Regional economic integration in sub-Saharan Africa

NARCIS (Netherlands)

Konings, P.J.J.; Meilink, H.A.

1998-01-01

The issue of regional integration has acquired a new relevance and urgency in Africa due to wide-reaching national and global changes. African leaders' commitment to regional economic integration was clearly expressed during the June 1991 OAU summit meeting in Abuja, Nigeria. On that occasion, they

Regional responses: Africa

International Nuclear Information System (INIS)

Wereko-Brobby, C.Y.

1992-01-01

In this paper, the author presents the theory that for Africa to work towards reduction of global warming, it must first address its environmental problems; i.e. land use, deforestation, desertification, poverty and hunger. He argues that Africa should aim for growth in the productivity and quantity of energy use. The following suggestions were made: Africa must shift from low-quantity biomass to secondary sources in the short term; developed countries must avoid pushing experimental and frontier technologies on Africa; with financial and technical help, Africa could develop its largely untapped reserves of hydropower. Nuclear power should not be an option because reliable production is not possible at present

The all-year rainfall region of South Africa: Satellite rainfall-estimate perspective

CSIR Research Space (South Africa)

Engelbrecht, CJ

2012-09-01

Full Text Available Climate predictability and variability studies over South Africa typically focus on the summer rainfall region and to a lesser extent on the winter rainfall region. The all-year rainfall region of South Africa, a narrow strip located along the Cape...

FLOSSWorld Africa regional workshop agenda

CSIR Research Space (South Africa)

Tucker, KC

2006-02-01

Full Text Available their activities – does this differ from country to country, and does it differ from Europe? Comparisons with previous studies such as FLOSS, FLOSS-US, FLOSS-Japan. • How are local FLOSS activities in target countries related with other institutions (public... administration, companies, schools, universities, etc.)? • What is the present and possible future impact of FLOSS activities on the labour market, education, governance, and the economy of developing countries? FLOSSWorld Africa Regional Agenda 4 FLOSSWorld...

Human vagus nerve branching in the cervical region.

Directory of Open Access Journals (Sweden)

Niels Hammer

Full Text Available Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation.Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections.Cervical vagus nerve branching was observed in 29% of all cases (26% unilaterally, 3% bilaterally and proven histologically in all cases. Right-sided branching (22% was more common than left-sided branching (12% and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79 mm vs. 3.78 mm and cross-sections (7.24 mm2 vs. 5.28 mm2.Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation.

Proposals for regional cooperation in Africa

International Nuclear Information System (INIS)

King'oriah, G.

1999-01-01

The CTBT verification regime employs four monitoring technologies, namely seismic, hydro acoustic, infrasound and radionuclides measurements. Although the purpose of the CTBTO is to assist Member states to monitor treaty compliance, these technologies can be useful tools for use in generating information for peaceful purposes. A thorough understanding of the range of data that can be obtained using the mentioned technologies is essential to derive the maximum benefits from their application. This presentation deals with the strategies for promoting cooperation among State Signatories, regional and international partners as well as the potential role of the CTBTO in regional cooperation in Africa

Optimal Operation System of the Integrated District Heating System with Multiple Regional Branches

Science.gov (United States)

Kim, Ui Sik; Park, Tae Chang; Kim, Lae-Hyun; Yeo, Yeong Koo

This paper presents an optimal production and distribution management for structural and operational optimization of the integrated district heating system (DHS) with multiple regional branches. A DHS consists of energy suppliers and consumers, district heating pipelines network and heat storage facilities in the covered region. In the optimal management system, production of heat and electric power, regional heat demand, electric power bidding and sales, transport and storage of heat at each regional DHS are taken into account. The optimal management system is formulated as a mixed integer linear programming (MILP) where the objectives is to minimize the overall cost of the integrated DHS while satisfying the operation constraints of heat units and networks as well as fulfilling heating demands from consumers. Piecewise linear formulation of the production cost function and stairwise formulation of the start-up cost function are used to compute nonlinear cost function approximately. Evaluation of the total overall cost is based on weekly operations at each district heat branches. Numerical simulations show the increase of energy efficiency due to the introduction of the present optimal management system.

Africa's intra-regional, inter-regional and intercontinental electricity trade - Techno-politico-economic considerations and future prospects

Energy Technology Data Exchange (ETDEWEB)

Ram, Babu

2007-07-01

The majority of Africa's population does not have access to electricity. The Sub-Saharan African is largely hit save South Africa. Among the many reasons for this situation, the major one is: the insufficient growth of the investment against the demand of electricity. This is to say that the investment has not been able to keep pace with the demand which has been rising with the growing population and with the economic activities. As a result, there is a backlog of investment. To circumvent this situation, 4 billion dollar annual investment is needed in the electricity sector. But the risks and high transaction costs of African economies deter investors and are relatively unable to attract them. Furthermore, a number of African economies are small due to which the benefits of the economy of scale are not realizable. Moreover, isolated and individualistic planning makes countries incur huge investment and makes the supply of electricity to disadvantaged areas even costlier. The supply costs can be reduced by invoking meticulously to coordinated combined planning and regional integration. New Partnership for Africa's Development (NEPAD) advocates a development paradigm based on the principles of interdependence, cooperation, and regional integration. However, the absence of infrastructure and institutions and harmonized policies obstruct the integration of electricity supply systems. Creating regional electricity markets is a way to reduce risks and transaction costs and to lure investors to develop much needed electricity generation and transmission facilities for increasing electricity access in rural areas. This paper extends the themes of regional integration to establishing the regional electricity markets/power pools. It considers the intra-regional and inter-regional electricity trade in Africa. It also considers Africa's inter-continental trade that is its trade with Europe and Asia. This paper examines technical constraints, proposes solutions

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

Science.gov (United States)

Lee, Jenny J.; Sehoole, Chika

2015-01-01

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

REGIONAL SECURITY IN THE HORN OF AFRICA: CONFLICTS, AGENDAS AND THREATS

Directory of Open Access Journals (Sweden)

Nilton César Fernandes Cardoso

2017-01-01

Full Text Available This paper aims at analyzing security dynamics in the Horn of Africa in the post-independence period, identifying the actors, agendas and threats. For this purpose, it is subdivided into three parts. The first one analyzes the security dynamics taking place in the Horn of Africa during the Cold War period, focusing on the regional rivalries and on the penetration of extraregional actors. In the second part, there is a discussion regarding the transformations which occurred in region in the immediate post-Cold War period, focusing both on the unities’ (states internal security dynamics and on the regional ones. The third and last section aims at identifying “new” threats and regional and international responses, as well as the emerging strategic importance of the region to traditional superpowers in the post-9/11 period, marked by the process of securitization.

Africa region population projections - 1988-89

OpenAIRE

Vu, My T.; Bos, Eduard; Bulatao, Rodolfo A.

1988-01-01

The report which is part of a series, presents population projection tables for each country in the Africa region. The report provides an explanation on projection results as well as a description of the projection methodology, summarizing the main results. The projections in the report cover the period 1985 - 2150. This time period allows countries to approach stability. The key elements in these projections are the base year (mid 1985). Total population estimates and age - sex structures ar...

Bias correction of daily precipitation projected by the CORDEX-Africa ensemble for a sparsely gauged region in West Africa with regionalized distribution parameters

Science.gov (United States)

Lorenz, Manuel; Bliefernicht, Jan; Laux, Patrick; Kunstmann, Harald

2017-04-01

Reliable estimates of future climatic conditions are indispensable for the sustainable planning of agricultural activities in West Africa. Precipitation time series of regional climate models (RCMs) typically exhibit a bias in the distribution of both rainfall intensities and wet day frequencies. Furthermore, the annual and monthly sums of precipitation may remarkably vary from the observations in this region. As West Africa experiences a distinct rainy season, sowing dates are oftentimes planned based on the beginning of this rainfall period. A biased representation of the annual cycle of precipitation in the uncorrected RCMs can therefore lead to crop failure. The precipitation ensemble, obtained from the Coordinated Downscaling Experiment CORDEX-Africa, was bias-corrected for the study region in West Africa (extending approximately 343,358 km2) which covers large parts of Burkina Faso, Ghana and Benin. In oder to debias the RCM precipitation simulations, a Quantile-Mapping method was applied to the historical period 1950-2005. For the RCM future projections (2006-2100), the Double-Quantile-Mapping procedure was chosen. This method makes use of the shift in the distribution function of the future precipitation values which allows to incorporate the climate change signal of the RCM projections into the bias correction. As large areas of the study region are ungauged, the assignment of the information from the nearest station to the ungauged location would lead to sharp changes in the estimated statistics from one location to another. Thus, the distribution parameters needed for the Quantile-Mapping were estimated by Kriging the distribution parameters of the available measurement stations. This way it is possible to obtain reasonable estimates of the expected distribution of precipitation at ungauged locations. The presentation will illustrate some aspects and trade-offs in the distribution parameter interpolation as well as an analysis of the uncertainties of the

BRICS Regional Policy in Africa

Directory of Open Access Journals (Sweden)

Tatiana Deych

2015-05-01

Full Text Available This article provides an analysis of the BRICS as a whole and an analysis of each member’s policies in Africa. It exploresthe countries’ political and economic interests in Africa, the various patterns and strategies of each country’s cooperationwith Africa, and estimates the impact of BRICS aid and investment on the African economy and Africa’s development. TheBRICS countries have emerged as the new effective actors in the world arena. Their global economic weight and politicalinfluence continue to grow. Not only is the group focusing its attention on strengthening the internal ties of its members, but itis also focusing on assistance to Africa, as a way to implement the emerging powers efforts to change the existing world order.The BRICS is deepening its engagement with African countries, which gained great success in their development in recentyears. Its focus on Africa is determined by the important role of African resources and by the continent’s growing influencein the world economy and contemporary international relations. BRICS countries are major trade partners of Africa, andAfrica’s trade with BRICS members is growing faster than its trade with the traditional partners. Africa has become themain destination for BRICS development aid and investment. The BRICS is also focusing on African infrastructure. BRICScountries use soft power widely, through developing humanitarian ties with Africa, particularly in health care and education.The BRICS is also an active participant in peacekeeping and conflict resolution in Africa. Members currently tend tocompete in Africa, but they are taking steps toward collaboration. The BRICS contributes much to the African economy. Itspresence has become important for the continent and receives a positive response there.

Cost-effectiveness of USAID's regional program for family planning in West Africa.

Science.gov (United States)

Shepard, Donald S; Bail, Richard N; Merritt, C Gary

2003-06-01

Between 1994 and 1996, the United States Agency for International Development (USAID) closed 23 country missions worldwide, of which eight were in West and Central Africa. To preserve United States support for family planning and reproductive health in four countries in that region, USAID created a subregional program through a consortium of US-based groups that hired mainly African managers and African organizations. This study assesses cost-effectiveness of the program through an interrupted time-series design spanning the 1990s and compares cost-effectiveness in four similar countries in which mission-based programs continued. Key indicators include costs, contraceptive prevalence rates, and imputed "women-years of protection." The study found that, taking into account all external financing for population and family planning, the USAID West Africa regional approach generated women-years of protection at one-third the cost of the mission-based programs. This regional approach delivered family planning assistance in West Africa cost-effectively, and the findings suggest that regional models may work well for many health and population services in small countries.

Danish Interests in Regional Security Institutions in East Africa

DEFF Research Database (Denmark)

Nordby, Johannes Riber; Jacobsen, Katja

2013-01-01

For the past decade, peace and security in East Africa have gained increasing focus internationally. The region has experienced armed conflicts, civil wars, rebellion, drought and famine. Yet, at the same time, there is an emerging ambition among a number of African states to handle security issues...... on the continent independently. Such ambitions have fostered a variety of military capacity building programmes supported by external donors. The present report explores how up until now Denmark has sought to contribute to strengthening political and military security in East Africa. This has mainly been done...... through capacity building projects anchored in different regional security institutions. The report illuminates some of the risks that such capacity building projects might confront. Furthermore the report points out some of the challenges that exist in the cooperation between the Ministry of Foreign...

Secondary School Admissions Policies in Eastern Africa: Some Regional Issues

Science.gov (United States)

Gould, W. T. S.

1974-01-01

This discussion considers some regional issues implicit in current procedures regulating admission to secondary education in four countries of Eastern Africa and places these procedures in their general political context. (Author)

Regionalizing Africa: Patterns of Precipitation Variability in Observations and Global Climate Models

Science.gov (United States)

Badr, Hamada S.; Dezfuli, Amin K.; Zaitchik, Benjamin F.; Peters-Lidard, Christa D.

2016-01-01

Many studies have documented dramatic climatic and environmental changes that have affected Africa over different time scales. These studies often raise questions regarding the spatial extent and regional connectivity of changes inferred from observations and proxies and/or derived from climate models. Objective regionalization offers a tool for addressing these questions. To demonstrate this potential, applications of hierarchical climate regionalizations of Africa using observations and GCM historical simulations and future projections are presented. First, Africa is regionalized based on interannual precipitation variability using Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data for the period 19812014. A number of data processing techniques and clustering algorithms are tested to ensure a robust definition of climate regions. These regionalization results highlight the seasonal and even month-to-month specificity of regional climate associations across the continent, emphasizing the need to consider time of year as well as research question when defining a coherent region for climate analysis. CHIRPS regions are then compared to those of five GCMs for the historic period, with a focus on boreal summer. Results show that some GCMs capture the climatic coherence of the Sahel and associated teleconnections in a manner that is similar to observations, while other models break the Sahel into uncorrelated subregions or produce a Sahel-like region of variability that is spatially displaced from observations. Finally, shifts in climate regions under projected twenty-first-century climate change for different GCMs and emissions pathways are examined. A projected change is found in the coherence of the Sahel, in which the western and eastern Sahel become distinct regions with different teleconnections. This pattern is most pronounced in high-emissions scenarios.

Towards a regional ontology of management education in Africa: A complexity leadership theory perspective

Directory of Open Access Journals (Sweden)

Nixon M. Ochara

2017-02-01

Full Text Available Orientation: The title of this critique, ‘Towards a regional ontology of management education in Africa: A complexity leadership theory perspective’, sought to capture a paradox in the prescriptive nature and universalistic leaning of current leadership theories; yet local realities may call for being cognisant of (possible extant regional ontologies. Motivation for the study: The argumentation and analysis developed in this article were based on a synthesis of ideas from literature to evolve a preliminary regional ontology for reorienting business and management education relevant for Africa. Research design, approach and method: The critique was structured on insights from complexity leadership theory. The outcome was a proposition for an Afrocentric regional ontology for strengthening business and management education anchored on four themes: ethical and moral engagement, entrepreneurial leadership, Ubuntu and local National Systems of Innovation (NSI. These emerging ideas were considered to be tentative and should be considered as a foundation to inform further inquiry into how business and management education in Africa can be better interpreted and legitimised in the behavioural sciences. Practical/managerial implications: From an Afrocentric perspective, conceptualising and maintaining the logic of leadership was considered to be desirable and imperative in evolving a regional ontology of leadership that takes into account local realities. Of course, we recognised that these defining rationalities are not unique to Africa, but that said; a regional perspective that is unique cannot continue to be ignored but should find their place in discourses about leadership in the 21st century. Contribution/value-add: The synthesis and narrative presented in this paper concisely summarises and provides traction on how to advance business and management education in Africa.

The effectiveness of regional peace- making in Southern Africa ...

African Journals Online (AJOL)

tension, with more than one organisation vying for the lead, or in other cases, trying to pass ... of successfully managing conflict resolution efforts and establishing peace. ... in Africa further argued that 'sub-regional organizations sometimes have a ... a 1999 study, commissioned by the OAU on the functioning of cooperation.

Impact of Zimbabwe - South Africa Trade Relations: A Bilateral, Regional, or Multilateral Approach?

National Research Council Canada - National Science Library

Mayihlome, Levi

1997-01-01

.... Whereas a functional bilateral trade agreement or a regional customs union culminating in a common market might improve Zimbabwe's regional competitiveness in the short run' due to South Africa's...

Proposals for regional cooperation in Africa

International Nuclear Information System (INIS)

Kleywegt, R.J.

1999-01-01

The CTBTO Prep Com is overseeing the rapid establishment of the verification-related means for the future CTBTO. It encourages support and participation in its development and would like to ensure that ancillary benefits are identified and utilised. One such benefit is to be derived from the global expertise, data and information which are developed and generated through its activities. This is particularly so in the field of seismology where the rapidly developing field of engineering seismology is dependent on quality data over an extended period. A national seismological capability is essential for countries that wish/expect to develop rapidly in the next few decades. Tremendous benefit can be derived by utilizing the verification-related monitoring data and information products of the CTBTO Prep Com, by making the organization (International Cooperation Section) aware of all national seismological needs and by interacting with member states. A regional co-operative programme or structure could be of benefit to countries to link with the CTBTO Prep Com in Vienna or for addressing problems common to a region. There are a number of regional organisations in Africa that can house or provide some form of support to further the cause of envisaged regional co-operative endeavours. The terms of reference and mechanisms by which the regional endeavours will operate should preferably be set up by the participating states within each region

Modelling the spread of farming in the Bantu-speaking regions of Africa: an archaeology-based phylogeography.

Directory of Open Access Journals (Sweden)

Thembi Russell

Full Text Available We use archaeological data and spatial methods to reconstruct the dispersal of farming into areas of sub-Saharan Africa now occupied by Bantu language speakers, and introduce a new large-scale radiocarbon database and a new suite of spatial modelling techniques. We also introduce a method of estimating phylogeographic relationships from archaeologically-modelled dispersal maps, with results produced in a format that enables comparison with linguistic and genetic phylogenies. Several hypotheses are explored. The 'deep split' hypothesis suggests that an early-branching eastern Bantu stream spread around the northern boundary of the equatorial rainforest, but recent linguistic and genetic work tends not to support this. An alternative riverine/littoral hypothesis suggests that rivers and coastlines facilitated the migration of the first farmers/horticulturalists, with some extending this to include rivers through the rainforest as conduits to East Africa. More recently, research has shown that a grassland corridor opened through the rainforest at around 3000-2500 BP, and the possible effect of this on migrating populations is also explored. Our results indicate that rivers and coasts were important dispersal corridors, but do not resolve the debate about a 'Deep Split'. Future work should focus on improving the size, quality and geographical coverage of the archaeological (14C database; on augmenting the information base to establish descent relationships between archaeological sites and regions based on shared material cultural traits; and on refining the associated physical geographical reconstructions of changing land cover.

Tropospheric ozone over Equatorial Africa: regional aspects from the MOZAIC data

Directory of Open Access Journals (Sweden)

B. Sauvage

2005-01-01

Full Text Available We analyze ozone observations recorded over Equatorial Africa between April 1997 and March 2003 by the MOZAIC programme, providing the first ozone climatology deriving from continental in-situ data over this region. Three-dimensional streamlines strongly suggests connections between the characteristics of the ozone monthly mean vertical profiles, the most persistent circulation patterns in the troposphere over Equatorial Africa (on a monthly basis such as the Harmattan, the African Easterly Jet, the Trades and the regions of ozone precursors emissions by biomass burning. During the biomass burning season in each hemisphere, the lower troposphere exhibits layers of enhanced ozone (i.e. 70 ppbv over the coast of Gulf of Guinea in December-February and 85 ppbv over Congo in June-August. The characteristics of the ozone monthly mean vertical profiles are clearly connected to the regional flow regime determined by seasonal dynamic forcing. The mean ozone profile over the coast of Gulf of Guinea in the burning season is characterized by systematically high ozone below 650hPa ; these are due to the transport by the Harmattan and the AEJ of the pollutants originating from upwind fires. The confinement of high ozone to the lower troposphere is due to the high stability of the Harmattan and the blocking Saharan anticyclone which prevents efficient vertical mixing. In contrast, ozone enhancements observed over Central Africa during the local dry season (June-August are not only found in the lower troposphere but throughout the troposphere. Moreover, this study highlights a connection between the regions of the coast of Gulf of Guinea and regions of Congo to the south that appears on a semi annual basis. Vertical profiles in wet-season regions exhibit ozone enhancements in the lower troposphere due to biomass burning products transport from fires situated in the opposite dry-season hemisphere.

Oceans around Southern Africa and regional effects of global change

CSIR Research Space (South Africa)

Lutjeharms, JRE

2001-03-01

Full Text Available In the last few decades, a great deal of work has been carried out on the nature of the oceanic circulation around southern Africa. Attempts have been made to determine regional ocean-atmosphere interactions and the effect of changing sea...

Thyroid cancer in South Africa - an indicator of regional iodine ...

African Journals Online (AJOL)

Objective. Because follicular thyroid cancers predominate in iodine-deficient and papillary cancers predominate in iodine·replete populations. we have analysed national and regional (former Transvaal) incidences of these cancer types as a surrogate measure of the population iodine nutritional status in South Africa.

Testing the Waters: Climate Change in Africa and Anticipating Regional Conflicts

Science.gov (United States)

2011-05-04

University of Illinois Special Report. (Champaign, IL: University of Illinois at Urbana -Champaign), 4. 15 Environmentally, there are many problems...various drainage channels of the Niger River (the greatest river system in Western Africa) crisscross over 11 countries in the region, which...Security in Nigeria: Ramifications of the Ecology-Security Nexus for Sub-Regional Peace. Champaign: University of Illinois at Urbana -Champaign, 1997

Method to acquire regions of fruit, branch and leaf from image of red apple in orchard

Science.gov (United States)

Lv, Jidong; Xu, Liming

2017-07-01

This work proposed a method to acquire regions of fruit, branch and leaf from red apple image in orchard. To acquire fruit image, R-G image was extracted from the RGB image for corrosive working, hole filling, subregion removal, expansive working and opening operation in order. Finally, fruit image was acquired by threshold segmentation. To acquire leaf image, fruit image was subtracted from RGB image before extracting 2G-R-B image. Then, leaf image was acquired by subregion removal and threshold segmentation. To acquire branch image, dynamic threshold segmentation was conducted in the R-G image. Then, the segmented image was added to fruit image to acquire adding fruit image which was subtracted from RGB image with leaf image. Finally, branch image was acquired by opening operation, subregion removal and threshold segmentation after extracting the R-G image from the subtracting image. Compared with previous methods, more complete image of fruit, leaf and branch can be acquired from red apple image with this method.

Regional approach to building operational level capacity for disaster planning: the case of the Eastern Africa region.

Science.gov (United States)

Bazeyo, W; Mayega, R W; Orach, G C; Kiguli, J; Mamuya, S; Tabu, J S; Sena, L; Rugigana, E; Mapatano, M; Lewy, D; Mock, N; Burnham, G; Keim, M; Killewo, J

2013-06-01

The Eastern Africa region is regularly affected by a variety of disasters ranging from drought, to human conflict and population displacement. The magnitude of emergencies and response capacities is similar across the region. In order to strengthen public health disaster management capacities at the operational level in six countries of the Eastern Africa region, the USAID-funded leadership project worked through the HEALTH Alliance, a network of seven schools of public health from six countries in the region to train district-level teams. To develop a sustainable regional approach to building operational level capacity for disaster planning. This project was implemented through a higher education leadership initiative. Project activities were spear-headed by a network of Deans and Directors of public health schools within local universities in the Eastern Africa region. The leadership team envisioned a district-oriented systems change strategy. Pre-service and in-service curricula were developed regionally and district teams were formed to attend short training courses. Project activities began with a situational analysis of the disaster management capacity at national and operational levels. The next steps were chronologically the formation of country training teams and training of trainers, the development of a regional disaster management training curriculum and training materials, the cascading of training activities in the region, and the incorporation of emerging issues into the training curriculum. An evaluation model included the analysis of preparedness impact of the training program. The output from the district teams was the creation of individual district-level disaster plans and their implementation. This 4-year project focused on building operational level public health emergency response capacity, which had not previously been part of any national program. Use of the all-hazard approach rather than a scenario-based contingency planning led to the

Toward a Regional Security Architecture for the Horn of Africa ...

International Development Research Centre (IDRC) Digital Library (Canada)

Moreover, conflict in one country tends to affect its neighbours, mainly through the flow of refugees and weapons. Building on work carried out during Phase I ... Extrants. Rapports. Towards Developing a Regional Security Architecture for the Horn of Africa: Developing Responses to Human (In) Security-Phase Two ...

Sub-Saharan Africa: A Regional Security Strategy

National Research Council Canada - National Science Library

Barr, Bill; Daoud, Beshir

1996-01-01

The history of Africa is of a continent colonized and deeply exploited by European powers In the late 1940's, only four countries in Africa were independent Egypt, Liberia, Ethiopia and South Africa...

Whole blood pathogen reduction technology and blood safety in sub-Saharan Africa: A systematic review with regional discussion.

Science.gov (United States)

Nkohkwo, Asa'ah; Agbor, Gabriel; Asongalem, Emmanuel; Tagny, Claude; Asonganyi, Tazoacha

2016-01-01

Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region. This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region. The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinicians, scientists and professional bodies in the region, including the World Health Organization's Regional Office for Africa, to examine the suitability of PRT for improving the safety of whole blood transfusion, a prevalent transfusion format in the region. Existing literature suggests that combining PRT with current blood safety measures (such as serology) would improve the safety and adequacy of the blood supply for transfusions in sub-Saharan Africa. This was echoed by the findings of the stakeholder meetings. Following a detailed appraisal of two leading PRT systems, the Mirasol ® PRT System and the Cerus S-303 System, we suggest that companies conduct comprehensive toxicological evaluation of the agents used for PRT and publish this in the scientific literature. We also recommend that the safety and efficacy of these technologies should be established in a randomised clinical trial conducted in sub-Saharan Africa.

Symplasmic, long-distance transport in xylem and cambial regions in branches of Acer pseudoplatanus (Aceraceae) and Populus tremula x P. tremuloides (Salicaceae).

Science.gov (United States)

Sokołowska, Katarzyna; Zagórska-Marek, Beata

2012-11-01

The picture of how long-distance transport proceeds in trees is still far from being complete. Beside the apoplasmic pathway, transport undoubtedly also takes place within the system of living cells in the secondary xylem and cambial region. Because detailed, thorough studies of the symplasmic routes in woody branches, using direct localization with fluorescent tracers, had not been done, here we focused on the main routes of long-distance symplasmic transport in xylem and cambial tissues and analyzed in detail tracer distribution in the rays on the extended cambial surface in branches of Acer pseudoplatanus and Populus tremula ×P. tremuloides. Fluorescent tracers were loaded into branches through the vascular system, then their distribution in xylem and cambial regions was analyzed. Tracer signal was present in the symplast of axial and radial xylem parenchyma cells and in both types of cambial cells. The living cells of xylem parenchyma and of the cambium were symplasmically interconnected via xylem rays. Tracer distribution in rays was uneven on the extended cambial surface; cambial regions with intensively or sparsely dyed rays alternated along the vertical axis of analyzed branches. Symplasmic, long-distance transport is present between the living cells of xylem and the cambial region in woody branches. The uneven distribution of fluorescent tracers in cambial rays along the stems is surprising and suggests the presence of an intrinsic pattern caused by an unknown mechanism.

The determinants of Foreign Direct Investment in the Middle East North Africa region

NARCIS (Netherlands)

Rogmans, T.J.; Ebbers, H.A.

2006-01-01

Although, there has been increasing interest in the determinants of Foreign Direct Investment in emerging markets, FDI into the Middle East North Africa (MENA) region has so far received little attention among academics. The MENA region provides a useful ground for the testing of traditional

Onset condition of the off take from the stratified region to the branch with arbitrary direction

International Nuclear Information System (INIS)

Lee, Jae Young; Choo, Kyo Seong; Kim, Man Woong

2004-01-01

Two phase discharge from a stratified region through single or multiple branches has been studied considerably in the past two decades. The flow distribution in the header-feeder system of CANDU(Canada Deuterium and Uranium) reactors during accident scenario is one of good examples of these applications. Recently, the passive safety feature for PWR(Pressurized Water Reactor) introduce the concept of DVI(Direct Vessel Injection) for the emergency core make up. The expected water sweep out phenomena needs careful models including the curvature effect of down comer shell and the multi branches. It has been generally accepted that the onset condition of the off take follows the 2.5 power law, but recently, Lee et al. discussed that the experimental data produced large scattering to the 2.5 power law. Also, the effect of branch angle on the onset point of off take remains still as an unsolved problem. Hwang et al produced the CANDU specific branch angles of 0, +-90, +-36, +-72. The experimental results showed severe deviation from the 2.5 power law and needs mechanistic understanding on these phenomena. In the present paper, we try to develop a general model of onset point including the branch orientation

Linking Environmental Protection and Poverty Reduction in Africa: An Analysis of the Regional Legal Responses to Environmental Protection

Directory of Open Access Journals (Sweden)

Emeka Polycarp Amechi

2010-09-01

Full Text Available Poverty has been identified as the main cause and consequence of environmental degradation in Africa . It follows that if poverty is the main cause of environmental degradation in Africa , then policies, programmes and legal provisions designed to protect the environment in the region will be unsuccessful without a significant improvement in the living standards, wellbeing and livelihoods of the poor. In the same breath, since poverty is a consequence of environmental degradation, then the protection of the environment is critical to the achievement of poverty reduction initiatives such as the Millennium Development Goals in Africa . Hence, it can be argued that there is a mutual relationship between the achievement of environmental protection and reduction of poverty in Africa . This article therefore examines the extent to which the various regional legal instruments for the protection of the environment in Africa recognise this mutual linkage by providing for the promotion of poverty reduction and socio-economic development as integral aspect of their objective of ensuring the protection of the environment in the region.

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

Science.gov (United States)

Miiro, George M; Oukem-Boyer, Odile Ouwe Missi; Sarr, Ousmane; Rahmani, Maerangis; Ntoumi, Francine; Dheda, Keertan; Pym, Alexander; Mboup, Souleymane; Kaleebu, Pontiano

2013-03-22

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

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

Science.gov (United States)

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.

Africa burning: A thematic analysis of the Southern African Regional Science Initiative (SAFARI 2000)

Science.gov (United States)

Swap, Robert J.; Annegarn, Harold J.; Suttles, J. Timothy; King, Michael D.; Platnick, Steven; Privette, Jeffrey L.; Scholes, Robert J.

2003-07-01

The Southern African Regional Science Initiative (SAFARI 2000) was a major surface, airborne, and spaceborne field campaign carried out in southern Africa in 2000 and 2001 that addressed a broad range of phenomena related to land-atmosphere interactions and the biogeochemical functioning of the southern African system. This paper presents a thematic analysis and integration of the Journal of Geophysical Research SAFARI 2000 Special Issue, presenting key findings of an intensive field campaign over southern Africa in August and September of 2000. The integrating themes deal with surface emissions characterization; airborne characterizations of aerosols and trace gases; regional haze and trace gas characterization; and radiant measurements by surface, aircraft, and remote sensing platforms. Enhanced regional fuel loads associated with the moist La Niña phase of the El Niño-Southern Oscillation (ENSO) cycle produced above average biomass burning emissions, which consequently dominated all other aerosol and trace gas emissions during the dry season. Southward transport of a broad plume of smoke originating in equatorial Africa and exiting off the east coast toward the Indian Ocean (the river of smoke) is attributed to unusual synoptic airflows associated the ENSO phase. New and revised biogenic and pyrogenic emission factors are reported, including a number of previously unreported oxygenated organic compounds and inorganic compounds from biomass combustion. Emission factors are scaled up to regional emission surfaces for biogenic species utilizing species specific and light-dependent emission factors. Fire scar estimates reveal contradictory information on the timing of the peak and extent of the biomass-burning season. Integrated tall stack coordinated measurements (between ground, airborne and remotely sensing platforms) of upwelling and downwelling radiation in massive thick aerosol layers covering much of southern Africa yield consistent estimates of large

Twenty-three years (1993-2015) of homicide trends in the Transkei region of South Africa.

Science.gov (United States)

Banwari, Meel

2018-01-01

Background Transkei is regarded as a rural part of South Africa. It was one of the black homelands where rigorous apartheid was practised. The incidence of firearm-related deaths used to be very high, but after the implementation of the Firearm Control Act in 2002, the trend changed. However, the murder rate is still a major public-health problem in this region of South Africa. Objective The aim of this study was to investigate 23 years (1993-2015) of homicide trends in the Transkei region of South Africa. Method A review of records of medico-legal autopsies performed at Mthatha Forensic Pathology Laboratory from 1993 to 2015 was undertaken. Results Between 1993 and 2015, the number of autopsies performed on people who had died unnatural deaths was 24,693. The records of 12,618 (51%) autopsies on victims of homicide between 1993 and 2015 were available for study. The average rate of murder was 85/100,000 of the population in this region. Of these deaths, on average 34/100,000 were caused by sharp-edged instruments, 30/100,000 by gunshot wounds and 21/100,000 by blunt trauma. The rate of murder of males was significantly higher than that of females, with a ratio of 5.7:1, and over the period of 23 years covered by this study, the incidence was highest (30.5/100,000) in the young age group between 21 and 30 years. Conclusion The rate of homicide is very high in the Transkei region of South Africa. It needs urgent intervention to curb unnecessary deaths.

African regional conferences as an indicator of research trends in South Africa

CSIR Research Space (South Africa)

Paige-Green, P

2011-07-01

Full Text Available The 2011 African Regional Conference on Soil Mechanics and Geotechnical Engineering is the 15th in the series of 4 yearly conferences. The majority of the early conferences were held in sub-Saharan Africa with significant contributions from South...

National data centres and other means of regional cooperation in Africa: prospects and benefits

International Nuclear Information System (INIS)

Masawi, L.

2002-01-01

Participation in regional cooperation by Bulawayo National Data Centre in Zimbabwe is noted. East and Southern Africa Working Group (ESAWORG) is given as an example of such cooperation. The coming of CTBT is expected to strengthen the said group together with regional cooperation. Expected new developments are listed

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

Science.gov (United States)

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.

Regional Scale Modelling for Exploring Energy Strategies for Africa

International Nuclear Information System (INIS)

Welsch, M.

2015-01-01

KTH Royal Institute of Technology was founded in 1827 and it is the largest technical university in Sweden with five campuses and Around 15,000 students. KTH-dESA combines an outstanding knowledge in the field of energy systems analysis. This is demonstrated by the successful collaborations with many (UN) organizations. Regional Scale Modelling for Exploring Energy Strategies for Africa include Assessing renewable energy potentials; Analysing investment strategies; ) Assessing climate resilience; Comparing electrification options; Providing web-based decision support; and Quantifying energy access. It is conclude that Strategies required to ensure a robust and flexible energy system (-> no-regret choices); Capacity investments should be in line with national & regional strategies; Climate change important to consider, as it may strongly influence the energy flows in a region; Long-term models can help identify robust energy investment strategies and pathways that Can help assess future markets and profitability of individual projects

Rapidly developing market regions : South Africa

International Nuclear Information System (INIS)

Spore, E.

1997-01-01

In South Africa, a country that is rich in natural resources, gross domestic product has risen steadily since the historic elections in April 1994. In 1995, foreign trade made up almost 50 per cent of the country's gross national product. Unemployment and concurrent shortage of skilled labour are some of the major challenges that still exist for South Africa. Sasol is one of South Africa's top 10 private companies. It was founded in 1950; it supplies 44 per cent of South Africa's liquid fuel needs and produces most of the feedstocks used by the chemical and plastics industries in the country. The company is known for innovative technologies, such as the Sasol Synthol Process. It produces high-quality synthetic fuels such as petrol, diesel, kerosene, gas and furnace oils. The unique Sasol Synthol Process was described. Coal is put under high pressure and high temperature in the presence of steam and oxygen, is converted to crude gas, purified by removing sulfur and is then used in the production of gasoline, diesel and other fuels. The process also yields 120 other chemical products for domestic and international markets. 3 refs., 5 figs

Regional flood frequency analysis in the KwaZulu-Natal province, South Africa, using the index-flood method

DEFF Research Database (Denmark)

Kjeldsen, Thomas Rødding; Smithers, J.C.; Schulze, R.E.

2002-01-01

A regional frequency analysis of annual maximum series (AMS) of flood flows from relatively unregulated rivers in the KwaZulu-Natal province of South Africa has been conducted, including identification of homogeneous regions and suitable regional frequency distributions for the regions. The study...

Thermoelectric effects in disordered branched nanowires

Science.gov (United States)

Roslyak, Oleksiy; Piriatinskiy, Andrei

2013-03-01

We shall develop formalism of thermal and electrical transport in Si1 - x Gex and BiTe nanowires. The key feature of those nanowires is the possibility of dendrimer type branching. The branching tree can be of size comparable to the short wavelength of phonons and by far smaller than the long wavelength of conducting electrons. Hence it is expected that the branching may suppress thermal and let alone electrical conductance. We demonstrate that the morphology of branches strongly affects the electronic conductance. The effect is important to the class of materials known as thermoelectrics. The small size of the branching region makes large temperature and electrical gradients. On the other hand the smallness of the region would allow the electrical transport being ballistic. As usual for the mesoscopic systems we have to solve macroscopic (temperature) and microscopic ((electric potential, current)) equations self-consistently. Electronic conductance is studied via NEGF formalism on the irreducible electron transfer graph. We also investigate the figure of merit ZT as a measure of the suppressed electron conductance.

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

Science.gov (United States)

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.

Whole blood pathogen reduction technology and blood safety in sub-Saharan Africa: A systematic review with regional discussion

OpenAIRE

Nkohkwo, Asa?ah; Agbor, Gabriel; Asongalem, Emmanuel; Tagny, Claude; Asonganyi, Tazoacha

2016-01-01

Background: Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region. Objective: This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region. Method: The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinic...

Notes on the Recent History of Neuroscience in Africa

Directory of Open Access Journals (Sweden)

Vivienne A. Russell

2017-11-01

Full Text Available Neuroscience began with neuroanatomy and neurosurgery in Egypt more than 5000 years ago. Knowledge grew over time and specialized neurosurgery centers were established in north Africa in the eleventh century. However, it was not until the twentieth century that neuroscience research became established in sub-Saharan Africa. In most African countries, clinical research focused on understanding the rationale and improving treatment of epilepsy, infections, nutritional neuropathies, stroke and tumors. Significant advances were made. In the twenty-first century, African knowledge expanded to include all branches of neuroscience, contributing to genetic, biochemical and inflammatory determinants of brain disorders. A major focus of basic neuroscience research has been, and is, investigation of plant extracts, drugs and stress in animal models, providing insight and identifying potential novel therapies. A significant event in the history of African neuroscience was the founding of the Society of Neuroscientists of Africa (SONA in 1993. The International Brain Research Organization (IBRO supported SONA conferences, as well as workshops and neuroscience training schools in Africa. Thanks to their investment, as well as that of funding agencies, such as the National Institutes of Health (NIH, International Society for Neurochemistry (ISN, World Federation of Neurosurgical Societies (WFNS, World Federation of Neurology (WFN and the International League Against Epilepsy (ILAE, neuroscience research is well-established in Africa today. However, in order to continue to develop, African neuroscience needs continued international support and African neuroscientists need to engage in policy and decision-making to persuade governments to fund studies that address the unique regional needs in Africa.

Spiral branches and star formation

International Nuclear Information System (INIS)

Zasov, A.V.

1974-01-01

Origin of spiral branches of galaxies and formation of stars in them are considered from the point of view of the theory of the gravitational gas condensation, one of comparatively young theories. Arguments are presented in favour of the stellar condensation theory. The concept of the star formation of gas is no longer a speculative hypothesis. This is a theory which assumes quantitative verification and explains qualitatively many facts observed. And still our knowledge on the nature of spiral branches is very poor. It still remains vague what processes give origin to spiral branches, why some galaxies have spirals and others have none. And shapes of spiral branches are diverse. Some cases are known when spiral branches spread outside boundaries of galaxies themselves. Such spirals arise exclusively in the region where there are two or some interacting galaxies. Only first steps have been made in the explanation of the galaxy spiral branches, and it is necessary to carry out new observations and new theoretical calculations

Telecommunications Liberalisation in Africa: Proposed Regulatory Model for the SADC Region

Directory of Open Access Journals (Sweden)

Z. Ntozintle Jobodwana

2009-12-01

Full Text Available The liberalisation of the telecommunication industry in Africa, and the further development of the region’s physical infrastructure was accompanied by the further development of Africa’s information, communication and technology infrastructure. Competition within the industry stimulated heavy economic investment in other sectors of the economy. The outcome of liberalisation also included the establishment of community-based structures that continue to enable communities to manage their own development and gain access to information and communication technologies (ICTs in an unprecedented manner. The telecommunication infrastructure further stimulated the fast development of other related services, for example, e-commerce and mobile commerce (m-commerce, e-government, internet banking, mobile banking etcetera. Latest reports and statistics disclose that in Africa m-commerce is set to even overtake the development of e-commerce, through the popular use and penetration of mobile telephony whilst e-commerce development is constrained by difficulties in rolling out speedily fixed telephone lines. These new methods of communication have so intensified that there is hope that further penetration of mobile telephony would leap-frog economic growth and development in Africa, especially in rural communities. Therefore, innovations and investment in ICT’s are changing the world in a number of ways, resulting in a globally connected digital economy.  However, there are regulatory challenges that need to be addressed as a matter of urgency. Certain sections of the continent’s population, especially those in rural areas, have very limited access to ICT’s. This prevents them from exploiting opportunities offered by ICT’s. The main barriers to ICT access relate to inadequate regimes and their supporting legal frameworks, high cost of internet access, connectivity problems, the lack of technical skills to support

Rethinking International Counterterrorism Assistance to the Greater Horn of Africa: Toward a Regional Risk Reduction Strategy

Directory of Open Access Journals (Sweden)

Matthew Schwartz

2013-12-01

Full Text Available The Horn of Africa has long been a recipient of foreign security assistance, with significant funds increasingly devoted to supporting subregional civilian-oriented counterterrorism efforts over the past decade. Despite efforts to better coordinate delivery, counterterrorism programming in the subregion generally remains fragmented, short-term, and siloed in implementation. This article argues that it is time to rethink the international community’s approach to counterterrorism assistance to the Horn of Africa and calls for a cohesive regional approach that not only bridges the gap between security and development, but also the gap between counterterrorism and human security. It emphasizes that the international community must not only better coordinate existing streams of counterterrorism assistance to the region, but also rethink how this assistance is designed and the ways it can be delivered to complement broader subregional development and security agendas. After a brief introduction to international counterterrorism assistance to the Horn of Africa, the article examines linkages across three thematic streams of programming being delivered to the subregion: anti-money laundering and countering the financing of terrorism; criminal justice capacity building assistance to counter terrorism; and, countering violent extremism. This discussion will highlight the need for a regional risk reduction strategy for the Horn of Africa that not only builds on the interplay of different streams of counterterrorism assistance, but on synergies across broader subregional development and security agendas as well.

A quantitative assessment of groundwater resources in the Middle East and North Africa region

Science.gov (United States)

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.

Bibliometric analysis of public health research in Africa: The overall trend and regional comparisons

Directory of Open Access Journals (Sweden)

Yuh-Shan Ho

2011-05-01

Full Text Available Many diseases in Africa can be prevented with appropriate public health interventions. This study aimed to assess the bibliometric characteristics of public health related research articles published by researchers in African institutions from 1991 to 2005. Data used in this study were obtained from the online version of the ISI Web of Science: Science Citation Index Expanded (SCI-Expanded. Articles published between 1991 and 2005 that had the phrase ‘public health’ in the title, author keywords or abstract, and had at least one author whose contact address was in an African country, were selected for analysis. The annual number of public health related articles published by African researchers significantly increased from 28 articles in 1991 to 135 articles in 2005, a 382% increase. International collaboration also increased: from 45% of articles having international collaborators during 1991–1995, to 52% during1996–2000, and to 67% during 2001–2005. Collaborations were mostly with European and North American countries. Keywords, subject categories and collaboration patterns of articles varied across regions, reflecting differences in needs and collaboration networks. Public health related research output, as well as international collaborations, have been increasing in Africa. Regional variation observed in this study may assist policymakers to facilitate the advancement of public health research in different regions of Africa, and could be useful for international organisations in identifying needs and to allocate research funding. Future bibliometric analyses of articles published by African researchers, can consider conducting regional comparisons using standardised methods, as well as describing the overall patterns, in order to provide a more comprehensive view of their bibliometric characteristics.

2nd East Africa Regional Workshop Report: Conservation Agriculture in AFRICA - Analysing and Foreseeing its Impact - Comprehending its Adoption

OpenAIRE

Apina, T.; Mkomwa, S.; Mutai, W.; Njeri, A.

2011-01-01

This resource provides a summary of the 2nd East Africa Sub-regional workshop held in Nanyuki, Kenya, on 28-30 March 2011. Attendees included the African Conservation Tillage Network (ACT), Tropical Soil Biology and Fertility Institute (TSBF/AFNET), Agricultural Research for Development (CIRAD), LEIBNIZ-Centre for Agricultural Landscape Research (ZALF), Agricultural Research Institute (ARI) UYOLE, SELIAN Agricultural Research Institute (SARI-MAFC), Conservation Agriculture for Sustainable Agr...

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

Science.gov (United States)

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

2016-07-01

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

From the twig tips to the deeper branches

DEFF Research Database (Denmark)

Betson, Martha; Nejsum, Peter; Stothard, J. Russell

2013-01-01

upon disease control. While useful in determining dynamics at the tips of the evolutionary tree, these molecular tools also provide insights into deeper evolutionary branches. Although Ascaris is found throughout the globe, molecular analysis of worms retrieved from sub-Saharan Africa point towards...... a significant center of genetic diversity, possibly denoting a likely center of evolutionary origin with subsequent parasite diaspora. Resolving these issues precisely, however, requires greater scrutiny of genetic variation within Parascaris and Baylisascaris. © 2013...

