Ring complexes and related rocks in Africa

Science.gov (United States)

Vail, J. R.

Over 625 igneous complexes throughout Africa and Arabia have been selected and classified on the basis of petrographic association and chronology into six broad age groups forming 29 provinces. The groups range from Mid-Proterozoic to Tertiary and include gabbro, granite, syenite, foid syenite and carbonatite plutonic rocks, the majority in the form of ring-dykes, cone-sheets, plugs, circular intrusions, and their associated extrusive phases. Pan-African late or post-orogenic complexes (720-490 Ma) are common in the Arabian-Nubian and Tuareg shields of north Africa originating from subduction zone derived magmatism. Anorogenic complexes in Egypt, NE and central Sudan, Niger, Nigeria, Cameroon, Zaïre-Burundi, Malawi, Mozambique, Zimbabwe, Namibia and Angola span 550 to 50 Ma and are dominantly alkali granites and foid syenites. Many groups occur as en-echelon bands within linear arrays, and show migrating centres of intrusion in variable directions. In W. Africa there was a progressive shift of emplacement southwards during early Ordovician to Mid-Cretaceous times. Distribution patterns suggest thatdeep seated features, such as shear zones associated with lithospheric plate movements,controlled melting, and the resultant location of the complexes. Economic mineralization is not widespread in the rocks of the African ring complexes and is mainly restricted to small deposits of Sn, W, F, U and Nb.

Technology learning for renewable energy: Implications for South Africa's long-term mitigation scenarios

Energy Technology Data Exchange (ETDEWEB)

Winkler, Harald, E-mail: Harald.Winkler@uct.ac.z [Energy Research Centre, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Hughes, Alison [Energy Research Centre, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Haw, Mary [PJ Carew Consulting, 103 Hout Street, Cape Town 8001 (South Africa)

2009-11-15

Technology learning can make a significant difference to renewable energy as a mitigation option in South Africa's electricity sector. This article considers scenarios implemented in a Markal energy model used for mitigation analysis. It outlines the empirical evidence that unit costs of renewable energy technologies decline, considers the theoretical background and how this can be implemented in modeling. Two scenarios are modelled, assuming 27% and 50% of renewable electricity by 2050, respectively. The results show a dramatic shift in the mitigation costs. In the less ambitious scenario, instead of imposing a cost of Rand 52/t CO{sub 2}-eq (at 10% discount rate), reduced costs due to technology learning turn renewables into negative cost option. Our results show that technology learning flips the costs, saving R143. At higher penetration rate, the incremental costs added beyond the base case decline from R92 per ton to R3. Including assumptions about technology learning turns renewable from a higher-cost mitigation option to one close to zero. We conclude that a future world in which global investment in renewables drives down unit costs makes it a much more cost-effective and sustainable mitigation option in South Africa.

Tree cover in Central Africa: determinants and sensitivity under contrasted scenarios of global change.

Science.gov (United States)

Aleman, Julie C; Blarquez, Olivier; Gourlet-Fleury, Sylvie; Bremond, Laurent; Favier, Charly

2017-01-30

Tree cover is a key variable for ecosystem functioning, and is widely used to study tropical ecosystems. But its determinants and their relative importance are still a matter of debate, especially because most regional and global analyses have not considered the influence of agricultural practices. More information is urgently needed regarding how human practices influence vegetation structure. Here we focused in Central Africa, a region still subjected to traditional agricultural practices with a clear vegetation gradient. Using remote sensing data and global databases, we calibrated a Random Forest model to correlatively link tree cover with climatic, edaphic, fire and agricultural practices data. We showed that annual rainfall and accumulated water deficit were the main drivers of the distribution of tree cover and vegetation classes (defined by the modes of tree cover density), but agricultural practices, especially pastoralism, were also important in determining tree cover. We simulated future tree cover with our model using different scenarios of climate and land-use (agriculture and population) changes. Our simulations suggest that tree cover may respond differently regarding the type of scenarios, but land-use change was an important driver of vegetation change even able to counterbalance the effect of climate change in Central Africa.

The ShakeOut Earthquake Scenario - A Story That Southern Californians Are Writing

Science.gov (United States)

Perry, Suzanne; Cox, Dale; Jones, Lucile; Bernknopf, Richard; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

2008-01-01

The question is not if but when southern California will be hit by a major earthquake - one so damaging that it will permanently change lives and livelihoods in the region. How severe the changes will be depends on the actions that individuals, schools, businesses, organizations, communities, and governments take to get ready. To help prepare for this event, scientists of the U.S. Geological Survey (USGS) have changed the way that earthquake scenarios are done, uniting a multidisciplinary team that spans an unprecedented number of specialties. The team includes the California Geological Survey, Southern California Earthquake Center, and nearly 200 other partners in government, academia, emergency response, and industry, working to understand the long-term impacts of an enormous earthquake on the complicated social and economic interactions that sustain southern California society. This project, the ShakeOut Scenario, has applied the best current scientific understanding to identify what can be done now to avoid an earthquake catastrophe. More information on the science behind this project will be available in The ShakeOut Scenario (USGS Open-File Report 2008-1150; http://pubs.usgs.gov/of/2008/1150/). The 'what if?' earthquake modeled in the ShakeOut Scenario is a magnitude 7.8 on the southern San Andreas Fault. Geologists selected the details of this hypothetical earthquake by considering the amount of stored strain on that part of the fault with the greatest risk of imminent rupture. From this, seismologists and computer scientists modeled the ground shaking that would occur in this earthquake. Engineers and other professionals used the shaking to produce a realistic picture of this earthquake's damage to buildings, roads, pipelines, and other infrastructure. From these damages, social scientists projected casualties, emergency response, and the impact of the scenario earthquake on southern California's economy and society. The earthquake, its damages, and

Technology learning for renewable energy. Implications for South Africa's long-term mitigation scenarios

Energy Technology Data Exchange (ETDEWEB)

Winkler, Harald; Hughes, Alison [Energy Research Centre, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Haw, Mary [PJ Carew Consulting, 103 Hout Street, Cape Town 8001 (South Africa)

2009-11-15

Technology learning can make a significant difference to renewable energy as a mitigation option in South Africa's electricity sector. This article considers scenarios implemented in a Markal energy model used for mitigation analysis. It outlines the empirical evidence that unit costs of renewable energy technologies decline, considers the theoretical background and how this can be implemented in modeling. Two scenarios are modelled, assuming 27% and 50% of renewable electricity by 2050, respectively. The results show a dramatic shift in the mitigation costs. In the less ambitious scenario, instead of imposing a cost of Rand 52/t CO{sub 2}-eq (at 10% discount rate), reduced costs due to technology learning turn renewables into negative cost option. Our results show that technology learning flips the costs, saving R143. At higher penetration rate, the incremental costs added beyond the base case decline from R92 per ton to R3. Including assumptions about technology learning turns renewable from a higher-cost mitigation option to one close to zero. We conclude that a future world in which global investment in renewables drives down unit costs makes it a much more cost-effective and sustainable mitigation option in South Africa. (author)

Scenarios for backing out of nuclear power

International Nuclear Information System (INIS)

Schefold, B.; Heeren, R.; Hege, U.

1987-01-01

The study takes as a basis the investigations published by an Enquete Commission of the Federal German Bundestag, on 'Future atomic energy policy', and a BMFT project on 'The social compatibility of various energy systems in the development of the industrialized society', carried out by the Vereinigung Deutscher Wissenschaftler. As it has become clear by now that the strategy of pushing forward the breeder reactor technology has lost support, the authors of the study thought that it is opportune to actualize the comparison of the strategy of continued utilisation of nuclear energy by means of light-water type nuclear power plant, and the strategy relying on rational energy utilisation and renewable energy sources. In contrast to sometimes short-sighted 'backing-out scenarios' that consider only the electricity sector, the study in hand also takes into account broader economic and social connections. It demonstrates the feasibility of a cost-efficient, environmentally acceptible and socially compatible energy supply system without nuclear energy, but also defines the necessary decisions energy policy must supply - also and especially those that foster the principles of the free market economy. (orig./UA) [de

The Colonial Pygmalion: Unsettling Dinesen in Out of Africa

Directory of Open Access Journals (Sweden)

Irlam, Shaun

2015-12-01

Full Text Available This paper explores the atavistic and feudal historical fantasies that structure Isak Dinesen’s 1937 memoir, Out of Africa. It analyses the imagery and symbolic logic of the memoir in conjunction with Dinesen’s letters from Africa in order to examine how Dinesen derives an idiom to speak of Africa that synthesizes the social structures of European feudalism, the discourse of the noble savage and the aesthetics of the sublime. The paper seeks to unpack the conundrum that fashions a modern, emancipated female subjectivity from the anachronistic paradigm of feudalism and within the framework of imperial domination and colonial occupation. The paper explores how Dinesen’s feudal idiom extends the genre of European pastoral to the colonial milieu and places it in the service of a larger search for a discourse of legitimacy. I argue that this is an abiding preoccupation of colonial literature. I analyze in detail the specular logic through which the narrator confronts Africa as a space that alternately panders to or challenges the psycho-political narcissism of the settler. Dinesen’s memoir reveals the myriad operations of the narcissistic structure through which the narrator strives to fill the copula of the question, “What is Africa to you or you to Africa?”Este trabajo explora las fantasías históricas de carácter atávico y feudal que vertebran las memorias de Isak Dinesen en Out of Africa (1937. Explora el imaginario y la lógica del simbolismo en las memorias junto con las cartas escritas por Dinesen desde África para analizar cómo Dinesen construyó todo un lenguaje para hablar de África que sintetiza las estructuras sociales del feudalismo europeo, el discurso del buen salvaje y la estética de lo sublime. El trabajo intenta explicar la manera rebuscada por medio de la cual se construye la subjetividad de la mujer moderna y emancipada desde el paradigma anacrónico del feudalismo y dentro del marco de la dominación imperial y

Enrolling adolescents in HIV vaccine trials: reflections on legal complexities from South Africa.

Science.gov (United States)

Slack, Catherine; Strode, Ann; Fleischer, Theodore; Gray, Glenda; Ranchod, Chitra

2007-05-13

South Africa is likely to be the first country in the world to host an adolescent HIV vaccine trial. Adolescents may be enrolled in late 2007. In the development and review of adolescent HIV vaccine trial protocols there are many complexities to consider, and much work to be done if these important trials are to become a reality. This article sets out essential requirements for the lawful conduct of adolescent research in South Africa including compliance with consent requirements, child protection laws, and processes for the ethical and regulatory approval of research. This article outlines likely complexities for researchers and research ethics committees, including determining that trial interventions meet current risk standards for child research. Explicit recommendations are made for role-players in other jurisdictions who may also be planning such trials. This article concludes with concrete steps for implementing these important trials in South Africa and other jurisdictions, including planning for consent processes; delineating privacy rights; compiling information necessary for ethics committees to assess risks to child participants; training trial site staff to recognize when disclosures trig mandatory reporting response; networking among relevant ethics committees; and lobbying the National Regulatory Authority for guidance.

Genetic diversity and distribution of Senegalia senegal (L.) Britton under climate change scenarios in West Africa

Science.gov (United States)

Duque-Lazo, Joaquín; Durka, Walter; Hauenschild, Frank; Schnitzler, Jan; Michalak, Ingo; Ogundipe, Oluwatoyin Temitayo; Muellner-Riehl, Alexandra Nora

2018-01-01

Climate change is predicted to impact species’ genetic diversity and distribution. We used Senegalia senegal (L.) Britton, an economically important species distributed in the Sudano-Sahelian savannah belt of West Africa, to investigate the impact of climate change on intraspecific genetic diversity and distribution. We used ten nuclear and two plastid microsatellite markers to assess genetic variation, population structure and differentiation across thirteen sites in West Africa. We projected suitable range, and potential impact of climate change on genetic diversity using a maximum entropy approach, under four different climate change scenarios. We found higher genetic and haplotype diversity at both nuclear and plastid markers than previously reported. Genetic differentiation was strong for chloroplast and moderate for the nuclear genome. Both genomes indicated three spatially structured genetic groups. The distribution of Senegalia senegal is strongly correlated with extractable nitrogen, coarse fragments, soil organic carbon stock, precipitation of warmest and coldest quarter and mean temperature of driest quarter. We predicted 40.96 to 6.34 per cent of the current distribution to favourably support the species’ ecological requirements under future climate scenarios. Our results suggest that climate change is going to affect the population genetic structure of Senegalia senegal, and that patterns of genetic diversity are going to influence the species’ adaptive response to climate change. Our study contributes to the growing evidence predicting the loss of economically relevant plants in West Africa in the next decades due to climate change. PMID:29659603

Coming-Out Confessions: Negotiating the Burden of Lesbian Identity Politics in South Africa.

Science.gov (United States)

Kotze, Ella; Bowman, Brett

2018-01-01

For lesbians, "coming out" or disclosing one's sexual orientation has come to be seen as a marker of self-acceptance, actualization, and the imperative first step in the authentication of a liberated subjectivity and social identity. However, other critical schools of thought, largely informed by Foucault's middle writings, have argued that "coming out" is merely a confessional response to an incitement to discourse about sex. This study explored constructions of coming out by a group of self-identified lesbians in South Africa. Data were collected via eight semistructured interviews and subjected to discourse analysis. Although the coming-out stories appear to conform to some discursive practices characterizing confessional modes of response to incitements to speak, they are also de-emphasized as central to the constitution of selfhood. The changing conditions of possibility for the production of sexual subjectivity in contemporary South Africa seem to disrupt understandings of coming out as either solely a confessional or liberatory practice.

South Africa's greenhouse gas emissions under business-as-usual: The technical basis of 'Growth without Constraints' in the Long-Term Mitigation Scenarios

International Nuclear Information System (INIS)

Winkler, Harald; Hughes, Alison; Marquard, Andrew; Haw, Mary; Merven, Bruno

2011-01-01

This article describes the methodology for projecting business-as-usual GHG trajectory developed in technical work for South Africa's Long-Term Mitigation Scenarios (LTMSs), in particular the 'Growth without Constraints' (GWCs) scenario. Technically rigorous projections are important as developing countries define their commitment to act on mitigation relative to business-as-usual (BAU). The key drivers for the GWC scenario include GDP (both growth rate and composition), population, discount rate and technological change. GDP emerged as an important driver in the research for LTMS and further analysis. If South Africa's economy grows without constraints over the next few decades, GHG emissions will continue to escalate, multiplying more than four-fold by mid-century. There is little gain in energy efficiency, and emissions continue to be dominated by energy use and supply, the latter remaining coal-based in GWC. We analyse the projections (not predictions) in relation to various measures. The LTMS GWC scenario is compared to other projections, nationally and internationally. A broadly comparable projection is being used at national level, for electricity planning. When compared to projections from international models, we find that the assumptions about GDP growth rates are a key factor, and suggest that comparisons of global data-sets against national analyses is important. - Highlights: → Specifies business-as-usual GHG trajectory for South Africa's Long-Term Mitigation Scenarios. → Provides details on methodology, drivers of emissions and key parameters. → In a scenario of Growth without Constraints, emissions would quadruple by 2050. → Analysis of resulting emission projection, not a prediction. → Compares projections from other national and international models.

Economic Impact Analyses of Interdisciplinary Multi-hazard Scenarios: ShakeOut and ARkStorm

Science.gov (United States)

Wein, A. M.; Rose, A.; Sue Wing, I.; Wei, D.

2011-12-01

U. S. Geological Survey (USGS) scientists are using an interdisciplinary strategy to develop and analyze multi-hazard scenarios to help communities enhance resilience to natural hazard disasters. Two such scenarios are the southern California ShakeOut earthquake and the California ARkStorm winter storm. Both scenarios are multi-hazard: Shakeout ground motions trigger landslides and liquefaction and ARkStorm involves wind, flood, landslide, and coastal hazards. A collaborative scenario-process engages partners and stakeholders throughout the development and use of the scenarios, In doing so, community resilience is enhanced by educating communities about hazards and hazard interdependencies, building networks from scientists to decision makers, exercising emergency management strategies, identifying emergency management issues, and motivating solutions prior to an event. In addition, interdisciplinary scenarios stimulate research on the various steps of analysis (e.g., natural hazard processes, physical damages, societal consequences, and policy connections). In particular, USGS scientists have collaborated with economists to advance methods to estimate the economic impacts (business interruption losses) of disasters. Our economic impact analyses evolved from the economic module in the Federal Emergency Management Agency's loss-estimation tool, HAZUS-MH, to a more encompassing input-output analysis for ShakeOut, to a more sophisticated Computable General Equilibrium model for ARkStorm. The analyses depend on physical damage and restoration time estimates from engineers and geographic analyses of economic assets in hazard zones. Economic resilience strategies are incorporated to represent resourcefulness and ingenuity that avoids potential losses during and after an event. Such strategies operate at three levels of the economy: micro (e.g., ability to catch up on lost production time), meso (e.g., coordination within a sector to share resources), and macro (e

Out-of-Africa migration and Neolithic coexpansion of Mycobacterium tuberculosis with modern humans.

Science.gov (United States)

Comas, Iñaki; Coscolla, Mireia; Luo, Tao; Borrell, Sonia; Holt, Kathryn E; Kato-Maeda, Midori; Parkhill, Julian; Malla, Bijaya; Berg, Stefan; Thwaites, Guy; Yeboah-Manu, Dorothy; Bothamley, Graham; Mei, Jian; Wei, Lanhai; Bentley, Stephen; Harris, Simon R; Niemann, Stefan; Diel, Roland; Aseffa, Abraham; Gao, Qian; Young, Douglas; Gagneux, Sebastien

2013-10-01

Tuberculosis caused 20% of all human deaths in the Western world between the seventeenth and nineteenth centuries and remains a cause of high mortality in developing countries. In analogy to other crowd diseases, the origin of human tuberculosis has been associated with the Neolithic Demographic Transition, but recent studies point to a much earlier origin. We analyzed the whole genomes of 259 M. tuberculosis complex (MTBC) strains and used this data set to characterize global diversity and to reconstruct the evolutionary history of this pathogen. Coalescent analyses indicate that MTBC emerged about 70,000 years ago, accompanied migrations of anatomically modern humans out of Africa and expanded as a consequence of increases in human population density during the Neolithic period. This long coevolutionary history is consistent with MTBC displaying characteristics indicative of adaptation to both low and high host densities.

Risk Analysis for Road Tunnels – A Metamodel to Efficiently Integrate Complex Fire Scenarios

DEFF Research Database (Denmark)

Berchtold, Florian; Knaust, Christian; Arnold, Lukas

2018-01-01

Fires in road tunnels constitute complex scenarios with interactions between the fire, tunnel users and safety measures. More and more methodologies for risk analysis quantify the consequences of these scenarios with complex models. Examples for complex models are the computational fluid dynamics...... complex scenarios in risk analysis. To face this challenge, we improved the metamodel used in the methodology for risk analysis presented on ISTSS 2016. In general, a metamodel quickly interpolates the consequences of few scenarios simulated with the complex models to a large number of arbitrary scenarios...... used in risk analysis. Now, our metamodel consists of the projection array-based design, the moving least squares method, and the prediction interval to quantify the metamodel uncertainty. Additionally, we adapted the projection array-based design in two ways: the focus of the sequential refinement...

Determining ancestry proportions in complex admixture scenarios in South Africa using a novel proxy ancestry selection method.

Directory of Open Access Journals (Sweden)

Emile R Chimusa

Full Text Available Admixed populations can make an important contribution to the discovery of disease susceptibility genes if the parental populations exhibit substantial variation in susceptibility. Admixture mapping has been used successfully, but is not designed to cope with populations that have more than two or three ancestral populations. The inference of admixture proportions and local ancestry and the imputation of missing genotypes in admixed populations are crucial in both understanding variation in disease and identifying novel disease loci. These inferences make use of reference populations, and accuracy depends on the choice of ancestral populations. Using an insufficient or inaccurate ancestral panel can result in erroneously inferred ancestry and affect the detection power of GWAS and meta-analysis when using imputation. Current algorithms are inadequate for multi-way admixed populations. To address these challenges we developed PROXYANC, an approach to select the best proxy ancestral populations. From the simulation of a multi-way admixed population we demonstrate the capability and accuracy of PROXYANC and illustrate the importance of the choice of ancestry in both estimating admixture proportions and imputing missing genotypes. We applied this approach to a complex, uniquely admixed South African population. Using genome-wide SNP data from over 764 individuals, we accurately estimate the genetic contributions from the best ancestral populations: isiXhosa [Formula: see text], ‡Khomani SAN [Formula: see text], European [Formula: see text], Indian [Formula: see text], and Chinese [Formula: see text]. We also demonstrate that the ancestral allele frequency differences correlate with increased linkage disequilibrium in the South African population, which originates from admixture events rather than population bottlenecks.The collective term for people of mixed ancestry in southern Africa is "Coloured," and this is officially recognized in South

Innovative TRU Burners and Fuel Cycles Options for Phase-Out and Regional Scenarios

International Nuclear Information System (INIS)

Vezzoni, B.; Gabrielli, F.; Rineiski, A.; Schwenk-Ferrero, A.; Andriolo, L.; Maschek, W.

2015-01-01

Partitioning and transmutation (P and T) technologies may be considered either for minor actinides (MAs) inventory stabilisation (typical for on-going/regional scenarios) or for a drastic reduction of the transuranics inventory (as in phasing-out scenarios). In this paper, two sodium-cooled fast reactor cores, based on the French ASTRID design and characterised by different amounts of MAs in the fuel, are proposed. Attention focuses on the safety and on the burning performances of the systems. The behaviour of the systems under dynamic conditions has been investigated considering phasing-out and on-going fuel cycle scenarios. The results demonstrate the flexibility of such systems when employed in different kinds of fuel cycles. The impact of different parameters, such as the initial isotopic vector (and Cm content) and the cooling time before reprocessing, on the simulation results is investigated as well. (authors)

Italian energy scenarios: Markal model

International Nuclear Information System (INIS)

Gracceva, Francesco

2005-01-01

Energy scenarios carried out through formal models comply with scientific criteria such as internal coherence and transparency. Besides, Markal methodology allows a good understanding of the complex nature of the energy system. The business-as-usual scenario carried out through the Markal-Italy model shows that structural changes occurring in end-use sectors will continue to drive up energy consumption, in spite of the slow economic growth and the quite high energy prices [it

Management of actinide waste inventories in nuclear phase-out scenarios

International Nuclear Information System (INIS)

Cometto, M.; Wydler, P.; Chawla, R.

2008-01-01

The improvement of the 'radiological cleanliness' of nuclear energy is a primary goal in the development of advanced reactors and fuel cycles. The multiple recycling of actinides in advanced nuclear systems with fast neutron spectra represents a key option for reducing the potential hazard from high-level waste, especially when the fuel cycle is fully closed. Such strategies, however, involve large inventories of radiotoxic, transuranic (TRU) nuclides in the nuclear park, both in-pile and out-of-pile. The management of these inventories with the help of actinide burners is likely to become an important issue, if nuclear energy systems are eventually phased out, i.e. replaced by other types of energy systems. The present paper compares phase-out scenarios for two transmutation strategies involving fast reactors (FRs) and accelerator-driven systems (ADSs), respectively, operating in symbiosis with conventional light water reactors (LWRs). Particular objectives are to evaluate and compare the TRU reduction performance of the systems as a function of the phase-out time and to determine the appropriate phase-out length for different phase-out criteria. In this connection, an interesting aspect concerns the continuous optimisation of the fuel cycle to counterbalance the reactivity decrease due to the depletion of the fissile isotopes in the fuel. It will be shown that both FRs and ADSs can achieve the goal, provided that the phase-out operation can be continued for about a hundred years

Out of Africa: modern human origins special feature: human origins: out of Africa.

Science.gov (United States)

Tattersall, Ian

2009-09-22

Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200-150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was "discovered" via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent.

Subgenotype A1 of HBV--tracing human migrations in and out of Africa.

Science.gov (United States)

Kramvis, Anna; Paraskevis, Dimitrios

2013-01-01

HBV subgenotype A1 is the dominant genotype A strain in Africa, with molecular characteristics differentiating it from A2, which prevails elsewhere. Outside Africa, A1 is confined to areas with migration history from Africa, including India and Latin America. The aim of this study was to reconstruct A1 phylogeny on a spatial scale in order to determine whether A1 can be used to track human migrations. A phylogenetic comparison of A1 was established using neighbour-joining analysis of complete genomes, and the Bayesian method, implemented in BEAST, was performed on the S region of isolates from 22 countries. Migration events were estimated by ancestral state reconstruction using the criterion of parsimony. From the tree reconstruction, nucleotide divergence calculations and migration analysis, it was evident that Africa was the source of dispersal of A1 globally, and its dispersal to Asia and Latin America occurred at a similar time period. Strains from South Africa were the most divergent, clustering in both the African and Asian/American clades and a South African subclade was the origin of A1. The effect of the 9th to 19th century trade and slave routes on the dispersal of A1 was evident and certain unexpected findings, such as the co-clustering of Somalian and Latin American strains, and the dispersal of A1 from India to Haiti, correlated with historical evidence. Phylogeographic analyses of subgenotype A1 can be used to trace human migrations in and out of Africa and the plausible sites of origin and migration routes are presented.

South Africa's greenhouse gas emissions under business-as-usual: The technical basis of 'Growth without Constraints' in the Long-Term Mitigation Scenarios

Energy Technology Data Exchange (ETDEWEB)

Winkler, Harald, E-mail: Harald.WInkler@uct.ac.za [University of Cape Town, Energy Research Centre, Upper Campus, Rondebosch, W Cape 7701 (South Africa); Hughes, Alison; Marquard, Andrew [University of Cape Town, Energy Research Centre, Upper Campus, Rondebosch, W Cape 7701 (South Africa); Haw, Mary [PJCarew Consulting, 103 Hout Street, Cape Town 8001 (South Africa); Merven, Bruno [University of Cape Town, Energy Research Centre, Upper Campus, Rondebosch, W Cape 7701 (South Africa)

2011-10-15

This article describes the methodology for projecting business-as-usual GHG trajectory developed in technical work for South Africa's Long-Term Mitigation Scenarios (LTMSs), in particular the 'Growth without Constraints' (GWCs) scenario. Technically rigorous projections are important as developing countries define their commitment to act on mitigation relative to business-as-usual (BAU). The key drivers for the GWC scenario include GDP (both growth rate and composition), population, discount rate and technological change. GDP emerged as an important driver in the research for LTMS and further analysis. If South Africa's economy grows without constraints over the next few decades, GHG emissions will continue to escalate, multiplying more than four-fold by mid-century. There is little gain in energy efficiency, and emissions continue to be dominated by energy use and supply, the latter remaining coal-based in GWC. We analyse the projections (not predictions) in relation to various measures. The LTMS GWC scenario is compared to other projections, nationally and internationally. A broadly comparable projection is being used at national level, for electricity planning. When compared to projections from international models, we find that the assumptions about GDP growth rates are a key factor, and suggest that comparisons of global data-sets against national analyses is important. - Highlights: > Specifies business-as-usual GHG trajectory for South Africa's Long-Term Mitigation Scenarios. > Provides details on methodology, drivers of emissions and key parameters. > In a scenario of Growth without Constraints, emissions would quadruple by 2050. > Analysis of resulting emission projection, not a prediction. > Compares projections from other national and international models.

U-Pb geochronology documents out-of-sequence emplacement of ultramafic layers in the Bushveld Igneous Complex of South Africa.

Science.gov (United States)

Mungall, James E; Kamo, Sandra L; McQuade, Stewart

2016-11-14

Layered intrusions represent part of the plumbing systems that deliver vast quantities of magma through the Earth's crust during the formation of large igneous provinces, which disrupt global ecosystems and host most of the Earth's endowment of Pt, Ni and Cr deposits. The Rustenburg Layered Suite of the enormous Bushveld Igneous Complex of South Africa has been presumed to have formed by deposition of crystals at the floor of a subterranean sea of magma several km deep and hundreds of km wide called a magma chamber. Here we show, using U-Pb isotopic dating of zircon and baddeleyite, that individual chromitite layers of the Rustenburg Layered Suite formed within a stack of discrete sheet-like intrusions emplaced and solidified as separate bodies beneath older layers. Our U-Pb ages and modelling necessitate reassessment of the genesis of layered intrusions and their ore deposits, and challenge even the venerable concept of the magma chamber itself.

The Expansion of mtDNA Haplogroup L3 within and out of Africa

Czech Academy of Sciences Publication Activity Database

Soares, P.; Alshamali, F.; Pereira, J. B.; Fernandes, V.; Silva, N. M.; Afonso, C.; Costa, M. D.; Musilová, E.; Macaulay, V.; Richards, M. B.; Černý, Viktor; Pereira, L.

2012-01-01

Roč. 29, č. 3 (2012), s. 915-927 ISSN 0737-4038 R&D Projects: GA MŠk ME 917 Institutional research plan: CEZ:AV0Z80020508 Keywords : mtDNA * complete genomes * haplogroup L3 * out of Africa * modern human expansions Sub ject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 10.353, year: 2012

Scenarios for energy forecasting: papers of the symposium

International Nuclear Information System (INIS)

1987-01-01

Energy planning is important for every developed country and therefore also for South Africa. However, during 1984 it was felt by interested parties that the work in this field should be coordinated through mutual discussion. With this in mind a 'Task Team for Energy Forecasting' was formed with the task to generate acceptable forecasts of the energy set-up in South Africa. Knowledge of the relationship between energy and variables such as the economy and the population is necessary to the Task Team. However, the Task Team also needs some insight into the future paths of such variables if it has to generate energy forecasts. It is the purpose of this symposium to improve this insight through having experts in all relevant fields to set out and develop their possible future scenarios independently of energy forecasting

Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate

Science.gov (United States)

Beyin, Amanuel

2011-01-01

Although there is a general consensus on African origin of early modern humans, there is disagreement about how and when they dispersed to Eurasia. This paper reviews genetic and Middle Stone Age/Middle Paleolithic archaeological literature from northeast Africa, Arabia, and the Levant to assess the timing and geographic backgrounds of Upper Pleistocene human colonization of Eurasia. At the center of the discussion lies the question of whether eastern Africa alone was the source of Upper Pleistocene human dispersals into Eurasia or were there other loci of human expansions outside of Africa? The reviewed literature hints at two modes of early modern human colonization of Eurasia in the Upper Pleistocene: (i) from multiple Homo sapiens source populations that had entered Arabia, South Asia, and the Levant prior to and soon after the onset of the Last Interglacial (MIS-5), (ii) from a rapid dispersal out of East Africa via the Southern Route (across the Red Sea basin), dating to ~74–60 kya. PMID:21716744

Human origins: Out of Africa

Science.gov (United States)

Tattersall, Ian

2009-01-01

Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent. PMID:19805256

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.

The success of failed Homo sapiens dispersals out of Africa and into Asia.

Science.gov (United States)

Rabett, Ryan J

2018-02-01

The evidence for an early dispersal of Homo sapiens from Africa into the Levant during Marine Isotope Stage 5 (MIS-5) 126-74 ka (thousand years ago) was characterized for many years as an 'abortive' expansion: a precursor to a sustained dispersal from which all extant human populations can be traced. Recent archaeological and genetic data from both western and eastern parts of Eurasia and from Australia are starting to challenge that interpretation. This Perspective reviews the current evidence for a scenario where the MIS-5 dispersal encompassed a much greater geographic distribution and temporal duration. The implications of this for tracking and understanding early human dispersal in Southeast Asia specifically are considered, and the validity of measuring dispersal success only through genetic continuity into the present is examined.

Management of disasters and complex emergencies in Africa: The challenges and constraints.

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Aliyu, Alhaji

2015-01-01

Natural and man-made catastrophes have caused significant destruction and loss of lives throughout human history. Disasters accompany a wide variety of events with multiple causes and consequences often leading to a cascade of related events. African continent has not been spared of these events. A new phenomenon in the continent is terrorism that is fuelled by globalization of arms trade and has contributed significantly to escalation of conflicts in sub-Saharan Africa (SSA) resulting in complex emergencies and destruction of socioeconomic structures. The aim of this paper is to review relevant papers on management of disasters and complex emergencies in Africa and the challenges and constraints against the background of a weakened health system. Systematic search of published literature was conducted between 1990 and 2013. Grey literature (technical reports, government documents), published peer review journals, abstracts, relevant books and internet articles were reviewed. The review revealed that the frequency of both natural and man-made disasters in Africa is escalating. Complex emergencies are also on the increase since the Rwandan crisis in 1994. The impact of these events has overstretched and overwhelmed the health care system that is least prepared to handle and cope with the surge capacity and also render normal services. In conclusion, there is an urgent need for national emergency agencies/departments across Africa to develop a robust emergency preparedness and response plan. Every hospital most have a disaster management committee with flexible disaster management plan to respond to these catastrophes. There is a need for curriculum review in tertiary institutions across SSA to introduce and or expand training in disaster management.

Integrating out resonances in strongly-coupled electroweak scenarios

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Rosell Ignasi

2017-01-01

Full Text Available Accepting that there is a mass gap above the electroweak scale, the Electroweak Effective Theory (EWET is an appropriate tool to describe this situation. Since the EWET couplings contain information on the unknown high-energy dynamics, we consider a generic strongly-coupled scenario of electroweak symmetry breaking, where the known particle fields are coupled to heavier states. Then, and by integrating out these heavy fields, we study the tracks of the lightest resonances into the couplings. The determination of the low-energy couplings (LECs in terms of resonance parameters can be made more precise by considering a proper short-distance behaviour on the Lagrangian with heavy states, since the number of resonance couplings is then reduced. Notice that we adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs.

Assessment of future agricultural conditions in southwestern Africa using fuzzy logic and high-resolution climate model scenarios

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Weinzierl, Thomas

2015-12-01

Full Text Available Climate change is expected to have a major impact on the arid savanna regions of southwestern Africa, such as the Okavango Basin. Precipitation is a major constraint for agriculture in countries like Namibia and Botswana and assessments of future crop growth conditions are in high demand. This GIS-based approach uses reanalysis data and climate model output for two scenarios and compares them to the precipitation requirements of the five most important crops grown in the region: maize, pearl millet, sorghum, cassava and cow pea. It also takes into account the dominant soil types, as plant growth is also limited by nutrient-poor soils with unfavorable physical and chemical properties. The two factors are then combined using a fuzzy logic algorithm. The assessment visualizes the expected shifts in suitable zones and identifies areas where farming without irrigation may experience a decline in yields or may even no longer be possible at the end of the 21st century. The results show that pearl millet is the most suitable crop in all scenarios while especially the cultivation of maize, sorghum and cow pea may be affected by a possible reduction of precipitation under the high-emission scenario.

Complex accident scenarios modelled and analysed by Stochastic Petri Nets

International Nuclear Information System (INIS)

Nývlt, Ondřej; Haugen, Stein; Ferkl, Lukáš

2015-01-01

This paper is focused on the usage of Petri nets for an effective modelling and simulation of complicated accident scenarios, where an order of events can vary and some events may occur anywhere in an event chain. These cases are hardly manageable by traditional methods as event trees – e.g. one pivotal event must be often inserted several times into one branch of the tree. Our approach is based on Stochastic Petri Nets with Predicates and Assertions and on an idea, which comes from the area of Programmable Logic Controllers: an accidental scenario is described as a net of interconnected blocks, which represent parts of the scenario. So the scenario is firstly divided into parts, which are then modelled by Petri nets. Every block can be easily interconnected with other blocks by input/output variables to create complex ones. In the presented approach, every event or a part of a scenario is modelled only once, independently on a number of its occurrences in the scenario. The final model is much more transparent then the corresponding event tree. The method is shown in two case studies, where the advanced one contains a dynamic behavior. - Highlights: • Event & Fault trees have problems with scenarios where an order of events can vary. • Paper presents a method for modelling and analysis of dynamic accident scenarios. • The presented method is based on Petri nets. • The proposed method solves mentioned problems of traditional approaches. • The method is shown in two case studies: simple and advanced (with dynamic behavior)

Economywide impacts of climate change on agriculture in Sub-Saharan Africa

NARCIS (Netherlands)

Calzadilla, Alvaro; Zhu, Tingju; Rehdanz, Katrin; Tol, Richard S J; Ringler, Claudia

2013-01-01

Two possible adaptation scenarios to climate change for Sub-Saharan Africa are analyzed under the SRES B2 scenario. The first scenario doubles the irrigated area in Sub-Saharan Africa by 2050, compared to the baseline, but keeps total crop area constant. The second scenario increases both rainfed

"Congo" red: out of Africa?

