Sample records for aaa east africa

  1. The enigma of yellow fever in East Africa.

    PubMed

    Ellis, Brett R; Barrett, Alan D T

    2008-01-01

    Despite a safe and effective vaccine, there are approximately 200,000 cases, including 30,000 deaths, due to yellow fever virus (YFV) each year, of which 90% are in Africa. The natural history of YFV has been well described, especially in West Africa, but in East Africa yellow fever (YF) remains characterised by unpredictable focal periodicity and a precarious potential for large epidemics. Recent outbreaks of YF in Kenya (1992-1993) and Sudan (2003 and 2005) are important because each of these outbreaks have involved the re-emergence of a YFV genotype (East Africa) that remained undetected for nearly 40 years and was previously unconfirmed in a clinically apparent outbreak. In addition, unlike West Africa and South America, YF has yet to emerge in urban areas of East Africa and be vectored by Aedes (Stegomyia) aegypti. This is a significant public health concern in a region where the majority of the population remains unvaccinated. This review describes historical findings, highlights a number of disease indicators, and provides clarification regarding the natural history, recent emergence and future risk of YF in East Africa. Copyright (c) 2008 John Wiley & Sons, Ltd.

  2. Andreas Goes to Africa: A Comparative Historical Study of the Teachers for East Africa Programs

    ERIC Educational Resources Information Center

    Vavrus, Frances

    2018-01-01

    This article uses a comparative historical approach to examine the Teachers for East Africa (TEA) and the Teacher Education in East Africa (TEEA) programs, an influential educational development effort that involved U.S. and British college graduates in East African schools and colleges during the decade of 1961-1971. Drawing on postcolonial…

  3. Near East/North Africa Report No. 2642.

    DTIC Science & Technology

    1982-10-19

    JPRS 82023 19 October 1982 Near East/North Africa Report No. 2642 0 0’- FBISl FOREIGN BROADCAST INFORMATION SERVICE NATIONAl TECHNICALINFORMATION...itI ’s Iz ioo. i ’ tI. xfr .1k3 r A V’ JPRS 82023. 19 October 1982 NEAR EAST/NORTH AFRICA REPORT No. 2642 CONTENTS OPEC AFFAIRS Arab Investment...and tri-.e-6~ve urzgrarme Uricer Pit lattef, Awl-Babta’i of Kjv.a’:. Ai Suda’ry. UALenk C’i-vee! %w te givqn "ho Chance Sliotokshyaond Siia-0a1y of

  4. East and Southern Africa English Accents.

    ERIC Educational Resources Information Center

    Bobda, Augustin Simo

    2001-01-01

    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)

  5. Johnsongrass mosaic virus contributes to maize lethal necrosis in East Africa

    USDA-ARS?s Scientific Manuscript database

    Maize lethal necrosis (MLN), a severe virus disease of maize, has emerged in East Africa in recent years with devastating effects on production and food security where maize is a staple subsistence crop. In extensive surveys of MLN-symptomatic plants in East Africa, sequences of Johnsongrass mosaic ...

  6. Assessment of conventional oil resources of the East African Rift Province, East Africa, 2016

    USGS Publications Warehouse

    Brownfield, Michael E.; Schenk, Christopher J.; Klett, Timothy R.; Mercier, Tracey J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Finn, Thomas M.; Le, Phuong A.; Leathers-Miller, Heidi M.

    2017-03-27

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 13.4 billion barrels of oil and 4.6 trillion cubic feet of gas in the East African Rift Province of east Africa.

  7. Translations on Near East and North Africa, Number 1647

    DTIC Science & Technology

    1977-04-28

    Production capacity of the two plants is to amount to 220,000 tons of ammonia and 800,000 tons of uric acid . Improving operations efficiency at the...JPRS 69019 28 April 1977 TRANSLATIONS’ON NEAR EAST AND NORTH AFRICA No, 1647 < 2 w ÜJCEE »- .Q-5 ^ Q. C «MM H— —• £2 a« ES.Q...3. Recipient’s Accession No. 4. Title and Subtitle TRANSLATIONS ON NEAR EAST AND NORTH AFRICA , No. 164 7 5. Report Date 28 April 1977 6

  8. Melamine milk powder and infant formula sold in East Africa.

    PubMed

    Schoder, Dagmar

    2010-09-01

    This is the first study proving the existence of melamine in milk powder and infant formula exported to the African market. A total of 49 milk powder batches were collected in Dar-es-Salaam (Tanzania, East Africa), the center of international trade in East Africa, which serves as a commercial bottleneck and shipment hub for sub-Saharan, Central, and East Africa. Two categories of samples were collected between October and December 2008, immediately after the melamine contamination of Chinese products became public: (i) market brands of all international companies supplying the East African market and (ii) illegally sold products from informal channels. Melamine concentration was determined with the AgraQuant Melamine Sensitive Assay. Despite the national import prohibition of Chinese milk products and unlabeled milk powder in Tanzania, 11% (22 of 200) of inspected microretailers sold milk powder on the local black market. Manufacturers could be identified for only 55% (27) of the 49 investigated batches. Six percent (3 of 49) of all samples and 11% (3 of 27) of all international brand name products tested revealed melamine concentrations up to 5.5 mg/kg of milk powder. This amount represents about twice the tolerable daily intake as suggested by the U.S Food and Drug Administration. Based on our study, we can assume that the number of affected children in Africa is substantial.

  9. The Growth of Neurosurgery in East Africa: Challenges.

    PubMed

    Santos, Maria M; Qureshi, Mubashir M; Budohoski, Karol P; Mangat, Halinder S; Ngerageza, Japhet G; Schöller, Karsten; Shabani, Hamisi K; Zubkov, Micaella R; Härtl, Roger

    2018-05-01

    As the second of 3 articles in this series, the aim of this article is to provide readers with an understanding of the development of neurosurgery in East Africa (foundations), the challenges that arise in providing neurosurgical care in developing countries (challenges), and an overview of traditional and novel approaches to overcoming these challenges and improving health care in the region (innovations). Recognizing the challenges that need to be addressed is the first step to implementing efficient and qualified surgery delivery systems in low- and middle-income countries. We reviewed the major challenges facing health care in East Africa and grouped them into 5 categories: 1) burden of surgical disease and workforce crisis; 2) global health view of surgery as "the neglected stepchild"; 3) need for recognizing the surgical system as an interdependent network and importance of organizational and equipment deficits; 4) lack of education in the community, failure of primary care systems, and net result of overwhelming tertiary care systems; 5) personal and professional burnout as well as brain drain of promising human resources from low- and middle-income countries in East Africa and similar regions across the world. Each major challenge was detailed and analyzed by authors who have worked or are currently working in the region, providing a personal perspective. Copyright © 2018. Published by Elsevier Inc.

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

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  11. Spatial phylodynamics of HIV-1 epidemic emergence in east Africa

    PubMed Central

    Gray, Rebecca R.; Tatem, Andrew J.; Lamers, Susanna; Hou, Wei; Laeyendecker, Oliver; Serwadda, David; Sewankambo, Nelson; Gray, Ronald H.; Wawer, Maria; Quinn, Thomas C.; Goodenow, Maureen M.; Salemi, Marco

    2009-01-01

    Design We sought to investigate the evolutionary and historical reasons for the different epidemiological patterns of HIV-1 in the early epidemic. In order to characterize the demographic history of HIV-1 subtypes A and D in east Africa, we examined molecular epidemiology, geographical and historical data. Methodology We employed high-resolution phylodynamics to investigate the introduction of HIV-1A and D into east Africa, the geographic trends of viral spread, and the demographic growth of each subtype. We also used geographic information system data to investigate human migration trends, population growth, and human mobility. Results HIV-1A and D were introduced into east Africa after 1950 and spread exponentially during the 1970s, concurrent with eastward expansion. Spatiotemporal data failed to explain the establishment and spread of HIV based on urban population growth and migration. The low prevalence of the virus in the Democratic Republic of Congo before and after the emergence of the pandemic was, however, consistent with regional accessibility data, highlighting the difficulty in travel between major population centers in central Africa. In contrast, the strong interconnectivity between population centers across the east African region since colonial times has likely fostered the rapid growth of the epidemic in this locale. Conclusion This study illustrates how phylodynamic analysis of pathogens informed by geospatial data can provide a more holistic and evidence-based interpretation of past epidemics. We advocate that this ‘landscape phylodynamics’ approach has the potential to provide a framework both to understand epidemics' spread and to design optimal intervention strategies. PMID:19644346

  12. Terrestrial heat flow in east and southern Africa

    NASA Astrophysics Data System (ADS)

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

    1990-10-01

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

  13. Risk of abdominal aortic aneurysm (AAA) among male and female relatives of AAA patients.

    PubMed

    van de Luijtgaarden, Koen M; Rouwet, Ellen V; Hoeks, Sanne E; Stolker, Robert J; Verhagen, Hence Jm; Majoor-Krakauer, Danielle

    2017-04-01

    Sex affects the presentation, treatment, and outcomes of abdominal aortic aneurysm (AAA). Although AAAs are less prevalent in women, at least in the general population, women with an AAA have a poorer prognosis in comparison to men. Sex differences in the genetic predisposition for aneurysm disease remain to be established. In this study we investigated the familial risk of AAA for women compared to men. All living AAA patients included in a 2004-2012 prospective database were invited to the multidisciplinary vascular/genetics outpatient clinic between 2009 and 2012 for assessment of family history using detailed questionnaires. AAA risk for male and female relatives was calculated separately and stratified by sex of the AAA patients. Families of 568 AAA patients were investigated and 22.5% of the patients had at least one affected relative. Female relatives had a 2.8-fold and male relatives had a 1.7-fold higher risk than the estimated sex-specific population risk. Relatives of female AAA patients had a higher aneurysm risk than relatives of male patients (9.0 vs 5.9%, p = 0.022), corresponding to 5.5- and 2.0-fold increases in aneurysm risk in the female and male relatives, respectively. The risk for aortic aneurysm in relatives of AAA patients is higher than expected from population risk. The excess risk is highest for the female relatives of AAA patients and for the relatives of female AAA patients. These findings endorse targeted AAA family screening for female and male relatives of all AAA patients.

  14. Precipitation Characteristics in West and East Africa from Satellite and in Situ Observations

    NASA Technical Reports Server (NTRS)

    Dezfuli, Amin K.; Ichoku, Charles M.; Mohr, Karen I.; Huffman, George J.

    2017-01-01

    Using in situ data, three precipitation classes are identified for rainy seasons of West and East Africa: weak convective rainfall (WCR), strong convective rainfall (SCR), and mesoscale convective systems (MCSs).Nearly 75% of the total seasonal precipitation is produced by the SCR and MCSs, even though they represent only 8% of the rain events. Rain events in East Africa tend to have a longer duration and lower intensity than in West Africa, reflecting different characteristics of the SCR and MCS events in these two regions. Surface heating seems to be the primary convection trigger for the SCR, particularly in East Africa, whereas the WCR requires a dynamical trigger such as low-level convergence. The data are used to evaluate the performance of the recently launched Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG)project. The IMERG-based precipitation shows significant improvement over its predecessor, the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), particularly in capturing the MCSs, due to its improved temporal resolution.

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

    PubMed

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

    2012-01-01

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

  16. Using Satellite Data to Build Climate Resilience: A Novel East Africa Drought Monitor

    NASA Astrophysics Data System (ADS)

    Slinski, K.; Hogue, T. S.; McCray, J. E.

    2016-12-01

    East Africa is affected by recurrent drought. The 2015-2016 El Niño triggered a severe drought across East Africa causing serious impacts to regional water security, health, and livelihoods. Ethiopia was the hardest hit, with the United Nations Office for the Coordination of Humanitarian Affairs calling the recent drought the worst in 50 years. Resources to monitor the severity and progression of droughts are a critical component to disaster risk reduction, but are challenging to implement in regions with sparse data collection networks such as East Africa. Satellite data is used by the United Nations Food and Agriculture Organization Global Information and Early Warning System, the USAID Famine Early Warning System, and the Africa Drought and Flood Monitor. These systems use remotely sensed vegetation, soil moisture, and meteorological data to develop drought indices. However, they do not directly monitor impacts to water resources, which is necessary to appropriately target drought mitigation efforts. The current study combines new radar data from the European Space Agency's Sentinel-1 mission with satellite imagery to perform a retrospective analysis of the impact of the 2015-2016 drought in East Africa on regional surface water. Inland water body extents during the drought are compared to historical trends to identify the most severely impacted areas. The developed tool has the potential to support on-the-ground humanitarian relief efforts and to refine predictions of water scarcity and crop impacts from existing hydrologic models and famine early warning systems.

  17. Mantle Structure Beneath East Africa and Zambia from Body Wave Tomography

    NASA Astrophysics Data System (ADS)

    Mulibo, G.; Nyblade, A.; Tugume, F.

    2011-12-01

    In this study, P and S travel time residuals from teleseismic earthquakes recorded on over 60 temporary AfricaArray seismic stations deployed in Uganda, Kenya, Tanzania and Zambia between 2007 and 2011 are being inverted, together with travel time residuals from previous deployments, for a 3D image of mantle wave speeds variations extending to a depth of 1200 km. Preliminary results show that at depths of 200 km of less, low wave speed anomalies are well developed beneath the Eastern and Western Branches of the East African Rift System. At deep depths, the low wave speed anomalies focus under the center and southern part of the East African Plateau and extend into the transition zone. At transition zone depths and within the top part of the lower mantle, the low wave speed anomaly shifts to the southwest beneath Zambia, indicating that the low wave speed anomaly is continuous across the transition zone and that it extends into the lower mantle. This result suggests that the upper mantle low wave speed anomaly beneath East Africa is connected to the African superplume anomaly in the lower mantle beneath southern Africa.

  18. Leveraging the Security -- Development Nexus in East Africa

    DTIC Science & Technology

    2012-02-28

    THE SECURITY-DEVELOPMENT NEXUS IN EAST AFRICA America is in a state of hypnosis . Many outside the beltway do not know, and/or care, how reckless...invariably, what policy makers are implicitly tasked to do, because America will not come out of its hypnosis at the count of three. Endnotes 1 Susan

  19. AAA Foundation for Traffic Safety

    MedlinePlus

    ... of Top Deadly Mistakes Made by Teen Drivers -- AAA AAA: Road debris causes avoidable crashes, deaths Save the ... and 500 deaths! Foundation News Stay Tuned New AAA Foundation for Traffic Safety website coming Fall 2017 ...

  20. Reducing the Burden of Cancer in East Africa

    Cancer.gov

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

  1. AAA-ATPases in Protein Degradation

    PubMed Central

    Yedidi, Ravikiran S.; Wendler, Petra; Enenkel, Cordula

    2017-01-01

    Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea. PMID:28676851

  2. AAA-ATPases in Protein Degradation.

    PubMed

    Yedidi, Ravikiran S; Wendler, Petra; Enenkel, Cordula

    2017-01-01

    Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea.

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

    ERIC Educational Resources Information Center

    Jones, Sam; Schipper, Youdi

    2015-01-01

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

  4. Socialisation in Architectural Education: A View from East Africa

    ERIC Educational Resources Information Center

    Olweny, Mark

    2017-01-01

    Purpose: Concern for the state of architectural education in East Africa was a catalyst for this exploration of socialisation, which sought to understand socialisation and its influence on educational outcomes in the region. Socialisation within architectural education has long been known to influence how students acquire important aspects of the…

  5. Perceptions and Misperceptions: The Middle East and South Africa.

    ERIC Educational Resources Information Center

    Moore, Michael; Tyson, G. A.

    1990-01-01

    Reports findings of a study examining the opinions and awareness level of South African, Israeli, and United States undergraduates about conflicts in either the Middle East or South Africa. Finds religious and racial characteristics determining differences in knowledge level and political support. Reveals South African Blacks and U.S. students…

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

    USDA-ARS?s Scientific Manuscript database

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

  7. Mineral facilities of Africa and the Middle East

    USGS Publications Warehouse

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

    2006-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1998-10-01

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

  9. LMIP/AAA: Local Authentication, Authorization and Accounting (AAA) Protocol for Mobile IP

    NASA Astrophysics Data System (ADS)

    Chenait, Manel

    Mobile IP represents a simple and scalable global mobility solution. However, it inhibits various vulnerabilities to malicious attacks and, therefore, requires the integration of appropriate security services. In this paper, we discuss two authentication schemes suggested for Mobile IP: standard authentication and Mobile IP/AAA authentication. In order to provide Mobile IP roaming services including identity verication, we propose an improvement to Mobile/AAA authentication scheme by applying a local politic key management in each domain, hence we reduce hando latency by avoiding the involvement of AAA infrastructure during mobile node roaming.

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

    ERIC Educational Resources Information Center

    Chamie, Mary

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  13. Dietary trends in the Middle East and North Africa: an ecological study (1961 to 2007).

    PubMed

    Golzarand, Mahdieh; Mirmiran, Parvin; Jessri, Mahsa; Toolabi, Karamollah; Mojarrad, Mehdi; Azizi, Fereidoun

    2012-10-01

    Middle Eastern and North African countries are undergoing nutrition transition, a transition which is associated with an increased burden of non-communicable diseases. This necessitates the evaluation of dietary patterns in these regions. The present study aimed to assess changes in dietary patterns in Middle Eastern and North African countries between 1961 and 2007. Availability of energy and fifteen main food items during 1961-2007 was examined using FAO food balance sheets from the FAOSTAT database. Fifteen countries including nine in the Middle East and six in North Africa were selected and the average availability of total energy and different food items in these regions were compared. Over the 47 years studied, energy and food availability (apart from animal fats and alcoholic beverages) has increased in the Middle East and North Africa. In both regions the proportion of energy derived from meat and vegetable oils has increased significantly while that from cereals decreased significantly. In addition, the proportion of energy from milk and dairy products and vegetables has shown an ascending trend in North Africa while the proportion of energy from fruits has shown a descending trend in the Middle East. The study results reveal an unfavourable trend towards a Westernized diet in the Middle East and, to a certain extent, in North Africa. Tailored nutritional education encouraging healthy eating for prevention of the burden of chronic diseases in these countries seems essential.

  14. The Precambrian crustal structure of East Africa

    NASA Astrophysics Data System (ADS)

    Young, A. J.; Tugume, F.; Nyblade, A.; Julia, J.; Mulibo, G.

    2011-12-01

    We present new results on crustal structure from East Africa from analyzing P wave receiver functions. The data for this study come from temporary AfricaArray broadband seismic stations deployed between 2007 and 2011 in Uganda, Tanzania and Zambia. Receiver functions have been computed using an iterative deconvolution method. Crustal structure has been imaged using the H-k stacking method and by jointly inverting the receiver functions and surface wave phase and group velocities. The results show remarkably uniform crust throughout the Archean and Proterozoic terrains that comprise the Precambrian tectonic framework of the region. Crustal thickness for most terrains is between 37 and 40 km, and Poisson's ratio is between 0.25 and 0.27. Results from the joint inversion yield average crustal Vs values of 3.6 to 3.7 km/s. For most terrains, a thin (1-5 km) thick high velocity (Vs>4.0 km/s) is found at the base of the crust.

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

    PubMed

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

    2015-09-01

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

  16. The International AIDS Vaccine Initiative's Capacity Building Activities in East Africa

    PubMed Central

    Cochrane, Gavin; Robin, Enora; Hanlin, Rebecca; Castle-Clarke, Sophie; MacLure, Calum; Parks, Sarah; Chataway, Joanna

    2016-01-01

    Abstract The International AIDS Vaccine Initiative (IAVI) is one of a number of Product Development Partnerships created to bridge the gap between scientific and technological potential and the needs of low income populations in low and middle income countries. Specifically IAVI is focused on creating a preventative vaccine for HIV/AIDS. Whilst the remit of IAVI is to create new science, technology and products, its work necessarily involves a wide range of stakeholders and different constituencies in industrially developing and developed countries. Its capacity building activities relate to strengthening the ability to conduct clinical trials and are broad based, spanning scientific and technological capacity through to organisational, advocacy and broader development capabilities. The aim of this study was to deepen IAVI's understanding of how it contributes to capacity building activities in East Africa (Uganda, Kenya and Rwanda), spanning scientific and technological capacity through to organisational, advocacy and broader development capabilities. IAVI's mission to develop an HIV vaccine has become increasingly connected to wider health systems strengthening, through its clinical research activities in East Africa. Since it began its operations in the region, IAVI has made a significant contribution to training interventions to support scientific excellence and good clinical practice and invested in infrastructure and laboratories at Clinical Research Centres in East Africa. Although clear challenges still exist with ensuring sustained investment, accessing marginalized populations and demonstrating progress in capacity building, the experiences of IAVI to date suggest that substantial progress is being made towards wider health systems strengthening in the region. PMID:28083400

  17. Brief communication: Drought likelihood for East Africa

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Huntingford, Chris

    2018-02-01

    The East Africa drought in autumn of year 2016 caused malnutrition, illness and death. Close to 16 million people across Somalia, Ethiopia and Kenya needed food, water and medical assistance. Many factors influence drought stress and response. However, inevitably the following question is asked: are elevated greenhouse gas concentrations altering extreme rainfall deficit frequency? We investigate this with general circulation models (GCMs). After GCM bias correction to match the climatological mean of the CHIRPS data-based rainfall product, climate models project small decreases in probability of drought with the same (or worse) severity as 2016 ASO (August to October) East African event. This is by the end of the 21st century compared to the probabilities for present day. However, when further adjusting the climatological variability of GCMs to also match CHIRPS data, by additionally bias-correcting for variance, then the probability of drought occurrence will increase slightly over the same period.

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  19. NASA Airborne Astronomy Ambassadors (AAA)

    NASA Astrophysics Data System (ADS)

    Backman, D. E.; Harman, P. K.; Clark, C.

    2016-12-01

    NASA's Airborne Astronomy Ambassadors (AAA) is a three-part professional development (PD) program for high school physics and astronomy teachers. The AAA experience consists of: (1) blended-learning professional development composed of webinars, asynchronous content learning, and a series of hands-on workshops (2) a STEM immersion experience at NASA Armstrong Flight Research Center's B703 science research aircraft facility in Palmdale, California, and (3) ongoing participation in the AAA community of practice (CoP) connecting participants with astrophysics and planetary science Subject Matter Experts (SMEs). The SETI Institute (SI) is partnering with school districts in Santa Clara and Los Angeles Counties during the AAA program's "incubation" period, calendar years 2016 through 2018. AAAs will be selected by the school districts based on criteria developed during spring 2016 focus group meetings led by the program's external evaluator, WestEd.. Teachers with 3+ years teaching experience who are assigned to teach at least 2 sections in any combination of the high school courses Physics (non-AP), Physics of the Universe (California integrated model), Astronomy, or Earth & Space Sciences are eligible. Partner districts will select at least 48 eligible applicants with SI oversight. WestEd will randomly assign selected AAAs to group A or group B. Group A will complete PD in January - June of 2017 and then participate in SOFIA science flights during fall 2017 (SOFIA Cycle 5). Group B will act as a control during the 2017-18 school year. Group B will then complete PD in January - June of 2018 and participate in SOFIA science flights in fall 2018 (Cycle 6). Under the current plan, opportunities for additional districts to seek AAA partnerships with SI will be offered in 2018 or 2019. A nominal two-week AAA curriculum component will be developed by SI for classroom delivery that will be aligned with selected California Draft Science Framework Disciplinary Core Ideas

  20. International trends in health science librarianship part 14: East Africa (Kenya, Uganda, Rwanda).

    PubMed

    Gathoni, Nasra; Kamau, Nancy; Nannozi, Judith; Singirankabo, Marcel

    2015-06-01

    This is the 14th in a series of articles exploring international trends in health science librarianship in the 21st century. This is the second of four articles pertaining to different regions in the African continent. The present issue focuses on countries in East Africa (Kenya, Uganda and Rwanda). The next feature column will investigate trends in West Africa. JM. © 2015 Health Libraries Group.

  1. Observations of equatorial ionization anomaly over Africa and Middle East during a year of deep minimum

    NASA Astrophysics Data System (ADS)

    Bolaji, Olawale; Owolabi, Oluwafisayo; Falayi, Elijah; Jimoh, Emmanuel; Kotoye, Afolabi; Odeyemi, Olumide; Rabiu, Babatunde; Doherty, Patricia; Yizengaw, Endawoke; Yamazaki, Yosuke; Adeniyi, Jacob; Kaka, Rafiat; Onanuga, Kehinde

    2017-01-01

    In this work, we investigated the veracity of an ion continuity equation in controlling equatorial ionization anomaly (EIA) morphology using total electron content (TEC) of 22 GPS receivers and three ground-based magnetometers (Magnetic Data Acquisition System, MAGDAS) over Africa and the Middle East (Africa-Middle East) during the quietest periods. Apart from further confirmation of the roles of equatorial electrojet (EEJ) and integrated equatorial electrojet (IEEJ) in determining hemispheric extent of EIA crest over higher latitudes, we found some additional roles played by thermospheric meridional neutral wind. Interestingly, the simultaneous observations of EIA crests in both hemispheres of Africa-Middle East showed different morphology compared to that reported over Asia. We also observed interesting latitudinal twin EIA crests domiciled at the low latitudes of the Northern Hemisphere. Our results further showed that weak EEJ strength associated with counter electrojet (CEJ) during sunrise hours could also trigger twin EIA crests over higher latitudes.

  2. Heart Failure in Africa, Asia, the Middle East and South America: The INTER-CHF study.

    PubMed

    Dokainish, Hisham; Teo, Koon; Zhu, Jun; Roy, Ambuj; AlHabib, Khalid F; ElSayed, Ahmed; Palileo-Villaneuva, Lia; Lopez-Jaramillo, Patricio; Karaye, Kamilu; Yusoff, Khalid; Orlandini, Andres; Sliwa, Karen; Mondo, Charles; Lanas, Fernando; Prabhakaran, Dorairaj; Badr, Amr; Elmaghawry, Mohamed; Damasceno, Albertino; Tibazarwa, Kemi; Belley-Cote, Emilie; Balasubramanian, Kumar; Yacoub, Magdi H; Huffman, Mark D; Harkness, Karen; Grinvalds, Alex; McKelvie, Robert; Yusuf, Salim

    2016-02-01

    There are few data on heart failure (HF) patients from Africa, Asia, the Middle East and South America. INTER-CHF is a prospective study that enrolled HF patients in 108 centers in 16 countries from 2012 to 2014. Consecutive ambulatory or hospitalized adult patients with HF were enrolled. Baseline data were recorded on sociodemographics, clinical characteristics, HF etiology and treatments. Age- and sex-adjusted results are reported. We recruited 5813 HF patients: mean(SE) age=59(0.2)years, 39% female, 65% outpatients, 31% from rural areas, 26% with HF with preserved ejection fraction, with 1294 from Africa, 2661 from Asia, 1000 from the Middle-East, and 858 from South America. Participants from Africa-closely followed by Asians-were younger, had lower literacy levels, and were less likely to have health or medication insurance or be on beta-blockers compared with participants from other regions, but were most likely to be in NYHA class IV. Participants from South America were older, had higher insurance and literacy levels, and, along with Middle Eastern participants, were more likely to be on beta-blockers, but had the lowest proportion in NYHA IV. Ischemic heart disease was the most common HF etiology in all regions except Africa where hypertensive heart disease was most common. INTER-CHF describes significant regional variability in socioeconomic and clinical factors, etiologies and treatments in HF patients from Africa, Asia, the Middle East and South America. Opportunities exist for improvement in health/medication insurance rates and proportions of patients on beta blockers, particularly in Africa and Asia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Multifunctional Mitochondrial AAA Proteases

    PubMed Central

    Glynn, Steven E.

    2017-01-01

    Mitochondria perform numerous functions necessary for the survival of eukaryotic cells. These activities are coordinated by a diverse complement of proteins encoded in both the nuclear and mitochondrial genomes that must be properly organized and maintained. Misregulation of mitochondrial proteostasis impairs organellar function and can result in the development of severe human diseases. ATP-driven AAA+ proteins play crucial roles in preserving mitochondrial activity by removing and remodeling protein molecules in accordance with the needs of the cell. Two mitochondrial AAA proteases, i-AAA and m-AAA, are anchored to either face of the mitochondrial inner membrane, where they engage and process an array of substrates to impact protein biogenesis, quality control, and the regulation of key metabolic pathways. The functionality of these proteases is extended through multiple substrate-dependent modes of action, including complete degradation, partial processing, or dislocation from the membrane without proteolysis. This review discusses recent advances made toward elucidating the mechanisms of substrate recognition, handling, and degradation that allow these versatile proteases to control diverse activities in this multifunctional organelle. PMID:28589125

  4. Multifunctional Mitochondrial AAA Proteases.

    PubMed

    Glynn, Steven E

    2017-01-01

    Mitochondria perform numerous functions necessary for the survival of eukaryotic cells. These activities are coordinated by a diverse complement of proteins encoded in both the nuclear and mitochondrial genomes that must be properly organized and maintained. Misregulation of mitochondrial proteostasis impairs organellar function and can result in the development of severe human diseases. ATP-driven AAA+ proteins play crucial roles in preserving mitochondrial activity by removing and remodeling protein molecules in accordance with the needs of the cell. Two mitochondrial AAA proteases, i-AAA and m-AAA, are anchored to either face of the mitochondrial inner membrane, where they engage and process an array of substrates to impact protein biogenesis, quality control, and the regulation of key metabolic pathways. The functionality of these proteases is extended through multiple substrate-dependent modes of action, including complete degradation, partial processing, or dislocation from the membrane without proteolysis. This review discusses recent advances made toward elucidating the mechanisms of substrate recognition, handling, and degradation that allow these versatile proteases to control diverse activities in this multifunctional organelle.

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

    ERIC Educational Resources Information Center

    Brock, Colin, Ed.; Levers, Lila Zia

    2007-01-01

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

  6. Near East and North Africa: A Selected Functional and Country Bibliography.

    ERIC Educational Resources Information Center

    Foreign Service (Dept. of State), Washington, DC. Foreign Service Inst.

    This selected bibliography focuses on the Near East and North Africa. Among the topics covered are: Documentary Collections, History, Politics, and International Relations, Islam and the Islamic World, the Arabs, Geography, Art, Literature, Education and Sociocultural Patterns, and Economics, Labor and Oil. An introduction to the series is in SO…

  7. Mantle transition zone structure beneath Tanzania, east Africa

    NASA Astrophysics Data System (ADS)

    Owens, Thomas J.; Nyblade, Andrew A.; Gurrola, Harold; Langston, Charles A.

    2000-03-01

    We apply a three-dimensional stacking method to receiver functions from the Tanzania Broadband Seismic Experiment to determine relative variations in the thickness of the mantle transition zone beneath Tanzania. The transition zone under the Eastern rift is 30-40 km thinner than under areas of the Tanzania Craton in the interior of the East African Plateau unaffected by rift faulting. The region of transition zone thinning under the Eastern rift is several hundred kilometers wide and coincides with a 2-3% reduction in S wave velocities. The thinning of the transition zone, as well as the reduction in S wave velocities, can be attributed to a 200-300°K increase in temperature. This thermal anomaly at >400 km depth beneath the Eastern rift cannot be easily explained by passive rifting and but is consistent with a plume origin for the Cenozoic rifting, volcanism and plateau uplift in East Africa.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  9. Current kinematics and dynamics of Africa and the East African Rift System

    NASA Astrophysics Data System (ADS)

    Stamps, D. S.; Flesch, L. M.; Calais, E.; Ghosh, A.

    2014-06-01

    Although the East African Rift System (EARS) is an archetype continental rift, the forces driving its evolution remain debated. Some contend buoyancy forces arising from gravitational potential energy (GPE) gradients within the lithosphere drive rifting. Others argue for a major role of the diverging mantle flow associated with the African Superplume. Here we quantify the forces driving present-day continental rifting in East Africa by (1) solving the depth averaged 3-D force balance equations for 3-D deviatoric stress associated with GPE, (2) inverting for a stress field boundary condition that we interpret as originating from large-scale mantle tractions, (3) calculating dynamic velocities due to lithospheric buoyancy forces, lateral viscosity variations, and velocity boundary conditions, and (4) calculating dynamic velocities that result from the stress response of horizontal mantle tractions acting on a viscous lithosphere in Africa and surroundings. We find deviatoric stress associated with lithospheric GPE gradients are ˜8-20 MPa in EARS, and the minimum deviatoric stress resulting from basal shear is ˜1.6 MPa along the EARS. Our dynamic velocity calculations confirm that a force contribution from GPE gradients alone is sufficient to drive Nubia-Somalia divergence and that additional forcing from horizontal mantle tractions overestimates surface kinematics. Stresses from GPE gradients appear sufficient to sustain present-day rifting in East Africa; however, they are lower than the vertically integrated strength of the lithosphere along most of the EARS. This indicates additional processes are required to initiate rupture of continental lithosphere, but once it is initiated, lithospheric buoyancy forces are enough to maintain rifting.

  10. Complete sequence and diversity of a maize-associated Polerovirus in East Africa

    USDA-ARS?s Scientific Manuscript database

    Since 2011-2012, Maize lethal necrosis (MLN) has emerged in East Africa, causing massive yield loss and propelling research to identify viruses and virus populations present in maize. As expected, next generation sequencing (NGS) has revealed diverse and abundant viruses from the family Potyviridae,...

  11. Exon-Enriched Libraries Reveal Large Genic Differences Between Aedes aegypti from Senegal, West Africa, and Populations Outside Africa

    PubMed Central

    Dickson, Laura B.; Campbell, Corey L.; Juneja, Punita; Jiggins, Francis M.; Sylla, Massamba; Black, William C.

    2016-01-01

    Aedes aegypti is one of the most studied mosquito species, and the principal vector of several arboviruses pathogenic to humans. Recently failure to oviposit, low fecundity, and poor egg-to-adult survival were observed when Ae. aegypti from Senegal (SenAae) West Africa were crossed with Ae. aegypti (Aaa) from outside of Africa, and in SenAae intercrosses. Fluorescent in situ hybridization analyses indicated rearrangements on chromosome 1, and pericentric inversions on chromosomes 2 and 3. Herein, high throughput sequencing (HTS) of exon-enriched libraries was used to compare chromosome-wide genetic diversity among Aaa collections from rural Thailand and Mexico, a sylvatic collection from southeastern Senegal (PK10), and an urban collection from western Senegal (Kaolack). Sex-specific polymorphisms were analyzed in Thailand and PK10 to assess genetic differences between sexes. Expected heterozygosity was greatest in SenAae. FST distributions of 15,735 genes among all six pairwise comparisons of the four collections indicated that Mexican and Thailand collections are genetically similar, while FST distributions between PK10 and Kaolack were distinct. All four comparisons of SenAae with Aaa indicated extreme differentiation. FST was uniform between sexes across all chromosomes in Thailand, but were different, especially on the sex autosome 1, in PK10. These patterns correlate with the reproductive isolation noted earlier. We hypothesize that cryptic Ae. aegypti taxa may exist in West Africa, and the large genic differences between Aaa and SenAae detected in the present study have accumulated over a long period following the evolution of chromosome rearrangements in allopatric populations that subsequently cause reproductive isolation when these populations became sympatric. PMID:28007834

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

    ERIC Educational Resources Information Center

    Stambach, Amy

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

  13. Pathophysiology of AAA: heredity vs environment.

    PubMed

    Björck, Martin; Wanhainen, Anders

    2013-01-01

    Abdominal aortic aneurysm (AAA) has a complex pathophysiology, in which both environmental and genetic factors play important roles, the most important being smoking. The recently reported falling prevalence rates of AAA in northern Europe and Australia/New Zeeland are largely explained by healthier smoking habits. Dietary factors and obesity, in particular abdominal obesity, are also of importance. A family history of AAA among first-degree relatives is present in approximately 13% of incident cases. The probability that a monozygotic twin of a person with an AAA has the disease is 24%, 71 times higher than that for a monozygotic twin of a person without AAA. Approximately 1000 SNPs in 100 candidate genes have been studied, and three genome-wide association studies were published, identifying different diverse weak associations. An example of interaction between environmental and genetic factors is the effect of cholesterol, where genetic and dietary factors affect levels of both HDL and LDL. True epigenetic studies have not yet been published. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

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

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

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

    PubMed

    André, F

    2000-02-18

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

  17. Annotated list of Tettigoniidae (Orthoptera) from the East Usambara Mountains, Tanzania and new Tettigoniidae species from East Africa.

    PubMed

    Hemp, Claudia

    2013-12-21

    A list of the Tettigoniidae (Orthoptera) of the East Usambara Mountains is presented and 16 new species are described from East Africa. A total number of 29 Tettigoniidae species is recorded for the East Usambara Mountains. New species are described from the Shimba Hills in Kenya, coastal Tanzania from the Kazimzumbwi forest reserve, Mt Kilimanjaro, the East and West Usambara and Uluguru Mountains in Tanzania, namely in Conocephalinae Afroagraecia pwania n. sp., Afroagraecia shimbaensis n. sp., Afroanthracites discolor n. sp., Afroanthracites jagoi n. sp. and Afroanthracites viridis n. sp., in Meconematinae Afrophisis flagellata n. sp., Afrophisis kisarawe n. sp., Afrophisis mazumbaiensis n. sp. and Afrophisis pseudoflagellata n. sp., in Hexacentrinae Aerotegmina megaloptera n. sp., in Mecopodinae Apteroscirtus cristatus n. sp., and A. planidorsatus n. sp., in Phaneropterinae Gelotopoia amabilis n. sp., and in Pseudophyllinae Cymatomerella pardopunctata n. sp. and Cymatomera viridimaculata n. sp. Seven species are endemic to the East Usambara Mountains which are 25% of the recorded forest-bound bush crickets. The Tettigoniidae fauna is compared between the East Usambara Mountains and Mt Kilimanjaro and mechanisms of speciation discussed in Orthoptera for the area. New Tettigoniidae records are given for Mt Kilimanjaro (Oxyecous apertus Ragge, Tropidonotacris grandis Ragge and Eurycorypha conclusa Hemp).

  18. POLITICAL DEVELOPMENT AND POLITICAL INTEGRATION IN THE ISLAMIC NEAR EAST AND NORTH AFRICA.

    DTIC Science & Technology

    trends in these countries, about the constraints on their foreign policies and about their potential for achieving political stability . More...specifically, this research has been directed at the question of whether the countries of the Near East and North Africa can achieve political stability without

  19. Genetic analysis of abdominal aortic aneurysms (AAA)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    St. Jean, P.L.; Hart, B.K.; Zhang, X.C.

    1994-09-01

    The association between AAA and gender, smoking (SM), hypertension (HTN) and inguinal herniation (IH) was examined in 141 AAA probands and 139 of their 1st degree relatives with aortic exam (36 affected, 103 unaffected). There was no significant difference between age at diagnosis of affecteds and age at exam of unaffecteds. Of 181 males, 142 had AAA; of 99 females, 35 had AAA. Using log-linear modeling AAA was significantly associated at the 5% level with gender, SM and HTN but not IH. The association of AAA with SM and HTN held when males and females were analyzed separately. HTN wasmore » -1.5 times more common in both affected males and females, while SM was 1.5 and 2 times more common in affected males and females, respectively. Tests of association and linkage analyses were performed with relevant candidate genes: 3 COL3A1 polymorphisms (C/T, ALA/THR, AvaII), 2 ELN polymorphisms (SER/GLY, (CA)n), FBN1(TAAA)n, 2 APOB polymorphisms (Xbal,Ins/Del), CLB4B (CA)n, PI and markers D1S243 (CA)n, HPR (CA)n and MFD23(CA)n. The loci were genotyped in > 100 AAA probands and > 95 normal controls. No statistically significant evidence of association at the 5% level was obtained for any of the loci using chi-square test of association. 28 families with 2 or more affecteds were analyzed using the affected pedigree member method (APM) and lod-score analyses. There was no evidence for linkage with any loci using APM. Lod-score analysis under an autosomal recessive model resulted in excluding linkage (lod score < -2) of all loci to AAA at {theta}=0.0. Under an autosomal dominant model, linkage was excluded at {theta}=0.0 to ELN, APOB, CLG4B, D1S243, HPR and MFD23. The various genes previously proposed in AAA pathogenesis are neither associated nor casually related in our study population.« less

  20. Cases of human brucellosis in Sweden linked to Middle East and Africa.

    PubMed

    Garofolo, Giuliano; Fasanella, Antonio; Di Giannatale, Elisabetta; Platone, Ilenia; Sacchini, Lorena; Persiani, Tiziana; Boskani, Talar; Rizzardi, Kristina; Wahab, Tara

    2016-05-17

    Human brucellosis cases are still reported each year in Sweden despite eradication of the disease in animals. Epidemiological investigation has never been conducted to trace back the source of human infection in the country. The purpose of the study was to identify the source of infection for 16 human brucellosis cases that occurred in Sweden, during the period 2008-2012. The isolates were identified as Brucella melitensis and MLVA-16 genotyping revealed 14 different genotypes of East Mediterranean and Africa lineages. We also reported one case of laboratory-acquired brucellosis (LAB) that was shown to be epidemiological linked to one of the cases in the current study. Brucella melitensis was the only species diagnosed, confirming its highest zoonotic potential in the genus Brucella, and MLVA-16 results demonstrated that the cases of brucellosis in Sweden herein investigated, are imported and linked to travel in the Middle East and Africa. Due to its zoonotic concerns, any acute febrile illness linked to recent travel within those regions should be investigated for brucellosis and samples should be processed according to biosafety level 3 regulations.

  1. Dust Tsunamis, Blackouts and 50 deg C: Teaching MATLAB in East Africa

    NASA Astrophysics Data System (ADS)

    Trauth, M. H.

    2016-12-01

    MATLAB is the tool of choice when analyzing earth and environmental data from East Africa. The software and companion toolboxes helps to process satellite images and digital elevation models, to detect trends, cycles, and recurrent, characteristic types of climate transitions in climate time series, and to model the hydrological balance of ancient lakes. The advantage of MATLAB is that the user can do many different types of analyses with the same software, making the software very attractive for young scientists at African universities. Since 2009 we are organizing summer schools on the subject of data analysis with various tools including MATLAB in Ethiopia, Kenya and Tanzania. Throughout the summerschool, participants are instructed by teams of senior researchers, together with young scientists, some of which were participants of an earlier summerschool. The participants are themselves integrated in teaching, depending on previous knowledge, so that the boundary between teachers and learners constantly shifts or even dissolves. From the extraordinarily positive experience, but also the difficulties in teaching data analysis methods with MATLAB in East Africa is reported.

  2. Cretaceous reconstructions of East Antarctica, Africa and Madagascar

    NASA Astrophysics Data System (ADS)

    Marks, K. M.; Tikku, A. A.

    2001-04-01

    Some Cretaceous reconstructions of East Antarctica, Africa, and Madagascar overlap the Mozambique ridge onto the margin of Dronning Maud Land, and others place Madagascar west of the Gunnerus ridge, into the Riiser-Larsen Sea. Our M10Ny (131.9 Ma), M0 (120.4 Ma), 96 Ma, and 34y (83 Ma) marine free-air gravity and topography reconstructions illustrate a solution to the overlap problem and also demonstrate that Madagascar separated from Antarctica east of the Gunnerus ridge. Our reconstructions chronicle the growth of the conjugate Mozambique and Riiser-Larsen Basins created at the Southwest Indian spreading ridge. Well defined spreading corridors, identified by conjugate fracture zones and Mesozoic magnetic anomaly identifications, extend from one basin into the other. We find that the eastern scarp of the Mozambique ridge aligns with the Astrid ridge, and there is no room for Madagascar west of the Gunnerus ridge. The overlap of the Mozambique ridge is solved by taking into account the motion of an independent Mozambique ridge microplate that existed from Chron M11 to circa M2.

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

    PubMed

    Hemp, Claudia

    2016-06-21

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

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

    ERIC Educational Resources Information Center

    Schafer, Shaun T.

    2012-01-01

    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…

  5. The influence of urbanisation on measures of Plasmodium falciparum infection prevalence in East Africa

    PubMed Central

    Omumbo, J.A.; Guerra, C.A.; Hay, S.I.; Snow, R.W.

    2011-01-01

    There is a growing interest in the effects of urbanisation in Africa on Plasmodium falciparum risks and disease outcomes. We undertook a review of published and unpublished literature to identify parasite survey data from communities in East Africa. Data were selected to represent the most reliable and contemporary estimates of infection prevalence and were categorised by urban or rural status using a number of approaches. We identified 329 spatially distinct surveys undertaken since 1980 in the sub-region of which 37 were undertaken in urban settlements and 292 in rural settlements. Overall rural settlements reported significantly higher parasite prevalence among children aged 0–14 than urban settlements (on average 10% higher infection rates; p < 0.05). No urban settlements recorded parasite prevalence in excess of 75%. In areas of East Africa where climatic conditions are likely to support higher parasite transmission, the rural–urban difference was most marked. There was a significant trend towards documenting higher classes of parasite prevalence in rural compared to urban settlements (p < 0.05) and the mean difference between rural and urban samples was 18% (p < 0.001). These results further highlight the need to better define urban extents in Africa in order to capture the non-climatic determinants of infection and disease risk and provide a more informed approach to describing the burden of disease across the continent. PMID:15589793

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

    USDA-ARS?s Scientific Manuscript database

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  12. Structural Elements Regulating AAA+ Protein Quality Control Machines.

    PubMed

    Chang, Chiung-Wen; Lee, Sukyeong; Tsai, Francis T F

    2017-01-01

    Members of the ATPases Associated with various cellular Activities (AAA+) superfamily participate in essential and diverse cellular pathways in all kingdoms of life by harnessing the energy of ATP binding and hydrolysis to drive their biological functions. Although most AAA+ proteins share a ring-shaped architecture, AAA+ proteins have evolved distinct structural elements that are fine-tuned to their specific functions. A central question in the field is how ATP binding and hydrolysis are coupled to substrate translocation through the central channel of ring-forming AAA+ proteins. In this mini-review, we will discuss structural elements present in AAA+ proteins involved in protein quality control, drawing similarities to their known role in substrate interaction by AAA+ proteins involved in DNA translocation. Elements to be discussed include the pore loop-1, the Inter-Subunit Signaling (ISS) motif, and the Pre-Sensor I insert (PS-I) motif. Lastly, we will summarize our current understanding on the inter-relationship of those structural elements and propose a model how ATP binding and hydrolysis might be coupled to polypeptide translocation in protein quality control machines.

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

    PubMed

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

    2012-11-01

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

  14. Molecular phylogeny of the tribe Torini Karaman, 1971 (Actinopterygii: Cypriniformes) from the Middle East and North Africa.

    PubMed

    Borkenhagen, Kai

    2017-02-22

    Freshwater fishes of the cyprinid tribe Torini are widespread in Africa the Middle East and Indomalaya. The relationships of Middle-Eastern Torini are analysed based on mitochondrial markers (Cyt b, ND4) of the majority of relevant species. I present a larely well resolved phylogeny, which confirms the validity of the morphologically defined genera Arabibarbus, Carasobarbus, Mesopotamichthys and Pterocapoeta. The Torini originated in Indomalaya and colonised Africa via the Middle East. Morocco was colonised two times independently, first from sub-Saharan Africa and secondly along the southern margin of the Mediterranean Sea. The Tigris-Euphrates system is an important crossroad for the colonisation of the Jordan River, the Orontes River and the watercourses of the Arabian Peninsula by freshwater fishes. The Jordan lost its connection to the Euphrates earlier than the Orontes. The Arabian Peninsula was colonised from the Tigris-Euphrates system in at least two independent events.

  15. Reconstruction of the East Africa and Antarctica continental margins

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  16. a Heritage Inventory for Documenting Endangered Archaeology in the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Sheldrick, N.; Zerbini, A.

    2017-08-01

    The heritage of the Middle East and North Africa is under growing threat from a variety of factors, including agricultural expansion, urban development, looting, and conflict. Recording and documenting this heritage is therefore a key priority to aid heritage practitioners tasked with protecting sites and evaluating their condition on the ground. The Endangered Archaeology in the Middle East and North Africa (EAMENA) project has developed a methodology for the identification, documentation, analysis, and monitoring of sites across the region to aid heritage professionals in these efforts. The project uses remote sensing techniques along with traditional archaeological research and prospection methods to collect data, which are stored and managed in a custom-designed database adapted from open-source Arches v.3 software, using CIDOC CRM standards and controlled vocabularies. In addition to these activities, the EAMENA project has initiated an international conference series and training workshops to support and establish partnerships with heritage professionals and institutions across the region.

  17. Community-based carbon sequestration in East Africa: Linking science and sustainability

    NASA Astrophysics Data System (ADS)

    Hultman, N. E.

    2004-12-01

    International agreements on climate change have set the stage for an expanding market for greenhouse gas emissions reduction credits. Projects that can generate credits for trading are diverse, but one of the more controversial types involve biological carbon sequestration. For several reasons, most of the activity on these "sinks" projects has been in Latin America and Southeast Asia. Yet people in sub-saharan Africa could benefit from properly implemented projects. This poster will discuss estimates of the potential and risks of such projects in East Africa, and will describe in detail a case study located in central Tanzania and now part of the World Bank's BioCarbon Fund portfolio. Understanding climate variability and risk can effectively link international agreements on climate change, local realities of individual projects, and the characteristics of targeted ecosystems.

  18. The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.

    PubMed

    Elhassan, Nuha; Gebremeskel, Eyoab Iyasu; Elnour, Mohamed Ali; Isabirye, Dan; Okello, John; Hussien, Ayman; Kwiatksowski, Dominic; Hirbo, Jibril; Tishkoff, Sara; Ibrahim, Muntaser E

    2014-01-01

    Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount.

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

    PubMed Central

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

    2011-01-01

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

  20. Physical, psychological, sexual, and systemic abuse of children with disabilities in East Africa: Mapping the evidence.

    PubMed

    Winters, Niall; Langer, Laurenz; Geniets, Anne

    2017-01-01

    Children with disabilities (CWDs) are at a higher risk of being maltreated than are typical children. The evidence base on the abuse of children with disabilities living in low- and middle-income countries is extremely limited but the problem is particularly acute in East Africa. We don't know the types of evidence that exist on this topic. This problem is compounded by the fact that key indicators of disability, such as reliable prevalence rates, are not available currently. This paper addresses this serious problem by mapping the existing evidence-base to document the coverage, patterns, and gaps in existing research on the abuse of children with disabilities in East Africa. An evidence map, following systematic review guidelines, was conducted and included a systematic search, transparent and structured data extraction, and critical appraisal. Health and social science databases (Medline, EMBASE, PsychInfo, Taylor&Francis, Web of Science, and SAGE) were systematically searched for relevant studies. A substantive grey literature search was also conducted. All empirical research on the abuse of CWDs in East Africa was eligible for inclusion: Data on abuse was systematically extracted and the research evidence, following critical appraisal, mapped according to the type of abuse and disability condition, highlighting gaps and patterns in the evidence-base. 6005 studies were identified and screened, of which 177 received a full-text assessment. Of these, 41 studies matched the inclusion criteria. By mapping the available data and reports and systematically assessing their trustworthiness and relevance, we highlight significant gaps in the available evidence base. Clear patterns emerge that show a major data gap and lack of research on sexual abuse of children with disabilities and an identifiable lack of methodological quality in many relevant studies. These make the development of a concerted and targeted research effort to tackle the abuse of children with

  1. Protein quality control in organelles - AAA/FtsH story.

    PubMed

    Janska, Hanna; Kwasniak, Malgorzata; Szczepanowska, Joanna

    2013-02-01

    This review focuses on organellar AAA/FtsH proteases, whose proteolytic and chaperone-like activity is a crucial component of the protein quality control systems of mitochondrial and chloroplast membranes. We compare the AAA/FtsH proteases from yeast, mammals and plants. The nature of the complexes formed by AAA/FtsH proteases and the current view on their involvement in degradation of non-native organellar proteins or assembly of membrane complexes are discussed. Additional functions of AAA proteases not directly connected with protein quality control found in yeast and mammals but not yet in plants are also described shortly. Following an overview of the molecular functions of the AAA/FtsH proteases we discuss physiological consequences of their inactivation in yeast, mammals and plants. The molecular basis of phenotypes associated with inactivation of the AAA/FtsH proteases is not fully understood yet, with the notable exception of those observed in m-AAA protease-deficient yeast cells, which are caused by impaired maturation of mitochondrial ribosomal protein. Finally, examples of cytosolic events affecting protein quality control in mitochondria and chloroplasts are given. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Updates on AAA screening and surveillance

    PubMed

    Theivendran, Mayo; Chuen, Jason

    2018-05-01

    Screening and diagnostic surveillance of latent conditions have a profound impact on public healthcare expenditure and clinical outcomes. Abdominal aortic aneurysm (AAA) remains one of the hallmark pathologies in vascular surgery and an area of intense research interest. This article is the second of two that will outline current areas of controversy and research in AAA disease in order to support a more detailed understanding of issues in managing patients with this condition, and inform the development of Australasian clinical guidelines and health policy. Screening and surveillance of AAA should be evidence-based and follow clinical guidelines; however, advances in treatment technology and epidemiological data have influenced results. Goals of care and cost‑effectiveness should play central parts in screening and surveillance strategies.

  3. Complete sequence and diversity of a maize-associated Polerovirus in East Africa.

    PubMed

    Massawe, Deogracious P; Stewart, Lucy R; Kamatenesi, Jovia; Asiimwe, Theodore; Redinbaugh, Margaret G

    2018-06-01

    Since 2011-2012, Maize lethal necrosis (MLN) has emerged in East Africa, causing massive yield loss and propelling research to identify viruses and virus populations present in maize. As expected, next generation sequencing (NGS) has revealed diverse and abundant viruses from the family Potyviridae, primarily sugarcane mosaic virus (SCMV), and maize chlorotic mottle virus (MCMV) (Tombusviridae), which are known to cause MLN by synergistic co-infection. In addition to these expected viruses, we identified a virus in the genus Polerovirus (family Luteoviridae) in 104/172 samples selected for MLN or other potential virus symptoms from Kenya, Uganda, Rwanda, and Tanzania. This polerovirus (MF974579) nucleotide sequence is 97% identical to maize-associated viruses recently reported in China, termed 'maize yellow mosaic virus' (MaYMV) and maize yellow dwarf virus (MaYMV; KU291101, KU291107, MYDV-RMV2; KT992824); and 99% identical to MaYMV (KY684356) infecting sugarcane and itch grass in Nigeria; 83% identical to a barley-associated polerovirus recently identified in Korea (BVG; KT962089); and 79% identical to the U.S. maize-infecting polerovirus maize yellow dwarf virus (MYDV-RMV; KT992824). Nucleotide sequences from ORF0 of 20 individual East African isolates collected from Kenya, Uganda, Rwanda, and Tanzania shared 98% or higher identity, and were detected in 104/172 (60.5%) of samples collected for virus-like symptoms, indicating extensive prevalence but limited diversity of this virus in East Africa. We refer to this virus as "MYDV-like polerovirus" until symptoms of the virus in maize are known.

  4. East Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  5. m-AAA and i-AAA complexes coordinate to regulate OMA1, the stress-activated supervisor of mitochondrial dynamics.

    PubMed

    Consolato, Francesco; Maltecca, Francesca; Tulli, Susanna; Sambri, Irene; Casari, Giorgio

    2018-04-09

    The proteolytic processing of dynamin-like GTPase OPA1, mediated by the activity of both YME1L1 [intermembrane (i)-AAA protease complex] and OMA1, is a crucial step in the regulation of mitochondrial dynamics. OMA1 is a zinc metallopeptidase of the inner mitochondrial membrane that undergoes pre-activating proteolytic and auto-proteolytic cleavage after mitochondrial import. Here, we identify AFG3L2 [matrix (m) - AAA complex] as the major protease mediating this event, which acts by maturing the 60 kDa pre-pro-OMA1 to the 40 kDa pro-OMA1 form by severing the N-terminal portion without recognizing a specific consensus sequence. Therefore, m - AAA and i - AAA complexes coordinately regulate OMA1 processing and turnover, and consequently control which OPA1 isoforms are present, thus adding new information on the molecular mechanisms of mitochondrial dynamics and neurodegenerative diseases affected by these phenomena.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

  6. A structural analysis of the AAA+ domains in Saccharomyces cerevisiae cytoplasmic dynein

    PubMed Central

    Gleave, Emma S.; Schmidt, Helgo; Carter, Andrew P.

    2014-01-01

    Dyneins are large protein complexes that act as microtubule based molecular motors. The dynein heavy chain contains a motor domain which is a member of the AAA+ protein family (ATPases Associated with diverse cellular Activities). Proteins of the AAA+ family show a diverse range of functionalities, but share a related core AAA+ domain, which often assembles into hexameric rings. Dynein is unusual because it has all six AAA+ domains linked together, in one long polypeptide. The dynein motor domain generates movement by coupling ATP driven conformational changes in the AAA+ ring to the swing of a motile element called the linker. Dynein binds to its microtubule track via a long antiparallel coiled-coil stalk that emanates from the AAA+ ring. Recently the first high resolution structures of the dynein motor domain were published. Here we provide a detailed structural analysis of the six AAA+ domains using our Saccharomycescerevisiae crystal structure. We describe how structural similarities in the dynein AAA+ domains suggest they share a common evolutionary origin. We analyse how the different AAA+ domains have diverged from each other. We discuss how this is related to the function of dynein as a motor protein and how the AAA+ domains of dynein compare to those of other AAA+ proteins. PMID:24680784

  7. NASA Airborne Astronomy Ambassadors (AAA) Professional Development and NASA Connections

    NASA Astrophysics Data System (ADS)

    Backman, D. E.; Clark, C.; Harman, P. K.

    2017-12-01

    NASA's Airborne Astronomy Ambassadors (AAA) program is a three-part professional development (PD) experience for high school physics, astronomy, and earth science teachers. AAA PD consists of: (1) blended learning via webinars, asynchronous content learning, and in-person workshops, (2) a STEM immersion experience at NASA Armstrong's B703 science research aircraft facility in Palmdale, California, and (3) ongoing opportunities for connection with NASA astrophysics and planetary science Subject Matter Experts (SMEs). AAA implementation in 2016-18 involves partnerships between the SETI Institute and seven school districts in northern and southern California. AAAs in the current cohort were selected by the school districts based on criteria developed by AAA program staff working with WestEd evaluation consultants. The selected teachers were then randomly assigned by WestEd to a Group A or B to support controlled testing of student learning. Group A completed their PD during January - August 2017, then participated in NASA SOFIA science flights during fall 2017. Group B will act as a control during the 2017-18 school year, then will complete their professional development and SOFIA flights during 2018. A two-week AAA electromagnetic spectrum and multi-wavelength astronomy curriculum aligned with the Science Framework for California Public Schools and Next Generation Science Standards was developed by program staff for classroom delivery. The curriculum (as well as the AAA's pre-flight PD) capitalizes on NASA content by using "science snapshot" case studies regarding astronomy research conducted by SOFIA. AAAs also interact with NASA SMEs during flight weeks and will translate that interaction into classroom content. The AAA program will make controlled measurements of student gains in standards-based learning plus changes in student attitudes towards STEM, and observe & record the AAAs' implementation of curricular changes. Funded by NASA: NNX16AC51

  8. Seasonal Forecast Skill And Teleconnections Over East Africa

    NASA Astrophysics Data System (ADS)

    MacLeod, D.; Palmer, T.

    2017-12-01

    Many people living in East Africa are significantly exposed to risks arising from climate variability. The region experiences two rainy seasons and poor performance of either or both of these (such as seen recently in 2016/17) reduces agricultural productivity and threatens food security. In combination with other factors this can lead to famine. By utilizing seasonal climate forecasts, preparatory actions can be taken in order to mitigate the risks arising from such climate variability. As part of the project ForPAc: "Towards forecast-based preparedness action", we are working with humanitarian agencies in Kenya to build such early warning systems on subseasonal-to-seasonal timescales. Here, the seasonal predictability and forecast skill of the two East African rainy seasons will be presented. Results from the new ECMWF operational forecasting system SEAS5 will be shown and compared to the previous System 4. Analysis of a new 110 year long atmosphere-only simulation will also be discussed, demonstrating impacts of atmosphere-ocean coupling as well as putting operational forecast skill in a long-term context. Particular focus will be given to the model representation of teleconnections of seasonal climate with global sea surface temperatures; highlighting sources of forecast error and informing future model development.

  9. The upper mantle shear wave velocity structure of East Africa derived from Rayleigh wave tomography

    NASA Astrophysics Data System (ADS)

    O'Donnell, J.; Nyblade, A.; Adams, A. N.; Weeraratne, D. S.; Mulibo, G.; Tugume, F.

    2012-12-01

    An expanded model of the three-dimensional shear wave velocity structure of the upper mantle beneath East Africa has been developed using data from the latest phases of the AfricaArray East African Seismic Experiment in conjunction with data from preceding studies. The combined dataset consists of 331 events recorded on a total of 95 seismic stations spanning Kenya, Uganda, Tanzania, Zambia and Malawi. In this latest study, 149 events were used to determine fundamental mode Rayleigh wave phase velocities at periods ranging from 20 to 182 seconds using the two-plane-wave method. These were subsequently combined with the similarly processed published measurements and inverted for an updated upper mantle three-dimensional shear wave velocity model. Newly imaged features include a substantial fast anomaly in eastern Zambia that may have exerted a controlling influence on the evolution of the Western Rift Branch. Furthermore, there is a suggestion that the Eastern Rift Branch trends southeastward offshore eastern Tanzania.

  10. A structural analysis of the AAA+ domains in Saccharomyces cerevisiae cytoplasmic dynein.

    PubMed

    Gleave, Emma S; Schmidt, Helgo; Carter, Andrew P

    2014-06-01

    Dyneins are large protein complexes that act as microtubule based molecular motors. The dynein heavy chain contains a motor domain which is a member of the AAA+ protein family (ATPases Associated with diverse cellular Activities). Proteins of the AAA+ family show a diverse range of functionalities, but share a related core AAA+ domain, which often assembles into hexameric rings. Dynein is unusual because it has all six AAA+ domains linked together, in one long polypeptide. The dynein motor domain generates movement by coupling ATP driven conformational changes in the AAA+ ring to the swing of a motile element called the linker. Dynein binds to its microtubule track via a long antiparallel coiled-coil stalk that emanates from the AAA+ ring. Recently the first high resolution structures of the dynein motor domain were published. Here we provide a detailed structural analysis of the six AAA+ domains using our Saccharomycescerevisiae crystal structure. We describe how structural similarities in the dynein AAA+ domains suggest they share a common evolutionary origin. We analyse how the different AAA+ domains have diverged from each other. We discuss how this is related to the function of dynein as a motor protein and how the AAA+ domains of dynein compare to those of other AAA+ proteins. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Antibacterial and cytotoxic activity of isoprenylated coumarin mammea A/AA isolated from Mammea africana.

    PubMed

    Canning, Corene; Sun, Shi; Ji, Xiangming; Gupta, Smiti; Zhou, Kequan

    2013-05-02

    The stem bark of Mammea africana is widely distributed in tropical Africa and commonly used in traditional medicine. This study aims to identify the active compound in Mammea africana and to evaluate its antimicrobial and antiproliferative activity. Methanol extract from the bark of the Mammea africana was separated by liquid-liquid extraction, followed by open column chromatography. A principal antimicrobial compound was purified by high performance liquid chromatography (HPLC) and its structure was elucidated by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). The antibacterial activity of the purified compound was determined using the broth microdilution method against 7 common pathogenic bacteria. The compound was also evaluated for cytotoxicity by cell proliferation assay (MTS) using the mouse embryonic fibroblast cell line NIH 3T3 and the non-small cell lung cancer cell line A549. The purified active compound was determined to be mammea A/AA and was found to be highly active against Campylobacter jejuni (MIC=0.5 μg/ml), Streptococcus pneumoniae (MIC=0.25 μg/ml), and Clostridium difficile (MIC=0.25 μg/ml). The compound exhibited significant antiproliferative activities against both NIH 3T3 and A549 cell lines. Mammea A/AA isolated from Mammea africana exerts specific inhibitory activity against Campylobacter jejuni, Streptococcus pneumoniae, and Campylobacter difficile. Mammea A/AA was also found to exhibit significant cytotoxicity against both cancer and normal cell lines. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. A Developmental Assets Approach in East Africa: Can Swahili Measures Capture Adolescent Strengths and Supports?

