMs show different capabilities in simulating the frequency of WERE in each group, some perform better than ERAINT while some perform worse. Results of this study could provide information on the usability of RCMs in downscaling the impact of climate change on widespread extreme rainfall events over South Africa.

  17. The Symptom and Genetic Diversity of Cassava Brown Streak Viruses Infecting Cassava in East Africa

    PubMed Central

    Mohammed, I. U.; Abarshi, M. M.; Muli, B.; Hillocks, R. J.; Maruthi, M. N.

    2012-01-01

    The genetic and symptom diversity of six virus isolates causing cassava brown streak disease (CBSD) in the endemic (Kenya, Mozambique, and Tanzania) and the recently affected epidemic areas (Uganda) of eastern Africa was studied. Five cassava varieties; Albert, Colombian, Ebwanateraka, TMS60444 (all susceptible) and Kiroba (tolerant) were graft inoculated with each isolate. Based on a number of parameters including the severity of leaf and root symptoms, and the extent of virus transmission by grafting, the viruses were classified as either severe or relatively mild. These results were further confirmed by the mechanical inoculation of 13 herbaceous hosts in which the virulent isolates caused plant death in Nicotiana clevelandii and N. benthamiana whereas the milder isolates did not. Phylogenetic analysis of complete coat protein gene sequences of these isolates together with sequences obtained from 14 other field-collected samples from Kenya and Zanzibar, and reference sequences grouped them into two distinct clusters, representing the two species of cassava brown streak viruses. Put together, these results did not suggest the association of a hypervirulent form of the virus with the current CBSD epidemic in Uganda. Identification of the severe and milder isolates, however, has further implications for disease management and quarantine requirements. PMID:22454639

  18. Integrating Ubunifu, informal science, and community innovations in science classrooms in East Africa

    NASA Astrophysics Data System (ADS)

    Semali, Ladislaus M.; Hristova, Adelina; Owiny, Sylvia A.

    2015-12-01

    This study examines the relationship between informal science and indigenous innovations in local communities in which students matured. The discussion considers methods for bridging the gap that exists between parents' understanding of informal science ( Ubunifu) and what students learn in secondary schools in Kenya, Tanzania, and Uganda. In an effort to reconcile the difference between students' lived experiences and Science, Technology, Engineering, and Mathematics (STEM) taught in classrooms, this study presents an experiential iSPACES instructional model as an example of curriculum integration in science classrooms. The culmination is presentation of lessons learned from history, including Africa's unique contributions to science, theory, and indigenous innovations, in the hope that these lessons can spur the development of new instructional practices, standards, curriculum materials, professional and community development, and dialogue among nations.

  19. Cultural conditionally and aid to education in east Africa

    NASA Astrophysics Data System (ADS)

    Brock-Utne, Birgit

    1995-05-01

    Aid to African education often involves the imposition of conditions that create dependency and undermine indigenous educational patterns. Such conditions can include the insistence on textbooks written and published abroad, the use of examination systems devised in Europe or North America, and the neglect of African culture and languages. In the first part of this article the author examines the attempts at educational reform after the African states had achieved independence. The second part highlights the renewed dangers of educational dependency following the 1990 World Conference on Education for All, held in Jomtien, Thailand. The last part of the article discusses whether there is such a thing as "educational aid for empowerment" and gives some examples of good educational aid projects in Africa.

  20. Climate change as a draw bridge between Africa and the Middle East

    NASA Astrophysics Data System (ADS)

    Issar, Arie S.

    2010-07-01

    Since the very beginning of the human race, the Middle East served as a bridge between Africa-where our species first evolved-and the rest of the world. The passage over this bridge opened and closed with the global fluctuations of climate. The first glacial periods at the beginning of the Quaternary caused the greenhouse of equatorial Africa to become less hospitable, while making the desert belt of the Middle East more humid, green, and thus passable. Flint tools found along the shores of dried up lakes and swamps in the Negev Desert provide evidence that members of the first wave, Homo erectus, as well as the last wave, Homo sapiens, camped there en route to all the other continents.

  1. Food and water security scenarios for East Africa over next 20 years

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Funk, C. C.; Verdin, J. P.; Peters-Lidard, C. D.

    2013-12-01

    Broad areas of East Africa face chronic water and agricultural insecurity. Over the last decade, the region has experienced frequent drought events leading to food security emergencies and even famine in Somalia in 2011. The impact of these drought events, associated with recent declines in rainfall during major growing seasons, has been particularly severe due to the high vulnerability of subsistence agricultural and pastoralist livelihoods, rapid population growth, and the limited availability of resources for agricultural development and climate change adaptation. The Famine Early Warning Systems Network (FEWS NET) is a United States Agency for International Development (USAID) funded activity that brings together international, regional and national partners to provide timely and rigorous early warning and food security information in Africa and other regions of the developing world. To assist USAID with planning agricultural development strategies over the next ten years in East Africa, FEWS NET is partnering with climate scientists and adaptation specialists at regional institutions to study and assess future changes in precipitation and temperature in light of global climate change, natural climate variability, and their related impacts on agricultural and water security in the region. The overarching objective of this study is to provide future scenarios of food and water security (as estimated by trends in soil moisture, evapotranspiration, and runoff) for East Africa. We do so by following two approaches: Constructed Analogs and the Composite Delta Method. In the first approach we downscaled climate projections (precipitation and temperature projections) of long-term Coupled Model Intercomparison Project Phase-5 (CMIP5) experiments over (a) historical (1850-2005) and (b) Representative Concentration Pathway (RCP) 8.5 (2006-2030) periods. Current climate is characterized by two ENSO modes, the intensity of the Pacific Decadal Oscillation, and the strength

  2. STS-55 Earth observation of Lake Natron, Tanzania, East Africa

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, shows Lake Natron in Tansania, in the 35-mile-wide East African Rift Valley. This lake is surrounded by sodium carbonate volcanoes. Through erosion, these salts of volcanic origin are transported into the rift valley lakes. The various shades of bright red reflecting from the lake result from the water chemistry and biotic blooms. The white spots in the lakebed are drying soda salts. The depth and circulation of the water in the southern end of the lake cause it to appear dark blue rather than bright red. In the repeated photographs of this lake from orbit, we have seen the extent and intensity of its colors fluctuate seasonally. In this photograph, the biotic activity appears to be at a peak. Such a large extent of red-colored water was not present in the photos taken from STS-56, just a few days before (04-10-93).

  3. Assessment of undiscovered oil and gas resources of four East Africa Geologic Provinces

    USGS Publications Warehouse

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

    2012-01-01

    Four geologic provinces along the east coast of Africa recently were assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 27.6 billion barrels of oil, 441.1 trillion cubic feet of natural gas, and 13.77 billion barrels of natural gas liquids.

  4. Skill Assessment of National Multi-Model Ensemble Forecasts for Seasonal Drought Prediction in East Africa

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Hoell, A.; Roberts, J. B.; Funk, C. C.; Robertson, F. R.

    2014-12-01

    The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. As recently as 2011, part of this region underwent one of the worst famine events in its history. Timely and skillful drought forecasts at a seasonal scale for this region can inform better water and agro-pastoral management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses incurred by droughts. However, seasonal drought prediction in this region faces several challenges including lack of skillful seasonal rainfall forecasts. The National Multi-model Ensemble (NMME); a state-of-the-art dynamical climate forecast system is potentially a promising tool for drought prediction in this region. The NMME incorporates climate forecasts from 6+ fully coupled dynamical models resulting in 100+ forecasts ensemble members. Recent studies have indicated that in general NMME offers improvement over forecasts from any of the individual model. However, thus far the skill of NMME for forecasting rainfall in a vulnerable region like East Africa has largely been unexplored. In this presentation we report findings of a comprehensive analysis that examines the strength and weakness of NMME in forecasting rainfall at seasonal scale in East Africa for all three of the prominent seasons of the region. (i.e. March-April-May, July-August-September, and October-November-December). Additionally we describe a hybrid approach that combines statistical method with NMME forecasts to improve rainfall forecast skill in the region when raw NMME forecasts skill is lacking. This approach uses constructed analog method to improve NMME's March-April-May rainfall forecast skill in East Africa.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  6. Vegetation Change in East Africa Under the Influence of Tectonic Uplift

    NASA Astrophysics Data System (ADS)

    Fer, I.; Tietjen, B.; Jeltsch, F.; Trauth, M. H.

    2014-12-01

    Today, when we look at the tropical latitudes all around the world, we see rainforests more or less everywhere, except the easternmost parts of tropical East Africa. Why do the environmental conditions elsewhere in the tropics support the rainforest biomes but not in East Africa? The suggested explanation for this is the progressive tectonic uplift of the region. The uplift of eastern African topography, together with the changes in Earth's orbital forcing, resulted in the aridification of the region over the past 10 million years. It follows that there must have been rainforest environments in tropical East Africa before the uplift began and there is evidence to support this claim. Then, it raises the questions about how extensive these forests were, when and under which environmental conditions they started to fragment and grasslands took over. To address these questions we ran a dynamic vegetation model under experimental scenarios with varying precipitation, temperature and atmospheric CO2 concentration values. Our results show that even an increase of rainfall by 100% with respect to present-day conditions is not enough by itself for sustaining forest biomes at the easternmost parts of tropical East Africa. Within the range of atmospheric CO2 concentrations estimated for the late Miocene (9 Ma) [250-320 ppmv], decrease in temperature must also accompany the increase in rainfall to support the woody vegetation. Although an increase in arboreal cover at the expense of herbaceous vegetation could clearly be simulated all over the region, a continuous forest cover was only established at the south of the equator which fragmented with the decreasing rainfall and increasing temperatures in the region.

  7. Water Uses and Children's Lives in East Africa. Water in Africa.

    ERIC Educational Resources Information Center

    Maher, Robert

    The Water in Africa Project was realized over a 2-year period by a team of Peace Corps volunteers, World Wise Schools (WWS) classroom teachers, and WWS staff members. As part of an expanded, detailed design, resources were collected from over 90 volunteers serving in African countries, photos and stories were prepared, and standards-based learning…

  8. Examining the impact of climate change and variability on sweet potatoes in East Africa

    NASA Astrophysics Data System (ADS)

    Ddumba, S. D.; Andresen, J.; Moore, N. J.; Olson, J.; Snapp, S.; Winkler, J. A.

    2013-12-01

    Climate change is one of the biggest challenges to food security for the rapidly increasing population of East Africa. Rainfall is becoming more variable and temperatures are rising, consequently leading to increased occurrence of droughts and floods, and, changes in the timing and length of growing seasons. These changes have serious implications on crop production with the greatest impact likely to be on C4 crops such as cereals compared to C3 crops such as root tubers. Sweet potatoes is one the four most important food crops in East Africa owing to its high nutrition and calorie content, and, high tolerance to heat and drought, but little is known about how the crop will be affected by climate change. This study identifies the major climatic constraints to sweet potato production and examines the impact of projected future climates on sweet potato production in East Africa during the next 10 to 30 years. A process-based Sweet POTato COMputer Simulation (SPOTCOMS) model is used to assess four sweet potato cultivars; Naspot 1, Naspot 10, Naspot 11 and SPK 004-Ejumula. This is work in progress but preliminary results from the crop modeling experiments and the strength and weakness of the crop model will be presented.

  9. Cenozoic magmatism throughout east Africa resulting from impact of a single plume

    NASA Astrophysics Data System (ADS)

    Ebinger, C. J.; Sleep, N. H.

    1998-10-01

    The geology of northern and central Africa is characterized by broad plateaux, narrower swells and volcanism occurring from ~45Myr ago to the present. The greatest magma volumes occur on the >1,000-km-wide Ethiopian and east African plateaux, which are transected by the Red Sea, Gulf of Aden and east African rift systems, active since the late Oligocene epoch. Evidence for one or more mantle plumes having impinged beneath the plateaux comes from the dynamic compensation inferred from gravity studies, the generally small degrees of extension observed and the geochemistry of voluminous eruptive products. Here we present a model of a single large plume impinging beneath the Ethiopian plateau that takes into account lateral flow and ponding of plume material in pre-existing zones of lithospheric thinning. We show that this single plume can explain the distribution and timing of magmatism and uplift throughout east Africa. The thin lithosphere beneath the Mesozoic-Palaeogene rifts and passive margins of Africa and Arabia guides the lateral flow of plume material west to the Cameroon volcanic line and south to the Comoros Islands. Our results demonstrate the strong control that the lithosphere exerts on the spatial distribution of plume-related melting and magmatism.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  11. Genome-wide analysis reveals the ancient and recent admixture history of East African Shorthorn Zebu from Western Kenya.

    PubMed

    Mbole-Kariuki, M N; Sonstegard, T; Orth, A; Thumbi, S M; Bronsvoort, B M de C; Kiara, H; Toye, P; Conradie, I; Jennings, A; Coetzer, K; Woolhouse, M E J; Hanotte, O; Tapio, M

    2014-10-01

    The Kenyan East African zebu cattle are valuable and widely used genetic resources. Previous studies using microsatellite loci revealed the complex history of these populations with the presence of taurine and zebu genetic backgrounds. Here, we estimate at genome-wide level the genetic composition and population structure of the East African Shorthorn Zebu (EASZ) of western Kenya. A total of 548 EASZ from 20 sub-locations were genotyped using the Illumina BovineSNP50 v. 1 beadchip. STRUCTURE analysis reveals admixture with Asian zebu, African and European taurine cattle. The EASZ were separated into three categories: substantial (⩾12.5%), moderate (1.56%

  12. Genome-wide analysis reveals the ancient and recent admixture history of East African Shorthorn Zebu from Western Kenya

    PubMed Central

    Mbole-Kariuki, M N; Sonstegard, T; Orth, A; Thumbi, S M; Bronsvoort, B M de C; Kiara, H; Toye, P; Conradie, I; Jennings, A; Coetzer, K; Woolhouse, M E J; Hanotte, O; Tapio, M

    2014-01-01

    The Kenyan East African zebu cattle are valuable and widely used genetic resources. Previous studies using microsatellite loci revealed the complex history of these populations with the presence of taurine and zebu genetic backgrounds. Here, we estimate at genome-wide level the genetic composition and population structure of the East African Shorthorn Zebu (EASZ) of western Kenya. A total of 548 EASZ from 20 sub-locations were genotyped using the Illumina BovineSNP50 v. 1 beadchip. STRUCTURE analysis reveals admixture with Asian zebu, African and European taurine cattle. The EASZ were separated into three categories: substantial (⩾12.5%), moderate (1.56%

  13. Persistence of Rift Valley fever virus in East Africa

    NASA Astrophysics Data System (ADS)

    Gachohi, J.; Hansen, F.; Bett, B.; Kitala, P.

    2012-04-01

    Rift Valley fever virus (RVFv) is a mosquito-borne pathogen of livestock, wildlife and humans that causes severe outbreaks in intervals of several years. One of the open questions is how the virus persists between outbreaks. We developed a spatially-explicit, individual-based simulation model of the RVFv transmission dynamics to investigate this question. The model, is based on livestock and mosquito population dynamics. Spatial aspects are explicitly represented by a set of grid cells that represent mosquito breeding sites. A grid cell measures 500 by 500m and the model considers a grid of 100 by 100 grid cells; the model thus operates on the regional scale of 2500km2. Livestock herds move between grid cells, and provide connectivity between the cells. The model is used to explore the spatio-temporal dynamics of RVFv persistence in absence of a wildlife reservoir in an east African semi-arid context. Specifically, the model assesses the importance of local virus persistence in mosquito breeding sites relative to global virus persistence mitigated by movement of hosts. Local persistence is determined by the length of time the virus remains in a mosquito breeding site once introduced. In the model, this is a function of the number of mosquitoes that emerge infected and their lifespan. Global persistence is determined by the level of connectivity between isolated grid cells. Our work gives insights into the ecological and epidemiological conditions under which RVFv persists. The implication for disease surveillance and management are discussed.

  14. Neonatal Mortality Risk Associated with Preterm Birth in East Africa, Adjusted by Weight for Gestational Age: Individual Participant Level Meta-Analysis

    PubMed Central

    Marchant, Tanya; Willey, Barbara; Katz, Joanne; Clarke, Siân; Kariuki, Simon; ter Kuile, Feiko; Lusingu, John; Ndyomugyenyi, Richard; Schmiegelow, Christentze; Watson-Jones, Deborah; Armstrong Schellenberg, Joanna

    2012-01-01

    Background Low birth weight and prematurity are amongst the strongest predictors of neonatal death. However, the extent to which they act independently is poorly understood. Our objective was to estimate the neonatal mortality risk associated with preterm birth when stratified by weight for gestational age in the high mortality setting of East Africa. Methods and Findings Members and collaborators of the Malaria and the MARCH Centers, at the London School of Hygiene & Tropical Medicine, were contacted and protocols reviewed for East African studies that measured (1) birth weight, (2) gestational age at birth using antenatal ultrasound or neonatal assessment, and (3) neonatal mortality. Ten datasets were identified and four met the inclusion criteria. The four datasets (from Uganda, Kenya, and two from Tanzania) contained 5,727 births recorded between 1999–2010. 4,843 births had complete outcome data and were included in an individual participant level meta-analysis. 99% of 445 low birth weight (<2,500 g) babies were either preterm (<37 weeks gestation) or small for gestational age (below tenth percentile of weight for gestational age). 52% of 87 neonatal deaths occurred in preterm or small for gestational age babies. Babies born <34 weeks gestation had the highest odds of death compared to term babies (odds ratio [OR] 58.7 [95% CI 28.4–121.4]), with little difference when stratified by weight for gestational age. Babies born 34–36 weeks gestation with appropriate weight for gestational age had just three times the likelihood of neonatal death compared to babies born term, (OR 3.2 [95% CI 1.0–10.7]), but the likelihood for babies born 34–36 weeks who were also small for gestational age was 20 times higher (OR 19.8 [95% CI 8.3–47.4]). Only 1% of babies were born moderately premature and small for gestational age, but this group suffered 8% of deaths. Individual level data on newborns are scarce in East Africa; potential biases arising due to the non

  15. The Sexual Risk Context among the FEM-PrEP Study Population in Bondo, Kenya and Pretoria, South Africa

    PubMed Central

    Headley, Jennifer; Lemons, Ansley; Corneli, Amy; Agot, Kawango; Ahmed, Khatija; Wang, Meng; Odhiambo, Jacob; Skhosana, Joseph; Tharaldson, Jenae; Van Damme, Lut; MacQueen, Kathleen

    2014-01-01

    Background Incidence rates in the FEM-PrEP and VOICE trials demonstrate that women from diverse sub-Saharan African communities continue to be at substantial HIV risk. Objective To describe and compare the sexual risk context of the study population from two FEM-PrEP trial sites–Bondo, Kenya, and Pretoria, South Africa. Methods At baseline we collected information about demographics, sexual behaviors, and partnership beliefs through quantitative questionnaires with all participants (Bondo, n = 720; Pretoria, n = 750). To explore the sexual risk context, we also conducted qualitative, semi-structured interviews with HIV-negative participants randomly selected at several time points (Bondo, n = 111; Pretoria, n = 69). Results Demographics, sexual behavior, and partnership beliefs varied significantly between the sites. Bondo participants were generally older, had fewer years of schooling, and were more likely to be employed and married compared to Pretoria participants. Bondo participants were more likely to report multiple partners and not knowing whether their partner had HIV than Pretoria participants. A significantly higher percentage of Bondo participants reported engaging in sex without a condom with their primary and other partners compared to Pretoria participants. We found a borderline association between participants who reported not using condoms in the 4 weeks prior to baseline and lower risk of HIV infection, and no association between having more than one sexual partner at baseline and HIV infection. Discussion Despite significantly different demographics, sexual behaviors, and partnership beliefs, many women in the FEM-PrEP trial were at risk of acquiring HIV as demonstrated by the sites’ high HIV incidence. Though gender dynamics differed between the populations, they appear to play a critical role in women’s sexual practices. The findings highlight different ways women from diverse contexts may be at-risk for HIV and the

  16. MERS and the dromedary camel trade between Africa and the Middle East.

    PubMed

    Younan, M; Bornstein, S; Gluecks, I V

    2016-08-01

    Dromedary camels are the most likely source for the coronavirus that sporadically causes Middle East respiratory syndrome (MERS) in humans. Serological results from archived camel sera provide evidence for circulation of MERS coronavirus (MERS-CoV) among dromedary camels in the Greater Horn of Africa as far back as 1983 and in Saudi Arabia as far back as 1992. High seroprevalences of MERS-CoV antibodies and the high virus prevalence in Saudi Arabian dromedary camels indicate an endemicity of the virus in the Arabian Peninsula, which predates the 2012 human MERS index case. Saudi Arabian dromedary camels show significantly higher MERS-CoV carrier rates than dromedary camels imported from Africa. Two MERS-CoV lineages identified in Nigerian camels were found to be genetically distinct from those found in camels and humans in the Middle East. This supports the hypothesis that camel imports from Africa are not of significance for circulation of the virus in camel populations of the Arabian Peninsula. PMID:27324244

  17. Sunspots, El Niño, and the levels of Lake Victoria, East Africa

    NASA Astrophysics Data System (ADS)

    Stager, J. Curt; Ruzmaikin, Alexander; Conway, Declan; Verburg, Piet; Mason, Peter J.

    2007-08-01

    An association of high sunspot numbers with rises in the level of Lake Victoria, East Africa, has been the focus of many investigations and vigorous debate during the last century. In this paper, we show that peaks in the ~11-year sunspot cycle were accompanied by Victoria level maxima throughout the 20th century, due to the occurrence of positive rainfall anomalies ~1 year before solar maxima. Similar patterns also occurred in at least five other East African lakes, which indicates that these sunspot-rainfall relationships were broadly regional in scale. Although irradiance fluctuations associated with the sunspot cycle are weak, their effects on tropical rainfall could be amplified through interactions with sea surface temperatures and atmospheric circulation systems, including ENSO. If this Sun-rainfall relationship persists in the future, then sunspot cycles can be used for long-term prediction of precipitation anomalies and associated outbreaks of insect-borne disease in much of East Africa. In that case, unusually wet rainy seasons and Rift Valley Fever epidemics should occur a year or so before the next solar maximum, which is expected to occur in 2011-2012 AD.

  18. Seasonal Drought Prediction in East Africa: Can National Multi-Model Ensemble Forecasts Help?

    NASA Technical Reports Server (NTRS)

    Shukla, Shraddhanand; Roberts, J. B.; Funk, Christopher; Robertson, F. R.; Hoell, Andrew

    2014-01-01

    The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. As recently as in 2011 part of this region underwent one of the worst famine events in its history. Timely and skillful drought forecasts at seasonal scale for this region can inform better water and agro-pastoral management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses incurred by droughts. However seasonal drought prediction in this region faces several challenges. Lack of skillful seasonal rainfall forecasts; the focus of this presentation, is one of those major challenges. In the past few decades, major strides have been taken towards improvement of seasonal scale dynamical climate forecasts. The National Centers for Environmental Prediction's (NCEP) National Multi-model Ensemble (NMME) is one such state-of-the-art dynamical climate forecast system. The NMME incorporates climate forecasts from 6+ fully coupled dynamical models resulting in 100+ ensemble member forecasts. Recent studies have indicated that in general NMME offers improvement over forecasts from any single model. However thus far the skill of NMME for forecasting rainfall in a vulnerable region like the East Africa has been unexplored. In this presentation we report findings of a comprehensive analysis that examines the strength and weakness of NMME in forecasting rainfall at seasonal scale in East Africa for all three of the prominent seasons for the region. (i.e. March-April-May, July-August-September and October-November- December). Simultaneously we also describe hybrid approaches; that combine statistical approaches with NMME forecasts; to improve rainfall forecast skill in the region when raw NMME forecasts lack in skill.

  19. Seasonal Drought Prediction in East Africa: Can National Multi-Model Ensemble Forecasts Help?

    NASA Technical Reports Server (NTRS)

    Shukla, Shraddhanand; Roberts, J. B.; Funk, Christopher; Robertson, F. R.; Hoell, Andrew

    2015-01-01

    The increasing food and water demands of East Africa's growing population are stressing the region's inconsistent water resources and rain-fed agriculture. As recently as in 2011 part of this region underwent one of the worst famine events in its history. Timely and skillful drought forecasts at seasonal scale for this region can inform better water and agro-pastoral management decisions, support optimal allocation of the region's water resources, and mitigate socio-economic losses incurred by droughts. However seasonal drought prediction in this region faces several challenges. Lack of skillful seasonal rainfall forecasts; the focus of this presentation, is one of those major challenges. In the past few decades, major strides have been taken towards improvement of seasonal scale dynamical climate forecasts. The National Centers for Environmental Prediction's (NCEP) National Multi-model Ensemble (NMME) is one such state-of-the-art dynamical climate forecast system. The NMME incorporates climate forecasts from 6+ fully coupled dynamical models resulting in 100+ ensemble member forecasts. Recent studies have indicated that in general NMME offers improvement over forecasts from any single model. However thus far the skill of NMME for forecasting rainfall in a vulnerable region like the East Africa has been unexplored. In this presentation we report findings of a comprehensive analysis that examines the strength and weakness of NMME in forecasting rainfall at seasonal scale in East Africa for all three of the prominent seasons for the region. (i.e. March-April-May, July-August-September and October-November- December). Simultaneously we also describe hybrid approaches; that combine statistical approaches with NMME forecasts; to improve rainfall forecast skill in the region when raw NMME forecasts lack in skill.

  20. HIV Surveillance and Epidemic Profile in the Middle East and North Africa

    PubMed Central

    Shawky, Sherine; Soliman, Cherif; Kassak, Kassem M.; Oraby, Doaa; El-Khoury, Danielle; Kabore, Inoussa

    2011-01-01

    Summary HIV infection is the most devastating infection that has emerged in the recent history. The risk of being infected can be associated with both individual’s knowledge and behavior and community vulnerability influenced by cultural norms, laws, politics, and social practices. Despite that the countries in the Middle East and North Africa have succeeded in keeping low the HIV epidemic rates, the number of identified infected cases are increasing. Since the appearance of the first AIDS cases, all the national authorities devoted their efforts to abort the epidemic in its early stages. The rate of new HIV infections across the Middle East and North Africa region are not at an alarming level, but the need for a concerted effort from nation-states and nongovernmental organizations to stem the spread of the virus across the region is vital. Most countries of the region have put in place better information systems to track the HIV epidemic, yet the passive HIV/AIDS reporting remains the cornerstone in the HIV surveillance systems. Several countries still believe that their current strategies are optimal to the HIV status within their territories and that their national strategies are appropriate to their low epidemic status that is not expected to grow. Additionally, these countries fear that establishing an HIV national program to survey risk behaviors may be perceived as an approval of these behaviors that are culturally and religiously unacceptable. This background article aims to summarize the HIV surveillance strategies and epidemic profile in 17 Arab countries in the Middle East and North Africa. The article, also, displays the national surveillance system and the epidemic profile in Egypt and Lebanon as models for the region. This information aims to provide useful insights that may help the national authorities in finding out the best surveillance strategies that allow merging and collecting biological and risk data which is an integral part of their

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

    PubMed

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

    2015-09-01

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

  2. Early diagnosis and treatment of ankylosing spondylitis in Africa and the Middle East.

    PubMed

    Rachid, Bahiri; El Zorkany, Bassel; Youseif, Ehab; Tikly, Mohammed

    2012-11-01

    Ankylosing spondylitis (AS) is the prototype for spondyloarthritis primarily affecting young men. Geographic and ethnic variations exist in the prevalence and severity of AS and relate to the wide disparity in the frequency of human leukocyte antigen (HLA)-B27, a major genetic risk factor. The strength of the disease association with HLA-B27 is lower in most Arab populations (25-75 %) than in Western European populations (>90 %), and there is no association in sub-Saharan Africa, where the prevalence of HLA-B27 is <1 %. Other epidemiologic differences between European and African populations are the apparent later age at presentation in sub-Saharan Africa, and the high rate of spondyloarthropathies associated with human immunodeficiency virus infection. Diagnosis of AS is often delayed 8-10 years; potential reasons for the delay in Africa and the Middle East include low awareness among physicians and patients, the requirement for radiographic evidence of sacroiliitis for diagnosis, and limited access to magnetic resonance imaging in some countries. Treatment should be initiated early to prevent or reduce skeletal deformity and physical disability. Nonsteroidal anti-inflammatory drugs are effective first-line treatment and anti-tumor necrosis factor-α drugs are indicated for patients who have an inadequate response to first-line therapy. In Africa and the Middle East, such treatments may be precluded either by cost or contraindicated because of the high prevalence of latent tuberculosis infection. Research is sorely needed to develop cost-effective tools to diagnose AS early as well as effective, inexpensive, and safe treatments for these developing regions. PMID:22903740

  3. Fluoride in groundwater in selected villages in Eritrea (North East Africa).

    PubMed

    Srikanth, R; Viswanatham, K S; Kahsai, Fikremariam; Fisahatsion, Abraham; Asmellash, Micheal

    2002-04-01

    A study was undertaken to estimate fluoride content in the groundwater in certain parts of rural Eritrea. North-East Africa, along the River Anseba. Standard procedure was adopted for fluoride detection. Results indicate elevated concentration of fluoride in groundwater. The highest concentration was found to be 3.73 mg L(-1), well above the safety level for consumption. Geological basis for the high concentration of high fluoride has been established; it is presumed to be the pegmatite intrusion hosted by a granitic batholith. Extensive dental fluorosis has been observed in the population exposed to drinking water of high fluoride content. PMID:12002285

  4. World Directory of Energy Information. Volume 2: Middle East, Africa and Asia/Pacific

    SciTech Connect

    Not Available

    1982-01-01

    Volume 2 of the four-part Directory includes a detailed review of energy resource development of 64 countries, 15 of which are in the Middle East, 30 in Africa, and 19 in the Asia and Pacific area. The volume is divided into four parts: (1) International Framework; (2) Country Reviews; (3) Energy Organizations; and (4) Energy Publications. The organizations and publications information covers both international and by country. Three indices list publications alphabetically, by subject and country, and publishing bodies. 6 figures, 2 tables. (DCK)

  5. Honor killings in the Middle East and North Africa: a systematic review of the literature.

    PubMed

    Kulczycki, Andrzej; Windle, Sarah

    2011-11-01

    A systematic review of the research literature on honor killings in the Middle East and North Africa (MENA) indicates a paucity of studies relative to the presumed magnitude of the problem. Forty articles were reviewed and critically appraised, of which only 9 contained primary data and 11 presented original secondary analyses. Despite a recent increase in published studies, persistent methodological limitations restrict the generalizability of findings. Most studies focus on legal aspects, determinants, and characteristics of victims and perpetrators. Victims are mostly young females murdered by their male kin. Unambiguous evidence of a decline in tolerance of honor killings remains elusive. PMID:22312039

  6. Eruption parameters elicitation for volcanoes in Ethiopia and Kenya Informing a World Bank GFDRR project on volcanic threat in sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Jenkins, Susanna; Lark, Murray; Loughlin, Sue; Fontijn, Karen; Mather, Tamsin; Pyle, David; Lewi, Elias; Yirgu, Gezahegn; Vye-Brown, Charlotte; Sparks, Steve

    2016-04-01

    Despite large numbers of very visible active volcanoes in sub-Saharan Africa, data about eruptions are limited compared to elsewhere in the world. We present the method and findings from elicitations carried out to characterise likely future eruptions in the region as part of a World Bank GFDRR risk profiling project for sub-Saharan Africa. The purpose of the elicitations was to better understand the characteristics and frequencies of explosive eruptions at volcanoes in Ethiopia and Kenya. The elicitations will provide source parameters for tephra fall modelling at select volcanoes in Ethiopia (Aluto, Corbetti, Fentale) and Kenya (Menegai, Longonot, Suswa). There were two stages of elicitation: 1) a 'sanity check' of initial assumptions around likely eruption style, magnitude and frequency for the six selected volcanoes; 2) a formal SHELF (SHeffield ELicitation Framework) elicitation that centred round establishing frequency-magnitude relationships for the volcanoes. The elicitation suggested that explosive eruptions at Aluto and Corbetti were less likely than at the other volcanoes, although the uncertainty was significant. Menengai and Rungwe volcano in Tanzania (elicited as an analogue for Fentale, Longonot and Suswa volcanoes) were characterised by approximately similar probabilities of eruption. However, Rungwe was considered more likely to produce larger explosive (VEI ≥ 4) eruptions than Menengai. Elicitation discussions highlighted the knowledge and data gaps for African volcanoes and raised important questions around whether gaps in the eruption record were real and related to changing regimes at the volcanoes over time or if they were a function of under-recording or lack of preservation. Further investigation is therefore needed to validate the findings of the elicitation. It is hoped that continued collaboration with local partners and studies within the ongoing NERC-funded RiftVolc project will address these issues and help to improve our knowledge

  7. A survey of Echinococcus species in wild carnivores and livestock in East Africa.

    PubMed

    Hüttner, Marion; Siefert, Ludwig; Mackenstedt, Ute; Romig, Thomas

    2009-09-01

    We examined 71 faecal samples of carnivores from Queen Elizabeth National Park (QENP), Uganda, for eggs of Echinococcus species. Thirty-nine faecal samples contained taeniid eggs. For species diagnosis, DNA was isolated from a total of 1984 individual taeniid eggs. To differentiate eggs of Echinococcus felidis from other taeniid taxa (including the closely related Echinococcus granulosus sensu stricto), a restriction fragment length polymorphism (RFLP)-PCR of the mitochondrial nad1 gene was developed. As the faecal samples were taken from the environment, the host species was determined for all samples, except for one, by RFLP-PCR of the cob gene. Seven hundred and ninety-one of the 1984 eggs yielded a suitable PCR product. E. felidis was present in 34 of 47 samples from lions, none of 18 samples from leopards, and one of five samples from spotted hyenas. No Echinococcus taxon other than E. felidis was found, but three samples from lions contained eggs of Taenia regis. Two hydatid cysts of warthog origin from QENP were available for this study; molecular examination showed that one belonged to E. felidis, the other to E. granulosus (G1 strain). As a comparison of methods demonstrated that molecular diagnostic tools used for previous surveys of Echinococcus isolates in eastern Africa are not suitable to discriminate between E. felidis and E. granulosus sensu stricto, we re-examined 412 hydatid cyst samples of human, sheep, cattle, camel and goat origin from Kenya. Previous results were confirmed, as E. granulosus sensu stricto and Echinococcus canadensis G6/7 strain, but no E. felidis was found among these samples. In conclusion, we provide evidence that E. felidis is a frequent parasite of lions in Uganda, and possibly also occurs in hyenas. Additionally, we show that warthogs interact as intermediate hosts for E. felidis. We did not find evidence that E. felidis is present in eastern Africa outside conservation areas. PMID:19275902

  8. When to Randomize: Lessons from Independent Impact Evaluation of Reading to Learn (RtL) Programme to Improve Literacy and Numeracy in Kenya and Uganda

    ERIC Educational Resources Information Center

    Oketch, Moses; Ngware, Moses; Mutisya, Maurice; Kassahun, Admassu; Abuya, Benta; Musyoka, Peter

    2014-01-01

    In East Africa, there is great effort directed toward ensuring that there is learning and value for money invested in universal education policies initiated over the past decade. Kenya and Uganda are two countries that typify this effort. The effort includes the work of research organisations such as Uwezo, which assess learning levels; RTI, which…

  9. Policies on Free Primary and Secondary Education in East Africa: A Review of the Literature. Create Pathways to Access. Research Monograph No. 10

    ERIC Educational Resources Information Center

    Oketch, Moses O.; Rolleston, Caine M.

    2007-01-01

    Kenya, Tanzania and Uganda are among the countries in Sub-Saharan Africa which have recently implemented policies for free primary education, motivated in part by renewed democratic accountability following the re-emergence of multi-party politics in the 1990s. However, it is not the first time that the goal of expanding primary education has been…

  10. Determinants of Rural Poverty in Africa: The Case of Small Holder Farmers in Kenya

    NASA Astrophysics Data System (ADS)

    Owuor, G.; Ngigi, M.; Ouma, A. S.; Birachi, E. A.

    Sub-Saharan Africa is likely to hold large numbers of very poor rural people in the near future unless sustainable intervention measures are undertaken. Although both history and theory point to the important role of agriculture in poverty reduction, such growth today faces even more difficulties. This study uses a probit model on a sample of 600 smallholder farmers to establish factors that influence probability of households= escaping chronic poverty. Results show that access to micro-credit, education, participation in agricultural seminars, livestock assets and location in high potential areas significantly influence the probability of households exiting chronic poverty. On the other hand, female gender and distance to the market increases the probability of persistence in chronic poverty. Present findings reveal that micro-credit access, gender, education and market access are key determinants of exit from rural poverty. Therefore through intensified micro-credit provision, education, women empowerment via legal rights to property and improvement of rural access roads, the poverty status could be ameliorated.

  11. Correlation of Pliocene and Pleistocene tephra layers between the Turkana Basin of East Africa and the Gulf of Aden

    USGS Publications Warehouse

    Brown, F.H.; Sarna-Wojcicki, A. M.; Meyer, C.E.; Haileab, B.

    1992-01-01

    Electron-microprobe analyses of glass shards from volcanic ash in Pliocene and Pleistocene deep-sea sediments in the Gulf of Aden and the Somali Basin demonstrate that most of the tephra layers correlate with tephra layers known on land in the Turkana Basin of northern Kenya and southern Ethiopia. Previous correlations are reviewed, and new correlations proposed. Together these data provide correlations between the deep-sea cores, and to the land-based sections at eight levels ranging in age from about 4 to 0.7 Ma. Specifically, we correlate the Moiti Tuff (???4.1 Ma) with a tephra layer at 188.6 m depth in DSDP hole 231 and with a tephra layer at 150 m depth in DSDP hole 241, the Wargolo Tuff with a tephra layer at 179.7 m in DSDP Hole 231 and with a tephra layer at 155.3 m depth in DSDP Hole 232, the Lomogol Tuff (defined here) with a tephra layer at 165 m in DSDP Hole 232A, the Lokochot Tuff with a tephra layer at 140.1 m depth in DSDP Hole 232, the Tulu Bor Tuff with a tephra layer at 160.8 m depth in DSDP Hole 231, the Kokiselei Tuff with a tephra layer at 120 m depth in DSDP Hole 231 and with a tephra layer at 90.3 m depth in DSDP Hole 232, the Silbo Tuff (0.74 Ma) with a tephra layer at 35.5 m depth in DSDP Hole 231 and possibly with a tephra layer at 10.9 m depth in DSDP Hole 241. We also present analyses of other tephra from the deep sea cores for which correlative units on land are not yet known. The correlated tephra layers provide eight chronostratigraphic horizons that make it possible to temporally correlate paleoecological and paleoclimatic data between the terrestrial and deep-sea sites. Such correlations may make it possible to interpret faunal evolution in the Lake Turkana basin and other sites in East Africa within a broader regional or global paleoclimatic context. ?? 1992.

  12. Temporal Changes in Lead Depositions in East Africa: A Case Study of Lake Tanganyika

    NASA Astrophysics Data System (ADS)

    Odigie, K. O.; Flegal, A. R.

    2011-12-01

    Environmental changes (e.g., increasing rates of soil erosion) in East Africa have been attributed to local human activities and global climate change. However, reports on the impacts of these changes on the remobilization and transport of heavy metals, such as lead, in the environment are presently limited in literature. Therefore, this study was designed to chronicle the historic transport and deposition of lead in East Africa as recorded in the sediments of Lake Tanganyika. Sediment cores collected from regions with varying anthropogenic impacts of Lake Tanganyika were divided into sections, dated using excess lead-210, and analyzed for lead concentrations and isotopic composition. The results show that the amount of lead deposited in some regions of the lake increased recently (e.g., by more than 25% over the past two decades preceding 2000) which is consistent with regional changes in sediment accumulation rates in Lake Tanganyika. Temporal changes in the sources of that lead are being characterized by their isotopic compositions.

  13. Studies on host resistance to tick infestations among trypanotolerant Bos indicus cattle breeds in east Africa.

    PubMed

    Mwangi, E K; Stevenson, P; Ndung'U, J M; Stear, M J; Reid, S W; Gettinby, G; Murray, M

    1998-06-29

    Recent epidemiological studies carried out in East Africa have indicated that some Bos indicus cattle breeds such as the Orma Boran and Maasai Zebu have a degree of trypanotolerance worth exploitation by their introduction into trypanosomosis endemic areas where other cattle breeds cannot survive. However, in most areas of East Africa, trypanosomosis, ticks, and tick-borne diseases occur together. It is therefore important to obtain information on the susceptibility of these breeds to tick infestation and tick-borne diseases. This study was therefore designed to determine the susceptibility of these cattle breeds to tick infestations. They were compared with the Galana Boran (trypanosusceptible) and the Friesian (susceptible to tick infestations, tick-borne diseases, and trypanosomosis). The four breeds of cattle were exposed to natural tick challenge for a period of seven months and whole body weekly tick counts were done on each animal. Significant differences to tick infestations among the four breeds were observed. For both Rhipicephalus appendiculatus and Boophilus decoloratus, susceptibility to infestation increased in the order, Maasai Zebu, Orma Boran, Galana Boran and Friesian. The results generated by this pilot study so far suggest that variation in susceptibility to tick infestations exists among the four breeds. The Orma Boran and Maasai Zebu showed greater resistance to tick-infestations than the Galana Boran and Friesian. This suggests that utilization of these trypanotolerant cattle breeds could be feasible even in the face of tick challenge and should therefore be considered when planning integrated trypanosomosis and tick control strategies. PMID:9668465

  14. High Resolution Population Maps for Low Income Nations: Combining Land Cover and Census in East Africa

    PubMed Central

    Tatem, Andrew J.; Noor, Abdisalan M.; von Hagen, Craig; Di Gregorio, Antonio; Hay, Simon I.

