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1

Sedimentation and recent history of a freshwater wetland in a semi-arid environment: Loboi Swamp, Kenya, East Africa  

E-print Network

, Kenya, East Africa G. M. ASHLEY*, J. MAITIMA MWORIA , A. M. MUASYAà, R. B. OWEN§, S. G. DRIESE­, V. C Livestock Research Institute, PO Box 30709, Nairobi, Kenya àEast African Herbarium, National Museums of Kenya, Nairobi, Kenya §Department of Geography, Hong Kong Baptist University, Hong Kong, China

2

Birth and a Vision: Lamaze Childbirth Education in Kenya, East Africa  

PubMed Central

Lamaze Certified Childbirth Education was an unknown entity in Kenya, East Africa, just a few years ago. Today, programs are firmly established in two leading private hospitals in Nairobi and gaining credibility in the region's medical community. Prepared childbirth is finding its place in the lives of the rapidly urbanizing African society. Implementation of Lamaze techniques in antenatal programs serving women outside the private sector is taking place as Kenyan midwives work toward their certification as Lamaze Certified Childbirth Educators. PMID:17273397

Carroll, Jennifer I.

2004-01-01

3

East African Rift Valley, Kenya  

NASA Technical Reports Server (NTRS)

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.

1990-01-01

4

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

NASA Astrophysics Data System (ADS)

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 investigations by different individuals and research groups. On the basis of earthquake data from these sources, the entire N-S trending Kenya rift valley and the NW-SE trending Nyanza (Kavirondo) rift are characterized by a high rate of seismicity, and the USGS network has been effective in detecting local M > 3.0 earthquakes. A peculiar trend is exhibited by earthquakes of Ml ? 5.1 in that these occur along the N-S and NW-SE trending Kenya rift valley and the Kavirondo (Nyanza) rift zone respectively. Earthquake data from the various sources for the period 1906-2010 is complete for Ml ? 4.4 earthquakes with a b-value of 0.79 which is characteristic of tectonic active regions like rifts. There is need to revive and extend the KNSN for a greater coverage and effective seismic monitoring in Kenya.

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

2014-01-01

5

East Africa  

NASA Technical Reports Server (NTRS)

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

2002-01-01

6

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

7

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

PubMed

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

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

2003-12-01

8

The Sun Rises in the East (of Africa): A Comparison of the Development and Status of the Solar Energy Markets in Kenya and Tanzania  

Microsoft Academic Search

This paper describes, compares and analyses the historical development and current status of Kenya's and Tanzania's emerging solar energy markets. The analysis is based on an extensive literature survey and 25 in-depth personal interviews with experts on the East African solar power market. Kenya's solar market is found to be one of the world's leading markets for off-grid solar uses,

Janosch Ondraczek

2012-01-01

9

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

SciTech Connect

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.

Tiercelin, J.J.; Lezzar, K.E. (Universite de Bretagne Occidentale, Brest (France)); Richert, J.P. (Elf Aquitaine, Pau (France))

1994-07-01

10

Glacier Change in the Rwenzori Mountains, East Africa  

Microsoft Academic Search

In East Africa glaciers currently exist on Mt. Kilimanjaro and Mt. Kenya, and in the Rwenzori Mountains. While the Mt. Kilimanjaro and Mt. Kenya glaciers have been the subject of many recent studies, the glaciers in the Rwenzori Range are less thoroughly studied. This study reexamines the satellite record of retreat of these glaciers, as well as the climatic factors

J. L. Kincaid; A. G. Klein

2007-01-01

11

East African Water Regimes: The Case of Kenya  

Microsoft Academic Search

This chapter outlines the evolution of water regimes in East Africa since pre-colonial times with a special focus on Kenya.\\u000a It discusses how institutions and organizations for managing water resources and domestic water supply have been successively\\u000a developed and fused with previous regimes. Institutions introduced as part of the colonization process in the early 1900s\\u000a have partly-but not completely-replaced customary

David Nilsson; Ezekiel Nyangeri Nyanchaga

12

East African and Kuunga Orogenies in Tanzania - South Kenya  

NASA Astrophysics Data System (ADS)

Tanzania and southern Kenya hold a key position for reconstructing Gondwana consolidation because here different orogen belts with different tectonic styles interfere. The older, ca. 650-620 Ma East African Orogeny resulted from the amalgamation of arc terranes in the northern Arabian-Nubian Shield (ANS) and continental collision between East African pieces and parts of the Azania terrane in the south (Collins and Pisarevsky, 2005). The change form arc suturing to continental collision settings is found in southern Kenya where southernmost arcs of the ANS conjoin with thickened continental margin suites of the Eastern Granulite Belt. The younger ca. 570-530 Ma Kuunga orogeny heads from the Damara - Zambesi - Irumide Belts (De Waele et al., 2006) over Tanzania - Mozambique to southern India and clashes with the East African orogen in southern-central Tanzania. Two transitional orogen settings may be defined, (1) that between island arcs and inverted passive continental margin within the East African Orogen and, (2) that between N-S trending East African and W-E trending Kuungan orogenies. The Neoproterozoic island arc suites of SE-Kenya are exposed as a narrow stripe between western Azania and the Eastern Granulite belt. This suture is a steep, NNW stretched belt that aligns roughly with the prominent southern ANS shear zones that converge at the southern tip of the ANS (Athi and Aswa shear zones). Oblique convergence resulted in low-vorticity sinstral shear during early phases of deformation. Syn-magmatic and syn-tectonic textures are compatible with deformation at granulite metamorphic conditions and rocks exhumed quickly during ongoing transcurrent motion. The belt is typified as wrench tectonic belt with horizontal northwards flow of rocks within deeper portions of an island arc. The adjacent Eastern Granulite Nappe experienced westward directed, subhorizontal, low-vorticity, high temperature flow at partly extreme metamorphic conditions (900C, 1.2 to 1.4 GPa) (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.

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

2012-04-01

13

Lake Challa (Kenya/Tanzania) sediments, a varved climate archive of environmental variability in equatorial East Africa of the last 25.000 years  

NASA Astrophysics Data System (ADS)

Recently, an increasing number of climate records from low-latitude regions underscore the importance of tropical atmospheric processes in the global climate system. Nevertheless, the regional synchrony of temperature and humidity variations, as well as teleconnecting mechanisms between high and low latitudes are still poorly understood. The EuroCLIMATE project CHALLACEA aims to provide a continuous high- resolution multi-proxy record of temperature and moisture-balance variability in equatorial East Africa from the Last Glacial Maximum (25 ka BP) to the present. Lake Challa is a crater lake located about 40 km east of Mt. Kilimanjaro at an altitude of 880 m a.s.l. It is a freshwater lake whose water column is stratified during most of the year. It is fed by subsurface inflow which derives mainly from percolation of precipitation falling in the montane forest zone higher up the mountain. Within the lake form lacustrine deposits which predominantly consist of autochthonous components (carbonate, biogenic silica, organic matter). The present study focuses on microfacies analyses and isotope measurements. Fine laminations are preserved over wide parts of a 22 m long sediment profile. Microfacies analyses reveal that the light/dark couplets represent true calcite varves. The darker layers contain organic matter and endogenic calcite. Sediment trap studies show that these layers form during the warm season (Nov to Mar) when water temperatures are high and the lake is biological productive. The light layers consist predominantly of diatom frustules. They accumulate in the sediment trap between June and October. By counting and measuring the thickness of the varves on thin sections, we establish a varve record that currently covers the last 1500 years. Stable isotope analyses on bulk carbonates will complement this record and give further insights into the hydrological variability of the region and enhance our knowledge of climate change in the highly sensitive climate region of the Mt. Kilimanjaro area.

Wolff, C.; Haug, G.; Plessen, B.; Kristen, I.; Verschuren, D.; Participants, C.

2008-12-01

14

The Sun Rises in the East (of Africa): A Comparison of the Development and Status of the Solar Energy Markets in Kenya and Tanzania  

Microsoft Academic Search

This paper describes and analyses the historical development and current status of the solar energy markets in Kenya and Tanzania. It examines the development of both the Kenyan and the Tanzanian solar energy markets since their beginnings in the 1970s, their current size and structure and it presents forecasts for their future development. In addition, it highlights and explains similarities

Janosch Ondraczek

2011-01-01

15

Phylodynamics of HIV-1 Subtype C Epidemic in East Africa  

PubMed Central

The HIV-1 subtype C accounts for an important fraction of HIV infections in east Africa, but little is known about the genetic characteristics and evolutionary history of this epidemic. Here we reconstruct the origin and spatiotemporal dynamics of the major HIV-1 subtype C clades circulating in east Africa. A large number (n?=?1,981) of subtype C pol sequences were retrieved from public databases to explore relationships between strains from the east, southern and central African regions. Maximum-likelihood phylogenetic analysis of those sequences revealed that most (>70%) strains from east Africa segregated in a single regional-specific monophyletic group, here called CEA. A second major Ethiopian subtype C lineage and a large collection of minor Kenyan and Tanzanian subtype C clades of southern African origin were also detected. A Bayesian coalescent-based method was then used to reconstruct evolutionary parameters and migration pathways of the CEA African lineage. This analysis indicates that the CEA clade most probably originated in Burundi around the early 1960s, and later spread to Ethiopia, Kenya, Tanzania and Uganda, giving rise to major country-specific monophyletic sub-clusters between the early 1970s and early 1980s. The results presented here demonstrate that a substantial proportion of subtype C infections in east Africa resulted from dissemination of a single HIV local variant, probably originated in Burundi during the 1960s. Burundi was the most important hub of dissemination of that subtype C clade in east Africa, fueling the origin of new local epidemics in Ethiopia, Kenya, Tanzania and Uganda. Subtype C lineages of southern African origin have also been introduced in east Africa, but seem to have had a much more restricted spread. PMID:22848653

Delatorre, Edson Oliveira; Bello, Gonzalo

2012-01-01

16

Phylodynamics of HIV-1 subtype C epidemic in east Africa.  

PubMed

The HIV-1 subtype C accounts for an important fraction of HIV infections in east Africa, but little is known about the genetic characteristics and evolutionary history of this epidemic. Here we reconstruct the origin and spatiotemporal dynamics of the major HIV-1 subtype C clades circulating in east Africa. A large number (n?=?1,981) of subtype C pol sequences were retrieved from public databases to explore relationships between strains from the east, southern and central African regions. Maximum-likelihood phylogenetic analysis of those sequences revealed that most (>70%) strains from east Africa segregated in a single regional-specific monophyletic group, here called C(EA). A second major Ethiopian subtype C lineage and a large collection of minor Kenyan and Tanzanian subtype C clades of southern African origin were also detected. A bayesian coalescent-based method was then used to reconstruct evolutionary parameters and migration pathways of the C(EA) African lineage. This analysis indicates that the C(EA) clade most probably originated in Burundi around the early 1960s, and later spread to Ethiopia, Kenya, Tanzania and Uganda, giving rise to major country-specific monophyletic sub-clusters between the early 1970s and early 1980s. The results presented here demonstrate that a substantial proportion of subtype C infections in east Africa resulted from dissemination of a single HIV local variant, probably originated in Burundi during the 1960s. Burundi was the most important hub of dissemination of that subtype C clade in east Africa, fueling the origin of new local epidemics in Ethiopia, Kenya, Tanzania and Uganda. Subtype C lineages of southern African origin have also been introduced in east Africa, but seem to have had a much more restricted spread. PMID:22848653

Delatorre, Edson Oliveira; Bello, Gonzalo

2012-01-01

17

Developing a Systemic Approach to Teacher Education in Sub-Saharan Africa: Emerging Lessons from Kenya, Tanzania and Uganda  

ERIC Educational Resources Information Center

While many countries in Eastern and Southern Africa are on track for meeting the Education for All targets, there is a growing recognition of the need to improve the quality of basic education and that a focus on pedagogy and its training implications needs to be at the heart of this commitment. By drawing on three East African countries, Kenya,

Hardman, Frank; Ackers, Jim; Abrishamian, Niki; O'Sullivan, Margo

2011-01-01

18

Forecasting droughts in East Africa  

NASA Astrophysics Data System (ADS)

The humanitarian crisis caused by the recent droughts (2008-2009 and 2010-2011) in East Africa have illustrated that the ability to make accurate drought predictions with sufficient lead time is essential. The use of dynamical model forecasts in combination with drought indices, such as the Standardized Precipitation Index (SPI), can potentially to lead to a better description of drought duration, magnitude and spatial extent. This study evaluates the use of the European Centre for Medium-Range Weather Forecasts (ECMWF) products in forecasting droughts in East Africa. ECMWF seasonal precipitation shows significant skill for both rain seasons when evaluated against measurements from the available in-situ stations from East Africa. The forecast for October-December rain season has higher skill than for the March-May season. ECMWF forecasts add value to the statistical forecasts produced during the Greater Horn of Africa Climate Outlook Forums (GHACOF), which is the present operational product. Complementing the raw precipitation forecasts with SPI provides additional information on the spatial extent and intensity of the drought event.

Mwangi, Emmah; Wetterhall, Fredrik; Dutra, Emanuel; Di Giuseppe, Francesca; Pappenberger, Florian

2014-05-01

19

East Africa continental margins  

SciTech Connect

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.

Bosellini, A.

1986-01-01

20

Kenya.  

PubMed

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 tourist centers proceeds with little regard for environmental and social impacts. With a faltering economy, industrial development in Mombasa proceeds with few checks on pollution and other impacts. In 1998 Kenya's coral reefs suffered 50-80% mortality from the El Nio-related coral bleaching event that affected the entire Indian Ocean. The institutional, human resource and legal infrastructure for managing the coastal environment has in the past been low, however these are rapidly improving with the revitalization of national institutions and the passing in 1999 of an Environment Act. Marine Protected Areas are the key tool currently used in management of marine ecosystems, and focus principally on coral reefs and biodiversity protection. New initiatives are underway to improve application of fisheries regulations, and to use Integrated Coastal Area Management (ICAM) as a framework for protecting marine and coastal environments. PMID:11827110

Obura, D O

2001-12-01

21

Race Portrayals in Ghana, Kenya, and South Africa Television Advertisements  

Microsoft Academic Search

The current study examines racial portrayals in television advertisements from Ghana, Kenya, and South Africa. Whites are over-represented relative to their actual demographic presence in all three countries, and both Blacks and Whites are depicted as over-employed. In general, however, depictions are not significantly different for either race, though there is a hint that a stereotyped portrayal of Blacks as

Laura M. Milner

2007-01-01

22

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

ERIC Educational Resources Information Center

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

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

2008-01-01

23

The role of soil science in agricultural development in East Africa  

Microsoft Academic Search

Agriculture is the mainstay of the economy of the three countries of East Africa (Kenya, Tanzania and Uganda). It employs about 80 to 90 percent of the population of these countries and is also the main source of food and foreign exchange earnings. However, the agricultural development in the region has remained below expectation during the last five decades. Although

F. N. Muchena; R. M. Kiome

1995-01-01

24

A Biocultural Framework for Examining Maternal Cravings and Aversions among Pastoral Women in East Africa  

Microsoft Academic Search

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

Alyson G. Young; Ivy L. Pike

2012-01-01

25

Leaf litter removal by the snail Terebralia palustris (Linnaeus) and sesarmid crabs in an East African mangrove forest (Gazi Bay, Kenya)  

Microsoft Academic Search

Quantitative data on leaf litter removal activity of macrozoobenthic organisms in the mangrove forests of East Africa are virtually non-existent. In the present study, litter removal activity was determined in two contrasting types of mangrove stands in Gazi Bay (Kenya). In the relatively elevated Ceriops tagal vegetation, which is only flooded during spring tides, the detritivorous snail Terebralia palustris (Linnaeus)

F. J Slim; M. A. Hemminga; C. Ochieng; N. T Jannink; E Cocheret de la Morinire; G. Van der Velde

1997-01-01

26

East and Southern Africa English Accents.  

ERIC Educational Resources Information Center

Discusses English pronunciation features in the anglophone countries of East and Southern Africa. Focus is on restructuring of the STRUT vowel to /a/,/i/, and /e/ epenthesis, and short tone groups.(Author/VWL)

Bobda, Augustin Simo

2001-01-01

27

The alternative of Chinese aid in Africa : impacts of China's development strategy through Chinese aid, finance, and firms in Kenya  

E-print Network

This thesis examines the differences of Chinese and Western aid implementation and its effects in Africa though the case study of Chinese aid and finance for road development in Kenya. Today, Kenya receives tangible benefits ...

Mullin, Deborah Wei

2009-01-01

28

Geopolitical influences on German development policies in Africa and AIDS policies in Kenya  

E-print Network

GEOPOLITICAL INFLUENCES ON GERMAN DEVELOPMENT POLICIES IN AFRICA AND AIDS POLICIES IN KENYA A Thesis by VEIT BACHMANN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 2006 Major Subject: Geography GEOPOLITICAL INFLUENCES ON GERMAN DEVELOPMENT POLICIES IN AFRICA AND AIDS POLICIES IN KENYA A Thesis by VEIT BACHMANN Submitted to the Office...

Bachmann, Veit

2009-06-02

29

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

PubMed

Interannual rainfall variations in equatorial East Africa are tightly linked to the El Nio Southern Oscillation (ENSO), with more rain and flooding during El Nio and droughts in La Nia 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

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

2011-08-01

30

Glacier Change in the Rwenzori Mountains, East Africa  

NASA Astrophysics Data System (ADS)

In East Africa glaciers currently exist on Mt. Kilimanjaro and Mt. Kenya, and in the Rwenzori Mountains. While the Mt. Kilimanjaro and Mt. Kenya glaciers have been the subject of many recent studies, the glaciers in the Rwenzori Range are less thoroughly studied. This study reexamines the satellite record of retreat of these glaciers, as well as the climatic factors most responsible for the change. A recent study of the retreat of the Rwenzori glaciers using Landsat images acquired between 1987 and 2003 has been questioned. Using visual mapping and the Normalized Difference Snow Index (NDSI) to analyze Landsat, ASTER and SPOT images, we have re-evaluated the ice areas for the period 1987 to 2006. After identifying sources for possible error, our mapping indicates that the glaciers in the Rwenzori have shrunk from an area of 2.55 km2 in 1987 to 1.31 km2 in 2006. Glacier retreat in the Rwenzori from 1906 to 1990 showed a strong spatial correlation with potential increase in shortwave radiation due to decreased cloud cover as a consequence of a shift to drier conditions in the region. Whether or not recent glacier retreat shows a similar spatial correlation is under investigation.

Kincaid, J. L.; Klein, A. G.

2007-12-01

31

Predictability of rainy season onset and cessation in east Africa  

NASA Astrophysics Data System (ADS)

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 find predictor variables, exploring successively the synchronous and lagged relationships between the rainfall descriptors and the main modes of the climate system, including those already known to affect East Africa rainfall such as El Nio Southern Oscillation (ENSO) and the Indian Ocean dipole (IOD). Candidate climatic fields include sea surface temperature, geopotential height and moisture fluxes at lower (850 hPa), mid (500 hPa) and higher (200 hPa) tropospheric levels.

Joseph, B.-M.

2012-04-01

32

View of east Africa ravaged by drought  

NASA Technical Reports Server (NTRS)

A near vertical view of a portion of east Africa revaged by drought for the past five years is seen in this Skylab 3 Earth Resources Experiments Package S190-B (five-inch earth terrain camera) photograph taken from the Skylab space station in Earth orbit. The semi-desert scene is in southwestern Niger.

1973-01-01

33

ASMET: 2009 Drought in East Africa  

NSDL National Science Digital Library

The module examines the 2009 drought in the Greater Horn of Africa (GHA), focusing on conditions in Kenya. The module begins by reviewing drought conditions in the years leading up to 2009. From there, it examines the seasonal climate forecast for the beginning of 2009 and see what it portends. Satellite products are used to study rainfall performance throughout the year and its impact on the drought situation. Finally, the module describes the climate oscillations that can impact drought in the GHA and identifies patterns that were present in 2009 and contributed to its severity. By the end of the module, weather forecasters and students should have a better understanding of drought and the tools available for its early detection and monitoring.

Comet

2012-01-17

34

Helicobacter pylori in Immigrants from East Africa  

PubMed Central

This study determines the prevalence of Helicobacter pylori infection in a group of immigrants from East Africa with dyspepsia symptoms. Costs of treatment (including financial costs, adverse effects of treatment, and complexity of care) are compared for empiric treatment and treatment guided by serologic testing. Of the symptomatic patients, 93% had H. pylori antibodies. Empiric treatment of all patients with dyspepsia could reduce the cost of care by approximately half, with minimal risk to uninfected patients. PMID:10491248

Wang, Peiyi; Adair, Richard

1999-01-01

35

Diabetes in sub-saharan Africa: kenya, mali, mozambique, Nigeria, South Africa and zambia.  

PubMed

Until a few years ago, a limited number of epidemiologists or public health experts mentioned the words "diabetes." As new lifestyles, imported dietary practices, and globalization take roots in the developing world, as Africa is, today, diabetes and its complications are considered an epidemic in Africa, compelling African governments to start paying more attention to its impact as thousands of Africans run the risk of dying young. The potential severity of diabetes is such that some epidemiologists predict that its economic impact and death toll will surpass the ravages of HIV and AIDS in the near future. On the African sub-continent, present literature and the work of the World Diabetes Foundation have highlighted three countries, namely, Mali, Mozambique, and Zambia. However, the conditions in South Africa, Kenya, and Nigeria, some of the most developed areas of the continent, provide a clue to how people are coping and how governments are responding to diabetes and its full impact. This study is, therefore, a meta-summary of the incidence and prevalence of today's emerging silent killer or diabetes in Sub-Saharan Africa. The theme is that time is running out for Africa and that, as was for HIV/AIDS, by the time the governments wake up and stop denying the catastrophic potential of the epidemic, diabetes will simply overwhelm the continent's resources, and the world will witness the death of millions of Africans. The last section is a call for action against diabetes in terms of advocacy, promotion of awareness, and public health policies that empower people to diabetes self-management. PMID:20165596

Azevedo, Mario; Alla, Sridevi

2008-10-01

36

Hydrocarbon potential of the Lamu basin of south-east Kenya  

SciTech Connect

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.

Nyagah, K.; Cloeter, J.J.; Maende, A. [National Oil Corp. of Kenya, Nairobi (Kenya)

1996-12-31

37

Hydrocarbon potential of the Lamu basin of south-east Kenya  

SciTech Connect

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.

Nyagah, K.; Cloeter, J.J.; Maende, A. (National Oil Corp. of Kenya, Nairobi (Kenya))

1996-01-01

38

Public health laboratory systems development in East Africa through training in laboratory management and field epidemiology  

PubMed Central

Laboratories are integral to the delivery of quality health care and for public health functions; however laboratory systems and services are often neglected in resource-poor settings such as the East African region. In order to sustainably strengthen national laboratory systems in resource-poor countries, there is a need to train laboratory personnel to work in clinical as well as public health laboratories. In 2004,Kenya, Uganda, Tanzania, and South Sudan began training public health laboratory workers jointly with field epidemiologists in the Kenya Field Epidemiology and Laboratory Training Program (FELTP), and later through the Tanzania FELTP, as a strategy to strengthen public health laboratories. These programs train laboratory epidemiologists through a two-year public health leadership development course, and also offer various types of short course training for frontline staff. The FELTP laboratory graduates in Kenya, Tanzania, Uganda, and South Sudan are working in their respective countries to strengthen public health laboratory systems while the short course participants provide a pool of frontline implementers with the capacity to support the lower tiers of health systems, as well as serve as surge capacity for the regions and the national level. Through training competent public health laboratory workers, the East African ministries of health, in collaboration with other regional partners and stakeholders are now engaged in developing and implementing a holistic approach that will guarantee an overall strengthening of the health system by using well-trained public health laboratory leaders to drive the process. Strengthening public health laboratory medicine in East Africa is critical to improve health-care systems. The experience with the FELTP model in East Africa is a step in the right direction towards ensuring a stronger role for the laboratory in public health. PMID:22359702

Mosha, Fausta; Oundo, Joseph; Mukanga, David; Njenga, Kariuki; Nsubuga, Peter

2011-01-01

39

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

PubMed Central

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 (20062007), Kenya (20062007), Tanzania (2007), and Sudan (20072008) 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 199798 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

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

2014-01-01

40

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

ERIC Educational Resources Information Center

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

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

41

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

SciTech Connect

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.

Marara, Madeleine; Okello, Nick; Kuhanwa, Zainab; Douven, Wim; Beevers, Lindsay, E-mail: l.beevers@hw.ac.uk; Leentvaar, Jan

2011-04-15

42

Analysis of the Junction of the East African Rift and the Cretaceous-Paleogene Rifts in Northern Kenya and Southern Ethiopia  

NASA Astrophysics Data System (ADS)

The East African rift (EAR) is a Tertiary-Miocene system that extends from the Middle East, through East Africa, to Mozambique in southern Africa. Much of the present information is from the Ethiopian and Kenyan parts of the rift. Several characteristics of the EAR such as rift-related volcanism, faulting and topographic relief being exposed make it attractive for studying continental rift processes. Structural complexities reflected in the geometries of grabens and half-grabens, the existence of transverse fault zones and accommodation zones, and the influence of pre-existing geologic structures have been documented. In particular, the EAR traverses the Anza graben and related structures near the Kenya/Ethiopian border. The Anza graben is one in a series of Cretaceous-Paleogene failed rifts that trend across Central Africa from Nigeria through Chad to Sudan and Kenya with an overall northwest-southeast trend. In spite of a number of recent studies, we do not understand the interaction of these two rift systems. In both Ethiopia and Kenya, the rift segments share some broad similarities in timing and are related in a geographic sense. For example, volcanism appears to have generally preceded or in some cases have been contemporaneous with major rift faulting. Although, these segments are distinct entities, each with its own tectonic and magmatic evolution, and they do connect in the region crossed by the Anza graben and related structures. In our present study, we are using a combination of recently collected seismic, gravity and remote sensing data to increase our understanding of these two segments of the EAR. We hope that by analysing the satellite data, the variety and differences in the volume of magmatic products extruded along in southern Ethiopia and northern Kenya will be identified. The geometry of structures (in particular, those causing the gravity axial high) will be modelled to study the impact of the older Anza graben structural trends with the younger EAR. For example there is significant crustal thinning in the Lake Turkana area of the northern Kenya segment of the EAR system. In regard to the recent EAGLE experiment in Ethiopia, we are ivestigating if the transition from relatively thick crust (~40 km) to thinned, rifted crust is as abrupt in Ethiopia as it is in Kenya.

Mariita, N. O.; Tadesse, K.; Keller, G. R.

2003-12-01

43

Somalian Earthquakes of May, 1980, East Africa  

SciTech Connect

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.

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

1981-04-01

44

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

NASA Astrophysics Data System (ADS)

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., 315'S, 409' 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 ?m 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 occurred between 1974 and 1980 where there is a five to tenfold increase relative to natural levels. This is attributed to the combined effects of dramatically increasing population, unregulated land use, deforestation and severe droughts in the early 1970s. It is concluded that despite laudable attempts to instigate soil conservation measures, it is unlikely that in Kenya there will be a sustainable reduction in soil erosion without a significant improvement in socio-economic conditions.

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

2006-12-01

45

Sexual Behavior of Female Sex Workers and Access to Condoms in Kenya and Uganda on the trans-Africa Highway  

Microsoft Academic Search

Female sex workers and their clients remain a high risk core group for HIV in Africa. We measured sexual behavior of a snowball\\u000a sample of female sex workers (FSW) along the Trans Africa highway from Mombasa, Kenya to Kampala, Uganda and surveyed the\\u000a availability of male condoms at 1,007 bars and lodgings in Kenya along the highway trucking stops where

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

2009-01-01

46

300 Years of East African Climate Variability from Oxygen Isotopes in a Kenya Coral  

NASA Astrophysics Data System (ADS)

Instrumental records of climate variability from the western Indian Ocean are relatively scarce and short. Here I present a monthly resolution stable isotopic record acquired from a large living coral head (Porites) from the Malindi Marine Reserve, Kenya (3^oS, 40^oE). The annual chronology is precise and is based on exceptionally clear high and low density growth band couplets. The record extends from 1696 to 1996 A.D., making it the longest coral climate record from the Indian Ocean and one of the longest available worldwide. We have analyzed the uppermost portion of the coral colony in triplicate, using 3 separate cores. This upper section, used for calibration purposes, also provides estimates of signal fidelity and noise in the climate recording system internal to the colony. Coral ?18O at this site primarily records SST; linear regression of monthly coral ?18O vs. SST yields a slope of -0.26 ppm ?18O per ^oC, and ?18O explains 57% of the SST variance. Additional isotopic variability may result from changes in seawater ?18O due to local runoff or regional evaporation/precipitation balance, but these changes are likely to be small because local rainfall ?18O is not strongly depleted relative to seawater and salinity gradients are small. The coral record indicates a clear warming trend of about 1.5^oC that accelerates in the latest 20th century, superimposed on strong decadal variability that persists throughout the record. In fact, ?18O values in the 1990's exceed the 300 year envelope (they are lower) and correspond with apparently unprecedented coral bleaching in coastal East Africa. The decadal component of the Malindi coral record reflects a regional climate signal spanning much of the western equatorial Indian Ocean. In general, East African SST and rainfall are better correlated with Pacific ENSO indicators than with the Indian Monsoon at all periods (inter-annual through multi-decadal) but the correlation weakens after 1975. One dramatic new result we report here is a strong indication of a major cool and dry period from 1750--1820 A.D. This is the single largest multi-decadal anomaly of the past 300 years and correlates perfectly in time with the historically and anecdotally defined Lapanarat Drought. Our results indicate a strong link between multi-decadal tropical cold SST anomalies And far-reaching continental droughts in East Africa. Causes and links to other climate recording systems will be explored. Interannual-decadal SST variations are strongly coherent with ENSO indices and other ENSO-sensitive coral records on decadal and interannual time scales. The decadal component of the Malindi coral record reflects a regional climate signal spanning much of the western equatorial Indian Ocean. Previous work has argued that this component likely reflects a monsoonal influence. However, decadal variance in both Malindi and Seychelles (Charles et al. 1997) coral records is more strongly coherent with ENSO indices than with the India or East Africa rain indices. The coherency of both coral records with Pacific indicators suggests instead that Indian Ocean variability reflects decadal ENSO-like variability originating in the Pacific. These records don't correlate significantly with the Pacific Decadal Oscillation implying a dominant role for the tropical Pacific (as opposed to extra-tropical regions) as a source of regional decadal variability in the western Indian Ocean. This work confirms that the tropical Pacific can act as an agent of decadal climate variability over a very large spatial scale.

Dunbar, R.

2003-04-01

47

Protected Areas: Mixed Success in Conserving East Africa's Evergreen Forests  

E-print Network

spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided

48

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 ...

49

Does the family Meesiaceae (Musci) occur in Africa?  

Microsoft Academic Search

Meesia kenyae P. Varde, a species originally described in 1955 from the altimontane elevation on Mt. Kenya in tropical East Africa, is briefly assessed taxonomically and some details of the type material are illustrated. This species is considered to be conspecific with Ceratodon purpureus (Hedw.) Brid., a weedy, cosmopolitan and highly protean species. Because M. kenyae is the only representative

Ryszard Ochyra

2001-01-01

50

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

PubMed Central

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

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

2013-01-01

51

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

PubMed

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 5948 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

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

2014-01-01

52

Permian to tertiary faunas and paleogeography: Somalia, Kenya Tanzania, Mozambique, Madagascar, South Africa  

Microsoft Academic Search

Permian to Tertiary faunas along the eastern margin of Africa, and on Madagascar, are presented, described, and discussed. Presentation of the faunas is made in four charts: Permo-Triassic, Jurassic, Cretaceous, and Tertiary. A correlation chart provides tentative time-rock units. Paleogeography northeast and east of Africa is derived from the writer's analysis of marine invertebrate fauna, and is delineated in sketches

Maurice Kamen-Kaye

1978-01-01

53

Kenya.  

PubMed

Kenya's 1st census, in 1948, counted 5.8 million people, the 1979 census counted 15.3 million, and the government estimates the 1984 population at 19.4 million. Development planning began in 1966; the current 5-year plan (1984-1988) stresses manpower, capital, and land development, mainly in the West. The government considers population growth an obstacle to meeting educational, health, housing, food, and employment needs. Kenya's high 4% growth rate results from a high birth rate and a declining death rate. The government intends to reduce population growth to 3.3% by 1988 by 1) informing Kenyans of the benefits of small families and 2) making family planning services easily available, especially in rural areas. Life expectancy is currently 52.9 years and infant mortality is 82/1000. Most health problems relate to childbearing, communicable diseases, malnutrition, and poor sanitation. The current development plan strives to expand services in 1) staff training, information, and education, 2) monitoring and evaluation, 3) contraceptive delivery, and 4) increasing family planning acceptors. Kenyan women desire 7 children and usually have 8. The government is trying to improve the status of women through education and employment, with the expectation of reducing fertility levels. Abortion for contraceptive purposes is illegal; sterilization and contraceptives are available. Neither emigration nor immigration are significant in Kenya. 90% of the people live on 20% of the land. Urban growth is increasing too rapidly and the government's policies to correct the population distribution inequity include 1) urban development, mainly in Western Kenya; 2) encouraging agricultural development; 3) development of export-oriented, resource based, and labor intensive industries; 4) funding development sites outside of Nairobi and Mombasa; 5) stimulating growth in undeveloped areas; 6) improving roads, rails, and ports; and 7) providing adequate water, housing, and energy. PMID:12314237

1985-07-01

54

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

PubMed Central

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

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

2014-01-01

55

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

PubMed

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

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

56

Summary of modeling studies of the East Olkaria geothermal field, Kenya  

SciTech Connect

A detailed three-dimensional well-by-well model of the East Olkaria geothermal field in Kenya has been developed. The model matches reasonably well the flow rate and enthalpy data from all wells, as well as the overall pressure decline in the reservoir. The model is used to predict the generating capacity of the field, well decline, enthalpy behavior, the number of make-up wells needed and the effects of injection on well performance and overall reservoir depletion. 26 refs., 10 figs.

Bodvarsson, G.S.; Pruess, K.; Stefansson, V.; Bjornsson, S.; Ojiambo, S.B.

1985-03-01

57

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

PubMed

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

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

2009-10-01

58

Epidemiology of cardiovascular diseases in Africa with special reference to Kenya: an overview.  