    ERIC Educational Resources Information Center

    Drescher, Christopher F.; Johnson, Laura R.; Kurz, A. Solomon; Scales, Peter C.; Kiliho, Ray P.

    2018-01-01

    Background: Assets-based approaches are well-suited to youth living in majority world contexts, such as East Africa. However, positive psychology research with African adolescents is rare. One hindering factor is the lack of translated measures for conducting research. Objective: This study builds capacity for positive youth development research…

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

    ERIC Educational Resources Information Center

    Howard, Harry N.

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

  14. Prior Radiological Investigations in 65-Year-Old Men Screened for AAA.

    PubMed

    Meecham, Lewis; Summerour, Virginia; Hobbs, Simon; Newman, Jeremy; Wall, Michael L

    2018-05-01

    The National Health Service abdominal aortic aneurysm screening programme (NAAASP) is now fully operational. Those who have previously been formally investigated for abdominal aortic aneurysm (AAA) are excluded; however, many patients undergo radiological investigation of the abdomen for other reasons. Such practices may find incidental AAA which may be eroding the performance of the NAAASP. We investigated the rates of preinvestigation before invitation to screening in our local AAA screening programme. Electronic patient records were retrospectively reviewed for all patients called between March 2013 and February 2016 in 1 local AAA screening programme. Their records were interrogated to identify any abdominal imaging within 5 years of their invitation to screening. Two thousand six hundred thirty-eight men were invited for screening; of these, 563 (21.3%) had been "prescreened". Median time between prescreening and screening was 19 months (0-60 months). Ultrasound abdomen was the most prevalent at 248 (44.0%). Two thousand two hundred forty-three (85.0%) men attended screening, and 6 (0.27%) were excluded for known AAA. Prevalence of AAA was 1.8% (n = 41). Of these, 15 (36.6%) had prior investigation with 6 (40.0%) having AAA diagnosed. Therefore, 9 (22.0%) had potential missed AAA on "prescreening" (mean diameter 35 mm [30-45], mean time lapse between investigation and screening 21.1 months [1-49]). Incidence of missed aneurysm in the "prescreened" cohort was 1.6% (9/563). Large numbers of men invited for AAA screening have undergone preinvestigation of their abdominal aorta, with 60% of the present AAA being missed. Reliance on incidental detection of AAA would leave many patients undiagnosed in the community-at risk of future rupture. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Fundamental Characteristics of AAA+ Protein Family Structure and Function

    PubMed Central

    2016-01-01

    Many complex cellular events depend on multiprotein complexes known as molecular machines to efficiently couple the energy derived from adenosine triphosphate hydrolysis to the generation of mechanical force. Members of the AAA+ ATPase superfamily (ATPases Associated with various cellular Activities) are critical components of many molecular machines. AAA+ proteins are defined by conserved modules that precisely position the active site elements of two adjacent subunits to catalyze ATP hydrolysis. In many cases, AAA+ proteins form a ring structure that translocates a polymeric substrate through the central channel using specialized loops that project into the central channel. We discuss the major features of AAA+ protein structure and function with an emphasis on pivotal aspects elucidated with archaeal proteins. PMID:27703410

  16. Fundamental Characteristics of AAA+ Protein Family Structure and Function.

    PubMed

    Miller, Justin M; Enemark, Eric J

    2016-01-01

    Many complex cellular events depend on multiprotein complexes known as molecular machines to efficiently couple the energy derived from adenosine triphosphate hydrolysis to the generation of mechanical force. Members of the AAA+ ATPase superfamily (ATPases Associated with various cellular Activities) are critical components of many molecular machines. AAA+ proteins are defined by conserved modules that precisely position the active site elements of two adjacent subunits to catalyze ATP hydrolysis. In many cases, AAA+ proteins form a ring structure that translocates a polymeric substrate through the central channel using specialized loops that project into the central channel. We discuss the major features of AAA+ protein structure and function with an emphasis on pivotal aspects elucidated with archaeal proteins.

  17. AAA-DDD triple hydrogen bond complexes.

    PubMed

    Blight, Barry A; Camara-Campos, Amaya; Djurdjevic, Smilja; Kaller, Martin; Leigh, David A; McMillan, Fiona M; McNab, Hamish; Slawin, Alexandra M Z

    2009-10-07

    Experiment and theory both suggest that the AAA-DDD pattern of hydrogen bond acceptors (A) and donors (D) is the arrangement of three contiguous hydrogen bonding centers that results in the strongest association between two species. Murray and Zimmerman prepared the first example of such a system (complex 3*2) and determined the lower limit of its association constant (K(a)) in CDCl(3) to be 10(5) M(-1) by (1)H NMR spectroscopy (Murray, T. J. and Zimmerman, S. C. J. Am. Chem. Soc. 1992, 114, 4010-4011). The first cationic AAA-DDD pair (3*4(+)) was described by Bell and Anslyn (Bell, D. A. and Anslyn, E. A. Tetrahedron 1995, 51, 7161-7172), with a K(a) > 5 x 10(5) M(-1) in CH(2)Cl(2) as determined by UV-vis spectroscopy. We were recently able to quantify the strength of a neutral AAA-DDD arrangement using a more chemically stable AAA-DDD system, 6*2, which has an association constant of 2 x 10(7) M(-1) in CH(2)Cl(2) (Djurdjevic, S., Leigh, D. A., McNab, H., Parsons, S., Teobaldi, G. and Zerbetto, F. J. Am. Chem. Soc. 2007, 129, 476-477). Here we report on further AA(A) and DDD partners, together with the first precise measurement of the association constant of a cationic AAA-DDD species. Complex 6*10(+)[B(3,5-(CF(3))(2)C(6)H(3))(4)(-)] has a K(a) = 3 x 10(10) M(-1) at RT in CH(2)Cl(2), by far the most strongly bound triple hydrogen bonded system measured to date. The X-ray crystal structure of 6*10(+) with a BPh(4)(-) counteranion shows a planar array of three short (NH...N distances 1.95-2.15 A), parallel (but staggered rather than strictly linear; N-H...N angles 165.4-168.8 degrees), primary hydrogen bonds. These are apparently reinforced, as theory predicts, by close electrostatic interactions (NH-*-N distances 2.78-3.29 A) between each proton and the acceptor atoms of the adjacent primary hydrogen bonds.

  18. Assessing heterogeneity in oligomeric AAA+ machines.

    PubMed

    Sysoeva, Tatyana A

    2017-03-01

    ATPases Associated with various cellular Activities (AAA+ ATPases) are molecular motors that use the energy of ATP binding and hydrolysis to remodel their target macromolecules. The majority of these ATPases form ring-shaped hexamers in which the active sites are located at the interfaces between neighboring subunits. Structural changes initiate in an active site and propagate to distant motor parts that interface and reshape the target macromolecules, thereby performing mechanical work. During the functioning cycle, the AAA+ motor transits through multiple distinct states. Ring architecture and placement of the catalytic sites at the intersubunit interfaces allow for a unique level of coordination among subunits of the motor. This in turn results in conformational differences among subunits and overall asymmetry of the motor ring as it functions. To date, a large amount of structural information has been gathered for different AAA+ motors, but even for the most characterized of them only a few structural states are known and the full mechanistic cycle cannot be yet reconstructed. Therefore, the first part of this work will provide a broad overview of what arrangements of AAA+ subunits have been structurally observed focusing on diversity of ATPase oligomeric ensembles and heterogeneity within the ensembles. The second part of this review will concentrate on methods that assess structural and functional heterogeneity among subunits of AAA+ motors, thus bringing us closer to understanding the mechanism of these fascinating molecular motors.

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

    USGS Publications Warehouse

    Deutsch, Morris

    1975-01-01

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

  20. Biomarkers for AAA: Encouraging steps but clinical relevance still to be delivered.

    PubMed

    Htun, Nay Min; Peter, Karlheinz

    2014-10-01

    Potential biomarkers have been investigated using proteomic studies in a variety of diseases. Some biomarkers have central roles in both diagnosis and monitoring of various disorders in clinical medicine, such as troponins, brain natriuretic peptide, and C-reactive protein. Although several biomarkers have been suggested in human abdominal aortic aneurysm (AAA), reliable markers have been lacking. In this issue, Moxon et al. [Proteomics Clin Appl. 2014, 8, 762-772] undertook a broad and systematic proteomic approach toward identification of biomarkers in a commonly used AAA mouse model (AAA created by angiotensin-II infusion). In this mouse model, apolipoprotein C1 and matrix metalloproteinase-9 were identified as novel biomarkers of stable AAA. This finding represents an important step forward, toward a clinically relevant role of biomarkers in AAA. This also encourages for further studies toward the identification of biomarkers (or their combinations) that can predict AAA progression and rupture, which would represent a major progress in AAA management and would establish an AAA biomarker as a much anticipated clinical tool. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Understanding Air Quality in East Africa: Estimating Biomass Burning and Anthropogenic Influence with Long-Term Measurements

    NASA Astrophysics Data System (ADS)

    DeWitt, L.; Gasore, J.; Rupakheti, M.; Potter, K. E.; Prinn, R. G.

    2017-12-01

    Air pollution is largely unstudied in sub-Saharan Africa, resulting in a large gap in scientific understanding of emissions, atmospheric processes and impacts of air pollutants in this region. The Rwanda Climate Observatory, a joint partnership between MIT and the government of Rwanda, has been measuring ambient concentrations of key long-lived greenhouse gases and short-lived climate-forcing pollutants (CO2, CO, CH4, BC, O3) on the summit of Mt. Mugogo (1.586°S, 29.566°E, 2500 m above sea level) since May 2015. Rwanda is a small, mountainous, and densely populated country in equatorial East Africa currently undergoing rapid development. The location and meteorology of Rwanda is such that emissions transported from both the northern and southern African biomass burning seasons affect BC, CO, and O3 concentrations in Rwanda. Black carbon concentrations during Rwanda's two dry seasons are higher at Mt. Mugogo, a rural site, than in major European cities. Higher BC baseline concentrations at Mugogo are correlated with fire radiative power data for the region acquired with MODIS satellite instrument. Spectral absorption of aerosol measured with a dual-spot aethalometer also varies seasonally, likely due to change in fuel burned and direction of pollution transport to the site. Ozone concentration was found to be higher in air masses from southern Africa than from northern Africa during their respective biomass burning seasons. The higher ozone concentration in air masses from the south could be indicative of more anthropogenic influence as Rwanda is downwind of major East African capitals in this season. During the rainy seasons, local emitting activities (e.g., cooking, driving, trash burning) remain steady, regional biomass burning is low, and transport distances are shorter as rainout of pollution occurs regularly, which allows estimation of local pollution during this time period. Urban PM2.5 measurements in the capital city of Kigali and from the neighboring

  2. AAAS: Politics. . . and Science

    ERIC Educational Resources Information Center

    Science News, 1978

    1978-01-01

    Reviews topics discussed during the American Association for the Advancement of Science (AAAS) meeting held in Washington, D.C. Topics included: the equal rights amendment, laetrile, nuclear radiation hazards, sociobiology, and various science topics. (SL)

  3. U.S. Students Study Abroad in the Middle East/North Africa: Factors Influencing Growing Numbers

    ERIC Educational Resources Information Center

    Lane-Toomey, Cara K.; Lane, Shannon R.

    2013-01-01

    The political events of the last decade and the Arab Spring have made it more important than ever for Americans to understand the language, culture, and history of the Middle East/North Africa (MENA) region. Study abroad is one important method that can significantly increase American students' understanding of the Arabic language and the culture…

  4. Electron cryomicroscopy structure of a membrane-anchored mitochondrial AAA protease.

    PubMed

    Lee, Sukyeong; Augustin, Steffen; Tatsuta, Takashi; Gerdes, Florian; Langer, Thomas; Tsai, Francis T F

    2011-02-11

    FtsH-related AAA proteases are conserved membrane-anchored, ATP-dependent molecular machines, which mediate the processing and turnover of soluble and membrane-embedded proteins in eubacteria, mitochondria, and chloroplasts. Homo- and hetero-oligomeric proteolytic complexes exist, which are composed of homologous subunits harboring an ATPase domain of the AAA family and an H41 metallopeptidase domain. Mutations in subunits of mitochondrial m-AAA proteases have been associated with different neurodegenerative disorders in human, raising questions on the functional differences between homo- and hetero-oligomeric AAA proteases. Here, we have analyzed the hetero-oligomeric yeast m-AAA protease composed of homologous Yta10 and Yta12 subunits. We combined genetic and structural approaches to define the molecular determinants for oligomer assembly and to assess functional similarities between Yta10 and Yta12. We demonstrate that replacement of only two amino acid residues within the metallopeptidase domain of Yta12 allows its assembly into homo-oligomeric complexes. To provide a molecular explanation, we determined the 12 Å resolution structure of the intact yeast m-AAA protease with its transmembrane domains by electron cryomicroscopy (cryo-EM) and atomic structure fitting. The full-length m-AAA protease has a bipartite structure and is a hexamer in solution. We found that residues in Yta12, which facilitate homo-oligomerization when mutated, are located at the interface between neighboring protomers in the hexamer ring. Notably, the transmembrane and intermembrane space domains are separated from the main body, creating a passage on the matrix side, which is wide enough to accommodate unfolded but not folded polypeptides. These results suggest a mechanism regarding how proteins are recognized and degraded by m-AAA proteases.

  5. m-AAA proteases, mitochondrial calcium homeostasis and neurodegeneration

    PubMed Central

    Patron, Maria; Sprenger, Hans-Georg; Langer, Thomas

    2018-01-01

    The function of mitochondria depends on ubiquitously expressed and evolutionary conserved m-AAA proteases in the inner membrane. These ATP-dependent peptidases form hexameric complexes built up of homologous subunits. AFG3L2 subunits assemble either into homo-oligomeric isoenzymes or with SPG7 (paraplegin) subunits into hetero-oligomeric proteolytic complexes. Mutations in AFG3L2 are associated with dominant spinocerebellar ataxia (SCA28) characterized by the loss of Purkinje cells, whereas mutations in SPG7 cause a recessive form of hereditary spastic paraplegia (HSP7) with motor neurons of the cortico-spinal tract being predominantly affected. Pleiotropic functions have been assigned to m-AAA proteases, which act as quality control and regulatory enzymes in mitochondria. Loss of m-AAA proteases affects mitochondrial protein synthesis and respiration and leads to mitochondrial fragmentation and deficiencies in the axonal transport of mitochondria. Moreover m-AAA proteases regulate the assembly of the mitochondrial calcium uniporter (MCU) complex. Impaired degradation of the MCU subunit EMRE in AFG3L2-deficient mitochondria results in the formation of deregulated MCU complexes, increased mitochondrial calcium uptake and increased vulnerability of neurons for calcium-induced cell death. A reduction of calcium influx into the cytosol of Purkinje cells rescues ataxia in an AFG3L2-deficient mouse model. In this review, we discuss the relationship between the m-AAA protease and mitochondrial calcium homeostasis and its relevance for neurodegeneration and describe a novel mouse model lacking MCU specifically in Purkinje cells. Our results pledge for a novel view on m-AAA proteases that integrates their pleiotropic functions in mitochondria to explain the pathogenesis of associated neurodegenerative disorders. PMID:29451229

  6. m-AAA proteases, mitochondrial calcium homeostasis and neurodegeneration.

    PubMed

    Patron, Maria; Sprenger, Hans-Georg; Langer, Thomas

    2018-03-01

    The function of mitochondria depends on ubiquitously expressed and evolutionary conserved m-AAA proteases in the inner membrane. These ATP-dependent peptidases form hexameric complexes built up of homologous subunits. AFG3L2 subunits assemble either into homo-oligomeric isoenzymes or with SPG7 (paraplegin) subunits into hetero-oligomeric proteolytic complexes. Mutations in AFG3L2 are associated with dominant spinocerebellar ataxia (SCA28) characterized by the loss of Purkinje cells, whereas mutations in SPG7 cause a recessive form of hereditary spastic paraplegia (HSP7) with motor neurons of the cortico-spinal tract being predominantly affected. Pleiotropic functions have been assigned to m-AAA proteases, which act as quality control and regulatory enzymes in mitochondria. Loss of m-AAA proteases affects mitochondrial protein synthesis and respiration and leads to mitochondrial fragmentation and deficiencies in the axonal transport of mitochondria. Moreover m-AAA proteases regulate the assembly of the mitochondrial calcium uniporter (MCU) complex. Impaired degradation of the MCU subunit EMRE in AFG3L2-deficient mitochondria results in the formation of deregulated MCU complexes, increased mitochondrial calcium uptake and increased vulnerability of neurons for calcium-induced cell death. A reduction of calcium influx into the cytosol of Purkinje cells rescues ataxia in an AFG3L2-deficient mouse model. In this review, we discuss the relationship between the m-AAA protease and mitochondrial calcium homeostasis and its relevance for neurodegeneration and describe a novel mouse model lacking MCU specifically in Purkinje cells. Our results pledge for a novel view on m-AAA proteases that integrates their pleiotropic functions in mitochondria to explain the pathogenesis of associated neurodegenerative disorders.

  7. 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

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

    2014-10-01

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    USGS Publications Warehouse

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

    2012-01-01

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

  9. Genetic and antigenic characterization of serotype O FMD viruses from East Africa for the selection of suitable vaccine strain.

    PubMed

    Lloyd-Jones, Katie; Mahapatra, Mana; Upadhyaya, Sasmita; Paton, David J; Babu, Aravindh; Hutchings, Geoff; Parida, Satya

    2017-12-14

    Foot-and-mouth disease (FMD) is endemic in Eastern Africa with circulation of multiple serotypes of the virus in the region. Most of the outbreaks are caused by serotype O followed by serotype A. The lack of concerted FMD control programmes in Africa has provided little incentive for vaccine producers to select vaccines that are tailored to circulating regional isolates creating further negative feedback to deter the introduction of vaccine-based control schemes. In this study a total of 80 serotype O FMD viruses (FMDV) isolated from 1993 to 2012 from East and North Africa were characterized by virus neutralisation tests using bovine antisera to three existing (O/KEN/77/78, O/Manisa and O/PanAsia-2) and three putative (O/EA/2002, O/EA/2009 and O/EA/2010) vaccine strains and by capsid sequencing. Genetically, these viruses were grouped as either of East African origin with subdivision into four topotypes (EA-1, 2, 3 and 4) or of Middle-East South Asian (ME-SA) topotype. The ME-SA topotype viruses were mainly detected in Egypt and Libya reflecting the trade links with the Middle East countries. There was good serological cross-reactivity between the vaccine strains and most of the field isolates analysed, indicating that vaccine selection should not be a major constraint for control of serotype O FMD by vaccination, and that both local and internationally available commercial vaccines could be used. The O/KEN/77/78 vaccine, commonly used in the region, exhibited comparatively lower percent in vitro match against the predominant topotypes (EA-2 and EA-3) circulating in the region whereas O/PanAsia-2 and O/Manisa vaccines revealed broader protection against East African serotype O viruses, even though they genetically belong to the ME-SA topotype. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Mitochondrial AAA proteases--towards a molecular understanding of membrane-bound proteolytic machines.

    PubMed

    Gerdes, Florian; Tatsuta, Takashi; Langer, Thomas

    2012-01-01

    Mitochondrial AAA proteases play an important role in the maintenance of mitochondrial proteostasis. They regulate and promote biogenesis of mitochondrial proteins by acting as processing enzymes and ensuring the selective turnover of misfolded proteins. Impairment of AAA proteases causes pleiotropic defects in various organisms including neurodegeneration in humans. AAA proteases comprise ring-like hexameric complexes in the mitochondrial inner membrane and are functionally conserved from yeast to man, but variations are evident in the subunit composition of orthologous enzymes. Recent structural and biochemical studies revealed how AAA proteases degrade their substrates in an ATP dependent manner. Intersubunit coordination of the ATP hydrolysis leads to an ordered ATP hydrolysis within the AAA ring, which ensures efficient substrate dislocation from the membrane and translocation to the proteolytic chamber. In this review, we summarize recent findings on the molecular mechanisms underlying the versatile functions of mitochondrial AAA proteases and their relevance to those of the other AAA+ machines. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  12. Towards the prediction of the East Africa short rains based on sea-surface temperature-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Mutai, C. C.; Ward, M. N.; Colman, A. W.

    1998-07-01

    It is shown that the July-September sea-surface temperature (SST) pattern contains moderately strong relationships with the October-December (OND) seasonal rainfall total averaged across East Africa 15°S-5°N, 30°-41.25°E. The relations can be described by using three rotated global SST empirical orthogonal functions (EOFs), mainly measuring aspects of SST patterns in the tropical Pacific (related to El Niño/Southern Oscillation), tropical Indian and, to a lesser extent, tropical Atlantic. Confidence in the relationships is raised because the three EOFs correlate significantly with OND near-surface divergence over the tropical Pacific, Indian and Atlantic Oceans (extending into Northern mid-latitudes), as well as with the rainfall in East Africa and also with rainfall across southern and western tropical Africa.For the East African region, multiple linear regression (MLR) and linear discriminant analysis prediction models are tested. The predictors are pre-rainfall season values of the three rotated SST EOFs. The predictors use information through September. Validating MLR hindcasts using a 1945-1966 (1967-1988) training period and a 1967-1988 (1945-1966) testing period between 30 to 60% of the area-averaged rainfall variance is explained. To achieve unbiased estimates of the expected skill of a forecast system, it is safest to keep model training and testing periods completely separate. The above strategy achieves this in the most important step of ensuring that the models fit the SST predictors to the rainfall predictand using years independent of the testing period. However, the EOFs were calculated over 1901-1980, so for hindcasts prior to 1981, the EOFs describe the SST variability a little better than could be achieved in real-time, which could inflate skill estimates. Tests in the years 1981-1994, independent of the 1901-1980 eigenvector analysis period, do produce similar levels of skill, but a few more forecast years are needed to confirm this result

  13. The Somalian earthquakes of May, 1980, East Africa

    NASA Astrophysics Data System (ADS)

    Ruegg, J. C.; Lépine, J. C.; Tarantola, A.; Lévêque, J. J.

    1981-04-01

    A seismic crisis, with a mb = 5.3 main shock, occured in the Somali Republic, East Africa (10°N, 43°E) from April to November 1980. Up to 2000 earthquakes with ML > 2 have been recorded during this period. This earthquake sequence is of particular interest because it occured 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 by the first one. These data show that the 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.

  14. Phylogeographic reconstruction of African yellow fever virus isolates indicates recent simultaneous dispersal into east and west Africa.

    PubMed

    Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B; Barrett, Alan D T

    2013-01-01

    Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease.

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

    ERIC Educational Resources Information Center

    Mtebe, Joel S.; Raisamo, Roope

    2014-01-01

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

  16. Genomic adaptation of admixed dairy cattle in East Africa

    PubMed Central

    Kim, Eui-Soo; Rothschild, Max F.

    2014-01-01

    Dairy cattle in East Africa imported from the U.S. and Europe have been adapted to new environments. In small local farms, cattle have generally been maintained by crossbreeding that could increase survivability under a severe environment. Eventually, genomic ancestry of a specific breed will be nearly fixed in genomic regions of local breeds or crossbreds when it is advantageous for survival or production in harsh environments. To examine this situation, 25 Friesians and 162 local cattle produced by crossbreeding of dairy breeds in Kenya were sampled and genotyped using 50K SNPs. Using principal component analysis (PCA), the admixed local cattle were found to consist of several imported breeds, including Guernsey, Norwegian Red, and Holstein. To infer the influence of parental breeds on genomic regions, local ancestry mapping was performed based on the similarity of haplotypes. As a consequence, it appears that no genomic region has been under the complete influence of a specific parental breed. Nonetheless, the ancestry of Holstein-Friesians was substantial in most genomic regions (>80%). Furthermore, we examined the frequency of the most common haplotypes from parental breeds that have changed substantially in Kenyan crossbreds during admixture. The frequency of these haplotypes from parental breeds, which were likely to be selected in temperate regions, has deviated considerably from expected frequency in 11 genomic regions. Additionally, extended haplotype homozygosity (EHH) based methods were applied to identify the regions responding to recent selection in crossbreds, called candidate regions, resulting in seven regions that appeared to be affected by Holstein-Friesians. However, some signatures of selection were less dependent on Holsteins-Friesians, suggesting evidence of adaptation in East Africa. The analysis of local ancestry is a useful approach to understand the detailed genomic structure and may reveal regions of the genome required for specialized

  17. Meiotic Clade AAA ATPases: Protein Polymer Disassembly Machines.

    PubMed

    Monroe, Nicole; Hill, Christopher P

    2016-05-08

    Meiotic clade AAA ATPases (ATPases associated with diverse cellular activities), which were initially grouped on the basis of phylogenetic classification of their AAA ATPase cassette, include four relatively well characterized family members, Vps4, spastin, katanin and fidgetin. These enzymes all function to disassemble specific polymeric protein structures, with Vps4 disassembling the ESCRT-III polymers that are central to the many membrane-remodeling activities of the ESCRT (endosomal sorting complexes required for transport) pathway and spastin, katanin p60 and fidgetin affecting multiple aspects of cellular dynamics by severing microtubules. They share a common domain architecture that features an N-terminal MIT (microtubule interacting and trafficking) domain followed by a single AAA ATPase cassette. Meiotic clade AAA ATPases function as hexamers that can cycle between the active assembly and inactive monomers/dimers in a regulated process, and they appear to disassemble their polymeric substrates by translocating subunits through the central pore of their hexameric ring. Recent studies with Vps4 have shown that nucleotide-induced asymmetry is a requirement for substrate binding to the pore loops and that recruitment to the protein lattice via MIT domains also relieves autoinhibition and primes the AAA ATPase cassettes for substrate binding. The most striking, unifying feature of meiotic clade AAA ATPases may be their MIT domain, which is a module that is found in a wide variety of proteins that localize to ESCRT-III polymers. Spastin also displays an adjacent microtubule binding sequence, and the presence of both ESCRT-III and microtubule binding elements may underlie the recent findings that the ESCRT-III disassembly function of Vps4 and the microtubule-severing function of spastin, as well as potentially katanin and fidgetin, are highly coordinated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Advanced, Analytic, Automated (AAA) Measurement of Engagement During Learning

    PubMed Central

    D’Mello, Sidney; Dieterle, Ed; Duckworth, Angela

    2017-01-01

    It is generally acknowledged that engagement plays a critical role in learning. Unfortunately, the study of engagement has been stymied by a lack of valid and efficient measures. We introduce the advanced, analytic, and automated (AAA) approach to measure engagement at fine-grained temporal resolutions. The AAA measurement approach is grounded in embodied theories of cognition and affect, which advocate a close coupling between thought and action. It uses machine-learned computational models to automatically infer mental states associated with engagement (e.g., interest, flow) from machine-readable behavioral and physiological signals (e.g., facial expressions, eye tracking, click-stream data) and from aspects of the environmental context. We present15 case studies that illustrate the potential of the AAA approach for measuring engagement in digital learning environments. We discuss strengths and weaknesses of the AAA approach, concluding that it has significant promise to catalyze engagement research. PMID:29038607

  19. Advanced, Analytic, Automated (AAA) Measurement of Engagement During Learning.

    PubMed

    D'Mello, Sidney; Dieterle, Ed; Duckworth, Angela

    2017-01-01

    It is generally acknowledged that engagement plays a critical role in learning. Unfortunately, the study of engagement has been stymied by a lack of valid and efficient measures. We introduce the advanced, analytic, and automated (AAA) approach to measure engagement at fine-grained temporal resolutions. The AAA measurement approach is grounded in embodied theories of cognition and affect, which advocate a close coupling between thought and action. It uses machine-learned computational models to automatically infer mental states associated with engagement (e.g., interest, flow) from machine-readable behavioral and physiological signals (e.g., facial expressions, eye tracking, click-stream data) and from aspects of the environmental context. We present15 case studies that illustrate the potential of the AAA approach for measuring engagement in digital learning environments. We discuss strengths and weaknesses of the AAA approach, concluding that it has significant promise to catalyze engagement research.

  20. A roaring trade? The legal trade in Panthera leo bones from Africa to East-Southeast Asia

    PubMed Central

    Loveridge, Andrew J.; Newton, David J.; Macdonald, David W.

    2017-01-01

    The African lion is the only big cat listed on CITES Appendix II, and the only one for which international commercial trade is legal under CITES. The trade in lion body parts, and especially the contentious trade in bones from South Africa to Asia, has raised concerns spanning continents and cultures. Debates were amplified at the 2016 CITES Conference of the Parties (CoP17) when a proposal to up-list lions to Appendix I was not supported and a compromise to keep them on Appendix II, with a bone trade quota for South Africa, was reached instead. CoP17 underscored a need for further information on the lion bone trade and the consequences for lions across the continent. Legal international trade in bones to Asia, allegedly to supply the substitute ‘tiger bone’ market, began in South Africa in February 2008 when the first CITES permits were issued. It was initially unclear the degree to which bones were sourced from captive-origin lions, and whether trade was a threat to wild lion populations. Our original assessment of the legal CITES-permitted lion bone trade from South Africa to East-Southeast Asia was for the period 2008–2011 (published 2015). In this paper, we consolidate new information that has become available for 2012–2016, including CITES reports from other African countries, and data on actual exports for three years to 2016 supplied by a freight forwarding company. Thus, we update the figures on the legal trade in lion bones from Africa to East-Southeast Asia in the period 2008–2016. We also contextualise the basis for global concerns by reviewing the history of the trade and its relation to tigers, poaching and wildlife trafficking. CITES permits issued to export bones escalated from ±314y-1 skeletons from 2008–2011, to ±1312y-1 skeletons from 2013–2015. South Africa was the only legal exporter of bones to Asia until 2013 when Namibia issued permits to export skeletons to Vietnam. While CITES permits to export ±5363 skeletons from Africa

  1. A roaring trade? The legal trade in Panthera leo bones from Africa to East-Southeast Asia.

    PubMed

    Williams, Vivienne L; Loveridge, Andrew J; Newton, David J; Macdonald, David W

    2017-01-01

    The African lion is the only big cat listed on CITES Appendix II, and the only one for which international commercial trade is legal under CITES. The trade in lion body parts, and especially the contentious trade in bones from South Africa to Asia, has raised concerns spanning continents and cultures. Debates were amplified at the 2016 CITES Conference of the Parties (CoP17) when a proposal to up-list lions to Appendix I was not supported and a compromise to keep them on Appendix II, with a bone trade quota for South Africa, was reached instead. CoP17 underscored a need for further information on the lion bone trade and the consequences for lions across the continent. Legal international trade in bones to Asia, allegedly to supply the substitute 'tiger bone' market, began in South Africa in February 2008 when the first CITES permits were issued. It was initially unclear the degree to which bones were sourced from captive-origin lions, and whether trade was a threat to wild lion populations. Our original assessment of the legal CITES-permitted lion bone trade from South Africa to East-Southeast Asia was for the period 2008-2011 (published 2015). In this paper, we consolidate new information that has become available for 2012-2016, including CITES reports from other African countries, and data on actual exports for three years to 2016 supplied by a freight forwarding company. Thus, we update the figures on the legal trade in lion bones from Africa to East-Southeast Asia in the period 2008-2016. We also contextualise the basis for global concerns by reviewing the history of the trade and its relation to tigers, poaching and wildlife trafficking. CITES permits issued to export bones escalated from ±314y-1 skeletons from 2008-2011, to ±1312y-1 skeletons from 2013-2015. South Africa was the only legal exporter of bones to Asia until 2013 when Namibia issued permits to export skeletons to Vietnam. While CITES permits to export ±5363 skeletons from Africa to Asia from

  2. The Weekend Effect in AAA Repair.

    PubMed

    O'Donnell, Thomas F X; Li, Chun; Swerdlow, Nicholas J; Liang, Patric; Pothof, Alexander B; Patel, Virendra I; Giles, Kristina A; Malas, Mahmoud B; Schermerhorn, Marc L

    2018-04-18

    Conflicting reports exist regarding whether patients undergoing surgery on the weekend or later in the week experience worse outcomes. We identified patients undergoing abdominal aortic aneurysm (AAA) repair in the Vascular Quality Initiative between 2009 and 2017 [n = 38,498; 30,537 endovascular aneurysm repair (EVAR) and 7961 open repair]. We utilized mixed effects logistic regression to compare adjusted rates of perioperative mortality based on the day of repair. Tuesday was the most common day for elective repair (22%), Friday for symptomatic repairs (20%), and ruptured aneurysms were evenly distributed. Patients with ruptured aneurysms experienced similar adjusted mortality whether they underwent repair during the week or on weekends. Transfers of ruptured AAA were more common over the weekend. However, patients transferred on the weekend experienced higher adjusted mortality than those transferred during the week (28% vs 21%, P = 0.02), despite the fact that during the week, transferred patients actually experienced lower adjusted mortality than patients treated at the index hospital (21% vs 31%, P < 0.01). Among symptomatic patients, adjusted mortality was higher for those undergoing repair over the weekend than those whose surgeries were delayed until a weekday (7.9% vs 3.1%, P = 0.02). Adjusted mortality in elective cases did not vary across the days of the week. Results were consistent between open and EVAR patients. We found no evidence of a weekend effect for ruptured or symptomatic AAA repair. However, patients with ruptured AAA transferred on the weekend experienced higher mortality than those transferred during the week, suggesting a need for improvement in weekend transfer processes.

  3. Prevalence and Severity of Oral Diseases in the Africa and Middle East Region.

    PubMed

    Abid, A; Maatouk, F; Berrezouga, L; Azodo, C; Uti, O; El-Shamy, H; Oginni, A

    2015-07-01

    This review aims to determine the prevalence and severity of oral health diseases in the Africa and Middle East region (AMER). The profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups. Reliable data are scarce. The prevalence and severity of oral diseases appear to be increasing in the African region, as does associated morbidity. There are substantial differences in inequalities in oral health. Dental caries prevalence is less severe in most African countries than in developed countries, but the high rate of untreated caries reflects the limited resources available and difficulties of access and affordability to essential oral health care services. The prevalence of gingival inflammation is very high in all age groups in several African countries. The prevalence of maxillofacial trauma has increased in many countries, with a wide variation of the incidence and high prevalence of traumatic dental injuries in primary and permanent teeth. Orofacial clefts are among the most common birth defects. Annual incidence of oral cancer is estimated as 25 cases per 100,000 people in Africa. Noma is a major public health problem for the Middle East and North African (MENA) region. Data about human immunodeficiency virus/AIDS are limited, particularly in the MENA region. According to the World Health Organization Regional Committee for Africa report, some fundamental key basic knowledge gaps need to be underlined. They include inequalities in oral health, low priority for oral health, lack of adequate funding, inadequate dental student training, obstacles to medical and dental research, and poor databases. There are very few effective public prevention and oral health promotion programs in the AMER. Universal health coverage is not achievable without scientific research on the effectiveness of health promotion interventions. © International & American Associations for Dental Research 2015.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-05-14

    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.

  6. Summary of the East Africa Training Consortium Biorisk Management Practices and Training Needs Survey

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilder, Julie; Mancini, Giulio M.; Wakabi, Timothy

    A survey was designed to query former Biorisk management (BRM) trainees in the East Africa region about their practices post-training and their perceived future training needs. A subset of those surveyed had been trained as BRM trainers. The survey was conducted to obtain a baseline of BRM practices that can serve as a benchmark for performance monitoring, to identify priorities for future BRM training and to gauge local BRM trainers' abilities to deliver effective training. The survey revealed that less than 50% of the respondents could identify evidence of a BRM system in their institute. Coaching and mentoring by BRMmore » experts was identified as being of highest benefit to enable success as BRM practitioners. Local trainers reached 1538 trainees in the previous year and reported that trainings positively correlated with desired BRM behavior. Acknowledgements The authors wish to sincerely thank all of the former biorisk management trainees in East Africa who agreed to participate in this survey. Their candid and honest input was extremely insightful. We also thank Lora Grainger (06826) and Ben Brodsky (Manager, 06824) for careful and critical review of the report. We are grateful for the financial support of the Defense Threat Reduction Agency, Cooperative Biological Engagement Program.« less

  7. The Mitochondrial m-AAA Protease Prevents Demyelination and Hair Greying.

    PubMed

    Wang, Shuaiyu; Jacquemyn, Julie; Murru, Sara; Martinelli, Paola; Barth, Esther; Langer, Thomas; Niessen, Carien M; Rugarli, Elena I

    2016-12-01

    The m-AAA protease preserves proteostasis of the inner mitochondrial membrane. It ensures a functional respiratory chain, by controlling the turnover of respiratory complex subunits and allowing mitochondrial translation, but other functions in mitochondria are conceivable. Mutations in genes encoding subunits of the m-AAA protease have been linked to various neurodegenerative diseases in humans, such as hereditary spastic paraplegia and spinocerebellar ataxia. While essential functions of the m-AAA protease for neuronal survival have been established, its role in adult glial cells remains enigmatic. Here, we show that deletion of the highly expressed subunit AFG3L2 in mature mouse oligodendrocytes provokes early-on mitochondrial fragmentation and swelling, as previously shown in neurons, but causes only late-onset motor defects and myelin abnormalities. In contrast, total ablation of the m-AAA protease, by deleting both Afg3l2 and its paralogue Afg3l1, triggers progressive motor dysfunction and demyelination, owing to rapid oligodendrocyte cell death. Surprisingly, the mice showed premature hair greying, caused by progressive loss of melanoblasts that share a common developmental origin with Schwann cells and are targeted in our experiments. Thus, while both neurons and glial cells are dependant on the m-AAA protease for survival in vivo, complete ablation of the complex is necessary to trigger death of oligodendrocytes, hinting to cell-autonomous thresholds of vulnerability to m-AAA protease deficiency.

  8. Uptake contexts and perceived impacts of HIV testing and counselling among adults in East and Southern Africa: A meta-ethnographic review.

    PubMed

    Witzel, T Charles; Lora, Wezzie; Lees, Shelley; Desmond, Nicola

    2017-01-01

    HIV testing and counselling (HTC) interventions are key to controlling the HIV epidemic in East and Southern Africa where HTC is primarily delivered through voluntary counselling and testing (VCT), provider initiated testing and counselling (PITC), and home-based counselling and testing (HBVCT). Decision making processes around uptake of HTC models must be taken into account when designing new interventions. Counselling in HTC aims to reduce post-test risk taking behaviour and to link individuals to care but its efficacy is unclear. This meta-ethnography aims to understand the contexts of HTC uptake in East and Southern Africa and to analyse the perceived impacts of counselling-based interventions in relation to sexual behaviour and linkage to care. We conducted a systematic literature review of studies investigating HTC in East and Southern Africa from 2003 -April 2014. The search and additional snowballing identified 20 studies that fit our selection criteria. These studies were synthesised through a thematic framework analysis. Twenty qualitative and mixed-methods studies examining impacts of HTC models in East and Southern Africa were meta-synthesised. VCT decisions were made individually while HBVCT decisions were located in family and community units. PITC was associated with coercion from healthcare providers. Low quality counselling components and multiple-intersecting barriers faced by individuals mean that counselling in HTC was not perceived to be effective in reducing post-test risk behaviour and had limited perceived effect in facilitating linkage to care. HBVCT is associated with minimal stigma and should be considered as an area of priority. Counselling components in HTC interventions were effective in transmitting information about HIV and sexual risk, but were perceived as ineffective in addressing the broader personal circumstances preventing sexual behaviour change and modulating access to care.

  9. Uptake contexts and perceived impacts of HIV testing and counselling among adults in East and Southern Africa: A meta-ethnographic review

    PubMed Central

    Witzel, T. Charles; Lora, Wezzie; Lees, Shelley; Desmond, Nicola

    2017-01-01

    Introduction HIV testing and counselling (HTC) interventions are key to controlling the HIV epidemic in East and Southern Africa where HTC is primarily delivered through voluntary counselling and testing (VCT), provider initiated testing and counselling (PITC), and home-based counselling and testing (HBVCT). Decision making processes around uptake of HTC models must be taken into account when designing new interventions. Counselling in HTC aims to reduce post-test risk taking behaviour and to link individuals to care but its efficacy is unclear. This meta-ethnography aims to understand the contexts of HTC uptake in East and Southern Africa and to analyse the perceived impacts of counselling-based interventions in relation to sexual behaviour and linkage to care. Methods We conducted a systematic literature review of studies investigating HTC in East and Southern Africa from 2003 –April 2014. The search and additional snowballing identified 20 studies that fit our selection criteria. These studies were synthesised through a thematic framework analysis. Results Twenty qualitative and mixed-methods studies examining impacts of HTC models in East and Southern Africa were meta-synthesised. VCT decisions were made individually while HBVCT decisions were located in family and community units. PITC was associated with coercion from healthcare providers. Low quality counselling components and multiple-intersecting barriers faced by individuals mean that counselling in HTC was not perceived to be effective in reducing post-test risk behaviour and had limited perceived effect in facilitating linkage to care. Conclusion HBVCT is associated with minimal stigma and should be considered as an area of priority. Counselling components in HTC interventions were effective in transmitting information about HIV and sexual risk, but were perceived as ineffective in addressing the broader personal circumstances preventing sexual behaviour change and modulating access to care. PMID

  10. Multi-environment selection of small sieve snap beans reduces production constraints in East Africa and subtropical regions

    USDA-ARS?s Scientific Manuscript database

    Common bean rust caused by Uromyces appendiculatus, and heat stress lower the yield and quality of snap beans (Phaseolus vulgaris L.) in East Africa. Four snap bean breeding lines previously selected for broad-spectrum rust resistance (involving Ur-4 and Ur-11 rust genes) and heat tolerance followin...

  11. SURVEY OF BIBLIOGRAPHIES AND REFERENCE WORKS ON ASIA, AFRICA, LATIN AMERICA, RUSSIA, AND EAST EUROPE--AND COMPILATION OF BIBLIOGRAPHIES ON EAST ASIA, SOUTH ASIA AND AFRICA SOUTH OF THE SAHARA FOR UNDERGRADUATE LIBRARIES. INTERIM REPORT, PHASE ONE.

    ERIC Educational Resources Information Center

    MOREHOUSE, WARD

    THE PURPOSE OF THE PROJECT IS TO ASSIST UNDERGRADUATE LIBRARIES IN STRENGTHENING THEIR RESOURCES ON AREAS OUTSIDE THE PERIMETER OF WESTERN CIVILIZATION USUALLY GIVEN LITTLE ATTENTION BY AMERICAN COLLEGES, WITH SPECIAL EMPHASIS ON EAST AND SOUTH ASIA AND AFRICA SOUTH OF THE SAHARA. UNDER THE PROJECT'S FIRST PHASE, A PANEL OF LIBRARY ADVISERS WAS…

  12. APC-PCI complex levels for screening of AAA in patients with peripheral atherosclerosis.

    PubMed

    Zarrouk, Moncef; Keshavarz, Kave; Lindblad, Bengt; Gottsäter, Anders

    2013-11-01

    To evaluate the use of activated protein C-protein C inhibitor (APC-PCI) complex levels for detection of abdominal aortic aneurysm (AAA) in patients with peripheral atherosclerotic disease (PAD). APC-PCI levels and aortic diameter evaluated in 511 PAD patients without previously known AAA followed-up concerning survival for 4.8(0.5) years. AAA was found in 13% of patients. Aortic diameter correlated (r = 0.138; p = 0.002) with APC-PCI levels which were higher (0.40[0.45] vs. 0.30[0.49] μg/l; p = 0.004) in patients with AAA. This difference persisted in multivariate analysis (p = 0.029). A threshold value of APC-PCI ≥0.15 μg/L showed a specificity of 11%, a sensitivity of 97% and a negative predictive value of 96% for an AAA diagnosis. APC-PCI levels were higher in patients with AAA, and showed high sensitivity but low specificity for the diagnosis and can therefore not be considered as a screening tool in PAD patients. An AAA prevalence of 13% in patients with PAD indicates a need for AAA screening within this population.

  13. Inhibition of early AAA formation by aortic intraluminal pentagalloyl glucose (PGG) infusion in a novel porcine AAA model.

    PubMed

    Kloster, Brian O; Lund, Lars; Lindholt, Jes S

    2016-05-01

    The vast majority of abdominal aortic aneurysms found in screening programs are small, and as no effective treatment exits, many will expand until surgery is indicated. Therefore, it remains intriguing to develop a safe and low cost treatment of these small aneurysms, that is able to prevent or delay their expansion. In this study, we investigated whether intraluminal delivered pentagalloyl glucose (PGG) can impair the early AAA development in a porcine model. The infrarenal aorta was exposed in thirty pigs. Twenty underwent an elastase based AAA inducing procedure and ten of these received an additional intraluminal PGG infusion. The final 10 were sham operated and served as controls. All pigs who only had an elastase infusion developed macroscopically expanding AAAs. In pigs treated with an additional PGG infusion the growth rate of the AP-diameter rapidly returned to physiological values as seen in the control group. In the elastase group, histology revealed more or less complete resolution of the elastic lamellae in the media while they were more abundant, coherent and structurally organized in the PGG group. The control group displayed normal physiological growth and histology. In our model, intraluminal delivered PGG is able to penetrate the aortic wall from the inside and impair the early AAA development by stabilizing the elastic lamellae and preserving their integrity. The principle holds a high clinical potential if it can be translated to human conditions, since it, if so, potentially could represent a new drug for stabilizing small abdominal aneurysms.

  14. Phylogeographic Reconstruction of African Yellow Fever Virus Isolates Indicates Recent Simultaneous Dispersal into East and West Africa

    PubMed Central

    Beck, Andrew; Guzman, Hilda; Li, Li; Ellis, Brett; Tesh, Robert B.; Barrett, Alan D. T.

    2013-01-01

    Yellow fever virus (YFV) is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease. PMID:23516640

  15. Establishing an online continuing and professional development library for nurses and midwives in east, central, and southern Africa

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2005-01-01

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

  17. Characterization of the modular design of the autolysin/adhesin Aaa from Staphylococcus aureus.

    PubMed

    Hirschhausen, Nina; Schlesier, Tim; Peters, Georg; Heilmann, Christine

    2012-01-01

    Staphylococcus aureus is a frequent cause of serious and life-threatening infections, such as endocarditis, osteomyelitis, pneumonia, and sepsis. Its adherence to various host structures is crucial for the establishment of diseases. Adherence may be mediated by a variety of adhesins, among them the autolysin/adhesins Atl and Aaa. Aaa is composed of three N-terminal repeated sequences homologous to a lysin motif (LysM) that can confer cell wall attachment and a C-terminally located cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain having bacteriolytic activity in many proteins. Here, we show by surface plasmon resonance that the LysM domain binds to fibrinogen, fibronectin, and vitronectin respresenting a novel adhesive function for this domain. Moreover, we demonstrated that the CHAP domain not only mediates the bacteriolytic activity, but also adherence to fibrinogen, fibronectin, and vitronectin, thus demonstrating for the first time an adhesive function for this domain. Adherence of an S. aureus aaa mutant and the complemented aaa mutant is slightly decreased and increased, respectively, to vitronectin, but not to fibrinogen and fibronectin, which might at least in part result from an increased expression of atl in the aaa mutant. Furthermore, an S. aureus atl mutant that showed enhanced adherence to fibrinogen, fibronectin, and endothelial cells also demonstrated increased aaa expression and production of Aaa. Thus, the redundant functions of Aaa and Atl might at least in part be interchangeable. Lastly, RT-PCR and zymographic analysis revealed that aaa is negatively regulated by the global virulence gene regulators agr and SarA. We identified novel functions for two widely distributed protein domains, LysM and CHAP, i.e. the adherence to the extracellular matrix proteins fibrinogen, fibronectin, and vitronectin. The adhesive properties of Aaa might promote S. aureus colonization of host extracellular matrix and tissue, suggesting a role for

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

    ERIC Educational Resources Information Center

    Mehrah, Golnar

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

  19. A spring forward for hominin evolution in East Africa.

    PubMed

    Cuthbert, Mark O; Ashley, Gail M

    2014-01-01

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

  20. Penetration of Atlantic Walker Circulation Into East Africa During Early to mid-Holocene: Hydrogen Isotope Evidence From Sacred Lake, Mt. Kenya

    NASA Astrophysics Data System (ADS)

    Hou, J.; Russell, J. M.; Huang, Y.

    2007-12-01

    The tropics play a very important role in global climate variability, yet the mechanisms behind the tropical climate variation remain poorly understood. Here, we present a high-resolution, well-dated record from Sacred Lake, Kenya, East Africa. We measured D/H ratios of botryococcenes, a class of highly specific biomarkers produced by freshwater algae ( Botrycoccus braunii) in a sediment core obtained from this open lake. Our main goal is to examine changes in East African rainfall amount and moisture source during the past 18kyr BP. During the late Pleistocene and late Holocene, the hydrogen isotope records track local hydrological variations inferred from numerous lake level and pollen records from the region. However, during the early to mid-Holocene (10-5ka cal yr BP), the D/H values from Sacred Lake were as much as 90 per mil heavier than during the late Pleistocene and late Holocene. If the "amount effect" is the main control on the isotopic compositions of rainfall during the early to mid Holocene, Our data would suggest drier conditions, which is inconsistent with the "African Humid Period" inferred by numerous records of the mid-Holocene. We propose that the high isotopic ratios in precipitation in East Africa during the early to mid-Holocene is due to an eastward shift in the large-scale atmospheric circulation of the tropics. In East Africa, this shift involves a major increase in moisture source from the Atlantic Ocean relative to Indian Ocean. Heavier isotope ratios of precipitation originated from Atlantic Ocean result from the intensive convection and recycling of water vapor over the Congo Basin, as opposed to Indian moisture that traverses dry land masses and losses moisture rapidly. In comparison to the late Holocene, the early to mid-Holocene is characterized by relatively northerly positioning of the ITCZ and intense monsoon systems as well as weak ENSO. These factors combine to shift the walker circulation eastward, allowing the Atlantic

  1. AAA (2010) CAPD clinical practice guidelines: need for an update.

    PubMed

    DeBonis, David A

    2017-09-01

    Review and critique of the clinical value of the AAA CAPD guidance document in light of criteria for credible and useful guidance documents, as discussed by Field and Lohr. A qualitative review of the of the AAA CAPD guidelines using a framework by Field and Lohr to assess their relative value in supporting the assessment and management of CAPD referrals. Relevant literature available through electronic search tools and published texts were used along with the AAA CAPD guidance document and the chapter by Field and Lohr. The AAA document does not meet many of the key requirements discussed by Field and Lohr. It does not reflect the current literature, fails to help clinicians understand for whom auditory processing testing and intervention would be most useful, includes contradictory suggestions which reduce clarity and appears to avoid conclusions that might cast the CAPD construct in a negative light. It also does not include input from diverse affected groups. All of these reduce the document's credibility. The AAA CAPD guidance document will need to be updated and re-conceptualised in order to provide meaningful guidance for clinicians.

  2. Advanced, Analytic, Automated (AAA) Measurement of Engagement during Learning

    ERIC Educational Resources Information Center

    D'Mello, Sidney; Dieterle, Ed; Duckworth, Angela

    2017-01-01

    It is generally acknowledged that engagement plays a critical role in learning. Unfortunately, the study of engagement has been stymied by a lack of valid and efficient measures. We introduce the advanced, analytic, and automated (AAA) approach to measure engagement at fine-grained temporal resolutions. The AAA measurement approach is grounded in…

  3. Molecularly Defined Nanostructures Based on a Novel AAA-DDD Triple Hydrogen-Bonding Motif.

    PubMed

    Papmeyer, Marcus; Vuilleumier, Clément A; Pavan, Giovanni M; Zhurov, Konstantin O; Severin, Kay

    2016-01-26

    A facile and flexible method for the synthesis of a new AAA-DDD triple hydrogen-bonding motif is described. Polytopic supramolecular building blocks with precisely oriented AAA and DDD groups are thus accessible in few steps. These building blocks were used for the assembly of large macrocycles featuring four AAA-DDD interactions and a macrobicyclic complex with a total of six AAA-DDD interactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The m-AAA Protease Associated with Neurodegeneration Limits MCU Activity in Mitochondria.

    PubMed

    König, Tim; Tröder, Simon E; Bakka, Kavya; Korwitz, Anne; Richter-Dennerlein, Ricarda; Lampe, Philipp A; Patron, Maria; Mühlmeister, Mareike; Guerrero-Castillo, Sergio; Brandt, Ulrich; Decker, Thorsten; Lauria, Ines; Paggio, Angela; Rizzuto, Rosario; Rugarli, Elena I; De Stefani, Diego; Langer, Thomas

    2016-10-06

    Mutations in subunits of mitochondrial m-AAA proteases in the inner membrane cause neurodegeneration in spinocerebellar ataxia (SCA28) and hereditary spastic paraplegia (HSP7). m-AAA proteases preserve mitochondrial proteostasis, mitochondrial morphology, and efficient OXPHOS activity, but the cause for neuronal loss in disease is unknown. We have determined the neuronal interactome of m-AAA proteases in mice and identified a complex with C2ORF47 (termed MAIP1), which counteracts cell death by regulating the assembly of the mitochondrial Ca 2+ uniporter MCU. While MAIP1 assists biogenesis of the MCU subunit EMRE, the m-AAA protease degrades non-assembled EMRE and ensures efficient assembly of gatekeeper subunits with MCU. Loss of the m-AAA protease results in accumulation of constitutively active MCU-EMRE channels lacking gatekeeper subunits in neuronal mitochondria and facilitates mitochondrial Ca 2+ overload, mitochondrial permeability transition pore opening, and neuronal death. Together, our results explain neuronal loss in m-AAA protease deficiency by deregulated mitochondrial Ca 2+ homeostasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. An AAA-DDD triply hydrogen-bonded complex easily accessible for supramolecular polymers.

    PubMed

    Han, Yi-Fei; Chen, Wen-Qiang; Wang, Hong-Bo; Yuan, Ying-Xue; Wu, Na-Na; Song, Xiang-Zhi; Yang, Lan

    2014-12-15

    For a complementary hydrogen-bonded complex, when every hydrogen-bond acceptor is on one side and every hydrogen-bond donor is on the other, all secondary interactions are attractive and the complex is highly stable. AAA-DDD (A=acceptor, D=donor) is considered to be the most stable among triply hydrogen-bonded sequences. The easily synthesized and further derivatized AAA-DDD system is very desirable for hydrogen-bonded functional materials. In this case, AAA and DDD, starting from 4-methoxybenzaldehyde, were synthesized with the Hantzsch pyridine synthesis and Friedländer annulation reaction. The association constant determined by fluorescence titration in chloroform at room temperature is 2.09×10(7)  M(-1) . The AAA and DDD components are not coplanar, but form a V shape in the solid state. Supramolecular polymers based on AAA-DDD triply hydrogen bonded have also been developed. This work may make AAA-DDD triply hydrogen-bonded sequences easily accessible for stimuli-responsive materials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Characterization of the Modular Design of the Autolysin/Adhesin Aaa from Staphylococcus Aureus

    PubMed Central

    Hirschhausen, Nina; Schlesier, Tim; Peters, Georg; Heilmann, Christine

    2012-01-01

    Background Staphylococcus aureus is a frequent cause of serious and life-threatening infections, such as endocarditis, osteomyelitis, pneumonia, and sepsis. Its adherence to various host structures is crucial for the establishment of diseases. Adherence may be mediated by a variety of adhesins, among them the autolysin/adhesins Atl and Aaa. Aaa is composed of three N-terminal repeated sequences homologous to a lysin motif (LysM) that can confer cell wall attachment and a C-terminally located cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domain having bacteriolytic activity in many proteins. Methodology/Principal Findings Here, we show by surface plasmon resonance that the LysM domain binds to fibrinogen, fibronectin, and vitronectin respresenting a novel adhesive function for this domain. Moreover, we demonstrated that the CHAP domain not only mediates the bacteriolytic activity, but also adherence to fibrinogen, fibronectin, and vitronectin, thus demonstrating for the first time an adhesive function for this domain. Adherence of an S. aureus aaa mutant and the complemented aaa mutant is slightly decreased and increased, respectively, to vitronectin, but not to fibrinogen and fibronectin, which might at least in part result from an increased expression of atl in the aaa mutant. Furthermore, an S. aureus atl mutant that showed enhanced adherence to fibrinogen, fibronectin, and endothelial cells also demonstrated increased aaa expression and production of Aaa. Thus, the redundant functions of Aaa and Atl might at least in part be interchangeable. Lastly, RT-PCR and zymographic analysis revealed that aaa is negatively regulated by the global virulence gene regulators agr and SarA. Conclusions/Significance We identified novel functions for two widely distributed protein domains, LysM and CHAP, i.e. the adherence to the extracellular matrix proteins fibrinogen, fibronectin, and vitronectin. The adhesive properties of Aaa might promote S. aureus

  7. Role of AAA(+)-proteins in peroxisome biogenesis and function.

    PubMed

    Grimm, Immanuel; Erdmann, Ralf; Girzalsky, Wolfgang

    2016-05-01

    Mutations in the PEX1 gene, which encodes a protein required for peroxisome biogenesis, are the most common cause of the Zellweger spectrum diseases. The recognition that Pex1p shares a conserved ATP-binding domain with p97 and NSF led to the discovery of the extended family of AAA+-type ATPases. So far, four AAA+-type ATPases are related to peroxisome function. Pex6p functions together with Pex1p in peroxisome biogenesis, ATAD1/Msp1p plays a role in membrane protein targeting and a member of the Lon-family of proteases is associated with peroxisomal quality control. This review summarizes the current knowledge on the AAA+-proteins involved in peroxisome biogenesis and function.

  8. Analysis of the summertime buildup of tropospheric ozone abundances over the Middle East and North Africa as observed by the Tropospheric Emission Spectrometer instrument

    NASA Astrophysics Data System (ADS)

    Liu, Jane J.; Jones, Dylan B. A.; Worden, John R.; Noone, David; Parrington, Mark; Kar, Jay

    2009-03-01

    We use the GEOS-Chem chemical transport model to interpret observations of tropospheric ozone from the Tropospheric Emission Spectrometer (TES) satellite instrument in summer 2005. Observations from TES reveal elevated ozone in the middle troposphere (500-400 hPa) across North Africa and the Middle East. Observed ozone abundances in the middle troposphere are at a maximum in summer and a minimum in winter, consistent with the previously predicted summertime "Middle East ozone maximum." This summertime enhancement in ozone is associated with the Arabian and Sahara anticyclones, centered over the Zagros and Atlas Mountains, respectively. These anticyclones isolate the middle troposphere over northeast Africa and the Middle East, with westerlies to the north and easterlies to the south, facilitating the buildup of ozone. Over the Middle East, we find that in situ production and transport from Asia provides comparable contributions of 30-35% to the ozone buildup. Over North Africa, in situ production is dominant (at about 20%), with transport from Asia, North America, and equatorial Africa each contributing about 10-15% to the total ozone. We find that although the eastern Mediterranean is characterized by strong descent in the middle and upper troposphere in summer, transport from the boundary layer accounts for about 25% of the local Middle Eastern contribution to the ozone enhancement in the middle troposphere. This upward transport of boundary layer air is associated with orographic lifting along the Zagros Mountains in Iran and the Asir and Hijaz Mountain ranges in Saudi Arabia, and is consistent with TES observations of deuterated water.

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

    ERIC Educational Resources Information Center

    Khattab, Mohammad Salih

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

  10. A methodology for developing anisotropic AAA phantoms via additive manufacturing.

    PubMed

    Ruiz de Galarreta, Sergio; Antón, Raúl; Cazón, Aitor; Finol, Ender A

    2017-05-24

    An Abdominal Aortic Aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta at least 1.5 times its normal diameter. The criterion of maximum diameter is still used in clinical practice, although numerical studies have demonstrated the importance of biomechanical factors for rupture risk assessment. AAA phantoms could be used for experimental validation of the numerical studies and for pre-intervention testing of endovascular grafts. We have applied multi-material 3D printing technology to manufacture idealized AAA phantoms with anisotropic mechanical behavior. Different composites were fabricated and the phantom specimens were characterized by biaxial tensile tests while using a constitutive model to fit the experimental data. One composite was chosen to manufacture the phantom based on having the same mechanical properties as those reported in the literature for human AAA tissue; the strain energy and anisotropic index were compared to make this choice. The materials for the matrix and fibers of the selected composite are, respectively, the digital materials FLX9940 and FLX9960 developed by Stratasys. The fiber proportion for the composite is equal to 0.15. The differences between the composite behavior and the AAA tissue are small, with a small difference in the strain energy (0.4%) and a maximum difference of 12.4% in the peak Green strain ratio. This work represents a step forward in the application of 3D printing technology for the manufacturing of AAA phantoms with anisotropic mechanical behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Loss of Drosophila i-AAA protease, dYME1L, causes abnormal mitochondria and apoptotic degeneration.

    PubMed

    Qi, Y; Liu, H; Daniels, M P; Zhang, G; Xu, H

    2016-02-01

    Mitochondrial AAA (ATPases Associated with diverse cellular Activities) proteases i-AAA (intermembrane space-AAA) and m-AAA (matrix-AAA) are closely related and have major roles in inner membrane protein homeostasis. Mutations of m-AAA proteases are associated with neuromuscular disorders in humans. However, the role of i-AAA in metazoans is poorly understood. We generated a deletion affecting Drosophila i-AAA, dYME1L (dYME1L(del)). Mutant flies exhibited premature aging, progressive locomotor deficiency and neurodegeneration that resemble some key features of m-AAA diseases. dYME1L(del) flies displayed elevated mitochondrial unfolded protein stress and irregular cristae. Aged dYME1L(del) flies had reduced complex I (NADH/ubiquinone oxidoreductase) activity, increased level of reactive oxygen species (ROS), severely disorganized mitochondrial membranes and increased apoptosis. Furthermore, inhibiting apoptosis by targeting dOmi (Drosophila Htra2/Omi) or DIAP1, or reducing ROS accumulation suppressed retinal degeneration. Our results suggest that i-AAA is essential for removing unfolded proteins and maintaining mitochondrial membrane architecture. Loss of i-AAA leads to the accumulation of oxidative damage and progressive deterioration of membrane integrity, which might contribute to apoptosis upon the release of proapoptotic molecules such as dOmi. Containing ROS level could be a potential strategy to manage mitochondrial AAA protease deficiency.

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

    PubMed Central

    2010-01-01

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

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

    PubMed

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

    2016-02-01

    By 2050, Africa's population is projected to exceed 2 billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of Sub-Saharan Africa, where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant-parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can produce symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe. © 2015 Society of Chemical Industry.

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

    ERIC Educational Resources Information Center

    Rihani, May; Prather, Cynthia J.

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

  15. Smoking prevention and cessation in the Africa and Middle East region: a consensus draft guideline for healthcare providers--executive summary.

    PubMed

    Ali, Ahmed Yousif M; Safwat, Tarek; Onyemelukwe, Geoffrey; Otaibi, Moh'd Amin Al; Amir, Ashraf A; Nawas, Yousef N; Aouina, Hichem; Afif, Moulay Hicham; Bolliger, Chris T

    2012-01-01

    Despite the abundance of scientific evidence confirming the health consequences of smoking and other forms of tobacco use, the tobacco epidemic remains an important public health problem and by 2030 it is predicted that more than 80% of tobacco deaths will be in developing countries. In Africa and the Middle East, many local factors contribute to the initiation and maintenance of tobacco use. Although efforts to reduce the mortality and morbidity associated with smoking and tobacco dependence are underway, there is a need for guidance on how to utilize appropriate tobacco control policies and psychology- and pharmacology-based therapies to counter tobacco dependence as recommended by the Framework Convention on Tobacco Control (FCTC). A group of tobacco cessation experts from public health services and/or academic institutions in Africa and the Middle East participated in a series of four meetings held in Cairo, Cape Town, and Dubai between May 2008 and February 2011 to develop a draft guideline tailored to their region. This article provides the background to the development of this draft smoking cessation guideline and discusses how the recommendations can be implemented and progress monitored to promote both primary prevention and cessation of tobacco use within our countries. The draft guideline for Africa and the Middle East provides an important resource in combating the devastating effects of tobacco use in these regions which can be further localized through engagement with local stakeholders in the countries of the region. Copyright © 2012 S. Karger AG, Basel.