Potential for Zika virus introduction and transmission in resource-limited countries in Africa and the Asia-Pacific region: a modelling study.

Science.gov (United States)

Bogoch, Isaac I; Brady, Oliver J; Kraemer, Moritz U G; German, Matthew; Creatore, Maria I; Brent, Shannon; Watts, Alexander G; Hay, Simon I; Kulkarni, Manisha A; Brownstein, John S; Khan, Kamran

2016-11-01

As the epidemic of Zika virus expands in the Americas, countries across Africa and the Asia-Pacific region are becoming increasingly susceptible to the importation and possible local spread of the virus. To support public health readiness, we aim to identify regions and times where the potential health, economic, and social effects from Zika virus are greatest, focusing on resource-limited countries in Africa and the Asia-Pacific region. Our model combined transportation network analysis, ecological modelling of mosquito occurrences, and vector competence for flavivirus transmission, using data from the International Air Transport Association, entomological observations from Zika's primary vector species, and climate conditions using WorldClim. We overlaid monthly flows of airline travellers arriving to Africa and the Asia-Pacific region from areas of the Americas suitable for year-round transmission of Zika virus with monthly maps of climatic suitability for mosquito-borne transmission of Zika virus within Africa and the Asia-Pacific region. An estimated 2·6 billion people live in areas of Africa and the Asia-Pacific region where the presence of competent mosquito vectors and suitable climatic conditions could support local transmission of Zika virus. Countries with large volumes of travellers arriving from Zika virus-affected areas of the Americas and large populations at risk of mosquito-borne Zika virus infection include India (67 422 travellers arriving per year; 1·2 billion residents in potential Zika transmission areas), China (238 415 travellers; 242 million residents), Indonesia (13 865 travellers; 197 million residents), Philippines (35 635 travellers; 70 million residents), and Thailand (29 241 travellers; 59 million residents). Many countries across Africa and the Asia-Pacific region are vulnerable to Zika virus. Strategic use of available health and human resources is essential to prevent or mitigate the health, economic, and social

Representation of aerosol particles and associated transport pathways in regional climate modelling in Africa

CSIR Research Space (South Africa)

Garland, Rebecca M

2016-11-01

Full Text Available Aerosol particles can have large impacts on air quality and on the climate system. Regional climate models for Africa have not been well-tested and validated for their representation and simulation of aerosol particles. This study aimed to validate...

FLOSS World Africa regional workshop

CSIR Research Space (South Africa)

Tucker, KC

2006-02-01

Full Text Available Education is fundamental to development and the foundation for addressing and improving some of the key development challenges facing Africa. The focus groups recommend that FOSSFA convene a working group to address these important, pivotal issues...

International cooperation workshop. Regional workshop for CTBTO international cooperation: Africa

International Nuclear Information System (INIS)

1999-08-01

Pursuant to the 1999 programme of work, and following the International Cooperation Workshop held in Vienna, Austria, in 1998, the Provisional Technical Secretariat (PTS) of the Preparatory Commission for the CTBTO (Prep Com) held a regional Workshop for CTBTO International Cooperation in Cairo. The purpose of the workshop was to identify how and by what means the Africa region can promote international cooperation in CTBT verification related technologies, and how the region can benefit from and contribute to Prep Com activity. PTS staff briefed the 40 participants from 22 African States who attended the Workshop on general aspects, including costs, of the establishment and operation of the CTBT verification system, including its four monitoring technologies. Participants were informed on opportunities for local institutions in the establishment of monitoring stations and on possible support for national and regional data centres. National experts presented their research and development activities and reviewed existing experiences on bi/multi-lateral cooperation. The main points of the discussion focused on the need to engage governments to advance signature/ratification, and further training opportunities for African states

First early hominin from central Africa (Ishango, Democratic Republic of Congo.

Directory of Open Access Journals (Sweden)

Isabelle Crevecoeur

Full Text Available Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma, and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25 from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma.

First Early Hominin from Central Africa (Ishango, Democratic Republic of Congo)

Science.gov (United States)

Crevecoeur, Isabelle; Skinner, Matthew M.; Bailey, Shara E.; Gunz, Philipp; Bortoluzzi, Silvia; Brooks, Alison S.; Burlet, Christian; Cornelissen, Els; De Clerck, Nora; Maureille, Bruno; Semal, Patrick; Vanbrabant, Yves; Wood, Bernard

2014-01-01

Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma. PMID:24427292

Potential risk of regional disease spread in West Africa through cross-border cattle trade.

Directory of Open Access Journals (Sweden)

Anna S Dean

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

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

Science.gov (United States)

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

2013-01-01

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

Impact of dynamical regionalization on precipitation biases and teleconnections over West Africa

Science.gov (United States)

Gómara, Iñigo; Mohino, Elsa; Losada, Teresa; Domínguez, Marta; Suárez-Moreno, Roberto; Rodríguez-Fonseca, Belén

2018-06-01

West African societies are highly dependent on the West African Monsoon (WAM). Thus, a correct representation of the WAM in climate models is of paramount importance. In this article, the ability of 8 CMIP5 historical General Circulation Models (GCMs) and 4 CORDEX-Africa Regional Climate Models (RCMs) to characterize the WAM dynamics and variability is assessed for the period July-August-September 1979-2004. Simulations are compared with observations. Uncertainties in RCM performance and lateral boundary conditions are assessed individually. Results show that both GCMs and RCMs have trouble to simulate the northward migration of the Intertropical Convergence Zone in boreal summer. The greatest bias improvements are obtained after regionalization of the most inaccurate GCM simulations. To assess WAM variability, a Maximum Covariance Analysis is performed between Sea Surface Temperature and precipitation anomalies in observations, GCM and RCM simulations. The assessed variability patterns are: El Niño-Southern Oscillation (ENSO); the eastern Mediterranean (MED); and the Atlantic Equatorial Mode (EM). Evidence is given that regionalization of the ENSO-WAM teleconnection does not provide any added value. Unlike GCMs, RCMs are unable to precisely represent the ENSO impact on air subsidence over West Africa. Contrastingly, the simulation of the MED-WAM teleconnection is improved after regionalization. Humidity advection and convergence over the Sahel area are better simulated by RCMs. Finally, no robust conclusions can be determined for the EM-WAM teleconnection, which cannot be isolated for the 1979-2004 period. The novel results in this article will help to select the most appropriate RCM simulations to study WAM teleconnections.

The balance of trade in alien species between South Africa and the rest of Africa

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Katelyn T. Faulkner

2017-03-01

Full Text Available Background: Alien organisms are not only introduced from one biogeographical region to another but also spread within regions. As South Africa shares land borders with six countries, multiple opportunities exist for the transfer of alien species between South Africa and other African countries; however, the direction and importance of intra-regional spread is unclear. Objectives: The aim of this study was to gain a greater understanding of the introduction of alien species into Africa and the spread of species between South Africa and other African countries. Method: We developed scenarios that describe the routes by which alien species are introduced to and spread within Africa and present case studies for each. Using data from literature sources and databases, the relative importance of each scenario for alien birds and insect pests of eucalypts was determined, and the direction and importance of intra-regional spread was assessed. Results: Alien species from many taxonomic groups have, through various routes, been introduced to and spread within Africa. For birds and eucalypt insect pests, the number of species spreading in the region has recently increased, with South Africa being a major recipient of birds (14 species received and 5 donated and a major donor of eucalypt insect pests (1 species received and 10 donated. For both groups, many introduced species have not yet spread in the region. Conclusion: The intra-regional spread of alien species in Africa represents an important and possibly increasing threat to biosecurity. To address this threat, we propose a framework that details how African countries could cooperate and develop a coordinated response to alien species introductions.

Estimation of some comfort parameters for sleeping environments in dry-tropical sub-Saharan Africa region

International Nuclear Information System (INIS)

Djongyang, Noël; Tchinda, René; Njomo, Donatien

2012-01-01

Highlights: ► Thermal comfort in sleeping environments in the sub-Saharan Africa is presented. ► Comfort charts for the dry-tropical regions were established. ► Total insulation values for bedding systems range between 0.81 clo and 0.94 clo. ► Thermoneutral operative temperature ranges between 29.5 °C and 31.7 °C. ► Thermoneutral air temperature ranges between 27.1 °C and 29.6 °C. - Abstract: A human being spends approximately one-third of his/her life in sleep. For an efficient and peaceful rest, he/she therefore needs some level of comfort. This includes acceptable environmental parameters as well as suitable bedding systems. While the theories of thermal comfort in workplaces at daytime are currently well established, research on thermal comfort for sleeping environment at night is limited. Further studies in relation with sleep are needed. This paper presents an investigation on thermal comfort in sleeping environments in the sub-Saharan Africa region. The comfort equation used is based on the energy balance of the human body derived from Fanger’s comfort model. Comfort charts for the dry-tropical sub-Saharan Africa region were established using indoor climatic conditions collected over five years in Ouagadougou (12°22′N, 1°32′W). Results obtained show that the suitable monthly total insulation values for bedding systems in the dry-tropical regions range between 0.81 clo and 0.94 clo. The thermoneutral operative temperature range between 29 °C and 32 °C, while the thermoneutral air temperature range between 27 °C and 30 °C.

Regional assessment of the status, distribution and conservation needs of cheetahs in southern Africa

OpenAIRE

Purchase, Gianetta; Marker, Laurie; Marnewick, Kelly; Klein, Rebecca; Williams, Samual

2007-01-01

A country by country assessment of the status, distribution and conservation needs for cheetah Acinonyx jubatus in the southern African region indicates that this area holds a significant proportion of the global population of cheetahs, at least 4 500 adults. The largest proportion of this regional population occurs in four range states, Namibia, Botswana, South Africa and Zimbabwe where it is under threat as a result of conflict with livestock and wildlife ranchers, removal of animals (both ...

Trade networks in West Africa

DEFF Research Database (Denmark)

Walther, Olivier

2014-01-01

To date, most of the literature on trade networks in West Africa has considered networks in a metaphorical way. The aim of this paper is to go one step further by showing how social network analysis may be applied to the study of regional trade in West Africa. After a brief review of the literature......, this exploratory paper investigates two main issues related to regional trade. We start by discussing how recent developments in regional trade in West Africa have contributed to challenging the social structure of traders. We then discuss the changes that have affected the spatiality of regional trade by looking...

Isotopic composition of groundwater in semi-arid regions of Southern Africa

International Nuclear Information System (INIS)

Vogel, J.C.; Urk, H. van

1975-01-01

Although the isotope content of precipitation in the semi-arid regions of southern Africa is extremely variable, groundwater samples from the same district are found to have a remarkably constant isotopic composition. The oxygen-18 content of the underground water, in general, varies by about 0.5% in a given area. The differences that occur between different regions are sufficiently large to allow the groundwater of an area to be characterized by means of its oxygen-18 content. In order to localize the infiltration area of an aquifer, radiocarbon dating of the water is used. It appears that the groundwater contains, in general, less of the heavy isotopes than does the precipitation in the recharge area. This indicates that infiltration only takes place during periods of heavy rainfall. Examples are given where the isotope content of the groundwater is used to distinguish between different aquifers in the same region

CTBTO as a new driving force for regional integration in Africa

International Nuclear Information System (INIS)

Nyobe, J.B.

2002-01-01

Major chellenges facing African states are listed as lack of human resources to address critical issues related to atmospheric and environmental monitoring, natural hazards such as earthquakes (Algeria), volcanic eruptions (Republic of Congo), floods (Mozambique) and Africa's social structure with many sub-regional linguistic and cultural entities. CTBTO assistance to address major challenges is indicated in the area of uprading of existing monitoring facilities, the introduction of new technologies (infrasound, radionuclides and seisimic) and setting up a multipurpose monitoring system through national data centres

Regional radiative impacts of mixed dust and carbonaceous aerosols over West Africa

Science.gov (United States)

Malavelle, Florent; Pont, Véronique; Solmon, Fabien; Mallet, Marc; Léon, Jean-François; Liousse, Catherine; Johnson, Ben

2010-05-01

Africa is a major source of aerosols at global scale. Two types of aerosols dominate the regional background: biomass burning aerosols as results of combustion of the vegetation and mineral dust aerosols related to erosion of arid soils by wind. These important burdens of aerosols are known to have each one a strong impact on the regional radiative budget. Whereas recent modelling efforts show significant impacts at climatic timescale on West African Monsoon due to the radiative effects of dust aerosols (see Solmon et al 2008 in GRL and references therein), biomass burning radiative effects in this region stand still poorly documented. What about West Africa, during the dry season (december-february) when both biomass burning and dust aerosols are encountered in the atmospheric background ? In that frame, we use ICTP Regional Climate Model versions 3 in order to estimate the radiative forcing due to the external mixing of mineral dust and carbonaceous aerosols from biomass burning, BioFuel and Fossil Fuel combustion during the dry season. Emissions of biomass burning aerosols are taken from new inventories based on SPOT vegetation burnt area products. Optical properties of carboneaceous aerosols are updated thanks to chemical sampling at Djougou during AMMA SOP-0. This presentation focuses on the model efficiency to correctly reproduce the main features concerning aerosols observed during AMMA-SOP0/DABEX field campaigns. It refers to (i) a strong stratification of dust and smoke layers, and (ii) a marked seasonal cycle of aerosol mixture optical properties. Those features are key parameters for modelling the direct and semi direct effects of aerosols over West Africa. Results of simulations indicate that the particular low value of single scattering albedo (SSA) for biomass burning aerosols (~0.81 at 550nm) involves important diabatic heating in the atmosphere. Values of aerosol heating rates are estimated and compared with aircraft measurement from DABEX

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

Science.gov (United States)

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

2013-04-01

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

Lower Silurian `hot shales' in North Africa and Arabia: regional distribution and depositional model

Science.gov (United States)

Lüning, S.; Craig, J.; Loydell, D. K.; Štorch, P.; Fitches, B.

2000-03-01

Lowermost Silurian organic-rich (`hot') shales are the origin of 80-90% of Palaeozoic sourced hydrocarbons in North Africa and also played a major role in petroleum generation on the Arabian Peninsula. In most cases, the shales were deposited directly above upper Ordovician (peri-) glacial sandstones during the initial early Silurian transgression that was a result of the melting of the late Ordovician icecap. Deposition of the main organic-rich shale unit in the North African/Arabian region was restricted to the earliest Silurian Rhuddanian stage ( acuminatus, atavus and probably early cyphus graptolite biozones). During this short period (1-2 m.y.), a favourable combination of factors existed which led to the development of exceptionally strong oxygen-deficiency in the area. In most countries of the study area, the post-Rhuddanian Silurian shales are organically lean and have not contributed to petroleum generation. The distribution and thickness of the basal Silurian `hot' shales have been mapped in detail for the whole North African region, using logs from some 300 exploration wells in Libya, Tunisia, Algeria and Morocco. In addition, all relevant, accessible published and unpublished surface and subsurface data of the lower Silurian shales in North Africa and Arabia have been reviewed, including sedimentological, biostratigraphic and organic geochemical data. The lowermost Silurian hot shales of northern Gondwana are laterally discontinuous and their distribution and thickness were controlled by the early Silurian palaeorelief which was shaped mainly by glacial processes of the late Ordovician ice age and by Pan-African and Infracambrian compressional and extensional tectonism. The thickest and areally most extensive basal Silurian organic-rich shales in North Africa occur in Algeria, Tunisia and western Libya, while on the Arabian Peninsula they are most prolific in Saudi Arabia, Oman, Jordan and Iraq. The hot shales were not deposited in Egypt, which was a

The prevalence of ovine herpesvirus-2 in 4 sheep breeds from different regions in South Africa

Directory of Open Access Journals (Sweden)

C.W. Bremer

2010-05-01

Full Text Available About 90% of bovine malignant catarrhal fever (BMCF PCR-positive cases in South Africa are caused by alcelaphine herpesvirus-1 (AlHV-1 and the other 10 % by ovine herpesvirus-2 (OvHV-2. The prevalence of OvHV-2 in different sheep breeds in South Africa was determined in order to investigate whether the lower incidence of BMCF caused by OvHV-2 in comparison with AlHV-1 can be ascribed to a low incidence of the virus in sheep. A single-tube hemi-nested PCR was developed, evaluated and applied to detect OvHV-2 DNA. The prevalence of the virus in 4 sheep breeds from various regions in South Africa was shown to be 77 %. No statistically significant difference was found amongst the sheep breeds tested.

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

Science.gov (United States)

Rosenzweig, C.

2014-12-01

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

Association mapping in sunflower (Helianthus annuus L.) reveals independent control of apical vs. basal branching.

Science.gov (United States)

Nambeesan, Savithri U; Mandel, Jennifer R; Bowers, John E; Marek, Laura F; Ebert, Daniel; Corbi, Jonathan; Rieseberg, Loren H; Knapp, Steven J; Burke, John M

2015-03-11

Shoot branching is an important determinant of plant architecture and influences various aspects of growth and development. Selection on branching has also played an important role in the domestication of crop plants, including sunflower (Helianthus annuus L.). Here, we describe an investigation of the genetic basis of variation in branching in sunflower via association mapping in a diverse collection of cultivated sunflower lines. Detailed phenotypic analyses revealed extensive variation in the extent and type of branching within the focal population. After correcting for population structure and kinship, association analyses were performed using a genome-wide collection of SNPs to identify genomic regions that influence a variety of branching-related traits. This work resulted in the identification of multiple previously unidentified genomic regions that contribute to variation in branching. Genomic regions that were associated with apical and mid-apical branching were generally distinct from those associated with basal and mid-basal branching. Homologs of known branching genes from other study systems (i.e., Arabidopsis, rice, pea, and petunia) were also identified from the draft assembly of the sunflower genome and their map positions were compared to those of associations identified herein. Numerous candidate branching genes were found to map in close proximity to significant branching associations. In sunflower, variation in branching is genetically complex and overall branching patterns (i.e., apical vs. basal) were found to be influenced by distinct genomic regions. Moreover, numerous candidate branching genes mapped in close proximity to significant branching associations. Although the sunflower genome exhibits localized islands of elevated linkage disequilibrium (LD), these non-random associations are known to decay rapidly elsewhere. The subset of candidate genes that co-localized with significant associations in regions of low LD represents the most

Co-movement of Africa's equity markets: Regional and global analysis in the frequency-time domains

Science.gov (United States)

Boako, Gideon; Alagidede, Paul

2017-02-01

This paper examines regional and global co-movement of Africa's stock markets using the three-dimensional continuous Morlet wavelet transform methodology. The analyses which are done in segments investigate co-movements with global markets; bilateral exchange rates expressed in US dollars and euro; and four regional markets in Africa. First, we find evidence of stronger co-movements broadly narrowed to short-run fluctuations. The co-movements are time-varying and commonly non-homogeneous - with phase difference arrow vectors implying lead-lag relationships. The presence of lead-lag effects and stronger co-movements at short-run fluctuations may induce arbitrage and diversification opportunities to both local and international investors with long-term investment horizons. The findings also reveal that some African equity markets are, to a degree, segmented from volatilities of the dollar and euro exchange rates. Thus, inferring that, ceteris paribus, international investors may diversify their portfolio investments across those markets without worrying about the effects of currency price volatility.

Integrated Assessment by the People: Insights from AgMIP Regional Teams in Sub-Saharan Africa and South Asia

Science.gov (United States)

Antle, J. M.

2017-12-01

AgMIP has developed innovative protocol-based methods for regional integrated assessment (RIA) that can be implemented by national researchers working with local and national stakeholders (http://www.agmip.org/regional-integrated-assessments-handbook/). The approach has been implemented by regional teams in Sub-Saharan Africa and South Asia. This presentation first summarizes novel elements of the AgMIP RIA methods, and their strengths and limitations, based on their application by AgMIP researchers. Key insights from the application of these methods for climate impact and adaptation in Sub-Saharan Africa and South Asia are presented. A major finding is that detailed, site-specific, systems-based analysis show much more local and regional variation in impacts than studies based on analysis of individual crops, and provide the basis for analysis of multi-faceted technology and policy options to facilitate the transition to sustainable and resilient development pathways. The presentation concludes with observations about advancing integrated assessments carried out by and for national and local researchers and stakeholders.

Sub-Saharan Africa at the global education market: role of South Africa

Directory of Open Access Journals (Sweden)

Ramil Ravilevich Asmyatullin

2016-12-01

Full Text Available This article is dedicated to the development of the higher education in Sub-Saharan countries, particularly to the topic of internationalization of education. Most African countries have underdeveloped education systems. The quality and availability of higher education is a formidable obstacle for economic and social development. There is a growing demand for higher education in the SSA, but national education systems can’t cope fully with it. Hence many students go abroad, mostly in other African countries. The article focuses on the position of South Africa in the global and regional education market. As it’s a regional leader in this field South Africa attracts more than a half of international students within the Sub-Saharan Africa. The main reasons why African students choose South Africa are geographic proximity, familiar culture, lack of wanted higher education programs in their countries. However, there are as well disadvantages like xenophobia and race discrimination. South Africa has become a leader in Africa in the field of higher education, but it plays still small part at a global scale.

Report on: FLOSSWorld Africa regional workshop

CSIR Research Space (South Africa)

Revat, E

2006-02-01

Full Text Available change of policies in African governments to adopt its use; Research and Development; Product Development uniformly across Africa; Local Capacity Building which will translate into jobs creation. Clearly there is a strong overlap of interests...

Internal variability in a regional climate model over West Africa

Energy Technology Data Exchange (ETDEWEB)

Vanvyve, Emilie; Ypersele, Jean-Pascal van [Universite catholique de Louvain, Institut d' astronomie et de geophysique Georges Lemaitre, Louvain-la-Neuve (Belgium); Hall, Nicholas [Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales/Centre National d' Etudes Spatiales, Toulouse Cedex 9 (France); Messager, Christophe [University of Leeds, Institute for Atmospheric Science, Environment, School of Earth and Environment, Leeds (United Kingdom); Leroux, Stephanie [Universite Joseph Fourier, Laboratoire d' etude des Transferts en Hydrologie et Environnement, BP53, Grenoble Cedex 9 (France)

2008-02-15

Sensitivity studies with regional climate models are often performed on the basis of a few simulations for which the difference is analysed and the statistical significance is often taken for granted. In this study we present some simple measures of the confidence limits for these types of experiments by analysing the internal variability of a regional climate model run over West Africa. Two 1-year long simulations, differing only in their initial conditions, are compared. The difference between the two runs gives a measure of the internal variability of the model and an indication of which timescales are reliable for analysis. The results are analysed for a range of timescales and spatial scales, and quantitative measures of the confidence limits for regional model simulations are diagnosed for a selection of study areas for rainfall, low level temperature and wind. As the averaging period or spatial scale is increased, the signal due to internal variability gets smaller and confidence in the simulations increases. This occurs more rapidly for variations in precipitation, which appear essentially random, than for dynamical variables, which show some organisation on larger scales. (orig.)

Turbulent penetration in T-junction branch lines with leakage flow

Energy Technology Data Exchange (ETDEWEB)

Kickhofel, John, E-mail: kickhofel@lke.mavt.ethz.ch; Valori, Valentina, E-mail: v.valori@tudelft.nl; Prasser, H.-M., E-mail: prasser@lke.mavt.ethz.ch

2014-09-15

Highlights: • New T-junction facility designed for adiabatic high velocity ratio mixing studies. • Trends in scalar mixing RMS and average in branch line presented and discussed. • Turbulent penetration has unique power spectrum relevant to thermal fatigue. • Forced flow oscillations translate to peaks in power spectrum in branch line. - Abstract: While the study of T-junction mixing with branch velocity ratios of near 1, so called cross flow mixing, is well advanced, to the point of realistic reactor environment fluid–structure interaction experiments and CFD benchmarking, turbulent penetration studies remain an under-researched threat to primary circuit piping. A new facility has been constructed for the express purpose of studying turbulent penetration in branch lines of T-junctions in the context of the high cycle thermal fatigue problem in NPPs. Turbulent penetration, which may be the result of a leaking valve in a branch line or an unisolable branch with heat losses, induces a thermal cycling region which may result in high cycle fatigue damage and failures. Leakage flow experiments have been performed in a perpendicular T-junction in a horizontal orientation with 50 mm diameter main pipe and branch pipe at velocity ratios (main/branch) up to 400. Wire mesh sensors are used as a means of measuring the mixing scalar in adiabatic tests with deionized and tap water. The near-wall region of highest scalar fluctuations is seen to vary circumferentially and in depth in the branch a great deal depending on the velocity ratio. The power spectra of the mixing scalar in the region of turbulent penetration are found to be dominated by high amplitude fluctuations at low frequencies, of particular interest to thermal fatigue. Artificial velocity oscillations in the main pipe manifest in the mixing spectra in the branch line in the form of a peak, the magnitude of which grows with increasing local RMS.

Regional Model Nesting Within GFS Daily Forecasts Over West Africa

Science.gov (United States)

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

2010-01-01

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

Astronomy Landscape in Africa

Science.gov (United States)

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.

Analysis of measured L-band airborne land clutter from the Western Cape region of South Africa

CSIR Research Space (South Africa)

De Witt, JJ

2014-10-01

Full Text Available -band Airborne Land Clutter from the Western Cape region of South Africa J.J. de Witt and J.J. Strydom Abstract: This paper presents backscatter analysis of L-band land clutter data, measured from an airborne platform, over various terrain types...

Energy in Africa by 2050

International Nuclear Information System (INIS)

Favennec, Jean-Pierre; Adedjoumon, Christele; Duhamel, Bernard; Giri, Jacques; Gilles, Henri; Tronche, Alain

2009-01-01

In this report, the authors propose an overview of the main perceivable orientations of the energy sector in African until 2050, and suggest some other perspectives and state some recommendations for new guidelines. In its first part, the report proposes an analysis of the present situation and identifies possible directions. Several issues are addressed: major challenges, African as a continent of energy divide, energy efficiency in Africa, situation of energy per sectors, per energies and per regions. The second part addresses the prospective dimension (by 2050): world context in 2050, Africa within this context, tomorrow's energy and economy for Africa. Appendices address the following topics: the Energizing Africa initiative, promotion of substitutes for wood, alternative fuels and energies for transport, energy in Africa per region and per source

Marketing of irradiated commodities in South Africa

Energy Technology Data Exchange (ETDEWEB)

Du Plessis, T A; Stevens, R C.B.

1985-01-01

Although the industrial exploitation of radiation processing in the medical and allied fields has been successfully marketed and applied for the past two decades in South Africa, the introduction of food radurisation on an industrial level adds a completely new dimension to the marketing of this processing technique. Extensive research into the use of radiation for the treatment of various foodstuffs has been carried out by the Nuclear Development Corporation of South Africa for more than a decade, resulting in South Africa being one of the first countries where a commercial irradiator dedicated to this branch of radiation processing, was established. The marketing of this process is especially difficult due to the emotive aspects associated with radiation and man's sensitive reaction to anything pertaining to his food. This situation was made even more difficult by the general public's apprehension towards nuclear activities throughout the world. Details are given of the steps taken in South Africa to transform the unfavourable public image associated with the process. The approach proved to be very successful and greatly assisted in creating a climate whereby the public in South Africa today generally has a favourable attitude towards the radurisation of foodstuffs.

Marketing of irradiated commodities in South Africa

International Nuclear Information System (INIS)

Du Plessis, T.A.; Stevens, R.C.B.

1985-01-01

Although the industrial exploitation of radiation processing in the medical and allied fields has been successfully marketed and applied for the past two decades in South Africa, the introduction of food radurisation on an industrial level adds a completely new dimension to the marketing of this processing technique. Extensive research into the use of radiation for the treatment of various foodstuffs has been carried out by the Nuclear Development Corporation of South Africa for more than a decade, resulting in South Africa being one of the first countries where a commercial irradiator dedicated to this branch of radiation processing, was established. The marketing of this process is especially difficult due to the emotive aspects associated with radiation and man's sensitive reaction to anything pertaining to his food. This situation was made even more difficult by the general public's apprehension towards nuclear activities throughout the world. Details are given of the steps taken in South Africa to transform the unfavourable public image associated with the process. The approach proved to be very successful and greatly assisted in creating a climate whereby the public in South Africa today generally has a favourable attitude towards the radurisation of foodstuffs. (author)

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

CSIR Research Space (South Africa)

Garland, Rebecca M

2015-10-01

Full Text Available Regional climate modelling was used to produce high resolution climate projections for Africa, under a “business as usual scenario”, that were translated into potential health impacts utilizing a heat index that relates apparent temperature...

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

Science.gov (United States)

Alonso, Santos; Armour, John A. L.

2001-01-01

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

Chikungunya: Its History in Africa and Asia and Its Spread to New Regions in 2013-2014.

Science.gov (United States)

Zeller, Herve; Van Bortel, Wim; Sudre, Bertrand

2016-12-15

Chikungunya virus (CHIKV) is transmitted by Aedes aegypti and Aedes albopictus mosquitoes and causes febrile illness with severe arthralgia in humans. There are 3 circulating CHIKV genotypes, Asia, East/Central/South Africa, and West Africa. CHIKV was first reported in 1953 in Tanzania, and up until the early 2000s, a few outbreaks and sporadic cases of CHIKV were mainly reported in Africa and Asia. However, from 2004 to 2005, a large epidemic spanned from Kenya over to the southwestern Indian Ocean region, India, and Southeast Asia. Identified in 2005, the E1 glycoprotein A226V mutation of the East/Central/South Africa genotype conferred enhanced transmission by the A. albopictus mosquito and has been implicated in CHIKV's further spread in the last decade. In 2013, the Asian CHIKV genotype emerged in the Caribbean and quickly took the Americas by storm. This review will discuss the history of CHIKV as well as its expanding geographic distribution. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

The reporting of a Bacillus anthracis B-clade strain in South Africa after more than 20 years.

Science.gov (United States)

Lekota, K E; Hassim, A; Rogers, P; Dekker, E H; Last, R; de Klerk-Lorist, L; van Heerden, H

2018-05-02

Anthrax is a disease with an age old history in Africa caused by the Gram-positive endospore forming soil bacterium Bacillus anthracis. Epizootics of wild ungulates occur annually in the enzootic region of Pafuri, Kruger National Park (KNP) in the Limpopo Province of South Africa. Rigorous routine surveillance and diagnostics in KNP, has not revealed these rare isolates since the 1990s, despite unabated annual outbreaks. In 2011 a cheetah was diagnosed as anthrax positive from a private game reserve in Limpopo Province and reported to State Veterinary Services for further investigation. Isolation, molecular diagnostics, whole genome sequencing and comparative genomics were carried out for B. anthracis KC2011. Bacteriological and molecular diagnostics confirmed the isolate as B. anthracis. Subsequent typing and whole genome single nucleotide polymorphisms analysis indicated it clustered alongside B. anthracis SA A0091 in the B.Br.010 SNP branch. Unlike B. anthracis KrugerB strain, KC2011 strain has unique SNPs and represents a new branch in the B-clade. The isolation and genotypic characterisation of KC2011 demonstrates a gap in the reporting of anthrax outbreaks in the greater Limpopo province area. The identification of vulnerable and susceptible cheetah mortalities due to this strain has implications for conservation measures and disease control.

RAB-10 Regulates Dendritic Branching by Balancing Dendritic Transport

Science.gov (United States)

Taylor, Caitlin A.; Yan, Jing; Howell, Audrey S.; Dong, Xintong; Shen, Kang

2015-01-01

The construction of a large dendritic arbor requires robust growth and the precise delivery of membrane and protein cargoes to specific subcellular regions of the developing dendrite. How the microtubule-based vesicular trafficking and sorting systems are regulated to distribute these dendritic development factors throughout the dendrite is not well understood. Here we identify the small GTPase RAB-10 and the exocyst complex as critical regulators of dendrite morphogenesis and patterning in the C. elegans sensory neuron PVD. In rab-10 mutants, PVD dendritic branches are reduced in the posterior region of the cell but are excessive in the distal anterior region of the cell. We also demonstrate that the dendritic branch distribution within PVD depends on the balance between the molecular motors kinesin-1/UNC-116 and dynein, and we propose that RAB-10 regulates dendrite morphology by balancing the activity of these motors to appropriately distribute branching factors, including the transmembrane receptor DMA-1. PMID:26633194

Rising global burden of breast cancer: the case of sub-Saharan Africa (with emphasis on Nigeria) and implications for regional development: a review.

Science.gov (United States)

Azubuike, Samuel O; Muirhead, Colin; Hayes, Louise; McNally, Richard

2018-03-22

Despite mortality from breast cancer in Africa being higher than in high income countries, breast cancer has not been extensively studied in the region. The aim of this paper was to highlight the rising burden of breast cancer with an emphasis on sub-Saharan Africa as well as trends, characteristics, controversies and their implications for regional development. A review of published studies and documents was conducted in Medline, Scopus, Pubmed and Google using combinations of key words-breast neoplasm, breast cancer, cancer, incidence, mortality, Africa, Nigeria. Graphical and frequency analyses were carried out on some of the incidence and mortality figures retrieved from published papers and the GLOBOCAN website. Globally, about 25% and 15% of all new cancer cases and cancer deaths respectively among females were due to breast cancer. Africa currently had the highest age-standardized breast cancer mortality rate globally, with the highest incidence rates being recorded within the sub-Saharan African sub-region. Incidence trends such as inherently aggressive tumour and younger age profile had been subject to controversies. Certain factors such as westernized diet, urbanization and possibly increasing awareness had been implicated, though their specific contributions were yet to be fully established. Unless urgent action is taken, breast cancer will compound sub-Saharan Africa's disease burden, increase poverty and gender inequality as well as reverse the current global gains against maternal and neonatal mortality.

Regional myocardial extraction of a radioiodinated branched chain fatty acid during right ventricular pressure overload due to acute pulmonary hypertension

International Nuclear Information System (INIS)

Hurford, W.; Lowenstein, E.; Zapol, W.; Barlai-Kovach, M.; Livni, E.; Elmaleh, D.R.; Strauss, H.W.

1985-01-01

To determine whether branched chain fatty acid extraction is reduced during right ventricular (RV) dysfunction due to acute pulmonary artery hypertension, studies were done in 6 anesthetized dogs. Regional branched chain fatty acid extraction was measured by comparing the myocardial uptake of I-125 labeled 15-[p-(iodophenyl)]-3-methylpentadecanoic acid (I-PDA) to myocardial blood flow. Acute pulmonary hypertension was induced by incremental intravenous injection of 100 micron diameter glass beads into six pentobarbital anesthetized, mechanically ventilated dogs. Myocardial blood flow was measured by radiolabeled microspheres both under baseline conditions and during pulmonary hypertension. Mean RV pressure rose from 12 +- 2 (mean +- SEM) to 30 +-3mmHg resulting in a 225 +- 16% increase in RV stroke work. RV ejection fraction, as assessed by gated blood pool scans fell from 39 +- 2 to 18 +- 2%. Left ventricular (LV) pressures, stroke work and ejection fraction were unchanged. Myocardial blood flow increased 132 + 59% in the RV free wall and 67 +- 22% in the RV septum. LV blood flow was unchanged. Despite increased RV work and myocardial blood flow, no differences were noted in the branched chain fatty acid extraction ratios among LV or RV free walls or septum. The authors conclude that early RV dysfunction associated with pulmonary artery hypertension is not due to inadequate myocardial blood flow or branched chain fatty acid extraction

The Formation of the Eastern Africa Rabies Network: A Sub-Regional Approach to Rabies Elimination.

Science.gov (United States)

Pieracci, Emily G; Scott, Terence P; Coetzer, Andre; Athman, Mwatondo; Mutembei, Arithi; Kidane, Abraham Haile; Bekele, Meseret; Ayalew, Girma; Ntegeyibizaza, Samson; Assenga, Justine; Markalio, Godson; Munyua, Peninah; Nel, Louis H; Blanton, Jesse

2017-01-01

International rabies networks have been formed in many of the canine-rabies endemic regions around the world to create unified and directed regional approaches towards elimination. The aim of the first sub-regional Eastern Africa rabies network meeting, which included Kenya, Ethiopia, Tanzania, Rwanda, and Uganda, was to discuss how individual country strategies could be coordinated to address the unique challenges that are faced within the network. The Stepwise Approach towards Rabies Elimination and the Global Dog Rabies Elimination Pathway tool were used to stimulate discussion and planning to achieve the elimination of canine-mediated human rabies by 2030. Our analysis estimated a total dog population of 18.3 million dogs in the Eastern Africa region. The current dog vaccination coverage was estimated to be approximately 5% (915,000 dogs), with an estimated 4910 vaccinators available. Assuming that every vaccinator performs rabies vaccination, this equated to each vaccinator currently vaccinating 186 dogs per year, whilst the target would be to vaccinate 2609 dogs every year for the community to reach 70% coverage. In order to achieve the World Health Organization-recommended 70% vaccination coverage, an additional 11 million dogs need to be vaccinated each year, pointing to an average annual shortfall of $ 23 million USD in current spending to achieve elimination by 2030 across the region. Improved vaccination efficiency within the region could be achieved by improving logistics and/or incorporating multiple vaccination methods to increase vaccinator efficiency, and could serve to reduce the financial burden associated with rabies elimination. Regional approaches to rabies control are of value, as neighboring countries can share their unique challenges while, at the same time, common approaches can be developed and resource-saving strategies can be implemented.

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

Science.gov (United States)

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

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

Science.gov (United States)

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

2015-04-01

-atmospheric processes involved in the atmospheric branch of the water cycle in West Africa, based on our WRF simulation. We will particularly focus on the respective contribution of local and remote water vapor to atmospheric processes involved in local precipitation, and compare the results at the 100 and 1000 km2 scales. The potential impact of local land use change on local precipitation will finally be discussed based on this quantitative analysis.

Plexin A3 and turnout regulate motor axonal branch morphogenesis in zebrafish.

Directory of Open Access Journals (Sweden)

Rajiv Sainath

Full Text Available During embryogenesis motor axons navigate to their target muscles, where individual motor axons develop complex branch morphologies. The mechanisms that control axonal branching morphogenesis have been studied intensively, yet it still remains unclear when branches begin to form or how branch locations are determined. Live cell imaging of individual zebrafish motor axons reveals that the first axonal branches are generated at the ventral extent of the myotome via bifurcation of the growth cone. Subsequent branches are generated by collateral branching restricted to their synaptic target field along the distal portion of the axon. This precisely timed and spatially restricted branching process is disrupted in turnout mutants we identified in a forward genetic screen. Molecular genetic mapping positioned the turnout mutation within a 300 kb region encompassing eight annotated genes, however sequence analysis of all eight open reading frames failed to unambiguously identify the turnout mutation. Chimeric analysis and single cell labeling reveal that turnout function is required cell non-autonomously for intraspinal motor axon guidance and peripheral branch formation. turnout mutant motor axons form the first branch on time via growth cone bifurcation, but unlike wild-type they form collateral branches precociously, when the growth cone is still navigating towards the ventral myotome. These precocious collateral branches emerge along the proximal region of the axon shaft typically devoid of branches, and they develop into stable, permanent branches. Furthermore, we find that null mutants of the guidance receptor plexin A3 display identical motor axon branching defects, and time lapse analysis reveals that precocious branch formation in turnout and plexin A3 mutants is due to increased stability of otherwise short-lived axonal protrusions. Thus, plexin A3 dependent intrinsic and turnout dependent extrinsic mechanisms suppress collateral branch

Adherence to antiretroviral therapy for HIV in sub-Saharan Africa and Asia: a comparative analysis of two regional cohorts.

Science.gov (United States)

Bijker, Rimke; Jiamsakul, Awachana; Kityo, Cissy; Kiertiburanakul, Sasisopin; Siwale, Margaret; Phanuphak, Praphan; Akanmu, Sulaimon; Chaiwarith, Romanee; Wit, Ferdinand W; Sim, Benedict Lh; Boender, Tamara Sonia; Ditangco, Rossana; Rinke De Wit, Tobias F; Sohn, Annette H; Hamers, Raph L

2017-03-03

Our understanding of how to achieve optimal long-term adherence to antiretroviral therapy (ART) in settings where the burden of HIV disease is highest remains limited. We compared levels and determinants of adherence over time between HIV-positive persons receiving ART who were enrolled in a bi-regional cohort in sub-Saharan Africa and Asia. This multicentre prospective study of adults starting first-line ART assessed patient-reported adherence at follow-up clinic visits using a 30-day visual analogue scale. Determinants of suboptimal adherence (Africa vs. Asia) was assessed as a potential effect modifier. Of 13,001 adherence assessments in 3934 participants during the first 24 months of ART, 6.4% (837) were suboptimal, with 7.3% (619/8484) in the African cohort versus 4.8% (218/4517) in the Asian cohort ( p  Africa (OR 5.8, 95% CI 4.3-7.7; p  health system resources may explain regional differences. Adherence-enhancing interventions should address patient-reported barriers tailored to local settings, prioritizing the first years of ART.

Symposium on nuclear technology in Southern Africa. Final programme [and papers

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-06-01

The symposium on Nuclear Technology in Southern Africa was organized by the Institution of Nuclear Engineers South Africa Branch. It was held at ESKOM Megawatt Park, June 20 and 21, 1990. The scope of the meeting covered nuclear activities in South Africa including performance and industry perspective of Koeberg, planning for nuclear siting, uranium resources, production and demand, uranium conversion and enrichment, fuel fabrication and post irradiation examination. National nuclear programmes of France, Spain, the United Kingdom and the United States were presented and the pubic acceptance in South Africa discussed. In addition papers dealt with future reactor types of advanced light water reactors and fast breeders, nuclear developments in Europe and Far East and accident management in the US. Developments in Southern Africa concentrated on the role of nuclear energy in the future energy strategy, trends in nuclear licensing and prerequisites for successful nuclear generation. 21 papers are indexed individually.

Symposium on nuclear technology in Southern Africa. Final programme [and papers

International Nuclear Information System (INIS)

1990-06-01

The symposium on Nuclear Technology in Southern Africa was organized by the Institution of Nuclear Engineers South Africa Branch. It was held at ESKOM Megawatt Park, June 20 and 21, 1990. The scope of the meeting covered nuclear activities in South Africa including performance and industry perspective of Koeberg, planning for nuclear siting, uranium resources, production and demand, uranium conversion and enrichment, fuel fabrication and post irradiation examination. National nuclear programmes of France, Spain, the United Kingdom and the United States were presented and the pubic acceptance in South Africa discussed. In addition papers dealt with future reactor types of advanced light water reactors and fast breeders, nuclear developments in Europe and Far East and accident management in the US. Developments in Southern Africa concentrated on the role of nuclear energy in the future energy strategy, trends in nuclear licensing and prerequisites for successful nuclear generation. 21 papers are indexed individually

South Africa

Science.gov (United States)

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

Branching structure and strain hardening of branched metallocene polyethylenes

International Nuclear Information System (INIS)

Torres, Enrique; Li, Si-Wan; Costeux, Stéphane; Dealy, John M.

2015-01-01

There have been a number of studies of a series of branched metallocene polyethylenes (BMPs) made in a solution, continuous stirred tank reactor (CSTR) polymerization. The materials studied vary in branching level in a systematic way, and the most highly branched members of the series exhibit mild strain hardening. An outstanding question is which types of branched molecules are responsible for strain hardening in extension. This question is explored here by use of polymerization and rheological models along with new data on the extensional flow behavior of the most highly branched members of the set. After reviewing all that is known about the effects of various branching structures in homogeneous polymers and comparing this with the structures predicted to be present in BMPs, it is concluded that in spite of their very low concentration, treelike molecules with branch-on-branch structure provide a large number of deeply buried inner segments that are essential for strain hardening in these polymers

Branching structure and strain hardening of branched metallocene polyethylenes

Energy Technology Data Exchange (ETDEWEB)

Torres, Enrique; Li, Si-Wan; Costeux, Stéphane; Dealy, John M., E-mail: john.dealy@mcgill.ca [Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C4 (Canada)

2015-09-15

There have been a number of studies of a series of branched metallocene polyethylenes (BMPs) made in a solution, continuous stirred tank reactor (CSTR) polymerization. The materials studied vary in branching level in a systematic way, and the most highly branched members of the series exhibit mild strain hardening. An outstanding question is which types of branched molecules are responsible for strain hardening in extension. This question is explored here by use of polymerization and rheological models along with new data on the extensional flow behavior of the most highly branched members of the set. After reviewing all that is known about the effects of various branching structures in homogeneous polymers and comparing this with the structures predicted to be present in BMPs, it is concluded that in spite of their very low concentration, treelike molecules with branch-on-branch structure provide a large number of deeply buried inner segments that are essential for strain hardening in these polymers.

INVERSION SYMMETRY, ARCHITECTURE AND DISPERSITY, AND THEIR EFFECTS ON THERMODYNAMICS IN BULK AND CONFINED REGIONS: FROM RANDOMLY BRANCHED POLYMERS TO LINEAR CHAINS, STARS AND DENDRIMERS

Directory of Open Access Journals (Sweden)

P.D.Gujrati

2002-01-01

Full Text Available Theoretical evidence is presented in this review that architectural aspects can play an important role, not only in the bulk but also in confined geometries by using our recursive lattice theory, which is equally applicable to fixed architectures (regularly branched polymers, stars, dendrimers, brushes, linear chains, etc. and variable architectures, i.e. randomly branched structures. Linear chains possess an inversion symmetry (IS of a magnetic system (see text, whose presence or absence determines the bulk phase diagram. Fixed architectures possess the IS and yield a standard bulk phase diagram in which there exists a theta point at which two critical lines C and C' meet and the second virial coefficient A2 vanishes. The critical line C appears only for infinitely large polymers, and an order parameter is identified for this criticality. The critical line C' exists for polymers of all sizes and represents phase separation criticality. Variable architectures, which do not possess the IS, give rise to a topologically different phase diagram with no theta point in general. In confined regions next to surfaces, it is not the IS but branching and monodispersity, which becomes important in the surface regions. We show that branching plays no important role for polydisperse systems, but become important for monodisperse systems. Stars and linear chains behave differently near a surface.