PubMed

At the beginning of this century, high blood pressure was virtually non-existent among the indigenous Kenyans. This phenomenon of normotension continued until the Second World War following which the Kenyan African began to exhibit progressive rise in blood pressure which was age-related. Similar changes were observed in Uganda at the same time. From about 25 years ago, high blood pressure became established in Kenya and the neighbouring countries, in particular Uganda. These trends have been observed in West Africa notably Ghana, Nigeria, Cote d'Ivoire and also in Cameroon and Zaire in the Central African region. Consumption of sodium salt and alcohol, psychological stress, obesity, physical inactivity and other dietary factors are thought to play important aetiologic role in the genesis of primary hypertension in the susceptible individuals. Low blood pressure communities still exist scattered all over the world, where blood pressure does not seem to rise with age. In Africa these have been observed in Kenya, Nigeria, Zaire and Kalahari Desert. They also exist in Pacific island, Australia, South America and elsewhere. Rural-urban migration coupled with acculturation and modernization trends have some relationship with the development of high blood pressure as observed in Kenyan and Ghanian epidemiologic studies. PMID:8261957

Lore, W

1993-06-01

59

Reducing Pesticide Hazards to Honey Bees in Tropical East Africa  

Microsoft Academic Search

Various insecticide uses in East Africa are analysed for their actual or potential danger to honey bees. A list of commonly used chemicals is classified according to bee hazard and specific recommendations made on the protection of honey bees under tropical conditions.

M. T. Chandler

1976-01-01

60

24 Sustainable Livelihoods for Coffee Producers in East Africa  

E-print Network

505 24 Sustainable Livelihoods for Coffee Producers in East Africa: Is Producing Speciality Coffee of coffee have resulted in diminishing export revenues, undermining the ability of the state to invest the market for undifferentiated coffee has stag- nated, the growth of the speciality market has created new

Richner, Heinz

61

Women of the World: Near East and North Africa.  

ERIC Educational Resources Information Center

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

Chamie, Mary

62

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

PubMed

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

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

2012-11-01

63

ADVANCES IN DEVELOPING INSECT RESISTANT MAIZE VARIETIES FOR KENYA WITHIN THE INSECT RESISTANT MAIZE FOR AFRICA (IRMA) PROJECT  

Microsoft Academic Search

Lepidopteran stem borers are economically important pests of maize, a major staple in Kenya. The Insect Resistant Maize for Africa (IRMA) Project aims at increasing maize production and food security through the development and deployment of insect resistant maize. Bt maize utilizes genes that encode delta-endotoxins; proteins derived from the soil bacterium Bacillus thuringiensis (Bt). Suitable genes have been acquired

S. Mugo; H. DeGroote; J. Songa; M. Mulaa; B. Odhiambo; C. Taracha; D. Bergvinson; D. Hoisington; M. Gethi

64

Country-wise Collaborations in HIV\\/AIDS Research in Kenya and South Africa, 19802005  

Microsoft Academic Search

This study uses co-word and factor analyses to identify and measure country collaborations between Kenya and South Africa and their respective country collaborators. Using the widely accepted indicator of research collaboration, co- authorship of papers, the study used three measurement indicators, namely, the Eigenvectors\\/scores, the collaboration coeffi cients (CC) and the strengths (S) of term association to identify key collaborators

Omwoyo Bosire Onyancha; Dennis N. Ocholla

2007-01-01

65

A recent outbreak of rinderpest in East Africa  

Microsoft Academic Search

Rinderpest was brought under control in Kenya in 1976 but in April 1986 an outbreak of the disease occurred in cattle in Western Kenya, five kilometres from the Kenya - Uganda border. This was the first confirmed field outbreak of the disease in Kenya after a lull of over 10 years. Clinical disease was confined to unvaccinated zebu calves aged

J. S. Wafula; D. P. Kariuki

1987-01-01

66

Climate Change Impacts on East Africa  

Microsoft Academic Search

\\u000a Africa contains about one-fifth of all known species of plants, mammals, and birds, as well as one-sixth of amphibians and\\u000a reptiles. These species make up some of the worlds most diverse and biologically important ecosystems, such as savannahs,\\u000a tropical forests, coral reef marines and freshwater habitats, wetlands, and montane ecosystems. These globally important ecosystems\\u000a provide the economic foundation that many

Muawya Ahmed Hussein

67

Anisotropic complexity in Tanzania and Kenya from teleseismic shear-wave splitting  

Microsoft Academic Search

Previous studies have found that shear-wave splitting fast directions in western Kenya are roughly parallel to the Kenya Rift, part of the East Africa rift system. This anisotropy can be explained by three different mechanisms: fossilized anisotropy in the lithosphere from previous orogenic events, vertically oriented magma-filled lenses in the lithosphere and asthenosphere, and asthenospheric flow along the base of

K. T. Walker; A. A. Nyblade; G. H. Bokelmann; S. L. Klemperer; T. J. Owens

2003-01-01

68

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

ERIC Educational Resources Information Center

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

Munene, Ishmael I.

2012-01-01

69

Contextual teaching of soteriology amongst the Central Bantu of Kenya  

Microsoft Academic Search

Qualitative and quantitative field research was carried out in 2002 and 2003 among rural, Central Bantu Christians of the Africa Inland Church in Kenya, East Africa, seeking to learn and describe the population's mental models of salvation and certain related beliefs. Historically, the Central Bantu peoples perceived salvation as a state of peaceful and harmonious relationship with God, with ancestors

Paul Mwangi Kamunge

2004-01-01

70

The Washington File for Middle East and North Africa  

NSDL National Science Digital Library

A new email list from the US Department of State's Office of International Information Programs, the Washington File for Middle East and North Africa offers email reports about US policies in the Middle East and North Africa. Mostly transcripts, excerpts, and text statements, the materials provided should give interested users primary source knowledge of US State Department positions, unfiltered by newspapers or other media. Each report has a summary list of all enclosed topics, making browsing much quicker and easier, especially considering the amount of information that some reports provide. Two examples of issues covered by the report are: "Transcript: Rumsfeld Sees Progress Toward Afghan National Army" and "Text: U.S. Sees No Credible Evidence of Ukraine Arms Transfers to Iraq." Interested readers should note that, while never unnecessary, a lot of information is provided, meaning that it could take some time to sort through all material in each report.

71

Visceral Leishmaniasis and HIV Coinfection in East Africa  

PubMed Central

Visceral Leishmaniasis (VL) is an important protozoan opportunistic disease in HIV patients in endemic areas. East Africa is second to the Indian subcontinent in the global VL caseload and first in VL-HIV coinfection rate. Because of the alteration in the disease course, the diagnostic challenges, and the poor treatment responses, VL with HIV coinfection has become a very serious challenge in East Africa today. Field experience with the use of liposomal amphotericin B in combination with miltefosine, followed by secondary prophylaxis and antiretroviral drugs, looks promising. However, this needs to be confirmed through clinical trials. Better diagnostic and follow-up methods for relapse and prediction of relapse should also be looked for. Basic research to understand the immunological interaction of the two infections may ultimately help to improve the management of the coinfection. PMID:24968313

Diro, Ermias; Lynen, Lutgarde; Ritmeijer, Koert; Boelaert, Marleen; Hailu, Asrat; van Griensven, Johan

2014-01-01

72

Regional stratigraphy and petroleum geology, North Africa-Middle East  

SciTech Connect

The North Africa-Middle East petroleum provinces are part of the broad sedimentary platform that occupied the northern and northeastern borders of the African-Arabian craton adjacent to the ancestral Hercynian (late Paleozoic) and subsequent Tethyan-Alpine oceans. Carbonate-clastic-evaporite sediments of infra-Cambrian through Holocene age were cyclically deposited in a relatively continuous belt around the eastern and northern borders of the craton, mainly on a broad, shallow-water platform adjacent to the proto-Tethys and Tethys seaway. The Paleozoic section reaches a substantial thickness in the subsurface of the Middle East and in northern Africa adjacent to the Mediterranean Sea, but all or part of it is absent because of nondeposition or erosion over much of the region. Post-Paleozoic deposition was more or less continuous across the entire craton border region in the Middle East and along the northern border of the Sahara platform in North Africa and in Somalia and eastern Ethiopia. Similar marine and associated sedimentary rock facies are present in all of these regions, although paleotectonic-stratigraphic interrelationships and continental paleolatitude positions have greatly affected petroleum generation and accumulation in the specific provinces along the craton border. A series of regional stratigraphic-sedimentary environment, and continental position, layer maps illustrates the relative influence of these factors through geologic time with respect to the relationship between petroleum reservoirs, source rocks, and confining rock facies.

Peterson, J.A. (Univ. of Montana, Missoula (United States))

1991-03-01

73

East Olkaria Geothermal Field, Kenya: 1. History match with production and pressure decline data  

NASA Astrophysics Data System (ADS)

A detailed three-dimensional model of the present well field of the Olkaria geothermal field in Kenya (East Olkaria) has been developed. The model matches reasonably well flow rate and enthalpy data from all existing wells at East Olkaria. The history match shows that the effective permeabilities in the steam zone and the underlying liquid-dominated zone are 7.5 and 4.0 mdarcy, respectively. These values are somewhat higher than those inferred from well test data. The effective fracture porosity in the liquid-dominated zone is estimated to be 2% on the average, with spatial variations of 0.25-5%. The modeling studies suggest that the reservoir system is of rather uniform permeability and that no barriers to fluid flow are necessary to match the data. However, there appears to be a high permeability anomaly below a depth of 1000 m extending north-south through some of the more productive wells (wells 12, 15, 16, and 20).

Bodvarsson, Gudmundur S.; Pruess, Karsten; Stefansson, Valgardur; Bjornsson, Sveinbjorn; Ojiambo, Sebastian B.

1987-01-01

74

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

SciTech Connect

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.

Jablonski, D.M. (ed.)

1982-01-01

75

Country Profile: Middle East, and North Africa (MENA)  

NSDL National Science Digital Library

The International Finance Corporation (reviewed in the November 11, 1997 Scout Report for Business & Economics) established the Middle East, and North Africa Department (MENA) to support research and investment projects in seventeen Central Asian, Middle Eastern, and North African nations. Socioeconomic data from these efforts are summarized in narrative and numerical form in the MENA Country Profiles. These overviews give background social information, key economic ratios, and long-term trends. Annotated links to relevant data from other IFC databases, the US State Department, and the Central Intelligence Agency point users to more information.

1998-01-01

76

The Polymorphic Linker Domain of pfmdr1 Is Associated with Resistance-Conferring Mutations in Plasmodium falciparum Populations from East and West Africa  

PubMed Central

Sequence variation in the asparagine/aspartate-rich domain of pfmdr1 in 215 isolates of Plasmodium falciparum from three African countries was compared with published data. The role of this domain in modulating antimalarial sensitivity has not been established. The pfmdr1 86Y allele was significantly associated with different configurations of the Asn/Asp-rich domain in West and East Africa. In Kenya, a specific form of the Asn/Asp-rich domain was significantly linked to the 86Y, 184Y, and 1246Y haplotype of pfmdr1. PMID:23836177

Okombo, John; Zongo, Issaka; Gadalla, Nahla; Bousema, Teun; Beshir, Khalid B.; Roper, Cally; Hallett, Rachel; Ochola-Oyier, Lynette Isabella

2013-01-01

77

Mineral facilities of Africa and the Middle East  

USGS Publications Warehouse

This map displays over 1,500 mineral facilities in Africa and the Middle East. The mineral facilities include mines, plants, mills, or refineries of aluminum, cement, coal, copper, diamond, gold, iron and steel, nickel, platinum-group metals, salt, and silver, among others. The data used in this poster were compiled from multiple sources, including the 2004 USGS Minerals Yearbook (Africa and Middle East volume), Minerals Statistics and Information from the USGS Web site (http://minerals.usgs.gov/minerals/), and data collected by USGS minerals information country specialists. Data reflect the most recent published table of industry structure for each country. Other sources include statistical publications of individual countries, annual reports and press releases of operating companies, and trade journals. Due to the sensitivity of some energy commodity data, the quality of these data should be evaluated on a country-by-country basis. Additional information and explanation is available from the country specialists. See Table 1 for general information about each mineral facility site including country, location and facility name, facility type, latitude, longitude, mineral commodity, mining method, main operating company, status, capacity, and units.

Eros, J.M.; Candelario-Quintana, Luissette

2006-01-01

78

Evaluating Downscaling Methods for Seasonal Climate Forecasts over East Africa  

NASA Astrophysics Data System (ADS)

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.

Roberts, J. B.; Robertson, F. R.; Bosilovich, M. G.; Lyon, B.

2013-12-01

79

Palaeoenvironmental perspectives for sustainable development in East Africa  

NASA Astrophysics Data System (ADS)

East African ecosystems are shaped by long-term interaction with changing climate, human population, fire and wildlife. There remains today a strong connection between people and ecosystems, a relationship that is being strained by the rapidly developing and growing East African population, and their associated resource needs. Predicted climatic and atmospheric change will further impact on ecosystems culminating in a host of challenges for their management and sustainable development, further compounded by a backdrop of political, land tenure and economic constraints. Given the many direct and indirect benefits that ecosystems provide to surrounding human populations, understanding how they have changed over time and space deserves a special place on the ecosystem management agenda. Such a perspective can only be derived from a palaeoecology, particularly where there is high resolution, both through time and across space. The East African palaeoecological archive is reviewed, in particular to assess how it can meet this need. Although there remain crucial gaps, the number of palaeoecological archives from East Africa growing rapidly, some employing new and novel techniques to trace past ecosystem response to climate change. When compared to the archaeological record it is possible to disentangle human from climate change impacts, and how the former interacts with major environmental changes such as increased use of fire, changing herbivore densities and increased atmospheric CO2 concentration. With this multi-dimensional perspective of environmental change impacts it is imperative that our understanding of past human-ecosystem interactions are considered to impart effective long term management strategies; such an approach will enhance possibilities for a sustainable future for East African ecosystems and maximise the livelihoods of the populations that rely on them.

Marchant, R.; Finch, J.; Kinyanjui, R.; Muiruri, V.; Mumbi, C.; Platts, P. J.; Rucina, S.

2010-05-01

80

Towards an integrated soil moisture drought monitor for East Africa  

NASA Astrophysics Data System (ADS)

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 monitoring systems to inform national and international drought response. At the same time, the very diversity and data scarcity that necessitate remote monitoring also make it difficult to evaluate the reliability of these systems. Here we apply a suite of remote monitoring techniques to characterize the temporal and spatial evolution of the 2010-2011 Horn of Africa drought. Diverse satellite observations allow for evaluation of meteorological, agricultural, and hydrological aspects of drought, each of which is of interest to different stakeholders. Focusing on soil moisture, we apply triple collocation analysis (TCA) to three independent methods for estimating soil moisture anomalies to characterize relative error between products and to provide a basis for objective data merging. The three soil moisture methods evaluated include microwave remote sensing using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) sensor, thermal remote sensing using the Atmosphere-Land Exchange Inverse (ALEXI) surface energy balance algorithm, and physically-based land surface modeling using the Noah land surface model. It was found that the three soil moisture monitoring methods yield similar drought anomaly estimates in areas characterized by extremely low or by moderate vegetation cover, particularly during the below-average 2011 long rainy season. Systematic discrepancies were found, however, in regions of moderately low vegetation cover and high vegetation cover, especially during the failed 2010 short rains. The merged, TCA-weighted soil moisture composite product takes advantage of the relative strengths of each method, as judged by the consistency of anomaly estimates across independent methods. This approach holds potential as a remote soil moisture-based drought monitoring system that is robust across the diverse climatic and ecological zones of East Africa.

Anderson, W. B.; Zaitchik, B. F.; Hain, C. R.; Anderson, M. C.; Yilmaz, M. T.; Mecikalski, J.; Schultz, L.

2012-04-01

81

Towards an integrated soil moisture drought monitor for East Africa  

NASA Astrophysics Data System (ADS)

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 monitoring systems to inform national and international drought response. At the same time, the very diversity and data scarcity that necessitate remote monitoring also make it difficult to evaluate the reliability of these systems. Here we apply a suite of remote monitoring techniques to characterize the temporal and spatial evolution of the 2010-2011 Horn of Africa drought. Diverse satellite observations allow for evaluation of meteorological, agricultural, and hydrological aspects of drought, each of which is of interest to different stakeholders. Focusing on soil moisture, we apply triple collocation analysis (TCA) to three independent methods for estimating soil moisture anomalies to characterize relative error between products and to provide a basis for objective data merging. The three soil moisture methods evaluated include microwave remote sensing using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) sensor, thermal remote sensing using the Atmosphere-Land Exchange Inverse (ALEXI) surface energy balance algorithm, and physically based land surface modeling using the Noah land surface model. It was found that the three soil moisture monitoring methods yield similar drought anomaly estimates in areas characterized by extremely low or by moderate vegetation cover, particularly during the below-average 2011 long rainy season. Systematic discrepancies were found, however, in regions of moderately low vegetation cover and high vegetation cover, especially during the failed 2010 short rains. The merged, TCA-weighted soil moisture composite product takes advantage of the relative strengths of each method, as judged by the consistency of anomaly estimates across independent methods. This approach holds potential as a remote soil moisture-based drought monitoring system that is robust across the diverse climatic and ecological zones of East Africa.

Anderson, W. B.; Zaitchik, B. F.; Hain, C. R.; Anderson, M. C.; Yilmaz, M. T.; Mecikalski, J.; Schultz, L.

2012-08-01

82

Health and Disease in East Africa Course Syllabus; Spring 2011 Interdisciplinary Perspectives on  

E-print Network

Health and Disease in East Africa Course Syllabus; Spring 2011 1 Interdisciplinary Perspectives on Global Health and Disease: Uganda PHS 644: Section 30 Course Syllabus ­ Spring 2012 Wednesdays 5 Prerequisites: Graduate and health professional students who plan field study in Uganda and/or East Africa

Sheridan, Jennifer

83

Diarrhoea and effects of different water sources, sanitation and hygiene behaviour in East Africa  

Microsoft Academic Search

published studies on domestic water use and environmental health in East Africa, based on direct observations or other reliable research methods. The objective of this study was to carry out a repeat analysis of domestic water use and environmental health in East Africa based on DOW I. The study was conducted in the same sites as DOW I. Field assistants

James K. Tumwine; John Thompson; Munguti Katua-Katua; Mark Mujwajuzi; Nick Johnstone; Elizabeth Wood; Ina Porras

2002-01-01

84

Basin and Range style tectonics in East Africa  

NASA Astrophysics Data System (ADS)

Geophysical and geological evidence suggest that the asthenospheric structure beneath the presently active east African rifts resembles that of the Basin and Range tectonic province of the western United States. Both regions are underlain by anomalously thin lithosphere riding on hot asthenospheric pillows that extend laterally for as much as 1500 km normal to structural trend. The continental rifts associated with these terranes do not appear to be leading to plate separation, and young oceanic rifts such as the Red Sea probably evolved from narrower, more restricted mantle thermal anomalies. Low-angle normal faults are interpreted to control the physiography and structural style in the east African rifts in a fashion analogous to that proposed for the Basin and Range. The limited horizontal extension that has occurred in east Africa, however, requires that mechanical thinning of the lithosphere must play a subsidiary role to thermal crosion from below. The upward migration of mantle isotherms has converted the base of the lithosphere to material with asthenospheric properties beneath thousands of square kilometers of crust. The presence of a broad zone of thin, warm lithosphere in both these tectonic provinces may help to distribute extensional strains over correspondingly broad regions. This in turn is expected to result in the development of numerous detachment surfaces (and corresponding surficial rifts), none of which ever completely thin the lithosphere or evolve to oceanic-style rifts.

Bosworth, William

85

Possible transcontinental dust transport from North Africa and the Middle East to East Asia  

NASA Astrophysics Data System (ADS)

From the evening of 25 March 2003 until 27 March an Asian dust event (Kosa) was observed at a total of 37 routine meteorological observatories in Japan, although no significant dust storms had been observed in the arid regions of China and Mongolia. A numerical simulation with a three-dimensional global aerosol transport model and meteorological observations reveal that the observed mineral dust particles were generated through dust storms in North Africa and the Middle East on 19 March. The simulation predicted that dust particles generated in the Sahara Desert and Arabian Peninsula on 19 March would be transported north of the Tien Shan Mountains in China and arrive over Japan in about 6-7 days. It also indicated that over 50% of the dust particles in Japan on 26-27 March came from North Africa, about 30% from the Middle East, and only about 10% from China in the boundary layer. The simulated result is consistent with polarization lidar and sky radiometer observations, indicating that the simulation is realistic. The simulation indicates that the Kosa phenomenon was caused by a mixture of transported dust and anthropogenic pollutants. The simulation of this dust event suggests the possible importance of dust transport from the Sahara and the Arabian Peninsula to East Asia.

Tanaka, Taichu Y.; Kurosaki, Yasunori; Chiba, Masaru; Matsumura, Takatsugu; Nagai, Tomohiro; Yamazaki, Akihiro; Uchiyama, Akihiro; Tsunematsu, Nobumitsu; Kai, Kenji

86

Remote sensing of geobotanical trends in East Africa  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

87

A Spring Forward for Hominin Evolution in East Africa  

PubMed Central

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

Cuthbert, Mark O.; Ashley, Gail M.

2014-01-01

88

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

PubMed

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

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

2014-09-01

89

Geophysical study of the East African margin  

E-print Network

for the Malagasy Republic (Nadagascar) relative to East Africa is presented based on several observations and analyses. An onshore-offshore Kenya Pre-Cambrian gabbroic basement ridge is aligned with a similar onshore Malagasy lineament, the Cap St. Andre. Both... ridge segments have similar Bouger gravity anomalies associated with them. A previously identified salt diapir field along East Africa appears to represent the location of a Tethyan seaway, which terminates against this basement ridge, and lies...

Matthias, Paul Kulman

2012-06-07

90

Energy system development in Africa : the case of grid and off-grid power in Kenya  

E-print Network

This research used a combination of a grounded theory approach and system dynamics to study the electric power system in Kenya and to model the feedback at work in the development of the system. The ethnographic study ...

Steel, Katherine Deaton

2008-01-01

91

Widespread Pyrethroid and DDT Resistance in the Major Malaria Vector Anopheles funestus in East Africa Is Driven by Metabolic Resistance Mechanisms  

PubMed Central

Background Establishing the extent, geographical distribution and mechanisms of insecticide resistance in malaria vectors is a prerequisite for resistance management. Here, we report a widespread distribution of insecticide resistance in the major malaria vector An. funestus across Uganda and western Kenya under the control of metabolic resistance mechanisms. Methodology/Principal Findings Female An. funestus collected throughout Uganda and western Kenya exhibited a Plasmodium infection rate between 4.2 to 10.4%. Widespread resistance against both type I (permethrin) and II (deltamethrin) pyrethroids and DDT was observed across Uganda and western Kenya. All populations remain highly susceptible to carbamate, organophosphate and dieldrin insecticides. Knockdown resistance plays no role in the pyrethroid and DDT resistance as no kdr mutation associated with resistance was detected despite the presence of a F1021C replacement. Additionally, no signature of selection was observed on the sodium channel gene. Synergist assays and qRT-PCR indicated that metabolic resistance plays a major role notably through elevated expression of cytochrome P450s. DDT resistance mechanisms differ from West Africa as the L119F-GSTe2 mutation only explains a small proportion of the genetic variance to DDT resistance. Conclusion The extensive distribution of pyrethroid and DDT resistance in East African An. funestus populations represents a challenge to the control of this vector. However, the observed carbamate and organophosphate susceptibility offers alternative solutions for resistance management. PMID:25333491

Mulamba, Charles; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Barnes, Kayla G.; Mukwaya, Louis G.; Birungi, Josephine; Wondji, Charles S.

2014-01-01

92

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

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

Keshavjee, Rashida

2010-01-01

93

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

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

Unterhalter, Elaine; North, Amy

2011-01-01

94

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

PubMed Central

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, Kenyatoday one of the hottest places on Earthhas been continually hot during the past 4 million years. The distribution of 13C-18O bonds in paleosol carbonates indicates that soil temperatures during periods of carbonate formation were typically above 30 C and often in excess of 35 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

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

2010-01-01

95

The Yellow, Fourmerous, Tubular Flowers of Kalanchoe marmorata from Central East Africa  

NSDL National Science Digital Library

The yellow, fourmerous, tubular flowers of Kalanchoe marmorata from Central East Africa illustrate two aspects of convergent evolution in Crassulaceae: sympetaly and variation in number of floral parts (either a reduction or increase).

Kindt, Frits; Hart, Henk'T

2004-03-09

96

Ten Years of Information Development in East, Central and Southern Africa.  

ERIC Educational Resources Information Center

Reviews 10 years of library and information developments in East, Central, and Southern Africa. Topics include school libraries; public libraries and rural information services; academic libraries; education and training; and professional library and information associations. (AEF)

Raseroka, H. Kay

1995-01-01

97

76 FR 55456 - The Trade and Investment Partnership for the Middle East and North Africa  

Federal Register 2010, 2011, 2012, 2013

...OFFICE OF THE UNITED STATES TRADE REPRESENTATIVE The Trade and Investment Partnership for the Middle East and North Africa AGENCY: Office of the United States Trade Representative. ACTION: Request for...

2011-09-07

98

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

NASA Astrophysics Data System (ADS)

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, in East African mangrove systems, domestic wastewater has detectable effects on crabs and molluscs, suggesting their usefulness as bioindicators of its effects in mangroves. Transformed benthic patterns at the peri-urban sites indicated the need for further study of the actual potential of natural mangrove forests to absorb pollution in sewage treatment.

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

2009-09-01

99

Mountain glaciers in the Mediterranean area and in Africa  

Microsoft Academic Search

Few glaciers or glacierets still exist in the Mediterranean area. The snow line between the Alps and the mountains of North Africa and the Near East must be reconstructed with the help of climatic data. The only glaciers in Africa are on Mt Kenya (covering an area of 0.8 km 2 ), on Kilimanjaro (5 km2) and in the Ruwenzori

B. Messerli

100

Quaternary glaciation in Africa: key chronologies and climatic implications  

Microsoft Academic Search

Multiple episodes of Quaternary glaciation are evidenced on >10 distinct mountain localities throughout Africa, with the best dated sites from Kilimanjaro and Mt Kenya in equatorial East Africa. A general paucity of radiogenic dates constrains the glacial chronology, and regional sequences have largely been based on correlations by relative weathering of features. Excellent glacial moraine preservation and other features of

Bryan G. Mark; Henry A. Osmaston

2008-01-01

101

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

PubMed Central

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

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

2014-01-01

102

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

PubMed

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

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

2014-01-01

103

EAST AFRICA EAST AFRICA  

E-print Network

Maternal, Child and Infant Health in Rwanda (2011-2014) $2million Grand Challenges Canada Canadian Rising,000 kilometres - Advertisement - 15°C Forecast | Traffic thestar.com Web find a businessadvanced search full text 19/09/11 4:00 PM NYTimes.com > Health Advertisement ARTICLE TOOLS E-Mail This Article Printer

Denham, Graham

104

Swahili as a National Language in East Africa.  

ERIC Educational Resources Information Center

The historical background and the current status of Swahili in Kenya and Tanzania, where it is designated as the national language, and in Uganda, where it has assumed a less prominent role, are described. Major factors contributing to the selection of national languages in the region are presented. The ways both linguistic and sociopolitical

Merritt, Marilyn; Abdulaziz, Mohamed H.

105

Terrestrial heat flow in east and southern Africa  

Microsoft Academic Search

We report 26 new heat production measurements from Zimbabwe, Zambia and Tanzania, together with details and some revisions of 18 previous heat flow measurements by other investigtors 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

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

1990-01-01

106

The Prevalence of HIV by Ethnic Group Is Correlated with HSV-2 and Syphilis Prevalence in Kenya, South Africa, the United Kingdom, and the United States  

PubMed Central

Background. This paper investigates two issues: do ethnic/racial groups with high HIV prevalences also have higher prevalences of other STIs? and is HIV prevalence by ethnic group correlated with the prevalence of circumcision, concurrency, or having more than one partner in the preceding year? Methods. We used Spearman's correlation to estimate the association between the prevalence of HIV per ethnic/racial group and HSV-2, syphilis, symptoms of an STI, having more than one partner in the past year, concurrency, and circumcision in Kenya, South Africa, the United Kingdom, and the United States. Results. We found that in each country HSV-2, syphilis, and symptomatic STIs were positively correlated with HIV prevalence (HSV-2: Kenya rho = 0.50, P = 0.207; South Africa rho-1, P = 0.000; USA rho-1, P = 0.000, Syphilis: Kenya rho = 0.33, P = 0.420; South Africa rho-1, P = 0.000; USA rho-1, P = 0.000, and STI symptoms: Kenya rho = 0.92, P = 0.001; South Africa rho-1, P = 0.000; UK rho = 0.87, P = 0.058; USA rho-1, P = 0.000). The prevalence of circumcision was only negatively associated with HIV prevalence in Kenya. Both having more than one partner in the previous year and concurrency were positively associated with HIV prevalence in all countries (concurrency: Kenya rho = 0.79, P = 0.036; South Africa rho-1, P = 0.000; UK 0.87, P = 0.058; USA rho-1, P = 0.000 and multiple partners: Kenya rho = 0.82, P = 0.023; South Africa rho-1, P = 0.000; UK rho = 0.87, P = 0.058; USA rho-1, P = 0.000). Not all associations were statistically significant. Conclusion. Further attention needs to be directed to what determines higher rates of partner change and concurrency in communities with high STI prevalence. PMID:25328516

Kenyon, Chris Richard

2014-01-01

107

Practice makes perfect: participatory innovation in soil fertility management to improve rural livelihoods in East Africa  

Microsoft Academic Search

Keywords: soil nutrient balances, soil fertility degradation, East Africa , participatory innovation, experiential learning, farmer field schools, smallholder agriculture Maintaining and improving soil fertility is crucial for Africa to attain the Millennium Development Goals. Fertile soil and balanced soil nutrient management are major foundations for sustainable food production, contribute to a sound management of natural resources and assist in controlling

Jager de A

2007-01-01

108

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

Microsoft Academic Search

Since the very beginning of the human race, the Middle East served as a bridge between Africawhere our species first evolvedand 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,

Arie S. Issar

2010-01-01

109

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

ERIC Educational Resources Information Center

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

Anderson, Teresa, Comp.; And Others

110

Learning from Logframes: Reflections on Three Educational Development Projects in East and Southern Africa  

ERIC Educational Resources Information Center

Against a backdrop of the importance of project evaluation in Africa, and the centrality of the project logical framework (logframes) to project evaluation, this paper reflects on experiences arising from evaluations of three educational development projects in East and Southern Africa. Each of these projects had a strong teacher development

Harley, Ken

2005-01-01

111

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

Microsoft Academic Search

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

D. Manful; K. Tscherning; K. Kersebaum; J. Dietz; O. Dietrich; C. Gomani; H. Bhm; M. Bchner; G. Lischeid; M. Ojoyi

2009-01-01

112

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

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 1422 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 technologies to national agricultural research systems (NARS) in sub-Saharan Africa. PMID:24400011

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

2013-01-01

113

Invasion of Africa by a single pfcrt allele of South East Asian type  

Microsoft Academic Search

BACKGROUND: Because of its dramatic public health impact, Plasmodium falciparum resistance to chloroquine (CQ) has been documented early on. Chloroquine-resistance (CQR) emerged in the late 1950's independently in South East Asia and South America and progressively spread over all malaria areas. CQR was reported in East Africa in the 1970's, and has since invaded the African continent. Many questions remain

Frdric Ariey; Thierry Fandeur; Remy Durand; Milijaona Randrianarivelojosia; Ronan Jambou; Eric Legrand; Marie Thrse Ekala; Christiane Bouchier; Sandrine Cojean; Jean Bernard Duchemin; Vincent Robert; Jacques Le Bras; Odile Mercereau-Puijalon

2006-01-01

114

Warming and stratification changes in Lake Kivu, east Africa  

NASA Astrophysics Data System (ADS)

To investigate changes in the temperature and stratification structure in Lake Kivu, we have installed a string of temperature recorders and performed CTD casts. The obtained data have been compared to historical profiles and the heat budget for the lake was analyzed. Lake Kivu is a meromictic lake characterized by an anomalous temperature distribution with a temperature minimum close to the base of the seasonally mixed layer. Warming rate at the depth of the temperature inversion is consistent with the historical warming rate of the surface layer of 0.14 +/-0.02 C per decade. Atmospheric warming rates since the 1970's in East Africa are between 0.20 and 0.25 C per decade. Reported warming in surface waters of other East-African rift lakes is 0.13 C per decade. Deep waters (greater than 350 m) in Lake Kivu exhibit variability in temperature and are currently warming at a rate of ?0.06+/-0.02 C per decade based on the increase in heat content since the 1970's and the increase in temperature seen in the deepest measurements between our 2011 and 2012 profiles. The monimolimnion of Lake Kivu cannot be considered to be in a steady state. The depth of wind-induced surface mixing during the dry season varies significantly between years. Mixing to 80 m (the present depth of the temperature inversion) requires continuous winds blowing from the south at 9--10 m s-1, whereas typical wind speed maxima are around 5--6 m s-1 and capable of mixing to around 65 m depth. Occasional stronger winds cause episodic mixing closer to the inversion which removes heat, but this does not happen on a regular basis. As the temperature inversion in recent historical profiles has been as shallow as 65 m, mixing to the temperature inversion depth is possible during years with stronger than average winds. With heat diffusing towards the temperature inversion from both above and below, the temperature at the inversion depth will continue to rise, resulting in a reduced transport of heat out of the deep waters that may increase the rate at which the water column is warming.

Aaberg, Arthur Allen

115

Geographical Variation in the Response of Visceral Leishmaniasis to Paromomycin in East Africa: A Multicentre, Open-Label, Randomized Trial  

PubMed Central

Background Visceral leishmaniasis (VL) is a major health problem in developing countries. The untreated disease is fatal, available treatment is expensive and often toxic, and drug resistance is increasing. Improved treatment options are needed. Paromomycin was shown to be an efficacious first-line treatment with low toxicity in India. Methods This was a 3-arm multicentre, open-label, randomized, controlled clinical trial to compare three treatment regimens for VL in East Africa: paromomycin sulphate (PM) at 15 mg/kg/day for 21 days versus sodium stibogluconate (SSG) at 20 mg/kg/day for 30 days; and the combination of both dose regimens for 17 days. The primary efficacy endpoint was cure based on parasite-free tissue aspirates taken 6 months after treatment. Findings Overall, 135 patients per arm were enrolled at five centres in Sudan (2 sites), Kenya (1) and Ethiopia (2), when the PM arm had to be discontinued due to poor efficacy. The trial has continued with the higher dose of PM as well as the combination of PM and SSG arms. These results will be reported later. Baseline patient characteristics were similar among treatment arms. The overall cure with PM was significantly inferior to that with SSG (63.8% versus 92.2%; difference 28.5%, 95%CI 18.8% to 38.8%, p<0.001). The efficacy of PM varied among centres and was significantly lower in Sudan (14.3% and 46.7%) than in Kenya (80.0%) and Ethiopia (75.0% and 96.6%). No major safety issues with PM were identified. Conclusion The efficacy of PM at 15 mg/kg/day for 21 days was inadequate, particularly in Sudan. The efficacy of higher doses and the combination treatment warrant further studies. PMID:21049059

Hailu, Asrat; Musa, Ahmed; Wasunna, Monique; Balasegaram, Manica; Yifru, Sisay; Mengistu, Getahun; Hurissa, Zewdu; Hailu, Workagegnehu; Weldegebreal, Teklu; Tesfaye, Samson; Makonnen, Eyasu; Khalil, Eltahir; Ahmed, Osama; Fadlalla, Ahmed; El-Hassan, Ahmed; Raheem, Muzamil; Mueller, Marius; Koummuki, Yousif; Rashid, Juma; Mbui, Jane; Mucee, Geoffrey; Njoroge, Simon; Manduku, Veronica; Musibi, Alice; Mutuma, Geoffrey; Kirui, Fredrick; Lodenyo, Hudson; Mutea, Dedan; Kirigi, George; Edwards, Tansy; Smith, Peter; Muthami, Lawrence; Royce, Catherine; Ellis, Sally; Alobo, Moses; Omollo, Raymond; Kesusu, Josephine; Owiti, Rhoda; Kinuthia, John

2010-01-01

116

Hypovitaminosis D in the Middle East and North Africa  

PubMed Central

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 20002012; 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 3090%, 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

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

2013-01-01

117

Predicting distribution of Aedes aegypti and Culex pipiens complex, potential vectors of Rift Valley fever virus in relation to disease epidemics in East Africa  

PubMed Central

Background The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. Methods Diverse ecological niche modelling techniques have been developed for this purpose: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Results Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Conclusion Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods. PMID:24137533

Mweya, Clement Nyamunura; Kimera, Sharadhuli Iddi; Kija, John Bukombe; Mboera, Leonard E. G.