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

    DTIC Science & Technology

    2010-01-01

    and Hygiene INTRODUCTION Rift Valley fever ( RVF ) is a mosquito-borne viral disease with pronounced health and economic impacts on domestic...animals and humans in much of sub-Saharan Africa. 1 The eco- nomic loss from RVF in East Africa is estimated to exceed $60 million because of disruption in...morbidity and mortality in humans. The RVF epizootics and epidemics are closely linked to the occurrence of the warm phase of the El Niño/Southern

  17. Multi-Centre Study on Cardiovascular Risk Management on Patients Undergoing AAA Surveillance.

    PubMed

    Saratzis, A; Dattani, N; Brown, A; Shalhoub, J; Bosanquet, D; Sidloff, D; Stather, P

    2017-07-01

    The risk of cardiovascular events and death in patients with abdominal aortic aneurysms (AAA) is high. Screening has been introduced to reduce AAA related mortality; however, after AAA diagnosis, cardiovascular modification may be as important to patient outcomes as surveillance. The aim of this study was to assess cardiovascular risk reduction in patients with small AAA. Institutional approval was granted for The Vascular and Endovascular Research Network (VERN) to retrospectively collect data pertaining to cardiovascular risk reduction from four tertiary vascular units in England. Patients with small AAA (January 2013-December 2015) were included. Demographic details, postcode, current medications, and smoking status were recorded using a bespoke electronic database and analysed. In a secondary analysis VERN contacted all AAA screening units in England and Wales to assess their current protocols relating to CV protection. In total, 1053 patients were included (mean age 74 ± 9 years, all men). Of these, 745 patients (70.8%) had been prescribed an antiplatelet agent and 787 (74.7%) a statin. Overall, only 666 patients (63.2%) were prescribed both a statin and antiplatelet. Two hundred and sixty eight patients (32.1%) were current smokers and the proportion of patients who continued to smoke decreased with age. Overall, only 401 patients (48.1%) were prescribed a statin, antiplatelet, and had stopped smoking. In the secondary analysis 38 AAA screening units (84% national coverage) replied. Thirty-one units (82%) suggest changes to the patient's prescription; however, none monitor compliance with these recommendations or assess whether the general practitioner has been made aware of the AAA diagnosis or prescription advice. Many patients with small AAA are not prescribed an antiplatelet/statin, and still smoke cigarettes, and therefore remain at high risk of cardiovascular morbidity and mortality. National guidance to ensure this high risk group of patients is

  18. The Governance of Animal Care and Use for Scientific Purposes in Africa and the Middle East.

    PubMed

    Mohr, Bert J; Fakoya, Francis A; Hau, Jann; Souilem, Ouajdi; Anestidou, Lida

    2016-05-01

    Animals are commonly used for scientific purposes in Africa and the Middle East. However, this field is often inadequately regulated, with many countries lacking national legislation, policies, or guidelines for the care and use of animals used for research, testing, or education. This results in an essentially uncontrolled system where scientific quality and animal wellbeing cannot robustly be guaranteed, which may hinder acceptance (i.e., publication) of results by the scientific community and limit public confidence. Though accepted international guidelines and best practice recommendations exist that could be adopted or adapted to meet local needs, the responsible conduct of research and animal welfare may not be prioritized in regions that are affected by instability, poverty, disease, or malnutrition. Some notable exceptions do, however, exist in individual countries or institutions where ethical review processes, oversight of animal health and welfare, the competence of personnel, and other scientific standards are appropriately regulated and implemented. These countries and institutions represent nodes of expertise that could act as platforms of support for surrounding regions in terms of the provision of education, training, and sharing of experience and resources. To make such regional capacity-strengthening efforts sustainable will require regional cooperation, the establishment of regional networks, harmonization of policies, pooled resources, and long-term investment in education, training, and infrastructure. An overarching system is needed to oversee the efficient promotion of scientific and ethical standards and the dissemination of information on laboratory animal science in Africa and the Middle East, while each country should remain able to maintain a system of oversight that reflects its own cultures, traditions, religions, laws, and regulations. This article provides an overview of the governance of the care and use of animals for scientific

  19. Impacts of Climate Change on Malaria Transmission in Africa

    NASA Astrophysics Data System (ADS)

    Eltahir, E. A. B.; Endo, N.; Yamana, T. K.

    2017-12-01

    Malaria is a major vector-borne parasitic disease transmitted to humans by Anopheles spp mosquitoes. Africa is the hotspot for malaria transmission where more than 90% of malaria deaths occur every year. Malaria transmission is an intricate function of climatic factors, which non-linearly affect the development of vectors and parasites. We project that the risk of malaria will increase towards the end of the 21st century in east Africa, but decrease in west Africa. We combine a novel malaria transmission simulator, HYDREMATS, that has been developed based on comprehensive multi-year field surveys both in East Africa and West Africa, and the most reliable climate projections through regional dynamical downscaling and rigorous selection of GCMs from among CMIP5 models. We define a bell-shaped relation between malaria intensity and temperature, centered around a temperature of 30°C. Future risks of malaria are projected for two highly populated regions in Africa: the highlands in East Africa and the fringes of the desert in West Africa. In the highlands of East Africa, temperature is substantially colder than this optimal temperature; warmer future climate exacerbate malaria conditions. In the Sahel fringes in West Africa, temperature is around this optimal temperature; warming is not likely to exacerbate and might even reduce malaria burden. Unlike the highlands of East Africa, which receive significant amounts of annual rainfall, dry conditions also limit malaria transmission in the Sahel fringes in West Africa. This disproportionate risk of malaria due to climate change should guide strategies for climate adaptation over Africa.

  20. Combination of endovascular graft exclusion and drug therapy in AAA with hypertension or hyperglycemia.

    PubMed

    Wang, Dile; Qu, Bihui; He, Tao

    2017-08-01

    The objective of the present study was to evaluate the efficacy of combination of endovascular graft exclusion and drugs for hypertension/hyperglycemia for the treatment of abdominal aortic aneurysm (AAA). We analyzed 156 patients with AAA. Eighty-four patients were hypertensive and 72 were hyperglycemic. After endovascular graft exclusion, hypertensive patients were divided into four groups and treated with cyclopenthiazide, reserpine, propranolol, and placebo respectively. Hyperglycemic patients were divided into three groups and treated with metformin, insulin, and placebo respectively. Body temperature and peripheral blood leukocytes were measured at day 1, 2, 7, and 14 after endovascular graft exclusion. Size of AAAs, blood pressure, and blood sugar were measured again after 1 year. In hypertensive patients, the size of AAAs reduced after endovascular graft exclusion, while the combined treatments with cyclopenthiazide, reserpine, or propranolol helped to reduce blood pressure (blood pressure decrease <10 mmHg (18/21), <10 mmHg (12/21), <10 mmHg (8/21), and <10 mmHg (10/21) in the control group, cyclopenthiazide group, reserpine group, and propranolol group, respectively. AAA size decreased in the control group (P<0.001) and in the other three groups (P<0.0001). Similar results were obtained in hyperglycemic patients. The size of AAAs reduced after endovascular graft exclusion. Combined treatment with Metformin and Insulin reduced blood sugar (control, blood sugar >7.8 mmol/L (22/24), AAA size (P<0.001); metformin, blood sugar >7.8 mmol/L (14/24), AAA size (P<0.0001); insulin, blood sugar >7.8 mmol/L (11/24), AAA size (P<0.0001). Combination of endovascular graft exclusion with medicine is more effective than the former treatment alone for AAA therapy.

  1. Measurement and evaluation of digital cervicography programs in two cervical cancer screening camps in East Africa

    NASA Astrophysics Data System (ADS)

    Peterson, Curtis W.; Mink, Jonah; Levitz, David

    2017-03-01

    Cervical cancer disproportionately affects women living in low- and middle-income countries. To address this global crisis, many governments and NGOs have implemented community-based screening and treatment programs at outreach camps. Here, high volumes of patients are able to access care: screening and diagnosis followed by immediate treatment of precancerous lesions onsite. However, monitoring and evaluation (M&E) of these efforts presents challenges, since each event typically relies on a different health workforce, and refers patients to different facilities for follow up and advanced care. To address these challenges, a digital imaging intervention was deployed at several screening camps in East Africa. Trained nurses screened women using a connected low-cost mobile colposcope built around a smartphone. A decision support job aid was integrated into the app controlling the device, guiding nurses and recording their diagnosis and treatment decisions. Aggregating the data from the job aid allowed M&E of the screening camp in real-time. In this paper, the M&E data from 2 different screening camps in East Africa are compared. Additionally, screening camps are compared to stationary clinics. Differences in the patient screening times, treatment rates, and individual nurse statistics were all documented through the job aid allowing for much improved epidemiological information following outreach events thus enabling targeted program improvements and provider training. Reporting data from screening camps were also shared online via public web pages, facilitating broader dissemination of health needs in specific East African communities, and sparking conversations with regional stakeholders about local disease burden.

  2. Morphotectonic evolution of the central Kenya rift flanks: Implications for late Cenozoic environmental change in East Africa

    NASA Astrophysics Data System (ADS)

    Spiegel, Cornelia; Kohn, Barry P.; Belton, David X.; Gleadow, Andrew J. W.

    2007-05-01

    The Kenya rift valley is the classic example of an active continental rift zone. We report the rift flank cooling history based on a combination of previous apatite fission track (AFT) and new (U-Th)/He (AHe) data. Our results corroborate the Late Cretaceous rapid cooling episode of continent-wide significance revealed previously by AFT dating. Post-Cretaceous cooling of the eastern rift flank was slow with net cooling of <20 °C through much of the Cenozoic. We interpret this cooling style in terms of the absence of significant relief. Samples from the western rift flank and from low elevations of the eastern rift flank reveal a late Neogene cooling episode associated with net cooling of ˜38 °C, indicating that this flank was eroded to a deeper level than that to the east. The late Neogene cooling episode is interpreted as the time of uplift and shaping of the present-day relief of the graben shoulders, which attain elevations of >3400 m in central Kenya. This timing also largely coincides with the uplift of the Western Rift flanks in Uganda and Congo and with the change toward drier conditions and grassland-dominated vegetation in East Africa. We propose that the regional morphotectonic evolution of the Kenyan rift flanks contributed to late Cenozoic environmental change in East Africa, thus superimposing a pronounced local effect on global climate change at that time.

  3. Readily functionalized AAA-DDD triply hydrogen-bonded motifs.

    PubMed

    Tong, Feng; Linares-Mendez, Iamnica J; Han, Yi-Fei; Wisner, James A; Wang, Hong-Bo

    2018-04-25

    Herein we present a new, readily functionalized AAA-DDD hydrogen bond array. A novel AAA monomeric unit (3a-b) was obtained from a two-step synthetic procedure starting with 2-aminonicotinaldehyde via microwave radiation (overall yield of 52-66%). 1H NMR and fluorescence spectroscopy confirmed the complexation event with a calculated association constant of 1.57 × 107 M-1. Likewise, the usefulness of this triple hydrogen bond motif in supramolecular polymerization was demonstrated through viscosity measurements in a crosslinked supramolecular alternating copolymer.

  4. Challenges of diagnosis and management of axial spondyloarthritis in North Africa and the Middle East: An expert consensus.

    PubMed

    Hammoudeh, Mohammed; Abdulaziz, Sultana; Alosaimi, Hanan; Al-Rayes, Hanan; Aldeen Sarakbi, Hussam; Baamer, Matouqa; Baraliakos, Xenofon; Dahou Makhloufi, Chafia; Janoudi, Nahid; Shirazy, Khalid; Sieper, Joachim; Sukhbir, Uppal

    2016-04-01

    Axial spondyloarthritis (SpA) is a spectrum of inflammatory disease with stages characterized by both nonradiographic and radiographic sacroiliitis. Nonradiographic axial SpA is associated with health-related quality-of-life impairment and may progress to ankylosing spondylitis. Axial SpA has a low prevalence in some countries in North Africa and the Middle East, and pooling of data and resources is needed to increase understanding of the regional picture. Early diagnosis and effective treatment are required to reduce disease burden and prevent progression. Anti-TNF therapy is recommended for patients with persistently high disease activity despite conventional treatment, and has been shown to be effective in patients without radiographic damage. Diagnostic delays can be an obstacle to early treatment and appropriate referral strategies are needed. In some countries, restricted access to magnetic resonance imaging and anti-TNF agents presents a challenge. In this article, a group of experts from North Africa and the Middle East evaluated the diagnosis and management of axial SpA with particular reference to this region. © The Author(s) 2016.

  5. Preclinical antivenom-efficacy testing reveals potentially disturbing deficiencies of snakebite treatment capability in East Africa

    PubMed Central

    Oluoch, George O.; Ainsworth, Stuart; Alsolaiss, Jaffer; Bolton, Fiona; Arias, Ana-Silvia; Gutiérrez, José-María; Rowley, Paul; Kalya, Stephen; Ozwara, Hastings; Casewell, Nicholas R.

    2017-01-01

    Background Antivenom is the treatment of choice for snakebite, which annually kills an estimated 32,000 people in sub-Saharan Africa and leaves approximately 100,000 survivors with permanent physical disabilities that exert a considerable socioeconomic burden. Over the past two decades, the high costs of the most polyspecifically-effective antivenoms have sequentially reduced demand, commercial manufacturing incentives and production volumes that have combined to create a continent-wide vacuum of effective snakebite therapy. This was quickly filled with new, less expensive antivenoms, many of which are of untested efficacy. Some of these successfully marketed antivenoms for Africa are inappropriately manufactured with venoms from non-African snakes and are dangerously ineffective. The uncertain efficacy of available antivenoms exacerbates the complexity of designing intervention measures to reduce the burden of snakebite in sub-Saharan Africa. The objective of this study was to preclinically determine the ability of antivenoms available in Kenya to neutralise the lethal effects of venoms from the most medically important snakes in East Africa. Methods We collected venom samples from the most medically important snakes in East Africa and determined their toxicity in a mouse model. Using a ‘gold standard’ comparison protocol, we preclinically tested the comparative venom-neutralising efficacy of four antivenoms available in Kenya with two antivenoms of clinically-proven efficacy. To explain the variant efficacies of these antivenoms we tested the IgG-venom binding characteristics of each antivenom using in vitro IgG titre, avidity and venom-protein specificity assays. We also measured the IgG concentration of each antivenom. Findings None of the six antivenoms are preclinically effective, at the doses tested, against all of the most medically important snakes of the region. The very limited snake polyspecific efficacy of two locally available antivenoms is of

  6. Capacity Building to Support Governmental Meteorological and Agricultural Communities in East Africa

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    There is a recognized need for data to support decision-making and planning in East Africa where people and national economies depend on rain fed agriculture and are vulnerable to a changing climate and extreme weather events. However, capacity to use existing global data stores and transition promising tools is a gap that severely limits the use and adoption of these data and tools. Although most people think of capacity building as simply training, it is really much more than that and has been more thoroughly described in the public health community as…."the process of developing and strengthening the skills, instincts, abilities, processes and resources that organizations and communities need to survive, adapt, and thrive in the fast-changing world." Data and tools from NASA and other providers are often not used as they could be for technical and institutional reasons. On the technical side, there is the perception that global data stores are impenetrable requiring special expertise to access them, even if the data can be accessed, the technical expertise to understand and use the data and tools may be lacking, and there can be a mismatch between science data and existing user tools. On the institutional side, it may be perceived that remote sensing data and tools are too "expensive", support from upper management may be non-existent due to limited resources or lack of interest, and there can be a lack of appreciation of data and statistics in decision making. How do we overcome some of these barriers to advance the use of remote sensing for applications and to ease transition of data and tools to stakeholders? Experience from recent capacity building efforts in East Africa in support of a NASA-SERVIR Applied Science Project to provide estimates of hydrologic extremes tied to crop yield will be discussed.

  7. The peroxisomal AAA ATPase complex prevents pexophagy and development of peroxisome biogenesis disorders

    PubMed Central

    Law, Kelsey B.; Bronte-Tinkew, Dana; Di Pietro, Erminia; Snowden, Ann; Jones, Richard O.; Moser, Ann; Brumell, John H.; Braverman, Nancy

    2017-01-01

    ABSTRACT Peroxisome biogenesis disorders (PBDs) are metabolic disorders caused by the loss of peroxisomes. The majority of PBDs result from mutation in one of 3 genes that encode for the peroxisomal AAA ATPase complex (AAA-complex) required for cycling PEX5 for peroxisomal matrix protein import. Mutations in these genes are thought to result in a defect in peroxisome assembly by preventing the import of matrix proteins. However, we show here that loss of the AAA-complex does not prevent matrix protein import, but instead causes an upregulation of peroxisome degradation by macroautophagy, or pexophagy. The loss of AAA-complex function in cells results in the accumulation of ubiquitinated PEX5 on the peroxisomal membrane that signals pexophagy. Inhibiting autophagy by genetic or pharmacological approaches rescues peroxisome number, protein import and function. Our findings suggest that the peroxisomal AAA-complex is required for peroxisome quality control, whereas its absence results in the selective degradation of the peroxisome. Thus the loss of peroxisomes in PBD patients with mutations in their peroxisomal AAA-complex is a result of increased pexophagy. Our study also provides a framework for the development of novel therapeutic treatments for PBDs. PMID:28521612

  8. The peroxisomal AAA ATPase complex prevents pexophagy and development of peroxisome biogenesis disorders.

    PubMed

    Law, Kelsey B; Bronte-Tinkew, Dana; Di Pietro, Erminia; Snowden, Ann; Jones, Richard O; Moser, Ann; Brumell, John H; Braverman, Nancy; Kim, Peter K

    2017-05-04

    Peroxisome biogenesis disorders (PBDs) are metabolic disorders caused by the loss of peroxisomes. The majority of PBDs result from mutation in one of 3 genes that encode for the peroxisomal AAA ATPase complex (AAA-complex) required for cycling PEX5 for peroxisomal matrix protein import. Mutations in these genes are thought to result in a defect in peroxisome assembly by preventing the import of matrix proteins. However, we show here that loss of the AAA-complex does not prevent matrix protein import, but instead causes an upregulation of peroxisome degradation by macroautophagy, or pexophagy. The loss of AAA-complex function in cells results in the accumulation of ubiquitinated PEX5 on the peroxisomal membrane that signals pexophagy. Inhibiting autophagy by genetic or pharmacological approaches rescues peroxisome number, protein import and function. Our findings suggest that the peroxisomal AAA-complex is required for peroxisome quality control, whereas its absence results in the selective degradation of the peroxisome. Thus the loss of peroxisomes in PBD patients with mutations in their peroxisomal AAA-complex is a result of increased pexophagy. Our study also provides a framework for the development of novel therapeutic treatments for PBDs.

  9. Roles of conserved arginines in ATP-binding domains of AAA+ chaperone ClpB from Thermus thermophilus.

    PubMed

    Yamasaki, Takashi; Nakazaki, Yosuke; Yoshida, Masasuke; Watanabe, Yo-hei

    2011-07-01

    ClpB, a member of the expanded superfamily of ATPases associated with diverse cellular activities (AAA+), forms a ring-shaped hexamer and cooperates with the DnaK chaperone system to reactivate aggregated proteins in an ATP-dependent manner. The ClpB protomer consists of an N-terminal domain, an AAA+ module (AAA-1), a middle domain, and a second AAA+ module (AAA-2). Each AAA+ module contains highly conserved WalkerA and WalkerB motifs, and two arginines (AAA-1) or one arginine (AAA-2). Here, we investigated the roles of these arginines (Arg322, Arg323, and Arg747) of ClpB from Thermus thermophilus in the ATPase cycle and chaperone function by alanine substitution. These mutations did not affect nucleotide binding, but did inhibit the hydrolysis of the bound ATP and slow the threading of the denatured protein through the central pore of the T. thermophilus ClpB ring, which severely impaired the chaperone functions. Previously, it was demonstrated that ATP binding to the AAA-1 module induced motion of the middle domain and stabilized the ClpB hexamer. However, the arginine mutations of the AAA-1 module destabilized the ClpB hexamer, even though ATP-induced motion of the middle domain was not affected. These results indicated that the three arginines are crucial for ATP hydrolysis and chaperone activity, but not for ATP binding. In addition, the two arginines in AAA-1 and the ATP-induced motion of the middle domain independently contribute to the stabilization of the hexamer. © 2011 The Authors Journal compilation © 2011 FEBS.

  10. Regionalization of Emergent Vascular Surgery for Patients With Ruptured AAA Improves Outcomes.

    PubMed

    Warner, Courtney J; Roddy, Sean P; Chang, Benjamin B; Kreienberg, Paul B; Sternbach, Yaron; Taggert, John B; Ozsvath, Kathleen J; Stain, Steven C; Darling, R Clement

    2016-09-01

    Safe and efficient endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (r-AAA) requires advanced infrastructure and surgical expertise not available at all US hospitals. The objective was to assess the impact of regionalizing r-AAA care to centers equipped for both open surgical repair (r-OSR) and EVAR (r-EVAR) by vascular surgeons. A retrospective review of all patients with r-AAA undergoing open or endovascular repair in a 12-hospital region. Patient demographics, transfer status, type of repair, and intraoperative variables were recorded. Outcomes included perioperative morbidity and mortality. Four hundred fifty-one patients with r-AAA were treated from 2002 to 2015. Three hundred twenty-one patients (71%) presented initially to community hospitals (CHs) and 130 (29%) presented to the tertiary medical center (MC). Of the 321 patients presenting to CH, 133 (41%) were treated locally (131 OSR; 2 EVAR) and 188 (59%) were transferred to the MC. In total, 318 patients were treated at the MC (122 OSR; 196 EVAR). At the MC, r-EVAR was associated with a lower mortality rate than r-OSR (20% vs 37%, P = 0.001). Transfer did not influence r-EVAR mortality (20% in r-EVAR presenting to MC vs 20% in r-EVAR transferred, P > 0.2). Overall, r-AAA mortality at the MC was 20% lower than CH (27% vs 46%, P < 0.001). Regionalization of r-AAA repair to centers equipped for both r-EVAR and r-OSR decreased mortality by approximately 20%. Transfer did not impact the mortality of r-EVAR at the tertiary center. Care of r-AAA in the US should be centralized to centers equipped with available technology and vascular surgeons.

  11. On the Impact of Intraluminal Thrombus Mechanical Behavior in AAA Passive Mechanics.

    PubMed

    Riveros, Fabián; Martufi, Giampaolo; Gasser, T Christian; Rodriguez-Matas, Jose F

    2015-09-01

    Intraluminal thrombus (ILT) is a pseudo-tissue that develops from coagulated blood, and is found in most abdominal aortic aneurysms (AAAs) of clinically relevant size. A number of studies have suggested that ILT mechanical characteristics may be related to AAA risk of rupture, even though there is still great controversy in this regard. ILT is isotropic and inhomogeneous and may appear as a soft (single-layered) or stiff (multilayered fibrotic) tissue. This paper aims to investigate how ILT constitution and topology influence the magnitude and location of peak wall stress (PWS). In total 21 patient-specific AAAs (diameter 4.2-5.4 cm) were reconstructed from computer tomography images and biomechanically analyzed using state-of-the-art modeling assumptions. Results indicated that PWS correlated stronger with ILT volume (ρ = 0.44, p = 0.05) and minimum thickness of ILT layer (ρ = 0.73, p = 0.001) than with maximum AAA diameter (ρ = 0.05, p = 0.82). On average PWS was 20% (SD 12%) higher for FE models that used soft instead of stiff ILT models (p < 0.001). PWS location strongly correlated with sites of minimum ILT thickness in the section of maximum AAA diameter and was independent from ILT stiffness. In addition, ILT heterogeneity, i.e., the spatial composition of soft and stiff thrombus tissue, can considerably influence stress in the AAA wall. The present study is limited to identification of influential biomechanical factors, and how its findings translate to an AAA rupture risk assessment remains to be explored by clinical studies.

  12. Cardiovascular risk factor burden in Africa and the Middle East across country income categories: a post hoc analysis of the cross-sectional Africa Middle East Cardiovascular Epidemiological (ACE) study.

    PubMed

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

    2018-01-01

    A significant number of cardiovascular disease (CVD)-related deaths occur in developing countries. An increasing prevalence of CVD is associated with a change in the macro-economy of these countries. In this post hoc analysis, CVD risk factor (CVDRF) prevalence is evaluated across countries based on national income in the Africa and Middle East Region (AfME). Data from the Africa Middle East Cardiovascular Epidemiological (ACE) study were used; a cross-sectional study in 14 AfME countries (94 clinics) from July 2011-April 2012, which evaluated CVDRF prevalence in stable adult outpatients. World Bank definitions were used to classify countries as low-income (LI), lower-middle-income (LMI), upper-middle-income (UMI) or high-income (HI) countries. Four thousand three hundred seventy-eight subjects were recruited where 260 (6%), 1324 (30%), 1509 (35%) and 1285 (29%) were from LI, LMI, UMI, and HI countries, respectively. Of all the CVDRFs evaluated, almost two-thirds of the study population across the national income groups had abdominal obesity and dyslipidemia. Countries in the HI category were associated with a higher prevalence of diabetes (32%), obesity (44%) and smoking (16%). UMI and HI countries were associated with higher clustering of CVDRFs where at least one-third of subjects having four or more CVDRFs. Lower income countries had lower blood pressure control rates and lower percentages of outpatients achieving LDL-cholesterol targets. The burden of CVDRFs in stable outpatients is high across the national income categories in the AfME region, with HI countries showing a higher prevalence of CVDRFs. The high burden in lower income countries is associated with sub-optimal control of dyslipidemia and hypertension. Lowering the CVDRF burden would need specific public health actions in line with positive changes in the macro-economy of these countries. The ACE trial is registered under NCT01243138.

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

    NASA Astrophysics Data System (ADS)

    Swenson, Sean; Wahr, John

    2009-05-01

    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

  14. Identifying patients with AAA with the highest risk following endovascular repair.

    PubMed

    Cadili, Ali; Turnbull, Robert; Hervas-Malo, Marilou; Ghosh, Sunita; Chyczij, Harold

    2012-08-01

    It has been demonstrated that endovascular repair of arterial disease results in reduced perioperative morbidity and mortality compared to open surgical repair. The rates of complications and need for reinterventions, however, have been found to be higher than that in open repair. The purpose of this study was to identify the predictors of endograft complications and mortality in patients undergoing endovascular abdominal aortic aneurysm (AAA) repair; specifically, our aim was to identify a subset of patients with AAA whose risk of periprocedure mortality was so high that they should not be offered endovascular repair. We undertook a prospective review of patients with AAA receiving endovascular therapy at a single institution. Collected variables included age, gender, date of procedure, indication for procedure, size of aneurysm (where applicable), type of endograft used, presence of rupture, American Society of Anesthesiologists (ASA) class, major medical comorbidities, type of anesthesia (general, epidural, or local), length of intensive care unit (ICU) stay, and length of hospital stay. These factors were correlated with the study outcomes (overall mortality, graft complications, morbidity, and reintervention) using univariate and multivariate logistic regression. A total of 199 patients underwent endovascular AAA repair during the study period. The ICU stay, again, was significantly correlated with the primary outcomes (death and graft complications). In addition, length of hospital stay greater than 3 days, also emerged as a statistically significant predictor of graft complications in this subgroup (P = .024). Survival analysis for patients with AAA revealed that age over 85 years and ICU stay were predictive of decreased survival. Statistical analysis for other subgroups of patients (inflammatory AAA or dissection) was not performed due to the small numbers in these subgroups. Patients with AAA greater than 85 years of age are at a greater risk of mortality

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

    USGS Publications Warehouse

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

    2001-01-01

    In this paper we describe a technique for mapping the lateral variation of Lg characteristics such as Lg blockage, efficient Lg propagation, and regions of very high attenuation in the Middle East, North Africa, Europe and the Mediterranean regions. Lg is used in a variety of seismological applications from magnitude estimation to identification of nuclear explosions for monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These applications can give significantly biased results if the Lg phase is reduced or blocked by discontinuous structure or thin crust. Mapping these structures using quantitative techniques for determining Lg amplitude attenuation can break down when the phase is below background noise. In such cases Lg blockage and inefficient propagation zones are often mapped out by hand. With our approach, we attempt to visually simplify this information by imaging crustal structure anomalies that significantly diminish the amplitude of Lg. The visualization of such anomalies is achieved by defining a grid of cells that covers the entire region of interest. We trace Lg rays for each event/ station pair, which is simply the great circle path, and attribute to each cell a value equal to the maximum value of the Lg/P-coda amplitude ratio for all paths traversing that particular cell. The resulting map, from this empirical approach, is easily interpreted in terms of crustal structure and can successfully image small blockage features often missed by analysis of raypaths alone. This map can then be used to screen out events with blocked Lg prior to performing Q tomography, and to avoid using Lg-based methods of event identification for the CTBT in regions where they cannot work. For this study we applied our technique to one of the most tectonically complex regions on the earth. Nearly 9000 earthquake/station raypaths, traversing the vast region comprised of the Middle East, Mediterranean, Southern Europe and Northern Africa, have been

  16. Is There an Enabling Environment for Nutrition-Sensitive Agriculture in East Africa? Stakeholder Perspectives From Ethiopia, Kenya, and Uganda.

    PubMed

    Hodge, Judith; Herforth, Anna; Gillespie, Stuart; Beyero, Mesfin; Wagah, Margaret; Semakula, Richard

    2015-12-01

    There is growing recognition that "nutrition-sensitive" development is necessary to ensure nutrition security and reduce malnutrition. While agriculture has the potential to be a strong driver of malnutrition reduction and serves as the main source of livelihood for approximately two-thirds of East Africa's population, its potential to reduce malnutrition is currently not being realized. Leveraging Agriculture for Nutrition in East Africa is a research study based in Ethiopia, Kenya, and Uganda that seeks to understand the enabling environment necessary for optimizing the contribution of the food and agriculture sector to nutrition outcomes. Its objectives were to explore stakeholder perceptions of nutrition-agriculture linkages, of political and institutional challenges and opportunities, of evidence that is available and influential for policy making, and of key issues with regard to capacity. Open-ended and semistructured interviews were conducted with 53 stakeholders from government, civil society, donors, United Nations organizations, private sector, and research/academic institutions in Ethiopia, Kenya, and Uganda in 2014. Although policy opportunities and contexts are different between the 3 countries, stakeholders identified similar barriers to greater action, including a narrow focus on solely market-oriented and staple crop production, a lack of clarity and incentives within the agriculture sector about improving nutrition and how to translate policy into action, and lack of capacity in human and financial resources. Many actions to improve the nutrition sensitivity of agriculture were mentioned, including crop diversification, value chain activities and improved market access, nutrition education, and reduction in time and labor costs to women. Many opportunities exist to strengthen the impact of agriculture on nutrition in East Africa, but stronger formulation and implementation of policies will require adequate human resources, funds, timely data on

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

    ERIC Educational Resources Information Center

    Bouhlila, Donia Smaali

    2011-01-01

    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…

  18. The Menengai Tuff: A 36 ka widespread tephra and its chronological relevance to Late Pleistocene human evolution in East Africa

    NASA Astrophysics Data System (ADS)

    Blegen, Nick; Brown, Francis H.; Jicha, Brian R.; Binetti, Katie M.; Faith, J. Tyler; Ferraro, Joseph V.; Gathogo, Patrick N.; Richardson, Jonathan L.; Tryon, Christian A.

    2016-11-01

    The East African Rift preserves the world's richest Middle and Late Pleistocene (∼780-12 ka) geological, archaeological and paleontological archives relevant to the emergence of Homo sapiens. This region also provides unparalleled chronological control for many important sites through tephrochronology, the dating and correlation of volcanic ashes as widespread isochronous markers in the geological record. There are many well-characterized Pliocene-Early Pleistocene tephras that are widespread across East Africa. A comparable framework is lacking for the Middle and Late Pleistocene; a period characterized by spatially and temporally complex patterns of climate change, as well as the emergence of modern Homo sapiens and the dispersal of this species across and out of Africa. Unraveling relationships among these spatial and temporally complex phenomena requires a precise chronology. To this end we report the Menengai Tuff, a widespread volcanic ash produced by the large-scale caldera-forming eruption in Kenya and 40Ar/39Ar dated to 35.62 ± 0.26 ka. Geochemical characterization of 565 glass shards from 36 samples by wavelength-dispersive electron probe microanalysis show the Menengai Tuff was deposited over >115,000 km2 and is found in the Baringo, Chalbi, Elmenteita, Nakuru, Olorgesailie, Turkana, and Victoria basins, all of which preserve rich Late Pleistocene paleoenvironmental and archaeological archives. Correlation and dating of the Menengai Tuff demonstrate that it is the most widespread tephra and largest eruption currently known from the Late Pleistocene of East Africa. As such, it is a valuable marker in establishing a Late Pleistocene chronology for paleoclimatic, archeological, and paleontological records relevant to the study of human evolution.

  19. Identification of dust source regions and dust emission trends across North Africa and the Middle East using MISR satellite observations

    NASA Astrophysics Data System (ADS)

    Yu, Y.; Kalashnikova, O. V.; Garay, M. J.; Notaro, M.

    2017-12-01

    Global arid and semi-arid regions supply 1100 to 5000 Tg of Aeolian dust to the atmosphere each year, primarily from North Africa and secondarily from the Middle East. Previous dust source identification methods, based on either remotely-sensed aerosol optical depth (AOD) or dust activity, yield distinct dust source maps, largely due to the limitations in each method and remote-sensing product. Here we apply a novel motion-based method for dust source identification. Dust plume thickness and motion vectors from Multi-angle Imaging SpectroRadiometer (MISR) Cloud Motion Vector Product (CMVP) are examined to identify the regions with high frequency of fast moving-dust plumes, by season. According to MISR CMVP, Bodele depression is the most important dust source across North Africa, consistent with previous studies. Seasonal variability of dust emission across the North Africa is largely driven by climatology of wind and precipitation, featuring the influence of Sharav Cyclone and western African monsoon. In the Middle East, Iraq, Kuwait, and eastern Saudi Arabia are identified as dust source regions, especially during summer months, when the Middle Eastern Shamal wind is active. Furthermore, dust emission trend at each dust source are diagnosed from the motion-based dust source dataset. Increase in dust emission from the Fertile Crescent, Sahel, and eastern African dust sources are identified from MISR CMVP, implying potential contribution from these dust sources to the upward trend in AOD and dust AOD over the Middle East in the 21st century. By comparing with various dust source identification studies, we conclude that the motion-based identification of dust sources is an encouraging alternative and compliment to the AOD-only source identification method.

  20. Assessment of the accuracy of AortaScan for detection of abdominal aortic aneurysm (AAA).

    PubMed

    Abbas, A; Smith, A; Cecelja, M; Waltham, M

    2012-02-01

    AortaScan AMI 9700 is a portable 3D ultrasound device that automatically measures the maximum diameter of the abdominal aorta without the need for a trained sonographer. It is designed to rapidly diagnose or exclude an AAA and may have particular use in screening programs. Our objective was to determine its accuracy to detect AAA. Subjects from our AAA screening and surveillance programs were examined. The aorta was scanned using the AortaScan and computed tomography (CT). Ninety-one subjects underwent imaging (44 AAA on conventional ultrasound surveillance and 47 controls). The largest measurement obtained by AortaScan was compared against the CT-aortic measurement. The mean aortic diameter was 2.8 cm. The CT scan confirmed the diagnosis of AAA in 43 subjects. There was one false positive measurement on conventional ultrasound. AortaScan missed the diagnosis of AAA in eight subjects. There were thirteen false positive measurements. The sensitivity, specificity, positive and negative predictive values were 81%, 72%, 72% and 81% respectively. A device to detect AAA without the need for a trained operator would have potential in a community-based screening programme. The AortaScan, however, lacks adequate sensitivity and significant technical improvement is necessary before it could be considered a replacement for trained screening personnel. Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  1. South Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of South Africa was acquired on May 14, 2000, by NASA's Moderate-resolution Imaging Spectroradiometer, or MODIS. The image was produced using a combination of the sensor's 250-m and 500-m resolution visible wavelength bands. As part of the opening ceremony to begin the joint U.S.-South Africa SAFARI Field Experiment, NASA presented print copies of this image as GIFts to Dr. Ben Ngubane, Minister of Arts, Science and Technology, and Honorable Advocate Ngoaka Ramathlodi, Premier of the Northern Province, South Africa. The area shown in this image encompasses seven capital cities and a number of the region's distinctive geological features can be seen clearly. Toward the northern (top) central part of the image, the browns and tans comprise the Kalahari Desert of southern Botswana. The Tropic of Capricorn runs right through the heart of the Kalahari and the Botswanan capital city of Gaborone sits on the Limpopo River, southeast of the Kalahari. Along the western coastline of the continent is the country of Namibia, where the Namib Desert is framed against the sea by the Kaokoveld Mountains. The Namibian capital of Windhoek is obscured by clouds. Looking closely in the center of the image, the Orange River can be seen running from east to west, demarcating the boundary between Namibia and South Africa. On the southwestern corner of the continent is the hook-like Cape of Good Hope peninsula and Cape Town, the parliamentary capital of South Africa. Running west to east away from Cape Town are the Great Karroo Mountains. The shadow in this image conveys a sense of the very steep grade of the cliffs along the southern coast of South Africa. Port Elizabeth sits on the southeasternmost point of South Africa, and a large phytoplankton bloom can be seen in the water about 100 miles east of there. Moving northward along the east coast, the Drakensberg Mountains are visible. The two small nations of Lesotho and Swaziland are in this region, completely

  2. Revision of the genus Amytta (Orthoptera: Tettigoniidae, Meconematinae) and new species from East Africa.

    PubMed

    Hemp, Claudia; Heller, Klaus-Gerhard

    2017-05-09

    New species of Amytta are described from East Africa. Beside tegminal length, they differ mainly in the structure of the complicated male genitalic organs, notably the last abdominal tergite and cerci. Data on habitat and the acoustics of some species and a key to the species are provided. The songs of all seven Amytta species studied are very similar, consisting of long trills with a syllable repetition rate of about 60 Hz (at 20ºC) and a broad frequency peak in the ultrasound at around 40 kHz. The biogeographic pattern and phylogenetic relationships are discussed for the group.

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

    ERIC Educational Resources Information Center

    Zaalouk, Malak

    2014-01-01

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

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

    PubMed

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

    2015-01-01

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

  5. U.S. Counterterrorism in Sub-Saharan Africa: Understanding Costs, Cultures, and Conflicts

    DTIC Science & Technology

    2008-09-01

    counterterrorism in SSA. Vast and diverse, SSA is divided subregionally into East, West, and Southern Africa so as to highlight the different ...divided into East, West, and Southern Africa subregions so as to highlight the different geographies, histories, threats, and perceptions. Section...subregional approach. It divides SSA into East, West, and Southern Africa to highlight the different geogra- phies, histories, threats, and perceptions

  6. Dosimetric comparison of peripheral NSCLC SBRT using Acuros XB and AAA calculation algorithms.

    PubMed

    Ong, Chloe C H; Ang, Khong Wei; Soh, Roger C X; Tin, Kah Ming; Yap, Jerome H H; Lee, James C L; Bragg, Christopher M

    2017-01-01

    There is a concern for dose calculation in highly heterogenous environments such as the thorax region. This study compares the quality of treatment plans of peripheral non-small cell lung cancer (NSCLC) stereotactic body radiation therapy (SBRT) using 2 calculation algorithms, namely, Eclipse Anisotropic Analytical Algorithm (AAA) and Acuros External Beam (AXB), for 3-dimensional conformal radiation therapy (3DCRT) and volumetric-modulated arc therapy (VMAT). Four-dimensional computed tomography (4DCT) data from 20 anonymized patients were studied using Varian Eclipse planning system, AXB, and AAA version 10.0.28. A 3DCRT plan and a VMAT plan were generated using AAA and AXB with constant plan parameters for each patient. The prescription and dose constraints were benchmarked against Radiation Therapy Oncology Group (RTOG) 0915 protocol. Planning parameters of the plan were compared statistically using Mann-Whitney U tests. Results showed that 3DCRT and VMAT plans have a lower target coverage up to 8% when calculated using AXB as compared with AAA. The conformity index (CI) for AXB plans was 4.7% lower than AAA plans, but was closer to unity, which indicated better target conformity. AXB produced plans with global maximum doses which were, on average, 2% hotter than AAA plans. Both 3DCRT and VMAT plans were able to achieve D95%. VMAT plans were shown to be more conformal (CI = 1.01) and were at least 3.2% and 1.5% lower in terms of PTV maximum and mean dose, respectively. There was no statistically significant difference for doses received by organs at risk (OARs) regardless of calculation algorithms and treatment techniques. In general, the difference in tissue modeling for AXB and AAA algorithm is responsible for the dose distribution between the AXB and the AAA algorithms. The AXB VMAT plans could be used to benefit patients receiving peripheral NSCLC SBRT. Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights

  7. AAA+ Machines of Protein Destruction in Mycobacteria.

    PubMed

    Alhuwaider, Adnan Ali H; Dougan, David A

    2017-01-01

    The bacterial cytosol is a complex mixture of macromolecules (proteins, DNA, and RNA), which collectively are responsible for an enormous array of cellular tasks. Proteins are central to most, if not all, of these tasks and as such their maintenance (commonly referred to as protein homeostasis or proteostasis) is vital for cell survival during normal and stressful conditions. The two key aspects of protein homeostasis are, (i) the correct folding and assembly of proteins (coupled with their delivery to the correct cellular location) and (ii) the timely removal of unwanted or damaged proteins from the cell, which are performed by molecular chaperones and proteases, respectively. A major class of proteins that contribute to both of these tasks are the AAA+ (ATPases associated with a variety of cellular activities) protein superfamily. Although much is known about the structure of these machines and how they function in the model Gram-negative bacterium Escherichia coli , we are only just beginning to discover the molecular details of these machines and how they function in mycobacteria. Here we review the different AAA+ machines, that contribute to proteostasis in mycobacteria. Primarily we will focus on the recent advances in the structure and function of AAA+ proteases, the substrates they recognize and the cellular pathways they control. Finally, we will discuss the recent developments related to these machines as novel drug targets.

  8. Functional Diversity of AAA+ Protease Complexes in Bacillus subtilis

    PubMed Central

    Elsholz, Alexander K. W.; Birk, Marlene S.; Charpentier, Emmanuelle; Turgay, Kürşad

    2017-01-01

    Here, we review the diverse roles and functions of AAA+ protease complexes in protein homeostasis, control of stress response and cellular development pathways by regulatory and general proteolysis in the Gram-positive model organism Bacillus subtilis. We discuss in detail the intricate involvement of AAA+ protein complexes in controlling sporulation, the heat shock response and the role of adaptor proteins in these processes. The investigation of these protein complexes and their adaptor proteins has revealed their relevance for Gram-positive pathogens and their potential as targets for new antibiotics. PMID:28748186

  9. Functional Diversity of AAA+ Protease Complexes in Bacillus subtilis.

    PubMed

    Elsholz, Alexander K W; Birk, Marlene S; Charpentier, Emmanuelle; Turgay, Kürşad

    2017-01-01

    Here, we review the diverse roles and functions of AAA+ protease complexes in protein homeostasis, control of stress response and cellular development pathways by regulatory and general proteolysis in the Gram-positive model organism Bacillus subtilis . We discuss in detail the intricate involvement of AAA+ protein complexes in controlling sporulation, the heat shock response and the role of adaptor proteins in these processes. The investigation of these protein complexes and their adaptor proteins has revealed their relevance for Gram-positive pathogens and their potential as targets for new antibiotics.

  10. Seismicity of the Earth 1900-2013 East African Rift

    USGS Publications Warehouse

    Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio; Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio

    2014-01-01

    Rifting in East Africa is not all coeval; volcanism and faulting have been an ongoing phenomenon on the continent since the Eocene (~45 Ma). The rifting began in northern East Africa, and led to the separation of the Nubia (Africa) and Arabia plates in the Red Sea and Gulf of Aden, and in the Lake Turkana area at the Kenya-Ethiopia border. A Paleogene mantle superplume beneath East Africa caused extension within the Nubia plate, as well as a first order topographic high known as the African superswell which now includes most of the eastern and southern sectors of the Nubia plate. Widespread volcanism erupted onto much of the rising plateau in Ethiopia during the Eocene-Oligocene (45–29 Ma), with chains of volcanoes forming along the rift separating Africa and Arabia. Since the initiation of rifting in northeastern Africa, the system has propagated over 3,000 km to the south and southwest, and it experiences seismicity as a direct result of the extension and active magmatism.

  11. Structural basis for the ATP-independent proteolytic activity of LonB proteases and reclassification of their AAA+ modules.

    PubMed

    An, Young Jun; Na, Jung-Hyun; Kim, Myung-Il; Cha, Sun-Shin

    2015-10-01

    Lon proteases degrade defective or denature proteins as well as some folded proteins for the control of cellular protein quality. There are two types of Lon proteases, LonA and LonB. Each consists of two functional components: a protease component and an ATPase associated with various cellular activities (AAA+ module). Here, we report the 2.03 -resolution crystal structure of the isolated AAA+ module (iAAA+ module) of LonB from Thermococcus onnurineus NA1 (TonLonB). The iAAA+ module, having no bound nucleotide, adopts a conformation virtually identical to the ADP-bound conformation of AAA+ modules in the hexameric structure of TonLonB; this provides insights into the ATP-independent proteolytic activity observed in a LonB protease. Structural comparison of AAA+ modules between LonA and LonB revealed that the AAA+ modules of Lon proteases are separated into two distinct clades depending on their structural features. The AAA+ module of LonB belongs to the -H2 & Ins1 insert clade (HINS clade)- defined for the first time in this study, while the AAA+ module of LonA is a member of the HCLR clade.

  12. Epidemiology of seasonal influenza in the Middle East and North Africa regions, 2010-2016: Circulating influenza A and B viruses and spatial timing of epidemics.

    PubMed

    Caini, Saverio; El-Guerche Séblain, Clotilde; Ciblak, Meral A; Paget, John

    2018-05-01

    There is a limited knowledge regarding the epidemiology of influenza in Middle East and North Africa. We described the patterns of influenza circulation and the timing of seasonal epidemics in countries of Middle East and North Africa. We used virological surveillance data for 2010-2016 from the WHO FluNet database. In each country, we calculated the median proportion of cases that were caused by each virus type and subtype; determined the timing and amplitude of the primary and secondary peaks; and used linear regression models to test for spatial trends in the timing of epidemics. We included 70 532 influenza cases from seventeen countries. Influenza A and B accounted for a median 76.5% and 23.5% of cases in a season and were the dominant type in 86.8% and 13.2% of seasons. The proportion of influenza A cases that were subtyped was 85.9%, while only 4.4% of influenza B cases were characterized. For most countries, influenza seasonality was similar to the Northern Hemisphere, with a single large peak between January and March; exceptions were the countries in the Arabian Peninsula and Jordan, all of which showed clear secondary peaks, and some countries had an earlier primary peak (in November-December in Bahrain and Qatar). The direction of the timing of influenza activity was east to west and south to north in 2012-2013 and 2015-2016, and west to east in 2014-2015. The epidemiology of influenza is generally uniform in countries of Middle East and North Africa, with influenza B playing an important role in the seasonal disease burden. © 2018 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  13. The AAA protein spastin possesses two levels of basal ATPase activity.

    PubMed

    Fan, Xiangyu; Lin, Zhijie; Fan, Guanghui; Lu, Jing; Hou, Yongfei; Habai, Gulijiazi; Sun, Linyue; Yu, Pengpeng; Shen, Yuequan; Wen, Maorong; Wang, Chunguang

    2018-05-01

    The AAA ATPase spastin is a microtubule-severing enzyme that plays important roles in various cellular events including axon regeneration. Herein, we found that the basal ATPase activity of spastin is negatively regulated by spastin concentration. By determining a spastin crystal structure, we demonstrate the necessity of intersubunit interactions between spastin AAA domains. Neutralization of the positive charges in the microtubule-binding domain (MTBD) of spastin dramatically decreases the ATPase activity at low concentration, although the ATP-hydrolyzing potential is not affected. These results demonstrate that, in addition to the AAA domain, the MTBD region of spastin is also involved in regulating ATPase activity, making interactions between spastin protomers more complicated than expected. © 2018 Federation of European Biochemical Societies.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  15. A conserved inter-domain communication mechanism regulates the ATPase activity of the AAA-protein Drg1.

    PubMed

    Prattes, Michael; Loibl, Mathias; Zisser, Gertrude; Luschnig, Daniel; Kappel, Lisa; Rössler, Ingrid; Grassegger, Manuela; Hromic, Altijana; Krieger, Elmar; Gruber, Karl; Pertschy, Brigitte; Bergler, Helmut

    2017-03-17

    AAA-ATPases fulfil essential roles in different cellular pathways and often act in form of hexameric complexes. Interaction with pathway-specific substrate and adaptor proteins recruits them to their targets and modulates their catalytic activity. This substrate dependent regulation of ATP hydrolysis in the AAA-domains is mediated by a non-catalytic N-terminal domain. The exact mechanisms that transmit the signal from the N-domain and coordinate the individual AAA-domains in the hexameric complex are still the topic of intensive research. Here, we present the characterization of a novel mutant variant of the eukaryotic AAA-ATPase Drg1 that shows dysregulation of ATPase activity and altered interaction with Rlp24, its substrate in ribosome biogenesis. This defective regulation is the consequence of amino acid exchanges at the interface between the regulatory N-domain and the adjacent D1 AAA-domain. The effects caused by these mutations strongly resemble those of pathological mutations of the AAA-ATPase p97 which cause the hereditary proteinopathy IBMPFD (inclusion body myopathy associated with Paget's disease of the bone and frontotemporal dementia). Our results therefore suggest well conserved mechanisms of regulation between structurally, but not functionally related members of the AAA-family.

  16. Do School Incentives and Accountability Measures Improve Skills in the Middle East and North Africa? The Cases of Jordan and Tunisia

    ERIC Educational Resources Information Center

    Shafiq, M. Najeeb

    2011-01-01

    There is general agreement that skill-enhancing school reforms in the Middle East and North Africa (MENA) region are necessary for economic, political and social reasons. Using student-level data from Jordan and Tunisia, this study assesses the relationship between skills and the following school incentive and accountability measures: pedagogical…

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

    ERIC Educational Resources Information Center

    Johnson, Dora E.; And Others

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

  18. Evaluation and inter-comparison of modern day reanalysis datasets over Africa and the Middle East

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Arsenault, K. R.; Hobbins, M.; Peters-Lidard, C. D.; Verdin, J. P.

    2015-12-01

    Reanalysis datasets are potentially very valuable for otherwise data-sparse regions such as Africa and the Middle East. They are potentially useful for long-term climate and hydrologic analyses and, given their availability in real-time, they are particularity attractive for real-time hydrologic monitoring purposes (e.g. to monitor flood and drought events). Generally in data-sparse regions, reanalysis variables such as precipitation, temperature, radiation and humidity are used in conjunction with in-situ and/or satellite-based datasets to generate long-term gridded atmospheric forcing datasets. These atmospheric forcing datasets are used to drive offline land surface models and simulate soil moisture and runoff, which are natural indicators of hydrologic conditions. Therefore, any uncertainty or bias in the reanalysis datasets contributes to uncertainties in hydrologic monitoring estimates. In this presentation, we report on a comprehensive analysis that evaluates several modern-day reanalysis products (such as NASA's MERRA-1 and -2, ECMWF's ERA-Interim and NCEP's CFS Reanalysis) over Africa and the Middle East region. We compare the precipitation and temperature from the reanalysis products with other independent gridded datasets such as GPCC, CRU, and USGS/UCSB's CHIRPS precipitation datasets, and CRU's temperature datasets. The evaluations are conducted at a monthly time scale, since some of these independent datasets are only available at this temporal resolution. The evaluations range from the comparison of the monthly mean climatology to inter-annual variability and long-term changes. Finally, we also present the results of inter-comparisons of radiation and humidity variables from the different reanalysis datasets.

  19. [Hydatidosis in Africa in 1996: epidemiological aspects].

    PubMed

    Develoux, M

    1996-01-01

    Hydatidosis is hyperendemic in most north African countries and in several areas of East Africa. The cycle of infestation involves dogs, ruminants and man. While sheep and goats appear to be the most common domestic intermediate, camels appear to act as the intermediate in some parts of North and East Africa. Hydatidosis is considered to be essentially rural but urban cycles have been reported in North Africa. During the last decade, echotomographic, and serologic screening for human hydatidosis were carried out in Tunisia and in nomadic populations from East Africa. These surveys have provided reliable accurate prevalence data showing that hydatidosis is a major public health problem in these areas. The highest worldwide incidence in man is in the Turkana district of Kenya. This high incidence is related to promiscuity between humans and dogs in Turkana. A pilot program to control hydatid disease was started in Turkana over 10 years ago. For unknown reasons human infestation is rare in West and Southern Africa despite the presence of hydatidosis in cattle.

  20. How boys become dogs: stigmatization and marginalization of uninitiated xhosa males in East London, South Africa.

    PubMed

    Mavundla, Thandisizwe R; Netswera, Fulufhelo G; Toth, Ferenc; Bottoman, Brian; Tenge, Stembele

    2010-07-01

    Male circumcision is practiced in South Africa among the Xhosa people as a rite of passage from boyhood to manhood. The manhood status achieved after the ritual accords men power and authority in the community over women and uncircumcised men. Therefore, uninitiated men experience great pressures to get circumcised. We describe the experience of newly initiated Xhosa men in East London, South Africa. Interpretive phenomenology was used as the inquiry of choice. Data were collected through focus group discussions in which 14 men participated. The theme of marginalization of uninitiated Xhosa males emerged with two categories: (a) rejection, and (b) lack of respect. The participants revealed that uninitiated men are rejected by the community, their own families, friends, and women. We frame the discussion around the concept of stigma. Acknowledging that uninitiated males are stigmatized can help mitigate stigma, and in turn, the incidence of medical complications from botched circumcisions.

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

    PubMed

    Kulczycki, Andrzej; Windle, Sarah

    2011-11-01

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

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

    PubMed

    Young, Alyson G; Pike, Ivy L

    2012-01-01

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

  3. Abdominal aorta aneurysm (AAA): Is there a role for prevention and therapy using antioxidants?

    PubMed

    Pincemail, Joël; Defraigne, Jean-Olivier; Courtois, Audrey; Albert, Adelin; Cheramy-Bien, Jean-Paul; Sakalihasan, Natzi

    2017-09-18

    Abdominal aortic aneurysm (AAA) is a degenerative disease that cause mortality in people aged > 65 years. Increased reactive oxygen species (ROS) and oxidative stress seems to play a pivotal role in AAA pathogenesis. Several sources of ROS have been identified in aortic tissues using experimental models: inflammation, increased activity of NAD(P)H or NOX, over-expression of inducible nitric oxide synthase (iNOS), uncoupled endothelial nitric oxide synthase (eNOS), platelets activation and iron release from hemoglobin. Reducing oxidative stress by antioxidants has been shown to be a potential strategy for limiting AAA development. Human studies confirmed that oxidative stress and endothelial dysfunction are well associated with AAA development. Unfortunately, there is currently no evidence showing that strategies using low molecular weight antioxidants (vitamins C and E, β-carotene) as target for ROS is effective to reduce human AAA progression. However, recent epidemiological data have highlighted the positive role of a diet enriched in fruits which contain high amounts of antioxidant polyphenols. By their ability to restore endothelial function but also their capacity to stimulate enzymatic antioxidants trough activation of the Keap1/Nrf2/ARE pathway, polyphenols can represent a promising treatment target for reducing human AAA progression. Clinical studies are therefore urgently necessary to confirm such a suggestion. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. JPRS Report East Europe.

    DTIC Science & Technology

    1993-01-22

    Latin America to West Europe. This has been made easier by the opening of our borders, the weakness of our customs and police ser- vices, Poland’s...past two years, two large drug shipments from Latin America were seized. They may have been the first attempts to open a route. UN experts who toured...Friday in eight volumes: China, East Europe, Central Eurasia, East Asia, Near East & South Asia, Sub- Saharan Africa, Latin America , and West

  5. Selective Intra-procedural AAA sac Embolization During EVAR Reduces the Rate of Type II Endoleak.

    PubMed

    Mascoli, C; Freyrie, A; Gargiulo, M; Gallitto, E; Pini, R; Faggioli, G; Serra, C; De Molo, C; Stella, A

    2016-05-01

    The pre-treatment presence of at least six efferent patent vessels (EPV) from the AAA sac and/or AAA thrombus volume ratio (VR%) <40% are considered to be positive predictive factors for persistent type II endoleak (ELIIp). The aim of the present study was to evaluate the effectiveness of sac embolization during EVAR in patients with pre-operative morphological risk factors (p-MRF) for ELIIp. Patients undergoing EVAR and intra-procedural AAA sac embolization (Group A, 2012-2013) were retrospectively selected and compared with a control group of patients with the same p-MRF, who underwent EVAR without intra-procedural sac embolization (Group B, 2008-2010). The presence of ELIIp was evaluated by duplex ultrasound at 0 and 6 months, and by contrast enhanced ultrasound at 12 months. The association between AAA diameter, age, COPD, smoking, anticoagulant therapy, and AAA sac embolization with ELIIp was evaluated using multiple logistic regression. The primary endpoint was the effectiveness of the intra-procedural AAA sac embolization for ELIIp prevention. Secondary endpoints were AAA sac evolution and freedom from ELIIp and embolization related re-interventions at 6-12 months. Seventy patients were analyzed: 26 Group A and 44 Group B; the groups were homogeneous for clinical/morphological characteristics. In Group A the median number of coils positioned in AAA sac was 4.1 (IQR 1). There were no complications related to the embolization procedures. A significantly lower number of ELIIp was detected in Group A than in Group B (8/26 vs. 33/44, respectively, p < .001) at discharge, and this was confirmed at 6-12 months (7/26 vs. 30/44 respectively, p = .001, and 5/25 vs. 32/44, respectively, p < .001). On multivariate analysis, intra-procedural AAA sac embolization was the only factor independently associated with freedom from ELIIp at 6 (OR 0.196, 95% CI 0.06-0.63; p = .007) and 12 months (OR 0.098, 95% CI 0.02-0.35; p < .001). No differences in median AAA sac

  6. The Airborne Astronomy Ambassadors (AAA) Program and NASA Astrophysics Connections

    NASA Astrophysics Data System (ADS)

    Backman, Dana Edward; Clark, Coral; Harman, Pamela

    2018-01-01

    The NASA Airborne Astronomy Ambassadors (AAA) program is a three-part professional development (PD) experience for high school physics, astronomy, and earth science teachers. AAA PD consists of: (1) blended learning via webinars, asynchronous content delivery, and in-person workshops, (2) a STEM immersion experience at NASA Armstrong’s B703 science research aircraft facility in Palmdale, California, including interactions with NASA astrophysics & planetary science Subject Matter Experts (SMEs) during science flights on SOFIA, and (3) continuing post-flight opportunities for teacher & student connections with SMEs.

  7. The seismic-stratigraphic record of lake-level fluctuations in Lake Challa: Hydrological stability and change in equatorial East Africa over the last 140 kyr

    NASA Astrophysics Data System (ADS)

    Moernaut, J.; Verschuren, D.; Charlet, F.; Kristen, I.; Fagot, M.; De Batist, M.

    2010-02-01

    Seismic-reflection data from crater lake Challa (Mt. Kilimanjaro, equatorial East Africa) reveal a ˜ 210-m thick sedimentary infill containing distinct seismic-stratigraphic signatures of late-Quaternary lake-level fluctuations. Extrapolation of a well-constrained age model on the cored upper part of the sequence suggests that these lake-level fluctuations represent a detailed and continuous record of moisture-balance variation in equatorial East Africa over the last 140 kyr. This record indicates that the most severe aridity occurred during peak Penultimate glaciation immediately before ˜ 128 kyr BP (coeval with Heinrich event 11) and during a Last Interglacial 'megadrought' period between ˜ 114 and ˜ 97 kyr BP; in comparison, Last Glacial Maximum (LGM) aridity was modest. It was preceded by ˜ 75 000 years of relatively stable and moist climate conditions interrupted by eleven short-lived dry spells, five of which match the timing of Heinrich events 2 to 6. Climate history near the East African equator reflects variation in the precessional forcing of monsoon rainfall modulated by orbital eccentricity, but precession-driven moisture fluctuations were less extreme than those observed in northern and southern tropical Africa. The near-continuous moist climate from ˜ 97 to 20.5 kyr BP recorded in the Lake Challa record contrasts with the trend towards greater aridity after ˜ 70 kyr BP documented in equatorial West Africa. This long period of moist glacial climate and a short, relatively modest LGM drought can be attributed to greater independence of western Indian Ocean monsoon dynamics from northern high-latitude glaciation than those in the tropical Atlantic Ocean. This rather persistent moist glacial climate regime may have helped maintain high biodiversity in the tropical forest ecosystems of the Eastern Arc mountains in Tanzania.

  8. Structure of Lmaj006129AAA, a hypothetical protein from Leishmania major

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arakaki, Tracy; Le Trong, Isolde; Structural Genomics of Pathogenic Protozoa

    2006-03-01

    The crystal structure of a conserved hypothetical protein from L. major, Pfam sequence family PF04543, structural genomics target ID Lmaj006129AAA, has been determined at a resolution of 1.6 Å. The gene product of structural genomics target Lmaj006129 from Leishmania major codes for a 164-residue protein of unknown function. When SeMet expression of the full-length gene product failed, several truncation variants were created with the aid of Ginzu, a domain-prediction method. 11 truncations were selected for expression, purification and crystallization based upon secondary-structure elements and disorder. The structure of one of these variants, Lmaj006129AAH, was solved by multiple-wavelength anomalous diffraction (MAD)more » using ELVES, an automatic protein crystal structure-determination system. This model was then successfully used as a molecular-replacement probe for the parent full-length target, Lmaj006129AAA. The final structure of Lmaj006129AAA was refined to an R value of 0.185 (R{sub free} = 0.229) at 1.60 Å resolution. Structure and sequence comparisons based on Lmaj006129AAA suggest that proteins belonging to Pfam sequence families PF04543 and PF01878 may share a common ligand-binding motif.« less

  9. Improved Resident Adherence to AAA Screening Guidelines via an Electronic Reminder.

    PubMed

    Sypert, David; Van Dyke, Kenneth; Dhillon, Namrata; Elliott, John O; Jordan, Kim

    The 2014 United States Preventive Services Task Force systematic review found abdominal aortic aneurysm (AAA) screening decreased related mortality by close to half. Despite the simplicity of screening, research suggests poor adherence to the recommended AAA screening guidelines. Using the quality improvement plan-study-do-act cycle, we retrospectively established poor adherence to AAA screening and poor documentation of smoking history in our resident clinic. An electronic reminder was prospectively implemented into our electronic medical record (EMR) with the goal of improving screening rates. After 1 year, a retrospective chart review was conducted. Comparisons of the pre- and post-electronic reminder intervention data were made using chi-square tests and odds ratios (OR). The purposeful AAA screening rate improved 27.8% during the intervention, 40.3% (95% confidence interval [CI]: 28.6-52.0%) versus 12.5% (95% CI: 3.1-21.9%), p = .002, suggesting patients were more likely to be screened as a result of the electronic reminder, OR = 4.73 (95% CI: 1.77-12.65). This improvement translates to a large effect size, Cohen's d = 0.86 (95% CI: 0.31-1.40). Electronic reminders are a simple EMR addition that can provide evidence-based education while improving adherence rates with preventive health screening measures.

  10. Chronology of volcanism and rift basin propagation - Rungwe volcanic province, East Africa

    NASA Technical Reports Server (NTRS)

    Ebinger, C. J.; Deino, A. L.; Drake, R. E.; Tesha, A. L.