    2007-01-01

    Background Between 2005 and 2050, the human population is forecast to grow by 2.7 billion, with the vast majority of this growth occurring in low income countries. This growth is likely to have significant social, economic and environmental impacts, and make the achievement of international development goals more difficult. The measurement, monitoring and potential mitigation of these impacts require high resolution, contemporary data on human population distributions. In low income countries, however, where the changes will be concentrated, the least information on the distribution of population exists. In this paper we investigate whether satellite imagery in combination with land cover information and census data can be used to create inexpensive, high resolution and easily-updatable settlement and population distribution maps over large areas. Methodology/Principal Findings We examine various approaches for the production of maps of the East African region (Kenya, Uganda, Burundi, Rwanda and Tanzania) and where fine resolution census data exists, test the accuracies of map production approaches and existing population distribution products. The results show that combining high resolution census, settlement and land cover information is important in producing accurate population distribution maps. Conclusions We find that this semi-automated population distribution mapping at unprecedented spatial resolution produces more accurate results than existing products and can be undertaken for as little as $0.01 per km2. The resulting population maps are a product of the Malaria Atlas Project (MAP: http://www.map.ox.ac.uk) and are freely available. PMID:18074022

  15. Distinct subspecies or phenotypic plasticity? Genetic and morphological differentiation of mountain honey bees in East Africa

    PubMed Central

    Gruber, Karl; Schöning, Caspar; Otte, Marianne; Kinuthia, Wanja; Hasselmann, Martin

    2013-01-01

    Identifying the forces shaping intraspecific phenotypic and genotypic divergence are of key importance in evolutionary biology. Phenotypic divergence may result from local adaptation or, especially in species with strong gene flow, from pronounced phenotypic plasticity. Here, we examine morphological and genetic divergence among populations of the western honey bee Apis mellifera in the topographically heterogeneous East African region. The currently accepted “mountain refugia hypothesis” states that populations living in disjunct montane forests belong to a different lineage than those in savanna habitats surrounding these forests. We obtained microsatellite data, mitochondrial sequences, and morphometric data from worker honey bees collected from feral colonies in three montane forests and corresponding neighboring savanna regions in Kenya. Honey bee colonies from montane forests showed distinct worker morphology compared with colonies in savanna areas. Mitochondrial sequence data did not support the existence of the two currently accepted subspecies. Furthermore, analyses of the microsatellite data with a Bayesian clustering method did not support the existence of two source populations as it would be expected under the mountain refugia scenario. Our findings suggest that phenotypic plasticity rather than distinct ancestry is the leading cause behind the phenotypic divergence observed between montane forest and savanna honey bees. Our study thus corroborates the idea that high gene flow may select for increased plasticity. PMID:24223262

  16. The Earliest Hominid Migration out of Africa and Near East Colonization

    NASA Astrophysics Data System (ADS)

    Ron, H.; Levi, S.; Porat, N.

    2001-12-01

    It is generally accepted that Central East Africa was the springboard for hominid evolution in the latest Miocene or Early Pliocene. However the timing and pathways of migrations from Africa to Eurasia are still debatable. The only certain land bridge and main route between Africa and Eurasia since the Late Pliocene-Early Pleistocene is the Levantine Corridor. This is evident in some of the most ancient remains of early hominids and tools outside Africa in the Middle East. The study of Lower Paleolithic sites in this region and in the neighboring area sheds some light on several potential migration and colonization events. The determination of ages of the prehistoric sites is crucial for any study of early human migration events, but it is also the most difficult data to recover. The typo-technological studies yield only relative age, and so do sequences of raised Pleistocene beaches, marine deposits, river terraces and paleo-lake formations. The scarcity of volcanic ash deposits excludes radiometric dating. Israel located at the Levantine Corridor yields a wealth of prehistoric findings and sites. We combine paleomagnetic and thermoluminescence measurements as dating tools. This new combination yields high quality, surprising results. Several preliminary paleomagnetic studies of lake deposits, cave deposits and soil sequences in well known sites in Israel such as the Erk-El Ahmar formation, and the Lower Paleolithic Tabun Cave in Mount Carmel, the Evron Quarry in northern Israel, and Rochama site in southern Israel. We conclude that the part of Erk-El-Ahmar Formation, which bears core-choppers and flakes, identified as typical Oldowan tools were deposited about 1.7-2.0 Ma. We found that the Rochama and Evron sites are located in soil sequences, several meters below the 0.78 Ma Brunhes-Matuyama boundary. Based on continuous soil accumulation rates and pedogenesis processes the age of these sites is about 1 Ma. This new data provides the first constraint for the 1

  17. Assessment of prediction and predictability of short rains over equatorial East Africa using a multi-model ensemble

    NASA Astrophysics Data System (ADS)

    Bahaga, T. K.; Kucharski, F.; Tsidu, G. Mengistu; Yang, Hongwei

    2016-02-01

    In this study, the performance of dynamical seasonal forecast systems is evaluated for the prediction of short rain anomalies over equatorial East Africa. The evaluation is based on observational datasets and the Asia-Pacific Climate Center (APCC) Ocean-Atmosphere coupled multi-model ensemble (MME) retrospective forecasts (hindcasts). These forecast systems have different hindcast periods; here, we have selected common years from 1982 to 2005. The ensembles of individual models and their MME mean are evaluated. Hindcasts initialized on the 1st of August from each year alone are considered, as these are the most relevant to short rain predictions. The coupled climate model ensemble reproduces the spatial distribution of mean September-October-November (SON) rainfall and seasonal climate variations over equatorial East Africa with further improvement in MME mean. Individual coupled models and MME mean also show statistically significant skill in forecasting sea surface temperatures anomalies (SSTAs) over the western and eastern parts of the equatorial Indian Ocean, giving significant correlation at 99 % confidence level for Indian Ocean dipole (IOD). Moreover, five out of ten coupled models and MME mean show statistically significant skill in predicting equatorial East Africa short rains. The fidelity of hindcasts is further measured by anomaly correlation coefficient (ACC) and four models as well as MME mean show significant skill over East Africa. It is shown that the reproduction of the observed variability in the East African region is mainly due to a realistic relationship of East African rainfall with the Indian Ocean dipole. Overall, the skill of the dynamical models is attributed to the fact that slowly evolving SSTs are the primary source of predictability and to the fact that coupled climate models produce skillful predictions of SON SST anomalies over the tropical Indian Ocean. This information opens the possibility of using readily available seasonal

  18. Building Capacity for Production of Gridded Precipitation Products in the East Africa Community

    NASA Astrophysics Data System (ADS)

    Budde, M. E.; Verdin, J. P.; Galu, G.; Magadzire, T.; Pedreros, D. H.; Funk, C. C.; Husak, G. J.; Peterson, P.; Landsfeld, M. F.; White, L.

    2014-12-01

    The Famine Early Warning Systems Network (FEWS NET) participates in the Group on Earth Observations' Global Agricultural Monitoring (GEOGLAM) activity in a number of ways. Recently, important progress has been made in meeting the need for improved precipitation data sets in East Africa. This has been done through capacity building activities with national meteorological and hydrological services (NMHS) in the region, carried out in partnership with the IGAD Climate Prediction and Applications Center (ICPAC), and with support from the WMO Office for Eastern and Southern Africa. Through a series of regional gatherings and individual country workshops, scientists from the NMHS have been introduced to the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) rainfall data set and the GeoCLIM software tool. The CHIRPS data set was developed by USGS and the University of California, Santa Barbara, by blending NOAA geostationary thermal infrared imagery with station observations, using robust geostatistical methods. The core data set consists of pentadal (5-daily) accumulations from 1981-2014 at 0.05 degree spatial resolution, between +/- 50 degrees latitude. The GeoCLIM software can operate on the CHIRPS to map the Standardized Precipitation Index, trends, anomalies, isohyets, and other types of spatio-temporal features. It can also produce new gridded rainfall data sets by geostatistical blending of station observations with existing rainfall grids. NMHS scientists have applied this latter capability to produce best-available national and regional gridded rainfall time-series for 1981-2014 for the East Africa Community (EAC). These data are a fundamental resource for the USAID-EAC climate change adaptation project known by the acronym PREPARED. They incorporate a larger and more complete collection of station observations than ever before. Further work is ongoing at the NMHS to take advantage of the data management capabilities of GeoCLIM, and incorporate

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

    PubMed

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

    2016-06-01

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

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

    PubMed Central

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

    2016-01-01

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

  1. Littoral sedimentation of rift lakes: an illustrated overview from the modern to Pliocene Lake Turkana (East African Rift System, Kenya)

    NASA Astrophysics Data System (ADS)

    Schuster, Mathieu; Nutz, Alexis

    2015-04-01

    Existing depositional models for rift lakes can be summarized as clastics transported by axial and lateral rivers, then distributed by fan-deltas and/or deltas into a standing water body which is dominated by settling of fine particles, and experiencing occasional coarser underflows. Even if known from paleolakes and modern lakes, reworking of clastics by alongshore drift, waves and storms are rarely considered in depositional models. However, if we consider the lake Turkana Basin (East African Rift System, Kenya) it is obvious that this vision is incomplete. Three representative time slices are considered here: the modern Lake Turkana, the Megalake Turkana which developed thanks to the African Humid Period (Holocene), and the Plio-Pleistocene highstand episodes of paleolake Turkana (Nachukui, Shungura and Koobi Fora Formations, Omo Group). First, remarkable clastic morphosedimentary structures such as beach ridges, spits, washover fans, lagoons, or wave-dominated deltas are very well developed along the shoreline of modern lake Turkana, suggesting strong hydrodynamics responsible for a major reworking of the fluvial-derived clastics all along the littoral zone (longshore and cross-shore transport) of the lake. Similarly, past hydrodynamics are recorded from prominent raised beach ridges and spits, well-preserved all around the lake, above its present water-level (~360 m asl) and up to ~455 m. These large-scale clastic morphosedimentary structures also record the maximum extent of Megalake Turkana during the African Humid Period, as well as its subsequent regression forced by the end of the Holocene climatic optimum. Several hundreds of meters of fluvial-deltaic-lacustrine deposits spanning the Pliocene-Pleistocene are exposed in the Turkana basin thanks to tectonic faulting. These deposits are world famous for their paleontological and archeological content that documents the very early story of Mankind. They also preserve several paleolake highstand episodes with

  2. Seismic Analysis of Magmatism in the Galapagos Archipelago and East Africa

    NASA Astrophysics Data System (ADS)

    Tepp, Gabrielle

    Magmatism and deformation are consequences of fundamental processes shaping Earth's ˜150 km-thick continental and <125 km-thick oceanic plates. Earthquake seismology encompasses many methods to detect compositional and thermal boundaries from Earth's surface to the dynamic mantle driving plate tectonics. This work uses three different seismic methods to probe magma migration and storage and tectonism in two intraplate hotspot provinces: the Galapagos and East Africa. First, seismic body-wave tomography is used to image magma within oceanic crust of the largest Galapagos volcano, Sierra Negra. A laterally large, low-velocity region with many smaller, high-magnitude velocity anomalies is imaged at 8--15.5 km depths. No sharp seismic velocity increase is imaged within the resolvable depths, indicating that the thickened crust is at least 16 km deep. The second study involves a spectral analysis of earthquakes induced by the intrusion of thin sheets of magma rising beneath the Afar rift, East Africa. Earthquakes have varying spectral content, some with unusually large amplitude low-frequency content and enhanced surface waves. The analysis showed no clear boundaries between spectral types, suggesting that they are all primarily the result of brittle failure. Deep dike segments (tops > 3 km) induce only high-frequency volcano-tectonic earthquakes, while shallower dike segments induce the full range of spectral types. This suggests that low-frequency content is a result of shallow hypocenters, with path and site effects, surface ruptures, and dike fluid interactions all possible secondary causes. In the final study, shear-wave splitting analysis of teleseismic body-wave phases is conducted to evaluate strain and crack fabrics at the base of the continental plate as a consequence of magmatism, mantle flow, and plate stretching in the Western rift, East Africa. On average, fast directions are northeast, consistent with geodynamic models of mantle flow from the African

  3. Clampdown on AIDS information in E. Africa.

    PubMed

    Hitchcock, B

    1986-01-01

    What is most alarming about Acquired Immune Deficiency Syndrome (AIDS) in East Africa is that it is taboo. The reason for the clamping down on publicity in Kenya is that the government sees AIDS as a killer of tourism, the country's 2nd largest revenue earner. The government of Kenya, like several other African governments, is reacting to the widespread belief in the West that AIDS originated in Africa and that it is rampant in Central and East Africa. These "facts" have yet to be proven conclusively by medical evidence. It is certain that a large percentage of the population of these regions have antibodies to the virus HTLV-III, which causes AIDS. From this, virologists deduce that the people concerned must have been exposed to the AIDS virus. The Western media has exaggerated the African AIDS connection and given the impression that African countries are gripped in raging AIDS epidemics. In response to the alarmist publicity, some African countries have clamped down in information about the disease. The result is that the Western press feels confirmed in its fears and the local population, depending on rumor and heresay, have been living in a state of absolute panic. Instead of allaying fears, the clampdown on news has fueled dangerous rumors at home and frightened away tourists. Whatever may be causing the disease and wherever it may have come from, there is no question at all that there are now confirmed cases of AIDS in East and Central Africa. Thus far, the number of confirmed cases if relatively small, but if governments continue to try and hide the facts from the public, there is a real danger of an epidemic developing. A ministerial statement admits to 7 confirmed AIDS cases in Kenya. There are discrepancies in the reports, however. Doctors interviewed by "New African" in Nairobi recently believe the situation is far more serious than the government admits. Doctors in Kenya make the point that the country is highly vulnerable to the spread of AIDS

  4. Improving Agricultural Drought Monitoring in East Africa with Unbiased Rainfall Fields and Detailed Land Surface Physics

    NASA Astrophysics Data System (ADS)

    McNally, A.; Yatheendradas, S.; Peters-Lidard, C. D.; Michaelsen, J.

    2010-12-01

    Monitoring drought is particularly challenging within rainfed agricultural and pastoral systems, where it can serve the greatest need. Such locations often have sparse or non-existent ground based measurements of precipitation, evapotranspiration (ET), and soil moisture. For more effective drought monitoring with limited hydroclimate observations, we simulate land surface states using the Community Noah Land Surface Model forced with different merged rainfall products inside a Land Information System (LIS). Using model outputs we will answer the questions: How sensitive are soil moisture and ET fields to differences in rainfall forcing and model physics? What are acceptable drought-specific tradeoffs between near-real time availability and skill of rainfall data? Preliminary results with the African Rainfall Estimation Algorithm Version 2 (RFE2.0) outperformed global products, suggesting that sub-global rainfall estimates are the way forward for regional drought monitoring. Specifically, the Noah model forced with RFE2.0 better resolved the heterogeneous patterns in crop stress than the Famine Early Warning System Network (FEWS NET) operational Water Requirement Satisfaction Index (WRSI) model. To further investigate the improvement in drought monitoring while maintaining timeliness, we unbias (using Africa specific climatology) the precipitation products from CPC Merged Analysis of Precipitation (CMAP), Tropical Rainfall Measurement Mission (TRMM), and RFE2.0. The skill (relative accuracy) and reliability (average agreement) of the unbiased rainfall are calculated against an unbiased precipitation product augmented with station data from Ethiopia and Kenya. Soil moisture and ET fields from Noah are compared to the operational FEWS NET WRSI, soil water anomaly index, and the World Food Program’s Crop and Food Security Assessment Mission reports. We anticipate that the unbiased rainfall fields will improve the accuracy, spatio-temporal resolution, and

  5. Mitochondrial DNA variation of domestic sheep (Ovis aries) in Kenya.

    PubMed

    Resende, Adriana; Gonçalves, Joana; Muigai, Anne W T; Pereira, Filipe

    2016-06-01

    The history of domestic sheep (Ovis aries) in Africa remains largely unknown. After being first introduced from the Near East, sheep gradually spread through the African continent with pastoral societies. The eastern part of Africa was important either for the first diffusion of sheep southward or for putative secondary introductions from the Arabian Peninsula or southern Asia. We analysed mitochondrial DNA control region sequences of 91 domestic sheep from Kenya and found a high diversity of matrilines from the widespread haplogroup B, whereas only a single individual from haplogroup A was detected. Our phylogeography analyses of more than 500 available mitochondrial DNA sequences also identified ancestral haplotypes that were probably first introduced in Africa and are now widely distributed. Moreover, we found no evidence of an admixture between East and West African sheep. The presence of shared haplotypes in eastern and ancient southern African sheep suggests the possible southward movement of sheep along the eastern part of Africa. Finally, we found no evidence of an extensive introduction of sheep from southern Asia into Africa via the Indian Ocean trade. The overall findings on the phylogeography of East African domestic sheep set the grounds for understanding the origin and subsequent movements of sheep in Africa. The richness of maternal lineages in Kenyan breeds is of prime importance for future conservation and breeding programmes. PMID:26765790

  6. Ocular rhinosporidiosis mimicking conjunctival squamous papilloma in Kenya – a case report

    PubMed Central

    2014-01-01

    Background Ocular rhinosporidiosis is a chronic granulomatous infection caused by a newly classified organism that is neither a fungus nor bacterium. It often presents as a benign conjunctival tumour but may mimic other ocular conditions. It is most often described in India. In Africa cases have been reported from South Africa, Kenya, Tanzania, Malawi, Uganda, Congo and Ivory Coast. Case presentation A 54 year old man was seen in Kenya with a lesion that resembled a conjunctival papilloma. We report resemblance to conjunctival papilloma and the result of vital staining with 0.05% Toluidine Blue. Conclusion Ocular rhinosporidiosis occurs in East Africa. It may resemble conjunctival squamous papilloma. Vital staining with 0.05% Toluidine blue dye did not distinguish the two lesions well. PMID:24708655

  7. Languages of the Middle East and North Africa. A Survey of Materials for the Study of the Uncommonly Taught Languages.

    ERIC Educational Resources Information Center

    Johnson, Dora E.; And Others

    This is an annotated bibliography of basic tools of access for the study of the uncommonly taught languages of the Middle East and North Africa. It is one of eight fascicles which constitute a revision of "A Provisional Survey of Materials for the Study of the Neglected Languages" (CAL 1969). The emphasis is on materials for the adult learner…

  8. A Comprehensive Review of the Status of Early Childhood Development in the Middle East and North Africa.

    ERIC Educational Resources Information Center

    Khattab, Mohammad Salih

    This report reviews the status of early childhood education (ECE) programs in UNICEF's Middle East and North Africa region. The report compiles information about ECE programs in 18 countries based on a questionnaire sent to UNICEF country offices and other sources. The introduction sets out the economic and social rationales for investing in early…

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

    ERIC Educational Resources Information Center

    Ogachi, Oanda

    2009-01-01

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

  10. Girls' Drop-Out from Primary Schooling in the Middle East and North Africa: Challenges and Alternatives.

    ERIC Educational Resources Information Center

    Mehrah, Golnar

    The present situation in the Middle East and North Africa Region (MENA) regarding primary school drop-out and repetition, with special reference to the situation of the girl child, is examined in this study. The in-school as well as out-of-school causes of primary school drop-out are examined, and solutions that help reduce or eliminate the…

  11. Strategies for Female Education in the Middle East and North Africa. Learning for the 21st Century.

    ERIC Educational Resources Information Center

    Rihani, May; Prather, Cynthia J.

    This paper is designed to assist education planners and policymakers in the Middle East and North Africa (MENA) region to identify a range of strategic options to increase the access and retention of girls in the education system. It provides a review of materials relating to the status of female education in the MENA region, statistical data on…

  12. A Human Economy: A "Third Way" for the Future of Young People in the Middle East and North Africa

    ERIC Educational Resources Information Center

    Zaalouk, Malak

    2014-01-01

    This paper looks at the vulnerability of today's youth worldwide, with a particular focus on the Middle East and North Africa (MENA), where the proportion of citizens aged 12-24 is particularly high at one-third of the total population. Cursed with poor education and few work opportunities, the youth unemployment rate has risen to 50 per cent…

  13. Randomized Impact Evaluation of Education Interventions: Experiences and Lessons from a Reading to Learn Intervention in East Africa

    ERIC Educational Resources Information Center

    Ngware, Moses Waithanji; Abuya, Benta; Oketch, Moses; Admassu, Kassahun; Mutisya, Maurice; Musyoka, Peter

    2015-01-01

    This paper presents the experiences and lessons learnt during the design and implementation of the randomized impact evaluation (IE) of a reading to learn (RtL) intervention in early primary grades. The study was to assess the impact of RtL on literacy and numeracy among pupils in low-performing districts in East Africa. The intervention was…

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    inspection of the Agere Selam (Mekele) intertrappean beds revealed the occurrence of lacustrine limestones and diatomites, which were contrastingly quite subordinate with respect to the fine clastic sediments found in the nearby Amba Alaji area. Further south, the intertrappean section in the Jema valley (100 km north of Addis Ababa and close to the Blue Nile gorge) is 120 m thick with predominant clastic sediments and a few diatomites at the top. Literature information from 35 additional sites, including northern Kenya, Yemen, Sudan and Saudi Arabia sections, confirms the fluvial and lacustrine depositional environment of the intertrappean beds, underlines the interest in their mammal fauna (Chilga, Losodok), and reports exploitable coal seams for some of them. As for the vegetal landscape in which the intertrappean beds were deposited, pollen and plant analysis results indicative of a tropical wet forest, similar to that of present-day western Africa. Another common feature of the intertrappean beds is their relatively limited thickness, averaging a few tens of meters, but reaching a few hundred meters in graben-related basins, such as Delbi Moye in southern Ethiopia. In most cases only thin, lens-shaped successions were deposited above the hummocky topography of their volcanic substratum, commonly unaffected by significant faulting. An average duration of the intertrappean beds is from one to three million years. This time interval is commonly matched by a few tens (or more rarely, hundreds) of meters of sediments left over after erosive episodes or depositional starvation. As to the lateral continuity of the intertrappean beds, the present-day outcrops show large differences: from some tens of kilometers in the Mendefera area, to a few tens of kilometres in the Jema valley, and to a few hundreds meters in the Agere Selam (Mekele) area. Even if it is difficult to quantify the original size of the sedimentation areas, it nevertheless proves that the intertrappean basins

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    inspection of the Agere Selam (Mekele) intertrappean beds revealed the occurrence of lacustrine limestones and diatomites, which were contrastingly quite subordinate with respect to the fine clastic sediments found in the nearby Amba Alaji area. Further south, the intertrappean section in the Jema valley (100 km north of Addis Ababa and close to the Blue Nile gorge) is 120 m thick with predominant clastic sediments and a few diatomites at the top. Literature information from 35 additional sites, including northern Kenya, Yemen, Sudan and Saudi Arabia sections, confirms the fluvial and lacustrine depositional environment of the intertrappean beds, underlines the interest in their mammal fauna (Chilga, Losodok), and reports exploitable coal seams for some of them. As for the vegetal landscape in which the intertrappean beds were deposited, pollen and plant analysis results indicative of a tropical wet forest, similar to that of present-day western Africa. Another common feature of the intertrappean beds is their relatively limited thickness, averaging a few tens of meters, but reaching a few hundred meters in graben-related basins, such as Delbi Moye in southern Ethiopia. In most cases only thin, lens-shaped successions were deposited above the hummocky topography of their volcanic substratum, commonly unaffected by significant faulting. An average duration of the intertrappean beds is from one to three million years. This time interval is commonly matched by a few tens (or more rarely, hundreds) of meters of sediments left over after erosive episodes or depositional starvation. As to the lateral continuity of the intertrappean beds, the present-day outcrops show large differences: from some tens of kilometers in the Mendefera area, to a few tens of kilometres in the Jema valley, and to a few hundreds meters in the Agere Selam (Mekele) area. Even if it is difficult to quantify the original size of the sedimentation areas, it nevertheless proves that the intertrappean basins

  16. Pathways to healing: curative travel among Muslims and non-Muslims in eastern East Africa.

    PubMed

    Parkin, David

    2014-01-01

    Two areas of therapeutic provision in eastern East Africa are contrasted: a coastal stretch inhabited mainly by Muslims, and a largely non-Muslim hinterland, each with its own healers, medicines, and customary ethic. Spread over both areas are providers of biomedicine associated originally, and to some extent today, with Christianity. Whether or not they also attend biomedical sites, Muslims seek healers in the coastal stretch and non-Muslims usually in the hinterland, each following ethico-religious preferences. However, because people move through the two areas and compare treatments, individuals' journeys can change direction, with non-Muslims sometimes seeking Muslim healers and either of these groups choosing the more dispersed biomedical outlets. The notion of 'pathways' to health thus combines set journeys to areas known for particular healers and a distinctive ethic, with possible detours to alternative sources of therapy, including biomedicine not regarded as governed by the same ethic. PMID:24383750

  17. Diet of Paranthropus boisei in the early Pleistocene of East Africa.

    PubMed

    Cerling, Thure E; Mbua, Emma; Kirera, Francis M; Manthi, Fredrick Kyalo; Grine, Frederick E; Leakey, Meave G; Sponheimer, Matt; Uno, Kevin T

    2011-06-01

    The East African hominin Paranthropus boisei was characterized by a suite of craniodental features that have been widely interpreted as adaptations to a diet that consisted of hard objects that required powerful peak masticatory loads. These morphological adaptations represent the culmination of an evolutionary trend that began in earlier taxa such as Australopithecus afarensis, and presumably facilitated utilization of open habitats in the Plio-Pleistocene. Here, we use stable isotopes to show that P. boisei had a diet that was dominated by C(4) biomass such as grasses or sedges. Its diet included more C(4) biomass than any other hominin studied to date, including its congener Paranthropus robustus from South Africa. These results, coupled with recent evidence from dental microwear, may indicate that the remarkable craniodental morphology of this taxon represents an adaptation for processing large quantities of low-quality vegetation rather than hard objects. PMID:21536914

  18. Strategy for managing water in the Middle East and North Africa. Arabic edition

    SciTech Connect

    Berkoff, J.

    1995-03-21

    Proposes a practical, step-by-step approach to managing water resources in a coordinated and sustainable manner. The people of the Middle East and North Africa have faced scarce water resources since time immemorial. Today, burgeoning populations dwarf the concerns of the past. New strategies for planning and managing water are urgently needed to avoid escalating conflicts and to reverse environmental degradation. This booklet details the implications of a new World Bank policy for the region, calling for a strong effort by governments and Bank staff to manage water resources in a coordinated and sustainable manner. A practical, step-by-step strategy is proposed that could lead to new Bank-funded operations throughout the water sector. The issues involved are complex but must be addressed if water scarcity is not to hinder development projects. The strategy proposed in this booklet could help build a new partnership for sustainable water management between the World Bank and regional governments.

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

    PubMed Central

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

    2009-01-01

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

  20. Why Did Abolishing Fees Not Increase Public School Enrollment in Kenya? Africa Growth Initiative. Working Paper 4

    ERIC Educational Resources Information Center

    Bold, Tessa; Kimenyi, Mwangi S.; Mwabu, Germano; Sandefur, Justin

    2013-01-01

    A large empirical literature has shown that user fees significantly deter public service utilization in developing countries. While most of these results reflect partial equilibrium analysis, we find that the nationwide abolition of public school fees in Kenya in 2003 led to no increase in net public enrollment rates, but rather a dramatic shift…

  1. A literature review: the role of the private sector in the production of nurses in India, Kenya, South Africa and Thailand

    PubMed Central

    2013-01-01

    Background The demand for nurses is growing and has not yet been met in most developing countries, including India, Kenya, South Africa, and Thailand. Efforts to increase the capacity for production of professional nurses, equitable distribution and better retention have been given high strategic priority. This study examines the supply of, demand for, and policy environment of private nurse production in four selected countries. Methods A scoping systematic review was undertaken to assess the evidence for the role of private sector involvement in the production of nurses in India, Kenya, South Africa, and Thailand. An electronic database search was performed, and grey literature was also captured from the websites of Human Resources for Health (HRH)-related organizations and networks. The articles were reviewed and selected according to relevancy. Results The review found that despite very different ratios of nurses to population ratios and differing degrees of international migration, there was a nursing shortage in all four countries which were struggling to meet growing demand. All four countries saw the private sector play an increasing role in nurse production. Policy responses varied from modifying regulation and accreditation schemes in Thailand, to easing regulation to speed up nurse production and recruitment in India. There were concerns about the quality of nurses being produced in private institutions. Conclusion Strategies must be devised to ensure that private nursing graduates serve public health needs of their populations. There must be policy coherence between producing nurses for export and ensuring sufficient supply to meet domestic needs, in particular in under-served areas. This study points to the need for further research in particular assessing the contributions made by the private sector to nurse production, and to examine the variance in quality of nurses produced. PMID:23587128

  2. 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

  3. Accuracy of teleseismic event locations in the Middle East and North Africa

    SciTech Connect

    Sweeney, J.J.

    1996-12-04

    Seismic characterization at the regional level requires accurate determination of phases and travel times for many combinations of stations and events. An important consideration in the process is the accuracy of event locations. The LLNL Comprehensive Test Ban Treaty Research Program is currently working on data from the Middle East and North Africa, where seismic station coverage is relatively sparse and ``ground truth`` seismic source information is practically nonexistent. In this report the investigator use after shock studies as a source of local ground truth. He evaluates teleseismic location accuracy by comparing hypocenters determined by local networks with those determined teleseismically [e.g. the International Seismological Center (ISC) and the National Earthquake Information Center (NEIC)]. Epicentral locations, origin times, and depth determinations of events from three aftershocks studies (Algeria, Armenia, and Iran) and one local network study (Iran) are compared with ISC and NEIC locations for the same events. The key parameter for the ISC locations is the number of observations used in the location determination. For more than 40-50 observations, the agreement rapidly diminishes and ISC locations can differ from local determinations by as much as 80 km or more. Events in Iran show a distinct bias of ISC location errors toward the northeast; events in Armenia and Algeria show no directional bias. This study shows that only events with ISC M{sub b} {gt} 4.4-4.5 or NEIS M{sub b} {gt} 4.7-4. should be used for compiling travel time information from teleseismic bulletins in the Middle East/North Africa region when locations from the NEIC and ISC bulletins are used.

  4. Metagenomic analysis demonstrates the diversity of the fecal virome in asymptomatic pigs in East Africa.

    PubMed

    Amimo, Joshua O; El Zowalaty, Mohamed E; Githae, Dedan; Wamalwa, Mark; Djikeng, Apollinaire; Nasrallah, Gheyath K

    2016-04-01

    Pigs harbor a variety of viruses that are closely related to human viruses and are suspected to have zoonotic potential. Little is known about the presence of viruses in smallholder farms where pigs are in close contact with humans and wildlife. This study provides insight into viral communities and the prevalence and characteristics of enteric viral co-infections in smallholder pigs in East Africa. Sequence-independent amplification and high-throughput sequencing were applied to the metagenomics analysis of viruses in feces collected from asymptomatic pigs. A total of 47,213 de novo-assembled contigs were constructed and compared with sequences from the GenBank database. Blastx search results revealed that 1039 contigs (>200 nt) were related to viral sequences in the GenBank database. Of the 1039 contigs, 612 were not assigned to any viral taxa because they had little similarity to known viral genomic or protein sequences, while 427 contigs had a high level of sequence similarity to known viruses and were assigned to viral taxa. The most frequent contigs related to mammalian viruses resembling members of the viral genera Astrovirus, Rotavirus, Bocavirus, Circovirus, and Kobuvirus. Other less abundant contigs were related to members of the genera Sapelovirus, Pasivirus, Posavirus, Teschovirus and Picobirnavirus. This is the first report on the diversity of the fecal virome of pig populations in East Africa. The findings of the present study help to elucidate the etiology of diarrheal diseases in pigs and identify potential zoonotic and emerging viruses in the region. Further investigations are required to compare the incidence of these viruses in healthy and diseased pigs in order to better elucidate their pathogenic role. PMID:26965436

  5. Overview of cervical cancer screening practices in the extended Middle East and North Africa countries.

    PubMed

    Sancho-Garnier, Hélène; Khazraji, Youssef Chami; Cherif, Moktar Hamdi; Mahnane, Abbes; Hsairi, Mohamed; El Shalakamy, Amr; Osgul, Nejat; Tuncer, Murat; Jumaan, Aisha O; Seoud, Muhieddine

    2013-12-30

    National Organized Cervical Cancer Screening (NOCCS) programs are lacking in most of the "Extended Middle East and North Africa" (EMENA) countries. Consequently, most cervical cancers are diagnosed late and are associated with high mortality. In fact, in most of these countries, national mortality data are unknown due to the absence of population-based mortality registries. Most countries of the EMENA practice more or less limited opportunistic, cytology-based, screening tests, which often lack quality assurance and follow-up care. A few countries, within the initiation of a National Cancer Control Plan, have just started to implement organized screening programs using, for cervical cancer detection, visual inspection with acetic acid (Morocco) or cytology (Turkey). Moreover, most countries of the EMENA lack national guideline, as well as resources for the management of abnormal cytologic screening (or any other screening test). The main obstacle for the implementation of NOCCS is a lack of political understanding to support such public health programs and provide the necessary resources. Other obstacles that hinder the participation of women in cervical screening include a lack of knowledge of the disease, socio-religious and cultural barriers, and geographic and economic difficulties in accessing medical services. These countries are already convinced that prevention of cervical cancers in women who have cervical intraepithelial neoplasia is possible through various screening and treatment algorithms, but most countries still need to invest in well organized programs that can reduce cervical cancer incidence and mortality in women. This article forms part of a regional report entitled "Comprehensive Control of HPV Infections and Related Diseases in the Extended Middle East and North Africa Region" Vaccine Volume 31, Supplement 6, 2013. Updates of the progress in the field are presented in a separate monograph entitled "Comprehensive Control of HPV Infections and

  6. Challenges with routine data sources for PMTCT programme monitoring in East Africa: insights from Tanzania

    PubMed Central

    Gourlay, Annabelle; Wringe, Alison; Todd, Jim; Michael, Denna; Reniers, Georges; Urassa, Mark; Njau, Prosper; Kajoka, Deborah; Lema, Levina; Zaba, Basia

    2015-01-01

    Routinely collected clinic data have the potential to provide much needed information on the uptake of services to prevent mother-to-child transmission (PMTCT) of HIV, and to measure HIV prevalence in pregnant women. This article describes the methodological challenges associated with using such data, based on the experiences of researchers and programme implementers in Tanzania and drawing from other examples from East Africa. PMTCT data are routinely collected in maternal and child health (MCH) clinics in East Africa using paper-based registers corresponding to distinct services within the PMTCT service continuum. This format has inherent limitations with respect to maintaining and accurately recording unique identifiers that can link patients across the different clinics (antenatal, delivery, child), and also poses challenges when compiling aggregate data. Recent improvements to recording systems include assigning unique identifiers to HIV-positive pregnant women in MCH clinics, although this should ideally be extended to all pregnant women, and recording mother and infant identifiers alongside each other in registers. The use of ‘health passports’, as in Malawi, which maintains the same antenatal clinic identifier over time, also holds promise. Routine data hold tremendous potential for clinic-level patient management, surveillance, and evaluating PMTCT/MCH programmes. Linking clinic data to community research datasets can also provide population-level estimates of coverage with PMTCT services, currently a problematic but vital statistic for monitoring programme performance and negotiating donor funding. Enhancements to indexing and recording of routine PMTCT/MCH data are needed if we are to capitalise on this rich data source. PMID:26715204

  7. Cropland land surface phenology and seasonality in East Africa: Ethiopia, Tanzania, and South Sudan

    NASA Astrophysics Data System (ADS)

    Alemu, W. G.; Henebry, G. M.

    2015-12-01

    Most people in East Africa depend on rainfed agriculture. Rainfall in the region has been decreasing recently and is highly variable in space and time leading to high food insecurity. A comprehensive understanding of the regional cropland dynamics is therefore needed. Land surface phenology and land surface seasonality have important roles in monitoring cropland dynamics in a region with sparse coverage of in situ climatic and biophysical observations. However, commonly used optical satellite data are often degraded by cloud cover, aerosols, and dust and they are restricted to daytime observations. Here we used near-daily passive microwave (PM) data at 25 km spatial resolution from a series of microwave radiometers—AMSR-E, FengYun3B/MWRI, AMSR2—to study cropland dynamics for 2003-2013 in three important grain production areas of East Africa: Ethiopia, Tanzania, and South Sudan. PM data can be collected through clouds and at night. Based on Google Earth imagery, we identified several cropland areas corresponding to PM grid cells. Rainfall from TRMM and atmospheric water vapor (V) from PM data displayed temporal patterns that were unimodal in Ethiopia and South Sudan, but bimodal in Tanzania. We fitted convex quadratic models to link growing season increments of V and vegetation optical depth (VOD) to accumulated V (AV). The models yielded high coefficients of determination (r2 ≥0.8) and phenometrics calculated from the parameter coefficients. Peak rainfall lagged peak V, but preceded peak VOD. Growing degree-days (GDD), calculated from the PM air temperature data, displayed a weaker bimodal seasonality in which the lowest values occurred during the peak rainy season, due to the cooling effect of latent heat flux and coupled with higher reflection of insolation by the cloud deck. V as a function of GDD displays quasi-periodic behavior. Drier sites in the region displayed larger (smaller) intra-annual dynamic range of V (GDD) compared to the moister sites.

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

    SciTech Connect

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

    2000-03-01

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

  9. Facility-Level Factors Influencing Retention of Patients in HIV Care in East Africa

    PubMed Central

    Easterbrook, Philippa; Genberg, Becky; Braithwaite, Ronald Scott; Cohen, Craig R.; Bukusi, Elizabeth A.; Kambugu, Andrew; Bwana, Mwebesa Bosco; Somi, Geoffrey R.; Geng, Elvin H.; Musick, Beverly; Yiannoutsos, Constantin T.; Wools-Kaloustian, Kara; Braitstein, Paula

    2016-01-01

    Losses to follow-up (LTFU) remain an important programmatic challenge. While numerous patient-level factors have been associated with LTFU, less is known about facility-level factors. Data from the East African International epidemiologic Databases to Evaluate AIDS (EA-IeDEA) Consortium was used to identify facility-level factors associated with LTFU in Kenya, Tanzania and Uganda. Patients were defined as LTFU if they had no visit within 12 months of the study endpoint for pre-ART patients or 6 months for patients on ART. Adjusting for patient factors, shared frailty proportional hazard models were used to identify the facility-level factors associated with LTFU for the pre- and post-ART periods. Data from 77,362 patients and 29 facilities were analyzed. Median age at enrolment was 36.0 years (Interquartile Range: 30.1, 43.1), 63.9% were women and 58.3% initiated ART. Rates (95% Confidence Interval) of LTFU were 25.1 (24.7–25.6) and 16.7 (16.3–17.2) per 100 person-years in the pre-ART and post-ART periods, respectively. Facility-level factors associated with increased LTFU included secondary-level care, HIV RNA PCR turnaround time >14 days, and no onsite availability of CD4 testing. Increased LTFU was also observed when no nutritional supplements were provided (pre-ART only), when TB patients were treated within the HIV program (pre-ART only), and when the facility was open ≤4 mornings per week (ART only). Our findings suggest that facility-based strategies such as point of care laboratory testing and separate clinic spaces for TB patients may improve retention. PMID:27509182

  10. AIDS and food production in East and Central Africa: a research outline.

    PubMed

    Barnett, T; Blaikie, P

    1989-02-01

    AIDS has penetrated at least 42 countries in Africa. Death of Africans usually occurs within 3 years of diagnosis. Not much is currently known about the demographics of the disease or about its impact on economic and social behavior, farming, and food production. There is currently a food crisis in Africa, so it is appropriate to study how much of an impact this disease has on future food production. In order to study the problem, one must predict the spread of AIDS. 2nd, one must infer how labor loss effects current rural production. Labor loss will cause changes in organization of production, technology, and types of crops grown. As a crisis increases, certain groups will be cut out of the food distribution. Characterizations such as these allow the mapping of areas vulnerable to labor loss. Field analysis and modeling must substantiate the theories and predictions. This paper describes the research design which will be used by 2 researchers from the Overseas Development Group of the University of East Anglia to measure the impact of AIDS on food production, working initially in a high HIV - prevalent area in Uganda. PMID:12281937

  11. Absence of kdr resistance alleles in the Union of the Comoros, East Africa

    PubMed Central

    Lee, Yoosook; Olson, Natalie; Yamasaki, Youki; Chang, Allison; Marsden, Clare; Ouledi, Ahmed; Lanzaro, Gregory; Cornel, Anthony

    2015-01-01

    Knockdown resistance ( kdr) and CYP9K1 genotypes were detected by a MOLDI-TOF based SNP genotyping assay (Sequenom iPLEX) in samples of Anopheles gambiae collected at 13 sites throughout the Union of the Comoros and Dar es Salaam, Tanzania during February and March 2011. All A. gambiae specimens collected in the Comoros were homozygous for the susceptible kdr alleles (+/+) while 96% of A. gambiae from Dar es Salaam were homozygous for the East African kdr resistant genotype (E/E). In contrast, all specimens from Dar es Salaam and the Comoros were homozygous for the cyp3 allele (c3/c3) at the CYP9K1 locus; the locus has been implicated in metabolic resistance against pyrethroid insecticides in West Africa. All specimens had typical A. gambiae genotypes for SNPs within the divergence Islands on all three chromosomes. Although further spatial and temporal studies are needed, the distribution of kdr genotypes between the Comoros and Tanzania further supports isolation of the Comoros populations from A. gambiae populations on mainland Africa . PMID:26339473

  12. New Proxies from Loess-Paleosols on Mount Kilimanjaro document Late Pleistocene Megadroughts in East Africa

    NASA Astrophysics Data System (ADS)

    Zech, R.; Huang, Y.; Russell, J. M.; Tarozo, R.; Gao, L.; Hemp, A.; Zech, W.

    2009-12-01

    Innovative, new proxies from loess and paleosol sediments hold great potential to obtain more quantitative information about paleoclimate changes in terrestrial environments. Here we present results from lipid biomarkers (GDGTs) and hydrogen isotopic measurements on long-chain fatty acids and alkanes that we extracted from 69 paleosol samples from Mt Kilimanjaro, Tanzania (~3°S). The respective soil pit and sediment core at ~2700 m above sea level is radiocarbon-dated to 38.4 ka BP, and probably covers most of the Late Pleistocene, making it one of the longest, continuous, terrestrial archives in the East African tropics. Our compound-specific deuterium measurements show lowest δD values from ~9 to 5 ka in the Early/Middle Holocene, consistent with regional evidence for an “African Humid Period,” followed by a shift towards more arid conditions during the Late Holocene (~5‰ shift). The Younger Dryas is characterized by a δD enrichment (=aridity) of ~15‰ compared to the Early/Middle Holocene, almost reaching LGM values (~20‰ shift). The enrichment during the LGM is, however, significantly smaller than the 50‰ change as observed in Lake Tanganyika further southwest. At present it is not possible to determine whether these differences result from geographic variations in precipitation and humidity, or isotopic distillation processes along the vapor transport trajectories across East Africa. Much more arid conditions (~40‰ enrichment) can be inferred for the paleosols older than ~60 ka. Although further dating efforts are required to determine the exact timing, this corroborates earlier findings from African lakes that suggested ‘megadroughts’ occurred during Marine Isotope Stages 5 and 4. Acknowledging the general perception that precipitation in East Africa is strongly controlled by ITCZ positioning, we highlight the role of (strong) eccentricity in modulating the precessional forcing, which - in combination with high-latitude glacial boundary

  13. Mapping the potential distribution of Phlebotomus martini and P. orientalis (Diptera: Psychodidae), vectors of kala-azar in East Africa by use of geographic information systems.