2013-01-01

118

High Prevalence of Rickettsia africae Variants in Amblyomma variegatum Ticks from Domestic Mammals in Rural Western Kenya: Implications for Human Health  

PubMed Central

Abstract 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 africaegenotype 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

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.

2014-01-01

119

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

120

Natural radioactivity and external dose in the high background radiation area of Lambwe East,Southwestern Kenya.  

PubMed

Absorbed dose rates around the North and South Ruri hills in Lambwe east, southwestern Kenya were measured using survey meters. The area lies roughly between latitudes 030'S and 100'S. It is bounded on the east by longitude 3430'E and on the west by the shores of Lake Victoria and Winnam Gulf. The measured absorbed dose varies from 0.7 to 6.0 Gy h(-1), and the mean is 2.3 Gy h(-1). Assuming an outdoor occupancy factor of 0.4, the corresponding range and mean annual effective doses are 1.7-14.7 and 5.7 mSv, respectively. The average activity concentrations (ACs) of (232)Th, (226)Ra and (40)K in samples of soils and rocks from the area are 1397, 179 and 509 Bq kg(-1), respectively. Values of absorbed dose rates calculated from the ACs are general lower than those obtained from in situ measurements. Possible causes of these discrepancies were discussed in the paper. PMID:22535833

Achola, S O; Patel, J P; Mustapha, A O; Angeyo, H K

2012-12-01

121

Fertilizer profitability in East Africa: A Spatially Explicit Policy Analysis  

Microsoft Academic Search

Even though it is clear that Substantial growth in inorganic fertilizer use is a prerequisite for sustained agricultural growth in Africa, fertilizer use is still one of the factors explaining lagging agricultural productivity growth in SSA. High transport costs and less policy support pose a significant barrier to make fertilizer application profitable in Africa. This paper is aimed to identify

Zhe Guo; Jawoo Koo; Stanley Wood

2009-01-01

122

A Reassortant Bunyavirus Isolated from Acute Hemorrhagic Fever Cases in Kenya and Somalia  

Microsoft Academic Search

In late 1997 and early 1998, a large outbreak of hemorrhagic fever occurred in East Africa. Clinical samples were collected in Kenya and southern Somalia, and 27 of 115 (23%) hemorrhagic fever patients tested showed evidence of acute infection with Rift Valley fever (RVF) virus as determined by IgM detection, virus isolation, detection of virus RNA by reverse transcription-polymerase chain

Michael D. Bowen; Sam G. Trappier; Angela J. Sanchez; Richard F. Meyer; Cynthia S. Goldsmith; Sherif R. Zaki; Lee M. Dunster; C. J. Peters; Thomas G. Ksiazek; Stuart T. Nichol

2001-01-01

123

Rethinking geochemical feature of the Afar and Kenya mantle plumes and geodynamic implications  

Microsoft Academic Search

We discuss the spatial and temporal variation in the geochemistry of mantle sources which were sampled by the Eocene to Quaternary mafic magmas in the vicinity of the Afar and Kenya plume upwelling zones, East Africa. Despite the contributions of lithospheric and crustal sources, carefully screened Eocene to Quaternary mafic lavas display wide range of Sr-Nd-Pb isotopic and incompatible trace

Daniel Meshesha; Ryuichi Shinjo

2008-01-01

124

AFRICA ASIA SOUTH AMERICA Algeria Afghanistan Argentina  

E-print Network

Timor-Leste (East Timor) South Sudan Turkey Sudan Turkmenistan Swaziland United Arab Emirates TanzaniaAFRICA ASIA SOUTH AMERICA Algeria Afghanistan Argentina Angola Armenia Bolivia Benin Azerbaijan Kazakhstan Guinea Korea (North) Guinea-Bissau Korea (South) Kenya Kuwait Lesotho Kyrgyzstan Liberia Lao PDR

Oxford, University of

125

Conclusion: Towards a Renewable Energy Transition in the Middle East and North Africa?  

Microsoft Academic Search

\\u000a For the Middle East and North Africa the notion of a renewable energy transition is no longer beyond the limits of technical\\u000a possibility. This conclusion examines one proposed sustainability transition the DESERTEC energy community that has received\\u000a high-level political support in Europe and also has influential champions in the Middle East. The DESERTEC vision anticipates\\u000a an unprecedented level

Michael Mason

126

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

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

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

2011-01-01

127

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

PubMed Central

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%

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

128

A survey of laboratory animal disease in Kenya.  

PubMed

Diseases and infections diagnosed in laboratory mice, rats, guinea-pigs, golden hamsters and rabbits at the Veterinary Research Laboratory, Kabete, Kenya, are listed and discussed. Zoonoses encountered included salmonellosis and lymphocytic choriomeningitis. A number of traditionally recognised conditions were recorded but there were some notable omissions. The changing picture in laboratory animal science in East Africa is outlined and attention is drawn to the need for work on related diseases and infections. PMID:1256011

Cooper, J E

1976-01-01

129

Centralization, decentralization, and conflict in the Middle East and North Africa  

Microsoft Academic Search

This paper examines broadly the intergovernmental structure in the Middle East and North Africa region, which has one of the most centralized government structures in the world. The authors address the reasons behind this centralized structure by looking first at the history behind the tax systems of the region. They review the Ottoman taxation system, which has been predominantly influential

Mehmet Serkan Tosun; Serdar Yilmaz

2008-01-01

130

Water Governance in the Middle East and North Africa: An Unfinished Agenda  

Microsoft Academic Search

All aspects of the fresh water situation in the Middle East and North Africa are underlain by the scarcity of fresh water in the region compared with the demands for it. However, physical scarcity has been worsened by institutions that may once have been adequate but that are increasingly failing to meet modern needs for water to be extracted in

Eglal Rached; David B. Brooks

2010-01-01

131

Concentrating solar power for seawater desalination in the Middle East and North Africa  

Microsoft Academic Search

The paper presents a long-term scenario for the demand of freshwater in the Middle East and North Africa (MENA) and shows how it may be covered by a better use of the existing renewable water sources and by sea water desalination powered with solar energy. Growth of population and economy, increasing urbanization and industrialization, and the rather limited natural resources

Franz Trieb; Hans Mller-Steinhagen

2008-01-01

132

MIDDLE EAST AND NORTH AFRICA DATABASE DEVELOPMENT AND RESEARCH TO POPULATE THE DOE KNOWLEDGE BASE  

Microsoft Academic Search

The objective of this work is to update, analyze, and document data for the Middle East and North Africa regions in order to provide accurate input to the DOE's Knowledge Base system. Specifically, we aim to provide assessments and comparison of different geophysical databases, such as Moho and basement maps, for the region of study, in an effort to document

Muawia Barazangi; Dogan Seber; Eric Sandvol; Francisco Gomez; Christine Sandvol; Carrie Brindisi

133

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

E-print Network

1 Components of rainy seasons variability in Equatorial East Africa : onset, cessation, rainfall-1987) are computed for each of these variables. The spatial coherence of monthly or seasonal P and NRD is always much in the course of the seasonal cycle. Coherence is highest at the peak of the Short Rains (October

Boyer, Edmond

134

Iodine Content in Fish and Other Food Products from East Africa Analyzed by ICP-MS  

Microsoft Academic Search

The purpose of this study was to measure the iodine content in sea water fish, fresh water fish, and different foods of plant origin commonly consumed in East Africa in order to evaluate dietary iodine sources for the population in the selected areas. Fish, and food items of cereals, vegetables, legumes, salt, and tea, were obtained from local market sampling

Karen M. Eckhoff; Amund Maage

1997-01-01

135

Revolution and Journalism Higher Education in the Middle East/North Africa Region  

ERIC Educational Resources Information Center

The disruptions brought by the Arab Spring revolutions in the Middle East/North Africa (MENA) region in 2010-2011 created a series of personal and professional challenges for those involved in higher education in journalism in the region. This research uses narrative inquiry to examine the impact revolution had on a group of educators in the MENA

Schafer, Shaun T.

2012-01-01

136

Role of land surface processes in monsoon development: East Asia and West Africa  

E-print Network

Role of land surface processes in monsoon development: East Asia and West Africa Yongkang Xue,1,2 H and West African monsoon development and are among the most important mechanisms governing the development of the monsoon. The results were obtained by conducting simulations for five months of 1987 using a general

Xue, Yongkang

137

Pleistocene desiccation in East Africa bottlenecked but did not extirpate the adaptive radiation  

E-print Network

of Lake Victoria haplochromine cichlid fishes Kathryn R. Elmera,1 , Chiara Reggioa,1 , Thierry Wirtha,2 March 3, 2009) The Great Lakes region of East Africa, including Lake Victoria, is the center, within that lake basin or elsewhere, from which Lake Victoria was recolonized. We studied the population

Wirth, Thierry

138

A Review Of Mercury in Lake Victoria, East Africa: Implications for Human and Ecosystem Health  

Microsoft Academic Search

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

Linda M. Campbell; D. G. Dixon; R. E. Hecky

2003-01-01

139

Evaluating U.S. Military Engineering Efforts In East Africa.  

National Technical Information Service (NTIS)

Some states in Africa in the 21st century possess many of the same challenges as Afghanistan did in 1989 when the Soviet Union pulled out. These regimes have weak or failing governments, high poverty and disease rates, porous borders, and serious security...

S. P. Dalton

2013-01-01

140

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

ERIC Educational Resources Information Center

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

Howard, Karen

2014-01-01

141

Influence of historical land use transformation on the Greater Horn of Africa climate: Case Study over Kenya  

NASA Astrophysics Data System (ADS)

The behavior of the planetary boundary layer (PBL) is largely influenced by its contact with the planetary surface. The land surface characteristics that include the surface roughness, albedo, moisture availability among others control the Land-atmosphere interaction. These surface conditions play a major role in turbulence transfer of mass, momentum and heat and provide a vital physical link between the atmosphere and the surface of the earth. In this study, we investigate relationship between land use/cover and regional patterns of precipitation and temperature over central highlands of the Greater Horn of Africa (Kenya) using both remote sensing techniques and model simulations. ERDAS imagine 9.3, a remote sensing tool, is employed in land use/land cover classification over Kenya for realistic model land cover representation. Idealized land use/cover scenarios (borrowing from the ERDAS classifications) are used in regional climate simulations (using RegCM3 model) since existing observations are inadequate to determine the extent and severity of historical land use changes. Our case study periods are for the years 1986, 1995 and 2000. We also focus on the two primary rainfall season over the study domain centered on March-April-May (MAM) and October-November-December (OND). Preliminary results shows areas of rainfall maximum over the western, central and coastal parts of Kenya tend to be co-located with Forest and agricultural zones. Analysis of precipitation variability over the years 1986, 1995 and 2000 in the neighborhood of inland lakes, in particular Lake Victoria (largest lake in Africa) shows persistent precipitation throughout the year. This we attribute to local convection induced by topography and Lake induced circulations and associated convection. Our analysis also shows a decline in MAM seasonal rainfall between the period 1986 to 2000 and a slight increase of OND seasonal rainfall over the same period. The decrease in MAM seasonal rainfall can be attributed to environmental (forests) degradation and other climate phenomena, which we will later investigate in our modeling work. MAM seasonal rainfall has earlier been linked to local scale factors while OND seasonal rainfall is linked to influence of large scale phenomena over the region. Temperature anomalies over the same region show temperature fluctuations to be minimal over the western and central parts of the country co-located with agricultural and forests zones. Nonetheless seasonal temperature anomalies shows an increase of approximately 0.50C during the MAM season between the periods 1986 and 2000 and approximately 0.20C in OND season over the same time period. Our finding in this study is important in the sense that detecting land use/land cover change accurately at appropriate scale and in a timely manner will help to better understand their impacts on climate and potentially improve the predictability and prediction of regional climates on both short and long time scales.

Anyah, R. O.; Otieno, V. O.

2010-12-01

142

SHORT PERIOD SURFACE WAVE DISPERSION MEASUREMENTS FROM AMBIENT SEISMIC NOISE IN NORTH AFRICA, THE MIDDLE EAST, AND CENTRAL ASIA  

E-print Network

, THE MIDDLE EAST, AND CENTRAL ASIA Michael H. Ritzwoller1 , Nikolai M. Shapiro1 , Michael E. Pasyanos2-band seismic data obtained in North Africa, the Middle East, and Central Asia. The goal is to improve, the Middle East, and Central Asia as a step toward calibrating the propagation of surface waves

Shapiro, Nikolai

143

Lettowia, a new genus of Vernonieae from East Africa (Asteraceae)  

PubMed Central

Abstract A new genus, Lettowia H. Rob. & Skvarla is named for the single East African species originally described as Vernonia nyassae Oliv. Its pollen is lophate and triporate, with a perforated tectum restricted to the muri. The new genus is placed near Vernoniastrum in the subtribe Erlangeinae. PMID:24198711

Robinson, Harold; Skvarla, John J.

2013-01-01

144

Plate Tectonics of the Red Sea and East Africa  

Microsoft Academic Search

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.

D. P. McKenzie; D. Davies; P. MOLNAR

1970-01-01

145

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

Microsoft Academic Search

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

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

2007-01-01

146

Systematic Monitoring of Voluntary Medical Male Circumcision Scale-Up: Adoption of Efficiency Elements in Kenya, South Africa, Tanzania, and Zimbabwe  

PubMed Central

Background SYMMACS, the Systematic Monitoring of the Voluntary Medical Male Circumcision Scale-up, tracked the implementation and adoption of six elements of surgical efficiency use of multiple surgical beds, pre-bundled kits, task shifting, task sharing, forceps-guided surgical method, and electrocauteryas standards of surgical efficiency in Kenya, South Africa, Tanzania, and Zimbabwe. Methods and Findings This multi-country study used two-staged sampling. The first stage sampled VMMC sites: 73 in 2011, 122 in 2012. The second stage involved sampling providers (358 in 2011, 591 in 2012) and VMMC procedures for observation (594 in 2011, 1034 in 2012). The number of VMMC sites increased significantly between 2011 and 2012; marked seasonal variation occurred in peak periods for VMMC. Countries adopted between three and five of the six elements; forceps-guided surgery was the only element adopted by all countries. Kenya and Tanzania routinely practiced task-shifting. South Africa and Zimbabwe used pre-bundled kits with disposable instruments and electrocautery. South Africa, Tanzania, and Zimbabwe routinely employed multiple surgical bays. Conclusions SYMMACS is the first study to provide data on the implementation of VMMC programs and adoption of elements of surgical efficiency. Findings have contributed to policy change on task-shifting in Zimbabwe, a review of the monitoring system for adverse events in South Africa, an increased use of commercially bundled VMMC kits in Tanzania, and policy dialogue on improving VMMC service delivery in Kenya. This article serves as an overview for five other articles following this supplement. PMID:24801374

Bertrand, Jane T.; Rech, Dino; Omondi Aduda, Dickens; Frade, Sasha; Loolpapit, Mores; Machaku, Michael D.; Oyango, Mathews; Mavhu, Webster; Spyrelis, Alexandra; Perry, Linnea; Farrell, Margaret; Castor, Delivette; Njeuhmeli, Emmanuel

2014-01-01

147

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)

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).

Castillo, Paterno; Hilton, David; Halldrsson, Smundur

2014-09-01

148

East Olkaria Geothermal Field, Kenya: 2. Predictions of well performance and reservoir depletion  

NASA Astrophysics Data System (ADS)

Performance predictions are presented for the East Olkaria geothermal field, using a three-dimensional well-by-well model calibrated against 6.5 years of production history. Various reservoir development schemes are investigated to study the effects of different well spacing on well deliverabilities, power production of 45 and 105 MWe (megawatts electric), and the effects of injection on well performance and reservoir depletion. It is shown that the present well density at Olkaria (20 wells/km2) is too high; recommended well density for future wells is 11 wells/km2 (300-m well spacing). The present production area at East Olkaria (2 km2) is capable of 45 MWe power production for a 30-year period, but 105 MWe power production requires a well field area of about 9.5 km2, which may not exist. Injection can help sustain steam flow rates from wells, thus reducing the need for new development wells.

Bodvarsson, Gudmundur S.; Pruess, Karsten; Stefansson, Valgardur; Bjornsson, Sveinbjorn; Ojiambo, Sebastian B.

1987-01-01

149

Isotopic composition of waters from Ethiopia and Kenya: Insights into moisture sources for eastern Africa  

Microsoft Academic Search

Oxygen and deuterium isotopic values of meteoric waters from Ethiopia are unusually high when compared to waters from other high-elevation settings in Africa and worldwide. These high values are well documented; however, the climatic processes responsible for the isotopic anomalies in Ethiopian waters have not been thoroughly investigated. We use isotopic data from waters and remote data products to demonstrate

Naomi E. Levin; Edward J. Zipser; Thure E. Cerling

2009-01-01

150

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

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

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

2013-01-01

151

Public Policy and the Management of Higher Education in Sub-Saharan Africa: The Case of Kenya.  

ERIC Educational Resources Information Center

Examines Kenya's policy concerning growth and development of higher education over the last 20 years. Concludes that Kenya has problems of infrastructure quality and physical plant similar to those of other Sub-Saharan African countries, that resource allocation policies are inconsistent, and that expansion should be guided by popular demand for

Gray, Kenneth R.; Credle, Sid Howard

1996-01-01

152

Abstract We used a data set of ungulate censuses from 31 natural ecosystems from East and Southern Africa to  

E-print Network

Abstract We used a data set of ungulate censuses from 31 natural ecosystems from East and Southern Africa to test two hypotheses: (1) megaherbivores should domi- nate ungulate communities in ecosystems

Illius, Andrew

153

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

NASA Astrophysics Data System (ADS)

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 of the Indo-Pacific warming signal (IPWS). These modes are used in conjunction with CMIP5-estimates of IPWS to project 2030 climate conditions. In the second approach we use the much simpler Composite Delta Method to generate climate projections. Future climate projections are generated by simply altering the mean observed climate to match the mean climate of the climate model projections. Projections of precipitation and temperature from both approaches were then used to drive NASA's FEWS NET Land Data Assimilation System (FLDAS) to simulate the hydrologic variables most relevant to agriculture and water security: runoff, soil moisture and evapotranspiration. These outputs inform 2030 food and water security scenarios for East Africa. Finally we also investigate the impact of precipitation versus temperature changes on agriculture and water security in East Africa. We do so by keeping either one of those forcings constant while using the actual projections of the other variable to generate projections of hydrologic variables as described above.

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

2013-12-01

154

Climate change, water resources, and the politics of adaptation in the Middle East and North Africa  

Microsoft Academic Search

Through an examination of global climate change models combined with hydrological data on deteriorating water quality in the\\u000a Middle East and North Africa (MENA), we elucidate the ways in which the MENA countries are vulnerable to climate-induced impacts\\u000a on water resources. Adaptive governance strategies, however, remain a low priority for political leaderships in the MENA region.\\u000a To date, most MENA

Jeannie Sowers; Avner Vengosh; Erika Weinthal

2011-01-01

155

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

USGS Publications Warehouse

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.

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

2012-01-01

156

The Great Lakes in East Africa: biological conservation considerations for species flocks  

Microsoft Academic Search

The three largest water bodies of East Africa, Lake Victoria, Tanganyika, and Malawi contain an estimated number of 2,000\\u000a endemic cichlid fish species, in addition, to a mostly uncounted wealth of invertebrates. While the terrestrial diversity\\u000a is reasonably well protected, as economic and touristic interests coincide with biological conservation strategies, this is\\u000a not the case for most African lakes and

Christian Sturmbauer

157

The Great Lakes in East Africa: biological conservation considerations for species flocks  

Microsoft Academic Search

The three largest water bodies of East Africa, Lake Victoria, Tanganyika, and Malawi contain an estimated number of 2,000\\u000a endemic cichlid fish species, in addition, to a mostly uncounted wealth of invertebrates. While the terrestrial diversity\\u000a is reasonably well protected, as economic and touristic interests coincide with biological conservation strategies, this is\\u000a not the case for most African lakes and

Christian Sturmbauer

2008-01-01

158

Results of injection and tracer tests in Olkaria north east field in Kenya  

SciTech Connect

Tracer and injection tests were performed in the Olkaria North East Field with the objective to reduce uncertainty in the engineering design and to determine the suitability of well OW-704 as a re-injection well for the waste brine from the steam field during production. An organic dye (sodium fluorescein) was injected into well OW-704 as a slug. The tracer returns were observed in well OW-M2 which is 580 m deep, 620 m from well OW-704 and well OW-716 which is 900 m from well OW-704. The other wells on discharge, OW-714, and OW-725 did not show any tracer returns. However, other chemical constituents suggested., that well OW-716 experienced a chemical breakthrough earlier than OW-M2. Tracer return velocities of 0.31 m/hr and 1.3 m/hr were observed. Results of the tracer and injection tests indicate that OW-704 may be used as a re-injection well provided a close monitoring program is put in place.

Karingithi, C.W. [Kenya Power Company Ltd., Naivasha (Kenya)

1995-12-31

159

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

ERIC Educational Resources Information Center

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

Maher, Robert

160

African 2, a clonal complex of Mycobacterium bovis epidemiologically important in East Africa.  

PubMed

We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2) clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of M. bovis have, in general, four or more copies of the insertion sequence IS6110, in contrast to the majority of M. bovis strains isolated from cattle, which are thought to carry only one or a few copies. PMID:21097608

Berg, Stefan; Garcia-Pelayo, M Carmen; Mller, Borna; Hailu, Elena; Asiimwe, Benon; Kremer, Kristin; Dale, James; Boniotti, M Beatrice; Rodriguez, Sabrina; Hilty, Markus; Rigouts, Leen; Firdessa, Rebuma; Machado, Adelina; Mucavele, Custodia; Ngandolo, Bongo Nare Richard; Bruchfeld, Judith; Boschiroli, Laura; Mller, Annlle; Sahraoui, Naima; Pacciarini, Maria; Cadmus, Simeon; Joloba, Moses; van Soolingen, Dick; Michel, Anita L; Djnne, Berit; Aranaz, Alicia; Zinsstag, Jakob; van Helden, Paul; Portaels, Franoise; Kazwala, Rudovick; Kllenius, Gunilla; Hewinson, R Glyn; Aseffa, Abraham; Gordon, Stephen V; Smith, Noel H

2011-02-01

161

Persistence of Rift Valley fever virus in East Africa  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

162

Spatial variation of primordial 3-He in crustal fluids along the East-African Rift system (the Ethiopian and the Kenya Rift section)  

NASA Technical Reports Server (NTRS)

(3)He/(4)He compositions are presented for groundwater samples from the Ethiopian segment of the East-Afrikan Rift and from its northern extension, the adjacent Afar region (Djibuti). Helium isotope data are compared to those obtained previously from the Gregory Rift, south of Ethiopia. The distribution pattern of mantle-derived volatiles along the entire East-African-Rift (-from south Kenya to Djibuti-) is discussed and their sources are identified. Helium isotope ratios (R) for samples from the Ethiopian part of the Rift range from 6.3 to 16.0 times the atmospheric ratio (Ra=1.4 x 10(exp -6) and thus show together with a MOR component a considerable hotspot helium component. These mantle helium concentrations are comparable to those observed in groundwaters and volcanic rocks from the Afar plume region in Djibuti. Here R/Ra values range from 9 to 13 times the atmospheric composition, with mantle-derived helium concentrations being higher than at spreading ocean ridges. R/Ra values from Ethiopia and Djibuti are entirely different from those observed in groundwaters at the southerly extending Gregory Rift in Kenya, where R/Ra values scatter between 0.5 and 6. At the northernmost part of the Gregory Rift, close to Ethiopia mantle helium contents are slightly higher, with R/Ra-values varying between 6.5 and 8.0.

Griesshaber, E.; Weise, S.; Darling, G.

1994-01-01

163

An Observational Study of the Relationship between Excessively Strong Short Rains in Coastal East Africa and Indian Ocean SST  

Microsoft Academic Search

Composites of SST, wind, rainfall, and humidity have been constructed for years of high rainfall during September, October, and November (SON) in equatorial and southern-central East Africa. These show that extreme East African short rains are associated with large-scale SST anomalies in the Indian Ocean that closely resemble those that develop during Indian Ocean dipole or zonal mode (IOZM) events.

Emily Black; Julia Slingo; Kenneth R. Sperber

2003-01-01

164

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

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

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

2014-01-01

165

Seasonal changes in abundances of waterbirds at Sabaki River Mouth (Malindi, Kenya), a key stopover site on the West AsianEast African Flyway  

Microsoft Academic Search

Information on seasonal changes in waterbird numbers in coastal East Africa is limited, but crucial for estimating global flyway populations and targeting conservation efforts. The Sabaki River Mouth is an important site for waterbirds in the region. We counted waterbirds at the site monthly from April 2004 to February 2005. Our counts confirmed the importance of the site for the

Simon Valle; Luigi Boitani

2012-01-01

166

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

NASA Astrophysics Data System (ADS)

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.

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

167

East African cassava mosaic-like viruses from Africa to Indian ocean islands: molecular diversity, evolutionary history and geographical dissemination of a bipartite begomovirus  

PubMed Central

Background Cassava (Manihot esculenta) is a major food source for over 200 million sub-Saharan Africans. Unfortunately, its cultivation is severely hampered by cassava mosaic disease (CMD). Caused by a complex of bipartite cassava mosaic geminiviruses (CMG) species (Family: Geminivirideae; Genus: Begomovirus) CMD has been widely described throughout Africa and it is apparent that CMG's are expanding their geographical distribution. Determining where and when CMG movements have occurred could help curtail its spread and reveal the ecological and anthropic factors associated with similar viral invasions. We applied Bayesian phylogeographic inference and recombination analyses to available and newly described CMG sequences to reconstruct a plausible history of CMG diversification and migration between Africa and South West Indian Ocean (SWIO) islands. Results The isolation and analysis of 114 DNA-A and 41 DNA-B sequences demonstrated the presence of three CMG species circulating in the Comoros and Seychelles archipelagos (East African cassava mosaic virus, EACMV; East African cassava mosaic Kenya virus, EACMKV; and East African cassava mosaic Cameroon virus, EACMCV). Phylogeographic analyses suggest that CMGs presence on these SWIO islands is probably the result of at least four independent introduction events from mainland Africa occurring between 1988 and 2009. Amongst the islands of the Comoros archipelago, two major migration pathways were inferred: One from Grande Comore to Mohli and the second from Mayotte to Anjouan. While only two recombination events characteristic of SWIO islands isolates were identified, numerous re-assortments events were detected between EACMV and EACMKV, which seem to almost freely interchange their genome components. Conclusions Rapid and extensive virus spread within the SWIO islands was demonstrated for three CMG complex species. Strong evolutionary or ecological interaction between CMG species may explain both their propensity to exchange components and the absence of recombination with non-CMG begomoviruses. Our results suggest an important role of anthropic factors in CMGs spread as the principal axes of viral migration correspond with major routes of human movement and commercial trade. Finer-scale temporal analyses of CMGs to precisely scale the relative contributions of human and insect transmission to their movement dynamics will require further extensive sampling in the SWIO region. PMID:23186303

2012-01-01

168

Shifts in IOD and their impacts on association with East Africa rainfall  

NASA Astrophysics Data System (ADS)

The decadal shift in the relationship between the Indian Ocean Dipole (IOD) and the East African rainfall is investigated using historical observational data. The climate system for equatorial East Africa (EEA) during the October to December (OND) `short rains' season is characterised by spatiotemporal variations of the equatorial East African rainfall (EEAR). Therefore, the EEAR index is derived from the first principal component of the empirical orthogonal function analysis (EOF) of the EEA's rainfall domain. The IOD, which has been linked with the EEAR in the previous studies, is the main climate mode controlling the tropical Indian Ocean during the OND period. It is usually represented by a dipole mode index based on the zonal gradient of SST anomalies in the tropical Indian Ocean. Therefore the climate modes, IOD and EEAR, are assumed to form a two-node network of subsystems which primarily control the climate of equatorial East Africa during the OND period. The collective behaviour of these climate modes is investigated through the examination of their representative indices for the period 1901 to 2009 using simple statistical techniques. The results suggest that the interaction between these two climate modes, which comprise the network, is not predominantly linear as previously assumed, but is characterised by shifts which are determined by the coupling and synchronisation processes of the tropical systems. In cases where synchronisation is preceded by an abrupt increase in coupling strength between the two subsystems, the established synchronous state is destroyed and a new climate state emerges such as in the years 1961 and 1997. This alteration in the regional climate is accompanied by notable changes in the regional rainfall and IOD variations. But in those events where synchronisation is followed by a sudden loss in coupling strength, the climate state is not disturbed and no shift in the climate of equatorial East Africa is noticed as in 1918. This climate shift mechanism appears to be consistent with the theory of synchronised chaos and is useful for long range predictions of the East African short rains.

Manatsa, Desmond; Chipindu, Barnabas; Behera, Swadhin K.

2012-10-01

169

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

PubMed Central

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 individuals 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 efforts to fight the HIV epidemic in the region. PMID:19553783

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

2011-01-01

170

Faulting and block rotation in the Afar triangle, East Africa: The Danakil "crank-arm" model  

NASA Astrophysics Data System (ADS)

Several domains of contrasted extensional deformation have been identified in the southern Afar triangle (East Africa) from fault patterns analyzed with panchromatic stereoscopic SPOT (Systme Probatoire d'Observation de la Terre) images. Stretching directions and statistical orientation and offset variations of faults fit with the Danakii "crank-arm" model of Sichler: A 10 sinistral rotation of the Danakil block explains the fault geometry and dextral block rotation in the southern part of the Afar triangle, as well as the oblique extension in the Tadjoura Gulf. Analogue modeling supports this interpretation.

Souriot, T.; Brun, J.-P.

1992-10-01

171

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

PubMed

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

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

2009-09-01

172

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

USGS Publications Warehouse

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.

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

1992-01-01

173

Ocular rhinosporidiosis mimicking conjunctival squamous papilloma in Kenya - a case report  

PubMed Central

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 54year 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

2014-01-01

174

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

PubMed Central

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

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

2013-01-01

175

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

PubMed

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

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

2013-09-01

176

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

PubMed Central

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

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

2007-01-01

177

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

ERIC Educational Resources Information Center

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

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

2013-01-01

178

The habitat use and selection of African elephants (Loxodonta africana) in a land use landscape in Kenya, Africa  

E-print Network

The habitat use and selection of African elephants (Loxodonta africana) in a land use landscape) to examine how land use and cover types affect the distribution of African elephants in Kenya (2, conservation, elephant density #12;Introduction Currently, the African elephant is listed as vulnerable by IUCN

Hansen, Andrew J.

179

A survey of Simulium control in Africa  

PubMed Central

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 Africanamely, 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 Lopoldville (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

Brown, A. W. A.

1962-01-01

180

Use of vegetation properties from EOS observations for land-climate modeling in East Africa  

NASA Astrophysics Data System (ADS)

Land use/cover change has been recognized as a key component in global climate change. Information on land surface biophysical properties and climatic variables based on in situ data fail to resolve the fine-scale variability that exists in many parts of the world, including East Africa. In this study, we used the NASA's Earth Observing System (EOS) products to improve the representation of the land surface in a regional climate model as well as assess the model performance. The Moderate Resolution Imaging Spectroradiometer (MODIS) data of leaf area index (LAI) and vegetation fractional cover (VFC) were directly incorporated in the Regional Atmospheric Modeling System (RAMS). The model was validated in terms of the land surface temperature (LST), utilizing the MODIS LST data from both Terra and Aqua satellites. Compared with the built-in land surface, the ingested MODIS LAI and VFC greatly improved the spatial and temporal dynamics of vegetation in East Africa. Three experiments were carried out for the year of 2003 to test the impacts of land surface conditions. The results showed that the spatial, seasonal, and diurnal characteristics of the RAMS simulated LST were improved because of MODIS LAI and VFC. Specifically, the Intertropical Convergence Zone (ITCZ)-related migration, bimodal temporal variation, and monthly averaged diurnal cycles of LST were more realistically reproduced. The need to realistically represent the spatial and temporal distribution of vegetation is thus highlighted, and the value of the EOS observations for the land-climate modeling is demonstrated.

Ge, Jianjun; Qi, Jiaguo; Lofgren, Brent

2008-08-01

181

Sexuality and sexual health: constructs and expressions in the extended Middle East and North Africa.  

PubMed

The extended Middle East and North Africa (EMENA) region is the world region with the second youngest population, where globalization, migration, information technology, and political changes are contributing to the shaping of sexuality and sexual behaviors. Understanding the various sociocultural, demographic and public health dimensions of sexual and reproductive health of young people is fundamental to understanding the pattern of sexual behavior and the burden of sexually transmitted infections (STIs), including human papillomavirus-related diseases. New norms and forms of marriage have emerged to accommodate the changing trends in sexual behavior of premarital and extra-marital sex, as well as reports of increased prevalence of premarital penetrative and non-penetrative sexual behavior. Despite these trends, the burden of sexual illnesses remains low and is estimated at 7% of the general population being infected with curable STIs. Other STIs, such as herpes simplex virus 2, are also prevalent. The existing policies and health systems remain short of promoting youth reproductive and sexual health. Efforts should address establishing national preventive programmes, such as screening for STIs, primary prevention, comprehensive sexuality education, as well as youth-friendly services. 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 Related Diseases" Vaccine Volume 30, Supplement 5, 2012. PMID:24331819

El-Kak, Faysal

2013-12-30

182

Iwo Eleru's place among Late Pleistocene and Early Holocene populations of North and East Africa.  