    1989-01-01

    The spatial and temporal development of along-axis segmentation in youthful continental rifts was investigated using the results of field, remote sensing, and K-Ar geochronology studies conducted in four (Rukwa, Songwe, Usangu, and Karonga) rift basins within the Rungwe volcanic province in East Africa. Results indicated that the Rukwa and Karonga border fault segments formed between 7.25 and 5 m.y. ago, the Usangu border fault segment developed between 3 and 2 m.y. ago, and subsidence along the Songwe border fault segment had occurred by 0.5 Ma. It is shown that individual basins developed diachronously, each following a similar sequence: (1) initial border fault development; (2) asymmetric basin subsidence/flank uplift and the development of monoclines opposite the border faults; and (3) continued subsidence and tilting along intrabasinal faults with flexural upwarping of the rift flanks, enhancing basinal asymmetries.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Walters, B.; Pasyanos, M.E.; Bhattacharyya, J.

    2000-03-01

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

  13. Persistent type II endoleak after EVAR: the predictive value of the AAA thrombus volume.

    PubMed

    Gallitto, Enrico; Gargiulo, Mauro; Mascoli, Chiara; Freyrie, Antonio; DE Matteis, Massimo; Serra, Carla; Bianchini Massoni, Claudio; Faggioli, Gianluca; Stella, Andrea

    2018-02-01

    Persistent type II endoleaks (ELIIp, ≥6 months) after an endovascular aneurysm repair (EVAR) can be associated with adverse outcomes. The aims of this study are the evaluation of the incidence of ELIIp, their preoperative morphological predictive features (PMF) and the post-EVAR abdominal aortic aneurysm (AAA) evolution in the presence of ELIIp. Patients underwent EVAR between 2008 and 2010 were prospectively collected. Cases with ELIIp (group A: AG) were identified. A control group without ELIIp (group B: BG), homogeneous for clinical characteristics, follow-up timing and methods (CTA and/or CEUS at 6.12 months and yearly thereafter) was retrospectively selected. The PMF evaluated by computed-tomography-angiography (CTA) were: AAA-diameter, number and diameter of AAA efferent patent vessels (EPV), AAA-total volume (TV), AAA-thrombus volume (THV) and TV/THV rate (%VR). Volumes were calculated by the dedicated vessels analysis software. AG and BG were compared. The primary endpoint was to evaluate the incidence of ELIIp. Secondary endpoints were to analyze the relation between PMF and ELIIp and to assess the post-EVAR AAA-evolution in the presence of ELIIp. Between 2008 and 2010, 200 patients underwent EVAR to treat AAA electively. An ELIIp was detected in 35cases (17.5%) (AG). Twenty-seven patients (13.5%) were included in BG. An overall of 62 patients (GA+GB) were analyzed. The mean pre-operative AAA diameter and EPV were 58±11.6 mm and 5.5±1.8 mm, respectively. The mean TV and THV were 187±111.5 cc and 82±75 cc, respectively. The median %VR was 42.3%. ELIIp was correlated to EPV≥6 (χ2, p=.015) and %VR <40% (logistic regression, P=0.032). The mean follow-up was 22±9 months. Seven (20%) ELIIp spontaneously sealed and 6 (17%) required reinterventions (2 conversions to OR). There were not PMF associated to ELIIp evolution and AAA growth post-EVAR. ELIIp is a not rare complication and it could require re-interventions. Our data suggest that VEP≥6 or %VT<40

  14. Middle East and North African Oil.

    ERIC Educational Resources Information Center

    Al-Quazzaz, Ayad

    1981-01-01

    Traces the history of oil and natural gas in the Middle East and relates the importance of the Middle East's current stores of oil to economic development. Information is presented on the relationship of major oil companies and local governments, OPEC, rate of production, and the impact of oil on the societies of the Middle East and North Africa.…

  15. Cardiovascular risk factor burden in Africa and the Middle East: the Africa Middle East Cardiovascular Epidemiological (ACE) study.

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Knowles, Michael; Sabourin, Michel

    2008-04-01

    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 Jordanian Psychological Association whose President was Dr. Asaad Zuby. The President of the Conference and the Local Organizing Committee was Dr. Adnan Farah, the Chair of the Scientific Program Committee was Dr. Mohammad Rimawi, and the Chair of the Regional Advisory Committee was Dr. Marwan Dwairy. The Conference succeeded in attracting participants from 28 countries, including 15 from the Middle East and North Africa region. The Scientific Program explored ways and means to promote the role of psychology in meeting life challenges at regional and international levels. The Conference concluded with the signing of a formal Declaration which called upon governments, academic and professional institutions and organizations, non-governmental organization and other civil society groups, and the United Nations, to work together and to make every possible effort individually and collectively to achieve these goals.

  18. Statins: the holy grail of Abdominal Aortic Aneurysm (AAA) growth attenuation? A systematic review of the literature.

    PubMed

    Dunne, Jonathan A; Bailey, Marc A; Griffin, Kathryn J; Sohrabi, Soroush; Coughlin, Patrick A; Scott, D Julian A

    2014-01-01

    In the era of Abdominal Aortic Aneurysm (AAA) screening, pharmacotherapies to attenuate AAA growth are sought. HMG Co-A reductase inhibitors (statins) have pleiotropic actions independent of their lipid lowering effects and have been suggested as potential treatment for small AAAs. We systematically review the clinical evidence for this effect. Medline, EMBASE and the Cochrane Central Register of Controlled Trials (1950-2011) were searched for studies reporting data on the role of statin therapy on AAA growth rate. No language restrictions were placed on the search. References of retrieved articles and pertinent journals were hand searched. Included studies were reviewed by 2 independent observers. The search retrieved 164 papers, 100 were irrelevant based on their title, 47 were reviews and 1 was a letter. 8 studies were excluded based on review of their abstract leaving 8 for inclusion in the study. Eight observational clinical studies with a total of 4,466 patients were reviewed. Four studies demonstrated reduced AAA expansion in statin users while 4 studies failed to demonstrate this effect. The method of determining AAA growth rates varied significantly between the studies and the ability of many studies to control for misclassification bias was poor. The claim that statins attenuate AAA growth remains questionable. Further prospective studies with stringent identification and verification of statin usage and a standardised method of estimating AAA growth rates are required. Statin type and dose also merit consideration.

  19. Lake Challa (Mt. Kilimanjaro) sediments as recorder of present and past seasonality in equatorial East Africa

    NASA Astrophysics Data System (ADS)

    Kristen, I.; Wolff, C.; Schettler, G.; Dulski, P.; Naumann, R.; Haug, G. H.; Blaauw, M.; Verschuren, D.

    2008-12-01

    In discussions on the impact of global warming on moisture balance and human water resources, natural archives of past hydrological variability in tropical regions are attracting increasing attention. The EuroCLIMATE project CHALLACEA studies the sediment archive of Lake Challa, a 4.5 km² and ~94 m deep crater lake located on the lower eastern slope of Mt. Kilimanjaro with the aim to produce a continuous, high-resolution and multi-proxy reconstruction of past temperature and moisture-balance variability in equatorial East Africa over the past 25,000 years. Lake Challa is a freshwater lake with a water budget controlled mostly by sub-surface in- and outflow and lake-surface evaporation. Accordingly, microscopic thin-section investigation of sediment composition reveals an overall dominance of autochthonous components (diatom frustules, calcite, and organic matter). First results from an ongoing sediment trap study point to distinct seasonality in sediment input: calcite and organic matter accumulate during the warm southern hemisphere summer months (November - March), whereas the principal diatom blooms occur during the cool and windy period between June and October. Here we present the results of physical and chemical investigations of the lake water column between September 1999 and November 2007, which document the concomitant seasonal changes in lake mixing/stratification and related element cycling. High-resolution μXRF profiles of these elements in the laminated sediments of Lake Challa thus also show marked seasonal cycles, as well as longer-term variability. In particular, variability in the Mn/Fe ratio along the top 15 cm of the sediment record is interpreted to reflect changes in lake stratification during the last ~100 years. This proxy record is evaluated in comparison with records of historical weather variability in East Africa, and of potentially influencing parameters such as the El Niño Southern Oscillation and the Indian Ocean Dipole. Eventually

  20. Cumulative Total Middle East/North Africa Freshwater Losses as Seen by NASA GRACE, 2002-15

    NASA Image and Video Library

    2015-12-08

    Cumulative total freshwater losses in North Africa and the Middle East from 2002 to 2015 (in inches) observed by NASA's Gravity Recovery and Climate Experiment (GRACE) mission. Total water refers to all of the snow, surface water, soil water and groundwater combined. Groundwater depletion in Turkey, Syria, Iraq and Iran, and along the Arabian Peninsula, are leading to large changes in total water storage in the region. Likewise, drought and groundwater pumping is contributing to the drying of the Caspian Sea Region. The Northwest Sahara Aquifer System, which underlies Tunisia and Libya, is also experiencing increasing water stress as shown in the map. Image updated from Voss et al., 2013. Citation of Record: Voss, K. A., J. S. Famiglietti, M. Lo, C. R. de Linage, M. Rodell and S. C. Swenson, Groundwater depletion in the Middle East from GRACE with Implications for Transboundary Water Management in the Tigris-Euphrates-Western Iran Region, Wat. Resour. Res., 49(2), 904-914, DOI: 10.1002/wrcr.20078. http://photojournal.jpl.nasa.gov/catalog/PIA20207

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

    PubMed Central

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    PubMed

    Doherty, Jane E

    2015-03-01

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

  4. The Impact of Cultural and Economic Globalization on the Planning and Function of Higher Education in North Africa and the Middle East.

    ERIC Educational Resources Information Center

    Sabour, M'Hammed

    1999-01-01

    Discusses the impact of globalization on higher education in the Arab World, particularly North Africa and the Middle East. The influence has been positive regarding the university's openness to the world and involvement in global intellectual and scientific activity and culture. However, globalization is also seen in the academia as tantamount to…

  5. Foreign Direct Investment and Energy Supply in the Middle East and North Africa: A Correlational Study

    NASA Astrophysics Data System (ADS)

    Elghali, Siddig

    Middle East and North Africa countries have been criticized for failing to utilize foreign direct investment energy resources efficiently. The changing of energy resources environment of the past decades with its growing emphasis on the importance of imminent energy supply challenges require strategists to consider different types of energy resources investment to improve energy supply. One type of energy investment will show effectiveness and efficiency in utilizing foreign direct investment in exposing RE, fossil fuels, natural gas, and reducing CO2 emissions. The purpose of this quantitative correlational study was to utilize foreign direct investment to predict total primary energy supply in the Middle East and North Africa region between 1971 and 2013. The study was conducted using a sample size of 43 years of energy supply resources and foreign direct investment from 1971 to 2013, which includes all of the years for which FDI is available. RE potential may equip Middle East and North Africa countries with sustainable and clean electricity for centuries to come, as non-renewable energy resources may not meet the demands globally and domestically or environmentally. As demands for fossil fuels grow, carbon emissions will increase. RE may be a better option of CO 2 emissions sequestration and will increase electricity to rural areas without government subsidies and complex decision-making policies. RE infrastructure will reduce water desalinization costs, cooling systems, and be useful in heating. Establishing concentrated solar power may be useful for the region cooperation, negotiations, and integration to share this energy. The alternative sought to fossil fuels was nuclear power. However, nuclear power depends on depleting, non-renewable uranium resources. The cost of uranium will increase if widely used and the presence of a nuclear plant in an unstable region is unsafe. Thus, renewable energy as a long-term option is efficient. A nonlinear regression

  6. Prevalence of abdominal aortic aneurysm (AAA) in a population undergoing computed tomography colonography in Canterbury, New Zealand.

    PubMed

    Khashram, M; Jones, G T; Roake, J A

    2015-08-01

    There is compelling level 1 evidence in support of screening men for abdominal aortic aneurysm (AAA) to reduce AAA mortality. However, New Zealand (NZ) lacks data on AAA prevalence, and national screening has not been implemented. The aim of this study was to determine the prevalence of AAA in a population undergoing a computed tomography colonography (CTC) for gastrointestinal symptoms. This was an observational study; all consecutive CTCs performed in three regions of the South Island of NZ over a 4 year period were reviewed. Data on abdominal and thoracic aorta diameters ≥30 mm, and iliac and femoral aneurysms ≥20 mm were recorded. Previous aortic surgical grafts or endovascular stents were also documented. Demographics, survival, and AAA related outcomes were collected and used for analysis. Included were 4,893 scans on 4,644 patients (1,933 men [41.6%], 2,711 women [58.4%]) with a median age of 69.3 years (range 17.0-97.0 years). There were 309 scans on 289 patients (75.4% men) who had either an aneurysm or a previous aortic graft with a median age of 79.6 years (range 57.0-96.0 years). Of these, 223 had a native AAA ≥30 mm. The prevalence of AAA rose with age from 1.3% in men aged 55-64 years, to 9.1% in 65-74 year olds, 16.8% in 75-84 year olds, and 22.0% in ≥85 year olds. The corresponding figures in women were 0.4%, 2%, 3.9%, and 6.2%, respectively. In this observational study, the prevalence of AAA was high and warrants further evaluation. The results acquired help to define a population that may benefit from a national AAA screening programme. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  7. A new tephrochronology for early diverse stone tool technologies and long-distance raw material transport in the Middle to Late Pleistocene Kapthurin Formation, East Africa.

    PubMed

    Blegen, Nick; Jicha, Brian R; McBrearty, Sally

    2018-05-09

    The Middle to Late Pleistocene (780-10 ka) of East Africa records evidence of significant behavioral change, early fossils of Homo sapiens, and the dispersals of our species across and out of Africa. Studying human evolution in this time period thus requires an extensive and precise chronology relating behavioral evidence from archaeological sequences to aspects of hominin biology and evidence of past environments from fossils and geological sequences. Tephrochronology provides the chronostratigraphic resolution to achieve this through correlation and dating of volcanic ashes. The tephrochronology of the Kapthurin Formation presented here, based on tephra correlations and 40 Ar/ 39 Ar dates, provides new ages between 395.6 ± 3.5 ka and 465.3 ± 1.0 ka for nine sites showing diverse blade and Levallois methods of core reduction. These are >110 kyr older than previously known in East Africa. New 40 Ar/ 39 Ar dates provide a refined age of 222.5 ± 0.6 ka for early evidence of long-distance (166 km) obsidian transport at the Sibilo School Road Site. A tephra correlation between the Baringo and Victoria basins also provides a new date of ∼100 ka for the Middle Stone Age site of Keraswanin. By providing new and older dates for 11 sites containing several important aspects of hominin behavior and extending the chronology of the Kapthurin Formation forward by ∼130,000 years, the tephrochronology presented here contributes one of the longest and most refined chronostratigraphic frameworks of Middle through Late Pleistocene East Africa. This tephrochronology thus provides the foundation to understand the process of modern human behavioral evolution as it relates to biological and paleoenvironmental circumstances. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Peak AAA fatty acid homolog contaminants present in the dietary supplement l-Tryptophan associated with the onset of eosinophilia-myalgia syndrome.

    PubMed

    Klarskov, Klaus; Gagnon, Hugo; Racine, Mathieu; Boudreault, Pierre-Luc; Normandin, Chad; Marsault, Eric; Gleich, Gerald J; Naylor, Stephen

    2018-05-22

    The eosinophilia-myalgia syndrome (EMS) outbreak that occurred in the USA and elsewhere in 1989 was caused by the ingestion of Showa Denko K.K. (SD) L-tryptophan (L-Trp). "Six compounds" detected in the L-Trp were reported as case-associated contaminants. Recently the final and most statistically significant contaminant, "Peak AAA" was structurally characterized. The "compound" was actually shown to be two structural isomers resulting from condensation reactions of L-Trp with fatty acids derived from the bacterial cell membrane. They were identified as the indole C-2 anteiso (AAA 1 -343) and linear (AAA 2 -343) aliphatic chain isomers. Based on those findings, we utilized a combination of on-line HPLC-electrospray ionization mass spectrometry (LC-MS), as well as both precursor and product ion tandem mass spectrometry (MS/MS) to facilitate identification of a homologous family of condensation products related to AAA 1 -343 and AAA 2 -343. We structurally characterized eight new AAA 1 -XXX/AAA 2 -XXX contaminants, where XXX represents the integer molecular ions of all the related homologs, differing by aliphatic chain length and isomer configuration. The contaminants were derived from the following fatty acids of the bacterial cell membrane, 5-methylheptanoic acid (anteiso-C8:0) for AAA 1 -315; n-octanoic acid (n-C8:0) for AAA 2 -315; 6-methyloctanoic acid (anteiso-C9:0) for AAA 1 -329; n-nonanoic acid (n-C9:0) for AAA 2 -329; 10-methyldodecanoic acid (anteiso-C13:0) for AAA 1 -385; n-tridecanoic acid (n-C13:0) for AAA 2 -385; 11-methyltridecanoic acid (anteiso-C14:0) for AAA 1 -399; and n-tetradecanoic acid (n-C14:0) for AAA 2 -399. The concentration levels for these contaminants were estimated to be 0.1-7.9 μg / 500 mg of an individual SD L-Trp tablet or capsule The structural similarity of these homologs to case-related contaminants of Spanish Toxic Oil Syndrome (TOS) is discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Multibands tunneling in AAA-stacked trilayer graphene

    NASA Astrophysics Data System (ADS)

    Redouani, Ilham; Jellal, Ahmed; Bahaoui, Abdelhadi; Bahlouli, Hocine

    2018-04-01

    We study the electronic transport through np and npn junctions for AAA-stacked trilayer graphene. Two kinds of gates are considered where the first is a single gate and the second is a double gate. After obtaining the solutions for the energy spectrum, we use the transfer matrix method to determine the three transmission probabilities for each individual cone τ = 0 , ± 1 . We show that the quasiparticles in AAA-stacked trilayer graphene are not only chiral but also labeled by an additional cone index τ. The obtained bands are composed of three Dirac cones that depend on the chirality indexes. We show that there is perfect transmission for normal or near normal incidence, which is a manifestation of the Klein tunneling effect. We analyze also the corresponding total conductance, which is defined as the sum of the conductance channels in each individual cone. Our results are numerically discussed and compared with those obtained for ABA- and ABC-stacked trilayer graphene.

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

    NASA Astrophysics Data System (ADS)

    Mutua, F.; Koike, T.

    2013-12-01

    Extreme weather events have been the leading cause of disasters and damage all over the world.The primary ingredient to these disasters especially floods is rainfall which over the years, despite advances in modeling, computing power and use of new data and technologies, has proven to be difficult to predict. Also, recent climate projections showed a pattern consistent with increase in the intensity and frequency of extreme events in the East African region.We propose a holistic integrated approach to climate change assessment and extreme event adaptation through coupling of analysis techniques, tools and data. The Lake Victoria Basin (LVB) in East Africa supports over three million livelihoods and is a valuable resource to five East African countries as a source of water and means of transport. However, with a Mesoscale weather regime driven by land and lake dynamics,extreme Mesoscale events have been prevalent and the region has been on the receiving end during anomalously wet years in the region. This has resulted in loss of lives, displacements, and food insecurity. In the LVB, the effects of climate change are increasingly being recognized as a significant contributor to poverty, by its linkage to agriculture, food security and water resources. Of particular importance are the likely impacts of climate change in frequency and intensity of extreme events. To tackle this aspect, this study adopted an integrated regional, mesoscale and basin scale approach to climate change assessment. We investigated the projected changes in mean climate over East Africa, diagnosed the signals of climate change in the atmosphere, and transferred this understanding to mesoscale and basin scale. Changes in rainfall were analyzed and similar to the IPCC AR4 report; the selected three General Circulation Models (GCMs) project a wetter East Africa with intermittent dry periods in June-August. Extreme events in the region are projected to increase; with the number of wet days

  11. SU-E-T-538: Evaluation of IMRT Dose Calculation Based on Pencil-Beam and AAA Algorithms.

    PubMed

    Yuan, Y; Duan, J; Popple, R; Brezovich, I

    2012-06-01

    To evaluate the accuracy of dose calculation for intensity modulated radiation therapy (IMRT) based on Pencil Beam (PB) and Analytical Anisotropic Algorithm (AAA) computation algorithms. IMRT plans of twelve patients with different treatment sites, including head/neck, lung and pelvis, were investigated. For each patient, dose calculation with PB and AAA algorithms using dose grid sizes of 0.5 mm, 0.25 mm, and 0.125 mm, were compared with composite-beam ion chamber and film measurements in patient specific QA. Discrepancies between the calculation and the measurement were evaluated by percentage error for ion chamber dose and γ〉l failure rate in gamma analysis (3%/3mm) for film dosimetry. For 9 patients, ion chamber dose calculated with AAA-algorithms is closer to ion chamber measurement than that calculated with PB algorithm with grid size of 2.5 mm, though all calculated ion chamber doses are within 3% of the measurements. For head/neck patients and other patients with large treatment volumes, γ〉l failure rate is significantly reduced (within 5%) with AAA-based treatment planning compared to generally more than 10% with PB-based treatment planning (grid size=2.5 mm). For lung and brain cancer patients with medium and small treatment volumes, γ〉l failure rates are typically within 5% for both AAA and PB-based treatment planning (grid size=2.5 mm). For both PB and AAA-based treatment planning, improvements of dose calculation accuracy with finer dose grids were observed in film dosimetry of 11 patients and in ion chamber measurements for 3 patients. AAA-based treatment planning provides more accurate dose calculation for head/neck patients and other patients with large treatment volumes. Compared with film dosimetry, a γ〉l failure rate within 5% can be achieved for AAA-based treatment planning. © 2012 American Association of Physicists in Medicine.

  12. Diagnosis and predictive molecular analysis of non-small-cell lung cancer in the Africa-Middle East region: challenges and strategies for improvement.

    PubMed

    Slavik, Tomas; Asselah, Fatima; Fakhruddin, Najla; El Khodary, Ahmed; Torjman, Fairouz; Anis, Elia; Quinn, Martin; Khankan, Azzam; Kerr, Keith M

    2014-11-01

    The identification of tumor biomarkers provides information on the prognosis and guides the implementation of appropriate treatment in patients with many different cancer types. In non-small cell lung cancer (NSCLC), targeted treatment plans based on biomarker identification have already been used in the clinic. However, such predictive molecular testing is not currently a universally used practice. This is the case, in particular, in developing countries where lung cancer is increasingly prevalent. In September 2012 and November 2013, a committee of 16 lung cancer experts from Africa and the Middle East met to discuss key issues related to diagnosis and biomarker testing in NSCLC and the implementation of personalized medicine in the region. The committee identified current challenges for effective diagnosis and predictive analysis in Africa and the Middle East. Moreover, strategies to encourage the implementation of biomarker testing were discussed. A practical approach for the effective diagnosis and predictive molecular testing of NSCLC in these regions was derived. We present the key issues and recommendations arising from the meetings. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

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

  14. Early childhood obesity: a survey of knowledge and practices of physicians from the Middle East and North Africa.

    PubMed

    Gies, Inge; AlSaleem, Bader; Olang, Beheshteh; Karima, Berkouk; Samy, Gamal; Husain, Khaled; Elhalik, Mahmoud; Miqdady, Mohamad; Rawashdeh, Mohamad; Salah, Mohamed; Mouane, Nezha; Rohani, Pejman; Singhal, Atul; Vandenplas, Yvan

    2017-04-28

    Childhood obesity is one of the most serious public health issues of the twenty-first century affecting even low- and middle-income countries. Overweight and obese children are more likely to stay obese into adulthood. Due to the paucity of data on local practices, our study aimed to assess the knowledge and practices of physicians from the Middle East and North Africa region with respect to early-onset obesity. A specific questionnaire investigating the perception and knowledge on early-onset obesity was circulated to healthcare providers (general physicians, pediatricians, pediatric gastroenterologist, neonatologists) practicing in 17 Middle East and North African countries. A total of 999/1051 completed forms (95% response) were evaluated. Of all respondents, 28.9% did not consistently use growth charts to monitor growth during every visit and only 25.2% and 46.6% of respondents were aware of the correct cut-off criterion for overweight and obesity, respectively. Of those surveyed, 22.3, 14.0, 36.1, 48.2, and 49.1% of respondents did not consider hypertension, type 2 diabetes, coronary heart disease, fatty liver disease, and decreased life span, respectively, to be a long-term complication of early childhood obesity. Furthermore, only 0.7% of respondents correctly answered all survey questions pertaining to knowledge of early childhood overweight and obesity. The survey highlights the low use of growth charts in the evaluation of early childhood growth in Middle East and North Africa region, and demonstrated poor knowledge of healthcare providers on the short- and long-term complications of early-onset obesity. This suggests a need for both continued professional education and development, and implementation of guidelines for the prevention and management of early childhood overweight and obesity.

  15. Structural Insights into the Allosteric Operation of the Lon AAA+ Protease.

    PubMed

    Lin, Chien-Chu; Su, Shih-Chieh; Su, Ming-Yuan; Liang, Pi-Hui; Feng, Chia-Cheng; Wu, Shih-Hsiung; Chang, Chung-I

    2016-05-03

    The Lon AAA+ protease (LonA) is an evolutionarily conserved protease that couples the ATPase cycle into motion to drive substrate translocation and degradation. A hallmark feature shared by AAA+ proteases is the stimulation of ATPase activity by substrates. Here we report the structure of LonA bound to three ADPs, revealing the first AAA+ protease assembly where the six protomers are arranged alternately in nucleotide-free and bound states. Nucleotide binding induces large coordinated movements of conserved pore loops from two pairs of three non-adjacent protomers and shuttling of the proteolytic groove between the ATPase site and a previously unknown Arg paddle. Structural and biochemical evidence supports the roles of the substrate-bound proteolytic groove in allosteric stimulation of ATPase activity and the conserved Arg paddle in driving substrate degradation. Altogether, this work provides a molecular framework for understanding how ATP-dependent chemomechanical movements drive allosteric processes for substrate degradation in a major protein-destruction machine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. A pull-back algorithm to determine the unloaded vascular geometry in anisotropic hyperelastic AAA passive mechanics.

    PubMed

    Riveros, Fabián; Chandra, Santanu; Finol, Ender A; Gasser, T Christian; Rodriguez, Jose F

    2013-04-01

    Biomechanical studies on abdominal aortic aneurysms (AAA) seek to provide for better decision criteria to undergo surgical intervention for AAA repair. More accurate results can be obtained by using appropriate material models for the tissues along with accurate geometric models and more realistic boundary conditions for the lesion. However, patient-specific AAA models are generated from gated medical images in which the artery is under pressure. Therefore, identification of the AAA zero pressure geometry would allow for a more realistic estimate of the aneurysmal wall mechanics. This study proposes a novel iterative algorithm to find the zero pressure geometry of patient-specific AAA models. The methodology allows considering the anisotropic hyperelastic behavior of the aortic wall, its thickness and accounts for the presence of the intraluminal thrombus. Results on 12 patient-specific AAA geometric models indicate that the procedure is computational tractable and efficient, and preserves the global volume of the model. In addition, a comparison of the peak wall stress computed with the zero pressure and CT-based geometries during systole indicates that computations using CT-based geometric models underestimate the peak wall stress by 59 ± 64 and 47 ± 64 kPa for the isotropic and anisotropic material models of the arterial wall, respectively.

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

    NASA Astrophysics Data System (ADS)

    Osipov, Sergey; Dogar, Mohammad; Stenchikov, Georgiy

    2016-04-01

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

  18. Rubisco Activases: AAA+ Chaperones Adapted to Enzyme Repair

    PubMed Central

    Bhat, Javaid Y.; Thieulin-Pardo, Gabriel; Hartl, F. Ulrich; Hayer-Hartl, Manajit

    2017-01-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key enzyme of the Calvin-Benson-Bassham cycle of photosynthesis, requires conformational repair by Rubisco activase for efficient function. Rubisco mediates the fixation of atmospheric CO2 by catalyzing the carboxylation of the five-carbon sugar ribulose-1,5-bisphosphate (RuBP). It is a remarkably inefficient enzyme, and efforts to increase crop yields by bioengineering Rubisco remain unsuccessful. This is due in part to the complex cellular machinery required for Rubisco biogenesis and metabolic maintenance. To function, Rubisco must undergo an activation process that involves carboxylation of an active site lysine by a non-substrate CO2 molecule and binding of a Mg2+ ion. Premature binding of the substrate RuBP results in an inactive enzyme. Moreover, Rubisco can also be inhibited by a range of sugar phosphates, some of which are “misfire” products of its multistep catalytic reaction. The release of the inhibitory sugar molecule is mediated by the AAA+ protein Rubisco activase (Rca), which couples hydrolysis of ATP to the structural remodeling of Rubisco. Rca enzymes are found in the vast majority of photosynthetic organisms, from bacteria to higher plants. They share a canonical AAA+ domain architecture and form six-membered ring complexes but are diverse in sequence and mechanism, suggesting their convergent evolution. In this review, we discuss recent advances in understanding the structure and function of this important group of client-specific AAA+ proteins. PMID:28443288

  19. Rubisco Activases: AAA+ Chaperones Adapted to Enzyme Repair.

    PubMed

    Bhat, Javaid Y; Thieulin-Pardo, Gabriel; Hartl, F Ulrich; Hayer-Hartl, Manajit

    2017-01-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key enzyme of the Calvin-Benson-Bassham cycle of photosynthesis, requires conformational repair by Rubisco activase for efficient function. Rubisco mediates the fixation of atmospheric CO 2 by catalyzing the carboxylation of the five-carbon sugar ribulose-1,5-bisphosphate (RuBP). It is a remarkably inefficient enzyme, and efforts to increase crop yields by bioengineering Rubisco remain unsuccessful. This is due in part to the complex cellular machinery required for Rubisco biogenesis and metabolic maintenance. To function, Rubisco must undergo an activation process that involves carboxylation of an active site lysine by a non-substrate CO 2 molecule and binding of a Mg 2+ ion. Premature binding of the substrate RuBP results in an inactive enzyme. Moreover, Rubisco can also be inhibited by a range of sugar phosphates, some of which are "misfire" products of its multistep catalytic reaction. The release of the inhibitory sugar molecule is mediated by the AAA+ protein Rubisco activase (Rca), which couples hydrolysis of ATP to the structural remodeling of Rubisco. Rca enzymes are found in the vast majority of photosynthetic organisms, from bacteria to higher plants. They share a canonical AAA+ domain architecture and form six-membered ring complexes but are diverse in sequence and mechanism, suggesting their convergent evolution. In this review, we discuss recent advances in understanding the structure and function of this important group of client-specific AAA+ proteins.

  20. Evaluating ESA CCI Soil Moisture in East Africa

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  1. Evaluating ESA CCI soil moisture in East Africa.

    PubMed

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

    2016-06-01

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

  2. Determining the influence of calcification on the failure properties of abdominal aortic aneurysm (AAA) tissue.

    PubMed

    O'Leary, Siobhan A; Mulvihill, John J; Barrett, Hilary E; Kavanagh, Eamon G; Walsh, Michael T; McGloughlin, Tim M; Doyle, Barry J

    2015-02-01

    Varying degrees of calcification are present in most abdominal aortic aneurysms (AAAs). However, their impact on AAA failure properties and AAA rupture risk is unclear. The aim of this work is evaluate and compare the failure properties of partially calcified and predominantly fibrous AAA tissue and investigate the potential reasons for failure. Uniaxial mechanical testing was performed on AAA samples harvested from 31 patients undergoing open surgical repair. Individual tensile samples were divided into two groups: fibrous (n=31) and partially calcified (n=38). The presence of calcification was confirmed by fourier transform infrared spectroscopy (FTIR). A total of 69 mechanical tests were performed and the failure stretch (λf), failure stress (σf) and failure tension (Tf) were recorded for each test. Following mechanical testing, the failure sites of a subset of both tissue types were examined using scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) to investigate the potential reasons for failure. It has been shown that the failure properties of partially calcified tissue are significantly reduced compared to fibrous tissue and SEM and EDS results suggest that the junction between a calcification deposit and the fibrous matrix is highly susceptible to failure. This study implicates the presence of calcification as a key player in AAA rupture risk and provides further motivation for the development of non-invasive methods of measuring calcification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Foot-and-mouth Disease Transmission in Africa: Implications for Control, a Review.

    PubMed

    Tekleghiorghis, T; Moormann, R J M; Weerdmeester, K; Dekker, A

    2016-04-01

    In Africa, for the control of foot-and-mouth disease (FMD), more information is needed on the spread of the disease at local, regional and inter-regional level. The aim of this review is to identify the role that animal husbandry, trade and wildlife have on the transmission of FMD and to provide a scientific basis for different FMD control measures in Africa. Review of literature, published reports and databases shows that there is more long distance spread of FMD virus serotypes within North, West, Central and East Africa than in southern Africa. In North, West, Central and East Africa migratory animal husbandry systems often related with search for grazing and water as well as trade are practiced to a greater extent than in southern Africa. In southern Africa, the role of African buffalo (Syncerus caffer) is more extensively studied than in the other parts of Africa, but based on the densities of African buffalo in Central and East Africa, one would assume that buffalo should also play a role in the epidemiology of FMD in this part of Africa. More sampling of buffalo is necessary in West, Central and East Africa. The genetic analysis of virus strains has proven to be valuable to increase our understanding in the spread of FMD in Africa. This review shows that there is a difference in FMD occurrence between southern Africa and the rest of the continent; this distinction is most likely based on differences in animal husbandry and trade systems. Insufficient data on FMD in wildlife outside southern Africa is limiting our understanding on the role wildlife plays in the transmission of FMD in the other buffalo inhabited areas of Africa. © 2014 Blackwell Verlag GmbH.

  4. National dosimetric audit network finds discrepancies in AAA lung inhomogeneity corrections.

    PubMed

    Dunn, Leon; Lehmann, Joerg; Lye, Jessica; Kenny, John; Kron, Tomas; Alves, Andrew; Cole, Andrew; Zifodya, Jackson; Williams, Ivan

    2015-07-01

    This work presents the Australian Clinical Dosimetry Service's (ACDS) findings of an investigation of systematic discrepancies between treatment planning system (TPS) calculated and measured audit doses. Specifically, a comparison between the Anisotropic Analytic Algorithm (AAA) and other common dose-calculation algorithms in regions downstream (≥2cm) from low-density material in anthropomorphic and slab phantom geometries is presented. Two measurement setups involving rectilinear slab-phantoms (ACDS Level II audit) and anthropomorphic geometries (ACDS Level III audit) were used in conjunction with ion chamber (planar 2D array and Farmer-type) measurements. Measured doses were compared to calculated doses for a variety of cases, with and without the presence of inhomogeneities and beam-modifiers in 71 audits. Results demonstrate a systematic AAA underdose with an average discrepancy of 2.9 ± 1.2% when the AAA algorithm is implemented in regions distal from lung-tissue interfaces, when lateral beams are used with anthropomorphic phantoms. This systemic discrepancy was found for all Level III audits of facilities using the AAA algorithm. This discrepancy is not seen when identical measurements are compared for other common dose-calculation algorithms (average discrepancy -0.4 ± 1.7%), including the Acuros XB algorithm also available with the Eclipse TPS. For slab phantom geometries (Level II audits), with similar measurement points downstream from inhomogeneities this discrepancy is also not seen. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  5. Adipocytes and abdominal aortic aneurysm: Putative potential role of adipocytes in the process of AAA development.

    PubMed

    Kugo, Hirona; Moriyama, Tatsuya; Zaima, Nobuhiro

    2018-01-15

    Background Adipose tissue plays a role in the storage of excess energy as triglycerides (TGs). Excess fat accumulation causes various metabolic and cardiovascular diseases. It has been reported that ectopic fat deposition and excess TG accumulation in non-adipose tissue might be important predictors of cardiometabolic and vascular risk. For example, ectopic fat in perivascular tissue promotes atherosclerotic plaque formation in the arterial wall. Objective Recently, it has been reported that ectopic fat (adipocyte) in the vascular wall of an abdominal aortic aneurysm (AAA) is present in both human and experimental animal models. The pathological significance of adipocytes in the AAA wall has not been fully understood. In this review, we summarized the functions of adipocytes and discussed potential new drugs that target vascular adipocytes for AAA treatment. Result Previous studies suggest that adipocytes in vascular wall play an important role in the development of AAA. Conclusion Adipocytes in the vascular wall could be novel targets for the development of AAA therapeutic drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Evidence for mafic lower crust in Tanzania, East Africa, from joint inversion of receiver functions and Rayleigh wave dispersion velocities

    NASA Astrophysics Data System (ADS)

    Julià, Jordi; Ammon, Charles J.; Nyblade, Andrew A.

    2005-08-01

    The S-wave velocity structure of Precambrian terranes in Tanzania, East Africa is modelled by jointly inverting receiver functions and surface wave dispersion velocities from the 1994-1995 Tanzania broad-band seismic experiment. The study region, which consists of an Archean craton surrounded by Proterozoic mobile belts, forms a unique setting for evaluating Precambrian crustal evolution. Our results show a uniform crustal structure across the region, with a 10-15 km thick upper crust with VS= 3.4-3.5 km s-1, overlying a gradational lower crust with S-wave velocities up to 4.1 km s-1 at 38-42 km depth. The upper-mantle lid displays uniform S-wave velocities of 4.5-4.7 km s-1 to depths of 100-150 km and overlays a prominent low-velocity zone. This low-velocity zone is required by the dispersion and receiver function data, but its depth interval is uncertain. The high crustal velocities within the lowermost crust characterize the entire region and suggest that mafic lithologies are present in both Archean and Proterozoic terranes. The ubiquitous mafic lower crust can be attributed to underplating associated with mafic dyke emplacement. This finding suggests that in East Africa there has been little secular variation in Precambrian crustal development.

  7. Analysis of a Typical Chinese High School Biology Textbook Using the AAAS Textbook Standards

    ERIC Educational Resources Information Center

    Liang, Ye; Cobern, William W.

    2013-01-01

    The purpose of this study was to evaluate a typical Chinese high school biology textbook using the textbook standards of the American Association for the Advancement of Science (AAAS). The data were composed of three chapters selected from the textbook. Each chapter was analyzed and rated using the AAAS textbook standards. Pearson correlations…

  8. Realizing Universal Health Coverage in East Africa: the relevance of human rights.

    PubMed

    Yamin, Alicia Ely; Maleche, Allan

    2017-08-03

    Applying a robust human rights framework would change thinking and decision-making in efforts to achieve Universal Health Coverage (UHC), and advance efforts to promote women's, children's, and adolescents' health in East Africa, which is a priority under the Sustainable Development Agenda. Nevertheless, there is a gap between global rhetoric of human rights and ongoing health reform efforts. This debate article seeks to fill part of that gap by setting out principles of human rights-based approaches (HRBAs), and then applying those principles to questions that countries undertaking efforts toward UHC and promoting women's, children's and adolescents' health, will need to face, focusing in particular on ensuring enabling legal and policy frameworks, establishing fair financing; priority-setting processes, and meaningful oversight and accountability mechanisms. In a region where democratic institutions are notoriously weak, we argue that the explicit application of a meaningful human rights framework could enhance equity, participation and accountability, and in turn the democratic legitimacy of health reform initiatives being undertaken in the region.

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

    PubMed

    Beckerleg, Susan

    2008-07-01

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

  10. Emerging East Africa Analysis Brief

    EIA Publications

    2013-01-01

    Although oil and natural gas exploration has been going on for decades in various East African countries, there has been limited success until recently. In the past there were doubts about the amount of recoverable resources in the region, along with regional and civil conflicts that presented challenges and risks to foreign companies.

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

    PubMed Central

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

    2011-01-01

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

  12. Some like it hot: the influence and implications of climate change on coffee berry borer (Hypothenemus hampei) and coffee production in East Africa.

    PubMed

    Jaramillo, Juliana; Muchugu, Eric; Vega, Fernando E; Davis, Aaron; Borgemeister, Christian; Chabi-Olaye, Adenirin

    2011-01-01

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

  13. Chemical ecology: studies from East Africa.

    PubMed

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

    1978-03-17

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

  14. SOFIA Technology: The NASA Airborne Astronomy Ambassador (AAA) Experience and Online Resources

    NASA Astrophysics Data System (ADS)

    Clark, C.; Harman, P. K.; Backman, D. E.

    2016-12-01

    SOFIA, an 80/20 partnership of NASA and the German Aerospace Center (DLR), consists of a modified Boeing 747SP carrying a reflecting telescope with an effective diameter of 2.5 meters. SOFIA is the largest airborne observatory in the world, capable of observations impossible for even the largest and highest ground-based telescopes. The SOFIA Program Office is at NASA ARC, Moffett Field, CA; the aircraft is based in Palmdale, CA. During its planned 20-year lifetime, SOFIA will foster development of new scientific instrumentation and inspire the education of young scientists and engineers. Astrophysicists are awarded time on SOFIA to study many kinds of astronomical objects and phenomena. Among the most interesting are: Star birth, evolution, and death Formation of new planetary systems Chemistry of complex molecules in space Planet and exoplanet atmospheres Galactic gas & dust "ecosystems" Environments around supermassive black holes SOFIA currently has eight instruments, five US-made and three German. The instruments — cameras, spectrometers, and a photometer,— operate at near-, mid- and far-infrared wavelengths, each spectral range being best suited to studying particular celestial phenomena. NASA's Airborne Astronomy Ambassadors' (AAAs) experience includes a STEM immersion component. AAAs are onboard during two overnight SOFIA flights that provide insight into the acquisition of scientific data as well as the interfaces between the telescope, instrument, & aircraft. AAAs monitor system performance and view observation targets from their dedicated workstation during flights. Future opportunities for school district partnerships leading to selection of future AAA cohorts will be offered in 2018-19. AAAs may access public archive data via the SOFIA Data Cycle System (DCS) https://dcs.sofia.usra.edu/. Additional SOFIA science and other resources are available at: www.sofia.usra.edu, including lessons that use photovoltaic circuits, and other technology for the

  15. Increased AAA-TOB3 correlates with lymph node metastasis and advanced stage of lung adenocarcinoma.

    PubMed

    Liu, Yanfeng; Bu, Lina; Li, Wei; Wu, Wei; Wang, Shengyu; Diao, Xin; Zhou, Jing; Chen, Guoan; Yang, Shuanying

    2017-07-24

    This study was to investigate the differential mitochondrial protein expressions in human lung adenocarcinoma and provide preliminary data for further exploration of the carcinogenic mechanism. Total proteins of A549 and 16HBE mitochondria were extracted through 2D polyacrylamide gel electrophoresis (2-DE). The differential mitochondria proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and were further confirmed by Western blot, immunoelectron microscopy and immunohistochemistry (IHC) in A549 cells as well as lung adenocarcinoma tissues. A total of 41 differentially expressed protein spots were found in A549 mitochondria. Of them, 15 proteins were highly expressed and 26 proteins were lowly expressed in the mitochondria of A549 (by more than 1.5 times). Among the 15 more highly expressed proteins, AAA-TOB3 (by more than 3 times) was highly expressed in the mitochondria of A549 compared with the 16HBE, by LC-MS/MS identification. High electron density and clear circular colloidal gold-marked AAA-TOB3 particles were observed in the A549 cells via immunoelectron microscopy. Besides, AAA-TOB3 was confirmed to be elevated in lung adenocarcinoma by Western blot and IHC. Moreover, increased AAA-TOB3 correlated with lymph node metastasis and advanced stage of lung adenocarcinoma (p<0.05). AAA-TOB3 was highly expressed in lung adenocarcinoma, and the up-regulation of AAA-TOB3 correlated with lymph node metastasis and advanced stage of lung adenocarcinoma, which suggested that it could serve as a potential molecular marker for lung adenocarcinoma.

  16. Clinical implementation of AXB from AAA for breast: Plan quality and subvolume analysis.

    PubMed

    Guebert, Alexandra; Conroy, Leigh; Weppler, Sarah; Alghamdi, Majed; Conway, Jessica; Harper, Lindsay; Phan, Tien; Olivotto, Ivo A; Smith, Wendy L; Quirk, Sarah

    2018-05-01

    Two dose calculation algorithms are available in Varian Eclipse software: Anisotropic Analytical Algorithm (AAA) and Acuros External Beam (AXB). Many Varian Eclipse-based centers have access to AXB; however, a thorough understanding of how it will affect plan characteristics and, subsequently, clinical practice is necessary prior to implementation. We characterized the difference in breast plan quality between AXB and AAA for dissemination to clinicians during implementation. Locoregional irradiation plans were created with AAA for 30 breast cancer patients with a prescription dose of 50 Gy to the breast and 45 Gy to the regional node, in 25 fractions. The internal mammary chain (IMC CTV ) nodes were covered by 80% of the breast dose. AXB, both dose-to-water and dose-to-medium reporting, was used to recalculate plans while maintaining constant monitor units. Target coverage and organ-at-risk doses were compared between the two algorithms using dose-volume parameters. An analysis to assess location-specific changes was performed by dividing the breast into nine subvolumes in the superior-inferior and left-right directions. There were minimal differences found between the AXB and AAA calculated plans. The median difference between AXB and AAA for breast CTV V 95% , was <2.5%. For IMC CTV , the median differences V 95% , and V 80% were <5% and 0%, respectively; indicating IMC CTV coverage only decreased when marginally covered. Mean superficial dose increased by a median of 3.2 Gy. In the subvolume analysis, the medial subvolumes were "hotter" when recalculated with AXB and the lateral subvolumes "cooler" with AXB; however, all differences were within 2 Gy. We observed minimal difference in magnitude and spatial distribution of dose when comparing the two algorithms. The largest observable differences occurred in superficial dose regions. Therefore, clinical implementation of AXB from AAA for breast radiotherapy is not expected to result in changes in clinical

  17. Engineering Silicone Rubbers for In vitro Studies: Creating AAA Models and ILT Analogues with Physiological Properties

    PubMed Central

    Corbett, T.J.; Doyle, B.J.; Callanan, A.; Walsh, M.T.; McGloughlin, T.M

    2010-01-01

    Background In vitro studies of abdominal aortic aneurysm (AAA) have been widely reported. Frequently mock artery models with intraluminal thrombus (ILT) analogues are used to mimic the AAA in vivo. While the models used may be physiological, their properties are frequently either not reported or investigated. Method of Approach This study is concerned with the testing and characterisation of previously used vessel analogue materials and the development of new materials for the manufacture of AAA models. These materials were used in conjunction with a previously validated injection moulding technique to manufacture AAA models of ideal geometry. To determine the model properties (stiffness (β) and compliance) the diameter change of each AAA model was investigated under incrementally increasing internal pressures and compared to published in vivo studies to determine if the models behaved physiologically. A FEA study was implemented to determine if the pressure – diameter change behaviour of the models could be predicted numerically. ILT analogues were also manufactured and characterised. Ideal models were manufactured with ILT analogue internal to the aneurysm region and the effect of the ILT analogue on the model compliance and stiffness was investigated. Results The wall materials had similar properties to aortic tissue at physiological pressures (Einit 2.22MPa and 1.57MPa (aortic tissue: 1.8MPa)). ILT analogues had similar Young’s modulus to the medial layer of ILT (0.24 and 0.33MPa (ILT: 0.28MPa)). All models had aneurysm sac compliance in the physiological range (2.62 – 8.01×10-4/mmHg (AAA in vivo: 1.8 – 9.4×10-4/mmHg)). The necks of our AAA models had similar stiffness to healthy aortas (20.44 – 29.83 (healthy aortas in vivo: 17.5±5.5)). Good agreement was seen between the diameter changes due to pressurisation in the experimental and FEA wall models with a maximum error of 7.3% at 120mmHg. It was also determined that the inclusion of ILT analogue

  18. Incarceration or mandatory treatment: Drug use and the law in the Middle East and North Africa.

    PubMed

    Al-Shazly, Fattouh; Tinasti, Khalid

    2016-05-01

    In the Middle East and North Africa (MENA), drug policies are embedded in the prohibition paradigm. Laws and legislation criminalize all types of activities related to illicit drugs. This article gives a detailed assessment of the provisions of Arab national laws to control the use of illicit drugs across the areas of punishment of drug users, penalties for drug dependence, legislation on use and dependence treatment, and the right of the convicted people who use drugs to confidentiality. It reviews the national legislations on drug control of 16 Arab countries as amended in January 2011. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  20. Modeling East Asian Dust and Its Radiative Feedbacks in CAM4-BAM

    NASA Astrophysics Data System (ADS)

    Xie, Xiaoning; Liu, Xiaodong; Che, Huizheng; Xie, Xiaoxun; Wang, Hongli; Li, Jiandong; Shi, Zhengguo; Liu, Yangang

    2018-01-01

    East Asian dust and its radiative feedbacks are analyzed by the use of the fourth version of the Community Atmosphere Model (CAM4) with a bulk aerosol model parameterization (BAM) for the dust size distribution (CAM4-BAM). Two numerical experiments are conducted and intercompared: one with (Active) and one without (Passive) the radiative effects of dust aerosols. This CAM4-BAM captures the main spatial distribution of the dust aerosol optical depth (AOD) and the dust surface concentrations over East Asia, with positive correlations with the local observational data on annual and seasonal means. A comparative analysis of the Active and Passive experiments reveals that consideration of the dust-radiation interaction can significantly reduce dust emissions, loading, transport, and dry and wet depositions over East Asia, which is opposite to the enhanced dust cycle over North Africa. Further analysis of the contrasting dust-radiation feedbacks between North Africa and East Asia shows that over North Africa, the dust radiative forcing significantly increases the surface temperature and 10 m wind speed, whereas it decreases the surface temperature and the surface wind speeds over East Asia. These contrasting radiative effects, in turn, result in distinct dust cycle changes over these two regions. Mechanistic analysis reveals that the radiative contrasts between East Asia and North Africa are mainly due to the differences in their regional surface albedo, dust vertical distribution, and size distribution.

  1. Introducing AAA-MS, a rapid and sensitive method for amino acid analysis using isotope dilution and high-resolution mass spectrometry.

    PubMed

    Louwagie, Mathilde; Kieffer-Jaquinod, Sylvie; Dupierris, Véronique; Couté, Yohann; Bruley, Christophe; Garin, Jérôme; Dupuis, Alain; Jaquinod, Michel; Brun, Virginie

    2012-07-06

    Accurate quantification of pure peptides and proteins is essential for biotechnology, clinical chemistry, proteomics, and systems biology. The reference method to quantify peptides and proteins is amino acid analysis (AAA). This consists of an acidic hydrolysis followed by chromatographic separation and spectrophotometric detection of amino acids. Although widely used, this method displays some limitations, in particular the need for large amounts of starting material. Driven by the need to quantify isotope-dilution standards used for absolute quantitative proteomics, particularly stable isotope-labeled (SIL) peptides and PSAQ proteins, we developed a new AAA assay (AAA-MS). This method requires neither derivatization nor chromatographic separation of amino acids. It is based on rapid microwave-assisted acidic hydrolysis followed by high-resolution mass spectrometry analysis of amino acids. Quantification is performed by comparing MS signals from labeled amino acids (SIL peptide- and PSAQ-derived) with those of unlabeled amino acids originating from co-hydrolyzed NIST standard reference materials. For both SIL peptides and PSAQ standards, AAA-MS quantification results were consistent with classical AAA measurements. Compared to AAA assay, AAA-MS was much faster and was 100-fold more sensitive for peptide and protein quantification. Finally, thanks to the development of a labeled protein standard, we also extended AAA-MS analysis to the quantification of unlabeled proteins.

  2. Snowpack Variation and Hydrologic Impacts across the Middle East and North Africa

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Ward, M. N.

    2017-12-01

    The Middle East is a region historically sensitive to climate variability and change, and contains snowpacks that have been shown to be important inputs to key regional water resources, including the Tigris-Euphrates river system. Focusing on the Middle East (and the smaller snowpacks of northwestern Africa), this presentation aims to (i) quantify each year's snowpack development and recession over recent decades, highlighting interannual to decadal variability, and (ii) advance understanding on the connection between the snowpack variations and aspects of regional hydrology. The presentation draws on satellite-based products, station data, and model reanalyses. Variation is summarized using space-time statistical techniques, as well as simpler regional indices: Northwestern Iran / Southern Caucasus (NWIC, includes Zagros Mountains); Eastern Turkey (ETKY, includes Taurus Mountains); and smaller scale indices for Lebanon and the Atlas Mountains. The Interactive Multisensor Snow and Ice Mapping System archives daily snow cover extent at 24 km resolution for 1999-present (primarily from visible satellite imagery). These data show that for both NWIC and ETKY, the mean snow extent peaks in late January with substantial coverage ( 300,000 km2 in each region), contracting to near zero by late June. A very large mid-winter interannual variance is also shown, implying substantial variation in hydrologic impacts during spring melt. Variability and decadal trends are compared with station snow depth reports (Global Historical Climatology Network - Daily). Strong agreement gives confidence in data quality, as well as, indicating high covariation of depth and extent. The connection with hydrologic impacts is investigated using reanalysis products, including the Global Land Data Assimilation System V2, which for the Middle East, shows broad agreement with observed maximum snow extent and spring retreat. The connections internal to the reanalysis between snow cover, melt and

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

    PubMed Central

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

    2012-01-01

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

  4. Molecular insights into the m-AAA protease-mediated dislocation of transmembrane helices in the mitochondrial inner membrane.

    PubMed

    Lee, Seoeun; Lee, Hunsang; Yoo, Suji; Kim, Hyun

    2017-12-08

    Protein complexes involved in respiration, ATP synthesis, and protein import reside in the mitochondrial inner membrane; thus, proper regulation of these proteins is essential for cell viability. The m -AAA protease, a conserved hetero-hexameric AAA (ATPase associated with diverse cellular activities) protease, composed of the Yta10 and Yta12 proteins, regulates mitochondrial proteostasis by mediating protein maturation and degradation. It also recognizes and mediates the dislocation of membrane-embedded substrates, including foreign transmembrane (TM) segments, but the molecular mechanism involved in these processes remains elusive. This study investigated the role of the TM domains in the m -AAA protease by systematic replacement of one TM domain at a time in yeast. Our data indicated that replacement of the Yta10 TM2 domain abolishes membrane dislocation for only a subset of substrates, whereas replacement of the Yta12 TM2 domain impairs membrane dislocation for all tested substrates, suggesting different roles of the TM domains in each m -AAA protease subunit. Furthermore, m -AAA protease-mediated membrane dislocation was impaired in the presence of a large downstream hydrophilic moiety in a membrane substrate. This finding suggested that the m -AAA protease cannot dislocate large hydrophilic domains across the membrane, indicating that the membrane dislocation probably occurs in a lipid environment. In summary, this study highlights previously underappreciated biological roles of TM domains of the m -AAA proteases in mediating the recognition and dislocation of membrane-embedded substrates. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Astronomy Landscape in Africa

    NASA Astrophysics Data System (ADS)

    Nemaungani, Takalani

    2015-01-01

    The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  7. Does Water Hyacinth on East African Lakes Promote Cholera Outbreaks?

    PubMed Central

    Feikin, Daniel R.; Tabu, Collins W.; Gichuki, John

    2010-01-01

    Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate on the floating aquatic plant, water hyacinth, which is periodically widespread in East African lakes since the late 1980s. From 1994 to 2008, Nyanza Province, which is the Kenyan province bordering Lake Victoria, accounted for a larger proportion of cholera cases than expected by its population size (38.7% of cholera cases versus 15.3% of national population). Yearly water-hyacinth coverage on the Kenyan section of Lake Victoria was positively associated with the number of cholera cases reported in Nyanza Province (r = 0.83; P = 0.0010). Water hyacinth on freshwater lakes might play a role in initiating cholera outbreaks and causing sporadic disease in East Africa. PMID:20682884

  8. SU-F-T-609: Impact of Dosimetric Variation for Prescription Dose Using Analytical Anisotropic Algorithm (AAA) in Lung SBRT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kawai, D; Takahashi, R; Kamima, T

    Purpose: Actual irradiated prescription dose to patients cannot be verified. Thus, independent dose verification and second treatment planning system are used as the secondary check. AAA dose calculation engine has contributed to lung SBRT. We conducted a multi-institutional study to assess variation of prescription dose for lung SBRT when using AAA in reference to using Acuros XB and Clarkson algorithm. Methods: Six institutes in Japan participated in this study. All SBRT treatments were planed using AAA in Eclipse and Adaptive Convolve (AC) in Pinnacle3. All of the institutes used a same independent dose verification software program (Simple MU Analysis: SMU,more » Triangle Product, Ishikawa, Japan), which implemented a Clarkson-based dose calculation algorithm using CT image dataset. A retrospective analysis for lung SBRT plans (73 patients) was performed to compute the confidence limit (CL, Average±2SD) in dose between the AAA and the SMU. In one of the institutes, a additional analysis was conducted to evaluate the variations between the AAA and the Acuros XB (AXB). Results: The CL for SMU shows larger systematic and random errors of 8.7±9.9 % for AAA than the errors of 5.7±4.2 % for AC. The variations of AAA correlated with the mean CT values in the voxels of PTV (a correlation coefficient : −0.7) . The comparison of AXB vs. AAA shows smaller systematic and random errors of −0.7±1.7%. The correlation between dose variations for AXB and the mean CT values in PTV was weak (0.4). However, there were several plans with more than 2% deviation of AAPM TG114 (Maximum: −3.3 %). Conclusion: In comparison for AC, prescription dose calculated by AAA may be more variable in lung SBRT patient. Even AXB comparison shows unexpected variation. Care should be taken for the use of AAA in lung SBRT. This research is partially supported by Japan Agency for Medical Research and Development (AMED)« less

  9. Increased galectin-3 levels are associated with abdominal aortic aneurysm progression and inhibition of galectin-3 decreases elastase-induced AAA development.

    PubMed

    Fernandez-García, Carlos-Ernesto; Tarin, Carlos; Roldan-Montero, Raquel; Martinez-Lopez, Diego; Torres-Fonseca, Monica; Lindhot, Jes S; Vega de Ceniga, Melina; Egido, Jesus; Lopez-Andres, Natalia; Blanco-Colio, Luis-Miguel; Martín-Ventura, Jose-Luis

    2017-11-15

    Abdominal aortic aneurysm (AAA) evolution is unpredictable and no specific treatment exists for AAA, except surgery to prevent aortic rupture. Galectin-3 has been previously associated with CVD, but its potential role in AAA has not been addressed. Galectin-3 levels were increased in the plasma of AAA patients ( n =225) compared with the control group ( n =100). In addition, galectin-3 concentrations were associated with the need for surgical repair, independently of potential confounding factors. Galectin-3 mRNA and protein expression were increased in human AAA samples compared with healthy aortas. Experimental AAA in mice was induced via aortic elastase perfusion. Mice were treated intravenously with the galectin-3 inhibitor modified citrus pectin (MCP, 10 mg/kg, every other day) or saline. Similar to humans, galectin-3 serum and aortic mRNA levels were also increased in elastase-induced AAA mice compared with control mice. Mice treated with MCP showed decreased aortic dilation, as well as elastin degradation, vascular smooth muscle cell (VSMC) loss, and macrophage content at day 14 postelastase perfusion compared with control mice. The underlying mechanism(s) of the protective effect of MCP was associated with a decrease in galectin-3 and cytokine (mainly CCL5) mRNA and protein expression. Interestingly, galectin-3 induced CCL5 expression by a mechanism involving STAT3 activation in VSMC. Accordingly, MCP treatment decreased STAT3 phosphorylation in elastase-induced AAA. In conclusion, increased galectin-3 levels are associated with AAA progression, while galectin-3 inhibition decreased experimental AAA development. Our data suggest the potential role of galectin-3 as a therapeutic target in AAA. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  10. Prevalence of previously undiagnosed abdominal aortic aneurysms in the area of Como: the ComoCuore "looking for AAA" ultrasonography screening.

    PubMed

    Corrado, Giovanni; Durante, Alessandro; Genchi, Vincenzo; Trabattoni, Loris; Beretta, Sandro; Rovelli, Enza; Foglia-Manzillo, Giovanni; Ferrari, Giovanni

    2016-08-01

    The prognosis for abdominal aortic aneurysm (AAA) rupture is poor. Long-term follow-up of population-based randomized trials has demonstrated that ultrasound (US) screening for abdominal aortic aneurysms (AAAs) measuring 3 cm or greater decreases AAA-related mortality rates and is cost-effective. We though to prospectively perform during a 26-month period a limited US examination of the infrarenal aorta in volunteers of both gender aged 60-85 years without history of AAA living in the area of Como, Italy. From September 2010 to November 2013 ComoCuore, a no-profit nongovernmental association, enrolled 1555 people (aged 68.8 ± 6.8 years; 48.6 % males). Clinical data and a US imaging of the aorta were collected for each participant. AAA was found in 22 volunteers (1.4 %) mainly males (2.5 % in males vs. 0.4 % in females p = 0.005). Overall, the prevalence of cardiovascular risk factors was higher in patients with vs. without AAA (mean 2.9 ± 3.0 vs. 1.4 ± 1.0 respectively, p < 0.0001). Independent predictors of AAA on multivariate analysis were age (OR 1.14, 1.06-1.22; p < 0.0001), male gender (OR 8.23, 1.79-37.91; p = 0.007), and both current (OR 4.98, 1.57-15.79; p = 0.007) and previous smoking (OR 2.76, 1.12-8.94; p = 0.03). Our study confirms the feasibility of one time US screening for AAA in a large cohort of asymptomatic people. Independent predictors of AAA were male sex, older age and a history of smoking. Accordingly to recent data the prevalence of AAA seems to be declining, maybe due to a reduction of smoking in Italy.

  11. Ecosystem productivity and water stress in tropical East Africa: A Case Study of the 2010-11 drought

    NASA Astrophysics Data System (ADS)

    Robinson, E. S.; Yang, X.; Lee, J. E.

    2015-12-01

    The characterization of changes in ecosystem productivity as a consequence of water stress and changing precipitation regimes is critical in defining the response of tropical ecosystems to water stress and projecting future land cover transitions in the East African tropics. Through the analysis of solar-induced chlorophyll fluorescence (SIF), soil moisture, rainfall and reanalysis data, this paper characterizes the 2010-11 drought in tropical East Africa. We demonstrated that SIF, a proxy of ecosystem productivity, varied with water availability during the 2010-11 drought. A comparison of the 2010-11 drought to previous regional droughts revealed that the consecutive failure of rainy seasons in fall 2010 and spring 2011 yielded a drought that is distinguished not only in intensity, but also in spatial and temporal extent as compared to an average of previous regional droughts: the 2010-11 event extended further east and with greater intensity in the southern hemisphere. Anomalously low SIF values during the 2010-11 drought are strongly correlated with those of soil moisture and precipitation. SIF also demonstrated a stronger temporal sensitivity to accumulated water deficit as compared to the conventional Normalized Difference Vegetation Index (NDVI), which approximates photosynthetic potential (chlorophyll content and leaf mass), from the Moderate Resolution Imaging Spectroradiometer (MODIS). Anomalously high rainfall during the dry seasons preceding failed rainy seasons suggest that the seasonality of East African rainfall may be transitioning from a regime characterized by biannual monsoons to one with increasing convective rainfall. Rising boundary layer height during the dry season further substantiates this conclusion by suggesting a transition towards increased deep convection during the summers. This work demonstrated the unique characteristics of the 2010-11 East African drought, and the ability of SIF to track the levels of water stress during the

  12. SU-F-T-413: Calculation Accuracy of AAA and Acuros Using Cerrobend Blocks for TBI at 400cm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lamichhane, N; Studenski, M

    2016-06-15

    Purpose: It is essential to assess the lung dose during TBI to reduce toxicity. Here we characterize the accuracy of the AAA and Acuros algorithms when using cerrobend lung shielding blocks at an extended distance for TBI. Methods: We positioned a 30×30×30 cm3 solid water slab phantom at 400 cm SSD and measured PDDs (Exradin A12 and PTW parallel plate ion chambers). A 2 cm thick, 10×10 cm2 cerrobend block was hung 2 cm in front of the phantom. This geometry was reproduced in the planning system for both AAA and Acuros. In AAA, the mass density of the cerrobendmore » block was forced to 9.38 g/cm3 and in Acuros it was forced to 8.0 g/cm3 (limited to selecting stainless steel). Three different relative electron densities (RED) were tested for each algorithm; 4.97, 6.97, and 8.97. Results: PDDs from both Acuros and AAA underestimated the delivered dose. AAA calculated that depth dose was higher for RED of 4.97 as compared to 6.97 and 8.97 but still lower than measured. There was no change in the percent depth dose with changing relative electron densities for Acuros. Conclusion: Care should be taken before using AAA or Acuros with cerrobend blocks as the planning system underestimates dose. Acuros limits the ability to modify RED when compared to AAA.« less

  13. A New Tephrochronology for Early Diverse Stone Tool Technologies and Long-Distance Raw Material Transport in the Middle-Late Pleistocene Kapthurin Formation, East Africa.

