scholarly journals Admixture into and within sub-Saharan Africa

2016 ◽  
Author(s):  
George Busby ◽  
Gavin Band ◽  
Quang Si Le ◽  
Muminatou Jallow ◽  
Edith Bougama ◽  
...  
Keyword(s):  
Large Scale ◽  
Haplotype Diversity ◽  
Geographic Region ◽  
Sub Saharan Africa ◽  
Agricultural Technologies ◽  
Population Movements ◽  
Crucial Component ◽  
Depth Analysis ◽  
Scale Population ◽  
Sub Saharan

Understanding patterns of genetic diversity is a crucial component of medical research in Africa. Here we use haplotype-based population genetics inference to describe gene-flow and admixture in a collection of 48 African groups with a focus on the major populations of the sub-Sahara. Our analysis presents a framework for interpreting haplotype diversity within and between population groups and provides a demographic foundation for genetic epidemiology in Africa. We show that coastal African populations have experienced an influx of Eurasian haplotypes as a series of admixture events over the last 7,000 years, and that Niger-Congo speaking groups from East and Southern Africa share ancestry with Central West Africans as a result of recent population expansions associated with the adoption of new agricultural technologies. We demonstrate that most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of large-scale population movements over the last 4,000 years. Our in-depth analysis of admixture provides an insight into haplotype sharing across different geographic groups and the recent movement of alleles into new climatic and pathogenic environments, both of which will aid the interpretation of genetic studies of disease in sub-Saharan Africa.

scholarly journals Admixture into and within sub-Saharan Africa

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
George BJ Busby ◽  
Gavin Band ◽  
Quang Si Le ◽  
Muminatou Jallow ◽  
Edith Bougama ◽  
...  
Keyword(s):  
Gene Flow ◽  
Geographic Region ◽  
Sub Saharan Africa ◽  
Genome Wide ◽  
A Genome ◽  
Depth Analysis ◽  
Shared Ancestry ◽  
Sub Saharan ◽  
Linguistic Groups ◽  
Insight Into

Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology.

scholarly journals Measuring Regional Ethnolinguistic Diversity in Sub-Saharan Africa: Surveys vs. GIS

2019 ◽  
Vol 34 (Supplement_1) ◽  
pp. S40-S45 ◽  
Author(s):  
Boris Gershman ◽  
Diego Rivera
Keyword(s):  
Geographic Information Systems ◽  
Rural Areas ◽  
Large Scale ◽  
Negative Association ◽  
The Other ◽  
Sub Saharan Africa ◽  
Population Surveys ◽  
Development Indicators ◽  
Scale Population ◽  
Sub Saharan

Abstract This paper compares two approaches to measuring subnational ethnolinguistic diversity in Sub-Saharan Africa, one based on censuses and large-scale population surveys and the other relying on the use of geographic information systems (GIS). The two approaches yield sets of regional fractionalization indices that show a moderately positive correlation, with a stronger association across rural areas. These differences matter for empirical analysis: in a common sample of regions, survey-based indices of deep-rooted diversity show a more strongly negative association with a range of development indicators relative to their highest-quality GIS-based counterparts.

Hybrid Information Systems for Agriculture: The Case of Cattle Trypanosomiasis in Africa

1994 ◽  
Vol 23 (4) ◽  
pp. 261-267 ◽  
Author(s):  
Iain J. Mckendrick ◽  
George Gettinby ◽  
Yiqun Gu ◽  
Andrew Peregrine ◽  
Crawford Revie
Keyword(s):  
Information Technology ◽  
Hybrid System ◽  
Food Production ◽  
Large Scale ◽  
Sub Saharan Africa ◽  
Software Systems ◽  
High Quality ◽  
Scale Population ◽  
Sub Saharan

Large scale population growth in sub-Saharan Africa makes it imperative to achieve an equivalent increase in food production in this area. It is also important that any increase be sustainable in the long-term, not causing lasting damage to local ecosystems. Recent advances in information technology make the successful diffusion of relevant expertise to farmers a more practical option than ever before. How this might be achieved is described in this paper, which considers the transfer of expertise in the diagnosis, treatment and management of trypanosomiasis in cattle. Using current technology, the combination of different software systems in one integrated hybrid system could allow the delivery of high quality, well focused information to the potential user.