Science.gov (United States)

Steensma, D P

2001-02-01

Congo red is the essential histologic stain for demonstrating the presence of amyloidosis in fixed tissues. To the best of my knowledge, nothing has been written about why the stain is named "Congo." To understand the etymology and history of the Congo red histologic stain. Primary sources were consulted extensively, including 19th-century corporate documents, newspapers, legal briefs, patents, memoirs, and scientific papers. Sources were obtained from multiple university libraries and German corporate archives. To Europeans in 1885, the word Congo evoked exotic images of far-off central Africa known as The Dark Continent. The African Congo was also a political flashpoint during the Age of Colonialism. "Congo" red was introduced in Berlin in 1885 as the first of the economically lucrative direct textile dyes. A patent on Congo red was filed by the AGFA Corporation of Berlin 3 weeks after the conclusion of the well-publicized Berlin West Africa Conference. During these important diplomatic talks, German Chancellor Otto von Bismarck presided over a discussion of free trade issues in the Congo River basin. A challenge to AGFA's Congo red patent led to a precedent-setting decision in intellectual property law. The Congo red stain was named "Congo" for marketing purposes by a German textile dyestuff company in 1885, reflecting geopolitical current events of that time.

Genomic and cranial phenotype data support multiple modern human dispersals from Africa and a southern route into Asia.

Science.gov (United States)

Reyes-Centeno, Hugo; Ghirotto, Silvia; Détroit, Florent; Grimaud-Hervé, Dominique; Barbujani, Guido; Harvati, Katerina

2014-05-20

Despite broad consensus on Africa as the main place of origin for anatomically modern humans, their dispersal pattern out of the continent continues to be intensely debated. In extant human populations, the observation of decreasing genetic and phenotypic diversity at increasing distances from sub-Saharan Africa has been interpreted as evidence for a single dispersal, accompanied by a series of founder effects. In such a scenario, modern human genetic and phenotypic variation was primarily generated through successive population bottlenecks and drift during a rapid worldwide expansion out of Africa in the Late Pleistocene. However, recent genetic studies, as well as accumulating archaeological and paleoanthropological evidence, challenge this parsimonious model. They suggest instead a "southern route" dispersal into Asia as early as the late Middle Pleistocene, followed by a separate dispersal into northern Eurasia. Here we test these competing out-of-Africa scenarios by modeling hypothetical geographical migration routes and assessing their correlation with neutral population differentiation, as measured by genetic polymorphisms and cranial shape variables of modern human populations from Africa and Asia. We show that both lines of evidence support a multiple-dispersals model in which Australo-Melanesian populations are relatively isolated descendants of an early dispersal, whereas other Asian populations are descended from, or highly admixed with, members of a subsequent migration event.

The Global Phylogeography of Lyssaviruses - Challenging the 'Out of Africa' Hypothesis.

Directory of Open Access Journals (Sweden)

David T S Hayman

2016-12-01

Full Text Available Rabies virus kills tens of thousands of people globally each year, especially in resource-limited countries. Yet, there are genetically- and antigenically-related lyssaviruses, all capable of causing the disease rabies, circulating globally among bats without causing conspicuous disease outbreaks. The species richness and greater genetic diversity of African lyssaviruses, along with the lack of antibody cross-reactivity among them, has led to the hypothesis that Africa is the origin of lyssaviruses. This hypothesis was tested using a probabilistic phylogeographical approach. The nucleoprotein gene sequences from 153 representatives of 16 lyssavirus species, collected between 1956 and 2015, were used to develop a phylogenetic tree which incorporated relevant geographic and temporal data relating to the viruses. In addition, complete genome sequences from all 16 (putative species were analysed. The most probable ancestral distribution for the internal nodes was inferred using three different approaches and was confirmed by analysis of complete genomes. These results support a Palearctic origin for lyssaviruses (posterior probability = 0.85, challenging the 'out of Africa' hypothesis, and suggest three independent transmission events to the Afrotropical region, representing the three phylogroups that form the three major lyssavirus clades.

Oblique Photogrammetry Supporting 3d Urban Reconstruction of Complex Scenarios

Science.gov (United States)

Toschi, I.; Ramos, M. M.; Nocerino, E.; Menna, F.; Remondino, F.; Moe, K.; Poli, D.; Legat, K.; Fassi, F.

2017-05-01

Accurate 3D city models represent an important source of geospatial information to support various "smart city" applications, such as space management, energy assessment, 3D cartography, noise and pollution mapping as well as disaster management. Even though remarkable progress has been made in recent years, there are still many open issues, especially when it comes to the 3D modelling of complex urban scenarios like historical and densely-built city centres featuring narrow streets and non-conventional building shapes. Most approaches introduce strong building priors/constraints on symmetry and roof typology that penalize urban environments having high variations of roof shapes. Furthermore, although oblique photogrammetry is rapidly maturing, the use of slanted views for façade reconstruction is not completely included in the reconstruction pipeline of state-of-the-art software. This paper aims to investigate state-of-the-art methods for 3D building modelling in complex urban scenarios with the support of oblique airborne images. A reconstruction approach based on roof primitives fitting is tested. Oblique imagery is then exploited to support the manual editing of the generated building models. At the same time, mobile mapping data are collected at cm resolution and then integrated with the aerial ones. All approaches are tested on the historical city centre of Bergamo (Italy).

Nonlinear finite element analysis of liquid sloshing in complex vehicle motion scenarios

Science.gov (United States)

Nicolsen, Brynne; Wang, Liang; Shabana, Ahmed

2017-09-01

The objective of this investigation is to develop a new total Lagrangian continuum-based liquid sloshing model that can be systematically integrated with multibody system (MBS) algorithms in order to allow for studying complex motion scenarios. The new approach allows for accurately capturing the effect of the sloshing forces during curve negotiation, rapid lane change, and accelerating and braking scenarios. In these motion scenarios, the liquid experiences large displacements and significant changes in shape that can be captured effectively using the finite element (FE) absolute nodal coordinate formulation (ANCF). ANCF elements are used in this investigation to describe complex mesh geometries, to capture the change in inertia due to the change in the fluid shape, and to accurately calculate the centrifugal forces, which for flexible bodies do not take the simple form used in rigid body dynamics. A penalty formulation is used to define the contact between the rigid tank walls and the fluid. A fully nonlinear MBS truck model that includes a suspension system and Pacejka's brush tire model is developed. Specified motion trajectories are used to examine the vehicle dynamics in three different scenarios - deceleration during straight-line motion, rapid lane change, and curve negotiation. It is demonstrated that the liquid sloshing changes the contact forces between the tires and the ground - increasing the forces on certain wheels and decreasing the forces on other wheels. In cases of extreme sloshing, this dynamic behavior can negatively impact the vehicle stability by increasing the possibility of wheel lift and vehicle rollover.

Rethinking HIV exceptionalism: the ethics of opt-out HIV testing in sub-Saharan Africa.

Science.gov (United States)

April, Michael D

2010-09-01

Opt-out testing for the human immunodeficiency virus (HIV) incorporates testing as a routine part of health care for all patients unless they refuse. The ethics of this approach to testing in sub-Saharan Africa is a source of controversy. Opt-out HIV testing is expected to improve survival by increasing case detection and thus linking more HIV-infected people to earlier treatment, provided there is effective patient follow-up and programme sustainability. At the population level, these benefits will likely outweigh the potential negative consequences of individuals experiencing HIV-related stigma. These justifications appeal to consequentialist moral theories that the acceptability of an action depends upon its outcomes. On the other hand, liberal moral theories state that the autonomy of individuals should always be protected unless restricting autonomy is necessary to protect the welfare of others. Opt-out consent may restrict autonomy and it is unclear whether it would benefit people other than those being tested. Yet, the doctrine of libertarian paternalism proposes that it is justifiable and desirable to use unobtrusive mechanisms to help individuals make choices to maximize their own welfare. Central to this idea are the premises featured by supporters of opt-out consent that individuals will not always make the best choices for their own welfare but they may be influenced to do so in ways that will not compromise their freedom of choice. Also important is the premise that all policies inevitably exert some such influence: opt-in consent encourages test refusal just as opt-out consent encourages acceptance. Based on these premises, opt-out testing may be an effective and ethically acceptable policy response to Africa's HIV epidemic.

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...

Out of Africa, but how and when? The case of hamadryas baboons (Papio hamadryas).

Science.gov (United States)

Kopp, Gisela H; Roos, Christian; Butynski, Thomas M; Wildman, Derek E; Alagaili, Abdulaziz N; Groeneveld, Linn F; Zinner, Dietmar

2014-11-01

Many species of Arabian mammals are considered to be of Afrotropical origin and for most of them the Red Sea has constituted an obstacle for dispersal since the Miocene-Pliocene transition. There are two possible routes, the 'northern' and the 'southern', for terrestrial mammals (including humans) to move between Africa and Arabia. The 'northern route', crossing the Sinai Peninsula, is confirmed for several taxa by an extensive fossil record, especially from northern Egypt and the Levant, whereas the 'southern route', across the Bab-el-Mandab Strait, which links the Red Sea with the Gulf of Aden, is more controversial, although post-Pliocene terrestrial crossings of the Red Sea might have been possible during glacial maxima when sea levels were low. Hamadryas baboons (Papio hamadryas) are the only baboon taxon to disperse out of Africa and still inhabit Arabia. In this study, we investigate the origin of Arabian hamadryas baboons using mitochondrial sequence data from 294 samples collected in Arabia and Northeast Africa. Through the analysis of the geographic distribution of genetic diversity, the timing of population expansions, and divergence time estimates combined with palaeoecological data, we test: (i) if Arabian and African hamadryas baboons are genetically distinct; (ii) if Arabian baboons exhibit population substructure; and (iii) when, and via which route, baboons colonized Arabia. Our results suggest that hamadryas baboons colonized Arabia during the Late Pleistocene (130-12 kya [thousands of years ago]) and also moved back to Africa. We reject the hypothesis that hamadryas baboons were introduced to Arabia by humans, because the initial colonization considerably predates the earliest records of human seafaring in this region. Our results strongly suggest that the 'southern route' from Africa to Arabia could have been used by hamadryas baboons during the same time period as proposed for modern humans. Copyright © 2014 The Authors. Published by Elsevier

Biogeography and climatic change as a context to human dispersal out of Africa and within Eurasia

Science.gov (United States)

van der Made, Jan

2011-06-01

The dispersal of the genus Homo occurred against a background of continuous environmental change. Here, dispersals of large mammals through the Levantine Corridor and into Western Europe and Java are studied and compared to existing records of climatic change and dispersals of early humans and lithic industry. The first human dispersal (with Oldowan lithic industry) out of Africa, around or shortly before 1.8 Ma may have been triggered by biological evolution and increased social organisation, rather than environmental change. After that event, increasing aridity led to decreased faunal exchange between Africa and Eurasia and may have isolated the human populations of Africa and Africa. Southern (Java) and Eastern Asia (China) also seem to have been isolated. Human dispersal into Western Europe may have been limited by closed environments in Central Europe until about 1.2 Ma ago, when faunal dispersal into Europe suggests the cyclic spread of open environments to the west. Acheulean technology originated in Africa, some 1.6-1.5 Ma ago, but its dispersal into Eurasia may have been obstructed by an arid Southwest Asia, until broadly about 0.9 Ma ago, when faunal exchange suggests that the area became temporarily less dry. By 0.6-0.5 Ma ago it reached Europe.

Agriculture in West Africa in the Twenty-First Century: Climate Change and Impacts Scenarios, and Potential for Adaptation

Science.gov (United States)

Sultan, Benjamin; Gaetani, Marco

2016-01-01

West Africa is known to be particularly vulnerable to climate change due to high climate variability, high reliance on rain-fed agriculture, and limited economic and institutional capacity to respond to climate variability and change. In this context, better knowledge of how climate will change in West Africa and how such changes will impact crop productivity is crucial to inform policies that may counteract the adverse effects. This review paper provides a comprehensive overview of climate change impacts on agriculture in West Africa based on the recent scientific literature. West Africa is nowadays experiencing a rapid climate change, characterized by a widespread warming, a recovery of the monsoonal precipitation, and an increase in the occurrence of climate extremes. The observed climate tendencies are also projected to continue in the twenty-first century under moderate and high emission scenarios, although large uncertainties still affect simulations of the future West African climate, especially regarding the summer precipitation. However, despite diverging future projections of the monsoonal rainfall, which is essential for rain-fed agriculture, a robust evidence of yield loss in West Africa emerges. This yield loss is mainly driven by increased mean temperature while potential wetter or drier conditions as well as elevated CO2 concentrations can modulate this effect. Potential for adaptation is illustrated for major crops in West Africa through a selection of studies based on process-based crop models to adjust cropping systems (change in varieties, sowing dates and density, irrigation, fertilizer management) to future climate. Results of the cited studies are crop and region specific and no clear conclusions can be made regarding the most effective adaptation options. Further efforts are needed to improve modeling of the monsoon system and to better quantify the uncertainty in its changes under a warmer climate, in the response of the crops to such

Economic resilience lessons from the ShakeOut earthquake scenario

Science.gov (United States)

Wein, A.; Rose, A.

2011-01-01

Following a damaging earthquake, “business interruption” (BI)—reduced production of goods and services—begins and continues long after the ground shaking stops. Economic resilience reduces BI losses by making the best use of the resources available at a given point in time (static resilience) or by speeding recovery through repair and reconstruction (dynamic resilience), in contrast to mitigation that prevents damage in the first place. Economic resilience is an important concept to incorporate into economic loss modeling and in recovery and contingency planning. Economic resilience framework includes the applicability of resilience strategies to production inputs and output, demand- and supply-side effects, inherent and adaptive abilities, and levels of the economy. We use our resilience framework to organize and share strategies that enhance economic resilience, identify overlooked resilience strategies, and present evidence and structure of resilience strategies for economic loss modelers. Numerous resilience strategies are compiled from stakeholder discussions about the ShakeOut Scenario (Jones et. al. 2008). Modeled results of ShakeOut BI sector losses reveal variable effectiveness of resilience strategies for lengthy disruptions caused by fire-damaged buildings and water service outages. Resilience is a complement to mitigation and may, in fact, have cost and all-hazards advantages.

Design scenarios for renovation of sports complex: a case study

Science.gov (United States)

Nižetić, S.

2018-02-01

This paper elaborates design scenarios for a sports complex in Croatia from a technical and economic aspect. Different energy options are analysed and two are additionally addressed and discussed as the most viable ones. The possibilities of sports complex renovation are shown by properly choosing the appropriate energy concept and thus reducing the overall cost for produced thermal energy by around 33% and reducing the carbon dioxide emission by a factor of 1.8 in comparison with its present state. Finally, this study presents an example of good practice, where renewable energy solutions can be proposed and where it is possible to cover around 70-80% of overall yearly costs from achieved energy savings for the novel plant that is assumed to be financed through a bank loan.

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.

Out of Africa: modern human origins special feature: middle and later Pleistocene hominins in Africa and Southwest Asia.

Science.gov (United States)

Rightmire, G Philip

2009-09-22

Approximately 700,000 years ago, Homo erectus in Africa was giving way to populations with larger brains accompanied by structural adjustments to the vault, cranial base, and face. Such early Middle Pleistocene hominins were not anatomically modern. Their skulls display strong supraorbital tori above projecting faces, flattened frontals, and less parietal expansion than is the case for Homo sapiens. Postcranial remains seem also to have archaic features. Subsequently, some groups evolved advanced skeletal morphology, and by ca. 200,000 years ago, individuals more similar to recent humans are present in the African record. These fossils are associated with Middle Stone Age lithic assemblages and, in some cases, Acheulean tools. Crania from Herto in Ethiopia carry defleshing cutmarks and superficial scoring that may be indicative of mortuary practices. Despite these signs of behavioral innovation, neither the Herto hominins, nor others from Late Pleistocene sites such as Klasies River in southern Africa and Skhūl/Qafzeh in Israel, can be matched in living populations. Skulls are quite robust, and it is only after approximately 35,000 years ago that people with more gracile, fully modern morphology make their appearance. Not surprisingly, many questions concerning this evolutionary history have been raised. Attention has centered on systematics of the mid-Pleistocene hominins, their paleobiology, and the timing of dispersals that spread H. sapiens out of Africa and across the Old World. In this report, I discuss structural changes characterizing the skulls from different time periods, possible regional differences in morphology, and the bearing of this evidence on recognizing distinct species.

Out of Africa: modern human origins special feature: additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa.

Science.gov (United States)

d'Errico, Francesco; Vanhaeren, Marian; Barton, Nick; Bouzouggar, Abdeljalil; Mienis, Henk; Richter, Daniel; Hublin, Jean-Jacques; McPherron, Shannon P; Lozouet, Pierre

2009-09-22

Recent investigations into the origins of symbolism indicate that personal ornaments in the form of perforated marine shell beads were used in the Near East, North Africa, and SubSaharan Africa at least 35 ka earlier than any personal ornaments in Europe. Together with instances of pigment use, engravings, and formal bone tools, personal ornaments are used to support an early emergence of behavioral modernity in Africa, associated with the origin of our species and significantly predating the timing for its dispersal out of Africa. Criticisms have been leveled at the low numbers of recovered shells, the lack of secure dating evidence, and the fact that documented examples were not deliberately shaped. In this paper, we report on 25 additional shell beads from four Moroccan Middle Paleolithic sites. We review their stratigraphic and chronological contexts and address the issue of these shells having been deliberately modified and used. We detail the results of comparative analyses of modern, fossil, and archaeological assemblages and microscopic examinations of the Moroccan material. We conclude that Nassarius shells were consistently used for personal ornamentation in this region at the end of the last interglacial. Absence of ornaments at Middle Paleolithic sites postdating Marine Isotope Stage 5 raises the question of the possible role of climatic changes in the disappearance of this hallmark of symbolic behavior before its reinvention 40 ka ago. Our results suggest that further inquiry is necessary into the mechanisms of cultural transmission within early Homo sapiens populations.

Human evolution out of Africa: the role of refugia and climate change.

Science.gov (United States)

Stewart, J R; Stringer, C B

2012-03-16

Although an African origin of the modern human species is generally accepted, the evolutionary processes involved in the speciation, geographical spread, and eventual extinction of archaic humans outside of Africa are much debated. An additional complexity has been the recent evidence of limited interbreeding between modern humans and the Neandertals and Denisovans. Modern human migrations and interactions began during the buildup to the Last Glacial Maximum, starting about 100,000 years ago. By examining the history of other organisms through glacial cycles, valuable models for evolutionary biogeography can be formulated. According to one such model, the adoption of a new refugium by a subgroup of a species may lead to important evolutionary changes.

Study on partitioning and transmutation as a possible option for spent fuel management within a nuclear phase-out scenario

Energy Technology Data Exchange (ETDEWEB)

Fazion, C.; Rineiski, A.; Salvatores, M.; Schwenk-Ferrero, A.; Romanello, V.; Vezzoni, B.; Gabrielli, F. [Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2013-07-01

Most Partitioning and Transmutation (PT) studies implicitly presuppose the continuous use of nuclear energy. In this case the development of new facilities or the modification of the fuel cycle can be justified in the long-term as an important feature in order to improve sustainability by minimizing radioactive waste and reducing the burden at waste disposal. In the case of a country with nuclear energy phase-out policy, the PT option might have also an important role for what concerns the final disposal strategies of the spent fuel. In this work three selected scenarios are analyzed in order to assess the impact of PT implementation in a nuclear energy phase out option. The scenarios are: -) Scenario 1: Identification of Research/Development activities needs for a technological development of PT while postponing the decision of PT implementation; -) Scenario 2: Isolated application of PT in a phase-out context; and -) Scenario 3: Implementation of PT in a European context. In order to facilitate the discrimination among the 3 scenarios, a number of figures of indicators have been evaluated for each scenario. The selected indicators are: the mass of High Level Waste (HLW), Uranium inventory, thermal output of HLW, Radiotoxicity, Fuel cycle secondary waste associated to the PT operation, and Facility capacity/number requirements. The reduction, due to PT implementation, of high level wastes masses and their associated volumes can be significant. For what concerns the thermal output and radiotoxicity a significant impact can be also expected. However, when assessing these two indicators the contribution coming from already vitrified waste should also not be neglected. Moreover, an increase of secondary waste inventory is also expected. On the contrary, the increase of fission product inventories due to the operation of the transmutation system has a relatively limited impact on the fuel cycle.

Future wind deployment scenarios for South Africa

CSIR Research Space (South Africa)

Wright, Jarrad G

2017-11-01

Full Text Available understood wind (and solar) resource in South Africa combined with large geographical land-area and technology cost reductions globally and domestically for wind and solar photovoltaics (PV) has made these technologies more than competitive with alternatives...

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

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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.

Estimating Client Out-of-Pocket Costs for Accessing Voluntary Medical Male Circumcision in South Africa.

Directory of Open Access Journals (Sweden)

Michel Tchuenche

Full Text Available In 2010, South Africa launched a countrywide effort to scale up its voluntary medical male circumcision (VMMC program on the basis of compelling evidence that circumcision reduces men's risk of acquiring HIV through heterosexual intercourse. Even though VMMC is free there, clients can incur indirect out-of-pocket costs (for example transportation cost or foregone income. Because these costs can be barriers to increasing the uptake of VMMC services, we assessed them from a client perspective, to inform VMMC demand creation policies. Costs (calculated using a bottom-up approach and demographic data were systematically collected through 190 interviews conducted in 2015 with VMMC clients or (for minors their caregivers at 25 VMMC facilities supported by the government and the President's Emergency Plan for AIDS Relief in eight of South Africa's nine provinces. The average age of VMMC clients was 22 years and nearly 92% were under 35 years of age. The largest reported out-of-pocket expenditure was transportation, at an average of US$9.20 (R 100. Only eight clients (4% reported lost days of work. Indirect expenditures were childcare costs (one client and miscellaneous items such as food or medicine (20 clients. Given competing household expense priorities, spending US$9.20 (R100 per person on transportation to access VMMC services could be a significant burden on clients and households, and a barrier to South Africa's efforts to create demand for VMMC. Thus, we recommend a more focused analysis of clients' transportation costs to access VMMC services.

Mitochondrial lineage M1 traces an early human backflow to Africa.

Science.gov (United States)

González, Ana M; Larruga, José M; Abu-Amero, Khaled K; Shi, Yufei; Pestano, José; Cabrera, Vicente M

2007-07-09

The out of Africa hypothesis has gained generalized consensus. However, many specific questions remain unsettled. To know whether the two M and N macrohaplogroups that colonized Eurasia were already present in Africa before the exit is puzzling. It has been proposed that the east African clade M1 supports a single origin of haplogroup M in Africa. To test the validity of that hypothesis, the phylogeographic analysis of 13 complete mitochondrial DNA (mtDNA) sequences and 261 partial sequences belonging to haplogroup M1 was carried out. The coalescence age of the African haplogroup M1 is younger than those for other M Asiatic clades. In contradiction to the hypothesis of an eastern Africa origin for modern human expansions out of Africa, the most ancestral M1 lineages have been found in Northwest Africa and in the Near East, instead of in East Africa. The M1 geographic distribution and the relative ages of its different subclades clearly correlate with those of haplogroup U6, for which an Eurasian ancestor has been demonstrated. This study provides evidence that M1, or its ancestor, had an Asiatic origin. The earliest M1 expansion into Africa occurred in northwestern instead of eastern areas; this early spread reached the Iberian Peninsula even affecting the Basques. The majority of the M1a lineages found outside and inside Africa had a more recent eastern Africa origin. Both western and eastern M1 lineages participated in the Neolithic colonization of the Sahara. The striking parallelism between subclade ages and geographic distribution of M1 and its North African U6 counterpart strongly reinforces this scenario. Finally, a relevant fraction of M1a lineages present today in the European Continent and nearby islands possibly had a Jewish instead of the commonly proposed Arab/Berber maternal ascendance.

Mitochondrial lineage M1 traces an early human backflow to Africa

Directory of Open Access Journals (Sweden)

Pestano José

2007-07-01

Full Text Available Abstract Background The out of Africa hypothesis has gained generalized consensus. However, many specific questions remain unsettled. To know whether the two M and N macrohaplogroups that colonized Eurasia were already present in Africa before the exit is puzzling. It has been proposed that the east African clade M1 supports a single origin of haplogroup M in Africa. To test the validity of that hypothesis, the phylogeographic analysis of 13 complete mitochondrial DNA (mtDNA sequences and 261 partial sequences belonging to haplogroup M1 was carried out. Results The coalescence age of the African haplogroup M1 is younger than those for other M Asiatic clades. In contradiction to the hypothesis of an eastern Africa origin for modern human expansions out of Africa, the most ancestral M1 lineages have been found in Northwest Africa and in the Near East, instead of in East Africa. The M1 geographic distribution and the relative ages of its different subclades clearly correlate with those of haplogroup U6, for which an Eurasian ancestor has been demonstrated. Conclusion This study provides evidence that M1, or its ancestor, had an Asiatic origin. The earliest M1 expansion into Africa occurred in northwestern instead of eastern areas; this early spread reached the Iberian Peninsula even affecting the Basques. The majority of the M1a lineages found outside and inside Africa had a more recent eastern Africa origin. Both western and eastern M1 lineages participated in the Neolithic colonization of the Sahara. The striking parallelism between subclade ages and geographic distribution of M1 and its North African U6 counterpart strongly reinforces this scenario. Finally, a relevant fraction of M1a lineages present today in the European Continent and nearby islands possibly had a Jewish instead of the commonly proposed Arab/Berber maternal ascendance.

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.

A Chargeless Complex Vector Matter Field in Supersymmetric Scenario

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L. P. Colatto

2015-01-01

Full Text Available We construct and study a formulation of a chargeless complex vector matter field in a supersymmetric framework. To this aim we combine two nochiral scalar superfields in order to take the vector component field to build the chargeless complex vector superpartner where the respective field strength transforms into matter fields by a global U1 gauge symmetry. For the aim of dealing with consistent terms without breaking the global U1 symmetry we imposes a choice to the complex combination revealing a kind of symmetry between the choices and eliminates the extra degrees of freedom which is consistent with the supersymmetry. As the usual case the mass supersymmetric sector contributes as a complement to dynamics of the model. We obtain the equations of motion of the Proca’s type field for the chiral spinor fields and for the scalar field on the mass-shell which show the same mass as expected. This work establishes the first steps to extend the analysis of charged massive vector field in a supersymmetric scenario.

Environmental Decision Making on Acid Mine Drainage Issues in South Africa: An Argument for the Precautionary Principle.

Science.gov (United States)

Morodi, T J; Mpofu, Charles

2017-06-28

This paper examines the issue of acid mine drainage in South Africa and environmental decision making processes that could be taken to mitigate the problem in the context of both conventional risk assessment and the precautionary principle. It is argued that conventional risk assessment protects the status quo and hence cannot be entirely relied upon as an effective tool to resolve environmental problems in the context of South Africa, a developing country with complex environmental health concerns. The complexity of the environmental issues is discussed from historical and political perspectives. An argument is subsequently made that the precautionary principle is an alternative tool, and its adoption can be used to empower local communities. This work, therefore, adds to new knowledge by problematising conventional risk assessment and proposing the framing of the acid mine drainage issues in a complex and contextual scenario of a developing country-South Africa.

Time to standardise levels of care amongst Out-of-Hospital Emergency Care providers in Africa

OpenAIRE

Mould-Millman, N.K.; Stein, C.; Wallis, L.A.

2016-01-01

The African Federation for Emergency Medicine’s Out-of-Hospital Emergency Care (OHEC) Committee convened 15 experts from various OHEC systems in Africa to participate in a consensus process to define levels of care within which providers in African OHEC systems should safely and effectively function. The expert panel concluded that four provider levels were relevant for African OHEC systems: (i) first aid, (ii) basic life support, (iii) intermediate life support, and (iv) advanced life suppor...

Shifting suitability for malaria vectors across Africa with warming climates

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Peterson A Townsend

2009-05-01

Full Text Available Abstract Background Climates are changing rapidly, producing warm climate conditions globally not previously observed in modern history. Malaria is of great concern as a cause of human mortality and morbidity, particularly across Africa, thanks in large part to the presence there of a particularly competent suite of mosquito vector species. Methods I derive spatially explicit estimates of human populations living in regions newly suitable climatically for populations of two key Anopheles gambiae vector complex species in Africa over the coming 50 years, based on ecological niche model projections over two global climate models, two scenarios of climate change, and detailed spatial summaries of human population distributions. Results For both species, under all scenarios, given the changing spatial distribution of appropriate conditions and the current population distribution, the models predict a reduction of 11.3–30.2% in the percentage of the overall population living in areas climatically suitable for these vector species in coming decades, but reductions and increases are focused in different regions: malaria vector suitability is likely to decrease in West Africa, but increase in eastern and southern Africa. Conclusion Climate change effects on African malaria vectors shift their distributional potential from west to east and south, which has implications for overall numbers of people exposed to these vector species. Although the total is reduced, malaria is likely to pose novel public health problems in areas where it has not previously been common.

Sustainable Electricity Supply Scenarios for West Africa. A Case Study Conducted by IAEA Member States in West Africa with the Support of the IAEA

International Nuclear Information System (INIS)

2016-06-01

This publication covers topics relevant to Member States in the process of evaluation of future electricity supply options and strategies, from resource evaluation to electricity demand analysis and connections to overall social, economic and demographic developments. It is an outcome of a study carried out in West Africa, providing a coherent sub regional platform for the development of a robust policy framework for an enhanced and sustainable provision of electricity services to support socio economic growth

Queering discourses of coming out in South Africa

African Journals Online (AJOL)

argues that GASA was “expressly apolitical about wider issues in South African society [and ...... 16 These participants are lesbians in western, eastern and southern Africa whose testaments were collected by women activists. 17 In “An Ethnography of Silence: Race, (Homo)Sexualities, and a Discourse of Africa”, Stanford ...

Horizon scanning for emergence of new viruses: from constructing complex scenarios to online games.

Science.gov (United States)

Gale, P; Breed, A C

2013-10-01

Horizon scanning techniques can be developed to identify novel routes and sources for the emergence of viruses in the medium to long term. Central to horizon scanning is prediction of the complex scenarios through which viruses could emerge before they occur. One approach involves 'spidergrams' in which complex scenarios are generated by combining factors randomly selected from different categories of events. Spidergrams provide a framework for how different factors could interact, irrespective of the virus, and also enable testing of combinations not previously considered but which would be 'tested' in nature by a virus. The emergence of viruses through new routes is often related to changes, for example, in environmental and social factors, and the Internet will undoubtedly be used to identify long-term trends for consideration. In addition, online games may provide horizon scanners with suggestions for new routes and strategies that could be used by emerging viruses. © 2012 Crown copyright Reproduced with the permission of the Controller of Her Majesty's Stationery Office and Animal Health and Veterinary Laboratories Agency.

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.

Application of scenario-neutral methods to quantify impacts of climate change on water resources in East Africa

Science.gov (United States)

Ascott, M.; Macdonald, D.; Lapworth, D.; Tindimugaya, C.

2017-12-01

Quantification of the impact of climate change on water resources is essential for future resource planning. Unfortunately, climate change impact studies in African regions are often hindered by the extent in variability in future rainfall predictions, which also diverge from current drying trends. To overcome this limitation, "scenario-neutral" methods have been developed which stress a hydrological system using a wide range of climate futures to build a "climate response surface". We developed a hydrological model and scenario-neutral framework to quantify climate change impacts on river flows in the Katonga catchment, Uganda. Using the lumped catchment model GR4J, an acceptable calibration to historic daily flows (1966 - 2010, NSE = 0.69) was achieved. Using a delta change approach, we then systematically changed rainfall and PET inputs to develop response surfaces for key metrics, developed with Ugandan water resources planners (e.g. Q5, Q95). Scenarios from the CMIP5 models for 2030s and 2050s were then overlain on the response surface. The CMIP5 scenarios show consistent increases in temperature but large variability in rainfall increases, which results in substantial variability in increases in river flows. The developed response surface covers a wide range of climate futures beyond the CMIP5 projections, and can help water resources planners understand the sensitivity of water resource systems to future changes. When future climate scenarios are available, these can be directly overlain on the response surface without the need to re-run the hydrological model. Further work will consider using scenario-neutral approaches in more complex, semi-distributed models (e.g. SWAT), and will consider land use and socioeconomic change.

Tracing the route of modern humans out of Africa by using 225 human genome sequences from Ethiopians and Egyptians.

Science.gov (United States)

Pagani, Luca; Schiffels, Stephan; Gurdasani, Deepti; Danecek, Petr; Scally, Aylwyn; Chen, Yuan; Xue, Yali; Haber, Marc; Ekong, Rosemary; Oljira, Tamiru; Mekonnen, Ephrem; Luiselli, Donata; Bradman, Neil; Bekele, Endashaw; Zalloua, Pierre; Durbin, Richard; Kivisild, Toomas; Tyler-Smith, Chris

2015-06-04

The predominantly African origin of all modern human populations is well established, but the route taken out of Africa is still unclear. Two alternative routes, via Egypt and Sinai or across the Bab el Mandeb strait into Arabia, have traditionally been proposed as feasible gateways in light of geographic, paleoclimatic, archaeological, and genetic evidence. Distinguishing among these alternatives has been difficult. We generated 225 whole-genome sequences (225 at 8× depth, of which 8 were increased to 30×; Illumina HiSeq 2000) from six modern Northeast African populations (100 Egyptians and five Ethiopian populations each represented by 25 individuals). West Eurasian components were masked out, and the remaining African haplotypes were compared with a panel of sub-Saharan African and non-African genomes. We showed that masked Northeast African haplotypes overall were more similar to non-African haplotypes and more frequently present outside Africa than were any sets of haplotypes derived from a West African population. Furthermore, the masked Egyptian haplotypes showed these properties more markedly than the masked Ethiopian haplotypes, pointing to Egypt as the more likely gateway in the exodus to the rest of the world. Using five Ethiopian and three Egyptian high-coverage masked genomes and the multiple sequentially Markovian coalescent (MSMC) approach, we estimated the genetic split times of Egyptians and Ethiopians from non-African populations at 55,000 and 65,000 years ago, respectively, whereas that of West Africans was estimated to be 75,000 years ago. Both the haplotype and MSMC analyses thus suggest a predominant northern route out of Africa via Egypt. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Seagrass radiation after Messinian salinity crisis reflected by strong genetic structuring and out-of-Africa scenario (Ruppiaceae.

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Ludwig Triest

Full Text Available Many aquatic plant and seagrass species are widespread and the origin of their continent-wide ranges might result from high gene flow levels. The response of species when extending northwards since the Last Glacial Maximum can be opposed to the structuring of their populations that survived glaciation cycles in southern regions. The peri-Mediterranean is a complex series of sea basins, coastlines, islands and river deltas with a unique history since the Messinian Crisis that potentially influenced allopatric processes of aquatic life. We tested whether vast ranges across Europe and the peri-Mediterranean of a global seagrass group (Ruppia species complexes can be explained by either overall high levels of gene flow or vicariance through linking population genetics, phylogeography and shallow phylogenetics. A multigene approach identified haplogroup lineages of two species complexes, of ancient and recent hybrids with most of the diversity residing in the South. High levels of connectivity over long distances were only observed at recently colonized northern ranges and in recently-filled seas following the last glaciation. A strong substructure in the southern Mediterranean explained an isolation-by-distance model across Europe. The oldest lineages of the southern Mediterranean Ruppia dated back to the period between the end of the Messinian and Late Pliocene. An imprint of ancient allopatric origin was left at basin level, including basal African lineages. Thus both vicariance in the South and high levels of connectivity in the North explained vast species ranges. Our findings highlight the need for interpreting global distributions of these seagrass and euryhaline species in the context of their origin and evolutionary significant units for setting up appropriate conservation strategies.