    NASA Astrophysics Data System (ADS)

    Blegen, N.; Jicha, B.

    2017-12-01

    The Middle to Late Pleistocene (780-10 ka) of East Africa records significant behavioral change, the earliest fossils of Homo sapiens and the dispersals of our species across and out of Africa. Studying human evolution in the Middle to Late Pleistocene thus requires an extensive and precise chronology relating the appearances of various behaviors preserved in archaeological sequences to aspects of hominin biology and evidence of past environments preserved in the fossils and geological sequences. Tephrochronology provides the chronostratigraphic resolution to achieve this through correlation and dating of volcanic ashes. The tephrochronology of the Kapthurin Formation presented here, based on tephra correlations and 40Ar/ 39Ar dates, provides new ages between 396.3 ± 3.4 ka and 465.3 ± 1.0 ka for nine sites showing some of the earliest evidence of diverse blade and Levallois methods of core reduction. These are >110 kyr older than previously known in East Africa. New 40Ar/ 39Ar dates provide a refined age of 222.5 ± 0.6 ka for early evidence of long-distance obsidian transport at the Sibilo School Road Site. Long-distance tephra correlation between the Baringo and Lake Victoria basins also provides a new date of 100 ka for the Middle Stone Age site of Keraswanin. By providing new or older dates for 11 sites containing several important aspects of hominin behavior and extending the chronology of the Kapthurin Formation forward by 130,000 years, the tephrochronology presented here contributes one of the longest and most refined chronostratigraphic frameworks relevant to modern human evolution. In conjunction with recent archaeological and paleoenvironmental data, this tephrochronology provides the foundation to understand the process of modern human behavioral evolution through the East African Middle and Late Pleistocene as it relates to biological and paleoenvironmental circumstances.

  14. Mantle plumes and associated flow beneath Arabia and East Africa

    NASA Astrophysics Data System (ADS)

    Chang, Sung-Joon; Van der Lee, Suzan

    2011-02-01

    We investigate mantle plumes and associated flow beneath the lithosphere by imaging the three-dimensional S-velocity structure beneath Arabia and East Africa. This image shows elongated vertical and horizontal low-velocity anomalies down to at least mid mantle depths. This three-dimensional S-velocity model is obtained through the joint inversion of teleseismic S- and SKS-arrival times, regional S- and Rayleigh waveform fits, fundamental-mode Rayleigh-wave group velocities, and independent Moho constraints from receiver functions, reflection/refraction profiles, and gravity measurements. In the resolved parts of our S-velocity model we find that the Afar plume is distinctly separate from the Kenya plume, showing the Afar plume's origin in the lower mantle beneath southwestern Arabia. We identify another quasi-vertical low-velocity anomaly beneath Jordan and northern Arabia which extends into the lower mantle and may be related to volcanism in Jordan, northern Arabia, and possibly southern Turkey. Comparing locations of mantle plumes from the joint inversion with fast axes of shear-wave splitting, we confirm horizontal mantle flow radially away from Afar. Low-velocity channels in our model support southwestward flow beneath Ethiopia, eastward flow beneath the Gulf of Aden, but not northwestwards beneath the entire Red Sea. Instead, northward mantle flow from Afar appears to be channeled beneath Arabia.

  15. Structural Insights into the Unusually Strong ATPase Activity of the AAA Domain of the Caenorhabditis elegans Fidgetin-like 1 (FIGL-1) Protein*

    PubMed Central

    Peng, Wentao; Lin, Zhijie; Li, Weirong; Lu, Jing; Shen, Yuequan; Wang, Chunguang

    2013-01-01

    The FIGL-1 (fidgetin like-1) protein is a homolog of fidgetin, a protein whose mutation leads to multiple developmental defects. The FIGL-1 protein contains an AAA (ATPase associated with various activities) domain and belongs to the AAA superfamily. However, the biological functions and developmental implications of this protein remain unknown. Here, we show that the AAA domain of the Caenorhabditis elegans FIGL-1 protein (CeFIGL-1-AAA), in clear contrast to homologous AAA domains, has an unusually high ATPase activity and forms a hexamer in solution. By determining the crystal structure of CeFIGL-1-AAA, we found that the loop linking helices α9 and α10 folds into the short helix α9a, which has an acidic surface and interacts with a positively charged surface of the neighboring subunit. Disruption of this charge interaction by mutagenesis diminishes both the ATPase activity and oligomerization capacity of the protein. Interestingly, the acidic residues in helix α9a of CeFIGL-1-AAA are not conserved in other homologous AAA domains that have relatively low ATPase activities. These results demonstrate that the sequence of CeFIGL-1-AAA has adapted to establish an intersubunit charge interaction, which contributes to its strong oligomerization and ATPase activity. These unique properties of CeFIGL-1-AAA distinguish it from other homologous proteins, suggesting that CeFIGL-1 may have a distinct biological function. PMID:23979136

  16. Structural insights into the unusually strong ATPase activity of the AAA domain of the Caenorhabditis elegans fidgetin-like 1 (FIGL-1) protein.

    PubMed

    Peng, Wentao; Lin, Zhijie; Li, Weirong; Lu, Jing; Shen, Yuequan; Wang, Chunguang

    2013-10-11

    The FIGL-1 (fidgetin like-1) protein is a homolog of fidgetin, a protein whose mutation leads to multiple developmental defects. The FIGL-1 protein contains an AAA (ATPase associated with various activities) domain and belongs to the AAA superfamily. However, the biological functions and developmental implications of this protein remain unknown. Here, we show that the AAA domain of the Caenorhabditis elegans FIGL-1 protein (CeFIGL-1-AAA), in clear contrast to homologous AAA domains, has an unusually high ATPase activity and forms a hexamer in solution. By determining the crystal structure of CeFIGL-1-AAA, we found that the loop linking helices α9 and α10 folds into the short helix α9a, which has an acidic surface and interacts with a positively charged surface of the neighboring subunit. Disruption of this charge interaction by mutagenesis diminishes both the ATPase activity and oligomerization capacity of the protein. Interestingly, the acidic residues in helix α9a of CeFIGL-1-AAA are not conserved in other homologous AAA domains that have relatively low ATPase activities. These results demonstrate that the sequence of CeFIGL-1-AAA has adapted to establish an intersubunit charge interaction, which contributes to its strong oligomerization and ATPase activity. These unique properties of CeFIGL-1-AAA distinguish it from other homologous proteins, suggesting that CeFIGL-1 may have a distinct biological function.

  17. Crystal Structure and Biochemical Characterization of a Mycobacterium smegmatis AAA-Type Nucleoside Triphosphatase Phosphohydrolase (Msm0858).

    PubMed

    Unciuleac, Mihaela-Carmen; Smith, Paul C; Shuman, Stewart

    2016-05-15

    AAA proteins (ATPases associated with various cellular activities) use the energy of ATP hydrolysis to drive conformational changes in diverse macromolecular targets. Here, we report the biochemical characterization and 2.5-Å crystal structure of a Mycobacterium smegmatis AAA protein Msm0858, the ortholog of Mycobacterium tuberculosis Rv0435c. Msm0858 is a magnesium-dependent ATPase and is active with all nucleoside triphosphates (NTPs) and deoxynucleoside triphosphates (dNTPs) as substrates. The Msm0858 structure comprises (i) an N-terminal domain (amino acids [aa] 17 to 201) composed of two β-barrel modules and (ii) two AAA domains, D1 (aa 212 to 473) and D2 (aa 476 to 744), each of which has ADP in the active site. Msm0858-ADP is a monomer in solution and in crystallized form. Msm0858 domains are structurally homologous to the corresponding modules of mammalian p97. However, the position of the N-domain modules relative to the AAA domains in the Msm0858-ADP tertiary structure is different and would impede the formation of a p97-like hexameric quaternary structure. Mutational analysis of the A-box and B-box motifs indicated that the D1 and D2 AAA domains are both capable of ATP hydrolysis. Simultaneous mutations of the D1 and D2 active-site motifs were required to abolish ATPase activity. ATPase activity was effaced by mutation of the putative D2 arginine finger, suggesting that Msm0858 might oligomerize during the ATPase reaction cycle. A truncated variant Msm0858 (aa 212 to 745) that lacks the N domain was characterized as a catalytically active homodimer. Recent studies have underscored the importance of AAA proteins (ATPases associated with various cellular activities) in the physiology of mycobacteria. This study reports the ATPase activity and crystal structure of a previously uncharacterized mycobacterial AAA protein, Msm0858. Msm0858 consists of an N-terminal β-barrel domain and two AAA domains, each with ADP bound in the active site. Msm0858 is a

  18. The two faces of hydrogen-bond strength on triple AAA-DDD arrays.

    PubMed

    Lopez, Alfredo Henrique Duarte; Caramori, Giovanni Finoto; Coimbra, Daniel Fernando; Parreira, Renato Luis Tame; da Silva, Éder Henrique

    2013-12-02

    Systems that are connected through multiple hydrogen bonds are the cornerstone of molecular recognition processes in biology, and they are increasingly being employed in supramolecular chemistry, specifically in molecular self-assembly processes. For this reason, the effects of different substituents (NO2, CN, F, Cl, Br, OCH3 and NH2) on the electronic structure, and consequently on the magnitude of hydrogen bonds in triple AAA-DDD arrays (A=acceptor, D=donor) were evaluated in the light of topological [electron localization function (ELF) and quantum theory of atoms in molecules (QTAIM)], energetic [Su-Li energy-decomposition analysis (EDA) and natural bond orbital analysis (NBO)], and geometrical analysis. The results based on local H-bond descriptors (geometries, QTAIM, ELF, and NBO) indicate that substitutions with electron-withdrawing groups on the AAA module tend to strengthen, whereas electron-donating substituents tend to weaken the covalent character of the AAA-DDD intermolecular H-bonds, and also indicate that the magnitude of the effect is dependent on the position of substitution. In contrast, Su-Li EDA results show an opposite behavior when compared to local H-bond descriptors, indicating that electron-donating substituents tend to increase the magnitude of H-bonds in AAA-DDD arrays, and thus suggesting that the use of local H-bond descriptors describes the nature of H bonds only partially, not providing enough insight about the strength of such H bonds. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Modeling East Asian Dust and Its Radiative Feedbacks in CAM4-BAM

    DOE PAGES

    Xie, Xiaoning; Liu, Xiaodong; Che, Huizheng; ...

    2018-01-18

    East Asian dust and its radiative feedbacks are analyzed by the use of the fourth version of the Community Atmosphere Model (CAM4) with a bulk aerosol model parameterization (BAM) for the dust size distribution (CAM4-BAM). Two numerical experiments are conducted and intercompared: one with (Active) and one without (Passive) the radiative effects of dust aerosols. This CAM4-BAM captures the main spatial distribution of the dust aerosol optical depth (AOD) and the dust surface concentrations over East Asia, with positive correlations with the local observational data on annual and seasonal means. A comparative analysis of the Active and Passive experiments revealsmore » that consideration of the dust-radiation interaction can significantly reduce dust emissions, loading, transport, and dry and wet depositions over East Asia, which is opposite to the enhanced dust cycle over North Africa. Further analysis of the contrasting dust-radiation feedbacks between North Africa and East Asia shows that over North Africa, the dust radiative forcing significantly increases the surface temperature and 10-m wind speed, whereas it decreases the surface temperature and the surface wind speeds over East Asia. These contrasting radiative effects, in turn, result in distinct dust cycle changes over these two regions. Thus, mechanistic analysis reveals that the radiative contrasts between East Asia and North Africa are mainly due to the differences in their regional surface albedo, dust vertical distribution and size distribution.« less

  20. Modeling East Asian Dust and Its Radiative Feedbacks in CAM4-BAM

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Xiaoning; Liu, Xiaodong; Che, Huizheng

    East Asian dust and its radiative feedbacks are analyzed by the use of the fourth version of the Community Atmosphere Model (CAM4) with a bulk aerosol model parameterization (BAM) for the dust size distribution (CAM4-BAM). Two numerical experiments are conducted and intercompared: one with (Active) and one without (Passive) the radiative effects of dust aerosols. This CAM4-BAM captures the main spatial distribution of the dust aerosol optical depth (AOD) and the dust surface concentrations over East Asia, with positive correlations with the local observational data on annual and seasonal means. A comparative analysis of the Active and Passive experiments revealsmore » that consideration of the dust-radiation interaction can significantly reduce dust emissions, loading, transport, and dry and wet depositions over East Asia, which is opposite to the enhanced dust cycle over North Africa. Further analysis of the contrasting dust-radiation feedbacks between North Africa and East Asia shows that over North Africa, the dust radiative forcing significantly increases the surface temperature and 10-m wind speed, whereas it decreases the surface temperature and the surface wind speeds over East Asia. These contrasting radiative effects, in turn, result in distinct dust cycle changes over these two regions. Thus, mechanistic analysis reveals that the radiative contrasts between East Asia and North Africa are mainly due to the differences in their regional surface albedo, dust vertical distribution and size distribution.« less

  1. Effects of doping and bias voltage on the screening in AAA-stacked trilayer graphene

    NASA Astrophysics Data System (ADS)

    Mohammadi, Yawar; Moradian, Rostam; Shirzadi Tabar, Farzad

    2014-09-01

    We calculate the static polarization of AAA-stacked trilayer graphene (TLG) and study its screening properties within the random phase approximation (RPA) in all undoped, doped and biased regimes. We find that the static polarization of undoped AAA-stacked TLG is a combination of the doped and undoped single-layer graphene static polarization. This leads to an enhancement of the dielectric background constant along a Thomas-Fermi screening with the Thomas-Fermi wave vector which is independent of carrier concentrations and a 1/r3 power law decay for the long-distance behavior of the screened Coulomb potential. We show that effects of a bias voltage can be taken into account by a renormalization of the interlayer hopping energy to a new bias-voltage-dependent value, indicating screening properties of AAA-stacked TLG can be tuned electrically. We also find that screening properties of doped AAA-stacked TLG, when μ exceeds √{2}γ, are similar to that of doped SLG only depending on doping. While for μ<√{2}γ, its screening properties are combination of SLG and AA-stacked bilayer graphene screening properties and they are determined by doping and the interlayer hopping energy.

  2. Modification and implementation of NCCN guidelines on lymphomas in the Middle East and North Africa region.

    PubMed

    Bazarbachi, Ali; Azim, Hamdy A; Alizadeh, Hussain; Aljurf, Mahmoud; Barista, Ibrahim; Chaudhri, Naeem A; Fahed, Zahira; Fahmy, Omar A; Ghavamzadeh, Ardeshir; Khalaf, Mohamed H; Khatib, Sami; Kutoubi, Aghiad; Paydas, Semra; Elayoubi, Hanadi Rafii; Zaatari, Ghazi; Zawam, Hamdy M; Zelenetz, Andrew D

    2010-07-01

    In the Middle East and North Africa (MENA) region, cancer has many epidemiologic and clinical features that are different from those in the rest of the world. Additionally, the region has a relatively young population and large disparities in the availability of resources at diagnostic and treatment levels. A critical need exists for regional guidelines on cancer care, including those for lymphoid malignancies. A panel of lymphoma experts from MENA reviewed the 2009 version of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) on Non-Hodgkin's Lymphoma and Hodgkin Lymphoma and suggested modifications for the region that were discussed with the United States NCCN Lymphoma Panels. This article presents the consensus recommendations.

  3. A seismic gap along an accreting plate boundary : Example of the Djibouti Ridge, Afar, East Africa

    NASA Astrophysics Data System (ADS)

    Ruegg, Jean-Claude; Lépine, Jean-Claude

    1983-05-01

    A segment of the Gulf of Tadjoura (Djibouti, East-Africa) accreting plate boundary, shows a period of quiescence in the seismic activity since 1974. This segment corresponds to the extension area of the aftershock activity that has occured after a cluster of magnitude 5.5 earthquakes in April 1973. From this example we propose that the seismic gap concept can be extended to moderate earthquakes occuring at extensional plate boundaries. The magnitude of the largest earthquakes at the spreading axis is limited by the size of the rupture length and by the strength of the brittle lithosphere. In the case of the Djibouti ridge recurrence time of 10-20 years are found for earthquakes of about M =6.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  5. Asymmetric processing of a substrate protein in sequential allosteric cycles of AAA+ nanomachines

    NASA Astrophysics Data System (ADS)

    Kravats, Andrea N.; Tonddast-Navaei, Sam; Bucher, Ryan J.; Stan, George

    2013-09-01

    Essential protein quality control includes mechanisms of substrate protein (SP) unfolding and translocation performed by powerful ring-shaped AAA+ (ATPases associated with various cellular activities) nanomachines. These SP remodeling actions are effected by mechanical forces imparted by AAA+ loops that protrude into the central channel. Sequential intra-ring allosteric motions, which underlie repetitive SP-loop interactions, have been proposed to comprise clockwise (CW), counterclockwise (CCW), or random (R) conformational transitions of individual AAA+ subunits. To probe the effect of these allosteric mechanisms on unfoldase and translocase functions, we perform Langevin dynamics simulations of a coarse-grained model of an all-alpha SP processed by the single-ring ClpY ATPase or by the double-ring p97 ATPase. We find that, in all three allosteric mechanisms, the SP undergoes conformational transitions along a common set of pathways, which reveals that the active work provided by the ClpY machine involves single loop-SP interactions. Nevertheless, the rates and yields of SP unfolding and translocation are controlled by mechanism-dependent loop-SP binding events, as illustrated by faster timescales of SP processing in CW allostery compared with CCW and R allostery. The distinct efficacy of allosteric mechanisms is due to the asymmetric collaboration of adjacent subunits, which involves CW-biased structural motions of AAA+ loops and results in CW-compatible torque applied onto the SP. Additional simulations of mutant ClpY rings, which render a subset of subunits catalytically-defective or reduce their SP binding affinity, reveal that subunit-based conformational transitions play the major role in SP remodeling. Based on these results we predict that the minimally functional AAA+ ring includes three active subunits, only two of which are adjacent.

  6. An overview of the transboundary aquifers in East Africa

    NASA Astrophysics Data System (ADS)

    Abiye, Tamiru Alemayehu

    2010-11-01

    A transboundary aquifer is a body of groundwater intersected by two or more countries with the potential threat of dispute over a shared groundwater resource. A large portion of the population in East Africa relies on surface water resources for day-to-day activities; in turn, this is dependent on episodic rainfall. Surface water in the region is vulnerable to pollution and potential climate change. Consequently, frequent conflict over the water use is a regular event in the region. This paper examines the transboundary aquifers and their significance for water supply in the six adjacent Intergovernmental Authority on Development (IGAD) countries (Ethiopia, Eritrea, Sudan, Kenya, Somalia and Djibouti). Analysis of available literature and short field visits to accessible areas were undertaken in order to examine the geology, hydrogeological dynamics, and water use. The geology of the transboundary aquifers is mainly represented by Precambrian basement, Mesozoic sedimentary rocks, Cenozoic volcanics and recent alluvial deposits. Taking into consideration the topographic setting and water circulation, the Ethiopian highlands are the major sources of recharge to the transboundary aquifers of the adjacent countries. The surface runoff drains through 11 major rivers into the neighbouring countries. The groundwater contained in the transboundary aquifers is yet to receive attention by the various countries, but the future trend is towards exploiting the resources to alleviate water shortages in the region. It is hoped that the systematic development of these groundwater resources would strengthen cooperation in this conflict-dominated region.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berkoff, J.

    1995-03-21

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

  8. Successes and Challenges in East African Conservation Education

    ERIC Educational Resources Information Center

    Johnson-Pynn, Julie S.; Johnson, Laura R.

    2005-01-01

    Environmental education (EE) programs that include service-learning components have great potential to positively impact East African youth, their communities, and their ecology. This exploratory study describes 2 programs in East Africa, The Jane Goodall Institute's Roots & Shoots (R&S) and Wildlife Clubs of Uganda (WCU). The authors…

  9. Exploring Evidence of Land Surface Dynamics of River Basin Development in East Africa

    NASA Astrophysics Data System (ADS)

    Eluwa, C.; Brown, C.

    2017-12-01

    Improving the productivity of agricultural lands in Africa in the face of climate variability and change is vital to achieving food security. A variety of possible approaches exist, many of which focus on the development and expansion of irrigation - at times associated with dam construction to provide co-benefits of hydropower and water supply. Optimal development of river basin infrastructure such as this has long been a topic of interest in water resources systems analysis. Recent advances have focused on addressing the uncertainty associated with climate change in the development of river basin plans. However, such studies rarely consider either the uncertainty from changing local surface-atmosphere interactions via basin development or the attendant effects on local ecosystems, precipitation, evapotranspiration and consequently the availability of water for the proposed projects. Some numerical experiments have described and reproduced the mechanisms via which river basin infrastructure influences local climatology in Sahelian Africa. However, no studies have explored available data for evidence of land-atmosphere interactions associated with actual development projects. This study explores the correlation of seasonal soil moisture and latent heat flux over currently dammed/irrigated areas on downwind precipitation in the East Africa region (bounded by 0N, -15N, 25E, 40E) at the mesoscale (30km - 100km) to unearth evidence of local climatological effects of river basin development (irrigation schemes). The adopted process is (1) use reanalysis data to derive mean wind directions at 800hPa for selected regions (2) use mean wind directions (and orthogonal directions) to locate high (and low) impact areas 30 -100km downwind (3) extract precipitation time series for downwind locations from three different gridded products (CRU, GCPC, PRINCETON) (4) compare precipitation time series across datasets in high/low impact areas and correlate with upwind latent heat flux

  10. Adherence to antiretroviral therapy in a clinical cohort of HIV-infected children in East Africa.

    PubMed

    Vreeman, Rachel C; Ayaya, Samuel O; Musick, Beverly S; Yiannoutsos, Constantin T; Cohen, Craig R; Nash, Denis; Wabwire, Deo; Wools-Kaloustian, Kara; Wiehe, Sarah E

    2018-01-01

    To describe antiretroviral therapy (ART) adherence and associated factors for a large HIV-infected pediatric cohort followed by sites of the East Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA) consortium. This study utilized prospectively collected clinical data from HIV-infected children less than 13 years of age who initiated ART within 4 clinical care programs (with 26 clinical sites) in Kenya, Uganda, and Tanzania and were followed for up to 6 years. Programs used one of 3 adherence measures, including 7-day quantitative recall, 7-day categorical recall, and clinician pill assessments. We fit a hierarchical, three-level, logistic-regression model to examine adherence, with observations nested within patient, and patients within the 26 sites providing pediatric HIV data to this analysis. In East Africa, 3,304 children, 52.0% male, were enrolled in care and were subsequently observed for a median of 92 weeks (inter-quartile range [IQR] 50.3-145.0 weeks). Median age at ART initiation was 5.5 years ([IQR] 3.0-8.5 years). "Good" adherence, as reported by each clinic's measures, was extremely high, remaining on average above 90% throughout all years of follow-up. Longer time on ART was associated with higher adherence (adjusted Odds Ratio-aOR-per log-transformed week on ART: 1.095, 95% Confidence Interval-CI-[1.052-1.150].) Patients enrolled in higher-volume programs exhibited higher rates of clinician-assessed adherence (aOR per log-500 patients: 1.174, 95% CI [1.108-1.245]). Significant site-level variability in reported adherence was observed (0.28), with even higher variability among patients (0.71). In a sub-analysis, being an orphan at the start of ART was strongly associated with lower ART adherence rates (aOR: 0.919, 95% CI [0.864-0.976]). Self-reported adherence remained high over a median of 1.8 years in HIV care, but varied according to patient-level and site-level factors. Consistent adherence monitoring with validated measures and

  11. Dosimetric comparison of Acuros XB, AAA, and XVMC in stereotactic body radiotherapy for lung cancer.

    PubMed

    Tsuruta, Yusuke; Nakata, Manabu; Nakamura, Mitsuhiro; Matsuo, Yukinori; Higashimura, Kyoji; Monzen, Hajime; Mizowaki, Takashi; Hiraoka, Masahiro

    2014-08-01

    To compare the dosimetric performance of Acuros XB (AXB), anisotropic analytical algorithm (AAA), and x-ray voxel Monte Carlo (XVMC) in heterogeneous phantoms and lung stereotactic body radiotherapy (SBRT) plans. Water- and lung-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. The radiation treatment machine Novalis (BrainLab AG, Feldkirchen, Germany) with an x-ray beam energy of 6 MV was used to calculate the doses in the composite phantom at a source-to-surface distance of 100 cm with a gantry angle of 0°. Subsequently, the clinical lung SBRT plans for the 26 consecutive patients were transferred from the iPlan (ver. 4.1; BrainLab AG) to the Eclipse treatment planning systems (ver. 11.0.3; Varian Medical Systems, Palo Alto, CA). The doses were then recalculated with AXB and AAA while maintaining the XVMC-calculated monitor units and beam arrangement. Then the dose-volumetric data obtained using the three different radiation dose calculation algorithms were compared. The results from AXB and XVMC agreed with measurements within ± 3.0% for the lung-equivalent phantom with a 6 × 6 cm(2) field size, whereas AAA values were higher than measurements in the heterogeneous zone and near the boundary, with the greatest difference being 4.1%. AXB and XVMC agreed well with measurements in terms of the profile shape at the boundary of the heterogeneous zone. For the lung SBRT plans, AXB yielded lower values than XVMC in terms of the maximum doses of ITV and PTV; however, the differences were within ± 3.0%. In addition to the dose-volumetric data, the dose distribution analysis showed that AXB yielded dose distribution calculations that were closer to those with XVMC than did AAA. Means ± standard deviation of the computation time was 221.6 ± 53.1 s (range, 124-358 s), 66.1 ± 16.0 s (range, 42-94 s), and 6.7 ± 1.1 s (range, 5-9 s) for XVMC, AXB, and AAA, respectively. In the phantom evaluations, AXB and XVMC agreed better with

  12. Resource use associated with type 2 diabetes in Asia, Latin America, the Middle East and Africa: results from the International Diabetes Management Practices Study (IDMPS).

    PubMed

    Ringborg, A; Cropet, C; Jönsson, B; Gagliardino, J J; Ramachandran, A; Lindgren, P

    2009-07-01

    To estimate diabetes-related resource use and investigate its predictors among individuals with type 2 diabetes in 24 countries in Asia, Latin America, the Middle East and Africa. Cross-sectional observational data on diabetes-related resource use were collected from 15,016 individuals with type 2 diabetes within the second wave of International Diabetes Management Practices Study. Mean (SD) annual quantities were determined and predictors of diabetes-related hospitalisations, inpatient days, emergency room visits and absenteeism were investigated using negative binomial regression. Patients in Asia (n = 4678), Latin America (n = 6090) and the Middle East and Africa (n = 4248) made a mean (SD) of 3.4 (6.9), 5.4 (6.7) and 2.5 (4.4) General Practitioner visits per year. The mean (SD) number of inpatient days amounted to 3.8 (18.1), 2.2 (13.9) and 2.6 (13.5) per year. Results of the regression analysis showed the major influence of diabetes-related complications and inadequate glycaemic control on resource use. The expected annual rate of hospitalisation of patients with macrovascular complications compared with those without was 4.7 times greater in Asia [incidence rate ratio (IRR) = 4.7, 95% CI: 2.8-7.8, n = 2551], 5.4 times greater in Latin America (IRR = 5.4, 95% CI: 3.0-9.8, n = 3228) and 4.4 times greater in the Middle East and Africa (IRR = 4.4, 95% CI: 2.8-6.9, n = 2630). Micro- and macrovascular complications and inadequate glycaemic control are significant predictors of resource use in people with type 2 diabetes of developing countries. This knowledge confirms the health economic importance of early diagnosis of diabetes, education of patients and glycaemic control.

  13. Structure determination of disease associated peak AAA from l-Tryptophan implicated in the eosinophilia-myalgia syndrome.

    PubMed

    Klarskov, Klaus; Gagnon, Hugo; Boudreault, Pierre-Luc; Normandin, Chad; Plancq, Baptiste; Marsault, Eric; Gleich, Gerald J; Naylor, Stephen

    2018-01-05

    The eosinophilia-myalgia syndrome (EMS) outbreak of 1989 that occurred in the USA and elsewhere was caused by the ingestion of l-Tryptophan (L-Trp) solely manufactured by the Japanese company Showa Denko K.K. (SD). Six compounds present in the SD L-Trp were reported to be case-associated contaminants. However, "one" of these compounds, Peak AAA has remained structurally uncharacterized, despite the fact that it was described as "the only statistically significant (p=0.0014) contaminant". Here, we employ on-line microcapillary-high performance liquid chromatography-electrospray ionization mass spectrometry (LC-MS), and tandem mass spectrometry (MS/MS) to determine that Peak AAA is in fact two structurally related isomers. Peak AAA 1 and Peak AAA 2 differed in LC retention times, and were determined by accurate mass-LC-MS to both have a protonated molecular ion (MH +) of mass 343.239Da (Da), corresponding to a molecular formula of C 21 H 30 N 2 O 2, and possessing eight degrees of unsaturation (DoU) for the non-protonated molecule. By comparing the LC-MS and LC-MS-MS retention times and spectra with authentic synthetic standards, Peak AAA 1 was identified as the intermolecular condensation product of L-Trp with anteiso 7-methylnonanoic acid, to afford (S)-2-amino-3-(2-((S,E)-7-methylnon-1-en-1-yl)-1H-indol-3-yl)propanoic acid. Peak AAA 2 was determined to be a condensation product of L-Trp with decanoic acid, which produced (S)-2-amino-3-(2-((E)-dec-1-en-1-yl)-1H-indol-3-yl)propanoic acid. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Structural dynamics of the MecA-ClpC complex: a type II AAA+ protein unfolding machine.

    PubMed

    Liu, Jing; Mei, Ziqing; Li, Ningning; Qi, Yutao; Xu, Yanji; Shi, Yigong; Wang, Feng; Lei, Jianlin; Gao, Ning

    2013-06-14

    The MecA-ClpC complex is a bacterial type II AAA(+) molecular machine responsible for regulated unfolding of substrates, such as transcription factors ComK and ComS, and targeting them to ClpP for degradation. The six subunits of the MecA-ClpC complex form a closed barrel-like structure, featured with three stacked rings and a hollow passage, where substrates are threaded and translocated through successive pores. Although the general concepts of how polypeptides are unfolded and translocated by internal pore loops of AAA(+) proteins have long been conceived, the detailed mechanistic model remains elusive. With cryoelectron microscopy, we captured four different structures of the MecA-ClpC complexes. These complexes differ in the nucleotide binding states of the two AAA(+) rings and therefore might presumably reflect distinctive, representative snapshots from a dynamic unfolding cycle of this hexameric complex. Structural analysis reveals that nucleotide binding and hydrolysis modulate the hexameric complex in a number of ways, including the opening of the N-terminal ring, the axial and radial positions of pore loops, the compactness of the C-terminal ring, as well as the relative rotation between the two nucleotide-binding domain rings. More importantly, our structural and biochemical data indicate there is an active allosteric communication between the two AAA(+) rings and suggest that concerted actions of the two AAA(+) rings are required for the efficiency of the substrate unfolding and translocation. These findings provide important mechanistic insights into the dynamic cycle of the MecA-ClpC unfoldase and especially lay a foundation toward the complete understanding of the structural dynamics of the general type II AAA(+) hexamers.

  15. [Sociocultural aspects of albinism in Sub-Saharan Africa: mutilations and ritual murders committed in east Africa (Burundi and Tanzania)].

    PubMed

    Aquaron, R; Djatou, M; Kamdem, L

    2009-10-01

    This report presents an overview of the many sociocultural prejudices confronting albinos and their parents in Sub-Saharan Africa at each stage of life (infancy, adolescence, and adulthood). The birth of an albino child to two black parents has always been an enigma for African peoples. French-speaking and English-speaking populations in Central, East and South African countries have invented numerous myths to account for this event. Albinos are believed to possess good and evil magical powers. On the white magic side, some organs are believed to confer luck, health, and prosperity. For this reason albinos in Tanzania and Burundi are still in 2008 prey to ritual murders and mutilations to obtain various body parts such as arms, legs, and genitals for preparation of amulets. This barbaric and iniquitous practice has been severely condemned by authorities in both countries as well as by the European Parliament. To end these atrocities disseminating accurate medical information explaining the genetic basis of albinism will be necessary to eliminate ignorance and superstition.

  16. Structure and evolution of N-domains in AAA metalloproteases.

    PubMed

    Scharfenberg, Franka; Serek-Heuberger, Justyna; Coles, Murray; Hartmann, Marcus D; Habeck, Michael; Martin, Jörg; Lupas, Andrei N; Alva, Vikram

    2015-02-27

    Metalloproteases of the AAA (ATPases associated with various cellular activities) family play a crucial role in protein quality control within the cytoplasmic membrane of bacteria and the inner membrane of eukaryotic organelles. These membrane-anchored hexameric enzymes are composed of an N-terminal domain with one or two transmembrane helices, a central AAA ATPase module, and a C-terminal Zn(2+)-dependent protease. While the latter two domains have been well studied, so far, little is known about the N-terminal regions. Here, in an extensive bioinformatic and structural analysis, we identified three major, non-homologous groups of N-domains in AAA metalloproteases. By far, the largest one is the FtsH-like group of bacteria and eukaryotic organelles. The other two groups are specific to Yme1: one found in plants, fungi, and basal metazoans and the other one found exclusively in animals. Using NMR and crystallography, we determined the subunit structure and hexameric assembly of Escherichia coli FtsH-N, exhibiting an unusual α+β fold, and the conserved part of fungal Yme1-N from Saccharomyces cerevisiae, revealing a tetratricopeptide repeat fold. Our bioinformatic analysis showed that, uniquely among these proteins, the N-domain of Yme1 from the cnidarian Hydra vulgaris contains both the tetratricopeptide repeat region seen in basal metazoans and a region of homology to the N-domains of animals. Thus, it is a modern-day representative of an intermediate in the evolution of animal Yme1 from basal eukaryotic precursors. Copyright © 2015. Published by Elsevier Ltd.

  17. Structure and Function of p97 and Pex1/6 Type II AAA+ Complexes.

    PubMed

    Saffert, Paul; Enenkel, Cordula; Wendler, Petra

    2017-01-01

    Protein complexes of the Type II AAA+ (ATPases associated with diverse cellular activities) family are typically hexamers of 80-150 kDa protomers that harbor two AAA+ ATPase domains. They form double ring assemblies flanked by associated domains, which can be N-terminal, intercalated or C-terminal to the ATPase domains. Most prominent members of this family include NSF (N-ethyl-maleimide sensitive factor), p97/VCP (valosin-containing protein), the Pex1/Pex6 complex and Hsp104 in eukaryotes and ClpB in bacteria. Tremendous efforts have been undertaken to understand the conformational dynamics of protein remodeling type II AAA+ complexes. A uniform mode of action has not been derived from these works. This review focuses on p97/VCP and the Pex1/6 complex, which both structurally remodel ubiquitinated substrate proteins. P97/VCP plays a role in many processes, including ER- associated protein degradation, and the Pex1/Pex6 complex dislocates and recycles the transport receptor Pex5 from the peroxisomal membrane during peroxisomal protein import. We give an introduction into existing knowledge about the biochemical and cellular activities of the complexes before discussing structural information. We particularly emphasize recent electron microscopy structures of the two AAA+ complexes and summarize their structural differences.

  18. Knowledge of High School Learners Regarding Substance Use within High School Premises in the Buffalo Flats of East London, Eastern Cape Province, South Africa

    ERIC Educational Resources Information Center

    Manu, Emmanuel; Maluleke, Xavela T.; Douglas, Mbuyiselo

    2017-01-01

    South Africa has a high rate of substance abuse among youths both in and out of school with East London in the Eastern Cape Province experiencing an increase in young people ages 20 years and below seeking treatment for substance abuse. The purpose of the study was to explore the knowledge of high school learners (grades 10 to 12) regarding…

  19. SMYD2 promoter DNA methylation is associated with abdominal aortic aneurysm (AAA) and SMYD2 expression in vascular smooth muscle cells.

    PubMed

    Toghill, Bradley J; Saratzis, Athanasios; Freeman, Peter J; Sylvius, Nicolas; Bown, Matthew J

    2018-01-01

    Abdominal aortic aneurysm (AAA) is a deadly cardiovascular disease characterised by the gradual, irreversible dilation of the abdominal aorta. AAA is a complex genetic disease but little is known about the role of epigenetics. Our objective was to determine if global DNA methylation and CpG-specific methylation at known AAA risk loci is associated with AAA, and the functional effects of methylation changes. We assessed global methylation in peripheral blood mononuclear cell DNA from 92 individuals with AAA and 93 controls using enzyme-linked immunosorbent assays, identifying hyper-methylation in those with large AAA and a positive linear association with AAA diameter ( P  < 0.0001, R 2  = 0.3175).We then determined CpG methylation status of regulatory regions in genes located at AAA risk loci identified in genome-wide association studies, using bisulphite next-generation sequencing (NGS) in vascular smooth muscle cells (VSMCs) taken from aortic tissues of 44 individuals (24 AAAs and 20 controls). In IL6R , 2 CpGs were hyper-methylated ( P  = 0.0145); in ERG , 13 CpGs were hyper-methylated ( P  = 0.0005); in SERPINB9 , 6 CpGs were hypo-methylated ( P  = 0.0037) and 1 CpG was hyper-methylated ( P  = 0.0098); and in SMYD2 , 4 CpGs were hypo-methylated ( P  = 0.0012).RT-qPCR was performed for each differentially methylated gene on mRNA from the same VSMCs and compared with methylation. This analysis revealed downregulation of SMYD2 and SERPINB9 in AAA, and a direct linear relationship between SMYD2 promoter methylation and SMYD2 expression ( P  = 0.038). Furthermore, downregulation of SMYD2 at the site of aneurysm in the aortic wall was further corroborated in 6 of the same samples used for methylation and gene expression analysis with immunohistochemistry. This study is the first to assess DNA methylation in VSMCs from individuals with AAA using NGS, and provides further evidence there is an epigenetic basis to AAA. Our study shows that

  20. Characterization of Foot-and-Mouth Disease Viruses Collected in Nigeria Between 2007 and 2014: Evidence for Epidemiological Links Between West and East Africa.

    PubMed

    Ularamu, H G; Ibu, J O; Wood, B A; Abenga, J N; Lazarus, D D; Wungak, Y S; Knowles, N J; Wadsworth, J; Mioulet, V; King, D P; Shamaki, D; Adah, M I

    2017-12-01

    This study describes the molecular characterization of 47 foot-and-mouth disease (FMD) viruses recovered from field outbreaks in Nigeria between 2007 and 2014. Antigen ELISA of viral isolates was used to identify FMD virus serotypes O, A and SAT 2. Phylogenetic analyses of VP1 nucleotide sequences provide evidence for the presence of multiple sublineages of serotype SAT 2, and O/EAST AFRICA 3 (EA-3) and O/WEST AFRICA topotypes in the country. In contrast, for serotype A, a single monophyletic cluster of viruses has persisted within Nigeria (2009-2013). These results demonstrate the close genetic relatedness of viruses in Nigeria to those from other African countries, including the first formal characterization of serotype O/EA-3 viruses in Nigeria. The introductions and persistence of certain viral lineages in Nigeria may reflect transmission patterns via nomadic pastoralism and animal trade. Continuous monitoring of field outbreaks is necessary to dissect the complexity of FMD epidemiology in sub-Saharan Africa. © 2016 Blackwell Verlag GmbH.

  1. The Rovuma Transform Margin: the enigmatic continent-ocean boundary of East Africa

    NASA Astrophysics Data System (ADS)

    Phethean, Jordan; Kalnins, Lara; van Hunen, Jeroen; McCaffrey, Ken; Davies, Richard

    2017-04-01

    The N-S trending Davie Fracture Zone (DFZ) is often assumed to form the continent-ocean transform margin (COTM) of the Western Somali Basin. However, multiple plate tectonic reconstructions favour a pre-breakup location for Madagascar that crosses the DFZ, incompatible with its interpretation as the COTM (e.g., Lottes & Rowley, 1990; Reeves, 2014; Phethean et al., 2016). For the first time, we have identified classic COTM features in seismic reflection data from the Southern Rovuma Basin, to the west and inboard of the DFZ. These suggest a NNW trend to the margin, consistent with the tectonic reconstructions. 2D gravity models, with the seabed and top basement constrained by seismic data, are used to investigate the Moho structure across the Rovuma margin and are best fit using steep 'transform style' geometries, confirming the nature of the margin. We thus model generic COTM geometries elsewhere along the East African and Madagascan transform margins to locate best-fitting positions for these conjugate COTMs. This analysis confirms that the COTMs follow a NNW trend along the Rovuma Basin and Southern Madagascar, respectively, and allows a restoration of the conjugate COTMs. This restoration is used alongside geological maps and satellite imagery from Madagascar and East Africa to refine early plate motions and further constrain the precise origin of Madagascar within Gondwana. Our refined plate tectonic model independently predicts major observations made from seismic reflection and gravity data across the basin, including: regions of major transpression/transtension along the DFZ, merging of fracture zones to form the DFZ, oceanic crust on either side of the DFZ and within the Tanzania coastal basin, and the location of an abandoned MOR within the Tanzania coastal basin. We believe that this study finally provides conclusive evidence that Madagascar originated from within the Tanzania Coastal Basin, inboard of the DFZ, after some 30 years of debate regarding this

  2. The Adult Asperger Assessment (AAA): A Diagnostic Method

    ERIC Educational Resources Information Center

    Baron-Cohen, Simon; Wheelwright, Sally; Robinson, Janine; Woodbury-Smith, Marc

    2005-01-01

    At the present time there are a large number of adults who have "suspected" Asperger syndrome (AS). In this paper we describe a new instrument, the Adult Asperger Assessment (AAA), developed in our clinic for adults with AS. The need for a new instrument relevant to the diagnosis of AS in adulthood arises because existing instruments are designed…

  3. Diet, Genetics, and Disease: A Focus on the Middle East and North Africa Region

    PubMed Central

    Fahed, Akl C.; El-Hage-Sleiman, Abdul-Karim M.; Farhat, Theresa I.; Nemer, Georges M.

    2012-01-01

    The Middle East and North Africa (MENA) region suffers a drastic change from a traditional diet to an industrialized diet. This has led to an unparalleled increase in the prevalence of chronic diseases. This review discusses the role of nutritional genomics, or the dietary signature, in these dietary and disease changes in the MENA. The diet-genetics-disease relation is discussed in detail. Selected disease categories in the MENA are discussed starting with a review of their epidemiology in the different MENA countries, followed by an examination of the known genetic factors that have been reported in the disease discussed, whether inside or outside the MENA. Several diet-genetics-disease relationships in the MENA may be contributing to the increased prevalence of civilization disorders of metabolism and micronutrient deficiencies. Future research in the field of nutritional genomics in the MENA is needed to better define these relationships. PMID:22536488

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

    PubMed

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

    2012-11-06

    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 climate-conflict 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 climate-conflict relationships are evident between the nine countries of the study region and across time periods.

  5. Perspectives of host faculty and trainees on international visiting faculty to paediatric academic departments in East Africa

    PubMed Central

    Russ, Christiana M; Ganapathi, Lakshmi; Marangu, Diana; Silverman, Melanie; Kija, Edward; Bakeera-Kitaka, Sabrina; Laving, Ahmed

    2016-01-01

    Background Investments in faculty exchanges to build physician workforce capacity are increasing. Little attention has been paid to the expectations of host institution faculty and trainees. This prospective qualitative research study explored faculty and resident perspectives about guest faculty in paediatric departments in East Africa, asking (1) What are the benefits and challenges of hosting guest faculty, (2) What factors influence the effectiveness of faculty visits and (3) How do host institutions prepare for faculty visits? Methods We recruited 36 faculty members and residents from among four paediatric departments in East Africa to participate in semistructured interviews which were audio recorded and transcribed. Data were qualitatively analysed using principles of open coding and thematic analysis. We achieved saturation of themes. Results Benefits of faculty visits varied based on the size and needs of host institutions. Emergent themes included the importance of guest faculty time commitment, and mutual preparation to ensure that visit goals and scheduling met host needs. We documented conflicts that developed around guest emotional responses and ethical approaches to clinical resource limitations, which some hosts tried to prepare for and mitigate. Imbalance in resources led to power differentials; some hosts sought partnerships to re-establish control over the process of having guests. Conclusions We identified that guest faculty can assist paediatric institutions in building capacity; however, effective visits require: (1) mutually agreed on goals with appropriate scheduling, visit length and commitment to ensure that the visits meet the host's needs, (2) careful selection and preparation of guest faculty to meet the host's goals, (3) emotional preparation by prospective guests along with host orientation to clinical work in the host's setting and (4) attention to funding sources for the visit and mitigation of resulting power differentials. PMID

  6. Genetic diversity of lactase persistence in East African populations.

    PubMed

    Hassan, Hisham Y; van Erp, Anke; Jaeger, Martin; Tahir, Hanan; Oosting, Marije; Joosten, Leo A B; Netea, Mihai G

    2016-01-04

    The expression of lactase which digests lactose from milk in humans is generally lost after weaning, but selected mutations influencing the promoter of the lactase gene have spread into the human populations. This is considered a classical example of gene-culture co-evolution, and several studies suggested that the lactase gene has been under strong directional evolutionary selective pressure in the past 5000 to 10,000 years. In the present study we investigated the distribution of three gene variants leading to lactase persistence in 12 different East African populations as well as one European population. Our results show that with the exception of Copts and Nilotic populations who are fully lactose non-persistent, the majority of populations of East Africa show at least partly lactose persistence, with both ethnic and socio-economic aspects playing an important role in the distribution of genetic variants. In this study, the variants C/G-13907 and T/G-13915, which are the major variants among the nomadic Arabs in the Arabia and Beja of East Africa, showed remarkable frequencies in Sudanese populations, especially those of pastoralists, in line with the historical links and bidirectional migration of nomadic populations between Arabia and East Africa. The C/T-13910 variant, generally associated with European populations is uniquely present among the Fulani. These data indicate that a combination of socio-economic, ethnic and evolutionary factors converged to shape the genetic structure of lactase persistence in East African populations.

  7. Characterization of the binding specificity of Anguilla anguilla agglutinin (AAA) in comparison to Ulex europaeus agglutinin I (UEA-I).

    PubMed

    Baldus, S E; Thiele, J; Park, Y O; Hanisch, F G; Bara, J; Fischer, R

    1996-08-01

    Using immunochemical and immunohistochemical methods, the binding site of Anguilla anguilla agglutinin (AAA) was characterized and compared with the related fucose-specific lectin from Ulex europaeus (UEA-I). In solid-phase enzyme-linked immunoassays, the two lectins recognized Fuc alpha 1-2Gal beta-HSA. AAA additionally cross-reacted with neoglycolipids bearing lacto-N-fucopentaose (LNFP) I [H type 1] and II [Le(a)] and lactodifucotetraose (LDFT) as glycan moieties. UEA-I, on the other hand, bound to a LDFT-derived neoglycolipid but not to the other neoglycolipids tested. Binding of AAA to gastric mucin was competitively neutralized by Le(a)-specific monoclonal antibodies. UEA-I binding, on the other hand, was reduced after co-incubation with H type 2- and Le(y)-specific monoclonal antibodies. According to our results, AAA reacts with fucosylated type 1 chain antigens, whereas UEA-I binds only to the alpha 1-2-fucosylated LDFT-derived neoglycolipid. In immunohistochemical studies, the reactivity of AAA and UEA-I in normal pyloric mucosa from individuals with known Lewis and secretor status was analysed. AAA showed a broad reaction in the superficial pyloric mucosa from secretors and non-secretors, but AAA reactivity was more pronounced in Le(a+b-) individuals. On the other hand, UEA-I stained the superficial pyloric mucosa only from secretor individuals. A staining of deep mucous glands by the lectins was found in all specimens. Both reacted with most human carcinomas of different origin. Slight differences in their binding pattern were observed and may be explained by the different fine-specificities of the lectins.

  8. Family Members of Patients with Abdominal Aortic Aneurysms are at Increased Risk for Aneurysms: Analysis of 618 Probands and their Families from the Liège AAA Family Study

    PubMed Central

    Sakalihasan, Natzi; Defraigne, Jean-Olivier; Kerstenne, Marie-Ange; Cheramy-Bien, Jean-Paul; Smelser, Diane T.; Tromp, Gerard; Kuivaniemi, Helena

    2014-01-01

    Background The objectives were to answer the following questions using a well-characterized population in Liège, Belgium: 1) what percentage of abdominal aortic aneurysm (AAA) patients have a positive family history for AAA, 2) what is the prevalence of AAAs among relatives of AAA patients; and 3) do familial and sporadic AAA cases differ in clinical characteristics. Methods and Results Unrelated AAA patients diagnosed at the Cardiovascular Surgery Department, University Hospital of Liège, Belgium, between 1999 and 2012 were invited to the study. A detailed family history was obtained in interviews and recorded using Progeny software. In the initial interview 62 (10%) of the 618 AAA patients reported a positive family history for AAA. We divided the 618 patients into two study groups: Group I: 296 AAA patients (268; 91% males) were followed up with computerized tomography combined with positron emission tomography, and Group II: 322 AAA patients (295; 92% males) whose families were invited to ultrasonography screening. Ultrasonography screening identified 24 new AAAs among 186 relatives (≥ 50 years) of 144 families yielding a prevalence of 13%. The highest prevalence (25%) was found among brothers. By combining the number of AAAs found by ultrasonography screening with those diagnosed previously the observed lifetime prevalence of AAA was estimated to be 32% in brothers. The familial AAA cases were more likely to have a ruptured AAA than the sporadic cases (8% vs. 2.4%; P<0.0001). Conclusions The findings confirm previously found high prevalence of AAA among brothers, support genetic contribution to AAA pathogenesis and provide rationale for targeted screening of relatives of AAA patients. PMID:24365082

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  10. Restricted genetic variation in populations of Achatina (Lissachatina) fulica outside of East Africa and the Indian Ocean Islands points to the Indian Ocean Islands as the earliest known common source.

    PubMed

    Fontanilla, Ian Kendrich C; Sta Maria, Inna Mikaella P; Garcia, James Rainier M; Ghate, Hemant; Naggs, Fred; Wade, Christopher M

    2014-01-01

    The Giant African Land Snail, Achatina ( =  Lissachatina) fulica Bowdich, 1822, is a tropical crop pest species with a widespread distribution across East Africa, the Indian subcontinent, Southeast Asia, the Pacific, the Caribbean, and North and South America. Its current distribution is attributed primarily to the introduction of the snail to new areas by Man within the last 200 years. This study determined the extent of genetic diversity in global A. fulica populations using the mitochondrial 16S ribosomal RNA gene. A total of 560 individuals were evaluated from 39 global populations obtained from 26 territories. Results reveal 18 distinct A. fulica haplotypes; 14 are found in East Africa and the Indian Ocean islands, but only two haplotypes from the Indian Ocean islands emerged from this region, the C haplotype, now distributed across the tropics, and the D haplotype in Ecuador and Bolivia. Haplotype E from the Philippines, F from New Caledonia and Barbados, O from India and Q from Ecuador are variants of the emergent C haplotype. For the non-native populations, the lack of genetic variation points to founder effects due to the lack of multiple introductions from the native range. Our current data could only point with certainty to the Indian Ocean islands as the earliest known common source of A. fulica across the globe, which necessitates further sampling in East Africa to determine the source populations of the emergent haplotypes.

  11. Restricted Genetic Variation in Populations of Achatina (Lissachatina) fulica outside of East Africa and the Indian Ocean Islands Points to the Indian Ocean Islands as the Earliest Known Common Source

    PubMed Central

    Fontanilla, Ian Kendrich C.; Sta. Maria, Inna Mikaella P.; Garcia, James Rainier M.; Ghate, Hemant; Naggs, Fred; Wade, Christopher M.

    2014-01-01

    The Giant African Land Snail, Achatina ( = Lissachatina) fulica Bowdich, 1822, is a tropical crop pest species with a widespread distribution across East Africa, the Indian subcontinent, Southeast Asia, the Pacific, the Caribbean, and North and South America. Its current distribution is attributed primarily to the introduction of the snail to new areas by Man within the last 200 years. This study determined the extent of genetic diversity in global A. fulica populations using the mitochondrial 16S ribosomal RNA gene. A total of 560 individuals were evaluated from 39 global populations obtained from 26 territories. Results reveal 18 distinct A. fulica haplotypes; 14 are found in East Africa and the Indian Ocean islands, but only two haplotypes from the Indian Ocean islands emerged from this region, the C haplotype, now distributed across the tropics, and the D haplotype in Ecuador and Bolivia. Haplotype E from the Philippines, F from New Caledonia and Barbados, O from India and Q from Ecuador are variants of the emergent C haplotype. For the non-native populations, the lack of genetic variation points to founder effects due to the lack of multiple introductions from the native range. Our current data could only point with certainty to the Indian Ocean islands as the earliest known common source of A. fulica across the globe, which necessitates further sampling in East Africa to determine the source populations of the emergent haplotypes. PMID:25203830

  12. Family members of patients with abdominal aortic aneurysms are at increased risk for aneurysms: analysis of 618 probands and their families from the Liège AAA Family Study.

    PubMed

    Sakalihasan, Natzi; Defraigne, Jean-Olivier; Kerstenne, Marie-Ange; Cheramy-Bien, Jean-Paul; Smelser, Diane T; Tromp, Gerard; Kuivaniemi, Helena

    2014-05-01

    The objectives were to answer the following questions with the help of a well-characterized population in Liège, Belgium: 1) what percentage of patients with abdominal aortic aneurysm (AAA) have a positive family history for AAA? 2) what is the prevalence of AAAs among relatives of patients with AAA? and 3) do familial and sporadic AAA cases differ in clinical characteristics? Patients with unrelated AAA diagnosed at the Cardiovascular Surgery Department, University Hospital of Liège, Belgium, between 1999 and 2012 were invited to the study. A detailed family history was obtained in interviews and recorded using Progeny software. We divided the 618 patients into 2 study groups: group I, 296 patients with AAA (268; 91% men) were followed up with computerized tomography combined with positron emission tomography; and group II, 322 patients with AAA (295; 92% men) whose families were invited to ultrasonographic screening. In the initial interview, 62 (10%) of the 618 patients with AAA reported a positive family history for AAA. Ultrasonographic screening identified 24 new AAAs among 186 relatives (≥50 years) of 144 families yielding a prevalence of 13%. The highest prevalence (25%) was found among brothers. By combining the number of AAAs found by ultrasonographic screening with those diagnosed previously the observed lifetime prevalence of AAA was estimated to be 32% in brothers. The familial AAA cases were more likely to have a ruptured AAA than the sporadic cases (8% vs. 2.4%; P < 0.0001). The findings confirm previously found high prevalence of AAA among brothers, support genetic contribution to AAA pathogenesis, and provide rationale for targeted screening of relatives of patients with AAA. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Skylab (SL)-3 - East Africa View - Ravaged by Drought

    NASA Image and Video Library

    1973-08-15

    S73-35082 (July-Sept. 1973) --- A near vertical view of a portion of west Africa ravaged 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 southeastern Niger about 200 nautical miles east-northeast of the capital city of Niamey. A polygonal-shaped area (dark) in the lower right corner of the picture represents a range-management ranch. The dry stream beds trending diagonally across the photograph locally contain some water or vegetation (green). The beds are sources of water through shallow drilling and contain soils suitable for production of crops. The variety of tans, browns and grays are typical desert colors that represent barren rocks and soil or sand-filled ancient stream valleys. Absence of vegetation is the singular feature of the area. Dr. G. Stuckmann of the Geographic Institute, University of Technology, Mannover, Federal Republic of Germany, will use this photograph in the study of the hydrologic regime of the region through analysis of fossil drainage patterns, geological structures and accumulations of surface water. Federal agencies participating with NASA on the EREP project are the Departments of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of Engineers. All EREP photography is available to the public through the Department of Interior?s Earth Resources Observations Systems Data Center, Sioux Falls, South Dakota, 57198. (Alternate number SL3-86-166) Photo credit: NASA

  14. Substituent effects in double-helical hydrogen-bonded AAA-DDD complexes.

    PubMed

    Wang, Hong-Bo; Mudraboyina, Bhanu P; Wisner, James A

    2012-01-27

    Two series of DDD and AAA hydrogen-bond arrays were synthesized that form triply-hydrogen-bonded double-helical complexes when combined in CDCl(3) solution. Derivatization of the DDD arrays with electron-withdrawing groups increases the complex association constants by up to a factor of 30 in those arrays examined. Derivatization of the AAA arrays with electron donating substituents reveals a similar magnitude effect on the complex stabilities. The effect of substitution on both types of arrays are modeled quite satisfactorily (R(2) > 0.96 in all cases) as free energy relationships with respect to the sums of their Hammett substituent constants. In all, the complex stabilities can be manipulated over more than three orders of magnitude (>20 kJ mol(-1)) using this type of modification. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Shoreline recovery from storms on the east coast of Southern Africa

    NASA Astrophysics Data System (ADS)

    Corbella, S.; Stretch, D. D.

    2012-01-01

    Episodic extreme waves due to sea storms can cause severe coastal erosion. The recovery times of such events are important for the analysis of risk and coastal vulnerability. The recovery period of a storm damaged coastline represents a time when the coastline is most vulnerable and nearby infrastructure is at the greatest risk. We propose that identification of the beach recovery period can be used as a coastal management tool when determining beach usage. As a case study, we analyse 37 yr of beach profile data on the east coast of South Africa. Considering beach length and cross-sectional area, we establish a global recovery period and rate and identify the physical characteristics of the coastlines that either accelerate or retard recovery. The beaches in the case study were found to take an average of two years to recover at a rate of approximately 90 m3 m-1 yr-1. Beach profiles with vegetated dunes recovered faster than urbanized beaches. Perpendicular beach structures have both positive and negative effects on beach recovery. Coastlines with rock outcrops in the surf zone tend to recover slowly and long-term sediment loss was identified in cases where storm damaged beaches have not recovered to pre-erosion levels.

  16. Cost-effectiveness of dog rabies vaccination programs in East Africa

    PubMed Central

    Borse, Rebekah H.; Atkins, Charisma Y.; Gambhir, Manoj; Undurraga, Eduardo A.; Blanton, Jesse D.; Kahn, Emily B.; Dyer, Jessie L.; Rupprecht, Charles E.

    2018-01-01

    Background Dog rabies annually causes 24,000–70,000 deaths globally. We built a spreadsheet tool, RabiesEcon, to aid public health officials to estimate the cost-effectiveness of dog rabies vaccination programs in East Africa. Methods RabiesEcon uses a mathematical model of dog-dog and dog-human rabies transmission to estimate dog rabies cases averted, the cost per human rabies death averted and cost per year of life gained (YLG) due to dog vaccination programs (US 2015 dollars). We used an East African human population of 1 million (approximately 2/3 living in urban setting, 1/3 rural). We considered, using data from the literature, three vaccination options; no vaccination, annual vaccination of 50% of dogs and 20% of dogs vaccinated semi-annually. We assessed 2 transmission scenarios: low (1.2 dogs infected per infectious dog) and high (1.7 dogs infected). We also examined the impact of annually vaccinating 70% of all dogs (World Health Organization recommendation for dog rabies elimination). Results Without dog vaccination, over 10 years there would a total of be approximately 44,000–65,000 rabid dogs and 2,100–2,900 human deaths. Annually vaccinating 50% of dogs results in 10-year reductions of 97% and 75% in rabid dogs (low and high transmissions scenarios, respectively), approximately 2,000–1,600 human deaths averted, and an undiscounted cost-effectiveness of $451-$385 per life saved. Semi-annual vaccination of 20% of dogs results in in 10-year reductions of 94% and 78% in rabid dogs, and approximately 2,000–1,900 human deaths averted, and cost $404-$305 per life saved. In the low transmission scenario, vaccinating either 50% or 70% of dogs eliminated dog rabies. Results were most sensitive to dog birth rate and the initial rate of dog-to-dog transmission (Ro). Conclusions Dog rabies vaccination programs can control, and potentially eliminate, dog rabies. The frequency and coverage of vaccination programs, along with the level of dog rabies

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  18. Inflammatory cell phenotypes in AAAs: their role and potential as targets for therapy.

    PubMed

    Dale, Matthew A; Ruhlman, Melissa K; Baxter, B Timothy

    2015-08-01

    Abdominal aortic aneurysms (AAAs) are characterized by chronic inflammatory cell infiltration. AAA is typically an asymptomatic disease and caused ≈15 000 deaths annually in the United States. Previous studies have examined both human and murine aortic tissue for the presence of various inflammatory cell types. Studies show that in both human and experimental AAAs, prominent inflammatory cell infiltration, such as CD4(+) T cells and macrophages, occurs in the damaged aortic wall. These cells have the ability to undergo phenotypic modulation based on microenvironmental cues, potentially influencing disease progression. Proinflammatory CD4(+) T cells and classically activated macrophages dominate the landscape of aortic infiltrates. The skew to proinflammatory phenotypes alters disease progression and plays a role in causing chronic inflammation. The local cytokine production and presence of inflammatory mediators, such as extracellular matrix breakdown products, influence the uneven balance of the inflammatory infiltrate phenotypes. Understanding and developing new strategies that target the proinflammatory phenotype could provide useful therapeutic targets for a disease with no current pharmacological intervention. © 2015 American Heart Association, Inc.

  19. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Small Business Corporations and Their Shareholders § 1.1368-2... earnings and profits or previously taxed income pursuant to an election made under section 1368(e)(3) and... AAA for redemptions and distributions in the year of a redemption. (c) Distribution of money and loss...

  20. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Small Business Corporations and Their Shareholders § 1.1368-2... earnings and profits or previously taxed income pursuant to an election made under section 1368(e)(3) and... AAA for redemptions and distributions in the year of a redemption. (c) Distribution of money and loss...

  1. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Small Business Corporations and Their Shareholders § 1.1368-2... earnings and profits or previously taxed income pursuant to an election made under section 1368(e)(3) and... AAA for redemptions and distributions in the year of a redemption. (c) Distribution of money and loss...

  2. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TAX (CONTINUED) INCOME TAXES Small Business Corporations and Their Shareholders § 1.1368-2 Accumulated... earnings and profits or previously taxed income pursuant to an election made under section 1368(e)(3) and... AAA for redemptions and distributions in the year of a redemption. (c) Distribution of money and loss...

  3. 26 CFR 1.1368-2 - Accumulated adjustments account (AAA).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Small Business Corporations and Their Shareholders § 1.1368-2... earnings and profits or previously taxed income pursuant to an election made under section 1368(e)(3) and... AAA for redemptions and distributions in the year of a redemption. (c) Distribution of money and loss...

  4. El Niño and the shifting geography of cholera in Africa.

    PubMed

    Moore, Sean M; Azman, Andrew S; Zaitchik, Benjamin F; Mintz, Eric D; Brunkard, Joan; Legros, Dominique; Hill, Alexandra; McKay, Heather; Luquero, Francisco J; Olson, David; Lessler, Justin

    2017-04-25

    The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa-and away from Madagascar and portions of southern, Central, and West Africa-where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk.