PubMed

The Iwo Eleru site in Nigeria preserves the only terminal Pleistocene fossil from tropical West Africa. The peoples of this region contributed to significant population movements throughout the continent during the Holocene. As such, characterizing the phenotype of Late Pleistocene West African populations is critical for disentangling the evolutionary signatures of a highly complex African population history and structure. Previous research approached the calvaria's morphology from a paleoanthropological perspective, noting its mosaic of archaic and modern neurocranial features and distinctiveness from Pleistocene fossil taxa and contemporary modern human samples. In this paper, I compare Iwo Eleru with contemporary Late Pleistocene Africans and also consider the specimen's affinities with Holocene populations of the central and western Sahara, Nile Valley, and East Africa. Craniometric data were recorded for 22 neurocranial dimensions and subjected to principal components analysis and Mahalanobis distance estimation. Multidimensional scaling of distances indicated that Iwo Eleru fell outside the observed range of variation of other terminal Pleistocene supra-equatorial African populations, confirming previous results that documented its divergence from Neanderthals, Upper Paleolithic Europeans, and modern Africans. The calvaria was also distinct from Holocene Saharan, Nile Valley, and East African populations, which suggests limited West African input into the Sahara during the African Humid Period. Results presented here bolster previous research that suggested Iwo Eleru's anatomy reflected either admixture with archaic humans or the long-term survival of populations with more archaic neurocranial anatomy until the end of the Pleistocene. PMID:25065342

Stojanowski, Christopher M

2014-10-01

183

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

184

Prey spectra of two swarm-raiding army ant species in East Africa  

E-print Network

. Kinuthia3 1 Institute of Biology, Neurobiology, Free University Berlin, K¨onigin-Luise-Strasse, Berlin, Nairobi, Kenya Keywords Dorylus molestus; Dorylus wilverthi; earthworms; Kibale; montane forest; Mount Kenya; polyphagy; predation. Correspondence Caspar Sch¨oning, Department of Population Biology

Menzel, Randolf - Institut für Biologie

185

High-Throughput High-Resolution Class I HLA Genotyping in East Africa  

PubMed Central

HLA, the most genetically diverse loci in the human genome, play a crucial role in host-pathogen interaction by mediating innate and adaptive cellular immune responses. A vast number of infectious diseases affect East Africa, including HIV/AIDS, malaria, and tuberculosis, but the HLA genetic diversity in this region remains incompletely described. This is a major obstacle for the design and evaluation of preventive vaccines. Available HLA typing techniques, that provide the 4-digit level resolution needed to interpret immune responses, lack sufficient throughput for large immunoepidemiological studies. Here we present a novel HLA typing assay bridging the gap between high resolution and high throughput. The assay is based on real-time PCR using sequence-specific primers (SSP) and can genotype carriers of the 49 most common East African class I HLA-A, -B, and -C alleles, at the 4-digit level. Using a validation panel of 175 samples from Kampala, Uganda, previously defined by sequence-based typing, the new assay performed with 100% sensitivity and specificity. The assay was also implemented to define the HLA genetic complexity of a previously uncharacterized Tanzanian population, demonstrating its inclusion in the major East African genetic cluster. The availability of genotyping tools with this capacity will be extremely useful in the identification of correlates of immune protection and the evaluation of candidate vaccine efficacy. PMID:20505773

Koehler, Rebecca N.; Walsh, Anne M.; Sanders-Buell, Eric E.; Eller, Leigh Anne; Eller, Michael; Currier, Jeffrey R.; Bautista, Christian T.; Wabwire-Mangen, Fred; Hoelscher, Michael; Maboko, Leonard; Kim, Jerome; Michael, Nelson L.; Robb, Merlin L.; McCutchan, Francine E.; Kijak, Gustavo H.

2010-01-01

186

Hot granulite nappes Tectonic styles and thermal evolution of the Proterozoic granulite belts in East Africa  

NASA Astrophysics Data System (ADS)

A section through the Neoproterozoic Mozambique Belt of Tanzania exposes western foreland (Archaean Tanzania Craton and Palaeoproterozoic Usagaran Belt), marginal (Western Granulites) and eastern, internal (Eastern Granulites) portions of the orogen. The assembly of granulite nappes at ca. 620 Ma displays westward emplacement along an eastward deepening basal decollement and forward propagation of thrusts, climbing from the deep crust to the surface. This goes along with eastward increase of syntectonic temperatures, derived from prevalent deformation mechanisms, and eastward decrease of the kinematic vorticity number. Distinctly different pressure - temperature paths with a branch of isothermal decompression (ITD) in Western Granulites and isobaric cooling (IBC) in Eastern Granulites reflect residence times of rocks within lower crustal levels. Western Granulites, exhumed rapidly at the orogen margin, display ITD and non-coaxial fabrics. Eastern Granulites in the internal orogen portions escaped from rapid exhumation and show IBC and co-axial flow fabrics. The vertical variation of structural elements, i.e. basement cover relations within the Eastern Granulites, shows decoupling between lower and middle crust with horizontal west east stretching in the basement and horizontal west east shortening in the cover. A model of hot fold nappes [Beaumont, C., Nguyen, M.H., Jamieson, R.A., Ellis, S., 2006. Crustal flow modes in large hot orogens. In: Law, R.D., Searle, M.P., Godin, L., (eds). Channel Flow, Ductile Extrusion and Exhumation in Continental Collision Zones. Geological Society, London, Special Publications. vol. 268, 91-145] is adopted to explain flow diversity in the deep crust. The lower crust represented by Eastern Granulite basement flowed coaxially outwards (westward) in response to thickened crust and elevated gravitational forces, supported by a melt-weakened, viscous channel at the crustal base. Horizontal flow with rates faster than thermal 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.

Fritz, Harald; Tenczer, Veronika; Hauzenberger, Christoph; Wallbrecher, Eckart; Muhongo, Sospeter

2009-11-01

187

On the relationship between extension and anisotropy: Constraints from shear wave splitting across the East African Plateau  

Microsoft Academic Search

East Africa is a tectonically complex region owing to the presence of a rigid craton, paleothrust belts and shear zones, active magmatism and rifting, and possibly even a mantle plume. We present new splitting results of teleseismic shear phases recorded by 21 broadband seismic stations in Tanzania, seven broadband stations in Kenya, and three permanent broadband Global Seismic Network stations

Kristoffer T. Walker; Andrew A. Nyblade; Simon L. Klemperer; Gtz H. R. Bokelmann; Thomas J. Owens

2004-01-01

188

Thrust -wrench interference tectonics in the Gulf of Cadiz (Africa -Iberia plate boundary in the North-East Atlantic): insights from  

E-print Network

Thrust - wrench interference tectonics in the Gulf of Cadiz (Africa - Iberia plate boundary to a segment of the Africa- Eurasia plate boundary previously described as tectonically diffuse (e.g. Sartori key segment of the Africa-Iberia plate boundary (North- East Atlantic ocean), three main different

Paris-Sud XI, Université de

189

The upper mantle seismic velocity structure beneath the Arabian Shield and East Africa  

NASA Astrophysics Data System (ADS)

Broadband seismic data from Ethiopia and the Arabian Shield have been used to image the seismic structure of the upper mantle beneath 70% of the Afar hotspot. In the northernmost area of the hotspot, the Arabian Shield, the results from a P wave tomography and a receiver function analysis of the mantle transition zone discontinuities reveal a low velocity anomaly in the upper mantle. The anomaly appears to extend to 300 kin depth but does not reach the transition zone. In contrast, the P and S wave velocity structure of the upper mantle and transition zone discontinuities beneath Ethiopia, also imaged using body wave tomography and receiver function analysis, reveal a broad, low wave speed anomaly in the upper mantle that extends to at least 660 km depth. Temperatures within the anomalous mantle, inferred from the tomographic models and relief on the 410 and 660 km discontinuities, are 300 K higher than normal. These results suggest that the Afar hotspot is caused by a broad, deep seated thermal upwelling in the mantle, possibly related to the African Superplume, as opposed to a shallow plume head. The southern extent of uplift associated with the Afar hotspot has also been examined. Rayleigh wave group velocities have been used in a grid search algorithm to model crustal and upper most mantle structure beneath a region of low elevation in northern Kenya and southeastern Sudan between the Ethiopian and East African Plateaus. Model results reveal a thinned crust and slow upper most mantle velocities, suggesting that the low elevations are an isostatic response to thinned (i.e., rifted) crust, instead of a boundary in lithospheric structure marking the southern end of the Afar hotspot.

Benoit, Margaret H.

190

SHORT PERIOD SURFACE WAVE DISPERSION MEASUREMENTS FROM AMBIENT SEISMIC NOISE IN NORTH AFRICA, THE MIDDLE EAST, AND CENTRAL ASIA  

Microsoft Academic Search

We have begun to apply ambient noise surface wave tomography to broad-band seismic data obtained in North Africa, the Middle East, and Central Asia. The goal is to improve the calibration of surface wave propagation in aseismic areas. The basic idea of the method is that ambient seismic noise contains a significant component of Rayleigh wave energy that is excited

Michael H. Ritzwoller; Nikolai M. Shapiro; Michael E. Pasyanos; Gregory D. Bensen; Yingjie Yang

191

The Quality of Secondary Education in the Middle East and North Africa: What Can We Learn from TIMSS' Results?  

ERIC Educational Resources Information Center

Research on educational quality has been scarce in the Middle East and North Africa (MENA) region, whereas the debates over educational quality date from 1966 in the USA with the Coleman Report. Fortunately TIMSS (Trends in International Mathematics and Science Study) starts to fill this gap by providing data on students' achievement and for many

Bouhlila, Donia Smaali

2011-01-01

192

Psychology and modern life challenges: The 2nd Middle East and North Africa Regional Conference of Psychology, Amman, Jordan, 2007  

Microsoft Academic Search

The Second Middle East and North Africa Regional Conference of Psychology was held in Amman from 27 April 1 May 2007 under the Royal Patronage of Her Majesty Queen Rania Al?Abdullah and the auspices of the International Union of Psychological Science, the International Association of Applied Psychology, and the International Association of Cross?Cultural Psychology. It was hosted by the

Michael Knowles; Michel Sabourin

2008-01-01

193

Rainfall Conditions in Equatorial East Africa during the Nineteenth Century as Inferred from the Record of Lake Victoria  

Microsoft Academic Search

The East African lakes have exhibited dramaticfluctuations on both historical and paleo-climatictime scales. Levels of these lakes, and otherhistorical indicators in Africa, suggested thatenvironmental conditions in the nineteenth centurywere much more extreme than anything evident in themodern record. In this study, a water balance modelis used to estimate the rainfall associated with theseconditions, based on the Lake Victoria record. Theresults

Sharon E. Nicholson; Xungang Yin

2001-01-01

194

22. F. Kaihura, M. Stocking, Agricultural Biodiversity in Small-holder Farms of East Africa (UNU Press, Tokyo,  

E-print Network

22. F. Kaihura, M. Stocking, Agricultural Biodiversity in Small-holder Farms of East Africa (UNU of Soil Science (Dekker, New York, 2003). 26. M. S. Girvan, J. Bullimore, J. N. Pretty, A. M. Osborn, A. S. Ball, Appl. Environ. Microbiol. 69, 1800 (2003). 27. Soil Quality Institute (http://soils

Pauly, Daniel

195

The quality of secondary education in the Middle East and North Africa: what can we learn from TIMSS results?  

Microsoft Academic Search

Research on educational quality has been scarce in the Middle East and North Africa (MENA) region, whereas the debates over educational quality date from 1966 in the USA with the Coleman Report. Fortunately TIMSS (Trends in International Mathematics and Science Study) starts to fill this gap by providing data on students achievement and for many MENA countries this is the

Donia Smaali Bouhlila

2011-01-01

196

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

ERIC Educational Resources Information Center

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

Zaalouk, Malak

2014-01-01

197

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

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

Johnson, Dora E.; And Others

198

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

NASA Astrophysics Data System (ADS)

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

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

199

Forest History in East Africa's Eastern Arc Mountains: Biological Science and the Uses of History  

NSDL National Science Digital Library

In this article, I argue that conservation science in its role of advocate for the natural world could profitably draw from site-specific histories that integrate human and natural histories. Both fields analyze the dynamic interaction of structure and process. In East Africa's Eastern Arc Mountains, where forests contain high levels of species endemism and biological diversity, the prevailing historical paradigm from conservation science represents today's forests as surviving fragments of much larger forests. This view builds upon a century-long tradition of scientific scholarship that has developed theories for the evolution of Eastern Arc forests that encompass geological time scales. However, the relatively brief, millennial-scale land-use history of the mountains, insofar as it is currently understood, suggests that human manipulation of forest biota involved periods of deforestation and regeneration, as well as the introduction of exotic plants.

Christopher Conte (Utah State University;Department of History)

2010-04-07

200

Burden of Chronic Respiratory Diseases (CRD) in Middle East and North Africa (MENA).  

PubMed

Chronic respiratory diseases involve a heterogenous group of diseases, including, chronic obstructive pulmonary disease (COPD), asthma, sleep apnea syndrome, pulmonary hypertension, and many occupational diseases. They affect more than one billion people worldwide. Their medical, social, and economic impacts are heavy, especially in developing countries such as Middle East and North Africa countries, where they represent a public health problem. They are essentially represented by COPD, asthma, and allergic diseases. Chronic respiratory diseases are increasing in frequency, morbidity, and mortality. In addition, their economic and social impact is increasing rapidly in this region. Main risk factors are represented by tobacco smoking and exposure to biomass fuel. Smoking prevention and standardized management programs for asthma and COPD are now available but prompt actions are needed to make them more effective in this region and thus avoid an adverse impact on national economic development. PMID:23283069

Ben Abdallah, F Chermiti; Taktak, S; Chtourou, A; Mahouachi, R; Kheder, Ali Ben

2011-01-01

201

The Road Not Traveled: Education Reform in the Middle East and North Africa [pdf  

NSDL National Science Digital Library

The World Bank has long been interested in looking at education throughout the world, and this recent report pays close attention to education systems across the Middle East and North Africa. The report was released in February 2008, and offers a comprehensive economic analysis of the impact of education investments in the region. The report notes that while most of the countries in this region have made great strides in recent decades, they will need to place a premium on so-called "soft skills" (such as problem solving) in order to compete in a global economy. Additionally, the report recommends that policy-makers should use incentives, public accountability, curriculum and labor market reforms in order to make the region's economies more dynamic.

Galal, Ahmed, 1948-

2008-01-01

202

Diet of Paranthropus boisei in the early Pleistocene of East Africa  

PubMed Central

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 C4 biomass such as grasses or sedges. Its diet included more C4 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

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

2011-01-01

203

Comparative SWOT analysis of strategic environmental assessment systems in the Middle East and North Africa region.  

PubMed

This paper presents a SWOT analysis of SEA systems in the Middle East North Africa region through a comparative examination of the status, application and structure of existing systems based on country-specific legal, institutional and procedural frameworks. The analysis is coupled with the multi-attribute decision making method (MADM) within an analytical framework that involves both performance analysis based on predefined evaluation criteria and countries' self-assessment of their SEA system through open-ended surveys. The results show heterogenous status with a general delayed progress characterized by varied levels of weaknesses embedded in the legal and administrative frameworks and poor integration with the decision making process. Capitalizing on available opportunities, the paper highlights measures to enhance the development and enactment of SEA in the region. PMID:23648267

Rachid, G; El Fadel, M

2013-08-15

204

Mycotoxin occurrence in commodities, feeds and feed ingredients sourced in the Middle East and Africa  

PubMed Central

Between February and October 2009, 324 grain, feed and feed commodity samples were sourced directly at animal farms or feed production sites in Middle East and Africa and tested for the presence of A- and B-trichothecenes, zearalenone, fumonisins, aflatoxins and ochratoxin A, or for selected groups of mycotoxins only. Samples were analyzed after clean-up by immunoaffinity or solid-phase extraction followed by HPLC with derivatization where appropriate and fluorescence, UV or mass spectrometric detection. The percentage of positive samples of B-trichothecenes ranged from 0 to 87% of tested samples. The prevalence of fumonisins in the different countries was >50% in most cases. Zearalenone was present in tested commodities from all countries except three. The presence of aflatoxin in analyzed samples varied from 0 to 94%. Ochratoxin A was present in 67% of samples in Sudan and in 100% of Nigerian samples. No A-trichothecenes were found in this survey. PMID:24786003

Rodrigues, I.; Handl, J.; Binder, E.M.

2011-01-01

205

Health teaching in the context of culture: nursing in East Africa.  

PubMed

A nurse from the US worked as a community health nurse with the Mennonite Central Committee in East Africa from 1981-1983. She addressed the importance of health care providers being able to incorporate the context of culture, religion, and socioeconomic status into identifying health care needs and intervention. This was complicated by differences in values and beliefs between the urban and rural populations. Many people believed that spirits of the dead influence their behavior and sense of family. Indeed many thought that spirits or mystical events cause illness. This made health education difficult. For example, people in rural Uganda believed infestation of guinea worm was due to mystical causes. Therefore they were not motivated to filter their water and visited traditional healers for treatment. Many in rural East Africa did not eat any meat so the nurse tried to find sources of protein for their diet, such as ground nuts and insects. Unlike urban areas, large families were preferred in rural areas so she promoted maternal and child health by child spacing. In fact, birth control in urban areas was used often. Rural women were often tired because of many demands on them. For example, they fetched 90% of the water involving 3-4 hours/day and planted 80% of the food. When wells were dug closer to the women, they had less time to interact socially which meant more work in the field. In urban areas, however, women had a higher status. Urban dwellers faced different values and individual priorities than rural dwellers. For example, the tribe and family did not have such a strong hold, but some tried to live an urban and a rural lifestyle. Rural-urban migration has created many social problems such as labor shortages. PMID:2046219

Blair, J

1991-04-01

206

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

PubMed

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 Related Diseases" Vaccine Volume 30, Supplement 5, 2012. PMID:24331820

Sancho-Garnier, Hlne; 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

207

Evaluation of estimating daily maximum and minimum air temperature with MODIS data in east Africa  

NASA Astrophysics Data System (ADS)

Real time and spatially distributed Ta (air temperature) data are desired for many applications. Ts (land surface temperature) derived from remote sensors has been used to estimate Ta in previous studies. Exploring MODIS Aqua Ts and station measured daily maximum and minimum Ta over east Africa, we found that Ts did not agree well with Ta during the day (MAE (Mean Absolute Error) = 6.9 5.0 C) but had better agreement during the night (MAE = 1.9 1.7 C). A stepwise linear regression method was applied to construct possible models to predict Ta based on MODIS data. Our results showed that, only considering elevation, high spatial resolution Ta could be obtained by simple linear models, with MAE = 1.9 C, agreement index = 0.79 for daily maximum Ta, and MAE = 1.9 C, agreement index = 0.92 for daily minimum Ta. MODIS Ts data could provide temporal variation information and slightly improve the accuracy of model predictions (by 0.2 C of MAE). However, considering (i) major absences (about 2/3 of days) of Ts data due to cloud cover and (ii) small Ta variations in time (? = 2.1 C) over east Africa, models without Ts might be more practical in particular applications such as tsetse fly distribution models. Other variables including solar zenith angle, low level precipitable water content, and vegetation index (NDVI and EVI) were insignificant in the daily maximum and minimum Ta estimation models after elevation and Ts had already been considered as predictors.

Lin, Shengpan; Moore, Nathan J.; Messina, Joseph P.; DeVisser, Mark H.; Wu, Jiaping

2012-08-01

208

Holocene precipitation and thermal coherence at Lakes Albert and Victoria, East Africa  

NASA Astrophysics Data System (ADS)

New molecular proxy records of temperature and rainfall from lacustrine sedimentary archives are helping to constrain the tropical response to global climate change and elucidate possible forcing mechanisms during the latest Pleistocene and Holocene in East Africa. It is often noted that tropical ecosystems are more sensitive to perturbations in rainfall than in temperature, due to the limited thermal range of tropical climate, however coincident shifts would likely enhance climate response to regional variability. Furthermore, on shorter time scales, patterns of moisture balance and temperature are often linked in East Africa. Here we present new records of rainfall from Lakes Albert and Victoria, using compound specific ?D from terrestrial leaf waxes, and compare these trends to TEX86 paleotemperature records in order to assess the coherence between tropical precipitation and temperature. Our results indicate generally synchronous shifts at these sites, roughly in-phase with regional climate behavior during this interval. A high resolution climate history at Lake Albert highlights a significant multi-stage cool and arid excursion characteristic of the last deglaciation, beginning ~13.8 ka and ending rapidly at ~11.5 ka and marked by a ~55% D-enrichment and 3C cooling, linking this tropical region to high latitude climate events. The molecular perspective on the climate surrounding Lake Victoria indicates a warm, humid interval peaking at 10-9 ka, and subsequent gradual cooling and drying over the remainder of the Holocene, exhibiting shifts of ~40% in ?D and ~5C, and thus showing a strong correlation to summer insolation. Palynological and ?13C biomarker evidence from these sites indicate significant, but not coinciding, shifts in aspects of the terrestrial vegetation ecosystem that are not well understood. Both regions support a linkage between high latitude and equatorial African climate systems, with likely teleconnections to the Indian monsoon system.

Berke, M. A.; Johnson, T. C.; Werne, J. P.; Grice, K.; Schouten, S.; Sinninghe Damst, J. S.

2011-12-01

209

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

SciTech Connect

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.

Sweeney, J.J.

1996-12-04

210

Indian Ocean Climate event brings floods to East Africa's lakes and the Sudd Marsh  

NASA Astrophysics Data System (ADS)

During an El Nio, the expected rainfall increase over most of the Lake Victoria catchment area is 15-25%. However, due to anomalous warming of the western equatorial Indian Ocean during 1997, strong convection developed over parts of the Horn and eastern Africa. This resulted in a much larger 20-160% precipitation excess during the short rainy season. Satellite radar altimetry data reveals that not only did Lake Victoria rise by 1.7 m, but that the rainfall event similarly affected lakes Tanganyika, Malawi and Turkana. In addition, the seasonal level minima of the Sudd marshes and Lakes T'ana and Nasser continue to increase. Such a rainfall event will have severe, long-term consequences for the natural surface flows and storages along the White Nile. Based on the hydrological impacts of the historic 1961 East Africa event, we can expect the current high levels of Lake Victoria to be maintained for the remainder of this decade. In addition, we anticipate a major expansion of the permanent swamp regions of the Sudd marshes over the forthcoming seasons. Blue Nile flows, further enhanced by the above-average 1998 rainfall season, can also be expected to remain high, at least until early 1999.

Birkett, Charon; Murtugudde, Ragu; Allan, Tony

211

From Denis Burkitt to Dar es Salaam. What happened next in East Africa?--Tanzania's story.  

PubMed

East Africa was at the forefront of early achievements and discoveries in paediatric oncology thanks to Denis Burkitt's seminal work. Although these successes have been built upon and continued elsewhere, they were sadly not sustained in sub-Saharan Africa for a variety of reasons. In recent years however this situation is slowly changing in countries across the continent. Tanzania is one such African country. Until very recently, survival rates of 5-10% for all children's cancers were expected. However, change has been brought about thanks to the combined efforts and commitments of the Tanzanian Ministry of Health, non-governmental organizations--such as The International Network for Cancer Treatment and Research, and Children in Crossfire-- and the participation of the private sector. Services are rapidly developing and outcomes are continuing to improve with 1-year survival rates of approximately 60% achieved. Efforts to maintain this early progress are concentrated around providing high quality local subspecialty medical training and continued local ownership of the programme. PMID:22233461

Scanlan, Trish; Kaijage, Jane

2012-03-01

212

Spatially explicit, individual-based modelling of pastoralists' mobility in the rangelands of east Africa  

E-print Network

An agent based-model of mobility of pastoralists was developed and applied to the semi-arid rangeland region extending from southern Ethiopia to northern Kenya. This model was used to investigate temporal adaptation of pastoralists to the spatial...

MacOpiyo, Laban Adero

2005-11-01

213

Geology and petroleum resources of central and east-central Africa  

SciTech Connect

The petroleum provinces of central and east-central Africa include the Somali basin, the Ethiopian plateau and rift belt, and the central African rift basins. The western shelf on the Somali basin in the horn of Africa contains a sedimentary cover 1000-10,000 m (3000-3500 ft) thick of Mesozoic and Tertiary marine and continental clastic, carbonate, and evaporite deposits with good reservoir and potentially adequate source rock properties. To date, no commercial oil or gas discoveries have been made. The Ethiopian plateau and rift belt is a high-risk area with minimum potential for commercial petroleum because the Neogene rifting origin of the province has resulted in high geothermal gradients, extensive volcanism, and inadequate marine deposits and petroleum source rocks. The central Africa interior basins are continental craton-rifted depressions of Late Cretaceous and Tertiary age containing as much as 4000 m (13,000 ft) or more of fluvial and lacustrine clastic beds, which inter-tongue with nearshore marine clastic and carbonate beds in the western basins. Since the mid-1970s, approximately 13 oil discoveries have been made in the Upper Nile, Doba-Doseo, and Chad basins. These basins produce from fluvial and lacustrine sandstone reservoirs, sourced by lacustrine organic shale beds of Cretaceous age. The Benue trough is a rifted depression of middle Cretaceous age adjoined on the southwest by the prolific Niger Delta petroleum province. The trough is filled with 6000 m (20,000 ft) or more of clastic and carbonate marine and continental rocks of late Early Cretaceous and early Cenozoic age. Very few exploratory wells have been drilled, and no commercial discoveries have been made although good reservoir and source rocks are present.

Peterson, J.A.

1986-05-01

214

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

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 temperature and readily available soil moisture of the CPSZ data as the best ecological determinants for P. martini while LST annual composite was the only important ecological determinant for P. orientalis. Spearman's rank correlation revealed several factors to be important determinants for the distribution of the two vectors. None of the soil types analysed appeared to be important determinant for the two species in East Africa, unlike in Sudan where P. orientalis is mainly associated with eutric vertisol (black cotton clay soil). PMID:14739026

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

2004-03-01

215

Influence of available browse on cattle diets in an Acacia savannah of East Africa  

E-print Network

&M University; Chairman of Advisory Committee: Dz. Jerry W. Stuth A six-month study was conducted in southeastern Kenya to determine the influence of varying bush canopy cover on dietary selection and nutrition of mature esophageally fistulated heifers... graduate program. I would also like to recognize the assistance from my sponsors, the Ministry of Livestock Development, Government of Kenya within the Kiboko Range Research Expansion Project, with funding from the United States Agency for International...

Kibet, Philip Kiptorus

2012-06-07

216

Temperature and hydrologic variability of Lake Victoria, East Africa since the Late Pleistocene  

NASA Astrophysics Data System (ADS)

Recent organic geochemical advances have facilitated the comparison between continental temperature change and hydrologic variability. TEX86, a proxy based on the lipids of aquatic Crenarchaeota that show a positive correlation with growth temperature, was used to reconstruct surface water temperatures from Lake Victoria, East Africa during the latest Pleistocene-Holocene. Hydrologic conditions were interpreted using paleoecological implications of shifting pollen and diatom assemblages found in the lake (Kendall, 1969; Stager et al., 2003) and will be compared with future compound specific ?13C data from terrestrial biomarkers in order to determine the patterns of rainfall and aridity in this region. Initial comparisons of climatic changes seen in temperature and hydrologic records appear to show consistency between warm/wet intervals and cool/dry intervals that is often assumed, but more rarely shown, in tropical Africa. Lake Victoria temperatures show a steady warming beginning 16 cal ka, with a pause around the Younger Dryas, dominated by arid conditions and strong savannah grassland development during this interval. There is continued warming to a sustained thermal maximum for this portion of the record at ~10.5-8.5 ka, which generally coincides with the beginning of the Holocene Hypsithermal, an interval of elevated temperatures and precipitation throughout much of tropical Africa. This thermal maximum occurs during the most humid interval of this record (~9.5-8.3 ka), shown by an increase of humid forest pollen and high diatom abundance (due to increased water column mixing and nutrient runoff). Temperatures abruptly cool ~1.5C in <800 years while precipitation becomes somewhat more seasonally restricted, coinciding with an abrupt drop in inferred P:E ratio and reduction in wind-driven mixing. The record then shows a general cooling, reaching a Holocene thermal minimum of ~18.4C at ~4.5 ka, contrary to other East African continental and marine paleoclimate records that exhibit a Holocene thermal maximum ~5 ka. These coolest Holocene temperatures correspond to the driest interval in the surrounding region (~5.8-2.7 ka), with an increase in grassland abundance and decrease in humid forest pollen. Though a 5 ka thermal maximum is not seen in Lake Victoria, this portion of the record shows a temperature inflection and variable hydrologic signals, potentially marking a response to the end of the Holocene Hypsithermal, where temperatures begin to rise ~3C over the remainder of the record.

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

2010-12-01

217

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

NASA Astrophysics Data System (ADS)

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 (~3S). 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 ?D 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 ?D 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 conditions - may have caused extreme amplitudes of seasonal ITCZ migration and corresponding variability of climate conditions in the tropics on orbital timescales. Counter-intuitively, our GDGT temperature reconstruction based on MBT and CBT indices shows temperatures ~5C warmer throughout the LGM and MIS3 than during the Holocene. Although local soil temperature may be affected by vegetation and/or cloud cover, such results advice caution and highlight the necessity to further validate and develop these new biomarker proxies.

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

2009-12-01

218

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

NASA Astrophysics Data System (ADS)

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 phases, subglacial tunnel valley networks were cut at or near the ice margin. These tunnel valleys were filled in two main phases. The initial phase was characterised by debris flow release, whereas during later phases of ice retreat a range of glaciofluvial, shallow glaciomarine to shelf deposits were laid down, depending on the water depth at the ice front. Production of linear accumulations of sediment, parallel to the ice front, also occurred between tunnel valleys at the grounding line. In Arabia, the geometry of these features may have been influenced by local tectonic uplift. As glaciogenic reservoirs, Hirnantian deposits are already of great economic significance across central North Africa. Therefore, an appreciation of the processes of ice sheet growth and decay provides significant insights into the controls on large-scale heterogeneities within these sediments, and in analogue deposits produced by glaciations of different ages. Deglacial, Early Silurian black shale represents the most important Palaeozoic source rock across the region. Existing models do not adequately explain the temporal and spatial development of anoxia, and hence of black shale/deglacial source rocks. The origins of a palaeotopography previously invoked as the primary driver for this anoxia is allied to a complex configuration of palaeo-ice stream pathways, "underfilled" tunnel valley incisions, glaciotectonic deformation structures and re-activation of older crustal structures during rebound. A putative link with the development of Silurian glaciation in northern Chad is suggested. Silurian glaciation appears to have been restricted to the southern Al Kufrah Basin in the eastern part of North Africa, and was associated with the deposition of boulder beds. Equivalent deposits are lacking in shallow marine deposits in neighbouring outcrop belts. Evidence for Carboniferous-Permian glaciation is tentative in the eastern Sahara (SW Egypt) but well established on the Arabian Peninsula in Oman and more recently in Saudi Arabia. Pennsylvanian-Sakmarian times saw r

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

2009-04-01

219

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

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 Cte 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 Cte 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(6)-10(8)CFU/mL. lacS and lacZ genes were detected in all Kenyan and 25.8% (June) to 65.4% (Dec/Jan) of Ivorian Sii isolates. Regional differences in prevalence of Sii and dairy adaptations were observed, but no clear effect of dairy animal, fermentation procedure and climate was revealed. Conclusively, the high prevalence of Sii in Kenya, Cte d'Ivoire in addition to Somalia, Sudan and Mali strongly indicates a pivotal role of Sii in traditional African dairy fermentations potentially paralleling that of typical western dairy species S. thermophilus. Putative health risks associated with the consumption of high amounts of live Sii and potential different degrees of evolutionary adaptation or ecological colonization require further epidemiologic and genomic investigations, particularly in Africa. PMID:24131584

Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Bck, Dsire; Njage, Patrick Murigu Kamau; Kouam-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

2013-10-15

220

Responses to satellite remote sensing opportunities in East and Southern Africa  

NASA Astrophysics Data System (ADS)

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 of distribution and applications work. Fragmentation could seriously disrupt the present growth in natural resources activity based on remote sensing data from satellites. The lack of financing for a regional ground receiving station is also a significant limiting factor.

Falconer, Allan; Odenyo, Victor A. O.

221

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

NASA Astrophysics Data System (ADS)

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 April) SM conditions, the skill of forecasting SM estimates until the end-of-season improved (correlation > 0.5 over several grid cells). We also found these SM forecasts to be more skillful than the ones generated using the Ensemble Streamflow Prediction (ESP) method, which derives its hydrologic forecast skill solely from the knowledge of the initial hydrologic conditions. Finally, we show that, in terms of forecasting spatial patterns of SM anomalies, the skill of this agricultural drought forecast system is generally greater (> 0.8 correlation) during drought years (when standardized anomaly of MAM precipitation is below 0). This indicates that this system might be particularity useful for identifying drought events in this region and can support decision-making for mitigation or humanitarian assistance.

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

2014-10-01

222

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

NASA Astrophysics Data System (ADS)

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 critical for end-of-season outcomes. Finally we show that, in terms of forecasting spatial patterns of SM anomalies, the skill of this agricultural drought forecast system is generally greater (> 0.8 correlation) during drought years. This means that this system might be particularity useful for identifying the events that present the greatest risk to the region.

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

2014-03-01

223

Monitoring the water balance of Lake Victoria, East Africa, from space  

NASA Astrophysics Data System (ADS)

SummaryUsing satellite gravimetric and altimetric data, we examine trends in water storage and lake levels of multiple lakes in the Great Rift Valley region of East Africa for the years 2003-2008. GRACE total water storage estimates reveal that water storage declined in much of East Africa, by as much as 60 {mm}/{year}, while altimetric data show that lake levels in some large lakes dropped by as much as 1-2 m. The largest declines occurred in Lake Victoria, the Earth's second largest freshwater body. Because the discharge from the outlet of Lake Victoria is used to generate hydroelectric power, the role of human management in the lake's decline has been questioned. By comparing catchment water storage trends to lake level trends, we confirm that climatic forcing explains only about 50decline. This analysis provides an independent means of assessing the relative impacts of climate and human management on the water balance of Lake Victoria that does not depend on observations of dam discharge, which may not be publically available. In the second part of the study, the individual components of the lake water balance are estimated. Satellite estimates of changes in lake level, precipitation, and evaporation are used with observed lake discharge to develop a parameterization for estimating subsurface inflows due to changes in groundwater storage estimated from satellite gravimetry. At seasonal timescales, this approach provides closure to Lake Victoria's water balance to within 17 {mm}/{month}. The third part of this study uses the water balance of a downstream water body, Lake Kyoga, to estimate the outflow from Lake Victoria remotely. Because Lake Kyoga is roughly 20 times smaller in area than Lake Victoria, its water balance is strongly influenced by inflow from Lake Victoria. Lake Kyoga has been shown to act as a linear reservoir, where its outflow is proportional to the height of the lake. This model can be used with satellite altimetric lake levels to estimate a time series of Lake Victoria discharge with an rms error of about 134 {m}/{s}.