Branching in current-voltage characteristics of intrinsic Josephson junctions

International Nuclear Information System (INIS)

Shukrinov, Yu M; Mahfouzi, F

2007-01-01

We study branching in the current-voltage characteristics of the intrinsic Josephson junctions of high-temperature superconductors in the framework of the capacitively coupled Josephson junction model with diffusion current. A system of dynamical equations for the gauge-invariant phase differences between superconducting layers for a stack of ten intrinsic junctions has been numerically solved. We have obtained a total branch structure in the current-voltage characteristics. We demonstrate the existence of a 'breakpoint region' on the current-voltage characteristics and explain it as a result of resonance between Josephson and plasma oscillations. The effect of the boundary conditions is investigated. The existence of two outermost branches and correspondingly two breakpoint regions for the periodic boundary conditions is shown. One branch, which is observed only at periodic boundary conditions, corresponds to the propagating of the plasma mode. The second one corresponds to the situation when the charge oscillations on the superconducting layers are absent, excluding the breakpoint. A time dependence of the charge oscillations at breakpoints is presented

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

Science.gov (United States)

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.

Branched nanotrees with immobilized acetylcholine esterase for nanobiosensor applications

DEFF Research Database (Denmark)

Risveden, Klas; Dick, Kimberly A; Bhand, Sunil

2010-01-01

A novel lab-on-a-chip nanotree enzyme reactor is demonstrated for the detection of acetylcholine. The reactors are intended for use in the RISFET (regional ion sensitive field effect transistor) nanosensor, and are constructed from gold-tipped branched nanorod structures grown on SiN(x)-covered w......A novel lab-on-a-chip nanotree enzyme reactor is demonstrated for the detection of acetylcholine. The reactors are intended for use in the RISFET (regional ion sensitive field effect transistor) nanosensor, and are constructed from gold-tipped branched nanorod structures grown on Si......N(x)-covered wafers. Two different reactors are shown: one with simple, one-dimensional nanorods and one with branched nanorod structures (nanotrees). Significantly higher enzymatic activity is found for the nanotree reactors than for the nanorod reactors, most likely due to the increased gold surface area...

Application of the Regional Water Mass Variations from GRACE Satellite Gravimetry to Large-Scale Water Management in Africa

Directory of Open Access Journals (Sweden)

Guillaume Ramillien

2014-08-01

Full Text Available Time series of regional 2° × 2° Gravity Recovery and Climate Experiment (GRACE solutions of surface water mass change have been computed over Africa from 2003 to 2012 with a 10-day resolution by using a new regional approach. These regional maps are used to describe and quantify water mass change. The contribution of African hydrology to actual sea level rise is negative and small in magnitude (i.e., −0.1 mm/y of equivalent sea level (ESL mainly explained by the water retained in the Zambezi River basin. Analysis of the regional water mass maps is used to distinguish different zones of important water mass variations, with the exception of the dominant seasonal cycle of the African monsoon in the Sahel and Central Africa. The analysis of the regional solutions reveals the accumulation in the Okavango swamp and South Niger. It confirms the continuous depletion of water in the North Sahara aquifer at the rate of −2.3 km3/y, with a decrease in early 2008. Synergistic use of altimetry-based lake water volume with total water storage (TWS from GRACE permits a continuous monitoring of sub-surface water storage for large lake drainage areas. These different applications demonstrate the potential of the GRACE mission for the management of water resources at the regional scale.

The relationship between urban neighbourhood type and commuting distance in Gauteng City region, South Africa. A preliminary analysis

CSIR Research Space (South Africa)

Moselakgomo, M

2013-07-01

Full Text Available This paper uses the 2001 and 2013 Gauteng household travel survey datasets to investigate the nature of change in commuting distances of commuters from different neighbourhood types in the Gauteng City Region, in South Africa. The investigation...

West Africa

International Development Research Centre (IDRC) Digital Library (Canada)

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NESDA: Network for Environment and Sustainable Development in Africa .... Some of the key natural resources of the region are transboundary—case of surface ..... The goals of the present study on the risk-sharing approach to regional ...... The reserve includes a World Heritage Site (Djoudj) and 5 Ramsar sites (Djoudj,.

U-Th dating reveals regional-scale decline of branching Acropora corals on the Great Barrier Reef over the past century

Science.gov (United States)

Clark, Tara R.; Roff, George; Zhao, Jian-xin; Feng, Yue-xing; Done, Terence J.; McCook, Laurence J.; Pandolfi, John M.

2017-09-01

Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (shifted baseline.

Comparisons of invasive plants in southern Africa originating from southern temperate, northern temperate and tropical regions

Directory of Open Access Journals (Sweden)

L. Henderson

2006-08-01

Full Text Available A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112 as from the tropics (121. Most southern temperate species came from Australia (28/36, most tropical species from tropical America (92/121 and most northern temperate species from Europe (including the Mediterranean and Asia (58/76. Transformers account for 33% of  all species. More transformers are of tropical origin (36 than of northern temperate (24 and southern temperate origin (18. However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.

Why Africa matters: evolution of Old World Salvia (Lamiaceae) in Africa.

Science.gov (United States)

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.

Regional scenarios of future climate change over southern Africa

CSIR Research Space (South Africa)

Engelbrecht, F

2010-08-01

Full Text Available positive chill units. 31 Winter (Apr - Sep) CASE STUDY - Global change impacts on agriculture and water: South Africa?s Garden Route 33 7 Global change and human health 35 CASE STUDY - Environmental health: Bridging the gap between traditional... days). Annual (Jan - Dec) 31 Map 6.2 Intermediate future - present (degree days). Accumulated heat units. 31 Annual (Jan - Dec) Map 6.3 Accumulated positive chill units. Winter (Apr - Sep) 31 Map 6.4 Intermediate future - present. Accumulated...

Disentangling regional trade agreements, trade flows and tobacco affordability in sub-Saharan Africa.

Science.gov (United States)

Appau, Adriana; Drope, Jeffrey; Labonté, Ronald; Stoklosa, Michal; Lencucha, Raphael

2017-11-14

In principle, trade and investment agreements are meant to boost economic growth. However, the removal of trade barriers and the provision of investment incentives to attract foreign direct investments may facilitate increased trade in and/or more efficient production of commodities considered harmful to health such as tobacco. We analyze existing evidence on trade and investment liberalization and its relationship to tobacco trade in Sub-Saharan African countries. We compare tobacco trading patterns to foreign direct investments made by tobacco companies. We estimate and compare changes in the Konjunkturforschungsstelle (KOF) Economic Globalization measure, relative price measure and cigarette prices. Preferential regional trade agreements appear to have encouraged the consolidation of cigarette production, which has shaped trading patterns of tobacco leaf. Since 2002, British American Tobacco has invested in tobacco manufacturing facilities in Nigeria, Kenya and South Africa strategically located to serve different regions in Africa. Following this, British America Tobacco closed factories in Ghana, Rwanda, Uganda, Mauritius and Angola. At the same time, Malawi and Tanzania exported a large percentage of tobacco leaf to European countries. After 2010, there was an increase in tobacco exports from Malawi and Zambia to China, which may be a result of preferential trade agreements the EU and China have with these countries. Economic liberalization has been accompanied by greater cigarette affordability for the countries included in our analysis. However, only excise taxes and income have an effect on cigarette prices within the region. These results suggest that the changing economic structures of international trade and investment are likely heightening the efficiency and effectiveness of the tobacco industry. As tobacco control advocates consider supply-side tobacco control interventions, they must consider carefully the effects of these economic agreements and

Controlling branching in streamer discharge by laser background ionization

International Nuclear Information System (INIS)

Takahashi, E; Kato, S; Furutani, H; Sasaki, A; Kishimoto, Y

2011-01-01

Irradiation with a KrF laser controlled the positive streamer branching in atmospheric argon gas. This laser irradiation changed the amount of background ionization before the streamer discharge. Measuring the ionization current allowed us to evaluate the initial electron density formed by the KrF laser. We observed characteristic feather-like branching structure and found that it was only suppressed in the irradiated region. The threshold of ionization density which can influence the branching was evaluated to be 5 x 10 5 cm -3 . The relationship between the size of avalanche head and mean distance between initial electrons explained this suppression behaviour. These experimental results support that the feather-like structure originates from the branching model of Loeb-Meek, a probabilistic merging of individual avalanches.

Vegetation Dynamics in the Upper Guinean Forest Region of West Africa from 2001 to 2015

Directory of Open Access Journals (Sweden)

Zhihua Liu

2016-12-01

Full Text Available The Upper Guinea Forest (UGF region of West Africa is one of the most climatically marginal and human-impacted tropical forest regions in the world. Research on the patterns and drivers of vegetation change is critical for developing strategies to sustain ecosystem services in the region and to understand how climate and land use change will affect other tropical forests around the globe. We compared six spectral indices calculated from the 2001–2015 MODIS optical-infrared reflectance data with manually-interpreted measurements of woody vegetation cover from high resolution imagery. The tasseled cap wetness (TCW index was found to have the strongest association with woody vegetation cover, whereas greenness indices, such as the enhanced vegetation index (EVI, had relatively weak associations with woody cover. Trends in woody vegetation cover measured with the TCW index were analyzed using Mann–Kendall statistics and were contrasted with trends in vegetation greenness measured with EVI. In the drier West Sudanian Savanna and Guinean Forest-Savanna Mosaic ecoregions, EVI trends were primarily positive, and TCW trends were primarily negative, suggesting that woody vegetation cover was decreasing, while herbaceous vegetation cover is increasing. In the wettest tropical forests in the Western Guinean Lowland Forest ecoregion, declining trends in both TCW and EVI were indicative of widespread forest degradation resulting from human activities. Across all ecoregions, declines in woody cover were less prevalent in protected areas where human activities were restricted. Multiple lines of evidence suggested that human land use and resource extraction, rather than climate trends or short-term climatic anomalies, were the predominant drivers of recent vegetation change in the UGF region of West Africa.

Electricity access. Southern Africa sub-regional study: South Africa and Zimbabwe

Energy Technology Data Exchange (ETDEWEB)

Davidson, O.R.; Mwakasonda, S.A.

2004-07-01

, grants and other sources. A standard connection subsidy is given to new households under the national electrification programme, with subsidy levels differentiated by geographic region, supply technology or other factors. The Electricity Basic Services Support Tariff (EBSST) is another initiative that the South African Government established in 2002 to provide free electricity of 20-50 kWh per household, per month to the poorest segments of the population. The support tariff is intended to provide an approximate amount of power required for basic lighting, media access and limited cooking. It is worth about ZAR 200 per year to a poor household. The initial cost to government is estimated at about ZAR 630 million annually and it is expected to increase with growth in the rate of electrification. An offgrid electrification programme that mainly involves the dissemination of solar home systems (SHS) to the disadvantaged areas was started in 2000. At present, about 12,000 such systems have been disseminated with over 70 per cent direct subsidy from government. Zimbabwe is a landlocked country in Southern Africa and a member of SADC. Independence in April 1980 ended its white-minority rule, with the country inheriting all the ilts of a racially divided society. Zimbabwe's economy relies heavily on agricultural trops, with significant levels of poverty that are Glosely related to the country's history of governance by the minority white government. After independence, the government embarked on policies aimed at redressing economic inbalances of the past, including reforms in the power sector. Power sector objectives in Zimbabwe include increasing electricity access to previously disadvantaged people through gnid electricity expansion and offgrid electrification. The Zimbabwe Electricity Supply Authority (ZESA) is the main utility responsible for the generation, transmission and distribution of electricity. Unfortunately, ZESA generating capacity is not sufficient to

Dynamic Models of Earthquake Rupture along branch faults of the Eastern San Gorgonio Pass Region in CA using Complex Fault Structure

Science.gov (United States)

Douilly, R.; Oglesby, D. D.; Cooke, M. L.; Beyer, J. L.

2017-12-01

Compilation of geomorphic and paleoseismic data have illustrated that the right-lateral Coachella segment of the southern San Andreas Fault is past its average recurrence time period. On its western edge, this fault segment is split into two branches: the Mission Creek strand, and the Banning fault strand, of the San Andreas. Depending on how rupture propagates through this region, there is the possibility of a through-going rupture that could lead to the channeling of damaging seismic energy into the Los Angeles Basin. The fault structures and rupture scenarios on these two strands are potentially very different, so it is important to determine which strand is a more likely rupture path, and under which circumstances rupture will take either one. In this study, we focus on the effect of different assumptions about fault geometry and stress pattern on the rupture process to test those scenarios and thus investigate the most likely path of a rupture that starts on the Coachella segment. We consider two types of fault geometry based on the SCEC Community Fault Model and create a 3D finite element mesh. These two meshes are then incorporated into the finite element method code FaultMod to compute a physical model for the rupture dynamics. We use the slip-weakening friction law, and we consider different assumptions of background stress such as constant tractions, regional stress regimes of different orientations, heterogeneous off-fault stresses and the results of long-term stressing rates from quasi-static crustal deformation models that consider time since last event on each fault segment. Both the constant and regional stress distribution show that it is more likely for the rupture to branch from the Coachella segment to the Mission Creek compared to the Banning fault segment. For the regional stress distribution, we encounter cases of super-shear rupture for one type of fault geometry and sub-shear rupture for the other one. The fault connectivity at this branch

Evolution of Corruption in Sub-Saharan Africa - from Nkruma To Mutharika The 2nd: Case Study Of South Africa

Directory of Open Access Journals (Sweden)

Mavhungu Abel Mafukata

2015-03-01

Full Text Available Since Sub-Saharan Africa's first independence in Ghana, the region has experienced massive and costly political and bureaucratic corruption within public service and administration. The causes of the corruption, its nature and form are wide and intertwined. In Sub-Saharan Africa, efforts to curb corruption have failed to discard it. The paper focused on the period from Nkruma in Ghana to Mutharika the 2nd in Malawi. This paper reviewed existing literature on political and bureaucratic corruption in Sub-Saharan Africa while on the other hand the paper employed key informant interviews to gather the required data to investigate, analyse and profile the genesis and evolution of corruption in Sub-Saharan Africa. The key informant interviews were employed to solicit public views and opinion from nineteen key informant participants (n=19 selected from 11 countries in Sub-Saharan Africa. The paper found that corruption is legendary; has entrenched itself to becoming some sort of culture in the region, and has become the most difficult socio-economic challenge to resolve in the region despite the various anti-corruption efforts employed by stakeholders to curb it. It emerged through the study that law-enforcement efforts against corruption need some reinforcement in order to be effective and eficient in uprooting corruption in the region. If Sub-Saharan Africa fails to address its corruption challenge, its development prospects would seriously curtailed.

Africa's Expanding Population: Old Problems, New Policies.

Science.gov (United States)

Goliber, Thomas J.

1989-01-01

Sub-Saharan Africa faces a historic challenge: to achieve economic and social progress while experiencing extraordinary population growth. With an estimated 1989 population of 512 million, the 42 countries of sub-Saharan Africa have the highest birth and death rates of any major world region. Throughout the region, population has outstripped…

On the pace of fertility decline in sub-Saharan Africa

Directory of Open Access Journals (Sweden)

David Shapiro

2017-10-01

Full Text Available Background: This descriptive finding examines the comparative pace of fertility decline in sub-Saharan Africa, relative to Asia, Latin America and the Caribbean, and Northern Africa. Objective: We seek to determine if fertility decline has been slower in sub-Saharan Africa than elsewhere in the developing world. Methods: United Nations 2017 estimates of national fertility are used in assessing the comparative pace of fertility decline, and the four regions are compared in terms of how far they are into their fertility transition. Results: The data shows clearly that fertility decline in sub-Saharan Africa, still at a comparatively early stage, has been considerably slower than the earlier declines in Asia, Latin America and the Caribbean, and Northern Africa at comparable stages of the transition, and displays less within-region heterogeneity than the transitions in these other regions. Conclusions: The slower pace of fertility decline in sub-Saharan Africa, in conjunction with the high current fertility levels in the region, means that in the absence of policies seeking to accelerate fertility decline, sub-Saharan Africa will continue to experience rapid population growth that in turn will constrain its development. Contribution: Presentation of data in a novel way (Figures 2‒4, and associated calculations unambiguously demonstrates the slow pace of fertility decline in sub-Saharan Africa compared with other regions of the world.

Impacts of regional land-grab on regional hydroclimate in southeastern Africa via modeling and remote sensing

Science.gov (United States)

Maksimowicz, M.; Masarik, M. T.; Brandt, J.; Flores, A. N.

2017-12-01

Land use/land cover (LULC) change directly impacts the partitioning of surface mass and energy fluxes. Regional-scale weather and climate are potentially altered by LULC if the resultant changes in partitioning of surface energy fluxes are significant enough to induce changes in the evolution of the planetary boundary layer and its interaction with the atmosphere above. Dynamics of land use, particularly those related to the social dimensions of the Earth System, are often simplified or not represented in regional land-atmosphere models or Earth System Models. This study explores the role of LULC change on a regional hydroclimate system, focusing on potential hydroclimate changes arising from timber harvesting due to a land grab boom in Mozambique. We also focus more narrowly at quantifying regional impacts on Gorongosa National Park, a nationally important economic and biodiversity resource in southeastern Africa. After nationalizing all land in 1975 after Mozambique gained independence, complex social processes, including an extended low intensity conflict civil war and economic hardships, led to an escalation of land use rights grants to foreign governments. Between 2004 and 2009, large tracts of land were requested for timber. Here we use existing tree cover loss datasets to more accurately represent land cover within a regional weather model. LULC in a region encompassing Gorongosa is updated at three instances between 2001 and 2014 using a tree cover loss dataset. We use these derived LULC datasets to inform lower boundary conditions in the Weather Research and Forecasting (WRF) model. To quantify potential hydrometeorological changes arising from land use change, we performed a factorial-like experiment by mixing input LULC maps and atmospheric forcing data from before, during, and after the land grab. Results suggest that the land grab has impacted microclimate parameters in a significant way via direct and indirect impacts on land-atmosphere interactions

Geology of the Cane Branch and Helton Branch watershed areas, McCreary County, Kentucky

Science.gov (United States)

Lyons, Erwin J.

1957-01-01

Cane Branch and Helton Branch in McCreary County, Kentucky, are about 1.4 miles apart (fig. 1). Can Branch, which is about 2.1 miles long, emptied into Hughes Fork of Beaver Creek. Its watershed area of about 1.5 square miles lies largely in the Wiborf 7 1/2-minute quadrangle (SW/4 Cumberland Falls 15-minute quadrangle), but the downstream part of the area extends northward into the Hail 7 1/2-minute quadrangle (NW/4 Cumberland Falls 15-minute quadrangle). Helton Branch, which is about 1.1 miles long, has two tributaries and empties into Little Hurricane Fork of Beaver Creek. It drains an area of about 0.8 square mile of while about 0.5 square mile is in the Hail quadrangle and the remainder in the Wilborg quadrangle. The total relief in the Can Branch area is about 500 feet and in the Helton Branch area about 400 feet. Narrow, steep-sided to canyon-like valley and winding ridges, typical of the Pottsville escarpment region, are characteristic of both areas. Thick woods and dense undergrowth cover much of the two areas. Field mapping was done on U.S. Geological Survey 7 1/2-minute maps having a scale of 1:24,000 and a contour interval of 20 feet. Elevations of lithologic contacts were determined with a barometer and a hand level. Aerial photographs were used principally to trace the cliffs formed by sandstone and conglomerate ledges. Exposures, except for those of the cliff- and ledge-forming sandstone and conglomerates, are not abundant. The most complete stratigraphic sections (secs. 3 and 4, fig. 2) in the two areas are exposed in cuts of newly completed Forest Service roads, but the rick in the upper parts of the exposures is weathered. To supplement these sections, additional sections were measured in cuts along the railroad and main highways in nor near the watersheds.

Outbreak of Rickettsia africae infections in participants of an adventure race in South Africa.

Science.gov (United States)

Fournier, P E; Roux, V; Caumes, E; Donzel, M; Raoult, D

1998-08-01

African tick-bite fever, caused by Rickettsia africae and transmitted by Amblyomma ticks, is an emerging rickettsiosis in southern Africa. Because of increased tourism to this area, several cases in tourists have been reported recently. We report 13 cases of R. africae infection diagnosed in France that occurred in competitors returning from an adventure race in South Africa and compare our data with previously reported findings. Most of our patients presented with fever, headache, multiple inoculation eschars, and regional lymphadenopathies, but only 15.4% had a cutaneous rash. Diagnosis was confirmed either by isolation of R. africae from an eschar biopsy specimen or by serological methods, including cross-adsorption between R. africae and Rickettsia conorii. The purpose of this study was to raise physicians' awareness of R. africae infections in an attempt to facilitate the rapid diagnosis and treatment of imported African tick-bite fever in developed countries.

Ecosystem carbon stocks of mangroves across broad environmental gradients in West-Central Africa: Global and regional comparisons.

Directory of Open Access Journals (Sweden)

J Boone Kauffman

Full Text Available Globally, it is recognized that blue carbon ecosystems, especially mangroves, often sequester large quantities of carbon and are of interest for inclusion in climate change mitigation strategies. While 19% of the world's mangroves are in Africa, they are among the least investigated of all blue carbon ecosystems. We quantified total ecosystem carbon stocks in 33 different mangrove stands along the Atlantic coast of West-Central Africa from Senegal to Southern Gabon spanning large gradients of latitude, soil properties, porewater salinity, and precipitation. Mangrove structure ranged from low and dense stands that were 35,000 trees ha-1 to tall and open stands >40m in height and 1,000 Mg C ha-1. The lowest carbon stocks were found in the low mangroves of the semiarid region of Senegal (463 Mg C ha-1 and in mangroves on coarse-textured soils in Gabon South (541 Mg C ha-1. At the scale of the entirety of West-Central Africa, total ecosystem carbon stocks were poorly correlated to aboveground ecosystem carbon pools, precipitation, latitude and soil salinity (r2 = ≤0.07 for all parameters. Based upon a sample of 158 sites from Africa, Asia and Latin America that were sampled in a similar manner to this study, the global mean of carbon stocks for mangroves is 885 Mg C ha-1. The ecosystem carbon stocks of mangroves for West-Central Africa are slightly lower than those of Latin America (940 Mg C ha-1 and Asia (1049 Mg C ha-1 but substantially higher than the default Intergovernmental Panel on Climate Change (IPCC values for mangroves (511 Mg C ha-1. This study provides an improved estimation of default estimates (Tier 1 values of mangroves for Asia, Latin America, and West Central Africa.

Water resources for Africa

International Nuclear Information System (INIS)

2003-01-01

Water scarcity is a matter of urgent, national, regional and international concern. For those people, usually women, who are responsible for the daily task of obtaining sufficient water for household use, water shortages are a perpetual worry. It is a situation which affects many individual families and communities throughout the arid and semi-arid regions of Africa. The isotope studies conducted thus far have proved that the majority of regional groundwater systems in northern Africa and the Sahel zone are paleowaters, replenished thousands of years ago, without the possibility of significant replenishment under present climatic conditions. Therefore, removal from such underground reservoirs will eventually deplete the resource. Mapping these paleowaters, and estimating their reservoir sizes, is a priority. (IAEA)

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

Science.gov (United States)

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

2014-12-01

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

Evaluating terrestrial water storage variations from regionally constrained GRACE mascon data and hydrological models over Southern Africa – Preliminary results

DEFF Research Database (Denmark)

Krogh, Pernille Engelbredt; Andersen, Ole Baltazar; Michailovsky, Claire Irene B.

2010-01-01

). In this paper we explore an experimental set of regionally constrained mascon blocks over Southern Africa where a system of 1.25° × 1.5° and 1.5° × 1.5° blocks has been designed. The blocks are divided into hydrological regions based on drainage patterns of the largest river basins, and are constrained...... Malawi with water level from altimetry. Results show that weak constraints across regions in addition to intra-regional constraints are necessary, to reach reasonable mass variations....

Analyzing Regional Climate Change in Africa in a 1.5, 2, and 3°C Global Warming World

Science.gov (United States)

Weber, T.; Haensler, A.; Rechid, D.; Pfeifer, S.; Eggert, B.; Jacob, D.

2018-04-01

At the 21st session of the United Nations Framework Convention on Climate Change Conference of the Parties (COP21) in Paris, an agreement to strengthen the effort to limit the global temperature increase well below 2°C was decided. However, even if global warming is limited, some regions might still be substantially affected by climate change, especially for continents like Africa where the socio-economic conditions are strongly linked to the climatic conditions. In the paper we will discuss the analysis of indices assigned to the sectors health, agriculture, and infrastructure in a 1.5, 2, and 3°C global warming world for the African continent. For this analysis an ensemble of 10 different general circulation model-regional climate model simulations conducted in the framework of the COordinated Downscaling EXperiment for Africa was investigated. The results show that the African continent, in particular the regions between 15°S and 15°N, has to expect an increase in hot nights and longer and more frequent heat waves even if the global temperature will be kept below 2°C. These effects intensify if the global mean temperature will exceed the 2°C threshold. Moreover, the daily rainfall intensity is expected to increase toward higher global warming scenarios and will affect especially the African Sub-Saharan coastal regions.

Development of oral health in Africa.

Science.gov (United States)

Thorpe, Samuel J

2003-01-01

Around 80% of African communities can be considered to be materially deprived. The presence of widespread poverty and underdevelopment in Africa means that communities are increasingly exposed to all of the major environmental determinants of oral disease. Previous approaches to oral health in Africa have failed to recognize the epidemiological priorities of the region or identify reliable and appropriate strategies to address them. Efforts have consisted of providing unplanned, ad hoc and spasmodic curative oral health services, which in most cases are poorly distributed and only reach affluent or urban communities. Realizing the limited impact of existing strategies, the World Health Organization Regional Office for Africa (WHO/AFRO) developed a regional oral health strategy to assist African countries and their partners in identifying priorities and planning preventive-oriented programmes, particularly at the district level. The long-term objective is to provide equitable and universal access to cost-effective quality oral healthcare and thereby significantly reduce the incidence of oral diseases in Africa. Copyright 2003 S. Karger AG, Basel

South Africa: Current Issues and U.S. Relations

National Research Council Canada - National Science Library

Ploch, Lauren

2008-01-01

.... With Africa's largest Gross Domestic Product (GDP) and a government eager to play an active role in the promotion of regional peace and stability, South Africa is poised to have a substantial impact on the economic and political future of Africa...

The Consortium for NCD Prevention and Control in Sub-Saharan Africa (CNCD-Africa): from concept to practice.

Science.gov (United States)

Amuyunzu-Nyamongo, Mary; Owuor, Jared O; Blanchard, Claire

2013-12-01

CNCD-Africa was established in July 2009 in response to and in recognition of the continuously increasing burden of diseases such as injuries, non-communicable diseases (NCDs) and mental health in low- and middle-income countries, and specifically in countries of sub-Saharan Africa. CNCD-Africa aims to comprehensively address specific and common objectives while building capacity in the region to prevent and control NCDs. With support from key partners and funders, and a keen interest in opportunities to address NCDs from health promotion and equity perspectives, the Consortium has excelled in four key areas: convening; knowledge generation and sharing; advocacy; and networking. However, the path to successful and sustainable efforts remains laden with challenges and barriers. Retaining interest of network partners through flagship efforts and continued efforts to ascertain support from local and international partners with interest in NCDs across the region remain essential to CNCD-Africa core activities. A key lesson learnt from the early years of CNCD-Africa is that existing regional platforms can and should be used to showcase what is being done locally, and to share best practices and best-buys. In addition, partnerships and stakeholder involvement have been key for CNCD-Africa and are essential to NCD action. Sustaining such partnerships requires incentives for the various partners to keep actively involved in NCD action. This can be achieved through joint inception, project planning, implementation, monitoring and evaluation. Another ingredient for success seems to be innovative financing for NCD efforts, which is possible through the establishment and sustaining of regional and global partnerships that are robust, locally relevant and respond to country needs.

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

Science.gov (United States)

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.

First-order regional seismotectonic model for South Africa

CSIR Research Space (South Africa)

Singh, M

2011-10-01

Full Text Available A first-order seismotectonic model was created for South Africa. This was done using four logical steps: geoscientific data collection, characterisation, assimilation and zonation. Through the definition of subunits of concentrations of earthquake...

Communications in case of radiological emergency: expertise exchange between IPSN and two agricultural branches of the region Provence-Alpes-Cote d'Azur

International Nuclear Information System (INIS)

Berthier, Laure; Pupin, Vincent

1997-01-01

A patrimonial audit organized by the 'Institut de Protection et de Surete Nucleaire' (IPSN) has mobilized the expertise of specialists in the nuclear sector and two sensible agricultural branches (salads and sheep) in Province-Alpes-Cote d'Azur (PACA) on the topic of communications among them in case of contamination of region (radiological emergency situation). Having in view their offers and requests of information we have identified the common fields of action involving the four concerned high-ranking actors of different culture: agricultural Administration, agricultural professionals, nuclear sector authorities and elected persons. We have analyzed the actions already completed in this field and established that the Chernobyl accident was a graveyard from the point of view of mobilization and awareness of actors. A project in the future allowed the determination of the stake implied in the relation between IPSN and the two branches and thus to establish the conditions of reaction in case of radiological emergency. Hence, we were able to make propositions to IPSN for building a French agro-nuclear expertise based upon a relation network covering (and even surpassing) the studied agricultural branches

The Africa Center for Biostatistical Excellence: a proposal for enhancing biostatistics capacity for sub-Saharan Africa.

Science.gov (United States)

Machekano, Rhoderick; Young, Taryn; Rusakaniko, Simbarashe; Musonda, Patrick; Sartorius, Ben; Todd, Jim; Fegan, Greg; Thabane, Lehana; Chikte, Usuf

2015-11-30

Sub-Saharan Africa has a shortage of well-trained biomedical research methodologists, in particular, biostatisticians. In July 2014, a group of biostatisticians and researchers from the region attended a brainstorming workshop to identify ways in which to reduce the deficit in this critical skill. The workshop recognized that recommendations from previous workshops on building biostatistics capacity in sub-Saharan Africa had not been implemented. The discussions culminated with a proposal to setup an Africa Center for Biostatistical Excellence, a collaborative effort across academic and researcher institutions within the region, as a vehicle for promoting biostatistics capacity building through specialized academic masters programs as well as regular workshops targeting researchers. Copyright © 2015 John Wiley & Sons, Ltd.

Incidence of female homicide in the Transkei sub-region of South Africa (1993-2015).

Science.gov (United States)

Meel, Banwari

2018-05-01

Female homicide is very complex and difficult to research. Xhosa women are poor, illiterate and live in a rural area where they are exposed to a number of risks to their lives. The previous apartheid regimen broke the fabric of the family value system in this region and this came on top of a traditional patriarchal view of women as little more than property. Women are most vulnerable in this traumatised society. To study the incidence of female homicide in the Transkei sub-region of South Africa. A record review was undertaken of all medico-legal autopsies performed from 1993 to 2015 at Mthatha Forensic Pathology Laboratory. In total, 26 972 autopsies were performed on victims of unnatural death between 1993 and 2015. Of these, 6091 (22.58%) were cases of unnatural death among females. Homicide accounted for 1865 (30.61%) of these deaths. The average rate of female homicide during the study period was 12.5 per 100 000. The rate of homicide decreased from 14.25/100 000 (1993) to 9.19/100 000 (2015). The average rate of death was 4.93/100 000 as a result of the use of firearms, 3.75/100 000 for stab injuries and 3.70/100 000 for blunt trauma. The rate of murder was highest (6.55/100 000) in the young age group between 11 and 40 years. Despite a one and half time decrease in the rate of female homicide in the last 23 years (1993-2015) in the Transkei sub-region of South Africa, it is still three times higher than the worldwide rate. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Realized Incomes And Revenues Of Local And Branch (Regional Self-Government Units With Audit Review On Income-Earning Property

Directory of Open Access Journals (Sweden)

Dubravka Mahaček

2009-07-01

Full Text Available In addition to other incomes, the incomes of local and branch (regional self-government units are made by the income-earning property as well. Statutory provisions determine their realization. This work presents basic kinds of these incomes with legal foundation, which is the base for their realization. The realization was observed on the county-level for a definite period (from 2003 to 2005. It is important to emphasise that the county-level realization includes the realization of the stated incomes within the frame of cities and communes on their area.

Southern Africa’s Transnational Threats

Science.gov (United States)

2013-04-01

private sectors lends evidence to sophisticated criminal activities.”5 As regional organizations contemplated on how to prevent and/or deter these crimes...distribution of Cannabis (also known as marijuana) is prevalent throughout Southern Africa. In most incidences, Cannabis profits dwarfs local income...had its source in Tanzania and Tanzanians have identified markets for their fake US dollars in South Africa. Cannabis South Africa, Lesotho

West Africa

International Development Research Centre (IDRC) Digital Library (Canada)

freelance

considered by many as a successful model of river basin organization. NBA, after years of ... a Regional Water Protocol for West Africa, following the model of the SADC ...... protection of water against pollution of all kinds (urban, industrial,.

Africa and U.S. Security

National Research Council Canada - National Science Library

Mullin, Moon; Gilbert, Taco

1996-01-01

The United States has limited, but enduring interests in Sub-Saharan Africa These interests parallel our concerns in other regions of the world regional political stability open markets and economic...

Mapping mHealth (mobile health) and mobile penetrations in sub-Saharan Africa for strategic regional collaboration in mHealth scale-up: an application of exploratory spatial data analysis.

Science.gov (United States)

Lee, Seohyun; Cho, Yoon-Min; Kim, Sun-Young

2017-08-22

Mobile health (mHealth), a term used for healthcare delivery via mobile devices, has gained attention as an innovative technology for better access to healthcare and support for performance of health workers in the global health context. Despite large expansion of mHealth across sub-Saharan Africa, regional collaboration for scale-up has not made progress since last decade. As a groundwork for strategic planning for regional collaboration, the study attempted to identify spatial patterns of mHealth implementation in sub-Saharan Africa using an exploratory spatial data analysis. In order to obtain comprehensive data on the total number of mHelath programs implemented between 2006 and 2016 in each of the 48 sub-Saharan Africa countries, we performed a systematic data collection from various sources, including: the WHO eHealth Database, the World Bank Projects & Operations Database, and the USAID mHealth Database. Additional spatial analysis was performed for mobile cellular subscriptions per 100 people to suggest strategic regional collaboration for improving mobile penetration rates along with the mHealth initiative. Global Moran's I and Local Indicator of Spatial Association (LISA) were calculated for mHealth programs and mobile subscriptions per 100 population to investigate spatial autocorrelation, which indicates the presence of local clustering and spatial disparities. From our systematic data collection, the total number of mHealth programs implemented in sub-Saharan Africa between 2006 and 2016 was 487 (same programs implemented in multiple countries were counted separately). Of these, the eastern region with 17 countries and the western region with 16 countries had 287 and 145 mHealth programs, respectively. Despite low levels of global autocorrelation, LISA enabled us to detect meaningful local clusters. Overall, the eastern part of sub-Saharan Africa shows high-high association for mHealth programs. As for mobile subscription rates per 100 population, the

Cultural phylogeography of the Bantu Languages of sub-Saharan Africa.

Science.gov (United States)

Currie, Thomas E; Meade, Andrew; Guillon, Myrtille; Mace, Ruth

2013-07-07

There is disagreement about the routes taken by populations speaking Bantu languages as they expanded to cover much of sub-Saharan Africa. Here, we build phylogenetic trees of Bantu languages and map them onto geographical space in order to assess the likely pathway of expansion and test between dispersal scenarios. The results clearly support a scenario in which groups first moved south through the rainforest from a homeland somewhere near the Nigeria-Cameroon border. Emerging on the south side of the rainforest, one branch moved south and west. Another branch moved towards the Great Lakes, eventually giving rise to the monophyletic clade of East Bantu languages that inhabit East and Southeastern Africa. These phylogenies also reveal information about more general processes involved in the diversification of human populations into distinct ethnolinguistic groups. Our study reveals that Bantu languages show a latitudinal gradient in covering greater areas with increasing distance from the equator. Analyses suggest that this pattern reflects a true ecological relationship rather than merely being an artefact of shared history. The study shows how a phylogeographic approach can address questions relating to the specific histories of certain groups, as well as general cultural evolutionary processes.

Acrylic and metal based Y-branch plastic optical fiber splitter with optical NOA63 polymer waveguide taper region

Science.gov (United States)

Ehsan, Abang Annuar; Shaari, Sahbudin; Rahman, Mohd Kamil Abd.

2011-01-01

We proposed a simple low-cost acrylic and metal-based Y-branch plastic optical fiber (POF) splitter which utilizes a low cost optical polymer glue NOA63 as the main waveguiding medium at the waveguide taper region. The device is composed of three sections: an input POF waveguide, a middle waveguide taper region and output POF waveguides. A desktop high speed CNC engraver is utilized to produce the mold inserts used for the optical devices. Short POF fibers are inserted into the engraved slots at the input and output ports. UV curable optical polymer glue NOA63 is injected into the waveguide taper region and cured. The assembling is completed when the top plate is positioned to enclose the device structure and connecting screws are secured. Both POF splitters have an average insertion loss of 7.8 dB, coupling ratio of 55: 45 and 57: 43 for the acrylic and metal-based splitters respectively. The devices have excess loss of 4.82 and 4.73 dB for the acrylic and metal-based splitters respectively.

Why sub-Saharan Africa lags in electronic health record adoption and possible strategies to increase its adoption in this region.

Science.gov (United States)

Odekunle, Florence Femi; Odekunle, Raphael Oluseun; Shankar, Srinivasan

2017-01-01

Poor health information system has been identified as a major challenge in the health-care system in many developing countries including sub-Saharan African countries. Electronic health record (EHR) has been shown as an important tool to improve access to patient information with attendance improved quality of care. However, EHR has not been widely implemented/adopted in sub-Saharan Africa. This study sought to identify factors that affect the adoption of an EHR in sub-Saharan Africa and strategies to improve its adoption in this region. A comprehensive literature search was conducted on three electronic databases: PubMed, Medline, and Google Scholar. Articles of interest were those published in English that contained information on factors that limit the adoption of an EHR as well as strategies that improve its adoption in sub-Saharan African countries. The available evidence indicated that there were many factors that hindered the widespread adoption of an EHR in sub-Saharan Africa. These were high costs of procurement and maintenance of the EHR system, lack of financial incentives and priorities, poor electricity supply and internet connectivity, and primary user's limited computer skills. However, strategies such as implementation planning, financial supports, appropriate EHR system selection, training of primary users, and the adoption of the phased implementation process have been identified to facilitate the use of an EHR. Wide adoption of an EHR in sub-Saharan Africa region requires a lot more effort than what is assumed because of the current poor level of technological development, lack of required computer skills, and limited resources.

Local and Regional Food Aid Procurement: An Assessment of Experience in Africa and Elements of Good Donor Practice

OpenAIRE

Tschirley, David L.; del Castillo, Anne Marie

2008-01-01

This Policy Synthesis is a summary of a longer report that discusses the procurement of food aid within the country or region where it is needed. Referred to as local and regional procurement – LRP – this practice has become a major element in multilateral food aid response over the past decade1. The paper examines the relevance and the rationale for using LRP, reviews the efficiency of World Food Program (WFP) LRP activities in Africa relative to inkind food aid and to prices in the markets ...

Future climate change over Southern Africa

CSIR Research Space (South Africa)

Davis, Claire L

2017-10-01

Full Text Available This chapter presents key messages drawn from recent subsets of future climate projections for the southern Africa region. Material in this chapter is drawn from Chapter 3 of Climate Risk and Vulnerability: A Handbook for Southern Africa (Davis 2011...

Climate change impacts in the Middle East and Northern Africa (MENA) region and their implications for vulnerable population groups

NARCIS (Netherlands)

Waha, Katharina; Krummenauer, Linda; Adams, Sophie; Aich, Valentin; Baarsch, Florent; Coumou, Dim; Fader, Marianela; Hoff, Holger; Jobbins, Guy; Marcus, Rachel; Mengel, Matthias; Otto, Ilona M.; Perrette, Mahé; Rocha, Marcia; Robinson, Alexander; Schleussner, Carl Friedrich

2017-01-01

The Middle East and North Africa (MENA) region emerges as one of the hot spots for worsening extreme heat, drought and aridity conditions under climate change. A synthesis of peer-reviewed literature from 2010 to date and own modeling work on biophysical impacts of climate change on selected sectors

Branches of the Facial Artery.

Science.gov (United States)

Hwang, Kun; Lee, Geun In; Park, Hye Jin

2015-06-01

The aim of this study is to review the name of the branches, to review the classification of the branching pattern, and to clarify a presence percentage of each branch of the facial artery, systematically. In a PubMed search, the search terms "facial," AND "artery," AND "classification OR variant OR pattern" were used. The IBM SPSS Statistics 20 system was used for statistical analysis. Among the 500 titles, 18 articles were selected and reviewed systematically. Most of the articles focused on "classification" according to the "terminal branch." Several authors classified the facial artery according to their terminal branches. Most of them, however, did not describe the definition of "terminal branch." There were confusions within the classifications. When the inferior labial artery was absent, 3 different types were used. The "alar branch" or "nasal branch" was used instead of the "lateral nasal branch." The angular branch was used to refer to several different branches. The presence as a percentage of each branch according to the branches in Gray's Anatomy (premasseteric, inferior labial, superior labial, lateral nasal, and angular) varied. No branch was used with 100% consistency. The superior labial branch was most frequently cited (95.7%, 382 arteries in 399 hemifaces). The angular branch (53.9%, 219 arteries in 406 hemifaces) and the premasseteric branch were least frequently cited (53.8%, 43 arteries in 80 hemifaces). There were significant differences among each of the 5 branches (P < 0.05) except between the angular branch and the premasseteric branch and between the superior labial branch and the inferior labial branch. The authors believe identifying the presence percentage of each branch will be helpful for surgical procedures.

Wind distribution and capacity factor estimation for wind turbines in the coastal region of South Africa

International Nuclear Information System (INIS)

Ayodele, T.R.; Jimoh, A.A.; Munda, J.L.; Agee, J.T.

2012-01-01

Highlights: ► We evaluate capacity factor of some commercially available wind turbines. ► Wind speed in the sites studied can best be modelled using Weibull distribution. ► Site WM05 has the highest wind power potential while site WM02 has the lowest. ► More wind power can be harnessed during the day period compared to the night. ► Turbine K seems to be the best turbine for the coastal region of South Africa. - Abstract: The operating curve parameters of a wind turbine should match the local wind regime optimally to ensure maximum exploitation of available energy in a mass of moving air. This paper provides estimates of the capacity factor of 20 commercially available wind turbines, based on the local wind characteristics of ten different sites located in the Western Cape region of South Africa. Ten-min average time series wind-speed data for a period of 1 year are used for the study. First, the wind distribution that best models the local wind regime of the sites is determined. This is based on root mean square error (RMSE) and coefficient of determination (R 2 ) which are used to test goodness of fit. First, annual, seasonal, diurnal and peak period-capacity factor are estimated analytically. Then, the influence of turbine power curve parameters on the capacity factor is investigated. Some of the key results show that the wind distribution of the entire site can best be modelled statistically using the Weibull distribution. Site WM05 (Napier) presents the highest capacity factor for all the turbines. This indicates that this site has the highest wind power potential of all the available sites. Site WM02 (Calvinia) has the lowest capacity factor i.e. lowest wind power potential. This paper can assist in the planning and development of large-scale wind power-generating sites in South Africa.

Vegetation-climate feedback causes reduced precipitation and tropical rainforest cover in CMIP5 regional Earth system model simulation over Africa

Science.gov (United States)

Wu, M.; Smith, B.; Samuelsson, P.; Rummukainen, M.; Schurgers, G.

2012-12-01

We applied a coupled regional climate-vegetation model, RCA-GUESS (Smith et al. 2011), over the CORDEX Africa domain, forced by boundary conditions from a CanESM2 CMIP5 simulation under the RCP8.5 future climate scenario. The simulations were from 1961 to 2100 and covered the African continent at a horizontal grid spacing of 0.44°. RCA-GUESS simulates changes in the phenology, productivity, relative cover and population structure of up to eight plant function types (PFTs) in response to forcing from the climate part of the model. These vegetation changes feed back to simulated climate through dynamic adjustments in surface energy fluxes and surface properties. Changes in the net ecosystem-atmosphere carbon flux and its components net primary production (NPP), heterotrophic respiration and emissions from biomass burning were also simulated but do not feed back to climate in our model. Constant land cover was assumed. We compared simulations with and without vegetation feedback switched "on" to assess the influence of vegetation-climate feedback on simulated climate, vegetation and ecosystem carbon cycling. Both positive and negative warming feedbacks were identified in different parts of Africa. In the Sahel savannah zone near 15°N, reduced vegetation cover and productivity, and mortality caused by a deterioration of soil water conditions led to a positive warming feedback mediated by decreased evapotranspiration and increased sensible heat flux between vegetation and the atmosphere. In the equatorial rainforest stronghold region of central Africa, a feedback syndrome characterised by reduced plant production and LAI, a dominance shift from tropical trees to grasses, reduced soil water and reduced rainfall was identified. The likely underlying mechanism was a decline in evaporative water recycling associated with sparser vegetation cover, reminiscent of Earth system model studies in which a similar feedback mechanism was simulated to force dieback of tropical

SERVIR-Africa: Developing an Integrated Platform for Floods Disaster Management in Africa

Science.gov (United States)

Macharia, Daniel; Korme, Tesfaye; Policelli, Fritz; Irwin, Dan; Adler, Bob; Hong, Yang

2010-01-01

SERVIR-Africa is an ambitious regional visualization and monitoring system that integrates remotely sensed data with predictive models and field-based data to monitor ecological processes and respond to natural disasters. It aims addressing societal benefits including floods and turning data into actionable information for decision-makers. Floods are exogenous disasters that affect many parts of Africa, probably second only to drought in terms of social-economic losses. This paper looks at SERVIR-Africa's approach to floods disaster management through establishment of an integrated platform, floods prediction models, post-event flood mapping and monitoring as well as flood maps dissemination in support of flood disaster management.