  5. Cenozoic vegetation, climate changes and hominid evolution in tropical Africa

    NASA Astrophysics Data System (ADS)

    Bonnefille, Raymonde

    2010-07-01

    This paper reviews information on past vegetation of tropical Africa during the Cenozoic, focused upon the last 10 Ma, a time spanning hominid record in Central and East Africa. Summary of palaeobotanical data collected at terrestrial sites are compared with new results on the long term evolution of the continental vegetation zones documented from marine pollen record of two deep sea cores recovered from the Atlantic and Indian Oceans. Section 2 includes a summary of modern distribution of vegetation belts in the African continent and a synthesis of the results of both macrobotanical (fossil wood, leaves and fruits) and microbotanical (mainly pollen) studies presented according to time scale and geographical location. The main features emphasized by the palaeobotanical results are 1) seasonal vegetation and climate documented as soon as the Eocene in Tanzania 2) well diversified forests existing in northern West Ethiopia during the Oligocene 3) high temporal and spatial variabilities of forests composition during the Miocene when deciduous Legume woodland was documented in Ethiopia whereas wetter evergreen forests existed in Western Kenya 4) lack of evidence for an evergreen forest belt, continuous from Western Congo to East Africa. Section 3 presents new original pollen data recovered from a long core in the Gulf of Aden documenting large scale past vegetation changes in East Africa during the last 11 Ma. These results are discussed in comparison with a summarized long pollen sequence previously published from a marine core offshore the Niger delta. This comparison illustrates variations in geographical distribution of large vegetation zone at the continental scale, through time. In Section 4, vegetation changes registered during the last 10 Ma are discussed in relation with the results of isotopic studies and an updated presentation of hominids evolution in Africa. Several changes are shown in the marine records. An expansion of savanna/grassland is shown at 10

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

    Rachid, G; El Fadel, M

    2013-08-15

    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  9. AAAS: Automated Affirmative Action System. General Description, Phase 1.

    ERIC Educational Resources Information Center

    Institute for Services to Education, Inc., Washington, DC. TACTICS Management Information Systems Directorate.

    This document describes phase 1 of the Automated Affirmative Action System (AAAS) of the Tuskegee Institute, which was designed to organize an inventory of any patterns of job classification and assignment identifiable by sex or minority group; any job classification or organizational unit where women and minorities are not employed or are…

  10. The Beginnings of Civilization in the Near East and Africa: Mesopotamia, Egypt, and Kush. Grade 6 Model Lesson for Unit II. California History-Social Science Course Models.

    ERIC Educational Resources Information Center

    Zachlod, Michelle, Ed.

    This model lesson for sixth graders about the beginnings of civilization in the Near East and Africa aims to have students focus on the cultural and geographical features of a region: landforms, climate, and vegetation. The lesson features three major topics: (1) Sumer and Mesopotamia, (2) Egypt, and (3) Kush. It addresses the uses and…

  11. Multi Plumes and Their Flows beneath Arabia and East Africa

    NASA Astrophysics Data System (ADS)

    Chang, S.; van der Lee, S.

    2010-12-01

    The three-dimensional S-velocity structure beneath Arabia and East Africa is estimated down to the lower mantle to investigate vertical and horizontal extension of low-velocity anomalies that bear out the presence of mantle plumes and their flows beneath lithosphere. We estimated this model through joint inversion of teleseismic S- and SKS-arrival times, regional S- and Rayleigh waveform fits, fundamental-mode Rayleigh-wave group velocities, and independent Moho constraints from receiver functions, reflection/refraction profiles, and gravity measurements. With the unprecedented resolution in our S-velocity model, we found different flow patterns of hot materials upwelling beneath Afar beneath the Red Sea and the Gulf of Aden. While the low-velocity anomaly from Afar is well confined beneath the Gulf of Aden, inferring mantle flow along the gulf, N-S channel of low velocity is found beneath Arabia, not along the Red Sea. The Afar plume is distinctively separate from the Kenya plume, showing its origin in the lower mantle beneath southwestern Arabia. We identified another low-velocity extension to the lower mantle beneath Jordan and northern Arabia, which is thought to have caused volcanism in Jordan, northern Arabia, and possibly southern Turkey. Comparing locations of mantle plumes from the joint inversion with fast axes of shear-wave splitting, we confirmed horizontal plume flow from Afar in NS direction beneath Arabia and in NE-SW direction beneath Ethiopia as a likely cause of the observed seismic anisotropy.

  12. Application of a GCM Ensemble Seasonal Climate Forecasts to Crop Yield Prediction in East Africa

    NASA Astrophysics Data System (ADS)

    Ogutu, G.; Franssen, W.; Supit, I.; Hutjes, R. W. A.

    2016-12-01

    We evaluated the potential use of ECMWF System-4 seasonal climate forecasts (S4) for impacts analysis over East Africa. Using the 15 member, 7 months ensemble forecasts initiated every month for 1981-2010, we tested precipitation (tp), air temperature (tas) and surface shortwave radiation (rsds) forecast skill against the WATCH forcing Data ERA-Interim (WFDEI) re-analysis and other data. We used these forecasts as input in the WOFOST crop model to predict maize yields. Forecast skill is assessed using anomaly correlation (ACC), Ranked Probability Skill Score (RPSS) and the Relative Operating Curve Skill Score (ROCSS) for MAM, JJA and OND growing seasons. Predicted maize yields (S4-yields) are verified against historical observed FAO and nationally reported (NAT) yield statistics, and yields from the same crop model forced by WFDEI (WFDEI-yields). Predictability of the climate forecasts vary with season, location and lead-time. The OND tp forecasts show skill over a larger area up to three months lead-time compared to MAM and JJA. Upper- and lower-tercile tp forecasts are 20-80% better than climatology. Good tas forecast skill is apparent with three months lead-time. The rsds is less skillful than tp and tas in all seasons when verified against WFDEI but higher against others. S4-forecasts captures ENSO related anomalous years with region dependent skill. Anomalous ENSO influence is also seen in simulated yields. Focussing on the main sowing dates in the northern (July), equatorial (March-April) and southern (December) regions, WFDEI-yields are lower than FAO and NAT but anomalies are comparable. Yield anomalies are predictable 3-months before sowing in most of the regions. Differences in interannual variability in the range of ±40% may be related to sensitivity of WOFOST to drought stress while the ACCs are largely positive ranging from 0.3 to 0.6. Above and below-normal yields are predictable with 2-months lead time. We evidenced a potential use of seasonal

  13. Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements

    PubMed Central

    Dickson, Laura B.; Sharakhova, Maria V.; Timoshevskiy, Vladimir A.; Fleming, Karen L.; Caspary, Alex; Sylla, Massamba; Black, William C.

    2016-01-01

    Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F1 intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F1 oviposition and low F2 egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane’s rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F1 males but average when a male mates with a hybrid F1 female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F1 females. These observations are therefore inconclusive with regards to Haldane’s rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining

  14. Synoptic scale convection and wave activity over tropical Africa and the Atlantic

    NASA Astrophysics Data System (ADS)

    Mekonnen, Ademe

    The objective of this research is to investigate synoptic scale convection and its association with wave disturbances over eastern Atlantic and tropical Africa. Analyses of convection highlight a significant peak periodicity in 2-6 day time scale over the Atlantic and most of tropical North Africa. The 2-6 day convective variance is the same order of magnitude over West and East Africa and accounts for 25%-35% of the total variance. However, dynamical measures of the African easterly wave (AEW) activity showed marked differences, variances over the West being more than the East. The explanation for this is that AEWs are initiated by convective precursors in the east and grow as they propagate westwards along the African easterly jet. Results show two major regions of synoptic time scale convection that are important for AEW initiation: the Darfur mountains (˜20°E) and the Ethiopian highlands (35°-40°E), with the former being more consistent and coherent. This study also shows the presence of eastward moving convective structures over tropical Africa, which are associated with Kelvin waves. The Kelvin waves originate in the Pacific and propagate across Africa. An important aspect of the Kelvin wave activity is its impact on convection and rainfall and its interaction with AEWs. Analysis of July-September 1987 weather events showed that convection and rainfall increase in association with Kelvin waves over tropical Africa. This event also suggested a series of AEWs initiated in association with Kelvin convection over tropical Africa. Spectral analysis of convection indicates a significant 3-4 day periodicity over Central Sudan, a region not known for wave disturbances. Two key factors that are associated with this variance are: (a) convective variability over equatorial Congo, and (b) upper level easterly waves that originate over Bay of Bengal-Southeast Asia. Results show the presence of a dipole pattern between the equatorial and East African convection that

  15. A quantitative assessment of groundwater resources in the Middle East and North Africa region

    NASA Astrophysics Data System (ADS)

    Lezzaik, Khalil; Milewski, Adam

    2018-02-01

    The Middle East and North Africa (MENA) region is the world's most water-stressed region, with its countries constituting 12 of the 15 most water-stressed countries globally. Because of data paucity, comprehensive regional-scale assessments of groundwater resources in the MENA region have been lacking. The presented study addresses this issue by using a distributed ArcGIS model, parametrized with gridded data sets, to estimate groundwater storage reserves in the region based on generated aquifer saturated thickness and effective porosity estimates. Furthermore, monthly gravimetric datasets (GRACE) and land surface parameters (GLDAS) were used to quantify changes in groundwater storage between 2003 and 2014. Total groundwater reserves in the region were estimated at 1.28 × 106 cubic kilometers (km3) with an uncertainty range between 816,000 and 1.93 × 106 km3. Most of the reserves are located within large sedimentary basins in North Africa and the Arabian Peninsula, with Algeria, Libya, Egypt, and Saudi Arabia accounting for approximately 75% of the region's total freshwater reserves. Alternatively, small groundwater reserves were found in fractured Precambrian basement exposures. As for groundwater changes between 2003 and 2014, all MENA countries except for Morocco exhibited declines in groundwater storage. However, given the region's large groundwater reserves, groundwater changes between 2003 and 2014 are minimal and represent no immediate short-term threat to the MENA region, with some exceptions. Notwithstanding this, the study recommends the development of sustainable and efficient groundwater management policies to optimally utilize the region's groundwater resources, especially in the face of climate change, demographic expansion, and socio-economic development.

  16. Endothelial MMP-9 drives the inflammatory response in abdominal aortic aneurysm (AAA).

    PubMed

    Ramella, Martina; Boccafoschi, Francesca; Bellofatto, Kevin; Md, Antonia Follenzi; Fusaro, Luca; Boldorini, Renzo; Casella, Francesco; Porta, Carla; Settembrini, Piergiorgio; Cannas, Mario

    2017-01-01

    Progression of abdominal aortic aneurysm (AAA) is typified by chronic inflammation and extracellular matrix (ECM) degradation of the aortic wall. Vascular inflammation involves complex interactions among inflammatory cells, endothelial cells (ECs), vascular smooth muscle cells (vSMCs), and ECM. Although vascular endothelium and medial neoangiogenesis play a key role in AAA, the molecular mechanisms underlying their involvement are only partially understood. In AAA biopsies, we found increased MMP-9, IL-6, and monocyte chemoattractant protein-1 (MCP-1), which correlated with massive medial neo-angiogenesis (C4d positive staining). In this study, we developed an in vitro model in order to characterize the role of endothelial matrix metalloproteinase-9 (e-MMP-9) as a potential trigger of medial disruption and in the inflammatory response bridging between ECs and vSMC. Lentiviral-mediated silencing of e-MMP-9 through RNA interference inhibited TNF-alpha-mediated activation of NF-κB in EA.hy926 human endothelial cells. In addition, EA.hy926 cells void of MMP-9 failed to migrate in a 3D matrix. Moreover, silenced EA.hy926 affected vSMC behavior in terms of matrix remodeling. In fact, also MMP-9 in vSMC resulted inhibited when endothelial MMP-9 was suppressed.

  17. Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

    NASA Astrophysics Data System (ADS)

    Bertola, L. D.; Jongbloed, H.; van der Gaag, K. J.; de Knijff, P.; Yamaguchi, N.; Hooghiemstra, H.; Bauer, H.; Henschel, P.; White, P. A.; Driscoll, C. A.; Tende, T.; Ottosson, U.; Saidu, Y.; Vrieling, K.; de Iongh, H. H.

    2016-08-01

    Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.

  18. Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo).

    PubMed

    Bertola, L D; Jongbloed, H; van der Gaag, K J; de Knijff, P; Yamaguchi, N; Hooghiemstra, H; Bauer, H; Henschel, P; White, P A; Driscoll, C A; Tende, T; Ottosson, U; Saidu, Y; Vrieling, K; de Iongh, H H

    2016-08-04

    Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.

  19. Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

    PubMed Central

    Bertola, L. D.; Jongbloed, H.; van der Gaag, K. J.; de Knijff, P.; Yamaguchi, N.; Hooghiemstra, H.; Bauer, H.; Henschel, P.; White, P. A.; Driscoll, C. A.; Tende, T.; Ottosson, U.; Saidu, Y.; Vrieling, K.; de Iongh, H. H.

    2016-01-01

    Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion. PMID:27488946

  20. Hepatorenal revascularization enables EVAR repair on a patient with AAA and an ectopic right renal artery.

    PubMed

    Lazaris, A M; Moulakakis, K; Mantas, G; Poulou, K; Alexiou, E; Vasdekis, S; Geroulakos, G

    2018-06-07

    The last thirty years the endovascular repair (EVAR) has become the standard method of treatment of abdominal aortic aneurysms (AAA). Nevertheless, the method has limitations based mainly on the anatomic characteristics of the specific aneurysm. In these cases a combination of endovascular and open techniques can be used. We describe a case of a patient with an infrarenal AAA and an ectopic right renal artery emerging from within the aneurysm sac. The patient was treated with a combination of endovascular and open techniques. In particular, he underwent a hepatorenal revascularization followed by a standard EVAR procedure, with a successful final outcome. For the treatment of AAA disease, the combination of open and endovascular procedures can overcome difficulties where a standard EVAR cannot be an option. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. What factors influence the production of orthopaedic research in East Africa? A qualitative analysis of interviews.

    PubMed

    Elliott, Iain S; Sonshine, Daniel B; Akhavan, Sina; Slade Shantz, Angelique; Caldwell, Amber; Slade Shantz, Jesse; Gosselin, Richard A; Coughlin, R Richard

    2015-06-01

    Research addressing the burden of musculoskeletal disease in low- and middle-income countries does not reflect the magnitude of the epidemic in these countries as only 9% of the world's biomedical resources are devoted to addressing problems that affect the health of 90% of the world's population. Little is known regarding the barriers to and drivers of orthopaedic surgery research in such resource-poor settings, the knowledge of which would help direct specific interventions for increasing research capacity and help surgeons from high-income countries support the efforts of our colleagues in low- and middle-income countries. We sought to identify through surveying academic orthopaedic surgeons in East Africa: (1) barriers impeding research, (2) factors that support or drive research, and (3) factors that were identified by some surgeons as barriers and others as drivers (what we term barrier-driver overlap) as they considered the production of clinical research in resource-poor environments. Semistructured interviews were conducted with 21 orthopaedic surgeon faculty members at four academic medical centers in Ethiopia, Kenya, Tanzania, and Uganda. Qualitative content analysis of the interviews was conducted using methods based in grounded theory. Grounded theory begins with qualitative data, such as interview transcripts, and analyzes the data for repeated ideas or concepts which then are coded and grouped into categories which allow for identification of subjects or problems that may not have been apparent previously to the interviewer. We identified and quantified 19 barriers to and 21 drivers of orthopaedic surgery research (mentioned n = 1688 and n = 1729, respectively). Resource, research process, and institutional domains were identified to categorize the barriers (n = 7, n = 5, n = 7, respectively) and drivers (n = 7, n = 8, n = 6, respectively). Resource barriers (46%) were discussed more often by interview subjects compared with the

  2. Obesity is not an independent risk factor for adverse perioperative and long-term clinical outcomes following open AAA repair or EVAR.

    PubMed

    Park, Brian; Dargon, Phong; Binette, Christopher; Babic, Bruna; Thomas, Tina; Divinagracia, Thomas; Dahn, Michael S; Menzoian, James O

    2011-10-01

    Moderate (body mass index [BMI] ≥30) and morbid obesity (BMI ≥35) is increasing at an alarming rate in vascular surgery patients. The objective of this study was to determine the impact of obesity on perioperative and long-term clinical outcomes following open abdominal aortic aneurysm (AAA) repair or endovascular aneurysm repair (EVAR). This review includes patients that underwent open AAA repair (n = 403) or EVAR (n = 223) from 1999 to 2009. Specific patient characteristics such as comorbid diseases, medications, and body mass index (BMI) were assessed. Specific perioperative outcomes such as length of stay, myocardial infarctions, and mortality were reviewed. In addition, long-term outcomes such as rates of reintervention, permanent renal dysfunction, and mortality beyond 30 days were also assessed. The incidence of obesity in open AAA patients was 25.3% (documented incidence 1.5%) and for EVAR was 24.6% (documented incidence 4%). Moderate and morbid obesity was associated with longer intensive care unit (ICU) admissions for both open AAA or EVAR patients (P < .05). However, no significant differences in perioperative outcomes in terms of overall length of stay, myocardial infarction, acute renal failure, wound infections, or mortality were noted between obese and nonobese patients underoing open AAA repair or EVAR (P > .05). Similarly, moderate and morbid obesity was not associated with significant differences in rates of reintervention, permanent renal dysfunction, and mortality beyond 30 days for patients undergoing open AAA repair or EVAR (P > .05). The results of this study indicate that moderate and morbid obesity are not independently associated with adverse perioperative and long-term clinical outcomes for patients undergoing open AAA repair or EVAR. Therefore, either open AAA repair or EVAR can be accomplished safely in moderately obese and morbidly obese patients.

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

    ERIC Educational Resources Information Center

    Maher, Robert

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

  4. Seismic anisotropy across the east African plateau from shear wave splitting analysis

    NASA Astrophysics Data System (ADS)

    Bagley, B. C.; Nyblade, A.; Mulibo, G.; Tugume, F.

    2011-12-01

    Previous studies of the east African plateau reveal complicated patterns of seismic anisotropy that are not easily explained by a single mechanism. The pattern is defined by rift-parallel fast directions for stations within or near Cenozoic rift valleys, and near-null results in Precambrian terrains away from the rift. Data from 65 temporary Africa Array stations deployed between 2007 and 2011 are being used to make new shear wave splitting measurements. The stations span the east African plateau and cover both the eastern and western branches of the east African rift system, as well as unrifted Proterozoic and Archean terrains in Uganda, Kenya, Tanzania, and Zambia. Through analysis of shear wave splitting we will better constrain the distribution of seismic anisotropy, and and from it gain new insight into the tectonic evolution of east Africa.

  5. Analysis of diurnal and seasonal climate patterns in the Rwenzori Mountains, East Africa, using satellite data and models

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. B.; Doughty, A. M.; Hatchett, B.

    2016-12-01

    The Rwenzori Mountains of Uganda and Democratic Republic of the Congo are one of only three remaining glaciated sites in Africa. Because of their remoteness and sparsity of meteorological data, the climate patterns are not well-known or well understood, which may lead to high uncertainty in glacier mass-balance estimates and paleoclimate reconstructions. This project uses remotely-sensed precipitation data, automatic weather station data, and back-trajectory modeling of air parcels to characterize the diurnal and seasonal climate patterns at the Rwenzori. Of the two wet seasons, we estimate that the short-rains (SON) provide up to 500% more snow accumulation. Precipitation is highly diurnal and driven by convection to the east of the Rwenzori as well as local up-valley convection (Mölg et al., 2003). Back-trajectory modeling shows that precipitation tends to occur at the Rwenzori when airstreams are able to pick up moisture during peak daytime convection on the East African Plateau the day before arriving at the Rwenzori. This relationship is supported by the fact that precipitation rates at the western end of the plateau follow a stronger diurnal cycle than precipitation rates at the eastern end, at Mount Kenya.

  6. Spatiotemporal distribution of diurnal yellow fever vectors (Diptera: Culicidae) at two sylvan interfaces in Kenya, East Africa.

    PubMed

    Ellis, Brett Richard; Wesson, Dawn M; Sang, Rosemary C

    2007-01-01

    Yellow fever virus (YFV) remains a significant public health threat in sub-Saharan Africa in which 90% of the estimated 200,000 cases occur annually. In East Africa, human cases of YFV are characterized by unpredictable focal periodicity, lengthy inter-epidemic periods, and a precarious potential for large epidemics. YFV had remained undetected in this region for nearly 40 years until emerging in Kenya in 1992-93 and more recently in Sudan during 2003 and 2005. From an ecological perspective the emergence and epidemiological outcomes associated with YFV, and related vector-borne diseases, are critically dependent upon the underlying vector ecology at a local scale. The study here was aimed at defining the dynamics of important vector interactions at two important sites in Kenya with previous YFV or related arbovirus activity. The temporal abundance, spatial distribution, and human host seeking behavior of diurnal man-landing mosquito species along sylvan interfaces were investigated. A number of YFV vectors were identified including their abundances for the duration of the main rainy season. Spatially, results indicated that the greatest human-mosquito interactions occurred within the forest and decreased across more domesticated biotopes. A discussion of significant differences, ecological associations, and epidemiological implications is included.

  7. Mechanism of Enzyme Repair by the AAA+ Chaperone Rubisco Activase.

    PubMed

    Bhat, Javaid Y; Miličić, Goran; Thieulin-Pardo, Gabriel; Bracher, Andreas; Maxwell, Andrew; Ciniawsky, Susanne; Mueller-Cajar, Oliver; Engen, John R; Hartl, F Ulrich; Wendler, Petra; Hayer-Hartl, Manajit

    2017-09-07

    How AAA+ chaperones conformationally remodel specific target proteins in an ATP-dependent manner is not well understood. Here, we investigated the mechanism of the AAA+ protein Rubisco activase (Rca) in metabolic repair of the photosynthetic enzyme Rubisco, a complex of eight large (RbcL) and eight small (RbcS) subunits containing eight catalytic sites. Rubisco is prone to inhibition by tight-binding sugar phosphates, whose removal is catalyzed by Rca. We engineered a stable Rca hexamer ring and analyzed its functional interaction with Rubisco. Hydrogen/deuterium exchange and chemical crosslinking showed that Rca structurally destabilizes elements of the Rubisco active site with remarkable selectivity. Cryo-electron microscopy revealed that Rca docks onto Rubisco over one active site at a time, positioning the C-terminal strand of RbcL, which stabilizes the catalytic center, for access to the Rca hexamer pore. The pulling force of Rca is fine-tuned to avoid global destabilization and allow for precise enzyme repair. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Climate variability and conflict risk in East Africa, 1990–2009

    PubMed Central

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

    2012-01-01

    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 climate–conflict 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 climate–conflict relationships are evident between the nine countries of the study region and across time periods. PMID:23090992

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

    USGS Publications Warehouse

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

    2009-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  11. El Niño and the shifting geography of cholera in Africa

    PubMed Central

    Moore, Sean M.; Azman, Andrew S.; Zaitchik, Benjamin F.; Mintz, Eric D.; Brunkard, Joan; Legros, Dominique; Hill, Alexandra; McKay, Heather; Luquero, Francisco J.; Olson, David; Lessler, Justin

    2017-01-01

    The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases ranging from dengue to cholera. In Africa, El Niño conditions are associated with increased rainfall in East Africa and decreased rainfall in southern Africa, West Africa, and parts of the Sahel. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between ENSO patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa. Using high-resolution mapping techniques, we find that the annual geographic distribution of cholera in Africa from 2000 to 2014 changes dramatically, with the burden shifting to continental East Africa—and away from Madagascar and portions of southern, Central, and West Africa—where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall, suggesting a complex relationship between rainfall and cholera incidence. Here, we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño years, likely mediated by El Niño’s impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with ENSO forecasting could be used to notify countries in Africa when they are likely to see a major shift in their cholera risk. PMID:28396423

  12. Identification of a Degradation Signal Sequence within Substrates of the Mitochondrial i-AAA Protease.

    PubMed

    Rampello, Anthony J; Glynn, Steven E

    2017-03-24

    The i-AAA protease is a component of the mitochondrial quality control machinery that regulates respiration, mitochondrial dynamics, and protein import. The protease is required to select specific substrates for degradation from among the diverse complement of proteins present in mitochondria, yet the rules that govern this selection are unclear. Here, we reconstruct the yeast i-AAA protease, Yme1p, to examine the in vitro degradation of two intermembrane space chaperone subunits, Tim9 and Tim10. Yme1p degrades Tim10 more rapidly than Tim9 despite high sequence and structural similarity, and loss of Tim10 is accelerated by the disruption of conserved disulfide bonds within the substrate. An unstructured N-terminal region of Tim10 is necessary and sufficient to target the substrate to the protease through recognition of a short phenylalanine-rich motif, and the presence of similar motifs in other small Tim proteins predicts robust degradation by the protease. Together, these results identify the first specific degron sequence within a native i-AAA protease substrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Role of mitochondrial processing peptidase and AAA proteases in processing of the yeast acetohydroxyacid synthase precursor.

    PubMed

    Dasari, Suvarna; Kölling, Ralf

    2016-07-01

    We studied presequence processing of the mitochondrial-matrix targeted acetohydroxyacid synthase (Ilv2). C-terminal 3HA-tagging altered the cleavage pattern from a single step to sequential two-step cleavage, giving rise to two Ilv2-3HA forms (A and B). Both cleavage events were dependent on the mitochondrial processing peptidase (MPP). We present evidence for the involvement of three AAA ATPases, m- and i-AAA proteases, and Mcx1, in Ilv2-3HA processing. Both, precursor to A-form and A-form to B-form cleavage were strongly affected in a ∆yme1 mutant. These defects could be suppressed by overexpression of MPP, suggesting that MPP activity is limiting in the ∆yme1 mutant. Our data suggest that for some substrates AAA ATPases could play an active role in the translocation of matrix-targeted proteins.

  14. The Cenozoic magmatism of East-Africa: Part I - Flood basalts and pulsed magmatism

    NASA Astrophysics Data System (ADS)

    Rooney, Tyrone O.

    2017-08-01

    Cenozoic magmatism in East Africa results from the interplay between lithospheric extension and material upwelling from the African Large Low Shear Velocity Province (LLSVP). The modern focusing of East African magmatism into oceanic spreading centers and continental rifts highlights the modern control of lithospheric thinning in magma generation processes, however the widespread, and volumetrically significant flood basalt events of the Eocene to Early Miocene suggest a significant role for material upwelling from the African LLSVP. The slow relative motion of the African plate during the Cenozoic has resulted in significant spatial overlap in lavas derived from different magmatic events. This complexity is being resolved with enhanced geochronological precision and a focus on the geochemical characteristics of the volcanic products. It is now apparent that there are three distinct pulses of basaltic volcanism, followed by either bimodal lavas or silicic volcanic products during this period: (A) Eocene Initial Phase from 45 to 34 Ma. This is a period of dominantly basaltic volcanism focused in Southern Ethiopia and Northern Kenya (Turkana). (B) Oligocene Traps phase from 33.9 to 27 Ma. This period coincides with a significant increase in the aerial extent of volcanism with broadly age equivalent 1 to 2 km thick sequences of dominantly basalt centered on the NW Ethiopian Plateau and Yemen, (C) Early Miocene resurgence phase from 26.9 to 22 Ma. This resurgence in basaltic volcanism is seen throughout the region at ca. 24-23 Ma, but is less volumetrically significant than the prior two basaltic pulses. With our developing understanding of the persistence of LLSVP anomalies within the mantle, I propose that the three basaltic pulses are ostensibly manifestations of the same plume-lithosphere interaction, requiring revision to the duration, magmatic extent, and magma volume of the African-Arabian Large Igneous Province.

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    A variety of regional and global models of the dust aerosol cycle have been developed since early 1990s. Dust models are essential to complement dust-related observations, understand the dust processes and predict the impact of dust on surface level PM concentrations. Dust generation and the parameterization of its deposition processes shows a high variability on spatial and temporal scales. It responds, in a non-linear way, to a variety of environmental factors, such as soil moisture content, the type of surface cover or surface atmospheric turbulence. Thus the modelling of this very complex process is a challenge. DREAM (Dust Regional Atmospheric Model; Nickovic et al., 2001) provides operational dust forecasts for Northern Africa, Europe and Middle East, as well as for the East-Asia regions. DREAM is operated and further developed in the Barcelona Supercomputing Center. DREAM is fully inserted as one of the governing equations in the NCEP/Eta atmospheric model and simulates all major processes of the atmospheric dust cycle. In order to implement new model versions for operational applications there is a need for extensive checking and validation against real observations. The present study focuses on the evaluation of forecasting capacity of the new version of DREAM by means of a model-to-observation comparison of the Aerosol Optical Depth (AOD) over Northern Africa, Southern Europe and Middle East for one year. The model provides 72h forecasts initialized at 12UTC of each day with outputs every 1 hour at horizontal resolution of about 1/3° and 24 z-vertical layers in the troposphere. Comparisons against 47 selected AERONET sites are used. Eight size bins between 0.1 and 10 µm are considered, and dust-radiation interactions are included (Pérez et al., 2006). Wet deposition scheme has been also improved. The simulation has been performed over one year (2004); statistics and time series for the model outputs and AERONET data are used to evaluate the ability of

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  17. A Non-Competitive Inhibitor of VCP/p97 and VPS4 Reveals Conserved Allosteric Circuits in Type I and II AAA ATPases.

    PubMed

    Pöhler, Robert; Krahn, Jan H; van den Boom, Johannes; Dobrynin, Grzegorz; Kaschani, Farnusch; Eggenweiler, Hans-Michael; Zenke, Frank T; Kaiser, Markus; Meyer, Hemmo

    2018-02-05

    AAA ATPases have pivotal functions in diverse cellular processes essential for survival and proliferation. Revealing strategies for chemical inhibition of this class of enzymes is therefore of great interest for the development of novel chemotherapies or chemical tools. Here, we characterize the compound MSC1094308 as a reversible, allosteric inhibitor of the type II AAA ATPase human ubiquitin-directed unfoldase (VCP)/p97 and the type I AAA ATPase VPS4B. Subsequent proteomic, genetic and biochemical studies indicate that MSC1094308 binds to a previously characterized drugable hotspot of p97, thereby inhibiting the D2 ATPase activity. Our results furthermore indicate that a similar allosteric site exists in VPS4B, suggesting conserved allosteric circuits and drugable sites in both type I and II AAA ATPases. Our results may thus guide future chemical tool and drug discovery efforts for the biomedically relevant AAA ATPases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Cost of illness due to typhoid Fever in pemba, zanzibar, East Africa.

    PubMed

    Riewpaiboon, Arthorn; 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

    2014-09-01

    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.

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

    PubMed Central

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

    2011-01-01

    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

  20. [Incidence and risk factors of ischemic colitis after AAA repair in our cohort of patients from 2005 through 2009].

    PubMed

    Biros, E; Staffa, R

    2011-12-01

    Using retrospective analysis, we sought to investigate the incidence, risk factors and therapeutic outcomes of ischemic colitis in patients after surgical and endovascular repair of abdominal aortic aneurysms (AAA). The complete inpatient and outpatient medical records of all patients undergoing surgical or endovascular AAA repair in our Department from January 2005 to December 2009 were retrospectively reviewed. We selected all patients who had developed an acute or chronic form of postoperative large or small bowel ischemia. We carried out data analysis and focused on determining the incidence and risk factors of this complication and the outcomes of its treatment. Two hundred and seven AAA repairs were performed in the 2nd Department of Surgery of St. Anne's University Hospital in Brno and the Faculty of Medicine of Masaryk University in Brno during the studied period. This number includes endovascular AAA repairs (13 patients; 6.3%) as well as one robot-assisted operation, and also the whole clinical spectrum of AAA manifestations, from non-symptomatic forms to ruptured aneurysm forms. The rest of the patients underwent open operation. Bowel ischemia developed in a total of 11 patients (5.3 %), who all underwent open AAA repair. Six of these patients presented with non-ruptured AAA and the remaining 5 with ruptured AAA. In 3 patients, bowel ischemia was diagnosed with a delay of several months from the original revascularization operation in the clinical form of postischemic stricture of the large bowel (2 patients) or postischemic colitis (1 patient). 8 patients were diagnosed with acute ischemic colitis affecting an isolated segment of the small bowel in one patient, extended segments of the large bowel (descending colon + sigmoid colon + rectum) in 2 patients, and typically the descending and sigmoid colon in 5 patients. None of the three patients with late manifestation of ischemic colitis died. Of the 8 patients with acute presentation, resection of the

  1. Middle East Environmental Ministries, Partners and other Resources

    EPA Pesticide Factsheets

    The EPA works with many partners to ensure capacity building and efficient, successful programs, including environmental ministries, enforcement networks, non-governmental organizations, and more in the Middle East and North Africa region.

  2. U.S. National Security Interests in Africa and the Future Global War on Terrorism (GWOT): A Proposal to Create an African Regional Combatant Command and a Regional African Special Operations Command

    DTIC Science & Technology

    2005-09-01

    distributed. The final recommendations concluded that the geographical boundaries of USPACOM would include the entire Indian Ocean to the east coast of...strategically be located within the sub-region of West Africa or East Africa. 15. NUMBER OF PAGES 94 14. SUBJECT TERMS US National Interests...should strategically be located within the sub-region of West Africa or East Africa. vi THIS PAGE

  3. Cocaine and Instability in Africa: Lessons from Latin America and the Caribbean (Africa Security Brief, Number 5, July 2010)

    DTIC Science & Technology

    2010-07-01

    however, that instability in East Africa is attracting heroin traffic (contributing to an esti- Davin O’Regan is a Research Associate at the Africa...Narcotics trafficking is not intrinsically violent. Violence within the international trade in cannabis and Ecstasy , a popular hallucinogen...70 people were killed in clashes and gun battles. Trafficking- associated violence can reach even more dangerous levels. In Mexico, traffickers fre

  4. Joint atmospheric-terrestrial water balances for East Africa: a WRF-Hydro case study for the upper Tana River basin

    NASA Astrophysics Data System (ADS)

    Kerandi, Noah; Arnault, Joel; Laux, Patrick; Wagner, Sven; Kitheka, Johnson; Kunstmann, Harald

    2018-02-01

    For an improved understanding of the hydrometeorological conditions of the Tana River basin of Kenya, East Africa, its joint atmospheric-terrestrial water balances are investigated. This is achieved through the application of the Weather Research and Forecasting (WRF) and the fully coupled WRF-Hydro modeling system over the Mathioya-Sagana subcatchment (3279 km2) and its surroundings in the upper Tana River basin for 4 years (2011-2014). The model setup consists of an outer domain at 25 km (East Africa) and an inner one at 5-km (Mathioya-Sagana subcatchment) horizontal resolution. The WRF-Hydro inner domain is enhanced with hydrological routing at 500-m horizontal resolution. The results from the fully coupled modeling system are compared to those of the WRF-only model. The coupled WRF-Hydro slightly reduces precipitation, evapotranspiration, and the soil water storage but increases runoff. The total precipitation from March to May and October to December for WRF-only (974 mm/year) and coupled WRF-Hydro (940 mm/year) is closer to that derived from the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data (989 mm/year) than from the TRMM (795 mm/year) precipitation product. The coupled WRF-Hydro-accumulated discharge (323 mm/year) is close to that observed (333 mm/year). However, the coupled WRF-Hydro underestimates the observed peak flows registering low but acceptable NSE (0.02) and RSR (0.99) at daily time step. The precipitation recycling and efficiency measures between WRF-only and coupled WRF-Hydro are very close and small. This suggests that most of precipitation in the region comes from moisture advection from the outside of the analysis domain, indicating a minor impact of potential land-precipitation feedback mechanisms in this case. The coupled WRF-Hydro nonetheless serves as a tool in quantifying the atmospheric-terrestrial water balance in this region.

  5. SU-E-T-122: Anisotropic Analytical Algorithm (AAA) Vs. Acuros XB (AXB) in Stereotactic Treatment Planning

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mynampati, D; Scripes, P Godoy; Kuo, H

    2015-06-15

    Purpose: To evaluate dosimetric differences between superposition beam model (AAA) and determinant photon transport solver (AXB) in lung SBRT and Cranial SRS dose computations. Methods: Ten Cranial SRS and ten Lung SBRT plans using Varian, AAA -11.0 were re-planned using Acuros -XB-11.0 with fixed MU. 6MV photon Beam model with HD120-MLC used for dose calculations. Four non-coplanar conformal arcs used to deliver 21Gy or 18Gy to SRS targets (0.4 to 6.2cc). 54Gy (3Fractions) or 50Gy (5Fractions) was planned for SBRT targets (7.3 to 13.9cc) using two VAMT non-coplanar arcs. Plan comparison parameters were dose to 1% PTV volume (D1), dosemore » to 99% PTV volume( D99), Target mean (Dmean), Conformity index (ratio of prescription isodose volume to PTV), Homogeneity Index [ (D2%-D98%)/Dmean] and R50 (ratio of 50% of prescription isodose volume to PTV). OAR parameters were Brain volume receiving 12Gy dose (V12Gy) and maximum dose (D0.03) to Brainstem for SRS. For lung SBRT, maximum dose to Heart and Cord, Mean lung dose (MLD) and volume of lung receiving 20Gy (V20Gy) were computed. PTV parameters compared by percentage difference between AXB and AAA parameters. OAR parameters and HI compared by absolute difference between two calculations. For analysis, paired t-test performed over the parameters. Results: Compared to AAA, AXB SRS plans have on average 3.2% lower D99, 6.5% lower CI and 3cc less Brain-V12. However, AXB SBRT plans have higher D1, R50 and Dmean by 3.15%, 1.63% and 2.5%. For SRS and SBRT, AXB plans have average HI 2 % and 4.4% higher than AAA plans. In both techniques, all other parameters vary within 1% or 1Gy. In both sets only two parameters have P>0.05. Conclusion: Even though t-test results signify difference between AXB and AAA plans, dose differences in dose estimations by both algorithms are clinically insignificant.« less

  6. Hypovitaminosis D in the Middle East and North Africa

    PubMed Central

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

    2013-01-01

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

  7. Coordinated gripping of substrate by subunits of a AAA+ proteolytic machine

    PubMed Central

    Iosefson, Ohad; Nager, Andrew R.; Baker, Tania A.; Sauer, Robert T.

    2014-01-01

    Hexameric AAA+ unfoldases of ATP-dependent proteases and protein-remodeling machines use conserved loops that line the axial pore to apply force to substrates during the mechanical processes of protein unfolding and translocation. Whether loops from multiple subunits act independently or coordinately in these processes is a critical aspect of mechanism but is currently unknown for any AAA+ machine. By studying covalently linked hexamers of the E. coli ClpX unfoldase bearing different numbers and configurations of wild-type and mutant pore loops, we show that loops function synergistically, with the number of wild-type loops required for efficient degradation depending upon the stability of the protein substrate. Our results support a mechanism in which a power stroke initiated in one subunit of the ClpX hexamer results in the concurrent movement of all six pore loops, which coordinately grip and apply force to the substrate. PMID:25599533

  8. From AAA to Acuros XB-clinical implications of selecting either Acuros XB dose-to-water or dose-to-medium.

    PubMed

    Zifodya, Jackson M; Challens, Cameron H C; Hsieh, Wen-Long

    2016-06-01

    When implementing Acuros XB (AXB) as a substitute for anisotropic analytic algorithm (AAA) in the Eclipse Treatment Planning System, one is faced with a dilemma of reporting either dose to medium, AXB-Dm or dose to water, AXB-Dw. To assist with decision making on selecting either AXB-Dm or AXB-Dw for dose reporting, a retrospective study of treated patients for head & neck (H&N), prostate, breast and lung is presented. Ten patients, previously treated using AAA plans, were selected for each site and re-planned with AXB-Dm and AXB-Dw. Re-planning was done with fixed monitor units (MU) as well as non-fixed MUs. Dose volume histograms (DVH) of targets and organs at risk (OAR), were analyzed in conjunction with ICRU-83 recommended dose reporting metrics. Additionally, comparisons of plan homogeneity indices (HI) and MUs were done to further highlight the differences between the algorithms. Results showed that, on average AAA overestimated dose to the target volume and OARs by less than 2.0 %. Comparisons between AXB-Dw and AXB-Dm, for all sites, also showed overall dose differences to be small (<1.5 %). However, in non-water biological media, dose differences between AXB-Dw and AXB-Dm, as large as 4.6 % were observed. AXB-Dw also tended to have unexpectedly high 3D maximum dose values (>135 % of prescription dose) for target volumes with high density materials. Homogeneity indices showed that AAA planning and optimization templates would need to be adjusted only for the H&N and Lung sites. MU comparison showed insignificant differences between AXB-Dw relative to AAA and between AXB-Dw relative to AXB-Dm. However AXB-Dm MUs relative to AAA, showed an average difference of about 1.3 % signifying an underdosage by AAA. In conclusion, when dose is reported as AXB-Dw, the effect that high density structures in the PTV has on the dose distribution should be carefully considered. As the results show overall small dose differences between the algorithms, when

  9. SU-E-T-516: Dosimetric Validation of AcurosXB Algorithm in Comparison with AAA & CCC Algorithms for VMAT Technique.

    PubMed

    Kathirvel, M; Subramanian, V Sai; Arun, G; Thirumalaiswamy, S; Ramalingam, K; Kumar, S Ashok; Jagadeesh, K

    2012-06-01

    To dosimetrically validate AcurosXB algorithm for Volumetric Modulated Arc Therapy (VMAT) in comparison with standard clinical Anisotropic Analytic Algorithm(AAA) and Collapsed Cone Convolution(CCC) dose calculation algorithms. AcurosXB dose calculation algorithm is available with Varian Eclipse treatment planning system (V10). It uses grid-based Boltzmann equation solver to predict dose precisely in lesser time. This study was made to realize algorithms ability to predict dose accurately as its delivery for which five clinical cases each of Brain, Head&Neck, Thoracic, Pelvic and SBRT were taken. Verification plans were created on multicube phantom with iMatrixx-2D detector array and then dose prediction was done with AcurosXB, AAA & CCC (COMPASS System) algorithm and the same were delivered onto CLINAC-iX treatment machine. Delivered dose was captured in iMatrixx plane for all 25 plans. Measured dose was taken as reference to quantify the agreement between AcurosXB calculation algorithm against previously validated AAA and CCC algorithm. Gamma evaluation was performed with clinical criteria distance-to-agreement 3&2mm and dose difference 3&2% in omnipro-I'MRT software. Plans were evaluated in terms of correlation coefficient, quantitative area gamma and average gamma. Study shows good agreement between mean correlation 0.9979±0.0012, 0.9984±0.0009 & 0.9979±0.0011 for AAA, CCC & Acuros respectively. Mean area gamma for criteria 3mm/3% was found to be 98.80±1.04, 98.14±2.31, 98.08±2.01 and 2mm/2% was found to be 93.94±3.83, 87.17±10.54 & 92.36±5.46 for AAA, CCC & Acuros respectively. Mean average gamma for 3mm/3% was 0.26±0.07, 0.42±0.08, 0.28±0.09 and 2mm/2% was found to be 0.39±0.10, 0.64±0.11, 0.42±0.13 for AAA, CCC & Acuros respectively. This study demonstrated that the AcurosXB algorithm had a good agreement with the AAA & CCC in terms of dose prediction. In conclusion AcurosXB algorithm provides a valid, accurate and speedy alternative to AAA

  10. What Do We Need To Live on Planet Earth? A Case Study of Traditional Rural Life in East Africa. A Curriculum Unit for History and Social Studies, Grades 2-4.

    ERIC Educational Resources Information Center

    Murphey, Carol; Wallace, Kendra R.

    The unit focuses on the lifestyles of two social groups in East Africa: the traditional nomadic Masai and the traditional agrarian Kikuyu. The activities engage students in an exploration of the dynamic interactions between these people and the animals that share the same land. Activities include: (1) "Houses"; (2) "Elephants";…

  11. Analysis of the cooperative ATPase cycle of the AAA+ chaperone ClpB from Thermus thermophilus by using ordered heterohexamers with an alternating subunit arrangement.

    PubMed

    Yamasaki, Takashi; Oohata, Yukiko; Nakamura, Toshiki; Watanabe, Yo-hei

    2015-04-10

    The ClpB/Hsp104 chaperone solubilizes and reactivates protein aggregates in cooperation with DnaK/Hsp70 and its cofactors. The ClpB/Hsp104 protomer has two AAA+ modules, AAA-1 and AAA-2, and forms a homohexamer. In the hexamer, these modules form a two-tiered ring in which each tier consists of homotypic AAA+ modules. By ATP binding and its hydrolysis at these AAA+ modules, ClpB/Hsp104 exerts the mechanical power required for protein disaggregation. Although ATPase cycle of this chaperone has been studied by several groups, an integrated understanding of this cycle has not been obtained because of the complexity of the mechanism and differences between species. To improve our understanding of the ATPase cycle, we prepared many ordered heterohexamers of ClpB from Thermus thermophilus, in which two subunits having different mutations were cross-linked to each other and arranged alternately and measured their nucleotide binding, ATP hydrolysis, and disaggregation abilities. The results indicated that the ATPase cycle of ClpB proceeded as follows: (i) the 12 AAA+ modules randomly bound ATP, (ii) the binding of four or more ATP to one AAA+ ring was sensed by a conserved Arg residue and converted another AAA+ ring into the ATPase-active form, and (iii) ATP hydrolysis occurred cooperatively in each ring. We also found that cooperative ATP hydrolysis in at least one ring was needed for the disaggregation activity of ClpB. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Deviation of the typical AAA substrate-threading pore prevents fatal protein degradation in yeast Cdc48.

    PubMed

    Esaki, Masatoshi; Islam, Md Tanvir; Tani, Naoki; Ogura, Teru

    2017-07-14

    Yeast Cdc48 is a well-conserved, essential chaperone of ATPases associated with diverse cellular activity (AAA) proteins, which recognizes substrate proteins and modulates their conformations to carry out many cellular processes. However, the fundamental mechanisms underlying the diverse pivotal roles of Cdc48 remain unknown. Almost all AAA proteins form a ring-shaped structure with a conserved aromatic amino acid residue that is essential for proper function. The threading mechanism hypothesis suggests that this residue guides the intrusion of substrate proteins into a narrow pore of the AAA ring, thereby becoming unfolded. By contrast, the aromatic residue in one of the two AAA rings of Cdc48 has been eliminated through evolution. Here, we show that artificial retrieval of this aromatic residue in Cdc48 is lethal, and essential features to support the threading mechanism are required to exhibit the lethal phenotype. In particular, genetic and biochemical analyses of the Cdc48 lethal mutant strongly suggested that when in complex with the 20S proteasome, essential proteins are abnormally forced to thread through the Cdc48 pore to become degraded, which was not detected in wild-type Cdc48. Thus, the widely applicable threading model is less effective for wild-type Cdc48; rather, Cdc48 might function predominantly through an as-yet-undetermined mechanism.

  13. m-AAA Complexes Are Not Crucial for the Survival of Arabidopsis Under Optimal Growth Conditions Despite Their Importance for Mitochondrial Translation.

    PubMed

    Kolodziejczak, Marta; Skibior-Blaszczyk, Renata; Janska, Hanna

    2018-05-01

    For optimal mitochondrial activity, the mitochondrial proteome must be properly maintained or altered in response to developmental and environmental stimuli. Based on studies of yeast and humans, one of the key players in this control are m-AAA proteases, mitochondrial inner membrane-bound ATP-dependent metalloenzymes. This study focuses on the importance of m-AAA proteases in plant mitochondria, providing their first experimentally proven physiological substrate. We found that the Arabidopsis m- AAA complexes composed of AtFTSH3 and/or AtFTSH10 are involved in the proteolytic maturation of ribosomal subunit L32. Consequently, in the double Arabidopsis ftsh3/10 mutant, mitoribosome biogenesis, mitochondrial translation and functionality of OXPHOS (oxidative phosphorylation) complexes are impaired. However, in contrast to their mammalian or yeast counterparts, plant m-AAA complexes are not critical for the survival of Arabidopsis under optimal conditions; ftsh3/10 plants are only slightly smaller in size at the early developmental stage compared with plants containing m-AAA complexes. Our data suggest that a lack of significant visible morphological alterations under optimal growth conditions involves mechanisms which rely on existing functional redundancy and induced functional compensation in Arabidopsis mitochondria.

  14. Barriers to the delivery of diabetes care in the Middle East and South Africa: a survey of 1,082 practising physicians in five countries.

    PubMed

    Assaad-Khalil, S H; Al Arouj, M; Almaatouq, M; Amod, A; Assaad, S N; Azar, S T; Belkhadir, J; Esmat, K; Hassoun, A A K; Jarrah, N; Zatari, S; Alberti, K G M M

    2013-11-01

    Developing countries face a high and growing burden of type 2 diabetes. We surveyed physicians in a diverse range of countries in the Middle East and Africa (Egypt, Kingdom of Saudi Arabia, United Arab Emirates, South Africa and Lebanon) with regard to their perceptions of barriers to type 2 diabetes care identified as potentially important in the literature and by the authors. One thousand and eighty-two physicians completed a questionnaire developed by the authors. Most physicians enrolled in the study employed guideline-driven care; 80-100% of physicians prescribed metformin (with lifestyle intervention, where there are no contraindications) for newly diagnosed type 2 diabetes, with lifestyle intervention alone used where metformin was not prescribed. Sulfonylureas were prescribed widely, consistent with the poor economic status of many patients. About one quarter of physicians were not undertaking any form of continuing medical education, and relatively low proportions of practices had their own diabetes educators, dieticians or diabetic foot specialists. Physicians identified the deficiencies of their patients (unhealthy lifestyles, lack of education and poor diet) as the most important barriers to optimal diabetes care. Low-treatment compliance was not ranked highly. Access to physicians did not appear to be a problem, as most patients were seen multiple times per year. Physicians in the Middle East and South Africa identified limitations relating to their patients as the main barrier to delivering care for diabetes, without giving high priority to issues relating to processes of care delivery. Further study would be needed to ascertain whether these findings reflect an unduly physician-centred view of their practice. More effective provision of services relating to the prevention of complications and improved lifestyles may be needed. © 2013 John Wiley & Sons Ltd.

  15. Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa.

    PubMed

    Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P

    2016-11-01

    Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. The plant i-AAA protease controls the turnover of an essential mitochondrial protein import component.

    PubMed

    Opalińska, Magdalena; Parys, Katarzyna; Murcha, Monika W; Jańska, Hanna

    2018-01-29

    Mitochondria are multifunctional organelles that play a central role in energy metabolism. Owing to the life-essential functions of these organelles, mitochondrial content, quality and dynamics are tightly controlled. Across the species, highly conserved ATP-dependent proteases prevent malfunction of mitochondria through versatile activities. This study focuses on a molecular function of the plant mitochondrial inner membrane-embedded AAA protease (denoted i -AAA) FTSH4, providing its first bona fide substrate. Here, we report that the abundance of the Tim17-2 protein, an essential component of the TIM17:23 translocase (Tim17-2 together with Tim50 and Tim23), is directly controlled by the proteolytic activity of FTSH4. Plants that are lacking functional FTSH4 protease are characterized by significantly enhanced capacity of preprotein import through the TIM17:23-dependent pathway. Taken together, with the observation that FTSH4 prevents accumulation of Tim17-2, our data point towards the role of this i -AAA protease in the regulation of mitochondrial biogenesis in plants. © 2018. Published by The Company of Biologists Ltd.

  17. Assessment of resistomycin, as an anticancer compound isolated and characterized from Streptomyces aurantiacus AAA5.

    PubMed

    Vijayabharathi, Rajendran; Bruheim, Per; Andreassen, Trygve; Raja, Duraisamy Senthil; Devi, Palanisamy Bruntha; Sathyabama, Sathyaseelan; Priyadarisini, Venkatesan Brindha

    2011-12-01

    A new actinomycete strain, isolated from humus soils in the Western Ghats, was found to be an efficient pigment producer. The strain, designated AAA5, was identified as a putative Streptomyces aurantiacus strain based on cultural properties, morphology, carbon source utilization, and analysis of the 16S rRNA gene. The strain produced a reddish-brown pigmented compound during the secondary metabolites phase. A yellow compound was derived from the extracted pigment and was identified as the quinone-related antibiotic resistomycin based on ultraviolet-visible spectrophotometry, fourier transform infrared spectroscopy, liquid chromatography and mass spectroscopy, and nuclear magnetic resonance analyses. The AAA5 strain was found to produce large quantities of resistomycin (52.5 mg/L). It showed potent cytotoxic activity against cell lines viz. HepG2 (hepatic carcinoma) and HeLa (cervical carcinoma) in vitro, with growth inhibition (GI(50)) of 0.006 and 0.005 μg/ml, respectively. The strain also exhibited broad antimicrobial activities against both Gram-positive and Gram-negative bacteria. Therefore, AAA5 may have great potential as an industrial resistomycin-producing strain.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  19. The Abdominal Aortic Aneurysm Statistically Corrected Operative Risk Evaluation (AAA SCORE) for predicting mortality after open and endovascular interventions.

    PubMed

    Ambler, Graeme K; Gohel, Manjit S; Mitchell, David C; Loftus, Ian M; Boyle, Jonathan R

    2015-01-01

    Accurate adjustment of surgical outcome data for risk is vital in an era of surgeon-level reporting. Current risk prediction models for abdominal aortic aneurysm (AAA) repair are suboptimal. We aimed to develop a reliable risk model for in-hospital mortality after intervention for AAA, using rigorous contemporary statistical techniques to handle missing data. Using data collected during a 15-month period in the United Kingdom National Vascular Database, we applied multiple imputation methodology together with stepwise model selection to generate preoperative and perioperative models of in-hospital mortality after AAA repair, using two thirds of the available data. Model performance was then assessed on the remaining third of the data by receiver operating characteristic curve analysis and compared with existing risk prediction models. Model calibration was assessed by Hosmer-Lemeshow analysis. A total of 8088 AAA repair operations were recorded in the National Vascular Database during the study period, of which 5870 (72.6%) were elective procedures. Both preoperative and perioperative models showed excellent discrimination, with areas under the receiver operating characteristic curve of .89 and .92, respectively. This was significantly better than any of the existing models (area under the receiver operating characteristic curve for best comparator model, .84 and .88; P < .001 and P = .001, respectively). Discrimination remained excellent when only elective procedures were considered. There was no evidence of miscalibration by Hosmer-Lemeshow analysis. We have developed accurate models to assess risk of in-hospital mortality after AAA repair. These models were carefully developed with rigorous statistical methodology and significantly outperform existing methods for both elective cases and overall AAA mortality. These models will be invaluable for both preoperative patient counseling and accurate risk adjustment of published outcome data. Copyright © 2015 Society

  20. Using Satellite Data and Land Surface Models to Monitor and Forecast Drought Conditions in Africa and Middle East

    NASA Astrophysics Data System (ADS)

    Arsenault, K. R.; Shukla, S.; Getirana, A.; Peters-Lidard, C. D.; Kumar, S.; McNally, A.; Zaitchik, B. F.; Badr, H. S.; Funk, C. C.; Koster, R. D.; Narapusetty, B.; Jung, H. C.; Roningen, J. M.

    2017-12-01

    Drought and water scarcity are among the important issues facing several regions within Africa and the Middle East. In addition, these regions typically have sparse ground-based data networks, where sometimes remotely sensed observations may be the only data available. Long-term satellite records can help with determining historic and current drought conditions. In recent years, several new satellites have come on-line that monitor different hydrological variables, including soil moisture and terrestrial water storage. Though these recent data records may be considered too short for the use in identifying major droughts, they do provide additional information that can better characterize where water deficits may occur. We utilize recent satellite data records of Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage (TWS) and the European Space Agency's Advanced Scatterometer (ASCAT) soil moisture retrievals. Combining these records with land surface models (LSMs), NASA's Catchment and the Noah Multi-Physics (MP), is aimed at improving the land model states and initialization for seasonal drought forecasts. The LSMs' total runoff is routed through the Hydrological Modeling and Analysis Platform (HyMAP) to simulate surface water dynamics, which can provide an additional means of validation against in situ streamflow data. The NASA Land Information System (LIS) software framework drives the LSMs and HyMAP and also supports the capability to assimilate these satellite retrievals, such as soil moisture and TWS. The LSMs are driven for 30+ years with NASA's Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), and the USGS/UCSB Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) rainfall dataset. The seasonal water deficit forecasts are generated using downscaled and bias-corrected versions of NASA's Goddard Earth Observing System Model (GEOS-5), and NOAA's Climate Forecast System (CFSv2) forecasts

  1. Editor's Choice - Prolonged ICU Length of Stay after AAA Repair: Analysis of Time Trends and Long-term Outcome.

    PubMed

    Gavali, H; Mani, K; Tegler, G; Kawati, R; Covaciu, L; Wanhainen, A

    2017-08-01

    The aim of the study was to investigate the frequency and outcome of prolonged intensive care unit (ICU) length of stay (LOS) after abdominal aortic aneurysm (AAA) repair in the endovascular era. All patients operated on for AAA between 1999 and 2013 at Uppsala University hospital were identified. Data were retrieved from the Swedish Vascular registry, the Swedish Intensive Care registry, the National Population registry, and case records. Prolonged ICU LOS was defined as ≥ 48 h during the primary hospital stay. Patients surviving ≥ 48 h after AAA surgery were included in the analysis. A total of 725 patients were identified, of whom 707 (97.5%) survived ≥ 48 h; 563 (79.6%) underwent intact AAA repair and 144 (20.4%) ruptured AAA repair. A total of 548 patients (77.5%) required < 48 h of intensive care, 115 (16.3%) 2-6 days and 44 (6.2%) ≥ 7 days. The rate of prolonged ICU LOS declined considerably over time, from 41.4% of all AAA repairs in 1999 to 7.3% in 2013 (p < .001) whereas the use of endovascular aortic repair (EVAR) increased from 6.9% in 1999 to 78.0% in 2013 (p < .001). The 30 day survival rate was 98.2% for those with < 48 h ICU stay versus 93.0% for 2-6 days versus 81.8% for ≥ 7 days (p < .001); the corresponding 90 day survival was 97.1% versus 86.1% versus 63.6% (p < .001) respectively. For patients surviving 90 days after repair, there was no difference in long-term survival between the groups. During the period of progressively increasing use of EVAR, a simultaneous significant reduction in frequency of prolonged ICU LOS occurred. Although prolonged ICU LOS was associated with a high short-term mortality, long-term outcome among those surviving the initial 90 days was less affected. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  2. Stan Bull, Long-Time NREL Leader, Named AAAS Fellow | News | NREL

    Science.gov Websites

    , Named AAAS Fellow January 11, 2011 Stanley R. Bull, former associate director for Science and Technology emeritus researcher. He was cited for "distinguished leadership in creating new programs, development partner with existing energy companies, including the fossil-fuel industry, and to "provide our

  3. Rethinking health sector procurement as developmental linkages in East Africa.

    PubMed

    Mackintosh, Maureen; Tibandebage, Paula; Karimi Njeru, Mercy; Kariuki Kungu, Joan; Israel, Caroline; Mujinja, Phares G M

    2018-03-01

    Health care forms a large economic sector in all countries, and procurement of medicines and other essential commodities necessarily creates economic linkages between a country's health sector and local and international industrial development. These procurement processes may be positive or negative in their effects on populations' access to appropriate treatment and on local industrial development, yet procurement in low and middle income countries (LMICs) remains under-studied: generally analysed, when addressed at all, as a public sector technical and organisational challenge rather than a social and economic element of health system governance shaping its links to the wider economy. This article uses fieldwork in Tanzania and Kenya in 2012-15 to analyse procurement of essential medicines and supplies as a governance process for the health system and its industrial links, drawing on aspects of global value chain theory. We describe procurement work processes as experienced by front line staff in public, faith-based and private sectors, linking these experiences to wholesale funding sources and purchasing practices, and examining their implications for medicines access and for local industrial development within these East African countries. We show that in a context of poor access to reliable medicines, extensive reliance on private medicines purchase, and increasing globalisation of procurement systems, domestic linkages between health and industrial sectors have been weakened, especially in Tanzania. We argue in consequence for a more developmental perspective on health sector procurement design, including closer policy attention to strengthening vertical and horizontal relational working within local health-industry value chains, in the interests of both wider access to treatment and improved industrial development in Africa. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Guidelines for sinkhole and subsidence rehabilitation based on generic geological models of a dolomite environment on the East Rand, South Africa

    NASA Astrophysics Data System (ADS)

    Kleinhans, Ilse; Van Rooy, J. Louis

    2016-05-01

    A sound understanding of the various factors influencing and associated with the formation of sinkholes or subsidences on dolomite land is essential for the selection of appropriate rehabilitation methods. The investigation and rehabilitation of numerous sinkholes and subsidences located on dolomite in the East Rand of South Africa, created an opportunity to develop a broad based understanding of different karst environments, their susceptibility to sinkhole and subsidence formation and best practice rehabilitation methods. This paper is based on the guidelines developed whereby the geological model of the sinkhole or subsidence is used to recommend an appropriate rehabilitation method. Nine typical geological models with recommended rehabilitation methods are presented in this paper.

  5. Genomic Ancestry of North Africans Supports Back-to-Africa Migrations

    PubMed Central

    Gravel, Simon; Wang, Wei; Brisbin, Abra; Byrnes, Jake K.; Fadhlaoui-Zid, Karima; Zalloua, Pierre A.; Moreno-Estrada, Andres; Bertranpetit, Jaume; Bustamante, Carlos D.; Comas, David

    2012-01-01

    North African populations are distinct from sub-Saharan Africans based on cultural, linguistic, and phenotypic attributes; however, the time and the extent of genetic divergence between populations north and south of the Sahara remain poorly understood. Here, we interrogate the multilayered history of North Africa by characterizing the effect of hypothesized migrations from the Near East, Europe, and sub-Saharan Africa on current genetic diversity. We present dense, genome-wide SNP genotyping array data (730,000 sites) from seven North African populations, spanning from Egypt to Morocco, and one Spanish population. We identify a gradient of likely autochthonous Maghrebi ancestry that increases from east to west across northern Africa; this ancestry is likely derived from “back-to-Africa” gene flow more than 12,000 years ago (ya), prior to the Holocene. The indigenous North African ancestry is more frequent in populations with historical Berber ethnicity. In most North African populations we also see substantial shared ancestry with the Near East, and to a lesser extent sub-Saharan Africa and Europe. To estimate the time of migration from sub-Saharan populations into North Africa, we implement a maximum likelihood dating method based on the distribution of migrant tracts. In order to first identify migrant tracts, we assign local ancestry to haplotypes using a novel, principal component-based analysis of three ancestral populations. We estimate that a migration of western African origin into Morocco began about 40 generations ago (approximately 1,200 ya); a migration of individuals with Nilotic ancestry into Egypt occurred about 25 generations ago (approximately 750 ya). Our genomic data reveal an extraordinarily complex history of migrations, involving at least five ancestral populations, into North Africa. PMID:22253600

  6. The Antiaircraft Journal. Volume 95, Number 2, March-April 1952

    DTIC Science & Technology

    1952-04-01

    Command, Yoko- hama. Breuning, E. G., Far East Command, Yoko- hama Cacchiotti, Ralph R., 31st AAA Brig., Ft Lewis, Wash. Colbert , Edward F., 197th AAA Gp...Wilbur B., 47th AAA Brig., Cp Stew- art, Ga. Frick, Edwin J., 336th AAA Gun Bn, Cp Ed- wards. Mass. Gildon, Milo E., USA Alaska, Fort Richard- son

  7. Abortion and Islam: policies and practice in the Middle East and North Africa.

    PubMed

    Hessini, Leila

    2007-05-01

    This paper provides an overview of legal, religious, medical and social factors that serve to support or hinder women's access to safe abortion services in the 21 predominantly Muslim countries of the Middle East and North Africa (MENA) region, where one in ten pregnancies ends in abortion. Reform efforts, including progressive interpretations of Islam, have resulted in laws allowing for early abortion on request in two countries; six others permit abortion on health grounds and three more also allow abortion in cases of rape or fetal impairment. However, medical and social factors limit access to safe abortion services in all but Turkey and Tunisia. To address this situation, efforts are increasing in a few countries to introduce post-abortion care, document the magnitude of unsafe abortion and understand women's experience of unplanned pregnancy. Religious fatāwa have been issued allowing abortions in certain circumstances. An understanding of variations in Muslim beliefs and practices, and the interplay between politics, religion, history and reproductive rights is key to understanding abortion in different Muslim societies. More needs to be done to build on efforts to increase women's rights, engage community leaders, support progressive religious leaders and government officials and promote advocacy among health professionals.