A New Paradigm: The African Early Iron Age without Bantu Migrations

2000 ◽  
Vol 27 ◽  
pp. 287-323 ◽  
Author(s):  
John H. Robertson ◽  
Rebecca Bradley
Keyword(s):  
Iron Age ◽  
Large Scale ◽  
Population Decline ◽  
Sub Saharan Africa ◽  
Early Iron Age ◽  
New Paradigm ◽  
Hunter Gatherers ◽  
Population Movements ◽  
Iron Technology ◽  
Sub Saharan

Between 1000 BC and AD 1000, or so the story goes, sub-Saharan Africa was the setting for one of the all-time great population movements of antiquity—the Bantu migrations. Sweeping to and fro across the continent in a kind of grand migrationary gavotte, absorbing or brushing aside the autochthonous hunter-gatherers, the ancestral Bantu speakers carried with them on their march the seeds of a settled life fueled by food production and iron technology. Their movements are represented by large arrows scything across big blank maps of the African interior. How good is the evidence that any of it ever happened?In this paper we shall examine some of the serious methodological and practical problems that bedevil the migrationary model. We shall also present an alternative model for the prehistory of sub-Saharan Africa: in brief, that the development of the Early Iron Age in Africa was a process rather than an event; that autochthonous populations gradually adopted the suite of traits that define the Early Iron Age, without any large-scale movement of peoples; and that increasing sedentarization actually led to a population decline which was only overcome after AD 500.The model constitutes a new paradigm that emphasizes continuity and takes into account a few observations that are awkward for the migrationary paradigm: that sub-Saharan Africa has a difficult topography that may put certain constraints on population movements, and that the continent was slowly filling up on its own when events starting in the sixteenth century turned the autochthonous peoples' lives upside down.

scholarly journals Civil Society and Land Use Policy in Uganda: The Mabira Forest Case

2014 ◽  
Vol 49 (2) ◽  
pp. 53-77 ◽  
Author(s):  
Patrick Hönig
Keyword(s):  
Civil Society ◽  
Identity Politics ◽  
Large Scale ◽  
Sub Saharan Africa ◽  
Post Conflict ◽  
Depth Analysis ◽  
Decision Making Processes ◽  
The Commons ◽  
Sub Saharan ◽  
The Government

Over the past few years, the Ugandan government has repeatedly initiated proceedings to clear one-fourth of the Mabira natural forest reserve in central Uganda and give the land to a sugar company controlled by a transnational business conglomerate. Each time the government took steps to execute the Mabira project, civil society groups organised large-scale protests that pressurised the government into shelving its plans. The Save Mabira Forest campaign has been widely cited as an example of how sustained protests by civil society groups serve as a corrective of democratic deficits in decision-making processes pertaining to the commons and as a deterrent to profit-driven business schemes hatched in collusion with carefree or corrupt bureaucrats and politicians. However, an in-depth analysis of the campaign suggests that ecological and social justice concerns are mixed up with identity politics and exclusionist agendas. Examining the complex web of interactions between state, big business and civil society in Uganda, this paper sheds light on the multi-layered and often ambiguous role played by non-governmental organisations in post-conflict societies of sub-Saharan Africa.