Earth System Science at NASA: Teleconnections Between Sea Surface Temperature and Epidemics in Africa

Science.gov (United States)

Meeson, Blanche W.

2000-01-01

The research carried out in the Earth Sciences in NASA and at NASA's Goddard Space Flight Center will be the focus of the presentations. In addition, one research project that links sea surface temperature to epidemics in Africa will be highlighted. At GSFC research interests span the full breath of disciplines in Earth Science. Branches and research groups focus on areas as diverse as planetary geomagnetics and atmospheric chemistry. These organizations focus on atmospheric sciences (atmospheric chemistry, climate and radiation, regional processes, atmospheric modeling), hydrological sciences (snow, ice, oceans, and seasonal-to-interannual prediction), terrestrial physics (geology, terrestrial biology, land-atmosphere interactions, geophysics), climate modeling (global warming, greenhouse gases, climate change), on sensor development especially using lidar and microwave technologies, and on information technologies, that enable support of scientific and technical research.

MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

Directory of Open Access Journals (Sweden)

E. N. Pavlyukova

2015-12-01

Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

Physics in Africa

Energy Technology Data Exchange (ETDEWEB)

Allotey, F K.A.

1996-09-01

The paper discusses the role of basic sciences in the development of technology. This is then tied up with the broader issue of the importance of scientific and technological knowledge in the socio-economic development of a country. Physics forms the basis for most of the natural and applied sciences and technology. The state of physics in Africa is reviewed. The need for regional and international cooperation in physics education and research in Africa is stressed. (author). 13 refs, 2 tabs.

Physics in Africa

International Nuclear Information System (INIS)

Allotey, F.K.A.

1996-09-01

The paper discusses the role of basic sciences in the development of technology. This is then tied up with the broader issue of the importance of scientific and technological knowledge in the socio-economic development of a country. Physics forms the basis for most of the natural and applied sciences and technology. The state of physics in Africa is reviewed. The need for regional and international cooperation in physics education and research in Africa is stressed. (author). 13 refs, 2 tabs

A review and assessment of energy policy in the Middle East and North Africa region

International Nuclear Information System (INIS)

Griffiths, Steven

2017-01-01

The energy landscape of the Middle East and North Africa (MENA) region has undergone a significant transformation in recent years as a result of intersecting technological, economic and political trends, both regional and international. The evolving dynamics of international energy markets, increased diversification of energy sources, global concerns for climate change, and regional conflict are among the leading factors impacting the evolution of MENA energy policy. This paper provides an assessment and outlook for energy policy in the MENA region within the context of the myriad factors impacting policy design and implementation. A review and analysis of the social, political and economic factors that are impacting regional energy policy is provided and followed by analysis of regional energy policy with consideration of hydrocarbon exploration and production, regional energy trade, demand management and clean energy production. The findings show that the MENA region is in the midst of an energy transition that has uncertain outcomes but will undoubtedly have long lasting impacts on the global energy system. - Highlights: • The MENA region is undergoing an energy transition shaped by political, social and economic dynamics. • Political, economic and social turmoil will constrain energy systems developments in many MENA countries. • MENA countries that can evolve their energy systems are prioritizing energy security and energy cost minimization. • Energy demand management, sustainable energy supply and regional cooperation are essential to achieving energy priorities.

Branched polynomial covering maps

DEFF Research Database (Denmark)

Hansen, Vagn Lundsgaard

2002-01-01

A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch ...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere. (C) 2001 Elsevier Science B.V. All rights reserved.......A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

Financial gradualism and banking crises in North Africa region: an investigation by a panel logit model

OpenAIRE

KHATTAB, Ahmed; IHADIYAN, Abid

2017-01-01

Abstract. In order to overcome the troubles of the crisis in the seventies, North African countries have adopted financial liberalization policies to enhance their economic growth. Moreover, these policies have affected the stability of their banking systems. The purpose of this study is to test the impact of financial liberalization on the probability of appearance of banking crises which covers a sample of four countries of the North Africa region during the period 1970-2003 by using a pane...

[Has the urban transition ended in sub-Saharan Africa?].

Science.gov (United States)

Bocquier, P

1999-01-01

In 1950, 28% of the world¿s population lived in cities. At that point, localities larger than 10,000 inhabitants were home to 0.7 billion people, of whom 36% were in developing countries. However, according to UN projections, the rate of urbanization will reach 47.4% in 2000, with cities housing 2.9 billion people, of whom 68.7% will be in developing countries. Africa, like other continents, is urbanizing. Although Africa is among the world¿s least urbanized regions, it is nonetheless the continent with the highest rate of urbanization. Urban population growth reached its height during the 1950s, then the urban population in the region multiplied by a factor of 10 during 1950-90, far outpacing the rate of overall population growth on the continent. However, during the 1980s and 1990s, urban growth in Africa declined sharply. The author discusses urbanization in Africa devoid of industrialization, declining rates of urban population growth in the region, the uncertain future of urbanization in Africa, and how future urbanization in Africa depends upon the role the continent will play in the global economy.

Variation in heterozygosity predicts variation in human substitution rates between populations, individuals and genomic regions.

Directory of Open Access Journals (Sweden)

William Amos

Full Text Available The "heterozygote instability" (HI hypothesis suggests that gene conversion events focused on heterozygous sites during meiosis locally increase the mutation rate, but this hypothesis remains largely untested. As humans left Africa they lost variability, which, if HI operates, should have reduced the mutation rate in non-Africans. Relative substitution rates were quantified in diverse humans using aligned whole genome sequences from the 1,000 genomes project. Substitution rate is consistently greater in Africans than in non-Africans, but only in diploid regions of the genome, consistent with a role for heterozygosity. Analysing the same data partitioned into a series of non-overlapping 2 Mb windows reveals a strong, non-linear correlation between the amount of heterozygosity lost "out of Africa" and the difference in substitution rate between Africans and non-Africans. Putative recent mutations, derived variants that occur only once among the 80 human chromosomes sampled, occur preferentially at the centre of 2 Kb windows that have elevated heterozygosity compared both with the same region in a closely related population and with an immediately adjacent region in the same population. More than half of all substitutions appear attributable to variation in heterozygosity. This observation provides strong support for HI with implications for many branches of evolutionary biology.

MNC reporting on CSR and conflict in Central Africa

NARCIS (Netherlands)

Kolk, A.; Lenfant, F.

2010-01-01

In recent years, corporate social responsibility (CSR) of Multinational Corporations (MNCs) in developing countries has received more attention. However, in this literature Africa is much less well represented than other regions, and existing studies about Africa have mainly focused on South Africa

Regional spread of Ebola virus, West Africa, 2014.

Science.gov (United States)

Rainisch, Gabriel; Shankar, Manjunath; Wellman, Michael; Merlin, Toby; Meltzer, Martin I

2015-03-01

To explain the spread of the 2014 Ebola epidemic in West Africa, and thus help with response planning, we analyzed publicly available data. We found that the risk for infection in an area can be predicted by case counts, population data, and distances between affected and nonaffected areas.

Regional Spread of Ebola Virus, West Africa, 2014

OpenAIRE

Rainisch, Gabriel; Shankar, Manjunath; Wellman, Michael; Merlin, Toby; Meltzer, Martin I.

2015-01-01

To explain the spread of the 2014 Ebola epidemic in West Africa, and thus help with response planning, we analyzed publicly available data. We found that the risk for infection in an area can be predicted by case counts, population data, and distances between affected and nonaffected areas.

Agricultural Adaptations to Climate Changes in West Africa

Science.gov (United States)

Guan, K.; Sultan, B.; Lobell, D. B.; Biasutti, M.; Piani, C.; Hammer, G. L.; McLean, G.

2014-12-01

Agricultural production in West Africa is highly vulnerable to climate variability and change and a fast growing demand for food adds yet another challenge. Assessing possible adaptation strategies of crop production in West Africa under climate change is thus critical for ensuring regional food security and improving human welfare. Our previous efforts have identified as the main features of climate change in West Africa a robust increase in temperature and a complex shift in the rainfall pattern (i.e. seasonality delay and total amount change). Unaddressed, these robust climate changes would reduce regional crop production by up to 20%. In the current work, we use two well-validated crop models (APSIM and SARRA-H) to comprehensively assess different crop adaptation options under future climate scenarios. Particularly, we assess adaptations in both the choice of crop types and management strategies. The expected outcome of this study is to provide West Africa with region-specific adaptation recommendations that take into account both climate variability and climate change.

Eastern Africa Social Science Research Review

African Journals Online (AJOL)

The Eastern Africa Social Science Research Review (EASSRR) is a bi-annual journal published by the Organization for Social Science Research in Eastern Africa (OSSREA). Since the publication of its maiden ... Emerging regions in Ethiopia: are they catching up with the rest of Ethiopia? EMAIL FULL TEXT EMAIL FULL ...

Powering Africa: Meeting the financing and reform challenges

International Nuclear Information System (INIS)

Eberhard, Anton; Shkaratan, Maria

2012-01-01

Sub-Saharan Africa faces chronic power problems, including insufficient generation capacity, low connectivity, poor reliability, and high costs, all of which constrain development. The investment requirements to meet Africa's power needs are noted and strategies to address the funding gap are set out. The time for an ideological debate on public versus private investment is over—both are needed. Africa's key challenges are the management of hybrid power markets, the reform of state-owned utilities, cost-reflective pricing, better targeting of subsidies, the nimbler rollout of electrification, and stronger regional integration. - Highlights: ► Africa has insufficient power generation, low connectivity, poor reliability, and high costs. ► Investment requirements to meet Africa's power needs are calculated. ► Key challenges are the management of hybrid power markets and the reform of state-owned utilities. ► Other challenges are cost-reflective pricing, extending access, and stronger regional integration.

Marketing of irradiated commodities in South Africa

Science.gov (United States)

Du Plessis, TA; Stevens, RCB

Although the industrial exploitation of radiation processing in the medical and allied fields has been successfully marketed and applied for the past two decades in South Africa, the introduction of food radurisation on an industrial level adds a completely new dimension to the marketing of this processing technique. Extensive research into the use of radiation for the treatment of various foodstuffs has been carried out by the Nuclear Development Corporation of South Africa for more than a decade, resulting in South Africa being one of the first countries where a commercial irradiator dedicated to this branch of radiation processing, was established. The marketing of this process is especially difficult due to the emotive aspects associated with radiation and man's sensitive reaction to anything pertaining to his food. This situation was made even more difficult by the general public's apprehension towards nuclear activities throughout the world. In an attempt to transform the unfavourable public image associated with this process, an important first step was to form a National Steering Committee for the Marketing of Radurised Food, the members of which were drawn from various agricultural controlling bodies, the Department of Health, and other controlling bodies held in high esteem by the public, such as the Consumer Council and representatives from commerce and industry. This approach proved to be very successful and greatly assisted in creating a climate whereby the public in South Africa today generally has a favourable attitude towards the radurisation of foodstuffs. The development of this marketing strategy for food radurisation in South Africa is discussed in detail.

Gradients in giant branch morphology in the core of 47 Tucanae

Science.gov (United States)

Bailyn, Charles D.

1994-01-01

I describe an algorithm which uses the high spatial resolution of the Hubble Space Telescope to complement the high spatial-to-noise, approximately symmetric point response function, relatively large spatial coverage, and standard filters available from ground based images of crowded fields. Applying this technique to the central regions of the globular cluster 47 Tucanae, I find that the morphology of the giant branch in the core is significantly different from that in more distant regions (r approximately equals 5 to 10 core radii) of the cluster. In particular, there appear to be fewer bright giants in the core, along with an enhanced `asymptotic giant branch' (AGB) sequence. Depletion of giants has been observed in the cores of other dense clusters, and may be due to `stripping' of large stars by stellar encounters and/or mass transfer in binary systems. Central concentrations of true asymptotic giant branch stars are not expected to result from dynamical processes; possibly some of these stars may be evolved blue stragglers.

Climate Risk in Southern and Eastern Africa's Hydropower Generation

Science.gov (United States)

Dalin, C.; Conway, D.; Landman, W.; Osborn, T.

2016-12-01

Hydropower comprises a major proportion of electricity production in southern and eastern Africa and is undergoing rapid expansion. Hydropower production in both regions is exposed to high levels of climate variability and regional linkages are strong, yet an understanding of aggregate climate risk is lacking. Here we map regions of coherent precipitation variability with current and planned (2030) hydropower sites, river basin configuration and regional energy grids to assess aggregate exposure to hydropower supply disruption. If fully implemented hydropower will be increasingly concentrated in the Nile basin in eastern Africa and the Zambezi basin in southern Africa. Regions of similar rainfall variability show close alignment with the main sites of hydropower. Future concentration of hydropower will greatly increase the concurrent risk of climate related electricity supply disruption. Nascent electricity sharing mechanisms could mitigate risk but face considerable political and infrastructural challenges.

Feasibility study for the computerized automation of the Laboratory Services Branch of EPA Region IV

International Nuclear Information System (INIS)

Boyle, W.G. Jr.; Barton, G.W. Jr.; Taber, L.

1978-01-01

This report is a study of the feasibility of computerized automation of the Laboratory Services Branch of the Environmental Protection Agency's Region IV. The LSB provides chemical analytical support for a number of EPA divisions; its primary function at present is compliance monitoring, field surveys, and oil identification. Automation of the LSB is not only feasible but also highly desirable. Automation systems are proposed that will make major improvements in analytical capacity, quality control, sample management, and reporting capabilities. Most of these automation systems are similar to those already developed and installed at other EPA laboratories. These systems have options that include limited modifications suggested as a result of the study of the LSB Laboratory, and also include communications hardware and software for a Sample File Control host computer. It is estimated that the initial cost of three of the four options considered would be recouped in approximately three years through increased capacity and efficiency of operation

Mitochondrial haplogroup H1 in north Africa: an early holocene arrival from Iberia.

Directory of Open Access Journals (Sweden)

Claudio Ottoni

Full Text Available The Tuareg of the Fezzan region (Libya are characterized by an extremely high frequency (61% of haplogroup H1, a mitochondrial DNA (mtDNA haplogroup that is common in all Western European populations. To define how and when H1 spread from Europe to North Africa up to the Central Sahara, in Fezzan, we investigated the complete mitochondrial genomes of eleven Libyan Tuareg belonging to H1. Coalescence time estimates suggest an arrival of the European H1 mtDNAs at about 8,000-9,000 years ago, while phylogenetic analyses reveal three novel H1 branches, termed H1v, H1w and H1x, which appear to be specific for North African populations, but whose frequencies can be extremely different even in relatively close Tuareg villages. Overall, these findings support the scenario of an arrival of haplogroup H1 in North Africa from Iberia at the beginning of the Holocene, as a consequence of the improvement in climate conditions after the Younger Dryas cold snap, followed by in situ formation of local H1 sub-haplogroups. This process of autochthonous differentiation continues in the Libyan Tuareg who, probably due to isolation and recent founder events, are characterized by village-specific maternal mtDNA lineages.

The New Presence of China in Africa

NARCIS (Netherlands)

M.P. van Dijk (Meine Pieter)

2010-01-01

textabstractThis book describes China's growing range of activities in Africa, especially in the sub-Saharan region. The three most important instruments China has at its disposal in Africa are development aid, investments and trade policy. The Chinese government, which believes the Western

Impacts of Climate Change on Malaria Transmission in Africa

Science.gov (United States)

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.

Entanglement branching operator

Science.gov (United States)

Harada, Kenji

2018-01-01

We introduce an entanglement branching operator to split a composite entanglement flow in a tensor network which is a promising theoretical tool for many-body systems. We can optimize an entanglement branching operator by solving a minimization problem based on squeezing operators. The entanglement branching is a new useful operation to manipulate a tensor network. For example, finding a particular entanglement structure by an entanglement branching operator, we can improve a higher-order tensor renormalization group method to catch a proper renormalization flow in a tensor network space. This new method yields a new type of tensor network states. The second example is a many-body decomposition of a tensor by using an entanglement branching operator. We can use it for a perfect disentangling among tensors. Applying a many-body decomposition recursively, we conceptually derive projected entangled pair states from quantum states that satisfy the area law of entanglement entropy.

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

Directory of Open Access Journals (Sweden)

Roger Sodjinou

2014-01-01

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

Projecting regional climate and cropland changes using a linked biogeophysical-socioeconomic modeling framework: 1. Model description and an equilibrium application over West Africa

Science.gov (United States)

Wang, Guiling; Ahmed, Kazi Farzan; You, Liangzhi; Yu, Miao; Pal, Jeremy; Ji, Zhenming

2017-03-01

Agricultural land use alters regional climate through modifying the surface mass, energy, and momentum fluxes; climate influences agricultural land use through their impact on crop yields. These interactions are not well understood and have not been adequately considered in climate projections. This study tackles the critical linkages within the coupled natural-human system of West Africa in a changing climate based on an equilibrium application of a modeling framework that asynchronously couples models of regional climate, crop yield, multimarket agricultural economics, and cropland expansion. Using this regional modeling framework driven with two global climate models, we assess the contributions of land use change (LUC) and greenhouse gas (GHGs) concentration changes to regional climate changes and assess the contribution of climate change and socioeconomic factors to agricultural land use changes. For future cropland expansion in West Africa, our results suggest that socioeconomic development would be the dominant driver in the east (where current cropland coverage is already high) and climate changes would be the primary driver in the west (where future yield drop is severe). For future climate, it is found that agricultural expansion would cause a dry signal in the west and a wet signal in the east downwind, with an east-west contrast similar to the GHG-induced changes. Over a substantial portion of West Africa, the strength of the LUC-induced climate signals is comparable to the GHG-induced changes. Uncertainties originating from the driving global models are small; human decision making related to land use and international trade is a major source of uncertainty.

Axisymmetric thermoviscoelastoplastic state of branched laminar shells, taking account of transverse-shear and torsional deformation

International Nuclear Information System (INIS)

Galishin, A.Z.

1995-01-01

The nonaxisymmetric thermoelastic stress-strain state (SSS) of branched laminar orthotropic shells was considered; the axisymmetric thermoviscoelastic SSS of branched laminar orthotropic shells was considered; and the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells was considered, taking into account of the transverse-shear deformation. In the present work, in contrast, the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells is considered, taking account of transverse-shear and torsional deformation. Layers that are made from orthotropic materials and deform in the elastic region may be present

Stronger links between CERN and South Africa

CERN Multimedia

Katarina Anthony

2011-01-01

iThemba LABS in South Africa is a research facility that, about twenty years ago, started to treat oncological patients with particle beams. Its collaboration with CERN has steadily grown over the years. After becoming a member of the ALICE and ATLAS Collaborations, today iThemba LABS is planning to buy a new medical-use cyclotron proton facility, and is seeking to strengthen its links with CERN and Europe also in this field by collaborating with ENLIGHT. The cyclotron will be dedicated to proton therapy – the only one of its kind in the southern hemisphere.   iThemba LABS (Laboratory for Accelerator Based Sciences) was established near Cape Town, South Africa almost 50 years ago as the continent's base for the Southern Universities Nuclear Institute that is now used mainly for material science research. In the 1980s, iThemba built a 200MeV cyclotron and, following its construction, in the early 1990s branched into a new scientific field: radiation and nuclear medicine. ...

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

Science.gov (United States)

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.

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo).

Science.gov (United States)

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.

Synergy of multi-scale toughening and protective mechanisms at hierarchical branch-stem interfaces

Science.gov (United States)

Müller, Ulrich; Gindl-Altmutter, Wolfgang; Konnerth, Johannes; Maier, Günther A.; Keckes, Jozef

2015-09-01

Biological materials possess a variety of artful interfaces whose size and properties are adapted to their hierarchical levels and functional requirements. Bone, nacre, and wood exhibit an impressive fracture resistance based mainly on small crystallite size, interface organic adhesives and hierarchical microstructure. Currently, little is known about mechanical concepts in macroscopic biological interfaces like the branch-stem junction with estimated 1014 instances on earth and sizes up to few meters. Here we demonstrate that the crack growth in the upper region of the branch-stem interface of conifer trees proceeds along a narrow predefined region of transversally loaded tracheids, denoted as sacrificial tissue, which fail upon critical bending moments on the branch. The specific arrangement of the tracheids allows disconnecting the overloaded branch from the stem in a controlled way by maintaining the stem integrity. The interface microstructure based on the sharply adjusted cell orientation and cell helical angle secures a zig-zag crack propagation path, mechanical interlock closing after the bending moment is removed, crack gap bridging and self-repairing by resin deposition. The multi-scale synergetic concepts allows for a controllable crack growth between stiff stem and flexible branch, as well as mechanical tree integrity, intact physiological functions and recovery after the cracking.

Hantaviruses in Africa.

Science.gov (United States)

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

2014-07-17

This paper summarizes the progress in the search for hantaviruses and hantavirus infections in Africa. After having collected molecular evidence of an indigenous African hantavirus in 2006, an intensive investigation for new hantaviruses has been started in small mammals. Various novel hantaviruses have been molecularly identified not only in rodents but also in shrews and bats. In addition, the first African hantavirus, Sangassou virus, has been isolated and functionally characterized in cell culture. Less is known about the ability of these hantaviruses to infect humans and to cause diseases. To date, no hantavirus genetic material could be amplified from patients' specimens collected in Africa. Serological studies in West Africa, based on a battery of screening and confirmatory assays, led to the detection of hantavirus antibodies in the human population and in patients with putative hantavirus disease. In addition to this overview, we present original data from seroepidemiological and field studies conducted in the Southern part of Africa. A human seroprevalence rate of 1.0% (n=1442) was detected in the South African Cape Region whereas no molecular evidence for the presence of hantavirus was found in 2500 small animals trapped in South Africa and Namibia. Copyright © 2014 Elsevier B.V. All rights reserved.

Detection of Rickettsia aeschlimannii and Rickettsia africae in ixodid ticks from Burkina Faso and Somali Region of Ethiopia by new real-time PCR assays.

Science.gov (United States)

Tomassone, L; De Meneghi, D; Adakal, H; Rodighiero, P; Pressi, G; Grego, E

2016-10-01

In the framework of cooperation for development projects in Burkina Faso and Ethiopia, we collected ixodid ticks from cattle, small ruminants and camels. We optimized new TaqMan Probe real-time PCR assays to detect Rickettsia aeschlimannii and Rickettsia africae OmpA gene in the collected samples. Rickettsia africae was identified in 75.0% Amblyomma variegatum (95%CI: 56.6-88.5), while R. aeschlimannii in 24.0% Hyalomma truncatum (95%CI: 9.4-45.1) and 50.0% H. rufipes (95%CI: 29.9-70.0) collected from cattle in different provinces throughout Burkina Faso. Ticks from the Libaan zone, Somali Region of Ethiopia, were also infected by R. africae (28.5% prevalence in Amblyomma gemma, 95%CI: 14.7-46.0) and R. aeschlimannii (27.0% H. truncatum, 95%CI: 5.0-62.9; 88.3% H. rufipes, 95%CI: 60.5-99.3). All tested ticks were adults. The developed diagnostic tools were highly sensitive and enabled us to rapidly classify R. aeschlimannii and R. africae, which were identified in Burkina Faso and in the Somali Region of Ethiopia for the first time. Further studies are needed to assess the zoonotic risk and prevalence of infection in local human populations, who have high contact rates with ticks and their animal hosts. Copyright © 2016 Elsevier GmbH. All rights reserved.

Branched polynomial covering maps

DEFF Research Database (Denmark)

Hansen, Vagn Lundsgaard

1999-01-01

A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...... set. Particular studies are made of branched polynomial covering maps arising from Riemann surfaces and from knots in the 3-sphere....

Field guide to trees of Southern Africa

OpenAIRE

Rishan Singh

2012-01-01

The mainland region of Africa is Southern Africa because it is considered to be robust with an estimate of around 1700 tree species that are native and a couple 100 more that are alien, but have become accustomed to the natural environment; invading, penetrating and replacing vegetation.

Markets, Climate Change and Food Security in West Africa

Science.gov (United States)

Brown, Molly E.; Hintermann, Beat; Higgins, Nathaniel

2009-01-01

West Africa is one of the most food insecure regions of the world. Sharply increased food and energy prices in 2008 brought the role of markets in food access and availability around the world into the spotlight, particularly in urban areas. The period of high prices had the immediate consequence of sharply increasing the number of hungry people in the region without boosting farmer incomes significantly. In this article, the interaction between markets, food prices, agricultural technology and development is explored in the context of West Africa. To improve food security in West Africa, sustained commitment to investment in the agriculture sector will be needed to provide some protection against global swings in both production and world markets. Climate change mitigation programs are likely to force global energy and commodity price increases in the coming decades, putting pressure on regions like West Africa to produce more food locally to ensure stability in food security for the most vulnerable.

Climate strategy for Africa

OpenAIRE

Hernes, Helga; Dalfelt, Arne; Berntsen, Terje; Holtsmark, Bjart; Næss, Lars Otto; Selrod, Rolf; Aaheim, H. Asbjørn

1995-01-01

1. General observations Africa south of the Sahara is probably the most vulnerable region when it comes to the impact and consequences of climate changes. Yet the African continent runs a serious risk of being marginalized in the global dialogue on climate issues. Africa contributes little to the global emissions of CO2, and other greenhouse gases. The major focus of the Framework Convention on Climate Change is on abatement and mitigation of emissions rather than adaptation to the con...

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

Science.gov (United States)

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

2012-01-01

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

Creating Programs for Africa's Urban Youth : The Challenge of Marginalization

OpenAIRE

Sommers, Marc

2007-01-01

Urban youth constitute the vanguard of Africa's twinned demographic transformations. Sub-Saharan Africa's youth population growth rate is the highest of any world region (North Africa's rate is also high). In addition, Africa's urban growth rate is the world's highest. Taken together, the need to provide adequate, effective support for urban youth is critical to fostering Africa's development – and its political, social and economic stability. This article is designed to help address this nee...

South Africa's marketing strategies towards major African regional economic players: the case of the 2010 FIFA World Cup –was it truly an African event?

Directory of Open Access Journals (Sweden)

PPS Sifolo

2014-01-01

Full Text Available This article critically examines the effect and the dynamics of the 2010 FIFA World Cup in relation to major African regional economic players. It was conducted with an assumption that the branding of the 2010 FIFA World Cup as „Africa‟s Time‟, „Africa‟s moment‟, and „Africa‟s turn‟ to the benefit of the continent would be viewed with pessimism, at least by the (Egypt, Algeria, Kenya, Ethiopia, Ghana and Nigeria major African regional economic players, as an event that did not benefit the continent as a whole but South Africa and the Southern African Development Community (SADC region. This article used phenomenological strategy under qualitative methods whereby face to face interviews were conducted from a sample drawn from the pool of diplomatic community and the staff of relevant Non-Governmental Organisations (NGOs and Inter-Governmental Organisations (IGOs in Addis Ababa, Ethiopia. The results revealed that an event was a tremendous boost to the pride and confidence of Africa and its people. Credit should be given to South Africa for taking the leading role in marketing an event as African and not as South African. Such marketing strategy did not only ensure African ownership but instilled the sense of African pride.

Multi-membership and the effectiveness of regional trade agreements in Western and Southern Africa : A comparative study of ECOWAS and SADC

NARCIS (Netherlands)

S.K. Afesorgbor (Sylvanus Kwaku); P.A.G. van Bergeijk (Peter)

2011-01-01

textabstractUsing a gravity model for 35 countries and the years 1995-2006 we estimate the impact of regional trade agreements in Africa (in particular ECOWAS and SADC) and compare this to the a benchmark of North South trade integration (Europe’s preferential trade agreement). We find that •

Evaluation of daily maximum and minimum 2-m temperatures as simulated with the Regional Climate Model COSMO-CLM over Africa

Directory of Open Access Journals (Sweden)

Stefan Krähenmann

2013-07-01

Full Text Available The representation of the diurnal 2-m temperature cycle is challenging because of the many processes involved, particularly land-atmosphere interactions. This study examines the ability of the regional climate model COSMO-CLM (version 4.8 to capture the statistics of daily maximum and minimum 2-m temperatures (Tmin/Tmax over Africa. The simulations are carried out at two different horizontal grid-spacings (0.22° and 0.44°, and are driven by ECMWF ERA-Interim reanalyses as near-perfect lateral boundary conditions. As evaluation reference, a high-resolution gridded dataset of daily maximum and minimum temperatures (Tmin/Tmax for Africa (covering the period 2008–2010 is created using the regression-kriging-regression-kriging (RKRK algorithm. RKRK applies, among other predictors, the remotely sensed predictors land surface temperature and cloud cover to compensate for the missing information about the temperature pattern due to the low station density over Africa. This dataset allows the evaluation of temperature characteristics like the frequencies of Tmin/Tmax, the diurnal temperature range, and the 90th percentile of Tmax. Although the large-scale patterns of temperature are reproduced well, COSMO-CLM shows significant under- and overestimation of temperature at regional scales. The hemispheric summers are generally too warm and the day-to-day temperature variability is overestimated over northern and southern extra-tropical Africa. The average diurnal temperature range is underestimated by about 2°C across arid areas, yet overestimated by around 2°C over the African tropics. An evaluation based on frequency distributions shows good model performance for simulated Tmin (the simulated frequency distributions capture more than 80% of the observed ones, but less well performance for Tmax (capture below 70%. Further, over wide parts of Africa a too large fraction of daily Tmax values exceeds the observed 90th percentile of Tmax, particularly

Evaluation of daily maximum and minimum 2-m temperatures as simulated with the regional climate model COSMO-CLM over Africa

Energy Technology Data Exchange (ETDEWEB)

Kraehenmann, Stefan; Kothe, Steffen; Ahrens, Bodo [Frankfurt Univ. (Germany). Inst. for Atmospheric and Environmental Sciences; Panitz, Hans-Juergen [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany)

2013-10-15

The representation of the diurnal 2-m temperature cycle is challenging because of the many processes involved, particularly land-atmosphere interactions. This study examines the ability of the regional climate model COSMO-CLM (version 4.8) to capture the statistics of daily maximum and minimum 2-m temperatures (Tmin/Tmax) over Africa. The simulations are carried out at two different horizontal grid-spacings (0.22 and 0.44 ), and are driven by ECMWF ERA-Interim reanalyses as near-perfect lateral boundary conditions. As evaluation reference, a high-resolution gridded dataset of daily maximum and minimum temperatures (Tmin/Tmax) for Africa (covering the period 2008-2010) is created using the regression-kriging-regression-kriging (RKRK) algorithm. RKRK applies, among other predictors, the remotely sensed predictors land surface temperature and cloud cover to compensate for the missing information about the temperature pattern due to the low station density over Africa. This dataset allows the evaluation of temperature characteristics like the frequencies of Tmin/Tmax, the diurnal temperature range, and the 90{sup th} percentile of Tmax. Although the large-scale patterns of temperature are reproduced well, COSMO-CLM shows significant under- and overestimation of temperature at regional scales. The hemispheric summers are generally too warm and the day-to-day temperature variability is overestimated over northern and southern extra-tropical Africa. The average diurnal temperature range is underestimated by about 2 C across arid areas, yet overestimated by around 2 C over the African tropics. An evaluation based on frequency distributions shows good model performance for simulated Tmin (the simulated frequency distributions capture more than 80% of the observed ones), but less well performance for Tmax (capture below 70%). Further, over wide parts of Africa a too large fraction of daily Tmax values exceeds the observed 90{sup th} percentile of Tmax, particularly across

The New Presence of China in Africa

OpenAIRE

2009-01-01

This book describes China's growing range of activities in Africa, especially in the sub-Saharan region. The three most important instruments China has at its disposal in Africa are development aid, investments and trade policy. The Chinese government, which believes the Western development aid model has failed, is looking for new forms of aid and development in Africa. China's economic success can partly be ascribed to the huge availability of cheap labour, which is primarily employed in exp...

Detecting Signatures of Positive Selection along Defined Branches of a Population Tree Using LSD.

Science.gov (United States)

Librado, Pablo; Orlando, Ludovic

2018-06-01

Identifying the genomic basis underlying local adaptation is paramount to evolutionary biology, and bears many applications in the fields of conservation biology, crop, and animal breeding, as well as personalized medicine. Although many approaches have been developed to detect signatures of positive selection within single populations and population pairs, the increasing wealth of high-throughput sequencing data requires improved methods capable of handling multiple, and ideally large number of, populations in a single analysis. In this study, we introduce LSD (levels of exclusively shared differences), a fast and flexible framework to perform genome-wide selection scans, along the internal and external branches of a given population tree. We use forward simulations to demonstrate that LSD can identify branches targeted by positive selection with remarkable sensitivity and specificity. We illustrate a range of potential applications by analyzing data from the 1000 Genomes Project and uncover a list of adaptive candidates accompanying the expansion of anatomically modern humans out of Africa and their spread to Europe.

Nigerian tourists to South Africa: Challenges, expectations and demands

Directory of Open Access Journals (Sweden)

Ikechukwu O. Ezeuduji

2013-08-01

Research purpose: This paper investigated the challenges, demands and expectations of Nigerian tourists to South Africa. Motivation for the study: Nigeria, along with other African nations, has been identified as one of the core regional source markets with air links to South Africa. Increasing revenue generated from regional tourism is important to South African Tourism. Research design, approach and method: Descriptive statistics and Chi-square tests were used to analyse the data collected using a questionnaire survey of 320 Nigerian tourists to South Africa. Main findings: Results showed that Nigerian tourists visit South Africa mostly for the purposes of business, holiday, visiting friends and relatives, education and medical care. Challenges perceived by these Nigerian tourists visiting South Africa include long waiting time for the visa process in Nigeria, expensive cost of living in South Africa, safety and security problems, not so many airlines to choose from and expensive flight costs. Nigerian tourists mostly expect South Africans to be friendlier and have expectations of linking up with new business partners or performing transactions. They also have a strong demand for shopping, leisure and quality education. Practical/managerial implications: This study recommends a bilateral tourism relationship agreement between the Nigerian and South African governments to ameliorate the visa process; targeted marketing communications by South African Tourism toward Nigerian tourists based on study results; strong police presence and proper policing in South Africa; air transport liberalisation and low-cost carriers implementation for shared economic growth within the African region. Contribution/value-add: No former research has specifically identified Nigerian tourists’ challenges, expectations and demands whilst visiting South Africa.

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

Science.gov (United States)

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.

Chemical safety of cassava products in regions adopting cassava production and processing - experience from Southern Africa

DEFF Research Database (Denmark)

Nyirenda, D.B.; Chiwona-Karltun, L.; Chitundu, M.

2011-01-01

and perceptions concerning cassava and chemical food safety. Chips, mixed biscuits and flour, procured from households and markets in three regions of Zambia (Luapula-North, Western and Southern) as well as products from the Northern, Central and Southern regions of Malawi, were analyzed for total cyanogenic...... of products commercially available on the market. Risk assessments disclose that effects harmful to the developing central nervous system (CNS) may be observed at a lower exposure than previously anticipated. We interviewed farmers in Zambia and Malawi about their cultivars, processing procedures......The cassava belt area in Southern Africa is experiencing an unforeseen surge in cassava production, processing and consumption. Little documentation exists on the effects of this surge on processing procedures, the prevailing levels of cyanogenic glucosides of products consumed and the levels...

Characteristics of intercontinental transport of tropospheric ozone from Africa to Asia

Science.gov (United States)

Han, Han; Liu, Jane; Yuan, Huiling; Zhuang, Bingliang; Zhu, Ye; Wu, Yue; Yan, Yuhan; Ding, Aijun

2018-03-01

In this study, we characterize the transport of ozone from Africa to Asia through the analysis of the simulations of a global chemical transport model, GEOS-Chem, from 1987 to 2006. The receptor region Asia is defined within 5-60° N and 60-145° E, while the source region Africa is within 35° S-15° N and 20° W-55° E and within 15-35° N and 20° W-30° E. The ozone generated in the African troposphere from both natural and anthropogenic sources is tracked through tagged ozone simulation. Combining this with analysis of trajectory simulations using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, we find that the upper branch of the Hadley cell connects with the subtropical westerlies in the Northern Hemisphere (NH) to form a primary transport pathway from Africa to Asia in the middle and upper troposphere throughout the year. The Somali jet that runs from eastern Africa near the equator to the Indian subcontinent in the lower troposphere is the second pathway that appears only in NH summer. The influence of African ozone mainly appears over Asia south of 40° N. The influence shows strong seasonality, varying with latitude, longitude, and altitude. In the Asian upper troposphere, imported African ozone is largest from March to May around 30° N (12-16 ppbv) and lowest during July-October around 10° N ( ˜ 2 ppbv). In the Asian middle and lower troposphere, imported African ozone peaks in NH winter between 20 and 25° N. Over 5-40° N, the mean fractional contribution of imported African ozone to the overall ozone concentrations in Asia is largest during NH winter in the middle troposphere ( ˜ 18 %) and lowest in NH summer throughout the tropospheric column ( ˜ 6 %). This seasonality mainly results from the collective effects of the ozone precursor emissions in Africa and meteorology and chemistry in Africa, in Asia and along the transport pathways. The seasonal swing of the Hadley circulation and subtropical westerlies along the

Dermatology and HIV/AIDS in Africa

Directory of Open Access Journals (Sweden)

Jenny Hu

2011-01-01

Full Text Available Human immunodeficiency virus and the acquired immunodeficiency syndrome (HIV/AIDS have greatly complicated dermatologic disease and the required care in most regions of Africa. Opportunistic infections, ectoparasites, Kaposi sarcoma, and skin manifestations of systemic infections are exceedingly common in patients with HIV/AIDS. Dermatologists have contributed significantly to our knowledge base about HIV/AIDS and have played an important educational role regarding the clinical manifestations historically. Because of the increased burden of skin disease in Africa due to the HIV/AIDS epidemic we must redouble our efforts to provide dermatology education to care providers in Africa. We review the burden of skin disease in Africa, how it relates to HIV/AIDS and global infectious disease, current educational strategies in Africa to address this need, and suggest potential solutions to move these efforts forward.

Implementation of Information Communication Technology in the Teaching/Learning Process for Sustainable Development of Adults in West Africa Sub Sahara Region

Science.gov (United States)

Nwobi, Anthonia; Ngozi, Ugwuoke; Rufina, Nwachukwu; Ogbonnaya, Kingsley A.

2016-01-01

This study examines the implementation of information technology in the teaching/learning process for sustainable development of adults in West Africa Sub Sahara Region (WASSR). Three research questions and two hypotheses guided the study. The population for the study was 3071 participants and instructors drawn from 10 education centres that were…

The Importance of Regional Economic Communities and Anchor States for Determining AFRICOM’s Receptivity in Sub Saharan Africa

Science.gov (United States)

2014-02-13

international trade and investment. From 2001 through 2011, Sub-Saharan Africa possessed four out of the world’s ten quickest growing economies . By 2007...together to largely encompass the geography of the future East African Community ( EAC ) REC. While colonial administrators leveraged regionalism to ease...emerging African nations had a “sparse population, small internal market, limited infrastructure, new and fragile borders, economies vulnerable to

Neuro-Oncology Branch

Science.gov (United States)

... BTTC are experts in their respective fields. Neuro-Oncology Clinical Fellowship This is a joint program with ... can increase survival rates. Learn more... The Neuro-Oncology Branch welcomes Dr. Mark Gilbert as new Branch ...

BranchAnalysis2D/3D automates morphometry analyses of branching structures.

Science.gov (United States)

Srinivasan, Aditya; Muñoz-Estrada, Jesús; Bourgeois, Justin R; Nalwalk, Julia W; Pumiglia, Kevin M; Sheen, Volney L; Ferland, Russell J

2018-01-15

Morphometric analyses of biological features have become increasingly common in recent years with such analyses being subject to a large degree of observer bias, variability, and time consumption. While commercial software packages exist to perform these analyses, they are expensive, require extensive user training, and are usually dependent on the observer tracing the morphology. To address these issues, we have developed a broadly applicable, no-cost ImageJ plugin we call 'BranchAnalysis2D/3D', to perform morphometric analyses of structures with branching morphologies, such as neuronal dendritic spines, vascular morphology, and primary cilia. Our BranchAnalysis2D/3D algorithm allows for rapid quantification of the length and thickness of branching morphologies, independent of user tracing, in both 2D and 3D data sets. We validated the performance of BranchAnalysis2D/3D against pre-existing software packages using trained human observers and images from brain and retina. We found that the BranchAnalysis2D/3D algorithm outputs results similar to available software (i.e., Metamorph, AngioTool, Neurolucida), while allowing faster analysis times and unbiased quantification. BranchAnalysis2D/3D allows inexperienced observers to output results like a trained observer but more efficiently, thereby increasing the consistency, speed, and reliability of morphometric analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

Bundle Branch Block

Science.gov (United States)

... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

Analysis of the radiation budget in regional climate simulations with COSMO-CLM for Africa

Directory of Open Access Journals (Sweden)

Steffen Kothe

2014-09-01

Full Text Available This study analysed two regional climate simulations for Africa regarding the radiation budgets with particular focus on the contribution of potentially influential parameters on uncertainties in the radiation components. The ERA-Interim driven simulations have been performed with the COSMO-CLM (grid-spacings of 0.44 ° or 0.22 °. The simulated budgets were compared to the satellite-based Global Energy and Water Cycle Experiment Surface Radiation Budget and ERA-Interim data sets. The COSMO-CLM tended to underestimate the net solar radiation and the outgoing long-wave radiation, and showed a regionally varying over- or underestimation in all budget components. An increase in horizontal resolution from 0.44 ° to 0.22 ° slightly reduced the mean errors by up to 5 %. Especially over sea regions, uncertainties in cloud fraction were the main influencing parameter on errors in the simulated radiation fluxes. Compared to former simulations the introduction of a new bare soil albedo treatment reduced the influence of uncertainties in surface albedo significantly. Over the African continent errors in aerosol optical depth and skin temperature were regionally important sources for the discrepancies within the simulated radiation. In a sensitivity test it was shown that the use of aerosol optical depth values from the MACC reanalysis product improved the simulated surface radiation substantially.

Separate structure of two branches of sheared slab ηi mode and effects of plasma rotation shear in weak magnetic shear region

International Nuclear Information System (INIS)

Jiquan Li; Kishimoto, Y.; Tuda, T.

2000-01-01

The separate structure of two branches of the sheared slab η i mode near the minimum-q magnetic surface is analysed and the effects of plasma rotation shears are considered in the weak magnetic shear region. Results show that the separation condition depends on the non-monotonous q profile and the deviation of rational surface from the minimum-q surface. Furthermore, it is found that the diamagnetic rotation shear may suppress the perturbation of the sheared slab η i mode at one side of the minimum-q surface, the poloidal rotation shear from the sheared E-vector x B-vector flow has a similar role to the slab mode structure when it possesses a direction same as the diamagnetic shear. A plausible interrelation between the separate structures of the two branches of the sheared slab mode and the discontinuity or gap of the radially global structure of the drift wave near the minimum-q surface observed in the toroidal particle simulation (Kishimoto Y et al 1998 Plasma Phys. Control. Fusion 40 A663) is discussed. It seems to support such a viewpoint: the double or/and global branches of the sheared slab η i mode near the minimum-q surface may become a bridge to connect the radially global structures of the drift wave at two sides of the minimum-q surface and the discontinuity may originate from the separate structures of these slab modes for a flatter q profile. (author)

Fault Branching and Long-Term Earthquake Rupture Scenario for Strike-Slip Earthquake

Science.gov (United States)

Klinger, Y.; CHOI, J. H.; Vallage, A.

2017-12-01

Careful examination of surface rupture for large continental strike-slip earthquakes reveals that for the majority of earthquakes, at least one major branch is involved in the rupture pattern. Often, branching might be either related to the location of the epicenter or located toward the end of the rupture, and possibly related to the stopping of the rupture. In this work, we examine large continental earthquakes that show significant branches at different scales and for which ground surface rupture has been mapped in great details. In each case, rupture conditions are described, including dynamic parameters, past earthquakes history, and regional stress orientation, to see if the dynamic stress field would a priori favor branching. In one case we show that rupture propagation and branching are directly impacted by preexisting geological structures. These structures serve as pathways for the rupture attempting to propagate out of its shear plane. At larger scale, we show that in some cases, rupturing a branch might be systematic, hampering possibilities for the development of a larger seismic rupture. Long-term geomorphology hints at the existence of a strong asperity in the zone where the rupture branched off the main fault. There, no evidence of throughgoing rupture could be seen along the main fault, while the branch is well connected to the main fault. This set of observations suggests that for specific configurations, some rupture scenarios involving systematic branching are more likely than others.

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

DEFF Research Database (Denmark)

Sangula, Abraham K.; Belsham, Graham; Muwanika, Vincent B.