  8. Outcomes of antiretroviral therapy in children in Asia and Africa: a comparative analysis of the IeDEA pediatric multiregional collaboration

    PubMed Central

    Leroy, Valeriane; Malateste, Karen; Rabie, Helena; Lumbiganon, Pagakrong; Ayaya, Samuel; Dicko, Fatoumata; Davies, Mary-Ann; Kariminia, Azar; Wools-Kaloustian, Kara; Aka, Edmond; Phiri, Samuel; Aurpibul, Linda; Yiannoutsos, Constantin; Signaté-Sy, Haby; Mofenson, Lynne; Dabis, François

    2013-01-01

    Background We investigated 18-month incidence and determinants of death and loss-to-follow-up of children after antiretroviral therapy (ART) initiation in a multiregional collaboration in lower-income countries. Methods HIV-infected children (positive PCR <18 months or positive serology ≥18 months) from IeDEA cohorts, <16 years, initiating ART were eligible. A competing risk regression model was used to analyze the independent risk of two failure types: death and loss-to-follow-up (>6 months). Findings Data on 13611 children, from Asia (N=1454), East-Africa (N=3114), Southern-Africa (N=6212) and West-Africa (N=2881) contributed 20,417 person-years of follow-up. At 18 months, the adjusted risk of death was 4.3% in East-Africa, 5.4% in Asia, 5.7% in Southern-Africa and 7.4% in West-Africa (P=0.01). Age<24 months, WHO stage 4, CD4<10%, attending a private sector clinic, larger cohort size and living in West-Africa were independently associated with poorer survival. The adjusted risk of loss-to-follow-up was 4.1% in Asia, 9.0% in Southern-Africa, 14.0% in East-Africa, and 21.8% in West-Africa (P <0.01). Age<12 months, non NNRTI-based ART regimen, WHO stage 4 at ART start, ART initiation after 2005, attending a public sector or a non-urban clinic, having to pay for laboratory tests or antiretroviral drugs, larger cohort size, and living in East or West-Africa were significantly associated with higher loss-to-follow-up. Conclusion Findings differed substantially across regions but raise overall concerns about delayed ART start, low access to free HIV-services for children, and increased workload on program retention in lower-income countries. Universal free access to ART services and innovative approaches are urgently needed to improve pediatric outcomes at program level. PMID:23187940

  9. East African upper mantle shear wave velocity structure derived from Rayleigh wave tomography

    NASA Astrophysics Data System (ADS)

    O'Donnell, J.; Nyblade, A.; Adams, A. N.; Mulibo, G.; Tugume, F.

    2011-12-01

    An expanded model of the three-dimensional shear wave velocity structure of the upper mantle beneath East Africa is being developed using data from the latest phases of the AfricaArray East African Seismic Experiment in conjunction with data from preceding studies. The combined dataset encompasses seismic stations which span Tanzania, Uganda and Zambia. From the new data, fundamental mode Rayleigh wave phase velocities are being measured at periods ranging from 20 to 180 seconds using the two-plane-wave method. These measurements will be combined with similarly processed measurements from previous studies and inverted for an upper mantle three-dimensional shear wave velocity model. In particular, the model will further constrain the morphology of the low velocity anomaly which underlies the East African Plateau extending to the southwest beneath Zambia.

  10. Indian Ocean dipole and rainfall drive a Moran effect in East Africa malaria transmission.

    PubMed

    Chaves, Luis Fernando; Satake, Akiko; Hashizume, Masahiro; Minakawa, Noboru

    2012-06-15

    Patterns of concerted fluctuation in populations-synchrony-can reveal impacts of climatic variability on disease dynamics. We examined whether malaria transmission has been synchronous in an area with a common rainfall regime and sensitive to the Indian Ocean Dipole (IOD), a global climatic phenomenon affecting weather patterns in East Africa. We studied malaria synchrony in 5 15-year long (1984-1999) monthly time series that encompass an altitudinal gradient, approximately 1000 m to 2000 m, along Lake Victoria basin. We quantified the association patterns between rainfall and malaria time series at different altitudes and across the altitudinal gradient encompassed by the study locations. We found a positive seasonal association of rainfall with malaria, which decreased with altitude. By contrast, IOD and interannual rainfall impacts on interannual disease cycles increased with altitude. Our analysis revealed a nondecaying synchrony of similar magnitude in both malaria and rainfall, as expected under a Moran effect, supporting a role for climatic variability on malaria epidemic frequency, which might reflect rainfall-mediated changes in mosquito abundance. Synchronous malaria epidemics call for the integration of knowledge on the forcing of malaria transmission by environmental variability to develop robust malaria control and elimination programs.

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

    PubMed

    Kagurusi, Patrick T

    2013-09-01

    The media has been employed to increase uptake of Family Planning through behaviour change communication (BCC). Understanding the barriers encountered in effectively undertaking this function would increase the strategy's effectiveness. Sixty journalists from East Africa participated in trainings to enhance their BCC skills for Family Planning in which a qualitative study was nested to identify barriers to effective Family Planning BCC in the region's media. The barriers were observed to be insufficient BCC skills, journalists' conflict of interest, interests of media houses, inaccessible sources of family planning information, editorial ideologies and absence of commercially beneficial demand. Coupled with the historical ideologies of the media in the region, the observed barriers have precipitated ineffective family planning BCC in the regions media. Effective BCC for family planning in the regions media requires capacity building among practitioners and alignment of the concept to the media's and consumers' aspirations.

  12. Regulatory coiled-coil domains promote head-to-head assemblies of AAA+ chaperones essential for tunable activity control.

    PubMed

    Carroni, Marta; Franke, Kamila B; Maurer, Michael; Jäger, Jasmin; Hantke, Ingo; Gloge, Felix; Linder, Daniela; Gremer, Sebastian; Turgay, Kürşad; Bukau, Bernd; Mogk, Axel

    2017-11-22

    Ring-forming AAA+ chaperones exert ATP-fueled substrate unfolding by threading through a central pore. This activity is potentially harmful requiring mechanisms for tight repression and substrate-specific activation. The AAA+ chaperone ClpC with the peptidase ClpP forms a bacterial protease essential to virulence and stress resistance. The adaptor MecA activates ClpC by targeting substrates and stimulating ClpC ATPase activity. We show how ClpC is repressed in its ground state by determining ClpC cryo-EM structures with and without MecA. ClpC forms large two-helical assemblies that associate via head-to-head contacts between coiled-coil middle domains (MDs). MecA converts this resting state to an active planar ring structure by binding to MD interaction sites. Loss of ClpC repression in MD mutants causes constitutive activation and severe cellular toxicity. These findings unravel an unexpected regulatory concept executed by coiled-coil MDs to tightly control AAA+ chaperone activity.

  13. Combination therapy for malaria in Africa: hype or hope?

    PubMed Central

    Bloland, P. B.; Ettling, M.; Meek, S.

    2000-01-01

    The development of resistance to drugs poses one of the greatest threats to malaria control. In Africa, the efficacy of readily affordable antimalarial drugs is declining rapidly, while highly efficacious drugs tend to be too expensive. Cost-effective strategies are needed to extend the useful life spans of antimalarial drugs. Observations in South-East Asia on combination therapy with artemisinin derivatives and mefloquine indicate that the development of resistance to both components is slowed down. This suggests the possibility of a solution to the problem of drug resistance in Africa, where, however, there are major obstacles in the way of deploying combination therapy effectively. The rates of transmission are relatively high, a large proportion of asymptomatic infection occurs in semi-immune persons, the use of drugs is frequently inappropriate and ill-informed, there is a general lack of laboratory diagnoses, and public health systems in sub-Saharan Africa are generally weak. Furthermore, the cost of combination therapy is comparatively high. We review combination therapy as used in South-East Asia and outline the problems that have to be overcome in order to adopt it successfully in sub-Saharan Africa. PMID:11196485

  14. AAAS Communicating Science Program: Reflections on Evaluation

    NASA Astrophysics Data System (ADS)

    Braha, J.

    2015-12-01

    The AAAS Center for Public Engagement (Center) with science builds capacity for scientists to engage public audiences by fostering collaboration among natural or physical scientists, communication researchers, and public engagement practitioners. The recently launched Leshner Leadership Institute empowers cohorts of mid-career scientists to lead public engagement by supporting their networks of scientists, researchers, and practitioners. The Center works closely with social scientists whose research addresses science communication and public engagement with science to ensure that the Communicating Science training program builds on empirical evidence to inform best practices. Researchers ( Besley, Dudo, & Storkdieck 2015) have helped Center staff and an external evaluator develop pan instrument that measures progress towards goals that are suggested by the researcher, including internal efficacy (increasing scientists' communication skills and confidence in their ability to engage with the public) and external efficacy (scientists' confidence in engagement methods). Evaluation results from one year of the Communicating Science program suggest that the model of training yields positive results that support scientists in the area that should lead to greater engagement. This talk will explore the model for training, which provides a context for strategic communication, as well as the practical factors, such as time, access to public engagement practitioners, and technical skill, that seems to contribute to increased willingness to engage with public audiences. The evaluation program results suggest willingness by training participants to engage directly or to take preliminary steps towards engagement. In the evaluation results, 38% of trained scientists reported time as a barrier to engagement; 35% reported concern that engagement would distract from their work as a barrier. AAAS works to improve practitioner-researcher-scientist networks to overcome such barriers.

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

    PubMed Central

    Williams, Richard AJ; Peterson, A Townsend

    2009-01-01

    Background The emerging highly pathogenic avian influenza strain H5N1 ("HPAI-H5N1") has spread broadly in the past decade, and is now the focus of considerable concern. We tested the hypothesis that spatial distributions of HPAI-H5N1 cases are related consistently and predictably to coarse-scale environmental features in the Middle East and northeastern Africa. We used ecological niche models to relate virus occurrences to 8 km resolution digital data layers summarizing parameters of monthly surface reflectance and landform. Predictive challenges included a variety of spatial stratification schemes in which models were challenged to predict case distributions in broadly unsampled areas. Results In almost all tests, HPAI-H5N1 cases were indeed occurring under predictable sets of environmental conditions, generally predicted absent from areas with low NDVI values and minimal seasonal variation, and present in areas with a broad range of and appreciable seasonal variation in NDVI values. Although we documented significant predictive ability of our models, even between our study region and West Africa, case occurrences in the Arabian Peninsula appear to follow a distinct environmental regime. Conclusion Overall, we documented a variable environmental "fingerprint" for areas suitable for HPAI-H5N1 transmission. PMID:19619336

  16. Fan filter cleaning on the CHeCS AAA in the US Lab

    NASA Image and Video Library

    2009-05-05

    ISS019-E-013710 (5 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, cleans a fan filter on the Crew Health Care System Avionics Air Assembly (CHeCS AAA) in the Destiny laboratory of the International Space Station.

  17. How critical are wetlands for provisioning ecosystem services in East Africa?

    NASA Astrophysics Data System (ADS)

    Gettel, G. M.; van Dam, A. A.; Hes, E.; Irvine, K.

    2017-12-01

    East Africa is rapidly losing wetlands as the region intensifies agricultural development in rice, sugarcane, and aquaculture production. However, these wetlands are critically important to the livelihoods of region's most vulnerable smallholders, who depend on them for fisheries, water abstraction, and dry-season subsistence agriculture, including livestock grazing. At the same time, wetlands are used for their regulating services, including for water purification of waste-water in some of the region's largest capital cities (e.g. Kampala and Kigali). They also store an enormous, but poorly quantified amount of below-ground carbon and prevent excess nitrogen inputs to sensitive downstream ecosystems. Our research in papyrus wetlands in the Lake Victoria Basin aims to quantify trade-offs in provisioning and regulating services and link these services to socio-economic conditions of the smallholders. We present a framework for evaluating these trade-offs, which can ultimately be used for more informed management decisions for sustainable wetland management and for evaluating impacts on livelihoods. Specifically, we have found that papyrus wetlands can maintain many of their regulating functions, including high plant productivity and denitrification rates when native vegetation is allowed to grow back during wet-seasons, while during dry seasons they can be developed for economically important agricultural activities, including livestock grazing and crop production. This shows the possibility to include wetlands in management plans aimed to increase agricultural production without jeopardizing their ability to maintain other important regulating services. These patterns highlight the need to evaluate the regional importance of these wetlands for both food production and regulating services.

  18. Dynamical downscaling with WRF for the Middle-East and North Africa

    NASA Astrophysics Data System (ADS)

    Dezfuli, A. K.; Zaitchik, B. F.; Badr, H. S.; Bergaoui, K.; Zaaboul, R.; Bhattacharjee, P.

    2014-12-01

    The Middle-East and North Africa (MENA) experience the highest risk of water stress in the world. This underlines the importance of climate analysis for water resources management and climate change adaptation for this region, particularly in transboundary basins such as the Tigris-Euphrates system. Such analysis, however, is difficult due to a paucity of high quality precipitation data. The network of gauge stations is quite sparse and the data are often available only at monthly time-scale. Satellite-based products, such as the Tropical Rainfall Measuring Mission (TRMM), offer better temporal resolution; however, these data are available only for periods that are short for hydroclimatic analysis, and they often misrepresent precipitation over regions with complex topography or strong convection. To fill this gap, we have implemented the Weather Research and Forecasting (WRF) Model, initialized with the NCEP/NCAR Reanalysis II, to generate high-resolution precipitation estimates for MENA. Several sensitivity analyses have been performed in order to find a set of physics parameters that appropriately captures the annual cycle and year-to-year variability of rainfall over select areas in MENA. The results show that WRF, particularly over highlands, estimates the precipitation more accurately than the satellite products. In addition to these reanalysis-driven simulations, we have performed several simulations using the historical and twenty first century outputs of a select number of GCMs available at the CMIP5 archive. These runs enable us to detect changes in rainfall behavior under different greenhouse gas scenarios and reveal synoptic to mesoscale mechanisms responsible for such changes.

  19. Clinical and diagnostic features of East Coast fever (Theileria parva) infection of cattle.

    PubMed

    Irvin, A D; Mwamachi, D M

    1983-08-27

    East Coast fever is a tick-borne protozoal disease affecting cattle in a large part of East and Central Africa. Since the vector occurs over an even wider range there is considerable potential for the disease to spread to countries which are currently disease free. This article, describing the clinical and diagnostic features of East Coast fever, may remind authorities in these countries of the potential hazards posed by the disease.

  20. Two phases of the Holocene East African Humid Period: Inferred from a high-resolution geochemical record off Tanzania

    NASA Astrophysics Data System (ADS)

    Liu, Xiting; Rendle-Bühring, Rebecca; Kuhlmann, Holger; Li, Anchun

    2017-02-01

    During the Holocene, the most notably climatic change across the African continent is the African Humid Period (AHP), however the pace and primary forcing for this pluvial condition is still ambiguous, particularly in East Africa. We present a high-resolution marine sediment record off Tanzania to provide insights into the climatic conditions of inland East Africa during the Holocene. Major element ratios (i.e., log-ratios of Fe/Ca and Ti/Ca), derived from X-Ray Fluorescence scanning, have been employed to document variations in humidity in East Africa. Our results show that the AHP is represented by two humid phases: an intense humid period from the beginning of the Holocene to 8 ka (AHP I); and a moderate humid period spanning from 8 to 5.5 ka (AHP II). On the basis of our geochemical record and regime detection, the termination of the AHP initiated at 5.5 ka and ceased around 3.5 ka. Combined with other paleoclimatic records around East Africa, we suggest that the humid conditions in this region responded to Northern Hemisphere (NH) summer insolation. The AHP I and II might have been related to an eastward shift of the Congo Air Boundary and warmer conditions in the western Indian Ocean, which resulted in additional moisture being delivered from the Atlantic and Indian Oceans during the NH summer and autumn, respectively. We further note a drought event throughout East Africa north of 10°S around 8.2 ka, which may have been related to the southward migration of the Intertropical Convergence Zone in response to the NH cooling event.

  1. Inferring human history in East Asia from Y chromosomes.

    PubMed

    Wang, Chuan-Chao; Li, Hui

    2013-06-03

    East Asia harbors substantial genetic, physical, cultural and linguistic diversity, but the detailed structures and interrelationships of those aspects remain enigmatic. This question has begun to be addressed by a rapid accumulation of molecular anthropological studies of the populations in and around East Asia, especially by Y chromosome studies. The current Y chromosome evidence suggests multiple early migrations of modern humans from Africa via Southeast Asia to East Asia. After the initial settlements, the northward migrations during the Paleolithic Age shaped the genetic structure in East Asia. Subsequently, recent admixtures between Central Asian immigrants and northern East Asians enlarged the genetic divergence between southern and northern East Asia populations. Cultural practices, such as languages, agriculture, military affairs and social prestige, also have impacts on the genetic patterns in East Asia. Furthermore, application of Y chromosome analyses in the family genealogy studies offers successful showcases of the utility of genetics in studying the ancient history.

  2. Inferring human history in East Asia from Y chromosomes

    PubMed Central

    2013-01-01

    East Asia harbors substantial genetic, physical, cultural and linguistic diversity, but the detailed structures and interrelationships of those aspects remain enigmatic. This question has begun to be addressed by a rapid accumulation of molecular anthropological studies of the populations in and around East Asia, especially by Y chromosome studies. The current Y chromosome evidence suggests multiple early migrations of modern humans from Africa via Southeast Asia to East Asia. After the initial settlements, the northward migrations during the Paleolithic Age shaped the genetic structure in East Asia. Subsequently, recent admixtures between Central Asian immigrants and northern East Asians enlarged the genetic divergence between southern and northern East Asia populations. Cultural practices, such as languages, agriculture, military affairs and social prestige, also have impacts on the genetic patterns in East Asia. Furthermore, application of Y chromosome analyses in the family genealogy studies offers successful showcases of the utility of genetics in studying the ancient history. PMID:23731529

  3. NASA Astrophysics E/PO Impact: NASA SOFIA AAA Program Evaluation Results

    NASA Astrophysics Data System (ADS)

    Harman, Pamela; Backman, Dana E.; Clark, Coral; Inverness Research Sofia Aaa Evaluation Team, Wested Sofia Aaa Evaluation Team

    2015-01-01

    SOFIA is an airborne observatory, studying the universe at infrared wavelengths, capable of making observations that are impossible for even the largest and highest ground-based telescopes. SOFIA also inspires the development of new scientific instrumentation and fosters the education of young scientists and engineers.SOFIA is an 80% - 20% partnership of NASA and the German Aerospace Center (DLR), consisting of an extensively modified Boeing 747SP aircraft carrying a reflecting telescope with an effective diameter of 2.5 meters (100 inches). The SOFIA aircraft is based at NASA Armstrong Flight Research Center, Building 703, in Palmdale, California. The Science Program and Outreach Offices are located at NASA Ames Research center. SOFIA is a program in NASA's Science Mission Directorate, Astrophysics Division.Data will be collected to study many different kinds of astronomical objects and phenomena, including star cycles, solar system formation, identification of complex molecules in space, our solar system, galactic dust, nebulae and ecosystems.Airborne Astronomy Ambassador (AAA) Program:The SOFIA Education and Communications program exploits the unique attributes of airborne astronomy to contribute to national goals for the reform of science, technology, engineering, and math (STEM) education, and to elevate public scientific and technical literacy.The AAA effort is a professional development program aspiring to improve teaching, inspire students, and inform the community. To date, 55 educators from 21 states; Cycles 0, 1 and 2; have completed their astronomy professional development and their SOFIA science flight experience. Evaluation has confirmed the program's positive impact on the teacher participants, on their students, and in their communities. The inspirational experience has positively impacted their practice and career trajectory. AAAs have incorporated content knowledge and specific components of their experience into their curricula, and have given

  4. Prevalence and associated factors of common mental disorders among Ethiopian migrant returnees from the Middle East and South Africa.

    PubMed

    Habtamu, Kassahun; Minaye, Abebaw; Zeleke, Waganesh A

    2017-04-19

    Ethiopian migrants to the Middle East and South Africa experience a range of problems at various stages of their migration including overwork, sleep deprivation, denial of food, emotional abuse, difficulty adapting to the host culture, salary denial, sexual abuse, labor exploitation, confiscation of their travel documents, confinement, denial of medication, lack of access to legal service and degrading attitude by employers, traffickers and smugglers. These experiences can be associated with different types of mental disorders. This study sought to determine the prevalence of common mental disorders (CMD) and socio-demographic and other migration related associated factors among Ethiopian migrant returnees from the Middle East and South Africa. A cross-sectional study was conducted using non-probability (i.e. purposive, availability and snowball) sampling techniques. Migrant returnees (n = 1036) were contacted individually at their homes in eight high prevalent immigrant returnee locations in Ethiopia. Common mental disorders were assessed using the self-reporting questionnaire (SRQ-20) and a structured questionnaire was employed to collect data on socio-demographic and migration related characteristics. Data were analyzed using descriptive statistics, univariate logistic regression, and multivariable logistic regression. The prevalence of CMD among migrant returnees was found to be 27.6%. Highly prevalent specific CMD symptoms included headaches, poor appetite, being tired, sleeping problems, and feeling unhappy or nervous. Being originally from Amhara and Oromia regions, being Christian, being divorced, not receiving salary on time, not being able to contact family, unable to prepare for domestic labor abroad, lack of cross- cultural awareness, and lack of knowledge and skills for work were all important risk factors for CMD. Migrants experienced adversities at different stages of their migration which are associated with psychological distress and even to long

  5. SFM-FDTD analysis of triangular-lattice AAA structure: Parametric study of the TEM mode

    NASA Astrophysics Data System (ADS)

    Hamidi, M.; Chemrouk, C.; Belkhir, A.; Kebci, Z.; Ndao, A.; Lamrous, O.; Baida, F. I.

    2014-05-01

    This theoretical work reports a parametric study of enhanced transmission through annular aperture array (AAA) structure arranged in a triangular lattice. The effect of the incidence angle in addition to the inner and outer radii values on the evolution of the transmission spectra is carried out. To this end, a 3D Finite-Difference Time-Domain code based on the Split Field Method (SFM) is used to calculate the spectral response of the structure for any angle of incidence. In order to work through an orthogonal unit cell which presents the advantage to reduce time and space of computation, special periodic boundary conditions are implemented. This study provides a new modeling of AAA structures useful for producing tunable ultra-compact devices.

  6. Forecasting The Onset Of The East African Rains

    NASA Astrophysics Data System (ADS)

    MacLeod, D.; Palmer, T.

    2017-12-01

    The timing of the rainy seasons is critical for East Africa, where many livelihoods depend on rain-fed agriculture. The exact onset date of the rains varies from year to year and a delayed start has significant implications for food security. Early warning of anomalous onset can help mitigate risks by informing farmer decisions on crop choice and timing of planting. Onset forecasts may also pre-warn governments and NGOs of upcoming need for financial support and humanitarian intervention. Here we assess the potential to forecast the onset of both the short and long rains over East Africa at subseasonal to seasonal timescales. Based on operational reforecasts from ECMWF, we will demonstrate skilful prediction of onset anomalies. An investigation to determine potential sources of this forecast skill will also be presented. This work has been carried out as part of the project ForPAc: "Towards forecast-based preparedness action".

  7. Late Pleistocene temperature, hydrology, and glaciation in equatorial East Africa

    NASA Astrophysics Data System (ADS)

    Russell, J. M.; Verschuren, D.; Kelly, M. A.; Loomis, S. E.; Jackson, M. S.; Morrill, C.; S Sinninghe Damsté, J.; Doughty, A. M.; De Cort, G.; Olago, D.; Street-Perrott, F. A.

    2016-12-01

    In the coming century the world's high tropical mountains are predicted to experience a magnitude of climate change second only to the Arctic due to amplification of warming with elevation in the tropics. Proxy data suggest that substantial changes in tropical temperature and hydroclimate also occurred during the last deglaciation, the most recent time period when rising atmospheric CO2 concentrations caused large changes in global climate. Determining whether the rate of temperature change with elevation (the lapse rate) was different from today during the Last Glacial Maximum (LGM) is therefore critical to understanding the future of tropical mountain environments and resources. Here we present a new 25,000-year temperature reconstruction based upon organic geochemical analyses of sediment cores from Lake Rutundu (3,078 m asl), Mount Kenya, East Africa. Through comparison with regional reconstructions of lower elevation temperature, we show that LGM cooling was amplified with elevation and hence that the lapse rate was significantly steeper than today. Comparison of our lapse rate reconstructions with equilibrium line altitude reconstructions from glacial moraines indicates that temperature, rather than precipitation, was the dominant control on tropical alpine glacier fluctuations at this time scale. Nevertheless, our results have important implications for the tropical hydrological cycle, as changes in the lapse rate are intimately linked with changes in atmospheric water vapour concentrations. Indeed, we attribute the steeper lapse rate to drying of the tropical ice-age atmosphere, a hypothesis supported by palaeoclimate models. However, comparison of our data to these simulations indicates that state-of-the-art models significantly underestimate tropical temperature changes at high elevation and therefore the lapse-rate change. Consequently, future high-elevation tropical warming may be even greater than currently predicted.

  8. Near East/North Africa Report, Number 2603

    DTIC Science & Technology

    1982-08-17

    Electricity Stations 118 Gum Arabic Belt 118 Popular Development 118 Foreign Exchange Regulating Measures 118 Tombura on HEC Policy 119...Middle East and that this underlines the need for a just solution to the Palestinian problem—a solution that guar - antees the legitimate rights of the...last months of 1360. It must be noted that prices of a number of goods & services, such as cold drinks, washing powder , some cigarettes and telephone

  9. Moyamoya disease-associated protein mysterin/RNF213 is a novel AAA+ ATPase, which dynamically changes its oligomeric state

    NASA Astrophysics Data System (ADS)

    Morito, Daisuke; Nishikawa, Kouki; Hoseki, Jun; Kitamura, Akira; Kotani, Yuri; Kiso, Kazumi; Kinjo, Masataka; Fujiyoshi, Yoshinori; Nagata, Kazuhiro

    2014-03-01

    Moyamoya disease is an idiopathic human cerebrovascular disorder that is characterized by progressive stenosis and abnormal collateral vessels. We recently identified mysterin/RNF213 as its first susceptibility gene, which encodes a 591-kDa protein containing enzymatically active P-loop ATPase and ubiquitin ligase domains and is involved in proper vascular development in zebrafish. Here we demonstrate that mysterin further contains two tandem AAA+ ATPase modules and forms huge ring-shaped oligomeric complex. AAA+ ATPases are known to generally mediate various biophysical and mechanical processes with the characteristic ring-shaped structure. Fluorescence correlation spectroscopy and biochemical evaluation suggested that mysterin dynamically changes its oligomeric forms through ATP/ADP binding and hydrolysis cycles. Thus, the moyamoya disease-associated gene product is a unique protein that functions as ubiquitin ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell.

  10. Moyamoya disease-associated protein mysterin/RNF213 is a novel AAA+ ATPase, which dynamically changes its oligomeric state

    PubMed Central

    Morito, Daisuke; Nishikawa, Kouki; Hoseki, Jun; Kitamura, Akira; Kotani, Yuri; Kiso, Kazumi; Kinjo, Masataka; Fujiyoshi, Yoshinori; Nagata, Kazuhiro

    2014-01-01

    Moyamoya disease is an idiopathic human cerebrovascular disorder that is characterized by progressive stenosis and abnormal collateral vessels. We recently identified mysterin/RNF213 as its first susceptibility gene, which encodes a 591-kDa protein containing enzymatically active P-loop ATPase and ubiquitin ligase domains and is involved in proper vascular development in zebrafish. Here we demonstrate that mysterin further contains two tandem AAA+ ATPase modules and forms huge ring-shaped oligomeric complex. AAA+ ATPases are known to generally mediate various biophysical and mechanical processes with the characteristic ring-shaped structure. Fluorescence correlation spectroscopy and biochemical evaluation suggested that mysterin dynamically changes its oligomeric forms through ATP/ADP binding and hydrolysis cycles. Thus, the moyamoya disease-associated gene product is a unique protein that functions as ubiquitin ligase and AAA+ ATPase, which possibly contributes to vascular development through mechanical processes in the cell. PMID:24658080

  11. Why Africa matters: evolution of Old World Salvia (Lamiaceae) in Africa

    PubMed Central

    Will, Maria; Claßen-Bockhoff, Regine

    2014-01-01

    Background and Aims Salvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus. Methods Maximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome. Key Results Salvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution. Conclusions The phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera. PMID:24966353

  12. An Islamic University in Cape Town Grows from Roots in East Asia

    ERIC Educational Resources Information Center

    Lindow, Megan

    2007-01-01

    This article features the International Peace University South Africa in Cape Town. The university, which was established in 2004, resulted from the merger of two local "madrassas", or religious colleges, yet seeks to prepare its students for success in the secular world. Its Islamic roots are not in the Middle East, but in East Asia.…

  13. Multi-model trends in East African rainfall associated with increased CO2

    NASA Astrophysics Data System (ADS)

    McHugh, Maurice J.

    2005-01-01

    Nineteen coupled ocean-atmosphere general circulation models participating in the Coupled Model Intercomparison Program (CMIP) were used to analyze future rainfall conditions over East Africa under enhanced CO2 conditions. 80 year control runs of these models indicated that four models produced mean annual rainfall distributions closely resembling climatological means and all four models had normalized root mean square errors well within the bounds of observed variability. East African (10°N-20°S, 25°-50°E) rainfall data from transient 80 year experiments which featured CO2 increases of 1% per year were compared with 80 year control simulations. Results indicate enhanced annual and seasonal rainfall rates, and increased extreme wet period frequency. These results indicate that East Africa may face a future in which mosquito-borne diseases such as malaria and Rift Valley fever proliferate resulting from increased CO2.

  14. Education Quality in the Middle East

    ERIC Educational Resources Information Center

    Chapman, David W.; Miric, Suzanne L.

    2009-01-01

    Some of the most dramatic growth in the provision of primary and secondary education over the last decade has occurred across countries of the Middle East and North Africa (MENA). Yet student achievement across MENA is lagging compared to many other parts of the world. Low quality of education is a primary concern and one of the greatest…

  15. The palaeoecological context of the Oldowan-Acheulean in southern Africa.

    PubMed

    Ecker, Michaela; Brink, James S; Rossouw, Lloyd; Chazan, Michael; Horwitz, Liora K; Lee-Thorp, Julia A

    2018-05-21

    The influence of climatic and environmental change on human evolution in the Pleistocene epoch is understood largely from extensive East African stable isotope records. These records show increasing proportions of C 4 plants in the Early Pleistocene. We know far less about the expansion of C 4 grasses at higher latitudes, which were also occupied by early Homo but are more marginal for C 4 plants. Here we show that both C 3 and C 4 grasses and prolonged wetlands remained major components of Early Pleistocene environments in the central interior of southern Africa, based on enamel stable carbon and oxygen isotope data and associated faunal abundance and phytolith evidence from the site of Wonderwerk Cave. Vegetation contexts associated with Oldowan and early Acheulean lithic industries, in which climate is driven by an interplay of regional rainfall seasonality together with global CO 2 levels, develop along a regional distinct trajectory compared to eastern South Africa and East Africa.

  16. Signatures of positive selection in East African Shorthorn Zebu: a genome-wide SNP analysis

    USDA-ARS?s Scientific Manuscript database

    The small East African Shorthorn Zebu is the main indigenous cattle across East Africa. A recent genome wide SNPs analysis has revealed their ancient stable African taurine x Asian zebu admixture. Here, we assess the presence of candidate signature of positive selection in their genome, with the aim...

  17. The gravity field of the Red Sea and East Africa

    NASA Astrophysics Data System (ADS)

    Makris, Jannis; Henke, Christian H.; Egloff, Frank; Akamaluk, Thomas

    1991-11-01

    Reevaluation of all gravity data from the Red Sea, the Gulf of Aden and East Africa permitted the compilation of a new Bouguer anomaly map. The intensity of the gravity field and its regional pattern correlate closely with the topographic features of the region. The maximum Bouguer values (> + 100 mGal) are located over the median troughs of the Red Sea and Gulf of Aden. Dense juvenile oceanic crust in these rifts and intruding magmas in stretched continental areas produce excess mass responsible for the anomaly highs. In the Red Sea the orientation of the gravity highs is NW-SE in the south, turning to NE-SW in the north, almost parallel to the Aqaba-Dead Sea strike. This pattern reveals that the present basin axis is not identical with that which formed the Tertiary coastal margins and the pre-Red Sea zones of crustal weakness. In the Gulf of Aden, new oceanic crust along the Tadjura Trench and its eastward extension is also expressed in the Bouguer anomaly map by gravity highs and a sharp bending of the isolines. A maximum of approx. +150 mGal is located over the central section of the Sheba Ridge. Bouguer gravity values over the East African and Yemen Plateaus are of the order of -180 to -240 mGal, indicating significant crustal thickening. On the Somali Plateau, the Marda Fault also has a strong gravity signature that can be traced towards Somalia. By constraining crustal thickness and structure with seismic data and density values from the velocity distribution by means of the Nafe-Drake and Birch relationships, we computed density models for the crust and upper mantle. The crustal thickness is of the order of 40 km beneath the plateaus and only 5 to 6 km at the oceanized parts in the central and southern portions of the Red Sea median trough. The flanks of the southern Red Sea and the corresponding Arabian side are underlain by 12 to 16 km thick stretched continental type crust. Oceanization offshore Sudan and Egypt is asymmetrical. The continental crust

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  19. Socially Inclusive Development: The Foundations for Decent Societies in East and Southern Africa.

    PubMed

    Abbott, Pamela; Wallace, Claire; Sapsford, Roger

    2017-01-01

    This article is concerned with how social processes and social provision are conceptualised and measured in societies in order to offer guidance on how to improve developmental progress. Significant advances have been made in developing multidimensional measures of development, but they provide little guidance to governments on how to build sustainable societies. We argue for the need to develop a theoretically informed social and policy framework that permits the foundations for building decent societies to be put in place by governments. In our view the recently developed Decent Society Model provides such a framework. Our example is the assessment of government provision, by function, within fourteen countries of East and Southern Africa. The context is the current debates about socially inclusive development, but we argue that it is necessary to range more widely, as social processes of different kinds are multiply interrelated. Social inclusion is recognised by governments as well as international agencies, including the World Bank and the United Nations, as not only an ethical imperative but smart economics; socially inclusive societies are more stable and have greater potential for economic growth. Societies that can develop sustainably need not only to be inclusive, however, but to provide economic security for all, to be socially cohesive and to empower citizens so that as individuals and communities they can take control over their own lives.

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

    NASA Astrophysics Data System (ADS)

    Howari, Fares; Goodell, Philip; Salman, Abdulaty

    2016-02-01

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

  1. First report of the East African kdr mutation in an Anopheles gambiae mosquito in Côte d'Ivoire.

    PubMed

    Chouaïbou, Mouhamadou; Kouadio, Fodjo Behi; Tia, Emmanuel; Djogbenou, Luc

    2017-02-09

    Background . The intensive use of insecticides in public health and agriculture has led to the development of insecticide resistances in malaria vectors across sub-Saharan Africa countries in the last two decades. The kdr target site point mutation which is among the best characterised resistance mechanisms seems to be changing its distribution patterns on the African continent. The 1014F  kdr mutation originally described only in West Africa is spreading to East Africa while the 1014S  kdr mutation originally described in East Africa, is spreading to West and Central Africa. However, the East- kdr mutation has not been reported in Côte d'Ivoire so far. Methods . Immature stages of Anopheles gambiae s.l. were collected from breeding sites at the outskirts of Yamoussoukro, Côte d'Ivoire. Emerging 3-5 day old adult female mosquitoes were tested for susceptibility to deltamethrin 0.05%, malathion 5%, bendiocarb 1% and dichlorodiphenyltrichloroethane (DDT) 4% according to WHO standard procedures. A total of 50 An. gambiae s.l. specimens were drawn at random for DNA extraction and identification down to the species level. A subsample of 30 mosquitoes was tested for the East-African kdr mutation using a Taqman assay. Results . The tested mosquito population appeared to be strongly resistant to deltamethrin (1.03% mortality), bendiocarb (38.46% mortality) and DDT (0% mortality) with probable resistance observed for malathion (92.47%). Among the 41 mosquitoes that were successfully characterized, An. coluzzii was predominant (68.3%) followed by An. gambiae   s.s. (19.5%) and a few hybrids (7.3%). Out of 30 specimens genotyped for East- kdr , a single hybrid mosquito appeared to be heterozygous for the mutation. Conclusion . The present study revealed the presence of the East- kdr mutation in Côte d'Ivoire for the first time in An. gambiae and highlights the urgent need to start monitoring the allele and genotype frequencies.

  2. Household Density and Infant Care in an East African Society

    ERIC Educational Resources Information Center

    Munroe, Ruth H.; Munroe, Robert L.

    1971-01-01

    A cross-cultural relationship between household density and infant indulgence was investigated among Logoli infants in East Africa. Findings were taken as supportive of the view that socialization practices are influenced by ecological variables. (Author/JB)

  3. Near East/South Asia Report.

    DTIC Science & Technology

    1987-02-17

    ASIA REPORT CONTENTS ARAB AFRICA ALGERIA Summary of 1987 Financial Law (EL MOUDJAHID, 4 Jan 87) 1 EGYPT Arrest of Communist Network Reported...Periodical Analyzes Nation’s Foreign Debt (Chedly Ayari; JEUNE AFRIQUE ECONOMIE, Nov 86) 17 -a - ARAB EAST/ISRAEL JORDAN Egg Consumption...48 YEMEN ARAB REPUBLIC Army’s Self-Sufficiency in Agriculture Reviewed (Tawfiq al-Shaybani; AL-THAWRAH, 15 Dec 86) 53 SOUTH ASIA

  4. Black Marble - Africa, Europe, and the Middle East

    NASA Image and Video Library

    2017-12-08

    NASA image acquired April 18 - October 23, 2012 This new image of Europe, Africa, and the Middle East at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. The new data was mapped over existing Blue Marble imagery of Earth to provide a realistic view of the planet. The nighttime view was made possible by the new satellite’s “day-night band” of the Visible Infrared Imaging Radiometer Suite. VIIRS detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as gas flares, auroras, wildfires, city lights, and reflected moonlight. In this case, auroras, fires, and other stray light have been removed to emphasize the city lights. “Night time imagery provides an intuitively graspable view of our planet,” says William Stefanov, senior remote sensing scientist for the International Space Station program office. “They provide a fairly straightforward means to map urban versus rural areas, and to show where the major population centers are and where they are not.” Named for satellite meteorology pioneer Verner Suomi, NPP flies over any given point on Earth's surface twice each day at roughly 1:30 a.m. and p.m. The polar-orbiting satellite flies 824 kilometers (512 miles) above the surface, sending its data once per orbit to a ground station in Svalbard, Norway, and continuously to local direct broadcast users distributed around the world. The mission is managed by NASA with operational support from NOAA and its Joint Polar Satellite System, which manages the satellite's ground system. NASA Earth Observatory image by Robert Simmon, using Suomi NPP VIIRS data provided courtesy of Chris Elvidge (NOAA National Geophysical Data Center). Suomi NPP is the result of a partnership between NASA, NOAA, and the Department of Defense. Caption by Mike Carlowicz. Instrument: Suomi NPP - VIIRS Credit: NASA Earth Observatory Click here to view all of the Earth

  5. Why Africa matters: evolution of Old World Salvia (Lamiaceae) in Africa.

    PubMed

    Will, Maria; Claßen-Bockhoff, Regine

    2014-07-01

    Salvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus. Maximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome. Salvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution. The phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. High-intensity interval exercise training before abdominal aortic aneurysm repair (HIT-AAA): protocol for a randomised controlled feasibility trial.

    PubMed

    Tew, Garry A; Weston, Matthew; Kothmann, Elke; Batterham, Alan M; Gray, Joanne; Kerr, Karen; Martin, Denis; Nawaz, Shah; Yates, David; Danjoux, Gerard

    2014-01-10

    In patients with large abdominal aortic aneurysm (AAA), open surgical or endovascular aneurysm repair procedures are often used to minimise the risk of aneurysm-related rupture and death; however, aneurysm repair itself carries a high risk. Low cardiopulmonary fitness is associated with an increased risk of early post-operative complications and death following elective AAA repair. Therefore, fitness should be enhanced before aneurysm repair. High-intensity interval exercise training (HIT) is a potent, time-efficient strategy for enhancing cardiopulmonary fitness. Here, we describe a feasibility study for a definitive trial of a pre-operative HIT intervention to improve post-operative outcomes in patients undergoing elective AAA repair. A minimum of 50 patients awaiting elective repair of a 5.5-7.0 cm infrarenal AAA will be allocated by minimisation to HIT or usual care control in a 1:1 ratio. The patients allocated to HIT will complete three hospital-based exercise sessions per week, for 4 weeks. Each session will include 2 or 4 min of high-intensity stationary cycling followed by the same duration of easy cycling or passive recovery, repeated until a total of 16 min of high-intensity exercise is accumulated. Outcomes to be assessed before randomisation and 24-48 h before aneurysm repair include cardiopulmonary fitness, maximum AAA diameter and health-related quality of life. In the post-operative period, we will record destination (ward or critical care unit), organ-specific morbidity, mortality and the durations of critical care and hospital stay. Twelve weeks after the discharge, participants will be interviewed to reassess quality of life and determine post-discharge healthcare utilisation. The costs associated with the exercise intervention and healthcare utilisation will be calculated. Ethics approval was secured through Sunderland Research Ethics Committee. The findings of the trial will be disseminated through peer-reviewed journals, and national and

  7. Migration in southern Africa: a comparative perspective.

    PubMed

    Solomon, H

    1994-01-01

    Population movement can be described as intra-state, East-West, South-North, and South-South. About 20 million persons globally are considered displaced, of which about 4.1 million are internally displaced persons in South Africa. East-West movement occurred for over 400 million when the Iron Curtain came down. South-North movements of asylum seekers were estimated at 442,000 in 1990. South-South movement amounted to 4 million official refugees in Africa in 1989 and 4.4 million in 1990. African has the largest concentration of refugees. This article does not address the 265,825 contract migrant workers in South Africa. South African migration is the South-South type and can be characterized as "brain-drain" of well-trained professionals in neighboring states and unskilled and illegal migrants from Mozambique and Angola. Movement is pushed or pulled according to sociocultural factors, communications and technology, geographic proximity, precedent, demographic factors, environmental factors, economic factors, and political factors. The effects of migration in South Africa include increased stress on housing, political and social tension, increased costs, overcrowding, transmission of disease, and marginalization of migrants into low status and low paid jobs. For Lesotho migrants in South Africa remittances are a major source of national wealth. South Africa has also experienced racial discord against Mozambicans and Chinese. Political right wing groups mobilize around anti-immigration platforms. Migrants can become policy tools, and many are used in wars of liberation. International attention may focus on mistreatment of refugees. Management can be construed as "carrot" or "stick" approaches. Stick approaches include forced repatriation, limiting immigration, housing in survival-level camps, public campaigns run by host countries in sending countries, or greater control of national borders. South Africa has extensively used stick approaches, which have been only

  8. OGLE16aaa - a signature of a hungry supermassive black hole

    NASA Astrophysics Data System (ADS)

    Wyrzykowski, Łukasz; Zieliński, M.; Kostrzewa-Rutkowska, Z.; Hamanowicz, A.; Jonker, P. G.; Arcavi, I.; Guillochon, J.; Brown, P. J.; Kozłowski, S.; Udalski, A.; Szymański, M. K.; Soszyński, I.; Poleski, R.; Pietrukowicz, P.; Skowron, J.; Mróz, P.; Ulaczyk, K.; Pawlak, M.; Rybicki, K. A.; Greiner, J.; Krühler, T.; Bolmer, J.; Smartt, S. J.; Maguire, K.; Smith, K.

    2017-02-01

    We present the discovery and first three months of follow-up observations of a currently on-going unusual transient detected by the Optical Gravitational Lensing Experiment (OGLE-IV) survey, located in the centre of a galaxy at redshift z = 0.1655. The long rise to absolute magnitude of -20.5 mag, slow decline, very broad He and H spectral features make OGLE16aaa similar to other optical/UV tidal disruption events (TDEs). Weak narrow emission lines in the spectrum and archival photometric observations suggest the host galaxy is a weak-line active galactic nucleus, which has been accreting at higher rate in the past. OGLE16aaa, along with SDSS J0748, seems to form a sub-class of TDEs by weakly or recently active supermassive black holes (SMBHs). This class might bridge the TDEs by quiescent SMBHs and flares observed as `changing-look quasars', if we interpret the latter as TDEs. If this picture is true, the previously applied requirement for identifying a flare as a TDE that it had to come from an inactive nucleus, could be leading to observational bias in TDE selection, thus affecting TDE-rate estimations.

  9. Designing a Frost Forecasting Service for Small Scale Tea Farmers in East Africa

    NASA Astrophysics Data System (ADS)

    Adams, E. C.; Nyaga, J. W.; Ellenburg, W. L.; Limaye, A. S.; Mugo, R. M.; Flores Cordova, A. I.; Irwin, D.; Case, J.; Malaso, S.; Sedah, A.

    2017-12-01

    our partner network developed at the stakeholder engagement meeting. This presentation will illustrate the efficacy of our frost forecasting algorithm, and a way forward for incorporating these forecasts in a meaningful way to the key decision makers - the small-scale farmers of East Africa.

  10. Patient and Aneurysm Characteristics Predicting Prolonged Length of Stay After Elective Open AAA Repair in the Endovascular Era.

    PubMed

    Casillas-Berumen, Sergio; Rojas-Miguez, Florencia A; Farber, Alik; Komshian, Sevan; Kalish, Jeffrey A; Rybin, Denis; Doros, Gheorghe; Siracuse, Jeffrey J

    2018-01-01

    Open aortic aneurysm repair (AAA) repair can be resource intensive and associated with a prolonged length of stay (LOS). We sought to examine patient and aneurysm predictors of prolonged LOS to better identify those at risk in the preoperative setting. Patient data were obtained from the targeted AAA American College of Surgery National Surgical Quality Improvement Program database from 2012 to 2014 of patients undergoing open AAA repair. Multivariable logistic regression was used to determine predictors of prolonged postoperative LOS defined as greater than 10 days (75th percentile). There were 1172 open AAA repairs identified. The majority (54%) of patients were older than 70 years and male (74%). Surgical approach was transperitoneal (70.9%) and retroperitoneal (29.1%). Aneurysms were 51.4% infrarenal, 33% juxtarenal, 5.7% pararenal, 7.4% suprarenal, and 2.5% type IV thoracoabdominal. Mean and median LOS were 9.1 ± 7.4 and 7 (0-72) days, respectively. Independently associated with extended LOS factors were visceral revascularization (odds ratio [OR]: 5.32, 95% confidence interval [CI]: 2.77-10.22, P < .001), type IV thoracoabdominal extent (OR: 3.09, 95% CI: 1.01-9.46, P = .048), suprarenal extent (OR: 1.89, 95% CI: 1.07-3.34, P = .029) and juxtarenal (OR: 1.43, 95% CI: 1.01-2.02, P = .004), non-Caucasian race (OR: 2.80, 95% CI: 1.77-4.41, P < .001), chronic obstructive pulmonary disease (OR: 1.76, 95% CI: 1.20-2.59, P = .004), not-from-home admission (OR: 1.91, 95% CI: 1.13-3.24), and age greater than 70 (OR: 1.49, 95% CI: 1.08-2.05, P = .014). We identified patient and aneurysm characteristics independently associated with protracted LOS following open AAA repair. Prospective identification of high-risk patients may allow physicians and hospitals to engage in multidisciplinary collaborations preoperatively to try to improve LOS in this resource-intensive population.

  11. East Asia: A Bibliography for Undergraduate Libraries.

    ERIC Educational Resources Information Center

    Gillin, Donald; And Others

    This bibliography, similar to others on Asia and Africa, contains over 2000 titles relevant to the study of East Asia. Book, journal, and a few government citations -- the majority of which have been published within the last twenty years -- emphasize the humanities and social studies. Intended as a book selection guide, entries are graded as to…

  12. Middle East Studies: A Catalogue of Middle East Studies Resources In or Near Connecticut. Area Studies Resource Guides, Number Two.

    ERIC Educational Resources Information Center

    Stone, Frank A., Comp.

    This directory of Middle Eastern resource materials in or near Connecticut is designed for use by educators, librarians, media specialists, and the general public. The Middle East is defined as the part of the world known as Southwest Asia/North Africa (SWANA). The information is organized under ten major categories: associations and…

  13. AAA and AXB algorithms for the treatment of nasopharyngeal carcinoma using IMRT and RapidArc techniques.

    PubMed

    Kamaleldin, Maha; Elsherbini, Nader A; Elshemey, Wael M

    2017-09-27

    The aim of this study is to evaluate the impact of anisotropic analytical algorithm (AAA) and 2 reporting systems (AXB-D m and AXB-D w ) of Acuros XB algorithm (AXB) on clinical plans of nasopharyngeal patients using intensity-modulated radiotherapy (IMRT) and RapidArc (RA) techniques. Six plans of different algorithm-technique combinations are performed for 10 patients to calculate dose-volume histogram (DVH) physical parameters for planning target volumes (PTVs) and organs at risk (OARs). The number of monitor units (MUs) and calculation time are also determined. Good coverage is reported for all algorithm-technique combination plans without exceeding the tolerance for OARs. Regardless of the algorithm, RA plans persistently reported higher D 2% values for PTV-70. All IMRT plans reported higher number of MUs (especially with AXB) than did RA plans. AAA-IMRT produced the minimum calculation time of all plans. Major differences between the investigated algorithm-technique combinations are reported only for the number of MUs and calculation time parameters. In terms of these 2 parameters, it is recommended to employ AXB in calculating RA plans and AAA in calculating IMRT plans to achieve minimum calculation times at reduced number of MUs. Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  14. Performance of the WRF model to simulate the seasonal and interannual variability of hydrometeorological variables in East Africa: a case study for the Tana River basin in Kenya

    NASA Astrophysics Data System (ADS)

    Kerandi, Noah Misati; Laux, Patrick; Arnault, Joel; Kunstmann, Harald

    2017-10-01

    This study investigates the ability of the regional climate model Weather Research and Forecasting (WRF) in simulating the seasonal and interannual variability of hydrometeorological variables in the Tana River basin (TRB) in Kenya, East Africa. The impact of two different land use classifications, i.e., the Moderate Resolution Imaging Spectroradiometer (MODIS) and the US Geological Survey (USGS) at two horizontal resolutions (50 and 25 km) is investigated. Simulated precipitation and temperature for the period 2011-2014 are compared with Tropical Rainfall Measuring Mission (TRMM), Climate Research Unit (CRU), and station data. The ability of Tropical Rainfall Measuring Mission (TRMM) and Climate Research Unit (CRU) data in reproducing in situ observation in the TRB is analyzed. All considered WRF simulations capture well the annual as well as the interannual and spatial distribution of precipitation in the TRB according to station data and the TRMM estimates. Our results demonstrate that the increase of horizontal resolution from 50 to 25 km, together with the use of the MODIS land use classification, significantly improves the precipitation results. In the case of temperature, spatial patterns and seasonal cycle are well reproduced, although there is a systematic cold bias with respect to both station and CRU data. Our results contribute to the identification of suitable and regionally adapted regional climate models (RCMs) for East Africa.

  15. Tectonics, orbital forcing, global climate change, and human evolution in Africa: introduction to the African paleoclimate special volume.

    PubMed

    Maslin, Mark A; Christensen, Beth

    2007-11-01

    The late Cenozoic climate of Africa is a critical component for understanding human evolution. African climate is controlled by major tectonic changes, global climate transitions, and local variations in orbital forcing. We introduce the special African Paleoclimate Issue of the Journal of Human Evolution by providing a background for and synthesis of the latest work relating to the environmental context for human evolution. Records presented in this special issue suggest that the regional tectonics, appearance of C(4) plants in East Africa, and late Cenozoic global cooling combined to produce a long-term drying trend in East Africa. Of particular importance is the uplift associated with the East African Rift Valley formation, which altered wind flow patterns from a more zonal to more meridinal direction. Results in this volume suggest a marked difference in the climate history of southern and eastern Africa, though both are clearly influenced by the major global climate thresholds crossed in the last 3 million years. Papers in this volume present lake, speleothem, and marine paleoclimate records showing that the East African long-term drying trend is punctuated by episodes of short, alternating periods of extreme wetness and aridity. These periods of extreme climate variability are characterized by the precession-forced appearance and disappearance of large, deep lakes in the East African Rift Valley and paralleled by low and high wind-driven dust loads reaching the adjacent ocean basins. Dating of these records show that over the last 3 million years such periods only occur at the times of major global climatic transitions, such as the intensification of Northern Hemisphere Glaciation (2.7-2.5 Ma), intensification of the Walker Circulation (1.9-1.7 Ma), and the Mid-Pleistocene Revolution (1-0.7 Ma). Authors in this volume suggest this onset occurs as high latitude forcing in both Hemispheres compresses the Intertropical Convergence Zone so that East Africa

  16. The state of harm reduction in the Middle East and North Africa: A focus on Iran and Morocco.

    PubMed

    Himmich, Hakima; Madani, Navid

    2016-05-01

    HIV/AIDS and hepatitis C among people who inject drugs are on the rise in the Middle East and North Africa (MENA) region. But the regional response to the epidemic falls short both in terms of the quality and scale of response. From the threat of the death sentence for drug offenses to the burden of refugees fleeing conflict, there are many legal, political and social barriers that hinder the introduction and expansion of harm reduction in the region. However Iran and Morocco are two pioneering countries and over the last decade they have been providing evidence that harm reduction is feasible and acceptable in MENA. Using different approaches, these two countries have overcome various obstacles and encouraged discussion and collaboration among stakeholders, including government, health professionals, civil society and community-based organizations. In so doing they have created an enabling environment to endorse a national harm strategy. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. East-looking view across Atlantic waters during MA-9 22 orbit

    NASA Technical Reports Server (NTRS)

    1963-01-01

    East looking view across Atlantic waters toward Africa, showing Mauritania and Spanish Sahara photographed from the Mercury-Atlas 9 capsule by Astronaut L. Gordon Cooper Jr., during his 22 orbit Mercury-Atlas 9 (MA-9) spaceflight.

  18. Preliminary Bibliography on East Asia for Undergraduate Libraries.

    ERIC Educational Resources Information Center

    Ehrman, Edith; Morehouse, Ward

    This classified bibliography on East Asia and similar bibliographies on Africa south of the Sahara (LI 000 882) and South Asia (LI 000 061) have been compiled under the first phase of a three-year cooperative project to strengthen bibliographical resources for undergraduate libraries on "neglected" foreign areas. The bibliography in its…

  19. Along-axis segmentation and isostasy in the Western rift, East Africa

    NASA Astrophysics Data System (ADS)

    Upcott, N. M.; Mukasa, R. K.; Ebinger, C. J.; Karner, G. D.

    1996-02-01

    Structural variations along the southern sectors of the Western rift, East Africa, have previously been described, but subsurface structures in the northern sector (Uganda, Zaire) are virtually unknown. Our aims are to investigate the along-axis segmentation of the northern sector, thereby adding to the structural picture of the Western rift, and to study the isostatic compensation of the varying rift morphology along the sector's length. This study describes the first gravity survey to be carried out on the shallow Lake Albert, forward models of these and existing gravity data, and the results from inverse modeling of existing aeromagnetic data designed to delimit border and transfer fault systems. Our tectonic model shows that the northern rift sector is segmented along-axis into five 25 to 65-km-wide, 80 to 100-km-long rift segments, characterized by closed-contour Bouguer anomaly lows, and bounded by steep gravity, aeromagnetic, and topographic/bathymetric gradients. Werner and Euler deconvolution results and gravity anomaly data reveal that some faulted basins are separated by structural highs and cross-rift ramps or faults and suggest sedimentary basin depths of 4-6 km. Forward modeling of structural and free-air gravity profiles across individual basins and flanks using a model that assumes flexural compensation also suggests sediment thicknesses of up to 5.5 km, similar to the estimates from magnetic data. The basin and flank morphology can be explained by 6-9 km of extension of a lithosphere with an effective elastic thickness (Te) of 25 km (equivalent to a flexural rigidity of 1.4 × 1023 N m), similar to results in other Western rift basins. Potential field data and lithospheric strength estimates in the Western rift system show small along-axis variations in lithospheric structure, regardless of the presence or absence of Cenozoic magmatism.

  20. Evidence of hotspot paths below Arabia and the Horn of Africa and consequences on the Red Sea opening

    NASA Astrophysics Data System (ADS)

    Vicente de Gouveia, S.; Besse, J.; Frizon de Lamotte, D.; Greff-Lefftz, M.; Lescanne, M.; Gueydan, F.; Leparmentier, F.

    2018-04-01

    Rifts are often associated with ancient traces of hotspots, which are supposed to participate to the weakening of the lithosphere. We investigated the expected past trajectories followed by three hotspots (Afar, East-Africa and Lake-Victoria) located around the Red Sea. We used a hotspot reference frame to compute their location with respect to time, which is then compared to mantle tomography interpretations and geological features. Their tracks are frequently situated under continental crust, which is known to strongly filter plume activity. We looked for surface markers of their putative ancient existence, such as volcanism typology, doming, and heat-flow data from petroleum wells. Surface activity of the East-Africa hotspot is supported at 110 Ma, 90 Ma and 30 Ma by uplift, volcanic activity and rare gas isotopic signatures, reminiscent of a deep plume origin. The analysis of heat-flow data from petroleum wells under the Arabian plate shows a thermal anomaly that may correspond to the past impact of the Afar hotspot. According to derived hotspot trajectories, the Afar hotspot, situated (at 32 Ma) 1000 km north-east of the Ethiopian-Yemen traps, was probably too far away to be accountable for them. The trigger of the flood basalts would likely be linked to the East-Africa hotspot. The Lake-Victoria hotspot activity appears to have been more recent, attested only by Cenozoic volcanism in an uplifted area. Structural and thermal weakening of the lithosphere may have played a major role in the location of the rift systems. The Gulf of Aden is located on inherited Mesozoic extensional basins between two weak zones, the extremity of the Carlsberg Ridge and the present Afar triangle, previously impacted by the East-Africa hotspot. The Red Sea may have opened in the context of extension linked to Neo-Tethys slab-pull, along the track followed by the East Africa hotspot, suggesting an inherited thermal weakening.

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

    ERIC Educational Resources Information Center

    Howard, Karen

    2014-01-01

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

  2. Avian Influenza: A growing threat to Africa

    USDA-ARS?s Scientific Manuscript database

    The H9N2 low pathogenic avian influenza (LPAI) is probably the most widespread avian influenza subtype in poultry around the world being endemic in a large part of Asia, the Middle East, Northern Africa, and in Germany. Currently, there is no standardized clade system to describe the antigenic vari...

  3. East African Cenozoic vegetation history.

    PubMed

    Linder, Hans Peter

    2017-11-01

    The modern vegetation of East Africa is a complex mosaic of rainforest patches; small islands of tropic-alpine vegetation; extensive savannas, ranging from almost pure grassland to wooded savannas; thickets; and montane grassland and forest. Here I trace the evolution of these vegetation types through the Cenozoic. Paleogene East Africa was most likely geomorphologically subdued and, as the few Eocene fossil sites suggest, a woodland in a seasonal climate. Woodland rather than rainforest may well have been the regional vegetation. Mountain building started with the Oligocene trap lava flows in Ethiopia, on which rainforest developed, with little evidence of grass and none of montane forests. The uplift of the East African Plateau took place during the middle Miocene. Fossil sites indicate the presence of rainforest, montane forest and thicket, and wooded grassland, often in close juxtaposition, from 17 to 10 Ma. By 10 Ma, marine deposits indicate extensive grassland in the region and isotope analysis indicates that this was a C 3 grassland. In the later Miocene rifting, first of the western Albertine Rift and then of the eastern Gregory Rift, added to the complexity of the environment. The building of the high strato-volcanos during the later Mio-Pliocene added environments suitable for tropic-alpine vegetation. During this time, the C 3 grassland was replaced by C 4 savannas, although overall the extent of grassland was reduced from the mid-Miocene high to the current low level. Lake-level fluctuations during the Quaternary indicate substantial variation in rainfall, presumably as a result of movements in the intertropical convergence zone and the Congo air boundary, but the impact of these fluctuations on the vegetation is still speculative. I argue that, overall, there was an increase in the complexity of East African vegetation complexity during the Neogene, largely as a result of orogeny. The impact of Quaternary climatic fluctuation is still poorly understood

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

    NASA Astrophysics Data System (ADS)

    Stenchikov, G.; Dogar, M.

    2012-04-01

    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.

  5. South-East Asian strains of Plasmodium falciparum display higher ratio of non-synonymous to synonymous polymorphisms compared to African strains

    PubMed Central

    Singh, Gajinder Pal; Sharma, Amit

    2016-01-01

    Resistance to frontline anti-malarial drugs, including artemisinin, has repeatedly arisen in South-East Asia, but the reasons for this are not understood. Here we test whether evolutionary constraints on Plasmodium falciparum strains from South-East Asia differ from African strains. We find a significantly higher ratio of non-synonymous to synonymous polymorphisms in P. falciparum from South-East Asia compared to Africa, suggesting differences in the selective constraints on P. falciparum genome in these geographical regions. Furthermore, South-East Asian strains showed a higher proportion of non-synonymous polymorphism at conserved positions, suggesting reduced negative selection. There was a lower rate of mixed infection by multiple genotypes in samples from South-East Asia compared to Africa. We propose that a lower mixed infection rate in South-East Asia reduces intra-host competition between the parasite clones, reducing the efficiency of natural selection. This might increase the probability of fixation of fitness-reducing mutations including drug resistant ones. PMID:27853513

  6. Yellow fever, Asia and the East African slave trade.

    PubMed

    Cathey, John T; Marr, John S

    2014-05-01

    Yellow fever is endemic in parts of sub-Saharan Africa and South America, yet its principal vectors--species of mosquito of the genus Aedes--are found throughout tropical and subtropical latitudes. Phylogenetic analyses indicate that yellow fever originated in Africa and that its spread to the New World coincided with the slave trade, but why yellow fever has never appeared in Asia remains a mystery. None of several previously proposed explanations for its absence there is considered satisfactory. We contrast the trans-Atlantic slave trade, and trade across the Sahara and to the Arabian Peninsula and Mesopotamia, with that to Far East and Southeast Asian ports before abolition of the African slave trade, and before the scientific community understood the transmission vector of yellow fever and the viral life cycle, and the need for shipboard mosquito control. We propose that these differences in slave trading had a primary role in the avoidance of yellow fever transmission into Asia in the centuries before the 20(th) century. The relatively small volume of the Black African slave trade between Africa and East and Southeast Asia has heretofore been largely ignored. Although focal epidemics may have occurred, the volume was insufficient to reach the threshold for endemicity.

  7. Clinical implications in the use of the PBC algorithm versus the AAA by comparison of different NTCP models/parameters

    PubMed Central

    2013-01-01

    Purpose Retrospective analysis of 3D clinical treatment plans to investigate qualitative, possible, clinical consequences of the use of PBC versus AAA. Methods The 3D dose distributions of 80 treatment plans at four different tumour sites, produced using PBC algorithm, were recalculated using AAA and the same number of monitor units provided by PBC and clinically delivered to each patient; the consequences of the difference on the dose-effect relations for normal tissue injury were studied by comparing different NTCP model/parameters extracted from a review of published studies. In this study the AAA dose calculation is considered as benchmark data. The paired Student t-test was used for statistical comparison of all results obtained from the use of the two algorithms. Results In the prostate plans, the AAA predicted lower NTCP value (NTCPAAA) for the risk of late rectal bleeding for each of the seven combinations of NTCP parameters, the maximum mean decrease was 2.2%. In the head-and-neck treatments, each combination of parameters used for the risk of xerostemia from irradiation of the parotid glands involved lower NTCPAAA, that varied from 12.8% (sd=3.0%) to 57.5% (sd=4.0%), while when the PBC algorithm was used the NTCPPBC’s ranging was from 15.2% (sd=2.7%) to 63.8% (sd=3.8%), according the combination of parameters used; the differences were statistically significant. Also NTCPAAA regarding the risk of radiation pneumonitis in the lung treatments was found to be lower than NTCPPBC for each of the eight sets of NTCP parameters; the maximum mean decrease was 4.5%. A mean increase of 4.3% was found when the NTCPAAA was calculated by the parameters evaluated from dose distribution calculated by a convolution-superposition (CS) algorithm. A markedly different pattern was observed for the risk relating to the development of pneumonitis following breast treatments: the AAA predicted higher NTCP value. The mean NTCPAAA varied from 0.2% (sd = 0.1%) to 2.1% (sd = 0

  8. Clinical implications in the use of the PBC algorithm versus the AAA by comparison of different NTCP models/parameters.