Swenson, Sean; Wahr, John

2009-05-01

224

What should the ideal HIV self-test look like? A usability study of test prototypes in unsupervised HIV self-testing in Kenya, Malawi, and South Africa.  

PubMed

HIV self-testing (HIVST) is increasingly being sought and offered globally, yet there is limited information about the test features that will be required for an HIV self-test to be easy to use, acceptable to users, and feasible for manufacturers to produce. We conducted formative usability research with participants who were nave to HIVST using five prototypes in Kenya, Malawi, and South Africa. The tests selected ranged from early-stage prototypes to commercially ready products and had a diverse set of features. A total of 150 lay users were video-recorded conducting unsupervised self-testing and interviewed to understand their opinions of the test. Participants did not receive a test result, but interpreted standardized result panels. This study demonstrated that users will refer to the instructions included with the test, but these can be confusing or difficult to follow. Errors were common, with less than 25% of participants conducting all steps correctly and 47.3% of participants performing multiple errors, particularly in sample collection and transfer. Participants also had difficulty interpreting results. To overcome these issues, the ideal HIV self-test requires pictorial instructions that are easy to understand, simple sample collection with integrated test components, fewer steps, and results that are easy to interpret. PMID:24947852

Peck, Roger B; Lim, Jeanette M; van Rooyen, Heidi; Mukoma, Wanjiru; Chepuka, Lignet; Bansil, Pooja; Knight, Lucia C; Muturi, Nelly; Chirwa, Ellen; Lee, Arthur M; Wellhausen, Jeff D; Tulloch, Olivia; Taegtmeyer, Miriam

2014-07-01

225

Urban Leptospirosis in Africa: A Cross-Sectional Survey of Leptospira Infection in Rodents in the Kibera Urban Settlement, Nairobi, Kenya  

PubMed Central

Leptospirosis is a widespread but under-reported cause of morbidity and mortality. Global re-emergence of leptospirosis has been associated with the growth of informal urban settlements in which rodents are thought to be important reservoir hosts. Understanding the multi-host epidemiology of leptospirosis is essential to control and prevent disease. A cross-sectional survey of rodents in the Kibera settlement in Nairobi, Kenya was conducted in SeptemberOctober 2008 to demonstrate the presence of pathogenic leptospires. A real-time quantitative polymerase chain reaction showed that 41 (18.3%) of 224 rodents carried pathogenic leptospires in their kidneys, and sequence data identified Leptospira interrogans and L. kirschneri in this population. Rodents of the genus Mus (37 of 185) were significantly more likely to be positive than those of the genus Rattus (4 of 39; odds ratio = 15.03). Questionnaire data showed frequent contact between humans and rodents in Kibera. This study emphasizes the need to quantify the public health impacts of this neglected disease at this and other urban sites in Africa. PMID:24080637

Halliday, Jo E. B.; Knobel, Darryn L.; Allan, Kathryn J.; de C. Bronsvoort, B. Mark; Handel, Ian; Agwanda, Bernard; Cutler, Sally J.; Olack, Beatrice; Ahmed, Ahmed; Hartskeerl, Rudy A.; Njenga, M. Kariuki; Cleaveland, Sarah; Breiman, Robert F.

2013-01-01

226

Urban leptospirosis in Africa: a cross-sectional survey of Leptospira infection in rodents in the Kibera urban settlement, Nairobi, Kenya.  

PubMed

Leptospirosis is a widespread but under-reported cause of morbidity and mortality. Global re-emergence of leptospirosis has been associated with the growth of informal urban settlements in which rodents are thought to be important reservoir hosts. Understanding the multi-host epidemiology of leptospirosis is essential to control and prevent disease. A cross-sectional survey of rodents in the Kibera settlement in Nairobi, Kenya was conducted in September-October 2008 to demonstrate the presence of pathogenic leptospires. A real-time quantitative polymerase chain reaction showed that 41 (18.3%) of 224 rodents carried pathogenic leptospires in their kidneys, and sequence data identified Leptospira interrogans and L. kirschneri in this population. Rodents of the genus Mus (37 of 185) were significantly more likely to be positive than those of the genus Rattus (4 of 39; odds ratio = 15.03). Questionnaire data showed frequent contact between humans and rodents in Kibera. This study emphasizes the need to quantify the public health impacts of this neglected disease at this and other urban sites in Africa. PMID:24080637

Halliday, Jo E B; Knobel, Darryn L; Allan, Kathryn J; de C Bronsvoort, B Mark; Handel, Ian; Agwanda, Bernard; Cutler, Sally J; Olack, Beatrice; Ahmed, Ahmed; Hartskeerl, Rudy A; Njenga, M Kariuki; Cleaveland, Sarah; Breiman, Robert F

2013-12-01

227

Focal mechanisms from regional earthquakes in East Africa and refinements in stress patterns  

NASA Astrophysics Data System (ADS)

Accurate event locations for eleven events with magnitude greater than 3.5 in Tanzania, East Africa have been obtained using data from the Tanzania Broadband Seismic Experiment. Focal mechanisms for most of these events have been determined by modeling P and SH polarities and amplitude ratios in a grid search method. Epicenters have been constrained by using P and S arrival times. Focal depths have been constrained by waveform modeling of regional and local depth phases. Most of the earthquakes occur in two areas along the western or eastern branch of the East African Rift. The first area is located between southern Lake Tanganyika and Lake Rukwa in the western branch, and the mechanisms in this region are characterized by strike-slip or oblique extension with nodal planes striking E-W to NW-SE. These events confirm that this part of the western rift is under transtension, as compared to the Lake Tanganyika and Rukwa rifts, where the stress field appears to be almost purely extensional. The second area for which we have obtained several new focal mechanisms is near the southern end of the eastern branch where the rift impinges on the eastern margin of the Tanzania craton. The focal mechanisms from this part of the rift have strike slip or normal motions but the orientations of the nodal planes are complex, consistent with the complicated orientation of the block faults. The focal depths for the events in the first area vary from 7 to 36 km, and in the second area, they vary from 11 to 34 km.

Brazier, R. A.; Nyblade, A.

2004-12-01

228

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

PubMed Central

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

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

2000-01-01

229

Alternative income and protein sources for rural communities: prospects for the rabbit in East Africa  

E-print Network

, while only 30% of the families consumed eggs at least twice a month. The per capita meat consumption in Kenya is 9. 2 kg/person/year, compared with 29. 8 kg, 52 kg and 60 kg/capita in the U. S. , Australia and New Zealand, respectively (Economic..., while only 30% of the families consumed eggs at least twice a month. The per capita meat consumption in Kenya is 9. 2 kg/person/year, compared with 29. 8 kg, 52 kg and 60 kg/capita in the U. S. , Australia and New Zealand, respectively (Economic...

Wanjaiya, James Kangethe

2012-06-07

230

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

NASA Astrophysics Data System (ADS)

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-day and mid-Holocene AET values suggests an increase in AET over north-eastern parts of East Africa, especially over Sudan region and Kenyan Rift during the mid-Holocene whereas a decrease in AET during the mid-Holocene over south-southeastern parts of East Africa. On the other hand, comparison of simulated present-day and mid-Holocene runoff values suggests an increase of runoff in north-eastern parts, especially along the East African Rift and decreased runoff in the southern parts of East Africa during the mid-Holocene.

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

2014-05-01

231

Ecological correlates of species richness and population abundance patterns in the amphibian communities from the Albertine Rift, East Africa  

Microsoft Academic Search

Broad-scale ecological correlates affecting species richness and abundance patterns of amphibians were studied in 37 sampling\\u000a sites from 15 independent protected areas in the Albertine Rift, East Africa. Amphibians were caught by a combination of sampling\\u000a techniques, including time-constrained visual searching, pitfalls with drift fences, dip-netting, and opportunistic observations.\\u000a In total, 73 species of amphibians were recorded, some of them

Mathias Behangana; Panta M. B. Kasoma; Luca Luiselli

2009-01-01

232

Combined cataract and trabeculectomy surgery for advanced glaucoma in East Africa; visual and intra-ocular pressure outcomes  

Microsoft Academic Search

AimTo investigate visual and intra-ocular pressure (IOP) outcomes of combined cataract and glaucoma surgery at a high-volume centre in East Africa carried out over a 1-year period (2006).MethodsA retrospective analysis of patient records.ResultsA total of 163 patients were identified. Mean age was 67 years (SD 11, range 2186 years) and 113 (69%) were men. Presenting visual acuity in the operated

R J C Bowman; A Hay; M L Wood; I E Murdoch; RJC Bowman

2010-01-01

233

The Late Pleistocene - Holocene palaeolimnology of Lake Victoria, East Africa, based upon elemental and isotopic analyses of sedimentary organic matter  

Microsoft Academic Search

Three piston cores from Lake Victoria (East Africa) have been analysed for organic carbon (TOC) and nitrogen (TN) content, stable isotopes (d13C and d15N), and Hydrogen Index (HI). These data are combined with published biogenic silica and water content analyses to produce a detailed palaeolimnological history of the lake over the past ca. 17.5 ka. Late Pleistocene desiccation produced a

Michael R. Talbot; Tine Lrdal

2000-01-01

234

Aerosol characterization in Northern Africa, Northeastern Atlantic, Mediterranean Basin and Middle East from direct-sun AERONET observations  

Microsoft Academic Search

We provide an atmospheric aerosol characterization for North Africa, Northeastern Atlantic, Mediterranean and Middle East based on the analysis of quality-assured direct-sun observations of 39 stations of the AErosol RObotic NETwork (AERONET) which include at least an annual cycle within the 1994-2007 period. We extensively test and apply the recently introduced graphical method of Gobbi and co-authors in order to

S. Basart; C. Prez; E. Cuevas; J. M. Baldasano; G. P. Gobbi

2009-01-01

235

Evaluation ofthe Middle East and North Africa Land Data Assimilation System  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

236

Aerial applications of insecticides for tsetse fly control in East Africa  

PubMed Central

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

Lee, C. W.

1969-01-01

237

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

PubMed Central

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

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

1962-01-01

238

Regional Climate Response to Volcanic Radiative Forcing in Middle East and North Africa  

NASA Astrophysics Data System (ADS)

We have tested the regional climate sensitivity in the Middle East and North Africa (MENA) to radiation perturbations caused by the large explosive equatorial volcanic eruptions of the second part of 20th century, El Chichon and Pinatubo occurred, respectively, in 1982 and 1991. The observations and reanalysis data show that the surface volcanic cooling in the MENA region is two-three times larger than the global mean response to volcanic forcing. The Red Sea surface temperature appears to be also very sensitive to the external radiative impact. E.g., the sea surface cooling, associated with the 1991 Pinatubo eruption, caused deep water mixing and coral bleaching for a few years. To better quantify these effects we use the Geophysical Fluid Dynamics Laboratory global High Resolution Atmospheric Model (HIRAM) to conduct simulations of both the El Chichon and Pinatubo impacts with the effectively 25-km grid spacing. We find that the circulation changes associated with the positive phase of the arctic oscillation amplified the winter temperature anomalies in 1982-1984 and 1991-1993. The dynamic response to volcanic cooling also is characterized by the southward shift of the inter-tropical convergence zone in summer and associated impact on the precipitation patterns. Thus, these results suggest that the climate regime in the MENA region is highly sensitive to external forcing. This is important for better understanding of the climate variability and change in this region.

Stenchikov, G.; Dogar, M.

2012-04-01

239

Geology and Nonfuel Mineral Deposits of Africa and the Middle East  

USGS Publications Warehouse

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).

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

2009-01-01

240

Have wet and dry Precambrian crust largely governed Cenozoic intraplate magmatism from Arabia to East Africa?  

NASA Astrophysics Data System (ADS)

To explain Cenozoic continental volcanism between Arabia and East Africa, the existing model infers that a plume impinged beneath Ethiopia, between 30 Ma and 20 Ma, and volcanism extruded within a 1000 km radius. Because relative motion of the Afro-Arabian plate was about northeast in the last 120 Ma, we infer that at 84 Ma a plume, originated from the core-mantle boundary, impinged beneath Nubia-Arabia and is now under the Tanzania craton. This plume caused uplift (Afro-Arabian swell) and magma under-plating. After Fyfe's idea (1992), the conceptual model proposed herein suggests that, following plume impact, there was in Nubia-Arabia only intrusion of mafic dykes because the crust was largely unprocessed (wet). At about 50 Ma the plume was under Ethiopia, and coeval volcanism extruded because the crust was highly recycled (dry). In Zaire-Burundi and Tanzania, volcanism is explained to be coeval with the arrival of the plume because there also the crust is recycled. In Arabia and Yemen-Ethiopia continental-flood basalts younger than 30 Ma formed because lithospheric extension along the Red Sea-Gulf of Aden was the cause of (or the result of) plume(s), probably originated from the upper mantle.

Bonavia, Franco F.; Chorowicz, Jean; Collet, Bernard

241

Telecytology in East Africa: a feasibility study of forty cases using a static imaging system.  

PubMed

We conducted a pilot study to assess the feasibility of telecytology as a diagnostic tool in difficult cases originating from a hospital in East Africa. Forty cytology cases considered difficult by a referring pathologist were posted on a telepathology website. Six pathologists independently assessed the static images. Telecytology diagnoses were compared with the consensus diagnoses made on glass slides and also with the histogical diagnoses when available. The diagnostic agreement of the six pathologists was 71-93% and tended to be higher for pathologists with more experience. Reasons for discordance included poor image quality, presence of diagnostic cells in thick areas of smears, sampling bias and screening errors. The consensus diagnoses agreed with histological diagnoses in all 17 cases in which a biopsy was performed. Diagnostic accuracy rates (i.e. telecytology diagnosis vs. histological diagnosis) for individual pathologists were 65-88%. To ensure diagnostic accuracy both referring and consulting pathologists must have adequate training in cytology, image acquisition and image-based diagnosis and the diagnostic questions of importance must be clearly communicated by the referring pathologist when posting a case. PMID:22052967

Kumar, Neeta; Busarla, Satya Vara Prasad; Sayed, Shahin; Kirimi, Jesca Muthoni; Okiro, Patricia; Gakinya, Samuel Mukono; Moloo, Zahir; Sohani, Aliyah R

2012-01-01

242

Cost of Illness Due to Typhoid Fever in Pemba, Zanzibar, East Africa  

PubMed Central

ABSTRACT The aim of this study was to estimate the economic burden of typhoid fever in Pemba, Zanzibar, East Africa. This study was an incidence-based cost-of-illness analysis from a societal perspective. It covered new episodes of blood culture-confirmed typhoid fever in patients presenting at the outpatient or inpatient departments of three district hospitals between May 2010 and December 2010. Cost of illness was the sum of direct costs and costs for productivity loss. Direct costs covered treatment, travel, and meals. Productivity costs were loss of income by patients and caregivers. The analysis included 17 episodes. The mean age of the patients, was 23 years (range=5-65, median=22). Thirty-five percent were inpatients, with a mean of 4.75 days of hospital stay (range=3-7, median=4.50). The mean cost for treatment alone during hospital care was US$ 21.97 at 2010 prices (US$ 1=1,430.50 Tanzanian Shilling?TSH). The average societal cost was US$ 154.47 per typhoid episode. The major expenditure was productivity cost due to lost wages of US$ 128.02 (83%). Our results contribute to the further economic evaluation of typhoid fever vaccination in Zanzibar and other sub-Saharan African countries.

Piatti, Moritz; Ley, Benedikt; Deen, Jacqueline; Thriemer, Kamala; von Seidlein, Lorenz; Salehjiddawi, Mohammad; Busch, Clara Jana-Lui; Schmied, Wolfgang H.; Ali, Said Mohammed; The Typhoid Economic Study Group (GiDeok Pak, Leon R. Ochiai, Mahesh K. Puri, Na Yoon Chang, Thomas F. Wierzba, and John D. Clemens)

2014-01-01

243

Sustainable wastewater management for small communities in the Middle East and North Africa.  

PubMed

Accelerated expansion of wastewater services to small communities in the Middle East and North Africa (MENA) is essential in order to address serious concerns over water scarcity and pollution in addition to meeting the demand for convenience and protecting public health. Centralized and conventional wastewater systems are currently the preferred choice of planners and decision-makers in MENA. Water and funding are not available to provide these centralized conventional services to small communities. This paper presents an integrated approach to sustainable wastewater management for small communities in MENA under the severe water resources crisis. The approach calls for a paradigm shift from centralized conventional wastewater systems to decentralized wastewater systems. Management of wastewater in MENA should start at home. Wastewater generation should be reduced through a combination of domestic water conservation measures. On-site systems must be improved and monitored to control pollution and to recover water for non-potable water uses. Should the circumstances not allow the use of on-site systems, wastewater should be transported and managed through a community system applying the principles of decentralized wastewater management and using the settled sewers for wastewater transportation where appropriate. This approach will facilitate the accelerated and sustainable extension of environmentally responsible wastewater services to MENA's small communities. It offers great potential for cost reduction, accommodates the necessary domestic water conservation efforts, reduces freshwater inputs in wastewater transportation thus eliminating unnecessary demand on freshwater, reduces associated environmental risks and increases wastewater reuse opportunities. PMID:11383104

Bakir, H A

2001-04-01

244

The Middle East and North Africa Land Data Assimilation System: First Results (Invited)  

NASA Astrophysics Data System (ADS)

The Arab region of the Middle East and North Africa (MENA) 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 hydroclimatic 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 MENA 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. This presentation will cover early results from 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. The MENA LDAS is envisaged 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 to be used for flood and drought assessment.

Bolten, J. D.; Rodell, M.; Zaitchik, B. F.; Ozdogan, M.; Toll, D. L.; Engman, E. T.; Habib, S.

2010-12-01

245

Climate variability and conflict risk in East Africa, 1990-2009  

PubMed Central

Recent studies concerning the possible relationship between climate trends and the risks of violent conflict have yielded contradictory results, partly because of choices of conflict measures and modeling design. In this study, we examine climateconflict relationships using a geographically disaggregated approach. We consider the effects of climate change to be both local and national in character, and we use a conflict database that contains 16,359 individual geolocated violent events for East Africa from 1990 to 2009. Unlike previous studies that relied exclusively on political and economic controls, we analyze the many geographical factors that have been shown to be important in understanding the distribution and causes of violence while also considering yearly and country fixed effects. For our main climate indicators at gridded 1 resolution (?100 km), wetter deviations from the precipitation norms decrease the risk of violence, whereas drier and normal periods show no effects. The relationship between temperature and conflict shows that much warmer than normal temperatures raise the risk of violence, whereas average and cooler temperatures have no effect. These precipitation and temperature effects are statistically significant but have modest influence in terms of predictive power in a model with political, economic, and physical geographic predictors. Large variations in the climateconflict relationships are evident between the nine countries of the study region and across time periods. PMID:23090992

O'Loughlin, John; Witmer, Frank D. W.; Linke, Andrew M.; Laing, Arlene; Gettelman, Andrew; Dudhia, Jimy

2012-01-01

246

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

USGS Publications Warehouse

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.

Key, R.M.; Pitfield, P.E.J.; Thomas, R.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

247

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

PubMed Central

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 subjectsmethods of obtaining morbidity data, intensity of infection, effects of the disease on human health, treatment, and the molluscan vectors. PMID:13383363

Blair, Dyson M.

1956-01-01

248

Aerosol Radiative Forcing and Regional Climate Impact over Middle East and North Africa  

NASA Astrophysics Data System (ADS)

Middle East and North Africa (MENA) is a unique region due in part to the abundance of atmospheric aerosols and their significant contribution to the energy balance of the region. Mineral dust plays a leading role in this process. In this study we evaluate the radiative forcing of dust aerosols in the MENA region and their impact on the regional circulation and temperature distribution using a global high-resolution atmospheric model HIRAM developed at the NOAA Geophysical Fluid Dynamics Laboratory. We found that dust aerosols reduce downward radiative fluxes at surface up to 30 W/m2 and warm by about this amount the lower five-km-deep atmospheric layer. To better quantify radiative impact of aerosols we have employed the available aerosol satellite observations that primarily provide column integral aerosol optical depth (AOD), as a measure of aerosol burden. Climatology of AOD from different satellites (MODIS, MISR, SEVIRI and CALIPSO) over MENA and their inter comparison is made to have a comprehension of the discrepancies and agreement between them. Though the observed AODs vary among the different instruments spatially and temporally, the difference falls within a factor of less than two. We implement these observed aerosols in HIRAM. The radiative forcing corresponding to the satellite aerosol observation and the sensitivity of regional climate to this forcing are analyzed. The analysis shows that the differential heating in the vertical and the corresponding response of the vertical temperature profile have a profound impact on the tropospheric dynamics and the structure of the boundary layer.

Bangalth, H. K.; Stenchikov, G.; Zampieri, M.; Bantges, R.; Brindley, H.

2012-04-01

249

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

ERIC Educational Resources Information Center

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

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

2011-01-01

250

Effects of crossbreeding East African, Galla and Boer goats on body size, growth rate and kid survivability in Kenya  

E-print Network

, 1982) in these countries, making it the most important and primary function of goats. Goats are widely distributed in ecological habitats and farm- ing systems (Gall, 1981a). A prominent characteristic of goats dis- tribution... variability in mature weight in these goat breed is indicated, Boer goats are noted to be heaviest in mature weight, followed by Galls goats and East Africans have lowest mature weight of the three breeds. Kid Survival Goats are recognized for their high...

Angwenyi, Geoffrey Noah

2012-06-07

251

Getting Books to School Pupils in Africa: Case Studies from Ghana and Tanzania, Mali, South Africa, Mozambique, and Kenya. Education Research Paper.  

ERIC Educational Resources Information Center

One of the fundamental requirements of all educational systems is the adequate provision of relevant and appropriate reading and other instructional and learning materials for use by teachers and their pupils. A study examined some of the modalities through which the school population in Africa gains access to supplementary reading materials and

Rosenberg, Diana, Ed.

252

First biologic and genetic characterization of Toxoplasma gondii isolates from chickens from Africa (Democratic Republic of Congo, Mali, Burkina Faso, and Kenya).  

PubMed

The prevalence of Toxoplasma gondii in free-ranging chickens (Gallus domesticus) is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. In the present study, prevalence of T. gondii in chickens from Democratic Republic of Congo, Mali, Burkina Faso, and Kenya is reported. The prevalence of T. gondii antibodies in sera of 50 free-range chickens from Congo was 50% based on the modified agglutination test (MAT); antibody titers were 1:5 in 7, 1:10 in 7, 1:20 in 6, 1:40 in 1, and 1:160 or more in 4 chickens. Hearts, pectoral muscles, and brains of 11 chickens with titers of 1:20 or more were bioassayed individually in mice; T. gondii was isolated from 9, from the hearts of 9, brains of 3, and muscles of 3 chickens. Tissues of each of the 14 chickens with titers of 1:5 or 1:10 were pooled and bioassayed in mice; T. gondii was isolated from 1 chicken with a titer of 1:10. Tissues from the remaining 25 seronegative chickens were pooled and fed to 1 T. gondii-free cat. Feces of the cat were examined for oocysts, but none was seen. The results indicate that T. gondii localizes in the hearts more often than in other tissues of naturally infected chickens. Genotyping of these 10 isolates using the SAG2 locus indicated that 8 were isolates were type III, 1 was type II, and 1 was type I. Two isolates (1 type I and 1 type III) were virulent for mice. Toxoplasma gondii was isolated by mouse bioassay from a pool of brains and hearts of 5 of 48 chickens from Mali and 1 of 40 chickens from Burkina Faso; all 6 isolates were avirulent for mice. Genetically, 4 isolates were type III and 2 were type II. Sera were not available from chickens from Mali and Burkina Faso. Toxoplasma gondii antibodies (MAT 100 or more) were found in 4 of 30 chickens from Kenya, and T. gondii was isolated from the brain of 1 of 4 seropositive chickens; this strain was avirulent for mice and was type II. This is the first report on isolation and genotyping of T. gondii from any source from these 4 countries in Africa. PMID:15856874

Dubey, J P; Karhemere, S; Dahl, E; Sreekumar, C; Diabat, A; Dabir, K R; Vianna, M C B; Kwok, O C H; Lehmann, T

2005-02-01

253

Participatory learning and action to reduce women's workloads in east Africa  

Microsoft Academic Search

This paper examines the multiple roles which women perform in their daily lives and considers how their heavy workloads impact on their own health and that of their children. It draws on the findings of a study carried out in Kenya and Tanzania to identify attitudinal and structural barriers to the reduction of women's workloads. It briefly contrasts this with

Aloysia Masoy; Pat Pridmore

1997-01-01

254

Towards Green-Sensibility in African Architecture - A Climate-sensitive Approach to Design in East Africa  

E-print Network

of Buildings. New York: Van Nostrand Reinhold. Givoni, B. 1976. Man, Climate & Architecture. London: Applied Science Publishers Ltd. GOK (Government of Kenya). 1997. National Development Plan for the period 1997 to 2000. Nairobi: Government Printers. Kenya... of Buildings. New York: Van Nostrand Reinhold. Givoni, B. 1976. Man, Climate & Architecture. London: Applied Science Publishers Ltd. GOK (Government of Kenya). 1997. National Development Plan for the period 1997 to 2000. Nairobi: Government Printers. Kenya...

Ogoli, D. M.

1998-01-01

255

18/03/2010 11:46IRIN Global | GLOBAL: Is humanitarianism genetic? | Asia East Africa ...Zambia Zimbabwe | In Brief Health & Nutrition Aid Policy | News Item Page 1 of 2http://www.irinnews.org/Report.aspx?ReportId=88437  

E-print Network

://www.irinnews.org/Report.aspx?ReportId=88437 Photo: Madeleine Price Ball/Wikimedia Are careers in our DNA code? Africa Asia Middle East reports: Home Africa Asia Middle East Latin America & Caribbean Weekly reports Global Issues In Item Page 2 of 2http://www.irinnews.org/Report.aspx?ReportId=88437 AFRICA: Talking about climate change

West, Stuart

256

A multipurpose serological survey in Kenya  

PubMed Central

Arbovirus infections are of public health interest in East Africa, where a very widespread epidemic of o'nyong-nyong fever was reported in 1959-60 and where the threat of yellow fever, present in neighbouring areas such as Ethiopia, remains. Sera collected in a serological survey in Kenya were therefore tested for antibodies against 3 group-A arboviruses (chikungunya, o'nyong-nyong and Sindbis), 6 group-B arboviruses (Zika, yellow fever, West Nile, Banzi, Wesselsbron and dengue 1), and Bunyamwera virus. The sera were examined mainly by the haemagglutination-inhibition test but a small proportion were also subjected to virus neutralization tests. The results showed that the prevalence of arbovirus tnfection varies markedly from area to area in Kenya. All types of arbovirus infections were more frequent on the coast than on the dry plateau around Kitui and the Lake Victoria area, The only exceptions were o'nyong-nyong and chikungunya, which were found to be just as prevalent on the coast as in Nyanza, where an epidemic was reported in 1959-60. Yellow fever antibodies were found to be present in about half of the people living on the coast but practically absent from the other two areas. It was concluded that the yellow fever antibodies in the coastal area must be due either to vaccination or to cross-reactions with other group-B arboviruses. PMID:5313066

Geser, Anton; Henderson, Brian E.; Christensen, Svend

1970-01-01

257

Agricultural Early Warning Informing Humanitarian Response in East Africa for 2012  

NASA Astrophysics Data System (ADS)

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 Nia 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 weighted scenarios based on February SSTs, the interquartile range shifted to 75-105% of normal. As the season progressed, March turned out to be exceptionally dry, with a lack of onset of rains for much of the region. This delayed start to the season allowed for the combination of satellite estimates for the start of March to be combined with scenarios to look ahead to end-of-season values. By the end of March, combining estimated 2012 rains with the scenarios built before the season resulted in the interquartile range for expected outcomes dropping to 60-85% of normal. This information was relayed to FEWS NET food security analysts and used in a special report, highlighting the potential for crisis in the region. In April, this forecasting effort, combined with FEWS NET's extensive monitoring activities, helped motivate allocation of an additional $50M in food aid from the U.S. government. This presentation examines the climate conditions associated with MAM drought in the eastern sector of the Greater Horn, reviews the techniques behind the 2012 forecasts, and analyzes the actual outcome for the region. Methods for improving the work to more accurately reflect the variability and future directions and applications will be discussed.

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

2012-12-01

258

Multi-spatial livelihoods in sub-Saharan Africa: rural farming by urban households - the case of Nakuru town, Kenya  

Microsoft Academic Search

Multispatial livelihoods refer to households with a livelihood foothold in both urban and rural areas. Although it is well-known that multispatial households are common in sub-Saharan Africa, the phenomenon has seldom been looked at from the urban household perspective. A review of the literature indicates that rural food and\\/or income sources are important for urban dwellers. This chapter presents data

D. W. J. Foeken; S. O. Owuor; Bruijn de M. E; R. A. Dijk

2001-01-01

259

Callwell versus Graziani: how the British Army applied small wars techniques in major operations in Africa and the Middle East, 194041  

Microsoft Academic Search

The period from December 1940 through to the spring of 1941 saw the British Army win a series of rapid and decisive victories over Italian and Vichy French forces in North and East Africa and the Middle East. A key feature of these operations was the extensive British use of fast-moving all-arms mobile formations utilising superior speed and mobility to

Simon Anglim

2008-01-01

260

Maternity Care and Childrearing: Preconditions for Educational Achievement. Experiences in a Cross-Cultural Perspective with Special Focus on East Africa.  

ERIC Educational Resources Information Center

East African maternity care and child rearing practices are discussed from a cross-cultural perspective. A brief background section is followed by discussion of: (1) health and nutrition as preconditions for educational achievement; (2) care of mothers and children and child rearing in East Africa--by far the longest section; (3) the roles of

Negussie, Birgit

261

Nursing and midwifery regulatory reform in east, central, and southern Africa: a survey of key stakeholders  

PubMed Central

Background In sub-Saharan Africa, nurses and midwives provide expanded HIV services previously seen as the sole purview of physicians. Delegation of these functions often occurs informally by shifting or sharing of tasks and responsibilities. Normalizing these arrangements through regulatory and educational reform is crucial for the attainment of global health goals and the protection of practitioners and those whom they serve. Enacting appropriate changes in both regulation and education requires engagement of national regulatory bodies, but also key stakeholders such as government chief nursing officers (CNO), professional associations, and educators. The purpose of this research is to describe the perspectives and engagement of these stakeholders in advancing critical regulatory and educational reform in east, central, and southern Africa (ECSA). Methods We surveyed individuals from these three stakeholder groups with regard to task shifting and the challenges related to practice and education regulation reform. The survey used a convenience sample of nursing and midwifery leaders from countries in ECSA who convened on 28 February 2011, for a meeting of the African Health Profession Regulatory Collaborative. Results A total of 32 stakeholders from 13 ECSA countries participated in the survey. The majority (72%) reported task shifting is practiced in their countries; however only 57% reported their national regulations had been revised to incorporate additional professional roles and responsibilities. Stakeholders also reported different roles and levels of involvement with regard to nursing and midwifery regulation. The most frequently cited challenge impacting nursing and midwifery regulatory reform was the absence of capacity and resources needed to implement change. Discussion While guidelines on task shifting and recommendations on transforming health professional education exist, this study provides new evidence that countries in the ECSA region face obstacles to adapting their practice and education regulations accordingly. Stakeholders such as CNOs, nursing associations, and academicians have varied and complementary roles with regard to reforming professional practice and education regulation. Conclusion This study provides information for effectively engaging leaders in regulatory reform by clarifying their roles, responsibilities, and activities regarding regulation overall as well as their specific perspectives on task shifting and pre-service reform. PMID:23800079

2013-01-01

262

Long-term outcomes of school-based treatment for control of urinary schistosomiasis: a review of experience in Coast Province, Kenya  

Microsoft Academic Search

Urinary schistosomiasis remains a significant burden for Africa and the Middle East. The success of population- based control programs will depend on their impact, over many years, on Schistosoma haematobium reinfection and associated disease. In a multi-year (1984-1992) control program in Kenya, we examined risk for S. haematobium reinfection and late disease during and after annual school-based treatment. In this

Charles H King

2006-01-01

263

Lake Naivasha, Kenya  

NASA Technical Reports Server (NTRS)

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.

2008-01-01

264

Controls on rifting in Africa and the regional tectonic model for the Nigeria and East Niger rift basins  

NASA Astrophysics Data System (ADS)

Since early Mesozoic times, three phases of rifting have occurred in Africa and are related to distinct phases of breakup of Gondwana. These contrasting rift episodes have provided an insight to the extent to which plate tectonic processes and more localised mechanical anisotropy processes within the African lithosphere have influenced rifting. Gravity modelling of the Nigeria and East Niger rift basins shows the extent and nature of the broad (regional) positive Bouguer anomaly associated with these rifts. The removal of this regional anomaly allows the delineation of the (residual) negative Bouguer anomaly which reflects the lateral extent and thickness of Mesozoic and Cenozoic sediments. This residual anomaly is interpreted using iterative three dimensional modelling, by incorporating a density-depth function derived from well logs. Results indicate that an extensive basin complex exists in eastern Niger with sedimentary sections greater than 7 km in depth and are in good agreement with the aeromagnetic data. A simple estimate of crustal extension across the East Niger rift basin indicates that up to 58 km of crustal stretching has occurred, placing an upper limit on the amount of sinistral strike-slip movement required within the Benue Trough to open the East Niger rift. A similar strike-slip and extension rift geometry is observed elsewhere in the West and Central African rift system which indicates that the Cretaceous period was an important time for strike-slip tectonics. Changes in the differential opening of the Central and South Atlantic Oceans during the Cretaceous can adequately explain the large strike-slip displacements and associated rift basins in West and North Central Africa and are considered here to more closely reflect the initial rift processes that shaped the continental margin of Africa than those associated with the modern East African rift system.

Fairhead, J. D.; Green, C. M.

265

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

PubMed

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

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

2013-05-14

266

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

PubMed Central

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

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

2013-01-01

267

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

NASA Astrophysics Data System (ADS)

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 19952000. 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.

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

2014-10-01

268

Smoking habits in the Middle East and North Africa: results of the BREATHE study.  