2010-01-01

Background: In East Africa, foot-and-mouth disease virus serotype SAT 1 is responsible for occasional severe outbreaks in livestock and is known to be maintained within the buffalo populations. Little is known about the evolutionary forces underlying its epidemiology in the region. To enhance our...... 1 FMD viruses from East Africa has been determined and compared with known sequences derived from other SAT 1 viruses from sub-Saharan Africa. Purifying (negative) selection and low substitution rates characterized the SAT 1 virus isolates in East Africa. Two virus groups with probable independent...... appreciation of the epidemiological status of serotype SAT 1 virus in the region, we inferred its evolutionary and phylogeographic history by means of genealogy-based coalescent methods using 53 VP1 coding sequences covering a sampling period from 1948-2007. Results: The VP1 coding sequence of 11 serotype SAT...

The recurrent branch of the lateral cutaneous nerve of the forearm.

OpenAIRE

Horiguchi, M

1981-01-01

Cutaneous nerves of the upper arm were observed in 31 Japanese cadavers dissected in a student course of gross anatomy dissection and in cadaver selected randomly for intensive dissection. Contrary to the descriptions in current textbooks of human anatomy, the lateral cutaneous nerve of the forearm supplies also the skin over the distal region of the anterolateral surface of the upper arm. A branch to the upper arm (the recurrent branch) arises from the proper trunk of the lateral cutaneous n...

Neonatal mortality in East Africa and West Africa: a geographic analysis of district-level demographic and health survey data

Directory of Open Access Journals (Sweden)

Sue C. Grady

2017-05-01

Full Text Available Under-five child mortality declined 47% since 2000 following the implementation of the United Nation’s (UN Millennium Development Goals. To further reduce under-five child mortality, the UN’s Sustainable Development Goals (SDGs will focus on interventions to address neonatal mortality, a major contributor of under-five mortality. The African region has the highest neonatal mortality rate (28.0 per 1000 live births, followed by that of the Eastern Mediterranean (26.6 and South-East Asia (24.3. This study used the Demographic and Health Survey Birth Recode data (http://dhsprogram.com/data/File-Types-and-Names.cfm to identify high-risk districts and countries for neonatal mortality in two sub-regions of Africa – East Africa and West Africa. Geographically weighted Poisson regression models were estimated to capture the spatially varying relationships between neonatal mortality and dimensions of potential need i care around the time of delivery, ii maternal education, and iii women’s empowerment. In East Africa, neonatal mortality was significantly associated with home births, mothers without an education and mothers whose husbands decided on contraceptive practices, controlling for rural residency. In West Africa, neonatal mortality was also significantly associated with home births, mothers with a primary education and mothers who did not want or plan their last child. Importantly, neonatal mortality associated with home deliveries were explained by maternal exposure to unprotected water sources in East Africa and older maternal age and female sex of infants in West Africa. Future SDG-interventions may target these dimensions of need in priority high-risk districts and countries, to further reduce the burden of neonatal mortality in Africa.

Post-Apartheid South Africa and United States National Security

National Research Council Canada - National Science Library

Cochran, Edwin

1998-01-01

.... It is based on the realist premise that the U.S. has limited national interests in Sub-Saharan Africa which would be best served by a regional security strategy explicitly predicated on engagement with South Africa...

Assessing existing drought monitoring and forecasting capacities, mitigation and adaptation practices in Africa

Science.gov (United States)

Nyabeze, W. R.; Dlamini, L.; Lahlou, O.; Imani, Y.; Alaoui, S. B.; Vermooten, J. S. A.

2012-04-01

Drought is one of the major natural hazards in many parts of the world, including Africa and some regions in Europe. Drought events have resulted in extensive damages to livelihoods, environment and economy. In 2011, a consortium consisting of 19 organisations from both Africa and Europe started a project (DEWFORA) aimed at developing a framework for the provision of early warning and response through drought impact mitigation for Africa. This framework covers the whole chain from monitoring and vulnerability assessment to forecasting, warning, response and knowledge dissemination. This paper presents the first results of the capacity assessment of drought monitoring and forecasting systems in Africa, the existing institutional frameworks and drought mitigation and adaptation practices. Its focus is particularly on the historical drought mitigation and adaptation actions identified in the North Africa - Maghreb Region (Morocco, Algeria and Tunisia) and in the Southern Africa - Limpopo Basin. This is based on an extensive review of historical drought experiences. From the 1920's to 2009, the study identified 37 drought seasons in the North African - Maghreb Region and 33 drought seasons in the Southern Africa - Limpopo Basin. Existing literature tends to capture the spatial extent of drought at national and administrative scale in great detail. This is driven by the need to map drought impacts (food shortage, communities affected) in order to inform drought relief efforts (short-term drought mitigation measures). However, the mapping of drought at catchment scale (hydrological unit), required for longer-term measures, is not well documented. At regional level, both in North Africa and Southern Africa, two organisations are involved in drought monitoring and forecasting, while at national level 22 organisations are involved in North Africa and 37 in Southern Africa. Regarding drought related mitigation actions, the inventory shows that the most common actions

Poisson branching point processes

International Nuclear Information System (INIS)

Matsuo, K.; Teich, M.C.; Saleh, B.E.A.

1984-01-01

We investigate the statistical properties of a special branching point process. The initial process is assumed to be a homogeneous Poisson point process (HPP). The initiating events at each branching stage are carried forward to the following stage. In addition, each initiating event independently contributes a nonstationary Poisson point process (whose rate is a specified function) located at that point. The additional contributions from all points of a given stage constitute a doubly stochastic Poisson point process (DSPP) whose rate is a filtered version of the initiating point process at that stage. The process studied is a generalization of a Poisson branching process in which random time delays are permitted in the generation of events. Particular attention is given to the limit in which the number of branching stages is infinite while the average number of added events per event of the previous stage is infinitesimal. In the special case when the branching is instantaneous this limit of continuous branching corresponds to the well-known Yule--Furry process with an initial Poisson population. The Poisson branching point process provides a useful description for many problems in various scientific disciplines, such as the behavior of electron multipliers, neutron chain reactions, and cosmic ray showers

Intratumor Heterogeneity and Branched Evolution Revealed by Multiregion Sequencing

DEFF Research Database (Denmark)

Gerlinger, Marco; Rowan, Andrew J.; Horswell, Stuart

2012-01-01

.RESULTS: Phylogenetic reconstruction revealed branched evolutionary tumor growth, with 63 to 69% of all somatic mutations not detectable across every tumor region. Intratumor heterogeneity was observed for a mutation within an autoinhibitory domain of the mammalian target of rapamycin (mTOR) kinase, correlating with S6...

Africa Insight - Vol 38, No 3 (2008)

African Journals Online (AJOL)

The impact of major sporting events on the economy and the people of a developing region: the case of the 2010 Fifa World Cup tournament · EMAIL FULL TEXT EMAIL FULL TEXT ... When will it be Africa's turn?: prospects and challenges for South Africa hosting the Olympic games · EMAIL FULL TEXT EMAIL FULL TEXT

Planning a new regional centre for West Africa | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-06-21

Jun 21, 2016 ... ... in line with shared political, economic, and corporate governance standards. ... only); The role of International Financial Institutions for WACAA (French only) ... Harnessing demographic change for economic growth in Africa.

Branches of the landscape

International Nuclear Information System (INIS)

Dine, Michael; O'Neil, Deva; Sun Zheng

2005-01-01

With respect to the question of supersymmetry breaking, there are three branches of the flux landscape. On one of these, if one requires small cosmological constant, supersymmetry breaking is predominantly at the fundamental scale; on another, the distribution is roughly flat on a logarithmic scale; on the third, the preponderance of vacua are at very low scale. A priori, as we will explain, one can say little about the first branch. The vast majority of these states are not accessible even to crude, approximate analysis. On the other two branches one can hope to do better. But as a result of the lack of access to branch one, and our poor understanding of cosmology, we can at best conjecture about whether string theory predicts low energy supersymmetry or not. If we hypothesize that are on branch two or three, distinctive predictions may be possible. We comment of the status of naturalness within the landscape, deriving, for example, the statistics of the first branch from simple effective field theory reasoning

Child mortality and poverty in three world regions (the West, Asia and Sub-Saharan Africa) 1988-2010: Evidence of relative intra-regional neglect?

Science.gov (United States)

Pritchard, Colin; Keen, Steven

2016-12-01

Poverty kills children. This study assesses the relationship between poverty and child mortality rates (CMRs) in 71 societies from three world regions to determine whether some countries, relative to their region, neglect their children. Spearman rank order correlations were calculated to determine any association between the CMR and poverty data, including income inequality and gross national income. A current CMR one standard deviation (SD) above or below the regional average and a percentage change between 1988 and 2010 were used as the measures to assess the progress of nations. There were positive significant correlations between higher CMRs and relative poverty measures in all three regions. In Western countries, the current CMRs in the USA, New Zealand and Canada were 1 SD below the Western mean. The narrowest income inequalities, apart from Japan, were seen in the Scandinavian nations alongside low CMRs. In Asia, the current CMRs in Pakistan, Myanmar and India were the highest in their region and were 1 SD below the regional mean. Alongside South Korea, these nations had the lowest percentage reductions in CMRs. In Sub-Saharan Africa, the current CMRs in Somalia, Burkina Faso, Sierra Leone, Chad, Democratic Republic of Congo and Angola were the highest in their region and were 1 SD below the regional mean. Those concerned with the pursuit of social justice need to alert their societies to the corrosive impact of poverty on child mortality. Progress in reducing CMRs provides an indication of how well nations are meeting the needs of their children. Further country-specific research is required to explain regional differences.

Electricity in Africa or the continent of paradoxes

International Nuclear Information System (INIS)

Heuraux, Christine

2011-01-01

This article first proposes an overview of the present situation of the electricity sector in Africa: the continent is an energy giant because of all the resources it possesses, but an electricity dwarf regarding its present and actual capacities. The author outlines the differences between potential and actual productions, gives an overview of the current status of supply and of production capacities. She comments the status of electricity demand, electricity consumption and electricity markets in the different parts of Africa (data of electricity consumption, of global, urban and rural electrification in Northern Africa, Western Africa, Central Africa, Eastern Africa, Southern Africa with or without South Africa), and issues related to costs and tariffs. She proposes some explanations for the observed discrepancies between African regions and countries: history, too small markets supported by too fragile economies, political and economic failures. Then, she discusses how to favour a durable development of the African electricity sector

A spatio-temporal analysis of fires in South Africa

Directory of Open Access Journals (Sweden)

Sheldon Strydom

2016-11-01

Full Text Available The prevalence and history of fires in Africa has led to the continent being named "the fire continent". Fires are common on the continent and lead to a high number of annual fire disasters which result in many human fatalities and considerable financial loss. Increased population growth and concentrated settlement planning increase the probability of fire disasters and the associated loss of human life and financial loss when disasters occur. In order to better understand the spatial and temporal variations and characteristics of fires in South Africa, an 11-year data set of MODIS-derived Active Fire Hotspots was analysed using an open source geographic information system. The study included the mapping of national fire frequency over the 11-year period. Results indicate that the highest fire frequency occurred in the northeastern regions of South Africa, in particular the mountainous regions of KwaZulu-Natal and Mpumalanga, and in the Western Cape. Increasing trends in provincial fire frequency were observed in eight of the nine provinces of South Africa, with Mpumalanga the only province for which a decrease in annual fire frequency was observed. Temporally, fires were observed in all months for all provinces, although distinct fire seasons were observed and were largely driven by rainfall seasons. The southwestern regions of South Africa (winter-rainfall regions experienced higher fire frequencies during the summer months and the rest of the country (summer-rainfall regions during the winter months. Certain regions those which experienced bimodal rainfall seasons did not display distinct fire seasons because of the complex wet and dry seasons. Investigation into the likely effects of climate change on South African fire frequency revealed that increased air temperatures and events such as La Niña have a marked effect on fire activity.

Regional Climate Change Impact on Agricultural Land Use in West Africa

Science.gov (United States)

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

2014-12-01

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

Modeling the differential incidence of "child abuse, neglect and exploitation" in poor households in South Africa: Focus on child trafficking

CSIR Research Space (South Africa)

Mbecke, P

2010-06-01

Full Text Available above hinders their care, protection and well- being. As a consequence of remarkable abuse, neglect and exploitation of children in South Africa, in 2005 Child Welfare South Africa (CWSA), an umbrella body representing 169 children?s organizations... (affiliates, branches and developing organizations) provided services to 108 379 children considered and defined by the Child Care Act as ?children in need of care?. Out of this number there were 5 000 physically abused children, 6 637 sexually abused...

Extremist Radicalism and Terrorist Inroads in West Africa: Understanding the Threat

Directory of Open Access Journals (Sweden)

Solomon Kofi Amoah

2017-12-01

Full Text Available While research has not yet established the regional consequences of terrorism, its immediate effects on states that have been hit (i.e. Mali, Niger, Burkina Faso and Nigeria, and the spill over effects in neighbouring countries cannot be discounted. This paper analyses the challenge of violent extremism in Africa based on existing evidence from across the West African sub- region. It pays particular attention to the recruitment of young people in Africa into extremist causes on the continent and beyond and proffers measures for their curtailment. The paper argues that terrorism in contemporary Africa undermines democratization, good governance, peace and security and regional development. It also recommends three-pronged strategies for addressing the miasma of extremist radicalism and its associated violence in West Africa, namely, governance, development and security reforms. While it may be difficult to absolutely curtail the activities of terrorist organizations in West Africa. Countries with minimal vulnerabilities like Ghana, Sierra Leone, Liberia and others should intensify efforts towards increased border and cyber security surveillance, sustained de-radicalization programmes and youth empowerment programmes to curb unemployment in earnest.

Child malnutrition in sub-Saharan Africa: A meta-analysis of demographic and health surveys (2006-2016).

Science.gov (United States)

Akombi, Blessing J; Agho, Kingsley E; Merom, Dafna; Renzaho, Andre M; Hall, John J

2017-01-01

Sub-Saharan Africa has one of the highest levels of child malnutrition globally. Therefore, a critical look at the distribution of malnutrition within its sub-regions is required to identify the worst affected areas. This study provides a meta-analysis of the prevalence of malnutrition indicators (stunting, wasting and underweight) within four sub-regions of sub-Saharan Africa. Cross-sectional data from the most recent Demographic and Health Surveys (2006-2016) of 32 countries in sub-Saharan Africa were used. The countries were grouped into four sub-regions (East Africa, West Africa, Southern Africa and Central Africa), and a meta-analysis was conducted to estimate the prevalence of each malnutrition indicator within each of the sub-regions. Significant heterogeneity was detected among the various surveys (I2 >50%), hence a random effect model was used, and sensitivity analysis was performed, to examine the effects of outliers. Stunting was defined as HAZAfrica; Niger (43.9%), Mali (38.3%), Sierra Leone (37.9%) and Nigeria (36.8%) in West Africa; Democratic Republic of Congo (42.7%) and Chad (39.9%) in Central Africa. Wasting was highest in Niger (18.0%), Burkina Faso (15.50%) and Mali (12.7%) in West Africa; Comoros (11.1%) and Ethiopia (8.70%) in East Africa; Namibia (6.2%) in Southern Africa; Chad (13.0%) and Sao Tome & Principle (10.5%) in Central Africa. Underweight was highest in Burundi (28.8%) and Ethiopia (25.2%) in East Africa; Niger (36.4%), Nigeria (28.7%), Burkina Faso (25.7%), Mali (25.0%) in West Africa; and Chad (28.8%) in Central Africa. The prevalence of malnutrition was highest within countries in East Africa and West Africa compared to the WHO Millennium development goals target for 2015. Appropriate nutrition interventions need to be prioritised in East Africa and West Africa if sub-Saharan Africa is to meet the WHO global nutrition target of improving maternal, infant and young child nutrition by 2025.

Module for the organization of a branch of the universal branch driver in the CAMAC standard

International Nuclear Information System (INIS)

Nguen Fuk; Smirnov, V.A.; Khmelevski, E.

1976-01-01

A module is elaborated for the organization of a branch of the universal branch driver in the CAMAC standard for the conjugation of a control crate trunk with a branch trunk. A block diagram of the module is described; its principal specifications are given. The universal branch driver system may accomodate up to 10 branch organization modules with one control source module

Peacekeeping in Africa: Reflections on developments and trends

Directory of Open Access Journals (Sweden)

Theo Neethling

1999-03-01

Full Text Available Africa is arguably the most important regional selling for United Nations peacekeeping challenges. Hence, Africa is the first continent where extensive efforts have recently been made between the United Nations and the Organisation of African Unity with the specific aim of enhancing the management of conflicts in the region. It is significant that the UN now seems prepared to form partnerships with willing regional organisations and alliances in Africa with regard to the conducting of peace-support operations. At the same time, the United States and certain European nations have begun to support the idea of an African response capability of some kind. Another significant development relates to the fact that sub-regional organisations in Africa have started to feature as important peacekeeping instruments in recent years as it has increasingly been accepted that there is a need for such institutions to take care of their own security requirements. In this regard, the “indigenous" intervention operations without UN endorsement or involvement in Sierra Leone, the Democratic Republic of the Congo and in Lesotho are of particular interest, as these would seem to represent a new dimension in the management of African peacekeeping requirements. What is needed in the African context is to establish an acceptable basis for involvement or intervention in intra-state conflicts that respects the dignity and independence of stales without sanctioning the misuse of sovereign rights to violate the security of people within a stale's borders. It would therefore be desirable that all the roleplayers in Africa and further afield should develop a set of broad principles to respond appropriately and speedily to situations where the security of people is imperilled.

Democratic South Africa in the International Migration–Development ...

African Journals Online (AJOL)

sub-Saharan Africa. However, the country has also experienced defi cits in net international migration relative to the core Organisation for Economic Cooperation and Development (OECD) region of the world system. The tentative conclusion to be drawn from. South Africa's involvement in international migration is that it has ...

Angola - an Oil Dependant Country in Sub-Saharan Africa

Directory of Open Access Journals (Sweden)

Baumgartner Boris

2016-12-01

Full Text Available The Sub-Saharan Africa belongs to the most underdeveloped regions in the world economy. This region consists of forty nine countries but it’s world GDP share is only a small percentage. There are some very resource rich countries in this region. One of them is Angola. This former Portuguese colony has one of the largest inventories of oil among all African countries. Angola recorded one of the highest growth of GDP between 2004-2008 from all countries in the world economy and nowadays is the third biggest economy in Sub-Saharan Africa after Nigeria and South Africa. The essential problem of Angola is the one-way oriented economy on oil and general on natural resources. Angola will be forced to change their one-way oriented economy to be more diversified and competitive in the future.

STATE COLLAPSE AND REGIONAL CONTAGION IN SUB-SAHARA AFRICA: LESSONS FOR ZIMBABWE

OpenAIRE

James J. Hentz

2012-01-01

Hollowing out the stateState collapse is one of the most important security threats in Sub-Sahara Africa. The George W. Bush administration's National Security Strategy includes failed and failing states as a national security priority. The U.S. European Command, whose area of responsibility includes much of Sub-Sahara Africa, are "concerned about ungoverned areas descending into chaos with terrorist and warlords…."2 The United Nations is trying to restore order to numerous collapsed states i...

Regional Meeting of Experts on Environmental Education in Africa, Brazzaville, People's Republic of the Congo, 11-16 September 1976. Final Report.

Science.gov (United States)

United Nations Educational, Scientific, and Cultural Organization, Paris (France). Environmental Education Section.

This is the final report on the background and proceedings of the Regional Meeting of Experts on Environmental Education in Africa, convened by UNESCO with the collaboration of the University of Brazzaville. This meeting was one of five similar ones held throughout the world as a follow-up to the UNESCO Conference held in Belgrade, Yugoslavia.…

Financing and Managing Infrastructure in Africa

OpenAIRE

Mthuli Ncube

2010-01-01

This paper discusses various ways of financing infrastructure under public private partnership (PPP) arrangements in Africa. The paper presents the standard literature on the relationship between infrastructure investment and economic growth, highlighting the contradictory findings in the literature. Stylised facts about the state of infrastructure in Africa, compared with other regions such as Asia and Latin America, are also presented. Examples of how PPPs structures work are discussed incl...

Linking Up : Public-Private Partnerships in Power Transmission in Africa

OpenAIRE

World Bank

2017-01-01

The 'Linking up: Public-Private Partnerships in Power Transmission in Africa' report examines private sector-led investments in transmission globally and how this approach is applicable in sub-Saharan Africa. The private sector has invested over US$25 billion in the generation sector in Africa, and across other regions, has also participated successfully in transmission networks in many co...

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

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Mobegi Victor A

2012-07-01

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

Nigerian tourists to South Africa: Challenges, expectations and demands

OpenAIRE

Ikechukwu O. Ezeuduji

2013-01-01

Orientation: Identification of tourists’ needs and finding ways of satisfying them is crucial to any tourism destination. Research purpose: This paper investigated the challenges, demands and expectations of Nigerian tourists to South Africa. Motivation for the study: Nigeria, along with other African nations, has been identified as one of the core regional source markets with air links to South Africa. Increasing revenue generated from regional tourism is important to South African To...

South Africa [National and regional programmes on the production of hydrogen using nuclear energy

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-03-15

South Africa has only small deposits of oil and natural gas and relies on coal production for most of its energy needs. South Africa's economy is structured around large scale, energy-intensive mining and primary minerals industries having a high commercial primary energy intensity. The supply of primary energy in 2007 was 128 Mtoe at a growth rate of 4.4 %/a. The main shares were given by coal (68%), crude oil (19%), renewables (8%), nuclear (3%) and natural gas (2%). South Africa accounts for a major fraction of the CO{sub 2} emissions of the whole continent. Due to its large coal deposits, South Africa is one of the cheapest electricity suppliers in the world. The main reason is its coal based power generating capacity, whose share is 79% (of {approx}40 GW(e)), followed by crude oil (10%), renewables (6%), nuclear (3%) and natural gas (2%). Eskom Holdings Ltd, the State owned power utility that supplies 95% of South Africa's electricity, is planning to increase the current generation capacity of 40 GW by 4%/a to 80 GW by 2025. The power supply crisis in January 2008, which forced shutdowns at mines, has accelerated recognition of the need to diversify the energy mix, such as with nuclear power and natural gas, as well as various forms of renewable energy. Starting in 1984, the national utility ESKOM has been successfully operating the Koeberg nuclear power station consisting of two 900 MW(e) PWR units which generated {approx}6.5% of the electricity needs. In addition, ESKOM has been pursuing the project of modular HTGRs for electricity production to meet the demand of its growing economy. In 2007-2008, the demand for electricity in South Africa started to exceed supply when the economy was growing and, at the same time, existing plants went out for maintenance. As a result, ESKOM and the South African Government decided to request proposals for new nuclear capacity and to expand the nuclear component in the energy supply mix of the country. In the strategic plan

Volcano-tectonic deformation in the Kivu Region, Central Africa: Results from six years of continuous GNSS observations of the Kivu Geodetic Network (KivuGNet)

Science.gov (United States)

Geirsson, Halldor; d'Oreye, Nicolas; Mashagiro, Niche; Syauswa, Muhindo; Celli, Gilles; Kadufu, Benjamin; Smets, Benoît; Kervyn, François

2017-10-01

We present an overview of the installation, operation, and initial results of the 15-station KivuGNet (Kivu Geodetic Network) in the Kivu Region, Central Africa. The network serves primarily as a research and monitoring tool for active volcanic, earthquake, and plate boundary processes in the region. Continuous operation of in-situ measurement networks in naturally and politically harsh environments is challenging, but has proven fruitful in this case. During the operation of the network since 2009, KivuGNet has captured: co-eruptive deformation from two eruptions of Nyamulagira (in 2010 and 2011-2012); inter-eruptive deformation, which we interpret as a combination of plate motion across the Western - East Africa Rift, and decreasing deep-seated magma accumulation under the Nyiragongo-Nyamulagira region; co-seismic deformation from the Mw5.8 August 7, 2015 Lwiro earthquake at the western border of Lake Kivu. We hope that this study will serve as a motivation for further implementation of in-situ geodetic networks in under-monitored and under-studied sections of the East African Rift.

Review of Remote Sensing Needs and Applications in Africa

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Brown, Molly E.

2007-01-01

Remote sensing data has had an important role in identifying and responding to inter-annual variations in the African environment during the past three decades. As a largely agricultural region with diverse but generally limited government capacity to acquire and distribute ground observations of rainfall, temperature and other parameters, remote sensing is sometimes the only reliable measure of crop growing conditions in Africa. Thus, developing and maintaining the technical and scientific capacity to analyze and utilize satellite remote sensing data in Africa is critical to augmenting the continent's local weather/climate observation networks as well as its agricultural and natural resource development and management. The report Review of Remote Sensing Needs and Applications in Africa' has as its central goal to recommend to the US Agency for International Development an appropriate approach to support sustainable remote sensing applications at African regional remote sensing centers. The report focuses on "RS applications" to refer to the acquisition, maintenance and archiving, dissemination, distribution, analysis, and interpretation of remote sensing data, as well as the integration of interpreted data with other spatial data products. The report focuses on three primary remote sensing centers: (1) The AGRHYMET Regional Center in Niamey, Niger, created in 1974, is a specialized institute of the Permanent Interstate Committee for Drought Control in the Sahel (CILSS), with particular specialization in science and techniques applied to agricultural development, rural development, and natural resource management. (2) The Regional Centre for Maiming of Resources for Development (RCMRD) in Nairobi, Kenya, established in 1975 under the auspices of the United Nations Economic Commission for Africa and the Organization of African Unity (now the African Union), is an intergovernmental organization, with 15 member states from eastern and southern Africa. (3) The

An analysis of spatial development paradigm for enhancing regional integration within national and it’s supporting spatial systems in Africa / Donald Chiuba Okeke

OpenAIRE

Okeke, Donald Chiuba

2015-01-01

The global aim of this research is to postulate a spatial development paradigm for regional integration in developing countries - more specifically, the research prospects to conceptualize form-based spatial planning theory for Africa. This was considered necessary on two grounds: first, the need for spatial regional integration as panacea for economic growth, and second the resilience of formal planning in the context of a neo-liberal paradigm shift in planning for economic gr...

Improving epidemic malaria planning, preparedness and response in Southern Africa. Report on the 1st Southern African Regional Epidemic Outlook Forum, Harare, Zimbabwe, 26-29 September, 2004.

Science.gov (United States)

DaSilva, Joaquim; Garanganga, Brad; Teveredzi, Vonai; Marx, Sabine M; Mason, Simon J; Connor, Stephen J

2004-10-22

Malaria is a major public health problem for countries in the Southern Africa Development Community (SADC). While the endemicity of malaria varies enormously across this region, many of the countries have districts that are prone to periodic epidemics, which can be regional in their extent, and to resurgent outbreaks that are much more localized. These epidemics are frequently triggered by climate anomalies and often follow periods of drought. Many parts of Southern Africa have suffered rainfall deficit over the past three years and countries expect to see increased levels of malaria when the rains return to more 'normal' levels. Problems with drug and insecticide resistance are documented widely and the region contains countries with the highest rates of HIV prevalence to be found anywhere in the world. Consequently, many communities are vulnerable to severe disease outcomes should epidemics occur. The SADC countries have adopted the Abuja targets for Roll Back Malaria in Africa, which include improved epidemic detection and response, i.e., that 60% of epidemics will be detected within two weeks of onset, and 60% of epidemics will be responded to within two weeks of detection. The SADC countries recognize that to achieve these targets they need improved information on where and when to look for epidemics. The WHO integrated framework for improved early warning and early detection of malaria epidemics has been recognized as a potentially useful tool for epidemic preparedness and response planning. Following evidence of successful adoption and implementation of this approach in Botswana, the SADC countries, the WHO Southern Africa Inter-Country Programme on Malaria Control, and the SADC Drought Monitoring Centre decided to organize a regional meeting where countries could gather to assess their current control status and community vulnerability, consider changes in epidemic risk, and develop a detailed plan of action for the forthcoming 2004-2005 season. The

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

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Y. C. Sud

2009-10-01

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

The Perplex of Deforestation in sub-Saharan Africa

OpenAIRE

A.W Yalew

2015-01-01

Deforestation has been a complex phenomenon to study in sub-Saharan Africa. The average annual deforestation rate in the region is by far higher than the world average. What causes and drives deforestation in the region are debated to date. The present paper is motivated by this debate. It attempts to test whether the maintained hypotheses on the causes of deforestation can give answer to the problem in sub-Saharan Africa. It used average cross-national data of forty eight countries in the re...

Substantial regional differences in human herpesvirus 8 seroprevalence in sub-Saharan Africa: insights on the origin of the "Kaposi's sarcoma belt".

Science.gov (United States)

Dollard, Sheila C; Butler, Lisa M; Jones, Alison M Graves; Mermin, Jonathan H; Chidzonga, Midion; Chipato, Tsungai; Shiboski, Caroline H; Brander, Christian; Mosam, Anisa; Kiepiela, Photini; Hladik, Wolfgang; Martin, Jeffrey N

2010-11-15

Equatorial Africa has among the highest incidences of Kaposi's sarcoma (KS) in the world, thus earning the name "KS Belt." This was the case even before the HIV epidemic. To date, there is no clear evidence that HHV-8 seroprevalence is higher in this region but interpretation of the available literature is tempered by differences in serologic assays used across studies. We examined representatively sampled ambulatory adults in Uganda, which is in the "KS Belt," and in Zimbabwe and South Africa which are outside the Belt, for HHV-8 antibodies. All serologic assays were uniformly performed in the same reference laboratory by the same personnel. In the base-case serologic algorithm, seropositivity was defined by reactivity in an immunofluorescence assay or in 2 enzyme immunoassays. A total of 2,375 participants were examined. In Uganda, HHV-8 seroprevalence was high early in adulthood (35.5% by age 21) without significant change thereafter. In contrast, HHV-8 seroprevalence early in adulthood was lower in Zimbabwe and South Africa (13.7 and 10.8%, respectively) but increased with age. After age adjustment, Ugandans had 3.24-fold greater odds of being HHV-8 infected than South Africans (p Africa. These findings help to explain the high KS incidence in the "KS Belt" and underscore the importance of a uniform approach to HHV-8 antibody testing.

New Regionalism in Africa: Waves of Integration | Bachinger | Africa ...

African Journals Online (AJOL)

The international trading environment is shaped by the so-called 'new regionalism', an increasingly complex phenomenon with a rapid proliferation of Regional Integration Agreements (RIAs), overlapping memberships, deeper integration efforts and trade blocs signed between developing and industrialised countries.

The state of space science in Africa | Mhlahlo | Africa Insight

African Journals Online (AJOL)

There has been an increase in the number of space science activities and facilities in Africa in the last 15 years. This increase, however, is not proportionate to the indigenous user community for these activities and facilities. In this paper, I discuss these activities and their benefits for the African region, and point out some of ...

Child malnutrition in sub-Saharan Africa: A meta-analysis of demographic and health surveys (2006-2016.

Directory of Open Access Journals (Sweden)

Blessing J Akombi

Full Text Available Sub-Saharan Africa has one of the highest levels of child malnutrition globally. Therefore, a critical look at the distribution of malnutrition within its sub-regions is required to identify the worst affected areas. This study provides a meta-analysis of the prevalence of malnutrition indicators (stunting, wasting and underweight within four sub-regions of sub-Saharan Africa.Cross-sectional data from the most recent Demographic and Health Surveys (2006-2016 of 32 countries in sub-Saharan Africa were used. The countries were grouped into four sub-regions (East Africa, West Africa, Southern Africa and Central Africa, and a meta-analysis was conducted to estimate the prevalence of each malnutrition indicator within each of the sub-regions. Significant heterogeneity was detected among the various surveys (I2 >50%, hence a random effect model was used, and sensitivity analysis was performed, to examine the effects of outliers. Stunting was defined as HAZ<-2; wasting as WHZ<-2 and underweight as WAZ<-2.Stunting was highest in Burundi (57.7% and Malawi (47.1% in East Africa; Niger (43.9%, Mali (38.3%, Sierra Leone (37.9% and Nigeria (36.8% in West Africa; Democratic Republic of Congo (42.7% and Chad (39.9% in Central Africa. Wasting was highest in Niger (18.0%, Burkina Faso (15.50% and Mali (12.7% in West Africa; Comoros (11.1% and Ethiopia (8.70% in East Africa; Namibia (6.2% in Southern Africa; Chad (13.0% and Sao Tome & Principle (10.5% in Central Africa. Underweight was highest in Burundi (28.8% and Ethiopia (25.2% in East Africa; Niger (36.4%, Nigeria (28.7%, Burkina Faso (25.7%, Mali (25.0% in West Africa; and Chad (28.8% in Central Africa.The prevalence of malnutrition was highest within countries in East Africa and West Africa compared to the WHO Millennium development goals target for 2015. Appropriate nutrition interventions need to be prioritised in East Africa and West Africa if sub-Saharan Africa is to meet the WHO global nutrition target

Can ICT belong in Africa, or is it owned by the North Atlantic Region?

NARCIS (Netherlands)

Binsbergen, van W.M.J.; Binsbergen W.M.J. van, van Dijk, R.A.

2004-01-01

This introductory chapter sketches globalization and Africa in broad theoretical terms, examining the meaning of the term globalization; the impact of globalization on daily life in Africa in economic as well as sociocultural terms; globalization as a historical phenomenon; the political aspects of

Branching pattern of lenticulostriate arteries observed by MR angiography at 3.0 T

International Nuclear Information System (INIS)

Akashi, Toshiaki; Taoka, Toshiaki; Ochi, Tomoko; Miyasaka, Toshiteru; Wada, Takeshi; Sakamoto, Masahiko; Kichikawa, Kimihiko; Takewa, Megumi

2012-01-01

We hypothesized that the pattern of branching of the lenticulostriate arteries (LSAs) is involved in the variation of the distribution of the infarction within the LSA region. Our purpose was to evaluate the visibility of LSAs in 3D time-of-flight (TOF) MR angiography (MRA) with a 3.0 T scanner and to investigate the branching patterns of LSAs. We performed 3D TOF MRA at 3.0 T for 100 healthy subjects. We assessed the number of LSAs and the number of branches arising from each LSA by evaluating MRA source images. In 200 hemispheres, 330 LSAs were visualized (mean=1.65/hemisphere). In 3.5% of all hemispheres, no LSA was depicted; one LSA was depicted in 39%, two in 46.5%, and three in 11%. The maximum number of depicted LSA branches was five in 2% of all subjects, four in 7%, three in 26%, and two in 49% (mean=2.3/subject). A large LSA trunk with three or more branches was found in 35% of subjects. Visualization of LSAs was possible in 96.5% of subjects by use of 3.0 T MRA. LSA branching patterns were variable, and a large LSA trunk with three or more branches was common. (author)

Africa : The Road to Opportunity

OpenAIRE

Wolfowitz, Paul

2006-01-01

Paul Wolfowitz, President of the World Bank, remarked that the past-quarter century has to count as the most successful 25 years in history in the fight against poverty. The one region that has so far been conspicuously left behind by that progress is Sub-Saharan Africa. The people of Africa are hard at work building a more hopeful future for their continent. There is no shortage of energy, ambition, or entrepreneurial spirit. What are most severely lacking are resources to support good plan...

MERS coronaviruses from camels in Africa exhibit region-dependent genetic diversity.

Science.gov (United States)

Chu, Daniel K W; Hui, Kenrie P Y; Perera, Ranawaka A P M; Miguel, Eve; Niemeyer, Daniela; Zhao, Jincun; Channappanavar, Rudragouda; Dudas, Gytis; Oladipo, Jamiu O; Traoré, Amadou; Fassi-Fihri, Ouafaa; Ali, Abraham; Demissié, Getnet F; Muth, Doreen; Chan, Michael C W; Nicholls, John M; Meyerholz, David K; Kuranga, Sulyman A; Mamo, Gezahegne; Zhou, Ziqi; So, Ray T Y; Hemida, Maged G; Webby, Richard J; Roger, Francois; Rambaut, Andrew; Poon, Leo L M; Perlman, Stanley; Drosten, Christian; Chevalier, Veronique; Peiris, Malik

2018-03-20

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal-human interface. Copyright © 2018 the Author(s). Published by PNAS.

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

Science.gov (United States)

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

2011-08-01

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

Science and Technology in Africa: The African Union New Initiative and Financial Support Perspectives

Science.gov (United States)

Ezin, Jean-Pierre

2010-02-01

Physics, which is widely touted as the most fundamental of the sciences, underpins the progress in all other branches of science and has a wide range of applications in economic development, including in health, energy research, food security, communication technology and climate change. The African Union (AU) Commission articulates the continental vision of its Member States and its programs are designed to directly contribute to its social and economic development and integration efforts. In the area of science and technology the Department has developed Africa's Science and Technology Consolidated Plan of Action as a strategic policy document through the AU system of conference of ministers responsible for science to guide the continent on common priority programs. The programs in this plan of action that have been transformed into bankable projects under the Book of ``lighthouse projects Phase 1'', adequately respond to Africa's challenges and development needs using science. They can be summarized into three main themes: a pan-African university (PAU) initiative (to combine higher education and scientific research as a network of differentiated PAU in each of the five African regions), African research grants (to strengthen the research capacity of the African institutions and upgrading infrastructures, consolidating their accumulated asset of scientific knowledge), popularization of science and technology and promotion of public participation (to build public understanding and raising awareness on science and technology as a driving agent for social and economic progress for Africa and its integration process) and a science and technology institutional capacity building program). This talk will review these programs as well as the vision of the African Development Bank role in it. )

Epidemiology of HIV in southern Africa

International Nuclear Information System (INIS)

Zanoni, Brian C.

2009-01-01

HIV/AIDS disproportionately affects sub-Saharan Africa and 90% of the children with HIV are found there. In addition, non-HIV-infected children in the region are also vulnerable with an estimated 11.4 million AIDS orphans (many of whom are also HIV-positive). South Africa has an estimated 5.5 million people infected with HIV, which is by far the highest in the world. South Africa was reluctant to accept international assistance and began to provide care and treatment much later than its neighbours, and access to care and treatment remains low. Only 36% of children with advanced AIDS living in South Africa were receiving antiretroviral drugs in 2007. This paper not only provides data expressing the extent of the HIV problem affecting children, but also compares neighbouring African countries' successes and failures in combating the disease. (orig.)

[Croatian Medical Association--Branch Zagreb].

Science.gov (United States)

Kaić, Zvonimir; Sain, Snjezana; Gulić, Mirjana; Mahovlić, Vjekoslav; Krznarić, Zeljko

2014-01-01

The available literature shows us that "Druztvo ljeciteljah u Zagrebus (the Society of Healers in Zagreb) was founded as far back as the year 1845 by a total of thirteen members. This data allows us to follow the role of doctors and health workers in Zagreb through their everyday profession, research, organizational and social work as well as management through a period of over one hundred to seventy years. The Branch Zagreb was active before the official establishment of subsidiaries of CMA which is evident from the minutes of the regular annual assembly of the Croatian Medical Association on 21 March 1948. Until the end of 1956, there was no clear division of labor, functions and competencies between the Branch and the Main Board. Their actions were instead consolidated and the Branch operated within and under the name of Croatian Medical Association. In that year the Branch became independent. The Branch Zagreb is the largest and one of the most active branches of the Croatian Medical Association. At the moment, the Branch brings together 3621 members, regular members--doctors of medicine (2497), doctors of dental medicine (384), retired physicians (710), and associate members (30 specialists with higher education who are not doctors). The Branch is especially accomplished in its activities in the area of professional development of its members and therefore organizes a series of scientific conferences in the framework of continuous education of physicians, allowing its members to acquire necessary points for the extension of their operating license. The choir "Zagrebacki lijecnici pjevaci" (Zagreb Physicians' Choir) of the Croatian Medical Music Society of the CMA and its activities are inseparable from the Branch Zagreb. The Branch is firmly linked to the parent body, the CMA, and thus has a visible impact on the strategy and the activities of the Association as a whole. Most professional societies of the CMA have their headquarters in Zagreb and this is

Costing and Budgeting for Preservation and Conservation in the ...

African Journals Online (AJOL)

Within the Eastern and Southern Africa Regional Branch of the International Council on Archives (ESARBICA) region, little or no information is available on budgeting systems for archival institutions in the region to enhance preservation and conservation programs. Preservation and conservation requires both economic ...

Vertical Differentiation of Cassava Marketing Channels in Africa

Directory of Open Access Journals (Sweden)

Enete, AA.

2008-01-01

Full Text Available Farming systems in sub-Saharan Africa are inherently risky because they are fundamentally dependent on vagaries of weather. Sub-Saharan Africa is also a region in crises; poverty, civil strife and HIV/AIDS. Attention must therefore be focused on improving the production and marketing of crops that could thrive under these circumstances. Because of its tolerance of extreme drought and low input use conditions, Cassava is perhaps the best candidate in this regard. And cassava is a basic food staple and a major source of farm income for the people of the region. Efficiency in cassava marketing is a very important determinant of both consumers' living cost and producers' income in Africa. Vertical differentiation of marketing channels improves marketing efficiency. Identified in this paper are factors that drive vertical differentiation of cassava marketing channels. The paper is based on primary data collected within the framework of the Collaborative Study of Cassava in Africa. High population density, good market access conditions, availability of mechanized cassava processing technology and cassava price information stimulate vertical differentiation of the marketing channels.

Generating emissions and meteorology to model the impacts of biomass burning emissions on regional air quality in South Africa

CSIR Research Space (South Africa)

Carter, WS

2008-10-01

Full Text Available inventory, trajectory analysis. 1. Introduction The Kruger National Park (KNP), situated on the border of South Africa and Mozambique was intensively studied for its emission contributions and effects on the atmosphere during both the SAFARI...-1992 and SAFARI-2000 campaigns. It is a region that is characterised by dry season biomass burning with more than 52% of its fires occurring throughout the winter months. As an initial step in this study, pyrogenic emissions from savanna...

An investigation of cognitive 'branching' processes in major depression

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Williams Steven CR

2009-11-01

Full Text Available Abstract Background Patients with depression demonstrate cognitive impairment on a wide range of cognitive tasks, particularly putative tasks of frontal lobe function. Recent models of frontal lobe function have argued that the frontal pole region is involved in cognitive branching, a process requiring holding in mind one goal while performing sub-goal processes. Evidence for this model comes from functional neuroimaging and frontal-pole lesion patients. We have utilised these new concepts to investigate the possibility that patients with depression are impaired at cognitive 'branching'. Methods 11 non-medicated patients with major depression were compared to 11 matched controls in a behavioural study on a task of cognitive 'branching'. In the version employed here, we recorded participant's performance as they learnt to perform the task. This involved participants completing a control condition, followed by a working memory condition, a dual-task condition and finally the branching condition, which integrates processes in the working memory and dual-task conditions. We also measured participants on a number of other cognitive tasks as well as mood-state before and after the branching experiment. Results Patients took longer to learn the first condition, but performed comparably to controls after six runs of the task. Overall, reaction times decreased with repeated exposure on the task conditions in controls, with this effect attenuated in patients. Importantly, no differences were found between patients and controls on the branching condition. There was, however, a significant change in mood-state with patients increasing in positive affect and decreasing in negative affect after the experiment. Conclusion We found no clear evidence of a fundamental impairment in anterior prefrontal 'branching processes' in patients with depression. Rather our data argue for a contextual learning impairment underlying cognitive dysfunction in this disorder. Our

An investigation of cognitive 'branching' processes in major depression.

Science.gov (United States)

Walsh, Nicholas D; Seal, Marc L; Williams, Steven C R; Mehta, Mitul A

2009-11-10

Patients with depression demonstrate cognitive impairment on a wide range of cognitive tasks, particularly putative tasks of frontal lobe function. Recent models of frontal lobe function have argued that the frontal pole region is involved in cognitive branching, a process requiring holding in mind one goal while performing sub-goal processes. Evidence for this model comes from functional neuroimaging and frontal-pole lesion patients. We have utilised these new concepts to investigate the possibility that patients with depression are impaired at cognitive 'branching'. 11 non-medicated patients with major depression were compared to 11 matched controls in a behavioural study on a task of cognitive 'branching'. In the version employed here, we recorded participant's performance as they learnt to perform the task. This involved participants completing a control condition, followed by a working memory condition, a dual-task condition and finally the branching condition, which integrates processes in the working memory and dual-task conditions. We also measured participants on a number of other cognitive tasks as well as mood-state before and after the branching experiment. Patients took longer to learn the first condition, but performed comparably to controls after six runs of the task. Overall, reaction times decreased with repeated exposure on the task conditions in controls, with this effect attenuated in patients. Importantly, no differences were found between patients and controls on the branching condition. There was, however, a significant change in mood-state with patients increasing in positive affect and decreasing in negative affect after the experiment. We found no clear evidence of a fundamental impairment in anterior prefrontal 'branching processes' in patients with depression. Rather our data argue for a contextual learning impairment underlying cognitive dysfunction in this disorder. Our data suggest that MDD patients are able to perform high

A National Security Strategy of Cooperative Engagement for Sub-Saharan Africa

National Research Council Canada - National Science Library

Gunzinger, Mark A; Thomas, David L

1996-01-01

Extending from the urban centers of South Africa to the lesser-developed regions of the arid Sahel, Sub-Saharan Africa spans the post-Cold War spectrum of political, economic, and military challenges...