Global energy context: future scenarios

International Nuclear Information System (INIS)

Beretta, Gian Paolo

2006-01-01

After a brief analysis of the history of global energy consumption, this paper discusses a plausible scenario of energy needs and related carbon emissions for the rest of the century. The global outlook and the probable evolution of several factors that impact on energy policy considerations - even on the local scale - demonstrate the great complexity and planetary dimension of the problems, as well as the almost certain sterility of out-of-context domestic energy-policy measures [it

Incorporating Medium-Range Weather Forecasts in Seasonal Crop Scenarios over the Greater Horn of Africa to Support National/Regional/Local Decision Makers

Science.gov (United States)

Shukla, S.; Husak, G. J.; Funk, C. C.; Verdin, J. P.

2015-12-01

The USAID's Famine Early Warning Systems Network (FEWS NET) provides seasonal assessments of crop conditions over the Greater Horn of Africa (GHA) and other food insecure regions. These assessments and current livelihood, nutrition, market conditions and conflicts are used to generate food security scenarios that help national, regional and local decision makers target their resources and mitigate socio-economic losses. Among the various tools that FEWS NET uses is the FAO's Water Requirement Satisfaction Index (WRSI). The WRSI is a simple yet powerful crop assessment model that incorporates current moisture conditions (at the time of the issuance of forecast), precipitation scenarios, potential evapotranspiration and crop parameters to categorize crop conditions into different classes ranging from "failure" to "very good". The WRSI tool has been shown to have a good agreement with local crop yields in the GHA region. At present, the precipitation scenarios used to drive the WRSI are based on either a climatological forecast (that assigns equal chances of occurrence to all possible scenarios and has no skill over the forecast period) or a sea-surface temperature anomaly based scenario (which at best have skill at the seasonal scale). In both cases, the scenarios fail to capture the skill that can be attained by initial atmospheric conditions (i.e., medium-range weather forecasts). During the middle of a cropping season, when a week or two of poor rains can have a devastating effect, two weeks worth of skillful precipitation forecasts could improve the skill of the crop scenarios. With this working hypothesis, we examine the value of incorporating medium-range weather forecasts in improving the skill of crop scenarios in the GHA region. We use the NCEP's Global Ensemble Forecast system (GEFS) weather forecasts and examine the skill of crop scenarios generated using the GEFS weather forecasts with respect to the scenarios based solely on the climatological forecast

Forecasting South Africa's performance at the 2010 Commonwealth ...

African Journals Online (AJOL)

Objectives. This paper predicts South Africa's performance at the Delhi 2010 Commonwealth Games. Methods. Potential scenarios are developed based on South Africa's previous performances. Results. South Africa will win up to 15 gold medals and 43 medals in total. Conclusions. After Delhi 2010, the actual results ...

Toxicovigilance Systems and Practices in Africa

Science.gov (United States)

Bertrand, Pouokam Guy; Ahmed, Hatem Abdel Moniem; Ngwafor, Randolph; Frazzoli, Chiara

2016-01-01

African consumers and citizens are growingly aware of the wide range of toxic poisoning scenarios from different products and hazards. Recurrent episodes on poisoning that have been reported in Africa include toxic hazards in consumers’ products ranging from food to herbal medicine, drugs, and cosmetics. Chemical poisoning remains an issue that is overlooked by public health stakeholders in Africa. Available information on toxicovigilance systems and practices in African countries is reviewed in terms of increasing development, organization and articulation levels. Less than nine out of 54 African countries have a legally recognized toxicovigilance system. Of these, the majority have created toxicovigilance systems recently, and are facing many challenges in developing them, at regional and country levels. Basic structures for a good toxicovigilance system include a phone line service (available 24/7), and hospital facilities. Pesticides emerge as the hazard recognized by all of the toxicovigilance systems, and may represent a prototypic toxicant towards a toxicovigilance system that is inclusive of a wider spectrum of toxicological hazards for the protection of community health. Toxicovigilance today is more reactive than preventive in Africa, but some milestones are present that constitute some promising seminal efforts. PMID:29051419

Assessing the potential impact of artemisinin and partner drug resistance in sub-Saharan Africa.

Science.gov (United States)

Slater, Hannah C; Griffin, Jamie T; Ghani, Azra C; Okell, Lucy C

2016-01-06

Artemisinin and partner drug resistant malaria parasites have emerged in Southeast Asia. If resistance were to emerge in Africa it could have a devastating impact on malaria-related morbidity and mortality. This study estimates the potential impact of artemisinin and partner drug resistance on disease burden in Africa if it were to emerge. Using data from Asia and Africa, five possible artemisinin and partner drug resistance scenarios are characterized. An individual-based malaria transmission model is used to estimate the impact of each resistance scenario on clinical incidence and parasite prevalence across Africa. Artemisinin resistance is characterized by slow parasite clearance and partner drug resistance is associated with late clinical failure or late parasitological failure. Scenarios with high levels of recrudescent infections resulted in far greater increases in clinical incidence compared to scenarios with high levels of slow parasite clearance. Across Africa, it is estimated that artemisinin and partner drug resistance at levels similar to those observed in Oddar Meanchey province in Cambodia could result in an additional 78 million cases over a 5 year period, a 7% increase in cases compared to a scenario with no resistance. A scenario with high levels of slow clearance but no recrudescence resulted in an additional 10 million additional cases over the same period. Artemisinin resistance is potentially a more pressing concern than partner drug resistance due to the lack of viable alternatives. However, it is predicted that a failing partner drug will result in greater increases in malaria cases and morbidity than would be observed from artemisinin resistance only.

Record-breaking climate extremes in Africa under stabilized 1.5 °C and 2 °C global warming scenarios

Science.gov (United States)

Nangombe, Shingirai; Zhou, Tianjun; Zhang, Wenxia; Wu, Bo; Hu, Shuai; Zou, Liwei; Li, Donghuan

2018-05-01

Anthropogenic forcing is anticipated to increase the magnitude and frequency of extreme events1, the impacts of which will be particularly hard-felt in already vulnerable locations such as Africa2. However, projected changes in African climate extremes remain little explored, particularly in the context of the Paris Agreement targets3,4. Here, using Community Earth System Model low warming simulations5, we examine how heat and hydrological extremes may change in Africa under stabilized 1.5 °C and 2 °C scenarios, focusing on the projected changing likelihood of events that have comparable magnitudes to observed record-breaking seasons. In the Community Earth System Model, limiting end-of-century warming to 1.5 °C is suggested to robustly reduce the frequency of heat extremes compared to 2 °C. In particular, the probability of events similar to the December-February 1991/1992 southern African and 2009/2010 North African heat waves is estimated to be reduced by 25 ± 5% and 20 ± 4%, respectively, if warming is limited to 1.5 °C instead of 2 °C. For hydrometeorological extremes (that is, drought and heavy precipitation), by contrast, signal differences are indistinguishable from the variation between ensemble members. Thus, according to this model, continued efforts to limit warming to 1.5 °C offer considerable benefits in terms of minimizing heat extremes and their associated socio-economic impacts across Africa.

The future of AIDS in Africa: lessons from two scenario projects ...

African Journals Online (AJOL)

Scenario planning or futures studies have their origin in military planning, but have also been used with great success in the private sector, most notably in the energy industry. UNAIDS and the South African financial services group Metropolitan each recently published a set of scenarios regarding the future impact of ...

Which comparative costs between phasing out nuclear within 20 years and carrying on nuclear energy like in the DGEC scenario

International Nuclear Information System (INIS)

Dessus, Benjamin

2011-01-01

The author proposes a comparison between two scenarios by 2031: phasing out nuclear or carrying on according to the DGEC scenario. According to the last one, nuclear power plants are progressively replaced by EPRs. The author analyses, assesses and compares the electricity production, transportation, distribution, and saving costs, and then the different investments to be made (in electricity production, for electricity saving, for the grid)

Out of Africa: modern human origins special feature: the origin of Neandertals.

Science.gov (United States)

Hublin, J J

2009-09-22

Western Eurasia yielded a rich Middle (MP) and Late Pleistocene (LP) fossil record documenting the evolution of the Neandertals that can be analyzed in light of recently acquired paleogenetical data, an abundance of archeological evidence, and a well-known environmental context. Their origin likely relates to an episode of recolonization of Western Eurasia by hominins of African origin carrying the Acheulean technology into Europe around 600 ka. An enhancement of both glacial and interglacial phases may have played a crucial role in this event, as well as in the subsequent evolutionary history of the Western Eurasian populations. In addition to climatic adaptations and an increase in encephalization, genetic drift seems to have played a major role in their evolution. To date, a clear speciation event is not documented, and the most likely scenario for the fixation of Neandertal characteristics seems to be an accretion of features along the second half of the MP. Although a separation time for the African and Eurasian populations is difficult to determine, it certainly predates OIS 11 as phenotypic Neandertal features are documented as far back as and possibly before this time. It is proposed to use the term "Homo rhodesiensis" to designate the large-brained hominins ancestral to H. sapiens in Africa and at the root of the Neandertals in Europe, and to use the term "Homo neanderthalensis" to designate all of the specimens carrying derived metrical or non-metrical features used in the definition of the LP Neandertals.

Smoothing out the volatility of South Africa's wind and PV energy resources

CSIR Research Space (South Africa)

Bofinger, S

2015-10-01

Full Text Available Solar PV & wind are the cheapest new-build options per kWh in South Africa. By 2020, a mix of PV, wind and flexible gas (LNG-based) costs the same as new coal, even without any value given to excess wind/PV energy. South Africa has abundant solar...

A world class nuclear research reactor complex for South Africa's nuclear future

International Nuclear Information System (INIS)

Keshaw, Jeetesh

2008-01-01

South Africa recently made public its rather ambitious goals pertaining to nuclear energy developments in a Draft Policy and Strategy issued for public comment. Not much attention was given to an important tool for nuclear energy research and development, namely a well equipped and maintained research reactor, which on its own does not do justice to its potential, unless it is fitted with all the ancillaries and human resources as most first world countries have. In South Africa's case it is suggested to establish at least one Nuclear Energy Research and Development Centre at such a research reactor, where almost all nuclear energy related research can be carried out on par with some of the best in the world. The purpose of this work is to propose how this could be done, and motivate why it is important that it be done with great urgency, and with full involvement of young professionals, if South Africa wishes to face up to the challenges mentioned in the Draft Strategy and Policy. (authors)

A model based bayesian solution for characterization of complex damage scenarios in aerospace composite structures.

Science.gov (United States)

Reed, H; Leckey, Cara A C; Dick, A; Harvey, G; Dobson, J

2018-01-01

Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. In recent years there has been an increased development of guided wave based methods. In real materials and structures, these dispersive waves result in complicated behavior in the presence of complex damage scenarios. Model-based characterization methods utilize accurate three dimensional finite element models (FEMs) of guided wave interaction with realistic damage scenarios to aid in defect identification and classification. This work describes an inverse solution for realistic composite damage characterization by comparing the wavenumber-frequency spectra of experimental and simulated ultrasonic inspections. The composite laminate material properties are first verified through a Bayesian solution (Markov chain Monte Carlo), enabling uncertainty quantification surrounding the characterization. A study is undertaken to assess the efficacy of the proposed damage model and comparative metrics between the experimental and simulated output. The FEM is then parameterized with a damage model capable of describing the typical complex damage created by impact events in composites. The damage is characterized through a transdimensional Markov chain Monte Carlo solution, enabling a flexible damage model capable of adapting to the complex damage geometry investigated here. The posterior probability distributions of the individual delamination petals as well as the overall envelope of the damage site are determined. Copyright © 2017 Elsevier B.V. All rights reserved.

U.S. Africa Command: Shaping Africa for the Future

National Research Council Canada - National Science Library

Sholley, Hans

2006-01-01

.... It is argued the current Unified Command Plan is ill designed to address the complexities of the continent of Africa and that a proposed United States Africa Command would be better positioned...

Hydrological Response and Complex Impact Pathways of the 2015/2016 El Niño in Eastern and Southern Africa

Science.gov (United States)

Siderius, C.; Gannon, K. E.; Ndiyoi, M.; Opere, A.; Batisani, N.; Olago, D.; Pardoe, J.; Conway, D.

2018-01-01

The 2015/2016 El Niño has been classified as one of the three most severe on record. El Niño teleconnections are commonly associated with droughts in southern Africa and high precipitation in eastern Africa. Despite their relatively frequent occurrence, evidence for their hydrological effects and impacts beyond agriculture is limited. We examine the hydrological response and impact pathways of the 2015/2016 El Niño in eastern and southern Africa, focusing on Botswana, Kenya, and Zambia. We use in situ and remotely sensed time series of precipitation, river flow, and lake levels complemented by qualitative insights from interviews with key organizations in each country about awareness, impacts, and responses. Our results show that drought conditions prevailed in large parts of southern Africa, reducing runoff and contributing to unusually low lake levels in Botswana and Zambia. Key informants characterized this El Niño through record high temperatures and water supply disruption in Botswana and through hydroelectric load shedding in Zambia. Warnings of flood risk in Kenya were pronounced, but the El Niño teleconnection did not materialize as expected in 2015/2016. Extreme precipitation was limited and caused localized impacts. The hydrological impacts in southern Africa were severe and complex, strongly exacerbated by dry antecedent conditions, recent changes in exposure and sensitivity and management decisions. Improved understanding of hydrological responses and the complexity of differing impact pathways can support design of more adaptive, region-specific management strategies.

The Global Phylogeography of Lyssaviruses - Challenging the 'Out of Africa' Hypothesis

Science.gov (United States)

Fooks, Anthony R.; Marston, Denise A.; Garcia-R, Juan C.

2016-01-01

Rabies virus kills tens of thousands of people globally each year, especially in resource-limited countries. Yet, there are genetically- and antigenically-related lyssaviruses, all capable of causing the disease rabies, circulating globally among bats without causing conspicuous disease outbreaks. The species richness and greater genetic diversity of African lyssaviruses, along with the lack of antibody cross-reactivity among them, has led to the hypothesis that Africa is the origin of lyssaviruses. This hypothesis was tested using a probabilistic phylogeographical approach. The nucleoprotein gene sequences from 153 representatives of 16 lyssavirus species, collected between 1956 and 2015, were used to develop a phylogenetic tree which incorporated relevant geographic and temporal data relating to the viruses. In addition, complete genome sequences from all 16 (putative) species were analysed. The most probable ancestral distribution for the internal nodes was inferred using three different approaches and was confirmed by analysis of complete genomes. These results support a Palearctic origin for lyssaviruses (posterior probability = 0.85), challenging the ‘out of Africa’ hypothesis, and suggest three independent transmission events to the Afrotropical region, representing the three phylogroups that form the three major lyssavirus clades. PMID:28036390

Complexity rating of abnormal events and operator performance

International Nuclear Information System (INIS)

Oeivind Braarud, Per

1998-01-01

The complexity of the work situation during abnormal situations is a major topic in a discussion of safety aspects of Nuclear Power plants. An understanding of complexity and its impact on operator performance in abnormal situations is important. One way to enhance understanding is to look at the dimensions that constitute complexity for NPP operators, and how those dimensions can be measured. A further step is to study how dimensions of complexity of the event are related to performance of operators. One aspect of complexity is the operator 's subjective experience of given difficulties of the event. Another related aspect of complexity is subject matter experts ratings of the complexity of the event. A definition and a measure of this part of complexity are being investigated at the OECD Halden Reactor Project in Norway. This paper focus on the results from a study of simulated scenarios carried out in the Halden Man-Machine Laboratory, which is a full scope PWR simulator. Six crews of two licensed operators each performed in 16 scenarios (simulated events). Before the experiment subject matter experts rated the complexity of the scenarios, using a Complexity Profiling Questionnaire. The Complexity Profiling Questionnaire contains eight previously identified dimensions associated with complexity. After completing the scenarios the operators received a questionnaire containing 39 questions about perceived complexity. This questionnaire was used for development of a measure of subjective complexity. The results from the study indicated that Process experts' rating of scenario complexity, using the Complexity Profiling Questionnaire, were able to predict crew performance quite well. The results further indicated that a measure of subjective complexity could be developed that was related to crew performance. Subjective complexity was found to be related to subjective work load. (author)

A DYNAMIC PHYSIOLOGICALLY-BASED TOXICOKINETIC (DPBTK) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS

Science.gov (United States)

A GENERAL PHYSIOLOGICAL AND TOXICOKINETIC (GPAT) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS. E M Kenyon1, T Colemen2, C R Eklund1 and V A Benignus3. 1U.S. EPA, ORD, NHEERL, ETD, PKB, RTP, NC, USA; 2Biological Simulators, Inc., Jackson MS, USA, 3U.S. EP...

Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

Energy Technology Data Exchange (ETDEWEB)

Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

2014-04-01

Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

Uranium in South Africa: 1983 assessment of resources and production

International Nuclear Information System (INIS)

1984-06-01

NUCOR assesses South Africa's uranium resource and production capabilities on an ongoing basis. Assessments are carried out in close co-operation with the mining companies and the Government Mining Engineer. In carrying out this evaluation, the classification recommended by the NEA/IAEA Working Party on Uranium Resources is followed. In order to preserve company confidentiality, the details of the findings are released in summary form only. Within South Africa, uranium occurrences are found in Precambrian quartz-pebble conglomerates, Precambrian alkaline complexes, Cambrian to Precambrian granite gneisses, Permo-Triassic sandstones and coal, and Recent to Tertiary surficial formations. South Africa's uranium resources were reassessed during 1983 and the total recoverable resources in the Reasonably Assured and Estimated Additional Resource categories recoverable at less than $130/kg U were estimated to be 460 000 t U. This represents a decrease of 13,4% when compared with the 1981 assessment. South Africa's uranium production for 1983 amounted to 6 060 t U, a 4,21 % increase over the 1982 production of 5 816 t U. Ninety-seven percent of the production is derived from the Witwatersrand quartz-pebble conglomerates, the rest being produced as a by-product of copper mining at Palabora. South Africa maintained its position as a major low-cost uranium producer, holding 14% of the WOCA uranium resources, and during 1982 it produced 14% of WOCA's uranium. In making future production capability projections it may be safely concluded that South Africa would be able to produce uranium at substantial levels well into the next century

Applying the global RCP-SSP-SPA scenario framework at sub-national scale: A multi-scale and participatory scenario approach.

Science.gov (United States)

Kebede, Abiy S; Nicholls, Robert J; Allan, Andrew; Arto, Iñaki; Cazcarro, Ignacio; Fernandes, Jose A; Hill, Chris T; Hutton, Craig W; Kay, Susan; Lázár, Attila N; Macadam, Ian; Palmer, Matthew; Suckall, Natalie; Tompkins, Emma L; Vincent, Katharine; Whitehead, Paul W

2018-09-01

To better anticipate potential impacts of climate change, diverse information about the future is required, including climate, society and economy, and adaptation and mitigation. To address this need, a global RCP (Representative Concentration Pathways), SSP (Shared Socio-economic Pathways), and SPA (Shared climate Policy Assumptions) (RCP-SSP-SPA) scenario framework has been developed by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC-AR5). Application of this full global framework at sub-national scales introduces two key challenges: added complexity in capturing the multiple dimensions of change, and issues of scale. Perhaps for this reason, there are few such applications of this new framework. Here, we present an integrated multi-scale hybrid scenario approach that combines both expert-based and participatory methods. The framework has been developed and applied within the DECCMA 1 project with the purpose of exploring migration and adaptation in three deltas across West Africa and South Asia: (i) the Volta delta (Ghana), (ii) the Mahanadi delta (India), and (iii) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India). Using a climate scenario that encompasses a wide range of impacts (RCP8.5) combined with three SSP-based socio-economic scenarios (SSP2, SSP3, SSP5), we generate highly divergent and challenging scenario contexts across multiple scales against which robustness of the human and natural systems within the deltas are tested. In addition, we consider four distinct adaptation policy trajectories: Minimum intervention, Economic capacity expansion, System efficiency enhancement, and System restructuring, which describe alternative future bundles of adaptation actions/measures under different socio-economic trajectories. The paper highlights the importance of multi-scale (combined top-down and bottom-up) and participatory (joint expert-stakeholder) scenario methods for addressing uncertainty in adaptation decision

Rethinking HIV exceptionalism: the ethics of opt-out HIV testing in sub-Saharan Africa

Science.gov (United States)

2010-01-01

Abstract Opt-out testing for the human immunodeficiency virus (HIV) incorporates testing as a routine part of health care for all patients unless they refuse. The ethics of this approach to testing in sub-Saharan Africa is a source of controversy. Opt-out HIV testing is expected to improve survival by increasing case detection and thus linking more HIV-infected people to earlier treatment, provided there is effective patient follow-up and programme sustainability. At the population level, these benefits will likely outweigh the potential negative consequences of individuals experiencing HIV-related stigma. These justifications appeal to consequentialist moral theories that the acceptability of an action depends upon its outcomes. On the other hand, liberal moral theories state that the autonomy of individuals should always be protected unless restricting autonomy is necessary to protect the welfare of others. Opt-out consent may restrict autonomy and it is unclear whether it would benefit people other than those being tested. Yet, the doctrine of libertarian paternalism proposes that it is justifiable and desirable to use unobtrusive mechanisms to help individuals make choices to maximize their own welfare. Central to this idea are the premises featured by supporters of opt-out consent that individuals will not always make the best choices for their own welfare but they may be influenced to do so in ways that will not compromise their freedom of choice. Also important is the premise that all policies inevitably exert some such influence: opt-in consent encourages test refusal just as opt-out consent encourages acceptance. Based on these premises, opt-out testing may be an effective and ethically acceptable policy response to Africa’s HIV epidemic. PMID:20865076

Low carbon energy scenarios for sub-Saharan Africa: An input-output analysis on the effects of universal energy access and economic growth

International Nuclear Information System (INIS)

Hamilton, Thomas Gerard Adam; Kelly, Scott

2017-01-01

Meeting Sub-Saharan African (SSA) human development goals will require economic development to be the priority over the coming decades, but economic development ‘at all cost’ may not be acceptable across these goals. This paper aims to explore five development scenarios for the five largest economies in SSA to understand the implications to CO_2-equivalent emissions (CO_2-e) and off-grid energy modernisation in 2030. Within this scope GDP growth; economic structure; availability of energy resources; international trade; and, the development of distributed generation for remote locations are considered. Regional CO_2 emissions were studied using a Multi-Regional Input-Output Model for Africa. Under the scenarios analysed all five nations will be unable to reduce 2030 CO_2-e emissions below 2012 levels, whilst simultaneously achieving forecast GDP growth and universal access to modernised energy services. 100% off-grid modernisation is estimated to require a three-fold increase in Primary Energy Supply and a 26% (1317 Mt) increase in 2030 CO_2-e emissions. Total regional CO_2-e emissions could be reduced from 45% to 35% by meeting a 50% renewable energy supply target by 2030. Climate Change policy would need to focus on multi-sector reform to reduce regional emissions as the agricultural sector is the largest emitter in Nigeria, Ethiopia and Kenya. - Highlights: • GHG"1 emissions were studied with a Multi-Regional Input-Output Model for Africa. • SSA"2 GDP growth is inextricably linked with access to additional energy supply. • SSA will not attain universal energy access and low carbon growth in parallel. • GHG emissions decline needs both renewable energy adoption and agriculture reform. • SSA Climate Change policy would need to target multiple GHG emitting sector reform.

On the effects of wildfires on precipitation in Southern Africa

Science.gov (United States)

De Sales, Fernando; Okin, Gregory S.; Xue, Yongkang; Dintwe, Kebonye

2018-03-01

This study investigates the impact of wildfire on the climate of Southern Africa. Moderate resolution imaging spectroradiometer derived burned area fraction data was implemented in a set of simulations to assess primarily the role of wildfire-induced surface changes on monthly precipitation. Two post-fire scenarios are examined namely non-recovering and recovering vegetation scenarios. In the former, burned vegetation fraction remains burned until the end of the simulations, whereas in the latter it is allowed to regrow following a recovery period. Control simulations revealed that the model can dependably capture the monthly precipitation and surface temperature averages in Southern Africa thus providing a reasonable basis against which to assess the impacts of wildfire. In general, both wildfire scenarios have a negative impact on springtime precipitation. September and October were the only months with statistically significant precipitation changes. During these months, precipitation in the region decreases by approximately 13 and 9% in the non-recovering vegetation scenario, and by about 10 and 6% in the recovering vegetation wildfire scenario, respectively. The primary cause of precipitation deficit is the decrease in evapotranspiration resulting from a reduction in surface net radiation. Areas impacted by the precipitation reduction includes the Luanda, Kinshasa, and Brazzaville metropolitan areas, The Angolan Highlands, which are the source of the Okavango Rive, and the Okavango Delta region. This study suggests that a probable intensification in wildfire frequency and extent resulting from projected population increase and global warming in Southern Africa could potentially exacerbate the impacts of wildfires in the region's seasonal precipitation.

As warm as in Germany or Northern Africa? Climate scenarios for the research programme Climatools; Lika varmt som i Tyskland eller Nordafrika? Klimatscenarier inom forskningsprogrammet Climatools

Energy Technology Data Exchange (ETDEWEB)

Parmhed, Oskar; Carlsson-Kanyama, Annika

2007-05-15

Future climate change may become larger or smaller depending on the development of greenhouse gas emissions. During 2007 the IPCC released its fourth assessment report on the dominant causes of climate change. At the end of this century it is expected that the global mean temperature may have risen with as much as six degrees. The heating may be even greater in Sweden, with effects on precipitation, vegetation, and snow cover. The Climatools research programme aims at maintaining or increasing the capacity of sectors and regions in Sweden to deliver services to the society by providing decision makers with tools for decision on issues of climate change. The tools are developed in scenario based case studies. Common to all scenarios in Climatools are assumptions on the future climate in Sweden. Within Climatools the effects on three regions are considered: Umeaa, Maelardalen, and Skaane. We have chosen three climate scenarios as a basis for coming work within the programme. These three scenarios are presented in this report, together with their motivation. The effects on the three regions of interest are also described. With these scenarios we want to span a challenging space of outcomes for the future work. The three scenarios are named after what the average temperature in Umeaa equals in terms of todays climate. They are called: Umeaa like Umeaa, Umeaa like Germany, and Umeaa like North Africa

Sustainable waste management in Africa through CDM projects

Energy Technology Data Exchange (ETDEWEB)

Couth, R. [CRECHE, Centre for Research in Environmental, Coastal and Hydrological Engineering, School of Engineering, University of KwaZulu-Natal, Durban 4041 (South Africa); Trois, C., E-mail: troisc@ukzn.ac.za [CRECHE, Centre for Research in Environmental, Coastal and Hydrological Engineering, School of Engineering, University of KwaZulu-Natal, Durban 4041 (South Africa)

2012-11-15

Highlights: Black-Right-Pointing-Pointer This is a compendium on GHG reductions via improved waste strategies in Africa. Black-Right-Pointing-Pointer This note provides a strategic framework for Local Authorities in Africa. Black-Right-Pointing-Pointer Assists LAs to select Zero Waste scenarios and achieve sustained GHG reduction. - Abstract: Only few Clean Development Mechanism (CDM) projects (traditionally focussed on landfill gas combustion) have been registered in Africa if compared to similar developing countries. The waste hierarchy adopted by many African countries clearly shows that waste recycling and composting projects are generally the most sustainable. This paper undertakes a sustainability assessment for practical waste treatment and disposal scenarios for Africa and makes recommendations for consideration. The appraisal in this paper demonstrates that mechanical biological treatment of waste becomes more financially attractive if established through the CDM process. Waste will continue to be dumped in Africa with increasing greenhouse gas emissions produced, unless industrialised countries (Annex 1) fund carbon emission reduction schemes through a replacement to the Kyoto Protocol. Such a replacement should calculate all of the direct and indirect carbon emission savings and seek to promote public-private partnerships through a concerted support of the informal sector.

Key biotic components of the indigenous Tortricidae and Heteroptera complexes occuring on macadamia in South Africa / by P.S. Schoeman

OpenAIRE

Schoeman, Pieter Schalk

2009-01-01

In South Africa macadamia nuts are attacked by a variety of mostly indigenous pests which can be divided into two basic complexes, namely a nut borer complex (consisting of 3 tortricid moths.) and a stink bug (Heteroptera) complex consisting of approximately 35 insect species. The Heteroptera complex causes approximately 60% damage in unsprayed orchards and the estimated annual heteropteran induced crop loss could be as high as R24 million. Gravid female tortricid moths could discriminate bet...

Visual Middle-Out Modeling of Problem Spaces

DEFF Research Database (Denmark)

Valente, Andrea

2009-01-01

Modeling is a complex and central activity in many domains. Domain experts and designers usually work by drawing and create models from the middle-out; however, visual and middle-out style modeling is poorly supported by software tools. In order to define a new class of software-based modeling...... tools, we propose a scenario and identify some requirements. Those requirements are contrasted against features of existing tools from various application domains, and the results show general lack of support for custom visualization and incremental knowledge specification, poor handling of temporal...... information, and little generative capabilities.Satisfaction of the requirements proved difficult, and our first two prototypes did not perform well. A new and streamlined prototype is currently under development: it should enable some useful form of middle-out modeling. Application domains will range from...

Linking regional stakeholder scenarios and shared socioeconomic pathways

DEFF Research Database (Denmark)

Palazzo, Amanda; Vervoort, Joost M.; Mason-D'Croz, Daniel

2017-01-01

levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise.In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder......-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate...... change.In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global...

Learning from global emissions scenarios

International Nuclear Information System (INIS)

O'Neill, Brian C; Nakicenovic, Nebojsa

2008-01-01

Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

Dynamics of Ebola epidemics in West Africa 2014 [v2; ref status: indexed, http://f1000r.es/5fh

Directory of Open Access Journals (Sweden)

Robin J. Evans

2015-05-01

Full Text Available This paper investigates the dynamics of Ebola virus transmission in West Africa during 2014. The reproduction numbers for the total period of epidemic and for different consequent time intervals are estimated based on a simple linear model. It contains one major parameter - the average infectious period that defines the dynamics of epidemics. Numerical implementations are carried out on data collected from three countries Guinea, Sierra Leone and Liberia as well as the total data collected worldwide. Predictions are provided by considering different scenarios involving the average times of infectiousness for the next few months and the end of the current epidemic is estimated according to each scenario.

Speleothem evidence for the greening of the Sahara and its implications for the early human dispersal out of sub-Saharan Africa

Science.gov (United States)

El-Shenawy, Mohammed I.; Kim, Sang-Tae; Schwarcz, Henry P.; Asmerom, Yemane; Polyak, Victor J.

2018-05-01

Although there is a consensus that there were wet periods (greening events) in the Sahara in the past, the spatial extent and the timing of these greening events are still in dispute, yet critical to our understanding of the early human dispersal out of Africa. Our U-series dates of speleothems from the Northeastern Sahara (Wadi Sannur cave, Egypt) reveal that the periods of speleothem growth were brief and restricted to the interglacial Marine Isotope Stages MIS 5.5, MIS 7.3, and the early MIS 9 with a remarkable absence of the Holocene deposition of speleothems. These growth periods of Wadi Sannur cave speleothems correspond to periods of high rainfall and spread of vegetation (green Sahara). Distinct low δ18O values of speleothems indicate a distal moisture source that we interpret to be the Atlantic Ocean. These two lines of evidence from the Wadi Sannur speleothems thus suggest that maximal northward shifts in the West African monsoon system occurred during the growth periods of the speleothems, leading to greening of the Sahara, facilitating human migration into Eurasia. The periods of speleothem growth at Wadi Sannur cave are contemporaneous with important archeological events: (1) the earliest occurrence of the Middle Stone Age assemblages and Homo sapiens in North Africa (Jebel Irhoud), suggesting wide spread of greening conditions over the East-West transect of the Sahara, (2) the sharp technological break between the Acheulo-Yabrudian and the Mousterian industries, and (3) the arrival of Homo sapiens in Levant, indicating a key role of the Sahara route in early human dispersal out of Africa.

Role of out-patient chemo- and radiotherapy in complex treatment of pediatric nephroblastoma

International Nuclear Information System (INIS)

Kamarli, Z.P.

1987-01-01

The paper discusses application of out-patient procedures for complex chemo- and radiotreatment of pediatric nephroblastoma. The data on 101 out-patients with nephroblastoma were analysed. Out-patient prophylactic chemotherapy was not accompanied by higher rates of toxic or side-effects. Among the basic indications for certain procedures for treatment of nephroblastoma on the out-patient basis are: fair general condition, absence of severe complications in the hospital case history, parents' readiness the nurse, age over 18 months and stage 2 disease

The National Qualifications Framework in South Africa and "out-of-School Youth": Problems and Possibilities

Science.gov (United States)

Kgobe, Madumetja

1997-07-01

Over the past few years, an initiative called the National Qualifications Framework (NQF) has been unfolding in South Africa. The NQF has as its vision the integration of education and training and the creation of mechanisms through which all learners can receive accreditation for their learning, irrespective of where such learning takes place, and can progress through the education and training system. The passage of the SAQA Act in 1995, and the establishment of the SAQA Board in 1996, provided the framework for the implementation of the NQF. The success or failure of the NQF will depend largely on the extent to which it addresses the major challenges facing South Africa, not only in terms of education and training but also the need to cope with the economic imperatives of society through the conquest of poverty, hunger and unemployment. This paper explores the extent to which the NQF addresses these issues by examining it in relation to "out-of- school youth". The paper begins by providing the background and origins of the NQF. It is argued that the NQF has its origins in a web of interlocking local and international economic, ideological, social and political concerns. The paper then considers some of the key proposals of the NQF for the restructuring of education and training, and finally focus on implications for youth.

Refugees in and out North Africa: a study of the Choucha refugee camp in Tunisia.

Science.gov (United States)

Dourgnon, Paul; Kassar, Hassène

2014-08-01

In recent years, North African (NA) countries ceased to be emigration-only countries and are now on the verge of becoming immigration as well as transit countries for economic migrants and refugees. Contextual as well as structural long-term factors are driving these changes. The ongoing crises in Africa and the Middle East are prompting strong outflows of refugees, which are likely to induce NA countries to share some common public policy and public health concerns with European countries in a near future. This article highlights some aspects of these changes, from the study of the consequences of the 2011 Libyan crisis in Tunisia. It addresses individual trajectories and health concerns of refugees in and out North Africa from a study of the Choucha camp in Tunisia. The camp opened to immigrants from Libya during the 2011 crisis and accommodated the bulk of the refugees flow to Tunisia until July 2012. The study includes a monographic approach and a qualitative survey in the Choucha camp refugees. We describe the crisis history and the health response with a focus on the camp. We then address refugees' trajectories, and health needs and concerns from the interviews we collected in the camp in April 2012. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

A world class nuclear research reactor complex for South Africa's nuclear future

Energy Technology Data Exchange (ETDEWEB)

Keshaw, Jeetesh [South African Young Nuclear Professional Society, PO Box 9396, Centurion, 0157 (South Africa)

2008-07-01

South Africa recently made public its rather ambitious goals pertaining to nuclear energy developments in a Draft Policy and Strategy issued for public comment. Not much attention was given to an important tool for nuclear energy research and development, namely a well equipped and maintained research reactor, which on its own does not do justice to its potential, unless it is fitted with all the ancillaries and human resources as most first world countries have. In South Africa's case it is suggested to establish at least one Nuclear Energy Research and Development Centre at such a research reactor, where almost all nuclear energy related research can be carried out on par with some of the best in the world. The purpose of this work is to propose how this could be done, and motivate why it is important that it be done with great urgency, and with full involvement of young professionals, if South Africa wishes to face up to the challenges mentioned in the Draft Strategy and Policy. (authors)

Anticipating and Communicating Plausible Environmental and Health Concerns Associated with Future Disasters: The ShakeOut and ARkStorm Scenarios as Examples

Science.gov (United States)

Plumlee, G. S.; Morman, S. A.; Alpers, C. N.; Hoefen, T. M.; Meeker, G. P.

