scholarly journals Ancient hybridization and strong adaptation to viruses across African vervet monkey populations

2016 ◽  
Author(s):  
Hannes Svardal ◽  
Anna Jasinska ◽  
Cristian Apetrei ◽  
Giovanni Coppola ◽  
Yu Huang ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Rhesus Macaques ◽  
Vervet Monkey ◽  
Sub Saharan Africa ◽  
Close Relative ◽  
Vervet Monkeys ◽  
Sequencing Data ◽  
Colonial Era ◽  
Natural Hosts ◽  
Sub Saharan

Vervet monkeys (genusChlorocebus, also known as African green monkeys), are highly abundant in savannahs and riverine forests throughout sub-Saharan Africa. They are amongst the most widely distributed nonhuman primates, show considerable phenotypic diversity, and have long been an important biomedical model for a variety of human diseases and in vaccine research. They are particularly interesting for HIV/AIDS research as they are the most abundant natural hosts of simian immunodeficiency virus (SIV), a close relative of HIV. Here we present the first genome-wide survey of polymorphism in vervets, using sequencing data from 163 individuals sampled from across Africa and the Caribbean islands where vervets were introduced during the colonial era. We find high diversity, within and between taxa, and clear evidence that taxonomic divergence was reticulate rather than following a simple branching pattern. A scan for diversifying selection across vervet taxa yields gene enrichments much stronger than in similar studies on humans. In particular, we report strong and highly polygenic selection signals affecting viral processes --- in line with recent evidence that proposes a driving role for viruses in protein evolution in mammals. Furthermore, selection scores are highly elevated in genes whose human orthologs interact with HIV, and in genes that show a response to experimental SIV infection in vervet monkeys but not in rhesus macaques, suggesting that part of the signal reflects taxon-specific adaptation to SIV. Intriguingly, rather than affecting genes with antiviral and inflammatory-related functions, selection in vervets appears to have primarily targeted genes involved in the transcriptional regulation of viruses, and in particular those that are harmful only under immunodeficiency, suggesting adaptation to living with SIV rather than defense against infection.

scholarly journals Distance from Africa, not climate, explains within-population phenotypic diversity in humans

2008 ◽  
Vol 276 (1658) ◽  
pp. 809-814 ◽  
Author(s):  
Lia Betti ◽  
François Balloux ◽  
William Amos ◽  
Tsunehiko Hanihara ◽  
Andrea Manica
Keyword(s):  
Climatic Factors ◽  
Phenotypic Diversity ◽  
Morphological Diversity ◽  
Sub Saharan Africa ◽  
Relative Role ◽  
Morphometric Traits ◽  
Perfect Agreement ◽  
Skull Measurements ◽  
Sub Saharan

The relative importance of ancient demography and climate in determining worldwide patterns of human within-population phenotypic diversity is still open to debate. Several morphometric traits have been argued to be under selection by climatic factors, but it is unclear whether climate affects the global decline in morphological diversity with increasing geographical distance from sub-Saharan Africa. Using a large database of male and female skull measurements, we apply an explicit framework to quantify the relative role of climate and distance from Africa. We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity, while climate plays no role. By selecting the most informative set of traits, it was possible to explain over half of the worldwide variation in phenotypic diversity. These results mirror those previously obtained for genetic markers and show that ‘bones and molecules’ are in perfect agreement for humans.

scholarly journals The Orphan Crop Crassocephalum crepidioides Accumulates the Pyrrolizidine Alkaloid Jacobine in Response to Nitrogen Starvation

2021 ◽  
Vol 12 ◽  
Author(s):  
Sebastian Schramm ◽  
Wilfried Rozhon ◽  
Adebimpe N. Adedeji-Badmus ◽  
Yuanyuan Liang ◽  
Shahran Nayem ◽  
...  
Keyword(s):  
Pyrrolizidine Alkaloid ◽  
Sub Saharan Africa ◽  
Close Relative ◽  
Environmental Cues ◽  
N Deficiency ◽  
Sub Saharan ◽  
Rate Limiting ◽  
Homospermidine Synthase ◽  
Orphan Crop

Crassocephalum crepidioides is an African orphan crop that is used as a leafy vegetable and medicinal plant. Although it is of high regional importance in Sub-Saharan Africa, the plant is still mainly collected from the wild and therefore efforts are made to promote its domestication. However, in addition to beneficial properties, there was first evidence that C. crepidioides can accumulate the highly toxic pyrrolizidine alkaloid (PA) jacobine and here it was investigated, how jacobine production is controlled. Using ecotypes from Africa and Asia that were characterized in terms of their PA profiles, it is shown that the tetraploid C. crepidioides forms jacobine, an ability that its diploid close relative Crassocephalum rubens appears to lack. Evidence is provided that nitrogen (N) deficiency strongly increases jacobine in the leaves of C. crepidioides, that this capacity depends more strongly on the shoot than the root system, and that homospermidine synthase (HSS) activity is not rate-limiting for this reaction. A characterization of HSS gene representation and transcription showed that C. crepidioides and C. rubens possess two functional versions, one of which is conserved, that the HSS transcript is mainly present in roots and that its abundance is not controlled by N deficiency. In summary, this work improves our understanding of how environmental cues impact PA biosynthesis in plants and provides a basis for the development of PA-free C. crepidioides cultivars, which will aid its domestication and safe use.