A westward extension of the warm pool leads to a westward extension of the Walker circulation, drying eastern Africa

Energy Technology Data Exchange (ETDEWEB)

Williams, A.P.; Funk, Chris [University of California, Santa Barbara, Geography Department, Santa Barbara, CA (United States)

2011-12-15

Observations and simulations link anthropogenic greenhouse and aerosol emissions with rapidly increasing Indian Ocean sea surface temperatures (SSTs). Over the past 60 years, the Indian Ocean warmed two to three times faster than the central tropical Pacific, extending the tropical warm pool to the west by {proportional_to}40 longitude (>4,000 km). This propensity toward rapid warming in the Indian Ocean has been the dominant mode of interannual variability among SSTs throughout the tropical Indian and Pacific Oceans (55 E-140 W) since at least 1948, explaining more variance than anomalies associated with the El Nino-Southern Oscillation (ENSO). In the atmosphere, the primary mode of variability has been a corresponding trend toward greatly increased convection and precipitation over the tropical Indian Ocean. The temperature and rainfall increases in this region have produced a westward extension of the western, ascending branch of the atmospheric Walker circulation. Diabatic heating due to increased mid-tropospheric water vapor condensation elicits a westward atmospheric response that sends an easterly flow of dry air aloft toward eastern Africa. In recent decades (1980-2009), this response has suppressed convection over tropical eastern Africa, decreasing precipitation during the 'long-rains' season of March-June. This trend toward drought contrasts with projections of increased rainfall in eastern Africa and more 'El Nino-like' conditions globally by the Intergovernmental Panel on Climate Change. Increased Indian Ocean SSTs appear likely to continue to strongly modulate the Warm Pool circulation, reducing precipitation in eastern Africa, regardless of whether the projected trend in ENSO is realized. These results have important food security implications, informing agricultural development, environmental conservation, and water resource planning. (orig.)

Flowering phenology in the arid winter rainfall region of southern Africa

Directory of Open Access Journals (Sweden)

M. Struck

1994-10-01

Full Text Available The impact of physical factors on the flowering phenology of a succulent karroid community in the winter rainfall region of the northwestern Cape, South Africa, based upon a three year study on permanent plots, is examined, (in the permanent plots, flowering of the shrubby species extended over a period of 4 to 4'/i> months each year, while blooming ot the therophytes peaked m the first half of the flowering season. Species composition and numbers of individuals in the therophytes and geophytes offering flowers varied greatly according to the pattern and amount of seasonal precipitation. Despite these variations a consistent flowering sequence between the years was observed. Possible relations between the flowering phenology and the climatic variables are discussed in detail. The present data suggest that the onset of flowering is determined indirectly by the first drop in temperature in autumn, indicating the beginning of the rainy season and presumably the start of the growing period, and/or by the increase of temperatures in the beginning of spring. The pattern and amount of rainfall within a given season mainly influenced the duration of anthesis and the number of flowers produced.

All projects related to South Africa | Page 2 | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

This study will adopt a groundbreaking approach to understanding and responding to urban ... Region: Brazil, South Africa, United Kingdom ... Urban upgrading for violence prevention in South Africa: Does it work? ... DEVELOPING COUNTRIES, Economic and social development, CASE STUDIES, POLICY MAKING, ...

European origin of Bradyrhizobium populations infecting lupins and serradella in soils of Western Australia and South Africa.

Science.gov (United States)

Stepkowski, Tomasz; Moulin, Lionel; Krzyzańska, Agnieszka; McInnes, Alison; Law, Ian J; Howieson, John

2005-11-01

We applied a multilocus phylogenetic approach to elucidate the origin of serradella and lupin Bradyrhizobium strains that persist in soils of Western Australia and South Africa. The selected strains belonged to different randomly amplified polymorphic DNA (RAPD)-PCR clusters that were distinct from RAPD clusters of applied inoculant strains. Phylogenetic analyses were performed with nodulation genes (nodA, nodZ, nolL, noeI), housekeeping genes (dnaK, recA, glnII, atpD), and 16S-23S rRNA intergenic transcribed spacer sequences. Housekeeping gene phylogenies revealed that all serradella and Lupinus cosentinii isolates from Western Australia and three of five South African narrow-leaf lupin strains were intermingled with the strains of Bradyrhizobium canariense, forming a well supported branch on each of the trees. All nodA gene sequences of the lupin and serradella bradyrhizobia formed a single branch, referred to as clade II, together with the sequences of other lupin and serradella strains. Similar patterns were detected in nodZ and nolL trees. In contrast, nodA sequences of the strains isolated from native Australian legumes formed either a new branch called clade IV or belonged to clade I or III, whereas their nonsymbiotic genes grouped outside the B. canariense branch. These data suggest that the lupin and serradella strains, including the strains from uncultivated L. cosentinii plants, are descendants of strains that most likely were brought from Europe accidentally with lupin and serradella seeds. The observed dominance of B. canariense strains may be related to this species' adaptation to acid soils common in Western Australia and South Africa and, presumably, to their intrinsic ability to compete for nodulation of lupins and serradella.

Assistance Focus: Africa

Energy Technology Data Exchange (ETDEWEB)

2017-05-18

The Clean Energy Solutions Center, an initiative of the Clean Energy Ministerial, helps countries throughout the world create policies and programs that advance the deployment of clean energy technologies. Through the Solutions Center's no-cost Ask an Expert service, a team of international experts has delivered assistance to countries in all regions of the world, including Africa.

Out of Africa:Miocene Dispersal, Vicariance, and Extinction within Hyacinthaceae Subfamily Urgineoideae

Institute of Scientific and Technical Information of China (English)

Syed Shujait Ali; Martin Pfosser; Wolfgang Wetschnig; Mario MartnezAzorn; Manuel B. Crespo; Yan Yu

2013-01-01

Disjunct distribution patterns in plant lineages are usually explained according to three hypotheses:vicariance, geodispersal, and long-distance dispersal. The role of these hypotheses is tested in Urgineoideae (Hyacinthaceae), a subfamily disjunctly distributed in Africa, Madagascar, India, and the Mediterranean region. The potential ancestral range, dispersal routes, and factors responsible for the current distribution in Urgineoideae are investigated using divergence time estimations. Urgineoideae originated in Southern Africa approximately 48.9 Mya. Two independent dispersal events in the Western Mediterranean region possibly occurred during Early Oligocene and Miocene (29.9-8.5 Mya) via Eastern and Northwestern Africa. A dispersal from Northwestern Africa to India could have occurred between 16.3 and 7.6 Mya. Vicariance and extinction events occurred approximately 21.6 Mya. Colonization of Madagascar occurred between 30.6 and 16.6 Mya, after a single transoceanic dispersal event from Southern Africa. The current disjunct distributions of Urgineoideae are not satisfactorily explained by Gondwana fragmentation or dispersal via boreotropical forests, due to the younger divergence time estimates. The flattened winged seeds of Urgineoideae could have played an important role in long-distance dispersal by strong winds and big storms, whereas geodispersal could have also occurred from Southern Africa to Asia and the Mediterranean region via the so-called arid and high-altitude corridors.

IDRC in South Africa

International Development Research Centre (IDRC) Digital Library (Canada)

To strengthen competition authorities in the region, IDRC supported the creation of the African Competition. Forum in 2010. IDRC-funded research also helped ... Saving lives, money, and ecosystems. Funding: $675,000. Duration: 2013–2016. Grantee: University of Pretoria,. South Africa. Environmental economists seek to ...

Opportunities for the power industry in South Africa

International Nuclear Information System (INIS)

Lynch, R.W.; Pinkney, C.; Feld, L.; Kreil, E.; Lockwood, A.W.

1996-01-01

South Africa is a country in the midst of transformation. Political changes within the country, and the ensuing empowerment of the black majority, have created a situation where dramatic improvements are needed in the country's infrastructure in order to enable it to meet the needs of all its people over the coming decades. Largely as a result of the international embargo placed on South Africa during the apartheid era, the South African government became heavily involved in the country's energy sector. This involvement included development of a synfuels program, price controls in the oil sector, monopolies in both upstream and downstream oil sectors, and a strong centralized electric power company. In 1994, South Africa became the eleventh member of the Southern Africa Development Community (SADC), an organization which was established in 1980 to synchronize development plans for its member countries. SADC is presently working to formulate a regional energy development plan, and coordinate technical information exchanges and joint research needs. Each of the SADC nations have also begun to develop their regional electricity grids and other parts of their energy infrastructure to plan for the growing needs of the 500 million people who live in sub-Saharan Africa. South Africa, in particular, must make significant changes in each of its energy sectors in the near future, to keep up with its growing energy requirements. These changes translate to opportunity for the US Power Industry

Opportunities for the power industry in South Africa

Energy Technology Data Exchange (ETDEWEB)

Lynch, R.W.; Pinkney, C.; Feld, L.; Kreil, E.; Lockwood, A.W. [Dept. of Energy, Washington, DC (United States)

1996-11-01

South Africa is a country in the midst of transformation. Political changes within the country, and the ensuing empowerment of the black majority, have created a situation where dramatic improvements are needed in the country`s infrastructure in order to enable it to meet the needs of all its people over the coming decades. Largely as a result of the international embargo placed on South Africa during the apartheid era, the South African government became heavily involved in the country`s energy sector. This involvement included development of a synfuels program, price controls in the oil sector, monopolies in both upstream and downstream oil sectors, and a strong centralized electric power company. In 1994, South Africa became the eleventh member of the Southern Africa Development Community (SADC), an organization which was established in 1980 to synchronize development plans for its member countries. SADC is presently working to formulate a regional energy development plan, and coordinate technical information exchanges and joint research needs. Each of the SADC nations have also begun to develop their regional electricity grids and other parts of their energy infrastructure to plan for the growing needs of the 500 million people who live in sub-Saharan Africa. South Africa, in particular, must make significant changes in each of its energy sectors in the near future, to keep up with its growing energy requirements. These changes translate to opportunity for the US Power Industry.

Current perspectives on shoot branching regulation

Directory of Open Access Journals (Sweden)

Cunquan YUAN,Lin XI,Yaping KOU,Yu ZHAO,Liangjun ZHAO

2015-03-01

Full Text Available Shoot branching is regulated by the complex interactions among hormones, development, and environmental factors. Recent studies into the regulatory mecha-nisms of shoot branching have focused on strigolactones, which is a new area of investigation in shoot branching regulation. Elucidation of the function of the D53 gene has allowed exploration of detailed mechanisms of action of strigolactones in regulating shoot branching. In addition, the recent discovery that sucrose is key for axillary bud release has challenged the established auxin theory, in which auxin is the principal agent in the control of apical dominance. These developments increase our understan-ding of branching control and indicate that regulation of shoot branching involves a complex network. Here, we first summarize advances in the systematic regulatory network of plant shoot branching based on current information. Then we describe recent developments in the synthesis and signal transduction of strigolactones. Based on these considerations, we further summarize the plant shoot branching regulatory network, including long distance systemic signals and local gene activity mediated by strigolactones following perception of external envi-ronmental signals, such as shading, in order to provide a comprehensive overview of plant shoot branching.

The Africa South America Intercontinental Teleconnection.

Science.gov (United States)

Cook, K. H.; Hsieh, J.-S.; Hagos, S. M.

2004-07-01

The influence of heating over Africa on the South American precipitation climatology, and the influence of South America on Africa, is examined through the application of GCM simulations with idealized boundary conditions and perpetual solstice (January and July) conditions.The presence of Africa is associated with a pronounced (up to 4 mm day-1) decrease in precipitation in Brazil's Nordeste region during austral summer. Low-level moisture divergence and dry-air advection associated with the downbranch of a Walker circulation induced by heating over southern Africa is amplified over the Nordeste due to the response of the land surface. The response is much smaller during austral winter due to differences in the heat source over Africa and a reduced sensitivity in the surface heat balance over tropical South America. Forcing from South America in January shifts the position of the South Indian convergence zone (SICZ) to the southwest over southern Africa in association with the formation of the South Atlantic convergence zone (SACZ). In July, a Rossby wave train generated over South America induces a response in the surface temperature of Africa that leads to stronger precipitation in central and western Africa.This study suggests a zonal mode of variability for South American and African circulation and precipitation fields. The resulting perturbations depend as much on land surface atmosphere interactions as on the direct forcing from the adjacent continent, and the mechanisms are highly nonlinear.

India-Africa: trade, investments and humanitarian projects

Directory of Open Access Journals (Sweden)

Alim Vidadievich Suleymanov

2016-12-01

Full Text Available Active growth of trade volume between India and Africa which has increased in twenty times since the beginning of the twenty-first century or in seventy times since 1991, certainly actualized a question of features of the modern Indo-African relations. In this regard the purpose of article is consideration of features of policy of India to the African countries. The author does the short historical review of the Indo-African relations, and considers key spheres of realization of modern regional strategy of India on the African continent - humanitarian projects, foreign trade and investments. The main methods of research are the comparative-historical approach and the statistical analysis, being used for identification of positive or negative dynamics of development of the Indo-African cooperation. Now the African region takes strategic significance for India. Rapid economic development of the African countries and increase in a standard of living of the population turn the continent into a perspective sales market of the Indian goods and services. Besides, India actively develops humanitarian projects and renders the financial help to many African countries. However, India faces set of problems and factors - geographical remoteness, the discrimination and racism, instability of political systems of many African countries and the African policy of China. The active economic policy of China on the African continent has compelled India to develop cooperation with the countries of Africa more actively. In recent years India also as well as China tries to make active and modernize the economic and humanitarian policy in Africa. Struggle for commodity markets of the goods and services in Africa makes Africa by strategic region not only in the Indo-Chinese relations, but in foreign policy of India as a whole.

Cultivate Africa's Future | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Sub-Saharan Africa's population is projected to reach 1.5 billion by 2050. As a result, the region will need to increase food production by 360% compared to 2006 levels to feed its people. Smallholder production accounts for about 80% of farms in the region, and directly employs over 175 million people.

Characterization of the Diameter, branch angle and longevity of axial branches of Nothofagusobliqua

Directory of Open Access Journals (Sweden)

Patricio Corvalán Vera

2017-08-01

Full Text Available The lack of knowledge about grow dynamics of the living tree crown of Nothofagusobliqua secondary growth forests strongly limits the objective formulation of silvicultural schemes oriented to the industrial production of high quality wood. Therefore, in this work, we described basic relationships between tree size, age and angle branches insertion and the crown. Considering a sample data of 59 dominant trees, distributed in different age conditions, we applied a combined analysis technique of stem analysis, steam taper analysis and thickest branch measurement in each decile of the total height. This approach allowed us to determine that there is a significant relationship between the steam diameter, the angle insertion and the age of the branch, as well as the size and age of the trees. Also, the thicker branches tend to have lower insertion angles, to be older, to be located at lower relative heights and to be located in larger diameter sections. Taking into consideration these relationships, it is possible to build new predicted branch models as tools for the development of silvicultural schemes to suit different log grade.

Measurement of the differential branching fraction of the decay $\\Lambda_b^0 \\rightarrow \\Lambda\\mu^+\\mu^-$

CERN Document Server

Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Di Ruscio, F; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Holtrop, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; Mc Skelly, B; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

2013-01-01

The differential branching fraction of the decay $\\Lambda_b^0\\rightarrow\\Lambda\\mu^+\\mu^-$ is measured as a function of the square of the dimuon invariant mass, $q^2$. A yield of $78\\pm12$ $\\Lambda_b^0\\rightarrow\\Lambda\\mu^+\\mu^-$ decays is observed using data, corresponding to an integrated luminosity of 1.0,fb$^{-1}$, collected by the LHCb experiment at a centre-of-mass energy of 7\\,TeV. A significant signal is found in the $q^2$ region above the square of the $J/\\psi$ mass, while at lower-$q^2$ values upper limits are set on the differential branching fraction. Integrating the differential branching fraction over $q^2$, while excluding the $J/\\psi$ and $\\psi(2S)$ regions, gives a branching fraction of $B(\\Lambda_b^0\\rightarrow\\Lambda\\mu^+\\mu^-)=(0.96\\pm 0.16(stat)\\pm 0.13(syst)\\pm 0.21 (\\mathrm{norm}))\\times 10^{-6}$, where the uncertainties are statistical, systematic and due to the normalisation mode, $\\Lambda_b^0\\rightarrow J/\\psi\\Lambda$, respectively.

Branch prediction in the pentium family

DEFF Research Database (Denmark)

Fog, Agner

1998-01-01

How the branch prediction mechanism in the Pentium has been uncovered with all its quirks, and the incredibly more effective branch prediction in the later versions.......How the branch prediction mechanism in the Pentium has been uncovered with all its quirks, and the incredibly more effective branch prediction in the later versions....

Effects of South Africa’s Economic Growth on Sub-Saharan Africa

Directory of Open Access Journals (Sweden)

Kwon Sik Kim

2007-06-01

Full Text Available Major countries, such as the United States, Japan, and China have already recognized the potential of Africa’s markets. Korea has also taken notice of Africa's diverse export markets recently. However, Africa is comprised of 53 different countries and, as a result, entry into the region poses a formidable strategic challenge. Korean authorities and export groups have suggested a "3 plus 2 Country Strategy" in order to make inroads into the African region. This paper contributes to discussions of this strategy by comparing the effects of economic growth in South Africa and Nigeria on Sub-Saharan Africa. In addition, because economic power in Africa is concentrated in a small number of countries, whose market characteristics are different from those of integrated unions, the determinants of economic growth in Africa as a whole and unions may be different. This paper investigates whether or not this is, in fact, the case. The empirical results can be summarized as follows: First, the effects of South Africa's economic growth on Sub-Saharan Africa and the SADC (a representative union of South Africa are much larger than the effects of Nigeria's growth on Sub-Saharan Africa and the ECOWAS (a representative union of Nigeria. These empirical results imply that the preferred country to pursue economic cooperation with is South Africa. Second, we confirm that determinants of economic growth are different for Africa and the unions. The main determinant of growth in African countries may be the population ratio, but in the SADC, growth appears to be determined by ratio trade volumes of GDP. Finally, we also find that the ratio investments of GDP have a positive influence on the economic growth of both Africa and SADC.

Radiation therapy services in South Africa

African Journals Online (AJOL)

available were pooled according to health regions and related to population ... Megavoltage radiation therapy units in South Africa. Photon. Electron. Machine energy beam. Tvl .... Remote afrerloading brachytherapy devices have developed ...

Building up climate change adaptation expertise in Africa: Lead ...

International Development Research Centre (IDRC) Digital Library (Canada)

Hayley Price

Developing Countries Farm Radio Network ... Resources Development in South Africa ... Rural-Urban Cooperation on Water Management ... Regional Institute for Population Studies, ... Interactions: the Case Study of Aba and its Region,.

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

Science.gov (United States)

Siseho Mutondo, Moola

2015-08-01

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

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

Science.gov (United States)

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.

Branching processes in biology

CERN Document Server

Kimmel, Marek

2015-01-01

This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

Reappraisal and identification of Olinia rochetiana (Oliniaceae in South Africa

Directory of Open Access Journals (Sweden)

R. J. Sebola

2006-08-01

Full Text Available A numerical phenetic analysis of data obtained from populations of the Olinia rochetiana A.Juss. complex occurring in South Africa (Mpumalanga and Limpopo Provinces revealed the existence of two forms: 1, a shrubby form (up to 2.5 m tall, with thick terminal branches, coriaceous leaves with a tinge of red on margins (towards the apices,short inflorescence axes, peduncles and deeply red pedicels and floral tubes/hypanthia: and 2, a slender tree form, measuring more than 4 m tall with slender terminal branches, glossy and slightly thin, papery leaves, margin colour the same as the entire lamina, and the inflor­escence axes, peduncles, pedicels and hypanthia pale green to creamy white. Differences in floral features between the twoforms correlate with differences observed in vegetative features. The two forms occupy distinct ecological niches and show tolerances and preferences for different environmental conditions such as soil type,elevation and humidity. An identificationkey for the two forms is presented.

Renal Branch Artery Stenosis

DEFF Research Database (Denmark)

Andersson, Zarah; Thisted, Ebbe; Andersen, Ulrik Bjørn

2017-01-01

Renovascular hypertension is a common cause of pediatric hypertension. In the fraction of cases that are unrelated to syndromes such as neurofibromatosis, patients with a solitary stenosis on a branch of the renal artery are common and can be diagnostically challenging. Imaging techniques...... that perform well in the diagnosis of main renal artery stenosis may fall short when it comes to branch artery stenosis. We report 2 cases that illustrate these difficulties and show that a branch artery stenosis may be overlooked even by the gold standard method, renal angiography....

Satellite Based Analysis of Wood Biomass and Fuelwood Sustainability in Senegal: Developing Approaches for Long-Term Monitoring in the SERVIR-West Africa Region

Science.gov (United States)

Hanan, N. P.; Anchang, J.; Dieye, A. M.; Yero, K.; Tredennick, A. T.

2017-12-01

Rural populations in most of Africa are highly dependent on woody biomass (wood or charcoal) for cooking and heating. Many rural families gather wood locally, while urban populations often rely on small-scale commercial charcoal producers, who make charcoal in rural areas for transport to urban centers. Given that cooking is essential for conversion of inedible protein and carbohydrate substrates into edible food, fuelwood is an essential part of the food security puzzle for most African families. The SERVIR program is a partnership between USAID, NASA and regional institutions designed to enhance access to, and application of, earth observation data for economic development and natural resource management in less developed countries. In this paper, we report on a SERVIR West Africa collaboration to develop above-ground wood biomass estimates using moderate resolution ( 20 m) data from Sentinel-1 and Sentinel-2 satellites, incorporating field data for calibration and validation, and using data retrieval and analysis workflows that can be replicated by SERVIR partners across the region. Using the country of Senegal as a test case, we analyze the spatial distribution of biomass stocks in relation to fuelwood demand to assess supply-demand patterns across scales from local (village), to district, regional and national scales.

Power sector reform and distributed generation in sub-Saharan Africa

DEFF Research Database (Denmark)

Turkson, J.K.; Wohlgemuth, N.

2001-01-01

As part of the current liberalisation process sweeping sub-Saharan Africa, power sectors across the region are being scrutinised and restructured. A critical aspect of the reform is improving access to electricity by large segments of the population. Many in the continent are, therefore,looking a......As part of the current liberalisation process sweeping sub-Saharan Africa, power sectors across the region are being scrutinised and restructured. A critical aspect of the reform is improving access to electricity by large segments of the population. Many in the continent are, therefore......, on average, 30-40 per cent of the region's population, the authors discuss the issues involved, drawing on the experiences of other countries whether there are any apparent 'preconditions' for success. Second, the role renewable energy can play in this process and the extent to which lessons from other parts...... of the world might be transferable to the countries of sub-Saharan Africa is assessed. The paper concludes by investigating the prospects for distributed generation in power sector reform in sub-Saharan Africa, arguing that though lessons from other parts of the world will be helpful, they cannot be all...

An Overview of Sub-Saharan Africa Today.

Science.gov (United States)

Brook, Diane L.

1997-01-01

Articulates many reasons to teach about Sub-Saharan Africa in social studies classes. Although the region will become increasingly important because of global interdependence, it suffers widespread misunderstanding concerning its history and culture. Discusses the region's need for economic development and the quest for political democracy. (MJP)

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

Directory of Open Access Journals (Sweden)

Chiara Barbieri

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

Automated Detection of Branch Shaking Locations for Robotic Cherry Harvesting Using Machine Vision

Directory of Open Access Journals (Sweden)

Suraj Amatya

2017-10-01

Full Text Available Automation in cherry harvesting is essential to reduce the demand for seasonal labor for cherry picking and reduce the cost of production. The mechanical shaking of tree branches is one of the widely studied and used techniques for harvesting small tree fruit crops like cherries. To automate the branch shaking operation, different methods of detecting branches and cherries in full foliage canopies of the cherry tree have been developed previously. The next step in this process is the localization of shaking positions in the detected tree branches for mechanical shaking. In this study, a method of locating shaking positions for automated cherry harvesting was developed based on branch and cherry pixel locations determined using RGB images and 3D camera images. First, branch and cherry regions were located in 2D RGB images. Depth information provided by a 3D camera was then mapped on to the RGB images using a standard stereo calibration method. The overall root mean square error in estimating the distance to desired shaking points was 0.064 m. Cherry trees trained in two different canopy architectures, Y-trellis and vertical trellis systems, were used in this study. Harvesting testing was carried out by shaking tree branches at the locations selected by the algorithm. For the Y-trellis system, the maximum fruit removal efficiency of 92.9% was achieved using up to five shaking events per branch. However, maximum fruit removal efficiency for the vertical trellis system was 86.6% with up to four shakings per branch. However, it was found that only three shakings per branch would achieve a fruit removal percentage of 92.3% and 86.4% in Y and vertical trellis systems respectively.

Vegetation survey of PEN Branch wetlands

Energy Technology Data Exchange (ETDEWEB)

1991-01-01

A survey was conducted of vegetation along Pen Branch Creek at Savannah River Site (SRS) in support of K-Reactor restart. Plants were identified to species by overstory, understory, shrub, and groundcover strata. Abundance was also characterized and richness and diversity calculated. Based on woody species basal area, the Pen Branch delta was the most impacted, followed by the sections between the reactor and the delta. Species richness for shrub and groundcover strata were also lowest in the delta. No endangered plant species were found. Three upland pine areas were also sampled. In support of K Reactor restart, this report summarizes a study of the wetland vegetation along Pen Branch. Reactor effluent enters Indian Grove Branch and then flows into Pen Branch and the Pen Branch Delta.

HIV/AIDS in sub-Saharan Africa: Current status, challenges and prospects

Directory of Open Access Journals (Sweden)

Nweze Justus Amuche

2017-04-01

Full Text Available The problem of HIV/AIDS was sort of a fairy tale and mere information till the immunological disorder was scientifically confirmed. Today, HIV/AIDS has continued to be a serious international health concern, and sub-Saharan Africa remains the most affected region. Over 25.6 million persons are currently living with HIV in sub-Saharan Africa. This accounts for two-thirds of the recent overall world HIV infections and more than 70 percent of all AIDSrelated deaths. In 2015, Eastern and Southern Africa had about 7.1% adult HIV prevalence rate (about 19 million HIV patients, while Western and Central Africa accounted for about 2.2% (about 6.5 million HIV patients. Few countries now boast of numerous signs of gradual to moderate declines in HIV occurrence. However, HIV prevalence rate has continued to increase in countries like Lesotho (22.7%, Botswana (22.2% and South Africa (19.2%. The nature, procedure and result of the scourge in this region have been fashioned by a mind-boggling interaction of traditional, behavioural, social and material factors. Even if there are notably strong prevention, treatment and care programmes, too many sexual partners are engaging in risky sexual practices. The aim of this article is to discuss the current trends of HIV/AIDS in sub-Saharan Africa, the factors that might have contributed to high prevalence of the virus in the region, the effect of the HIV/AIDS scourge, the prevention programmes and the way forward.

Importance of bovine mastitis in Africa.

Science.gov (United States)

Motaung, Thabiso E; Petrovski, Kiro R; Petzer, Inge-Marie; Thekisoe, Oriel; Tsilo, Toi J

2017-06-01

Bovine mastitis is an important animal production disease that affects the dairy industry globally. Studies have estimated the prevalence of this disease in approximately 30% of African countries, with the highest prevalence found in Ethiopia. This is despite the wide cattle distribution in Africa, and the largest number of dairy farms and herds in countries such as South Africa, Kenya and Uganda. Furthermore, the estimated financial losses due to direct and indirect impacts of bovine mastitis are lacking in this continent. Therefore, intensive research efforts will help determine the continent-wide economic impacts and advance careful monitoring of disease prevalence and epidemiology. Here, published cases supporting the occurrence and importance of bovine mastitis in certain regions of Africa are outlined.

Residents' attitudes to proposed wind farms in the West Coast region of South Africa: A social perspective from the South

International Nuclear Information System (INIS)

Lombard, Andrea; Ferreira, Sanette

2014-01-01

The West Coast Region (WCR) of the Western Cape Province in South Africa is earmarked for 13 onshore wind farm projects totaling approximately 700 wind turbines. The developed world debate about the social acceptance of wind farm projects has impeded and illuminated a number of these developments. This paper is aimed at understanding people's reaction to proposed wind farm projects in the WCR – a region of a developing country – and to investigate whether the reasoning behind opposition to or acceptance of wind farm projects is similar to the discourse on the topic by scholars in the developed world. Quantitative and qualitative methods were used to collect primary data by semi-structured interviews and a questionnaire survey. A spatial dimension was added through a map-based approach. Reactions by WCR residents to the wind farm projects were mainly positive, although some opposition was detected. International scholarship holds that place attachment serves as a reason for opposition to wind farm projects. Although most of the WCR residents had strong place attachments to their region, most of the respondents also supported the proposed wind farm projects. - Highlights: • A case study on social acceptance of proposed wind farm projects in South Africa is discussed. • The main focus is on the relation between place attachment and social acceptance or rejection of wind farm projects. • The results of the study correspond to the findings on place attachment and wind farm projects in the developed world

Strengthening international health co-operation in Africa through the ...

African Journals Online (AJOL)

kemrilib

), as ... Introduction. The New Partnership for Africa's Development. (NEPAD) is ... are: better harmonization of the health policies of member ... cultural development, and the integration of .... promote regional public goods and combat regional.

Electricity in South Africa

International Nuclear Information System (INIS)

Davis, Mark; Steyn, Grove

1998-09-01

Contains Executive Summary and Chapters on: Introductory background; The South African energy sector; The development and regulation of the South African electricity supply industry; Electricity supply and demand; Eskom: South Africa's public utility; Electricity distribution; Household electrification; Regional integration and environmental issues; Regulation and emerging policies - pointers to the future. (Author)

High growth and rapid internationalisation of firms from emerging markets: the case of the Middle East and North Africa (MENA) Region

OpenAIRE

Hatem, Omaima

2012-01-01

The aim of this thesis is to understand the phenomena of the high growth and rapid internationalisation of firms from emerging markets. It explores the applicability of international entrepreneurship theory to the context of the emerging market enterprises in the Middle East and North Africa (MENA) region. It integrates the literature of strategic entrepreneurship and that of portfolio entrepreneurship with the literature of international entrepreneurship to provide a closer fi...

Regional patterns in South Africa's postapartheid election in 1994

OpenAIRE

A J Christopher

1996-01-01

The first universal-franchise elections in South Africa, for the National Assembly and nine provincial councils, were conducted under a system of proportional representation in April 1994. The African National Congress won a substantial victory but failed to secure control of two key provinces: the Western Cape and KwaZulu - Natal. Ethnic voting patterns among the spatially concentrated Coloured and Zulu populations were at variance with the otherwise national-liberationary nature of the elec...

Groundwater resources in Southern and Eastern Africa

International Nuclear Information System (INIS)

2003-01-01

Water shortage, water quality, and the protection of investments in water supply, are of continuing concern to countries in Africa. As more countries join those already short of water, sound management of groundwater resources becomes more critical. Isotope techniques provide information that is unobtainable by other means and help to achieve a better understanding of mechanisms and processes through which water resources can be managed. The International Atomic Energy Agency is sponsoring a regional technical co-operation project addressing practical issues related to water resources assessment and development in Kenya, Madagascar, Namibia, South Africa, Tanzania, Uganda and Zimbabwe. The project also seeks to strengthen isotope hydrology capacity in the sub-region. (IAEA)

All projects related to south africa | Page 5 | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

Region: South of Sahara, Angola, Ethiopia, Ghana, Zimbabwe, Uganda, South Africa. Program: Networked Economies. Total Funding: CA$ 503,000.00. Creating a Common Platform for HIV Vaccine Research and HIV Care and Treatment Program. Project. Second only to South Africa in HIV burden, Nigeria's complex ...

Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai–Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions

Directory of Open Access Journals (Sweden)

S. Ding

2015-06-01

Full Text Available The methylation index of branched tetraethers (MBT and cyclization ratio of branched tetraethers (CBT based on the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGT are useful proxies for the reconstruction of mean annual air temperature (MAT and soil pH. Recently, a series of 6-methyl brGDGTs were identified which were previously co-eluted with 5-methyl brGDGTs. However, little is known about 6-methyl brGDGTs in the Qinghai–Tibetan Plateau (QTP, a critical region of the global climate system. Here, we analyze 30 surface soils covering a large area of the QTP, among which 6-methyl brGDGTs were the most abundant components (average 53 ± 17% of total brGDGT. The fractional abundance of 6-methyl brGDGTs showed a good correlation with soil pH, while the global MBT'5ME calibration overestimates MAT in the QTP. We therefore proposed a MBT5/6 index including both 5- and 6-methyl brGDGTs, presenting a strong correlation with MAT in QTP: MAT = −20.14 + 39.51 × MBT5/6 (n = 27, r2 = 0.82; RMSE = 1.3 °C. Another index, namely IBT (isomerization of branched tetraether, based on carbon skeleton isomerization of the 5-methyl to 6-methyl brGDGTs, is dependent on soil pH: pH = 6.77 − 1.56 × IBT (n = 27; r2 = 0.74, RMSE = 0.32. Our study suggests that changing the position of methyl group of brGDGTs may be another mechanism for some soil bacteria to adapt to the ambient pH change in addition to the well-known cyclization.

Migration of Chadic speaking pastoralists within Africa based on population structure of Chad Basin and phylogeography of mitochondrial L3f haplogroup.

Science.gov (United States)

Cerný, Viktor; Fernandes, Verónica; Costa, Marta D; Hájek, Martin; Mulligan, Connie J; Pereira, Luísa

2009-03-23

Chad Basin, lying within the bidirectional corridor of African Sahel, is one of the most populated places in Sub-Saharan Africa today. The origin of its settlement appears connected with Holocene climatic ameliorations (aquatic resources) that started ~10,000 years before present (YBP). Although both Nilo-Saharan and Niger-Congo language families are encountered here, the most diversified group is the Chadic branch belonging to the Afro-Asiatic language phylum. In this article, we investigate the proposed ancient migration of Chadic pastoralists from Eastern Africa based on linguistic data and test for genetic traces of this migration in extant Chadic speaking populations. We performed whole mitochondrial genome sequencing of 16 L3f haplotypes, focused on clade L3f3 that occurs almost exclusively in Chadic speaking people living in the Chad Basin. These data supported the reconstruction of a L3f phylogenetic tree and calculation of times to the most recent common ancestor for all internal clades. A date ~8,000 YBP was estimated for the L3f3 sub-haplogroup, which is in good agreement with the supposed migration of Chadic speaking pastoralists and their linguistic differentiation from other Afro-Asiatic groups of East Africa. As a whole, the Afro-Asiatic language family presents low population structure, as 92.4% of mtDNA variation is found within populations and only 3.4% of variation can be attributed to diversity among language branches. The Chadic speaking populations form a relatively homogenous cluster, exhibiting lower diversification than the other Afro-Asiatic branches (Berber, Semitic and Cushitic). The results of our study support an East African origin of mitochondrial L3f3 clade that is present almost exclusively within Chadic speaking people living in Chad Basin. Whole genome sequence-based dates show that the ancestral haplogroup L3f must have emerged soon after the Out-of-Africa migration (around 57,100 +/- 9,400 YBP), but the "Chadic" L3f3 clade has

Energy security in South America and Southern Africa: synthesis report

International Nuclear Information System (INIS)

Kiratu, Sheila

2011-01-01

In developing countries, the ability to provide adequate and reliable energy supplies is a key to sustainable economic development. The aim of this report is to study the energy supply security in both Southern Africa and South America and how these regions can participate in the international effort to combat climate change. This report showed that South Africa's energy sector mostly relies on carbon intensive coal while Brazil is mainly supplied by hydroelectricity. It was found that in both countries energy needs will increase significantly due to rising demand both internally and at a regional scale. However it was also shown that both Southern Africa and South America have important hydro, solar and wind renewable resources which could enhance their electricity security while minimizing their environmental impacts. This study demonstrated that Southern Africa and South America can enhance their electricity security through the use of renewable energies but that technology and financing is needed to develop the sector.

Specializacijos įtaka Lietuvos regionų ekonominio išsivystymo skirtumams

OpenAIRE

Butkus, Mindaugas; Tamašauskienė, Zita

2005-01-01

Economic development in the regions depends on the branch structure of the regions, which is why it is necessary to search for opportunities to develop the branches of economy that comply with the specifics of the region and which help create new products and services, and discontinue the branches characterized by low effectiveness. Economic development should be based on production and the service sector, and because of increased productivity in the agricultural sector, the free labour force...

Africa: the new family planning frontier.

Science.gov (United States)

Caldwell, John C; Caldwell, Pat

2002-03-01

Sub-Saharan Africa will be the family planning frontier of the twenty-first century. Fertility levels and population growth rates are still high, and family planning programs suited to the region are still being developed. Nevertheless, by the end of the twentieth century, fertility transition was under way in Southern Africa and a few countries elsewhere. Successful regional family planning in the twenty-first century will depend upon stronger political leadership, the development of family planning programs that meet the needs of all segments of society and not only currently married women, assistance to the market, and a recognition of the central importance of hormonal methods, especially injectables. Problems include stagnation in economic growth and in child mortality decline, as well as the persistence of the AIDS epidemic.

The African Standby Force and Regional Security Integration

DEFF Research Database (Denmark)

Mandrup, Thomas

2015-01-01

the challenges facing the region? The regional enmities between the states seem to be widespread, deep-rooted and of a nearly chronic nature. In June 2015 the African Union and its member-states announced that they expected the five regionally based standby brigades to be fully operational by December 2015....... The readiness is to be tested at a continental field exercise, Amani Africa 11 to take place in South Africa October 2015. (Defence Web, 2015) The article will start by mapping out the security dynamics and architecture in East Africa, including its membership circles and priorities. The article...

A proactive and holistic information management approach is crucial ...

African Journals Online (AJOL)

ESARBICA Journal: Journal of the Eastern and Southern Africa Regional Branch of ... holistic information management approach is crucial to e-government development ... and to develop new electronic services hence boosting innovation.

Road Expansion and the Fate of Africa's Tropical Forests

Directory of Open Access Journals (Sweden)

William F. Laurance

2017-07-01

Full Text Available The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa's most biologically diverse regions.

On the pace of fertility decline in sub-Saharan Africa

OpenAIRE

David Shapiro; Andrew Hinde

2017-01-01

Background: This descriptive finding examines the comparative pace of fertility decline in sub-Saharan Africa, relative to Asia, Latin America and the Caribbean, and Northern Africa.Objective: We seek to determine if fertility decline has been slower in sub-Saharan Africa than elsewhere in the developing world.Methods: United Nations 2017 estimates of national fertility are used in assessing the comparative pace of fertility decline, and the four regions are compared in terms of how far they ...

Innovative activity in chosen branches of the tertiary sector in the Czech Republic

Directory of Open Access Journals (Sweden)

Eliska Jiraskova

2015-03-01

Full Text Available The aim of this paper is to provide a brief overview on innovation in services and their approach to the protection of intellectual property. The submitted article summarizes preparing part of a starting project mostly focused on investment environment. The area of interest is companies providing services in the territory of the Czech Republic. The aim of the project is supporting actions of promoting investment and innovative environment. It is necessary to exactly define innovation in services and to analyze innovative activity first so the aim could be achieved. A partial aim of the project will be finding out whether branches which report higher revenues from innovative activities are actively using the opportunity to patent their service because innovations are closely connected to the protection of intellectual property as well. The described part concerns innovations in selected branches of tertiary sector whereas all the branches which have been registered by Czech Statistical office, because of a validation of application for patent proceeding at least in two examined periods since 1993 are examined. Furthermore a possible dependency between an amount of patents in single regions and an amount of revenues coming from innovative companies to a region.

Assistance Focus: Africa

Energy Technology Data Exchange (ETDEWEB)

2017-03-29

The Clean Energy Solutions Center, an initiative of the Clean Energy Ministerial, helps countries throughout the world create policies and programs that advance the deployment of clean energy technologies. Through the Solutions Center's no-cost 'Ask an Expert' service, a team of international experts has delivered assistance to countries in all regions of the world. High-impact examples from Africa are featured here.

Cross-border Co-operation and Policy Networks in West Africa

DEFF Research Database (Denmark)

Trémolières, Marie; Walther, Olivier

This publication examines how policy actors involved in cross-border co-operation contribute to the regional integration process in West Africa. It uses a pioneering methodology, known as social network analysis, to visualise the formal and informal relationships between actors involved in cross...... West Africa to develop cross-border initiatives in a number of ways. Combining these two analyses with the perceptions of regional policy makers as to which border areas they consider as priorities for regional integration, the publication concludes with the analytical foundations for more effective......-border policy networks, showing that borders have notable and diverse impacts on exchanges of information and the relative power of networks. The report then analyses a range of regional indicators of co-operation potential, visually demonstrating that borders can also affect the ability of sub-regions within...

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

Science.gov (United States)

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

Numerical simulation of surface solar radiation over Southern Africa. Part 1: Evaluation of regional and global climate models

Science.gov (United States)

Tang, Chao; Morel, Béatrice; Wild, Martin; Pohl, Benjamin; Abiodun, Babatunde; Bessafi, Miloud

2018-02-01

This study evaluates the performance of climate models in reproducing surface solar radiation (SSR) over Southern Africa (SA) by validating five Regional Climate Models (RCM, including CCLM4, HIRHAM5, RACMO22T, RCA4 and REMO2009) that participated in the Coordinated Regional Downscaling Experiment program over Africa (CORDEX-Africa) along with their ten driving General Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 over SA. The model simulated SSR was thereby compared to reference data from ground-based measurements, satellite-derived products and reanalyses over the period 1990-2005. Results show that (1) the references obtained from satellite retrievals and reanalyses overall overestimate SSR by up to 10 W/m2 on average when compared to ground-based measurements from the Global Energy Balance Archive, which are located mainly over the eastern part of the southern African continent. (2) Compared to one of the satellite products (Surface Solar Radiation Data Set—Heliosat Edition 2; SARAH-2): GCMs overestimate SSR over SA in terms of their multi-model mean by about 1 W/m2 (compensation of opposite biases over sub-regions) and 7.5 W/m2 in austral summer and winter respectively; RCMs driven by GCMs show in their multimodel mean underestimations of SSR in both seasons with Mean Bias Errors (MBEs) of about - 30 W/m2 in austral summer and about - 14 W/m2 in winter compared to SARAH-2. This multi-model mean low bias is dominated by the simulations of the CCLM4, with negative biases up to - 76 W/m2 in summer and - 32 W/m2 in winter. (3) The discrepancies in the simulated SSR over SA are larger in the RCMs than in the GCMs. (4) In terms of trend during the "brightening" period 1990-2005, both GCMs and RCMs (driven by European Centre for Medium-Range Weather Forecasts Reanalysis ERA-Interim, short as ERAINT and GCMs) simulate an SSR trend of less than 1 W/m2 per decade. However, variations of SSR trend exist among different references data

Climatology of Aerosol Optical Properties in Southern Africa

Science.gov (United States)

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

2011-01-01

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

Modeling of the branches of the Tsushima Warm Current in the eastern Japan sea

International Nuclear Information System (INIS)

Kawamura, Hideyuki; Ito, Toshimichi; Hirose, Naoki; Yoon, Jong-Hwan; Takikawa, Tetsutaro

2009-01-01

The branches of the Tsushima Warm Current (TWC) are realistically reproduced using a three-dimensional ocean general circulation model (OGCM). Simulated structures of the First Branch and the Second Branch of the TWC (FBTWC and SBTWC) in the eastern Japan Sea are mainly addressed in this study, being compared with measurement in the period September-October 2000. This is the first numerical experiment so far in which the OGCM is laterally exerted by real volume transports measured by acoustic Doppler current profiler (ADCP) through the Tsushima Straits and the Tsugaru Strait. In addition, sea level variation measured by tide-stations along the Japanese coast as well as satellite altimeters is assimilated into the OGCM through a sequential data assimilation method. It is demonstrated that the assimilation of sea level variation at the coastal tide-stations is useful in reproducing oceanic conditions in the nearshore region. We also examine the seasonal variation of the branches of the TWC in the eastern Japan Sea in 2000. It is suggested as a consequence that the FBTWC is continuous along northwestern Honshu Island in summertime, while it degenerates along the coast between the Sado Strait and the Oga Peninsula in other seasons. On the other hand, a mainstream of the SBTWC exists with meanders and eddies in the offshore region deeper than 1000 m to the north of the Sado Island throughout the year. (author)

Vegetation-climate feedbacks modulate rainfall patterns in Africa under future climate change

Science.gov (United States)

Wu, Minchao; Schurgers, Guy; Rummukainen, Markku; Smith, Benjamin; Samuelsson, Patrick; Jansson, Christer; Siltberg, Joe; May, Wilhelm

2016-07-01

Africa has been undergoing significant changes in climate and vegetation in recent decades, and continued changes may be expected over this century. Vegetation cover and composition impose important influences on the regional climate in Africa. Climate-driven changes in vegetation structure and the distribution of forests versus savannah and grassland may feed back to climate via shifts in the surface energy balance, hydrological cycle and resultant effects on surface pressure and larger-scale atmospheric circulation. We used a regional Earth system model incorporating interactive vegetation-atmosphere coupling to investigate the potential role of vegetation-mediated biophysical feedbacks on climate dynamics in Africa in an RCP8.5-based future climate scenario. The model was applied at high resolution (0.44 × 0.44°) for the CORDEX-Africa domain with boundary conditions from the CanESM2 general circulation model. We found that increased tree cover and leaf-area index (LAI) associated with a CO2 and climate-driven increase in net primary productivity, particularly over subtropical savannah areas, not only imposed important local effect on the regional climate by altering surface energy fluxes but also resulted in remote effects over central Africa by modulating the land-ocean temperature contrast, Atlantic Walker circulation and moisture inflow feeding the central African tropical rainforest region with precipitation. The vegetation-mediated feedbacks were in general negative with respect to temperature, dampening the warming trend simulated in the absence of feedbacks, and positive with respect to precipitation, enhancing rainfall reduction over the rainforest areas. Our results highlight the importance of accounting for vegetation-atmosphere interactions in climate projections for tropical and subtropical Africa.