    PubMed

    Gebre-Michael, T; Malone, J B; Balkew, M; Ali, A; Berhe, N; Hailu, A; Herzi, A A

    2004-03-01

    The distribution of two principal vectors of kala-azar in East Africa, Phlebotomus martini and Phlebotomus orientalis were analysed using geographic information system (GIS) based on (1) earth observing satellite sensor data: Normalized Difference Vegetation Index (NDVI) and midday Land Surface Temperature (LST) derived from advanced very high resolution radiometer (AVHRR) of the global land 1km project of United States Geological Survey (USGS), (2) agroclimatic data from the FAO Crop Production System Zone (CPSZ) of the Intergovernmental Authority on Development (IGAD) sub-region, and (3) the FAO 1998 soils digital map for the IGAD sub-region. The aim was to produce a predictive risk model for the two vectors. Data used for the analysis were based on presence and absence of the two species from previous survey collections in the region (mainly Ethiopia, Kenya and Somalia). Annual, wet season and dry season models were constructed. Although all models resulted in more than 85% positive predictive values for both species, the best fit for the distribution of P. martini was the dry season composite (NDVI 0.07-0.38 and LST 22-33 degrees C) with a predictive value of 93.8%, and the best fit for P. orientalis was the wet season composite (NDVI -0.01 to 0.34 and LST 23-34 degrees C) with a predictive value of 96.3%. The two seasonal composites models derived from satellite data were largely similar with best fit models developed based on the CPSZ climate data: average altitude (12-1900m), average annual mean temperature (15-30 degrees C), annual rainfall (274-1212mm), average annual potential evapotranspiration (1264-1938mm) and readily available soil moisture (62-113mm) for P. martini; and average altitude (200-2200m), annual rainfall (180-1050mm), annual mean temperature (16-36 degrees C) and readily available soil moisture (67-108mm) for P. orientalis. Logistic regression analysis indicated LST dry season composite of the satellite data, average altitude, mean annual

  14. 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

  15. Ancient glaciations and hydrocarbon accumulations in North Africa and the Middle East

    NASA Astrophysics Data System (ADS)

    Le Heron, Daniel Paul; Craig, Jonathan; Etienne, James L.

    2009-04-01

    At least six glaciations are purported to have affected North Africa and the Middle East region over the last one billion years, including two in the Cryogenian (Neoproterozoic), Hirnantian (Late Ordovician), Silurian, Carboniferous and Early Permian events. The sedimentary record associated with these glaciations, together with the intensity to which each has been investigated, is highly variable. As hydrocarbon exploration proceeds aggressively across the North Africa and Middle East regions, we review the relationship between glaciation and hydrocarbon accumulations. With the exception of Oman, and locally Egypt, which were tectonically active both during the Neoproterozoic and Early Palaeozoic all glaciations took place along an essentially stable passive continental margin. During the Neoproterozoic, two glaciations are recognised, referred to as older and younger Cryogenian glaciations respectively. Both of these Cryogenian events are preserved in Oman; only the younger Cryogenian has been reported in North Africa in Mauritania and Mali at the flanks of the Taoudenni Basin. The process of initial deglaciation in younger Cryogenian glaciations resulted in incision, at least locally producing large-bedrock palaeovalleys in Oman, and the deposition of glacial diamictites, gravels, sandstones and mudstones. As deglaciation progressed "cap carbonates" were deposited, passing vertically into shale with evidence for deposition in an anoxic environment. Hence, younger Cryogenian deglaciation may be associated with hydrocarbon source rock deposits. Hirnantian (Late Ordovician) glaciation was short lived (< 0.5 Myr) and affected intracratonic basins of Mauritania, Morocco, Algeria, Libya, Egypt and Saudi Arabia. The organisation of the glacial sedimentary record is considered to be controlled at the basin-scale by the location of fast-flowing ice streams active during glacial maxima, and by the processes of meltwater release during glacial recession. In these latter

  16. Continental rift evolution: From rift initiation to incipient break-up in the Main Ethiopian Rift, East Africa

    NASA Astrophysics Data System (ADS)

    Corti, Giacomo

    2009-09-01

    The Main Ethiopian Rift is a key sector of the East African Rift System that connects the Afar depression, at Red Sea-Gulf of Aden junction, with the Turkana depression and Kenya Rift to the South. It is a magmatic rift that records all the different stages of rift evolution from rift initiation to break-up and incipient oceanic spreading: it is thus an ideal place to analyse the evolution of continental extension, the rupture of lithospheric plates and the dynamics by which distributed continental deformation is progressively focused at oceanic spreading centres. The first tectono-magmatic event related to the Tertiary rifting was the eruption of voluminous flood basalts that apparently occurred in a rather short time interval at around 30 Ma; strong plateau uplift, which resulted in the development of the Ethiopian and Somalian plateaus now surrounding the rift valley, has been suggested to have initiated contemporaneously or shortly after the extensive flood-basalt volcanism, although its exact timing remains controversial. Voluminous volcanism and uplift started prior to the main rifting phases, suggesting a mantle plume influence on the Tertiary deformation in East Africa. Different plume hypothesis have been suggested, with recent models indicating the existence of deep superplume originating at the core-mantle boundary beneath southern Africa, rising in a north-northeastward direction toward eastern Africa, and feeding multiple plume stems in the upper mantle. However, the existence of this whole-mantle feature and its possible connection with Tertiary rifting are highly debated. The main rifting phases started diachronously along the MER in the Mio-Pliocene; rift propagation was not a smooth process but rather a process with punctuated episodes of extension and relative quiescence. Rift location was most probably controlled by the reactivation of a lithospheric-scale pre-Cambrian weakness; the orientation of this weakness (roughly NE-SW) and the Late

  17. 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.

  18. Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa

    PubMed Central

    Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

    2016-01-01

    Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 106 CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 106–108

  19. Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa.

    PubMed

    Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

    2013-10-15

    Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 10(6)CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 10

  20. Climate Change Impact Assessment and Adaptation Options in Vulnerable Agro-Landscapes in East-Africa

    NASA Astrophysics Data System (ADS)

    Manful, D.; Tscherning, K.; Kersebaum, K.; Dietz, J.; Dietrich, O.; Gomani, C.; Böhm, H.; Büchner, M.; Lischeid, G.,; Ojoyi, M.,

    2009-04-01

    Climate change poses a risk to the livelihoods of large populations in the developing world, especially in Africa. In East Africa, climate change is expected to affect the spatial distribution and quantity of precipitation. The proposed project will assess aspects of climate impacts and adaptation options in Tanzania. The project will attempt to quantify (1) projected impacts including: variability in temperature, rainfall, flooding and drought (2) the affect changes in 1. will have on specific sectors namely agriculture (food security), water resources and ecosystem services. The cumulative effects of diminished surface and ground water flow on agricultural production coupled with increasing demand for food due to increase in human pressure will also be evaluated. Expected outputs of the project include (1) downscaled climate change scenarios for different IPCC emission scenarios (2) model based estimations of climate change impacts on hydrological cycle and assessment of land use options (3) scenarios of sustainable livelihoods and resilient agro-landscapes under climate change (4) assessment of adaptive practices and criteria for best adaptation practices. The presentation will focus on novel approaches that focus on the use of agro-ecosystem models to predict local and regional impacts of climate variability on food with specific needs of the end-user factored into model set-up process. In other words, model configurations adapted to the information needs of a specific end-user or audience are evaluated. The perception of risk within different end-users (small scale farmer versus a regional or state level policy maker) are explicitly taken into consideration with the overarching aim of maximizing the impact of the results obtained from computer-based simulations.

  1. Repetitive dengue outbreaks in East Africa: A proposed phased mitigation approach may reduce its impact.

    PubMed

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

    2016-05-01

    Dengue outbreaks have persistently occurred in eastern African countries for several decades. We assessed each outbreak to identify risk factors and propose a framework for prevention and impact mitigation. Seven out of ten countries in eastern Africa and three islands in the Indian Ocean have experienced dengue outbreaks between 1823 and 2014. Major risk factors associated with past dengue outbreaks include climate, virus and vector genetics and human practices. Appropriate use of dengue diagnostic tools and their interpretation are necessary for both outbreak investigations and sero-epidemiological studies. Serosurvey findings during inter-epidemic periods have not been adequately utilised to prevent re-occurrence of dengue outbreaks. Local weather variables may be used to predict dengue outbreaks, while entomological surveillance can complement other disease-mitigation efforts during outbreaks and identify risk-prone areas during inter-epidemic periods. The limitations of past dengue outbreak responses and the enormous socio-economic impacts of the disease on human health are highlighted. Its repeated occurrence in East Africa refutes previous observations that susceptibility may depend on race. Alternate hypotheses on heterotypic protection among flaviviruses may not be applied to all ecologies. Prevention and mitigation of severe dengue outbreaks should necessarily consider the diverse factors associated with their occurrence. Implementation of phased dengue mitigation activities can enforce timely and judicious use of scarce resources, promote environmental sanitation, and drive behavioural change, hygienic practices and community-based vector control. Understanding dengue epidemiology and clinical symptoms, as determined by its evolution, are significant to preventing future dengue epidemics. PMID:26922851

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

    USGS Publications Warehouse

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  5. Holocene shelf sedimentation patterns off equatorial East Africa constrained by climatic and sea-level changes

    NASA Astrophysics Data System (ADS)

    Liu, Xiting; Rendle-Bühring, Rebecca; Meyer, Inka; Henrich, Rüdiger

    2016-01-01

    Equatorial East Africa experienced significant variations in paleoclimatic and paleoceanographic conditions during the Holocene. These environmental changes influenced sedimentation patterns on the continental shelf. To date, however, little is known about the sediment source, its transport to, and deposition on, the Tanzanian shelf. This paper presents a new high-resolution Holocene sedimentary record off northeast Tanzania (equatorial East Africa) and provides insights into how sedimentation patterns responded to climatic and oceanographic changes during the Holocene. Based on grain-size distribution patterns and mineral assemblages, three types of shelf sediments were identified: Type I (fine-grained terrigenous sediment) is dominated by clay minerals that originated from continental weathering; Type II (coarse-grained terrigenous sediment) is mainly composed of feldspar and quartz, derived from reworking of pre-existing deposits; and Type III (biogenic marine sediment), with low- and high-magnesium calcite, was produced by marine carbonate-secreting organisms. The high input of Type I sediment during the early Holocene (10-8 cal kyr BP) was caused by river mouth bypassing. This supply-dominated regime was controlled by intense river discharge and subsequent resuspension of mud in shelf settings, responding to the humid climate in the hinterland and sea-level rise with low rate off Tanzania. The first occurrence of Type II sediments was around 8 cal kyr BP and dominated when sedimentation rates lowered. This accommodation-dominated regime was caused by shoreface bypassing due to an arid climate and sea-level highstand. Type III sediments increased significantly from the early to late Holocene, resulting from the weakening dilution effect of the terrigenous component. The sedimentation pattern on the Tanzanian shelf shifted from allochthonous to autochthonous sedimentation constrained by climatic changes and relative sea-level fluctuations at the end of the early

  6. 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

  7. Surgical Efficiencies and Quality in the Performance of Voluntary Medical Male Circumcision (VMMC) Procedures in Kenya, South Africa, Tanzania, and Zimbabwe

    PubMed Central

    Rech, Dino; Bertrand, Jane T.; Thomas, Nicholas; Farrell, Margaret; Reed, Jason; Frade, Sasha; Samkange, Christopher; Obiero, Walter; Agot, Kawango; Mahler, Hally; Castor, Delivette; Njeuhmeli, Emmanuel

    2014-01-01

    Introduction This analysis explores the association between elements of surgical efficiency in voluntary medical male circumcision (VMMC), quality of surgical technique, and the amount of time required to conduct VMMC procedures in actual field settings. Efficiency outcomes are defined in terms of the primary provider’s time with the client (PPTC) and total elapsed operating time (TEOT). Methods Two serial cross-sectional surveys of VMMC sites were conducted in Kenya, Republic of South Africa, Tanzania and Zimbabwe in 2011 and 2012. Trained clinicians observed quality of surgical technique and timed 9 steps in the VMMC procedure. Four elements of efficiency (task-shifting, task-sharing [of suturing], rotation among multiple surgical beds, and use of electrocautery) and quality of surgical technique were assessed as explanatory variables. Mann Whitney and Kruskal Wallis tests were used in the bivariate analysis and linear regression models for the multivariate analyses to test the relationship between these five explanatory variables and two outcomes: PPTC and TEOT. The VMMC procedure TEOT and PPTC averaged 23–25 minutes and 6–15 minutes, respectively, across the four countries and two years. The data showed time savings from task-sharing in suturing and use of electrocautery in South Africa and Zimbabwe (where task-shifting is not authorized). After adjusting for confounders, results demonstrated that having a secondary provider complete suturing and use of electrocautery reduced PPTC. Factors related to TEOT varied by country and year, but task-sharing of suturing and/or electrocautery were significant in two countries. Quality of surgical technique was not significantly related to PPTC or TEOT, except for South Africa in 2012 where higher quality was associated with lower TEOT. Conclusions SYMMACS data confirm the efficiency benefits of task-sharing of suturing and use of electrocautery for decreasing TEOT. Reduced TEOT and PPTC in high volume setting did

  8. Peralkaline nephelinites. I. Comparative petrology of Shombole and Oldoinyo L'engai, East Africa

    NASA Astrophysics Data System (ADS)

    Peterson, Tony D.

    1989-04-01

    Shombole, a nephelinite-carbonatite volcano in south Kenya, erupted silicate lavas, carbonatite dikes and tuffs, and pyroclastic rocks similar to those at other East African alkaline centres. Shombole lavas containing cpx + nepheline + accessory minerals range from perovskite-bearing nephelinites (43% SiO2, volatile-free) to sphene-bearing and phonolitic nephelinites (46 49% SiO2) and phonolites (49 56% SiO2) and have low peralkalinity ([Na+K]/Al ≈ 1.15) which does not correlate with SiO2. Early fractionation of olivine and clinopyroxene strongly depleted Ni and Cr concentrations (≈10 ppm); fractionation of perovskite, melanite, sphene, and apatite produced negative correlations of all REE with SiO2. Many lavas contain cognate intrusive xenoliths and xenocrysts and oscillatory zoning is a common feature of clinopyroxene, nepheline, and melanite crystals, indicating recycling of intrusive material. Irregular calcite-rich bodies in many samples are interpreted as quenched immiscible Ca-carbonatite liquid, and [Ca-carbonate]-silicate liquid immiscibility is observed in experiments with one nephelinite. Chemical variation in the Shombole suite can be modeled as a combination of crystal fractionation (clinopyroxene and heavy minor phases) and retention of neutral density nepheline derived from disaggregated xenoliths entrained during emplacement of dike swarms. Six newly analyzed lavas from Oldoinyo L'engai, northern Tanzania, are geochemically similar to Shombole nephelinites except that they have relatively high Na2O+K2O (average 18% vs 12%) and Zr (average 680 ppm vs 400 ppm). They are extremely peralkaline and are not typical of nephelinites from other centres. Three with [Na+K]/Al≈1.5 contain euhedral wollastonite phenocrysts; three with [Na+K]/Al≈2.0 contain combeite (Na2Ca2Si3O9) phenocrysts and pseudomorphs after wollastonite. Both types contain abundant sodalite phenocrysts (+nepheline+clinopyroxene+melanite+sphene). Seven other wollastonite nephelinite

  9. The origin and age of haplochromine fishes in Lake Victoria, east Africa.

    PubMed

    Nagl, S; Tichy, H; Mayer, W E; Takezaki, N; Takahata, N; Klein, J

    2000-05-22

    According to a widely held view, the more than 300 species of haplochromine cichlid fishes in Lake Victoria (LV), East Africa, originated from a single founder species in less than 12,000 years. This view, however, does not follow from the published geological and molecular evidence. The former does indeed suggest that the LV basin dried out less than 15,000 years ago, but it does not provide any information about the species that re-colonized the new lake or that remained in the rivers draining the area. The molecular evidence is inconclusive with respect to the origin of the LV haplochromines because cichlids from critical regions around LV were not adequately sampled; and as far as the age of the LV haplochromines is concerned, it in fact led to an estimate of 250,000-750,000 years old. In the present study, mitochondrial DNA (control region) variation was determined by heteroduplex and sequencing analyses of more than 670 specimens collected at widely distributed East African riverine and lacustrine localities. The analyses revealed the existence of seven haplogroups (I-VII) distinguishable by characteristic substitutions. All endemic LV samples tested fell into one of these haplogroups (V) which, however, was also found to be present at various other localities, both riverine and lacustrine, outside LV. Within this haplogroup, four subgroups (VA through VD) could be distinguished, two of which (VB and VC) were represented in LV and at other localities. The great majority of the LV haplochromine species could be classified as belonging to the VC subgroup, which was found only in LV and in the rivers draining into it. Hence, while the endemic haplochromine species of LV could not have originated from a single founding population, the lake does harbour a large species flock which probably arose in situ. PMID:10874756

  10. The origin and age of haplochromine fishes in Lake Victoria, east Africa.

    PubMed Central

    Nagl, S; Tichy, H; Mayer, W E; Takezaki, N; Takahata, N; Klein, J

    2000-01-01

    According to a widely held view, the more than 300 species of haplochromine cichlid fishes in Lake Victoria (LV), East Africa, originated from a single founder species in less than 12,000 years. This view, however, does not follow from the published geological and molecular evidence. The former does indeed suggest that the LV basin dried out less than 15,000 years ago, but it does not provide any information about the species that re-colonized the new lake or that remained in the rivers draining the area. The molecular evidence is inconclusive with respect to the origin of the LV haplochromines because cichlids from critical regions around LV were not adequately sampled; and as far as the age of the LV haplochromines is concerned, it in fact led to an estimate of 250,000-750,000 years old. In the present study, mitochondrial DNA (control region) variation was determined by heteroduplex and sequencing analyses of more than 670 specimens collected at widely distributed East African riverine and lacustrine localities. The analyses revealed the existence of seven haplogroups (I-VII) distinguishable by characteristic substitutions. All endemic LV samples tested fell into one of these haplogroups (V) which, however, was also found to be present at various other localities, both riverine and lacustrine, outside LV. Within this haplogroup, four subgroups (VA through VD) could be distinguished, two of which (VB and VC) were represented in LV and at other localities. The great majority of the LV haplochromine species could be classified as belonging to the VC subgroup, which was found only in LV and in the rivers draining into it. Hence, while the endemic haplochromine species of LV could not have originated from a single founding population, the lake does harbour a large species flock which probably arose in situ. PMID:10874756

  11. Capacity Building in NASA Remote Sensing Data for Meteorological and Agricultural Communities in East Africa

    NASA Astrophysics Data System (ADS)

    Granger, S. L.; Andreadis, K.; Das, N. N.; Macharia, D.

    2015-12-01

    Across the globe, planners and decision makers are hampered by a lack of historic data and scant in situ observations on which to base policy and action plans. Data is often sorely lacking in poorly developed regions such as East Africa where people are vulnerable to a changing climate, extreme weather events, and economies and food security are tied directly to rain fed agriculture or pastoral cultures. NASA global remote sensing observations and research are promising in this regard, as they have great potential to inform policy- and decision-making at global, regional and even local scales the world over, However that potential is not realized as often as it should for a variety of reasons: the data stores are often impenetrable requiring special expertise to "crack the code", sustainability of observations remains a concern, and research and data are not focused on applications, thus results don't "fit" in existing tools or are developed for a short-term science objective without long-term use in mind. Although there are good examples of the use of NASA Earth Science research and observations for applications, capacity is lacking and must be built to advance the use of remote sensing for applications and to ease transition of research to the stakeholder. Capacity building is a critical component to transition Earth science research results to stakeholder communities, and is more than traditional training,, it has been described as…."the process of developing and strengthening the skills, instincts, abilities, processes and resources that organizations and communities need to survive, adapt, and thrive in the fast-changing world. Best practices and lessons learned from recent capacity building efforts for Agricultural and Environmental Ministires in East African in support of a NASA-SERVIR Applied Science Project to provide estimates of hydrologic extremes tied to crop yield are described.

  12. Establishing an Online Continuing and Professional Development Library for Nurses and Midwives in East, Central, and Southern Africa.

    PubMed

    Hosey, Kristen N; Kalula, Alphonce; Voss, Joachim

    2016-01-01

    Over the past 4 years, the African Health Profession Regulatory Collaborative for nurses and midwives has supported 12 countries establish national continuing and professional development frameworks and programs, linking continuing education to nursing and midwifery re-licensure through technical assistance and improvement grants. However, lack of electronic media and rural practice sites, differences in priority content, and varying legal frameworks make providing accessible, certifiable, and up-to-date online continuing education content for the more than 300,000 nurses and midwives in the 17 member countries of the East, Central, and Southern Africa College of Nursing a major challenge. We report here on how the East, Central, and Southern Africa College of Nursing, with technical assistance from an Afya Bora Fellow, developed an online continuing professional development library hosted on their Web site using data collected in a survey of nursing and midwifery leaders in the region. PMID:27086190

  13. Emergence of virulence to SrTmp in the Ug99 race group of wheat stem rust, Puccinia graminis f.sp. tritici in Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Ug99 race (TTKSK) of wheat stem rust was first detected in Uganda in 1998, and since then seven additional variants have been reported, i.e., TTKSF, TTKST, TTTSK, TTKSP, PTKSK, PTKST, and TTKSF+. In this study, 84 stem rust samples from the 2014 surveys of wheat fields in east Africa (Kenya, 9; ...

  14. Drivers of actual evapotranspiration and runoff in East Africa during the mid-Holocene: assessments from an ecosystem model

    NASA Astrophysics Data System (ADS)

    Fer, Istem; Jeltsch, Florian; Tietjen, Britta; Trauth, Martin

    2014-05-01

    Understanding the evolution and response of the hydrological cycle under changing climate is of vital importance for human populations all around the world. Especially so in regions like East Africa, where society largely depends on the availability of water and the hydrologic conditions are highly sensitive to changes in the distribution and amount of precipitation. In this endeavor, studying past hydrological changes provides us realistic scenarios and data to better understand and predict the extent of the future hydrological changes. However while studying the past, paleovegetation, which plays a pivotal role in the paleo-hydrological cycle, is difficult to determine from fossil pollen records as pollen data can provide very limited information on spatial distribution and composition of the vegetation cover. Here ecosystem models driven by paleo-climate conditions can provide spatially-extensive information on the coupled dynamics of past vegetation and hydrological measures such as actual evapotranspiration (AET), potential evapotranspiration (PET) and runoff. In this study, we looked at AET and runoff estimates of an ecosystem model as these are important elements of water transfer in the hydrological cycle and critical for water balance calculations. We applied the ecosystem model, LPJ-GUESS, for present-day with data from Climatic Research Unit CRU TS3.20 climate dataset, and for mid-Holocene (6 kyrs BP) with data from an atmosphere-ocean coupled global climate model EC-Earth. Climate data for both periods were downscaled to a 10 arc min resolution in order to better resolve the impacts of the complex topography on vegetation distribution, AET and runoff. Comparison of the simulated AET and runoff values for East Africa, show similar patterns as annual AET estimates for the period 1961-1990 by Food and Agriculture Organization of the United Nations (FAO), and with the observed runoff data from Cogley (1998), respectively. Comparison of simulated present

  15. Pregnancy history and current use of contraception among women of reproductive age in Burundi, Kenya, Rwanda, Tanzania and Uganda: analysis of demographic and health survey data

    PubMed Central

    Bakibinga, Pauline; Matanda, Dennis J; Ayiko, Rogers; Rujumba, Joseph; Muiruri, Charles; Amendah, Djesika; Atela, Martin

    2016-01-01

    Objective To examine the relationship between pregnancy history and the use of contraception among women of reproductive age (15–49 years) in East Africa. Methods Demographic and Health Surveys data from Burundi (2010), Kenya (2008–2009), Rwanda (2010), Tanzania (2010) and Uganda (2011) were used in the analysis. Logistic regression was used to determine the effects of women's pregnancy history on their use of contraception. Setting Burundi, Kenya, Rwanda, Tanzania and Uganda. Participants 3226, 2377, 4396, 3250 and 2596 women of reproductive age (15–49 years) from Burundi, Kenya, Rwanda, Tanzania and Uganda, respectively, were included in the analysis. Results Women who had experienced a mistimed pregnancy were more likely to use a modern contraceptive method during their most recent sexual encounter in Kenya, Rwanda, Burundi and Uganda. Other significant correlates of women's contraceptive use were: desire for more children, parity, household wealth, maternal education and access information through radio. In-country regional differences on use of modern contraceptive methods were noted across five East African countries. Conclusions Women's birth histories were significantly associated with their decision to adopt a modern contraceptive method. This highlights the importance of considering women's birth histories, especially women with mistimed births, in the promotion of contraceptive use in East Africa. Variations as a result of place of residency, educational attainment, access to family planning information and products, and wealth ought to be addressed in efforts to increase use of modern contraceptive methods in the East African region. PMID:26966059

  16. Seismic Migration Imaging of the Lithosphere beneath the Afar Rift System, East Africa

    NASA Astrophysics Data System (ADS)

    Lee, T. T. Y.; Chen, C. W.; Rychert, C.; Harmon, N.

    2015-12-01

    The Afar Rift system in east Africa is an ideal natural laboratory for investigating the incipient continental rifting, an essential component of plate tectonics. The Afar Rift is situated at the triple junction of three rifts, namely the southern Red Sea Rift, Gulf of Aden Rift and Main Ethiopian Rift (MER). The ongoing continental rifting at Afar transitions to seafloor spreading toward the southern Red Sea. The tectonic evolution of Afar is thought to be influenced by a mantle plume, but how the plume affects and interacts with the Afar lithosphere remains elusive. In this study, we use array seismic data to produce high-resolution migration images of the Afar lithosphere from scattered teleseismic wavefields to shed light on the lithospheric structure and associated tectonic processes. Our preliminary results indicate the presence of lithospheric seismic discontinuities with depth variation across the Afar region. Beneath the MER axis, we detect a pronounced discontinuity at 55 km depth, characterized by downward fast-to-slow velocity contrast, which appears to abruptly deepen to 75 km depth to the northern flank of MER. This discontinuity may be interpreted as the lithosphere-asthenosphere boundary. Beneath the Ethiopian Plateau, on the other hand, a dipping structure with velocity increase is identified at 70-90 km depth. Further synthesis of observations from seismic tomography, receiver functions, and seismic anisotropy in the Afar region will offer better understanding of tectonic significance of the lithospheric discontinuities.

  17. Polyphase Neoproterozoic orogenesis within the east Africa- Antarctica orogenic belt in central and northern Madagascar

    USGS Publications Warehouse

    Key, R.M.; Pitfield, P.E.J.; Thomas, Ronald J.; Goodenough, K.M.; Waele, D.; Schofield, D.I.; Bauer, W.; Horstwood, M.S.A.; Styles, M.T.; Conrad, J.; Encarnacion, J.; Lidke, D.J.; O'connor, E. A.; Potter, C.; Smith, R.A.; Walsh, G.J.; Ralison, A.V.; Randriamananjara, T.; Rafahatelo, J.-M.; Rabarimanana, M.

    2011-01-01

    Our recent geological survey of the basement of central and northern Madagascar allowed us to re-evaluate the evolution of this part of the East Africa-Antarctica Orogen (EAAO). Five crustal domains are recognized, characterized by distinctive lithologies and histories of sedimentation, magmatism, deformation and metamorphism, and separated by tectonic and/or unconformable contacts. Four consist largely of Archaean metamorphic rocks (Antongil, Masora and Antananarivo Cratons, Tsaratanana Complex). The fifth (Bemarivo Belt) comprises Proterozoic meta-igneous rocks. The older rocks were intruded by plutonic suites at c. 1000 Ma, 820-760 Ma, 630-595 Ma and 560-520 Ma. The evolution of the four Archaean domains and their boundaries remains contentious, with two end-member interpretations evaluated: (1) all five crustal domains are separate tectonic elements, juxtaposed along Neoproterozoic sutures and (2) the four Archaean domains are segments of an older Archaean craton, which was sutured against the Bemarivo Belt in the Neoproterozoic. Rodinia fragmented during the early Neoproterozoic with intracratonic rifts that sometimes developed into oceanic basins. Subsequent Mid- Neoproterozoic collision of smaller cratonic blocks was followed by renewed extension and magmatism. The global 'Terminal Pan-African' event (560-490 Ma) finally stitched together the Mid-Neoproterozoic cratons to form Gondwana. ?? The Geological Society of London 2011.

  18. Evaluation ofthe Middle East and North Africa Land Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Bolten, John D.; Rodell, Matthew; Zaitchik, Benjamin; Ozdogan, Mutlu; Anderson, Martha; Bergaoui, Karim B.; Khalaf, Adla J.; McDonnell, Rachael A.

    2012-01-01

    The Middle East and North Africa (MENA) region is dominated by dry, warm deserts, areas of dense population, and inefficient use of fresh water resources. Due to the scarcity, high intensity, and short duration of rainfall in the MENA, the region is prone to hydro climatic extremes that are realized by devastating floods and times of drought. However, given its widespread water stress and the considerable demand for water, the MENA remains relatively poorly monitored. This is due in part to the shortage of meteorological observations and the lack of data sharing between nations. As a result, the accurate monitoring of the dynamics of the water cycle in the MENA is difficult. The Land Data Assimilation System for the MENA region (MENA LDAS) has been developed to provide regional, gridded fields of hydrological states and fluxes relevant for water resources assessments. As an extension of the Global Land Data Assimilation System (GLDAS), the MENA LDAS was designed to aid in the identification and evaluation of regional hydrological anomalies by synergistically combining the physically-based Catchment Land Surface Model (CLSM) with observations from several independent data products including soil-water storage variations from the Gravity Recovery and Climate Experiment (GRACE) and irrigation intensity derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). In this fashion, we estimate the mean and seasonal cycle of the water budget components across the MENA.

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

    PubMed

    Ercevik Amado, Liz

    2004-05-01

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

  20. Y chromosome STR allelic and haplotype diversity in a Rwanda population from East Central Africa.

    PubMed

    Balamurugan, Kuppareddi; Duncan, George

    2012-03-01

    We have analyzed 17 Y-chromosomal STR loci in a population sample of 69 unrelated male individuals of the Rwanda-Hutu population from East Central Africa using an AmpFlSTR® Yfiler™ PCR amplification kit. A total of 62 unique haplotypes were identified among the 69 individuals studied. The haplotype diversity was found to be 0.9970 for this population. The gene diversity ranged from 0.1130 (DYS392) to 0.7722 (DYS385). Comparison of populations in this study with twenty-five other national and global populations using Principal Co-ordinate Analysis (PCA) and phylogenetic molecular analysis using a genetic distance matrix indicates a delineation of all the African populations from other unrelated populations. The results of population pair-wise Fst p values indicate statistically significant differentiation of the Rwandan population when compared with 25 other global populations including four African populations (p=0.0000). Analysis of Molecular Variance (AMOVA) of the Rwanda population with four other African populations indicated a 93% variance within populations and 7% variance among the five populations. A data base search of the 62 haplotypes yielded only one non-African haplotype match, suggesting these haplotypes are unique to the African continent. PMID:22285642

  1. Concentrating solar power in Europe, the Middle East and North Africa: achieving its potential

    NASA Astrophysics Data System (ADS)

    Pitz-Paal, R.; Amin, A.; Bettzüge, M.; Eames, P.; Fabrizi, F.; Flamant, G.; Garcia Novo, F.; Holmes, J.; Kribus, A.; van der Laan, H.; Lopez, C.; Papagiannakopoulos, P.; Pihl, E.; Smith, P.; Wagner, H.-J.

    2012-10-01

    Concentrating solar power (CSP) is a commercially available renewable energy technology capable of harnessing the immense solar resource in Southern Europe, the Middle East and North Africa (the MENA region), and elsewhere. This paper summarises the findings of a study by the European Academies Science Advisory Council which has examined the current status and development challenges of CSP, and consequently has evaluated the potential contribution of CSP in Europe and the MENA region to 2050. It identifies the actions that will be required by scientists, engineers, policy makers, politicians, business and investors alike, to enable this vast solar resource to make a major contribution to establishing a sustainable energy system. The study concludes that cost reductions of 50-60% in CSP electricity may reasonably be expected in the next 10-15 years, enabling the technology to be cost competitive with fossil-fired power generation at some point between 2020 and 2030. Incorporation of storage delivers added value in enabling CSP to deliver dispatchable power. Incentive schemes will be needed in Europe and MENA countries to enable this point to be achieved. Such schemes should reflect the true value of electricity to the grid, effectively drive R&D, and ensure transparency of performance and cost data.

  2. Bilharziasis control in relation to water resources development in Africa and the Middle East

    PubMed Central

    McMullen, Donald B.; Buzo, Z. J.; Rainey, Marshall B.; Francotte, Jean

    1962-01-01

    As part of its world-wide programme for the control of bilharziasis, the World Health Organization has set up a Bilharziasis Advisory Team, composed of an epidemiologist and an engineer, to investigate in different countries the prevalence of the disease and its relationship to irrigation, agriculture and a variety of factors associated with the development of water resources. This paper is an appraisal of the situation in 15 countries in Africa and the Middle East, based largely on surveys conducted by the Bilharziasis Advisory Team in the period 1958-60. Analyses of data from these 15 countries indicate that about 26 million people, out of a total population of 107 million, have bilharziasis. In spite of considerable expenditure on control measures, the prevalence of the disease is increasing. This trend is closely related to water resources development. On the basis of observations in the field, it is believed that improved water management and agricultural methods, stream and water impoundment control, the proper use of molluscicides and mechanical barriers, and certain aspects of environmental sanitation offer practical solutions to this problem. The complexity of these measures requires the closest co-operation between the various agencies, national and international, concerned with agriculture, water resources and public health. PMID:20604119

  3. Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits

    NASA Astrophysics Data System (ADS)

    Howari, Fares; Goodell, Philip; Salman, Abdulaty

    2016-02-01

    This paper is briefly involved in classification and distributions of the Middle East and North Africa (MENA) uranium deposits. The study of these mineral systems can significantly contribute to our further understanding of the metallogeny of known and poorly explored deposits. This provides contribution to, and further enhancement of, current classifications and metallogenic models of uranium systems, allowing researchers to emphasize on unknown or poorly studied mineral systems found in MENA. The present study identified eight metallogenic types of uranium associated with: 1) the Archean rocks and intra-cratonic basins, 2) the Pan-African granites and rhyolites which are characterized by igneous activity, 3) Phanerozoic (Paleozoic) clastics, these deposits are the sedimentological response to Pan African magmatism, 4) Mesozoic (basal) clastics type e.g. Nubia sandstones which are characterized by uranium minerals, 5) regional sedimentary phosphate deposits which are categorized as geosynclinal, or continental margin deposits, on the shelf of the Tethys Ocean, 6) Cenozoic Intracratonic Felsic Magmatism of the Tibesti and Hoggar, and the sandstone U deposits of adjoining Niger. These are similar to the Pan-African magmatism metallogenic, 7) Calcretes, and 8) Resistate minerals which are often enriched in rare earth elements, sometimes including uranium. They are thus sometimes considered as U resources but poorly explored in the MENA region. These metallogenic types are described and discussed in the current paper.

  4. Aerial applications of insecticides for tsetse fly control in East Africa

    PubMed Central

    Lee, C. W.

    1969-01-01

    Since 1948, research has progressed in East Africa on the control of tsetse flies by aeria, applications of insecticides. Initial experiments proved that residual spray treatments were ineffective while repeated applications of coarse aerosols gave promising fly mortalities. In recent years, with the development of more toxic insecticides used in conjunction with improved thermal exhaust equipment and modified rotary atomizers, sprays with fine aerosol characteristics have been produced at considerably reduced cost. Aerial applications of aerosols are confined to early morning and late afternoon when weather conditions are stable, but large areas can be treated during these short intervals, and the technique is efficient and economical. Control of tsetse flies has been good; where complete isolation of an area has been possible, eradication has been achieved. It would be economically worth while to assess the possibility of increasing spray swath widths, and also to continue with research into the biological effectiveness of pyrethrum, primarily because of its absolute safety in use. There is a need for a simple method for the determination of tsetse fly populations in woodland and savanna habitats. Finally, it is recommended that the results of research to date should be brought more forcefully to the attention of government bodies and commercial airspray operators so that the techniques be more fully exploited. PMID:5308701

  5. Treated Wastewater's Potential for Improving Water and Food Security in the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Dare, A. E.

    2014-12-01

    The Middle East and North Africa (MENA) contains just 1% of the world's freshwater; however, even in the very arid countries of the Gulf region, high quality treated wastewater rarely sees a productive use. As countries deal with growing populations and strive for increased food security, freshwater alone cannot be relied upon to meet these demands. This research identifies best practices from the MENA for reusing treated wastewater in agricultural production, and calculates the potential of treated wastewater for increasing food production in select countries. Drawing upon both published and original treated wastewater quality data for locations in the MENA, the annual volume of treated wastewater produced, and crop water demands, estimates for potential crop production from treated wastewater are calculated. The volume of wastewater treated annually is equivalent to 10-40% of agricultural withdrawals in most MENA countries. Irrigation by treated wastewater has significant potential to impact water and food security by reducing agricultural water withdrawals and increasing domestic food production. Such initiatives require application of best management practices, such as transparent monitoring and evaluation of reuse projects for public and environmental health risks, and support from both farmers and policy makers.

  6. Geology and Nonfuel Mineral Deposits of Africa and the Middle East

    USGS Publications Warehouse

    Taylor, Cliff D.; Schulz, Klaus J.; Doebrich, Jeff L.; Orris, Greta; Denning, Paul D.; Kirschbaum, Michael J.

    2009-01-01

    A nation's endowment of nonfuel mineral resources, relative to the world's endowment, is a fundamental consideration in decisions related to a nation's economic and environmental well being and security. Knowledge of the worldwide abundance, distribution, and general geologic setting of mineral commodities provides a framework within which a nation can make decisions about economic development of its own resources, and the economic and environmental consequences of those decisions, in a global perspective. The information in this report is part of a U.S. Geological Survey (USGS) endeavor to evaluate the global endowment of both identified and undiscovered nonfuel mineral resources. The results will delineate areas of the world that are geologically permissive for the occurrence of undiscovered selected nonfuel mineral resources together with estimates of the quantity and quality of the resources. The results will be published as a series of regional reports; this one provides basic data on the identified resources and geologic setting, together with a brief appraisal of the potential for undiscovered mineral resources in Africa and the Middle East. Additional information, such as production statistics, economic factors that affect the mineral industries of the region, and historical information, is available in U.S. Geological Survey publications such as the Minerals Yearbook and the annual Mineral Commodity Summaries (available at http://minerals.usgs.gov/minerals).

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

    SciTech Connect

    Sweeney, J.J.

    1995-09-06

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

  8. Mitochondrial haplotype diversity in the tortoise species Testudo graeca from North Africa and the Middle East

    PubMed Central

    van der Kuyl, Antoinette C; Ballasina, Donato LP; Zorgdrager, Fokla

    2005-01-01

    Background To help conservation programs of the endangered spur-thighed tortoise and to gain better insight into its systematics, genetic variation and evolution in the tortoise species Testudo graeca (Testudines: Testudinidae) was investigated by sequence analysis of a 394-nucleotide fragment of the mitochondrial 12S rRNA gene for 158 tortoise specimens belonging to the subspecies Testudo graeca graeca, Testudo graeca ibera, Testudo graeca terrestris, and a newly recognized subspecies Testudo graeca whitei. A 411-nucleotide fragment of the mitochondrial D-loop was additionally sequenced for a subset of 22 T. graeca, chosen because of their 12S gene haplotype and/or geographical origin. Results Haplotype networks generated by maximum-likelihood and neighbor-joining analyses of both the separate and the combined sequence data sets suggested the existence of two main clades of Testudo graeca, comprising Testudo graeca from northern Africa and Testudo graeca from the Turkey and the Middle East, respectively. Conclusion Mitochondrial DNA haplotyping suggests that the tortoise subspecies of T. g. graeca and T. g. ibera are genetically distinct, with a calculated divergence time in the early or middle Pleistocene. Other proposed subspecies could not clearly be recognized based upon their mt haplotypes and phylogenetic position, and were either part of the T. g. graeca or of the T. g. ibera clade, suggesting that genetic evidence for the existence of most of the 15 proposed subspecies of T. graeca is weak. PMID:15836787

  9. Maternal recall of symptoms associated with childhood deaths in rural east Africa.

    PubMed

    Snow, R W; Basto de Azevedo, I; Forster, D; Mwankuyse, S; Bomu, G; Kassiga, G; Nyamawi, C; Teuscher, T; Marsh, K

    1993-08-01

    Verbal autopsies (VA) are frequently used to determine causes of death for individuals for whom there is no reliable clinical information regarding the terminal illness. VA interviews are used to note key symptoms and signs recalled by relatives of the deceased and diagnoses ascribed according to the symptom complexes. The VA technique assumes that individual disease entities have discrete symptom complexes and that these can be accurately recognized and recalled by the interviewees. We have examined the accuracy with which specific symptoms are recalled over time by mothers or normal guardians of 491 children who died on the paediatric wards of two district hospitals in East Africa. Kwashiorkor, measles, trauma, generalized convulsions and neonatal tetanus were all reported with a high degree of accuracy for children who died of these conditions and had low false positive rates for children without these conditions. Recall was similar within 1 month of death compared to recall after 6 months for most symptoms and signs except neonatal tetanus where false positive reports by mothers increased with time since death. Symptoms and signs commonly used to describe malaria, respiratory tract and diarrhoea-related deaths were reported by mothers to have been present during the terminal illness in 43% of cases where these features were absent. Recall abilities differed between the two communities studied for some symptoms and signs highlighting the importance of such studies in every setting where VA are applied. PMID:8225743

  10. Evaluation of MODIS surrogates for meteorological humidity data in east Africa.

    PubMed

    Lin, Shengpan; Moore, Nathan J; Messina, Joseph P; Wu, Jiaping

    2013-01-01

    Satellite remote sensing technology has shown promising results in characterizing the environment in which plants and animals thrive. Remote sensing scientists, biologists, and epidemiologists are adopting remotely sensed imagery to compensate for the paucity of weather information measured by weather stations. With measured humidity from three stations as baselines, our study reveals that Normalised Difference Vegetation Index (NDVI) and atmosphere saturation deficits at the 780 hPa pressure level (D MODIS), both of which were derived from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensor, were significantly correlated with station saturation deficits (D stn)(ȣrȣ = 0.42-0.63, p < 0.001). These metrics have the potential to estimate saturation deficits over east Africa. Four to nine days of lags were found in the NDVI responding to D stn. For the daily estimations of D stn, D MODIS had a better performance than the NDVI. However, both of them poorly explained the variances in daily D stn using simple regression models (adj. R (2) = 0.17-0.39). When the estimation temporal scale was changed to 16-day, their performances were similar, and both were better than daily estimations. For D stn estimations at coarser geographic scales, given that many factors such as soil, vegetation, slope, aspect, and wind speed might complicate the NDVI response lags and model construction, D MODIS is more favourable as a proxy of the saturation deficit over ground due to its simple relationship with D stn. PMID:23956475

  11. Evaluation of MODIS surrogates for meteorological humidity data in east Africa

    PubMed Central

    LIN, SHENGPAN; MOORE, NATHAN J.; MESSINA, JOSEPH P.; WU, JIAPING

    2013-01-01

    Satellite remote sensing technology has shown promising results in characterizing the environment in which plants and animals thrive. Remote sensing scientists, biologists, and epidemiologists are adopting remotely sensed imagery to compensate for the paucity of weather information measured by weather stations. With measured humidity from three stations as baselines, our study reveals that Normalised Difference Vegetation Index (NDVI) and atmosphere saturation deficits at the 780 hPa pressure level (DMODIS), both of which were derived from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensor, were significantly correlated with station saturation deficits (Dstn)(ȣrȣ = 0.42–0.63, p < 0.001). These metrics have the potential to estimate saturation deficits over east Africa. Four to nine days of lags were found in the NDVI responding to Dstn. For the daily estimations of Dstn, DMODIS had a better performance than the NDVI. However, both of them poorly explained the variances in daily Dstn using simple regression models (adj. R2 = 0.17–0.39). When the estimation temporal scale was changed to 16-day, their performances were similar, and both were better than daily estimations. For Dstn estimations at coarser geographic scales, given that many factors such as soil, vegetation, slope, aspect, and wind speed might complicate the NDVI response lags and model construction, DMODIS is more favourable as a proxy of the saturation deficit over ground due to its simple relationship with Dstn. PMID:23956475

  12. Basicranial anatomy of Plio-Pleistocene hominids from East and South Africa.

    PubMed

    Dean, M C; Wood, B A

    1982-10-01

    The results of a metrical analysis of the basicranium of 19 Plio-Pleistocene fossil hominid crania are presented. The sample includes crania attributed to Australopithecus africanus, Australopithecus boisei, and robustus, and Homo erectus as well as crania whose attribution is still under discussion. These results confirm significant differences between the cranial base patterns of the "gracile" and "robust" australopithecines and the three crania attributed to Homo erectus have a pattern which resembles that of modern humans. None of the crania examined from East Africa sites have base patterns which resemble that of the "gracile" australopithecines. The crania KNM-ER 407 and 732 have patterns which are compatible with them being smaller-bodied females of Australopithecus boisei; KNM-ER 1470 and 1813 have base patterns which most closely resemble that of Homo erectus. The cranial base pattern of KNM-ER 1805 is compatible with its inclusion in either Australopithecus boisei or Homo. When account is taken of the immaturity of Taung, the evidence of its cranial base pattern suggests that if it had reached adulthood it would have resembled the "gracile" australopithecine crania from Sterkfontein and Makapansgat. PMID:6816071

  13. Bilharziasis survey in British West and East Africa, Nyasaland, and the Rhodesias*

    PubMed Central

    Blair, Dyson M.