2010-12-01

Disasters commonly pose immediate threats to human safety, but can also produce hazardous materials (HM) that pose short- and long-term environmental-health threats. The U.S. Geological Survey (USGS) has helped assess potential environmental health characteristics of HM produced by various natural and anthropogenic disasters, such as the 2001 World Trade Center collapse, 2005 hurricanes Katrina and Rita, 2007-2009 southern California wildfires, various volcanic eruptions, and others. Building upon experience gained from these responses, we are now developing methods to anticipate plausible environmental and health implications of the 2008 Great Southern California ShakeOut scenario (which modeled the impacts of a 7.8 magnitude earthquake on the southern San Andreas fault, http://urbanearth.gps.caltech.edu/scenario08/), and the recent ARkStorm scenario (modeling the impacts of a major, weeks-long winter storm hitting nearly all of California, http://urbanearth.gps.caltech.edu/winter-storm/). Environmental-health impacts of various past earthquakes and extreme storms are first used to identify plausible impacts that could be associated with the disaster scenarios. Substantial insights can then be gleaned using a Geographic Information Systems (GIS) approach to link ShakeOut and ARkStorm effects maps with data extracted from diverse database sources containing geologic, hazards, and environmental information. This type of analysis helps constrain where potential geogenic (natural) and anthropogenic sources of HM (and their likely types of contaminants or pathogens) fall within areas of predicted ShakeOut-related shaking, firestorms, and landslides, and predicted ARkStorm-related precipitation, flooding, and winds. Because of uncertainties in the event models and many uncertainties in the databases used (e.g., incorrect location information, lack of detailed information on specific facilities, etc.) this approach should only be considered as the first of multiple steps

From scenarios to components

NARCIS (Netherlands)

Fahland, D.

2010-01-01

Scenario-based modeling has evolved as an accepted paradigm for developing complex systems of various kinds. Its main purpose is to ensure that a system provides desired behavior to its users. A scenario is generally understood as a behavioral requirement, denoting a course of actions that shall

The scenario approach to possible futures for oil and natural gas

International Nuclear Information System (INIS)

Bentham, Jeremy

2014-01-01

Shell has been using scenario planning for 40 years to help deepen its strategic thinking. Developing and applying scenarios is part of an ongoing process in Shell that encourages decision-makers to explore the features, uncertainties, and boundaries of the future landscape, and engage with alternative points of view. Shell scenarios go beyond conventional energy outlooks and consider long-term trends in economics, energy supply and demand, geopolitical shifts and social change. They are based on plausible assumptions and quantification, and include the impact of different patterns of individual and collective choices. Shell′s latest scenario publication, the New Lens Scenarios, published in 2013, provides an in-depth analysis of how economic, social and political forces might play out over the 21st century, as well as their consequences for the global energy system and environment. Its ‘Mountains’ and ‘Oceans’ scenarios set out two distinct paths the world might take in the decades ahead. They reinforce the urgency and complexity of addressing the world's resource and environmental stresses, and highlight the need for business, government and society to find new ways to collaborate, fostering policies that promote the development and use of cleaner energy, and improve energy efficiency. - Highlights: • Shell has used scenarios to deepen its strategic thinking for 40 years. • Shell scenarios cover a broader set of drivers than traditional energy outlooks. • Shell's New Lens Scenarios were published in February 2013. • They look at trends in the economy, politics and energy over the 21st century. • Coordinated policies are essential to meeting the world's rising energy needs

Predicting the current and future potential distributions of lymphatic filariasis in Africa using maximum entropy ecological niche modelling.

Directory of Open Access Journals (Sweden)

Hannah Slater

Full Text Available Modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. Here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (LF, in Africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. We used 508 community-specific infection presence data collated from the published literature in conjunction with five predictive environmental/climatic and demographic variables, and a maximum entropy niche modelling method to construct the first ecological niche maps describing potential distribution and burden of LF in Africa. We also ran the best-fit model against climate projections made by the HADCM3 and CCCMA models for 2050 under A2a and B2a scenarios to simulate the likely distribution of LF under future climate and population changes. We predict a broad geographic distribution of LF in Africa extending from the west to the east across the middle region of the continent, with high probabilities of occurrence in the Western Africa compared to large areas of medium probability interspersed with smaller areas of high probability in Central and Eastern Africa and in Madagascar. We uncovered complex relationships between predictor ecological niche variables and the probability of LF occurrence. We show for the first time that predicted climate change and population growth will expand both the range and risk of LF infection (and ultimately disease in an endemic region. We estimate that populations at risk to LF may range from 543 and 804 million currently, and that this could rise to between 1.65 to 1.86 billion in the future depending on the climate scenario used and thresholds applied to signify infection presence.

Health care professionals' perspectives on the requirements facilitating the roll-out of kangaroo mother care in South Africa

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Wilma ten Ham

2016-10-01

Purpose of the research: To explore and describe the perspectives of health professionals on the requirements for the rolling-out process of KMC as a best practice in South Africa. Methodology: Twelve semi-structured individual interviews were conducted in 2012 with health professionals from various South African healthcare levels, involved in the implementation and the rolling-out process of kangaroo mother care. Content analysis were guided in terms of the four requirements for roll-out of best practices, identified in Edwards and Grinspun's Evidence Informed Model of Care. Results: The requirements for the successful rollout of best practices mentioned by the participants in this study concur with the requirements of Edwards and Grinspun: personal alignment and protocol/policy alignment with the best practice; a roll-out plan; leadership; and supporting and reinforcing structures such as: resources, communicating, education and development regarding the best practice, and the organisational structure. The requirements were identified at four different levels: individual level (e.g. the nurse and medical specialists, management level (of the hospital, provincial level and national level.

Using futures methods to create transformative spaces: visions of a good Anthropocene in southern Africa

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Laura M. Pereira

2018-03-01

Full Text Available The unique challenges posed by the Anthropocene require creative ways of engaging with the future and bringing about transformative change. Envisioning positive futures is a first step in creating a shared understanding and commitment that enables radical transformations toward sustainability in a world defined by complexity, diversity, and uncertainty. However, to create a transformative space in which truly unknowable futures can be explored, new experimental approaches are needed that go beyond merely extrapolating from the present into archetypal scenarios of the future. Here, we present a process of creative visioning where participatory methods and tools from the field of futures studies were combined in a novel way to create and facilitate a transformative space, with the aim of generating positive narrative visions for southern Africa. We convened a diverse group of participants in a workshop designed to develop radically different scenarios of good Anthropocenes, based on existing "seeds" of the future in the present. These seeds are innovative initiatives, practices, and ideas that are present in the world today, but are not currently widespread or dominant. As a result of a carefully facilitated process that encouraged a multiplicity of perspectives, creative immersion, and grappling with deeply held assumptions, four radical visions for southern Africa were produced. Although these futures are highly innovative and exploratory, they still link back to current real-world initiatives and contexts. The key learning that arose from this experience was the importance of the imagination for transformative thinking, the need to capitalize on diversity to push boundaries, and finally, the importance of creating a space that enables participants to engage with emotions, beliefs, and complexity. This method of engagement with the future has the potential to create transformative spaces that inspire and empower people to act toward positive

Telephone triage by nurses in primary care out-of-hours services in Norway: an evaluation study based on written case scenarios.

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Hansen, Elisabeth Holm; Hunskaar, Steinar

2011-05-01

The use of nurses for telephone-based triage in out-of-hours services is increasing in several countries. No investigations have been carried out in Norway into the quality of decisions made by nurses regarding our priority degree system. There are three levels: acute, urgent and non-urgent. Nurses working in seven casualty clinics in out-of-hours districts in Norway (The Watchtowers) were all invited to participate in a study to assess priority grade on 20 written medical scenarios validated by an expert group. 83 nurses (response rate 76%) participated in the study. A one-out-of-five sample of the nurses assessed the same written cases after 3 months (n = 18, response rate 90%) as a test-retest assessment. Among the acute, urgent and non-urgent scenarios, 82%, 74% and 81% were correctly classified according to national guidelines. There were significant differences in the proportion of correct classifications among the casualty clinics, but neither employment percentage nor profession or work experience affected the triage decision. The mean intraobserver variability measured by the Cohen kappa was 0.61 (CI 0.52 to 0.70), and there were significant differences in kappa with employment percentage. Casualty clinics and work experience did not affect intrarater agreement. Correct classification of acute and non-urgent cases among nurses was quite high. Work experience and employment percentage did not affect triage decision. The intrarater agreement was good and about the same as in previous studies performed in other countries. Kappa increased significantly with increasing employment percentage.

Investigating the need for complex vs. simple scenarios to improve predictions of aquatic ecosystem exposure with the SoilPlus model

International Nuclear Information System (INIS)

Ghirardello, Davide; Morselli, Melissa; Otto, Stefan; Zanin, Giuseppe; Di Guardo, Antonio

2014-01-01

A spatially-explicit version of the recent multimedia fate model SoilPlus was developed and applied to predict the runoff of three pesticides in a small agricultural watershed in north-eastern Italy. In order to evaluate model response to increasing spatial resolution, a tiered simulation approach was adopted, also using a dynamic model for surface water (DynA model), to predict the fate of pesticides in runoff water and sediment, and concentrations in river water. Simulation outputs were compared to water concentrations measured in the basin. Results showed that a high spatial resolution and scenario complexity improved model predictions of metolachlor and terbuthylazine in runoff to an acceptable performance (R 2 = 0.64–0.70). The importance was also shown of a field-based database of properties (i.e. soil texture and organic carbon, rainfall and water flow, pesticides half-life in soil) in reducing the distance between predicted and measured surface water concentrations and its relevance for risk assessment. Highlights: • A GIS based model was developed to predict pesticide fate in soil and water. • Spatial scenario was obtained at field level for a small agricultural basin. • A tiered strategy was applied to test the performance gain with complexity. • Increased details of scenario as well as the role of surface water are relevant. -- In order to obtain more ecologically realistic predictions of pulse exposure in aquatic ecosystems detailed information about the scenario is required

Interactive simulations for promoting transdisciplinary understanding: a case study of the Western Cape fisheries, South Africa

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Cecile Proches

2012-07-01

Full Text Available Simulations have proven beneficial in enabling participants from various backgrounds to meaningfully engage in learning from experience. The aim of this paper is to investigate how interactive simulations can play a role in navigating the changes faced in a multi- stakeholder setting, characterised by users dependent on marine resources and an authorising institution. Relevant literature in the areas of simulation and gaming, change management, systems thinking, and complexity theory was examined. A qualitative research approach and purposive sampling were employed. Interviews were first conducted with diverse stakeholders in the Western Cape fisheries of South Africa to determine the issues. A simulation was thereafter designed. The main findings from this study indicate that simulation use illustrates how the various stakeholders in a system interact, and how their actions and decisions influence each other. The simulation may be used in other areas of natural resource management, as well as in other kinds of multi- stakeholder scenarios. Keywords: Simulation and gaming, Change management, Fisheries, Multi-stakeholder scenarios, Systems thinking, Complexity theory Disciplines: Conflict Resolution, Leadership Studies, Management Studies, Natural Resource Management

Coverage of alcohol consumption by national surveys in South Africa.

Science.gov (United States)

Probst, Charlotte; Shuper, Paul A; Rehm, Jürgen

2017-04-01

Evidence suggests that adult per-capita alcohol consumption, as estimated from self-reports of nationally representative surveys, underestimates 'true' consumption, as measured as the sum of recorded and unrecorded consumption. The proportion of total adult alcohol per capita reported in representative surveys is usually labelled 'coverage'. The aim of the present paper was to estimate coverage for South Africa under different scenarios of alcohol use assessment and 'true' consumption. Five nationally representative surveys from South Africa were used to estimate the prevalence of drinking and the grams per day among current drinkers. All surveys used a complex multi-stage sampling frame that was accounted for by using survey weights. The total (recorded and unrecorded), the recorded and the adjusted total adult per-capita alcohol consumption in South Africa served as different estimates of the 'true' consumption. South Africa. Alcohol use information was assessed on a total of 8115, 16 398 and 13 181 adults (15 years or older) in surveys from the years 2003, 2005 and 2008, respectively. Two surveys in 2012 included 27 070 and 18 688 adults. Coverage of the alcohol use reported in the surveys was calculated, compared with the 'true' adult per-capita alcohol. The survey data covered between 11.8% [2005; 95% uncertainty interval (UI) = 9.3-16.2%)] and 19.4% (2003; 95% UI = 14.9-24.2%) of the total alcohol used per capita. The highest coverage of 27.9% (95% UI = 22.4-36.8%) was observed when looking only at recorded alcohol in 2003. Evidence from five nationally representative surveys assessing alcohol use suggests that less than 20% of the total adult per-capita alcohol consumption in South Africa is reported in surveys. © 2016 Society for the Study of Addiction.

Early Human Evolution in the Western Palaearctic: Ecological Scenarios

Science.gov (United States)

Carrión, José S.; Rose, James; Stringer, Chris

2011-06-01

This review presents the themes of a special issue dealing with environmental scenarios of human evolution during the Early Pleistocene (2.6-0.78 Ma; MIS 103-MIS 19) and early Middle Pleistocene (0.78-0.47 Ma; MIS 19-base of MIS 12) within the western Palaearctic. This period is one of dramatic changes in the climates and the distribution of Palaearctic biota. These changes have played their role in generating adaptive and phyletic patterns within the human ancestry, involving several species such as Homo habilis, "Homo georgicus", Homo erectus, Homo antecessor and Homo heidelbergensis. In the archaeological record, these species include the Oldowan (Mode 1) and Acheulian (Mode 2) lithic technologies. Taphonomic considerations of palaeoecological research in hominin-bearing sites are provided and evaluated. Syntheses are provided for north Africa, western Asia, the Mediterranean Basin, Britain, and continental Europe. Palaeoenvironmental reconstructions based on multidisciplinary data are given for Ain Boucherit, Ain Hanech and El-Kherba in Algeria, Dmanisi in Georgia, Atapuerca, Cueva Negra, and the Orce Basin in Spain, Monte Poggiolo and Pirro Nord in Italy, Pont-de-Lavaud in France, and Mauer in Germany. The state of the art with the Out of Africa 1 dispersal model is reviewed. A source-sink dynamics model for Palaeolithic Europe is described to explain the morphological disparity of H. heidelbergensis (we will sometimes use the informal name "Heidelbergs") and early Neanderthals. Other aspects debated here are the selective value of habitat mosaics including reconstructions based on mammal and avian databases, and the role of geological instability combined with topographic complexity. This review is completed by addressing the question of whether the appearance of evolutionary trends within hominins is concentrated in regions of highest worldwide biological diversity (biodiversity hotspots). It is concluded that the keys for the activation of evolutionary

The dispersal of Homo sapiens across southern Asia: how early, how often, how complex?

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Dennell, Robin; Petraglia, Michael D.

2012-07-01

The timing and the paths of colonization of southern Asia by Homo sapiens are poorly known, though many population geneticists, paleoanthropologists, and archaeologists have contended that this process began with dispersal from East Africa, and occurred between 60,000 and 40,000 years ago. However, the evidence for this scenario is very weak, particularly the lack of human skeletal evidence between the Levant and Borneo before 40 ka, and other explanations are possible. Here we argue that environmental and archaeological information is increasingly indicating the likelihood that H. sapiens exited Africa much earlier than commonly thought, and may have colonized much of southern Asia well before 60,000 years ago. Additionally, we cannot exclude the possibility that several dispersal events occurred, from both North and East Africa, nor the likelihood that early populations of H. sapiens in southern Asia interbred with indigenous populations of Neanderthals, Denisovans and Homo erectus. The population history of southern Asia during the Upper Pleistocene is likely far more complex than currently envisaged.

SEA for strategic grid planning in South Africa: Enabling the efficient and effective roll out of strategic electricity transmission infrastructure

CSIR Research Space (South Africa)

Fischer, TD

2016-05-01

Full Text Available | Resilience and Sustainability 36th Annual Conference of the International Association for Impact Assessment 11 - 14 May 2016 | Nagoya Congress Center | Aichi-Nagoya | Japan | www.iaia.org SEA FOR STRATEGIC GRID PLANNING IN SOUTH AFRICA: Enabling... the efficient and effective roll out of strategic electricity transmission infrastructure Abstract ID: 409 Authors: Marshall Mabin(1) , Paul Lochner and Dee Fischer Council for Scientific and Industrial Research (CSIR), PO Box 320 Stellenbosch 7599 South...

Globalisation and local power: influences on health matters in South Africa.

Science.gov (United States)

Gilbert, Tal; Gilbert, Leah

2004-03-01

This paper reviews some of the multiple influences on health issues in South Africa, placing them in the context of globalisation. By examining the complexity of factors, both domestic and global, which impact on these issues, it questions the extent to which global patterns in areas such as health policy, HIV/AIDS, health care pluralism, and neo-liberal macroeconomic policy have played out in South Africa. The identification of some of the multiple and complex forces in each case reveals a relatively consistent story of global pressures interacting with domestic realities, with some recognizably local results. There is no doubt that a full and nuanced understanding of health in South Africa requires an appreciation of developments in the global political economy, international organizations such as the WHO and World Bank, and forces which operate outside of institutions. In each case, however, the specific opportunities available to actors within the country, as well as the relative power of those actors, should be given their due consideration in analysing their potential impact on health matters.

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

Service Approaches to Young People with Complex Needs Leaving Out-of-Home Care

Science.gov (United States)

Malvaso, Catia; Delfabbro, Paul; Hackett, Louisa; Mills, Hayley

2016-01-01

Although leaving statutory out-of-home care can be a challenging time for many young people, it is recognised that young people who have multiple or complex needs find this transition particularly difficult. This study aims to gain a deeper understanding of the challenges faced by care leavers who have complex needs, as well as to identify some of…

International bioenergy trade. Scenario study on international biomass market in 2020

Energy Technology Data Exchange (ETDEWEB)

Heinimoe, J.; Pakarinen, V.; Ojanen, V.; Kaessi, T.

2007-07-01

The markets of biomass for energy are developing rapidly and becoming more international. A remarkable increase in the use of biomass for energy needs parallel and positive development in several areas, and there will be plenty of challenges to overcome. The main objective of the study was to clarify the alternative future scenarios for the international biomass market until the year 2020, and based on the scenario process, to identify underlying steps needed towards the vital working and sustainable biomass market for energy purposes. Two scenario processes were conducted for this study. The first was carried out with a group of Finnish experts and the second involved an international group. A heuristic, semi structured approach, including the use of preliminary questionnaires as well as manual and computerised group support systems (GSS), was applied in the scenario processes. The scenario processes reinforced the picture of the future of international biomass and bioenergy markets as a complex and multi layer subject. The scenarios estimated that the biomass market will develop and grow rapidly as well as diversify in the future. The results of the scenario process also opened up new discussion and provided new information and collective views of experts for the purposes of policy makers. An overall view resulting from this scenario analysis are the enormous opportunities relating to the utilisation of biomass as a resource for global energy use in the coming decades. The scenario analysis shows the key issues in the field: global economic growth including the growing need for energy, environmental forces in the global evolution, possibilities of technological development to solve global problems, capabilities of the international community to find solutions for global issues and the complex interdependencies of all these driving forces. The results of the scenario processes provide a starting point for further research analysing the technological and commercial

International bioenergy trade. Scenario study on international biomass market in 2020

International Nuclear Information System (INIS)

Heinimoe, J.; Pakarinen, V.; Ojanen, V.; Kaessi, T.

2007-01-01

The markets of biomass for energy are developing rapidly and becoming more international. A remarkable increase in the use of biomass for energy needs parallel and positive development in several areas, and there will be plenty of challenges to overcome. The main objective of the study was to clarify the alternative future scenarios for the international biomass market until the year 2020, and based on the scenario process, to identify underlying steps needed towards the vital working and sustainable biomass market for energy purposes. Two scenario processes were conducted for this study. The first was carried out with a group of Finnish experts and the second involved an international group. A heuristic, semi structured approach, including the use of preliminary questionnaires as well as manual and computerised group support systems (GSS), was applied in the scenario processes. The scenario processes reinforced the picture of the future of international biomass and bioenergy markets as a complex and multi layer subject. The scenarios estimated that the biomass market will develop and grow rapidly as well as diversify in the future. The results of the scenario process also opened up new discussion and provided new information and collective views of experts for the purposes of policy makers. An overall view resulting from this scenario analysis are the enormous opportunities relating to the utilisation of biomass as a resource for global energy use in the coming decades. The scenario analysis shows the key issues in the field: global economic growth including the growing need for energy, environmental forces in the global evolution, possibilities of technological development to solve global problems, capabilities of the international community to find solutions for global issues and the complex interdependencies of all these driving forces. The results of the scenario processes provide a starting point for further research analysing the technological and commercial

Methods for Developing Multiscale Participatory Scenarios: Insights from Southern Africa and Europe

NARCIS (Netherlands)

Kok, K.; Biggs, R.; Zurek, M.

2007-01-01

Scenario planning is increasingly recognized as a useful tool for exploring change in social-ecological systems on decadal to centennial time horizons. In environmental decision making, scenario development tends to include participatory methods for engaging stakeholders and is conducted at multiple

Effects of IPCC SRES* emissions scenarios on river runoff: a global perspective

Directory of Open Access Journals (Sweden)

N. W. Arnell

2003-01-01

Full Text Available This paper describes an assessment of the implications of future climate change for river runoff across the entire world, using six climate models which have been driven by the SRES emissions scenarios. Streamflow is simulated at a spatial resolution of 0.5°x0.5° using a macro-scale hydrological model, and summed to produce total runoff for almost 1200 catchments. The effects of climate change have been compared with the effects of natural multi-decadal climatic variability, as determined from a long unforced climate simulation using HadCM3. By the 2020s, change in runoff due to climate change in approximately a third of the catchments is less than that due to natural variability but, by the 2080s, this falls to between 10 and 30%. The climate models produce broadly similar changes in runoff, with increases in high latitudes, east Africa and south and east Asia, and decreases in southern and eastern Europe, western Russia, north Africa and the Middle East, central and southern Africa, much of North America, most of South America, and south and east Asia. The pattern of change in runoff is largely determined by simulated change in precipitation, offset by a general increase in evaporation. There is little difference in the pattern of change between different emissions scenarios (for a given model, and only by the 2080s is there evidence that the magnitudes of change in runoff vary, with emissions scenario A1FI producing the greatest change and B1 the smallest. The inter-annual variability in runoff increases in most catchments due to climate change — even though the inter-annual variability in precipitation is not changed — and the frequency of flow below the current 10-year return period minimum annual runoff increases by a factor of three in Europe and southern Africa and of two across North America. Across most of the world climate change does not alter the timing of flows through the year but, in the marginal zone between cool and

'We are left in the cold': nurses' perceptions and responses to antiretroviral treatment roll-out in the Free State, South Africa.

Science.gov (United States)

de Wet, Katinka; du Plooy, Shirley

2012-01-01

The unprecedented roll-out of antiretroviral therapy (ART) in South Africa is a complex process where no previous endeavour exists that can measure, predict, or direct an intervention of this scale. In the Free State province, unique characteristics and problems distinguish its ART programme, although countrywide problems also occur within the province. The Free State province faces high vacancy rates among its health-care workers, the programme has lower patient enrolment rates because of an obsession with quality to the detriment of quantity, and various incidents of ART shortages have also shook the province. The ART roll-out intervention thus far has been largely nurse-driven (however not nurse initiated), and they form what many refer to as the 'backbone' of the programme. In order to respond to the challenges faced by these front-line ART providers, continuous transformations inevitably take place to respond to new needs associated with the roll-out programme, but also to strengthen the primary health-care system in general. The objective of this article is to present a typology of contradictory contextual factors in the antiretroviral programme as identified through group interviews that were conducted with PNs at public health-care clinics in the five districts of the Free State province during 2005 and 2006. We intend to show that transformations often have contradictory and problematic outcomes as expressed and perceived by the nurses themselves. This unprecedented endeavour of ART roll-out inevitably has to treasure and support its most valued implementers, i.e. the front-line providers who are not only professionals in the health-care setting, but also social agents in a wider contextual framework.

How front-line healthcare workers respond to stock-outs of essential medicines in the Eastern Cape Province of South Africa.

Science.gov (United States)

Hodes, R; Price, I; Bungane, N; Toska, E; Cluver, L

2017-08-25

Shortages of essential medicines are a daily occurrence in many of South Africa (SA)'s public health facilities. This study focuses on the responses of healthcare workers to stock-outs, investigating how actors at the 'front line' of public health delivery understand, experience and respond to shortages of essential medicines and equipment in their facilities. Findings are based on focus groups, observations and interviews with healthcare workers and patients at healthcare facilities in the Eastern Cape Province of SA, conducted as part of the Mzantsi Wakho study. The research revealed a discrepancy between 'informal' definitions of stock-outs and their reporting through formal stock-out management channels. Front-line healthcare workers had designed their own systems for classifying the severity of stock-outs, based on the product in question, and on their potential to access stocks from other facilities. Beyond formal systems of procurement and supply, healthcare workers had established vast networks of alternative communication and action, often using personal resources to procure medical supplies. Stock-outs were only reported when informal methods of stock-sharing did not secure top-up supplies. These findings have implications for understanding the frequency and severity of stock-outs, and for taking action to prevent and manage stock-outs effectively.

Community-based field implementation scenarios of a short message service reporting tool for lymphatic filariasis case estimates in Africa and Asia.

Science.gov (United States)

Mableson, Hayley E; Martindale, Sarah; Stanton, Michelle C; Mackenzie, Charles; Kelly-Hope, Louise A

2017-01-01

Lymphatic filariasis (LF) is a neglected tropical disease (NTD) targeted for global elimination by 2020. Currently there is considerable international effort to scale-up morbidity management activities in endemic countries, however there remains a need for rapid, cost-effective methods and adaptable tools for obtaining estimates of people presenting with clinical manifestations of LF, namely lymphoedema and hydrocele. The mHealth tool ' MeasureSMS-Morbidity ' allows health workers in endemic areas to use their own mobile phones to send clinical information in a simple format using short message service (SMS). The experience gained through programmatic use of the tool in five endemic countries across a diversity of settings in Africa and Asia is used here to present implementation scenarios that are suitable for adapting the tool for use in a range of different programmatic, endemic, demographic and health system settings. A checklist of five key factors and sub-questions was used to determine and define specific community-based field implementation scenarios for using the MeasureSMS-Morbidity tool in a range of settings. These factors included: (I) tool feasibility (acceptability; community access and ownership); (II) LF endemicity (high; low prevalence); (III) population demography (urban; rural); (IV) health system structure (human resources; community access); and (V) integration with other diseases (co-endemicity). Based on experiences in Bangladesh, Ethiopia, Malawi, Nepal and Tanzania, four implementation scenarios were identified as suitable for using the MeasureSMS-Morbidity tool for searching and reporting LF clinical case data across a range of programmatic, endemic, demographic and health system settings. These include: (I) urban, high endemic setting with two-tier reporting; (II) rural, high endemic setting with one-tier reporting; (III) rural, high endemic setting with two-tier reporting; and (IV) low-endemic, urban and rural setting with one

Aggregate electricity demand in South Africa: Conditional forecasts to 2030

International Nuclear Information System (INIS)

Inglesi, Roula

2010-01-01

In 2008, South Africa experienced a severe electricity crisis. Domestic and industrial electricity users had to suffer from black outs all over the country. It is argued that partially the reason was the lack of research on energy, locally. However, Eskom argues that the lack of capacity can only be solved by building new power plants. The objective of this study is to specify the variables that explain the electricity demand in South Africa and to forecast electricity demand by creating a model using the Engle-Granger methodology for co-integration and Error Correction models. By producing reliable results, this study will make a significant contribution that will improve the status quo of energy research in South Africa. The findings indicate that there is a long run relationship between electricity consumption and price as well as economic growth/income. The last few years in South Africa, price elasticity was rarely taken into account because of the low and decreasing prices in the past. The short-run dynamics of the system are affected by population growth, too After the energy crisis, Eskom, the national electricity supplier, is in search for substantial funding in order to build new power plants that will help with the envisaged lack of capacity that the company experienced. By using two scenarios for the future of growth, this study shows that the electricity demand will drop substantially due to the price policies agreed - until now - by Eskom and the National Energy Regulator South Africa (NERSA) that will affect the demand for some years. (author)

Aggregate electricity demand in South Africa: Conditional forecasts to 2030

Energy Technology Data Exchange (ETDEWEB)

Inglesi, Roula [Department of Economics, Faculty of Economic and Management Sciences, University of Pretoria, Main Campus, Pretoria 0002 (South Africa)

2010-01-15

In 2008, South Africa experienced a severe electricity crisis. Domestic and industrial electricity users had to suffer from black outs all over the country. It is argued that partially the reason was the lack of research on energy, locally. However, Eskom argues that the lack of capacity can only be solved by building new power plants. The objective of this study is to specify the variables that explain the electricity demand in South Africa and to forecast electricity demand by creating a model using the Engle-Granger methodology for co-integration and Error Correction models. By producing reliable results, this study will make a significant contribution that will improve the status quo of energy research in South Africa. The findings indicate that there is a long run relationship between electricity consumption and price as well as economic growth/income. The last few years in South Africa, price elasticity was rarely taken into account because of the low and decreasing prices in the past. The short-run dynamics of the system are affected by population growth, too After the energy crisis, Eskom, the national electricity supplier, is in search for substantial funding in order to build new power plants that will help with the envisaged lack of capacity that the company experienced. By using two scenarios for the future of growth, this study shows that the electricity demand will drop substantially due to the price policies agreed - until now - by Eskom and the National Energy Regulator South Africa (NERSA) that will affect the demand for some years. (author)

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

Directory of Open Access Journals (Sweden)

Nuha Elhassan

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

Model Complexity and Out-of-Sample Performance: Evidence from S&P 500 Index Returns

NARCIS (Netherlands)

Kaeck, Andreas; Rodrigues, Paulo; Seeger, Norman J.

We apply a range of out-of-sample specification tests to more than forty competing stochastic volatility models to address how model complexity affects out-of-sample performance. Using daily S&P 500 index returns, model confidence set estimations provide strong evidence that the most important model

Freshwater on the route of hominids "out of Africa" during the last interglacial revealed by U-Th in northern Red Sea fossil reefs

Science.gov (United States)

Lazar, B.; Stein, M.; Agnon, A.; Shaked, Y.

2012-04-01

The migration of Anatomically Modern Hominids (AMH) "out of Africa" is a fundamental problem in the study of human culture concerning that the route passed through the presently hyperarid deserts surrounding the Red Sea. Here, we outline the evidence for significant presence of freshwater in a well developed phreatic coastal aquifer along the Red Sea shores during the last interglacial period. The fringing coral reefs were tectonically uplifted through the freshwater lens resulting in extensive recrystallization of reef framework from the primary aragonite into calcite. We developed a novel open-system U-Th dating methodology that enabled us estimating two ages for the calcitic reef terrace: 1. The original age of the reef terrace, deposited at ~190 ka BP; and 2. the time of freshwater recrystallization (from the primary aragonite into calcite) at ~140 ka BP. The age of freshwater recrystallization is consistent with other geological lines of evidence placing the time of AMH migration "out of Africa" at the onset of the last interglacial. It is likely therefore that during that time the hyperarid Red Sea area was wetter than today facilitating the migration of AMH to Europe and Asia.

Arbitration Foundation of South Africa

Directory of Open Access Journals (Sweden)

Vladimir O. Kramarenko

2016-12-01

Full Text Available In the present article author explores the history and legal framework for the creation and operation of international commercial arbitration in South Africa. Author notes that South Africa is the most economically developed country in Africa, it is among dozens of major international organizations. From the point of view of the development of the system of law, legal proceedings and arbitration, South Africa is an attractive state for study. Author emphasizes that the South African Republic throughout its existence has been influenced by two legal families: Anglo-Saxon and Romano-Germanic. Therefore, it is important to note that South Africa refers to a mixed system of law. To date, South Africa has two international commercial arbitration: the Arbitration Foundation of South Africa and the Association of Arbitrators. In the conclusion author points out that the development and establishment of the centers of the arbitration fund continues: new centers are being established, and the system of procedures for dealing with cases in already established centers is being improved.

Toward Managing & Automating CyberCIEGE Scenario Definition File Creation

National Research Council Canada - National Science Library

Johns, Kenneth

2004-01-01

.... These scenarios are written CyberCIEGE Scenarios Definition Language. Unfortunately, the trade-off for flexibility, extendibility and fully customizable Scenarios is syntax complexity in the Scenarios definition language...

Global warming: Climate scenarios and international agriculture

International Nuclear Information System (INIS)

Downing, T.E.; Parry, M.L.

1991-01-01

The potential impacts of climatic change on international agriculture are summarized, drawing on results from the Intergovernmental Panel on Climate Change impacts working group. The four different climate change scenarios used for investigating impacts: historical studies, artificial scenarios, analogues, and general circulation models, are briefly reviewed. Climate change will affect agriculture in three ways: direct effects of increased carbon dioxide concentration, effects of altered weather patterns, and secondary effects on social and economic situations. The effect of increased carbon dioxide concentration is uncertain, but potentially will enhance plant growth and water use efficiency. The sensitivity of grain maize to incremental changes in annual temperature is described, with the suitable zone expanding from the middle of Europe to southern Scandinavia. Potential damage from insect pests may increase under warmer climates, with northerly movement of insect breeding grounds. Temperature increases are likely to lengthen the growing season where temperature is a limiting factor, especially at higher lattitudes in the Northern Hemisphere. Higher temperatures, shorter periods of grain filling, and reduced winter chilling will reduce potential yields in current core grain-growing areas, and changing moisture regimes will shift agricultural patterns. The horn of Africa and parts of western Africa are likely to suffer enhanced food supply vulnerability. 16 refs., 4 figs

Linking regional stakeholder scenarios and shared socioeconomic pathways: Quantified West African food and climate futures in a global context.

Science.gov (United States)

Palazzo, Amanda; Vervoort, Joost M; Mason-D'Croz, Daniel; Rutting, Lucas; Havlík, Petr; Islam, Shahnila; Bayala, Jules; Valin, Hugo; Kadi Kadi, Hamé Abdou; Thornton, Philip; Zougmore, Robert

2017-07-01

The climate change research community's shared socioeconomic pathways (SSPs) are a set of alternative global development scenarios focused on mitigation of and adaptation to climate change. To use these scenarios as a global context that is relevant for policy guidance at regional and national levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise. In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate change. In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population coupled with rising incomes leads to increases in the region's imports. For West Africa, climate change is projected to have negative effects on both crop yields and grassland productivity, and a lack of investment may exacerbate these effects. Linking multi-stakeholder regional scenarios to the global SSPs ensures scenarios that are regionally appropriate and useful for policy development as evidenced in the case study, while allowing for a critical link to global contexts.

Model France. Efficiently achieving climate protection targets. Nuclear power phase-out scenario adapted in favour of climate protection; Vorbild Frankreich. Klimaschutzziele effizient erreichen. Ausstiegszenario Kernkraft zugunsten des Klimaschutzes angepasst

Energy Technology Data Exchange (ETDEWEB)

Leidinger, Tobias [Luther Rechtsanwaltsgesellschaft, Duesseldorf (Germany)

2017-12-15

In Germany - after an abrupt, legally controversial and in some cases unconstitutional phase-out of nuclear power (''at any price'') - the next phase-out of is now being negotiated among new coalition partners. In France, on the other hand, energy and climate protection seem to be in the clear sense of the word: the French nuclear phase-out scenario is clearly being ''stretched out'' in order to achieve the promised climate protection targets. Reason seems to have the upper hand in France: instead of ''black-and-white scenarios'', one prefers to stick to what is in reality feasible and achievable. In reality, the expansion of renewable energies, the regulation of the transport sector and electricity production from nuclear energy are not opposites, but complement each other in the interests of affordable energy and effective climate protection.