Below-unitarity-threshold branch cut in the left angle anti q q right angle coefficient of the axial-vector two-current correlation function

International Nuclear Information System (INIS)

Elias, V.; Univ. of Western Ontario, London, ON; Murison, J.L.; Scadron, M.D.; Steele, T.G.

1993-01-01

The dimension-3 quark-condensate component of the flavour-diagonal axial-vector two-current correlation function is evaluated to all orders in the quark mass m qk through use of the quark-condensate component of the nonperturbative fermion propagator. The result obtained is analytic in p 2 except for a branch cut for 0 2 qk ) 2 , corresponding to a branch cut occurring helow the anti qq kinematic threshold. The deep Euclidean region of the longitudinal component of this correlation function is utilized to obtain leading and subleading contributions to the QCD sum-rule relating m qk to . These same sum-rule results are obtained by means of an alternative derivation involving integration over the discontinuity in the correlation function along the branch cut, demonstrating the consistency of the physical-momentum-region branch cut with results obtained via standard means in the deep Euclidean region. (orig.)

A Framework for Developing a Knowledge Base for Indigenous ...

African Journals Online (AJOL)

ESARBICA Journal: Journal of the Eastern and Southern Africa Regional Branch of the International Council on Archives. Journal Home · ABOUT THIS ... framework information scientists can document, preserve and disseminate indigenous ...

Evolution of Corruption in Sub-Saharan Africa - from Nkruma to Mutharika The 2nd: Case Study Of South Africa

OpenAIRE

Mavhungu Abel Mafukata

2016-01-01

Since Sub-Saharan Africa's first independence in Ghana, the region has experienced massive and costly political and bureaucratic corruption within public service and administration. The causes of the corruption, its nature and form are wide and intertwined. In Sub-Saharan Africa, efforts to curb corruption have failed to discard it. The paper focused on the period from Nkruma in Ghana to Mutharika the 2nd in Malawi. This paper reviewed existing literature on political and bureaucratic corrupt...

External branch spinal nerve paralysis on keloid scar | Frioui | Pan ...

African Journals Online (AJOL)

The paralysis of the external branch of spinal nerve is very rare. It manifests clinically by a weakness and abnormal morphology of the shoulder. We must think about it in front of any simple surgery of the cervical region. We report the case of a 20 year old patient, who consulted several doctors for pain and progressive ...

The economic impact of Bluetongue and other orbiviruses in sub-Saharan Africa, with special reference to Southern Africa.

Science.gov (United States)

Grewar, John Duncan

2016-09-30

Bluetongue (BT) and African horse sickness (AHS) are considered the most important orbiviral diseases in Southern Africans countries. The general endemic status makes these diseases challenging to be quanti ed in terms of their economic impact. Using country reported data from BT and AHS outbreaks and cases, as well as international trade data, the economic impact of BT and AHS is evaluated on local, regional, and global scales. Local scale impact in the Southern African region is underestimated as shown by the underreporting of BT and AHS. Exceptions occur during epidemic cycles of the diseases and when the diseases impact regional animal movement and global trade, as in the case of AHS in South Africa. While BT is not directly implicated as a signi cant non-tari barrier for regional movement, there are unspeci ed clauses in import permits which refer to the 'OIE listed diseases' and the freedom thereof includes endemic diseases like BT. African horse sickness has a much more tangible regional and global economic impact because of movement restrictions within AHS control zones in South Africa and through international movement of horses from this country.

The efficiency of bank branches

OpenAIRE

Omid Takbiri; Mohammad Mohammadi; Bahman Naderi

2015-01-01

Banking industry has significant contribution in development of economies of developing countries. Most banks execute their operations through different branches. Therefore it is important to measure the relative efficiencies of these branches. Data envelopment analysis (DEA) is one of the most useful tools in measuring banks’ performance. The present paper aims to extract ranking pattern of banks based on performance evaluation using DEA analysis. In the present research, 120 bank branches o...

Developing solar: PV solar system markets in Africa

International Nuclear Information System (INIS)

Asali, Karim

2002-01-01

Governments, NGO's and UN organisations are increasingly convinced that renewable energies not only help to solve energy problems in Africa but are indispensable in alleviating regional disparities, social problems and bridging the digital gap. Still, many years after introducing high efficiency solar PV systems the necessary breakthrough of implementing them on a mass scale is still not a reality. The author provides perspectives on developing solar PV in Africa. (Author)

Energy, North Africa and Europe

International Nuclear Information System (INIS)

Boussena, S.

1995-01-01

The energy situation in the North African countries not only offers a multitude of opportunities for regional cooperation, but also for consolidating ties with the European Union. What are the medium-term chances of putting these possibilities to use ? This article reviews the energy issues in Algeria, Morocco, and Tunisia, all in the middle of a complete economic, political, and cultural mutations. It identifies the intra-regional cooperative projects and certain potential obstacles, and analyzes the energy relations between North Africa and Europe from the strategic viewpoint of both regions. (author). 7 tabs

Sensitivity experiments of a regional climate model to the different convective schemes over Central Africa

Science.gov (United States)

Armand J, K. M.

2017-12-01

In this study, version 4 of the regional climate model (RegCM4) is used to perform 6 years simulation including one year for spin-up (from January 2001 to December 2006) over Central Africa using four convective schemes: The Emmanuel scheme (MIT), the Grell scheme with Arakawa-Schulbert closure assumption (GAS), the Grell scheme with Fritsch-Chappell closure assumption (GFC) and the Anthes-Kuo scheme (Kuo). We have investigated the ability of the model to simulate precipitation, surface temperature, wind and aerosols optical depth. Emphasis in the model results were made in December-January-February (DJF) and July-August-September (JAS) periods. Two subregions have been identified for more specific analysis namely: zone 1 which corresponds to the sahel region mainly classified as desert and steppe and zone 2 which is a region spanning the tropical rain forest and is characterised by a bimodal rain regime. We found that regardless of periods or simulated parameters, MIT scheme generally has a tendency to overestimate. The GAS scheme is more suitable in simulating the aforementioned parameters, as well as the diurnal cycle of precipitations everywhere over the study domain irrespective of the season. In JAS, model results are similar in the representation of regional wind circulation. Apart from the MIT scheme, all the convective schemes give the same trends in aerosols optical depth simulations. Additional experiment reveals that the use of BATS instead of Zeng scheme to calculate ocean flux appears to improve the quality of the model simulations.

Critical evaluation of branch polarity and apical dominance as dictators of colony astogeny in a branching coral.

Directory of Open Access Journals (Sweden)

Lee Shaish

Full Text Available The high morphological resemblance between branching corals and trees, can lead to comparative studies on pattern formation traits, best exemplified in plants and in some cnidarians. Here, 81 branches of similar size of the hermatypic coral Stylophora pistillata were lopped of three different genets, their skeletons marked with alizarin red-S, and divided haphazardly into three morphometric treatment groups: (I upright position; (II horizontal position, intact tip; and (III horizontal position, cut tip. After 1 y of in-situ growth, the 45 surviving ramets were brought to the laboratory, their tissues removed and their architectures analyzed by 22 morphological parameters (MPs. We found that within 1 y, isolated branches developed into small coral colonies by growing new branches from all branch termini, in all directions. No architectural dissimilarity was assigned among the three studied genets of treatment I colonies. However, a major architectural disparity between treatment I colonies and colonies of treatments II and III was documented as the development of mirror structures from both sides of treatments II and III settings as compared to tip-borne architectures in treatment I colonies. We did not observe apical dominance since fragments grew equally from all branch sides without documented dominant polarity along branch axis. In treatment II colonies, no MP for new branches originating either from tips or from branch bases differed significantly. In treatment III colonies, growth from the cut tip areas was significantly lower compared to the base, again, suggesting lack of apical dominance in this species. Changes in branch polarity revealed genet associated plasticity, which in one of the studied genets, led to enhanced growth. Different genets exhibited canalization flexibility of growth patterns towards either lateral growth, or branch axis extension (skeletal weight and not porosity was measured. This study revealed that colony

Branch xylem density variations across the Amazon Basin

Science.gov (United States)

Patiño, S.; Lloyd, J.; Paiva, R.; Baker, T. R.; Quesada, C. A.; Mercado, L. M.; Schmerler, J.; Schwarz, M.; Santos, A. J. B.; Aguilar, A.; Czimczik, C. I.; Gallo, J.; Horna, V.; Hoyos, E. J.; Jimenez, E. M.; Palomino, W.; Peacock, J.; Peña-Cruz, A.; Sarmiento, C.; Sota, A.; Turriago, J. D.; Villanueva, B.; Vitzthum, P.; Alvarez, E.; Arroyo, L.; Baraloto, C.; Bonal, D.; Chave, J.; Costa, A. C. L.; Herrera, R.; Higuchi, N.; Killeen, T.; Leal, E.; Luizão, F.; Meir, P.; Monteagudo, A.; Neil, D.; Núñez-Vargas, P.; Peñuela, M. C.; Pitman, N.; Priante Filho, N.; Prieto, A.; Panfil, S. N.; Rudas, A.; Salomão, R.; Silva, N.; Silveira, M.; Soares Dealmeida, S.; Torres-Lezama, A.; Vásquez-Martínez, R.; Vieira, I.; Malhi, Y.; Phillips, O. L.

2009-04-01

Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m-3 for a Cordia sagotii (Boraginaceae) from Mountagne de Tortue, French Guiana to 1130 kg m-3 for an Aiouea sp. (Lauraceae) from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species) accounted for 33% with environment (geographic location and plot) accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

[Branches of the National Institute of Hygiene].

Science.gov (United States)

Gromulska, Marta

2008-01-01

National Epidemiological Institute (National Institute of Hygiene, from 7th September 1923) was established in 1918 in Warsaw and acted at national level. Its actions in the field of diseases combat were supported by bacteriological stations and vaccine production in voivodeship cities, which were taken charge of by the state, and names "National Epidemiological Institutes". According to the ministers resolution from 6th July 1921,Epidemiological Institutes were merged to National Central Epidemiological Institutes (PZH), the epidemiological institutes outside Warsaw were named branches, which were to be located in every voivodeship city, according to the initial organizational resolutions. There were country branches of NCEI in: Cracow, Lwów, Lódź, Toruń, Lublin, and Wilno in the period 1919-1923. New branches in Poznań (1925), Gdynia(1934), Katowice (Voivodeship Institute of Hygiene (1936), Luck (1937), Stanisławów (1937), Kielce(1938), and Brześć/Bug (Municipal Station acting as branch of National Central Epidemiological Institute. Branches were subordinated to NCEI-PZH) in Warsaw where action plans and unified research and diagnostic method were established and annual meeting of the country branches managers took place. All branches cooperated with hospitals, national health services, district general practitioners and administration structure in control of infectious diseases. In 1938, the post of branch inspector was established, the first of whom was Feliks Przesmycki PhD. Branches cooperated also with University of Cracow, University of Lwów and University of Wilno. In 1935, National Institutes of Food Research was incorporated in PZH, Water Department was established, and these areas of activity began to develop in the branches accordingly. In 1938 there were 13 branches of PZH, and each had three divisions: bacteriological, food research and water research. Three branches in Cracow, Kielce and Lublin worked during World War II under German

E-record readiness – Can we build a contextual and conceptual ...

African Journals Online (AJOL)

... of the Eastern and Southern Africa Regional Branch of the International Council on Archives ... quantitative in measurement, focus on government agencies and do ... of e-records readiness assessment tools in labour organizations in

Density structure of the cratonic mantle in southern Africa

DEFF Research Database (Denmark)

Artemieva, Irina; Vinnik, Lev P.

2016-01-01

contributions of the both factors to surface topography in the cratons of southern Africa. Our analysis takes advantage of the SASE seismic experiment which provided high resolution regional models of the crustal thickness.We calculate the model of density structure of the lithospheric mantle in southern Africa...... that mantle residual (dynamic) topography may be associated with the low-density region below the depth of isostatic compensation. A possible candidate is the low velocity layer between the lithospheric base and the mantle transition zone, where a temperature anomaly of 100-200. °C in a ca. 100-150. km thick...... layer may explain the observed reduction in Vs velocity and may produce ca. 0.5-1.0. km to the regional topographic uplift....

The epidemiology of Norovirus in the Middle East and North Africa (MENA) region: a systematic review.

Science.gov (United States)

Kreidieh, Khalil; Charide, Rana; Dbaibo, Ghassan; Melhem, Nada M

2017-11-10

Norovirus (NoV) is considered the second leading cause of viral acute gastroenteritis (AGE). To our knowledge, there are no systematic reviews assessing the role of NoV in AGE in the Middle East and North Africa (MENA) region. Consequently, we conducted an extensive systematic literature review on articles studying NoV in the 24 countries of the MENA region during the past 15 years (2000-2015). The methods and reporting were set according to the 2015 PRISMA-P and based on the elements from the international prospective register of systematic reviews (PROSPERO). We retrieved 38 studies meeting our predefined inclusion criteria and were used to extract full data. Studies reporting on NoV were conducted in 15 out of the 24 countries of the region. The reported NoV infection rates in MENA countries ranged between 0.82% and 36.84%. The majority of studies were clinical observational studies assessing NoV rates mainly among children. Participants were recruited from in- and outpatient clinics. NoV infection was reported all year round with with peaks observed mainly during cold months. GII.4 was the predominant genotype detected in stool of participants as reported by 16 out of 25 studies (64%). Overall, there is an increasing recognition of NoV as an important causative agent of AGE across all age groups in the MENA region. Further studies are needed to assess the national and the regional burden of NoV among different age groups, its molecular diversity and seasonal variability.

Foot-and-mouth Disease Transmission in Africa

NARCIS (Netherlands)

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

2016-01-01

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

Giant landslides and turbidity currents in the Agadir Canyon Region, NW-Africa

Science.gov (United States)

Krastel, Sebastian; Wynn, Russell B.; Stevenson, Christopher; Feldens, Peter; Mehringer, Lisa; Schürer, Anke

2017-04-01

Coring and drilling of the Moroccan Turbidite System off NW-Africa revealed a long sequence of turbidites, mostly sourced from the Moroccan continental margin and the volcanic Canary Islands. The largest individual flow deposits in the Moroccan Turbidite System contain sediment volumes >100 km3, although these large-scale events are relatively infrequent with a recurrence interval of 10,000 years (over the last 200,000 years). The largest siliciclastic flow in the last 200,000 years was the 'Bed 5 event', which transported 160 km3 of sediment up to 2000 km from the Agadir Canyon region to the southwest Madeira Abyssal Plain. While the Moroccan Turbidite System is extremely well investigated, almost no data from the source region, i.e. the Agadir Canyon, are available. Understanding why some submarine landslides remain as coherent blocks of sediment throughout their passage downslope, while others mix and disintegrate almost immediately after initial failure, is a major scientific challenge, which was addressed in the Agadir Canyon source region during RV Maria S. Merian Cruise MSM32 in late 2013. A major landslide area was identified 200 km south of the Agadir Canyon. A landslide was traced from this failure area to the Agadir Canyon. This landslide entered the canyon in about 2500 m water depth. Despite a significant increase in slope angle, the landslide did not disintegrate into a turbidity current when entering the canyon but moved on as landslide for at least another 200 km down the canyon. The age of the landslide ( 145 ka) does not correspond to any major turbidte deposit in the Moroccan Turbidite System, further supporting the fact that the landslide did not disintegrate into a major turbidity current. A core taken about 350 m above the thalweg in the head region of Agadir Canyon shows a single coarse-grained turbidite, which resembles the composition of the Bed 5 event in the Madeira Abyssal Plain. Hence, the Bed 5 turbidite originated as a failure in the

Organic and inorganic correlations for Northwest Africa 852 by synchrotron-based Fourier transform infrared microspectroscopy

Science.gov (United States)

Yesiltas, Mehmet; Peale, Robert E.; Unger, Miriam; Sedlmair, Julia; Hirschmugl, Carol J.

2015-10-01

Relationships between organic molecules and inorganic minerals are investigated in a single 34 μm diameter grain of the CR2 chondrite Northwest Africa 852 (NWA) 852 with submicron spatial resolution using synchrotron-based imaging micro-FTIR spectroscopy. Correlations based on absorption strength for the various constituents are determined using statistical correlation analysis. The silicate band is found to be correlated with the hydration band, and the latter is highly correlated with stretching modes of aliphatic hydrocarbons. Spatial distribution maps show that water+organic combination, silicate, OH, and C-H distributions overlap, suggesting a possible catalytic role of phyllosilicates in the formation of organics. In contrast, the carbonate band is anticorrelated with water+organic combination, however uncorrelated with any other spectral feature. The average ratio of asymmetric CH2 and CH3 band strengths (CH2/CH3 = 2.53) for NWA 852 is similar to the average ratio of interplanetary dust particles (~2.40) and Wild 2 cometary dust particles (2.50), but it significantly exceeds that of interstellar medium objects (~1.00) and several aqueously altered carbonaceous chondrites (~1.40). This suggests organics of similar length/branching, and perhaps similar formation regions, for NWA 852, Wild 2 dust particles, and interplanetary dust particles. The heterogeneous spatial distribution of ratio values indicates the presence of a mixture of aliphatic organic material with different length/branching, and thus a wide range of parent body processes, which occurred before the considered grain was formed.

Aids prevention in sub-Saharan Africa: as easy as ABC? | Bertrand ...

African Journals Online (AJOL)

Background: The failure to stem HIV in sub-Saharan Africa and the unique epidemiological modes of infection within this region have demonstrated that unique strategies for combatting the virus are required. This review article discusses why international AIDS campaigns in sub- Saharan Africa have largely been ...

Variations of relative humidity in relation to meningitis in Africa

Science.gov (United States)

Seefeldt, M. W.; Hopson, T. M.

2011-12-01

The meningitis belt is a region covering Sub-Saharan Africa from the Sahel of West Africa eastward to western Ethiopia. The region is prone to meningitis epidemics during the dry season extending from approximately January to May, depending on the region. Relative humidity has been found to be a critical environmental factor indicating the susceptibility of a region to meningitis epidemics. This study evaluates the variation of relative humidity across West Africa over 30 dry-seasons (1979 - 2009) using the NASA-MERRA dataset. The method of self-organizing maps is employed to characterize the changes in relative humidity patterns across the region within a given dry season as well as changes over the 30 years. A general pattern of changes in relative humidity is indicated as the rainbelt retreats to the south at the onset of the dry season and then returns to the region at the end of the dry season. Within each dry season there is a unique pattern. The climatological conditions of relative humidity at the onset of the dry season provide an indication of the moisture environment for the entire dry season. Year to year variation in the relative humidity patterns are found to be gradual. Future applications involve using the results from the SOM evaluation to be used for future decisions involving prevention of meningitis epidemics.

Africa gaining importance in world LPG trade

International Nuclear Information System (INIS)

Haun, R.R.; Otto, K.W.; Whitley, S.C.

1997-01-01

Major LPG projects planned or under way in Africa will increase the importance of that region's presence in world LPG trade. Supplies will nearly double between 1995 and 2005, at which time they will remain steady for at least 10 years. At the same time that exports are leveling, however, increasing domestic demand for PG is likely to reduce export-market participation by Algeria, Nigeria, Egypt, and Libya. The growth of Africa's participation in world LPG supply is reflected in comparisons for the next 15--20 years. Total world supply of LPG in 1995 was about 165 million metric tons (tonnes), of which Africans share was 7.8 million tonnes. By 2000, world supply will grow to slightly more than 200 million tonnes, with Africa's share expected to increase to 13.2 million tonnes (6.6%). And by 2005, world LPG supply will reach nearly 230 million tonnes; Africa's overall supply volumes by that year will be nearly 16.2 million tonnes (7%). World LPG supply for export in 1995 was on order of 44 million tonnes with Africa supply about 4 million tonnes (9%). By 2005, world export volumes of LPG will reach nearly 70 million tonnes; Africa's share will have grown by nearly 10 million tonnes (14.3%)

World market or regional integration and food security in West Africa

NARCIS (Netherlands)

L.J. de Haan (Leo); A. Klaasse Bos (Andries); C. Lutz (Clemens)

1994-01-01

textabstractThe problem of food security in West Africa was put on the international agenda in 1974 at the international food conference in Rome following the Great Sahelian Drought of 1968-1973. In those years preoccupation with food security was limited mainly to the Sahel countries and

Multilocus phylogeography of a widespread savanna-woodland-adapted rodent reveals the influence of Pleistocene geomorphology and climate change in Africa's Zambezi region.

Science.gov (United States)

McDonough, Molly M; Šumbera, Radim; Mazoch, Vladimír; Ferguson, Adam W; Phillips, Caleb D; Bryja, Josef

2015-10-01

Understanding historical influences of climate and physiographic barriers in shaping patterns of biodiversity remains limited for many regions of the world. For mammals of continental Africa, phylogeographic studies, particularly for West African lineages, implicate both geographic barriers and climate oscillations in shaping small mammal diversity. In contrast, studies for southern African species have revealed conflicting phylogenetic patterns for how mammalian lineages respond to both climate change and geologic events such as river formation, especially during the Pleistocene. However, these studies were often biased by limited geographic sampling or exclusively focused on large-bodied taxa. We exploited the broad southern African distribution of a savanna-woodland-adapted African rodent, Gerbilliscus leucogaster (bushveld gerbil) and generated mitochondrial, autosomal and sex chromosome data to quantify regional signatures of climatic and vicariant biogeographic phenomena. Results indicate the most recent common ancestor for all G. leucogaster lineages occurred during the early Pleistocene. We documented six divergent mitochondrial lineages that diverged ~0.270-0.100 mya, each of which was geographically isolated during periods characterized by alterations to the course of the Zambezi River and its tributaries as well as regional 'megadroughts'. Results demonstrate the presence of a widespread lineage exhibiting demographic expansion ~0.065-0.035 mya, a time that coincides with savanna-woodland expansion across southern Africa. A multilocus autosomal perspective revealed the influence of the Kafue River as a current barrier to gene flow and regions of secondary contact among divergent mitochondrial lineages. Our results demonstrate the importance of both climatic fluctuations and physiographic vicariance in shaping the distribution of southern African biodiversity. © 2015 John Wiley & Sons Ltd.

Morphometry of medial gaps of human brain artery branches.

Science.gov (United States)

Canham, Peter B; Finlay, Helen M

2004-05-01

The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or "medial defects." Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation. Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps. A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.

Studies on the fatigue of branched connections related to the shakedown pressure

International Nuclear Information System (INIS)

Cook, T.R.

1977-01-01

The concept of shakedown is that regions which plastically deform during initial loading subsequently adopt an elastic mode of deformation. High strain fatigue, i.e. up to 10,000 cycles, will be eliminated. Two branches of different thickness were welded to a common cylindrical vessel and hydraulically tested, simultaneously. The test pressure was the shakedown limit for the stronger branch and about 1.5 x shakedown for the weaker branch. The thinner branch failed by penetration through the weld near the crotch corner at 3,543 cycles. The thicker branch was given 10,000 cycles when, since no cracks were apparent, a starter notch was made in the crotch corner. Leakage occurred after another 10,678 cycles. This crack was also influenced by weld defects. Using fracture mechanics and a reported relationship between crack rate and stress intensity factors, some predictions of endurance at design pressure are derived for these branches. These lives are compared with the British Standard 1515 formula for fatigue avoidance and with the curves given in Section III of the ASME Boiler and Pressure Vessel Code. The former is considered conservative, while the ASME Code curve requires an additional safety factor as suggested by Jettam; A multiplication factor of 2 on the nominal stress concentration factor for welds is then considered satisfactory. It is tentatively considered that such junctions manufactured to Class 1 standard are satisfactory for daily cycling for 30 years, but are marginal for twice daily cycling for that time. This conclusion is tentative, since it depends critically on the size of weld defects present

Africa and the global carbon cycle

Directory of Open Access Journals (Sweden)

Denning A Scott

2007-03-01

Full Text Available Abstract The African continent has a large and growing role in the global carbon cycle, with potentially important climate change implications. However, the sparse observation network in and around the African continent means that Africa is one of the weakest links in our understanding of the global carbon cycle. Here, we combine data from regional and global inventories as well as forward and inverse model analyses to appraise what is known about Africa's continental-scale carbon dynamics. With low fossil emissions and productivity that largely compensates respiration, land conversion is Africa's primary net carbon release, much of it through burning of forests. Savanna fire emissions, though large, represent a short-term source that is offset by ensuing regrowth. While current data suggest a near zero decadal-scale carbon balance, interannual climate fluctuations (especially drought induce sizeable variability in net ecosystem productivity and savanna fire emissions such that Africa is a major source of interannual variability in global atmospheric CO2. Considering the continent's sizeable carbon stocks, their seemingly high vulnerability to anticipated climate and land use change, as well as growing populations and industrialization, Africa's carbon emissions and their interannual variability are likely to undergo substantial increases through the 21st century.

West and Central Africa — Addressing new challenges | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-01-25

Jan 25, 2011 ... From his office in Dakar, Senegal, IDRC West and Central Africa Regional ... Privatization of former common land often spells trouble for herders and ... First, the region is increasingly dry, meaning that a source of water that is ...

Structure of FabH and factors affecting the distribution of branched fatty acids in Micrococcus luteus.

Science.gov (United States)

Pereira, Jose H; Goh, Ee-Been; Keasling, Jay D; Beller, Harry R; Adams, Paul D

2012-10-01

Micrococcus luteus is a Gram-positive bacterium that produces iso- and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters [coenzyme A (CoA) or acyl carrier protein (ACP)]; this activity is of interest for the production of advanced biofuels. In an effort to better understand the control of the formation of branched fatty acids in M. luteus, the structure of FabH (MlFabH) was determined. FabH, or β-ketoacyl-ACP synthase III, catalyzes the initial step of fatty-acid biosynthesis: the condensation of malonyl-ACP with an acyl-CoA. Analysis of the MlFabH structure provides insights into its substrate selectivity with regard to length and branching of the acyl-CoA. The most structurally divergent region of FabH is the L9 loop region located at the dimer interface, which is involved in the formation of the acyl-binding channel and thus limits the substrate-channel size. The residue Phe336, which is positioned near the catalytic triad, appears to play a major role in branched-substrate selectivity. In addition to structural studies of MlFabH, transcriptional studies of M. luteus were also performed, focusing on the increase in the ratio of anteiso:iso-branched alkenes that was observed during the transition from early to late stationary phase. Gene-expression microarray analysis identified two genes involved in leucine and isoleucine metabolism that may explain this transition.

Structure of FabH and factors affecting the distribution of branched fatty acids in Micrococcus luteus

International Nuclear Information System (INIS)

Pereira, Jose H.; Goh, Ee-Been; Keasling, Jay D.; Beller, Harry R.; Adams, Paul D.

2012-01-01

In an effort to better understand the control of the formation of branched fatty acids in Micrococcus luteus, the structure of β-ketoacyl-ACP synthase III, which catalyzes the initial step of fatty-acid biosynthesis, has been determined. Micrococcus luteus is a Gram-positive bacterium that produces iso- and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters [coenzyme A (CoA) or acyl carrier protein (ACP)]; this activity is of interest for the production of advanced biofuels. In an effort to better understand the control of the formation of branched fatty acids in M. luteus, the structure of FabH (MlFabH) was determined. FabH, or β-ketoacyl-ACP synthase III, catalyzes the initial step of fatty-acid biosynthesis: the condensation of malonyl-ACP with an acyl-CoA. Analysis of the MlFabH structure provides insights into its substrate selectivity with regard to length and branching of the acyl-CoA. The most structurally divergent region of FabH is the L9 loop region located at the dimer interface, which is involved in the formation of the acyl-binding channel and thus limits the substrate-channel size. The residue Phe336, which is positioned near the catalytic triad, appears to play a major role in branched-substrate selectivity. In addition to structural studies of MlFabH, transcriptional studies of M. luteus were also performed, focusing on the increase in the ratio of anteiso:iso-branched alkenes that was observed during the transition from early to late stationary phase. Gene-expression microarray analysis identified two genes involved in leucine and isoleucine metabolism that may explain this transition

Turing mechanism underlying a branching model for lung morphogenesis.

Science.gov (United States)

Xu, Hui; Sun, Mingzhu; Zhao, Xin

2017-01-01

The mammalian lung develops through branching morphogenesis. Two primary forms of branching, which occur in order, in the lung have been identified: tip bifurcation and side branching. However, the mechanisms of lung branching morphogenesis remain to be explored. In our previous study, a biological mechanism was presented for lung branching pattern formation through a branching model. Here, we provide a mathematical mechanism underlying the branching patterns. By decoupling the branching model, we demonstrated the existence of Turing instability. We performed Turing instability analysis to reveal the mathematical mechanism of the branching patterns. Our simulation results show that the Turing patterns underlying the branching patterns are spot patterns that exhibit high local morphogen concentration. The high local morphogen concentration induces the growth of branching. Furthermore, we found that the sparse spot patterns underlie the tip bifurcation patterns, while the dense spot patterns underlies the side branching patterns. The dispersion relation analysis shows that the Turing wavelength affects the branching structure. As the wavelength decreases, the spot patterns change from sparse to dense, the rate of tip bifurcation decreases and side branching eventually occurs instead. In the process of transformation, there may exists hybrid branching that mixes tip bifurcation and side branching. Since experimental studies have reported that branching mode switching from side branching to tip bifurcation in the lung is under genetic control, our simulation results suggest that genes control the switch of the branching mode by regulating the Turing wavelength. Our results provide a novel insight into and understanding of the formation of branching patterns in the lung and other biological systems.

Tackling Africa's chronic disease burden: from the local to the global

NARCIS (Netherlands)

de-Graft Aikins, Ama; Unwin, Nigel; Agyemang, Charles; Allotey, Pascale; Campbell, Catherine; Arhinful, Daniel

2010-01-01

ABSTRACT: Africa faces a double burden of infectious and chronic diseases. While infectious diseases still account for at least 69% of deaths on the continent, age specific mortality rates from chronic diseases as a whole are actually higher in sub Saharan Africa than in virtually all other regions

A Political Economy of Water in Southern Africa

Directory of Open Access Journals (Sweden)

Larry A. Swatuk

2008-06-01

Full Text Available Southern Africa is a region characterised by extensive socio-economic underdevelopment. Given water’s key role in social organisation, water allocation, use and management in Southern Africa is embedded in deep historical and structural processes of regional underdevelopment. Gini coefficients of income inequality in several states of the region are the most extreme in the world. Recent data from South Africa shows that Gini coefficients of water inequality vary directly with income inequality. Recent attempts to improve water resources management in the region through IWRM have failed to consider these facts, focusing instead on a mix of institutional, policy and legal reforms. The results of these reforms have been poor. In this essay, I employ a modified version of Allan’s (2003 'water paradigms' framework to locate and assess the positions and interests of actors involved in water resources management in Southern Africa. The essay shows that Southern Africa’s history of underdevelopment has created a dense web of powerful political, economic and social interests linked by a shared technocentric understanding of and approach to water use: i.e. water for 'high modern-style' development, or as labelled by Allen, 'the hydraulic mission'. What is less readily acknowledged is the wide-spread societal support for this mission. For this reason, ecocentric approaches to water management most commonly associated with influential international actors such as the IUCN and World Wide Fund for Nature have limited local support and are of minor relevance to Southern African decision-makers. However, actors supportive of an ecocentric perspective demonstrate considerable ability to inhibit water infrastructure development across the region. In the face of abiding poverty and inequality, and vulnerability to water insecurity, widespread societal support for a technocentric approach to resource use offers a pathway toward broad-based social benefits

Lion (Panthera leo) populations are declining rapidly across Africa, except in intensively managed areas.

Science.gov (United States)

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.

Crisis and Regional Integration

DEFF Research Database (Denmark)

Dosenrode, Søren

, Tunisia, Egypt …. ), where the crisis referred to could be humanitarian, environmental, economic, political … Europe, too, has also according to mass media, been a victim of a crisis, the financial one. Could ‘crisis’ be a beginning of enhanced regional integration? This paper will try to look...... at the processes of regional integration in relation to ‘crisis’ in Africa and Europe. First, this paper will look at the concept of ‘crisis’, before it moves on to discuss ‘regional integration’ and the correlation between the two, emphasizing the approaches of neo-functionalism and federal theory....... This is the basis for two short case studies of African and European regional integration. The paper tentative answers to the question: will the crisis in Africa and Europe respectively further or block regional integration? With a ‘that depends’. But the use of Federalism theory and neo-functionalism is seen...

Dynamic Crack Branching - A Photoelastic Evaluation,

Science.gov (United States)

1982-05-01

0.41 mPai and a 0.18 MPa, and predicted a theoretical kinking angle of 84°whichagreed well with experimentally measured angle. After crack kinking...Consistent crack branching’at KIb = 2.04 MPaI -i- and r = 1.3 mm verified this crack branching criterion. The crack branching angle predicted by--.’ DD

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

Directory of Open Access Journals (Sweden)

M. Sahle

2007-09-01

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

Erythristic leopards Panthera pardus in South Africa

Directory of Open Access Journals (Sweden)

Tara J. Pirie

2016-05-01

Objectives: To record the presence of erythristic leopards in our study site (Thaba Tholo Wilderness Reserve, Mpumalanga and to collate records from across South Africa. Method: A network of camera traps was used to record individual leopards at Thaba Tholo. We also surveyed local experts, searched the popular South African press, and used social media to request observations. Results: Two out of 28 individual leopards (7.1% recorded in our study site over 3 years were of this colour morph. We obtained records of five other erythristic leopards in the North West and Mpumalanga regions, with no reports outside of this population. Conclusions: Erythristic leopards are widely dispersed across north-east South Africa, predominantly in the Lydenburg region, Mpumalanga. The presence of this rare colour morph may reflect the consequences of population fragmentation.

Predictors of HIV Testing among Youth in Sub-Saharan Africa: A Cross-Sectional Study.

Science.gov (United States)

Asaolu, Ibitola O; Gunn, Jayleen K; Center, Katherine E; Koss, Mary P; Iwelunmor, Juliet I; Ehiri, John E

2016-01-01

In spite of a high prevalence of HIV infection among adolescents and young adults in sub-Saharan Africa, uptake of HIV testing and counseling among youth in the region remains sub-optimal. The objective of this study was to assess factors that influence uptake of HIV testing and counseling among youth aged 15-24 years in sub-Saharan Africa. This study used the Demographic and Health Survey (DHS) data from countries that represent four geographic regions of sub-Saharan Africa: Congo (Brazzaville), representing central Africa (DHS 2011-2012); Mozambique, representing southern Africa (DHS 2011); Nigeria, representing western Africa (DHS 2013); and Uganda, representing eastern Africa (DHS 2011). Analyses were restricted to 23,367 male and female respondents aged 15-24 years with complete data on the variables of interest. Chi-square tests and logistic regression models were used to assess predictors of HIV testing. Statistical significance was set at psub-Saharan Africa for HIV testing continues to be a challenge. Public health programs that seek to increase HIV counseling and testing among youth should pay particular attention to efforts that target high-risk subpopulations of youth. The results further suggest that these initiatives would be strengthened by including strategies to increase HIV comprehensive knowledge.

Change detection of bare areas in the Xolobeni region, South Africa ...

African Journals Online (AJOL)

Rebekah

Kemp (2010), the application of remote sensing in erosion research within South Africa has focussed on mapping bare soil and characterisation of vegetation as precursors of erosion potential. This study has used remote sensing as a tool to map the broad vegetation structure categories of the predominant land cover types ...

Role of Public Archivists and Records Managers in Governance and ...

African Journals Online (AJOL)

Role of Public Archivists and Records Managers in Governance and Local ... and Southern Africa Regional Branch of the International Council on Archives ... accountability, respect for the rule of law and citizens' rights could be gauged.

Public Records and Archives as Tools for Good Governance ...

African Journals Online (AJOL)

Public Records and Archives as Tools for Good Governance: Reflections Within the ... and Southern Africa Regional Branch of the International Council on Archives ... they could be used as instruments of repression and human rights abuses.

Controls on stream network branching angles, tested using landscape evolution models

Science.gov (United States)

Theodoratos, Nikolaos; Seybold, Hansjörg; Kirchner, James W.

2016-04-01

Stream networks are striking landscape features. The topology of stream networks has been extensively studied, but their geometry has received limited attention. Analyses of nearly 1 million stream junctions across the contiguous United States [1] have revealed that stream branching angles vary systematically with climate and topographic gradients at continental scale. Stream networks in areas with wet climates and gentle slopes tend to have wider branching angles than in areas with dry climates or steep slopes, but the mechanistic linkages underlying these empirical correlations remain unclear. Under different climatic and topographic conditions different runoff generation mechanisms and, consequently, transport processes are dominant. Models [2] and experiments [3] have shown that the relative strength of channel incision versus diffusive hillslope transport controls the spacing between valleys, an important geometric property of stream networks. We used landscape evolution models (LEMs) to test whether similar factors control network branching angles as well. We simulated stream networks using a wide range of hillslope diffusion and channel incision parameters. The resulting branching angles vary systematically with the parameters, but by much less than the regional variability in real-world stream networks. Our results suggest that the competition between hillslope and channeling processes influences branching angles, but that other mechanisms may also be needed to account for the variability in branching angles observed in the field. References: [1] H. Seybold, D. H. Rothman, and J. W. Kirchner, 2015, Climate's watermark in the geometry of river networks, Submitted manuscript. [2] J. T. Perron, W. E. Dietrich, and J. W. Kirchner, 2008, Controls on the spacing of first-order valleys, Journal of Geophysical Research, 113, F04016. [3] K. E. Sweeney, J. J. Roering, and C. Ellis, 2015, Experimental evidence for hillslope control of landscape scale, Science, 349

Tax solutions for optimal reduction of tobacco use in West Africa ...

International Development Research Centre (IDRC) Digital Library (Canada)

Tax solutions for optimal reduction of tobacco use in West Africa. During the first phase of this project, numerous decision-makers were engaged and involved in discussions with the goal of establishing a new taxation system to reduce tobacco use in West Africa. Although regional economic authorities (ECOWAS and ...

Branch xylem density variations across the Amazon Basin

Directory of Open Access Journals (Sweden)

S. Patiño

2009-04-01

Full Text Available Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρ_x, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m⁻³ for a Cordia sagotii (Boraginaceae from Mountagne de Tortue, French Guiana to 1130 kg m⁻³ for an Aiouea sp. (Lauraceae from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average ρ_x across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species accounted for 33% with environment (geographic location and plot accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

On the development of a coupled regional climate-vegetation model RCM-CLM-CN-DV and its validation in Tropical Africa

Science.gov (United States)

Wang, Guiling; Yu, Miao; Pal, Jeremy S.; Mei, Rui; Bonan, Gordon B.; Levis, Samuel; Thornton, Peter E.

2016-01-01

This paper presents a regional climate system model RCM-CLM-CN-DV and its validation over Tropical Africa. The model development involves the initial coupling between the ICTP regional climate model RegCM4.3.4 (RCM) and the Community Land Model version 4 (CLM4) including models of carbon-nitrogen dynamics (CN) and vegetation dynamics (DV), and further improvements of the models. Model improvements derive from the new parameterization from CLM4.5 that addresses the well documented overestimation of gross primary production (GPP), a refinement of stress deciduous phenology scheme in CN that addresses a spurious LAI fluctuation for drought-deciduous plants, and the incorporation of a survival rule into the DV model to prevent tropical broadleaf evergreens trees from growing in areas with a prolonged drought season. The impact of the modifications on model results is documented based on numerical experiments using various subcomponents of the model. The performance of the coupled model is then validated against observational data based on three configurations with increasing capacity: RCM-CLM with prescribed leaf area index and fractional coverage of different plant functional types (PFTs); RCM-CLM-CN with prescribed PFTs coverage but prognostic plant phenology; RCM-CLM-CN-DV in which both the plant phenology and PFTs coverage are simulated by the model. Results from these three models are compared against the FLUXNET up-scaled GPP and ET data, LAI and PFT coverages from remote sensing data including MODIS and GIMMS, University of Delaware precipitation and temperature data, and surface radiation data from MVIRI and SRB. Our results indicate that the models perform well in reproducing the physical climate and surface radiative budgets in the domain of interest. However, PFTs coverage is significantly underestimated by the model over arid and semi-arid regions of Tropical Africa, caused by an underestimation of LAI in these regions by the CN model that gets exacerbated

Selected aspects of GDP value and structure development in sub-Saharan Africa

Directory of Open Access Journals (Sweden)

Luboš Smutka

2011-01-01

Full Text Available Africa belongs to the poorest regions of the world. This statement may be applied especially to its sub-Saharan part. The paper analyses some basic structural characteristics related to the economic development of sub-Saharan region. The article reveals existing differences between countries and regions of sub-Saharan Africa and analyses key problems which influence economic development of individual states. An emphasis is placed on analysing an unsuitable GDP structure and on external economic relations which affect this structure. Results of an investigation show that the GDP of sub-Saharan countries is to a large extend generated by the primary sector of their economies, which is dominant in the total GDP value and its position is continuously strengthening due to a high dynamics of its growth. Having regard to the external environment, there can be stated that the foreign trade has contributed to the GDP growth of the whole region only to a limited degree (this does not apply to all countries seen as individuals. The integration process in sub-Saharan Africa may be characterized as questionable. Many integration groupings are operating in the region, but their influence on economic growth is limited due a low potential for mutual cooperation based on specialisation and use of comparative advantages. The economies of sub-Saharan countries are very sensitive to changes in their external economic environment. In this regard, there is important to highlight the very strong sensitivity of the GDP in the sub-Saharan region in relation to the World GDP (mainly to European and US GDP because both regions belong to the most important trading partners of Africa as a whole.

Stochastic rainfall modeling in West Africa: Parsimonious approaches for domestic rainwater harvesting assessment

Science.gov (United States)

Cowden, Joshua R.; Watkins, David W., Jr.; Mihelcic, James R.

2008-10-01

SummarySeveral parsimonious stochastic rainfall models are developed and compared for application to domestic rainwater harvesting (DRWH) assessment in West Africa. Worldwide, improved water access rates are lowest for Sub-Saharan Africa, including the West African region, and these low rates have important implications on the health and economy of the region. Domestic rainwater harvesting (DRWH) is proposed as a potential mechanism for water supply enhancement, especially for the poor urban households in the region, which is essential for development planning and poverty alleviation initiatives. The stochastic rainfall models examined are Markov models and LARS-WG, selected due to availability and ease of use for water planners in the developing world. A first-order Markov occurrence model with a mixed exponential amount model is selected as the best option for unconditioned Markov models. However, there is no clear advantage in selecting Markov models over the LARS-WG model for DRWH in West Africa, with each model having distinct strengths and weaknesses. A multi-model approach is used in assessing DRWH in the region to illustrate the variability associated with the rainfall models. It is clear DRWH can be successfully used as a water enhancement mechanism in West Africa for certain times of the year. A 200 L drum storage capacity could potentially optimize these simple, small roof area systems for many locations in the region.

Operative needs in HIV+ populations: An estimation for sub-Saharan Africa.