    1956-01-01

    The author, in his capacity as a WHO consultant, undertook a survey of bilharziasis in British West and East Africa and Nyasaland during 1950-51. The information thus obtained has been revised and brought up to date and is recorded in the present article together with similar observations on Northern Rhodesia, which was not visited, and on Southern Rhodesia, the author's own country. In Part I, each country is dealt with in turn. The history of the disease and the findings of field surveys are reviewed, and, wherever possible, personal observations have been included. The fact that the information is of a scanty and incomplete nature is an indication that further local studies in all areas are badly needed. In Part II an attempt is made to survey the situation from the point of view of the various aspects of the subjects—methods of obtaining morbidity data, intensity of infection, effects of the disease on human health, treatment, and the molluscan vectors. PMID:13383363

  14. Comparative analysis of development and survival of two Natal fruit fly Ceratitis rosa Karsch (Diptera, Tephritidae) populations from Kenya and South Africa.

    PubMed

    Tanga, Chrysantus M; Manrakhan, Aruna; Daneel, John-Henry; Mohamed, Samira A; Fathiya, Khamis; Ekesi, Sunday

    2015-01-01

    Comparative analysis of development and survivorship of two geographically divergent populations of the Natal fruit fly Ceratitis rosa Karsch designated as Ceratitis rosa R1 and Ceratitis rosa R2 from Kenya and South Africa were studied at seven constant temperatures (10, 15, 20, 25, 30, 33, 35 °C). Temperature range for development and survival of both populations was 15-35 °C. The developmental duration was found to significantly decrease with increasing temperature for Ceratitis rosa R1 and Ceratitis rosa R2 from both countries. Survivorship of all the immature stages of Ceratitis rosa R1 and Ceratitis rosa R2 from Kenya was highest over the range of 20-30 °C (87-95%) and lowest at 15 and 35 °C (61-76%). Survivorship of larvae of Ceratitis rosa R1 and Ceratitis rosa R2 from South Africa was lowest at 35 °C (22%) and 33 °C (0.33%), respectively. Results from temperature summation models showed that Ceratitis rosa R2 (egg, larva and pupa) from both countries were better adapted to low temperatures than R1, based on lower developmental threshold. Minimum larval temperature threshold for Kenyan populations were 11.27 °C and 6.34 °C (R1 and R2, respectively) compared to 8.99 °C and 7.74 °C (R1 and R2, respectively) for the South African populations. Total degree-day (DD) accumulation for the Kenyan populations were estimated at 302.75 (Ceratitis rosa R1) and 413.53 (Ceratitis rosa R2) compared to 287.35 (Ceratitis rosa R1) and 344.3 (Ceratitis rosa R2) for the South African populations. These results demonstrate that Ceratitis rosa R1 and Ceratitis rosa R2 from both countries were physiologically distinct in their response to different temperature regimes and support the existence of two genetically distinct populations of Ceratitis rosa. It also suggests the need for taxonomic revision of Ceratitis rosa, however, additional information on morphological characterization of Ceratitis rosa R1 and Ceratitis rosa R2 is needed. PMID:26798273

  15. Comparative analysis of development and survival of two Natal fruit fly Ceratitis rosa Karsch (Diptera, Tephritidae) populations from Kenya and South Africa

    PubMed Central

    Tanga, Chrysantus M.; Manrakhan, Aruna; Daneel, John-Henry; Mohamed, Samira A.; Fathiya, Khamis; Ekesi, Sunday

    2015-01-01

    Abstract Comparative analysis of development and survivorship of two geographically divergent populations of the Natal fruit fly Ceratitis rosa Karsch designated as Ceratitis rosa R1 and Ceratitis rosa R2 from Kenya and South Africa were studied at seven constant temperatures (10, 15, 20, 25, 30, 33, 35 °C). Temperature range for development and survival of both populations was 15–35 °C. The developmental duration was found to significantly decrease with increasing temperature for Ceratitis rosa R1 and Ceratitis rosa R2 from both countries. Survivorship of all the immature stages of Ceratitis rosa R1 and Ceratitis rosa R2 from Kenya was highest over the range of 20–30 °C (87–95%) and lowest at 15 and 35 °C (61–76%). Survivorship of larvae of Ceratitis rosa R1 and Ceratitis rosa R2 from South Africa was lowest at 35 °C (22%) and 33 °C (0.33%), respectively. Results from temperature summation models showed that Ceratitis rosa R2 (egg, larva and pupa) from both countries were better adapted to low temperatures than R1, based on lower developmental threshold. Minimum larval temperature threshold for Kenyan populations were 11.27 °C and 6.34 °C (R1 and R2, respectively) compared to 8.99 °C and 7.74 °C (R1 and R2, respectively) for the South African populations. Total degree-day (DD) accumulation for the Kenyan populations were estimated at 302.75 (Ceratitis rosa R1) and 413.53 (Ceratitis rosa R2) compared to 287.35 (Ceratitis rosa R1) and 344.3 (Ceratitis rosa R2) for the South African populations. These results demonstrate that Ceratitis rosa R1 and Ceratitis rosa R2 from both countries were physiologically distinct in their response to different temperature regimes and support the existence of two genetically distinct populations of Ceratitis rosa. It also suggests the need for taxonomic revision of Ceratitis rosa, however, additional information on morphological characterization of Ceratitis rosa R1 and Ceratitis rosa R2 is needed. PMID:26798273

  16. Integrating "Ubunifu," Informal Science, and Community Innovations in Science Classrooms in East Africa

    ERIC Educational Resources Information Center

    Semali, Ladislaus M.; Hristova, Adelina; Owiny, Sylvia A.

    2015-01-01

    This study examines the relationship between informal science and indigenous innovations in local communities in which students matured. The discussion considers methods for bridging the gap that exists between parents' understanding of informal science ("Ubunifu") and what students learn in secondary schools in Kenya, Tanzania, and…

  17. Agricultural Early Warning Informing Humanitarian Response in East Africa for 2012

    NASA Astrophysics Data System (ADS)

    Husak, G. J.; Funk, C. C.

    2012-12-01

    Long rains during the March-April-May (MAM) 2011 growing season were a failure for much of the Greater Horn of Africa. These conditions resulted in severe food shortages, with the Famine Early Warning Systems Network (FEWS NET) estimating that 12.4 million people were in need of food assistance in Kenya, Somalia, Ethiopia and Djibouti. Heading into the 2012 season, La Niña conditions, an exceptionally strong western-to-central Pacific sea surface temperature (SST) gradient, and warm SSTs in the eastern Indian Ocean foretold further dryness, compounding the difficulties faced by the already vulnerable populations of this region. In an effort to assess the potential for greater food insecurity in the region, FEWS NET scientists attempted to quantify the likelihood of a dry event. This work used satellite rainfall estimates with a 13-year rainfall history. Weights were assigned to previous years based on the similarity of existing SST conditions to those of previous years in the rainfall record. Scenarios were created by randomly combining dekadal rainfall from the historical record, in accordance with the weights. This bootstrapping resulted in a suite of simulations which could be used to identify the likelihood of specific rainfall outcomes. Areal averages of each simulation were used in the analysis. Analysis of the Global Precipitation Climatology Centre (GPCC) rainfall record, a gridded rainfall product based on available station data, showed that the mean rainfall value for the time period of the satellite data for this region was only about 80% of the 30-year mean. The bootstrapped scenarios were corrected for this bias during the period of the satellite record. Results were expressed as percent of average rather than in absolute rainfall amounts, to account for biases in the satellite products as well as variability in spatial amounts. The results showed that during a normal year the interquartile range is typically 80-120% of normal. However, using the

  18. Hotspot-ridge interaction in the Gulf of Aden, East Africa

    NASA Astrophysics Data System (ADS)

    Tamaki, K.; Fujimoto, H.; Orihashi, Y.; Nakanishi, M.; Huchon, P.

    2001-12-01

    We have conducted a mapping and sampling cruise at the Gulf of Aden along its spreading axis by Aden New Century Cruise (R/V Hakuho-maru, Dec. 2000 - Jan. 2001). The mapping was done by SeaBeam 2120 with gravity and magnetics from 45.5 degree E to 50.5 degree E that occupies the main part of the Gulf of Aden. The obtained data shows the first and clear detailed bathymetry of the spreading system of the Gulf of Aden. The data were jointly analyzed with the bathymetric data at the Tadjoura Rift at the western end of the Gulf of Aden that was obtained by a French Tadjouraden cruise in 1995. The spreading system in the Gulf of Aden is characterized with an oblique and ultraslow spreading system (2.0 cm/y for full rate with N30E direction between Arabia and Africa plates). To the east from 46 deg 20 min E, the spreading system exhibits ridge-transform system with the lengths of each segment with 30 to 60 km. To the west from 46 deg 20 min East, E-W trending Tadjoura Rift is well developed with distinct en-echelon structures in the rift. In the easternmost part of Tadjoura Rift at 45 deg 35 min E we observed shallow peaked twin mountains (Aden New Century Mountains) along the central axis of the rift with the summit depth of 500m. We recovered fresh basaltic lavas from the mountain and the mountains are surrounded by many small volcanic knolls. Based on along-axis bottom rock sampling during the cruise with the compilation of Shilling et al. (1992) data, the Aden New Century Mountains zone shows highly positive anomaly of La/Sm REE anomaly suggesting deep mantle source and we temporarily calls the volcanic zone, the Aden New Century Hotspot. Along-axis profile of bathymetry and La/Sm REE anomaly displays typical pattern of hotspot-ridge interaction with the shallowing of each segment toward the hotspot as well as the increasing geochemical anomalies. Horizontal view of the ridge-transform pattern shows increasing distortion toward the hotspot. The case of hotspot

  19. Using information communication technologies to increase the institutional capacity of local health organisations in Africa: a case study of the Kenya Civil Society Portal for Health

    PubMed Central

    Juma, Charles; Sundsmo, Aaron; Maket, Boniface; Powell, Richard; Aluoch, Gilbert

    2015-01-01

    Introduction Achieving the healthcare components of the United Nations’ Millennium Development Goals is significantly premised on effective service delivery by civil society organisations (CSOs). However, many CSOs across Africalack the necessary capacity to perform this role robustly. This paper reports on an evaluation of the use, and perceived impact, of aknowledge management tool upon institutional strengthening among CSOs working in Kenya's health sector. Methods Three methods were used: analytics data; user satisfaction surveys; and a furtherkey informant survey. Results Satisfaction with the portal was consistently high, with 99% finding the quality and relevance of the content very good or good for institutional strengthening standards, governance, and planning and resource mobilisation. Critical facilitators to the success of knowledge management for CSO institutional strengthening were identified as people/culture (developed resources and organisational narratives) and technology (easily accessible, enabling information exchange, tools/resources available, access to consultants/partners). Critical barriers were identified as people/culture (database limitations, materials limitations, and lack of active users), and process (limited access, limited interactions, and limited approval process). Conclusion This pilot study demonstrated the perceived utility of a web-based knowledge management portal among developing nations’ CSOs, with widespread satisfaction across multiple domains, which increased over time. Providing increased opportunities for collective mutual learning, promoting a culture of data use for decision making, and encouraging all health organisations to be learning institutions should be a priority for those interested in promoting sustainable long-term solutions for Africa. PMID:26401217

  20. Ash from the Toba supereruption in Lake Malawi shows no volcanic winter in East Africa at 75 ka

    PubMed Central

    Lane, Christine S.; Chorn, Ben T.; Johnson, Thomas C.

    2013-01-01

    The most explosive volcanic event of the Quaternary was the eruption of Mt. Toba, Sumatra, 75,000 y ago, which produced voluminous ash deposits found across much of the Indian Ocean, Indian Peninsula, and South China Sea. A major climatic downturn observed within the Greenland ice cores has been attributed to the cooling effects of the ash and aerosols ejected during the eruption of the Youngest Toba Tuff (YTT). These events coincided roughly with a hypothesized human genetic bottleneck, when the number of our species in Africa may have been reduced to near extinction. Some have speculated that the demise of early modern humans at that time was due in part to a dramatic climate shift triggered by the supereruption. Others have argued that environmental conditions would not have been so severe to have such an impact on our ancestors, and furthermore, that modern humans may have already expanded beyond Africa by this time. We report an observation of the YTT in Africa, recovered as a cryptotephra layer in Lake Malawi sediments, >7,000 km west of the source volcano. The YTT isochron provides an accurate and precise age estimate for the Lake Malawi paleoclimate record, which revises the chronology of past climatic events in East Africa. The YTT in Lake Malawi is not accompanied by a major change in sediment composition or evidence for substantial temperature change, implying that the eruption did not significantly impact the climate of East Africa and was not the cause of a human genetic bottleneck at that time. PMID:23630269

  1. Spatial Distribution, Sources, and Age of Sedimentary Carbon in Lake Malawi, East Africa

    NASA Astrophysics Data System (ADS)

    Kruger, B. R.; Minor, E. C.; Werne, J. P.; Johnson, T. C.

    2011-12-01

    Currently, the source of organic matter to surface sediments of Lake Malawi (East Africa) is unclear; studies of offshore north-basin cores (363 m to 403 m water depth) have produced conflicting results regarding the proportion of aquatic versus terrestrial organic carbon (OC) contained in these sediments. To address this question, ten multi-cores were recovered from the north basin of Lake Malawi along a transect that follows a major river delta into the lake's deep basin, from 82 m to 386 m water depth. Bulk surface sediment data indicate that while the C/N ratio of organic matter decreases with distance from shore (ranging from 9.8 to 8.3, R2 = 0.58), and stable carbon isotope values become increasingly 13C-depleted (ranging from -21.65 to -25.25, R2 = 0.80), the concentration of OC (wt %) generally increases (ranging from 1.9% to 4.5%, R2 = 0.77). These combined trends suggest substantial carbon contribution from aquatic sources, particularly in the deeper-water, open-lake sites. This trend is supported by preliminary biomarker results. N-alcohols from surface sediments were isolated and grouped into aquatically sourced (C20, C22, and C24) and terrestrially sourced (C28 and C30) fractions for quantification as well as radiocarbon dating. N-alcohol abundance results indicate consistent contribution of terrestrial n-alcohols to surface sediments as distance from shore increases, while aquatic n-alcohol input appears to increase. Preliminary results from compound class specific radiocarbon dating indicate that aquatically sourced n-alcohols isolated from surface sediments may be significantly aged relative to bulk surface sediment.

  2. Atmospheric concentrations of polycyclic aromatic hydrocarbons in the watershed of Lake Victoria, East Africa.

    PubMed

    Arinaitwe, Kenneth; Kiremire, Bernard T; Muir, Derek C G; Fellin, Phil; Li, Henrik; Teixeira, Camilla; Mubiru, Drake N

    2012-11-01

    In the first study of its kind in Africa, PAHs were measured in high volume (24 h) air samples collected from two sampling stations, at Kakira and Entebbe (KAK and EBB, respectively) within the Lake Victoria watershed in Uganda, to assess source contributions and generate a baseline reference data set for future studies in the East African region. Sampling was conducted over two periods [2000-2004 (KAK and EBB1) and 2008-2010 (EBB2)]. The samples were extracted by accelerated solvent extraction and analyzed for 30 PAHs by GC-MS. The mean total PAH concentrations (ng/m(3)) were found to be 74.3 (range; 19.3-311, N = 39) for KAK, 56.8 (range; 13.3-126, N = 22) for EBB1 and 33.1 (range; 4.91-108, N = 56) for EBB2. The 3-ringed PAHs were the most predominant group with mean concentrations of 35.9 ng/m(3)(EBB1), 30.5 ng/m(3)(KAK) and 23.2 ng/m(3)(EBB2). Naphthalene had an exceptionally high mean concentration (21.9 ng/m(3)) for KAK compared to 0.44 and 0.39 ng/m(3) in EBB1 and EBB2 respectively, likely due to intensive agricultural operations nearby KAK. Principal component and diagnostic ratio analyses showed that the measured levels of PAHs were associated with mixed sources, combustion of petroleum, and biomass being the major sources. PMID:23020709

  3. Kanda fault: A major seismogenic element west of the Rukwa Rift (Tanzania, East Africa)

    NASA Astrophysics Data System (ADS)

    Vittori, Eutizio; Delvaux, Damien; Kervyn, François

    1997-09-01

    The NW-SE trending Rukwa Rift, part of the East African Rift System, links the approximately N-S oriented Tanganyika and Nyassa (Malawi) depressions. The rift has a complex half-graben structure, generally interpreted as the result of normal and strike-slip faulting. Morphological and structural data (e.g. fault scarps, faceted spurs, tilting of Quaternary continental deposits, volcanism, seismicity) indicate Late Quaternary activity within the rift. In 1910 an earthquake of M = 7.4 (historically the largest felt in Africa) struck the Rukwa region. The epicentre was located near the Kanda fault, which affects the Ufipa plateau, separating the Rukwa depression from the south-Tanganyika basin. The geomorphic expression of the Kanda fault is a prominent fresh-looking scarp more than 180 km long, from Tunduma to north of Sumbawanga, that strikes roughly NW-SE, and dips constantly northeast. No evidence for horizontal slip was observed. Generally, the active faulting affects a very narrow zone, and is only locally distributed over several subparallel scarps. The height of the scarp progressively decreases towards the northwest, from about 40-50 m to a few metres north of Sumbawanga. Faulted lacustrine deposits exposed in a road cut near Kaengesa were dated as 8340 ± 700 and 13 600 ± 1240 radiocarbon years. These low-energy deposits now hang more than 15 m above the present-day valley floor, suggesting rapid uplift during the Holocene. Due to its high rate of activity in very recent times, the Kanda Fault could have produced the 1910 earthquake. Detailed paleoseismological studies are used to characterize its recent history. In addition, the seismic hazard posed by this fault, which crosses the fast growing town of Sumbawanga, must be seriously considered in urban planning.

  4. Temporal and spatial variability of temperature and precipitation over East Africa from 1951 to 2010

    NASA Astrophysics Data System (ADS)

    Ongoma, Victor; Chen, Haishan

    2016-05-01

    This study presents temporal and spatial changes in temperature and precipitation over East Africa (EA) from 1951 to 2010. The study utilized monthly Climate Research Unit (CRU) rainfall and temperature datasets, and Global Precipitation Climate Centre (GPCC) rainfall datasets. Sequential Mann-Kendall test statistic was used for trend analysis. The CRU data performs better than GPCC data in reproducing EA annual rainfall cycle. Overall decrease and increase in rainfall and temperature trends were observed, respectively, with the reduction in the March-May rainfall being significant. The highest rate of change in annual rainfall was experienced in the 1960s at -21.76 mm/year. Although there has been increase in temperature from the late 1960s to date, sudden change in its trend change happened in 1994. The increase in temperature reached a significant level in the year 1992. The highest warming rate of 0.05 °C/year was observed in the 1990s. The highest drying rate was recorded in the 1960s at -21.76 mm/year. There was an observed change in rainfall trend in the year 1953 and about four times in 1980, although the changes are insignificant throughout the study period except for 1963 when a positive significant change occurred at 5 % significance level. The highest amount of rainfall was recorded in the 1960s. Generally, positive rainfall and temperature anomalies are observed over the northern sector of the study area and opposite conditions are noted in the southern sector. The results of this study provide a reliable basis for future climate monitoring, as well as investigating extreme weather phenomena in EA.

  5. Evaluating and Communicating Seismo-Volcanic Hazards Within and Between Countries in East Africa

    NASA Astrophysics Data System (ADS)

    Ebinger, C. J.; Yirgu, G.; Mbede, E. I.; Calais, E.; Wright, T.

    2007-12-01

    The 2005 seismo-volcanic crisis in a remote area of Ethiopia graphically illustrated the problems faced by research scientists in East Africa, as well as the need for regional hazard mitigation programs. Over a 3-week period in 2005, 163 mb > 3.9 earthquakes and a silicic eruption occurred as a 60 km-long dike was intruded along a previously identified rift segment ; the spatial scale is larger, and the deformation more intense, than historical seafloor spreading episodes in Iceland. A similar, but smaller dike intrusion episode with volcanic eruption began in July, 2007 in northern Tanzania. In both situations, geoscientists had communicated the potential seismic and volcanic hazards to politicians and planners, but they had little success obtaining funds for permanent seismic and geodetic monitoring networks. Ethiopian scientists seized the opportunity to both communicate science to the general public, and to increase pressure to develop national and regional hazard mitigation programs. The scientific aspects are equally daunting: how to coordinate international teams, each of whom has a national funding agency expecting output; how to incorporate geophysical training opportunities into field data acquisition programs; how to share seismic and geodetic data across sometimes tense political boundaries; how to allow E African scientists to be equal partners in the data analysis and interpretation? We use the response to these two volcano-seismic rifting events to illustrate ways to use short-term blue skies research projects to improve national and regional geophysical infrastructure in developing countries, and we discuss ongoing programs to communicate science to pastoralists and planners.

  6. Early initiation of antiretroviral treatment: Challenges in the Middle East and North Africa

    PubMed Central

    Sardashti, Sara; Samaei, Mehrnoosh; Firouzeh, Mona Mohammadi; Mirshahvalad, Seyed Ali; Pahlaviani, Fatemeh Golsoorat; SeyedAlinaghi, SeyedAhmad

    2015-01-01

    New World Health Organization guidelines recommend the initiation of antiretroviral treatment (ART) for asymptomatic patients with CD4+ T-cell counts of ≤ 500 cells/mm3. Substantial reduction of human immunodeficiency virus (HIV) transmission is addressed as a major public health outcome of this new approach. Middle East and North Africa (MENA), known as the area of controversies in terms of availability of comprehensive data, has shown concentrated epidemics among most of it’s at risk population groups. Serious challenges impede the applicability of new guidelines in the MENA Region. Insufficient resources restrict ART coverage to less than 14%, while only one fourth of the countries had reportable data on patients’ CD4 counts at the time of diagnosis. Clinical guidelines need to be significantly modified to reach practical utility, and surveillance systems have not yet been developed in many countries of MENA. Based on available evidence in several countries people who inject drugs and men who have sex with men are increasingly vulnerable to HIV and viral hepatitis, while their sexual partners - either female sex workers or women in monogamous relationships with high-risk men - are potential bridging populations that are not appropriately addressed by regional programs. Research to monitor the response to ART among the mentioned groups are seriously lacking, while drug resistant HIV strains and limited information on adherence patterns to treatment regimens require urgent recognition by health policymakers. Commitment to defined goals in the fight against HIV, development of innovative methods to improve registration and reporting systems, monitoring and evaluation of current programs followed by cost-effective modifications are proposed as effective steps to be acknowledged by National AIDS Programs of the countries of MENA Region. PMID:25964878

  7. Thermophilic Sulfate Reduction in Hydrothermal Sediment of Lake Tanganyika, East Africa

    PubMed Central

    Elsgaard, Lars; Prieur, Daniel; Mukwaya, Gashagaza M.; Jørgensen, Bo B.

    1994-01-01

    In environments with temperatures above 60°C, thermophilic prokaryotes are the only metabolically active life-forms. By using the 35SO42- tracer technique, we studied the activity of sulfate-reducing microorganisms (SRM) in hot sediment from a hydrothermal vent site in the northern part of freshwater Lake Tanganyika (East Africa). Incubation of slurry samples at 8 to 90°C demonstrated meso- and thermophilic sulfate reduction with optimum temperatures of 34 to 45°C and 56 to 65°C, respectively, and with an upper temperature limit of 80°C. Sulfate reduction was stimulated at all temperatures by the addition of short-chain fatty acids and benzoate or complex substrates (yeast extract and peptone). A time course experiment showed that linear thermophilic sulfate consumption occurred after a lag phase (12 h) and indicated the presence of a large population of SRM in the hydrothermal sediment. Thermophilic sulfate reduction had a pH optimum of about 7 and was completely inhibited at pH 8.8 to 9.2. SRM could be enriched from hydrothermal chimney and sediment samples at 60 and 75°C. In lactate-grown enrichments, sulfide production occurred at up to 70 and 75°C, with optima at 63 and 71°C, respectively. Several sporulating thermophilic enrichments were morphologically similar to Desulfotomaculum spp. Dissimilatory sulfate reduction in the studied hydrothermal area of Lake Tanganyika apparently has an upper temperature limit of 80°C. PMID:16349249

  8. Hydrologic modeling for monitoring water availability in Africa and the Middle East

    NASA Astrophysics Data System (ADS)

    McNally, A.; Getirana, A.; Arsenault, K. R.; Peters-Lidard, C. D.; Verdin, J. P.

    2015-12-01

    Drought impacts water resources required by crops and communities, in turn threatening lives and livelihoods. Early warning systems, which rely on inputs from hydro-climate models, are used to help manage risk and provide humanitarian assistance to the right place at the right time. However, translating advancements in hydro-climate science into action is a persistent and time-consuming challenge: scientists and decision-makers need to work together to enhance the salience, credibility, and legitimacy of the hydrological data products being produced. One organization that tackles this challenge is the Famine Early Warning Systems Network (FEWS NET), which has been using evidence-based approaches to address food security since the 1980s.In this presentation, we describe the FEWS NET Land Data Assimilation System (FLDAS), developed by FEWS NET and NASA hydrologic scientists to maximize the use of limited hydro-climatic observations for humanitarian applications. The FLDAS, an instance of the NASA Land Information System (LIS), is comprised of land surface models driven by satellite rainfall inputs already familiar to FEWS NET food security analysts. First, we evaluate the quality of model outputs over parts of the Middle East and Africa using remotely sensed soil moisture and vegetation indices. We then describe derived water availability indices that have been identified by analysts as potentially useful sources of information. Specifically, we demonstrate how the Baseline Water Stress and Drought Severity Index detect recent water availability crisis events in the Tigris-Euphrates Basin and the Gaborone Reservoir, Botswana. Finally we discuss ongoing work to deliver this information to FEWS NET analysts in a timely and user-friendly manner, with the ultimate goal of integrating these water availability metrics into regular decision-making activities.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  10. Usefulness of ECMWF system-4 ensemble seasonal climate forecasts for East Africa

    NASA Astrophysics Data System (ADS)

    Ogutu, Geoffrey; Franssen, Wietse; Supit, Iwan; Omondi, Philip; Hutjes, Ronald

    2016-04-01

    This study evaluates whether European Centre for Medium-Range Weather Forecast (ECMWF) system-4 seasonal forecasts can potentially be used as input for impact analysis over East Africa. To be of any use, these forecasts should have skill. We used the 15-member ensemble runs and tested potential forecast skill of precipitation (tp), near surface air temperature (tas) and surface downwelling shortwave radiation (rsds) for future use in impact models. Probabilistic measures verified the ECMWF ensemble forecasts against the WATCH Forcing Data methodology applied to ERA-Interim data (WFDEI) climatology for the period 1981-2010. The Ranked Probability Skill Score (RPSS) assesses the overall forecast skill, whereas the Relative Operating Curve Skill Score (ROCSS) analyses skill of the forecasted tercile at both grid cell and over sub-regions with homogeneous rainfall characteristics. The results show that predictability of the three variables varies with season, location and forecast month (lead-time) before start of the seasons. Quantile-quantile bias correction clears biases in the raw forecasts but does not improve probabilistic skills. The October-December (OND) tp forecasts show skill over a larger area up to lead-time of three months compared to the March-May (MAM) and June-August (JJA) seasons. Temperature forecasts are skillful up to a minimum three months lead-time in all seasons, while the rsds is less skillful. ROCSS analyses indicate high skill in simulation of upper- and lower-tercile forecasts compared to simulation of the middle-terciles. Upper- and lower-tercile precipitation forecasts are 20-80% better than climatology over a larger area at 0-3 month lead-time; tas forecasts are 40-100% better at shorter lead-times while rsds forecasts are less skillful in all seasons. The forecast system captures manifestations of strong El Niño and La Niña years in terms of precipitation but the skill scores are region dependent.

  11. TeleEducation Initiatives for Sub-Saharan Africa: The Case of the African Virtual University in Kenya

    ERIC Educational Resources Information Center

    Wilkerson, DerKirra; Simmons, Lakisha; Mbarika, Victor; Thomas, Carlos; Mbarika, Irene; Tsuma, Clive; Wade, Tamiara L.

    2011-01-01

    Sub-Saharan Africa (SSA) lags behind the rest of the world in education. Less than 25 percent of qualified high school graduates in this region will make it to the university level, mainly because most countries within the region have less than three universities. Furthermore, alternatives to universities such as two year colleges and training…

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

    NASA Astrophysics Data System (ADS)

    Osipov, Sergey; Dogar, Mohammad; Stenchikov, Georgiy

    2016-04-01

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

  13. The Lamu Basin deepwater fold-and-thrust belt: An example of a margin-scale, gravity-driven thrust belt along the continental passive margin of East Africa

    NASA Astrophysics Data System (ADS)

    Cruciani, Francesco; Barchi, Massimiliano R.

    2016-03-01

    In recent decades, advances in seismic processing and acquisition of new data sets have revealed the presence of many deepwater fold-and-thrust belts (DW-FTBs), often developing along continental passive margins. These kinds of tectonic features have been intensively studied, due to their substantial interest. This work presents a regional-scale study of the poorly explored Lamu Basin DW-FTB, a margin-scale, gravity-driven system extending for more than 450 km along the continental passive margin of Kenya and southern Somalia (East Africa). A 2-D seismic data set was analyzed, consisting of both recently acquired high-quality data and old reprocessed seismic profiles, for the first detailed structural and stratigraphic interpretation of this DW-FTB. The system originated over an Early to mid-Cretaceous shale detachment due to a mainly gravity-spreading mechanism. Analysis of synkinematic strata indicates that the DW-FTB was active from the Late Cretaceous to the Early Miocene, but almost all of the deformation occurred before the Late Paleocene. The fold-and-thrust system displays a marked N-S variation in width, the northern portion being more than 150 km wide and the southern portion only a few dozen kilometers wide; this along-strike variation is thought to be related to the complex tectonosedimentary evolution of the continental margin at the Somalia-Kenya boundary, also reflected in the present-day bathymetry. Locally, a series of volcanic edifices stopped the basinward propagation of the DW-FTB. A landward change in the dominant structural style, from asymmetric imbricate thrust sheets to pseudo-symmetric detachment folds, is generally observed, related to the landward thickening of the detached shales.

  14. The Eastern Arc Mountains and coastal forests of East Africa-an archive to understand large-scale biogeographical patterns: Pseudotomias, a new genus of African Pseudophyllinae (Orthoptera: Tettigoniidae).

    PubMed

    Hemp, Claudia

    2016-01-01

    A new genus of Pseudophyllinae restricted to East Africa is described. Data on the ecology, and the habitat are provided. The biogeographical pattern and morphology suggests an old radiation since Tomias from Central and West Africa is the closest relative to Pseudotomias. The old forests of East Africa could hereby be the source of representatives of this old radiation since venation is less reduced in East African taxa of Phyllomimini. PMID:27395601

  15. Contrasted seismogenic and rheological behaviours from shallow and deep earthquake sequences in the North Tanzanian Divergence, East Africa

    NASA Astrophysics Data System (ADS)

    Albaric, J.; Perrot, J.; Déverchère, J.; Deschamps, A.; Le Gall, B.; Ferdinand, R. W.; Petit, C.; Tiberi, C.; Sue, C.; Songo, M.

    2010-12-01

    We report preliminary results of a seismological experiment, SEISMO-TANZ' 07, which consisted in the deployment of a local network (35 stations) in the East African Rift System (EARS), North Tanzania, during 6 months in 2007. We compare two earthquake sequences (Gelai and Manyara) occurring, respectively, in the southern end of the Kenya rift and in the North Tanzanian Divergence (NTD). Only distant of ˜150 km, their triggering mechanisms are different. None of the sequences depicts typical swarm or mainshock-aftershock patterns. They highlight the change in the magmatic/tectonic nature of the rift where the eastern branch of the EARS enters the Tanzanian craton. The similar shape and long-axis of the elongate sequences emphasize the preferred locus of active strain release along NE-SW discontinuities which probably root at depth into steep Proterozoic shear zones. At Gelai, the deformation is dominated by aseismic process involving slow slip on normal fault and dyke intrusion within the upper crust (Calais et al., 2008). The spatial and temporal earthquake distribution indicates a possible correlation between the Gelai crisis and the eruption of the nearby Oldoinyo Lengai volcano. At Manyara, the sequence is more uncommon, revealing a long-lasting seismic activity deeply rooted (˜20-35 km depth) possibly related to stress loading transmitted laterally. The yield strength envelope modelled from the depth frequency distribution of earthquakes in the NTD is consistent with the presence of a mafic lower crust and further supports the strength increase of the rifted crust from south Kenya to the NTD.

  16. Aerosol Transport Over Equatorial Africa

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  17. Morphology and DNA barcoding reveal a new species of Eudicella from East Africa (Coleoptera: Scarabaeidae: Cetoniinae).

    PubMed

    Seidel, Matthias

    2016-01-01

    A new species of Eudicella White, 1839 (Coleoptera: Scarabaeidae: Cetoniinae), is described from Uganda and Kenya: E. nana new species. Morphological and genetic analyses of the new taxon and phenotypically allied species are given. Eudicella nana is compared with its hypothesized sister species, E. darwiniana Kraatz, 1880, and diagnostic characters that distinguish it from other species occurring in the same region are provided. PMID:27470742

  18. Climate-disease connections: Rift Valley Fever in Kenya

    NASA Technical Reports Server (NTRS)

    Anyamba, A.; Linthicum, K. J.; Tucker, C. J.

    2001-01-01

    All known Rift Valley fever(RVF) outbreaks in Kenya from 1950 to 1998 followed periods of abnormally high rainfall. On an interannual scale, periods of above normal rainfall in East Africa are associated with the warm phase of the El Nino/Southern Oscillation (ENSO) phenomenon. Anomalous rainfall floods mosquito-breeding habitats called dambos, which contain transovarially infected mosquito eggs. The eggs hatch Aedes mosquitoes that transmit the RVF virus preferentially to livestock and to humans as well. Analysis of historical data on RVF outbreaks and indicators of ENSO (including Pacific and Indian Ocean sea surface temperatures and the Southern Oscillation Index) indicates that more than three quarters of the RVF outbreaks have occurred during warm ENSO event periods. Mapping of ecological conditions using satellite normalized difference vegetation index (NDVI) data show that areas where outbreaks have occurred during the satellite recording period (1981-1998) show anomalous positive departures in vegetation greenness, an indicator of above-normal precipitation. This is particularly observed in arid areas of East Africa, which are predominantly impacted by this disease. These results indicate a close association between interannual climate variability and RVF outbreaks in Kenya.

  19. Early hominin diet included diverse terrestrial and aquatic animals 1.95 Ma in East Turkana, Kenya.

    PubMed

    Braun, David R; Harris, John W K; Levin, Naomi E; McCoy, Jack T; Herries, Andy I R; Bamford, Marion K; Bishop, Laura C; Richmond, Brian G; Kibunjia, Mzalendo

    2010-06-01

    The manufacture of stone tools and their use to access animal tissues by Pliocene hominins marks the origin of a key adaptation in human evolutionary history. Here we report an in situ archaeological assemblage from the Koobi Fora Formation in northern Kenya that provides a unique combination of faunal remains, some with direct evidence of butchery, and Oldowan artifacts, which are well dated to 1.95 Ma. This site provides the oldest in situ evidence that hominins, predating Homo erectus, enjoyed access to carcasses of terrestrial and aquatic animals that they butchered in a well-watered habitat. It also provides the earliest definitive evidence of the incorporation into the hominin diet of various aquatic animals including turtles, crocodiles, and fish, which are rich sources of specific nutrients needed in human brain growth. The evidence here shows that these critical brain-growth compounds were part of the diets of hominins before the appearance of Homo ergaster/erectus and could have played an important role in the evolution of larger brains in the early history of our lineage. PMID:20534571

  20. Early hominin diet included diverse terrestrial and aquatic animals 1.95 Ma in East Turkana, Kenya

    PubMed Central

    Braun, David R.; Harris, John W. K.; Levin, Naomi E.; McCoy, Jack T.; Herries, Andy I. R.; Bamford, Marion K.; Bishop, Laura C.; Richmond, Brian G.; Kibunjia, Mzalendo

    2010-01-01

    The manufacture of stone tools and their use to access animal tissues by Pliocene hominins marks the origin of a key adaptation in human evolutionary history. Here we report an in situ archaeological assemblage from the Koobi Fora Formation in northern Kenya that provides a unique combination of faunal remains, some with direct evidence of butchery, and Oldowan artifacts, which are well dated to 1.95 Ma. This site provides the oldest in situ evidence that hominins, predating Homo erectus, enjoyed access to carcasses of terrestrial and aquatic animals that they butchered in a well-watered habitat. It also provides the earliest definitive evidence of the incorporation into the hominin diet of various aquatic animals including turtles, crocodiles, and fish, which are rich sources of specific nutrients needed in human brain growth. The evidence here shows that these critical brain-growth compounds were part of the diets of hominins before the appearance of Homo ergaster/erectus and could have played an important role in the evolution of larger brains in the early history of our lineage. PMID:20534571

  1. Towards Optimization of Reservoir Operations for Hydropower Production in East Africa: Application of Seasonal Climate Forecasts and Remote Sensing Products

    NASA Astrophysics Data System (ADS)

    Demissie, S. S.; Gebremichael, M.; Hopson, T. M.; Riddle, E. E.; Yeh, W. W. G.

    2015-12-01

    Hydroelectric generation and interconnections are the major priority areas of infrastructure development in Africa. A number of hydropower projects are currently being developed in East Africa in order to meet the energy demands of the fast growing economy in sustainable and climate-resilient manner. However, the performance efficiency of existing hydropower systems in Africa is much lower (about 30% in some cases) than their design capacity. This study proposes a decision support system (DSS) that integrates climate forecasts and remote sensing products into modeling and optimization of the hydropower systems in order to achieve reliable reservoir operations and enhance hydropower production efficiency. The DSS has three main components; climate system, hydrologic and water resources system, and optimization system. The climate system comprises of tools and interfaces for accessing, customizing and integrating climate forecasts and remote sensing data. The North America Multi-Model Ensemble (NMME) seasonal retrospective forecasts for the East Africa Power Pool (EAPP) region are compared with the TRMM rainfall estimates and the CPC unified gauged rainfall data. The errors of the NMME seasonal forecasts have portrayed significant spatial and temporal variability in the EAPP region. The root mean square errors of the seasonal forecasts are relatively higher for wetter locations and months. However, the skills of the NMME seasonal forecasts are not significantly depreciating with lead time for the study region. The seasonal forecast errors vary from one model to another. Here, we present the skills of NMME seasonal forecasts, the physical factors and mechanisms that affect the skills. In addition, we discuss our methodology that derives the best seasonal forecasts for the study region from the NMME seasonal forecasts, and show how the climate forecast errors propagate through hydrologic models into hydrological forecasting.

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

    NASA Astrophysics Data System (ADS)

    Nyblade, Andrew A.; Pollack, Henry N.

    1993-03-01

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

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

    PubMed

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

    2003-01-01

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

  4. Holocene Millennial Time Scale Hydrological Changes In Central-east Africa

    NASA Astrophysics Data System (ADS)

    Jolly, D.; Bonnefille, R.; Beaufort, L.