An early and enduring advanced technology originating 71,000 years ago in South Africa.

Science.gov (United States)

Brown, Kyle S; Marean, Curtis W; Jacobs, Zenobia; Schoville, Benjamin J; Oestmo, Simen; Fisher, Erich C; Bernatchez, Jocelyn; Karkanas, Panagiotis; Matthews, Thalassa

2012-11-22

There is consensus that the modern human lineage appeared in Africa before 100,000 years ago. But there is debate as to when cultural and cognitive characteristics typical of modern humans first appeared, and the role that these had in the expansion of modern humans out of Africa. Scientists rely on symbolically specific proxies, such as artistic expression, to document the origins of complex cognition. Advanced technologies with elaborate chains of production are also proxies, as these often demand high-fidelity transmission and thus language. Some argue that advanced technologies in Africa appear and disappear and thus do not indicate complex cognition exclusive to early modern humans in Africa. The origins of composite tools and advanced projectile weapons figure prominently in modern human evolution research, and the latter have been argued to have been in the exclusive possession of modern humans. Here we describe a previously unrecognized advanced stone tool technology from Pinnacle Point Site 5-6 on the south coast of South Africa, originating approximately 71,000 years ago. This technology is dominated by the production of small bladelets (microliths) primarily from heat-treated stone. There is agreement that microlithic technology was used to create composite tool components as part of advanced projectile weapons. Microliths were common worldwide by the mid-Holocene epoch, but have a patchy pattern of first appearance that is rarely earlier than 40,000 years ago, and were thought to appear briefly between 65,000 and 60,000 years ago in South Africa and then disappear. Our research extends this record to ~71,000 years, shows that microlithic technology originated early in South Africa, evolved over a vast time span (~11,000 years), and was typically coupled to complex heat treatment that persisted for nearly 100,000 years. Advanced technologies in Africa were early and enduring; a small sample of excavated sites in Africa is the best explanation for any

Transitional dispersive scenarios driven by mesoscale flows on complex terrain under strong dry convective conditions

Directory of Open Access Journals (Sweden)

J. L. Palau

2009-01-01

Full Text Available By experimentation and modelling, this paper analyses the atmospheric dispersion of the SO₂ emissions from a power plant on complex terrain under strong convective conditions, describing the main dispersion features as an ensemble of "stationary dispersive scenarios" and reformulating some "classical" dispersive concepts to deal with the systematically monitored summer dispersive scenarios in inland Spain. The results and discussions presented arise from a statistically representative study of the physical processes associated with the multimodal distribution of pollutants aloft and around a 343-m-tall chimney under strong dry convective conditions in the Iberian Peninsula. This paper analyses the importance of the identification and physical implications of transitional periods for air quality applications. The indetermination of a transversal plume to the preferred transport direction during these transitional periods implies a small (or null physical significance of the classical definition of horizontal standard deviation of the concentration distribution.

Echinococcosis in sub-Saharan Africa: emerging complexity

NARCIS (Netherlands)

Romig, T.; Omer, R. A.; Zeyhle, E.; Hüttner, M.; Dinkel, A.; Siefert, L.; Elmahdi, I. E.; Magambo, J.; Ocaido, M.; Menezes, C. N.; Ahmed, M. E.; Mbae, C.; Grobusch, M. P.; Kern, P.

2011-01-01

Cystic echinococcosis occurs in most regions of sub-Saharan Africa, but the frequency of this zoonosis differs considerably among and within countries. Especially human cases seem to be focally distributed. A number of environmental and behavioural factors partially explain this pattern, i.e.

'These are not luxuries, it is essential for access to life': Disability related out-of-pocket costs as a driver of economic vulnerability in South Africa.

Science.gov (United States)

Hanass-Hancock, Jill; Nene, Siphumelele; Deghaye, Nicola; Pillay, Simmi

2017-01-01

With the dawn of the new sustainable development goals, we face not only a world that has seen great successes in alleviating poverty but also a world that has left some groups, such as persons with disabilities, behind. Middle-income countries (MICs) are home to a growing number of persons with disabilities. As these countries strive to achieve the new goals, we have ample opportunity to include persons with disabilities in the emerging poverty alleviation strategies. However, a lack of data and research on the linkages between economic vulnerability and disability in MICs hampers our understanding of the factors increasing economic vulnerability in people with disabilities. This article aims to present data related to elements of this vulnerability in one MIC, South Africa. Focusing on out-of-pocket costs, it uses focus group discussions with 73 persons with disabilities and conventional content analysis to describe these costs. A complex and nuanced picture of disability-driven costs evolved on three different areas: care and support for survival and safety, accessibility of services and participation in community. Costs varied depending on care and support needs, accessibility (physical and financial), availability, and knowledge of services and assistive devices. The development of poverty alleviation and social protection mechanisms in MICs like South Africa needs to better consider diverse disability-related care and support needs not only to improve access to services such as education and health (National Health Insurance schemes, accessible clinics) but also to increase the effect of disability-specific benefits and employment equity policies.

The use of defence mechanisms as precursors to coming out in post-apartheid South Africa: a gay and lesbian youth perspective.

Science.gov (United States)

Butler, Allister H; Astbury, Gaynor

2008-01-01

This article comprises one facet of a larger, three-year phenomenological study (1997-2000) of gay and lesbian youth coming out in post-apartheid South Africa. A nonprobability sample of 18 young people, aged between 16 and 21 years, was interviewed. The resultant data was content analyzed, and the trustworthiness of the information was ensured via member checking and utilizing an independent coder. Results consistently revealed that gay and lesbian youth use defense mechanisms, such as denial, avoidance, compartmentalization, suppression, compensation, sublimation, undoing, displacement, rationalization, and intellectualization, in a conscious manner during their coming out process. The young people in this study demonstrated resilience despite the prejudice and inner turmoil that they had experienced. Practice guidelines are suggested in terms of how health and social care practitioners can support gay and lesbian youth in coping with their coming out process.

The ShakeOut scenario: A hypothetical Mw7.8 earthquake on the Southern San Andreas Fault

Science.gov (United States)

Porter, K.; Jones, L.; Cox, D.; Goltz, J.; Hudnut, K.; Mileti, D.; Perry, S.; Ponti, D.; Reichle, M.; Rose, A.Z.; Scawthorn, C.R.; Seligson, H.A.; Shoaf, K.I.; Treiman, J.; Wein, A.

2011-01-01

In 2008, an earthquake-planning scenario document was released by the U.S. Geological Survey (USGS) and California Geological Survey that hypothesizes the occurrence and effects of a Mw7.8 earthquake on the southern San Andreas Fault. It was created by more than 300 scientists and engineers. Fault offsets reach 13 m and up to 8 m at lifeline crossings. Physics-based modeling was used to generate maps of shaking intensity, with peak ground velocities of 3 m/sec near the fault and exceeding 0.5 m/sec over 10,000 km2. A custom HAZUS??MH analysis and 18 special studies were performed to characterize the effects of the earthquake on the built environment. The scenario posits 1,800 deaths and 53,000 injuries requiring emergency room care. Approximately 1,600 fires are ignited, resulting in the destruction of 200 million square feet of the building stock, the equivalent of 133,000 single-family homes. Fire contributes $87 billion in property and business interruption loss, out of the total $191 billion in economic loss, with most of the rest coming from shakerelated building and content damage ($46 billion) and business interruption loss from water outages ($24 billion). Emergency response activities are depicted in detail, in an innovative grid showing activities versus time, a new format introduced in this study. ?? 2011, Earthquake Engineering Research Institute.

Informational Entropy and Bridge Scour Estimation under Complex Hydraulic Scenarios

Science.gov (United States)

Pizarro, Alonso; Link, Oscar; Fiorentino, Mauro; Samela, Caterina; Manfreda, Salvatore

2017-04-01

Bridges are important for society because they allow social, cultural and economic connectivity. Flood events can compromise the safety of bridge piers up to the complete collapse. The Bridge Scour phenomena has been described by empirical formulae deduced from hydraulic laboratory experiments. The range of applicability of such models is restricted by the specific hydraulic conditions or flume geometry used for their derivation (e.g., water depth, mean flow velocity, pier diameter and sediment properties). We seek to identify a general formulation able to capture the main dynamic of the process in order to cover a wide range of hydraulic and geometric configuration, allowing to extend our analysis in different contexts. Therefore, exploiting the Principle of Maximum Entropy (POME) and applying it on the recently proposed dimensionless Effective flow work, W*, we derived a simple model characterized by only one parameter. The proposed Bridge Scour Entropic (BRISENT) model shows good performances under complex hydraulic conditions as well as under steady-state flow. Moreover, the model was able to capture the evolution of scour in several hydraulic configurations even if the model contains only one parameter. Furthermore, results show that the model parameter is controlled by the geometric configurations of the experiment. This offers a possible strategy to obtain a priori model parameter calibration. The BRISENT model represents a good candidate for estimating the time-dependent scour depth under complex hydraulic scenarios. The authors are keen to apply this idea for describing the scour behavior during a real flood event. Keywords: Informational entropy, Sediment transport, Bridge pier scour, Effective flow work.

Scenario planning.

Science.gov (United States)

Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

2011-03-01

suggest which basic features among the "possible futures" are playing out. Scenario planning provides for the implementation of appropriate constructed strategic responses. Scenarios allow for a pre-prepared game plan available for ready use as the future unfolds. They allow a deliberative response rather than a hastily constructed, urgent response. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Analysis of Evolutionarily Independent Protein-RNA Complexes Yields a Criterion to Evaluate the Relevance of Prebiotic Scenarios.

Science.gov (United States)

Blanco, Celia; Bayas, Marco; Yan, Fu; Chen, Irene A

2018-02-19

A central difficulty facing study of the origin of life on Earth is evaluating the relevance of different proposed prebiotic scenarios. Perhaps the most established feature of the origin of life was the progression through an RNA World, a prebiotic stage dominated by functional RNA. We use the appearance of proteins in the RNA World to understand the prebiotic milieu and develop a criterion to evaluate proposed synthetic scenarios. Current consensus suggests that the earliest amino acids of the genetic code were anionic or small hydrophobic or polar amino acids. However, the ability to interact with the RNA World would have been a crucial feature of early proteins. To determine which amino acids would be important for the RNA World, we analyze non-biological protein-aptamer complexes in which the RNA or DNA is the result of in vitro evolution. This approach avoids confounding effects of biological context and evolutionary history. We use bioinformatic analysis and molecular dynamics simulations to characterize these complexes. We find that positively charged and aromatic amino acids are over-represented whereas small hydrophobic amino acids are under-represented. Binding enthalpy is found to be primarily electrostatic, with positively charged amino acids contributing cooperatively to binding enthalpy. Arginine dominates all modes of interaction at the interface. These results suggest that proposed prebiotic syntheses must be compatible with cationic amino acids, particularly arginine or a biophysically similar amino acid, in order to be relevant to the invention of protein by the RNA World. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of a Diagnostic Complexity Questionnaire

International Nuclear Information System (INIS)

Collier, Steve

1998-02-01

The HRP human error analysis project has for some time been investigating what makes certain fault scenarios difficult for operators. One line of research has been to develop a questionnaire to measure diagnostic complexity. This report concerns some theoretical and experimental work underpinning the development of the questionnaire. A study of the literature reviewed the factors or components thought to contribute to difficulty in diagnosing and problem-solving. Two experimental studies of complexity were carried out using two versions of a questionnaire based on the review. The studies were simulator based, using scenarios designed to be diagnostically challenging. A factor-analytic approach to the analysis of the study data was suggested in the literature review. This is reported here (together with other analyses) though the factor analysis did not produce so clear results as was hoped. The present analysis found no clear factor structure with the first version of the complexity questionnaire used in experiment I. Partly because of this result, a factor-analytic approach to a second version of the questionnaire used in experiment II was not considered appropriate. A descriptive and qualitative analysis of the two questionnaire studies and a synthesis of the results from them both was promising. There were indications of components of complexity and some indications of what contributes to a personal perception of high or low diagnostic difficulty in fault scenarios. Components adding to diagnostic difficulty were tentatively named 'severity', 'need for co-operation', 'stress' and 'spread of changes'. Components not adding to difficulty were 'directness of indications', 'familiarity' and 'lack of stress'. There was some evidence of different responses to these components in a comparison of rule-based vs. knowledge-based diagnostic scenarios. These findings and experience with analysis techniques will feed into the design of further work on the human error

AgMIP Climate Data and Scenarios for Integrated Assessment. Chapter 3

Science.gov (United States)

Ruane, Alexander C.; Winter, Jonathan M.; McDermid, Sonali P.; Hudson, Nicholas I.

2015-01-01

Climate change presents a great challenge to the agricultural sector as changes in precipitation, temperature, humidity, and circulation patterns alter the climatic conditions upon which many agricultural systems rely. Projections of future climate conditions are inherently uncertain owing to a lack of clarity on how society will develop, policies that may be implemented to reduce greenhouse-gas (GHG) emissions, and complexities in modeling the atmosphere, ocean, land, cryosphere, and biosphere components of the climate system. Global climate models (GCMs) are based on well-established physics of each climate component that enable the models to project climate responses to changing GHG concentration scenarios (Stocker et al., 2013).The most recent iteration of the Coupled Model Intercomparison Project (CMIP5; Taylor et al., 2012) utilized representative concentration pathways (RCPs) to cover the range of plausible GHG concentrations out past the year 2100, with RCP8.5 representing an extreme scenario and RCP4.5 representing a lower concentrations scenario (Moss et al., 2010).

The Out of Africa hypothesis and the ancestry of recent humans: Cherchez la femme (et l'homme).

Science.gov (United States)

Árnason, Úlfur

2016-07-01

The Out of Africa hypothesis (OOAH) has been a mainstay in the discussion of human evolution since its presentation in the 1980's. However, recent advances in palaeontology and molecular genetics have made it possible to examine the hypothesis in a manner that was inconceivable at the time of its proposal. The palaeontological progress relates to early Homo finds in the Caucasus, Denisova finds in the Altai Mountains and Neanderthal finds in a wide range of localities from the Altai Mountains, the Caucasus, the Levant, Asia Minor, southern and Central Europe and the Iberian Peninsula. The Eurasian location of these finds and recognition of the principle of Last common ancestor (LCA) lend no support to OOAH. The same conclusion is drawn from genomic findings, which (a) have revealed the presence of Denisovan and Neanderthal nuclear DNA, primarily in the genomes of recent Eurasians and (b) have shown genomic introgression from early modern humans into Neanderthals in the Altai Mountains. Similarly, archaeological finds in Sulawesi and the discovery of ≈100,000years old human teeth in southern China constitute strong independent challenges to OOAH. The genomic and palaeogenomic results and the new palaeontological and archaeological discoveries suggest (a) that the ancestors of modern humans had their origin in a Eurasian (largely Asian) biogeographic region which may also have extended into NE Africa, and (b) that the founders of basal African lineages became separated, geographically and genetically, in the westernmost part of this region and spread from there to different parts of the African continent. Copyright © 2016 Elsevier B.V. All rights reserved.

‘These are not luxuries, it is essential for access to life’: Disability related out-of-pocket costs as a driver of economic vulnerability in South Africa

Science.gov (United States)

Nene, Siphumelele; Deghaye, Nicola; Pillay, Simmi

2017-01-01

Background With the dawn of the new sustainable development goals, we face not only a world that has seen great successes in alleviating poverty but also a world that has left some groups, such as persons with disabilities, behind. Middle-income countries (MICs) are home to a growing number of persons with disabilities. As these countries strive to achieve the new goals, we have ample opportunity to include persons with disabilities in the emerging poverty alleviation strategies. However, a lack of data and research on the linkages between economic vulnerability and disability in MICs hampers our understanding of the factors increasing economic vulnerability in people with disabilities. Methods This article aims to present data related to elements of this vulnerability in one MIC, South Africa. Focusing on out-of-pocket costs, it uses focus group discussions with 73 persons with disabilities and conventional content analysis to describe these costs. Results A complex and nuanced picture of disability-driven costs evolved on three different areas: care and support for survival and safety, accessibility of services and participation in community. Costs varied depending on care and support needs, accessibility (physical and financial), availability, and knowledge of services and assistive devices. Conclusions The development of poverty alleviation and social protection mechanisms in MICs like South Africa needs to better consider diverse disability-related care and support needs not only to improve access to services such as education and health (National Health Insurance schemes, accessible clinics) but also to increase the effect of disability-specific benefits and employment equity policies. PMID:28730066

A Complex Systems Approach to Energy Poverty in sub-Saharan Africa: Nigeria as a Case Study

Science.gov (United States)

Chidebell Emordi, Chukwunonso

Energy poverty is pervasive in sub-Saharan Africa. Nigeria, located in sub-Saharan West Africa, is the world's seventh largest oil exporting country and is a resource-rich nation. It however experiences the same levels of energy poverty as most of its neighboring countries. Attributing this paradox only to corruption or the "Dutch Disease", where one sector booms at the expense of other sectors of the economy, is simplistic and enervates attempts at reform. In addition, data on energy consumption is aggregated at the national level via estimates, disaggregated data is virtually non-existent. Finally, the wave of decentralization of vertically integrated national utilities sweeping the developing world has caught on in sub-Saharan Africa. However, little is known of the economic and social implications of these transitions within the unique socio-technical system of the region's electricity sector, especially as it applies to energy poverty. This dissertation proposes a complex systems approach to measuring and mitigating energy poverty in Nigeria due to its multi-dimensional nature. This is done via a three-fold approach: the first section of the study delves into causation by examining the governance institutions that create and perpetuate energy poverty; the next section proposes a context-specific minimum energy poverty line based on field data collected on energy consumption; and the paper concludes with an indicator-based transition management framework encompassing institutional, economic, social, and environmental themes of sustainable transition within the electricity sector. This work contributes to intellectual discourse on systems-based mitigation strategies for energy poverty that are widely applicable within the sub-Saharan region, as well as adds to the knowledge-base of decision-support tools for addressing energy poverty in its complexity.

A scenario framework to explore the future migration and adaptation in deltas: A multi-scale and participatory approach

Science.gov (United States)

Kebede, Abiy S.; Nicholls, Robert J.; Allan, Andrew; Arto, Inaki; Cazcarro, Ignacio; Fernandes, Jose A.; Hill, Chris T.; Hutton, Craig W.; Kay, Susan; Lawn, Jon; Lazar, Attila N.; Whitehead, Paul W.

2017-04-01

Coastal deltas are home for over 500 million people globally, and they have been identified as one of the most vulnerable coastal environments during the 21st century. They are susceptible to multiple climatic (e.g., sea-level rise, storm surges, change in temperature and precipitation) and socio-economic (e.g., human-induced subsidence, population and urbanisation changes, GDP growth) drivers of change. These drivers also operate at multiple scales, ranging from local to global and short- to long-term. This highlights the complex challenges deltas face in terms of both their long-term sustainability as well as the well-being of their residents and the health of ecosystems that support the livelihood of large (often very poor) population under uncertain changing conditions. A holistic understanding of these challenges and the potential impacts of future climate and socio-economic changes is central for devising robust adaptation policies. Scenario analysis has long been identified as a strategic management tool to explore future climate change and its impacts for supporting robust decision-making under uncertainty. This work presents the overall scenario framework, methodology, and processes adopted for the development of scenarios in the DECCMA* project. DECCMA is analysing the future of three deltas in South Asia and West Africa: (i) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India), (ii) the Mahanadi delta (India), and (iii) the Volta delta (Ghana). This includes comparisons between these three deltas. Hence, the scenario framework comprises a multi-scale hybrid approach, with six levels of scenario considerations: (i) global (climate change, e.g., sea-level rise, temperature change; and socio-economic assumptions, e.g., population and urbanisation changes, GDP growth); (ii) regional catchments (e.g., river flow modelling), (iii) regional seas (e.g., fisheries modelling), (iv) regional politics (e.g., transboundary disputes), (v) national (e.g., socio

CIEMAT analyses of transition fuel cycle scenarios

International Nuclear Information System (INIS)

Alvarez-Velarde, F.; Gonzalez-Romero, E.M.

2010-01-01

The efficient design of strategies for the long-term sustainability of nuclear energy or the phase-out of this technology is possible after the study of transition scenarios from the current fuel cycle to a future one with advanced technologies and concepts. CIEMAT has participated in numerous fuel cycle scenarios studies for more than a decade and, from some years ago, special attention has been put in the study of transition scenarios. In this paper, the main characteristics of each studied transition scenario are described. The main results and partial conclusions of each scenario are also analyzed. As general conclusions of transition studies, we highlight that the advantages of advanced technologies in transition scenarios can be obtained by countries or regions with sufficiently large nuclear parks, with a long-term implementation of the strategy. For small countries, these advantages are also accessible with an affordable cost, by means of the regional collaboration during several decades. (authors)

Regional scenario building as a tool to support vulnerability assessment of food & water security and livelihood conditions under varying natural resources managements

Science.gov (United States)

Reinhardt, Julia; Liersch, Stefan; Dickens, Chris; Kabaseke, Clovis; Mulugeta Lemenih, Kassaye; Sghaier, Mongi; Hattermann, Fred

2013-04-01

Participatory regional scenario building was carried out with stakeholders and local researchers in four meso-scale case studies (CS) in Africa. In all CS the improvement of food and / or water security and livelihood conditions was identified as the focal issue. A major concern was to analyze the impacts of different plausible future developments on these issues. The process of scenario development is of special importance as it helps to identify main drivers, critical uncertainties and patterns of change. Opportunities and constraints of actors and actions become clearer and reveal adaptation capacities. Effective strategies must be furthermore reasonable and accepted by local stakeholders to be implemented. Hence, developing scenarios and generating strategies need the integration of local knowledge. The testing of strategies shows how they play out in different scenarios and how robust they are. Reasons and patterns of social and natural vulnerability can so be shown. The scenario building exercise applied in this study is inspired by the approach from Peter Schwartz. It aims at determining critical uncertainties and to identify the most important driving forces for a specific focal issue which are likely to shape future developments of a region. The most important and uncertain drivers were analyzed and systematized with ranking exercises during meetings with local researchers and stakeholders. Cause-effect relationships were drawn in the form of concept maps either during the meetings or by researchers based on available information. Past observations and the scenario building outcomes were used to conduct a trend analysis. Cross-comparisons were made to find similarities and differences between CS in terms of main driving forces, patterns of change, opportunities and constraints. Driving forces and trends which aroused consistently over scenarios and CS were identified. First results indicate that livelihood conditions of people rely often directly on the

Calculation of freight externality costs for South Africa

Directory of Open Access Journals (Sweden)

Stefaan Swarts

2012-11-01

Full Text Available The purpose of this study is to quantify the marginal external costs associated with freight transport in South Africa. Six cost elements are included as externality cost items, namely, costs related to accidents, emissions, roadway land availability, policing, noise and congestion. Inputs in the calculations were a gravity-oriented freight flow model, a road transport cost model, actual transport costs for other modes, a warehousing cost survey, an inventory delay calculation and various national sources of information such as accident statistics and government budgets. Estimation techniques resulted in advances for externality cost measurement in South Africa. The quantification of the cost elements will be used to update the South African Freight Demand Model. The results show that the cost of transportation would have been 20% more if external factors were taken into account. The marginal rates of externalities can be used to develop scenarios based on alternative choices for South Africa's freight transport infrastructure configuration.

Phasing out nuclear, a credible scenario

International Nuclear Information System (INIS)

Chatelain, C.; Mulot, R.; Chauveau, L.; Hait, J.F.

2011-01-01

Based on data from different companies, institutions and associations involved in nuclear energy (either in its production or in its critic), this article comments the possible energy savings (50 to 64%) that may be reached in the different sectors, and more particularly in the building sector and in electrical equipment. It discusses the potential production from solar, wind and biogas energy. It notices that phasing out nuclear is possible by 2030-2050, but would entail an increase of electricity prices. The German approach is presented. An article comments the anger of Fukushima Japanese farmers and evokes the slow building up of a solidarity network between France and Japan. A last article comments the authorization given to a further exploitation of the Fessenheim nuclear power plant (ten more years)

South Africa

International Nuclear Information System (INIS)

Fischer, D.

1990-01-01

This paper reports that South Africa's main reason for entering the international nuclear market is, and always has been, to sell its uranium abroad. From 1939-45 South Africa took part in the war against Nazi Germany, and the South African government of the time sought to help the Allied war effort in all ways that were practical. Later, during the Cold War, it tried to help build up the West's nuclear arsenal. In 1944, the British government secretly asked General Smuts---prime minister of South Africa since 1939 and a member of Churchill's War Cabinet---to survey South Africa's deposits of uranium. The survey, carried out with U.S. and British help, showed that the deposits were large, generally low-grade, but, in most cases, associated with gold and therefore could be profitably mined. In 1951, South Africa became a significant producer, with lucrative contracts for the sale of all its output to the U.S.-U.K.-Canada Joint Development Agency and one of the three main suppliers to the U.S. nuclear weapons program. In time, government controls eased and uranium production and marketing became a purely commercial operation

Managing Natural Resources for Development in Africa: A Resource ...

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

The moral rights of the authors have been asserted. .... Examples of Important NRM Issues in Africa. 37 ... by the Hadcm3 Climate Model if a Business as Usual Scenario is Assumed for Economic Growth and Greenhouse Gas Emissions. In this ...

Erratum: International Journal of Global Energy Issues, Vol. 13, Nos. 1-3, 2000, p.247. Bent Soerensen and Peter Meibom 'A global renewable energy scenario'

International Nuclear Information System (INIS)

2001-01-01

5.1 ecentralised renewable energy 2050 scenario. The demand categories have already, as shown in Table 6, been simplified under the assumption of an abundant fraction of the supply being in the form of electric energy. We now determine the sources of supply for each demand type. For the vegetable food-fraction, the results of comparing local supply and demand are shown in Figures 38 and 39, where Figure 38 shows the amount of surplus for those geographical grid cells, where supply exceeds demand, and Figure 39 shows the amount of deficit for those local cells where demand exceeds supply. Regional sums are given in Table 10, while the sums of individual contributions to demand and supply are given in Tables 6 and 8. It follows that on average, worldwide supply exceeds demand by 35%. This must be considered reasonable, as there has to be room for variations in crop harvests and thus food production from year to year, and further the transportation required for evening out supply and demand will entail some additional losses. Like today, there is surplus vegetable food production in the Americas and Western Europe (regions 1, 2 and 4), and by the year 2050 also in region 3 (including Russia), due to substantial improvements in agricultural practices assumed for this region. Region 5 (including China and India) will be just self-sufficient by the year 2050, whereas Africa (region 6) will have a deficit that must be covered by imports. In the scenario, Africa is the only region that by 2050 is in a development situation where it may offer labour at lower expense that the other regions, and thus there will be the possibility of paying for food imports by industrial revenues, provided that an education policy is pursued, that will give the workforce the necessary skills. In addition to inter-regional exchange, Figures 38 and 39 indicate scenario requirements for transport of vegetable food within regions, especially from farming areas into cities. The scenario assumptions

Identification of reference accident scenarios in SEVESO establishments

International Nuclear Information System (INIS)

Delvosalle, C.; Fievez, C.; Pipart, A.; Fabrega, J. Casal; Planas, E.; Christou, M.; Mushtaq, F.

2005-01-01

In the frame of the ESREL special session on ARAMIS project, this paper aims at presenting the work carried out in the first Work Package, devoted to the definition of accident scenarios. This topic is a key-point in risk assessment, and serves as basis for the whole risk quantification. A first part of the work aims at building a Methodology for the Identification of Major Accident Hazards (MIMAH), which is carried out with the development of generic fault and event trees based on a typology of equipment and substances. This work is coupled with an historical analysis of accidents. In a second part, influence of safety devices and policies will be considered, in order to build a Methodology for the Identification of Reference Accident Scenarios (MIRAS). This last one will take into account safety systems and lead to obtain more realistic scenarios

Scenarios in the development of Mediterranean cyclones

Directory of Open Access Journals (Sweden)

M. Romem

2007-07-01

Full Text Available The Mediterranean is one of the most cyclogenetic regions in the world. The cyclones are concentrated along its northern coasts and their tracks are oriented more or less west-east, with several secondary tracks connecting them to Europe and to North Africa. The aim of this study is to examine scenarios in the development of Mediterranean cyclones, based on five selected winter seasons (October–March. We detected the cyclones subjectively using 6-hourly Sea-Level Pressure maps, based on the NCAR/NCEP reanalysis archive.

HMSO (1962 has shown that most Mediterranean cyclones (58% enter the Mediterranean from the Atlantic Ocean (through Biscay and Gibraltar, and from the south-west, the Sahara Desert, while the rest are formed in the Mediterranean Basin itself. Our study revealed that only 13% of the cyclones entered the Mediterranean, while 87% were generated in the Mediterranean Basin. The entering cyclones originate in three different regions: the Sahara Desert (6%, the Atlantic Ocean (4%, and Western Europe (3%.

The cyclones formed within the Mediterranean Basin were found to generate under the influence of external cyclonic systems, i.e. as "daughter cyclones" to "parent cyclones" or troughs. These parent systems are located in three regions: Europe (61%, North Africa and the Red Sea (34.5% and the Mediterranean Basin itself (4.5%. The study presents scenarios in the development of Mediterranean cyclones during the winter season, emphasizing the cyclogenesis under the influence of various external forcing.

The large difference with respect to the findings of HMSO (1962 is partly explained by the dominance of spring cyclones generating in the Sahara Desert, especially in April and May that were not included in our study period.

Culture and biomedical care in Africa: the influence of culture on biomedical care in a traditional African society, Nigeria, West Africa.

Science.gov (United States)

Chukwuneke, F N; Ezeonu, C T; Onyire, B N; Ezeonu, P O

2012-01-01

Biomedical Care in Africa and the influence of culture on the health-seeking behaviour of Africans can not be underestimated; many African cultures have different understanding of the causes of disease which more often affect our public health system, policy, planning and implementations. The traditional African healer unlike a doctor trained in western biomedicine, looks for the cause of the patient's ailments as misfortune in relationship between the patient and the social, natural and spiritual environments. The complexity of African society with different cultural and religious practices also reflects on the people's attitude and understanding of their health matters. This paper is an overview of the cultural influence on biomedical care in a traditional African society, Nigeria, West Africa. A research on the patients' health seeking behaviour and Primary Health Care service organization in 10 health centres in the five eastern states of the Federal Republic of Nigeria was carried out using a multistage cross-sectional study. A semi-structured questionnaire was administered to the health care providers and patients while an in-depth semi- structured interview was also conducted. We observed there is underutilization of health care services at the primary level because most people do not accept the model of health care system provided for them. Most people believe diseases are caused by supernatural beings, the handiwork of neighbours or vengeance from an offended god as a result of transgressions committed in the past by an individual or parents. This group of people therefore prefers seeking traditional medicine to seeking orthodox medicine and often ends up in the hands of witch doctors who claim to have cure to almost all the diseases. Biomedical care in Africa is influence by culture because of different understanding of what ailment is and also due to limited knowledge of health matters, poverty and ignorance. There is a need therefore to focus on health

Testing water demand management scenarios in a water-stressed basin in South Africa: application of the WEAP model

Science.gov (United States)

Lévite, Hervé; Sally, Hilmy; Cour, Julien

Like many river basins in South Africa, water resources in the Olifants river basin are almost fully allocated. Respecting the so-called “reserve” (water flow reservation for basic human needs and the environment) imposed by the Water Law of 1998 adds a further dimension, if not difficulty, to water resources management in the basin, especially during the dry periods. Decision makers and local stakeholders (i.e. municipalities, water users’ associations, interest groups), who will soon be called upon to work together in a decentralized manner within Catchment Management Agencies (CMAs) and Catchment Management Committees (CMCs), must therefore be able to get a rapid and simple understanding of the water balances at different levels in the basin. This paper seeks to assess the pros and cons of using the Water Evaluation and Planning (WEAP) model for this purpose via its application to the Steelpoort sub-basin of the Olifants river. This model allows the simulation and analysis of various water allocation scenarios and, above all, scenarios of users’ behavior. Water demand management is one of the options discussed in more detail here. Simulations are proposed for diverse climatic situations from dry years to normal years and results are discussed. It is evident that the quality of data (in terms of availability and reliability) is very crucial and must be dealt with carefully and with good judgment. Secondly, credible hypotheses have to be made about water uses (losses, return flow) if the results are to be meaningfully used in support of decision-making. Within the limits of data availability, it appears that some water users are not able to meet all their requirements from the river, and that even the ecological reserve will not be fully met during certain years. But the adoption of water demand management procedures offers opportunities for remedying this situation during normal hydrological years. However, it appears that demand management alone will not

A Simple Key for Identifying the Sibling Species of the Malaria Vector Anopheles gambiae (Giles Complex by Polytene Chromosome Cytogenetics

Directory of Open Access Journals (Sweden)

Music Temitope OBEMBE

2018-03-01

Full Text Available It has been established that Anopheles gambiae complex sibling species are the major Plasmodium malaria vectors in Africa; however, not all the sibling species transmit the infection. Easier molecular methods, PCR-based assays, have been developed to distinguish the several members of the A. gambiae complex. However, malaria vector research in less developed countries, particularly sub-Saharan Africa, is being hampered by the lack of PCR facilities in laboratories and the cost of carrying out the assay within lack of funding. Hence, the present study was designed to develop a simple identification key, based on an affordable method of polytene chromosome cytotaxonomy, for identifying the major P. falciparum vectors. The Identification Key was successfully used to identify two members of the A. gambiae complex, A. gambiae sensu stricto and A. arabiensis, which are the most potent malaria vectors in Africa; even so, it could not be used to establish the infective and the refractory strains.

Trapped in Development Crisis and Balkanization: Africa versus ...

African Journals Online (AJOL)

Undoubtedly, globalisation is a complex process. It is touted as having the potential to accelerate Africa\\'s development if the continent\\'s economies would be reformed in accordance with market principles. But clearly, globalisation is widening the disparities between the developed and developing economies. Africa\\'s ...

Costs of reducing water use of concentrating solar power to sustainable levels: Scenarios for North Africa

International Nuclear Information System (INIS)

Damerau, Kerstin; Williges, Keith; Patt, Anthony G.; Gauche, Paul

2011-01-01

Concentrating solar power (CSP) has the potential to become a leading sustainable energy technology for the European electricity system. In order to reach a substantial share in the energy mix, European investment in CSP appears most profitable in North Africa, where solar potential is significantly higher than in southern Europe. As well as sufficient solar irradiance, however, the majority of today's CSP plants also require a considerable amount of water, primarily for cooling purposes. In this paper we examine water usage associated with CSP in North Africa, and the cost penalties associated with technologies that could reduce those needs. We inspect four representative sites to compare the ecological and economical drawbacks from conventional and alternative cooling systems, depending on the local environment, and including an outlook with climate change to the mid-century. Scaling our results up to a regional level indicates that the use of wet cooling technologies would likely be unsustainable. Dry cooling systems, as well as sourcing of alternative water supplies, would allow for sustainable operation. Their cost penalty would be minor compared to the variance in CSP costs due to different average solar irradiance values. - Highlights: → Scaling up CSP with wet cooling from ground water will be unsustainable in North Africa. → Desalination and alternative cooling systems can assure a sustainable water supply. → On large-scale, the cost penalties of alternative cooling technologies appear minor.