Retreating from the Brink: Theorizing Mass Violence and the Dynamics of Restraint

2012 ◽  
Vol 10 (2) ◽  
pp. 343-362 ◽  
Author(s):  
Scott Straus
Keyword(s):  
Political Violence ◽  
Comparative Politics ◽  
Large Scale ◽  
Research Problem ◽  
Analytical Framework ◽  
Sub Saharan Africa ◽  
Mass Violence ◽  
Depth Analysis ◽  
Violence Against Civilians ◽  
Sub Saharan

The research problem driving this paper is the absence of a strong theory that accounts for variation among cases that have similar probabilities of escalating to genocide and similar forms of organized (usually state-led) mass violence against civilians. Much of the existing theory on genocide focuses on explaining under what conditions and by what processes regimes commit large-scale violence against civilians. I argue that a critical missing dimension to studies of genocide, but also more generally to the study of political violence, is a methodological recognition of negative cases and a theoretical recognition of the dynamics of restraint that helps to explain such negative cases. That is, in addition to asking what causes leaders to choose to escalate violence, I argue that scholars should emphasize conditions that prompt moderation, de-escalation, or non-escalation. I propose an alternative framework for how to conceptualize the process of political violence and review the literature to identify key restraint mechanisms at micro, meso, and macro levels of analysis. I further articulate a provisional theory of genocide using this new analytical framework. I illustrate my argument with an empirical analysis of mass violence cases in Sub-Saharan Africa since independence, and with a more in-depth analysis of comparable crises in Rwanda and Côte d'Ivoire, where the trajectories of violence differed significantly. While this paper draws on extensive empirical research, my primary purpose is not to advance a developed new theory or to test particular hypotheses, but rather to outline a research agenda that promises to draw from and contribute to recent work on the comparative politics of violence.

scholarly journals Precision Agriculture for Resource Use Efficiency in Smallholder Farming Systems in Sub-Saharan Africa: A Systematic Review

2021 ◽  
Vol 13 (3) ◽  
pp. 1158
Author(s):  
Cecilia M. Onyango ◽  
Justine M. Nyaga ◽  
Johanna Wetterlind ◽  
Mats Söderström ◽  
Kristin Piikki
Keyword(s):  
Resource Use ◽  
Precision Agriculture ◽  
Large Scale ◽  
English Language ◽  
Management Practices ◽  
Smallholder Farmers ◽  
Management Strategies ◽  
Sub Saharan Africa ◽  
Smallholder Farming ◽  
Sub Saharan

Opportunities exist for adoption of precision agriculture technologies in all parts of the world. The form of precision agriculture may vary from region to region depending on technologies available, knowledge levels and mindsets. The current review examined research articles in the English language on precision agriculture practices for increased productivity among smallholder farmers in Sub-Saharan Africa. A total of 7715 articles were retrieved and after screening 128 were reviewed. The results indicate that a number of precision agriculture technologies have been tested under SSA conditions and show promising results. The most promising precision agriculture technologies identified were the use of soil and plant sensors for nutrient and water management, as well as use of satellite imagery, GIS and crop-soil simulation models for site-specific management. These technologies have been shown to be crucial in attainment of appropriate management strategies in terms of efficiency and effectiveness of resource use in SSA. These technologies are important in supporting sustainable agricultural development. Most of these technologies are, however, at the experimental stage, with only South Africa having applied them mainly in large-scale commercial farms. It is concluded that increased precision in input and management practices among SSA smallholder farmers can significantly improve productivity even without extra use of inputs.

scholarly journals Using Bus Ticketing Big Data to Investigate the Behaviors of the Population Flow of Chinese Suburban Residents in the Post-COVID-19 Phase

2021 ◽  
Vol 18 (11) ◽  
pp. 6066
Author(s):  
Yanbing Bai ◽  
Lu Sun ◽  
Haoyu Liu ◽  
Chao Xie
Keyword(s):  
Travel Behavior ◽  
Large Scale ◽  
Behavior Patterns ◽  
Population Movements ◽  
Economic Level ◽  
Passenger Travel ◽  
Scale Population ◽  
Travel Behaviors ◽  
Railway Passenger ◽  
And Control