    The Holocene hydrological changes of a tropical swamp is reconstructed using a high resolution pollen record (ca 50 yrs) from the Kuruyange valley (Burundi, Africa, 3°35'S, 29°41'E), at 2000 m elevation. The sequence was dated by 10 radiocarbon dates, allowing reconstruction between ca 12 500 and 1000 cal yr B.P. In the Kuruyange swamp, peat accumulated rapidly at a sedimentation rate varying from 0.73 (prior to 6200 cal yr B.P.) to 1.51 mm/yr (during the late Holocene). A pollen index of water table, based on a ratio of aquatic versus non-aquatic plants has been used in order to test the hypothesis of hydrological constraints on the swampy ecosystem. Eight arid phases are evidenced by the index minima at 12 200, 11 200, 9900, 8600, 6500, 5000, 3400, 1600 cal yr B.P. The good agreement existing between this index and independent data such as (i) low-resolution East-African lake level reconstruct ions (Gillespie et al., 1983) and (ii) ?18O analyses from Arabian Sea (Sirocko et al., 1993) suggests the water table level responds to the monsoon dynamic. The Index varies periodically with a combination of 1/1515, 1/880 and 1/431 years-1 frequencies, revealed by time series analyses (Blackman-Tukey and Maximum Entropy). The extrapolation of the composite curve based on these 3 periodicities show that two major climatic events defined in the high latitudes between 1000 and 660 cal yr B.P. (Medieval Warm Period) and between 500 and 100 cal yr B.P. (Little Ice Age) are recorded in our data and show respectively high and low stands of the water table. Our results support some previous pollen-derived climate estimates in Ethiopia done by Bonnefille and Umer (1994). Moreover, the "1500 year" cycle registered in our data from the tropics, already evidenced in higher latitudes (Wijmstra et al., 1984; Bondet al., 1997; Schulz et al., 1999; Bond et al., 2001) support the hypothesis of strong teleconnections between tropical/subtropical and polar climates during the deglaciation

  5. LLNL Middle East and North Africa and Former Soviet Union Research Database

    SciTech Connect

    O'Boyle, J.L.; Ruppert, S.D.; Hauk, T.F.; Dodge, D.; Firpo, M.

    2000-07-14

    The Lawrence Livermore National Laboratory (LLNL) Ground-Based Nuclear Explosion Monitoring (GNEM) R and D program has made significant progress populating a comprehensive Seismic Research knowledge Base (SRKB) and deriving calibration parameters for the Middle East and North Africa (ME/NA) and Former Soviet Union (FSU) regions. The LLNL SRKB provides not only a coherent framework in which to store and organize very large volumes of collected seismic waveforms, associated event parameter information, and spatial contextual data, but also provides an efficient data processing/research environment for deriving location and discrimination correction surfaces. The SRKB is a flexible and extensible framework consisting of a relational database (RDB), Geographical Information System (GIS), and associated product/data visualization and data management tools. This SRKB framework is designed to accommodate large volumes of data (over 2 million waveforms from 20,000 events) in diverse formats from many sources in addition to maintaining detailed quality control and metadata. Using the SRKB framework, they are combining travel-time observations, event characterization studies, and regional tectonic models to assemble a library of ground truth information and phenomenology correction surfaces required for support of the ME/NA and FSU regionalization program. Corrections and parameters distilled from the LLNL SRKB provide needed contributions to the DOE Knowledge Base (DOE KB) for the ME/NA and FSU regions and will help improve monitoring for underground nuclear testing. The LLNL research products will facilitate calibration of IMS stations (primary and auxiliary), their surrogates (if not yet installed) and selected gamma stations necessary to complete the above tasks in the ME/NA and FSU regions. They present expanded lookup tables for critical station parameter information (including location and response) and a new integrated and reconciled event catalog dataset including

  6. Sustainable Electricity and Water for Europe, Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Müller-Steinhagen, H.; Trieb, F.

    2009-04-01

    Sufficient supply of energy and water are among the key requirements for a sustainable development of nations. Both depend strongly on energy carriers such as oil, gas, coal and uranium which have limited availability and a negative impact on the environment during their use. Within the framework of a series of detailed studies, conventional and renewable energy sources available for electricity production and desalination in Europe, North Africa and the Middle East (EU-MENA) have been analysed. Scenarios have been developed for a sustainable electricity supply based on increased plant and user efficiency, and an accelerated introduction of renewable energy sources. Even if all potential exclusion criteria are applied and only those technologies are considered which will become economically competitive within the next decades, a potential has been identified which exceeds the present electricity demand by orders of magnitude. Solar energy is, in this context, the by far largest resource which will most economically be exploited in centralised solar thermal power plants. In combination with heat storage, these power plants can provide bulk and peak electricity, and can be combined with thermal or reverse osmosis desalination plants. At present, solar thermal power plants with a total capacity exceeding 10 GW are in operation or under construction in Abu Dhabi, Algeria, Egypt, Iran, Israel, Italy, Morocco, Spain and the USA. Ultimately, the increasing electricity demand of EU-MENA can only be secured in conjunction with the required climate and resource protection targets, if all renewable energy sources are exploited where appropriate, and conversion and user efficiency are increased. To utilise the enormous energy resources of the Mediterranean countries, high voltage direct current power lines will have to be built, linking the most abundant and economic resources with the load centres in the North. With electricity losses below 10% over a distance of 3000 km

  7. Geochemical and Sedimentological Records of Late Quaternary Climate Change, Lake Tanganyika, Tropical East Africa

    NASA Astrophysics Data System (ADS)

    Felton, A. A.; Russell, J. M.; Cohen, A. S.; Baker, M. E.; McGlue, M. M.; Lezzar, K. E.

    2005-12-01

    We have analyzed piston core records from Lake Tanganyika (western Tanzania, East African Rift Valley) to investigate possible signals of tropical paleoclimate change during the Late Quaternary. Long paleoclimate records from East Africa are of importance for understanding climatic processes such as the role of solar variability in regulating tropical climates at Milankovitch time scales, and the relationship between abrupt climate changes, migration of Intertropical Convergence Zone, and regional climate variability (Nicholson, 2000). However, records of pre-Holocene climate variability from tropical African lakes (>25ka) are still quite rare. Long records from Lake Tanganyika are of particular interest given the lake's antiquity and its demonstrated potential for producing high resolution (frequently annually laminated) sedimentary records (Cohen et al., 1993). We analyzed physical properties, grain size, total organic carbon, major, minor and trace element variability, and biogenic silica data for a 7.75 m core from the Kalya slope and horst region of central Lake Tanganyika at 640m water depth. Nine 14C dates provide an age model for the core, which spans ~62 cal kyr. Elemental concentrations preserved in Lake Tanganyika sediments record variability in deposition and runoff into the lake basin. Under conditions of rapid erosion, exposure and rapid weathering of bedrock has been shown to generate high concentrations of original silicate minerals enriched in soluble cations such as sodium and potassium, elements that are also biologically conservative. Prior to 40ka cal yr. core sediments are characterized by high magnetic susceptibility, intermediate levels of organic carbon, low to intermediate levels of biogenic silica, and fine grain size, indicative of relatively high precipitation. There is a profound decrease in magnetic susceptibility, a decrease in organic carbon and an increase in grain size at 40ka cal yr, which persists until ~16ka cal yr. Seismic

  8. 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…

  9. 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…

  10. Climate change or urbanization? Impacts on a traditional coffee production system in East Africa over the last 80 years.

    PubMed

    Jaramillo, Juliana; Setamou, Mamoudou; Muchugu, Eric; Chabi-Olaye, Adenirin; Jaramillo, Alvaro; Mukabana, Joseph; Maina, Johnson; Gathara, Simon; Borgemeister, Christian

    2013-01-01

    Global environmental changes (GEC) such as climate change (CC) and climate variability have serious impacts in the tropics, particularly in Africa. These are compounded by changes in land use/land cover, which in turn are driven mainly by economic and population growth, and urbanization. These factors create a feedback loop, which affects ecosystems and particularly ecosystem services, for example plant-insect interactions, and by consequence agricultural productivity. We studied effects of GEC at a local level, using a traditional coffee production area in greater Nairobi, Kenya. We chose coffee, the most valuable agricultural commodity worldwide, as it generates income for 100 million people, mainly in the developing world. Using the coffee berry borer, the most serious biotic threat to global coffee production, we show how environmental changes and different production systems (shaded and sun-grown coffee) can affect the crop. We combined detailed entomological assessments with historic climate records (from 1929-2011), and spatial and demographic data, to assess GEC's impact on coffee at a local scale. Additionally, we tested the utility of an adaptation strategy that is simple and easy to implement. Our results show that while interactions between CC and migration/urbanization, with its resultant landscape modifications, create a feedback loop whereby agroecosystems such as coffee are adversely affected, bio-diverse shaded coffee proved far more resilient and productive than coffee grown in monoculture, and was significantly less harmed by its insect pest. Thus, a relatively simple strategy such as shading coffee can tremendously improve resilience of agro-ecosystems, providing small-scale farmers in Africa with an easily implemented tool to safeguard their livelihoods in a changing climate. PMID:23341884

  11. Climate Change or Urbanization? Impacts on a Traditional Coffee Production System in East Africa over the Last 80 Years

    PubMed Central

    Jaramillo, Juliana; Setamou, Mamoudou; Muchugu, Eric; Chabi-Olaye, Adenirin; Jaramillo, Alvaro; Mukabana, Joseph; Maina, Johnson; Gathara, Simon; Borgemeister, Christian

    2013-01-01

    Global environmental changes (GEC) such as climate change (CC) and climate variability have serious impacts in the tropics, particularly in Africa. These are compounded by changes in land use/land cover, which in turn are driven mainly by economic and population growth, and urbanization. These factors create a feedback loop, which affects ecosystems and particularly ecosystem services, for example plant-insect interactions, and by consequence agricultural productivity. We studied effects of GEC at a local level, using a traditional coffee production area in greater Nairobi, Kenya. We chose coffee, the most valuable agricultural commodity worldwide, as it generates income for 100 million people, mainly in the developing world. Using the coffee berry borer, the most serious biotic threat to global coffee production, we show how environmental changes and different production systems (shaded and sun-grown coffee) can affect the crop. We combined detailed entomological assessments with historic climate records (from 1929–2011), and spatial and demographic data, to assess GEC's impact on coffee at a local scale. Additionally, we tested the utility of an adaptation strategy that is simple and easy to implement. Our results show that while interactions between CC and migration/urbanization, with its resultant landscape modifications, create a feedback loop whereby agroecosystems such as coffee are adversely affected, bio-diverse shaded coffee proved far more resilient and productive than coffee grown in monoculture, and was significantly less harmed by its insect pest. Thus, a relatively simple strategy such as shading coffee can tremendously improve resilience of agro-ecosystems, providing small-scale farmers in Africa with an easily implemented tool to safeguard their livelihoods in a changing climate. PMID:23341884

  12. Contribution of Transverse Structures, Magma, and Crustal Fluids to Continental Rift Evolution: The East African Rift in Southern Kenya

    NASA Astrophysics Data System (ADS)

    Kattenhorn, S. A.; Muirhead, J.; Dindi, E.; Fischer, T. P.; Lee, H.; Ebinger, C. J.

    2013-12-01

    The Magadi rift in southern Kenya formed at ~7 Ma within Proterozoic rocks of the Mozambique orogenic belt, parallel to its contact with the Archean Tanzania craton. The rift is bounded to the west by the ~1600-m-high Nguruman border fault. The rift center is intensely dissected by normal faults, most of which offset ~1.4-0.8 Ma lavas. Current E-W extensional velocities are ~2-4 mm/yr. Published crustal tomography models from the rift center show narrow high velocity zones in the upper crust, interpreted as cooled magma intrusions. Local, surface-wave, and SKS-splitting measurements show a rift-parallel anisotropy interpreted to be the result of aligned melt zones in the lithosphere. Our field observations suggest that recent fault activity is concentrated at the rift center, consistent with the location of the 1998 seismic swarm that was associated with an inferred diking event. Fault zones are pervasively mineralized by calcite, likely from CO2-rich fluids. A system of fault-fed springs provides the sole fluid input for Lake Magadi in the deepest part of the basin. Many of these springs emanate from the Kordjya fault, a 50-km-long, NW-SE striking, transverse structure connecting a portion of the border fault system (the NW-oriented Lengitoto fault) to the current locus of strain and magmatism at the rift center. Sampled springs are warm (44.4°C) and alkaline (pH=10). Dissolved gas data (mainly N2-Ar-He) suggests two-component mixing (mantle and air), possibly indicating that fluids are delivered into the fault zone from deep sources, consistent with a dominant role of magmatism to the focusing of strain at the rift center. The Kordjya fault has developed prominent fault scarps (~150 m high) despite being oblique to the dominant ~N-S fault fabric, and has utilized an en echelon alignment of N-S faults to accommodate its motion. These N-S faults show evidence of sinistral-oblique motion and imply a bookshelf style of faulting to accommodate dextral-oblique motion

  13. Additional results on palaeomagnetic stratigraphy of the Koobi Fora Formation, east of Lake Turkana (Lake Rudolf), Kenya

    USGS Publications Warehouse

    Hillhouse, J.W.; Ndombi, J.W.M.; Cox, A.; Brock, A.

    1977-01-01

    The magnetostratigraphy of the hominid-bearing sediments exposed east of Lake Turkana has been strengthened by new palaeomagnetic results. Ages obtained from several tuffs by the 40Ar/39Ar method suggest an approxmate match between the observed magnetozones and the geomagnetic polarity time scale; however, the palaeomagnetic results are also compatible with a younger chronology suggested by conventional K-Ar dating of the KBS Tuff. ?? 1977 Nature Publishing Group.

  14. Expanding access to off-grid rural electrification in Africa: An analysis of community-based micro-grids in Kenya

    NASA Astrophysics Data System (ADS)

    Kirubi, Charles Gathu

    Community micro-grids have played a central role in increasing access to off-grid rural electrification (RE) in many regions of the developing world, notably South Asia. However, the promise of community micro-grids in sub-Sahara Africa remains largely unexplored. My study explores the potential and limits of community micro-grids as options for increasing access to off-grid RE in sub-Sahara Africa. Contextualized in five community micro-grids in rural Kenya, my study is framed through theories of collective action and combines qualitative and quantitative methods, including household surveys, electronic data logging and regression analysis. The main contribution of my research is demonstrating the circumstances under which community micro-grids can contribute to rural development and the conditions under which individuals are likely to initiate and participate in such projects collectively. With regard to rural development, I demonstrate that access to electricity enables the use of electric equipment and tools by small and micro-enterprises, resulting in significant improvement in productivity per worker (100--200% depending on the task at hand) and a corresponding growth in income levels in the order of 20--70%, depending on the product made. Access to electricity simultaneously enables and improves delivery of social and business services from a wide range of village-level infrastructure (e.g. schools, markets, water pumps) while improving the productivity of agricultural activities. Moreover, when local electricity users have an ability to charge and enforce cost-reflective tariffs and electricity consumption is closely linked to productive uses that generate incomes, cost recovery is feasible. By their nature---a new technology delivering highly valued services by the elites and other members, limited local experience and expertise, high capital costs---community micro-grids are good candidates for elite-domination. Even so, elite control does not necessarily

  15. Understanding Models of Palliative Care Delivery in Sub-Saharan Africa: Learning From Programs in Kenya and Malawi.

    PubMed

    Downing, Julia; Grant, Liz; Leng, Mhoira; Namukwaya, Elizabeth

    2015-09-01

    The need for palliative care has never been greater. From being significantly present in only five African countries in 2004, palliative care is now delivered in nearly 50% of African countries; however, less than 5% of people in need receive it. To scale-up palliative care, we need greater knowledge about how different models of palliative care work within different health systems. A case study evaluation was undertaken in Kenya and Malawi to define the models used, contextualize them, and identify challenges, best practices, and transferable lessons for scale-up. Visits were made to seven sites and, using an audit tool, data were collected from program staff, hospital staff, and local stakeholders, and care observed as appropriate. Three models of palliative care service delivery were identified, which supports the existing literature, that is, specialist, district hospital level, and community level. However, in looking further, findings show that the major determinants for each model were a set of philosophical questions and assumptions underpinning each and influencing staff and patient decision-making, planning, and allocation of resources. The health system structure and the beliefs about palliative care determined, and were determined most by, referrals, the patient journey, the centeredness of the model, and role definition and training. The models are also closely associated with the physical setting of services. Understanding how the services have developed because of, and indeed despite the geographical setting and the system level, provides us with a different set of indicators of program structure incorporated into the three models. The analysis of models provides pointers to future planning for palliative care. PMID:25936938

  16. Motivations for Reducing Other HIV Risk-Reduction Practices if Taking Pre-Exposure Prophylaxis: Findings from a Qualitative Study Among Women in Kenya and South Africa

    PubMed Central

    Namey, Emily; Ahmed, Khatija; Agot, Kawango; Skhosana, Joseph; Odhiambo, Jacob; Guest, Greg

    2015-01-01

    Abstract Findings from a survey conducted among women at high risk for HIV in Bondo, Kenya, and Pretoria, South Africa, demonstrated that a substantial proportion would be inclined to reduce their use of other HIV risk-reduction practices if they were taking pre-exposure prophylaxis (PrEP). To explore the motivations for their anticipated behavior change, we conducted qualitative interviews with 60 women whose survey responses suggested they would be more likely to reduce condom use or have sex with a new partner if they were taking PrEP compared to if they were not taking PrEP. Three interrelated themes were identified: (1) “PrEP protects”—PrEP was perceived as an effective HIV prevention method that replaced the need for condoms; (2) condoms were a source of conflict in relationships, and PrEP would provide an opportunity to resolve or avoid this conflict; and (3) having sex without a condom or having sex with a new partner was necessary for receiving material goods and financial assistance—PrEP would provide reassurance in these situations. Many believed that PrEP alone would be a sufficient HIV risk-reduction strategy. These findings suggest that participants' HIV risk-reduction intentions, if they were to use PrEP, were based predominately on their understanding of the high efficacy of PrEP and their experiences with the limitations of condoms. Enhanced counseling is needed to promote informed decision making and to ensure overall sexual health for women using PrEP for HIV prevention, particularly with respect to the prevention of pregnancy and other sexually transmitted infections when PrEP is used alone. PMID:26196411

  17. Where Do Female Sex Workers Seek HIV and Reproductive Health Care and What Motivates These Choices? A Survey in 4 Cities in India, Kenya, Mozambique and South Africa

    PubMed Central

    Lafort, Yves; Greener, Ross; Roy, Anuradha; Greener, Letitia; Ombidi, Wilkister; Lessitala, Faustino; Haghparast-Bidgoli, Hassan; Beksinska, Mags; Gichangi, Peter; Reza-Paul, Sushena; Smit, Jenni A.; Chersich, Matthew; Delva, Wim

    2016-01-01

    Background A baseline cross-sectional survey among female sex workers (FSWs) was conducted in four cities within the context of an implementation research project aiming to improve FSWs’ access to HIV, and sexual and reproductive health (SRH) services. The survey measured where FSWs seek HIV/SRH care and what motivates their choice. Methods Using respondent-driven sampling (RDS), FWSs were recruited in Durban, South Africa (n = 400), Tete, Mozambique (n = 308), Mombasa, Kenya (n = 400) and Mysore, India (n = 458) and interviewed. RDS-adjusted proportions were estimated by non-parametric bootstrapping, and compared across cities using post-hoc pairwise comparison tests. Results Across cities, FSWs most commonly sought care for the majority of HIV/SRH services at public health facilities, most especially in Durban (ranging from 65% for condoms to 97% for HIV care). Services specifically targeting FSWs only had a high coverage in Mysore for STI care (89%) and HIV testing (79%). Private-for-profit clinics were important providers in Mombasa (ranging from 17% for STI care and HIV testing to 43% for HIV care), but not in the other cities. The most important reason for the choice of care provider in Durban and Mombasa was proximity, in Tete ‘where they always go’, and in Mysore cost of care. Where available, clinics specifically targeting FSWs were more often chosen because of shorter waiting times, perceived higher quality of care, more privacy and friendlier personnel. Conclusion The place where care is sought for HIV/SRH services differs substantially between cities. Targeted services have limited coverage in the African cities compared to Mysore. Convenience appears more important for choosing the place of care than aspects of quality of care. The best model to improve access, linking targeted interventions with general health services, will need to be tailored to the specific context of each city. PMID:27494412

  18. How Closed are Closed Lakes in Rifts? Significance of Hydraulic Gradients for the Budgets of Paleo-Lakes in East Africa

    NASA Astrophysics Data System (ADS)

    Olaka, L. A.

    2015-12-01

    The hydrogeology of rift lakes is complex due to the potential influence of faults and porous volcanic and volcanoclastic media on groundwater flow. We conducted a comprehensive study that integrated geological and hydrogeological data as well as the application of a linear decay model to estimate the groundwater flow between the two of the best-studied lake systems in East Africa, the adjacent Lakes Naivasha and Nakuru- Elmenteita in the Central Kenya Rift. Whereas both lake basins host relatively shallow lakes today, paleo-shorelines and sediments suggest >100 m deep lakes during a wetter climate during the Early Holocene during the so-called African Humid Period. Stable isotope data show variations form highly depleted to more enriched d18O waters. The linear-reservoir depletion model simulates the decline of the Early Holocene lakes in both basins to the modern levels. The altitude difference of ca. 100 m of both paleo-lake levels enables us to estimate the duration of the groundwater decline and the connectivity of the two basins via the Eburru/Gilgil barrier. The results suggest a decline of the groundwater levels during ca. 5 kyrs if there is no recharge, and between 2-2.7 kyrs based on the modern recharge of 0.52 m/yr as the end members of the delay time introduced by subsurface water flow to the hydrology of the lake system. The latter value suggests that ca. 40.95 cubic kilometres of water flowed from Lake Naivasha to Nakuru- Elmenteita at maximum lake level in the Early Holocene following the hydraulic gradient concurrent to the topographic slope. The unexpectedly large volume, more than half of the volume of the paleo-Lake Naivasha during the Early Holocene, emphasizes the importance of groundwater in hydrological modelling of paleo-lakes in rifts. Moreover, the subsurface connectivity of rift lakes also causes a significant lag time to the system introducing a nonlinear component to the system that has to be considered while interpreting paleo

  19. A geographic information system on the potential distribution and abundance of Fasciola hepatica and F. gigantica in east Africa based on Food and Agriculture Organization databases.

    PubMed

    Malone, J B; Gommes, R; Hansen, J; Yilma, J M; Slingenberg, J; Snijders, F; Nachtergaele, F; Ataman, E

    1998-07-31

    An adaptation of a previously developed climate forecast computer model and digital agroecologic database resources available from FAO for developing countries were used to develop a geographic information system risk assessment model for fasciolosis in East Africa, a region where both F. hepatica and F. gigantica occur as a cause of major economic losses in livestock. Regional F. hepatica and F. gigantica forecast index maps were created. Results were compared to environmental data parameters, known life cycle micro-environment requirements and to available Fasciola prevalence survey data and distribution patterns reported in the literature for each species (F. hepatica above 1200 m elevation, F. gigantica below 1800 m, both at 1200-1800 m). The greatest risk, for both species, occurred in areas of extended high annual rainfall associated with high soil moisture and surplus water, with risk diminishing in areas of shorter wet season and/or lower temperatures. Arid areas were generally unsuitable (except where irrigation, water bodies or floods occur) due to soil moisture deficit and/or, in the case of F. hepatica, high average annual mean temperature >23 degrees C. Regions in the highlands of Ethiopia and Kenya were identified as unsuitable for F. gigantica due to inadequate thermal regime, below the 600 growing degree days required for completion of the life cycle in a single year. The combined forecast index (F. hepatica+F. gigantica) was significantly correlated to prevalence data available for 260 of the 1220 agroecologic crop production system zones (CPSZ) and to average monthly normalized difference vegetation index (NDVI) values derived from the advanced very high resolution radiometer (AVHRR) sensor on board the NOAA polar-orbiting satellites. For use in Fasciola control programs, results indicate that monthly forecast parameters, developed in a GIS with digital agroecologic zone databases and monthly climate databases, can be used to define the

  20. Vitamin D deficiency and insufficiency in Africa and the Middle East, despite year-round sunny days.

    PubMed

    Green, R J; Samy, G; Miqdady, M S; El-Hodhod, M; Akinyinka, O O; Saleh, G; Haddad, J; Alsaedi, S A; Mersal, A Y; Edris, A; Salah, M

    2015-07-01

    Exposure to sunlight, specifically ultraviolet B (UVB), is essential for cutaneous vitamin D synthesis. Despite significant daily sunlight availability in Africa and the Middle East, persons living in these regions are frequently vitamin D insufficient or deficient. Vitamin D insufficiency (25-hydroxyvitamin D (25(OH)D) between 15 and 20 ng/mL (37.5-50 nmol/L)) has been described in various population groups, ranging from 5% to 80%. Risk factors include traditional dress and avoidance of sunlight exposure, and multiple dietary factors as a result of specific cultural beliefs. Vitamin D resistance due to calcium deficiency mechanisms has been described in similar population groups, which may lead to hypovitaminosis D. Should the new diseases related to hypovitaminosis D prove to be truly associated, Africa and the Middle East will become an epicentre for many of these conditions. Urgent attention will need to be paid to cultural dress and dietary behaviours if hypovitaminosis D is to be taken seriously. Should such factors not be correctable, new strategies for supplementation or food fortification will have to be devised. PMID:26447257

  1. Challenges of diagnosis and management of axial spondyloarthritis in North Africa and the Middle East: An expert consensus.

    PubMed

    Hammoudeh, Mohammed; Abdulaziz, Sultana; Alosaimi, Hanan; Al-Rayes, Hanan; Aldeen Sarakbi, Hussam; Baamer, Matouqa; Baraliakos, Xenofon; Dahou Makhloufi, Chafia; Janoudi, Nahid; Shirazy, Khalid; Sieper, Joachim; Sukhbir, Uppal

    2016-04-01

    Axial spondyloarthritis (SpA) is a spectrum of inflammatory disease with stages characterized by both nonradiographic and radiographic sacroiliitis. Nonradiographic axial SpA is associated with health-related quality-of-life impairment and may progress to ankylosing spondylitis. Axial SpA has a low prevalence in some countries in North Africa and the Middle East, and pooling of data and resources is needed to increase understanding of the regional picture. Early diagnosis and effective treatment are required to reduce disease burden and prevent progression. Anti-TNF therapy is recommended for patients with persistently high disease activity despite conventional treatment, and has been shown to be effective in patients without radiographic damage. Diagnostic delays can be an obstacle to early treatment and appropriate referral strategies are needed. In some countries, restricted access to magnetic resonance imaging and anti-TNF agents presents a challenge. In this article, a group of experts from North Africa and the Middle East evaluated the diagnosis and management of axial SpA with particular reference to this region. PMID:26811411

  2. A single lineage in early Pleistocene Homo: size variation continuity in early Pleistocene Homo crania from East Africa and Georgia.

    PubMed

    Van Arsdale, Adam P; Wolpoff, Milford H

    2013-03-01

    The relationship between Homo habilis and early African Homo erectus has been contentious because H. habilis was hypothesized to be an evolutionary stage between Australopithecus and H. erectus, more than a half-century ago. Recent work re-dating key African early Homo localities and the discovery of new fossils in East Africa and Georgia provide the opportunity for a productive re-evaluation of this topic. Here, we test the hypothesis that the cranial sample from East Africa and Georgia represents a single evolutionary lineage of Homo spanning the approximately 1.9-1.5 Mya time period, consisting of specimens attributed to H. habilis and H. erectus. To address issues of small sample sizes in each time period, and uneven representation of cranial data, we developed a novel nonparametric randomization technique based on the variance in an index of pairwise difference from a broad set of fossil comparisons. We fail to reject the hypothesis of a single lineage this period by identifying a strong, time-dependent pattern of variation throughout the sequence. These results suggest the need for a reappraisal of fossil evidence from other regions within this time period and highlight the critical nature of the Plio-Pleistocene boundary for understanding the early evolution of the genus Homo. PMID:23461332

  3. 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. PMID:25727455

  4. The Leishmaniasis East Africa Platform (LEAP): strengthening clinical trial capacity in resource-limited countries to deliver new treatments for visceral leishmaniasis

    PubMed Central

    Wasunna, Monique; Musa, Ahmed; Hailu, Asrat; Khalil, Eltahir A. G.; Olobo, Joseph; Juma, Rashid; Wells, Susan; Alvar, Jorge; Balasegaram, Manica

    2016-01-01

    Visceral leishmaniasis is a neglected tropical disease endemic in East Africa where improved patient-adapted treatments are needed. The Leishmaniasis East Africa Platform (LEAP) was created in 2003 to strengthen clinical research capacity, serve as a base for training, and evaluate and facilitate implementation of new treatments. Major infrastructure upgrades and personnel training have been carried out. A short course of Sodium Stibogluconate and Paramomycin (SSG&PM) was evaluated and is now first-line treatment in the region; alternative treatments have also been assessed. LEAP can serve as a successful model of collaboration between different partners and countries when conducting clinical research in endemic countries to international standards. PMID:27268714

  5. The Leishmaniasis East Africa Platform (LEAP): strengthening clinical trial capacity in resource-limited countries to deliver new treatments for visceral leishmaniasis.

    PubMed

    Wasunna, Monique; Musa, Ahmed; Hailu, Asrat; Khalil, Eltahir A G; Olobo, Joseph; Juma, Rashid; Wells, Susan; Alvar, Jorge; Balasegaram, Manica

    2016-06-01

    Visceral leishmaniasis is a neglected tropical disease endemic in East Africa where improved patient-adapted treatments are needed. The Leishmaniasis East Africa Platform (LEAP) was created in 2003 to strengthen clinical research capacity, serve as a base for training, and evaluate and facilitate implementation of new treatments. Major infrastructure upgrades and personnel training have been carried out. A short course of Sodium Stibogluconate and Paramomycin (SSG&PM) was evaluated and is now first-line treatment in the region; alternative treatments have also been assessed. LEAP can serve as a successful model of collaboration between different partners and countries when conducting clinical research in endemic countries to international standards. PMID:27268714

  6. Orbital- versus glacial-mode forcing of tropical African climate: Results of scientific drilling in Lake Malawi, East Africa

    NASA Astrophysics Data System (ADS)

    Scholz, C. A.; Cohen, A. S.; Johnson, T. C.; King, J. W.; Brown, E. T.; Lyons, R. P.; Stone, J. R.; Beuning, K. R.

    2007-12-01

    Lake Malawi extends from 9-14 degrees S within the East African Rift Valley, and at 700 m deep, contains more than 20 percent of the surface water on the African continent. In 2005 the Lake Malawi Scientific Drilling Project drilled 7 holes at two sites in the lake, recovering a continuous sediment record that samples much of the Quaternary. Detailed studies completed to date on sediments deposited during the past 145 ka indicate periods of severe aridity at precessional frequency between 135 and 75 ka, when the lake's water volume was periodically reduced by at least 95 percent. These dramatic drops in lake level (more than 550 m), signifying markedly arid conditions in the catchment, are documented in sediment lithology (decreased organic carbon content and increased authigenic carbonate content during severe lowstands), aquatic microfossils (appearance of a littoral ostracode fauna, and saline/alkaline lake diatom flora during extreme low lake stages), as well as in dramatic reductions in catchment pollen production. These intervals of pronounced tropical African aridity in the early late-Pleistocene were much more severe than the Last Glacial Maximum, and are consistent with sediment records from Lakes Tanganyika (East Africa) and Bosumtwi (West Africa). In all three lakes a major rise in water levels and a shift to more humid conditions is observed after ~70 ka. The transition to wetter, more stable conditions coincides with the relaxation of orbital eccentricity and a reduction in the amplitude of precession. The observed climate mode switch to decreased environmental variability is consistent with terrestrial and marine records from in and around tropical Africa, but these new drill cores provide evidence for dramatically drier conditions prior to 70 ka that have not as yet been detected in marine sediment records. Such climate change may have stimulated the expansion and migrations of early modern human populations.

  7. Serological Evidence of MERS-CoV Antibodies in Dromedary Camels (Camelus dromedaries) in Laikipia County, Kenya

    PubMed Central

    Deem, Sharon L.; Fèvre, Eric M.; Kinnaird, Margaret; Browne, A. Springer; Muloi, Dishon; Godeke, Gert-Jan; Koopmans, Marion; Reusken, Chantal B.

    2015-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) is a recently identified virus causing severe viral respiratory illness in people. Little is known about the reservoir in the Horn of Africa. In Kenya, where no human MERS cases have been reported, our survey of 335 dromedary camels, representing nine herds in Laikipia County, showed a high seroprevalence (46.9%) to MERS-CoV antibodies. Between herd differences were present (14.3%– 82.9%), but was not related to management type or herd isolation. Further research should focus on identifying similarity between MERS-CoV viral isolates in Kenya and clinical isolates from the Middle East and elsewhere. PMID:26473733

  8. Miocene Onset of Extension in the Turkana Depression, Kenya: Implications for the Geodynamic Evolution of the East African Rift System

    NASA Astrophysics Data System (ADS)

    Boone, S.; Gleadow, A. J. W.; Kohn, B. P.; Seiler, C.

    2015-12-01

    The Paleogene-Recent East African Rift System (EARS) is the foremost modern example of continental rifting, providing much of our understanding of the early stages of continental breakup. The EARS traverses two regions of crustal uplift, the Ethiopian and East African Domes, separated by the Turkana Depression. This wide region of subdued topography coincides with the NW-SE trend of the Jurassic-Paleogene Anza Rift. Opinions on the fundamental geodynamic driver for EARS rifting are divided, however, principally between models involving migrating plume(s) and a single elongated 'superplume'. While competing models have similar topographic outcomes, they predict different morphotectonic evolutions for the Turkana Depression. Models inferring southward plume-migration imply that the plume must have passed below the Turkana Depression during the Paleogene, in order to have migrated to the East African Dome by the Miocene. The possible temporal denudational response to such plume activity is testable using low temperature thermochronology. We present apatite fission track (AFT) and (U-Th)/He (AHe), and zircon (U-Th)/He (ZHe) data from the Lapurr Range, an uplifted Precambrian basement block in northern Turkana. Low radiation damage ZHe results displaying an age range of ~70-210 Ma, and combined with stratigraphic evidence, suggest ~4-6 km of Jurassic-Early Cretaceous denudation, probably associated with early Anza Rift tectonism. AFT ages of ~9-15 Ma imply subsequent burial beneath no more than ~4 km of overburden, thus preserving the Jurassic-Cretaceous ZHe ages. Together with AFT results, AHe data (~3-19 Ma) support ~2-4 km of Miocene-Pliocene uplift of the Lapurr Range in the footwall of the E-dipping Lapurr normal fault. Miocene AFT and AHe ages are interpreted to reflect the initiation of the EARS in the Turkana Depression. If extension is associated with plume activity, then upwelling in the Turkana region is unlikely to have started prior to the Miocene, much

  9. The Role of Economic Development in Curriculum Development Process in Sub-Saharan Africa: A Call for New Approach to Socioeconomic Development in Africa with a Special Reference to Kenya

    ERIC Educational Resources Information Center

    Odiemo, Luke Okunya

    2008-01-01

    The main hypothesis here is that the notion of economic and social development has been misconceived by most stakeholders in matters of development. This misconception is the main cause of underdevelopment in Kenya, which leads to all the reasons most authors and commentators have given to explain Kenya's situation. Therefore, it is only possible…

  10. Multilingual Education in Kenya: Debunking the Myths

    ERIC Educational Resources Information Center

    Orwenjo, Daniel Ochieng

    2012-01-01

    Arguments that have been advanced against multilingual education in Kenya and Africa in general are not new. Most post-colonial African governments have stuck to the pre-colonial education policies which have no relevance to the present day Africa and were, at best, guided by the interests of the colonial power. Unfortunately, most of the claims…

  11. The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.

    PubMed

    Elhassan, Nuha; Gebremeskel, Eyoab Iyasu; Elnour, Mohamed Ali; Isabirye, Dan; Okello, John; Hussien, Ayman; Kwiatksowski, Dominic; Hirbo, Jibril; Tishkoff, Sara; Ibrahim, Muntaser E

    2014-01-01

    Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount. PMID:24845801

  12. Isotopic evidence for neogene hominid paleoenvironments in the Kenya Rift Valley

    SciTech Connect

    Kingston, J.D.; Hill, A. ); Marino, B.D. )

    1994-05-13

    Bipedality, the definitive characteristic of the earliest hominids, has been regarded as an adaptive response to a transition from forested to more-open habitats in East Africa sometime between 12 million and 5 million years ago. Analyses of the stable carbon isotopic composition ([delta][sup 13]C) of paleosol carbonate and organic matter from the Tugen Hills succession in Kenya indicate that a heterogeneous environment with a mix of C3 and C4 plants has persisted for the last 15.5 million years. Open grasslands at no time dominated this portion of the rift valley. The observed [delta][sup 13]C values offer no evidence for a shift from more-closed C3 environments to C4 grasslands habitats. If hominids evolved in East Africa during the Late Miocene, they did so in an ecologically diverse setting.

  13. Isotopic Evidence for Neogene Hominid Paleoenvironments in the Kenya Rift Valley

    NASA Astrophysics Data System (ADS)

    Kingston, John D.; Marino, Bruno D.; Hill, Andrew

    1994-05-01

    Bipedality, the definitive characteristic of the earliest hominids, has been regarded as an adaptive response to a transition from forested to more-open habitats in East Africa sometime between 12 million and 5 million years ago. Analyses of the stable carbon isotopic composition (δ13C) of paleosol carbonate and organic matter from the Tugen Hills succession in Kenya indicate that a heterogeneous environment with a mix of C3 and C4 plants has persisted for the last 15.5 million years. Open grasslands at no time dominated this portion of the rift valley. The observed δ13C values offer no evidence for a shift from more-closed C3 environments to C4 grassland habitats. If hominids evolved in East Africa during the Late Miocene, they did so in an ecologically diverse setting.

  14. Lake Naivasha, Kenya

    NASA Technical Reports Server (NTRS)

    2008-01-01

    If you live in Europe and buy roses, there is a good chance that they were grown in Kenya specifically, in one of the colossal greenhouses that blot out the once wild shores of Lake Naivasha, 90km north-west of Nairobi. Some 25% of Europe's cut flowers come from Kenya. After a tentative start in the 1980s the industry is now the country's third-largest foreign-currency earner, bringing in $120m a year. But the recent violence in Kenya is having a major impact on the flower growers. A local trade union says 3,000 of the 30,000 workers employed in Naivasha's flower farms have abandoned their jobs. Kenya emerged as a flower power when Israel scaled down its own industry. It has since lost business to neighboring Ethiopia, which offers tax breaks and better security, but Naivasha's perfect intensity of sunlight and days of near-constant length should keep it on top.

    The ASTER image was acquired February 2, 2008, covers an area of 25 x 26.6 km, and is located near 0.8 degrees south latitude, 36.4 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  15. 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

  16. Migration and manpower needs in the Middle East and North Africa, 1975-85.

    PubMed

    Serageldin, I; Socknat, J

    1980-01-01

    The authors review current flows and expected changes in the volume and characteristics of international labor migration to eight oil-producing Middle East countries. The implications for both labor-exporting and importing countries are explored PMID:12279365

  17. Astronomical Site Testing Initiatives in Africa

    NASA Astrophysics Data System (ADS)

    Buckley, David A. H.; Graham, Edward; Vaughan, Richard; Belay, Solomon; Biressa, Tolu

    2015-08-01

    Two astronomical site testing initiatives are beginning in both Kenya and Ethiopia, with the aim of selecting suitable locations in those countries for modest sized (1-2m) optical telescopes.The first project, in Kenya, has initially involved a desk-top study of ~30 years of low resolution (~80 km) meteorological satellite data from the European Centre for Medium Range Weather Forecasting (so called “ERA-reanalysis” data). This was later supplemented by ~2 years of higher resolution (~12 km) United Kingdom Met Office Limited Area Model for Africa (“Africa-LAM”) data, kindly made available by the British Atmospheric Data Centre (BADC).The analysis looked at cloud cover, aerosol distribution, integrated water vapour and wind conditions, On the basis of this study, we determined a number of regions in the north of Kenya, east of the Rift Valley, which show promise as potential observatory sites. We are now in the process of installing Automatic Weather Stations (AWS) at 3 selected sites (~2000-2700 m altitude) to begin monitoring meteorological conditions over the next few years. It is eventually hoped to supplement this study with instrumentation to allow the measurement of sky brightness, local cloud cover and seeing (e.g. with a DIMM system).A similar program of astronomical site testing is due to start in 2015 in the Lalibela region of northern Ethiopia, at three potential dark sky sites with expected relatively low cloud cover, ranging in altitude from ~3600 to 4100 m.

  18. Occupational exposure to roadway emissions and inside informal settlements in sub-Saharan Africa: A pilot study in Nairobi, Kenya

    PubMed Central

    Ngo, Nicole S.; Gatari, Michael; Yan, Beizhan; Chillrud, Steven N.; Bouhamam, Kheira; Kinneym, Patrick L.

    2015-01-01

    Few studies examine urban air pollution in sub-Saharan Africa (SSA), yet urbanization rates there are among the highest in the world. In this study, we measured 8-hr average occupational exposure levels of fine particulate matter (PM2.5), black carbon (BC), ultra violet active-particulate matter (UV-PM), and trace elements for individuals who worked along roadways in Nairobi, specifically bus drivers, garage workers, street vendors, and women who worked inside informal settlements. We found BC and re-suspended dust were important contributors to PM2.5 levels for all study populations, particularly among bus drivers, while PM2.5 exposure levels for garage workers, street vendors, and informal settlement residents were not statistically different from each other. We also found a strong signal for biomass emissions and trash burning, which is common in Nairobi’s low-income areas and open-air garages. These results suggest that the large portion of urban residents in SSA who walk along roadways would benefit from air quality regulations targeting roadway emissions from diesel vehicles, dust, and trash burning. This is the first study to measure occupational exposure to urban air pollution in SSA and results imply that roadway emissions are a serious public health concern. PMID:26034383

  19. Occupational exposure to roadway emissions and inside informal settlements in sub-Saharan Africa: A pilot study in Nairobi, Kenya

    NASA Astrophysics Data System (ADS)

    Ngo, Nicole S.; Gatari, Michael; Yan, Beizhan; Chillrud, Steven N.; Bouhamam, Kheira; Kinney, Patrick L.

    2015-06-01

    Few studies examine urban air pollution in sub-Saharan Africa (SSA), yet urbanization rates there are among the highest in the world. In this study, we measured 8-hr average occupational exposure levels of fine particulate matter (PM2.5), black carbon (BC), ultra violet active-particulate matter (UV-PM), and trace elements for individuals who worked along roadways in Nairobi, specifically bus drivers, garage workers, street vendors, and women who worked inside informal settlements. We found BC and re-suspended dust were important contributors to PM2.5 levels for all study populations, particularly among bus drivers, while PM2.5 exposure levels for garage workers, street vendors, and informal settlement residents were not statistically different from each other. We also found a strong signal for biomass emissions and trash burning, which is common in Nairobi's low-income areas and open-air garages. These results suggest that the large portion of urban residents in SSA who walk along roadways would benefit from air quality regulations targeting roadway emissions from diesel vehicles, dust, and trash burning. This is the first study to measure occupational exposure to urban air pollution in SSA and results imply that roadway emissions are a serious public health concern.