Scientific data and climate scenarios. Study report nr 2

International Nuclear Information System (INIS)

Alex, Bastien; Baillat, Alice; Francois Gemenne; Jean Jouzel

2017-05-01

The objective of this report is to present climate evolutions and their impacts according to two warming scenarios: a 2 degree increase of the average surface temperature by 2100 (i.e. the most optimistic IPCC scenario), and a 5 degree increase by 2100 (the most pessimistic scenario). As far as possible, physical, social and economic, and health impacts are assessed by 2030 and 2050. The authors notice that the differences between both scenarios are hardly discernible by 2030, but more obviously by 2050. After a brief recall on IPCC scenarios, a first part addresses the evolutions of the world climate by considering the atmosphere (temperature increase, modification of precipitation regimes), seas and oceans (temperature, currents and thermal circulation, ocean acidification, seal level rise), extreme climate events (observations and trends, main impacts on populations and infrastructures), and the cryo-sphere (observations and impacts). The second part discusses regional predictions in terms of trends and impacts for metropolitan France and its overseas territories, for Africa, and for the Asia-Pacific region. The last part briefly discusses the possibly necessary evolution of the typology chosen to determine sources of vulnerability and the level of exposure to different risks. Many appendices propose more detailed presentations on specific issues and examples. A summarised version of the report is also provided

Solar Energy and Telemedicine in West Africa : A strategic solution

OpenAIRE

Ihuoma, Phineese

2011-01-01

It is important to bring medical help to those living in West Africa. A good way to do this is by telemedicine. Telemedicine, although it uses power, can be achieved easily with solar panels, and the best solar panels are monocrystalline and cadmium telluride. Using graphical scenarios, statistical derivations, theoretical ideologies acquired from literature reviews, usability ideas and two personal case scenarios, the objective of this project was achieved. Criteria like cost, temperatur...

Scenario Methodology for Modelling of Future Landscape Developments as Basis for Assessing Ecosystem Services

Directory of Open Access Journals (Sweden)

Matthias Rosenberg

2014-04-01

��political control“, three scenarios were developed up to the time horizons in 2030 and 2050. They are titled „Trend“, „Tradition and Ecology“ and „Technology and Energy“. These scenarios differ markedly in the degree of the future lignite exploitation, in the use of renewable energy and in the environmental compatibility of the agricultural production. In total, the investigation shows that the integration of the ecosystem services approach into the scenario technology has brought new aspects. However, the procedure became more complex. For the development of the scenarios a precise definition of the driving forces turned out to be essential. The experiences of the project further show that only two or at most three key driving forces (KDF can be distinguished really sensibly or can be looked at in their interactions. It could be shown that from these results itself concrete measures can be derived which support desirable developments or counteract against undesirable effects. By the integration of stakeholders in different working steps, the scenarios can contribute to the sensitization and better perception of future problems and chances of a region.

The influence of scenario-based training and real-time audiovisual feedback on out-of-hospital cardiopulmonary resuscitation quality and survival from out-of-hospital cardiac arrest.

Science.gov (United States)

Bobrow, Bentley J; Vadeboncoeur, Tyler F; Stolz, Uwe; Silver, Annemarie E; Tobin, John M; Crawford, Scott A; Mason, Terence K; Schirmer, Jerome; Smith, Gary A; Spaite, Daniel W

2013-07-01

We assess whether an initiative to optimize out-of-hospital provider cardiopulmonary resuscitation (CPR) quality is associated with improved CPR quality and increased survival from out-of-hospital cardiac arrest. This was a before-after study of consecutive adult out-of-hospital cardiac arrest. Data were obtained from out-of-hospital forms and defibrillators. Phase 1 included 18 months with real-time audiovisual feedback disabled (October 2008 to March 2010). Phase 2 included 16 months (May 2010 to September 2011) after scenario-based training of 373 professional rescuers and real-time audiovisual feedback enabled. The effect of interventions on survival to hospital discharge was assessed with multivariable logistic regression. Multiple imputation of missing data was used to analyze the effect of interventions on CPR quality. Analysis included 484 out-of-hospital cardiac arrest patients (phase 1 232; phase 2 252). Median age was 68 years (interquartile range 56-79); 66.5% were men. CPR quality measures improved significantly from phase 1 to phase 2: Mean chest compression rate decreased from 128 to 106 chest compressions per minute (difference -23 chest compressions; 95% confidence interval [CI] -26 to -19 chest compressions); mean chest compression depth increased from 1.78 to 2.15 inches (difference 0.38 inches; 95% CI 0.28 to 0.47 inches); median chest compression fraction increased from 66.2% to 83.7% (difference 17.6%; 95% CI 15.0% to 20.1%); median preshock pause decreased from 26.9 to 15.5 seconds (difference -11.4 seconds; 95% CI -15.7 to -7.2 seconds), and mean ventilation rate decreased from 11.7 to 9.5/minute (difference -2.2/minute; 95% CI -3.9 to -0.5/minute). All-rhythms survival increased from phase 1 to phase 2 (20/231, 8.7% versus 35/252, 13.9%; difference 5.2%; 95% CI -0.4% to 10.8%), with an adjusted odds ratio of 2.72 (95% CI 1.15 to 6.41), controlling for initial rhythm, witnessed arrest, age, minimally interrupted cardiac resuscitation

Economic and Ecological Consequences of Four European Land Use Scenarios

NARCIS (Netherlands)

Eickhout, B.; Meijl, van H.; Tabeau, A.A.; Rheenen, van T.

2007-01-01

The impact of globalization on trade, production and land use is key to the Doha development round. This paper deals with the complex interaction between agricultural trade, production, land-use change and environmental consequences on the basis of four different scenarios. In these scenarios, major

A networks analysis of terrorism in Africa: implications for Kenya

Directory of Open Access Journals (Sweden)

Steven Kigen Morumbasi

2016-12-01

Full Text Available This paper highlights the challenges that the international community faces in responding to the terrorists and the need to change tactics to respond more effectively to an increasingly nebulous enemy. Terrorism can take different forms and is perpetrated by both state and non-state actors. This research looks into the network structure of terrorism and terrorist groups. In the contemporary setting, terrorist organizations operate transnationally hence the use of the term ‘terrorism without borders’. An enabling factor of terrorism today is the network structure that it has adopted which gives it the ability to both project its reach and prevent easy infiltration. The network structure has also brought about renewed interests in Africa, where global terror networks such as al-Qaeda and the Islamic State compete for influence. Boko Haram in West Africa is an affiliate of the Islamic State and this provides possible linkages with the Islamic State in Libya. Boko Haram refers to itself as the Islamic State’s Western Province. Al-Shabaab has dominated headlines by carrying out deadly attacks in East Africa. The al-Qaeda affiliate has however faced resistance from a section of its members who seek ties with the Islamic State. This resulted in the formation of Jabha East Africa, a group that aligns itself to the Islamic State. The Sinai Peninsula has also witnessed an upsurge of terror attacks perpetrated by the Sinai Province, which views itself as a province of the Islamic State. This surmounts to a complex network structure of terrorist networks in Africa and the growing threat to militant Islam. The special attention is paid to analysis of terrorist challenges in Kenia.

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.

Investigating stock–outs in the warehouse retail liquor sector in Johannesburg

OpenAIRE

2015-01-01

M.Com. (Business Management) The retail industry in South Africa is faced with economic pressure, which is affecting growth in the sector. Consumers are affected by inflation which affects their purchasing power. Added to this many retail businesses in South Africa are experiencing the phenomena of stock-outs. Retail stock-outs can amount to 4% of annual turnover for an average retail business in South Africa. This is putting huge strain on retail businesses to remain competitive in the in...

Cooperation, complexity and adaptation: higher education capacity initiatives in international development assistance programmes in sub-Saharan Africa.

OpenAIRE

McEvoy, Peter

2018-01-01

At a time when global relations are characterised by great complexity, uncertainty and inequality, the role of higher education is crucial for a balanced and coherent development strategy, and achievement of the Sustainable Development Goals (SDGs). This is especially true for countries of sub-Saharan Africa, where there is a critical need to generate knowledge that can be used in the service of social and economic development, human rights and climate change adaptation. The study concern...

We can still get out

International Nuclear Information System (INIS)

Bach, W.

1986-01-01

The book contains the complete scenario on the nuclear power phase-out written by the Hessian Minister of Environment and Energy, Joschka Fischer, and comments. Both the scenarios and the articles written by Wilfried Bach, Hermann Boemer, and Harry Kunz disprove the statement of a phase-out of nuclear power in the Federal Republic of Germany presently being impossible or at least connected with considerable disadvantages. The book proves: The phase-out is urgently necessary and possible, also immediately. It can take place without negatively affecting the energy supply. Negative consequences for the labour market can also be avoided. And as for costs and risk: the faster the phase-out begins, the lower are the costs and risks. (orig.) [de

Future atmospheric abundances and climate forcings from scenarios of global and regional hydrofluorocarbon (HFC) emissions

Science.gov (United States)

Velders, Guus J. M.; Fahey, David W.; Daniel, John S.; Andersen, Stephen O.; McFarland, Mack

2015-12-01

Hydrofluorocarbons (HFCs) are manufactured for use as substitutes for ozone-depleting substances that are being phased out globally under Montreal Protocol regulations. While HFCs do not deplete ozone, many are potent greenhouse gases that contribute to climate change. Here, new global scenarios show that baseline emissions of HFCs could reach 4.0-5.3 GtCO2-eq yr-1 in 2050. The new baseline (or business-as-usual) scenarios are formulated for 10 HFC compounds, 11 geographic regions, and 13 use categories. The scenarios rely on detailed data reported by countries to the United Nations; projections of gross domestic product and population; and recent observations of HFC atmospheric abundances. In the baseline scenarios, by 2050 China (31%), India and the rest of Asia (23%), the Middle East and northern Africa (11%), and the USA (10%) are the principal source regions for global HFC emissions; and refrigeration (40-58%) and stationary air conditioning (21-40%) are the major use sectors. The corresponding radiative forcing could reach 0.22-0.25 W m-2 in 2050, which would be 12-24% of the increase from business-as-usual CO2 emissions from 2015 to 2050. National regulations to limit HFC use have already been adopted in the European Union, Japan and USA, and proposals have been submitted to amend the Montreal Protocol to substantially reduce growth in HFC use. Calculated baseline emissions are reduced by 90% in 2050 by implementing the North America Montreal Protocol amendment proposal. Global adoption of technologies required to meet national regulations would be sufficient to reduce 2050 baseline HFC consumption by more than 50% of that achieved with the North America proposal for most developed and developing countries.

Unlocking the potential of Africa's young entrepreneurs | CRDI ...

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

The report, Africa's Young Entrepreneurs: Unlocking the Potential for a Brighter Future, is the first to focus on Africa's young entrepreneurs and is the culmination of a 3-year project carried out by GEM with financial support from IDRC. It draws on data collected from nine countries (Angola, Botswana, Ghana, Malawi, Namibia ...

Developing a body of knowledge for sport marketing in Africa | van ...

African Journals Online (AJOL)

This paper aims to stimulate the development of a scientific body of knowledge for sport marketing in Africa. A review of current journals indicates that African academics are not devoting sufficient attention to the development of a body of knowledge for sport marketing. In this paper three scenarios are formulated that ...

Performance Evaluation Of Africa Elemi Melon And Africa Locust Bean Oil As Potential Quenchants For Medium Carbon Steel

Directory of Open Access Journals (Sweden)

C. S. Ibeh

2017-06-01

Full Text Available A qualitative and comparative study was carried out on some locally sourced oils melon oil Africa elemi oil and Africa locust bean oil to evaluate suitability as substitute quenching media to mineral-based oil. The cooling ability of the oils was investigated using AISI 1034 medium carbon steel. The effect of heat transfer coefficient on quench severity mechanical properties of the quenched specimens were investigated in the course of the study. Results showed that the peak rate of heat extraction of melon oil Africa locust bean and Africa elemi oil were higher than that of mineral oil. Higher heat transfer coefficient of 1463 1023 Wm2k were obtained for melon oil and Africa locust bean Africa elemi and SAE 40 oil have heat transfer coefficient of 982 and 469 Wm2k respectively. The selected oils can be used as quenchants for medium carbon steel since the oils exhibits better cooling properties and mechanical properties than mineral-based oil.

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 ...

Northwest Africa 5790: Revisiting nakhlite petrogenesis

Science.gov (United States)

Jambon, A.; Sautter, V.; Barrat, J.-A.; Gattacceca, J.; Rochette, P.; Boudouma, O.; Badia, D.; Devouard, B.

2016-10-01

Northwest Africa 5790, the latest nakhlite find, is composed of 58 vol.% augite, 6% olivine and 36% vitrophyric intercumulus material. Its petrology is comparable to previously discovered nakhlites but with key differences: (1) Augite cores display an unusual zoning between Mg# 54 and 60; (2) Olivine macrocrysts have a primary Fe-rich core composition (Mg# = 35); (3) The modal proportion of mesostasis is the highest ever described in a nakhlite; (4) It is the most magnetite-rich nakhlite, together with MIL 03346, and exhibits the least anisotropic fabric. Complex primary zoning in cumulus augite indicates resorption due to complex processes such as remobilization of former cumulates in a new magma batch. Textural relationships indicate unambiguously that olivine was growing around resorbed augite, and that olivine growth was continuous while pyroxene growth resumed at a final stage. Olivine core compositions (Mg# = 35) are out of equilibrium with the augite core compositions (Mg# 60-63) and with the previously inferred nakhlite parental magma (Mg# = 29). The presence of oscillatory zoning in olivine and augite precludes subsolidus diffusion that could have modified olivine compositions. NWA 5790 evidences at least two magma batches before eruption, with the implication that melt in equilibrium with augite cores was never in contact with olivine. Iddingsite is absent. Accordingly, the previous scenarios for nakhlite petrogenesis must be revised. The first primary parent magmas of nakhlites generated varied augite cumulates at depth (Mg# 66-60) as they differentiated to different extents. A subsequent more evolved magma batch entrained accumulated augite crystals to the surface where they were partly resorbed while olivine crystallized. Trace element variations indicate unambiguously that they represent consanguineous but different magma batches. The compositional differences among the various nakhlites suggest a number of successive lava flows. To account for all

A complex scenario of tuberculosis transmission is revealed through genetic and epidemiological surveys in Porto.

Science.gov (United States)

Rito, Teresa; Matos, Carlos; Carvalho, Carlos; Machado, Henrique; Rodrigues, Gabriela; Oliveira, Olena; Ferreira, Eduarda; Gonçalves, Jorge; Maio, Lurdes; Morais, Clara; Ramos, Helena; Guimarães, João Tiago; Santos, Catarina L; Duarte, Raquel; Correia-Neves, Margarida

2018-01-25

Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases. We genotyped the M. tuberculosis strains using the MIRU-VNTR system. We performed an evolutionary reconstruction of the genotypes with median networks, used in this context for the first time. TB cases from a period of two years were evaluated combining genetic, epidemiological and georeferencing information. The data reveal a unique complex scenario in Porto where the autochthonous population acts as a genetic reservoir of M. tuberculosis diversity with discreet episodes of transmission, mostly undetected using classical epidemiology alone. Although control policies have been successful in decreasing incidence in Porto, the discerned complexity suggests that, for elimination to be a realistic goal, strategies need to be adjusted and coupled with a continuous genetic characterization of strains and detailed epidemiological evaluation, in order to successfully identify and interrupt transmission chains.

A model for the analysis of a normal evolution scenarios for a deep geological granite repository for high-level radioactive waste

International Nuclear Information System (INIS)

Cormenzana Lopez, J.L.; Cunado, M.A.; Lopez, M.T.

1996-01-01

The methodology usually used to evaluate the behaviour of deep geological repositories for high-level radioactive wastes comprises three phases: Identification of factors (processes, characteristics and events) that can affect the repository. Generation of scenarios. In general, a normal evolution scenario (Reference Scenario) and various disruptive scenarios (earthquake, human intrusion, etc) are considered. Evaluation of the behaviour of the repository in each scenario. The normal evolution scenario taking into account all factors with a high probability of occurrence is the first to be analysed. The performance assessment of behaviour being carried out by ENRESA for the AGP Granite has led to the identification of 63 of these factors. To analyse repository behaviour in the normal evolution scenario, it is necessary to first of all create an integrated model of the global system. This is a qualitative model including the 63 factors identified. For a global view of a such a complex system, it is very useful to graphically display the relationship between factors in an Influence Diagram. This paper shows the Influence Diagram used in the analysis of the AGP Granite Reference Scenario. (Author)

Towards Validating Game Scenarios for Teaching Conflict Resolution

DEFF Research Database (Denmark)

Cheong, Yun-Gyung; Grappiolo, Corrado; Pedersen, Christoffer Holmgård

2013-01-01

Teaching conflict resolution skills via serious games has received increasing attention in recent years. This paper describes game scenarios that were developed to evoke variant levels of conflict intensity to children. To validate the scenarios, we implemented a prototype and created videos from...... play-throughs of the prototype. We then carried out a user study and ran statistical analyses to test if children would perceive the game scenarios as intended by scenario designers in terms of conflict....

Unprecedented emergency in Southern Africa.

Science.gov (United States)

1999-03-01

Despite knowledge of better prevention strategies, AIDS continues to be an unprecedented emergency in southern Africa. Statistics show that in 1998, 1.4 million people between the ages of 15 and 49 in the 9 countries of southern Africa were infected, with nearly three-quarters of a million of these new infections occurring in South Africa. In addition, some 2 million people died of AIDS in sub-Saharan Africa in 1998 and millions of new infections are occurring every year. Factors such as the loneliness suffered by migrant laborers, the wars and armed conflicts in Rwanda, and the stigma of shame, silence, and denial associated with AIDS all generate fertile conditions for the spread of HIV in southern Africa. Overcoming silence and denial, and bringing AIDS out into the open, has been considered by some countries in southern Africa. In Botswana and South Africa, appeals for greater awareness and openness by the top leadership have been coupled with a decision to set up government funding and AIDS. The challenge now will be to translate these into effective prevention and care programs.

A multi-dimensional assessment of urban vulnerability to climate change in Sub-Saharan Africa

DEFF Research Database (Denmark)

Herslund, Lise Byskov; Jalyer, Fatameh; Jean-Baptiste, Nathalie

2016-01-01

In this paper, we develop and apply a multi-dimensional vulnerability assessment framework for understanding the impacts of climate change-induced hazards in Sub- Saharan African cities. The research was carried out within the European/African FP7 project CLimate change and Urban Vulnerability...... in Africa, which investigated climate change-induced risks, assessed vulnerability and proposed policy initiatives in five African cities. Dar es Salaam (Tanzania) was used as a main case with a particular focus on urban flooding. The multi-dimensional assessment covered the physical, institutional...... encroachment on green and flood-prone land). Scenario modeling suggests that vulnerability will continue to increase strongly due to the expected loss of agricultural land at the urban fringes and loss of green space within the city. However, weak institutional commitment and capacity limit the potential...

A 3D potential field model of the Pilanesberg Complex shape and structure

CSIR Research Space (South Africa)

Lee, SA

2013-10-01

Full Text Available ). Mineralization of the Pilanesberg Alkaline Complex. In Mineral Deposits of South Africa 2 (C. R. Anhaeusser& S. Maske, eds.). The Geological Society of South Africa, Johannesburg, South Africa. p. 2215-2228. Michell, R. H. and Liferovich, R. P. (2006... the gabbro-norite of the Rustenburg Layered Suite and red granite of the Lebowa Granite Suite on the western limb of the Bushveld Complex, South Africa (Hansen et al., 2006). The Pilanesberg Complex intruded between 1200 and 1450 Ma during...

Exploring the biogeophysical limits of global food production under different climate change scenarios

Science.gov (United States)

de Vrese, Philipp; Stacke, Tobias; Hagemann, Stefan

2018-04-01

An adapted Earth system model is used to investigate the limitations that future climate and water availability impose on the potential expansion and productivity of croplands. The model maximizes the cropland area under prevailing climate conditions and accounts for an optimized, sustainable irrigation practice, thus allowing us to consider the two-way feedback between climate and agriculture. For three greenhouse gas concentration scenarios (RCP2.6, RCP4.5, RCP8.5), we show that the total cropland area could be extended substantially throughout the 21st century, especially in South America and sub-Saharan Africa, where the rising water demand resulting from increasing temperatures can largely be met by increasing precipitation and irrigation rates. When accounting for the CO2 fertilization effect, only a few agricultural areas have to be abandoned owing to declines in productivity, while increasing temperatures allow for the expansion of croplands even into high northern latitudes. Without the CO2 fertilization effect there is no increase in the overall cropland fraction during the second half of the century but areal losses in increasingly water-stressed regions can be compensated for by an expansion in regions that were previously too cold. However, global yields are more sensitive and, without the benefits of CO2 fertilization, they may decrease when greenhouse gas concentrations exceed the RCP4.5 scenario. For certain regions the situation is even more concerning and guaranteeing food security in dry areas in Northern Africa, the Middle East and South Asia will become increasingly difficult, even for the idealized scenarios investigated in this study.

Contextualizing group rape in post-apartheid South Africa.

Science.gov (United States)

Wood, Kate

2005-01-01

Collective male sexual violence is part of a continuum of sexual coercion in South Africa. This paper is based on long-term ethnographic work in an urban township in the former Transkei region. Drawing on intensive participant observation and interviews with young men in particular, it attempts to make sense of emergent narratives relating to streamlining, a local term for a not uncommon form of collective sexual coercion involving a group of male friends and one or more women. The paper begins with an overview of existing anthropological literature on collective male sexual violence, going onto elaborate the different scenarios associated with group sexual violence in the fieldsite. It seeks to provide a multi-layered contextualization of the phenomenon by considering prevailing gender discourses, subcultural issues pertaining to the urban tsotsi phenomenon, the rural practice of ukuthwala (bride capture), young working-class Africans' experiences of marginalization, and the complex links between political economy and violence in this setting.

The role of fusion power in energy scenarios. Proposed method and review of existing scenarios

International Nuclear Information System (INIS)

Lako, P; Ybema, J.R.; Seebregts, A.J.

1998-04-01

The European Commission wishes more insight in the potential role of fusion energy in the second half of the 21st century. Therefore, several scenario studies are carried out in the so-called macro-task Long Term Scenarios to investigate the potential role of fusion power in the energy system. The main contribution of ECN to the macro-task is to perform a long term energy scenario study for Western Europe with special focus on the role of fusion power. This interim report gives some methodological considerations for such an analysis. A discussion is given on the problems related to the long time horizon of the scenario study such as the forecast of technological innovations, the selection of appropriate discount rates and the links with climate change. Key parameters which are expected to have large effects on the role and cost-effectiveness are discussed in general terms. The key parameters to be varied include level and structure of energy demand, availability and prices of fossil energy, CO2 reduction policy, discount rates, cost and potential of renewable energy sources, availability of fission power and CO2 capture and disposal and the cost and the maximum rate of market growth of fusion power. The scenario calculations are to be performed later in the project with the help of an existing cost minimisation model of the Western European energy system. This MARKAL model is briefly introduced. The results of the model calculations are expected to make clear under which combinations of scenario parameters fusion power is needed and how large the expected financial benefits will be. The present interim report also gives an evaluation of existing energy scenarios with respect to the role of fusion power. 18 refs

Scenarios for Ecosystem Services: An Overview

Directory of Open Access Journals (Sweden)

Stephen R. Carpenter

2006-06-01

Full Text Available The Millennium Ecosystem Assessment (MA scenarios address changes in ecosystem services and their implications for human well-being. Ecological changes pose special challenges for long-term thinking, because of the possibility of regime shifts that occur rapidly yet alter the availability of ecosystem services for generations. Moreover, ecological feedbacks can intensify human modification of ecosystems, creating a spiral of poverty and ecosystem degradation. Such complex dynamics were evaluated by a mixture of qualitative and quantitative analyses in the MA scenarios. Collectively, the scenarios explore problems such as the connections of poverty reduction and ecosystem services, and trade-offs among ecosystem services. Several promising approaches are considered by the scenarios, including uses of biodiversity to build resilience of ecosystem services, actively adaptive management, and green technology. Although the scenarios do not prescribe an optimal path, they illuminate the consequences of different policies toward ecosystem services.

Model based climate information on drought risk in Africa

Science.gov (United States)

Calmanti, S.; Syroka, J.; Jones, C.; Carfagna, F.; Dell'Aquila, A.; Hoefsloot, P.; Kaffaf, S.; Nikulin, G.

2012-04-01

The United Nations World Food Programme (WFP) has embarked upon the endeavor of creating a sustainable Africa-wide natural disaster risk management system. A fundamental building block of this initiative is the setup of a drought impact modeling platform called Africa Risk-View that aims to quantify and monitor weather-related food security risk in Africa. The modeling approach is based the Water Requirement Satisfaction Index (WRSI), as the fundamental indicator of the performances of agriculture and uses historical records of food assistance operation to project future potential needs for livelihood protection. By using climate change scenarios as an input to Africa Risk-View it is possible, in principles, to evaluate the future impact of climate variability on critical issues such as food security and the overall performance of the envisaged risk management system. A necessary preliminary step to this challenging task is the exploration of the sources of uncertainties affecting the assessment based on modeled climate change scenarios. For this purpose, a limited set of climate models have been selected in order verify the relevance of using climate model output data with Africa Risk-View and to explore a minimal range of possible sources of uncertainty. This first evaluation exercise started before the setup of the CORDEX framework and has relied on model output available at the time. In particular only one regional downscaling was available for the entire African continent from the ENSEMBLES project. The analysis shows that current coarse resolution global climate models can not directly feed into the Africa RiskView risk-analysis tool. However, regional downscaling may help correcting the inherent biases observed in the datasets. Further analysis is performed by using the first data available under the CORDEX framework. In particular, we consider a set of simulation driven with boundary conditions from the reanalysis ERA-Interim to evaluate the skill drought

Accident scenario diagnostics with neural networks

International Nuclear Information System (INIS)

Guo, Z.

1992-01-01

Nuclear power plants are very complex systems. The diagnoses of transients or accident conditions is very difficult because a large amount of information, which is often noisy, or intermittent, or even incomplete, need to be processed in real time. To demonstrate their potential application to nuclear power plants, neural networks axe used to monitor the accident scenarios simulated by the training simulator of TVA's Watts Bar Nuclear Power Plant. A self-organization network is used to compress original data to reduce the total number of training patterns. Different accident scenarios are closely related to different key parameters which distinguish one accident scenario from another. Therefore, the accident scenarios can be monitored by a set of small size neural networks, called modular networks, each one of which monitors only one assigned accident scenario, to obtain fast training and recall. Sensitivity analysis is applied to select proper input variables for modular networks

Estimating the resources needed and savings anticipated from roll-out of adult male circumcision in sub-Saharan Africa

NARCIS (Netherlands)

B. Auvert (Bertran); E. Marseille (Elliot); E.L. Korenromp (Eline); J. Lloyd-Smith (James); R. Sitta (Remi); D. Taljaard (Dirk); C. Pretorius (Carel); B. Williams (Brian); J.G. Kahn (James)

2008-01-01

textabstractBackground: Trials in Africa indicate that medical adult male circumcision (MAMC) reduces the risk of HIV by 60%. MAMC may avert 2 to 8 million HIV infections over 20 years in sub-Saharan Africa and cost less than treating those who would have been infected. This paper estimates the

Climate Scenarios for the NASA / USAID SERVIR Project: Challenges for Multiple Planning Horizons

Science.gov (United States)

Robertson, Franklin R.; Roberts, J. B.; Lyon, B.; Funk, C.; Bosilovich, M. G.

2014-01-01

SERVIR, an acronym meaning "to serve" in Spanish, is a joint venture between NASA and the U.S. Agency for International Development (USAID) which provides satellite-based Earth observation data, modeling, and science applications to help developing nations in Central America, East Africa and the Himalayas improve environmental decision making. Anticipating climate variability / climate change impacts has now become an important component of the SERVIR efforts to build capacity in these regions. Uncertainty in hydrometeorological components of climate variations and exposure to extreme events across scales from weather to climate are of particular concern. We report here on work to construct scenarios or outlooks that are being developed as input drivers for decision support systems (DSSs) in a variety of settings. These DSSs are being developed jointly by a broad array NASA Applied Science Team (AST) Investigations and user communities in the three SERVIR Hub Regions, Central America, East Africa and the Himalayas. Issues span hydrologic / water resources modeling, agricultural productivity, and forest carbon reserves. The scenarios needed for these efforts encompass seasonal forecasts, interannual outlooks, and likely decadal / multi-decadal trends. Providing these scenarios across the different AST efforts enables some level of integration in considering regional responses to climate events. We will discuss a number of challenges in developing this continuum of scenarios including the identification and "mining" of predictability, addressing multiple continental regions, issues of downscaling global model integrations to regional / local applications (i.e. hydrologic and crop modeling). We compare / contrast the role of the U.S. National Multi- Model Experiment initiative in seasonal forecasts and the CMIP-5 climate model experiments in supporting these efforts. Examples of these scenarios, their use, and an assessment of their utility as well as limitations will

Scenarios : tools for coping with complexity and future uncertainty

NARCIS (Netherlands)

Perez-Soba, M.; Maas, R.

2015-01-01

We cannot predict the future with certainty, but we know that it is influenced by our current actions, and that these in turn are influenced by our expectations. This is why future scenarios have existed from the dawn of civilization and have been used for developing military, political and economic

Viral bioterrorism: Learning the lesson of Ebola virus in West Africa 2013-2015.

Science.gov (United States)

Cenciarelli, Orlando; Gabbarini, Valentina; Pietropaoli, Stefano; Malizia, Andrea; Tamburrini, Annalaura; Ludovici, Gian Marco; Carestia, Mariachiara; Di Giovanni, Daniele; Sassolini, Alessandro; Palombi, Leonardo; Bellecci, Carlo; Gaudio, Pasquale

2015-12-02

Among the potential biological agents suitable as a weapon, Ebola virus represents a major concern. Classified by the CDC as a category A biological agent, Ebola virus causes severe hemorrhagic fever, characterized by high case-fatality rate; to date, no vaccine or approved therapy is available. The EVD epidemic, which broke out in West Africa since the late 2013, has got the issue of the possible use of Ebola virus as biological warfare agent (BWA) to come to the fore once again. In fact, due to its high case-fatality rate, population currently associates this pathogen to a real and tangible threat. Therefore, its use as biological agent by terrorist groups with offensive purpose could have serious repercussions from a psychosocial point of view as well as on closely sanitary level. In this paper, after an initial study of the main characteristics of Ebola virus, its potential as a BWA was evaluated. Furthermore, given the spread of the epidemic in West Africa in 2014 and 2015, the potential dissemination of the virus from an urban setting was evaluated. Finally, it was considered the actual possibility to use this agent as BWA in different scenarios, and the potential effects on one or more nation's stability. Copyright © 2015 Elsevier B.V. All rights reserved.

EDITORIAL: Where next with global environmental scenarios? Where next with global environmental scenarios?

Science.gov (United States)

O'Neill, Brian; Pulver, Simone; Van Deveer, Stacy; Garb, Yaakov

2008-12-01

Scenarios have become a standard tool in the portfolio of techniques that scientists and policy-makers use to envision and plan for the future. Defined as plausible, challenging and relevant stories about how the future might unfold that integrate quantitative models with qualitative assessments of social and political trends, scenarios are a central component in assessment processes for a range of global issues, including climate change, biodiversity, agriculture, and energy. Yet, despite their prevalence, systematic analysis of scenarios is in its beginning stages. Fundamental questions remain about both the epistemology and scientific credibility of scenarios and their roles in policymaking and social change. Answers to these questions have the potential to determine the future of scenario analyses. Is scenario analysis moving in the direction of earth system governance informed by global scenarios generated through increasingly complex and comprehensive models integrating socio-economic and earth systems? Or will global environmental scenario analyses lose favour compared to more focused, policy-driven, regionally specific modelling? These questions come at an important time for the climate change issue, given that the scenario community, catalyzed by the Intergovernmental Panel on Climate Change (IPCC), is currently preparing to embark on a new round of scenario development processes aimed at coordinating research and assessment, and informing policy, over the next five to ten years. These and related questions about where next to go with global environmental scenarios animated a workshop held at Brown University (Note1) that brought together leading practitioners and scholars of global environmental change scenarios from research, policy-making, advocacy, and business settings. The workshop aimed to provide an overview of current practices/best practices in scenario production and scenario use across a range of global environmental change arenas. Participants

Effects of Population Growth and Climate Variability on Sustainable Groundwater in Mali, West Africa

Directory of Open Access Journals (Sweden)

Alexandra Lutz

2010-12-01

Full Text Available Groundwater is increasingly relied on as a source of potable water in developing countries, but factors such as population growth, development, and climate variability, pose potential challenges for ongoing sustainable supply. The effect of these factors on the groundwater system was considered in four scenarios using a numerical model to represent the Bani area of Mali, West Africa. By 2040, population growth, climate variability, and development as urbanization, agriculture, and industry creates scenarios in which groundwater extraction is an increasingly larger percentage of the groundwater system. Consumption from agriculture and industry increases extraction rates from less than 1 to 3.8% of mean annual precipitation, which will likely affect the groundwater system. For instance, concentrated pumping in local areas may result in water level declines. The results of this study contribute to an ongoing evaluation of sustainable groundwater resources in West Africa.

Projections of rapidly rising surface temperatures over Africa under low mitigation

International Nuclear Information System (INIS)

Engelbrecht, Francois; Bopape, Mary-Jane; Naidoo, Mogesh; Garland, Rebecca; Adegoke, Jimmy; Thatcher, Marcus; McGregor, John; Katzfey, Jack; Werner, Micha; Ichoku, Charles; Gatebe, Charles

2015-01-01

An analysis of observed trends in African annual-average near-surface temperatures over the last five decades reveals drastic increases, particularly over parts of the subtropics and central tropical Africa. Over these regions, temperatures have been rising at more than twice the global rate of temperature increase. An ensemble of high-resolution downscalings, obtained using a single regional climate model forced with the sea-surface temperatures and sea-ice fields of an ensemble of global circulation model (GCM) simulations, is shown to realistically represent the relatively strong temperature increases observed in subtropical southern and northern Africa. The amplitudes of warming are generally underestimated, however. Further warming is projected to occur during the 21st century, with plausible increases of 4–6 °C over the subtropics and 3–5 °C over the tropics by the end of the century relative to present-day climate under the A2 (a low mitigation) scenario of the Special Report on Emission Scenarios. High impact climate events such as heat-wave days and high fire-danger days are consistently projected to increase drastically in their frequency of occurrence. General decreases in soil-moisture availability are projected, even for regions where increases in rainfall are plausible, due to enhanced levels of evaporation. The regional dowscalings presented here, and recent GCM projections obtained for Africa, indicate that African annual-averaged temperatures may plausibly rise at about 1.5 times the global rate of temperature increase in the subtropics, and at a somewhat lower rate in the tropics. These projected increases although drastic, may be conservative given the model underestimations of observed temperature trends. The relatively strong rate of warming over Africa, in combination with the associated increases in extreme temperature events, may be key factors to consider when interpreting the suitability of global mitigation targets in terms of

Baikal-1 stand complex. Preparation and carrying out of the first energy start-up of the IVG-1 reactor

International Nuclear Information System (INIS)

Tikhomirov, L.N.

1995-01-01

The IVG-1 reactor was a first ground prototype of nuclear rocket engine. The reactor was built on the site 10 of the Semipalatinsk test site. Since the first energy start-up in 1975 the reactor was exploited 14 years till its modernization in 1989. The Bajkal-1 stand complex was designed and built for the carrying out of tests for fuel assemblies of different modifications. The energy start-up has been sum of long creative work of different research and constructive staffs on creation of high-temperature gas-cooled IVG-1 reactor. The history of construction, project and assembling of the stand complex is presented. Complex start and put works were carried out in the December 1974. Control physical start-up was carried out in the January 1975. Cold start-up by hydrogen was in the February 1975. Hot start-up was in the March 1975. The result of the hot start-up was experimental confirmation of metodics of thermohydrovlical estimations. 2 figs., 3 tabs

Comparative phylogeography in rainforest trees from Lower Guinea, Africa.