PubMed

Few recent comparative data exist on smoking habits in the Middle East and North Africa (MENA) region. The objective of this analysis was to evaluate smoking patterns in a large general population sample of individuals aged ? 40 years in ten countries in the region (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), together with Pakistan, using a standardised methodology. A random sample of 457,258 telephone numbers was generated and called. This identified 65,154 eligible subjects, of whom 62,086 agreed to participate. A screening questionnaire was administered to each participant, which included six questions relating to cigarette consumption and waterpipe use. The age- and gender-adjusted proportion of respondents reporting current or past smoking of cigarettes or waterpipes was 31.2% [95% CI: 30.9-31.6%]. This proportion was significantly higher (p < 0.001) in men (48.0%) than in women (13.8%), but no relevant differences were observed between age groups. Smoking rates were in general lowest in the Maghreb countries and Pakistan and highest in the Eastern Mediterranean countries, ranging from 15.3% in Morocco to 53.9% in Lebanon. Consumption rates were 28.8% [28.4-29.2%] for cigarette smoking and 3.5% [3.4-3.6%] for waterpipe use. Use of waterpipes was most frequent in Saudi Arabia (8.5% of respondents) but remained low in the Maghreb countries (< 1.5%). Cumulative cigarette exposure was high, with a mean number of pack years smoked of 18.5 20.5 for women and 29.1 26.2 for men. In conclusion, smoking is a major health issue in the MENA region. PMID:23290700

Khattab, Adel; Javaid, Arshad; Iraqi, Ghali; Alzaabi, Ashraf; Ben Kheder, Ali; Koniski, Marie-Louise; Shahrour, Naem; Taright, Samya; Idrees, Magdy; Polatli, Mehmet; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

269

Characterising the progress in HIV/AIDS research in the Middle East and North Africa  

PubMed Central

Objectives The Middle East and North Africa (MENA) region is perceived to have limited HIV data. The objective of this study was to quantitatively characterise the progress in HIV research in this region since the discovery of the epidemic. Methods Four indices were defined and implemented to measure the progress of HIV research using the PubMed, Embase, MENA HIV/AIDS Epidemiology Synthesis Project and US Census Bureau HIV/AIDS Surveillance databases. The four indices provide complementary measures to characterise different aspects of the progress of HIV research. Results A total of 2118, 2352, 683 and 4889 records were identified through the PubMed, the Embase, the Synthesis Project and the HIV Prevalence indices, respectively. The proportion of the total global HIV records that relate to MENA is 1.2%. Overall, the indices show steady progress in the number of new records every year, with an accelerated pace in the last few years. The rate of progress in MENA was also higher than the rate of progress in HIV records globally. There is no evidence so far of stabilisation or a peak in the number of new records year by year. About half of the records were produced after the year 2005. The number of records shows large heterogeneity across countries. Conclusions MENA has witnessed a rapid growth in HIV research over the last decade. However, there are still large gaps in HIV scientific evidence in the region, and the progress is far from being uniform across countries. Ongoing and future research needs to be geared towards academic standard and production of scientific publications. PMID:23596206

Saba, Hanan F; Kouyoumjian, Silva P; Mumtaz, Ghina R; Abu-Raddad, Laith J

2013-01-01

270

Anthropogenic pressure in East Africa-Monitoring 20 years of land cover changes by means of medium resolution satellite data  

NASA Astrophysics Data System (ADS)

The East Africa IGAD (Intergovernmental Authority on Development in Eastern Africa) region with its great variety of ecological regions experienced major changes during the last decades. This study assesses and quantifies the land cover dynamics in the region by applying a systematic sampling of medium resolution Landsat and DMC Deimos imagery. 445 samples covering about 3% of the study area taken as a box of 20 km 20 km around each 1 degree latitude and longitude intersects are processed and analyzed. Statistical estimates of land cover change are produced by means of an automatic object-based classification in seven broad classes for the years 1990-2000 and 2000-2010. Figures of change for the East Africa IGAD region are presented and land cover change processes such as loss of natural vegetation and increase of agriculture areas are analyzed. Results highlight the geographical distribution of land cover dynamics and show a 28% increase in agriculture area over the analyzed 20-year time frame. The yearly agriculture area increase rate is around 1.4% for both assessed decades, however a strong increase in yearly deforestation rate - from 0.2% in the first period to 0.4% in the second period - has been observed. These figures are discussed within the context of the drivers of changes and the resulting impact to the natural ecosystem.

Brink, Andreas B.; Bodart, Catherine; Brodsky, Lukas; Defourney, Pierre; Ernst, Celine; Donney, Francois; Lupi, Andrea; Tuckova, Katerina

2014-05-01

271

Aerosol characterization in Northern Africa, Northeastern Atlantic, Mediterranean Basin and Middle East from direct-sun AERONET observations  

NASA Astrophysics Data System (ADS)

We provide an atmospheric aerosol characterization for North Africa, Northeastern Atlantic, Mediterranean and Middle East based on the analysis of quality-assured direct-sun observations of 39 stations of the AErosol RObotic NETwork (AERONET) which include at least an annual cycle within the 1994-2007 period. We extensively test and apply the recently introduced graphical method of Gobbi and co-authors in order to track and discriminate different aerosol types and quantify the contribution of mineral dust. The method relies on the combined analysis of the ngstrm exponent (?) and its spectral curvature. Plotting data in these coordinates allows to infer aerosol fine mode size (Rf) and fractional contribution (?) to total Aerosol Optical Depth (AOD) and separate AOD growth due to fine-mode aerosol humidification and/or coagulation from AOD growth due to the increase in coarse particles or cloud contamination. Our results confirm the robustness of this graphical method. Large mineral dust is the most important constituent in Northern Africa and Middle East; and under specific meteorological conditions, its transport to Europe is observed from spring to autumn. Small pollution particles are abundant in sites close to urban and industrial areas of Continental and Eastern Europe and Middle East; as well as, important contributions of biomass burning are observed in the sub-Sahel region in winter. Dust is usually found to mix with these fine, pollution aerosols.

Basart, S.; Prez, C.; Cuevas, E.; Baldasano, J. M.; Gobbi, G. P.

2009-03-01

272

Sodium Stibogluconate (SSG) & Paromomycin Combination Compared to SSG for Visceral Leishmaniasis in East Africa: A Randomised Controlled Trial  

PubMed Central

Background Alternative treatments for visceral leishmaniasis (VL) are required in East Africa. Paromomycin sulphate (PM) has been shown to be efficacious for VL treatment in India. Methods A multi-centre randomized-controlled trial (RCT) to compare efficacy and safety of PM (20 mg/kg/day for 21 days) and PM plus sodium stibogluconate (SSG) combination (PM, 15 mg/kg/day and SSG, 20 mg/kg/day for 17 days) with SSG (20 mg/kg/day for 30 days) for treatment of VL in East Africa. Patients aged 460 years with parasitologically confirmed VL were enrolled, excluding patients with contraindications. Primary and secondary efficacy outcomes were parasite clearance at 6-months follow-up and end of treatment, respectively. Safety was assessed mainly using adverse event (AE) data. Findings The PM versus SSG comparison enrolled 205 patients per arm with primary efficacy data available for 198 and 200 patients respectively. The SSG & PM versus SSG comparison enrolled 381 and 386 patients per arm respectively, with primary efficacy data available for 359 patients per arm. In Intention-to-Treat complete-case analyses, the efficacy of PM was significantly lower than SSG (84.3% versus 94.1%, difference?=?9.7%, 95% confidence interval, CI: 3.6 to 15.7%, p?=?0.002). The efficacy of SSG & PM was comparable to SSG (91.4% versus 93.9%, difference?=?2.5%, 95% CI: ?1.3 to 6.3%, p?=?0.198). End of treatment efficacy results were very similar. There were no apparent differences in the safety profile of the three treatment regimens. Conclusion The 17 day SSG & PM combination treatment had a good safety profile and was similar in efficacy to the standard 30 day SSG treatment, suggesting suitability for VL treatment in East Africa. Clinical Trials Registration www.clinicaltrials.gov NCT00255567 PMID:22724029

Musa, Ahmed; Khalil, Eltahir; Hailu, Asrat; Olobo, Joseph; Balasegaram, Manica; Omollo, Raymond; Edwards, Tansy; Rashid, Juma; Mbui, Jane; Musa, Brima; Abuzaid, Abuzaid Abdalla; Ahmed, Osama; Fadlalla, Ahmed; El-Hassan, Ahmed; Mueller, Marius; Mucee, Geoffrey; Njoroge, Simon; Manduku, Veronica; Mutuma, Geoffrey; Apadet, Lilian; Lodenyo, Hudson; Mutea, Dedan; Kirigi, George; Yifru, Sisay; Mengistu, Getahun; Hurissa, Zewdu; Hailu, Workagegnehu; Weldegebreal, Teklu; Tafes, Hailemariam; Mekonnen, Yalemtsehay; Makonnen, Eyasu; Ndegwa, Serah; Sagaki, Patrick; Kimutai, Robert; Kesusu, Josephine; Owiti, Rhoda; Ellis, Sally; Wasunna, Monique

2012-01-01

273

A 12,400 14C yr offshore diatom record from east central Lake Victoria, East Africa  

Microsoft Academic Search

The diatom record of V95-2P, a 7.6 m long sediment core collected from 67 m depth, is the first from the east central portion of Lake Victoria. A soil horizon developed at the coring site shortly before 12,400 14C yr BP due to a lakewide desiccation event. The radiocarbon chronology of the older half of this core is problematic, but

J. C. Stager; T. C. Johnson

2000-01-01

274

A 12,400 14c yr Offshore Diatom Record From East Central Lake Victoria, East Africa  

Microsoft Academic Search

The diatom record of V95-2P, a 7.6 m long sediment core collected from 67 m depth, is the first from the east central portion of Lake Victoria. A soil horizon developed at the coring site shortly before 12,400 14C yr BP due to a lakewide desiccation event. The radiocarbon chronology of the older half of this core is problematic, but

J. C. Stager; T. C. Johnson

2000-01-01

275

A reappraisal of the geomagnetic polarity time scale to 4 Ma using data from the Turkana Basin, East Africa  

NASA Astrophysics Data System (ADS)

Recalibration of the Pliocene and early Pleistocene geomagnetic time scale using the K-Ar dated fluvial sequence of the Turkana Basin in East Africa agrees with calibrations based on astronomical calculations. Ages estimated here are: Olduvai Subchron, 1.78-1.96 Ma; Reunion Subchrons, 2.11-2.15 Ma and 2.19-2.27 Ma; Matuyama-Gauss boundary, 2.60 Ma; Kaena Subchron 3.02-3.09 Ma; Mammoth Subchron, 3.21-3.29 Ma; Gauss-Gilbert boundary, 3.57 Ma.

McDougall, I.; Brown, F. H.; Cerling, T. E.; Hillhouse, J. W.

1992-12-01

276

Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa  

E-print Network

ral International Journal of Health ssBioMed CentGeographics Open AcceResearch Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa Richard AJ Williams* and A Townsend Peterson Address... Asia [6]. Between May and June 2005, however, >6000 birds of 8 wild waterbird species were found dead at Qinghai Lake, in central China: HPAI-H5N1 was Published: 20 July 2009 International Journal of Health Geographics 2009, 8:47 doi:10.1186/1476-072X-8...

Williams, Richard A.J.; Peterson, A. Townsend

2009-07-20

277

Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa  

E-print Network

International Journal of Health BioMed Central Geographics Open Access Research Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa Richard AJ Williams* and A Townsend Peterson Address... Asia [6]. Between May and June 2005, however, >6000 birds of 8 wild waterbird species were found dead at Qinghai Lake, in central China: HPAI-H5N1 was Published: 20 July 2009 International Journal of Health Geographics 2009, 8:47 doi:10.1186/1476-072X-8...

Williams, Richard A. J.; Peterson, A. Townsend

2009-07-20

278

Isotopic evidence for neogene hominid paleoenvironments in the Kenya Rift Valley  

SciTech Connect

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.

Kingston, J.D.; Hill, A. (Yale Univ., New Haven, CT (United States)); Marino, B.D. (Harvard Univ., Cambridge, MA (United States))

1994-05-13

279

Climate Change or Urbanization? Impacts on a Traditional Coffee Production System in East Africa over the Last 80 Years  

PubMed Central

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 19292011), 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

Jaramillo, Juliana; Setamou, Mamoudou; Muchugu, Eric; Chabi-Olaye, Adenirin; Jaramillo, Alvaro; Mukabana, Joseph; Maina, Johnson; Gathara, Simon; Borgemeister, Christian

2013-01-01

280

Geochemical and Sedimentological Records of Late Quaternary Climate Change, Lake Tanganyika, Tropical East Africa  

NASA Astrophysics Data System (ADS)

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 reflection profiles demonstrate the existence of paleodeltas at ~360m below modern lake level that may have formed during this period, although it is unclear whether this deposit represents a Late Quaternary (OIS 2) or earlier (OIS 6) event. Maximum aridity occurred at about 20-20.5ka cal yr, consist with earlier interpretations of lake lowstands (Gasse et al., 1989, Scholz et al., 1997). The late Pleistocene and earliest Holocene sediments in our record are characterized by generally rising magnetic susceptibility, declining organic carbon and biogenic silica, and finer grain size. However during this period there are marked fluctuations in magnetic susceptibility and biogenic silica at millennial time-scales. These indicate intervals of fluctuating precipitation, productivity, and possibly windiness and are particularly prominent during the Pleistocene-Holocene transition. Massive clays, rising magnetic susceptibility, low biogenic silica and low organic carbon mark the early Holocene, indicative of increased rainfall during a regionally wet interval. These sediments are capped by a laminated ooze, indicative of drier conditions and a more stratified water body.

Felton, A. A.; Russell, J. M.; Cohen, A. S.; Baker, M. E.; McGlue, M. M.; Lezzar, K. E.

2005-12-01

281

Agriculture, Education, and Rural Transformation: With Particular Reference to East Africa.  

ERIC Educational Resources Information Center

Independence for Africa has not resulted in the expected economic development of industrialization. Mineral-poor states in Africa must rely on limited prosperity coming from an expansion of agricultural commodities. The problem is that despite the prevalence of an agriculture economic base, most African leaders are committed to industrial

Liebenow, J. Gus

282

Chert and its sodium-silicate precursors in sodium-carbonate lakes of East Africa  

Microsoft Academic Search

Chert has formed from two sodium-silicate minerals, magadiite (NaSi7,O13(OH)33H2O) and kenyaite (NaSi11O20.5(OH)43H2O), in uppermost Pleistocene deposits of lakes Magadi and Natron in Kenya and Tanzania. The chert consists of finely crystalline quartz and characteristically forms nodules of irregular shape with white coatings having reticulate surface patterns. Similar nodules are widespread in lower and middle Pleistocene lacustrine deposits in the vicinity

Richard L. Hay

1968-01-01

283

Status and ecosystem interactions of the invasive Louisianan red swamp crayfish Procambarus clarkii in East Africa  

Microsoft Academic Search

There are no indigenous crayfish in continental Africa although there are indigenous crayfish on the island of Madagascar\\u000a (Hobbs 1988). However, various non-indigenous North American and Australian crayfish have been introduced to continental Africa\\u000a since the 1970s, notably the Louisianan red swamp crayfish Procambarus clarkii (Girard). This is a relatively large, prolific, aggressive, burrowing crayfish (Hobbs et al. 1989 quoted

John Foster; David Harper

284

Orbital- versus glacial-mode forcing of tropical African climate: Results of scientific drilling in Lake Malawi, East Africa  

NASA Astrophysics Data System (ADS)

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.

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

285

Aerosol characterization in Northern Africa, Northeastern Atlantic, Mediterranean Basin and Middle East from direct-sun AERONET observations  

NASA Astrophysics Data System (ADS)

We provide an atmospheric aerosol characterization for North Africa, Northeastern Atlantic, Mediterranean and Middle East based on the analysis of quality-assured direct-sun observations of 39 stations of the AErosol RObotic NETwork (AERONET) which include at least an annual cycle within the 1994-2007 period. We extensively test and apply the recently introduced graphical method of Gobbi and co-authors to track and discriminate different aerosol types and quantify the contribution of mineral dust. The method relies on the combined analysis of the ngstrm exponent (?) and its spectral curvature ??. Plotting data in these coordinates allows to infer aerosol fine mode radius (Rf) and fractional contribution (?) to total Aerosol Optical Depth (AOD) and separate AOD growth due to fine-mode aerosol humidification and/or coagulation from AOD growth due to the increase in coarse particles or cloud contamination. Our results confirm the robustness of this graphical method. Large mineral dust is found to be the most important constituent in Northern Africa and Middle East. Under specific meteorological conditions, its transport to Southern Europe is observed from spring to autumn and decreasing with latitude. We observe "pure Saharan dust" conditions to show AOD>0.7 (ranging up to 5), ?<0.3 and ??<0 corresponding to ?<40% and (Rf)~0.13 ?m. Small pollution particles are abundant in sites close to urban and industrial areas of Continental and Eastern Europe and Middle East, as well as, important contributions of biomass burning are observed in the sub-Sahel region in winter. These small aerosols are associated to AOD<1, ?>1.5 and ??~-0.2 corresponding to ?>70% and Rf~0.13 ?m. Here, dust mixed with fine pollution aerosols shifts the observations to the region ?<0.75, in which the fine mode contribution is less than 40%.

Basart, S.; Prez, C.; Cuevas, E.; Baldasano, J. M.; Gobbi, G. P.

2009-11-01

286

Africa.  

ERIC Educational Resources Information Center

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

Martz, Carlton

2001-01-01

287

Africa.  

ERIC Educational Resources Information Center

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

Happel, Sue; Loeb, Joyce

288

The geothermal fields of the Kenya rift  

NASA Astrophysics Data System (ADS)

From the standpoint of geothermal energy, Kenya's resources are due to the presence of the Kenya rift which is part of the East African rift system. Geological, geophysical and geothermal studies indicate that Neogene volcanic activity has led to the presence of near surface heat generating sources. Geothermal fields of the Kenya rift occur in two types of environments. The main geothermal fields are associated with Quaternary volcanoes. The second type is associated with fissures that are related to active fault zones. In either case, these fields are dissected by numerous rift faults that give rise to a number of geothermal springs and fumaroles.

Riaroh, Don; Okoth, William

1994-09-01

289

Africa  

NSDL National Science Digital Library

Africa is the companion Website to a PBS series being broadcast September 9 - October 28, 2001. The Photoscope section has five photo essays, on AIDS, Conflict, Urban Africa, Environment, and Women. Urban Africa presents views of contrasts, like a man cutting lettuce in a field under a billboard advertising Internet access, an aerial view of shacks in Cape Town's Philippi Township, and a well-dressed woman bargaining for vegetables in a street market in Lagos. Also included are Africa Challenge, a history game; Africa for Kids; Teacher Tools, including lesson plans; and About the Series, with descriptions of episodes, series profiles (what has happened to people featured in the shows), a link to hear the theme music, and more.

2001-01-01

290

The genus Atheris (Serpentes: Viperidae) in East Africa: Phylogeny and the role of rifting and climate in shaping the current pattern of species diversity.  

PubMed

Past climatic and tectonic events are believed to have strongly influenced species diversity in the Eastern Afromontane Biodiversity Hotspot. We investigated the phylogenetic relationships and historical biogeography of the East African genus Atheris (Serpentes: Viperidae), and explored temporal and spatial relationships between Atheris species across Africa, and the impact of palaeoclimatic fluctuations and tectonic movements on cladogenesis of the genus. Using mitochondrial sequence data, the phylogeny of East African species of Atheris shows congruent temporal patterns that link diversification to major tectonic and aridification events within East Africa over the last 15million years (my). Our results are consistent with a scenario of a delayed direct west-east colonisation of the Eastern Arc Mountains of Atheris by the formation of the western rift. Based on the phylogenetic patterns, this terrestrial, forest-associated genus has dispersed into East Africa across a divided route, on both west-southeasterly and west-northeasterly directions (a C-shaped route). Cladogenesis in the Eastern Arc Mountains and Southern Highlands of Tanzania corresponds to late Miocene and Plio-Pleistocene climatic shifts. Taxonomically, our data confirmed the monophyly of Atheris as currently defined, and reveal four major East African clades, three of which occur in discrete mountain ranges. Possible cryptic taxa are identified in the Atheris rungweensis and A. ceratophora clades. PMID:24952316

Menegon, M; Loader, S P; Marsden, S J; Branch, W R; Davenport, T R B; Ursenbacher, S

2014-10-01

291

Geochemistry and age of the Essimingor volcano, northern Tanzania (East Africa)  

Microsoft Academic Search

Essimingor is the oldest of a line of north-south trending pre-rift volcanoes in northern Tanzania associated with the opening of the southern sector of the Gregory Rift, part of the East African Rift system (EAR). Essimingor is centrally located within the present day rift, on the East-West alignment between the large volcanoes of Kilimanjaro and Ngorongoro. Based on K-Ar data

S. Mana; G. F. Mollel; M. Feigenson; M. J. Carr; B. D. Turrin; T. Furman; C. C. Swisher

2009-01-01

292

Mapping crustal heterogeneity using Lg propagation efficiency throughout the Middle East, Mediterranean, Southern Europe and Northern Africa  

USGS Publications Warehouse

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 analyzed. We measured the amplitude of Lg relative to the P-coda and mapped the lateral variation of Lg propagation efficiency. With the relatively dense coverage provided by the numerous crossing paths we are able to map out the pattern of crustal heterogeneity that gives rise to the observed character of Lg propagation. We observe that the propagation characteristics of Lg within the region of interest are very complicated but are readily correlated with the different tectonic environments within the region. For example, clear strong Lg arrivals are observed for paths crossing the stable continental interiors of Northern Africa and the Arabian Shield. In contrast, weakened to absent Lg is observed for paths crossing much of the Middle East, and Lg is absent for paths traversing the Mediterranean. Regions that block Lg transmission within the Middle East are very localized and include the Caspian Sea, the Iranian Plateau and the Red Sea. Resolution is variable throughout the region and strongly depends on the distribution of seismicity and recording stations. Lg propagation is best resolved within the Middle East where regions of crustal heterogeneity on the order of 100 km are imaged (e.g., South Caspian Sea and Red Sea). Crustal heterogeneity is resolvable but is poorest in seismically quiescent Northern Africa.

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

2001-01-01

293

Nursing and midwifery regulation and HIV scale-up: establishing a baseline in east, central and southern Africa  

PubMed Central

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 contribute to further scale-up HIV services and other global health priorities. Conclusions This study provides fundamental information from which to articulate goals and to measure the impact of regulation strengthening efforts. PMID:23531276

McCarthy, Carey F; Voss, Joachim; Verani, Andre R; Vidot, Peggy; Salmon, Marla E; Riley, Patricia L

2013-01-01

294

Kenya's infrastructure: a continental perspective  

Microsoft Academic Search

In the past decade, infrastructure contributed 0.5 percentage points to Kenya's annual per capita GDP growth. Raising the countrys infrastructure endowment to that of Africa's middle-income countries could increase that contribution by 3 percentage points. Several accomplishments are notable. More than 90 percent of the population has access to GSM cell signals. A successful public-private partnership in air transport has

Cecilia M. Briceno-Garmendia; Maria Shkaratan

2011-01-01

295

LANDSAT image studies as applied to petroleum exploration in Kenya  

NASA Technical Reports Server (NTRS)

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.

Miller, J. B.

1975-01-01

296

Examining the Response of Tropical Terrestrial Vegetation to Paleoenvironmental Variability: an Organic and Isotopic Geochemical Record from Lake Malawi, East Africa  

Microsoft Academic Search

In this study, molecular biomarkers and compound-specific carbon isotopes are used to investigate terrestrial vegetation change in East Africa since the Last Glacial Maximum (LGM). Lake Malawi, located in the southern hemisphere between 9 S and 14 S, provides a particularly interesting and sensitive location to examine the response of terrestrial vegetation to climatic change as the lake is presently

I. S. Castaneda; J. P. Werne; T. C. Johnson; T. R. Filley

2005-01-01

297

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

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

Zachlod, Michelle, Ed.

298

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

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

Sabour, M'Hammed

1999-01-01

299

Think globally, act locally: using international treaties for women's empowerment in East Africa  

Microsoft Academic Search

Women activists in Africa need to develop innovative ways to use international treaties and instruments in a way that strengthens domestic guarantees of equality for women in their countries writes SYLVIA TAMALE. She looks at the ways in which two such instruments, CEDAW and the Banjul Charter, have been used to advance women's empowerment

SYLVIA TAMALE

2001-01-01

300

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

ERIC Educational Resources Information Center

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

Stewart, Rohn

301

Fluoride Content in Selected Food Items from Five Areas in East Africa  

Microsoft Academic Search

Dental fluorosis is widespread in the eastern part of Africa. Drinking water has traditionally been considered the main reason for the development of fluorosis, but food items may also be a contributor in areas with high concentrations of fluoride in the soil. The purpose of this study was to assess the fluoride content of fish and staple food items commonly

Marian Kjellevold Malde; Amund Maage; Elizabeth Macha; Kre Julshamn; Kjell Bjorvatn

1997-01-01

302

An updated atlas of human helminth infections: the example of East Africa  

Microsoft Academic Search

BACKGROUND: Reliable and updated maps of helminth (worm) infection distributions are essential to target control strategies to those populations in greatest need. Although many surveys have been conducted in endemic countries, the data are rarely available in a form that is accessible to policy makers and the managers of public health programmes. This is especially true in sub-Saharan Africa, where

Simon Brooker; Narcis B Kabatereine; Jennifer L Smith; Denise Mupfasoni; Mariam T Mwanje; Onsime Ndayishimiye; Nicholas JS Lwambo; Deborah Mbotha; Peris Karanja; Charles Mwandawiro; Eric Muchiri; Archie CA Clements; Donald AP Bundy; Robert W Snow

2009-01-01

303

Indian Ocean climate event brings floods to East Africa's lakes and the Sudd marsh  

Microsoft Academic Search

During an El Nio, the expected rainfall increase over most of the Lake Victoria catchment area is ~15-25%. However, due to anomalous warming of the western equatorial Indian Ocean during 1997, strong convection developed over parts of the Horn and eastern Africa. This resulted in a much larger 20-160% precipitation excess during the ``short rainy'' season. Satellite radar altimetry data

Charon Birkett; Ragu Murtugudde; Tony Allan

1999-01-01

304

The life and death of a street boy in East Africa: everyday violence in the time of AIDS.  

PubMed

This article focuses on the life history of a single street boy in northwestern Tanzania, whom I name Juma. I suggest that Juma's experiences and the life trajectory of himself and of significant individuals around him (particularly his mother) were structured by everyday violence. I describe everyday violence in terms of a conjuncture between macrostructural forces in East Africa (including a history of failed development schemes and the contemporary political economy of neoliberalism) and the lived experience of individuals as they negotiate local, contextual factors (including land-tenure practices, the power dynamics between immediate and extended kin, life on the streets, and constructions of gender and sexuality). I suggest that AIDS and its many impacts on Juma's life course can only be understood in a broader context of everyday violence. From this basis, I draw several general conclusions regarding AIDS prevention and intervention strategies. PMID:18610815

Lockhart, Chris

2008-03-01

305

Impediments to media communication of social change in family planning and reproductive health: experiences from East Africa.  

PubMed

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

Kagurusi, Patrick T

2013-09-01

306

Grid search modeling of receiver functions: Implications for crustal structure in the Middle East and North Africa  

SciTech Connect

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

Sandvol, E.; Seber, D.; Calvert, A.; Barazangi, M. [Institute for the Study of the Continents, Cornell University, Ithaca, New York (United States)] [Institute for the Study of the Continents, Cornell University, Ithaca, New York (United States)

1998-11-01

307

Identifying important breast cancer control strategies in Asia, Latin America and the Middle East/North Africa  

PubMed Central

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

2011-01-01

308

Holistic view to integrated climate change assessment and extreme weather adaptation in the Lake Victoria Basin East Africa  

NASA Astrophysics Data System (ADS)

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 exceeding the 90% percentile of 1981-2000 likely to increase by 20-40% in the whole region. We also focused on short-term weather forecasting as a step towards adapting to a changing climate. This involved dynamic downscaling of global weather forecasts to high resolution with a special focus on extreme events. By utilizing complex model dynamics, the system was able to reproduce the Mesoscale dynamics well, simulated the land/lake breeze and diurnal pattern but was inadequate in some aspects. The quantitative prediction of rainfall was inaccurate with overestimation and misplacement but with reasonable occurrence. To address these shortcomings we investigated the value added by assimilating Advanced Microwave Scanning Radiometer (AMSR-E) brightness temperature during the event. By assimilating 23GHz (sensitive to water) and 89GHz (sensitive to cloud) frequency brightness temperature; the predictability of an extreme rain weather event was investigated. The assimilation through a Cloud Microphysics Data Assimilation (CMDAS) into the weather prediction model considerably improved the spatial distribution of this event.

Mutua, F.; Koike, T.

2013-12-01

309

Open system evolution of trachyte and phonolite magmas from the East Africa Rift  

NASA Astrophysics Data System (ADS)

The Quaternary Suswa volcanic system consists of a large shield volcano that developed two nested summit calderas and erupted metaluminous to peralkaline trachyte and phonolite lavas and tuffs. Suswa is adjacent to the Greater Olkaria Volcanic Center, Longonot, Eburru, and Menengai volcanic systems, which erupted trachyte, comendite, and pantellerite. These volcanoes comprise the Central Kenya Peralkaline Province and are the site of active geothermal energy production and exploration. Mafic to intermediate lavas (Elementieta, Ndabibi, and Lolonito-Akira-Tandamara volcanic fields) lie in the rift floor between the shield volcanoes and occur as components of mixed magmas within the complexes. Suswa includes two suites of trachyte-phonolite lavas and tuffs. The first suite (C1) consists of lavas that built the original shield volcano and lavas and tuffs related to the formation of the first caldera; the second suite (C2) consists of lavas and tuffs erupted during and after the formation of the second caldera. Trachyte-carbonate immiscibility has been recorded in C1 ash flow units. The lavas and tuffs of the C2 suite are generally less peralkaline and more silica undersaturated than those of the C1 suite and did not share a common parental magma. Geochemical modeling precludes fractional crystallization as the sole process for Suswa magmas. Instead, assimilation of syenitic material (probably the crystal mush left over from C1 fractional crystallization), resorption, and mixing between the mafic to intermediate lavas satellite to the shield volcanoes have contributed to the composition and eruptive style of these volcanoes.

Anthony, E. Y.; Espejel, V.

2011-12-01

310

Ecology and geography of avian influenza (HPAI H5N1) transmission in the Middle East and northeastern Africa  

PubMed Central

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

Williams, Richard AJ; Peterson, A Townsend

2009-01-01

311

Workplace Learning in the Horti\\/Floriculture Sector in East-Africa  

Microsoft Academic Search

This chapter discusses the relevance of and possibi lities for developing work-oriented curricula in East-African countries for the purpose of increasing the competitive strengths of businesses, economic value of the country and th e value of graduates for the work field in this rapid changing and global society. To this end, this chapter discusses a case study dealing with developing

Martin Mulder; Judith Gulikers

2009-01-01

312

Focal mechanisms and the stress regime in NE and SW Tanzania, East Africa  

Microsoft Academic Search

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

Richard A. Brazier; Andrew A. Nyblade; Juliette Florentin

2005-01-01

313

The sup 36 Cl ages of the brines in the Magadi-Natron basin, east Africa  

Microsoft Academic Search

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 ³⁶Cl methodology as a geochemical and hydrological tracer. The main

A. Kaufman; M. A. Margaritz; G. Hollos; M. Paul; E. Boaretto; C. Hillaire-Marcel; M. Taieb

1990-01-01

314

The 36 C1 ages of the brines in the Magadi-Natron basin, East Africa  

Microsoft Academic Search

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 36 Cl methodology as a geochemical and hydrological tracer. The

Aaron Kaufman; Mordeckai Margaritz; Michael Paul; Claude Hillaire-Marcel; George Hollos; Elisabetta Boaretto; Maurice Taieb

1990-01-01

315

Oil and the economic geography of the Middle East and North Africa  

SciTech Connect

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.

Kortepeter, C.M. (New York Univ., NY (United States))

1990-01-01

316

Slavery and Freedom in Nineteenth Century East Africa: The Case of Waungwana Caravan Porters  

Microsoft Academic Search

The nineteenth century East African caravan system was organised around the labour of itinerant caravan porters, most of whom were free wage labourers. However, a minority of the caravan labour force and a section of the populations of new market and caravan towns on the coast and in the interior were slaves or freed slaves known as Waungwana, or gentlemen.

Stephen J. Rockel

2009-01-01

317

Adapting to climate change: Agricultural system and household impacts in East Africa  

Microsoft Academic Search

The East African region exhibits considerable climatic and topographic variability. Much spatial and temporal variation in the response of different crops to climate change can thus be anticipated. In previous work we showed that a large part of this variation can be explained in terms of temperature and, to a lesser extent, water effects. Here, we summarise simulated yield response

Philip K. Thornton; Peter G. Jones; Gopal Alagarswamy; Jeff Andresen; Mario Herrero

2010-01-01

318

Origin of the Superflock of Cichlid Fishes from Lake Victoria, East Africa  

Microsoft Academic Search

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

Erik Verheyen; Walter Salzburger; Jos Snoeks; Axel Meyer

2003-01-01

319

Simulated Physical Mechanisms Associated with Climate Variability over Lake Victoria Basin in East Africa  

E-print Network

Simulated Physical Mechanisms Associated with Climate Variability over Lake Victoria Basin in East the physical mechanisms associated with the multiscale variability of the Lake Victoria basin climate advanced in some of the previous studies that Lake Victoria generates its own climate (rainfall) through

Liu, Paul

320

Tobacco smoking in Tanzania, East Africa: population based smoking prevalence using expired alveolar carbon monoxide as a validation tool  

PubMed Central

Objectives: To describe the prevalence of tobacco smoking in an urban East African population while using a simple validation procedure to examine the degree of under reporting in men and women. Design: A cross sectional population based study in adults (15 years and over) with sampling from a well maintained census register. Setting: Ilala Ilala, a middle income district of Dar es Salaam, Tanzania. Subjects: An age and sex stratified random sample of 973 men and women. Main outcome measures: Self reported smoking status with correction by exhaled alveolar carbon monoxide (EACO). Results: From the 605 participants (response rate 67.9%) age standardised (new world population) smoking prevalence, based on questionnaire and EACO, was 27.0% (95% confidence interval (CI) 20.8% to 33.2%) in males and 5.0% (95% CI 2.8% to 7.2%) in females. The age specific prevalence of smoking was highest in the age group 3554 years (34.3%) for men and in the over 54 years group (16%) for women. Of those classified as smokers, 7.3% of men and 27.3% of women were reclassified as current smokers based on EACO (? 9 parts per million), after they had reported themselves to be an ex- or non-smoker in the questionnaire. Conclusions: The data suggest: (1) high rates of smoking among men in an urban area of East Africa; and (2) the importance of validating self reports of smoking status, particularly among women. PMID:12198270

Jagoe, K; Edwards, R; Mugusi, F; Whiting, D; Unwin, N

2002-01-01

321

Use of participatory epidemiology to compare the clinical veterinary knowledgeof pastoralists and veterinarians in East Africa  

Microsoft Academic Search

Because of severe resource and logistical constraints in large areas of Africa, disease surveillance systems need to maximize\\u000a the use of information provided by livestock keepers and make correct interpretations of indigenous livestock knowledge. This\\u000a paper describes the use of participatory epidemiology (PE) to compare the names, clinical signs and epidemiological features\\u000a of cattle diseases as perceived by pastoralists and

A. Catley

2006-01-01

322

Lake level change and total water discharge in East Africa Rift Valley from satellite-based observations  

NASA Astrophysics Data System (ADS)

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. It is found that the computed ET represents approximately 90% of the rainfall over the study region.