  20. Patterns of genetic structuring in the coral Pocillopora damicornis on reefs in East Africa

    PubMed Central

    Souter, Petra; Henriksson, Oskar; Olsson, Niklas; Grahn, Mats

    2009-01-01

    Background Studies of population genetic structures provide an indication of direction and magnitude of larval transport and hence are an important component in the assessment of the ability of reefs to recover from severe disturbance. This paper reports data on population genetic structures in the coral Pocillopora damicornis from 26 reefs in Kenya and Tanzania. Results Gene flow among reefs was found to be variable, with a significant overall genetic subdivision (FST = 0.023 ± 0.004 SE; p < 0.001), however, only 34% of all pairwise population comparisons showed significant differentiation. Panmixia could not be rejected between reefs separated by as much as 697 km, while other sites, separated by only a single kilometre, were found to be significantly differentiated. An analysis of molecular variance indicated that population genetic differentiation was significant only at the smaller spatial scale (< 10 km), whereas panmixia could not be rejected between groups of samples separated by over 100 km. Estimates of contemporary gene flow showed similar results, with numbers of first generation migrants within each population ranging from 0 to 4 (~5% of the total number of colonies sampled) and likely dispersal distances ranging between 5 and 500 km. Conclusion This study showed that population differentiation in P. damicornis varied over spatial scales and that this variability occurred at both evolutionary and ecological time scales. This paradox is discussed in light of stochastic recruitment and small scale population structures found in other species of coral. The study also identifies potential source reefs, such as those within Mnemba Conservation area near Zanzibar and genetically isolated reefs such as those within Malindi Marine National Park and Reserve in northern Kenya. PMID:19709407

  1. Hot granulite nappes — Tectonic styles and thermal evolution of the Proterozoic granulite belts in East Africa

    NASA Astrophysics Data System (ADS)

    Fritz, Harald; Tenczer, Veronika; Hauzenberger, Christoph; Wallbrecher, Eckart; Muhongo, Sospeter

    2009-11-01

    equilibration gave rise to isobaric cooling. Simultaneously the mid crust (Eastern Granulite cover) was shortened when hot fold nappes moved along upward climbing thrust planes. Western Granulites preserved isothermal decompression through exhumation by thrusting and coeval erosion at the orogen front. Two different styles define the Neoproterozoic East African Orogen between northern Egypt and southern Mozambique. The Arabian Nubian Shield in the north is classified as small and cold orogen in which thin — skinned thrusting was associated with lateral extrusion. The Central Mozambique Belt in Tanzania/Southern Kenya is classified as large and hot orogen characterized by thick-skinned thrusting and assembly of large granulite nappes.

  2. Nursing and midwifery regulation and HIV scale-up: establishing a baseline in east, central and southern Africa

    PubMed Central

    McCarthy, Carey F; Voss, Joachim; Verani, Andre R; Vidot, Peggy; Salmon, Marla E; Riley, Patricia L

    2013-01-01

    Introduction Shifting HIV treatment tasks from physicians to nurses and midwives is essential to scaling-up HIV services in sub-Saharan Africa. Updating nursing and midwifery regulations to include task shifting and pre-service education reform can help facilitate reaching new HIV targets. Donor-supported initiatives to update nursing and midwifery regulations are increasing. However, there are gaps in our knowledge of current practice and education regulations and a lack of information to target and implement regulation strengthening efforts. We conducted a survey of national nursing and midwifery councils to describe current nursing and midwifery regulations in 13 African countries. Methods A 30-item survey was administered to a convenience sample of 13 national nursing and midwifery regulatory body leaders in attendance at the PEPFAR-supported African Health Profession Regulatory Collaborative meeting in Nairobi, Kenya on 28 February, 2011. The survey contained questions on task shifting and regulations such as registration, licensure, scope of practice, pre-service education accreditation, continuing professional development and use of international guidelines. Survey data were analyzed to present country-level, comparative and regional findings. Results Task shifting to nurses and midwives was reported in 11 of the 13 countries. Eight countries updated their scope of practice within the last five years; only one reported their regulations to reflect task shifting. Countries vary with regard to licensure, pre-service accreditation and continuing professional development regulations in place. There was no consistency in terms of what standards were used to design national practice and education regulations. Discussion Many opportunities exist to assist countries to modernise regulations to incorporate important advancements from task shifting and pre-service reform. Appropriate, revised regulations can help sustain successful health workforce strategies and

  3. A pterodactyloid pterosaur from the Upper Cretaceous Lapurr sandstone, West Turkana, Kenya.

    PubMed

    O'Connor, Patrick M; Sertich, Joseph J W; Manthi, Fredrick K

    2011-03-01

    An isolated pterosaurian caudal cervical (~ postcervical) vertebra was recovered from the Upper Cretaceous Lapurr sandstone of West Turkana, northwestern Kenya. The vertebral centrum is short, wide, and dorsoventrally compressed. Although the specimen is lightly built similar to most pterosaurs, it is here referred to Pterodactyloidea and tentatively to the Azhdarchidae in that it lacks pneumatic features on both the centrum and neural arch. This represents one of the few pterosaurs recovered from the entirety of Afro-Arabia, the first pterosaur recovered from the Cretaceous of East Africa, and, significantly, a specimen that was recovered from fluvial deposits rather than the near-shore marine setting typical of most pterosaur discoveries. PMID:21437388

  4. Seismicity of the Earth 1900-2013 East African Rift

    USGS Publications Warehouse

    Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio

    2014-01-01

    Rifting in East Africa is not all coeval; volcanism and faulting have been an ongoing phenomenon on the continent since the Eocene (~45 Ma). The rifting began in northern East Africa, and led to the separation of the Nubia (Africa) and Arabia plates in the Red Sea and Gulf of Aden, and in the Lake Turkana area at the Kenya-Ethiopia border. A Paleogene mantle superplume beneath East Africa caused extension within the Nubia plate, as well as a first order topographic high known as the African superswell which now includes most of the eastern and southern sectors of the Nubia plate. Widespread volcanism erupted onto much of the rising plateau in Ethiopia during the Eocene-Oligocene (45–29 Ma), with chains of volcanoes forming along the rift separating Africa and Arabia. Since the initiation of rifting in northeastern Africa, the system has propagated over 3,000 km to the south and southwest, and it experiences seismicity as a direct result of the extension and active magmatism.

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

    ERIC Educational Resources Information Center

    Stewart, Rohn

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

  6. Reference, Coherence and Complexity in Students' Academic Writing: Examples from Cameroon and East-Africa Corpus

    ERIC Educational Resources Information Center

    Schmied, Josef; Nkemleke, Daniel

    2011-01-01

    This contribution discusses problems of students' academic writing in Africa. It sketches the wide field of English for Academic Purposes (EAP) and argues that reference, coherence and complexity are key concepts for evaluating student writing at university level. It uses material from African corpora to substantiate this claim and to illustrate…

  7. Adapting to climate change and disaster risk reduction through sustainable land management: Experiences in Tajikistan, East Africa, US, Argentina and Mongolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The special session will share and discuss experiences from different regions, namely from Tajikistan, East Africa, US, Argentina and Mongolia. Within the Pilot Program for Climate Resilience (PPCR) in Tajikistan 70 SLM technologies and approaches on how to implement SLM were documented with the Wor...

  8. Observed and expected frequencies of structural hemoglobin variants in newborn screening surveys in Africa and the Middle East: Deviations from Hardy-Weinberg equilibrium

    PubMed Central

    Piel, Frédéric B.; Adamkiewicz, Thomas V.; Amendah, Djesika; Williams, Thomas N.; Gupta, Sunetra; Grosse, Scott D.

    2015-01-01

    Purpose Our objective was to compare observed and expected genotype proportions from newborn screening surveys of structural hemoglobin variants. Methods We conducted a systematic review of newborn screening surveys of hemoglobins S and C in Africa and the Middle-East. We compared observed frequencies to those expected assuming Hardy-Weinberg equilibrium (HWE). Significant deviations were identified by an exact test. The fixation index FIS was calculated to assess excess homozygosity. We compared newborn estimates corrected and uncorrected for HWE deviations using demographic data. Results Sixty samples reported genotype counts for hemoglobin variants in Africa and the Middle-East. Observed and expected counts matched in 27%. The observed number of sickle-cell anemia (SCA) individuals was higher than expected in 42 samples, reaching significance (p<0.05) in 24. High FIS were common across the study regions. The estimated total number of newborns with SCA, corrected based on FIS, were 33,261 annual births instead of 24,958 for the 38 samples across sub-Saharan Africa and 1,109 annual births instead of 578 for 12 samples from the Middle East. Conclusion Differences between observed and expected genotype frequencies are common in surveys of hemoglobin variants in the study regions. Further research is required to identify and quantify factors responsible for such deviations. Estimates based on HWE might substantially underestimate the annual number of SCA affected newborns (up to one third in sub-Saharan Africa and one half in the Middle East). PMID:26633548

  9. The Beginnings of Civilization in the Near East and Africa: Mesopotamia, Egypt, and Kush. Grade 6 Model Lesson for Unit II. California History-Social Science Course Models.

    ERIC Educational Resources Information Center

    Zachlod, Michelle, Ed.

    This model lesson for sixth graders about the beginnings of civilization in the Near East and Africa aims to have students focus on the cultural and geographical features of a region: landforms, climate, and vegetation. The lesson features three major topics: (1) Sumer and Mesopotamia, (2) Egypt, and (3) Kush. It addresses the uses and…

  10. Do School Incentives and Accountability Measures Improve Skills in the Middle East and North Africa? The Cases of Jordan and Tunisia

    ERIC Educational Resources Information Center

    Shafiq, M. Najeeb

    2011-01-01

    There is general agreement that skill-enhancing school reforms in the Middle East and North Africa (MENA) region are necessary for economic, political and social reasons. Using student-level data from Jordan and Tunisia, this study assesses the relationship between skills and the following school incentive and accountability measures: pedagogical…

  11. The Impact of Cultural and Economic Globalization on the Planning and Function of Higher Education in North Africa and the Middle East.

    ERIC Educational Resources Information Center

    Sabour, M'Hammed

    1999-01-01

    Discusses the impact of globalization on higher education in the Arab World, particularly North Africa and the Middle East. The influence has been positive regarding the university's openness to the world and involvement in global intellectual and scientific activity and culture. However, globalization is also seen in the academia as tantamount to…

  12. A Community-based Oral Health Promotion Model for HIV Patients in Nairobi, East District in Kenya: a Study Protocol

    PubMed Central

    Koyio, Lucina N.; van der Sanden, Wil J.M.; van der Ven, Andre; Mulder, Jan; Creugers, Nico H.J.; Merkx, Matthias A.W.; Frencken, Jo E.

    2013-01-01

    General HIV-related orofacial lesions, most commonly oropharyngeal candidiasis, have a typical clinical appearance and can be recognised by members of the community. Although affected patients often experience pain leading to compromised eating and swallowing, barriers such as social stigma and lack of knowledge regarding available services may prevent them from seeking early care. Educating the community about these lesions through community health workers (CHWs) who are democratically elected community members may encourage individuals affected to seek early oral healthcare in the health facilities. A health facility (HF) is a health centre mainly run by clinical officers (CO), i.e. personnel with a 3-year medical training, and nurses. This study aims to evaluate the effect of a CHW training programme on: i) their knowledge and recognition of HIV-related oral-facial lesions at a community level; and ii) referral of affected patients from the community to the HFs. Design and Methods All 800 CHWs in 2 administrative divisions of Nairobi East District (test group n=400; control group n=400) will be selected. The test group will receive training. CHWs in both groups will be assessed at 4 time points: −3, 0, +3 and +6 months with reference to the training on: i) their knowledge of HIV-related orofacial lesions (using a written questionnaire); and ii) their performance in referring affected patients to the HFs (using clinical data). Expected Impact Early recognition of HIV-related orofacial lesions at a community level will prompt community members to seek early oral care, leading to early HIV testing and counselling regarding failure of antiretroviral therapy, while treatment outcomes are still favourable. PMID:25170476

  13. Nd and Sr isotope systematics of Shombole volcano, East Africa, and the links between nephelinites, phonolites, and carbonatites

    SciTech Connect

    Bell, K. ); Peterson, T. )

    1991-06-01

    Nd and Sr isotope compositions of nephelinites, carbonatites, and phonolites from Shombole, a Pliocene volcano in East Africa, show that the phonolites cannot be derived by simple fractional crystallization of nephelinite magma. For a given initial {sup 87}Sr/{sup 86}Sr ratio, {sup 143}Nd/{sup 144}Nd is lower in most phonolites than in the nephelinites and carbonatites. Interaction between nephelinitic magma and lower-crustal granulites can account for these differences. The similar ranges in isotopic composition of the carbonatites and nephelinites are consistent with repeated melting events involving heterogeneous mantle. The carbonatites could have formed by immiscibility with nephelinite magma or by direct partial melting of the same mantle source(s) as the nephelinites.

  14. Impediments to media communication of social change in family planning and reproductive health: experiences from East Africa.

    PubMed

    Kagurusi, Patrick T

    2013-09-01

    The media has been employed to increase uptake of Family Planning through behaviour change communication (BCC). Understanding the barriers encountered in effectively undertaking this function would increase the strategy's effectiveness. Sixty journalists from East Africa participated in trainings to enhance their BCC skills for Family Planning in which a qualitative study was nested to identify barriers to effective Family Planning BCC in the region's media. The barriers were observed to be insufficient BCC skills, journalists' conflict of interest, interests of media houses, inaccessible sources of family planning information, editorial ideologies and absence of commercially beneficial demand. Coupled with the historical ideologies of the media in the region, the observed barriers have precipitated ineffective family planning BCC in the regions media. Effective BCC for family planning in the regions media requires capacity building among practitioners and alignment of the concept to the media's and consumers' aspirations. PMID:24069769

  15. The state of harm reduction in the Middle East and North Africa: A focus on Iran and Morocco.

    PubMed

    Himmich, Hakima; Madani, Navid

    2016-05-01

    HIV/AIDS and hepatitis C among people who inject drugs are on the rise in the Middle East and North Africa (MENA) region. But the regional response to the epidemic falls short both in terms of the quality and scale of response. From the threat of the death sentence for drug offenses to the burden of refugees fleeing conflict, there are many legal, political and social barriers that hinder the introduction and expansion of harm reduction in the region. However Iran and Morocco are two pioneering countries and over the last decade they have been providing evidence that harm reduction is feasible and acceptable in MENA. Using different approaches, these two countries have overcome various obstacles and encouraged discussion and collaboration among stakeholders, including government, health professionals, civil society and community-based organizations. In so doing they have created an enabling environment to endorse a national harm strategy. PMID:27012581

  16. Seismic anisotropy across the east African plateau from shear wave splitting analysis

    NASA Astrophysics Data System (ADS)

    Bagley, B. C.; Nyblade, A.; Mulibo, G.; Tugume, F.

    2011-12-01

    Previous studies of the east African plateau reveal complicated patterns of seismic anisotropy that are not easily explained by a single mechanism. The pattern is defined by rift-parallel fast directions for stations within or near Cenozoic rift valleys, and near-null results in Precambrian terrains away from the rift. Data from 65 temporary Africa Array stations deployed between 2007 and 2011 are being used to make new shear wave splitting measurements. The stations span the east African plateau and cover both the eastern and western branches of the east African rift system, as well as unrifted Proterozoic and Archean terrains in Uganda, Kenya, Tanzania, and Zambia. Through analysis of shear wave splitting we will better constrain the distribution of seismic anisotropy, and and from it gain new insight into the tectonic evolution of east Africa.

  17. Grid search modeling of receiver functions: Implications for crustal structure in the Middle East and North Africa

    SciTech Connect

    Sandvol, E.; Seber, D.; Calvert, A.; Barazangi, M.

    1998-11-01

    A grid search is used to estimate average crustal thickness and shear wave velocity structure beneath 12 three-component broadband seismic stations in the Middle East, North Africa, and nearby regions. The crustal thickness in these regions is found to vary from a minimum of 8.0{plus_minus}1.5&hthinsp;km in East Africa (Afar) region to possibly a maximum of 64{plus_minus}4.8&hthinsp;km in the lesser Caucasus. Stations located within the stable African platform indicate a crustal thickness of about 40 km. Teleseismic three-component waveform data produced by 165 earthquakes are used to create receiver function stacks for each station. Using a grid search, we have solved for the optimal and most simple shear velocity models beneath all 12 stations. Unlike other techniques (linearized least squares or forward modeling), the grid search methodology guarantees that we solve for the global minimum within our defined model parameter space. Using the grid search, we also qualitatively estimate the least number of layers required to model the observed receiver functions{close_quote} major seismic phases (e.g., PS{sub Moho}). A jackknife error estimation method is used to test the stability of our receiver function inversions for all 12 stations in the region that had recorded a sufficient number of high-quality broadband teleseismic waveforms. Five of the 12 estimates of crustal thicknesses are consistent with what is known of crustal structure from prior geophysical work. Furthermore, the remaining seven estimates of crustal structure are in regions for which previously there were few or no data about crustal thickness. {copyright} 1998 American Geophysical Union

  18. Identifying important breast cancer control strategies in Asia, Latin America and the Middle East/North Africa

    PubMed Central

    2011-01-01

    Background Breast cancer is the most frequent cause of cancer death in women worldwide, but global disparities in breast cancer control persist, due to a lack of a comprehensive breast cancer control strategy in many countries. Objectives To identify and compare the need for breast cancer control strategies in Asia, Latin America and the Middle East/North Africa and to develop a common framework to guide the development of national breast cancer control strategies. Methods Data were derived from open-ended, semi-structured interviews conducted in 2007 with 221 clinicians, policy makers, and patient advocates; stratified across Asia (n = 97), Latin America (n = 46), the Middle East/North Africa (ME/NA) (n = 39) and Australia and Canada (n = 39). Respondents were identified using purposive and snowballing sampling. Interpretation of the data utilized interpretive phenomenological analysis where transcripts and field notes were coded and analyzed and common themes were identified. Analysis of regional variation was conducted based on the frequency of discussion and the writing of the manuscript followed the RATS guidelines. Results Analysis revealed four major themes that form the foundation for developing national breast cancer control strategies: 1) building capacity; 2) developing evidence; 3) removing barriers; and 4) promoting advocacy - each specified across five sub-ordinate dimensions. The propensity to discuss most dimensions was similar across regions, but managing advocacy was discussed more frequently (p = 0.004) and organized advocacy was discussed less frequently (p < 0.001) in Australia and Canada. Conclusions This unique research identified common themes for the development of breast cancer control strategies, grounded in the experience of local practitioners, policy makers and advocacy leaders across diverse regions. Future research should be aimed at gathering a wider array of experiences, including those of patients. PMID:21933435

  19. Holistic view to integrated climate change assessment and extreme weather adaptation in the Lake Victoria Basin East Africa

    NASA Astrophysics Data System (ADS)

    Mutua, F.; Koike, T.

    2013-12-01

    Extreme weather events have been the leading cause of disasters and damage all over the world.The primary ingredient to these disasters especially floods is rainfall which over the years, despite advances in modeling, computing power and use of new data and technologies, has proven to be difficult to predict. Also, recent climate projections showed a pattern consistent with increase in the intensity and frequency of extreme events in the East African region.We propose a holistic integrated approach to climate change assessment and extreme event adaptation through coupling of analysis techniques, tools and data. The Lake Victoria Basin (LVB) in East Africa supports over three million livelihoods and is a valuable resource to five East African countries as a source of water and means of transport. However, with a Mesoscale weather regime driven by land and lake dynamics,extreme Mesoscale events have been prevalent and the region has been on the receiving end during anomalously wet years in the region. This has resulted in loss of lives, displacements, and food insecurity. In the LVB, the effects of climate change are increasingly being recognized as a significant contributor to poverty, by its linkage to agriculture, food security and water resources. Of particular importance are the likely impacts of climate change in frequency and intensity of extreme events. To tackle this aspect, this study adopted an integrated regional, mesoscale and basin scale approach to climate change assessment. We investigated the projected changes in mean climate over East Africa, diagnosed the signals of climate change in the atmosphere, and transferred this understanding to mesoscale and basin scale. Changes in rainfall were analyzed and similar to the IPCC AR4 report; the selected three General Circulation Models (GCMs) project a wetter East Africa with intermittent dry periods in June-August. Extreme events in the region are projected to increase; with the number of wet days

  20. Potential Predictability of the Sea-Surface Temperature Forced Equatorial East Africa Short Rains Interannual Variability in the 20th Century

    NASA Astrophysics Data System (ADS)

    Bahaga, T. K.; Gizaw, G.; Kucharski, F.; Diro, G. T.

    2014-12-01

    In this article, the predictability of the 20th century sea-surface temperature (SST) forced East African short rains variability is analyzed using observational data and ensembles of long atmospheric general circulation model (AGCM) simulations. To our knowledge, such an analysis for the whole 20th century using a series of AGCM ensemble simulations is carried out here for the first time. The physical mechanisms that govern the influence of SST on East African short rains in the model are also investigated. It is found that there is substantial skill in reproducing the East African short rains variability, given that the SSTs are known. Consistent with previous recent studies, it is found that the Indian Ocean and in particular the western pole of the Indian Ocean dipole (IOD) play a dominant role for the prediction skill, whereas SSTs outside the Indian Ocean play a minor role. The physical mechanism for the influence of the western Indian Ocean on East African rainfall in the model is consistent with previous findings and consists of a gill-type response to a warm (cold) anomaly that induces a westerly(easterly) low-level flow anomaly over equatorial Africa and leads to moisture flux convergence (divergence) over East Africa. On the other hand, a positive El Nino-Southern Oscillation (ENSO) anomaly leads to a spatially non-coherent reducing effect over parts of East Africa, but the relationship is not strong enough to provide any predictive skill in our model. The East African short rains prediction skill is also analyzed within a model-derived potential predictability framework and it is shown that the actual prediction skill is broadly consistent with the model potential prediction skill. Low-frequency variations of the prediction skill are mostly related to SSTs outside the Indian Ocean region and are likely due to an increased interference of ENSO with the Indian Ocean influence on East African short rains after the mid-1970s climate shift.

  1. Can Static Habitat Protection Encompass Critical Areas for Highly Mobile Marine Top Predators? Insights from Coastal East Africa

    PubMed Central

    Pérez-Jorge, Sergi; Pereira, Thalia; Corne, Chloe; Wijtten, Zeno; Omar, Mohamed; Katello, Jillo; Kinyua, Mark; Oro, Daniel; Louzao, Maite

    2015-01-01

    Along the East African coast, marine top predators are facing an increasing number of anthropogenic threats which requires the implementation of effective and urgent conservation measures to protect essential habitats. Understanding the role that habitat features play on the marine top predator’ distribution and abundance is a crucial step to evaluate the suitability of an existing Marine Protected Area (MPA), originally designated for the protection of coral reefs. We developed species distribution models (SDM) on the IUCN data deficient Indo-Pacific bottlenose dolphin (Tursiops aduncus) in southern Kenya. We followed a comprehensive ecological modelling approach to study the environmental factors influencing the occurrence and abundance of dolphins while developing SDMs. Through the combination of ensemble prediction maps, we defined recurrent, occasional and unfavourable habitats for the species. Our results showed the influence of dynamic and static predictors on the dolphins’ spatial ecology: dolphins may select shallow areas (5-30 m), close to the reefs (< 500 m) and oceanic fronts (< 10 km) and adjacent to the 100m isobath (< 5 km). We also predicted a significantly higher occurrence and abundance of dolphins within the MPA. Recurrent and occasional habitats were identified on large percentages on the existing MPA (47% and 57% using presence-absence and abundance models respectively). However, the MPA does not adequately encompass all occasional and recurrent areas and within this context, we propose to extend the MPA to incorporate all of them which are likely key habitats for the highly mobile species. The results from this study provide two key conservation and management tools: (i) an integrative habitat modelling approach to predict key marine habitats, and (ii) the first study evaluating the effectiveness of an existing MPA for marine mammals in the Western Indian Ocean. PMID:26186438

  2. Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa

    PubMed Central

    Williams, Richard AJ; Peterson, A Townsend

    2009-01-01

    Background The emerging highly pathogenic avian influenza strain H5N1 ("HPAI-H5N1") has spread broadly in the past decade, and is now the focus of considerable concern. We tested the hypothesis that spatial distributions of HPAI-H5N1 cases are related consistently and predictably to coarse-scale environmental features in the Middle East and northeastern Africa. We used ecological niche models to relate virus occurrences to 8 km resolution digital data layers summarizing parameters of monthly surface reflectance and landform. Predictive challenges included a variety of spatial stratification schemes in which models were challenged to predict case distributions in broadly unsampled areas. Results In almost all tests, HPAI-H5N1 cases were indeed occurring under predictable sets of environmental conditions, generally predicted absent from areas with low NDVI values and minimal seasonal variation, and present in areas with a broad range of and appreciable seasonal variation in NDVI values. Although we documented significant predictive ability of our models, even between our study region and West Africa, case occurrences in the Arabian Peninsula appear to follow a distinct environmental regime. Conclusion Overall, we documented a variable environmental "fingerprint" for areas suitable for HPAI-H5N1 transmission. PMID:19619336

  3. Revisiting a hoary chestnut: the nature of early cattle domestication in North-East Africa

    PubMed Central

    Brass, Michael

    2013-01-01

    Summary It has been almost three decades since the Wendorf & Schild-Andrew Smith debate over the timing and location of domesticated cattle in North Africa reached its climax. The time is now appropriate for a review of the old models in light of subsequent anatomical and genetic data which have come to light. This article summarises the main issues and models, and attempts to provide suggestions for future investigations. PMID:24077927

  4. East Africa's pastoralist emergency: is climate change the straw that breaks the camel's back?

    PubMed

    Blackwell, P J

    2010-01-01

    The global warming trend of climate change is having severe adverse effects on the livelihoods of the Turkana pastoralists of northwestern Kenya. Care has to be taken in making assertions about the impact of climate change. The biggest effects may come not from lower average rainfall but from a widening of the standard deviation as weather extremes become more frequent. In a region already prone to drought, disease and conflict, climate change, access to modern weapons and new viral livestock diseases are now overwhelming pastoralists' coping capacity and deepening the region's roughly 30-year dependency on famine relief. This article examines the livelihood strategies of the Turkana and several poverty reduction programmes currently established, while addressing the reality that traditional pastoralism may no longer be a viable livelihood option, given the effects of climate change, disease and the ensuing conflict over diminishing resources. The findings conclude that the future for traditional Turkana pastoralists is dismal because they continue to depend on an environment that may no longer support them. Humanitarians are recommended to shift their focus to advocate and invest in alternative livelihood strategies that generate economic independence and help the Turkana adapt to their changing environment. PMID:21506297

  5. Updating Historical Maps of Malaria Transmission Intensity in East Africa Using Remote Sensing

    PubMed Central

    Omumbo, J.A.; Hay, S.I.; Goetz, S.J.; Snow, R.W.; Rogers, D.J.

    2013-01-01

    Remotely sensed imagery has been used to update and improve the spatial resolution of malaria transmission intensity maps in Tanzania, Uganda, and Kenya. Discriminant analysis achieved statistically robust agreements between historical maps of the intensity of malaria transmission and predictions based on multitemporal meteorological satellite sensor data processed using temporal Fourier analysis. The study identified land surface temperature as the best predictor of transmission intensity. Rainfall and moisture availability as inferred by cold cloud duration (ccd) and the normalized difference vegetation index (ndvi), respectively, were identified as secondary predictors of transmission intensity. Information on altitude derived from a digital elevation model significantly improved the predictions. “Malaria-free” areas were predicted with an accuracy of 96 percent while areas where transmission occurs only near water, moderate malaria areas, and intense malaria transmission areas were predicted with accuracies of 90 percent, 72 percent, and 87 percent, respectively. The importance of such maps for rationalizing malaria control is discussed, as is the potential contribution of the next generation of satellite sensors to these mapping efforts. PMID:23814324

  6. Academic Programmes in Universities in East Africa: A Catalyst to Development

    ERIC Educational Resources Information Center

    Karimi, Florah Katanu

    2015-01-01

    The types of academic programmes offered by universities, both public and private, are considered to be critical to the realization of development agendas. This study was descriptive in nature and sought to establish whether universities in the East African region were offering academic programmes that were relevant to the realization of the…

  7. Oil and the economic geography of the Middle East and North Africa

    SciTech Connect

    Kortepeter, C.M. )

    1990-01-01

    This book gives us the opportunity to follow the development of the field of economic geography as applied to the Middle East during the past half century. The materials are arranged under the following three headings: Geography and Petroleum: Boundaries and Boundary Disputes: and Social Geography.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  10. Evaluation of the performance of the WRF 1-Dimensional Lake model over the East Africa Great Lakes

    NASA Astrophysics Data System (ADS)

    Gudoshava, M.; Semazzi, F. H. M.

    2015-12-01

    This study seeks to investigate the performance of the 1-Dimensional lake model coupled to WRF over East Africa. The Africa Great lakes exert a great influence on the climate of the region and a number of studies have shown how the lake influences the circulation and the total precipitation over the region. The lakes have highly variable depths, with Lake Victoria having an average depth of 40m and Lake Tanganyika a depth of 450m. The Lake model for WRF was tested and calibrated for the Great lakes, however it was not tested for tropical lakes. We hypothesize that the inclusion of a 1-dimensional lake will reduce the precipitation bias as compared to the WRF model without the lake model. In addition initializing the lake temperature using a vertical temperature profile that closes resembles the one over these lakes will greatly reduce the spin up time. The simulations utilized three nested domains at 36, 12 and 4km. The 4km domain is centered over Lake Victoria Basin, while the 12 km domain includes all the lakes in East Africa. The Tropical Rainfall Measuring Mission (TRMM) datasets are used in evaluating the precipitation, and the following statistics were calculated: root mean square error, standard deviation of the model and observations and mean bias. The results show that the use of the 1-dimensional lake model improves the precipitation over the region considerably compared to an uncoupled model. The asymmetrical rainfall pattern is evident in the simulations. However using the default vertical temperature profile with a three-month spin up is not adequate to transfer heat to the bottom of the lake. Hence the temperatures are still very cold at the bottom. A nine-month spin up improves the lake surface temperatures and lake temperatures at the bottom. A two year spin up greatly improves the lake surface temperatures and hence the total precipitation over the lake. Thus longer spin up time allows for adequate heat transfer in the lake. Initializing the

  11. Lake level change and total water discharge in East Africa Rift Valley from satellite-based observations

    NASA Astrophysics Data System (ADS)

    Hassan, Ayman A.; Jin, Shuanggen

    2014-06-01

    The measurement of total basin water discharge is important for understanding the hydrological and climatologic issues related to the water and energy cycles. Climatic extreme events are normal climatic occurrences in Africa. For example, extensive droughts are regular features in the last few decades in parts of East Africa, which suffers from a lack of in situ observations as well as a lack of regional hydrological models. In this study, multi-disciplinary different types of space-borne observations and global hydrological models are used to study total water discharge in the Great Rift Valley of East Africa (i.e. Lakes Victoria, Tanganyika, and Malawi) from January 2003 to December 2012. The data include the following: (1) total water storage (TWS) variations from Gravity Recovery and Climate Experiment (GRACE), (2) the lake level variations from Satellite Alimetric data, (3) rainfall from Tropical Rainfall Measurement Mission (TRMM) products, (4) soil moisture from WaterGAP Global Hydrology Model (WGHM), and (5) water fluxes from Global Land Data Assimilation System (GLDAS). Results show that a significant decline in the average lake level is found for all of the three lakes between 2003 and 2006. GRACE TWS variations of the whole basin area show the same pattern of variation as the average lake level variations estimated from Altimetric data. The TWS in the basin area of Lakes Victoria and Malawi is governed by the surface water stored in each lake itself, while for Lake Tanganyika, it is governed by both surface water and the soil moisture content in the basin area. Furthermore, the effect of rainfall on TWS is also studied. A phase lag of ~ 2 months is found between TRMM rainfall and GRACE TWS (generally, rainfall precedes the GRACE TWS) for the three lakes. In addition, the regional evapotranspiration ET is estimated from the water balance equation using GRACE land-water solutions, rainfall data from TRMM and runoff values obtained as a fraction of rainfall

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  13. Along-dip variations of structural style in the Somali Basin deep-water fold and thrust belt (East Africa)

    NASA Astrophysics Data System (ADS)

    Cruciani, Francesco; Rinaldo Barchi, Massimiliano

    2014-05-01

    Continental passive margins are place of extended slope-failure phenomena, which can lead to the formation of gravity-driven deep-water fold and thrust belts (DW-FTBs), in regions where no far-field compressional stress is active. These giant geological features, which are confined to the sedimentary section, consist of extensional-compressional linked systems detached over a common décollement, generally salt or shales. The continental passive margin of northern Kenya and southern Somalia is an excellent and relatively unexplored site for recognizing and understanding the DW-FTBs originated over a regional shale décollement. In this study we have interpreted a 2D seismic data-set of the 1980s, hosted by Marine Geoscience Data System at Lamont-Doherty Earth Observatory of Columbia University (http://www.marine-geo.org), and recently reprocessed by ENI, in order to investigate the structural style of a DW-FTB developed offshore of northern Kenya and southern Somalia (Somali Basin). This region records the oldest sedimentary section of the Indian Ocean since the breakup of Gondwana began in the Middle-Lower Jurassic separating Madagascar from Africa. From the Upper Cretaceous to at least the Lower Miocene, the margin has been characterized by gravitational collapse leading to the formation of a DW-FTB extending more than 400 km along-strike. The northern portion of the DW-FTB is about 150 km wide, whilst in the southern portion is few tens of km wide. We analysed the northern portion along a regional seismic section. Our study represents the first detailed structural interpretation of this DW-FTB since its discovery in the 1980s. The good quality of the available reprocessed seismic data has allowed us to identify remarkable along-dip variations in the structural style. The basal detachment constantly deepens landward, in agreement with a prevailing gravity-spreading deformation process (as in the case of the Niger Delta). On the seismic data are not visible, as

  14. The demographics of human and malaria movement and migration patterns in East Africa

    PubMed Central

    2013-01-01

    Introduction The quantification of parasite movements can provide valuable information for control strategy planning across all transmission intensities. Mobile parasite carrying individuals can instigate transmission in receptive areas, spread drug resistant strains and reduce the effectiveness of control strategies. The identification of mobile demographic groups, their routes of travel and how these movements connect differing transmission zones, potentially enables limited resources for interventions to be efficiently targeted over space, time and populations. Methods National population censuses and household surveys provide individual-level migration, travel, and other data relevant for understanding malaria movement patterns. Together with existing spatially referenced malaria data and mathematical models, network analysis techniques were used to quantify the demographics of human and malaria movement patterns in Kenya, Uganda and Tanzania. Movement networks were developed based on connectivity and magnitudes of flow within each country and compared to assess relative differences between regions and demographic groups. Additional malaria-relevant characteristics, such as short-term travel and bed net use, were also examined. Results Patterns of human and malaria movements varied between demographic groups, within country regions and between countries. Migration rates were highest in 20–30 year olds in all three countries, but when accounting for malaria prevalence, movements in the 10–20 year age group became more important. Different age and sex groups also exhibited substantial variations in terms of the most likely sources, sinks and routes of migration and malaria movement, as well as risk factors for infection, such as short-term travel and bed net use. Conclusion Census and survey data, together with spatially referenced malaria data, GIS and network analysis tools, can be valuable for identifying, mapping and quantifying regional connectivities

  15. Tectonics and Volcanism of East Africa as Seen Using Remote Sensing Imagery

    NASA Technical Reports Server (NTRS)

    Hutt, Duncan John

    1996-01-01

    The East African Rift is the largest area of active continental geology. The tectonics of this area has been studied with remote sensing data, including AVHRR, Landsat MSS and TM, SPOT, and electronic still camera from Shuttle. Lineation trends have been compared to centers of volcanic and earthquake activity as well as the trends shown on existing geologic maps. Remote sensing data can be used effectively to reveal and analyze significant tectonic features in this area.

  16. Development of the roadmap and guidelines for the prevention and management of high blood pressure in Africa: Proceedings of the PASCAR Hypertension Task Force meeting: Nairobi, Kenya, 27 October 2014.

    PubMed

    Dzudie, A; Ojji, D; Anisiuba, B C; Abdou, B A; Cornick, R; Damasceno, A; Kane, A L; Mocumbi, A O; Mohamed, A; Nel, G; Ogola, E; Onwubere, B; Otieno, H; Rainer, B; Schutte, A; Ali, I T; Twagirumukiza, M; Poulter, N; Mayosi, B

    2015-01-01

    Africa has one of the fastest growing economies in the world. The economic changes are associated with a health transition characterised by a rise in cardiovascular risk factors and complications, which tend to affect the African population at their age of maximum productivity. Recent data from Africa have highlighted the increasing importance of high blood pressure in this region of the world. This condition is largely underdiagnosed and poorly treated, and therefore leads to stroke, renal and heart failure, and death. Henceforth, African countries are taking steps to develop relevant policies and programmes to address the issue of blood pressure and other cardiovascular risk factors in response to a call by the World Health Organisation (WHO) to reduce premature deaths from non-communicable diseases (NCDs) by 25% by the year 2025 (25 × 25). The World Heart Federation (WHF) has developed a roadmap for global implementation of the prevention and management of raised blood pressure using a health system approach to help realise the 25 × 25 goal set by the WHO. As the leading continental organisation of cardiovascular professionals, the Pan-African Society of Cardiology (PASCAR) aims to contextualise the roadmap framework of the WHF to the African continent through the PASCAR Taskforce on Hypertension. The Taskforce held a workshop in Kenya on 27 October 2014 to discuss a process by which effective prevention and control of hypertension in Africa may be achieved. It was agreed that a set of clinical guidelines for the management of hypertension are needed in Africa. The ultimate goal of this work is to develop a roadmap for implementation of the prevention and management of hypertension in Africa under the auspices of the WHF. PMID:25940121

  17. Rainfall consistently enhanced around the Gezira Scheme in East Africa due to irrigation

    NASA Astrophysics Data System (ADS)

    Alter, Ross E.; Im, Eun-Soon; Eltahir, Elfatih A. B.

    2015-10-01

    Land-use and land-cover changes have significantly modified regional climate patterns around the world. In particular, the rapid development of large-scale cropland irrigation over the past century has been investigated in relation to possible modification of regional rainfall. In regional climate simulations of the West African Sahel, hypothetical large-scale irrigation schemes inhibit rainfall over irrigated areas but enhance rainfall remotely. However, the simulated influence of large-scale irrigation schemes on precipitation patterns cannot be substantiated without direct comparison to observations. Here we present two complementary analyses: numerical simulations using a regional climate model over an actual, large-scale irrigation scheme in the East African Sahel--the Gezira Scheme--and observational analyses over the same area. The simulations suggest that irrigation inhibits rainfall over the Gezira Scheme and enhances rainfall to the east. Observational analyses of rainfall, temperature and streamflow in the same region support the simulated results. The findings are consistent with a mechanistic framework in which irrigation decreases surface air temperature, causing atmospheric subsidence over the irrigated area and clockwise wind anomalies (in background southwesterly winds) that increase upward vertical motion to the east. We conclude that irrigation development can consistently modify rainfall patterns in and around irrigated areas, warranting further examination of potential agricultural, hydrologic and economic implications.

  18. Negligible effect of hydrogen content on plate strength in East Africa

    NASA Astrophysics Data System (ADS)

    Selway, Kate

    2015-07-01

    Continental rifting requires weak zones to exist within the strong continental plates. This weakening is thought to be induced primarily by high hydrogen contents and temperatures, as well as small grain size. An ideal location to test models of plate strength in situ is the East African Rift--the best exposed continental rift on Earth--which is forming adjacent to the unrifted Tanzanian Craton. Here I use magnetotelluric data to investigate electrical conductivity, and hence hydrogen content, across the East African Rift and Tanzanian Craton. The images show that the Tanzanian Craton is extremely rich in hydrogen, whereas the parts of the continent that are being rifted are anhydrous, suggesting that high hydrogen content does not systematically reduce plate strength. Earlier deformation events may have reduced the grain size of the continental lithosphere in the East African Rift compared to the Tanzanian Craton. I therefore suggest that the localization of rifting and repeated reactivation of deformed regions may not be due to hydrogen content and is instead controlled by small grain size.

  19. Development of an early warning system for extreme rainfall, surface inundation, and malaria in East Africa

    NASA Astrophysics Data System (ADS)

    Hirt, C.; Jensen, K.; McDonald, K. C.; Ceccato, P.

    2013-12-01

    Malaria is a major health issue in Eastern Africa. In this study, we focus on rainfall and surface inundation, which are both major environmental factors in the transmission and contraction of the disease. We use the two alternative forced choice (2AFC) score and other comparative methods to analyze the efficacy of using a six-day lead precipitation forecast to predict extreme precipitation and inundation events by comparing these forecasts to historical, satellite-based precipitation and inundation observations. We also investigate the dynamics between observed surface inundation, rainfall, and malaria incidence rates in four districts of Eritrea.

  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. PMID:14015908

  1. Towards better-informed consent: Research with livestock-keepers and informal traders in East Africa.

    PubMed

    Cooper, Tarni Louisa; Kirino, Yumi; Alonso, Silvia; Lindahl, Johanna; Grace, Delia

    2016-06-01

    With the rise of the One Health paradigm, ethicists have called for new research approaches, considering the interdependent relationships of humans, animals, and their environment. These relationships can be particularly complex within resource-poor, smallholder livestock systems, necessitating a rigorous informed-consent process. Little has been published on informed consent beyond human-subject research. This paper outlines two studies on informed consent, for research identifying diseases of animal and human importance, within smallholder livestock value chains. Firstly, a randomized independent-group study compared three communication tools (written, cartoons, and photographs) for informing 22 Tanzanian livestock-keepers before seeking their consent. A significant difference in comprehension and engagement in the informed-consent process was found between tools, and cartoons had the highest (i.e. best combined comprehension and engagement) scores. Most (21 out of 22) farmers answered half or more the questions correctly, but none were able to answer all questions. Comprehension testing allowed identification of common misunderstandings, such as immediate benefits the farmers would receive and the process to be used for relaying research results. Dialogue stimulated by cartoons and photographs allowed researchers to determine and respond to participants' varied relationships with their livestock. The second study assessed preferred methods for indicating consent among informal-sector milk vendors in Nairobi, Kenya. Of consenting participants, 61% (140/230) indicated consent verbally, 39% (90/230) signed consent and none chose thumbprint. There was a significant enumerator-effect on both overall consent and the methods chosen. Several of these findings echo those published in human-medical research. Additionally, highlighted here is the importance of facilitating dialogue during the informed-consent process in One Health research, for a more nuanced understanding

  2. Modelling The Magnitude of Climatic Changes In East Africa During The Last 150 Kyr

    NASA Astrophysics Data System (ADS)

    Bergner, A. G. N.; Duehnforth, M.; Strecker, M. R.; Trauth, M. H.