Large-scale population movements can turn local diseases into widespread epidemics. Grasping the characteristic of the population flow in the context of the COVID-19 is of great significance for providing information to epidemiology and formulating scientific and reasonable prevention and control policies. Especially in the post-COVID-19 phase, it is essential to maintain the achievement of the fight against the epidemic. Previous research focuses on flight and railway passenger travel behavior and patterns, but China also has numerous suburban residents with a not-high economic level; investigating their travel behaviors is significant for national stability. However, estimating the impacts of the COVID-19 for suburban residents’ travel behaviors remains challenging because of lacking apposite data. Here we submit bus ticketing data including approximately 26,000,000 records from April 2020–August 2020 for 2705 stations. Our results indicate that Suburban residents in Chinese Southern regions are more likely to travel by bus, and travel frequency is higher. Associated with the economic level, we find that residents in the economically developed region more likely to travel or carry out various social activities. Considering from the perspective of the traveling crowd, we find that men and young people are easier to travel by bus; however, they are exactly the main workforce. The indication of our findings is that suburban residents’ travel behavior is affected profoundly by economy and consistent with the inherent behavior patterns before the COVID-19 outbreak. We use typical regions as verification and it is indeed the case.

Intraclass Correlation Coefficients for Designing Cluster-Randomized Trials in Sub-Saharan Africa Education

2016 ◽  
Vol 40 (6) ◽  
pp. 500-525 ◽  
Author(s):  
Ben Kelcey ◽  
Zuchao Shen ◽  
Jessaca Spybrook
Keyword(s):  
Large Scale ◽  
Randomized Trials ◽  
Intraclass Correlation ◽  
Educational Interventions ◽  
Sub Saharan Africa ◽  
Design Stage ◽  
Education Outcomes ◽  
Randomized Studies ◽  
Sub Saharan ◽  
Variance Explained

Objective: Over the past two decades, the lack of reliable empirical evidence concerning the effectiveness of educational interventions has motivated a new wave of research in education in sub-Saharan Africa (and across most of the world) that focuses on impact evaluation through rigorous research designs such as experiments. Often these experiments draw on the random assignment of entire clusters, such as schools, to accommodate the multilevel structure of schooling and the theory of action underlying many school-based interventions. Planning effective and efficient school randomized studies, however, requires plausible values of the intraclass correlation coefficient (ICC) and the variance explained by covariates during the design stage. The purpose of this study was to improve the planning of two-level school-randomized studies in sub-Saharan Africa by providing empirical estimates of the ICC and the variance explained by covariates for education outcomes in 15 countries. Method: Our investigation drew on large-scale representative samples of sixth-grade students in 15 countries in sub-Saharan Africa and includes over 60,000 students across 2,500 schools. We examined two core education outcomes: standardized achievement in reading and mathematics. We estimated a series of two-level hierarchical linear models with students nested within schools to inform the design of two-level school-randomized trials. Results: The analyses suggested that outcomes were substantially clustered within schools but that the magnitude of the clustering varied considerably across countries. Similarly, the results indicated that covariance adjustment generally reduced clustering but that the prognostic value of such adjustment varied across countries.

Land conflicts and social differentiation in eastern Uganda

2017 ◽  
Vol 55 (3) ◽  
pp. 395-422 ◽  
Author(s):  
Matt Kandel
Keyword(s):  
Large Scale ◽  
Local Level ◽  
Sub Saharan Africa ◽  
Social Differentiation ◽  
Land Conflicts ◽  
Current Period ◽  
Post Conflict ◽  
Sub Saharan ◽  
Historical Developments ◽  
Eastern Uganda

ABSTRACTRising competition and conflict over land in rural sub-Saharan Africa continues to attract the attention of researchers. Recent work has especially focused on land governance, post-conflict restructuring of tenure relations, and large-scale land acquisitions. A less researched topic as of late, though one deserving of greater consideration, pertains to how social differentiation on the local-level shapes relations to land, and how these processes are rooted in specific historical developments. Drawing on fieldwork conducted in Teso sub-region of eastern Uganda, this paper analyses three specific land conflicts and situates them within a broad historical trajectory. I show how each dispute illuminates changes in class relations in Teso since the early 1990s. I argue that this current period of socioeconomic transformation, which includes the formation of a more clearly defined sub-regional middle class and elite, constitutes the most prominent period of social differentiation in Teso since the early 20th century.

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