    PubMed

    Bufacchi, Antonella; Nardiello, Barbara; Capparella, Roberto; Begnozzi, Luisa

    2013-07-04

    Retrospective analysis of 3D clinical treatment plans to investigate qualitative, possible, clinical consequences of the use of PBC versus AAA. The 3D dose distributions of 80 treatment plans at four different tumour sites, produced using PBC algorithm, were recalculated using AAA and the same number of monitor units provided by PBC and clinically delivered to each patient; the consequences of the difference on the dose-effect relations for normal tissue injury were studied by comparing different NTCP model/parameters extracted from a review of published studies. In this study the AAA dose calculation is considered as benchmark data. The paired Student t-test was used for statistical comparison of all results obtained from the use of the two algorithms. In the prostate plans, the AAA predicted lower NTCP value (NTCPAAA) for the risk of late rectal bleeding for each of the seven combinations of NTCP parameters, the maximum mean decrease was 2.2%. In the head-and-neck treatments, each combination of parameters used for the risk of xerostemia from irradiation of the parotid glands involved lower NTCPAAA, that varied from 12.8% (sd=3.0%) to 57.5% (sd=4.0%), while when the PBC algorithm was used the NTCPPBC's ranging was from 15.2% (sd=2.7%) to 63.8% (sd=3.8%), according the combination of parameters used; the differences were statistically significant. Also NTCPAAA regarding the risk of radiation pneumonitis in the lung treatments was found to be lower than NTCPPBC for each of the eight sets of NTCP parameters; the maximum mean decrease was 4.5%. A mean increase of 4.3% was found when the NTCPAAA was calculated by the parameters evaluated from dose distribution calculated by a convolution-superposition (CS) algorithm. A markedly different pattern was observed for the risk relating to the development of pneumonitis following breast treatments: the AAA predicted higher NTCP value. The mean NTCPAAA varied from 0.2% (sd = 0.1%) to 2.1% (sd = 0.3%), while the mean NTCPPBC

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

    PubMed

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

    2014-09-01

    Rainfall controls fire in tropical savanna ecosystems through impacting both the amount and flammability of plant biomass, and consequently, predicted changes in tropical precipitation over the next century are likely to have contrasting effects on the fire regimes of wet and dry savannas. We reconstructed the long-term dynamics of biomass burning in equatorial East Africa, using fossil charcoal particles from two well-dated lake-sediment records in western Uganda and central Kenya. We compared these high-resolution (5 years/sample) time series of biomass burning, spanning the last 3800 and 1200 years, with independent data on past hydroclimatic variability and vegetation dynamics. In western Uganda, a rapid (<100 years) and permanent increase in burning occurred around 2170 years ago, when climatic drying replaced semideciduous forest by wooded grassland. At the century time scale, biomass burning was inversely related to moisture balance for much of the next two millennia until ca. 1750 ad, when burning increased strongly despite regional climate becoming wetter. A sustained decrease in burning since the mid20th century reflects the intensified modern-day landscape conversion into cropland and plantations. In contrast, in semiarid central Kenya, biomass burning peaked at intermediate moisture-balance levels, whereas it was lower both during the wettest and driest multidecadal periods of the last 1200 years. Here, burning steadily increased since the mid20th century, presumably due to more frequent deliberate ignitions for bush clearing and cattle ranching. Both the observed historical trends and regional contrasts in biomass burning are consistent with spatial variability in fire regimes across the African savanna biome today. They demonstrate the strong dependence of East African fire regimes on both climatic moisture balance and vegetation, and the extent to which this dependence is now being overridden by anthropogenic activity. © 2014 John Wiley & Sons Ltd.

  10. NASA's East and Southeast Asia Initiatives: BASE-ASIA and EAST-AIRE

    NASA Technical Reports Server (NTRS)

    Tsay, S.; Maring, H.

    2005-01-01

    Airborne dust from northern China influences air quality and regional climate in Asia during springtime. However, with the economic growth in China, increased emission of particulate air pollutants from industrial and vehicular sources will not only impact the earth's radiation balance, but also adversely affect human health year round. In addition, both of dust and aerosol pollutants can be transported swiftly across the Pacific affecting North America within a few days. Asian dust and pollutant aerosols can be detected by their colored appearance using current Earth observing satellites (e.g., MODIS, SeaWiFS, TOMS, etc.) and by sunphotometers deployed on the surface of the earth. Biomass burning has been a regular practice for land clearing and conversion in many countries, especially those in Africa, South America, and Southeast Asia. However, the climatology of Southeast Asia is very different than that of Africa and South America, such that large-scale biomass burning causes smoke to interact extensively with clouds during the peak-burning season of March to April. Globally significant sources of greenhouse gases (eg., CO2, CH4), chemically active gases (e.g., NO, CO, HC, CH3Br), and atmospheric aerosols are produced by biomass burning. These gases influence the Earth-atmosphere system, impacting both global climate and tropospheric chemistry. Some aerosols can serve as cloud condensation nuclei, which play a role in determining cloud lifetime and precipitation, altering the earth's radiation and water budgets. Biomass burning also affects the biogeochemical cycling of nitrogen and carbon compounds; the hydrological cycle; land surface reflectivity and emissivity; and ecosystem biodiversity and stability. Two NASA initiatives, EAST-AIRE (East Asian Study of Tropospheric Aerosols: an International Regional Experiment) and BASE-ASIA (Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment) will be presented. The objectives of these initiatives is to

  11. Genetic structure and diversity of coffee (Coffea) across Africa and the Indian Ocean islands revealed using microsatellites

    PubMed Central

    Razafinarivo, Norosoa J.; Guyot, Romain; Davis, Aaron P.; Couturon, Emmanuel; Hamon, Serge; Crouzillat, Dominique; Rigoreau, Michel; Dubreuil-Tranchant, Christine; Poncet, Valerie; De Kochko, Alexandre; Rakotomalala, Jean-Jacques; Hamon, Perla

    2013-01-01

    Background and Aims The coffee genus (Coffea) comprises 124 species, and is indigenous to the Old World Tropics. Due to its immense economic importance, Coffea has been the focus of numerous genetic diversity studies, but despite this effort it remains insufficiently studied. In this study the genetic diversity and genetic structure of Coffea across Africa and the Indian Ocean islands is investigated. Methods Genetic data were produced using 13 polymorphic nuclear microsatellite markers (simple sequence repeats, SSRs), including seven expressed sequence tag-SSRs, and the data were analysed using model- and non-model-based methods. The study includes a total of 728 individuals from 60 species. Key Results Across Africa and the Indian Ocean islands Coffea comprises a closely related group of species with an overall pattern of genotypes running from west to east. Genetic structure was identified in accordance with pre-determined geographical regions and phylogenetic groups. There is a good relationship between morpho-taxonomic species delimitations and genetic units. Genetic diversity in African and Indian Ocean Coffea is high in terms of number of alleles detected, and Madagascar appears to represent a place of significant diversification in terms of allelic richness and species diversity. Conclusions Cross-species SSR transferability in African and Indian Ocean islands Coffea was very efficient. On the basis of the number of private alleles, diversification in East Africa and the Indian Ocean islands appears to be more recent than in West and West-Central Africa, although this general trend is complicated in Africa by the position of species belonging to lineages connecting the main geographical regions. The general pattern of phylogeography is not in agreement with an overall east to west (Mascarene, Madagascar, East Africa, West Africa) increase in genome size, the high proportion of shared alleles between the four regions or the high numbers of exclusive shared

  12. Social context of human immunodeficiency virus transmission in Africa: historical and cultural bases of east and central African sexual relations.

    PubMed

    Larson, A

    1989-01-01

    The literature relating to the social context of sexual relations in East and Central Africa has several implications for the heterosexual transmission of human immunodeficiency virus (HIV). Colonially created cities in the region still discriminate economically and socially against women. Rapid urbanization is occurring, but migrants maintain strong ties with rural areas. Traditional attitudes towards marriage and sexuality affect urban behavior in the extent of marital stability, the frequency of polygyny, and the emotional bond between spouses. Ethnic groups in Kampala and Nairobi exemplify the cultural foundations of two forms of sexual relations found in the region, one characterized by prostitution and the other by small circles of interchanging lovers. The first results in a more rapid spread of HIV through the urban population and outwards into rural areas. Each pattern exerts unique constraints on behavioral change and requires different prevention campaigns.

  13. United States Strategic Military Access in Northeast Africa.

    DTIC Science & Technology

    1984-12-01

    strategy in the Northwest quadrant of the Indian Ocean. Kenya’s ruling elite was anxious to prove to the U.S. that Kenya desired a role in the containment...1968. 22. Fisher, W.B., "Egypt" in The Middle East and North Africa, p.. 352, Europa Publishers, London, 1983. 23. McDermott, Anthony, "Egypt" in... Europa Publishers, 1983. 31. Henze, Paul B., "How Stable is Siad Barre’s Regime?," Africa Report, pp. 8-10, March-April 1982. 32. U.S Department of

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

    NASA Astrophysics Data System (ADS)

    Dare, A. E.

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  16. Protected Areas: Mixed Success in Conserving East Africa’s Evergreen Forests

    PubMed Central

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

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and ‘leakage’ (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at −9.3% (17,167 km2), but varied between countries (range: −0.9% to −85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa’s forest conservation efforts. PMID:22768074

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

    USGS Publications Warehouse

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

    2011-01-01

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

  18. THE EAST AFRICAN MEDICAL JOURNAL: ITS HISTORY AND CONTRIBUTION TO REGIONAL MALARIA RESEARCH DURING THE LAST 75 YEARS

    PubMed Central

    OMBONGI, K S; DOBSON, M; MALOWANY, M; SNOW, R W

    2013-01-01

    SUMMARY Since its inception seventy five years ago, the East African Medical Journal has provided an uninterrupted forum through which medical practitioners and scientists could publish their research. Although the EAMJ was initially prepared for an audience of colonial medical officers, by the 1930s the journal expanded to include subscription and submissions from Northern Rhodesia (now Zimbabwe) and West Africa. Our review begins with a history of the journal’s production, exploring the shifts in editorial composition. We then focus more directly on a discussion of papers and editorials on malaria, a disease that continues to challenge the region of East Africa. Our review highlights the importance of the journal’s commitment to publications on this major health problem within the East African environment. Of particular interest, our review shows that many of today’s concerns, debates and recommendations for control or treatment of malaria in East Africa were discussed and debated in earlier issues of the EAMJ. Medical policy for the region with regard to malaria will benefit from revisiting previous volumes of the EAMJ. These contributions will ensure the journal a significant place in the world of research publications for the coming seventy five years. PMID:24137043

  19. Morphological State as a Predictor for Reintervention and Mortality After EVAR for AAA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohrlander, Tomas; Dencker, Magnus; Acosta, Stefan, E-mail: stefan.acosta@telia.com

    2012-10-15

    Purpose: This study was designed to assess aorto-iliac morphological characteristics in relation to reintervention and all-cause long-term mortality in patients undergoing standard EVAR for infrarenal AAA. Methods: Patients treated with EVAR (Zenith{sup Registered-Sign} Stentgrafts, Cook) between May 1998 and February 2006 were prospectively enrolled in a computerized database where comorbidities and preoperative aneurysm morphology were entered. Reinterventions and mortality were checked until December 1, 2010. Median follow-up time was 68 months. Results: A total of 304 patients were included, of which 86% were men. Median age was 74 years. The reintervention rate was 23.4% (71/304). A greater diameter of themore » common iliac artery (p = 0.037; hazard ratio (HR) 1.037 [1.002-1.073]) was an independent factor for an increased number of reinterventions. The 30-day mortality rate was 3.0% (9/304). Aneurysm-related deaths due to AAA occurred in 4.9% (15/304). Five patients died due to a concomitant ruptured thoracic aortic aneurysm. The mortality until end of follow-up was 54.3% (165/304). The proportion of deaths caused by vascular diseases was 61.6%. The severity of angulation of the iliac arteries (p = 0.014; HR 1.018 [95% confidence interval (CI) 1.004-1.033]) and anemia (p = 0.044; HR 2.79 [95% CI 1.029-7.556]) remained as independent factors associated with all-cause long-term mortality. The crude reintervention-free survival rate at 1, 3, and 5 years was 84.5%, 64.8%, and 51.6%, respectively. Conclusions: The initial aorto-iliac morphological state in patients scheduled for standard EVAR for AAA seems to be strongly related to the need for reinterventions and long-term mortality.« less

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  1. The Dispersal of East Gondwana from Continental Breakup to the Start of the Cretaceous Quiet Zone

    NASA Astrophysics Data System (ADS)

    Davis, J. K.; Lawver, L. A.; Norton, I. O.; Gahagan, L.

    2014-12-01

    Existing plate models for the breakup of Africa and East Gondwana (Australia, East Antarctica, India, Madagascar, the Seychelles, and Sri Lanka) are problematic and require revision. Specific problems include the utilization of dubious Gondwana configurations, improbable plate motion, and/or a failure to satisfy the holistic marine magnetic anomaly data. I present here a new model for the breakup of East Gondwana. This new model begins from a constrained, pre-breakup, Gondwana configuration. Out of this initial "tight-fit" configuration, East Gondwana rifts from West Gondwana (Africa & South America) as a cohesive unit. During this breakup and subsequent seafloor spreading, East Gondwana is devoid of any internal compression or anomalous plate motion. The overall motion of East Gondwana is constrained by seafloor spreading in the coeval Somali Basin and Mozambique/Riiser Larsen Basins. Seafloor spreading in these basins is modeled using existing marine magnetic anomaly interpretations and satellite-derived gravity data. Our model is uniquely able to satisfy the magnetic anomaly observations in both of the aforementioned basins without invoking improbable plate motion or configurations. Additionally, our plate model provides valuable insight into the breakup of India and East Antarctica. In this model, we fix India to Madagascar from breakup to 90 Ma, thus eventual separation between India and East Antarctica is an output, not an input of our model. We suggest that this separation occurred diachronously from ~140 Ma in the east to ~120 Ma in the west. This modeled motion between India and East Antarctica agrees well with geophysical observations from the margin of East Antarctica and our preliminary analysis of margin character and variability.

  2. Structural Basis of ATP Hydrolysis and Intersubunit Signaling in the AAA+ ATPase p97.

    PubMed

    Hänzelmann, Petra; Schindelin, Hermann

    2016-01-05

    p97 belongs to the superfamily of AAA+ ATPases and is characterized by a tandem AAA module, an N-terminal domain involved in substrate and cofactor interactions, and a functionally important unstructured C-terminal tail. The ATPase activity is controlled by an intradomain communication within the same protomer and an interdomain communication between neighboring protomers. Here, we present for the first time crystal structures in which the physiologically relevant p97 hexamer constitutes the content of the asymmetric unit, namely in the apo state without nucleotide in either the D1 or D2 module and in the pre-activated state with ATPγS bound to both modules. The structures provide new mechanistic insights into the interdomain communication mediated by conformational changes of the C terminus as well as an intersubunit signaling network, which couples the nucleotide state to the conformation of the central putative substrate binding pore. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Structural basis of protein translocation by the Vps4-Vta1 AAA ATPase

    PubMed Central

    Monroe, Nicole; Han, Han; Shen, Peter S; Sundquist, Wesley I; Hill, Christopher P

    2017-01-01

    Many important cellular membrane fission reactions are driven by ESCRT pathways, which culminate in disassembly of ESCRT-III polymers by the AAA ATPase Vps4. We report a 4.3 Å resolution cryo-EM structure of the active Vps4 hexamer with its cofactor Vta1, ADP·BeFx, and an ESCRT-III substrate peptide. Four Vps4 subunits form a helix whose interfaces are consistent with ATP binding, is stabilized by Vta1, and binds the substrate peptide. The fifth subunit approximately continues this helix but appears to be dissociating. The final Vps4 subunit completes a notched-washer configuration as if transitioning between the ends of the helix. We propose that ATP binding propagates growth at one end of the helix while hydrolysis promotes disassembly at the other end, so that Vps4 ‘walks’ along ESCRT-III until it encounters the ordered N-terminal domain to destabilize the ESCRT-III lattice. This model may be generally applicable to other protein-translocating AAA ATPases. DOI: http://dx.doi.org/10.7554/eLife.24487.001 PMID:28379137

  4. Inflammatory cell phenotypes in AAAs; their role and potential as targets for therapy

    PubMed Central

    Dale, Matthew A; Ruhlman, Melissa K.; Baxter, B. Timothy

    2015-01-01

    Abdominal aortic aneurysms are characterized by chronic inflammatory cell infiltration. AAA is typically an asymptomatic disease and caused approximately 15,000 deaths annually in the U.S. Previous studies have examined both human and murine aortic tissue for the presence of various inflammatory cell types. Studies show that in both human and experimental AAAs, prominent inflammatory cell infiltration, such as CD4+ T cells and macrophages, occurs in the damaged aortic wall. These cells have the ability to undergo phenotypic modulation based on microenvironmental cues, potentially influencing disease progression. Pro-inflammatory CD4+ T cells and classically activated macrophages dominate the landscape of aortic infiltrates. The skew to pro-inflammatory phenotypes alters disease progression and plays a role in causing chronic inflammation. The local cytokine production and presence of inflammatory mediators, such as extracellular matrix breakdown products, influence the uneven balance of the inflammatory infiltrate phenotypes. Understanding and developing new strategies that target the pro-inflammatory phenotype could provide useful therapeutic targets for a disease with no current pharmacological intervention. PMID:26044582

  5. Processes Affecting Tropospheric Ozone over Africa

    NASA Technical Reports Server (NTRS)

    Diab, Roseanne D.; Thompson, Anne M.

    2004-01-01

    This is a Workshop Report prepared for Eos, the weekly AGU magazine, The workshop took place between 26-28 January 2004 at the University of KwaZulu-Natal in Durban, South Africa and was attended by 26 participants (http//www.geography.und.ac.za). Considerable progress has been made in ozone observations except for northern Africa (large data gaps) and west Africa (to be covered by the French-sponsored AMMA program). The present-day ozone findings were evaluated and reviewed by speakers using Aircraft data (MOZAIC program), NASA satellites (MOPITT, TRMM, TOMS) and ozone soundings (SHADOZ). Besides some ozone gaps, there are challenges posed by the need to assess the relative strengths of photochemical and dynamic influences on the tropospheric ozone budget. Biogenic, biofuels, biomass burning sources of ozone precursors remain highly uncertain. Recent findings (by NASA's Chatfield and Thompson, using satellite and sounding data) show significant impact of Indian Ocean pollution on African ozone. European research on pollutants over the Mediterranean and the middle east, that suggests that ozone may be exported to Africa from these areas, also needs to be considered.

  6. Point Mutations in the Stem Region and the Fourth AAA Domain of Cytoplasmic Dynein Heavy Chain Partially Suppress the Phenotype of NUDF/LIS1 Loss in Aspergillus nidulans

    PubMed Central

    Zhuang, Lei; Zhang, Jun; Xiang, Xin

    2007-01-01

    Cytoplasmic dynein performs multiple cellular tasks but its regulation remains unclear. The dynein heavy chain has a N-terminal stem that binds to other subunits and a C-terminal motor unit that contains six AAA (ATPase associated with cellular activities) domains and a microtubule-binding site located between AAA4 and AAA5. In Aspergillus nidulans, NUDF (a LIS1 homolog) functions in the dynein pathway, and two nudF6 partial suppressors were mapped to the nudA dynein heavy chain locus. Here we identified these two mutations. The nudAL1098F mutation resides in the stem region, and nudAR3086C is in the end of AAA4. These mutations partially suppress the phenotype of nudF deletion but do not suppress the phenotype exhibited by mutants of dynein intermediate chain and Arp1. Surprisingly, the stronger ΔnudF suppressor, nudAR3086C, causes an obvious decrease in the basal level of dynein's ATPase activity and an increase in dynein's distribution along microtubules. Thus, suppression of the ΔnudF phenotype may result from mechanisms other than simply the enhancement of dynein's ATPase activity. The fact that a mutation in the end of AAA4 negatively regulates dynein's ATPase activity but partially compensates for NUDF loss indicates the importance of the AAA4 domain in dynein regulation in vivo. PMID:17237507

  7. Out of southern East Asia: the natural history of domestic dogs across the world

    PubMed Central

    Wang, Guo-Dong; Zhai, Weiwei; Yang, He-Chuan; Wang, Lu; Zhong, Li; Liu, Yan-Hu; Fan, Ruo-Xi; Yin, Ting-Ting; Zhu, Chun-Ling; Poyarkov, Andrei D; Irwin, David M; Hytönen, Marjo K; Lohi, Hannes; Wu, Chung-I; Savolainen, Peter; Zhang, Ya-Ping

    2016-01-01

    The origin and evolution of the domestic dog remains a controversial question for the scientific community, with basic aspects such as the place and date of origin, and the number of times dogs were domesticated, open to dispute. Using whole genome sequences from a total of 58 canids (12 gray wolves, 27 primitive dogs from Asia and Africa, and a collection of 19 diverse breeds from across the world), we find that dogs from southern East Asia have significantly higher genetic diversity compared to other populations, and are the most basal group relating to gray wolves, indicating an ancient origin of domestic dogs in southern East Asia 33 000 years ago. Around 15 000 years ago, a subset of ancestral dogs started migrating to the Middle East, Africa and Europe, arriving in Europe at about 10 000 years ago. One of the out of Asia lineages also migrated back to the east, creating a series of admixed populations with the endemic Asian lineages in northern China before migrating to the New World. For the first time, our study unravels an extraordinary journey that the domestic dog has traveled on earth. PMID:26667385

  8. Out of southern East Asia: the natural history of domestic dogs across the world.

    PubMed

    Wang, Guo-Dong; Zhai, Weiwei; Yang, He-Chuan; Wang, Lu; Zhong, Li; Liu, Yan-Hu; Fan, Ruo-Xi; Yin, Ting-Ting; Zhu, Chun-Ling; Poyarkov, Andrei D; Irwin, David M; Hytönen, Marjo K; Lohi, Hannes; Wu, Chung-I; Savolainen, Peter; Zhang, Ya-Ping

    2016-01-01

    The origin and evolution of the domestic dog remains a controversial question for the scientific community, with basic aspects such as the place and date of origin, and the number of times dogs were domesticated, open to dispute. Using whole genome sequences from a total of 58 canids (12 gray wolves, 27 primitive dogs from Asia and Africa, and a collection of 19 diverse breeds from across the world), we find that dogs from southern East Asia have significantly higher genetic diversity compared to other populations, and are the most basal group relating to gray wolves, indicating an ancient origin of domestic dogs in southern East Asia 33 000 years ago. Around 15 000 years ago, a subset of ancestral dogs started migrating to the Middle East, Africa and Europe, arriving in Europe at about 10 000 years ago. One of the out of Asia lineages also migrated back to the east, creating a series of admixed populations with the endemic Asian lineages in northern China before migrating to the New World. For the first time, our study unravels an extraordinary journey that the domestic dog has traveled on earth.

  9. Vitamin D status in recently arrived immigrants from Africa and Asia: a cross-sectional study from Norway of children, adolescents and adults

    PubMed Central

    Eggemoen, Åse R; Knutsen, Kirsten V; Dalen, Ingvild; Jenum, Anne K

    2013-01-01

    Objectives To estimate the prevalence of vitamin D deficiency (25(OH)D) <50 nmol/L among recently arrived immigrants from Africa and Asia in Oslo, and to explore 25(OH)D levels according to origin, gender and age. Design A cross-sectional study. Setting Primary healthcare unit in Oslo, Norway, offering family immigrants, asylum seekers, United Nations (UN) refugees or individuals granted asylum a free medical examination on arrival. Participants All individuals from African and Asian countries (n=591) referred to the Centre of Migrant Health, Health Agency, Oslo, Norway in 2010, estimated to cover 60% of the targeted population. Results 25(OH)D <50 nmol/L was very prevalent in immigrants from the Middle East (81% (95% CI 75.4% to 86.6%)), South Sahara Africa (73% (CI 67.5% to 78.5%)) and South Asia (75% (CI 64.0% to 86.0%)), in contrast to East Asians (24% (CI 12.6% to 35.4%)), p<0.001 for differences. The prevalence of 25(OH)D<25 nmol/L was lower but followed the same pattern (Middle East: 38% (CI 31.1% to 45.0%), South Sahara Africa: 24% (CI 18.7% to 29.3%) and South Asia: 35% (CI 22.9% to 47.1%), although it was not observed in East Asians (p<0.001 for differences)). The ethnic differences persisted after adjusting for the duration of residence, seasonality and residence status in multiple linear regression analyses. Female adolescents from South Asia, the Middle East and South Sahara Africa had the lowest levels of 25(OH)D. Further, country-specific median levels of 25(OH)D were low (24–38 nmol/L) among groups from Somalia, Eritrea, Afghanistan and Iraq, the countries with the largest number of immigrants in our study. Conclusions The majority of recently settled immigrant groups from the Middle East, South Asia and Africa had 25(OH)D <50 nmol/L, in contrast to East Asians. Female adolescents from these regions had the lowest levels of 25(OH)D. PMID:24157818

  10. IDEAL Symposium on the East African Lakes

    NASA Astrophysics Data System (ADS)

    Johnson, T. C.; Kelts, K.; Lehman, J. T.; Wuest, A.

    A vast array of interdisciplinary problems presented by the African Great Lakes were highlighted at the International Symposium on the Limnology, Climatology and Paleoclimatology of the East African Lakes, organized by the International Decade for the East African Lakes (IDEAL) February 17-21 in Jinja, Uganda. Approximately 125 scientists attended from North America, Europe, Africa, and New Zealand. Jinja is located on the northern shore of Lake Victoria at the head-waters of the Nile and is the site of the host institution for the symposium, the Uganda Freshwater Fisheries Research Organization (UFFRO). The conveners of the symposium were Tom Johnson of Duke University, George Kitaka of UNESCO-ROSTA, and Eric Odada of the University of Nairobi.

  11. Ecology and distribution of Bulinus truncatus in the Middle East

    PubMed Central

    Watson, J. M.

    1958-01-01

    The author gives a comprehensive account of the present status of knowledge regarding the ecology and distribution of Bulinus truncatus, the intermediate host of Schistosoma haematobium in the Middle East and North Africa. He discusses in detail the types of habitat favoured by this snail, its life-cycle and seasonal variations in its populations, the effect of ecological factors on its distribution and occurrence, and the relationship between its control and its bionomics, stressing the many aspects of these subjects that require further investigation and suggesting lines for future research. In addition, the author outlines briefly the effect of some human activities (for example, extension of irrigation and agriculture), in their relationship to the snail host, on the incidence of bilharziasis haematobia in the Middle East and Africa. He concludes the paper with a summary of the three basic needs in respect of bilharziasis control: ecological research; prevention of pollution of waters with human excrement; and avoidance of human contact with infective water. PMID:13573115

  12. PspF-binding domain PspA1-144 and the PspA·F complex: New insights into the coiled-coil-dependent regulation of AAA+ proteins.

    PubMed

    Osadnik, Hendrik; Schöpfel, Michael; Heidrich, Eyleen; Mehner, Denise; Lilie, Hauke; Parthier, Christoph; Risselada, H Jelger; Grubmüller, Helmut; Stubbs, Milton T; Brüser, Thomas

    2015-11-01

    Phage shock protein A (PspA) belongs to the highy conserved PspA/IM30 family and is a key component of the stress inducible Psp system in Escherichia coli. One of its central roles is the regulatory interaction with the transcriptional activator of this system, the σ(54) enhancer-binding protein PspF, a member of the AAA+ protein family. The PspA/F regulatory system has been intensively studied and serves as a paradigm for AAA+ enzyme regulation by trans-acting factors. However, the molecular mechanism of how exactly PspA controls the activity of PspF and hence σ(54) -dependent expression of the psp genes is still unclear. To approach this question, we identified the minimal PspF-interacting domain of PspA, solved its structure, determined its affinity to PspF and the dissociation kinetics, identified residues that are potentially important for PspF regulation and analyzed effects of their mutation on PspF in vivo and in vitro. Our data indicate that several characteristics of AAA+ regulation in the PspA·F complex resemble those of the AAA+ unfoldase ClpB, with both proteins being regulated by a structurally highly conserved coiled-coil domain. The convergent evolution of both regulatory domains points to a general mechanism to control AAA+ activity for divergent physiologic tasks via coiled-coil domains. © 2015 John Wiley & Sons Ltd.

  13. Lion (Panthera leo) populations are declining rapidly across Africa, except in intensively managed areas.

    PubMed

    Bauer, Hans; Chapron, Guillaume; Nowell, Kristin; Henschel, Philipp; Funston, Paul; Hunter, Luke T B; Macdonald, David W; Packer, Craig

    2015-12-01

    We compiled all credible repeated lion surveys and present time series data for 47 lion (Panthera leo) populations. We used a Bayesian state space model to estimate growth rate-λ for each population and summed these into three regional sets to provide conservation-relevant estimates of trends since 1990. We found a striking geographical pattern: African lion populations are declining everywhere, except in four southern countries (Botswana, Namibia, South Africa, and Zimbabwe). Population models indicate a 67% chance that lions in West and Central Africa decline by one-half, while estimating a 37% chance that lions in East Africa also decline by one-half over two decades. We recommend separate regional assessments of the lion in the World Conservation Union (IUCN) Red List of Threatened Species: already recognized as critically endangered in West Africa, our analysis supports listing as regionally endangered in Central and East Africa and least concern in southern Africa. Almost all lion populations that historically exceeded ∼ 500 individuals are declining, but lion conservation is successful in southern Africa, in part because of the proliferation of reintroduced lions in small, fenced, intensively managed, and funded reserves. If management budgets for wild lands cannot keep pace with mounting levels of threat, the species may rely increasingly on these southern African areas and may no longer be a flagship species of the once vast natural ecosystems across the rest of the continent.

  14. New interpretation of the so-called Nubian strata in northeast Africa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Klitzsch, E.H.; Squyres, C.H.

    1988-08-01

    Stratigraphical interpretation of the so-called Nubian Sandstone of Egypt and northern Sudan have led to new ideas on the structural and paleogeographical development of northeast Africa. The strata formerly comprised under the term Nubian Sandstone include sediments from Cambrian to Paleocene age. Based on field work and paleontological investigations during the last 10 years, these strata can be subdivided into three major cycles, each characterizing a certain structural situation of northeast Africa. The first or Paleozoic cycle comprises strata of Cambrian to Early Carboniferous age. These strata were deposited during a period of generally northern dip of northeast Africa; continentalmore » sediments transported northward interfinger with marine strata resulting from southward transgressions. Sediments of the second cycle were deposited during and after Gondwana and northern continents collided, which caused updoming of large areas of Egypt and bordering areas to the west and east. As a result, most of Egypt became subject to erosion; transgressions remained near the present northern edge of the continent, and purely continental deposition took place in northern Sudan and bordering areas in Chad and Libya. The resulting strata are similar to the Karroo of East Africa. Strata of the third cycle were deposited after Pangea began to disintegrate. Northeast Africa now had a generally northern dip again, and consequently deposition was controlled - as during the first cycle - by northward drainage and southward transgressions. This last cycle began during Late Jurassic time.« less

  15. Comparison of Acuros (AXB) and Anisotropic Analytical Algorithm (AAA) for dose calculation in treatment of oesophageal cancer: effects on modelling tumour control probability.

    PubMed

    Padmanaban, Sriram; Warren, Samantha; Walsh, Anthony; Partridge, Mike; Hawkins, Maria A

    2014-12-23

    To investigate systematic changes in dose arising when treatment plans optimised using the Anisotropic Analytical Algorithm (AAA) are recalculated using Acuros XB (AXB) in patients treated with definitive chemoradiotherapy (dCRT) for locally advanced oesophageal cancers. We have compared treatment plans created using AAA with those recalculated using AXB. Although the Anisotropic Analytical Algorithm (AAA) is currently more widely used in clinical routine, Acuros XB (AXB) has been shown to more accurately calculate the dose distribution, particularly in heterogeneous regions. Studies to predict clinical outcome should be based on modelling the dose delivered to the patient as accurately as possible. CT datasets from ten patients were selected for this retrospective study. VMAT (Volumetric modulated arc therapy) plans with 2 arcs, collimator rotation ± 5-10° and dose prescription 50 Gy / 25 fractions were created using Varian Eclipse (v10.0). The initial dose calculation was performed with AAA, and AXB plans were created by re-calculating the dose distribution using the same number of monitor units (MU) and multileaf collimator (MLC) files as the original plan. The difference in calculated dose to organs at risk (OAR) was compared using dose-volume histogram (DVH) statistics and p values were calculated using the Wilcoxon signed rank test. The potential clinical effect of dosimetric differences in the gross tumour volume (GTV) was evaluated using three different TCP models from the literature. PTV Median dose was apparently 0.9 Gy lower (range: 0.5 Gy - 1.3 Gy; p < 0.05) for VMAT AAA plans re-calculated with AXB and GTV mean dose was reduced by on average 1.0 Gy (0.3 Gy -1.5 Gy; p < 0.05). An apparent difference in TCP of between 1.2% and 3.1% was found depending on the choice of TCP model. OAR mean dose was lower in the AXB recalculated plan than the AAA plan (on average, dose reduction: lung 1.7%, heart 2.4%). Similar trends were seen for CRT plans

  16. The strange case of East African annual fishes: aridification correlates with diversification for a savannah aquatic group?

    PubMed

    Dorn, Alexander; Musilová, Zuzana; Platzer, Matthias; Reichwald, Kathrin; Cellerino, Alessandro

    2014-10-14

    Annual Nothobranchius fishes are distributed in East and Southern Africa and inhabit ephemeral pools filled during the monsoon season. Nothobranchius show extreme life-history adaptations: embryos survive by entering diapause and they are the vertebrates with the fastest maturation and the shortest lifespan. The distribution of Nothobranchius overlaps with the East Africa Rift System. The geological and paleoclimatic history of this region is known in detail: in particular, aridification of East Africa and expansion of grassland habitats started 8 Mya and three humid periods between 3 and 1 Mya are superimposed on the longer-term aridification. These climatic oscillations are thought to have shaped evolution of savannah African mammals. We reconstructed the phylogeny of Nothobranchius and dated the different stages of diversification in relation to these paleoclimatic events. We sequenced one mitochondrial locus and five nuclear loci in 63 specimens and obtained a robust phylogeny. Nothobranchius can be divided in four geographically separated clades whose boundaries largely correspond to the East Africa Rift system. Statistical analysis of dispersal and vicariance identifies a Nilo-Sudan origin with southwards dispersion and confirmed that these four clades are the result of vicariance events In the absence of fossil Nothobranchius, molecular clock was calibrated using more distant outgroups (secondary calibration). This method estimates the age of the Nothobranchius genus to be 8.3 (6.0 - 10.7) My and the separation of the four clades 4.8 (2.7-7.0) Mya. Diversification within the clades was estimated to have started ~3 Mya and most species pairs were estimated to have an age of 0.5-1 My. The mechanism of Nothobranchius diversification was allopatric and driven by geographic isolation. We propose a scenario where diversification of Nothobranchius started in rough coincidence with aridification of East Africa, establishment of grassland habitats and the appearance

  17. Computers, the Internet and medical education in Africa.

    PubMed

    Williams, Christopher D; Pitchforth, Emma L; O'Callaghan, Christopher

    2010-05-01

    OBJECTIVES This study aimed to explore the use of information and communications technology (ICT) in undergraduate medical education in developing countries. METHODS Educators (deans and heads of medical education) in English-speaking countries across Africa were sent a questionnaire to establish the current state of ICT at medical schools. Non-respondents were contacted firstly by e-mail, subsequently by two postal mailings at 3-month intervals, and finally by telephone. Main outcome measures included cross-sectional data about the availability of computers, specifications, Internet connection speeds, use of ICT by students, and teaching of ICT and computerised research skills, presented by country or region. RESULTS The mean computer : student ratio was 0.123. Internet speeds were rated as 'slow' or 'very slow' on a 5-point Likert scale by 25.0% of respondents overall, but by 58.3% in East Africa and 33.3% in West Africa (including Cameroon). Mean estimates showed that campus computers more commonly supported CD-ROM (91.4%) and sound (87.3%) than DVD-ROM (48.1%) and Internet (72.5%). The teaching of ICT and computerised research skills, and the use of computers by medical students for research, assignments and personal projects were common. CONCLUSIONS It is clear that ICT infrastructure in Africa lags behind that in other regions. Poor download speeds limit the potential of Internet resources (especially videos, sound and other large downloads) to benefit students, particularly in East and West (including Cameroon) Africa. CD-ROM capability is more widely available, but has not yet gained momentum as a means of distributing materials. Despite infrastructure limitations, ICT is already being used and there is enthusiasm for developing this further. Priority should be given to developing partnerships to improve ICT infrastructure and maximise the potential of existing technology.

  18. Existing capacity to manage pharmaceuticals and related commodities in East Africa: an assessment with specific reference to antiretroviral therapy

    PubMed Central

    Waako, Paul J; Odoi-adome, Richard; Obua, Celestino; Owino, Erisa; Tumwikirize, Winnie; Ogwal-okeng, Jasper; Anokbonggo, Willy W; Matowe, Lloyd; Aupont, Onesky

    2009-01-01

    managing medicines and related commodities in East Africa. There is an urgent need for training in aspects of pharmaceutical management to different categories of health workers. Skills building activities that do not take healthcare workers from their places of work are preferred. PMID:19272134

  19. Gender attitudes and fertility aspirations among young men in five high fertility East African countries.

    PubMed

    Snow, Rachel C; Winter, Rebecca A; Harlow, Siobán D

    2013-03-01

    The relationship between women's attitudes toward gender equality and their fertility aspirations has been researched extensively, but few studies have explored the same associations among men. Using recent Demographic and Health Survey data from five high fertility East African countries, we examine the association between young men's gender attitudes and their ideal family size. Whereas several DHS gender attitude responses were associated with fertility aspirations in select countries, men's greater tolerance of wife beating was consistently associated with higher fertility aspirations across all countries, independent of education, income, or religion. Our findings highlight the overlapping values of male authority within marriage and aspirations for large families among young adult males in East Africa. Total lifetime fertility in East Africa remains among the highest worldwide: thus, governments in the region seeking to reduce fertility may need to explicitly scrutinize and address the reproduction of prevailing masculine values. © 2013 The Population Council, Inc.

  20. The East African monsoon system: Seasonal climatologies and recent variations: Chapter 10

    USGS Publications Warehouse

    Funk, Christopher C.; Hoell, Andrew; Shukla, Shraddhanand; Husak, Gregory J.; Michaelsen, J.

    2016-01-01

    This chapter briefly reviews the complex climatological cycle of the East African monsoon system, paying special attention to its connection to the larger Indo-Pacific-Asian monsoon cycle. We examine the seasonal monsoon cycle, and briefly explore recent circulation changes. The spatial footprint of our analysis corresponds with the “Greater Horn of Africa” (GHA) region, extending from Tanzania in the south to Yemen and Sudan in the north. During boreal winter, when northeast trade winds flow across the northwest Indian Ocean and the equatorial moisture transports over the Indian Ocean exhibit strong westerly mean flows over the equatorial Indian Ocean, East African precipitation is limited to a few highland areas. As the Indian monsoon circulation transitions during boreal spring, the trade winds over the northwest Indian Ocean reverse, and East African moisture convergence supports the “long” rains. In boreal summer, the southwesterly Somali Jet intensifies over eastern Africa. Subsidence forms along the westward flank of this jet, shutting down precipitation over eastern portions of East Africa. In boreal fall, the Jet subsides, but easterly moisture transports support rainfall in limited regions of the eastern Horn of Africa. We use regressions with the trend mode of global sea surface temperatures to explore potential changes in the seasonal monsoon circulations. Significant reductions in total precipitable water are indicated in Kenya, Tanzania, Rwanda, Burundi, Uganda, Ethiopia, South Sudan, Sudan, and Yemen, with moisture transports broadly responding in ways that reinforce the climatological moisture transports over the Indian Ocean. Over Kenya, southern Ethiopia and Somalia, regressions with velocity potential indicate increased convergence aloft. Near the surface, this convergence appears to manifest as a surface high pressure system that modifies moisture transports in these countries as well as Uganda, Tanzania, Rwanda, and Burundi. An analysis

  1. Mediterranean extension and the Africa-Eurasia collision

    NASA Astrophysics Data System (ADS)

    Jolivet, Laurent; Faccenna, Claudio

    2000-12-01

    A number of tectonic events occurred contemporaneously in the Mediterranean region and the Middle East 30-25 Myr ago. These events are contemporaneous to or immediately followed a strong reduction of the northward absolute motion of Africa. Geological observations in the Neogene extensional basins of the Mediterranean region reveal that extension started synchronously from west to east 30-25 Myr ago. In the western Mediterranean it started in the Gulf of Lion, Valencia trough, and Alboran Sea as well as between the Maures massif and Corsica between 33 and 27 Ma ago. It then propagated eastward and southward to form to Liguro-Provençal basin and the Tyrrhenian Sea. In the eastern Mediterranean, extension started in the Aegean Sea before the deposition of marine sediments onto the collapsed Hellenides in the Aquitanian and before the cooling of high-temperature metamorphic core complexes between 20 and 25 Ma. Foundering of the inner zones of the Carpathians and extension in the Panonnian basin also started in the late Oligocene-early Miocene. The body of the Afro-Arabian plate first collided with Eurasia in the eastern Mediterranean region progressively from the Eocene to the Oligocene. Extensional tectonics was first recorded in the Gulf of Aden, Afar triple junction, and Red Sea region also in the Oligocene. A general magmatic surge occurred above all African hot spots, especially the Afar one. We explore the possibility that these drastic changes in the stress regime of the Mediterranean region and Middle East and the contemporaneous volcanic event were triggerred by the Africa/Arabia-Eurasia collision, which slowed down the motion of Africa. The present-day Mediterranean Sea was then locked between two collision zones, and the velocity of retreat of the African slab increased and became larger than the velocity of convergence leading to backarc extension. East of the Caucasus and northern Zagros collision zone the Afro-Arabian plate was still pulled by the slab

  2. Trends of human immunodeficiency virus type-1 infection in female prostitutes and males diagnosed with a sexually transmitted disease in Djibouti, east Africa.

    PubMed

    Rodier, G R; Couzineau, B; Gray, G C; Omar, C S; Fox, E; Bouloumie, J; Watts, D

    1993-05-01

    A cross-sectional serosurvey for human immunodeficiency virus type 1 (HIV-1) was conducted during the first quarter of 1991 among high risk groups in Djibouti, East Africa, and compared with previous surveys in 1987, 1988, and 1990. The survey demonstrated evidence of HIV-1 infection in 36.0% (n = 292) of street prostitutes, 15.3% (n = 360) of prostitutes working as bar hostesses, and 10.4% (n = 193) of males diagnosed with a sexually transmitted disease. By multivariate modeling, HIV-1 seropositivity in prostitutes was associated with Ethiopian nationality, working as a street prostitute, and residing in Djibouti for two years or less. We suggest that prostitution, particularly street prostitution, is a major route of HIV-1 transmission in Djibouti.

  3. Preferences of AAA/AAG codon recognition by modified nucleosides, τm5s2U34 and t6A37 present in tRNALys.

    PubMed

    Sonawane, Kailas D; Kamble, Asmita S; Fandilolu, Prayagraj M

    2017-12-27

    Deficiency of 5-taurinomethyl-2-thiouridine, τm 5 s 2 U at the 34th 'wobble' position in tRNA Lys causes MERRF (Myoclonic Epilepsy with Ragged Red Fibers), a neuromuscular disease. This modified nucleoside of mt tRNA Lys , recognizes AAA/AAG codons during protein biosynthesis process. Its preference to identify cognate codons has not been studied at the atomic level. Hence, multiple MD simulations of various molecular models of anticodon stem loop (ASL) of mt tRNA Lys in presence and absence of τm 5 s 2 U 34 and N 6 -threonylcarbamoyl adenosine (t 6 A 37 ) along with AAA and AAG codons have been accomplished. Additional four MD simulations of multiple ASL mt tRNA Lys models in the context of ribosomal A-site residues have also been performed to investigate the role of A-site in recognition of AAA/AAG codons. MD simulation results show that, ASL models in presence of τm 5 s 2 U 34 and t 6 A 37 with codons AAA/AAG are more stable than the ASL lacking these modified bases. MD trajectories suggest that τm 5 s 2 U recognizes the codons initially by 'wobble' hydrogen bonding interactions, and then tRNA Lys might leave the explicit codon by a novel 'single' hydrogen bonding interaction in order to run the protein biosynthesis process smoothly. We propose this model as the 'Foot-Step Model' for codon recognition, in which the single hydrogen bond plays a crucial role. MD simulation results suggest that, tRNA Lys with τm 5 s 2 U and t 6 A recognizes AAA codon more preferably than AAG. Thus, these results reveal the consequences of τm 5 s 2 U and t 6 A in recognition of AAA/AAG codons in mitochondrial disease, MERRF.

  4. East-looking view across Atlantic waters during MA-9 22 orbit

    NASA Image and Video Library

    1963-05-16

    S63-06434 (15-16 May 1963) --- East looking view across Atlantic waters toward Africa, showing Mauritania and Spanish Sahara photographed from the Mercury-Atlas 9 (MA-9) capsule by astronaut L. Gordon Cooper Jr., during his 22-orbit MA-9 spaceflight. Photo credit: NASA

  5. Southern Africa as seen from STS-61 Shuttle Endeavour

    NASA Image and Video Library

    1993-12-09

    STS061-106-091 (December 1993) --- The entire southern tip of Africa is shown in this high altitude 50mm photograph. The center of the photograph is at approximately 28.0 degrees south and 24.0 degrees east Cape Columbine is at the upper right with Durban at the lower center. The Orange River is at the upper center of the frame. Cape Agulas is the southernmost part of the African continent and is visible toward the upper right corner with the great bays of South Africa trending toward the bottom right. Continuing clockwise along the coast, Durban projects out into the Indian Ocean. The oceanic clouds on the right side of the photograph probably depict a current boundary. The Drakensberg Range on the east, the great Karoo Range to the south and the Karas Mountains on the west surround the drier central plateau. The southern Kalahari Desert is at the upper left of the photograph.

  6. Africa's Megafans and Their Tectonic Setting

    NASA Technical Reports Server (NTRS)

    Wilkinson, M. J.; Burke, K.

    2016-01-01

    Megafans are a really extensive continental sediment bodies, fluvially derived, and fan-shaped in planform. Only those >80 km long were included in this study. Africa's megafans were mapped for purposes of both comprehensive geomorphic description and as a method of mapping by remote sensing large probable fluvial sediment bodies (we exclude sediment bodies deposited in well defined, modern floodplains and coastal deltas). Our criteria included a length dimension of >80 km and maximum width >40 km, partial cone morphology, and a radial drainage pattern. Visible and especially IR imagery were used to identify the features, combined with topographic SRTM data. We identified 99 megafans most of which are unstudied thus far. Their feeder rivers responsible for depositing megafan sediments rise on, and are consequent drainages oriented down the slopes of the swells that have dominated African landscapes since approximately 34 Ma (the high points in Africa's so-called basin-and-swell topography [1]). Most megafans (66%) have developed along these consequent rivers relatively near the swell cores, oriented radially away from the swells. The vast basins between the swells provide accommodation for megafan sediment wedges. Although clearly visible remotely, most megafans are inactive as a result of incision by the feeder river (which then no longer operates on the fan surface). Two tectonic settings control the location of Africa's megafans, 66% on swell flanks, and 33% related to rifts. (i) Swell flanks Most megafans are apexed relatively near the core of the parent swell, and are often clustered in groups: e.g., six on the west and north flanks of the Hoggar Swell (Algeria), seven on the north and south flanks of the Tibesti Swell (Libya-Chad borderlands), twelve on the west flank of the Ethiopian Swell, four on the east flank of the East African Swell (Kenya), Africa's largest, and eight around Angola's Bié Swell (western Zambia, northern Namibia). A cluster of possible

  7. Africa-wide monitoring of small surface water bodies using multisource satellite data: a monitoring system for FEWS NET: chapter 5

    USGS Publications Warehouse

    Velpuri, Naga Manohar; Senay, Gabriel B.; Rowland, James; Verdin, James P.; Alemu, Henok; Melesse, Assefa M.; Abtew, Wossenu; Setegn, Shimelis G.

    2014-01-01

    Continental Africa has the highest volume of water stored in wetlands, large lakes, reservoirs, and rivers, yet it suffers from problems such as water availability and access. With climate change intensifying the hydrologic cycle and altering the distribution and frequency of rainfall, the problem of water availability and access will increase further. Famine Early Warning Systems Network (FEWS NET) funded by the United States Agency for International Development (USAID) has initiated a large-scale project to monitor small to medium surface water points in Africa. Under this project, multisource satellite data and hydrologic modeling techniques are integrated to monitor several hundreds of small to medium surface water points in Africa. This approach has been already tested to operationally monitor 41 water points in East Africa. The validation of modeled scaled depths with field-installed gauge data demonstrated the ability of the model to capture both the spatial patterns and seasonal variations. Modeled scaled estimates captured up to 60 % of the observed gauge variability with a mean root-mean-square error (RMSE) of 22 %. The data on relative water level, precipitation, and evapotranspiration (ETo) for water points in East and West Africa were modeled since 1998 and current information is being made available in near-real time. This chapter presents the approach, results from the East African study, and the first phase of expansion activities in the West Africa region. The water point monitoring network will be further expanded to cover much of sub-Saharan Africa. The goal of this study is to provide timely information on the water availability that would support already established FEWS NET activities in Africa. This chapter also presents the potential improvements in modeling approach to be implemented during future expansion in Africa.

  8. A synthesis of Plio-Pleistocene leaf wax biomarker records of hydrological variation in East Africa and their relationship with hominin evolution

    NASA Astrophysics Data System (ADS)

    Lupien, R.; Russell, J. M.; Campisano, C. J.; Feibel, C. S.; Deino, A. L.; Kingston, J.; Potts, R.; Cohen, A. S.

    2017-12-01

    Climate change is thought to play a critical role in human evolution. However, the mechanisms behind this relationship are difficult to test due to a lack of long, high-quality paleoclimate records from hominin fossil locales. We improve the understanding of this relationship by examining Plio-Pleistocene lake sediment cores from East Africa that were drilled by the Hominin Sites and Paleolakes Drilling Project, an international effort to study the environment in which our hominin ancestors evolved and dispersed. We have analyzed organic geochemical signals of climate from drill cores from Ethiopia and Kenya spanning the Pliocene to recent time (from north to south: paleolake Hadar, Lake Turkana, Lake Baringo, and paleolake Koora). Specifically, we analyzed the hydrogen isotopic composition of terrestrial leaf waxes, which records changes in regional atmospheric circulation and hydrology. We reconstructed quantitative records of rainfall amount at each of the study sites, which host sediment spanning different geologic times and regions. By compiling these records, we test hominin evolutionary hypotheses as well as crucial questions about climate trend and variability. We find that there is a gradual or step-wise enrichment in δDwax, signifying a trend from a wet to dry climate, from the Pliocene to the Pleistocene, perhaps implying an influence of global temperature, ice sheet extent, and/or atmospheric greenhouse gas concentrations on East African climate. However, the shift is small relative to the amplitude of orbital-scale isotopic variations. The records indicate a strong influence of eccentricity-modulated orbital precession, and imply that local insolation effects are the likely cause of East African precipitation. Several of the intervals of high isotopic variability coincide with key hominin fossil or technological transitions, suggesting that climate variability plays a key role in hominin evolution.

  9. Near East/South Asia Report, No. 2747

    DTIC Science & Technology

    1983-05-02

    South Asia Report Sub-Saharan Africa Report West Europe Report West Europe Report: Science and Technology Latin America Report Political and...Quality Eoidemiology China FBIS DAILY REPORT . Eastern Europe Soviet Union Western Europe South Asia Latin America Asia and Pacific Middle East and...at subsequent conferences in New York and also in Kuwait regarding, for example, Latin America or the Palestinian cause. There is no doubt that these

  10. Genetic diversity and connectivity in the East African giant mud crab Scylla serrata: Implications for fisheries management.

    PubMed

    Rumisha, Cyrus; Huyghe, Filip; Rapanoel, Diary; Mascaux, Nemo; Kochzius, Marc

    2017-01-01

    The giant mud crab Scylla serrata provides an important source of income and food to coastal communities in East Africa. However, increasing demand and exploitation due to the growing coastal population, export trade, and tourism industry are threatening the sustainability of the wild stock of this species. Because effective management requires a clear understanding of the connectivity among populations, this study was conducted to assess the genetic diversity and connectivity in the East African mangrove crab S. serrata. A section of 535 base pairs of the cytochrome oxidase subunit I (COI) gene and eight microsatellite loci were analysed from 230 tissue samples of giant mud crabs collected from Kenya, Tanzania, Mozambique, Madagascar, and South Africa. Microsatellite genetic diversity (He) ranged between 0.56 and 0.6. The COI sequences showed 57 different haplotypes associated with low nucleotide diversity (current nucleotide diversity = 0.29%). In addition, the current nucleotide diversity was lower than the historical nucleotide diversity, indicating overexploitation or historical bottlenecks in the recent history of the studied population. Considering that the coastal population is growing rapidly, East African countries should promote sustainable fishing practices and sustainable use of mangrove resources to protect mud crabs and other marine fauna from the increasing pressure of exploitation. While microsatellite loci did not show significant genetic differentiation (p > 0.05), COI sequences revealed significant genetic divergence between sites on the East coast of Madagascar (ECM) and sites on the West coast of Madagascar, mainland East Africa, as well as the Seychelles. Since East African countries agreed to achieve the Convention on Biological Diversity (CBD) target to protect over 10% of their marine areas by 2020, the observed pattern of connectivity and the measured genetic diversity can serve to provide useful information for designing networks of

  11. Addressing the Challenges of Collective Security in West Africa: In View of Recent Conflicts

    DTIC Science & Technology

    2017-06-09

    Distribution is Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Understanding that achieving peace and security is a primary condition for an economic ...condition for an economic integration, ECOWAS has developped various approachs in resolving crises and overcoming threats within West Africa. Using...System CS Collective Security CSO Civil Society Organizations CSS Center for Security Studies EAC East Africa Community ECCAS Economic Community of

  12. Model-based impact and cost-effectiveness of cervical cancer prevention in the Extended Middle East and North Africa (EMENA).

    PubMed

    Kim, Jane J; Sharma, Monisha; O'Shea, Meredith; Sweet, Steven; Diaz, Mireia; Sancho-Garnier, Hélène; Seoud, Muhieddine

    2013-12-30

    To date, no studies have evaluated the cost-effectiveness of human papillomavirus (HPV) vaccination in countries in the Extended Middle East and North Africa (EMENA) region. We synthesized population and epidemiologic data for 20 EMENA countries using a model-based approach to estimate averted cervical cancer cases and deaths, disability-adjusted life years (DALYs) and cost-effectiveness ratios (I$ [international dollars] per DALY averted) associated with HPV vaccination of pre-adolescent girls. We utilized additional epidemiologic data from Algeria, Lebanon, and Turkey to evaluate select cervical cancer screening strategies either alone or in combination with vaccination. Results showed that pre-adolescent vaccination of five consecutive birth cohorts at 70% coverage has the potential to prevent over 180,000 cervical cancer cases. Cases averted varied by country, largely due to differences in cancer burden and population size; 69% of cases averted occurred in the three GAVI-eligible countries in EMENA. Despite the low cervical cancer incidence in EMENA, we found that HPV vaccination was cost-effective using a threshold of each country's gross domestic product per capita (a common metric for evaluating cost-effectiveness) in all but five countries at a cost per vaccinated girl of I$25 ($5 per dose). However, cost-effectiveness diminished with increasing vaccine cost; at a cost of I$200 per vaccinated girl, HPV vaccination was cost-effective in only five countries. When the cost per vaccinated girl exceeded I$50 in Lebanon and Turkey and I$150 in Algeria, screening alone was most attractive. We identified opportunities to improve upon current national screening guidelines, involving less frequent screening every 3-5 years. While pre-adolescent HPV vaccination promises to be a cost-effective strategy in most EMENA countries at low costs, decision makers will need to consider many other factors, such as affordability, acceptability, feasibility, and competing health

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  14. Toward a Late Quaternary tephrostratigraphic framework for East African palaeoenvironmental records

    NASA Astrophysics Data System (ADS)

    Lane, Christine; Martin-Jones, Catherine; Johnson, Thomas; Lamb, Henry; Pearce, Nick; Scholz, Christopher; Smith, Victoria; Verschuren, Dirk

    2015-04-01

    Understanding the spatial and temporal variability of climate forcing and environmental response across a continent as climatically diverse as Africa relies upon comparison of data from widespread palaeoenvironmental archives. Accurate, precise and independent chronologies for such records are essential; however this remains a challenge in many environments, often preventing the valid comparison of detailed palaeo-proxy records. Many studies have now shown that volcanic ash (tephra) can be detected in terrestrial and marine sediments thousands of kilometres from their source, often as microscopic or "cryptic" layers. As well as offering opportunities for both direct (e.g. by 40Ar/39Ar methods) and indirect (e.g. by associated 14C dates) dating of the sediment sequence, tephra layers can provide stratigraphic tie-lines between archives, facilitating precise correlations at single moments in time. Furthermore, where two or more tephra layers are co-located in multiple records, rates of change can be compared within a period of equivalent duration, even in the absence of absolute age estimates. Investigations into the presence of visible and non-visible (crypto-) tephra layers within lacustrine palaeoenvironmental records of the last ~150 ka BP from across East Africa are revealing the potential for this approach to (i) correlate palaeoclimate archives from across and beyond tropical Africa within a regional tephrostratigraphic framework; (ii) provide age constraints for individual core chronologies, in particular beyond the limits of radiocarbon dating; and (iii) increase our knowledge of the history of Late Quaternary explosive volcanism in East Africa.

  15. Modelling the potential impacts of afforestation on extreme precipitation over West Africa

    NASA Astrophysics Data System (ADS)

    Odoulami, Romaric C.; Abiodun, Babatunde J.; Ajayi, Ayodele E.

    2018-05-01

    This study examines how afforestation in West Africa could influence extreme precipitation over the region, with a focus on widespread extreme rainfall events (WEREs) over the afforestation area. Two regional climate models (RegCM and WRF) were applied to simulate the present-day climate (1971-2000) and future climate (2031-2060, under IPCC RCP 4.5 emission scenario) with and without afforestation of the Savannah zone in West Africa. The models give a realistic simulation of precipitation indices and WEREs over the subcontinent. On average, the regional models projected future decreases in total annual wet day precipitation (PRCPTOT) and total annual daily precipitation greater than or equal to the 95th percentile of daily precipitation threshold (R95pTOT) and increases in maximum number of consecutive dry days (CDD) over Sahel. Over Savannah, the models projected decreases in PRCPTOT but increases in R95pTOT and CDD. Also, an increase in WEREs frequency is projected over west, central and east Savannah, except that RegCM simulated a decrease in WEREs over east Savannah. In general, afforestation increases PRCPTOT and R95pTOT but decreases CDD over the afforestation area. The forest-induced increases in PRCPTOT and decreases in CDD affect all ecological zones in West Africa. However, the simulations show that afforestation of Savannah also decreases R95pTOT over the Guinea Coast. It further increases WEREs over west and central Savannah and decreases them over east Savannah because of the local decrease in R95pTOT. Results of this study suggest that the future changes in characteristics of extreme precipitation events over West Africa are sensitive to the ongoing land modification.

  16. Diverse Perceptions of Cross-Racial Adoption in South Africa

    ERIC Educational Resources Information Center

    Tanga, Pius T.; Nyasha, Kausi

    2017-01-01

    Purpose: This study explored the perceptions of stakeholders regarding the practice of cross-racial adoption (CRA) in East London, South Africa. Method: A qualitative research design was used. Data were collected through individual interviews and focus group discussions from 23 participants. The data were analyzed qualitatively, using thematic…

  17. The Impact of the Colonial Legacy on Civil-Military Relations in Africa: Chad and the Sudan as Comparative Case Studies

    DTIC Science & Technology

    1997-12-01

    A. HISTORICAL BACKGROUND OF PRE-COLONIAL AFRICA Map 2: Culture areas of Africa.17 ~7~ /NORTH AFRICA^ EXTENSION OF / EAST AFRICAN ...The colonial military rule was experienced in the same ’undemocratic’ manner. Many scholars have neglected the background of the African political...34 discussed, among others, the Zulu Kingdom and the Afrikaner Trekker Republics in South Africa, and the West African Jihads. Ibid, pp. 24-30. 22

  18. Half-precessional climate forcing of Indian Ocean monsoon dynamics on the East African equator

    NASA Astrophysics Data System (ADS)

    Verschuren, D.; Sinninghe Damste, J. S.; Moernaut, J.; Kristen, I.; Fagot, M.; Blaauw, M.; Haug, G. H.; Project Members, C.

    2008-12-01

    The EuroCLIMATE project CHALLACEA produced a detailed multi-proxy reconstruction of the climate history of equatorial East Africa, based on the sediment record of Lake Challa, a 4.2 km2, 92-m deep crater lake on the lower East slope of Mt. Kilimanjaro (Kenya/Tanzania). Relatively stable sedimentation dynamics over the past 25,000 years resulted in a unique combination of high temporal resolution, excellent radiometric (210Pb, 14C) age control, and confidence that recording parameters of the climatic proxy signals extracted from the sediment have remained constant through time. The equatorial (3 deg. S) location of our study site in East Africa, where seasonal migration of convective activity spans the widest latitude range worldwide, produced unique information on how varying rainfall contributions from the northeasterly and southeasterly Indian Ocean monsoons shaped regional climate history. The Challa proxy records for temperature (TEX86) and moisture balance (reflection-seismic stratigraphy and the BIT index of soil bacterial input) uniquely weave together tropical climate variability at orbital and shorter time scales. The temporal pattern of reconstructed moisture balance bears the clear signature of half- precessional insolation forcing of Indian Ocean monsoon dynamics, modified by northern-latitude influence on moisture-balance variation at millennial and century time scales. During peak glacial time (but not immediately before) and the Younger Dryas, NH ice sheet influences overrode local insolation influence on monsoon intensity. After the NH ice sheets had melted and a relatively stable interglacial temperature regime developed, precession-driven summer insolation became the dominant determinant of regional moisture balance, with anti-phased patterns of Holocene hydrological change in the northern and southern (sub)tropics, and a uniquely hybrid pattern on the East African equator. In the last 2-3000 years a series of multi-century droughts with links to

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    USGS Publications Warehouse

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

    1988-01-01

    Stable isotopic analyses of Plio-Pleistocene and modern sediments in the fluvial-lacustrine system occupying the Turkana Basin, East Africa provide constraints on the paleoenvironmental and diagenetic histories of the Pliocene through the Recent sediments in the basin. The ??13C values for carbonates in lacustrine sediments range from -15 to +22??? relative to PDB, depending on the varying proportions of CO2 from the atmospheric reservoir and from various metabolic sources. The ??18O values of carbonates in lacustrine sediments indicate that the isotopic composition of paleolake water varied by over 10??? from the Pliocene to the present. The ??13C values for pedogenic carbonates record paleoccologic variations and suggest that C4 plants did not become well established in the preserved depositional parts of the basin until about 1.8 myr ago. The ??18O values pedogenic carbonates suggest a range of over 10??? for the isotopic composition of soil water during this interval. They also suggest a period of major climatic instability from about 3.4 to 3.1 myr and at about 1.8 myr. Together, the ??13C and ??18O values of pedogenic carbonates indicate that the present conditions are as arid and hot as any that had prevailed during deposition of these Plio-Pleistocene sediments. ?? 1988.