    In order to assess the links between hydrology and climate in continental basins, water- balance modelling of lakes is a useful tool, because lakes are sensitive recorders of hydrologic fluctuations due to regional climate change. In the Central Kenya Rift, 40Ar/39Ar- dated lake sediments from the Naivasha and Nakuru-Elmenteita basins provide detailed information on extent and chronology of environmental changes and their effect on paleo-lakes. Mapping of lake deposits in surface outcrops and boreholes suggests that the extent of the lakes was comparable during highstands at 9 and 138 kyr BP, respectively, but significantly different compared to present conditions. Whereas the present Lake Naivasha (180 km2), Nakuru (40 km2) and Elmenteita (26 km2) have a water volume < 1 km3, paleo-lake areas were larger by factor of 3 to 4, and lake volumes increased by factor of 50 to 60. Simultaneously, these lakes were subject to considerable hydrochemical changes. For example, diatom and authigenic mineral assemblages indicate pH fluctuations between 7 and 11 for Lake Naivasha during the last 150 kyr, in contrast to a pH of 8.2. Hydroclimatic lake-balance modelling of the most prominent lake phases of Lake Naivasha and Lake Nakuru-Elmenteita were performed in order to compare past and present-day climate conditions. Our results show that a +15% increase in precipitation compared to modern values may have been responsible for a lake-level highstand at 9 kyr BP. In addition, the increase in precipitation may reach as much as +30% if a change in vegetation due to increased humidity in the catchment is taken into account. Preliminary modelling results for an earlier highstand of Lake Naivasha at 138 kyr BP suggests hydroclimatic conditions comparable to the Holocene highstand. From the analysis of lake sediments we infer that Lake Nakuru-Elmenteita also experienced significant lake highstands at 138 kyr BP most probably caused by the same wetter cli- mate conditions. Our

  3. 18O 16O ratios in cherts associated with the saline lake deposits of East Africa

    USGS Publications Warehouse

    O'Neil, J.R.; Hay, R.L.

    1973-01-01

    The cherts formed from sodium silicate precursors in East African saline, alkaline lakes have ??18O values ranging from 31.1 to 44.1. The ??18O values correlate in general with lake salinities as inferred from geologic evidence, indicating that most chert was formed from its precursor in contact with lake water trapped at the time of deposition. A few of the analyzed cherts probably formed in contact with dilute meteoric water. From the widely varying ??18O values we conclude that precursors were transformed to chert in fluids of widely varying salinity and aNa+/aH+ ratio. ?? 1973.

  4. Examining the relationship between environmental factors and conflict in pastoralist areas of East Africa.

    PubMed

    Ayana, Essayas K; Ceccato, Pietro; Fisher, Jonathan R B; DeFries, Ruth

    2016-07-01

    The eastern Africa region has long been known for recurring drought, prolonged civil war and frequent pastoral conflicts. Several researchers have suggested that environmental factors can trigger conflicts among pastoralist communities, but quantitative support for this hypothesis is lacking. Here we use 29years of georeferenced precipitation and Normalized Difference Vegetation Index (NDVI) data to evaluate long term trends in scarcity of water and forage for livestock, and then ask whether these environmental stressors have any predictive power with respect to the location and timing of 11years of conflict data based on Armed Conflict Location and Event Data Project (ACLED) and Uppsala Conflict Data Program (UCDP). Results indicate that environmental stressors were only partly predictive of conflict events. To better understand the drivers behind conflict, the contribution of other potential stressors to conflict need to be systematically quantified and be taken into consideration. PMID:27037881

  5. LANDSAT image studies as applied to petroleum exploration in Kenya

    NASA Technical Reports Server (NTRS)

    Miller, J. B.

    1975-01-01

    The Chevron-Kenya oil license, acquired in 1972, covers an area at the north end of the Lamu Embayment. Immediately after acquisition, a photogeologic study of the area was made followed by a short field inspection. An interpretation of LANDSAT-1 images as a separate attempt to improve geological knowledge was completed. The method used in the image study, the multispectral characteristics of rock units and terrain, and the observed anomalous features as seen in the LANDSAT imagery are described. It was found that the study helped to define the relationship of the Lamu Embayment and its internal structure with surrounding regional features, such as the East Africa rifting, the Rudolf Trough, the Bur Acaba structural ridge, and the Ogaden Basin.

  6. A ~1.3Ma paleoecological record from scientific drilling at Lake Malawi, East Africa

    NASA Astrophysics Data System (ADS)

    Cohen, Andrew S.; Blome, Margaret; Ivory, Sarah; King, John; Cole, Julie; McGlue, Michael

    2016-04-01

    Long records of Quaternary ecological and climatic change are critical to understanding the range of potential responses of ecosystems to environmental forcing. Here we present an integrated lake and watershed paleoecological analysis from drill core records obtained by the Lake Malawi Drilling Project, documenting extraordinary fluctuations in climate, hydrology and ecosystem response for the southern tropics of Africa. High resolution lacustrine and terrestrial paleoecology and sedimentology data sets from these Early Pleistocene-Holocene drill cores provide the most complete record of this duration currently available from Africa. Time series analyses of these records demonstrate strong orbital forcing of regional hydroclimate that drives high-amplitude changes in Malawi ecosystems. Prior to ~600ka we also observe a secondary overprint of watershed processes involving river capture or diversion that may have a tectonic origin. We observe shifts between more arid conditions (shallow alkaline and well mixed lake, with discontinuous desert vegetation) and more humid environments (deep, stratified, freshwater lake with dense forest). These broadly synchronous changes in lake paleoecology, lake sedimentology, and watershed vegetation demonstrate the major role of climate in regulating this system. Transitions between these lake/watershed state extremes is often very abrupt, suggesting that the combined lake/watershed repeatedly passed through hydroclimate thresholds, with important implications for the evolution of the lake's endemic biodiversity and ecosystem. The tempo of lake/watershed state fluctuations changes at the Mid-Pleistocene Transition, altering from one of higher frequency/lower amplitude variability prior to 900ka to lower frequency/higher amplitude variability after that time.

  7. Use of a crop climate modeling system to evaluate climate change adaptation practices: maize yield in East Africa

    NASA Astrophysics Data System (ADS)

    Moore, N. J.; Alagarswamy, G.; Andresen, J.; Olson, J.; Thornton, P.

    2013-12-01

    Sub Saharan African agriculture is dominated by small-scale farmers and is heavily depend on growing season precipitation. Recent studies indicate that anthropogenic- induced warming including the Indian Ocean sea surface significantly influences precipitation in East Africa. East Africa is a useful region to assess impacts of future climate because of its large rainfall gradient, large percentage of its area being sub-humid or semi-arid, complex climatology and topography, varied soils, and because the population is particularly vulnerable to shifts in climate. Agronomic adaptation practices most commonly being considered include include a shift to short season, drought resistant maize varieties, better management practices especially fertilizer use, and irrigation. The effectiveness of these practices with climate change had not previously been tested. We used the WorldClim data set to represent current climate and compared the current and future climate scenarios of 4 Global Climate Models (GCMs) including a wetter (CCSM) and drier (HadCM3) GCM downscaled to 6 km resolution. The climate data was then used in the process-based CERES maize crop model to simulate the current period (representing 1960- 1990) and change in future maize production (from 2000 to 2050s). The effectiveness of agronomic practices, including short duration maize variety, fertilizer use and irrigation, to reduce projected future yield losses due to climate change were simulated. The GCMs project an increase in maximum temperature during growing season ranging from 1.5 to 3°C. Changes in precipitation were dependent on the GCM, with high variability across different topographies land cover types and elevations. Projected warmer temperatures in the future scenarios accelerated plant development and led to a reduction in growing season length and yields even where moisture was sufficient Maize yield changes in 2050 relative to the historical period were highly varied, in excess of +/- 500 kg

  8. Molecular records of climate variability and vegetation response since the Late Pleistocene in the Lake Victoria basin, East Africa

    NASA Astrophysics Data System (ADS)

    Berke, Melissa A.; Johnson, Thomas C.; Werne, Josef P.; Grice, Kliti; Schouten, Stefan; Sinninghe Damsté, Jaap S.

    2012-11-01

    New molecular proxies of temperature and hydrology are helping to constrain tropical climate change and elucidate possible forcing mechanisms during the Holocene. Here, we examine a ˜14,000 year record of climate variability from Lake Victoria, East Africa, the world's second largest freshwater lake by surface area. We determined variations in local hydroclimate using compound specific δD of terrestrial leaf waxes, and compared these results to a new record of temperature utilizing the TEX86 paleotemperature proxy, based on aquatic Thaumarchaeotal membrane lipids. In order to assess the impact of changing climate on the terrestrial environment, we generated a record of compound specific δ13C from terrestrial leaf waxes, a proxy for ecosystem-level C3/C4 plant abundances, and compared the results to previously published pollen-inferred regional vegetation shifts. We observe a general coherence between temperature and rainfall, with a warm, wet interval peaking ˜10-9 ka and subsequent gradual cooling and drying over the remainder of the Holocene. These results, particularly those of rainfall, are in general agreement with other tropical African climate records, indicating a somewhat consistent view of climate over a wide region of tropical East Africa. The δ13C record from Lake Victoria leaf waxes does not appear to reflect changes in regional climate or vegetation. However, palynological analyses document an abrupt shift from a Poaceae (grasses)-dominated ecosystem during the cooler, arid late Pleistocene to a Moraceae-dominated (trees/shrubs) landscape during the warm, wet early Holocene. We theorize that these proxies are reflecting vegetation in different locations around Lake Victoria. Our results suggest a predominantly insolation-forced climate, with warm, wet conditions peaking at the maximum interhemispheric seasonal insolation contrast, likely intensifying monsoonal precipitation, while maximum aridity coincides with the rainy season insolation and the

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

    SciTech Connect

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

    2007-07-08

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

  10. Chinese propriety medicines: an "alternative modernity?" The case of the anti-malarial substance artemisinin in East Africa.

    PubMed

    Hsu, Elisabeth

    2009-01-01

    This article discusses various modes of "modernizing" traditional Chinese medical drugs (zhongyao [image: see text]) and transforming them into so-called Chinese propriety medicines (zhongchengyao [image: see text]) that are flooding the current neoliberal wellness markets. This article argues that the chemical procedures used in the manufacture of Chinese propriety medicines are highly culture-specific and deserve being considered as instantiations of an "alternative modernity" (e.g., Knauft 2002), rather than of "Westernization." These Western-Chinese combinations, produced in strife toward fulfilling Mao Zedong's Communist-revolutionary vision, have a potential to represent a critical alterity to Western health policies, challenging rhetoric against such combinations. However, as is also noted in this article based on ethnographic fieldwork in East Africa, their potential alterity has been corroded for at least two reasons. First, the medical rationale for dispensing these medications has been shaped by commercial demands in ways that have worked toward transforming the formerly scholarly Chinese medical tradition (as outlined by Bates 1995) into a consumer-near and popular "folk medicine" (as defined by Farquhar 1994:212). Second, the repertoire of Chinese propriety medicines is impoverished as its efficacious "alternatively modern" drugs are being redefined as "modern" biomedical drugs. The article concludes that the potentially critical alterity of any formerly scholarly traditional medicine is more likely to be lost in those fields of health care that are both highly commercialized and polarized by the biomedical imperative to distinguish between "traditional" and "modern" medicines. As example for demonstrating how contentious the issue is, qinghaosu [image: see text] (artemisinin) is put center stage. It is an anti-malarial substance which in the 1970s Chinese scientists extracted from the Chinese medical drug qinghao [image: see text] (Herba Artemisiae

  11. Geometry and Kinematics of the Lamu Basin Deep-Water Fold-and-Thrust Belt (East Africa)

    NASA Astrophysics Data System (ADS)

    Barchi, Massimiliano R.; Cruciani, Francesco; Porreca, Massimiliano

    2016-04-01

    Even if most thin-skinned fold-and-thrust belt are generated at convergent plate boundaries, in the last decades advances in seismic exploration and acquisition of large datasets have shown that they are also notably widespread along continental passive margins, driven by gravity processes in deep-water areas. In this study a composite set of modern and vintage reprocessed seismic reflection profiles is used to investigate the internal structure and kinematic evolution of the Lamu Basin Deep-Water Fold-and-Trust Belt (DW-FTB). The Lamu Basin is an example of giant-scale, gravity driven compressional belt developed in Late Cretaceous-Early Tertiary along a still poorly explored sector of the East-African continental margin, at the Kenya-Somalia border. The compressional domain extends longitudinally for more than 450 km, is up to 180 km wide and shows remarkable structural complexity both along strike and along dip. The external part is dominated by ocean-verging imbricate thrusts, above a gently landward-dipping basal detachment. The internal part is characterised by almost symmetrical detachment folds and double verging structures, sustaining bowl-shaped syn-tectonic basins. Here the basal detachment surface is almost flat. The mean fold wavelength displays a progressive landward increase, from 2.5 km, at the toe of the belt, to about 10 km. This structural variability is thought to be related to the lateral variation of the section under shortening and particularly to the different thickness of the Early Cretaceous shaly unit involved in the deformations, increasing landward from about 400 m to more than 1 km. Through the sequential restoration of regional cross-sections, we evaluated that the northern portion of the thrust belt experienced a shortening of almost 50 km (corresponding to 20%), with a shortening rate (during the Late Cretaceous-Paleocene main event) of about 3.5 mm/yr. Under many respects, the dimensions and internal structure of this thrust belt

  12. The evolving contribution of border faults and intra-rift faults in early-stage East African rifts: insights from the Natron (Tanzania) and Magadi (Kenya) basins

    NASA Astrophysics Data System (ADS)

    Muirhead, J.; Kattenhorn, S. A.; Dindi, E.; Gama, R.

    2013-12-01

    In the early stages of continental rifting, East African Rift (EAR) basins are conventionally depicted as asymmetric basins bounded on one side by a ~100 km-long border fault. As rifting progresses, strain concentrates into the rift center, producing intra-rift faults. The timing and nature of the transition from border fault to intra-rift-dominated strain accommodation is unclear. Our study focuses on this transitional phase of continental rifting by exploring the spatial and temporal evolution of faulting in the Natron (border fault initiation at ~3 Ma) and Magadi (~7 Ma) basins of northern Tanzania and southern Kenya, respectively. We compare the morphologies and activity histories of faults in each basin using field observations and remote sensing in order to address the relative contributions of border faults and intra-rift faults to crustal strain accommodation as rifting progresses. The ~500 m-high border fault along the western margin of the Natron basin is steep compared to many border faults in the eastern branch of the EAR, indicating limited scarp degradation by mass wasting. Locally, the escarpment shows open fissures and young scarps 10s of meters high and a few kilometers long, implying ongoing border fault activity in this young rift. However, intra-rift faults within ~1 Ma lavas are greatly eroded and fresh scarps are typically absent, implying long recurrence intervals between slip events. Rift-normal topographic profiles across the Natron basin show the lowest elevations in the lake-filled basin adjacent to the border fault, where a number of hydrothermal springs along the border fault system expel water into the lake. In contrast to Natron, a ~1600 m high, densely vegetated, border fault escarpment along the western edge of the Magadi basin is highly degraded; we were unable to identify evidence of recent rupturing. Rift-normal elevation profiles indicate the focus of strain has migrated away from the border fault into the rift center, where

  13. Origin of the superflock of cichlid fishes from Lake Victoria, East Africa.

    PubMed

    Verheyen, Erik; Salzburger, Walter; Snoeks, Jos; Meyer, Axel

    2003-04-11

    Lake Victoria harbors a unique species-rich flock of more than 500 endemic haplochromine cichlid fishes. The origin, age, and mechanism of diversification of this extraordinary radiation are still debated. Geological evidence suggests that the lake dried out completely about 14,700 years ago. On the basis of phylogenetic analyses of almost 300 DNA sequences of the mitochondrial control region of East African cichlids, we find that the Lake Victoria cichlid flock is derived from the geologically older Lake Kivu. We suggest that the two seeding lineages may have already been lake-adapted when they colonized Lake Victoria. A haplotype analysis further shows that the most recent desiccation of Lake Victoria did not lead to a complete extinction of its endemic cichlid fauna and that the major lineage diversification took place about 100,000 years ago. PMID:12649486

  14. Focal mechanisms and the stress regime in NE and SW Tanzania, East Africa

    NASA Astrophysics Data System (ADS)

    Brazier, Richard A.; Nyblade, Andrew A.; Florentin, Juliette

    2005-07-01

    We report 12 new focal mechanisms from earthquakes in NE and SW Tanzania where the stress regime within the East African rift system is not well constrained. Focal mechanisms for events at the intersection of the Lake Tanganyika and Rukwa rifts in SW Tanzania indicate a complicated stress pattern with possible dextral strike-slip motion on some faults but oblique motion on others (either sinistral on NW striking faults or dextral on NE striking faults). Within the Rukwa rift, focal mechanisms indicate normal dip-slip motion with NE-SW opening. In NE Tanzania where the Eastern rift impinges on the margin of the Tanzania Craton, fault motions are consistent with a zone of distributed block faults and sub E-W extension. All twelve earthquakes likely nucleated within the crust.

  15. MicroResearch--Finding sustainable solutions to local health challenges in East Africa.

    PubMed

    Kollmann, Tobias R; Bortolussi, Robert; MacDonald, Noni E

    2015-06-01

    The urgent need in Africa for research capacity building has been recognized by African leaders and governments for many years. However, lack of large research funding opportunities has been seen as a major obstacle to improving research capacity in precisely those countries that need it the most. Microfinance has shown that a small infusion of capital can "prime the pump" to creative local economic productivity. In a similar way, MicroResearch has proven effective in promoting a similar bottom-up strategy to find sustainable solutions to local health challenges through local community focused research. Specifically, MicroResearch through hands-on didactic courses, mentoring and small-scale research funding promotes small research projects that improve research skills across the entire health-care provider spectrum to unleash a culture of inquiry. This in turn stimulates health care providers to identify the locally most relevant obstacles that need to be overcome and implement locally feasible and sustainable solutions. MicroResearch is a bottom-up strategy proven effective at finding sustainable solutions to local health challenges. PMID:25934328

  16. Rainfall intensity and groundwater recharge: evidence from ground-based observations in East Africa (Invited)

    NASA Astrophysics Data System (ADS)

    Taylor, R. G.; Owor, M.; Kaponda, A.

    2013-12-01

    Global greenhouse-gas emissions serve to warm Africa more rapidly than the rest of the world. The intensification of precipitation that is associated with this warming, strongly influences terrestrial water budgets. This shift toward fewer but heavier rainfall events is expected to lead to more frequent and intense floods as well as more variable and lower soil moisture. However, its impact on groundwater recharge is unclear and in dispute. We review evidence from long (1 to 5 decades) time series of groundwater levels recorded in deeply weathered crystalline rock aquifers systems underlying land surfaces of low relief in Uganda and Tanzania. Borehole hydrographs consistently demonstrate a non-linear relationship between rainfall and recharge wherein heavy rainfalls exceeding a threshold contribute disproportionately to the recharge flux. Rapid responses observed in groundwater levels to rainfall events attest further to the importance of preferential pathways in enabling rain-fed recharge via soil macro-pores. Our results suggest that, in these environments, increased use of groundwater to offset periods of low surface flow and to supplement soil moisture through irrigation may prove a logical strategy to enhance regional water and food security.

  17. Characterizing the Effects of Irrigation in the Middle East and North Africa Using Remotely Sensed Vegetation and Water Cycle Observations

    NASA Technical Reports Server (NTRS)

    Bolten, John; Ozdogan, Mutlu; Beaudoing, Hiroko; Rodell, Matthew

    2012-01-01

    A majority of the countries in the Middle East and North Africa (MENA) region suffer from water scarcity due in part to widespread rainfall deficits, unprecedented levels of water demand, and the inefficient use of renewable freshwater resources. Since a majority of the water withdrawal in the MENA is used for irrigation, there is a desperate need for improved understanding of irrigation practices and agricultural water use in the region. Here, satellite-derived irrigation maps and crop-type agricultural data are applied to the Land Data Assimilation System for the MENA region (MENA LDAS), designed to provide regional, gridded fields of hydrological states and fluxes relevant for water resources assessments. Within MENA-LDAS, the Catchment Land Surface Model (CLSM) simulates the location, timing, and amount of water applied through agricultural irrigation practices over the region from 2002-2012. In addition to simulating the irrigation impact on evapotranspiration, soil moisture, and runoff, we also investigate regional changes in terrestrial water storage (TWS) observed from the Gravity Recovery and Climate Experiment (GRACE) and simulated by CLSM.

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

    NASA Astrophysics Data System (ADS)

    Zaalouk, Malak

    2014-06-01

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

  19. Tidal loading along a profile Europe-East Africa-South Asia-Australia and the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Melchior, P.; Moens, M.; Ducarme, B.; van Ruymbeke, M.

    1981-04-01

    Precision measurements of earth tides along a profile stretching from Europe to Polynesia through East Africa, Asia and Australia are used to characterize ocean tides in different basins and thus provide a check on proposed cotidal maps. Ocean tide information was extracted from tidal gravity profiles made with correctly intercalibrated gravimeters at 91 tidal gravity stations by the subtraction of electric earth tide model vectors from the observed tidal vector. Analysis of possible instrumental errors due to calibration, thermal, barometric and power supply interruption effects indicates the data observed at a level of 0.5 microgal cannot be ascribed to computational or instrumental errors. Calculations of the ocean load and attraction signal obtained from the earth tide measurements are observed to be in very good agreement with those obtained from the cotidal maps of Schwiderski (1979, 1980) for satellite altimetry reductions for the diurnal components of the tides, however, less satisfactory agreement is observed in some large areas for the semi-diurnal components. The maps of Hendershott (1973) and Parke (1979) are also found to provide good results in several large areas, but not everywhere. Regions where a more detailed investigation is required are indicated, including Iran-Pakistan, Malaysia, the South China Sea and the South Pacific.

  20. An isotopic study of a fluvial-lacustrine sequence: The Plio-Pleistocene koobi fora sequence, East Africa

    USGS Publications Warehouse

    Cerling, T.E.; Bowman, J.R.; O'Neil, J.R.

    1988-01-01

    Stable isotopic analyses of Plio-Pleistocene and modern sediments in the fluvial-lacustrine system occupying the Turkana Basin, East Africa provide constraints on the paleoenvironmental and diagenetic histories of the Pliocene through the Recent sediments in the basin. The ??13C values for carbonates in lacustrine sediments range from -15 to +22??? relative to PDB, depending on the varying proportions of CO2 from the atmospheric reservoir and from various metabolic sources. The ??18O values of carbonates in lacustrine sediments indicate that the isotopic composition of paleolake water varied by over 10??? from the Pliocene to the present. The ??13C values for pedogenic carbonates record paleoccologic variations and suggest that C4 plants did not become well established in the preserved depositional parts of the basin until about 1.8 myr ago. The ??18O values pedogenic carbonates suggest a range of over 10??? for the isotopic composition of soil water during this interval. They also suggest a period of major climatic instability from about 3.4 to 3.1 myr and at about 1.8 myr. Together, the ??13C and ??18O values of pedogenic carbonates indicate that the present conditions are as arid and hot as any that had prevailed during deposition of these Plio-Pleistocene sediments. ?? 1988.

  1. Comorbidities associated with COPD in the Middle East and North Africa region: association with severity and exacerbations

    PubMed Central

    Mahboub, Bassam; Alzaabi, Ashraf; Iqbal, Mohammed Nizam; Salhi, Hocine; Lahlou, Aïcha; Tariq, Luqman; El Hasnaoui, Abdelkader

    2016-01-01

    Objective To assess the frequency of comorbidities in subjects with COPD and their association with respiratory symptom severity and COPD exacerbations. Materials and methods This was an analysis of the BREATHE study, a cross-sectional survey of COPD conducted in the general population of eleven countries in the Middle East and North Africa, including Pakistan. The study population consisted of a sample of subjects with COPD for whom the presence of comorbidities was documented. Three questionnaires were used. The screening questionnaire identified subjects who fulfilled an epidemiological case definition of COPD and documented any potential comorbidities; the detailed COPD questionnaire collected data on respiratory symptoms, COPD exacerbations, and comorbidities associated with COPD; the COPD Assessment Test collected data on the impact of respiratory symptoms on well-being and daily life. Results A total of 2,187 subjects were positively screened for COPD, of whom 1,392 completed the detailed COPD questionnaire. COPD subjects were more likely to report comorbidities (55.2%) than subjects without COPD (39.1%, P<0.0001), most frequently cardiovascular diseases. In subjects who screened positively for COPD, the presence of comorbidities was significantly (P=0.03) associated with a COPD Assessment Test score ≥10 and with antecedents of COPD exacerbations in the previous 6 months (P=0.03). Conclusion Comorbidities are frequent in COPD and associated with more severe respiratory symptoms. This highlights the importance of identification and appropriate management of comorbidities in all subjects with a diagnosis of COPD. PMID:26917957

  2. Evaluation of a regional mineral dust model over Northern Africa, Southern Europe and Middle East with AERONET data

    NASA Astrophysics Data System (ADS)

    Basart, S.; Pérez, C.; Cuevas, E.; Baldasano, J. M.

    2009-04-01

    A variety of regional and global models of the dust aerosol cycle have been developed since early 1990s. Dust models are essential to complement dust-related observations, understand the dust processes and predict the impact of dust on surface level PM concentrations. Dust generation and the parameterization of its deposition processes shows a high variability on spatial and temporal scales. It responds, in a non-linear way, to a variety of environmental factors, such as soil moisture content, the type of surface cover or surface atmospheric turbulence. Thus the modelling of this very complex process is a challenge. DREAM (Dust Regional Atmospheric Model; Nickovic et al., 2001) provides operational dust forecasts for Northern Africa, Europe and Middle East, as well as for the East-Asia regions. DREAM is operated and further developed in the Barcelona Supercomputing Center. DREAM is fully inserted as one of the governing equations in the NCEP/Eta atmospheric model and simulates all major processes of the atmospheric dust cycle. In order to implement new model versions for operational applications there is a need for extensive checking and validation against real observations. The present study focuses on the evaluation of forecasting capacity of the new version of DREAM by means of a model-to-observation comparison of the Aerosol Optical Depth (AOD) over Northern Africa, Southern Europe and Middle East for one year. The model provides 72h forecasts initialized at 12UTC of each day with outputs every 1 hour at horizontal resolution of about 1/3° and 24 z-vertical layers in the troposphere. Comparisons against 47 selected AERONET sites are used. Eight size bins between 0.1 and 10 µm are considered, and dust-radiation interactions are included (Pérez et al., 2006). Wet deposition scheme has been also improved. The simulation has been performed over one year (2004); statistics and time series for the model outputs and AERONET data are used to evaluate the ability of

  3. Environmental Magnetism as an Instrument for Characterizing Paleoclimatic Variations in the Sediment Record of Lake Tanganyika, East Africa.

    NASA Astrophysics Data System (ADS)

    Wetter, L.; Verosub, K.; Acton, G.; Russell, J.

    2004-12-01

    Due to their age and their continuous record of sedimentation, the lacustrine sediments of Lake Tanganyika, East Africa, provide an excellent resource for paleoclimatic research. During an eight-day cruise in July of 2004, participants in the Nyanza Project collected four Kullenburg piston cores in the vicinity of the Kalya horst, a mid-lake topographic high located south of the Mahale Mountains. Thirty meters of core were recovered. Initial lithologic analysis of the cores revealed that they consist of massive silty clay beds alternating with laminated diatomaceous oozes. U-channel samples were collected from the cores in order to obtain a continuous record of paleomagnetic directions recorded by the sediments as well as an environmental record of changes in the composition and concentration of magnetic minerals. In conjunction with other techniques, the directional record will help to provide a chronology for the cores, which are thought to extend well into Marine Isotope Stage 3. This chronology will be used to place the evolution of the lake system and its sedimentary processes within the context of global climate variability. The environmental magnetic record will provide information about both large-scale and small-scale climatic variations. The paleomagnetic and environmental magnetic information obtained from these cores will make it possible to draw definitive conclusions about past climate variations, current atmospheric composition, and the present-day quality of the lake.

  4. Population history of the Red Sea--genetic exchanges between the Arabian Peninsula and East Africa signaled in the mitochondrial DNA HV1 haplogroup.

    PubMed

    Musilová, Eliška; Fernandes, Verónica; Silva, Nuno M; Soares, Pedro; Alshamali, Farida; Harich, Nourdin; Cherni, Lotfi; Gaaied, Amel Ben Ammar El; Al-Meeri, Ali; Pereira, Luísa; Cerný, Viktor

    2011-08-01

    Archaeological studies have revealed cultural connections between the two sides of the Red Sea dating to prehistory. The issue has still not been properly addressed, however, by archaeogenetics. We focus our attention here on the mitochondrial haplogroup HV1 that is present in both the Arabian Peninsula and East Africa. The internal variation of 38 complete mitochondrial DNA sequences (20 of them presented here for the first time) affiliated into this haplogroup testify to its emergence during the late glacial maximum, most probably in the Near East, with subsequent dispersion via population expansions when climatic conditions improved. Detailed phylogeography of HV1 sequences shows that more recent demographic upheavals likely contributed to their spread from West Arabia to East Africa, a finding concordant with archaeological records suggesting intensive maritime trade in the Red Sea from the sixth millennium BC onwards. Closer genetic exchanges are apparent between the Horn of Africa and Yemen, while Egyptian HV1 haplotypes seem to be more similar to the Near Eastern ones. PMID:21660931

  5. Social context, sexual risk perceptions and stigma: HIV vulnerability among male sex workers in Mombasa, Kenya.

    PubMed

    Okal, Jerry; Luchters, Stanley; Geibel, Scott; Chersich, Matthew F; Lango, Daniel; Temmerman, Marleen

    2009-11-01

    Knowledge about sexual practices and life experiences of men having sex with men in Kenya, and indeed in East Africa, is limited. Although the impact of male same-sex HIV transmission in Africa is increasingly acknowledged, HIV prevention initiatives remain focused largely on heterosexual and mother-to-child transmission. Using data from ten in-depth interviews and three focus group discussions (36 men), this analysis explores social and behavioural determinants of sexual risks among men who sell sex to men in Mombasa, Kenya. Analysis showed a range and variation of men by age and social class. First male same-sex experiences occurred for diverse reasons, including love and pleasure, as part of sexual exploration, economic exchange and coercion. Condom use is erratic and subject to common constraints, including notions of sexual interference and motivations of clients. Low knowledge compounds sexual risk taking, with a widespread belief that the risk of HIV transmission through anal sex is lower than vaginal sex. Traditional family values, stereotypes of abnormality, gender norms and cultural and religious influences underlie intense stigma and discrimination. This information is guiding development of peer education programmes and sensitisation of health providers, addressing unmet HIV prevention needs. Such changes are required throughout Eastern Africa. PMID:19484638

  6. Deltas of the Lake Malawi rift, east Africa: Seismic expression and exploration implications

    SciTech Connect

    Scholz, C.A.

    1995-11-01

    High-resolution, air-gun-sourced seismic reflection surveys over the offshore regions of five river deltas in Lake Malawi in the East African rift system reveal considerable variability in acoustic facies and stratigraphic architecture. This variability can largely be attributed to the influences of different structural settings, and to a lesser degree to high-amplitude (100-400 m) and high-frequency (1000 to 100,000 yr) fluctuations in lake level. Deltas on flexural and axial margins in the rift lake show well-developed progradational geometries. In contrast, a delta on a steep, accommodation zone margin distributes coarse sediments over a broad depositional apron, rather than concentrating sediment in discrete progradational lobes as on the other deltas. A large border fault margin river delta displays the most complex tectonic and stratigraphic architecture of all the deltas studied. It contains several delta-associated facies, including prograding clinoform packages, fan deltas stacked against a boundary fault, and extensive subaqueous fans. Flexural margin lowstand deltas may be the most prospective for hydrocarbon exploration due to their large, internally well-organized, progradational lobes and their close proximity to deep-water, high total organic carbon lacustrine source facies.

  7. Visualizing East Africa Drought and Vegetation Response in GIS using NASA Satellite Data

    NASA Astrophysics Data System (ADS)

    Yang, W.; Zhao, P.; Chen, A.; Pham, L.; Kempler, S.

    2012-12-01

    NASA's Tropical Rainfall Measuring Mission (TRMM) provides extensive and timely estimation of precipitation at high spatial and temporal resolutions. The TRMM data products, ranging from near real-time to monthly average, are valuable in mapping and monitoring of drought events. Geographic information systems (GIS) has been widely used in drought related modeling and applications However, the TRMM data products have been under utilized by the GIS community, partly because most TRMM data are archived and distributed in generic binary and native Hierarchical Data Format (HDF), which are not directly addable to widely used GIS software packages. In this presentation, we'll show how the TRMM precipitation data can actually be readily imported into a GIS and be integrated with other types of spatial data, such as watershed and administrative boundaries, to map, visualize, and analyze drought events. We'll present, in a GIS environment, how the 2010-2011 East African drought, which caused significant decrease in crop production and left more than 10 million people in need for food assistance, is clearly captured by TRMM measurements; how the region's vegetation growing conditions, as depicted by NASA's normalized difference vegetation index data product which is archived in HDF-EOS format, respond to the drought; and how the drought and the vegetation response can be visualized and assessed at different watersheds in GIS.

  8. Preliminary definition of geophysical regions for the Middle East and North Africa

    SciTech Connect

    Sweeney, J J; Walter, B

    1998-12-01

    The ability to calibrate seismic stations to improve the monitoring of the Comprehensive Test Ban Treaty is partially limited by the availability of seismic events with known locations and source properties. To confidently extrapolate from these events to aseismic regions, and to properly account for discontinuities in seismic properties requires accurate geophysical models. This paper lays out a preliminary, first-order, regionalization of the Middle East and North African (MENA) region. The model specifies boundaries and velocity structures based on the geology and tectonics of the region, previously published studies, and empirical data observations by the LLNL group. This model is a starting point and is expected to be improved and refined by comparisons with ongoing tomography efforts and the collection of new data. We anticipate that this model and its successors will prove useful as a background model in the process of forming station calibration maps based on intelligent interpolation techniques such as kriging. We also hope the model, as it improves and demonstrates some predictive power, will provide a reference model for broader CTBT research efforts in detection, location and discrimination as well as other aspects of earth science.

  9. Late Quaternary hydrology in North Africa and the Near East (Hans Oeschger Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Gasse, Françoise

    2010-05-01

    The present-day arid-semiarid belt from North Africa to West Asia has experienced huge hydrological changes together with a long history of human civilisations. This belt straddles the boundary between a temperate domain (winter rains linked to the mid-latitude Westerlies), and a subtropical one (rare monsoonal summer precipitation). What are the timing and direction of major hydrological changes in these two domains ? How does the transitional zone migrate through time, and why ? How did human societies respond to changes in water availability ? These questions are addressed using records illustrating both long and short-term environmental changes. At the glacial-interglacial time scale, hydrological changes broadly follow the orbitally-induced Northern Hemisphere summer insolation, but with different regional expressions. In the winter rain domain, the best-dated records come from southern Levant : stable isotope records from speleothems in Israel (120-230 ka) show a remarkable consistency with those from the Eastern Mediterranean Sea(1,2), but the prominant role of rainfall amount or of moisture source isotopic composition on inland records is still debated (1-4); lake-level reconstructions in the Lisan-Dead Sea basin during the past 70 ka demonstrate higher winter rains during the last glacial period than during the Holocene (4,5). However, a new multi-proxy lacustrine record (230 ka) from northern Levant (Yammoûneh, Lebanon) shows relatively wet environments during interglacial periods(6,7), suggesting temporal changes in the NS climatic gradients over the Levantine region. Extratropical rainfalls apparently remained predominant over northern Sahara, with a major period of aquifer recharge during the Late Pleistocene(8). Conversely, south of about 25-22° N, the subtropical deserts experienced pluvial periods during interglacials, including the remarkable early-Mid Holocene wetting of the Saharan heart(8). Older pluvial periods, precisely dated in speleothems

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

    PubMed Central

    2010-01-01

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

  11. The sup 36 Cl ages of the brines in the Magadi-Natron basin, east Africa

    SciTech Connect

    Kaufman, A.; Margaritz, M.A.; Hollos, G. ); Paul, M.; Boaretto, E. ); Hillaire-Marcel, C. ); Taieb, M. )

    1990-10-01

    The depression in the East African Rift which includes both Lake Magadi and Lake Natron forms a closed basin within which almost all the dissolved chloride originates in precipitation, since there is no important source of very ancient sedimentary chloride. This provides an ideal setting for the evaluation of the {sup 36}Cl methodology as a geochemical and hydrological tracer. The main source of recent water, as represented by the most dilute samples measured, is characterized by a {sup 36}Cl/Cl ratio of 2.5 {times} 10{sup {minus}14}, in agreement with the calculated value expected in precipitation. Surface evaporation increases the chlorinity of the local freshwater inflow by about a factor of 110 without changing the isotopic ratio, indicating that little chloride enters the system in the form of sediment leachate. A second type of brine found in the basin occurs in a hot deep groundwater reservoir and is characterized by lower {sup 36}Cl/Cl ratios (<1.2 {times} 10{sup {minus}14}). By comparing this value with the 2.5 {times} 10{sup {minus}14} in recent recharge, one obtains an approximate salt accumulation age of 760 Ka which is consistent with thee time of the first appearance of the lake. These older brines also have lower {sup 18}O and {sup 2}H values which indicate that they were recharged during a climatically different era. The {sup 36}Cl/Cl ratios in the inflowing waters and in the accumulated brine, together with the known age of the Lake Magadi basin, may be used to estimate the importance of the hypogene and epigene, as opposed to the meteoric, mode of {sup 36}Cl production. Such a calculation shows that the hypogene and epigene processes together contribute less than 6% of the total {sup 36}Cl present in the lake.

  12. Rejection of an innovation: health information management training materials in east Africa.

    PubMed

    Gladwin, J; Dixon, R A; Wilson, T D

    2002-12-01

    A shift towards decentralization in many low-income countries has meant more skills are demanded of primary health care managers, including data and information handling at all levels of the health care system. Ministries of Health are changing their central reporting health information systems to health management information systems with emphasis on managers utilizing information at the point of collection. This paper reports on a research study to investigate the introduction of new information management strategies intended to promote an informational approach to management at the operational health service level in low-income countries. It aims to understand the process taking place when externally developed training materials (PHC MAP), which are intended to strengthen health management information systems, are introduced to potential users in an east African country. A case study has been undertaken and this research has demonstrated that the dynamic equilibrium approach to organizational change is applicable to the introduction of new information management strategies and management approaches in low-income countries. Although PHC MAP developers envisaged a technical innovation needing implementation, potential users saw the situation as one of organizational change. Contributions to theory have been made and many implications for introducing new information systems or the informational approach to management are identified. This theoretical framework could also facilitate the introduction of future information management innovations and would allow practitioners to perceive the introduction of information management innovations as one of organizational change that needs to be managed. Consequently, issues that may facilitate or inhibit adoption could be identified in advance. PMID:12424207

  13. Spatial-explicit modeling of social vulnerability to malaria in East Africa

    PubMed Central

    2014-01-01

    Background Despite efforts in eradication and control, malaria remains a global challenge, particularly affecting vulnerable groups. Despite the recession in malaria cases, previously malaria free areas are increasingly confronted with epidemics as a result of changing environmental and socioeconomic conditions. Next to modeling transmission intensities and probabilities, integrated spatial methods targeting the complex interplay of factors that contribute to social vulnerability are required to effectively reduce malaria burden. We propose an integrative method for mapping relative levels of social vulnerability in a spatially explicit manner to support the identification of intervention measures. Methods Based on a literature review, a holistic risk and vulnerability framework has been developed to guide the assessment of social vulnerability to water-related vector-borne diseases (VBDs) in the context of changing environmental and societal conditions. Building on the framework, this paper applies spatially explicit modeling for delineating homogeneous regions of social vulnerability to malaria in eastern Africa, while taking into account expert knowledge for weighting the single vulnerability indicators. To assess the influence of the selected indicators on the final index a local sensitivity analysis is carried out. Results Results indicate that high levels of malaria vulnerability are concentrated in the highlands, where immunity within the population is currently low. Additionally, regions with a lack of access to education and health services aggravate vulnerability. Lower values can be found in regions with relatively low poverty, low population pressure, low conflict density and reduced contributions from the biological susceptibility domain. Overall, the factors characterizing vulnerability vary spatially in the region. The vulnerability index reveals a high level of robustness in regard to the final choice of input datasets, with the exception of the

  14. Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr

    USGS Publications Warehouse

    Scholz, C.A.; King, J.W.; Ellis, G.S.; Swart, Peter K.; Stager, J.C.; Colman, Steven M.

    2003-01-01

    New sediment core data from a unique slow-sedimentation rate site in Lake Tanganyika contain a much longer and continuous record of limnological response to climate change than have been previously observed in equatorial regions of central Africa. The new core site was first located through an extensive seismic reflection survey over the Kavala Island Ridge (KIR), a sedimented basement high that separates the Kigoma and Kalemie Basins in Lake Tanganyika. Proxy analyses of paleoclimate response carried out on core T97-52V include paleomagnetic and index properties, TOC and isotopic analyses of organic carbon, and diatom and biogenic silica analyses. A robust age model based on 11 radiocarbon (AMS) dates indicates a linear, continuous sedimentation rate nearly an order of magnitude slower here compared to other core sites around the lake. This age model indicates continuous sedimentation over the past 79 k yr, and a basal age in excess of 100 k yr. The results of the proxy analyses for the past ??? 20 k yr are comparable to previous studies focused on that interval in Lake Tanganyika, and show that the lake was about 350 m lower than present at the Last Glacial Maximum (LGM). Repetitive peaks in TOC and corresponding drops in ??13C over the past 79 k yr indicate periods of high productivity and mixing above the T97-52V core site, probably due to cooler and perhaps windier conditions. From ??? 80 through ??? 58 k yr the ??13C values are relatively negative (-26 to -28???) suggesting predominance of algal contributions to bottom sediments at this site during this time. Following this interval there is a shift to higher values of ??13C, indicating a possible shift to C-4 pathway-dominated grassland-type vegetation in the catchment, and indicating cooler, dryer conditions from ??? 55 k yr through the LGM. Two seismic sequence boundaries are observed at shallow stratigraphic levels in the seismic reflection data, and the upper boundary correlates to a major discontinuity

  15. Rural Development in Africa: A Bibliography. (Part I: General, Central, East). Training & Methods Series Number 16 (Supplement), March 1973.

    ERIC Educational Resources Information Center

    Anderson, Teresa, Comp.; Strey, Gerry, Comp.