Hassan, Ayman A.; Jin, Shuanggen

2014-06-01

323

Along-dip variations of structural style in the Somali Basin deep-water fold and thrust belt (East Africa)  

NASA Astrophysics Data System (ADS)

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 dcollement, 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 dcollement. 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 expected, relevant extensional growth faults and normal faults, which can balance the significant amount of shortening of the compressional domain. We recognised four sectors, characterized by different structural styles and amount of shortening. Moving from the ocean towards the land, they are: i) a series of imbricate thrusts with basinward vergence, forming a critical taper; ii) basinward stacked horses forming a duplex-like system; iii) double verging, out-of syncline thrusts, transporting bowl-shaped syn-kinematic basins; and iv) symmetric, diapir-like detachment folds, likely cored by poorly compacted mobile shales. We hypothesise that these strong and often abrupt variations could be related to: i) lateral differences in the stratigraphy of the sedimentary successions involved in the deformation; ii) time and space variations of the sediment supply along the continental slope.

Cruciani, Francesco; Rinaldo Barchi, Massimiliano

2014-05-01

324

HIV and population dynamics: A general model and maximum-likelihood standards for East Africa  

Microsoft Academic Search

In high-prevalence populations, the HIV epidemic undermines the validity of past empirical models and related demographic\\u000a techniques. A parsimonious model of HIV and population dynamics is presented here and fit to 46,000 observations, gathered\\u000a from 11 East African populations. The fitted model simulates HIV and population dynamics with standard demographic inputs\\u000a and only two additional parameters for the onset and

Patrick Heuveline

2003-01-01

325

ITCZ Position Over East Africa Since the Late Glacial: The Lake Malawi Record  

Microsoft Academic Search

Varved sediments of the north basin of Lake Malawi, the southernmost of the East African Rift lakes, have yielded records of past climate conditions for a range of temporal scales. Profiles of biogenic silica and Nb:Ti spanning nearly 25,000 years in Malawi may be compared with the Cariaco Basin high-resolution records of Haug et al. (2001). During the past 1000

E. T. Brown; T. C. Johnson

2003-01-01

326

Tectonics and Volcanism of East Africa as Seen Using Remote Sensing Imagery  

NASA Technical Reports Server (NTRS)

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.

Hutt, Duncan John

1996-01-01

327

Family planning in Africa.  

PubMed

The population growth rates and population policies and programs in African countries are summarized. Individual attention is given to Algeria, Gambia, Ghana, Liberia, Mali, Nigeria, Ethiopia, Kenya, Mauritius, Tanzania, Gabon, Zaire, Botswana and the Republic of South Africa. In addition, cultural and educational obstacles to family planning programs in Africa are briefly examined. PMID:12333999

1975-01-01

328

Child Labor and School Attendance in Kenya  

ERIC Educational Resources Information Center

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

Moyi, Peter

2011-01-01

329

Relationship Transitions among Youth in Urban Kenya  

ERIC Educational Resources Information Center

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

Clark, Shelley; Kabiru, Caroline; Mathur, Rohini

2010-01-01

330

Plio-Pleistocene climatic change in the Turkana Basin (East Africa): evidence from large mammal faunas.  

PubMed

We investigated palaeoclimatic change in the Turkana Basin during the Pliocene climatic shift toward increased aridity in Africa. We analyzed the palaeoecology of this area using mammal faunas as environmental indicators. Twenty Plio-Pleistocene fossil assemblages and a comparative dataset of 16 modern localities covering a wide range of climatic and ecological conditions across Africa were analyzed. We constructed community profiles using taxonomic variables which reflect ecological information. Principal component analysis and bivariate correlation were used to study changes in the community structure of these mammalian faunas and to draw palaeoenvironmental inferences. Subsequently, least-squares regressions yielded climatic estimates (annual rainfall and drought length) for the studied period. An additional set of 8 modern faunas was used to validate these regression models. The climatic estimates showed a drying trend throughout the sequence. The biomes in the Turkana Basin changed from semi-evergreen rain forest to deciduous woodland and savanna during the middle-late Pliocene. This was the most important climatic shift detected in our study. Evidence suggests a continuous presence of savannas from 2.5 million years ago onwards. This pattern of climatic change is consistent with isotopic evidence on global climate, and with independently derived regional palaeoenvironmental evidence (i.e., micromammals, palaeovegetation, soil carbonates and palaeosols). PMID:16630645

Hernndez Fernndez, Manuel; Vrba, Elisabeth S

2006-06-01

331

18O 16O ratios in cherts associated with the saline lake deposits of East Africa  

USGS Publications Warehouse

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.

O'Neil, J.R.; Hay, R.L.

1973-01-01

332

High-Resolution Geochemical and Paleoecological Records of Climate Change Since the Late Glacial at Lake Tanganyika, East Africa  

NASA Astrophysics Data System (ADS)

We used high-resolution geochemical and paleoecological records from shallow-water sediment cores to refine previous descriptions of climatic conditions at Lake Tanganyika, East Africa, for the period from the Late Glacial to the present. Radiocarbon and 210Pb dating were used to establish chronologies for the cores. Sedimentological changes indicate that lake level has risen approximately 50-70 m since the Late Glacial. A depositional hiatus occurred between 6.4 and 11.4 ka BP (all dates in calendar years) in several of the shallow-water cores. Elemental abundance (%C, %N) and stable isotopic (?15N, ?13C) data for one core suggest that substantial changes in primary productivity and nutrient recycling regimes have occurred since 6.4 ka BP. Carbonate and ostracode crustacean preservation were low and nil, respectively, prior to 2.4 ka BP. Generally, these data support previous interpretations of regional paleoclimate and lake conditions, with wet and warm conditions during the interval from 6.4 to 4.0 ka, and increasingly arid conditions since 2.4 ka. However, for the interval from 4.0 to 2.4 ka, paleoenvironmental indicators (?15N, reduced carbonate and ostracode preservation) suggest that the central part of Lake Tanganyika was stably stratified at a shallower depth than present as a result of diminished southerly trade winds. After 2.4 ka BP, sedimentary carbonate concentrations increase, and ?13C values become enriched, suggesting that lacustrine productivity increased with the resumption of deeper wind-driven mixing, lasting until 1 ka BP. For post-2.4 ka samples, species abundance data for ostracodes were used to generate an ostracode water depth index (OWDI). OWDI indicated that severe drought conditions were persistent or recurred at Lake Tanganyika between 1550 and 1850 A.D. Droughts resulted in marked lowstands at Lake Tanganyika at 1580+/-15 A.D., 1730+/-35 A.D., and 1800+/-30 A.D. These data contribute new information on the timing of Little Ice Age droughts and Mid-Late Holocene changes in trade wind intensity in tropical East Africa.

Alin, S. R.; Cohen, A. S.

2002-12-01

333

Natalizumab treatment for multiple sclerosis: Middle East and North Africa regional recommendations for patient selection and monitoring  

PubMed Central

Background Natalizumab, a highly specific ?4-integrin antagonist, , has recently been registered across the Middle East and North Africa region. It improves clinical and magnetic resonance imaging (MRI) outcomes and reduces the rate of relapse and disability progression in relapsing-remitting multiple sclerosis (MS). Natalizumab is recommended for patients who fail first-line disease-modifying therapy or who have very active disease. Progressive multifocal leukoencephalopathy is a rare, serious adverse event associated with natalizumab. We aim to develop regional recommendations for the selection and monitoring of MS patients to be treated with natalizumab in order to guide local neurological societies. Methods After a review of available literature, a group of neurologists with expertise in the management of MS met to discuss the evidence and develop regional recommendations to guide appropriate use of natalizumab in the region. Results Disease breakthrough is defined as either clinical (relapse or disability progression) or radiological activity (new T2 lesion or gadolinium-enhancing lesions on MRI), or a combination of both. Natalizumab is recommended as an escalation therapy in patients with breakthrough disease based on its established efficacy in Phase III studies. Several factors including prior immunosuppressant therapy, anti-John Cunningham virus (JCV) antibody status and patient choice will affect the selection of natalizumab. In highly active MS, natalizumab is considered as a first-line therapy for naive patients with disabling relapses in association with MRI activity. The anti-JCV antibody test is used to assess anti-JCV antibody status and identify the risk of PML. While seronegative patients should continue treatment with natalizumab, anti-JCV antibody testing every 6months and annual MRI scans are recommended as part of patient monitoring. In seropositive patients, the expected benefits of natalizumab treatment have to be weighed against the risks of PML. Clinical vigilance and follow-up MRI scans remain the cornerstone of monitoring. After 2years of natalizumab therapy, monitoring should include more frequent MRI scans (every 34months) for seropositive patients, and the risk-benefit ratio should be reassessed and discussed with patients. Conclusions Recommendations have been developed to guide neurologists in the Middle East and North Africa on patient selection for natalizumab treatment and monitoring. PMID:24521176

2014-01-01

334

Molecular records of climate variability and vegetation response since the Late Pleistocene in the Lake Victoria basin, East Africa  

NASA Astrophysics Data System (ADS)

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 ?D 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 ?13C 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 ?13C 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 interhemispheric contrast gradient minima. We interpret a shift in conditions at the Younger Dryas to indicate a limited switch in insolation-dominated control on climate of the Lake Victoria region, to remote teleconnections with the coupled Atlantic and Pacific climate system.

Berke, Melissa A.; Johnson, Thomas C.; Werne, Josef P.; Grice, Kliti; Schouten, Stefan; Sinninghe Damst, Jaap S.

2012-11-01

335

Sedimentary provinces of Africa, Middle East, and South America, classification and hydrocarbon potential  

SciTech Connect

In all, 243 sedimentary provinces (basins, foldbelts) were analyzed, classified, and graphically displayed on continental maps (1:5,000,000). An elaborate system of symbols and colors shows the plate tectonic history of each province, the stratigraphic extent and thickness of the sedimentary fill, the type of basin-forming and basin-modifying tectonics, and the distribution of oil and gas fields. The provinces are grouped into five classes which correspond to principal plate tectonic settings: (1) intracontinental basins (rifts, sags), (2) divergent margins, (3) convergent margins, (4) oceanic basins, and (5) orogenic belts and associated basins (e.g., foreland and intermontane basins). The history of each province is determined by critical stages of the plate tectonic cycle: (1) rifting, (2) drifting and sagging, (3) subduction and continental collision. Simple basins form during a single stage of a plate tectonic cycle, e.g., the Tertiary Red Sea rift. Polyhistory provinces have several stages of a primary cycle (e.g., the divergent continental margins of west Africa overlap the intracontinental rift stage). In more complexes provinces the history may extend over two cycles (e.g., northwest Africa with elements of the Paleozoic cycle ending at the Hercynian orogeny overlain by the Mesozoic and Cenozoic cycle which ends with the Alpine orogeny). The provinces affected and/or associated with continental collision such as the folded and faulted forelands and foreland basins contain more than 80% of all proven reserves of hydrocarbons. The maps reveal many aspects of the Phanerozoic history on a continental scale relevant to exploration for hydrocarbons.

Picha, F.J.

1988-02-01

336

Alternative antiretroviral monitoring strategies for HIV-infected patients in east Africa: opportunities to save more lives?  

PubMed Central

Background Updated World Health Organization guidelines have amplified debate about how resource constraints should impact monitoring strategies for HIV-infected persons on combination antiretroviral therapy (cART). We estimated the incremental benefit and cost effectiveness of alternative monitoring strategies for east Africans with known HIV infection. Methods Using a validated HIV computer simulation based on resource-limited data (USAID and AMPATH) and circumstances (east Africa), we compared alternative monitoring strategies for HIV-infected persons newly started on cART. We evaluated clinical, immunologic and virologic monitoring strategies, including combinations and conditional logic (e.g., only perform virologic testing if immunologic testing is positive). We calculated incremental cost-effectiveness ratios (ICER) in units of cost per quality-adjusted life year (QALY), using a societal perspective and a lifetime horizon. Costs were measured in 2008 US dollars, and costs and benefits were discounted at 3%. We compared the ICER of monitoring strategies with those of other resource-constrained decisions, in particular earlier cART initiation (at CD4 counts of 350 cells/mm3 rather than 200 cells/mm3). Results Monitoring strategies employing routine CD4 testing without virologic testing never maximized health benefits, regardless of budget or societal willingness to pay for additional health benefits. Monitoring strategies employing virologic testing conditional upon particular CD4 results delivered the most benefit at willingness-to-pay levels similar to the cost of earlier cART initiation (approximately $2600/QALY). Monitoring strategies employing routine virologic testing alone only maximized health benefits at willingness-to-pay levels (> $4400/QALY) that greatly exceeded the ICER of earlier cART initiation. Conclusions CD4 testing alone never maximized health benefits regardless of resource limitations. Programmes routinely performing virologic testing but deferring cART initiation may increase health benefits by reallocating monitoring resources towards earlier cART initiation. PMID:21801434

2011-01-01

337

The Plio-Pleistocene Evolution of the Indian Ocean Monsoonal System: Evidence from the Arabian Sea and East Africa  

NASA Astrophysics Data System (ADS)

It is important to identify the teleconnections between high latitude forcing and tropical monsoonal circulation in order to understand climate change in East Africa during the Plio-Pleistocene. Here we present a record of aeolian dust transport to the Arabian Sea between approximately 2.9 and 2.3 million years ago (Ma), constructed from the high-resolution XRF scanning of sediment cores from ODP Sites 721 and 722. Variations in the delivery of aeolian dust to the Arabian Sea, reflected in normalised flux of titanium, show that monsoonal circulation prior to 2.6 Ma, and after 2.5 Ma, was highly variable and primarily driven by orbitally-forced changes in tropical summer insolation, strongly modulated by the 400,000 year cycle of orbital eccentricity. This is confirmed by the presence of lakes in the East African Rift Valley during key eccentricity maxima. The dust record is coupled with the analysis of a well-dated series of diatomite units from the Baringo-Bogoria Basin which document the rhythmic cycling of large, precessionally-driven freshwater lakes which periodically occupied the Central Kenyan Rift Valley between 2.7 and 2.58 Ma. Analysis of one of these lake sequences using stable oxygen isotope measurements of diatom silica, combined with the XRF analysis of whole-sample geochemistry, reveals that the deep lake phase was characterised by fluctuations in rainfall and lake depth over cycles lasting, on average, 1,400 years. The presence of these millennial-scale fluctuations is confirmed by evidence of abrupt climate cycles in the oceanic dust record from the Arabian Sea.

Wilson, K. E.; Maslin, M. A.; Mackay, A. W.; Leng, M. J.; Kingston, J.; Deino, A.

2011-12-01

338

Focal mechanisms and the stress regime in NE and SW Tanzania, East Africa  

NASA Astrophysics Data System (ADS)

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.

Brazier, Richard A.; Nyblade, Andrew A.; Florentin, Juliette

2005-07-01

339

Unequal Access, Unequal Participation: Some Spatial and Socio-Economic Dimensions of the Gender Gap in Education in Africa with Special Reference to Ghana, Zimbabwe and Kenya  

ERIC Educational Resources Information Center

The question of unequal access to education among males and females appears to be universal in the developing world. However, females in Africa seem to suffer more discrimination in terms of access to education. This study revisits the question of gender disparities in educational access in Africa by analyzing data from recent comparative national

Shabaya, Judith; Konadu-Agyemang, Kwadwo

2004-01-01

340

The fertility decline in Kenya.  

PubMed

In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key features of reform appear to be political stability, public sector programs, and supply of contraception through the health service. PMID:12319914

Robinson, W C; Harbison, S F

1995-01-01

341

A Seasonal Air Transport Climatology for Kenya  

NASA Technical Reports Server (NTRS)

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.

Gatebe, C. K.; Tyson, P. D.; Annegarn, H.; Piketh, S.; Helas, G.

1998-01-01

342

Lake-level history of Lake Tanganyika, East Africa, for the past 2500 years based on ostracode-inferred water-depth reconstruction  

Microsoft Academic Search

Assemblages of ostracodes from sediment cores illuminate lake-level history at decadal to centennial timescales during the late Holocene at Lake Tanganyika, East Africa. The ostracode-based lake-level curves for several cores resemble both each other and the only previously published lake-level record of comparable resolution for Lake Tanganyika during this interval, successfully reconstructing known highstands, improving the chronology of known lowstands,

Simone R. Alin; Andrew S. Cohen

2003-01-01

343

Analysis of genetic variability within Argulus japonicus from representatives of Africa, Middle East, and Asia revealed by sequences of three mitochondrial DNA genes  

Microsoft Academic Search

This study investigated the genetic variability within fish louse Argulus japonicus (Crustacea: Branchiura) from Africa, Middle East, and Asia by polymerase chain reaction in three mitochondrial DNA (mtDNA)\\u000a regions, namely, cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunits 1 and 4 (nad1 and nad4). Six different sequences from a portion of the cox1 gene (pcox1) and a portion

Hicham Wadeh; Muhamd Alsarakibi; Guoqing Li

2010-01-01

344

The Risks and Macroeconomic Impact of HIV\\/AIDS in the Middle East and North Africa: Why Waiting to Intervene Can Be Costly  

Microsoft Academic Search

Robalino, Jenkins, and El Maroufi develop a model of optimal growth to assess the risks of an HIV\\/AIDS epidemic and the expected economic impact in nine countries in the Middle East and North Africa region?Algeria, Djibouti, Egypt, Iran, Jordan, Lebanon, Morocco, Tunisia, and Yemen. The model incorporates an HIV\\/AIDS diffusion component based on two transmission factors?sexual intercourse and exchange of

David A. Robalino; Carol Jenkins; Karim El Maroufi

2002-01-01

345

Environmental Magnetism as an Instrument for Characterizing Paleoclimatic Variations in the Sediment Record of Lake Tanganyika, East Africa.  

NASA Astrophysics Data System (ADS)

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.

Wetter, L.; Verosub, K.; Acton, G.; Russell, J.

2004-12-01

346

Tidal loading along a profile Europe-East Africa-South Asia-Australia and the Pacific Ocean  

NASA Astrophysics Data System (ADS)

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.

Melchior, P.; Moens, M.; Ducarme, B.; van Ruymbeke, M.

1981-04-01

347

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)

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.

Bolten, John; Ozdogan, Mutlu; Beaudoing, Hiroko; Rodell, Matthew

2012-01-01

348

Evaluation of a regional mineral dust model over Northern Africa, Southern Europe and Middle East with AERONET data  

NASA Astrophysics Data System (ADS)

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 m are considered, and dust-radiation interactions are included (Prez 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 the model to reproduce AOD (at 550nm) associated to mineral dust 24, 48 and 72h ahead. A suit of discrete statistics as Mean Normalized Bias Error (MNBE), Mean Normalized Gross Error (MNGE) and Root Mean Square Error (RMSE) has been used in order to evaluate the model behaviour. Categorical statistics or skill scores, as model accuracy, bias, probability of detection, false alarm rate and critical success index have been implemented to test the capability of the model to simulate AOD exceeding thresholds defined by the quartiles of each AERONET site. A previous aerosol characterization of AERONET data has been performed for our study region in order to discriminate desert dust contributions (Basart et al., 2008). The first results of the comparison reveal that the modelled dust field agrees in general reasonably well with sun photometer data. Since dust long-range transport is mainly driven by smaller dust particles, the results of this new 8-bins version (with increased number of dust size bins) is considerably better, since the small particle size range (<10m effective radius) is well described. The best scores are found in North Africa and Middle East. In the Sahel region, an important sub-estimation is observed in wintertime, when the Atlantic outflow transport is important. This is partially due to the more complex processes associated to dust generation in this region (Warren et al., 2007), not well parameterized in dust models yet. Other causes, such as the correct simulation of regional winds or the threshold friction velocity are under research. Moreover, the interaction of mineral dust and biomass burning aerosols from Savannah fires is at its maximum over the region in this season. In southern Europe, the relative errors are higher than in the rest of our study domain mainly due to the presence of different types of aerosols (such as fine pollution aerosols) which appear well-mixed with desert dust. References: Basart, S., C. Prez, E. Cuevas and J.M. Baldasano. 2008. "Aerosol retrospective analysis over North Africa, North-eastern Atlant

Basart, S.; Prez, C.; Cuevas, E.; Baldasano, J. M.

2009-04-01

349

An isotopic study of a fluvial-lacustrine sequence: The Plio-Pleistocene koobi fora sequence, East Africa  

USGS Publications Warehouse

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.

Cerling, T.E.; Bowman, J.R.; O'Neil, J.R.

1988-01-01

350

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

NASA Astrophysics Data System (ADS)

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.

Zaalouk, Malak

2014-06-01

351

Africa Aerosol Optical Depth Obtained From MISR  

E-print Network

OpticalDepth Central African Republic Chad Djibouti Egypt Ethiopia Libya Kenya Somalia Sudan Uganda #12;Southern Africa Madagascar Malawi Mozambique Namibia Rwanda South Africa Swaziland Tanzania, United Republic of Zaire Zambia Ethiopia Libya Kenya Somalia Sudan Uganda #12;Southern Africa 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Mean Seasonal

Frank, Thomas D.

352

Visualizing East Africa Drought and Vegetation Response in GIS using NASA Satellite Data  

NASA Astrophysics Data System (ADS)

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.

Yang, W.; Zhao, P.; Chen, A.; Pham, L.; Kempler, S.

2012-12-01

353

Population Vulnerability and Disability in Kenya's Tsetse Fly Habitats  

PubMed Central

Background Human African Trypanosomiasis (HAT), also referred to as sleeping sickness, and African Animal Trypanosomaisis (AAT), known as nagana, are highly prevalent parasitic vector-borne diseases in sub-Saharan Africa. Humans acquire trypanosomiasis following the bite of a tsetse fly infected with the protozoa Trypanosoma brucei (T.b.) spp. i.e., T.b. gambiense in West and Central Africa and T.b. rhodesiense in East and Southern Africa. Over the last decade HAT diagnostic capacity to estimate HAT prevalence has improved in active case-finding areas but enhanced passive surveillance programs are still lacking in much of rural sub-Saharan Africa. Methodology/Principal Findings This retrospective-cross-sectional study examined the use of national census data (1999) to estimate population vulnerability and disability in Kenya's 7 tsetse belts to assess the potential of HAT-acquired infection in those areas. A multilevel study design estimated the likelihood of disability in individuals, nested within households, nested within tsetse fly habitats of varying levels of poverty. Residents and recent migrants of working age were studied. Tsetse fly's impact on disability was conceptualised via two exposure pathways: directly from the bite of a pathogenic tsetse fly resulting in HAT infection or indirectly, as the potential for AAT takes land out of agricultural production and diseased livestock leads to livestock morbidity and mortality, contributing to nutritional deficiencies and poverty. Tsetse belts that were significantly associated with increased disability prevalence were identified and the direct and indirect exposure pathways were evaluated. Conclusions/Significance Incorporating reports on disability from the national census is a promising surveillance tool that may enhance future HAT surveillance programs in sub-Saharan Africa. The combined burdens of HAT and AAT and the opportunity costs of agricultural production in AAT areas are likely contributors to disability within tsetse-infested areas. Future research will assess changes in the spatial relationships between high tsetse infestation and human disability following the release of the Kenya 2009 census at the local level. PMID:21347453

Grady, Sue C.; Messina, Joseph P.; McCord, Paul F.

2011-01-01

354

Genetic differentiation of Anopheles gambiae populations from East and West Africa: comparison of microsatellite and allozyme loci  

Microsoft Academic Search

Genetic variation of Anopheles gambiae was analysed to assess interpopulation divergence over a 6000 km distance using short tandem repeat (microsatellite) loci and allozyme loci. Differentiation of populations from Kenya and Senegal measured by allele length variation at five microsatellite loci was compared with estimates calculated from published data on six allozyme loci (Miles, 1978). The average Wright's FST of

Tovi Lehmann; William A Hawley; Luna Kamau; Didier Fontenille; Frederic Simard; Frank H Collins

1996-01-01

355

Emergence, spread and strategies for controlling the pandemic of cassava mosaic virus disease in east and central Africa  

Microsoft Academic Search

During the 1990s, an epidemic of an unusually severe form of cassava mosaic virus disease (CMD) has expanded to cover virtually all of Uganda, and substantial areas in the neighbouring countries of Kenya, Tanzania, Sudan and the Democratic Republic of Congo. Losses in the generally sensitive local cassava cultivars have been so great that a common farmer response to the

J. P Legg

1999-01-01

356

The sup 36 Cl ages of the brines in the Magadi-Natron basin, east Africa  

SciTech Connect

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.

Kaufman, A.; Margaritz, M.A.; Hollos, G. (Weizmann Institute of Science, Rehovot (Israel)); Paul, M.; Boaretto, E. (Hebrew Univ., Jerusalem (Israel)); Hillaire-Marcel, C. (Universite du Quebec, Montreal (Canada)); Taieb, M. (Universite-Luminy, Marseille (France))

1990-10-01

357

Estimation of the sexual transmission of HIV in Kenya and Uganda on the trans-Africa highway: the continuing role for prevention in high risk groups  

Microsoft Academic Search

Objective: To explore the effect of transactional sex on the trans-Africa highway from Mombasa-Kampala in contributing to the HIV epidemic and the impact that an effective prevention intervention could have.Methods: Variables for input into a simple model of HIV prevention, AVERT, were derived from a study of hot spots of transactional sex on the trans-Africa highway. Diaries were completed by

C N Morris; A G Ferguson

2006-01-01

358

The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic pr?cis  

PubMed Central

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.) labranchiae, An. (Ano.) messeae, An. (Ano.) sacharovi, An. (Cel.) sergentii and An. (Cel.) superpictus*. These maps are presented alongside a bionomics summary for each species relevant to its control. PMID:21129198

2010-01-01

359

Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr  

USGS Publications Warehouse

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 near the base of T97-52V. We interpret these discontinuities to reflect major, prolonged drops in lake level below the core site (393 m), with the lower boundary correlating to marine oxygen isotope Stage 6. This suggests that the previous glacial period was considerably cooler and more arid in the equatorial tropics than was the last glacial period.

Scholz, C.A.; King, J.W.; Ellis, G.S.; Swart, Peter K.; Stager, J.C.; Colman, Steven M.

2003-01-01

360

Spatial-explicit modeling of social vulnerability to malaria in East Africa  

PubMed Central

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 immunity indicator which has a marked impact on the composite vulnerability index. Conclusions We introduce a conceptual framework for modeling risk and vulnerability to VBDs. Drawing on the framework we modeled social vulnerability to malaria in the context of global change using a spatially explicit approach. The results provide decision makers with place-specific options for targeting interventions that aim at reducing the burden of the disease amongst the different vulnerable population groups. PMID:25127688

2014-01-01

361

Task shifting for cataract surgery in eastern Africa: productivity and attrition of non-physician cataract surgeons in Kenya, Malawi and Tanzania  

PubMed Central

Background This project examined the surgical productivity and attrition of non-physician cataract surgeons (NPCSs) in Tanzania, Malawi, and Kenya. Methods Baseline (2008-9) data on training, support, and productivity (annual cataract surgery rate) were collected from officially trained NPCSs using mailed questionnaires followed by telephone interviews. Telephone interviews were used to collect follow-up data annually on productivity and semi-annually on attrition. A detailed telephone interview was conducted if a surgeon left his/her post. Data were entered into and analysed using STATA. Results Among the 135 NPCSs, 129 were enrolled in the study (Kenya 88, Tanzania 38, and Malawi 3) mean age 42 years; average time since completing training 6.6 years. Employment was in District 44%, Regional 24% or mission/ private 32% hospitals. Small incision cataract surgery was practiced by 38% of the NPCSs. The mean cataract surgery rate was 188/year, median 76 (range 0-1700). For 39 (31%) NPCSs their surgical rate was more than 200/year. Approximately 22% in Kenya and 25% in Tanzania had years where the cataract surgical rate was zero. About 11% of the surgeons had no support staff. Factors significantly associated with increased productivity were: 1) located at a regional or private/mission hospital compared to a district hospital (OR = 8.26; 95 % CI 2.89 23.81); 2) 3 or more nurses in the eye unit (OR = 8.69; 95% CI 3.27-23.15); 3) 3 or more cataract surgical sets (OR = 3.26; 95% CI 1.48-7.16); 4) a separate eye theatre (OR = 5.41; 95% CI 2.15-13.65); 5) a surgical outreach program (OR = 4.44; 95% CI 1.88-10.52); and 6) providing transport for patients to hospital (OR = 6.39; 95% CI 2.62-15.59). The associations were similar for baseline and follow-up assessments. Attrition during the 3 years occurred in 13 surgeons (10.3%) and was due to retirement or promotion to administration. Conclusions High quality training is necessary but not sufficient to result in cataract surgical activity that meets population needs and maintains surgical skill. Needed are supporting institutions and staff, functioning equipment and programs to recruit and transport patients.

2014-01-01

362

MSU at Work in Africa: A Unique Capacity  

E-print Network

, Ivory Coast, Kenya, Liberia, Malawi, Mali, Morocco, Mozambique, Namibia, Nigeria, Rwanda, Senegal, South Africa, Sudan, Tanzania, Uganda, Zambia, and Zimbabwe. MSU's work in Africa spans a wide range of human

363

New specimens of a fossil ostrich from the Miocene of Kenya  

NASA Astrophysics Data System (ADS)

Fossilised hind limb bones from the late Middle Miocene (approximately 14 million-year-old [MYA]) Fort Ternan, Kadianga West and Ngorora localities in Western Kenya indicate the presence of a new representative of the ostrich genus Struthio. These new fossils represent some of the oldest known records for Struthio yet described, slightly younger than Struthio coppensi, from the Lower Miocene of Namibia. Because the four sub-species of the modern-day ostrich ( Struthio camelus camelus, Struthio camelus australis, Struthio camelus massaicus, and Struthio camelus molybdophanes) inhabit the plains of Africa, and as recently as the 1940s, a fifth sub-species was also present in the Middle East and Saudi Arabia ( Struthio camelus syriacus), records of Struthio from Kenya and Namibia testify to the much wider distribution of these cursorial birds in the relatively recent past. This is further supported by the very high frequency of ostrich eggshell fragments found across Africa and Eurasia, which vastly outweighs the amount of skeletal material uncovered over the last century.

Leonard, Leona M.; Dyke, Gareth J.; Walker, Cyril A.

2006-08-01

364

Rural Development in Africa: A Bibliography. (Part I: General, Central, East). Training & Methods Series Number 16 (Supplement), March 1973.  

ERIC Educational Resources Information Center

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

Anderson, Teresa, Comp.; Strey, Gerry, Comp.

365

GROUND TRUTH, MAGNITUDE CALIBRATION AND REGIONAL PHASE PROPAGATION AND DETECTION IN THE MIDDLE EAST AND HORN OF AFRICA  

SciTech Connect

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 Peninsula obtained from travel time tomography. Travel time measurements were obtained using a data set provided by King Abdulaziz City for Science and Technology (KACST) for the Saudi Arabia National Digital Seismic Network. The network consists of 38 stations (27 broadband and 11 short period). We augmented the KACST data with delay times measured from permanent stations in the region and the 1995-7 Saudi Arabian PASSCAL Experiment. Tomographic images reveal a low velocity feature in the upper mantle stretching north-south beneath the central portion of the Arabian Shield.

Nyblade, A; Adams, A; Brazier, R; Park, Y; Rodgers, A

2006-07-10

366

Greening of the Sahara - a paleo perspective on the history of water in the Middle East and North Africa  

NASA Astrophysics Data System (ADS)

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 humans and animals who enjoyed a variety of ecological niches for living (Frumkin et al., 2011). Almogi-Labin, A. et a.l (2009) Quat. Sci. Rev. 28, 2882-2896. Bar-Matthews, M. et al (2003 Geochim. Cosmochim. Acta 67, 3181-99. Fleitmann, D. et al. (2011). Quat. Sci. Rev. 30, 783-787. Frumkin, et al. A. (2011). Jour. Human Evol. 60, 437-451 Lisker et al, (2010). Quat. Sci. Rev 29, 1201-1211. Osborne A.H. et al. (2008). Proc. Nat. Acad. Sci. 105, 16444-16447 Vaks et al. (2010). Quat. Sci. Rev. 29, 2647-2662.

Bar-Matthews, M.

2012-04-01

367

Abrupt Climatic Events Observed in Organic-Rich Sediments From Lake Tanganyika, Tropical East Africa, Over the Past 50 kyr  

NASA Astrophysics Data System (ADS)

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 ?13C 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 ?13C, ?15N, 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.

Burnett, A. P.; Weyhenmeyer, C. E.; Scholz, C. A.; Swart, P. K.

2006-12-01

368

A molecular perspective on Late Quaternary climate and vegetation change in the Lake Tanganyika basin, East Africa  

NASA Astrophysics Data System (ADS)

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 ( ?13C wax) are a reliable proxy for vegetation change. In addition we argue that the D/H ratio of higher plant leaf waxes ( ?D 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.

Tierney, Jessica E.; Russell, James M.; Huang, Yongsong

2010-03-01

369

Pleistocene desiccation in East Africa bottlenecked but did not extirpate the adaptive radiation of Lake Victoria haplochromine cichlid fishes.  