Directory of Open Access Journals (Sweden)

Myriam Heuertz

Full Text Available Comparative phylogeography is an effective approach to assess the evolutionary history of biological communities. We used comparative phylogeography in fourteen tree taxa from Lower Guinea (Atlantic Equatorial Africa to test for congruence with two simple evolutionary scenarios based on physio-climatic features 1 the W-E environmental gradient and 2 the N-S seasonal inversion, which determine climatic and seasonality differences in the region. We sequenced the trnC-ycf6 plastid DNA region using a dual sampling strategy: fourteen taxa with small sample sizes (dataset 1, mean n = 16/taxon, to assess whether a strong general pattern of allele endemism and genetic differentiation emerged; and four taxonomically well-studied species with larger sample sizes (dataset 2, mean n = 109/species to detect the presence of particular shared phylogeographic patterns. When grouping the samples into two alternative sets of two populations, W and E, vs. N and S, neither dataset exhibited a strong pattern of allelic endemism, suggesting that none of the considered regions consistently harboured older populations. Differentiation in dataset 1 was similarly strong between W and E as between N and S, with 3-5 significant F ST tests out of 14 tests in each scenario. Coalescent simulations indicated that, given the power of the data, this result probably reflects idiosyncratic histories of the taxa, or a weak common differentiation pattern (possibly with population substructure undetectable across taxa in dataset 1. Dataset 2 identified a common genetic break separating the northern and southern populations of Greenwayodendron suaveolens subsp. suaveolens var. suaveolens, Milicia excelsa, Symphonia globulifera and Trichoscypha acuminata in Lower Guinea, in agreement with differentiation across the N-S seasonal inversion. Our work suggests that currently recognized tree taxa or suspected species complexes can contain strongly differentiated genetic lineages

Bayesian analyses of Yemeni mitochondrial genomes suggest multiple migration events with Africa and Western Eurasia.

Science.gov (United States)

Vyas, Deven N; Kitchen, Andrew; Miró-Herrans, Aida T; Pearson, Laurel N; Al-Meeri, Ali; Mulligan, Connie J

2016-03-01

Anatomically, modern humans are thought to have migrated out of Africa ∼60,000 years ago in the first successful global dispersal. This initial migration may have passed through Yemen, a region that has experienced multiple migrations events with Africa and Eurasia throughout human history. We use Bayesian phylogenetics to determine how ancient and recent migrations have shaped Yemeni mitogenomic variation. We sequenced 113 mitogenomes from multiple Yemeni regions with a focus on haplogroups M, N, and L3(xM,N) as these groups have the oldest evolutionary history outside of Africa. We performed Bayesian evolutionary analyses to generate time-measured phylogenies calibrated by Neanderthal and Denisovan mitogenomes in order to determine the age of Yemeni-specific clades. As defined by Yemeni monophyly, Yemeni in situ evolution is limited to the Holocene or latest Pleistocene (ages of clades in subhaplogroups L3b1a1a, L3h2, L3x1, M1a1f, M1a5, N1a1a3, and N1a3 range from 2 to 14 kya) and is often situated within broader Horn of Africa/southern Arabia in situ evolution (L3h2, L3x1, M1a1f, M1a5, and N1a1a3 ages range from 7 to 29 kya). Five subhaplogroups show no monophyly and are candidates for Holocene migration into Yemen (L0a2a2a, L3d1a1a, L3i2, M1a1b, and N1b1a). Yemeni mitogenomes are largely the product of Holocene migration, and subsequent in situ evolution, from Africa and western Eurasia. However, we hypothesize that recent population movements may obscure the genetic signature of more ancient migrations. Additional research, e.g., analyses of Yemeni nuclear genetic data, is needed to better reconstruct the complex population and migration histories associated with Out of Africa. © 2015 Wiley Periodicals, Inc.

Cocoa Intensification Scenarios and Their Predicted Impact on CO2 Emissions, Biodiversity Conservation, and Rural Livelihoods in the Guinea Rain Forest of West Africa

Science.gov (United States)

Gockowski, Jim; Sonwa, Denis

2011-08-01

The Guinean rain forest (GRF) of West Africa, identified over 20 years ago as a global biodiversity hotspot, had reduced to 113,000 km2 at the start of the new millennium which was 18% of its original area. The principal driver of this environmental change has been the expansion of extensive smallholder agriculture. From 1988 to 2007, the area harvested in the GRF by smallholders of cocoa, cassava, and oil palm increased by 68,000 km2. Field results suggest a high potential for significantly increasing crop yields through increased application of seed-fertilizer technologies. Analyzing land-use change scenarios, it was estimated that had intensified cocoa technology, already developed in the 1960s, been pursued in Cote d'Ivoire, Ghana, Nigeria and Cameroon that over 21,000 km2 of deforestation and forest degradation could have been avoided along with the emission of nearly 1.4 billion t of CO2. Addressing the low productivity of agriculture in the GRF should be one of the principal objectives of REDD climate mitigation programs.

ComplexRec 2017

DEFF Research Database (Denmark)

a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

Decolonizing Bioethics in Africa.

Science.gov (United States)

Fayemi, Ademola Kazeem; Macaulay-Adeyelure, O C

2016-01-01

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

Storyboards of crimes. Examining crime scenario creation and investigative experience

NARCIS (Netherlands)

van der Kemp, J.J.; de Gruijter, M.

2011-01-01

To solve a crime a chronological description of what went on, when, how, why and by who must be given; a crime scenario. As to avoid the risk of wrongful conviction due to tunnel vision in an investigation, Dutch investigators are obliged to create multiple scenarios and rule but one out. Although

Readership survey. A big welcome for Diagnostics in Africa.

Science.gov (United States)

Chinnock, P

1994-09-01

Targeted to physicians, Africa Health is circulated free to 5600 readers in 23 African countries. Diagnostics in Africa (DIA) is a young publication included as a supplement of Africa Health aimed at laboratory personnel. Readers of DIA were surveyed in the first two issues to find out what they thought of the supplement, how it could be improved, and which problems they currently faced in their work. 98 questionnaires were returned from twelve African countries. 46% of respondents were qualified in laboratory science and 41% were physicians; the others were unqualified laboratory staff and other medical personnel. 73% responded that DIA was very useful and 27% useful, with 80% finding the articles of appropriate depth and complexity. Respondents would like to read about clinical chemistry, histopathology/histology, immunology, management issues, serology, and education/professional development, and would particularly enjoy material in the form of readers' letters and quizzes. Readers responded variously that they were regularly exposed to either Medicine Digest, Dialogue on Diarrhea, Postgraduate Doctor, Labmedica, Lancet, International Diabetes Digest, New England Journal of Medicine, British Medical Journal, or ARI News. Problems typically faced in their work include lack of resources, problems related to HIV testing/screening, poor access to literature, problems with professional development, and difficulty understanding the theory and practice of Western blot tests. These findings confirm assessments of the situation in Africa's medical labs which led to the launching of DIA.

Pediatric HIV/AIDS in sub-Saharan Africa: emerging issues and way ...

African Journals Online (AJOL)

Conclusion: HIV infected children and their families in sub-Saharan Africa face myriad of complex medical and psychosocial issues. A holistic health promotional approach is being advocated as the required step for eradication of pediatric HIV in Africa. Keywords: Pediatric HIV, sub-Saharan Africa, Challenges.

Biogas - Bioenergy potential in East Africa

International Nuclear Information System (INIS)

1997-01-01

The workshop is part of the project: 'Energy production from Sisal Waste in East Africa' sponsored by the Danish Energy Agency, an agency under the Danish Ministry of Environment and Energy. This project has been carried out in close cooperation between the Danish Technological Institute and University of Dar es Salaam, Applied Microbiology Unit, who has also taken care of the practical arrangement. The main objectives of the workshop was: To present the ongoing research in East Africa on biogas production from organic residues; To get an overview of political and administrative issues related to promotion and implementation of renewable energy facilities in East Africa; To discuss appropriate set-ups for bioenergy facilities in East Africa. (au)

Biogas - Bioenergy potential in East Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

The workshop is part of the project: `Energy production from Sisal Waste in East Africa` sponsored by the Danish Energy Agency, an agency under the Danish Ministry of Environment and Energy. This project has been carried out in close cooperation between the Danish Technological Institute and University of Dar es Salaam, Applied Microbiology Unit, who has also taken care of the practical arrangement. The main objectives of the workshop was: To present the ongoing research in East Africa on biogas production from organic residues; To get an overview of political and administrative issues related to promotion and implementation of renewable energy facilities in East Africa; To discuss appropriate set-ups for bioenergy facilities in East Africa. (au)

Biogas - Bioenergy potential in East Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The workshop is part of the project: `Energy production from Sisal Waste in East Africa` sponsored by the Danish Energy Agency, an agency under the Danish Ministry of Environment and Energy. This project has been carried out in close cooperation between the Danish Technological Institute and University of Dar es Salaam, Applied Microbiology Unit, who has also taken care of the practical arrangement. The main objectives of the workshop was: To present the ongoing research in East Africa on biogas production from organic residues; To get an overview of political and administrative issues related to promotion and implementation of renewable energy facilities in East Africa; To discuss appropriate set-ups for bioenergy facilities in East Africa. (au)

Comparison of environmental performance for different waste management scenarios in East Africa: The case of Kampala City, Uganda

NARCIS (Netherlands)

Oyoo, R.; Leemans, R.; Mol, A.P.J.

2014-01-01

Poor waste flows management in East African cities has become an environmental and public health concerns to the city authorities and the general public. We assessed the environmental impacts of waste recycling in Kampala City, for four designed waste management scenarios, namely: (1) Scenario S1

Phasing out nuclear, a credible scenario; Sortir du nucleaire, un scenario credible

Energy Technology Data Exchange (ETDEWEB)

Chatelain, C.; Mulot, R.; Chauveau, L.; Hait, J.F.

2011-08-15

Based on data from different companies, institutions and associations involved in nuclear energy (either in its production or in its critic), this article comments the possible energy savings (50 to 64%) that may be reached in the different sectors, and more particularly in the building sector and in electrical equipment. It discusses the potential production from solar, wind and biogas energy. It notices that phasing out nuclear is possible by 2030-2050, but would entail an increase of electricity prices. The German approach is presented. An article comments the anger of Fukushima Japanese farmers and evokes the slow building up of a solidarity network between France and Japan. A last article comments the authorization given to a further exploitation of the Fessenheim nuclear power plant (ten more years)

FIP Symposium 1997 (South Africa); FIP Symposium 1997 (Minami Africa) ni sankashite

Energy Technology Data Exchange (ETDEWEB)

Niwano, T. [Oriental Construction Co. Ltd., Tokyo (Japan); Shinagawa, K.; Takahashi, T.

1997-07-31

FIP (Federation Internationale de la Precontrainte) Symposium was held in Johannesburg, South Africa. Ikeda and others were sent by the Japan Prestressed Concrete Engineering Association to participate the symposium and visit some bridges in Hong Kong and South Africa. As the keynote addresses, the trends of PC in South Africa, Europe, America, East Asia and Australia was reported. Japanese papers among 105 presented papers are as follows: Iwasaki`s `Construction method of the railway PC skew slab bridge, Natori-Gawa bridge`, Toda`s `Construction of the suspended slab bridge longest in the world, Yume Tsuri-bashi`, Iizuka`s `Experiment on earthquake characteristics of precast concrete columns` and Sugita`s `Study on concrete using high-activity rice hull ash`. The group visited Kap Shui Mun bridge (Hong Kong) of 750m long constructed by Japanese JV which is the 5-span continuous complex cable stayed bridge, and featured by PC box girder structure of side spans. The group also visited Gouritz River PC bridge in South Africa. 5 refs., 10 figs.

Future waste treatment and energy systems – examples of joint scenarios

DEFF Research Database (Denmark)

Münster, Marie; Finnveden, G.; Wenzel, H.

2013-01-01

of scenarios is recommended, too, in order to adapt to the methods and tools of different disciplines, such as developing predictive scenarios with general equilibrium tools and analysing explorative scenarios with energy system analysis tools. Furthermore, as marginals identified in differing future......Development and use of scenarios for large interdisciplinary projects is a complicated task. This article provides practical examples of how it has been carried out in two projects addressing waste management and energy issues respectively. Based on experiences from the two projects......, recommendations are made for an approach concerning development of scenarios in projects dealing with both waste management and energy issues. Recommendations are given to develop and use overall scenarios for the project and leave room for sub-scenarios in parts of the project. Combining different types...

Projected global ground-level ozone impacts on vegetation under different emission and climate scenarios

Directory of Open Access Journals (Sweden)

P. Sicard

2017-10-01

Full Text Available The impact of ground-level ozone (O3 on vegetation is largely under-investigated at the global scale despite large areas worldwide that are exposed to high surface O3 levels. To explore future potential impacts of O3 on vegetation, we compared historical and projected surface O3 concentrations simulated by six global atmospheric chemistry transport models on the basis of three representative concentration pathways emission scenarios (i.e. RCP2.6, 4.5, 8.5. To assess changes in the potential surface O3 threat to vegetation at the global scale, we used the AOT40 metric. Results point out a significant exceedance of AOT40 in comparison with the recommendations of UNECE for the protection of vegetation. In fact, many areas of the Northern Hemisphere show that AOT40-based critical levels will be exceeded by a factor of at least 10 under RCP8.5. Changes in surface O3 by 2100 worldwide range from about +4–5 ppb in the RCP8.5 scenario to reductions of about 2–10 ppb in the most optimistic scenario, RCP2.6. The risk of O3 injury for vegetation, through the potential O3 impact on photosynthetic assimilation, decreased by 61 and 47 % under RCP2.6 and RCP4.5, respectively, and increased by 70 % under RCP8.5. Key biodiversity areas in southern and northern Asia, central Africa and North America were identified as being at risk from high O3 concentrations.

Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

Science.gov (United States)

Wang, Zhi-Wei; Steele, T. G.; Hanif, T.; Mann, R. B.

2016-08-01

We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model's couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ ≈ 0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F , which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Wei; Steele, T.G. [Department of Physics and Engineering Physics, University of Saskatchewan,116 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Hanif, T. [Department of Theoretical Physics, University of Dhaka,Dhaka-1000 (Bangladesh); Mann, R.B. [Department of Physics, University of Waterloo,Waterloo, ON, N2L 3G1 (Canada)

2016-08-09

We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model’s couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ≈0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F, which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

The Impact of Inventory Management on Stock-Outs of Essential Drugs in Sub-Saharan Africa: Secondary Analysis of a Field Experiment in Zambia.

Science.gov (United States)

Leung, Ngai-Hang Z; Chen, Ana; Yadav, Prashant; Gallien, Jérémie

2016-01-01

To characterize the impact of widespread inventory management policies on stock-outs of essential drugs in Zambia's health clinics and develop related recommendations. Daily clinic storeroom stock levels of artemether-lumefantrine (AL) products in 2009-2010 were captured in 145 facilities through photography and manual transcription of paper forms, then used to determine historical stock-out levels and estimate demand patterns. Delivery lead-times and estimates of monthly facility accessibility were obtained through worker surveys. A simulation model was constructed and validated for predictive accuracy against historical stock-outs, then used to evaluate various changes potentially affecting product availability. While almost no stock-outs of AL products were observed during Q4 2009 consistent with primary analysis, up to 30% of surveyed facilities stocked out of some AL product during Q1 2010 despite ample inventory being simultaneously available at the national warehouse. Simulation experiments closely reproduced these results and linked them to the use of average past monthly issues and failure to capture lead-time variability in current inventory control policies. Several inventory policy enhancements currently recommended by USAID | DELIVER were found to have limited impact on product availability. Inventory control policies widely recommended and used for distributing medicines in sub-Saharan Africa directly account for a substantial fraction of stock-outs observed in common situations involving demand seasonality and facility access interruptions. Developing central capabilities in peripheral demand forecasting and inventory control is critical. More rigorous independent peer-reviewed research on pharmaceutical supply chain management in low-income countries is needed.

Sustainable waste management in Africa through CDM projects.

Science.gov (United States)

Couth, R; Trois, C

2012-11-01

Only few Clean Development Mechanism (CDM) projects (traditionally focussed on landfill gas combustion) have been registered in Africa if compared to similar developing countries. The waste hierarchy adopted by many African countries clearly shows that waste recycling and composting projects are generally the most sustainable. This paper undertakes a sustainability assessment for practical waste treatment and disposal scenarios for Africa and makes recommendations for consideration. The appraisal in this paper demonstrates that mechanical biological treatment of waste becomes more financially attractive if established through the CDM process. Waste will continue to be dumped in Africa with increasing greenhouse gas emissions produced, unless industrialised countries (Annex 1) fund carbon emission reduction schemes through a replacement to the Kyoto Protocol. Such a replacement should calculate all of the direct and indirect carbon emission savings and seek to promote public-private partnerships through a concerted support of the informal sector. Copyright © 2012 Elsevier Ltd. All rights reserved.

South Africa in the BRICS: Opportunities, Challenges and Prospects1

African Journals Online (AJOL)

This study investigates the participation of South Africa in the BRICS group from an analytical perspective. It is argued that South Africa's membership to this group entails both opportunities and challenges for South Africa, the continent and the system of global governance. We seek to flesh out the potential mediumand ...

Complexity factors and prediction of performance

International Nuclear Information System (INIS)

Braarud, Per Oeyvind

1998-03-01

Understanding of what makes a control room situation difficult to handle is important when studying operator performance, both with respect to prediction as well as improvement of the human performance. A factor analytic approach identified eight factors from operators' answers to an 39 item questionnaire about complexity of the operator's task in the control room. A Complexity Profiling Questionnaire was developed, based on the factor analytic results from the operators' conception of complexity. The validity of the identified complexity factors was studied by prediction of crew performance and prediction of plant performance from ratings of the complexity of scenarios. The scenarios were rated by both process experts and the operators participating in the scenarios, using the Complexity Profiling Questionnaire. The process experts' complexity ratings predicted both crew performance and plant performance, while the operators' rating predicted plant performance only. The results reported are from initial studies of complexity, and imply a promising potential for further studies of the concept. The approach used in the study as well as the reported results are discussed. A chapter about the structure of the conception of complexity, and a chapter about further research conclude the report. (author)

Developing a Scenario for widespread use: Best practices, lessons learned

Science.gov (United States)

Perry, S.; Jones, L.; Cox, D.

2011-01-01

The ShakeOut Scenario is probably the most widely known and used earthquake scenario created to date. Much of the credit for its widespread dissemination and application lies with scenario development criteria that focused on the needs and involvement of end users and with a suite of products that tailored communication of the results to varied end users, who ranged from emergency managers to the general public, from corporations to grassroots organizations. Products were most effective when they were highly visual, when they emphasized the findings of social scientists, and when they communicated the experience of living through the earthquake. This paper summarizes the development criteria and the products that made the ShakeOut Scenario so widely known and used, and it provides some suggestions for future improvements. ?? 2011, Earthquake Engineering Research Institute.

Predicting, deciding, learning: can one evaluate the 'success' of national climate scenarios?

International Nuclear Information System (INIS)

Hulme, Mike; Dessai, Suraje

2008-01-01

Scenarios may be understood as products and/or processes. Viewing scenario exercises as productive tends to emphasize their tangibility: scenario products may acquire value unrelated to the processes of their creation. Viewing scenario exercises as procedural tends to emphasize their modes of formation: the process of constructing scenarios may have benefits irrespective of the value of ensuing products. These two framings yield different expectations about how one might evaluate the 'success' or otherwise of scenario exercises. We illustrate three approaches to evaluating the success or otherwise of scenarios using the example of the series of national UK climate scenarios published between 1991 and 2002. These are: predictive success (has the future turned out as envisaged?), decision success (have 'good' decisions subsequently been made?) and learning success (have scenarios proved engaging and enabled learning?). We reflect on the different ways the 'success' of national climate scenarios might be evaluated and on the relationship between the productive and procedural dimensions of scenario exercises.

Approximate Analysis of Multi-State Weighted k-Out-of-n Systems Applied to Transmission Lines

Directory of Open Access Journals (Sweden)

Xiaogang Song

2017-10-01

Full Text Available Multi-state weighted k-out-of-n systems are widely applied in various scenarios, such as multiple line (power/oil transmission line transmission systems where the capability of fault tolerance is desirable. However, the complex operating environment and the dynamic features of load demands influence the evaluation of system reliability. In this paper, a stochastic multiple-valued (SMV approach is proposed to efficiently predict the reliability of two models of systems with non-repairable components and dynamically repairable components. The weights/performances and reliabilities of multi-state components (MSCs are represented by stochastic sequences consisting of a fixed number of multi-state values with the positions being randomly permutated. Using stochastic sequences with L multiple values, linear computational complexities with parameters n and L are required by the SMV approach to compute the reliability of different multi-state k-out-of-n systems at a reasonable accuracy, compared to the complexities of universal generating functions (UGF and fuzzy universal generating functions (FUGF that increase exponentially with the value of n. The analysis of two benchmarks shows that the proposed SMV approach is more efficient than the analysis using UGF or FUGF.

Climate change, crop yields, and undernutrition: development of a model to quantify the impact of climate scenarios on child undernutrition.

Science.gov (United States)

Lloyd, Simon J; Kovats, R Sari; Chalabi, Zaid

2011-12-01

Global climate change is anticipated to reduce future cereal yields and threaten food security, thus potentially increasing the risk of undernutrition. The causation of undernutrition is complex, and there is a need to develop models that better quantify the potential impacts of climate change on population health. We developed a model for estimating future undernutrition that accounts for food and nonfood (socioeconomic) causes and can be linked to available regional scenario data. We estimated child stunting attributable to climate change in five regions in South Asia and sub-Saharan Africa (SSA) in 2050. We used current national food availability and undernutrition data to parameterize and validate a global model, using a process-driven approach based on estimations of the physiological relationship between a lack of food and stunting. We estimated stunting in 2050 using published modeled national calorie availability under two climate scenarios and a reference scenario (no climate change). We estimated that climate change will lead to a relative increase in moderate stunting of 1-29% in 2050 compared with a future without climate change. Climate change will have a greater impact on rates of severe stunting, which we estimated will increase by 23% (central SSA) to 62% (South Asia). Climate change is likely to impair future efforts to reduce child malnutrition in South Asia and SSA, even when economic growth is taken into account. Our model suggests that to reduce and prevent future undernutrition, it is necessary to both increase food access and improve socioeconomic conditions, as well as reduce greenhouse gas emissions.

Discussion of ISV Scenario Scope with Operating Process Element

Energy Technology Data Exchange (ETDEWEB)

Kim, Yun Goo; Oh, Eungse [Korea Hydro and Nuclear Power Co. ltd. Central Research Institute, Daejeon (Korea, Republic of)

2015-10-15

NUREG-0711 identifies the sampling dimension of operational conditions which includes normal operation,I and C and HSI failures, transient, and accidents. Because of practical limitation of sampling, ISV scenarios do not include every expected operational condition. To develop a scenario for the ISV, it requires much time and efforts. It takes about 1 month with 3 operating crew team for 7 scenarios for the ISV. Therefore, operational conditions are screened out for integration to scenario. TSV can be used for the evaluation of monitoring, detection, and response implementation about the inventory of information and control. However, validity of operational walkthrough for other operating process element needs to be discussed. For the situation awareness, the general acceptance check list can be derived from the result of representative scenario set of ISV. The check list may contain the number of information, type of information, level of procedure and training program. For the response planning, procedure can be used for evaluation.

Methodology implementation for multi objective optimisation for nuclear fleet evolution scenarios

International Nuclear Information System (INIS)

Freynet, David

2016-01-01

The issue of the evolution French nuclear fleet can be considered through the study of nuclear transition scenarios. These studies are of paramount importance as their results can greatly affect the decision making process, given that they take into account industrial concerns, investments, time, and nuclear system complexity. Such studies can be performed with the COSI code (developed at the CEA/DEN), which enables the calculation of matter inventories and fluxes across the fuel cycle (nuclear reactors and associated facilities), especially when coupled with the CESAR depletion code. The studies today performed with COSI require the definition of the various scenarios' input parameters, in order to fulfil different objectives such as minimising natural uranium consumption, waste production and so on. These parameters concern the quantities and the scheduling of spent fuel destined for reprocessing, and the number, the type and the commissioning dates of deployed reactors.This work aims to develop, validate and apply an optimisation methodology coupled with COSI, in order to determine optimal nuclear transition scenarios for a multi-objective platform. Firstly, this methodology is based on the acceleration of scenario evaluation, enabling the use of optimisation methods in a reasonable time-frame. With this goal in mind, artificial neural network irradiation surrogate models are created with the URANIE platform (developed at the CEA/DEN) and are implemented within COSI. The next step in this work is to use, adapt and compare different optimisation methods, such as URANIE's genetic algorithm and particle swarm methods, in order to define a methodology suited to this type of study. This methodology development is based on an incremental approach which progressively adds objectives, constraints and decision variables to the optimisation problem definition. The variables added, which are related to reactor deployment and spent fuel reprocessing strategies, are chosen

Modeling sustainable long-term electricity supply-demand in Africa

International Nuclear Information System (INIS)

Ouedraogo, Nadia S.

2017-01-01

Highlights: • This study is one of the first detailed and complete representation of the African power system. • It models, within LEAP, possible future paths for the regional power systems. • All the end-users and supply side activities and actors are considered. • Three scenarios are examined: the baseline, the renewable energy, and the energy efficiency. • The energy efficiency scenario has allowed to draw a sustainable pathway for electrification. - Abstract: This paper develops a scenario-based model to identify and provide an array of electricity demand in Africa, and to derive them from the African power system of development. A system-based approach is performed by applying the scenario methodology developed by Schwartz in the context of the energy-economic modeling platform ‘Long-range Energy Alternative Planning’. Four scenarios are investigated. The Business as Usual scenario (BAU) replicates the regional and national Master Plans. The renewable-promotion scenario increases the share of renewable energy in the electricity mix. The demand and supply side efficiency scenarios investigate the impact of energy efficiency measures on the power system. The results show an increase in electricity demand by 4% by 2040, supply shortages and high emissions of Greenhouse Gases. Contrary to expectations, the renewable energy scenario did not emerge as the best solution to a sustainable electrification of the region. The energy efficiency scenarios have allowed us to draw a sustainable pathway for electrification.

A new tectonic model for the Cameroon Line, Central Africa

Science.gov (United States)

Moreau, C.; Regnoult, J.-M.; Déruelle, B.; Robineau, B.

1987-10-01

The Cameroon Line, a major geological feature in Central Africa, has been considered successively as a series of horsts and grabens, a continental rift and a mega-shear zone. It is marked out by about 60 anorogenic complexes and a dozen volcanic centres, all of which have alkaline affinity. Remote sensing allows us recognition of the main lineament trends: N70°, N-S, N135° and E-W, while autocorrelation analysis reveals a major fault zone striking N30° in western Cameroon and N15° in the northern region. A mega left-lateral shear zone is the model that best accounts for the fracture pattern and associated features such as linear and circular structures alignment of subvolcanic complexes, syntectonic leucogranites marking out older shear zones and vein dykes. The N70° Adamawa fault zone, a Pan-African fracture reworked during Albian-Aptian times, is the only shear zone of continental scale that could have initiated "en echelon" mega-tension gashes within the Cameroon Line during a Cainozoic left-lateral transcurrent movement.

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)

The GEO-3 Scenarios 2002-2032. Quantification and Analysis of Environmental Impacts

International Nuclear Information System (INIS)

Bakkes, J.; Potting, J.; Kemp-Benedict, E.; Raskin, P.; Masui, T.; Rana, A.; Nellemann, C.; Rothman, D.

2004-01-01

The four contrasting visions of the world's next three decades as presented in the third Global Environment Outlook (GEO-3) have many implications for policy - from hunger to climate change and from freshwater issues to biodiversity. The four scenarios analysed are Markets First, Policy First, Security First, Sustainability First. Presenting a deeper analysis than the original GEO-3 report, this Technical Report quantifies the impacts of the scenarios for all 19 GEO 'sub-regions', such as Eastern Africa and Central Europe. Regional impacts are discussed in the context of sustainable development. The report summary compares the impacts of the four scenarios across regions - and for the world as a whole - in the light of internationally agreed targets including those in the Millennium Declaration where applicable. It provides an account of the analytical methods, key assumptions, models and other tools, along with the approaches used in the analyses. Based on the methods and results, the report looks back on the process of producing the forward-looking analysis for GEO-3. Were all analytical centres on the same track? Did the approach adopted for GEO-3 contribute to the overall GEO objective of strengthening global-regional involvement and linkages?

Modeling the Complexities of Water and Hygiene in Limpopo Province South Africa

Science.gov (United States)

Mellor, J. E.; Smith, J. A.; Learmonth, G.; Netshandama, V.; Dillingham, R.

2012-12-01

Access to sustainable water and sanitation services is one of the biggest challenges the developing world faces as an increasing number of people inhabit those areas. Inadequate access to water and sanitation infrastructure often leads children to drink poor quality water which can result in early childhood diarrhea (ECD). Repeated episodes of ECD can cause serious problems such as growth stunting, cognitive impairment, and even death. Although researchers have long studied the connection between poor access to water and hygiene facilities and ECD, most studies have relied on intervention-control methods to study the effects of singular interventions. Such studies are time-consuming, costly, and fail to acknowledge that the causes and prevention strategies for ECD are numerous and complex. An alternate approach is to think of a community as a complex system in which the engineered, natural and social environments interact in ways that are not easily predicted. Such complex systems have no central or coordinating mechanism and may exhibit emergent behavior which can be counterintuitive and lead to valuable insights. The goal of this research is to develop a robust, quantitative understanding of the complex pathogen transmission chain that leads to ECD. To realize this goal, we have developed an Agent-Based Model (ABM) which simulates individual community member behavior. We have validated this transdisciplinary model with four years of field data from a community in Limpopo Province, South Africa. Our model incorporates data such as household water source preferences, collection habits, household- and source-water quality, water-source reliability and biological regrowth. Our outcome measures are household water quality, ECD incidences, and child growth stunting. This technique allows us to test hypotheses on the computer. Future researchers can implement promising interventions with our partner institution, the University of Venda, and the model can be refined as

Competent Governance for Sustainable Development in Africa: A Philosophical Reflection

Science.gov (United States)

Kadenyi, Misia; George, Kegode; Marcella, Mwaka; Kyalo, Wambua B.

2013-01-01

Africa has been known to be the bedrock of numerous natural resources. However, it seems to be the home of the poorest of the poor in the world. Much of the situation is pathetically characterized by hunger, extreme poverty, corruption, and insecurity. All of these offer the greatest compromise to any hope of change. Aware of this scenario,…

Negatep: A Scenario for Combating Global Warming; Le scenario Negatep. Un scenario de lutte contre le rechauffement climatique

Energy Technology Data Exchange (ETDEWEB)

Acket, C.; Bacher, P. [Sauvons Le Climat, 92 - Boulogne Billancourt (France)

2011-07-15

There have been an increasing number of foresight exercises in the field of energy and global warming in recent years, as we have seen from the articles devoted to these questions by Futuribles in 2011 (both in this special issue and in the April number). It is certainly the case that the goals for greenhouse-gas emission reduction are rather ambitious, particularly in France, it being the aim of the 2005 French framework law on energy to reduce carbon gas discharges by a factor of four. Among these scenarios, the Negatep scenario developed by Claude Acket and Pierre Bacher from the 'Sauvons le climat' [Let's save the climate] Association proposes to achieve this ('factor 4') goal in France by 2050 by reducing fossil fuel use by 75% and replacing this as quickly as possible with electricity produced from non-carbon-gas-emitting sources - chiefly, nuclear power and renewables. The authors lay out their goals here, backed up by figures, comparing these with the reference scenario. They also show the path that must be followed to arrive at these goals, particularly in the residential and tertiary sectors, and in transport and industry (through control of needs and recourse to alternative energy sources). They close by comparing the Negatep scenario with two other more recent scenarios aimed also at reducing greenhouse gas emissions, on the one hand in Europe, and on the other in Germany. The comparison confirms that they were right to rely on electricity as a substitute for oil, but gives them cause for concern in respect of the consequences (formidable in their view) that the replacement of nuclear power and coal energy by intermittent renewable energies might have in Europe, both with regard to costs and to the effects on the power network. (authors)

An assessment of the information content of likelihood ratios derived from complex mixtures.

Science.gov (United States)

Marsden, Clare D; Rudin, Norah; Inman, Keith; Lohmueller, Kirk E

2016-05-01

With the increasing sensitivity of DNA typing methodologies, as well as increasing awareness by law enforcement of the perceived capabilities of DNA typing, complex mixtures consisting of DNA from two or more contributors are increasingly being encountered. However, insufficient research has been conducted to characterize the ability to distinguish a true contributor (TC) from a known non-contributor (KNC) in these complex samples, and under what specific conditions. In order to investigate this question, sets of six 15-locus Caucasian genotype profiles were simulated and used to create mixtures containing 2-5 contributors. Likelihood ratios were computed for various situations, including varying numbers of contributors and unknowns in the evidence profile, as well as comparisons of the evidence profile to TCs and KNCs. This work was intended to illustrate the best-case scenario, in which all alleles from the TC were detected in the simulated evidence samples. Therefore the possibility of drop-out was not modeled in this study. The computer program DNAMIX was then used to compute LRs comparing the evidence profile to TCs and KNCs. This resulted in 140,000 LRs for each of the two scenarios. These complex mixture simulations show that, even when all alleles are detected (i.e. no drop-out), TCs can generate LRs less than 1 across a 15-locus profile. However, this outcome was rare, 7 of 140,000 replicates (0.005%), and associated only with mixtures comprising 5 contributors in which the numerator hypothesis includes one or more unknown contributors. For KNCs, LRs were found to be greater than 1 in a small number of replicates (75 of 140,000 replicates, or 0.05%). These replicates were limited to 4 and 5 person mixtures with 1 or more unknowns in the numerator. Only 5 of these 75 replicates (0.004%) yielded an LR greater than 1,000. Thus, overall, these results imply that the weight of evidence that can be derived from complex mixtures containing up to 5 contributors

Literacy in Francophone Africa.

Science.gov (United States)

Kokora, Pascal D.

1991-01-01

Literacy in francophone Africa, where literacy is still a privilege, is reviewed in terms of the complex linguistic situation, effects of population change, concepts and definitions of literacy, promotion of literacy in adult nonformal settings (e.g., African language literacy materials, multilingual settings). (23 references) (LB)

Renewable energy alternatives to mega hydropower: a case study of Inga 3 for Southern Africa

Science.gov (United States)

Deshmukh, R.; Mileva, A.; Wu, G. C.

2018-06-01

We assess the feasibility and cost-effectiveness of renewable energy alternatives to Inga 3, a 4.8-GW hydropower project on the Congo River, to serve the energy needs of the host country, the Democratic Republic of Congo (DRC), and the main buyer, South Africa. To account for a key uncertainty in the literature regarding the additional economic impacts of managing variable wind and solar electricity, we built a spatially and temporally detailed power system investment model for South Africa. We find that a mix of wind, solar photovoltaics, and some natural gas is more cost-effective than Inga 3 to meet future demand except in scenarios with pessimistic assumptions about wind technology performance. If a low load growth forecast is used, including Inga 3 in the power mix results in higher system cost across all sensitivities. In our scenarios, the effect of Inga 3 deployment on South African power system cost ranges from an increase of ZAR 4300 (US 330) million annually to savings of ZAR 1600 (US 120) million annually by 2035. A cost overrun as low as 20% makes the Inga 3 scenarios more expensive in all sensitivity cases. Including time and cost overruns and losses in transmission from DRC to South Africa make Inga 3 an even less attractive investment. For DRC, through analysis of spatial datasets representing technical, physical, and environmental constraints, we find abundant renewable energy potential: 60 GW of solar photovoltaic and 0.6–2.3 GW of wind located close to transmission infrastructure have levelized costs less than US 0.07 per kWh, or the anticipated cost of Inga 3 to residential consumers.

South Africa mobilises: the first five months of the war | Samson ...