    A supplement to the bibliography of materials dealing with Africa in the Land Tenure Center Library at the University of Wisconsin, this bibliography on rural development in Africa is divided into three major sections as follows: (1) General (400 entries); (2) Central Africa including a general section (2 entries); Cameroon (26 entries); Central…

  16. The Albertine Rift, East Africa: Initial rifting, long-term landscape evolution and final surface uplift

    NASA Astrophysics Data System (ADS)

    Bauer, Friederike U.; Glasmacher, Ulrich A.; Ring, Uwe; Grobe, René W.; Starz, Matthias; Mambo, Vikandy S.

    2013-04-01

    The Albertine Rift and associated Rwenzori Mountains form a striking feature at the north-western portion of the East African Rift System. The Rwenzori Mtns are built up by a dissected Precambrian metamorphic basement block that has been uplifted to heights of more than 5 km. The fundamental subject addressed by this study is the temporal and spatial evolution of the Rwenzori Mtns and adjacent Albertine Rift (western Uganda and Eastern Congo) at different time scales. In order to unlock how and at what time the extreme surface uplift occurred, low-temperature thermochronology methods were applied and combined with thermokinematic modelling. By means of apatite fission-track, apatite and zircon (U-Th-Sm)/He dating, combined with 2D (HeFTy) and 3D (Pecube) thermokinematic modelling different phases of landscape evolution could be determined for the Albertine area, where movements of surface uplift can be traced from Palaeozoic to Neogene times. Since the Palaeozoic several cooling events affected the Albertine area and Rwenzori Mtns, as revealed from samples along the rift shoulders and across the mountain range. Results from low-temperature thermochronology and thermokinematic modelling demonstrate that the Rwenzoris were not exhumed as a coherent block but are composed of distinct decoupled blocks with diverging exhumation histories and block movements along inherited faults. Thus, the evolution of the Rwenzoris was not solely triggered by Neogene rifting; moreover, a Mesozoic topographic Albertine high is conceivable. Since the Miocene renewed rock and surface uplift of distinct blocks with forced movements at the western flank of the Rwenzoris occurred. Rock uplift, thereby, outweighed erosion, resulting in the recent high topography of the Rwenzoris and their asymmetric character. Detrital thermochronology data confirm a Neogene surface uplift and indicate transition of erosional forces in Plio-/Pleistocene times. Thermokinematic modelling, applied to samples

  17. The seismic-stratigraphic record of lake-level fluctuations in Lake Challa: Hydrological stability and change in equatorial East Africa over the last 140 kyr

    NASA Astrophysics Data System (ADS)

    Moernaut, J.; Verschuren, D.; Charlet, F.; Kristen, I.; Fagot, M.; De Batist, M.

    2010-02-01

    Seismic-reflection data from crater lake Challa (Mt. Kilimanjaro, equatorial East Africa) reveal a ˜ 210-m thick sedimentary infill containing distinct seismic-stratigraphic signatures of late-Quaternary lake-level fluctuations. Extrapolation of a well-constrained age model on the cored upper part of the sequence suggests that these lake-level fluctuations represent a detailed and continuous record of moisture-balance variation in equatorial East Africa over the last 140 kyr. This record indicates that the most severe aridity occurred during peak Penultimate glaciation immediately before ˜ 128 kyr BP (coeval with Heinrich event 11) and during a Last Interglacial 'megadrought' period between ˜ 114 and ˜ 97 kyr BP; in comparison, Last Glacial Maximum (LGM) aridity was modest. It was preceded by ˜ 75 000 years of relatively stable and moist climate conditions interrupted by eleven short-lived dry spells, five of which match the timing of Heinrich events 2 to 6. Climate history near the East African equator reflects variation in the precessional forcing of monsoon rainfall modulated by orbital eccentricity, but precession-driven moisture fluctuations were less extreme than those observed in northern and southern tropical Africa. The near-continuous moist climate from ˜ 97 to 20.5 kyr BP recorded in the Lake Challa record contrasts with the trend towards greater aridity after ˜ 70 kyr BP documented in equatorial West Africa. This long period of moist glacial climate and a short, relatively modest LGM drought can be attributed to greater independence of western Indian Ocean monsoon dynamics from northern high-latitude glaciation than those in the tropical Atlantic Ocean. This rather persistent moist glacial climate regime may have helped maintain high biodiversity in the tropical forest ecosystems of the Eastern Arc mountains in Tanzania.

  18. Upper Mantle Structure of the Eastern Africa from Body Wave Tomography

    NASA Astrophysics Data System (ADS)

    Mulibo, G. D.; Nyblade, A.; Ferdinand, R. W.; Reusch, A. M.; Adams, A. N.; Tugume, F. A.

    2009-12-01

    This study presents preliminary results of the upper mantle structure beneath the east Africa from body wave tomography. This work is part of an on-going study aimed at investigating the origin and structure of the African Superplume. The available global tomographic studies suggest that the African Superplume is a low velocity-anomaly extending from the core-mantle boundary upward into the mid mantle beneath southern Africa and may reach the upper mantle beneath eastern Africa. However, the limited vertical resolution of global tomographic models makes it difficult to confirm a connection from the lower to the upper mantle. Previous regional studies of upper mantle structure in east Africa have found evidence of a low velocity anomaly beneath the region that has been suggested as the upper mantle expression of the Superplume. Models from previous tomographic studies in east Africa have limited resolution below ~400 km beneath the eastern rift and are less well resolved beneath the western part of the rift due to less data coverage. This study uses teleseismic data from a wider region in east Africa than previously used. Data for this study are from a 3-year (2007-2010) deployment of 40 broadband seismic stations in Uganda and Tanzania. The dataset is supplemented by data from the 1994-1995 Tanzania broadband seismic experiment, the 2001-2002 Kenya broadband seismic experiment, the permanent AfricaArray seismic stations and IRIS/GSN stations. The data have been used for body wave tomography by computing relative travel time delays using a multi-channel cross-correlation technique and then inverting them for a 3D wave speed model. Preliminary results from the inversion of the relative delay times show that there is a low wave speed anomaly beneath east Africa extending from shallow upper mantle depths to at least 500 km.

  19. Color reflectance spectroscopy of profundal lake sediments: a novel moisture-balance proxy for tropical East Africa

    NASA Astrophysics Data System (ADS)

    Meyer, Inka; Van Daele, Maarten; Fiers, Geraldine; Verleyen, Eli; De Batist, Marc; Verschuren, Dirk

    2016-04-01

    Investigations of the continuous sediment record from Lake Challa, a deep freshwater crater lake on the eastern slope of Mt. Kilimanjaro, are expanding our knowledge about past climate and environmental changes in equatorial East Africa. During a field campaign in 2005 a 20.65-m long composite sediment sequence was retrieved from the center of the lake, covering the past 25,000 years. Unlike many other East African lakes, Lake Challa never dried out during this period and therefore provides one of the few continuous and high-resolution regional climate-proxy records since before the LGM. Continuously taken digital line-scan images (GeoTek MSCL core logger) revealed systematic colour variation from greenish to yellow-brownish sediments throughout the core sequence. To characterize the origin of these colour variations, high-resolution colour reflectance spectrometry was carried out. The relative absorption band depth (RABD) at different wavelengths was calculated to distinguish between sediment components with distinct absorption/ reflection characteristics. RABD660/670 can be used as a proxy for chlorophyll and its derivates, and RABD610 as a proxy for carotenoids and their derivates. Comparison of RABD660/670 with independent reconstructions of rainfall (the Branched and Isoprenoid Tetraether (BIT) index of bacterial lipids) and seismic lake level reconstructions showed a positive correlation between these proxies. During times of wetter climate and higher lake level, e.g. the early Holocene, the RABD660/670 value is higher than during times of inferred dry conditions and low lake level, e.g. the early late-Glacial period (during which no chlorophyll or its derivates were detected). We attribute this positive correlation to reduced preservation of chlorophyll contained in the settling remains of dead phytoplankton during lowstands, when bottom waters may have been better oxygenated. This data is supported by the variation in fossil pigment concentration and

  20. Greening of the Sahara - a paleo perspective on the history of water in the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Bar-Matthews, M.

    2012-04-01

    The Middle-East, mostly at its southern edge together with North Africa, the northern edge of the Sahara Desert, are located at the boundary between high- to-mid latitude and tropical-subtropical climate systems. The geographical duality of desert adjacent to Mediterranean-type climate regions played and still plays a major role on the water availability. Thanks to the number of important paleoclimate studies that been made on accurate dating of cave speleothems in Southern Arabia and Oman (Fleitmann et al., 2011) and in the northeast Sahara, the Negev Desert Israel (Vaks et al., 2010) and the study of sapropels in Eastern and central Mediterranean (Almogi-Labin et al., 2009; Osborne et al, 2008), it is clear that the region was graced with water during peak interglacials when the African monsoon and westerly storm/rainfall systems intensified. Northward penetration of the Inter Tropical Convergence Zone over the Arabian and African continents resulted in increased discharge of the Nile River and rivers that emerged from central Sahara into the Eastern Mediterranean Sea. Correspondingly, enhanced westerly wind activity led to an increase in rainfall from Atlantic-Mediterranean sources over the entire Mediterranean basin, which even penetrated south into the north-east corner of the Sahara Desert. The Saharo-Arabian Desert became narrower and climatic "windows" opened for the dispersal of hominids and animals out of the African continent at 250-239, 210-193, 138-120, 108-98, 87-84 and 10-6.5 ka BP, with severe dry conditions in between. Greening of the Sahara Desert at these intervals is supported also by various marine and terrestrial records, such as corals, lakes, tufa deposits and archeological findings. Dry conditions prevailed in the Sahara desert during glacials. This is in contrast to the climatic conditions in the Eastern Mediterranean coastal region and the Jordan Rift Valley (Bar-Matthews et al., 2003; Lisker et al., 2010), where water was available for

  1. GROUND TRUTH, MAGNITUDE CALIBRATION AND REGIONAL PHASE PROPAGATION AND DETECTION IN THE MIDDLE EAST AND HORN OF AFRICA

    SciTech Connect

    Nyblade, A; Adams, A; Brazier, R; Park, Y; Rodgers, A

    2006-07-10

    In this project, we are exploiting unique and open source seismic data sets to improve seismic monitoring across the Middle East (including the Iranian Plateau, Zagros Mountains, Arabian Peninsula, Turkish Plateau, Gulf of Aqaba, Dead Sea Rift) and the Horn of Africa (including the northern part of the East African Rift, Afar Depression, southern Red Sea and Gulf of Aden). The data sets are being used to perform three related tasks. (1) We are determining moment tensors, moment magnitudes and source depths for regional events in the magnitude 3.0 to 6.0 range. (2) These events are being used to characterize high-frequency (0.5-16 Hz) regional phase attenuation and detection thresholds, especially from events in Iran recorded at stations across the Arabian Peninsula. (3) We are collecting location ground truth at GT5 (local) and GT20 (regional) levels for seismic events with M > 2.5, including source geometry information and source depths. In the first phase of this project, seismograms from earthquakes in the Zagros Mountains recorded at regional distances have been inverted for moment tensors, and source depths for the earthquakes have been determined via waveform matching. Early studies of the distribution of seismicity in the Zagros region found evidence for earthquakes in the upper mantle. But subsequent relocations of teleseismic earthquakes suggest that source depths are generally much shallower, lying mainly within the upper crust. Nine events with magnitudes between 5 and 6 have been studied so far. Source depths for six of the events are within the upper crust, and three are located within the lower crust. The uncertainty in the source depths of the lower crustal events allows for the possibility that some of them may have even nucleated within the upper mantle. Eight events have thrust mechanisms and one has a strike-slip mechanism. We also report estimates of three-dimensional P- and S-wave velocity structure of the upper mantle beneath the Arabian

  2. Child Labor and School Attendance in Kenya

    ERIC Educational Resources Information Center

    Moyi, Peter

    2011-01-01

    Sub-Saharan Africa has the highest incidence of child labor in the world and estimates show that it continues to grow. This paper examines the causes and magnitude of child labor in Kenya. Unlike previous studies that examined child labor as only an economic activity, this paper includes household chores. Including household chores is important…

  3. Relationship Transitions among Youth in Urban Kenya

    ERIC Educational Resources Information Center

    Clark, Shelley; Kabiru, Caroline; Mathur, Rohini

    2010-01-01

    The process of courtship and marriage in sub-Saharan Africa has changed remarkably. These changes, however, have received scant attention because recent research has focused on adolescent relationships' links to HIV/AIDS rather than to marriage. Drawing on detailed reports of 1,365 romantic and sexual partnerships from youths in Kisumu, Kenya, we…

  4. The Tendaguru formation of southeastern Tanzania, East Africa: An alternating Late Jurassic to Early Cretaceous palaeoenvironment of exceptional status

    NASA Astrophysics Data System (ADS)

    Sames, B.

    2009-04-01

    Dinosaur remains have inspired considerable scientific interest in the Tendaguru formation of southeastern Tanzania during the 20th century; however, this formation is exceptional in many other respects. The Late Jurassic to Early Cretaceous deposits of the Tendaguru formation in the southwestern Tethys are unique because they represent a marginal marine palaeoenvironment with nonmarine faunal and floral content. It is a threefold succession of marginal marine to terrestrial, carbonate-siliciclastic sediments with cyclic character, consisting of three transgressive-regressive cycles. Revisitation of the type locality (the Tendaguru, a hill approximately 60km northwest of the town of Lindi) by a German-Tanzanian expedition in summer 2000 (Heinrich et al., 2001) resulted in a new standard section (hitherto unpublished, the informal terminology is indicated by the use of lower case in Tendaguru formation), a refined environmental model (Aberhan et al., 2002) and many new insights towards its geology (with evidence of event-sedimentation, Bussert and Aberhan, 2004), biostratigraphy and a better understanding of the Tendaguru palaeo-ecosystems and the palaeoclimate. Within the scope of the designation of a new standard section at the type locality, calcareous microfossils (ostracods, charophytes) have been described to supplement the ongoing discussion about the age and palaeoecology of the Tendaguru formation (Sames, 2008). Although only a few unevenly distributed layers across the section produced calcareous microfossils, the results are very promising. A total of 40 ostracode and 2 charophyte taxa could be distinguished. The non-marine part of the ostracod fauna provides an important contribution to the documentation of Purbeck/Wealden-type nonmarine palaeoenvironments and its microfaunas and -floras previously unknown from East Africa. The marine faunal part belongs to a relatively endemic southern (Gondwana) fauna. Together with other fossil groups, the

  5. 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. PMID:8932577

  6. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa.

    PubMed

    McKinney, Melissa A; Dean, Kylie; Hussey, Nigel E; Cliff, Geremy; Wintner, Sabine P; Dudley, Sheldon F J; Zungu, M Philip; Fisk, Aaron T

    2016-01-15

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH3Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n=283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg(-1) dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg(-1) dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ(15)N), whereas measures of foraging habitat (using carbon stable isotopes, δ(13)C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. PMID:26409147

  7. Modelling the impact of agroforestry on hydrology of Mara River basin in East Africa using a distributed model

    NASA Astrophysics Data System (ADS)

    Mwangi, Hosea; Julich, Stefan; Patil, Sopan; McDonald, Morag; Feger, Karl-Heinz

    2016-04-01

    Land use change is one of the main drivers of change of watershed hydrology. The effect of forestry related land use changes (e.g., afforestation, deforestation, agroforestry) on watershed hydrology depends on climate, watershed characteristics and watershed scale. The Soil and Water Assessment Tool (SWAT) model was calibrated, validated and used to simulate the impact of agroforestry on the water balance in Mara River Basin (MRB) in East Africa. Model performance was assessed by Nash-Sutcliffe Efficiency (NSE) and Kling-Gupta Efficiency (KGE). The NSE (and KGE) values for calibration and validation were 0.77 (0.88) and 0.74 (0.85) for the Nyangores sub-watershed and 0.78 (0.89) and 0.79 (0.63) for the entire MRB. It was found that agroforestry in the catchment would generally reduce surface runoff, mainly due to enhanced infiltration. However, it would also increase evapotranspiration and consequently reduce the baseflow and the overall water yield, which was attributed to increased water use by trees. Spatial scale was found to have a significant effect on water balance; the impact of agroforestry was higher at the smaller headwater catchment (Nyangores) than for the larger watershed (entire MRB). However, the rate of change in water yield with increase in area under agroforestry was different for the two and could be attributed to the spatial variability of climate within MRB. Our results suggest that direct extrapolation of the findings from a small sub-catchment to a larger watershed may not always be accurate. These findings could guide watershed managers on the level of trade-offs to make between reduced water yields and other benefits (e.g., soil erosion control, improved soil productivity) offered by agroforestry.

  8. Neglected tropical diseases of the Middle East and North Africa: review of their prevalence, distribution, and opportunities for control.

    PubMed

    Hotez, Peter J; Savioli, Lorenzo; Fenwick, Alan

    2012-01-01

    The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination. PMID:22389729

  9. Drug policy and harm reduction in the Middle East and North Africa: The role of civil society.

    PubMed

    Aaraj, Elie; Jreij Abou Chrouch, Micheline

    2016-05-01

    Civil society organizations (CSOs) in Middle East and North Africa (MENA) are the principal partners of government in scaling up the response to HIV and in implementing national policies. In return, CSOs expect endorsement of their work by the governments. Some CSOs face weaknesses and need capacity-building in order for them to reach the level of response required for reducing drug-related harm in this region. Substance use and the transmission of HIV are increasing in the MENA region. The limited data available on drug use show that there are approximately 630,000 people who inject drugs (PWID) across the region. The HIV epidemic remains concentrated among PWID and other key populations in the region. Comprehensive harm reduction programs which include prevention, care, and HIV treatment for PWID are being implemented by CSOs. This could not happen without the presence of a conducive environment which has been facilitated by the CSOs, and which aims to lead to a positive response in health policies, and thus to harm reduction programs in some countries in the region. However, based on the international data, antiretroviral therapy (ART) coverage remains low in these countries, even if the number of people living with HIV (PLHIV) receiving ART is increasing. This increase can sometimes mask important challenges in equity: in several countries PWID are the most likely to be infected with HIV while being the least likely to be receiving care and ART. Therefore, concentrated efforts need to continue toward the goal of having mainstream harm reduction approaches in region. PMID:27140430

  10. Neglected Tropical Diseases of the Middle East and North Africa: Review of Their Prevalence, Distribution, and Opportunities for Control

    PubMed Central

    Hotez, Peter J.; Savioli, Lorenzo; Fenwick, Alan

    2012-01-01

    The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination. PMID:22389729

  11. A molecular perspective on Late Quaternary climate and vegetation change in the Lake Tanganyika basin, East Africa

    NASA Astrophysics Data System (ADS)

    Tierney, Jessica E.; Russell, James M.; Huang, Yongsong

    2010-03-01

    Characterizing the nature of past hydrological change and its interactions with vegetation is fundamental to acquiring a better understanding of continental tropical climate dynamics. Here, we outline major shifts in the climate and ecosystem of tropical East Africa for the past 60,000 years (60 ka) by examining molecular records of hydrology, vegetation, and temperature from a sediment sequence from Lake Tanganyika. We demonstrate, via comparison with pollen spectra, that stable carbon isotopes measured on higher plant leaf waxes ( δ13C wax) are a reliable proxy for vegetation change. In addition we argue that the D/H ratio of higher plant leaf waxes ( δD wax) is a robust and independent indicator of past changes in aridity, and is not affected by regional vegetation change directly. Our paired, compound-specific isotope data show that shifts in vegetation lead major changes in hydrology in the Tanganyika basin at several major climate transitions during the past 60,000 years, suggesting that vegetation in the Tanganyika basin is not as sensitive to aridity as previous studies have suggested and that variations in carbon dioxide, temperature, and internal ecosystem dynamics are equally, if not more, important. We hypothesize that regional vegetation change may exert a positive feedback on regional hydrology, thus partially accounting for the abrupt threshold behavior evident in our paleohydrological data. Furthermore, we find that past changes in Tanganyika basin climate and ecology are closely linked to concentrations of atmospheric trace gases, highlighting the paramount influence of global climatic shifts upon regional tropical climate over glacial/interglacial timescales.

  12. Abrupt Climatic Events Observed in Organic-Rich Sediments From Lake Tanganyika, Tropical East Africa, Over the Past 50 kyr

    NASA Astrophysics Data System (ADS)

    Burnett, A. P.; Weyhenmeyer, C. E.; Scholz, C. A.; Swart, P. K.

    2006-12-01

    Abrupt climate changes such as Dansgaard-Oeschger Cycles and Heinrich Events were first detected in high- latitude records, but an increasing number of studies suggest that these rapid changes are actually global events. The degree to which the tropics drive, control and/or respond to such rapid changes is still poorly understood due to a scarcity of data from low-latitude regions. A recently acquired sediment core from Lake Tanganyika, East Africa, provides a unique archive to study abrupt climate events in the tropics throughout the last glaciation. The core provides a continuous, undisturbed and high resolution climate record over the past 100 kyr. An age-depth model based on 25 new radiocarbon dates provides a solid, high-resolution chronology for the past 50 kyr. Throughout this time, several rapid changes in paleoclimate proxy data are observed along the core. Sedimentation rates remained fairly constant from the Holocene until the Last Glacial Maximum (LGM) but increased abruptly from ~80 mm/1000 yr to ~150 mm/1000 yr around 18 kyr BP. At the same time, the sediment record reveals a sudden increase in total organic carbon (TOC) from 4% to 12% indicating a rapid increase in organic matter contributions at the end of the LGM. Abrupt changes in TOC and δ13C values are also found at ~38 kyr, ~30 kyr and ~16 kyr BP, suggesting a possible link to Heinrich events 4, 3 and 1, respectively. Forthcoming very high-resolution analyses, to augment existing low-resolution data, include δ13C, δ15N, C/N ratios and TOC values. Furthermore, TEX86 measurements will be carried out to determine whether the observed changes in organic matter contributions are associated with changes in water temperatures. In combination with the solid 14C chronology, the new data will allow us to precisely determine the onset, timing and nature of abrupt changes and evaluate them in the global context.

  13. Patient-reported factors associated with reengagement among HIV-infected patients disengaged from care in East Africa

    PubMed Central

    Camlin, Carol S.; Neilands, Torsten B.; Odeny, Thomas A.; Lyamuya, Rita; Nakiwogga-Muwanga, Alice; Diero, Lameck; Bwana, Mwebesa; Braitstein, Paula; Somi, Geoffrey; Kambugu, Andrew; Bukusi, Elizabeth A.; Glidden, David V.; Wools-Kaloustian, Kara K.; Wenger, Megan; Geng, Elvin H.

    2016-01-01

    Objective Engagement in care is key to successful HIV treatment in resource-limited settings; yet little is known about the magnitude and determinants of reengagement among patients out of care. We assessed patient-reported reasons for not returning to clinic, identified latent variables underlying these reasons, and examined their influence on subsequent care reengagement. Design We used data from the East Africa International Epidemiologic Databases to Evaluate AIDS to identify a cohort of patients disengaged from care (>3 months late for last appointment, reporting no HIV care in preceding 3 months) (n = 430) who were interviewed about reasons why they stopped care. Among the 399 patients for whom follow-up data were available, 104 returned to clinic within a median observation time of 273 days (interquartile range: 165–325). Methods We conducted exploratory and confirmatory factor analyses (EFA, CFA) to identify latent variables underlying patient-reported reasons, then used these factors as predictors of time to clinic return in adjusted Cox regression models. Results EFA and CFA findings suggested a six-factor structure that lent coherence to the range of barriers and motivations underlying care disengagement, including poverty, transport costs, and interference with work responsibilities; health system ‘failures,’ including poor treatment by providers; fearing disclosure of HIV status; feeling healthy; and treatment fatigue/seeking spiritual alternatives to medicine. Factors related to poverty and poor treatment predicted higher rate of return to clinic, whereas the treatment fatigue factor was suggestive of a reduced rate of return. Conclusion Certain barriers to reengagement appear easier to overcome than factors such as treatment fatigue. Further research will be needed to identify the easiest, least expensive interventions to reengage patients lost to HIV care systems. Interpersonal interventions may continue to play an important role in addressing

  14. A survey of Simulium control in Africa

    PubMed Central

    Brown, A. W. A.

    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. PMID:14015908

  15. Cenozoic vegetation, climate changes and hominid evolution in tropical Africa

    NASA Astrophysics Data System (ADS)

    Bonnefille, Raymonde

    2010-07-01

    This paper reviews information on past vegetation of tropical Africa during the Cenozoic, focused upon the last 10 Ma, a time spanning hominid record in Central and East Africa. Summary of palaeobotanical data collected at terrestrial sites are compared with new results on the long term evolution of the continental vegetation zones documented from marine pollen record of two deep sea cores recovered from the Atlantic and Indian Oceans. Section 2 includes a summary of modern distribution of vegetation belts in the African continent and a synthesis of the results of both macrobotanical (fossil wood, leaves and fruits) and microbotanical (mainly pollen) studies presented according to time scale and geographical location. The main features emphasized by the palaeobotanical results are 1) seasonal vegetation and climate documented as soon as the Eocene in Tanzania 2) well diversified forests existing in northern West Ethiopia during the Oligocene 3) high temporal and spatial variabilities of forests composition during the Miocene when deciduous Legume woodland was documented in Ethiopia whereas wetter evergreen forests existed in Western Kenya 4) lack of evidence for an evergreen forest belt, continuous from Western Congo to East Africa. Section 3 presents new original pollen data recovered from a long core in the Gulf of Aden documenting large scale past vegetation changes in East Africa during the last 11 Ma. These results are discussed in comparison with a summarized long pollen sequence previously published from a marine core offshore the Niger delta. This comparison illustrates variations in geographical distribution of large vegetation zone at the continental scale, through time. In Section 4, vegetation changes registered during the last 10 Ma are discussed in relation with the results of isotopic studies and an updated presentation of hominids evolution in Africa. Several changes are shown in the marine records. An expansion of savanna/grassland is shown at 10

  16. Paleoclimate change in the Nakuru basin, Kenya, at 119 - 109 ka derived from δ18Odiatom and diatom assemblages and 40Ar/39Ar geochronology

    NASA Astrophysics Data System (ADS)

    Bergner, Andreas; Deino, Alan; Leng, Melanie; Gasse, Francoise

    2016-04-01

    A 4.5m-thick diatomite bed deposited during the cold interval of the penultimate interglacial at ~119 - 109 ka documents a period in which a deep freshwater lake filled the Nakuru basin in the Central Kenya Rift (CKR), East Africa. Palaeohydrological conditions of the basin are reconstructed for the paleolake highstand using δ18Odiatom and characterization of diatom assemblages. The age of the diatomite deposit is established by precise 40Ar/39Ar-dating of intercalated pumice tuffs. The paleolake experienced multiple hydrological fluctuations on sub-orbital (~1,500 to 2,000 years) time scales. The magnitude of the δ18Odiatom change (+/- 3‰) and significant changes in the plankton-littoral ratio of the diatom assemblage (+/- 25%) suggest that the paleolake record can be interpreted in the context of long-term climatic change in East Africa. Using 40Ar/39Ar age control and nominal diatomite-sedimentation rates we establish a simplified age model of paleohydrological vs. climatic change, from which we conclude that more humid conditions prevailed in equatorial East Africa during the late Pleistocene over a relatively long time interval of several thousands years. Then, extreme insolation at eccentricity maximum and weakened zonal air-pressure gradients in the tropics favored intensified ITCZ-like convection over East Africa and deep-freshwater lake conditions.

  17. Male involvement for the Prevention of Mother-to-Child HIV Transmission: A Brief Review of Initiatives in East, West and Central Africa

    PubMed Central

    Dunlap, Julie; Foderingham, Nia; Bussell, Scottie; Wester, C. William; Audet, Carolyn M; Aliyu, Muktar H

    2015-01-01

    Current trends in HIV/AIDS research in sub-Saharan Africa (SSA) highlight socially and culturally sensitive interventions that mobilize community members and resources for universal access to HIV prevention, treatment, and care services. These factors are particularly important when addressing the complex social and cultural nature of implementing services for prevention of mother-to-child transmission of HIV (PMTCT). Across the globe approximately 34% fewer children were infected with HIV through the perinatal or breastfeeding route in 2011 (est. 330,000) than in 2001 (est. 500,000), but ongoing mother-to-child HIV transmission is concentrated in sub-Saharan Africa, where fully 90% of 2011 cases are estimated to have occurred. Recent literature suggests that PMTCT in Africa is optimized when interventions engage and empower community members, including male partners, to support program implementation and confront the social, cultural and economic barriers that facilitate continued vertical transmission of HIV. In resource-limited settings the feasibility and sustainability of PMTCT programs require innovative approaches to strengthening male engagement by leveraging lessons learned from successful initiatives in SSA. This review presents an overview of studies assessing barriers and facilitators of male participation in PMTCT and new interventions designed to increase male engagement in East, West and Central Africa from 2000–2013, and examines the inclusion of men in PMTCT programs through the lens of community and facility activities that promote the engagement and involvement of both men and women in transformative PMTCT initiatives. PMID:24633806

  18. Male involvement for the prevention of mother-to-child HIV transmission: A brief review of initiatives in East, West, and Central Africa.

    PubMed

    Dunlap, Julie; Foderingham, Nia; Bussell, Scottie; Wester, C William; Audet, Carolyn M; Aliyu, Muktar H

    2014-06-01

    Current trends in HIV/AIDS research in sub-Saharan Africa (SSA) highlight socially and culturally sensitive interventions that mobilize community members and resources for universal access to HIV prevention, treatment, and care services. These factors are particularly important when addressing the complex social and cultural nature of implementing services for prevention of mother-to-child transmission of HIV (PMTCT). Across the globe approximately 34 % fewer children were infected with HIV through the perinatal or breastfeeding route in 2011 (est. 330,000) than in 2001 (est. 500,000), but ongoing mother-to-child HIV transmission is concentrated in sub-Saharan Africa, where fully 90 % of 2011 cases are estimated to have occurred. Recent literature suggests that PMTCT in Africa is optimized when interventions engage and empower community members, including male partners, to support program implementation and confront the social, cultural and economic barriers that facilitate continued vertical transmission of HIV. In resource-limited settings the feasibility and sustainability of PMTCT programs require innovative approaches to strengthening male engagement by leveraging lessons learned from successful initiatives in SSA. This review presents an overview of studies assessing barriers and facilitators of male participation in PMTCT and new interventions designed to increase male engagement in East, West, and Central Africa from 2000-2013, and examines the inclusion of men in PMTCT programs through the lens of community and facility activities that promote the engagement and involvement of both men and women in transformative PMTCT initiatives. PMID:24633806

  19. Musculoskeletal imaging insight 2015: Kenya.

    PubMed

    Stevens, Kathryn J; Mutiso, Kavulani; Sconfienza, Luca Maria; Monu, Johnny

    2016-07-01

    Over the past 6 years the International Skeletal Society (ISS) outreach programs have become popular amongst the various radiology organizations in sub-Saharan Africa. So much so that that the ISS outreach is now routinely expected to participate in many of the international radiology conferences in that part of the world. The organizational planning for an outreach visit to Kenya took place over a 3-year period. Eventually a double-headed event; the seventh and eighth sub-Saharan outreach efforts were organized in Nairobi and in Mombasa, Kenya. The Nairobi outreach was an educational course on musculoskeletal imaging at the University of Nairobi and the Aga Khan University in Nairobi from 26 to 28 May 2015. The Mombasa outreach was organized in collaboration with the African Society of Radiology (ASR) at their annual meeting in Mombasa from 30 May to 2 June 2015. PMID:27115883

  20. Neotectonic faults and stress field in the East African Rift System around the Tanzanian Craton - A contribution to the seismotectonic map of Africa

    NASA Astrophysics Data System (ADS)

    Delvaux, Damien; Macheyeki, Athanas Simon; Fernandes, Rui-Manuel; Ayele, Atalay; Meghraoui, Mustapha

    2015-04-01

    As a contribution to the UNESCO-IUGS IGCP 601 project "Seismotectonics and seismic hazards in Africa" and in preparation of the Seismotectonic Map of Africa, we compiled the neotectonic faults related to the East African Rift System around the Tanzanian craton. The initial aim was to identify and map the potentially active faults. Faults are usually defined as active when they show seismogenic displacement during the last 10,000 to 100,000 years, generally on the basis of paleoseismic investigation. In East Africa, however, very few faults have been studied by paleoseismic techniques and even fewer have known historical seismic activation. To address this issue, we mapped faults that show morphological indications of displacement. We used the SRTM DTM (90 and 30 m when available to us), with artificial shading as basis for identify neotectonic faults, in combination with existing data from geological maps, publications and reports, complemented by our own field observations. Thermal springs often occur along tectonically active faults. We use them to distinguish present-day faulting from other mapped faults as they are in most cases structurally controlled. In parallel, we used also the available focal mechanisms and geological fault-slip data to constrain the stress second-order stress field (at the scale of rift segments) and locally also the third-order stress field (at the local scale). All these elements are combined and compared with existing kinematic models for the East African Rift based on earthquake slip vectors, GPS measurements and geologic indicators. The comparison evidences some local discrepancies between the stress field and the direction of opening, probably due to the interactions between different rift segments, as in the Rukwa rift, Mbeya southern junction between the eastern and western rift branches, and in the Manyara-Natron area.

  1. A Seasonal Air Transport Climatology for Kenya

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H.; Piketh, S.; Helas, G.

    1998-01-01

    A climatology of air transport to and from Kenya has been developed using kinematic trajectory modeling. Significant months for trajectory analysis have been determined from a classification of synoptic circulation fields. Five-point back and forward trajectory clusters to and from Kenya reveal that the transport corridors to Kenya are clearly bounded and well defined. Air reaching the country originates mainly from the Saharan region and northwestern Indian Ocean of the Arabian Sea in the northern hemisphere and from the Madagascan region of the Indian Ocean in the southern hemisphere. Transport from each of these source regions show distinctive annual cycles related to the northeasterly Asian monsoon and the southeasterly trade wind maximum over Kenya in May. The Saharan transport in the lower troposphere is at a maximum when the subtropical high over northern Africa is strongly developed in the boreal winter. Air reaching Kenya between 700 and 500 hPa is mainly from Sahara and northwest India Ocean flows in the months of January and March, which gives way to southwest Indian Ocean flow in May and November. In contrast, air reaching Kenya at 400 hPa is mainly from southwest Indian Ocean in January and March, which is replaced by Saharan transport in May and November. Transport of air from Kenya is invariant, both spatially and temporally, in the tropical easterlies to the Congo Basin and Atlantic Ocean in comparison to the transport to the country. Recirculation of air has also been observed, but on a limited and often local scale and not to the extent reported in southern Africa.

  2. Guidelines for sinkhole and subsidence rehabilitation based on generic geological models of a dolomite environment on the East Rand, South Africa

    NASA Astrophysics Data System (ADS)

    Kleinhans, Ilse; Van Rooy, J. Louis

    2016-05-01

    A sound understanding of the various factors influencing and associated with the formation of sinkholes or subsidences on dolomite land is essential for the selection of appropriate rehabilitation methods. The investigation and rehabilitation of numerous sinkholes and subsidences located on dolomite in the East Rand of South Africa, created an opportunity to develop a broad based understanding of different karst environments, their susceptibility to sinkhole and subsidence formation and best practice rehabilitation methods. This paper is based on the guidelines developed whereby the geological model of the sinkhole or subsidence is used to recommend an appropriate rehabilitation method. Nine typical geological models with recommended rehabilitation methods are presented in this paper.

  3. Evidence for early Pleistocene Glaciation(s) in tropical Africa: Stratigraphy, Paleomagnetism, Paleosols and Paleoclimate of the Gorges Moraine System, Mount Kenya

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Barendregt, R. W.; Hamilton, T.; Hancock, R.

    2011-12-01

    Moraines marking an Early Pleistocene glaciation on Mt. Kenya are known from several valleys marking the lowermost extent of the Early Pleistocene Gorges Glaciation (2850 m a.s.l.). The lowermost paleosols at these sites formed either in till predating the Gorges Glaciation or in weathered phonolitic bedrock and related lavas, similar to the lithology forming the base of the Mt. Kenya volcanic series of Miocene/Pliocene age. Paleomagnetism and weathering characteristics have been used to refine the age of sediments assigned to the Gorges Glaciation. These deposits are normally magnetized but carry a persistent reversed overprint, suggesting that they were deposited during one of the normal subchrons within the Matuyama Reversed Chron. They are underlain either by a reversely magnetized weathered till (GOR 68), or weathered bedrock (GOR 64 and GOR 69), the latter exhibiting normal magnetization (Gauss?) with reversed overprint (Matuyama?). The sediments are overlain at all three sites by normally magnetized loesses and paleosols of presumable Brunhes age. The normal magnetization and reversed overprint recorded in sediments of the Gorges Glaciation most likely span a considerable portion of the Olduvai subchron (1.78-1.950 Ma.), which persisted for sufficient time to accommodate an extensive montane glaciation and prolonged period of weathering and soil formation. While the somewhat younger Jaramillo subchron cannot be ruled out, the extensive sediment and weathering record is more easily accommodated within the longer-lived Olduvai subchron. The characteristics of the lowermost buried paleosols and weathered bedrock substrate indicate wetter conditions prior to the onset of Pleistocene glaciation, a period that initially may have fostered a higher elevation forest cover of substantial spatial extent. These wetter conditions, punctuated with dry events, depict a progressive transition to alpine grassland at the start of the Quaternary. In light of new paleomagnetic

  4. Status of HIV and hepatitis C virus infections among prisoners in the Middle East and North Africa: review and synthesis

    PubMed Central

    Heijnen, Marieke; Mumtaz, Ghina R; Abu-Raddad, Laith J

    2016-01-01

    Introduction The status of HIV and hepatitis C virus (HCV) infections among incarcerated populations in the Middle East and North Africa (MENA) and the links between prisons and the HIV epidemic are poorly understood. This review synthesized available HIV and HCV data in prisons in MENA and highlighted opportunities for action. Methods The review was based on data generated through the systematic searches of the MENA HIV/AIDS Epidemiology Synthesis Project (2003 to December 15, 2015) and the MENA HCV Epidemiology Synthesis Project (2011 to December 15, 2015). Sources of data included peer-reviewed publications and country-level reports and databases. Results and discussion We estimated a population of 496,000 prisoners in MENA, with drug-related offences being a major cause for incarceration. Twenty countries had data on HIV among incarcerated populations with a median prevalence of 0.6% in Afghanistan, 6.1% in Djibouti, 0.01% in Egypt, 2.5% in Iran, 0% in Iraq, 0.1% in Jordan, 0.05% in Kuwait, 0.7% in Lebanon, 18.0% in Libya, 0.7% in Morocco, 0.3% in Oman, 1.1% in Pakistan, 0% in Palestine, 1.2% in Saudi Arabia, 0% in Somalia, 5.3% in Sudan and South Sudan, 0.04% in Syria, 0.05% in Tunisia, and 3.5% in Yemen. Seven countries had data on HCV, with a median prevalence of 1.7% in Afghanistan, 23.6% in Egypt, 28.1% in Lebanon, 15.6% in Pakistan, and 37.8% in Iran. Syria and Libya had only one HCV prevalence measure each at 1.5% and 23.7%, respectively. There was strong evidence for injecting drug use and the use of non-sterile injecting-equipment in prisons. Incarceration and injecting drugs, use of non-sterile injecting-equipment, and tattooing in prisons were found to be independent risk factors for HIV or HCV infections. High levels of sexual risk behaviour, tattooing and use of non-sterile razors among prisoners were documented. Conclusions Prisons play an important role in HIV and HCV dynamics in MENA and have facilitated the emergence of large HIV epidemics in

  5. Crust and upper-mantle structure of North Africa, Europe and the Middle East from inversion of surface waves

    NASA Astrophysics Data System (ADS)

    Pasyanos, Michael E.; Walter, William R.

    2002-05-01

    We estimate the crust and upper-mantle seismic velocity structure in North Africa, southern Europe, and the Middle East using our surface-wave dispersion tomography results from a previous study. The surface wave tomography study provided high-resolution coverage across the region from more than 6800 Rayleigh and 3800 Love wave paths over the period range from 10-60 s. We have also included additional tomography results from 65 to 120 s. The tomography model provides average Rayleigh and Love wave dispersion curves for each 2°× 2° block in the region. We use these results to determine velocity structure by fitting the synthetic curves from simplified crust and upper-mantle models to the tomographic data for each block via a grid search. The grid search technique was chosen in order to map out the complete error space and to easily incorporate other data sets or a priori information. The initial grid search is conducted over sediment thickness, crustal velocity, crustal thickness, and upper-mantle velocity. To keep the grid search computationally reasonable, other parameters are held fixed (sediment velocity, Poisson's ratios, and density). Despite the well-known trade-off between crustal thickness and crustal velocity that occurs when fitting surface wave data, the initial grid search is quite successful in retrieving first order features, such as ocean-continent crustal thickness differences and crustal thickening in all but the oldest orogenic zones. We can resolve major sedimentary basins, active ridges, and see differences based on crustal age (e.g. Archean cratons vs Phanarozoic crust). To better control the trade-off inherent in fitting group velocity curves, we also explore using other information to better constrain the grid searches. In particular, we use a global sediment depth and velocity model to fix those parameters and a regional P n tomography to constrain the upper-mantle velocities. In this constrained grid search, we vary crustal thickness

  6. 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

  7. Trends and variability of East African rainfall and its relationship to the Mascarene High pressure system

    NASA Astrophysics Data System (ADS)

    Seregina, Larisa; Pinto, Joaquim G.; Fink, Andreas H.; Ermert, Volker

    2016-04-01

    In the recent decades, East Africa needs to deal with strong fluctuations in seasonal rainfall including precipitation extremes. In context of climate change, such extremes can become more frequent in the future. However, regional climate projections are uncertain about the future development of seasonal precipitation in the region. Rainfall regimes over East Africa are influenced by multiple factors, including two monsoon systems, several convergence zones and the Rift Valley lakes. In addition, local conditions, like topography, modulate the large-scale rainfall pattern. East African rainfall variability is also influenced by various teleconnections like the Indian Ocean Zonal Mode and El Niño Southern Oscillation. The study of past climate variability in East Africa requires sufficient observational data coverage in the region. As East Africa does not have a dense observational network of meteorological stations, satellite rainfall observations gain on importance in studies on climate variability in the region. The specific aim of the present study is the analysis of historic data from weather stations in East Africa (Kenya, Tanzania, Ruanda and Uganda), the use of gridded satellite products, and three-dimensional atmospheric reanalysis (e.g., ERA-Interim) to quantify climate variability in the recent past and to understand its causes. Climate variability and trends, including changes in extreme events, are evaluated using ETCCDI climate change and standardized precipitation indices. These climate indices are determined in order to investigate the variability of rainfall and its trends with the focus on recent decades. For seasonal trend analysis, an independent and non-calendaric rainfall onset criterion is introduced. In the follow-up, statistical and dynamical analyses are conducted to quantify the local impact of Mascarene High as a part of the Subtropical High Pressure Ridge on East African seasonal rainfall. Possible connections to pertinent large