Science.gov (United States)

Cherewick, Megan L; Cherewick, Steven D; Kushner, Adam L

2017-05-01

In 2015, it was estimated that approximately 36.7 million people were living with HIV globally and approximately 25.5 million of those people were living in sub-Saharan Africa. Limitations in the availability and access to adequate operative care require policy and planning to enhance operative capacity. Data estimating the total number of persons living with HIV by country, sex, and age group were obtained from the Joint United Nations Programme on HIV/AIDS (UNAIDS) in 2015. Using minimum proposed surgical rates per 100,000 for 4, defined, sub-Saharan regions of Africa, country-specific and regional estimates were calculated. The total need and unmet need for operative procedures were estimated. A minimum of 1,539,138 operative procedures were needed in 2015 for the 25.5 million persons living with HIV in sub-Saharan Africa. In 2015, there was an unmet need of 908,513 operative cases in sub-Saharan Africa with the greatest unmet need in eastern sub-Saharan Africa (427,820) and western sub-Saharan Africa (325,026). Approximately 55.6% of the total need for operative cases is adult women, 38.4% are adult men, and 6.0% are among children under the age of 15. A minimum of 1.5 million operative procedures annually are required to meet the needs of persons living with HIV in sub-Saharan Africa. The unmet need for operative care is greatest in eastern and western sub-Saharan Africa and will require investments in personnel, infrastructure, facilities, supplies, and equipment. We highlight the need for global planning and investment in resources to meet targets of operative capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Migration of Chadic speaking pastoralists within Africa based on population structure of Chad Basin and phylogeography of mitochondrial L3f haplogroup

Directory of Open Access Journals (Sweden)

Mulligan Connie J

2009-03-01

Full Text Available Abstract Background Chad Basin, lying within the bidirectional corridor of African Sahel, is one of the most populated places in Sub-Saharan Africa today. The origin of its settlement appears connected with Holocene climatic ameliorations (aquatic resources that started ~10,000 years before present (YBP. Although both Nilo-Saharan and Niger-Congo language families are encountered here, the most diversified group is the Chadic branch belonging to the Afro-Asiatic language phylum. In this article, we investigate the proposed ancient migration of Chadic pastoralists from Eastern Africa based on linguistic data and test for genetic traces of this migration in extant Chadic speaking populations. Results We performed whole mitochondrial genome sequencing of 16 L3f haplotypes, focused on clade L3f3 that occurs almost exclusively in Chadic speaking people living in the Chad Basin. These data supported the reconstruction of a L3f phylogenetic tree and calculation of times to the most recent common ancestor for all internal clades. A date ~8,000 YBP was estimated for the L3f3 sub-haplogroup, which is in good agreement with the supposed migration of Chadic speaking pastoralists and their linguistic differentiation from other Afro-Asiatic groups of East Africa. As a whole, the Afro-Asiatic language family presents low population structure, as 92.4% of mtDNA variation is found within populations and only 3.4% of variation can be attributed to diversity among language branches. The Chadic speaking populations form a relatively homogenous cluster, exhibiting lower diversification than the other Afro-Asiatic branches (Berber, Semitic and Cushitic. Conclusion The results of our study support an East African origin of mitochondrial L3f3 clade that is present almost exclusively within Chadic speaking people living in Chad Basin. Whole genome sequence-based dates show that the ancestral haplogroup L3f must have emerged soon after the Out-of-Africa migration (around

Migration of Chadic speaking pastoralists within Africa based on population structure of Chad Basin and phylogeography of mitochondrial L3f haplogroup

Science.gov (United States)

Černý, Viktor; Fernandes, Verónica; Costa, Marta D; Hájek, Martin; Mulligan, Connie J; Pereira, Luísa

2009-01-01

Background Chad Basin, lying within the bidirectional corridor of African Sahel, is one of the most populated places in Sub-Saharan Africa today. The origin of its settlement appears connected with Holocene climatic ameliorations (aquatic resources) that started ~10,000 years before present (YBP). Although both Nilo-Saharan and Niger-Congo language families are encountered here, the most diversified group is the Chadic branch belonging to the Afro-Asiatic language phylum. In this article, we investigate the proposed ancient migration of Chadic pastoralists from Eastern Africa based on linguistic data and test for genetic traces of this migration in extant Chadic speaking populations. Results We performed whole mitochondrial genome sequencing of 16 L3f haplotypes, focused on clade L3f3 that occurs almost exclusively in Chadic speaking people living in the Chad Basin. These data supported the reconstruction of a L3f phylogenetic tree and calculation of times to the most recent common ancestor for all internal clades. A date ~8,000 YBP was estimated for the L3f3 sub-haplogroup, which is in good agreement with the supposed migration of Chadic speaking pastoralists and their linguistic differentiation from other Afro-Asiatic groups of East Africa. As a whole, the Afro-Asiatic language family presents low population structure, as 92.4% of mtDNA variation is found within populations and only 3.4% of variation can be attributed to diversity among language branches. The Chadic speaking populations form a relatively homogenous cluster, exhibiting lower diversification than the other Afro-Asiatic branches (Berber, Semitic and Cushitic). Conclusion The results of our study support an East African origin of mitochondrial L3f3 clade that is present almost exclusively within Chadic speaking people living in Chad Basin. Whole genome sequence-based dates show that the ancestral haplogroup L3f must have emerged soon after the Out-of-Africa migration (around 57,100 ± 9,400 YBP), but

Critical success factors in electronic document and records ...

African Journals Online (AJOL)

... and Southern Africa Regional Branch of the International Council on Archives ... The quest by the Government of Botswana to leverage the benefits brought ... The Ministry of Trade and Industry (MTI) implemented an EDRMS, called the ...

Africa's expanding population: old problems, new policies.

Science.gov (United States)

Goliber, T J

1989-11-01

Sub-Saharan Africa faces an historic challenge: to achieve economic and social progress while experiencing extraordinary population growth. With an estimated 1989 population of 512 million, the 42 countries of sub-Saharan Africa have the highest birth and death rates of any major world region. While death rates have fallen since the 1960s, persistently high birth rates yield annual growth rates above 3% in many countries. The United Nations projects that the region's population will increase 2.7 times by 2025--to 1.4 billion. Throughout the region, population has outstripped economic growth since the mid-1970s. In addition, many African countries are experiencing an epidemic of AIDS (Acquired Immunodeficiency Syndrome). The extent and demographic impact of the epidemic still are unknown, but disturbing social and political effects are already being felt. The region's population growth will slow only when African couples begin to have fewer children. The average number of children per woman ranges from 6 to 8 for most countries. The Africans' preference for large families is deeply rooted in the culture and fed by the perceived economic benefits they receive from their children. Economic stagnation during the 1980s prompted many national governments to recognize that rapid population growth was hindering their socioeconomic development. The political climate has shifted away from pronatalist or laissez-faire attitudes toward official policies to slow population growth. The policy formation process--detailed here for 4 countries (Zambia, Nigeria, Zaire, and Liberia)--is ponderous and beset with political and bureaucratic pitfalls, However, policy shifts in more and more countries combined with evidence of increased contraceptive use and fertility downturns in a few countries give some hope that the region's extraordinary population growth may have peaked and will start a descent. Whatever the case, the decade of the 1990s will be crucial for the future of sub

Tree Branching: Leonardo da Vinci's Rule versus Biomechanical Models

Science.gov (United States)

Minamino, Ryoko; Tateno, Masaki

2014-01-01

This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule. PMID:24714065

Tree branching: Leonardo da Vinci's rule versus biomechanical models.

Science.gov (United States)

Minamino, Ryoko; Tateno, Masaki

2014-01-01

This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule.

Manpower development in Africa and the regional manpower development project RAF/0/003. Special evaluation

International Nuclear Information System (INIS)

1992-01-01

At the start of the Agency's technical co-operation activities in 1958, many of its developing Member States were just embarking on nuclear activities. To make basic nuclear training available for these countries became the first concern of the Agency and initially fellowships constituted more than 80% of the assistance provided. During the 1960s, while the programmes' expert and equipment components grew steadily, fellowships still represented more than 50% of the assistance provided to individual Member States. As counterpart institutions slowly build up small cadres of qualified staff, the share of training in the Agency's programme of technical co-operation became less dominant and, by 1986, only 22% of the funds spent on country programmes were devoted to fellowships. In the Africa region, where the share of fellowship training provided to individual Member States had dropped even below the 20% mark, and where the participation in group training events was the lowest of any region, this was having serious consequences on manpower development, as was pointed out in two separate evaluations. At least some opportunities exist in about 60% of the countries in the region for training in selected areas of nuclear science and technology, but only 20% of the countries provide training up to the MSc/PhD level. The number of trainees in nuclear science and technology graduating each year from national institutions is very small and cannot be considered adequate to satisfy existing manpower needs of the country concerned and of the region as a whole. Very few - if any - opportunities for nuclear training abroad are available for candidates from the region other than those funded by the Agency. There is very little awareness at the national level as to the actual training needs in the nuclear field in most countries of the region, underlining the importance of the role of the Agency, not only as a provider of training, but also as an adviser on assessing training needs at

BRANCH ASPECTS OF ACCOUNTING PAYMENTS BY COMPANIES OF MOBILE NETWORK

Directory of Open Access Journals (Sweden)

I.R. Konovalova

2007-12-01

Full Text Available In the paper some branch aspects of accounting payments by companies of mobile network are analyzed. Analyzed topical by regarded problem for Sverdlovskaya region. Researched civic-law notions, that applying at the telecommunication area. The authors gives recommendations for system of accounting specific aspects of payments on the basis of they economic essence, and gives sentences to change legislation activeing at the Russian Federation.

Cravity modulation of the moss Tortula modica branching

Science.gov (United States)

Khorkavtsiv, Yaroslava; Kit, Nadja

Among various abiotic factors the sensor system of plants constantly perceives light and gravitation impulses and reacts on their action by photo- and gravitropisms. Tropisms play fundamental part in ontogenesis and determination of plant forms. Essentially important question is how light initiating phototropic bending modulates gravitropism. In contrast to flower plants, red light is phototropically active for mosses, and phytochromic system controls initiation of apical growth, branching and photomorphogenesis of mosses. The aim of this investigation was to analyse cell branching of protonemata Tortula modica Zander depending on the direction of light and gravitation vector. The influence of light and gravitation on the form of protonemal turf T. modica, branching and the angle of lateral branches relative to axis of mother cell growth has been investigated. As moss protonemata is not branched in the darkness, light is necessary for branching activation. Minimally low intensity of the red light (0.2 mmol (.) m (-2) ({) .}sec (-1) ) induced branching without visual display of phototropic growth. It has been established that unidirectional action of light and gravitation intensifies branching, and, on the contrary, perpendicularly oriented vectors of factors weaken branches formation. Besides, parallel oriented vectors initiated branching from both cell sides, but oppositely directed vectors initiated branching only from one side. Clinostate rotation the change of the vector gravity and causes uniform cell branching, hence, light and gravitation mutually influence the branching system form of the protonemata cell. It has been shown that the angle of lateral branches in darkness does not depend on the direction of light and gravitation action. After lighting the local growth of the cell wall took place mainly under the angle 90 (o) to the axes of mother cell growth. Then the angle gradually decreased and in 3-4 cell divisions the lateral branch grew under the angle

HIV/AIDS, conflict and security in Africa: rethinking relationships.

Science.gov (United States)

Becker, Joseph U; Theodosis, Christian; Kulkarni, Rick

2008-09-22

The effect of conflict on HIV transmission and regional and global security has been the subject of much recent discussion and debate. Many long held assumptions regarding these relationships are being reconsidered. Conflict has long been assumed to contribute significantly to the spread of HIV infection. However, new research is casting doubt on this assumption. Studies from Africa suggest that conflict does not necessarily predispose to HIV transmission and indeed, there is evidence to suggest that recovery in the "post-conflict" state is potentially dangerous from the standpoint of HIV transmission. As well, refugee populations have been previously considered as highly infected vectors of HIV transmission. But in light of new investigation this belief is also being reconsidered. There has additionally been concern that high rates of HIV infection among many of the militaries of sub-Saharan Africa poses a threat to regional security. However, data is lacking on both dramatically elevated prevalence amongst soldiers and a possible negative effect on regional security. Nevertheless, HIV/AIDS remain a serious threat to population health and economic well being in this region. These issues are of vital importance for HIV programming and health sector development in conflict and "post-conflict" societies and will constitute formidable challenges to the international community. Further research is required to better inform the discussion of HIV, conflict, and security in sub-Saharan Africa.

Additional chain-branching pathways in the low-temperature oxidation of branched alkanes

KAUST Repository

Wang, Zhandong

2015-12-31

Chain-branching reactions represent a general motif in chemistry, encountered in atmospheric chemistry, combustion, polymerization, and photochemistry; the nature and amount of radicals generated by chain-branching are decisive for the reaction progress, its energy signature, and the time towards its completion. In this study, experimental evidence for two new types of chain-branching reactions is presented, based upon detection of highly oxidized multifunctional molecules (HOM) formed during the gas-phase low-temperature oxidation of a branched alkane under conditions relevant to combustion. The oxidation of 2,5-dimethylhexane (DMH) in a jet-stirred reactor (JSR) was studied using synchrotron vacuum ultra-violet photoionization molecular beam mass spectrometry (SVUV-PI-MBMS). Specifically, species with four and five oxygen atoms were probed, having molecular formulas of C8H14O4 (e.g., diketo-hydroperoxide/keto-hydroperoxy cyclic ether) and C8H16O5 (e.g., keto-dihydroperoxide/dihydroperoxy cyclic ether), respectively. The formation of C8H16O5 species involves alternative isomerization of OOQOOH radicals via intramolecular H-atom migration, followed by third O2 addition, intramolecular isomerization, and OH release; C8H14O4 species are proposed to result from subsequent reactions of C8H16O5 species. The mechanistic pathways involving these species are related to those proposed as a source of low-volatility highly oxygenated species in Earth\\'s troposphere. At the higher temperatures relevant to auto-ignition, they can result in a net increase of hydroxyl radical production, so these are additional radical chain-branching pathways for ignition. The results presented herein extend the conceptual basis of reaction mechanisms used to predict the reaction behavior of ignition, and have implications on atmospheric gas-phase chemistry and the oxidative stability of organic substances. © 2015 The Combustion Institute.

Optimization of multi-branch switched diversity systems

KAUST Repository

Nam, Haewoon

2009-10-01

A performance optimization based on the optimal switching threshold(s) for a multi-branch switched diversity system is discussed in this paper. For the conventional multi-branch switched diversity system with a single switching threshold, the optimal switching threshold is a function of both the average channel SNR and the number of diversity branches, where computing the optimal switching threshold is not a simple task when the number of diversity branches is high. The newly proposed multi-branch switched diversity system is based on a sequence of switching thresholds, instead of a single switching threshold, where a different diversity branch uses a different switching threshold for signal comparison. Thanks to the fact that each switching threshold in the sequence can be optimized only based on the number of the remaining diversity branches, the proposed system makes it easy to find these switching thresholds. Furthermore, some selected numerical and simulation results show that the proposed switched diversity system with the sequence of optimal switching thresholds outperforms the conventional system with the single optimal switching threshold. © 2009 IEEE.

Same-sex marriage in South Africa: The road ahead

Directory of Open Access Journals (Sweden)

J Swanepoel

2004-06-01

Full Text Available The status of same-sex partnerships is currently a hotly debated issue in various jurisdictions and also in South Africa. Section 9 of the Bill of Rights in the Constitution of the Republic of South Africa2 prohibits unfair discrimination by the State, inter alia, on grounds of gender, sex and sexual orientation. The question that arises is whether the legal definition of marriage, being a relationship between one man and one woman, constitutes discrimination, and if so, whether such discrimination is unfair. The legal position has become acute in South Africa. Legal uncertainty prevails with regard to the legal status of such couples. Various applications have been brought before branches of the High Court and the Constitutional Court for relief relating to particular personal and patrimonial consequences of marriage. In some cases the respective courts had to establish on an ad hoc basis whether a long term relationship indicative of a marriage-like relationship existed in order to bestow the particular relief requested by the applicant couple. The very fact that an ad hoc determination has to be made because, of course, there is no celebration of a valid marriage creates an untenable situation for such couples. The question posed above, forms the focal point of serious, and often insulting, legal debate. This contribution endeavors to give a brief overview of the various viewpoints, and thereafter to add to the debate.

Examining leadership as a strategy to enhance health care service delivery in regional hospitals in South Africa.

Science.gov (United States)

Govender, Sagaren; Gerwel Proches, Cecile N; Kader, Abdulla

2018-01-01

Four public hospitals in South Africa, which render both specialized and nonspecialized services to thousands of patients, were examined to determine the impact of leadership on health care service delivery. These hospitals were inundated by various problems that were impacting negatively on health care service delivery. This research study aimed to gain a comprehensive understanding of the challenges, complexities and constraints facing public health care in KwaZulu-Natal (KZN) and to examine leadership as a strategy to enhance healthcare service delivery with a particular focus on four regional hospitals in the KZN Province. The mixed-method research approach was utilized. Purposive sampling and stratified random sampling were employed in the research setting, and in-depth, semistructured interviews and questionnaires were used to collect data. Data were analyzed using the Nvivo computer software package for in-depth interviews and the Statistical Package for the Social Sciences (SPSS) software for the quantitative analysis. The research findings showed that the current leadership framework adopted by the health care leaders in regional hospitals in KZN is weak and is contributing to poor health care service delivery. This study, therefore, aimed to address the current challenges and weaknesses that are impacting negatively on health care service delivery in regional hospitals in the KZN Province and made recommendations for improvement.

Climate change and global warming: implications for sub-Saharan Africa

Energy Technology Data Exchange (ETDEWEB)

Christian, E.

2010-07-01

The study reviews the potential threats of climate change in sub-Sahara Africa. It paints a picture of how the major green house gases (GHGs) -- CO{sub 2}, CH{sub 4} -- will grow in the sub-continent before the year 2015. The study also highlights the potential causes of climate change in the sub-continent based on anthropogenic and physical factors. It further examined the impacts of climate change in the sub-region based on the sensitivity, vulnerability and adaptations opened to the sub-region. Observation shows that overall social and economic activities in sub-Sahara Africa will be substantially worse than in any other developing world. Consequently, mitigation and adaptation measures were suggested to alleviate the impacts of climate change in the sub-region.

Trauma in sub-Saharan Africa: review of cost, estimation methods, and interventions.

Science.gov (United States)

Smigelsky, Melissa A; Aten, Jamie D; Gerberich, Stacy; Sanders, Mark; Post, Rachael; Hook, Kimberly; Ku, Angie; Boan, David M; Monroe, Phil

2014-01-01

Trauma is a widely acknowledged problem facing individuals and communities in developing countries. In sub-Saharan Africa-a region that is home to some of the world's worst human rights violations, ethnic and civil conflicts, disease epidemics, and conditions of poverty-trauma is an all-too-common experience in citizens' daily lives. In order to address these conditions effectively, the impact of trauma must be understood. The authors reviewed recent literature on the cost and consequences of psychological trauma in sub-Saharan Africa to provide a substantive perspective on how trauma affects individuals, communities, and organizations and to inform the effort to determine a method for measuring the impact of trauma in sub-Saharan Africa and the efficacy of trauma interventions in the region. Several recommendations are offered to help broaden and deepen the current approaches to conceptualizing trauma, evaluating its cost, and intervening on behalf of those impacted by trauma in sub-Saharan Africa.

Powering Africa's sustainable development: The potential role of nuclear energy

International Nuclear Information System (INIS)

Kessides, Ioannis N.

2014-01-01

The electricity deficit is one of the most serious contemporary issues facing sub-Saharan Africa. Many countries in the region have insufficient generation capacity to meet rapidly rising demand. Electricity shortages have become a binding and powerful constraint on the continent's sustainable development. Their resolution will require coordinated effort to improve the effectiveness and governance of the region's utilities and to significantly scale-up generation capacity. A broad portfolio of low carbon (low-C) technologies needs to be deployed in order to address the electricity deficit in a cost-effective way and not be disruptive to economic growth. Since nuclear power can deliver low-C electricity in bulk, reliably and without intermittency, it could make a significant contribution towards resolving Africa's power crisis. However, the post-Fukushima safety concerns related to large nuclear plants with substantial radioactive inventories will be especially pronounced in Africa. Moreover, large scale reactors with huge upfront investment requirements are likely to be unsuitable for capital-constrained African countries with small electricity grids. One promising direction for nuclear development in Africa might be to downsize reactors from the gigawatt scale to less-complex smaller units (with substantially smaller radioactive inventory) that are more affordable. - Highlights: • We examine the potential role of nuclear power in Africa. • There is growing African interest in nuclear power. • Nuclear power in Africa will require grid strengthening. • Small modular reactors could enhance Africa's energy security. • There are concerns about Africa's safety culture for nuclear power

Auxin transport in the evolution of branching forms.

Science.gov (United States)

Harrison, C Jill

2017-07-01

Contents 545 I. 545 II. 546 III. 546 IV. 548 V. 548 VI. 549 VII. 549 Acknowledgements 549 References 549 SUMMARY: Branching is one of the most striking aspects of land plant architecture, affecting resource acquisition and yield. Polar auxin transport by PIN proteins is a primary determinant of flowering plant branching patterns regulating both branch initiation and branch outgrowth. Several lines of experimental evidence suggest that PIN-mediated polar auxin transport is a conserved regulator of branching in vascular plant sporophytes. However, the mechanisms of branching and auxin transport and relationships between the two are not well known outside the flowering plants, and the paradigm for PIN-regulated branching in flowering plants does not fit bryophyte gametophytes. The evidence reviewed here suggests that divergent auxin transport routes contributed to the diversification of branching forms in distinct land plant lineages. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Quality management: the challenges of regional governance in West Africa

Directory of Open Access Journals (Sweden)

Osseni Loukoumanou

2015-01-01

Full Text Available With a total area of 3 509 600 km2 and a population of over 80 340 000 people, the eight WAEMU countries (the West Africa Economic and Monetary Union have many products to offer the international market. These products can be classified into three categories: fishery products, agricultural products, and agro-industrial products resulting from the processing in the first two categories. Despite the real independence of these categories, they share a common thread: efficient quality management. The crux of the matter is efficient quality management which denotes both effective and efficient management of the products. While all the theories of efficiency acknowledge a border between effectiveness and efficiency and highlight the complementarity of the two concepts, it is nonetheless interesting to note that the Russian language combines the two concepts into a single word: “effectivnost”. The efficiency of a quality infrastructure is determined by both its effectiveness and its efficiency since a quality product is one that meets the standards in place, has a number of inherent characteristics that fulfil stated requirements, and can be sold within budget limits set by the consumer. In other words, quality must be managed at a restricted cost so that it is not a source of increased production costs. The formal ratification of the SOAMET (West African Secretariat of Metrology, the NORMCERQ (Regional Body of Standardization, Certification and Quality Promotion and the SOAC (Regional Body of Accreditation by the eight WAEMU countries through the signing of Regulation No. 01/2005/CM/UEMOA (Scheme for the Harmonization of the Activities of Accreditation, Certification, Standardization and Metrology in the WAEMU is a very positive step. Nevertheless, both the successful implementation of this regulation and the quality of work that will derive from these organizations depend on the quality of the human factor, i.e. the competence of the

Branch Width and Height Influence the Incorporation of Branches into Foraging Trails and Travel Speed in Leafcutter Ants Atta cephalotes (L.) (Hymenoptera: Formicidae).

Science.gov (United States)

Freeman, B M; Chaves-Campos, J

2016-06-01

Fallen branches are often incorporated into Atta cephalotes (L.) foraging trails to optimize leaf tissue transport rates and economize trail maintenance. Recent studies in lowlands show laden A. cephalotes travel faster across fallen branches than on ground, but more slowly ascending or descending a branch. The latter is likely because (1) it is difficult to travel up or downhill and (2) bottlenecks occur when branches are narrower than preceding trail. Hence, both branch height and width should determine whether branches decrease net travel times, but no study has evaluated it yet. Laden A. cephalotes were timed in relation to branch width and height across segments preceding, accessing, across, and departing a fallen branch in the highlands of Costa Rica. Ants traveled faster on branches than on cleared segments of trunk-trail, but accelerated when ascending or descending the branch-likely because of the absence of bottlenecks during the day in the highlands. Branch size did not affect ant speed in observed branches; the majority of which (22/24) varied from 11 to 120 mm in both height and width (average 66 mm in both cases). To determine whether ants exclude branches outside this range, ants were offered the choice between branches within this range and branches that were taller/wider than 120 mm. Ants strongly preferred the former. Our results indicate that A. cephalotes can adjust their speed to compensate for the difficulty of traveling on branch slopes. More generally, branch size should be considered when studying ant foraging efficiency.

Impact of the transition to continous trading on emerging financial market's liquidity : Case study of the West Africa Regional Exchange Market (BRVM)

OpenAIRE

OUATTARA, Aboudou

2016-01-01

After 18 years of activities and take-off difficulties due to socio-economic and political environment of the WAEMU zone, the west Africa regional exchange market (BRVM)’s authorities decided to move to continuous trading. The decision was effective on 16th september 2013. This action, beyond the upgrading of this stock exchange market to international standards, aims at improving market liquidity. Two years after its implementation, it seemed interesting to question the relevancy of this dec...

Persistence-Based Branch Misprediction Bounds for WCET Analysis

DEFF Research Database (Denmark)

Puffitsch, Wolfgang

2015-01-01

Branch prediction is an important feature of pipelined processors to achieve high performance. However, it can lead to overly pessimistic worst-case execution time (WCET) bounds when being modeled too conservatively. This paper presents bounds on the number of branch mispredictions for local...... dynamic branch predictors. To handle interferences between branch instructions we use the notion of persistence, a concept that is also found in cache analyses. The bounds apply to branches in general, not only to branches that close a loop. Furthermore, the bounds can be easily integrated into integer...... linear programming formulations of the WCET problem. An evaluation on a number of benchmarks shows that with these bounds, dynamic branch prediction does not necessarily lead to higher WCET bounds than static prediction schemes....

Branched GDGT-based paleotemperature reconstruction of the last 30,000 years in humid monsoon region of Southeast China

Science.gov (United States)

Wang, M.

2017-12-01

The use of bacterial branched glycerol dialkyl glycerol tetraethers (brGDGTs) to reconstruct mean annual air temperatures (MAATs) and environmental pH from soils has sparked significant interest in the terrestrial paleoclimate community. However, the reconstruction of these climate proxies from peat bogs is rare in monsoonal regions of the East Asia. This research was carried out on a core from the Shuizhuyang (SZY) peat bog located in Fujian Province. Branched GDGT (brGDGT) indexes were used for reconstructing the paleoclimate of the last 30 cal ka. The aim was to evaluate quantitatively the MAAT and pH values since the Last Glacial Maximum (LGM) in the subtropical zone of China. Results show that the CBT-MBT'-derived MAAT at MIS 3 is about 15.6 °C on average, which is followed by a significant fall at the LGM (11.7-12.1 °C). The temperature difference between the LGM and the present-day value is as high as 5.8 °C. The synchronous variation of biomarker and pollen proxies indicates that replacement of subtropical evergreen broadleaved forests by coldtolerant, deciduous broadleaved forests was driven by the significant drop in air temperature. Our results also indicate that the Younger Dryas event lasted from about 12.9 to about 11.3 cal ka, and cooling event at 3.2 cal ka in the late Holocene was detected, showing the sensitivity of peat bogs to rapid cooling. Our pH reconstructions indicate that the pH of the bog rose during Heinrich 1 and Bølling-Allerød periods, probably due to low precipitation, and were lowest in the Holocene thermal maximum between 8 ka and 2.5 ka, probably due to higher precipitation. The decoupling of reconstructed MAAT and pH during particularly deglaciation and YD periods supports the hypothesis that the variations in temperature and precipitation are not always synchronous.

Genetic Origins of Lactase Persistence and the Spread of Pastoralism in Africa

Science.gov (United States)

Ranciaro, Alessia; Campbell, Michael C.; Hirbo, Jibril B.; Ko, Wen-Ya; Froment, Alain; Anagnostou, Paolo; Kotze, Maritha J.; Ibrahim, Muntaser; Nyambo, Thomas; Omar, Sabah A.; Tishkoff, Sarah A.

2014-01-01

In humans, the ability to digest lactose, the sugar in milk, declines after weaning because of decreasing levels of the enzyme lactase-phlorizin hydrolase, encoded by LCT. However, some individuals maintain high enzyme amounts and are able to digest lactose into adulthood (i.e., they have the lactase-persistence [LP] trait). It is thought that selection has played a major role in maintaining this genetically determined phenotypic trait in different human populations that practice pastoralism. To identify variants associated with the LP trait and to study its evolutionary history in Africa, we sequenced MCM6 introns 9 and 13 and ∼2 kb of the LCT promoter region in 819 individuals from 63 African populations and in 154 non-Africans from nine populations. We also genotyped four microsatellites in an ∼198 kb region in a subset of 252 individuals to reconstruct the origin and spread of LP-associated variants in Africa. Additionally, we examined the association between LP and genetic variability at candidate regulatory regions in 513 individuals from eastern Africa. Our analyses confirmed the association between the LP trait and three common variants in intron 13 (C-14010, G-13907, and G-13915). Furthermore, we identified two additional LP-associated SNPs in intron 13 and the promoter region (G-12962 and T-956, respectively). Using neutrality tests based on the allele frequency spectrum and long-range linkage disequilibrium, we detected strong signatures of recent positive selection in eastern African populations and the Fulani from central Africa. In addition, haplotype analysis supported an eastern African origin of the C-14010 LP-associated mutation in southern Africa. PMID:24630847

Controlling the unstable emission of a semiconductor laser subject to conventional optical feedback with a filtered feedback branch.

Science.gov (United States)

Ermakov, I V; Tronciu, V Z; Colet, Pere; Mirasso, Claudio R

2009-05-25

We show the advantages of controlling the unstable dynamics of a semiconductor laser subject to conventional optical feedback by means of a second filtered feedback branch. We give an overview of the analytical solutions of the double cavity feedback and show numerically that the region of stabilization is much larger when using a second branch with filtered feedback than when using a conventional feedback one.

Controlling the unstable emission of a semiconductor laser subject to conventional optical feedback with a filtered feedback branch

OpenAIRE

Ermakov, Ilya; Tronciu, Vasile; Colet, Pere; Mirasso, Claudio R.

2009-01-01

We show the advantages of controlling the unstable dynamics of a semiconductor laser subject to conventional optical feedback by means of a second filtered feedback branch. We give an overview of the analytical solutions of the double cavity feedback and show numerically that the region of stabilization is much larger when using a second branch with filtered feedback than when using a conventional feedback one.

Branched-chain fatty acid biosynthesis in a branched-chain amino acid aminotransferase mutant of Staphylococcus carnosus

DEFF Research Database (Denmark)

Beck, Hans Christian

2005-01-01

Fatty acid biosynthesis by a mutant strain of Staphylococcus carnosus deficient in branched-chain amino acid aminotransferase (IlvE) activity was analysed. This mutant was unable to produce the appropriate branched-chain alpha-ketoacid precursors for branched-chain fatty acid biosynthesis from...... in rich medium and growth in defined medium supplemented with 2-methylpropanoic acid lead to extensive alteration of the fatty acid composition in the cell membrane. In rich medium, a change from 51.7% to 17.1% anteiso-C15:0, and from 3.6% to 33.9% iso-C14:0 fatty acids as compared to the wild-type strain...... for 2-methylpropanoic acid production, revealing that the IlvE protein plays an important, but not essential role in the biosynthesis of branched-chain fatty acids and secondary metabolites in S. carnosus....

Commercial breaks: building the market for PV in Africa

International Nuclear Information System (INIS)

Hankins, M.

2001-01-01

The article focuses on the huge potential market for off-grid photovoltaics in Africa, in the sub-Saharan region in particular. However, so far the potential market remains largely untapped and several multimillion-dollar projects aimed at developing the market have been disappointing. The result has been a reduction in the activities of PV companies in Africa. The article seeks reasons for the lack of success and offers suggestions for improving the situation

Regional vegetation water effects on satellite soil moisture estimations for West Africa

NARCIS (Netherlands)

Friesen, J.C.

2008-01-01

Soil moisture information is a vital parameter for water resources planning and food production. In particular for West Africa, where income largely depends on rainfed agriculture, reliable information on available soil water is required for modeling and prediction. Over large areas and,

Analysis of Genetic Diversity and Population Structure of Sesame Accessions from Africa and Asia as Major Centers of Its Cultivation

Directory of Open Access Journals (Sweden)

Komivi Dossa

2016-04-01

Full Text Available Sesame is an important oil crop widely cultivated in Africa and Asia. Understanding the genetic diversity of accessions from these continents is critical to designing breeding methods and for additional collection of sesame germplasm. To determine the genetic diversity in relation to geographical regions, 96 sesame accessions collected from 22 countries distributed over six geographic regions in Africa and Asia were genotyped using 33 polymorphic SSR markers. Large genetic variability was found within the germplasm collection. The total number of alleles was 137, averaging 4.15 alleles per locus. The accessions from Asia displayed more diversity than those from Africa. Accessions from Southern Asia (SAs, Eastern Asia (EAs, and Western Africa (WAf were highly diversified, while those from Western Asia (WAs, Northern Africa (NAf, and Southeastern Africa (SAf had the lowest diversity. The analysis of molecular variance revealed that more than 44% of the genetic variance was due to diversity among geographic regions. Five subpopulations, including three in Asia and two in Africa, were cross-identified through phylogenetic, PCA, and STRUCTURE analyses. Most accessions clustered in the same population based on their geographical origins. Our results provide technical guidance for efficient management of sesame genetic resources in breeding programs and further collection of sesame germplasm from these different regions.

Wind-Induced Reconfigurations in Flexible Branched Trees

Science.gov (United States)

Ojo, Oluwafemi; Shoele, Kourosh

2017-11-01

Wind induced stresses are the major mechanical cause of failure in trees. We know that the branching mechanism has an important effect on the stress distribution and stability of a tree in the wind. Eloy in PRL 2011, showed that Leonardo da Vinci's original observation which states the total cross section of branches is conserved across branching nodes is the best configuration for resisting wind-induced fracture in rigid trees. However, prediction of the fracture risk and pattern of a tree is also a function of their reconfiguration capabilities and how they mitigate large wind-induced stresses. In this studies through developing an efficient numerical simulation of flexible branched trees, we explore the role of the tree flexibility on the optimal branching. Our results show that the probability of a tree breaking at any point depends on both the cross-section changes in the branching nodes and the level of tree flexibility. It is found that the branching mechanism based on Leonardo da Vinci's original observation leads to a uniform stress distribution over a wide range of flexibilities but the pattern changes for more flexible systems.

Lion (Panthera leo) populations are declining rapidly across Africa, except in intensively managed areas

OpenAIRE

Bauer, Hans; Chapron, Guillaume; Nowell, Kristin; Henschel, Philipp; Funston, Paul; Hunter, Luke T. B.; Macdonald, David W.; Packer, Craig

2015-01-01

At a regional scale, lion populations in West, Central, and East Africa are likely to suffer a projected 50% decline over the next two decades, whereas lion populations are only increasing in southern Africa. Many lion populations are either now gone or expected to disappear within the next few decades to the extent that the intensively managed populations in southern Africa may soon supersede the iconic savannah landscapes in East Africa as the most successful sites for lion conservation. Th...

Regional blood flow analysis and its relationship with arterial branch lengths and lumen volume in the coronary arterial tree

International Nuclear Information System (INIS)

Molloi, Sabee; Wong, Jerry T

2007-01-01

The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions (30-70% diameter stenosis) where it is difficult to determine whether a particular lesion is the cause of ischaemia. Therefore, a functional measure of stenosis severity is needed. The purpose of this study is to determine whether the expected maximum coronary blood flow in an arterial tree is predictable from its sum of arterial branch lengths or lumen volume. Using a computer model of a porcine coronary artery tree, an analysis of blood flow distribution was conducted through a network of millions of vessels that included the entire coronary artery tree down to the first capillary branch. The flow simulation results show that there is a linear relationship between coronary blood flow and the sum of its arterial branch lengths. This relationship holds over the entire arterial tree. The flow simulation results also indicate that there is a 3/4 er relation between coronary blood flow (Q) and the sum of its arterial lumen volume (V). Moreover, there is a linear relationship between normalized Q and normalized V raised to a power of 3/4 over the entire arterial tree. These results indicate that measured arterial branch lengths or lumen volumes can be used to predict the expected maximum blood flow in an arterial tree. This theoretical maximum blood flow, in conjunction with an angiographically measured blood flow, can potentially be used to calculate fractional flow reserve based entirely on angiographic data

Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations

KAUST Repository

Dogar, Muhammad Mubashar; Stenchikov, Georgiy L.; Osipov, Sergey; Wyman, Bruce; Zhao, Ming

2017-01-01

The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations

KAUST Repository

Dogar, Muhammad Mubashar

2017-07-27

The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory\\'s High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

Sensitivity of the regional climate in the Middle East and North Africa to volcanic perturbations

Science.gov (United States)

Dogar, Muhammad Mubashar; Stenchikov, Georgiy; Osipov, Sergey; Wyman, Bruce; Zhao, Ming

2017-08-01

The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/National Centers for Environmental Prediction Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model. A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon, and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

Atmospheric Chemistry Over Southern Africa

Science.gov (United States)

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

2011-01-01

During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

All change at the CERN UBS branch

CERN Multimedia

Antonella Del Rosso

2012-01-01

UBS branches across the country are being modernised, and the CERN branch is no exception. The Bulletin brings you a preview of the project, which will get under way in January 2013.   Mock-up of the renovated UBS branch. The changes at the UBS branch in CERN's Main Building will be no simple facelift. The entire bank will be renovated, transforming the present relatively confined premises into an open and attractive area. "The renovation of the UBS branches is part of a wider campaign designed to further enhance our customer relations," explains Ezio Mangia, the head of the CERN branch.  The UBS bank currently occupies three sets of premises in CERN's Main Building (two on the ground floor and one in the basement). "By the end of the work, which is scheduled to be completed by the middle of next year, CERN customers will benefit from a new area with open-plan counters and "hole-in-the-wall" machines accessible to...

Receptor modelling and risk assessment of volatile organic compounds measured at a regional background site in South Africa

Science.gov (United States)

Jaars, Kerneels; Vestenius, Mika; van Zyl, Pieter G.; Beukes, Johan P.; Hellén, Heidi; Vakkari, Ville; Venter, Marcell; Josipovic, Miroslav; Hakola, Hannele

2018-01-01

Volatile organic compounds (VOCs) can have significant impacts on climate and human health. Certain VOCs are proven to be carcinogenic and toxic, which can affect human health directly and indirectly. In order to develop climate change reduction strategies and to assess the impacts of VOCs on human health, it is crucial to determine the sources of VOCs, which can be emitted from biogenic and anthropogenic sources. The aim of this study was to perform source apportionment using positive matrix factorisation (PMF) analysis on VOC data collected at a regional background location affected by the major sources in the interior of South Africa, which include the western- and eastern Bushveld Igneous Complex, the Johannesburg-Pretoria metropolitan conurbation, the Vaal Triangle, the Mpumalanga Highveld and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. In addition, a risk assessment study was also performed in view of the major source regions affecting Welgegund in order to quantify the impacts of anthropogenic VOCs measured at Welgegund on human health. Measurements were conducted at the Welgegund measurement station located on a commercial farm approximately 100 km west of Johannesburg for a period of more than two years. PMF analysis revealed ten meaningful factor solutions, of which five factors were associated with biogenic emissions and five with anthropogenic sources. Three of the biogenic factors were characterised by a specific biogenic species, i.e. isoprene, limonene and 2-methyl-3-buten-2-ol (MBO), while the other two biogenic factors comprised mixtures of biogenic species with different tracer species. The temporal factor contribution for the isoprene, limonene and MBO factors correlated relatively well with the seasonal wet pattern. One anthropogenic factor was associated with emissions from a densely populated anthropogenic source region to the east of Welgegund with a large number of industrial activities, while

The Anterior Branch of the Left Inferior Phrenic Artery Arising from the Right Inferior Phrenic Artery: An Angiographic and CT Study

International Nuclear Information System (INIS)

Hieda, Masashi; Toyota, Naoyuki; Kakizawa, Hideaki; Ishikawa, Masaki; Horiguchi, Jun; Ito, Katsuhide

2009-01-01

The purpose of this study was to retrospectively analyze the frequency and anatomical pattern of the anterior branch of the left inferior phrenic artery (LIPA) arising from the right inferior phrenic artery (RIPA). Angiography of the RIPA for patients (n = 140) with hepatic malignancy was retrospectively reviewed. The frequency at which the anterior branch of the LIPA arose from the RIPA was 14.3% (20 of 140 patients [pts]). Among the three branches that may arise from the RIPA in these cases (the anterior branch of the LIPA and the anterior and posterior branches of the RIPA), the anterior branch of the LIPA was the first branch of the RIPA in 9 of 20 pts (45%), and the posterior branch of the RIPA in 11 of 20 pts (55%). The anterior branch of the LIPA ran along the ventral side of the esophagus or stomach and supplied the esophagogastric region and dome of the left diaphragm in all cases. In conclusion, the anterior branch of the LIPA arises from the RIPA at a comparatively high frequency. In embolization of the RIPA, to effectively treat and avoid possible complications, interventionalists should be aware of this potential variant anatomy.

Prebiotic branched galacto-oligosaccharides (gos)

NARCIS (Netherlands)

Lammerts van Bueren-Brandt, Alica; Dijkhuizen, Lubbert

2018-01-01

The invention relates to galacto-oligosaccharide (GOS) compositions and the use thereof. Provided is the use of a GOS composition comprising branched and linear GOS species having a degree of polymerization (DP) of 3, wherein the branched DP3 GOS species are present in excess of linear DP3 GOS

The Rise of Food Prices and the Challenge of Development in Africa ...

African Journals Online (AJOL)

This article examines the rise of food prices and analyses the factors that contribute to price hikes and the overall implication in Africa's development. Africa is a conspicuous laggard among contemporary developing regions in the world. The continent bears the brunt of starvation, malnutrition, hunger and diseases that arise ...

Sub-Saharan Africa at a Glance.

Science.gov (United States)

Social Education, 1997

1997-01-01

Presents a wealth of statistical, geographic, and economic information on Sub-Saharan Africa arranged and displayed for easy and immediate access. Lists all of the countries of the region along with pertinent information including religious affiliation, capital, Gross National Product, main exports, population growth, education, and literacy. (MJP)

The earliest modern humans outside Africa.

Science.gov (United States)

Hershkovitz, Israel; Weber, Gerhard W; Quam, Rolf; Duval, Mathieu; Grün, Rainer; Kinsley, Leslie; Ayalon, Avner; Bar-Matthews, Miryam; Valladas, Helene; Mercier, Norbert; Arsuaga, Juan Luis; Martinón-Torres, María; Bermúdez de Castro, José María; Fornai, Cinzia; Martín-Francés, Laura; Sarig, Rachel; May, Hila; Krenn, Viktoria A; Slon, Viviane; Rodríguez, Laura; García, Rebeca; Lorenzo, Carlos; Carretero, Jose Miguel; Frumkin, Amos; Shahack-Gross, Ruth; Bar-Yosef Mayer, Daniella E; Cui, Yaming; Wu, Xinzhi; Peled, Natan; Groman-Yaroslavski, Iris; Weissbrod, Lior; Yeshurun, Reuven; Tsatskin, Alexander; Zaidner, Yossi; Weinstein-Evron, Mina

2018-01-26

To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the Homo sapiens clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Inland valley research in sub-Saharan Africa; priorities for a regional consortium

NARCIS (Netherlands)

Jamin, J.Y.; Andriesse, W.; Thiombiano, L.; Windmeijer, P.N.

1996-01-01

These proceedings are an account of an international workshop in support of research strategy development for the Inland Valley Consortium in sub-Saharan Africa. This consortium aims at concerted research planning for rice-based cropping systems in the lower parts of inland valleys. The Consortium

Campaign to kick polio out of Africa.

Science.gov (United States)

Letore, D

1998-12-01

This article discusses the goal of eradicating poliomyelitis (polio) in Africa by the year 2000. Polio is a crippling disease that paralyzes hundreds of thousands of children yearly. Polio was endemic in Africa during the 1970s. Today, polio is confined to sub-Saharan Africa and, specifically, to the Congo, Ethiopia, Nigeria, Somalia, and the Sudan. Considerable progress is evident. Full eradication is necessary because of the ease with which the virus is transmitted. The World Health Organization (WHO) set the goal of eradication by the year 2000 at a 1988 assembly meeting. The Plan of Action for a Global Polio Eradication Initiative was approved in 1989. The WHO Regional Committee for Africa adopted the resolution and urged again in 1995 for vigorous implementation. The Organization of African Unity endorsed the initiative in 1996. South African President Mandela led a region-wide mobilization campaign to increase public awareness of the initiative. Since 1997, leading players from the African Football Confederation have participated in awareness campaigns by spreading the message through a variety of channels. The initiative includes routine immunization complemented by the National Immunization Days (NIDs), training at the local level, surveillance, and door-to-door campaigns. The initiative must assure functioning systems of cold storage of vaccines and must continue to educate communities about the importance of routine immunization. There must be a strong laboratory network for isolating the 3 types of the virus. NIDs will be scheduled for 1999 in countries with civil conflict. The polio model is useful for other disease eradication campaigns.

Branching trajectory continual integral

International Nuclear Information System (INIS)

Maslov, V.P.; Chebotarev, A.M.

1980-01-01

Heuristic definition of the Feynman continual integral over branching trajectories is suggested which makes it possible to obtain in the closed form the solution of the Cauchy problem for the model Hartree equation. A number of properties of the solution is derived from an integral representation. In particular, the quasiclassical asymptotics, exact solution in the gaussian case and perturbation theory series are described. The existence theorem for the simpliest continual integral over branching trajectories is proved [ru

Three phylogenetic groups of nodA and nifH genes in Sinorhizobium and Mesorhizobium isolates from leguminous trees growing in Africa and Latin America.

Science.gov (United States)

Haukka, K; Lindström, K; Young, J P

1998-02-01

The diversity and phylogeny of nodA and nifH genes were studied by using 52 rhizobial isolates from Acacia senegal, Prosopis chilensis, and related leguminous trees growing in Africa and Latin America. All of the strains had similar host ranges and belonged to the genera Sinorhizobium and Mesorhizobium, as previously determined by 16S rRNA gene sequence analysis. The restriction patterns and a sequence analysis of the nodA and nifH genes divided the strains into the following three distinct groups: sinorhizobia from Africa, sinorhizobia from Latin America, and mesorhizobia from both regions. In a phylogenetic tree also containing previously published sequences, the nodA genes of our rhizobia formed a branch of their own, but within the branch no correlation between symbiotic genes and host trees was apparent. Within the large group of African sinorhizobia, similar symbiotic gene types were found in different chromosomal backgrounds, suggesting that transfer of symbiotic genes has occurred across species boundaries. Most strains had plasmids, and the presence of plasmid-borne nifH was demonstrated by hybridization for some examples. The nodA and nifH genes of Sinorhizobium teranga ORS1009T grouped with the nodA and nifH genes of the other African sinorhizobia, but Sinorhizobium saheli ORS609T had a totally different nodA sequence, although it was closely related based on the 16S rRNA gene and nifH data. This might be because this S. saheli strain was originally isolated from Sesbania sp., which belongs to a different cross-nodulation group than Acacia and Prosopis spp. The factors that appear to have influenced the evolution of rhizobial symbiotic genes vary in importance at different taxonomic levels.

What factors might have led to the emergence of Ebola in West Africa?

Science.gov (United States)

Alexander, Kathleen A; Sanderson, Claire E; Marathe, Madav; Lewis, Bryan L; Rivers, Caitlin M; Shaman, Jeffrey; Drake, John M; Lofgren, Eric; Dato, Virginia M; Eisenberg, Marisa C; Eubank, Stephen

2015-01-01