PubMed

The Great Lakes region of East Africa, including Lake Victoria, is the center of diversity of the mega-diverse cichlid fishes (Perciformes: Teleostei). Paleolimnological evidence indicates dramatic desiccation of this lake ca. 18,000-15,000 years ago. Consequently, the hundreds of extant endemic haplochromine species in the lake must have either evolved since then or refugia must have existed, within that lake basin or elsewhere, from which Lake Victoria was recolonized. We studied the population history of the Lake Victoria region superflock (LVRS) of haplochromine cichlids based on nuclear genetic analysis (12 microsatellite loci from 400 haplochomines) of populations from Lake Kivu, Lake Victoria, and the connected and surrounding rivers and lakes. Population genetic analyses confirmed that Lake Kivu haplochromines colonized Lake Victoria. Coalescent analyses show a 30- to 50-fold decline in the haplochromine populations of Lake Victoria, Lake Kivu, and the region ca. 18,000-15,000 years ago. We suggest that this coincides with drastic climatic and geological changes in the late Pleistocene. The most recent common ancestor of the Lake Victoria region haplochromines was estimated to have existed about 4.5 million years ago, which corresponds to the first radiation of cichlids in Lake Tanganyika and the origin of the tribe Haplochrominii. This relatively old evolutionary origin may explain the high levels of polymorphism still found in modern haplochromines. This degree of polymorphism might have acted as a "genetic reservoir" that permitted the explosive radiation of hundreds of haplochromines and their array of contemporary adaptive morphologies. PMID:19651614

Elmer, Kathryn R; Reggio, Chiara; Wirth, Thierry; Verheyen, Erik; Salzburger, Walter; Meyer, Axel

2009-08-11

370

Pleistocene desiccation in East Africa bottlenecked but did not extirpate the adaptive radiation of Lake Victoria haplochromine cichlid fishes  

PubMed Central

The Great Lakes region of East Africa, including Lake Victoria, is the center of diversity of the mega-diverse cichlid fishes (Perciformes: Teleostei). Paleolimnological evidence indicates dramatic desiccation of this lake ca. 18,00015,000 years ago. Consequently, the hundreds of extant endemic haplochromine species in the lake must have either evolved since then or refugia must have existed, within that lake basin or elsewhere, from which Lake Victoria was recolonized. We studied the population history of the Lake Victoria region superflock (LVRS) of haplochromine cichlids based on nuclear genetic analysis (12 microsatellite loci from 400 haplochomines) of populations from Lake Kivu, Lake Victoria, and the connected and surrounding rivers and lakes. Population genetic analyses confirmed that Lake Kivu haplochromines colonized Lake Victoria. Coalescent analyses show a 30- to 50-fold decline in the haplochromine populations of Lake Victoria, Lake Kivu, and the region ca. 18,00015,000 years ago. We suggest that this coincides with drastic climatic and geological changes in the late Pleistocene. The most recent common ancestor of the Lake Victoria region haplochromines was estimated to have existed about 4.5 million years ago, which corresponds to the first radiation of cichlids in Lake Tanganyika and the origin of the tribe Haplochrominii. This relatively old evolutionary origin may explain the high levels of polymorphism still found in modern haplochromines. This degree of polymorphism might have acted as a genetic reservoir that permitted the explosive radiation of hundreds of haplochromines and their array of contemporary adaptive morphologies. PMID:19651614

Elmer, Kathryn R.; Reggio, Chiara; Wirth, Thierry; Verheyen, Erik; Salzburger, Walter; Meyer, Axel

2009-01-01

371

The burden of chronic obstructive pulmonary disease in the Middle East and North Africa: results of the BREATHE study.  

PubMed

COPD is a progressive pulmonary disease which may have a profound impact on general health status and quality of life. This article presents data on the burden of COPD obtained from the BREATHE study in the Middle East, North Africa and Pakistan. This study was a large general population survey of COPD conducted in eleven countries of the region using a standardised methodology. A total of 62,086 subjects were screened, of whom 2,187 fulfilled the "epidemiological" definition of COPD. Data on symptoms, perceived disease severity, impact on work, limitations in activities and psychological distress were collected. 1,392 subjects were analysable of whom 661 (47.5%) reported experiencing an exacerbation of their respiratory condition, 49.4% reported comorbidities and 5.5% reported severe breathlessness as measured with the MRC breathlessness questionnaire. The degree of breathlessness, as well as the perceived severity, was correlated with the overall disease impact as measured with the COPD Assessment Test (p < 0.001). 374 subjects (28.4%) reported that their respiratory condition prevented them from working and this proportion rose to 47.8% in subjects who perceived their respiratory condition as severe. 47.9% of subjects reported difficulties in normal physical exertion, 37.5% in social activities and 31.7% in family activities. Psychological distress was reported by between 42.3% and 53.2% of subjects, depending on the item. In conclusion, the burden of COPD is important, and covers central aspects of daily life. For this reason, physicians should take time to discuss it with their patients, and ensure that the management strategy proposed addresses all their needs. PMID:23290704

Uzaslan, Esra; Mahboub, Bassam; Beji, Majed; Nejjari, Chakib; Tageldin, Mohamed Awad; Khan, Javaid Ahmed; Nafti, Salim; Obeidat, Nathir M; Sayiner, Abdullah; Wali, Siraj; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

372

Management of chronic obstructive pulmonary disease in the Middle East and North Africa: results of the BREATHE study.  

PubMed

Chronic obstructive pulmonary disease (COPD) is a potentially severe chronic progressive respiratory condition requiring long-term treatment and frequently involving episodic hospitalisations to manage exacerbations. The objective of this analysis was to document diagnosis, evaluation, treatment and management of COPD-related respiratory symptoms in 1,392 subjects fulfilling an epidemiological definition of COPD identified in a general population sample of 62,086 individuals aged ? 40 years in ten countries in the Middle East and North Africa region (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), together with Pakistan. 442 subjects (31.8%) claimed to have received a diagnosis of COPD from a physician and 287 (20.6%) had undergone spirometry in the previous year. Use of specific treatments for respiratory symptoms was reported by 218 subjects (15.7%). Use of inhaled long-acting bronchodilators together with corticosteroids (53 subjects; 3.8%) and use of oxygen therapy (31 subjects; 2.3%) was very low. 852 subjects (61.2%) had consulted a physician about their respiratory condition at least once in the previous year, with a mean number of consultations of 3.4 3.6. Moreover, 284 subjects (20.4%) had been hospitalised overnight for their COPD, with a mean of 2.3 3.7 hospitalisations per year. Use of all healthcare resources was significantly higher (p < 0.001) in subjects with CAT scores ? 10 than in those with scores < 10, and greater in those with exacerbations than in those without. In conclusion, COPD in the region is under-diagnosed, inadequately evaluated and inadequately treated. Nonetheless, COPD symptoms are responsible for considerable healthcare consumption, with high levels of physician consultation and hospitalisation. PMID:23290703

Idrees, Majdy; Koniski, Marie-Louise; Taright, Samya; Shahrour, Naeem; Polatli, Mehmet; Ben Kheder, Ali; Alzaabi, Ashraf; Iraqi, Ghali; Khattab, Adel; Javed, Arshad; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

373

Chronic obstructive pulmonary disease and associated healthcare resource consumption in the Middle East and North Africa: the BREATHE study.  

PubMed

Data on COPD-related healthcare resources use are rarely documented in developing countries. This article presents data on COPD-related healthcare resource consumption in the Middle East, North Africa and Pakistan and addresses the association of this variable with illness severity. A large survey of COPD was conducted in eleven countries of the region, namely Algeria, Egypt, Jordan, Lebanon, Morocco, Pakistan, Saudi-Arabia, Syria, Tunisia, Turkey and United Arab Emirates, using a standardised methodology. A total of 62,086 subjects were screened. This identified 2,187 subjects fulfilling the "epidemiological" definition of COPD. A detailed questionnaire was administered to document data on COPD-related healthcare consumption. Symptom severity was assessed using the COPD Assessment Test (CAT). 1,392 subjects were analysable. Physician consultations were the most frequently used healthcare resource, ranging from 43,118 [95% CI: 755-85,548] consultations in UAE to 4,276,800 [95% CI: 2,320,164-6,230,763] in Pakistan, followed by emergency room visits, ranging from 15,917 [95% CI: 0-34,807] visits in UAE to 683,697 [95% CI: 496,993-869,737] in Turkey and hospitalisations, ranging from 15,563 [95% CI: 7,911-23,215] in UAE to 476,674 [95% CI: 301,258-652,090] in Turkey. The use of each resource increased proportionally with the GOLD 2011 severity groups and was significantly (p < 0.0001) higher in subjects with more symptoms compared to those with lower symptoms and in subjects with exacerbations to those without exacerbations. The occurrence of exacerbations and the CAT score were independently associated with use of each healthcare resource. In conclusion, the BREATHE study revealed that physician consultation is the most frequently COPD-related healthcare resource used in the region. It showed that the deterioration of COPD symptoms and the frequency of exacerbations raised healthcare resource consumption. PMID:23290706

Polatli, Mehmet; Ben Kheder, Ali; Wali, Siraj; Javed, Arshad; Khattab, Adel; Mahboub, Bassam; Iraqi, Ghali; Nejjari, Chakib; Taright, Samya; Koniski, Marie-Louise; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

374

Distribution of COPD-related symptoms in the Middle East and North Africa: results of the BREATHE study.  

PubMed

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. However, its epidemiology in many developing countries is poorly characterised. The objective of this analysis was to evaluate respiratory symptoms which could be COPD-related in a large sample of individuals aged ? 40 years in ten countries in the Middle East and North Africa (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), together with Pakistan, using a standardised methodology. A random sample of 457,258 telephone numbers was contacted. A screening questionnaire was administered to each eligible participant, which included six questions relating to respiratory symptoms. Of 65,154 eligible subjects, 62,086 agreed to participate and 61,551 provided usable data. The age- and gender-adjusted prevalence of symptoms (persistent productive cough or breathlessness or both) was 14.3% [95% CI: 14.0-14.6%], ranging from 7.2% in UAE to 19.1% in Algeria. Symptoms were more frequent (p < 0.0001) in women (16.7%) than in men (12.2%). The adjusted prevalence of COPD according to the "epidemiological" definition (symptoms or diagnosis and cigarette use ? 10 pack years) was 3.6% [95% CI: 3.5-3.7%] (range: 1.9% in UAE to 6.1% in Syria). COPD was more frequent (p < 0.0001) in men (5.2%) than in women (1.8%). The frequency of symptoms was significantly higher in cigarette smokers (p< 0.001), as well as in waterpipe users (p < 0.026). In conclusion, the prevalence of COPD in this region seems to be lower than that reported in industrialised countries. Under-reporting and risk factors other than smoking may contribute to this difference. PMID:23290701

Tageldin, Mohamed Awad; Nafti, Salim; Khan, Javaid Ahmed; Nejjari, Chakib; Beji, Majed; Mahboub, Bassam; Obeidat, Nathir M; Uzaslan, Esra; Sayiner, Abdullah; Wali, Siraj; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

375

Evolutionary relationships of the limnochromini, a tribe of benthic deepwater cichlid fish endemic to Lake Tanganyika, East Africa.  

PubMed

Lake Tanganyika harbors an enormous diversity of cichlid fish that stem from eight distinct ancestral lineages, which colonized the lake after its formation 9 to 12 million years ago. Six of twelve currently described tribes are assigned to the "H-lineage," an assemblage of exclusively mouthbrood-ing cichlids, all of which evolved during a short period of time during the course of the primary radiation of lacustrine species. Our study focuses on the deepwater tribe Limnochromini, comprising bi-parental mouthbrooders, and is based on phylogenetic analysis of two mitochondrial gene segments. We confirm the polyphyletic origin of the Limnochromini as they are defined to date, in that Gnathochromis pfefferi is placed among the Tropheini, whereas the genus Benthochromis is presented as an independent lineage. The remaining nine species were unambiguously resolved as monophyletic and should be redefined as the tribe Limnochromini. Concerning generic assignments, the genus Greenwoodochromis appeared as monophyletic, Limnochromis as paraphyletic, and the genera Reganochromis and Baileychromis as monophyletic sister genera. The linearized tree analysis and the comparison of average sequence divergences to that of the remaining tribes of the H-lineage revealed a relatively recent but simultaneous proliferation of the Limnochromini, suggesting that the same environmental changes triggered the radiation of particular deepwater, benthic, pelagic, and littoral lineages. By using a preliminary calibration of a molecular clock based on gamma-corrected amino acid distances of the NADH2 gene, the diversification of the Limnochromini could tentatively be dated to 2.9-3.5 MYA, coinciding with a period of aridification in East Africa between 2.5 and 3 MYA. The lack of geographic color morphs and the structural uniformity and resource scarcity of deepwater habitats suggest that competition and resource partitioning leading to differential trophic specialization promoted speciation within the Limnochromini, rather than an allopatric model. PMID:15871039

Duftner, Nina; Koblmller, Stephan; Sturmbauer, Christian

2005-03-01

376

Decadal rainfall variability modes in observed rainfall records over East Africa and their relations to historical sea surface temperature changes  

NASA Astrophysics Data System (ADS)

SummaryDetailed knowledge about the long-term interface of climate and rainfall variability is essential for managing agricultural activities in Eastern African countries. To this end, the space-time patterns of decadal rainfall variability modes over East Africa and their predictability potentials using Sea Surface Temperature (SST) are investigated. The analysis includes observed rainfall data from 1920 to 2004 and global SSTs for the period 1950-2004. Simple correlation, trend and cyclical analyses, Principal Component Analysis (PCA) with VARIMAX rotation and Canonical Correlation Analysis (CCA) are employed. The results show decadal signals in filtered observed rainfall record with 10 years period during March-May (MAM) and October-December (OND) seasons. During June-August (JJA), however, cycles with 20 years period are common. Too much/little rainfall received in one or two years determines the general trend of the decadal mean rainfall. CCA results for MAM showed significant positive correlations between the VARIMAX-PCA of SST and the canonical component time series over the central equatorial Indian Ocean. Positive loadings were spread over the coastal and Lake Victoria regions while negative loading over the rest of the region with significant canonical correlation skills. For the JJA seasons, Atlantic SSTs had negative loadings centred on the tropical western Atlantic Ocean associated with the wet/dry regimes over western/eastern sectors. The highest canonical correlation skill between OND rainfall and the Pacific SSTs showed that El Nio/La Nia phases are associated with wet/dry decades over the region.

Omondi, P.; Awange, J. L.; Ogallo, L. A.; Okoola, R. A.; Forootan, E.

2012-09-01

377

Carbon dioxide measurements in tropical east African biomes  

SciTech Connect

From January 1977 through May 1978 atmospheric CO/sub 2/ concentrations were measured hourly and/or continuously at bimonthly intervals over periods varying from 5 to 8 days at 10 different locations in Kenya, East Africa. During each of these periods, at least two, and in some cases five, vertical profile measurements of CO/sub 2/ concentrations were conducted above different biomes. A large diurnal CO/sub 2/ periodicity was observed over land, with daytime drawdowns to 322 ppm and nighttime buildups to more than 400 ppm observed in savannah regions. In and around tropical rain forests, drawdowns to 310 ppm and buildups to more than 400 ppm were regularly observed. On the higher reaches of Mount Kenya, the diurnal CO/sub 2/ cycle was considerably reduced in amplitude, with variations in the range of 2-6 ppm throughout the 16-month study period. On sunny days, the drawdown of CO/sub 2/ was measurable to heights of at least 4000 m above ground level. Other CO/sub 2/ measurements in air over the Indian Ocean (to distances of up to 450 km upwind of the coast) produced fairly consistent concentrations of about 328.5 ppm which did not fluctuate diurnally. The weekly mean CO/sub 2/ concentrations over Kenya appear to have a bimodal structure, with minima occurring in July and January. On the basis of the data collected during the study it appears likely that regular observations at a high-altitude station on Mount Kenya, either with flask sampling or continuous analyzer measurements, are likely to yield data useful for estimates of CO/sub 2/ concentration backgrounds and trends. Also, there is strong evidence that Mount Kenya would be a good location to measure large-scale interhemispheric CO/sub 2/ exchanges and provide a unique base from which to study the effects of the tropical biome on biogeochemical phenomena. 20 references, 12 figures, 2 tables.

Schnell, R.C.; Odh, S.A.; Njau, L.N.

1981-06-20

378

Spatial Variation of Primordial 3-He in Crustal Fluids Along the East-African Rift System (Ethiopian and the Kenya Rift Section).  

National Technical Information Service (NTIS)

(3)He/(4)He compositions are presented for groundwater samples from the Ethiopian segment of the East-African Rift and from its northern extension, the adjacent Afar region (Djibuti). Helium isotope data are compared to those obtained previously from the ...

E. Griesshaber, S. Weise, G. Darling

1994-01-01

379

The invasion of an introduced predator, Nile perch ( Lates niloticus , L.) in Lake Victoria (East Africa): chronology and causes  

Microsoft Academic Search

Nile perch, a large predatory fish, was introduced into Lake Victoria in 1954. The upsurge of Nile perch in Lake Victoria\\u000a was first observed in the Nyanza Gulf, Kenya, in 1979. In Ugandan waters this occurred 23years later and in the Tanzanian\\u000a Mwanza Gulf 45years later. At the beginning of the upsurge in the Mwanza Gulf in 1983\\/1984 only sub-adult

Frans Witte; Egid F. B. Katunzi

2008-01-01

380

Attitudes and perceptions of urban households in sub-Saharan Africa on water sources, threats and sustainability: A study in Bondo, Kenya  

E-print Network

Methods Attitudes and perceptions of urban households in sub-Saharan Africa on water sources sources of drinking water 3. To understand how women are involved in activities / interventions aimed, during June 2011 to examine how attitudes and perceptions of urban residents on water sources, threats

Hall, Sharon J.

381

China's Cooperation in Education and Training with Kenya: A Different Model?  

ERIC Educational Resources Information Center

This is the first detailed study of the character and particularity of China's rapidly growing education and training cooperation with Kenya. Set against the 50-year history of Kenya's engagement with China, it pays special attention to the human resources targets of the Forum for China-Africa Cooperation (FOCAC) from 2000. It argues that the

King, Kenneth

2010-01-01

382

Male involvement for the prevention of mother-to-child HIV transmission: A brief review of initiatives in East, West, and Central Africa.  

PubMed

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

Dunlap, Julie; Foderingham, Nia; Bussell, Scottie; Wester, C William; Audet, Carolyn M; Aliyu, Muktar H

2014-06-01

383

Family planning needs in the context of the HIV\\/AIDS epidemic: Findings from a three-country assessment covering Kenya, South Africa and Zimbabwe  

Microsoft Academic Search

One of the key contours of the post-ICPD era is the broadening of family planning programs to encompass reproductive health needs and rights. In sub-Saharan Africa, such an agenda has been blurred by HIV\\/AIDS, the leading cause of death among women and men of reproductive ages. Family planning (FP) programs are key pillars to the reduction of maternal mortality and

Pierre Ngom; Rose Wilcher; Maureen Kuyoh; Hazel Dube; Sonja Martin; Joshua Kimani; Tara Nutley; Ndugga Maggwa

384

Psychometric evaluation of the COPD assessment test: data from the BREATHE study in the Middle East and North Africa region.  

PubMed

The objective of this study was to assess the validity and performance of the Arabic and Turkish versions of the COPD Assessment Test (CAT) for evaluating the severity and impact of COPD symptoms. The data were obtained from the BREATHE study in the Middle East and North Africa region, a large general population survey of COPD conducted in ten countries of the region (Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and United Arab Emirates), using a standardised methodology. A total of 62,086 subjects were screened, of whom a random sample of 5,681 subjects were administered the CAT by telephone. 5,639 evaluable questionnaires were recovered, representing a completion rate of 99%. In addition, the CAT was administered to an additional 833 subjects fulfilling the epidemiological diagnostic criteria for COPD. Mean scores in the general population were 6.99 6.91 for the Arabic version and 9.88 9.04 for the Turkish version. In patients with COPD, mean scores were 16.2 9.1 and 20.9 10.2 respectively. Scores were consistently higher in smokers than in non-smokers. In the general population, the proportion of respondents fulfilling criteria for COPD rose with higher CAT scores, and particularly above the 80th percentile, where 63% of COPD cases were to be found. This suggests that the CAT may be useful as a case-finding tool in the general population. In the COPD population, healthcare resource consumption rose linearly with CAT score above a threshold score of twenty, arguing in favour of the good criterion validity of the CAT. The internal consistency of the CAT was high (Cronbach's ? 0.85 for the Arabic and 0.86 for the Turkish versions) and the factorial structure was unidimensional. In conclusion, this study performed in Arabic and Turkish speaking populations confirms the utility and validity of the CAT as a simple tool to collect data on the severity and impact of COPD symptoms, and suggests that it may potentially be useful as a case-finding tool to identify people at risk for COPD in the general population. PMID:23290707

Jones, Paul W; Shahrour, Naem; Nejjari, Chakib; Lahlou, Aicha; Doble, Adam; Rashid, Nauman; El Hasnaoui, Abdelkader

2012-12-01

385

Effect of Temporally and Spatially Variable Meteorological Forcing on the Stratification Dynamics of Lake Victoria, East Africa  

NASA Astrophysics Data System (ADS)

The annual cycle of stratification of tropical lakes is driven by seasonal changes in cloud cover as it affects solar radiation and net long wave radiation and seasonal changes in wind speed and relative humidity as they affect latent heat fluxes. For large tropical lakes, latent heat fluxes and net long wave radiation vary across the lake due to lake effects but remain largely unquantified, as are the resulting spatial differences in temperature. Here we present meteorological data and surface energy budgets for six stations around Lake Victoria, East Africa, and time series temperature profiles and transect data taken during different times of day and different seasons. Seasonality is determined by the northeast and southeast monsoons and intervening rainy seasons. Winds were higher in the afternoon to the north in the northeast monsoon and higher at night and in the morning to the south during the southeast monsoon. Cloud cover was least during the monsoons. Lakewide, latent heat fluxes range from 150W m-2 to 250 W m-2 in the afternoon with larger values to the north during the northeast monsoon. Values during the morning range from 100 W m-2 to 150 W m-2 but increase to 200 W m-2 - 300 W m-2 to the south and west during the southeast monsoon. The seasonal thermocline is generated during the northeast monsoon due to the higher afternoon winds which mix heat downwards and overall net heating. Holomixis, but with warmer temperatures to the north, occurs during the southeast monsoon due to the accentuated night time cooling and net heat loss. Wind speeds are lower and the diel range of air temperature and relative humidity is higher inshore than off. Consequently, computed monthly heat losses were at least 30% higher offshore and water temperatures are cooler offshore. Scaling analyses indicate that the stratification induced by inflows of cool water to the north at the end of the southeast monsoon are wind driven and that despite the warmer waters inshore which would enable convective circulation, inshore-offshore exchanges are mediated by wind and internal waves.

MacIntyre, S.; Romero, J. R.

2011-12-01

386

Rift propagation at craton margin.: Distribution of faulting and volcanism in the North Tanzanian Divergence (East Africa) during Neogene times  

NASA Astrophysics Data System (ADS)

A revised kinematic model is proposed for the Neogene tectono-magmatic development of the North Tanzanian Divergence where the axial valley in S Kenya splits southwards into a wide diverging pattern of block faulting in association with the disappearance of volcanism. Propagation of rifting along the S Kenya proto-rift during the last 8 Ma is first assumed to have operated by linkage of discrete magmatic cells as far S as the Ngorongoro-Kilimanjaro transverse volcanic belt that follows the margin of cratonic blocks in N Tanzania. Strain is believed to have nucleated throughout the thermally-weakened lithosphere in the transverse volcanic belt that might have later linked the S Kenya and N Tanzania rift segments with marked structural changes along-strike. The North Tanzanian Divergence is now regarded as a two-armed rift pattern involving: (1) a wide domain of tilted fault blocks to the W (Mbulu) that encompasses the Eyasi and Manyara fault systems, in direct continuation with the Natron northern trough. The reactivation of basement fabrics in the cold and intact Precambrian lithosphere in the Mbulu domain resulted in an oblique rift pattern that contrasts with the orthogonal extension that prevailed in the Magadi-Natron trough above a more attenuated lithosphere. (2) To the E, the Pangani horst-like range is thought to be a younger (< 1 Ma) structure that formed in response to the relocation of extension S of the Kilimanjaro magmatic center. A significant contrast in the mechanical behaviour of the stretched lithosphere in the North Tanzanian diverging rift is assumed to have occurred on both sides of the Masai cratonic block with a mid-crustal decoupling level to the W where asymmetrical fault-basin patterns are dominant (Magadi-Natron and Mbulu), whereas a component of dynamical uplift is suspected to have caused the topographic elevation of the Pangani range in relation with possible far-travelled mantle melts produced at depth further N.

Le Gall, B.; Nonnotte, P.; Rolet, J.; Benoit, M.; Guillou, H.; Mousseau-Nonnotte, M.; Albaric, J.; Deverchre, J.

2008-02-01

387

Plague in Africa from 1935 to 1949  

PubMed Central

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 weather60-80F (15-27C)than in hot dry, or cold, weatherover 80F (27C) or under 60F (15C). 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

Davis, D. H. S.

1953-01-01

388

The Development of Capital Markets in Africa, with Particular Reference to Kenya and Nigeria (Le développement des marchés de capitaux en Afrique, et tout particulièrement au Kenya et au Nigéria) (La evolución de los mercados de capital en Africa, especialmente en Kenia y Nigeria)  

Microsoft Academic Search

Le document étudie l'utilisation du mécanisme des marchés de capitaux dans la mobilisation intérieure du capital en Afrique, et en particulier au Kenya et au Nigéria. Le manque de marchés de capitaux organisés tient avant tout aux niveaux relativement faibles du revenu national et du revenu par habitant dans presque tous les pays africains; elle s'explique aussi par la modicité

Edward A. Arowolo

1971-01-01

389

Out of Africa  

ERIC Educational Resources Information Center

Karen Blixen (Isak Dinesen), author of "Out of Africa," said, "God made the world round so people would never be able to see too far down the road." The author embraced this wonderful thought by venturing on a three-week journey to Kenya and Tanzania in search of grand adventure. In this article, the author shares her adventure with her students

Wilbert, Nancy Corrigan

2009-01-01

390

Facing Kenya's energy predicament  

SciTech Connect

Kenya's bleak economic future is not helped by its dependence on foreign oil and lack of fossil-fuel reserves. At a conference on Kenya's energy needs, held in May 1979, options for averting a fuel-food crisis were considered. Recognition of Kenya's resource poverty and the immediate need to establish wood-fuel production products, charcoal conversion, conservation projects, and a research agenda were the main themes of that conference and the bases for a Kenyan energy policy.

O'Keefe, P.; Shakow, D.

1980-06-01

391

Complex seismic anisotropy in the Earth's inner core beneath Africa  

NASA Astrophysics Data System (ADS)

Seismic anisotropy in the top of the inner core is important to the understanding of the growth and dynamics of the Earth's inner core. The anisotropic structures beneath Africa in the top 80 km of the inner core were not well constrained, due to limited sampling coverage. Here, we analyze a large data-set of the PKiKP-PKIKP phases sampling the top 80 km of the inner core beneath Africa along various sampling directions. The differential travel times of the PKiKP-PKIKP phases sampling Africa reveal polar-equatorial differences. The differential travel times along polar paths are about 0-1.4 s larger than those along equatorial paths, suggesting the presence of anisotropy in velocity in the top 80 km of the inner core beneath Africa. The PKiKP-PKIKP phases along polar paths exhibit a complex lateral gradient from the East to the Middle Africa and a correlation of large (small) differential travel time with small (large) amplitude ratio. Largest differential travel times and smallest amplitude ratios are observed beneath the East Africa (Kenya, Tanzania, Mozambique), while small differential travel times and large amplitude ratios are observed beneath the Middle Africa (Democratic Republic of Congo, Congo, Gabon, Angola). The polar PKiKP-PKIKP waveforms are grouped based on the geographic sampling regions. We perform waveform modeling and iteratively search for the anisotropic velocity and attenuation models that explain the polar PKiKP-PKIKP waveforms in various groups. Most complexities observed in the PKiKP-PKIKP waveforms can be explained by the presence of uniform anisotropy, but with onset of the anisotropy occurring at various depths. The region beneath the East Africa can be explained by a uniform anisotropy model with a magnitude of about 1.7% and an average Q value of 250 present at the inner core boundary (ICB), while the region beneath the Middle Africa can be explained by a model with an isotropic layer in the top and a uniform anisotropy with a magnitude of about 1.7% and an average Q value of 400 present at a depth of 50 km below the ICB. The region between the East and the Middle Africa can be explained by a model with an isotropic layer in the top and a uniform anisotropy with a magnitude of about 1.7% and Q values of about 150-400 present at depths 10-20 km below the ICB.

Yu, W.; Wen, L.

2006-05-01

392

The Impact of Gender Inequality in Education and Employment on Economic Growth in the Middle East and North Africa  

E-print Network

and North Africa Stephan Klasen, University of Munich Klasen@lrz.uni-muenchen.de and Francesca Lamanna, University of Munich1 Francesca.lamanna@lrz.uni-muenchen.de October 25, 2003. Abstract: Using cross

Krivobokova, Tatyana

393

Potential Applications of LANDSAT Data in Energy Management Associated with Kenya's Forests  

NASA Technical Reports Server (NTRS)

LANDSAT can be effectively used to monitor the extent and magnitude of forest cover change in Kenya in order to evaluate the potential for energy supply. Digital processing of LANDSAT data provides a reliable monitoring technique for forest resource management in Kenya. Data analysis was used to illustrate that Kenya's forests are indeed diminishing. A model used to make projections for the availability of fuelwood as an energy source is presented. The resulting figures imply that Kenya's forest will all but disappear around the end of the 20th century. Analysis of LANDSAT data for Mau East substantiates these alarming findings.

Maghenda, M. M.; Bloemer, H. L.; Brumfield, J. O.

1982-01-01

394

HIV among People Who Inject Drugs in the Middle East and North Africa: Systematic Review and Data Synthesis  

PubMed Central

Background It is perceived that little is known about the epidemiology of HIV infection among people who inject drugs (PWID) in the Middle East and North Africa (MENA). The primary objective of this study was to assess the status of the HIV epidemic among PWID in MENA by describing HIV prevalence and incidence. Secondary objectives were to describe the risk behavior environment and the HIV epidemic potential among PWID, and to estimate the prevalence of injecting drug use in MENA. Methods and Findings This was a systematic review following the PRISMA guidelines and covering 23 MENA countries. PubMed, Embase, regional and international databases, as well as country-level reports were searched up to December 16, 2013. Primary studies reporting (1) the prevalence/incidence of HIV, other sexually transmitted infections, or hepatitis C virus (HCV) among PWIDs; or (2) the prevalence of injecting or sexual risk behaviors, or HIV knowledge among PWID; or (3) the number/proportion of PWID in MENA countries, were eligible for inclusion. The quality, quantity, and geographic coverage of the data were assessed at country level. Risk of bias in predefined quality domains was described to assess the quality of available HIV prevalence measures. After multiple level screening, 192 eligible reports were included in the review. There were 197 HIV prevalence measures on a total of 58,241 PWID extracted from reports, and an additional 226 HIV prevalence measures extracted from the databases. We estimated that there are 626,000 PWID in MENA (range: 335,0001,635,000, prevalence of 0.24 per 100 adults). We found evidence of HIV epidemics among PWID in at least one-third of MENA countries, most of which are emerging concentrated epidemics and with HIV prevalence overall in the range of 10%15%. Some of the epidemics have however already reached considerable levels including some of the highest HIV prevalence among PWID globally (87.1% in Tripoli, Libya). The relatively high prevalence of sharing needles/syringes (18%28% in the last injection), the low levels of condom use (20%54% ever condom use), the high levels of having sex with sex workers and of men having sex with men (15%30% and 2%10% in the last year, respectively), and of selling sex (5%29% in the last year), indicate a high injecting and sexual risk environment. The prevalence of HCV (31%64%) and of sexually transmitted infections suggest high levels of risk behavior indicative of the potential for more and larger HIV epidemics. Conclusions Our study identified a large volume of HIV-related biological and behavioral data among PWID in the MENA region. The coverage and quality of the data varied between countries. There is robust evidence for HIV epidemics among PWID in multiple countries, most of which have emerged within the last decade and continue to grow. The lack of sufficient evidence in some MENA countries does not preclude the possibility of hidden epidemics among PWID in these settings. With the HIV epidemic among PWID in overall a relatively early phase, there is a window of opportunity for prevention that should not be missed through the provision of comprehensive programs, including scale-up of harm reduction services and expansion of surveillance systems. Please see later in the article for the Editors' Summary PMID:24937136

Mumtaz, Ghina R.; Weiss, Helen A.; Thomas, Sara L.; Riome, Suzanne; Setayesh, Hamidreza; Riedner, Gabriele; Semini, Iris; Tawil, Oussama; Akala, Francisca Ayodeji; Wilson, David; Abu-Raddad, Laith J.

2014-01-01

395

Micrometeorological conditions and surface mass and energy fluxes on Lewis Glacier, Mt Kenya, in relation to other tropical glaciers  

NASA Astrophysics Data System (ADS)

The Lewis Glacier on Mt Kenya is one of the best-studied tropical glaciers, but full understanding of the interaction of the glacier mass balance and its climatic drivers has been hampered by a lack of long-term meteorological data. Here we present 2.5 yr of meteorological data collected from the glacier surface from October 2009 to February 2012. The location of measurements is in the upper portion of Lewis Glacier, but this location experiences negative annual mass balance, and the conditions are comparable to those experienced in the lower ablation zones of South American glaciers in the inner tropics. In the context of other glaciated mountains of equatorial East Africa, the summit zone of Mt Kenya shows strong diurnal cycles of convective cloud development as opposed to the Rwenzoris, where cloud cover persists throughout the diurnal cycle, and Kilimanjaro, where clear skies prevail. Surface energy fluxes were calculated for the meteorological station site using a physical mass- and energy-balance model driven by measured meteorological data and additional input parameters that were determined by Monte Carlo optimization. Sublimation rate was lower than those reported on other tropical glaciers, and melt rate was high throughout the year, with the glacier surface reaching the melting point on an almost daily basis. Surface mass balance is influenced by both solid precipitation and air temperature, with radiation providing the greatest net source of energy to the surface. Cloud cover typically reduces the net radiation balance compared to clear-sky conditions, and thus the frequent formation of convective clouds over the summit of Mt Kenya and the associated higher rate of snow accumulation are important in limiting the rate of mass loss from the glacier surface. The analyses shown here form the basis for future glacier-wide mass and energy balance modeling to determine the climate proxy offered by the glaciers of Mt Kenya.

Nicholson, L. I.; Prinz, R.; Mlg, T.; Kaser, G.

2013-08-01

396

A MATLAB based orientation analysis of Acheulean handaxe accumulations in Olorgesailie and Kariandusi, Kenya Rift.  

PubMed

The Pleistocene archeological record in East Africa has revealed unusual accumulations of Acheulean handaxes at prehistoric sites. In particular, there has been intensive debate concerning whether the artifact accumulation at the Middle Pleistocene Olorgesailie (Southern Kenya Rift) and Kariandusi (Central Kenya Rift) sites were a result of fluvial reworking or of in situ deposition by hominids. We used a two-step approach to test the hypothesis of fluvial reworking. Firstly, the behavior of handaxes in water currents was investigated in a current flume and the flow threshold required to reorientate the handaxes was determined. The results of these experiments suggested that, in relatively high energy and non-steady flow conditions, handaxes will reorientate themselves perpendicular to the current direction. Secondly, an automated image analysis routine was developed and applied to archeological plans from three Acheulean sites, two at Olorgesailie and one at Kariandusi, in order to determine the orientations of the handaxes. A Rayleigh test was then applied to the orientation data to test for a preferred orientation. The results revealed that the handaxes at the Upper Kariandusi Site and the Olorgesailie Main Site Mid Trench had a preferential orientation, suggesting reworking by a paleocurrent. The handaxes from the Olorgesailie Main Site H/6A, however, appeared to be randomly oriented and in situ deposition by the producers therefore remains a possibility. PMID:23561645

Walter, Marius J; Trauth, Martin H

2013-06-01