African Journals Online (AJOL)

When war broke out in August 1914, the Union of South Africa found itself unprepared for what lay ahead. When the Imperial garrison left the Union during September 1914, supplies, equipment and a working knowledge of British military procedures reduced considerably. South Africa was, in effect, left starting from scratch.

Temperature effects on future energy demand in Sub-Saharan Africa

Science.gov (United States)

Shivakumar, Abhishek

2016-04-01

Climate change is projected to adversely impact different parts of the world to varying extents. Preliminary studies show that Sub-Saharan Africa is particularly vulnerable to climate change impacts, including changes to precipitation levels and temperatures. This work will analyse the effect of changes in temperature on critical systems such as energy supply and demand. Factors that determine energy demand include income, population, temperature (represented by cooling and heating degree days), and household structures. With many countries in Sub-Saharan Africa projected to experience rapid growth in both income and population levels, this study aims to quantify the amplified effects of these factors - coupled with temperature changes - on energy demand. The temperature effects will be studied across a range of scenarios for each of the factors mentioned above, and identify which of the factors is likely to have the most significant impact on energy demand in Sub-Saharan Africa. Results of this study can help set priorities for decision-makers to enhance the climate resilience of critical infrastructure in Sub-Saharan Africa.

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...

Shipping container response to three severe railway accident scenarios

International Nuclear Information System (INIS)

Mok, G.C.; Fischer, L.E.; Murty, S.S.; Witte, M.C.

1998-01-01

The probability of damage and the potential resulting hazards are analyzed for a representative rail shipping container for three severe rail accident scenarios. The scenarios are: (1) the rupture of closure bolts and resulting opening of closure lid due to a severe impact, (2) the puncture of container by an impacting rail-car coupler, and (3) the yielding of container due to side impact on a rigid uneven surface. The analysis results indicate that scenario 2 is a physically unreasonable event while the probabilities of a significant loss of containment in scenarios 1 and 3 are extremely small. Before assessing the potential risk for the last two scenarios, the uncertainties in predicting complex phenomena for rare, high- consequence hazards needs to be addressed using a rigorous methodology

The European Union's Africa Policy

DEFF Research Database (Denmark)

Olsen, Gorm Rye

2013-01-01

For a number of years, there has been an international debate on whether and to what extent small member states can influence the common external policies of the European Union. Recent research on the role of small EU states concludes that these states are neither per se political dwarfs nor power...... including North–South and specifically Africa policies. Five separate analyses are carried out addressing the question of Nordicization and Europeanization. Based on the empirical analyses, it is not possible to confirm the hypothesis that a Nordicization of the European Union's Africa policy has taken...... place. Rather, it appears adequate to talk about convergence of policies between the Nordics and the EU and therefore, the Africa policies of both actors are basically the result of Europeanization....

Financial and Economic Costs of the Elimination and Eradication of Onchocerciasis (River Blindness in Africa.

Directory of Open Access Journals (Sweden)

Young Eun Kim

Full Text Available Onchocerciasis (river blindness is a parasitic disease transmitted by blackflies. Symptoms include severe itching, skin lesions, and vision impairment including blindness. More than 99% of all cases are concentrated in sub-Saharan Africa. Fortunately, vector control and community-directed treatment with ivermectin have significantly decreased morbidity, and the treatment goal is shifting from control to elimination in Africa.We estimated financial resources and societal opportunity costs associated with scaling up community-directed treatment with ivermectin and implementing surveillance and response systems in endemic African regions for alternative treatment goals--control, elimination, and eradication. We used a micro-costing approach that allows adjustment for time-variant resource utilization and for the heterogeneity in the demographic, epidemiological, and political situation.The elimination and eradication scenarios, which include scaling up treatments to hypo-endemic and operationally challenging areas at the latest by 2021 and implementing intensive surveillance, would allow savings of $1.5 billion and $1.6 billion over 2013-2045 as compared to the control scenario. Although the elimination and eradication scenarios would require higher surveillance costs ($215 million and $242 million than the control scenario ($47 million, intensive surveillance would enable treatments to be safely stopped earlier, thereby saving unnecessary costs for prolonged treatments as in the control scenario lacking such surveillance and response systems.The elimination and eradication of onchocerciasis are predicted to allow substantial cost-savings in the long run. To realize cost-savings, policymakers should keep empowering community volunteers, and pharmaceutical companies would need to continue drug donation. To sustain high surveillance costs required for elimination and eradication, endemic countries would need to enhance their domestic funding capacity

South Africa makes some decisions

Energy Technology Data Exchange (ETDEWEB)

Anon.

1996-08-01

The potential heritage of apartheid still affects energy availability in South Africa. This article describes a new Energy Policy White paper, to be presented to Parliament, which will start to rectify current inequalities. Most of the black citizens have no access to electricity, while the affluent white minority have cheap electricity readily available to them. The complexities of funding necessary changes are addressed. South Africa`s low-cost coal reserves, mined from opencast pits next to power stations, are likely to continue to be exploited. As yet the country`s solar potential is unlikely to be developed because of the availability of coal. The production of electricity and the future of liquid fuel industries are likely to remain in crisis, even after the White Paper`s implementation. (UK)

Water limited agriculture in Africa: Climate change sensitivity of large scale land investments

Science.gov (United States)

Rulli, M. C.; D'Odorico, P.; Chiarelli, D. D.; Davis, K. F.

2015-12-01

The past few decades have seen unprecedented changes in the global agricultural system with a dramatic increase in the rates of food production fueled by an escalating demand for food calories, as a result of demographic growth, dietary changes, and - more recently - new bioenergy policies. Food prices have become consistently higher and increasingly volatile with dramatic spikes in 2007-08 and 2010-11. The confluence of these factors has heightened demand for land and brought a wave of land investment to the developing world: some of the more affluent countries are trying to secure land rights in areas suitable for agriculture. According to some estimates, to date, roughly 38 million hectares have been acquired worldwide by large scale investors, 16 million of which in Africa. More than 85% of large scale land acquisitions in Africa are by foreign investors. Many land deals are motivated not only by the need for fertile land but for the water resources required for crop production. Despite some recent assessments of the water appropriation associated with large scale land investments, their impact on the water resources of the target countries under present conditions and climate change scenarios remains poorly understood. Here we investigate irrigation water requirements by various crops planted in the acquired land as an indicator of the pressure likely placed by land investors on ("blue") water resources of target regions in Africa and evaluate the sensitivity to climate changes scenarios.

Analysis of uncertainty propagation in nuclear fuel cycle scenarios

International Nuclear Information System (INIS)

Krivtchik, Guillaume

2014-01-01

Nuclear scenario studies model nuclear fleet over a given period. They enable the comparison of different options for the reactor fleet evolution, and the management of the future fuel cycle materials, from mining to disposal, based on criteria such as installed capacity per reactor technology, mass inventories and flows, in the fuel cycle and in the waste. Uncertainties associated with nuclear data and scenario parameters (fuel, reactors and facilities characteristics) propagate along the isotopic chains in depletion calculations, and through out the scenario history, which reduces the precision of the results. The aim of this work is to develop, implement and use a stochastic uncertainty propagation methodology adapted to scenario studies. The method chosen is based on development of depletion computation surrogate models, which reduce the scenario studies computation time, and whose parameters include perturbations of the depletion model; and fabrication of equivalence model which take into account cross-sections perturbations for computation of fresh fuel enrichment. Then the uncertainty propagation methodology is applied to different scenarios of interest, considering different options of evolution for the French PWR fleet with SFR deployment. (author) [fr

Decolonizing Bioethics in Africa

Science.gov (United States)

Macaulay-Adeyelure, O.C.

2017-01-01

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

Scenarios for the future

International Nuclear Information System (INIS)

Haegermark, H.; Bergmark, M.

1995-06-01

This project aims primarily to give a basis for the joint R and D program for the Swedish electric utility industry, in the form of pictures of the future up to 2020. The work was performed during four seminars in a group of managers and R and D planners. The four scenarios differ mainly in the assumptions of high or low economic growth and on market or political rule. Assumptions on essential uncertainties about the future have been combined in a consistent manner, e.g. on the structure of the utility industry, the role of nuclear power, the importance of the greenhouse gas issue, the influence of new technology developments and on changes of values in society. Certain other development appear in all scenarios, e.g. the impact of information technology throughout society, the internationalization of business in general and industrial production in particular, considerations for the environment and care for natural resources. The four scenarios are: 'Technology on the throne' (market rule/high growth); 'Intense competition' (market rule/low growth); 'Monopoly takes over' (political rule/high growth); and 'Green local society' (political rule/low growth). Some of the important factors pointed out by the study are: Increased customer mobility between regions and countries; The impact of information technology; Societal value changes; Sustainable development as an important driving force; Structure of the utility industry. Diversifying into new services. New players; Access to knowledge and competence; Ways for handling the greenhouse gas problem; Preparedness for nuclear power phase-out. 12 figs, 6 tabs

Disruption scenarios for a nuclear-waste repository on the Nevada Test Site

International Nuclear Information System (INIS)

Link, R.L.; Bingham, F.W.; Barr, G.E.

1981-01-01

Scenarios are being constructed for the release of radioactive maerial from hypothetical repositories in different types of rock at NTS. Deductive event trees are constructed; each path through an event tree is a scenario. The complete set of NTS event trees comprises about 340 scenarios, not counting the multiple paths through the subtrees made by expanding complex events. Each of these scenarios is being analyzed for 10 different types of rocks

Sea level and shoreline reconstructions for the Red Sea: isostatic and tectonic considerations and implications for hominin migration out of Africa

Science.gov (United States)

Lambeck, Kurt; Purcell, Anthony; Flemming, Nicholas. C.; Vita-Finzi, Claudio; Alsharekh, Abdullah M.; Bailey, Geoffrey N.

2011-12-01

The history of sea level within the Red Sea basin impinges on several areas of research. For archaeology and prehistory, past sea levels of the southern sector define possible pathways of human dispersal out of Africa. For tectonics, the interglacial sea levels provide estimates of rates for vertical tectonics. For global sea level studies, the Red Sea sediments contain a significant record of changing water chemistry with implications on the mass exchange between oceans and ice sheets during glacial cycles. And, because of its geometry and location, the Red Sea provides a test laboratory for models of glacio-hydro-isostasy. The Red Sea margins contain incomplete records of sea level for the Late Holocene, for the Last Glacial Maximum, for the Last Interglacial and for earlier interglacials. These are usually interpreted in terms of tectonics and ocean volume changes but it is shown here that the glacio-hydro-isostatic process is an additional important component with characteristic spatial variability. Through an iterative analysis of the Holocene and interglacial evidence a separation of the tectonic, isostatic and eustatic contributions is possible and we present a predictive model for palaeo-shorelines and water depths for a time interval encompassing the period proposed for migrations of modern humans out of Africa. Principal conclusions include the following. (i) Late Holocene sea level signals evolve along the length of the Red Sea, with characteristic mid-Holocene highstands not developing in the central part. (ii) Last Interglacial sea level signals are also location dependent and, in the absence of tectonics, are not predicted to occur more than 1-2 m above present sea level. (iii) For both periods, Red Sea levels at 'expected far-field' elevations are not necessarily indicative of tectonic stability and the evidence points to a long-wavelength tectonic uplift component along both the African and Arabian northern and central sides of the Red Sea. (iv) The

Future waste treatment and energy systems – examples of joint scenarios

International Nuclear Information System (INIS)

Münster, M.; Finnveden, G.; Wenzel, H.

2013-01-01

Highlights: • Approach for use of scenarios dealing with both waste management and energy issues. • Overall scenarios for the common project and sub-scenarios in parts of the project. • Combining different types of scenarios to the tools of different disciplines. • Use of explorative external scenarios based on marginals for consequential LCA. - Abstract: Development and use of scenarios for large interdisciplinary projects is a complicated task. This article provides practical examples of how it has been carried out in two projects addressing waste management and energy issues respectively. Based on experiences from the two projects, recommendations are made for an approach concerning development of scenarios in projects dealing with both waste management and energy issues. Recommendations are given to develop and use overall scenarios for the project and leave room for sub-scenarios in parts of the project. Combining different types of scenarios is recommended, too, in order to adapt to the methods and tools of different disciplines, such as developing predictive scenarios with general equilibrium tools and analysing explorative scenarios with energy system analysis tools. Furthermore, as marginals identified in differing future background systems determine the outcomes of consequential life cycle assessments (LCAs), it is considered advisable to develop and use explorative external scenarios based on possible marginals as a framework for consequential LCAs. This approach is illustrated using an on-going Danish research project

A world of differences, the normative EOS-scenarios. Final report of a study to found the normative scenarios of the project Energy research scenarios of the Energy Study Centre (ECN, Petten, Netherlands). Een wereld van verschil, de normatieve EOS-scenario's. Eindrapport van een studie ter onderbouwing van de normatieve scenario's van het project Energie Onderzoek Scenario's van het Energie Studie Centrum (ECN, Petten)

Energy Technology Data Exchange (ETDEWEB)

Dinkelman, G.

1987-11-01

Three competing political and economical 'concepts of control' which underlie three normative energy-scenarios are described. The aim of the literature-research carried out for this report was to make the original scenarios more recognizable, and to find out which groups could be expected to support them. The concepts of control bear the names 'Dynamic and growth', 'Dirigation and blockbuilding' and 'Shared development'. They can be seen, so is argued, as competing perspectives on a so-called 'post-Fordist' world. The three concepts of control differ on what they see as common interests and the way they should be looked after. Topics in the description are: the desired rate of European political and economical integration, the borders of Europe, Europe's position in the world, the acceptance of new technologies, the goals they should be used for, and perceived relationships between energy, environment and economy. The scenarios show what happens if these three concepts of control become hegemonic without being forced to compromises. For all three scenarios a short sketch is given of the corresponding dominating energy- and environmental policy and of future relationships within OECD and between OECD on the one hand and NIC's/LDC's on the other. The conclusion of the report is that the ideological differences between the neoliberalism of 'Dynamic and growth' and the green, direct-democracy-politics of 'Shared development' are not as big as they were in the seventies. Especially on the new policy-areas like technology, energy and environment they get closer. But this does not mean that the concept of 'Dirigation and blockbuilding' can be put completely aside. Its goal of economic equality and its emphasis on government dirigation may become more attractive again if it comes out that market regulation leads to a dual society and that it was state-intervention (by

Scenario-based table top simulations

DEFF Research Database (Denmark)

Broberg, Ole; Edwards, Kasper; Nielsen, J.

2012-01-01

This study developed and tested a scenario-based table top simulation method in a user-driven innovation setting. A team of researchers worked together with a user group of five medical staff members from the existing clinic. Table top simulations of a new clinic were carried out in a simple model...

A tool for the consensual analysis of decision-making scenarios.

Science.gov (United States)

Hunt, Geoffrey; Merzeder, Christine; Bischofberger, Iren

2018-05-01

The authors believe there is a need for novel ways of enhancing professional judgment and discretion in the contemporary healthcare environment. The objective is to provide a framework to guide a discursive analysis of an ongoing clinical scenario by a small group of healthcare professionals (4-12) to achieve consensual understanding in the decision-making necessary to resolve specific healthcare inadequacies and promote organisational learning. REPVAD is an acronym for the framework's five decision-making dimensions of reasoning, evidence, procedures, values, attitudes and defences. The design is set out in terms of well-defined definitions of the dimensions, a rationale for using REPVAD, and explications of dimensions one at a time. Furthermore, the REPVAD process of application to a scenario is set out, and a didactic scenario is given to show how REPVAD works together with a sample case. A discussion is fleshed out in four real life student cases, and a conclusion indicates strengths and weaknesses and the possibility of further development and transferability. In terms of findings, the model has been tried, tested and refined over a number of years in the development of advanced practitioners at university healthcare faculties in two European countries. Consent was obtained from the four participating students.

Pangaea and the Out-of-Africa Model of Varicella-Zoster Virus Evolution and Phylogeography.

Science.gov (United States)

Grose, Charles

2012-09-01

The goal of this minireview is to provide an overview of varicella-zoster virus (VZV) phylogenetics and phylogeography when placed in the broad context of geologic time. Planet Earth was formed over 4 billion years ago, and the supercontinent Pangaea coalesced around 400 million years ago (mya). Based on detailed tree-building models, the base of the phylogenetic tree of the Herpesviridae family has been estimated at 400 mya. Subsequently, Pangaea split into Laurasia and Gondwanaland; in turn, Africa rifted from Gondwanaland. Based on available data, the hypothesis of this minireview is that the ancestral alphaherpesvirus VZV coevolved in simians, apes, and hominins in Africa. When anatomically modern humans first crossed over the Red Sea 60,000 years ago, VZV was carried along in their dorsal root ganglia. Currently, there are five VZV clades, distinguishable by single nucleotide polymorphisms. These clades likely represent continued VZV coevolution, as humans with latent VZV infection left Arabia and dispersed into Asia (clades 2 and 5) and Europe (clades 1, 3, and 4). The prototype VZV sequence contains nearly 125,000 bp, divided into 70 open reading frames. Generally, isolates within a clade display >99.9% identity to one another, while members of one clade compared to a second clade show 99.8% identity to one another. Recently, four different VZV genotypes that do not segregate into the previously defined five clades have been identified, a result indicating a wider than anticipated diversity among newly collected VZV strains around the world.

Intrusion scenarios in fusion waste disposal sites

International Nuclear Information System (INIS)

Zucchetti, M.; Zucchetti, M.; Rocco, P.

1998-01-01

Results of analyses on human intrusions into repositories of fusion radioactive waste are presented. The main topics are: duration of the institutional control, occurrence of intrusion, intrusion scenarios, acceptable risk limits and probabilistic data. Application to fusion waste repositories is implemented with a computational model: wells drilling is considered as the possible scenario. Doses and risks to intruder for different SEAFP-2 cases turn out to be very small. No intervention to reduce the hazard is necessary. (authors)

Intrusion scenarios in fusion waste disposal sites

Energy Technology Data Exchange (ETDEWEB)

Zucchetti, M. [European Commission, JRC, Institute for Advanced Material, Ispra, Vatican City State, Holy See (Italy); Zucchetti, M.; Rocco, P. [Energetics Dept., Polytechnic of Turin (Italy)

1998-07-01

Results of analyses on human intrusions into repositories of fusion radioactive waste are presented. The main topics are: duration of the institutional control, occurrence of intrusion, intrusion scenarios, acceptable risk limits and probabilistic data. Application to fusion waste repositories is implemented with a computational model: wells drilling is considered as the possible scenario. Doses and risks to intruder for different SEAFP-2 cases turn out to be very small. No intervention to reduce the hazard is necessary. (authors)

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.

Online scenario labeling using a hidden Markov model for assessment of nuclear plant state

International Nuclear Information System (INIS)

Zamalieva, Daniya; Yilmaz, Alper; Aldemir, Tunc

2013-01-01

By taking into account both aleatory and epistemic uncertainties within the same probabilistic framework, dynamic event trees (DETs) provide more comprehensive and systematic coverage of possible scenarios following an initiating event compared to conventional event trees. When DET generation algorithms are applied to complex realistic systems, extremely large amounts of data can be produced due to both the large number of scenarios generated following a single initiating event and the large number of data channels that represent these scenarios. In addition, the computational time required for the simulation of each scenario can be very large (e.g. about 24 h of serial run simulation time for a 4 h station blackout scenario). Since scenarios leading to system failure are more of interest, a method is proposed for online labeling of scenarios as failure or non-failure. The algorithm first trains a Hidden Markov Model, which represents the behavior of non-failure scenarios, using a training set from previous simulations. Then, the maximum likelihoods of sample failure and non-failure scenarios fitting this model are computed. These values are used to determine the timestamp at which the labeling of a certain scenario should be performed. Finally, during the succeeding timestamps, the likelihood of each scenario fitting the learned model is computed, and a dynamic thresholding based on the previously calculated likelihood values is applied. The scenarios whose likelihood is higher than the threshold are labeled as non-failure. The proposed algorithm can further delay the non-failure scenarios or discontinue them in order to redirect the computational resources toward the failure scenarios, and reduce computational time and complexity. Experiments using RELAP5/3D model of a fast reactor utilizing an Reactor Vessel Auxiliary Cooling System (RVACS) passive decay heat removal system and dynamic analysis of a station blackout (SBO) event show that the proposed method is

An air quality assessment in the industrialised western Bushveld Igneous Complex, South Africa

Directory of Open Access Journals (Sweden)

Andrew D. Venter

2012-09-01

Full Text Available South Africa has the largest industrialised economy in Africa, with significant mining and metallurgical activities. A large fraction of the South African mineral assets is concentrated in the Bushveld Igneous Complex (BIC, with the western limb being the most exploited. Because the majority of the world’s platinum is produced in the BIC, this area is also of international interest. There are some indications that the western BIC should be considered an air pollution hotspot; however, inadequate data exist to substantiate these claims scientifically. To partially address this knowledge gap, a comprehensive air quality monitoring station was operated for more than 2 years in this area. Meteorological parameters, trace gas concentrations and total mass concentration of particulate matter up to 10 µm in size (PM10 were measured. Compared with South African and European ambient air quality standards, SO2, NO2 and CO concentrations were generally acceptable. The major sources of SO2 were identified as high-stack industry emissions, while household combustion from semi-formal and informal settlements was identified as the predominant source of NO2 and CO. In contrast, O3 exceeded the 8-h moving average more than 322 times per year. The main contributing factor was identified to be the influx of regional air masses, with high O3 precursor concentrations. PM10 exceeded the current South African 24-h standard 6.6 times per year, the future (2015 standard 42.3 times per year and the European standard more than 120 times per year. The main source of PM10 was identified as household combustion from semi-formal and informal settlements. The findings clearly indicate that atmospheric O3 and PM10 levels in the western BIC need to be addressed to avoid negative environmental and human health impacts.

Proliferation resistance of a hypothetical sodium fast reactor under an assumed breakout scenario

Energy Technology Data Exchange (ETDEWEB)

Whitlock, Jeremy [Non-Proliferation and Safeguards, AECL Chalk River Laboratories, Stn. 91, Chalk River, Ontario, K0J 1J0 (Canada); Inoue, Naoko; Senzaki, Masao [Japan Atomic Energy Agency - JAEA (Japan); Bley, Dennis [Buttonwood Consulting Inc., Oakton, VA (United States); Wonder, Ed [National Nuclear Security Administration, Department of Energy (United States)

2009-06-15

The Proliferation Resistance and Physical Protection (PR and PP) Working Group of the Generation IV International Forum (GIF) conducted a high-level pathway analysis of a hypothetical sodium fast reactor and integral fuel processing facility (called collectively the 'Example Sodium Fast Reactor' or ESFR), as a test of the effectiveness of its analysis methodology. From a common set of assumed host-state capabilities and objectives, a number of threat scenarios emerge (Concealed Diversion, Concealed Misuse, Breakout or Overt Misuse, and Theft/Sabotage). This paper presents the results of the analysis based on the Breakout scenario. A distinguishing aspect of Breakout scenario consideration concerns the optimal use of the time from breakout to weapons readiness, which is related to the Proliferation Time measure. The goal of analyzing the breakout scenario was therefore to complement other analyses involving the Concealed Misuse and Diversion scenarios by exploring the minimum post-breakout time to weapons readiness. Four target strategies were chosen for analysis: (1) Diversion of LEU feed material at front-end of the ESFR facility; (2) Misuse of the reactor facility to irradiate fertile material; (3) Misuse of the reactor facility to irradiate material in the in-core fuel storage basket; and (4) Misuse of the fuel processing facility to higher-purity TRU. The investigation identified several general 'sub-strategies' within the Breakout scenario, dependent upon the aggressiveness with which a State pursues its intent to break out (including its aversion to the risk of detection). The sub-strategy chosen by a proliferant state will affect both the time available and potential complexity for proliferation activities. The sub-strategy chosen is itself affected by political factors (foreign relations agenda of state, probability of external intervention after breakout, external dependence of proliferant state's supply chain, etc.) These factors

The many outcomes from contracting out: The voice of public managers

DEFF Research Database (Denmark)

Lindholst, Andrej Christian; Hansen, Morten Balle; Randrup, Thomas Barfoed

2018-01-01

perspective is summarised in a best-case, worst-case and complex-case scenario highlighting the mix, complexities and trade-offs in a composite set of contracting outcomes. The nature of contracting outcomes as complex and composite rather than unidimensional is one key finding. Furthermore, the importance...

Expanding radio astronomy in Africa

International Nuclear Information System (INIS)

Gaylard, M J

2013-01-01

The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

Bibliometric trends of health economic evaluation in Sub-Saharan Africa.

Science.gov (United States)

Hernandez-Villafuerte, Karla; Li, Ryan; Hofman, Karen J

2016-08-24

Collaboration between Sub-Saharan African researchers is important for the generation and transfer of health technology assessment (HTA) evidence, in order to support priority-setting in health. The objective of this analysis was to evaluate collaboration patterns between countries. We conducted a rapid evidence assessment that included a random sample of health economic evaluations carried out in 20 countries (Angola, Botswana, Congo, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namibia, Seychelles, South Africa, Swaziland, Tanzania, Zambia, Zimbabwe, Ghana, Kenya, Nigeria, Ethiopia, Uganda). We conducted bibliometric network analysis based on all first authors with a Sub-Saharan African academic affiliation and their co-authored publications ("network-articles"). Then we produced a connection map of collaboration patterns among Sub-Saharan African researchers, reflecting the number of network-articles and the country of affiliation of the main co-authors. The sample of 119 economic evaluations mostly related to treatments of communicable diseases, in particular HIV/AIDS (42/119, 35.29 %) and malaria (26/119, 21.85 %). The 39 first authors from Sub-Saharan African institutions together co-authored 729 network-articles. The network analysis showed weak collaboration between health economic researchers in Sub-Saharan Africa, with researchers being more likely to collaborate with Europe and North America than with other African countries. South Africa stood out as producing the highest number of health economic evaluations and collaborations. The development and evaluation of HTA research networks in Sub-Saharan Africa should be supported, with South Africa central to any such efforts. Organizations and institutions from high income countries interested in supporting priority setting in Sub-Saharan Africa should include promoting collaboration as part of their agendas, in order to take advantage of the potential transferability of results and methods of the

Economic and geopolitical dimensions of renewable vs. nuclear energy in North Africa

International Nuclear Information System (INIS)

Marktanner, Marcus; Salman, Lana

2011-01-01

Addressing issues of renewable energy in North Africa must incorporate concerns regarding the compatibility of energy mixes with the nature of political regimes, their geopolitical relevance, and their socio-economic effects, in addition to economic cost-benefit deliberations. One important and under-researched aspect of nuclear energy refers to the trade-off between socio-economic development and political power conservation. Competing interests in North Africa's energy market as well as aspects of regional cooperation capacity are important when assessing the choice between renewable and nuclear energy. Therefore, the future course of meeting North Africa's energy needs is subject to a complex political and economic interplay between domestic and geopolitical development interests. The objective of this paper is to explore this complexity in more detail. We argue that the identification of any energy alternative as superior is hardly convincing unless certain standards of inclusive governance are met. We also find that it is important to highlight political-economic differences between energy importers like Morocco and Tunisia and energy exporters like Algeria, Libya, and Egypt. - Research highlights: → North Africa confronted with severe energy supply challenges in near future. → Trade-off between socio-economic development and political power conservation matters. → Economic and geopolitical dimensions of trade-off heterogeneous across North Africa.

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 ...

'Land grabs' in Africa: can the deals work for development?

Energy Technology Data Exchange (ETDEWEB)

Cotula, Lorenzo; Vermeulen, Sonja

2009-09-15

For many millions in the developing world, land is central to livelihoods, food security, even identity – the result of a direct dependence on agriculture and natural resources. It is not surprising, then, that a recent wave of large-scale land acquisitions in poorer countries has sparked a major debate. Through these acquisitions, interests in richer countries are buying or leasing large tracts of farmland for agricultural investment in Africa, Central and Southeast Asia, Eastern Europe and Latin America. With some deals involving hundreds of thousands of hectares, these investments have been dubbed 'land grabs' by the media. But this is too simplistic. Depending on the way they are structured, these investments can either create new opportunities to improve local living standards, or further marginalise the poor. An analysis of this complex and shifting situation, focusing on Africa, lays out key trends, drivers and main features, and outlines how to make the renewed momentum in agricultural investment work for local development and livelihoods.

Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes

Science.gov (United States)

Stoetzel, Emmanuelle; Cornette, Raphaël; Lalis, Aude; Nicolas, Violaine; Cucchi, Thomas; Denys, Christiane

2017-05-01

Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture

The dynamics of HIV transmission in out of school young heterosexual men in South Africa: a systematic scoping review protocol.

Science.gov (United States)

Ntombela, Nonzwakazi; Mashamba-Thompson, Tivani P; Mtshali, Andile; Voce, Anna; Kharsany, Ayesha B M

2017-01-17

In South Africa, gender inequality dominated by males and heterosexual HIV epidemic are associated with high HIV infection. Underlying epidemiological and social determinants driving HIV acquisition and transmission are critical to understand the extent and complexity of sexual networks as primary mechanisms through which HIV is likely to spread. The aim of the study is to provide an overview of empiric evidence that links the complex interaction of risk of HIV infection in men. We will conduct a systematic scoping review to identify, describe, and map literature on the dynamics of HIV infection in men, and we will determine the quality of the studies reporting on the dynamics of HIV infections in men. Primary research articles, published in peer-reviewed journals, review articles, and gray literature that address the research question, will be included. We will search PubMed, Web of Knowledge, Science Direct, EBSCOhost, Google Scholar, World Health Organization library, and UNAIDS database. Reference lists and existing networks such as government organizations and conferences will also be included to source relevant literature. Two independent reviewers will extract data in parallel from all relevant search engines, using specific inclusion and exclusion criteria. A thematic content analysis will be used to present the narrative account of the reviews, using NVivo version 10. We anticipate finding relevant literature on the dynamics of HIV transmission in South African men. Once summarized, data will be useful to guide future research. PROSPERO CRD42016039489.

Reducing the Burden of Cancer in East Africa

Science.gov (United States)

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

The GEO-3 Scenarios 2002-2032. Quantification and Analysis of Environmental Impacts

Energy Technology Data Exchange (ETDEWEB)

Bakkes, J.; Potting, J. (eds.) [National Institute for Public Health and the Environment RIVM, Bilthoven (Netherlands); Henrichs, T. [Center for Environmental Systems Research CESR, University of Kassel, Kassel (Germany); Kemp-Benedict, E.; Raskin, P. [Stockholm Environment Institute SEI, Boston, MA (United States); Masui, T.; Rana, A. [National Institute for Environmental Studies NIES, Ibaraki (Japan); Nellemann, C. [United Nations Environment Programme UNEP, GRID Global and Regional Integrated Data centres Arendal, Lillehammer (Norway); Rothman, D. [International Centre for Integrative Studies ICIS, Maastricht University, Maastricht (Netherlands)

2004-07-01

The four contrasting visions of the world's next three decades as presented in the third Global Environment Outlook (GEO-3) have many implications for policy - from hunger to climate change and from freshwater issues to biodiversity. The four scenarios analysed are Markets First, Policy First, Security First, Sustainability First. Presenting a deeper analysis than the original GEO-3 report, this Technical Report quantifies the impacts of the scenarios for all 19 GEO 'sub-regions', such as Eastern Africa and Central Europe. Regional impacts are discussed in the context of sustainable development. The report summary compares the impacts of the four scenarios across regions - and for the world as a whole - in the light of internationally agreed targets including those in the Millennium Declaration where applicable. It provides an account of the analytical methods, key assumptions, models and other tools, along with the approaches used in the analyses. Based on the methods and results, the report looks back on the process of producing the forward-looking analysis for GEO-3. Were all analytical centres on the same track? Did the approach adopted for GEO-3 contribute to the overall GEO objective of strengthening global-regional involvement and linkages?.

Assessing the impact of new technology on complex sociotechnical systems

CSIR Research Space (South Africa)

Oosthuizen, R

2016-08-01

Full Text Available , South Africa roosthuizen@csir.co.za Department of Engineering and Technology Management University of Pretoria, South Africa Leon.Pretorius@up.ac.za ABSTRACT In complex sociotechnical systems, cognitive and social humans use technology...

Modeling the complexities of water, hygiene, and health in Limpopo Province, South Africa.

Science.gov (United States)

Mellor, Jonathan E; Smith, James A; Learmonth, Gerard P; Netshandama, Vhonani O; Dillingham, Rebecca A

2012-12-18

Researchers have long studied the causes and prevention strategies of poor household water quality and early childhood diarrhea using intervention-control trials. Although the results of such trails can lead to useful information, they do not capture the complexity of this natural/engineered/social system. We report on the development of an agent-based model (ABM) to study such a system in Limpopo, South Africa. The study is based on four years of field data collection to accurately capture essential elements of the communities and their water contamination chain. An extensive analysis of those elements explored behaviors including water collection and treatment frequency as well as biofilm buildup in water storage containers, source water quality, and water container types. Results indicate that interventions must be optimally implemented in order to see significant reductions in early childhood diarrhea (ECD). Household boiling frequency, source water quality, water container type, and the biofilm layer contribution were deemed to have significant impacts on ECD. Furthermore, concurrently implemented highly effective interventions were shown to reduce diarrhea rates to very low levels even when other, less important practices were suboptimal. This technique can be used by a variety of stakeholders when designing interventions to reduce ECD incidences in similar settings.

Africa and the Green Revolution : A Global Historical Perspective

NARCIS (Netherlands)

Frankema, Ewout

2014-01-01

Two decades of substantial economic growth in Africa have challenged the deep-seated Afro-pessimism of the 1990s and 2000s and re-invigorated the academic debate on Africa's ability to grow out of poverty in the 21st century. Although the opinions differ widely on how sustainable current African

Child Soldiers in Africa: Solutions to a Complex Dilemma | Kalis ...

African Journals Online (AJOL)

This article focuses on the dilemma of using child soldiers in violent conflicts throughout Africa and on ways of resolving it in the future. The first section briefly examines some important domestic and international aspects and dimensions of the problem. Then, attention is shifted to particular individual countries on the ...

The Evolving Role of Physicians - Don’t Forget the Generalist Primary Care Providers; Comment on “Non-physician Clinicians in Sub-Saharan Africa and the Evolving Role of Physicians”

Directory of Open Access Journals (Sweden)

Vincent Kalumire Cubaka

2016-10-01

Full Text Available The editorial “Non-physician Clinicians in Sub-Saharan Africa and the Evolving Role of Physicians” by Eyal et al describes non-physician clinicians’ (NPC need for mentorship and support from physicians. We emphasise the same need of support for front line generalist primary healthcare providers who carry out complex tasks yet may have an inadequate skill mix.

Implications for complex cognition from the hafting of tools with compound adhesives in the Middle Stone Age, South Africa

Science.gov (United States)

Wadley, Lyn; Hodgskiss, Tamaryn; Grant, Michael

2009-01-01

Compound adhesives made from red ochre mixed with plant gum were used in the Middle Stone Age (MSA), South Africa. Replications reported here suggest that early artisans did not merely color their glues red; they deliberately effected physical transformations involving chemical changes from acidic to less acidic pH, dehydration of the adhesive near wood fires, and changes to mechanical workability and electrostatic forces. Some of the steps required for making compound adhesive seem impossible without multitasking and abstract thought. This ability suggests overlap between the cognitive abilities of modern people and people in the MSA. Our multidisciplinary analysis provides a new way to recognize complex cognition in the MSA without necessarily invoking the concept of symbolism. PMID:19433786

The Corruption Bogey in South Africa: Is Public Education Safe?

Science.gov (United States)

Serfontein, Erika; de Waal, Elda

2015-01-01

Corruption is a constant global phenomenon, which is becoming more complex and intense as competition for resources increases. It is even more so amongst those living in developing countries, particularly emerging economies such as South Africa. Acts of corruption directly contest the basic principles of South Africa's Constitution, which aims at…