scholarly journals Writing African History in France during the Colonial Era

2018 ◽  
Author(s):  
Sophie Dulucq
Keyword(s):  
19Th Century ◽  
Point Of View ◽  
Sub Saharan Africa ◽  
African History ◽  
Colonial History ◽  
Colonial Era ◽  
Diverse Range ◽  
Collège De France ◽  
History Of ◽  
Sub Saharan

In the second half of the 19th century, French imperial expansion in the south of the Sahara led to the control of numerous African territories. The colonial rule France imposed on a diverse range of cultural groups and political entities brought with it the development of equally diverse inquiry and research methodologies. A new form of scholarship, africanisme, emerged as administrators, the military, and amateur historians alike began to gather ethnographic, linguistic, judicial, and historical information from the colonies. Initially, this knowledge was based on expertise gained in the field and reflected the pragmatic concerns of government rather than clear, scholarly, interrogation in line with specific scientific disciplines. Research was thus conducted in many directions, contributing to the emergence of the so-called colonial sciences. Studies by Europeans scholars, such as those carried out by Maurice Delafosse and Charles Monteil, focused on West Africa’s past. In so doing, the colonial context of the late 19th century reshaped the earlier orientalist scholarship tradition born during the Renaissance, which had formerly produced quality research about Africa’s past, for example, about medieval Sudanese states. This was achieved through the study of Arabic manuscripts and European travel narratives. In this respect, colonial scholarship appears to have perpetuated the orientalist legacy, but in fact, it transformed the themes, questions, and problems historians raised. In the first instance, histoire coloniale (colonial history) focused the history of European conquests and the interactions between African societies and their colonizers. Between 1890 and 1920 a network of scientists, including former colonial administrators, struggled to institutionalize colonial history in metropolitan France. Academic positions were established at the Sorbonne and the Collège de France. Meanwhile, research institutions were created in French West Africa (Afrique Occidentale Française [AOF]), French Equatorial Africa (Afrique Équatoriale Française [AEF]), and Madagascar between 1900 and the 1930s. Yet, these imperial and colonial concerns similarly coincided with the rise of what was then known as histoire indigène (native history) centered on the precolonial histories of African societies. Through this lens emerged a more accurate vision of the African past, which fundamentally challenged the common preconception that the continent had no “history.” This innovative knowledge was often co-produced by African scholars and intellectuals. After the Second World War, interest in colonial history started to wane, both from an intellectual and a scientific point of view. In its place, the history of sub-Saharan Africa gained popularity and took root in French academic institutions. Chairs of African history were created at the Sorbonne in 1961 and 1964, held by Raymond Mauny and Hubert Deschamps, respectively, and in 1961 at the École Pratique des Hautes Études, fulfilled by Henri Brunschwig. African historians, who were typically trained in France, began to challenge the existing European scholarship. As a result, some of the methods and sources that had been born in the colonial era, were adopted for use by a new generation of historians, whose careers blossomed after the independences.

scholarly journals Globalization and the Postcolonial World

2002 ◽  
Vol 19 (3) ◽  
pp. 132-135
Author(s):  
David Wilmsen
Keyword(s):  
Third World ◽  
The United States ◽  
Sub Saharan Africa ◽  
Wealth Accumulation ◽  
Economic Regulation ◽  
Colonial Era ◽  
The Third ◽  
World Economic ◽  
Sub Saharan ◽  
The Third World

According to Ankie Hoogvelt, this book is intended to "introduce students todebates regarding the development prospects of the Third World." This sheaccomplishes in very compact and richly documented detail. Indeed, thereare so many citations that the lack of a bibliography is sorely felt.The book is divided into three parts, each addressing a broad themeaffecting development and the Third World. The first considers the historicalroute of capitalist expansion into a world economic system by means of,among other things, the core countries' depredations of their peripheralcolonies. The second treats the world economy's increasing internationalizationand the retrenchment of wealth accumulation by means of strategichegemony and economic regulation, especially by the United States. Thefinal part examines the resultant situations in the four distinct socioculturalrealms of the Third World, devoting a chapter to each: sub-Saharan Africa,the Islamic world, East Asia, and Latin America.True to the spirit of debate she is trying to foster in her students,Hoogvelt challenges some of the conventional assumptions about humansociety's advancement under globalization. She points out that, contraryto expert consensus, the flow of wealth to the Third world has declinedsince the colonial era. Or, again, that world trade represented a greaterpercentage of world production at the beginning of the twentieth century,before the era of globalization, than it did at its end, when it was in fullstride. Or, yet again, that much of the apparent increase in trade, especially ...

Music Archives and Repatriation

2018 ◽  
pp. 36-62
Author(s):  
Diane Thram
Keyword(s):  
Early Life ◽  
White Privilege ◽  
Sub Saharan Africa ◽  
African Music ◽  
Digital Conversion ◽  
Colonial Era ◽  
Field Recordings ◽  
Online Access ◽  
Sub Saharan ◽  
Archival Ethics

This chapter considers issues in repatriation of digital copies of field recordings of music obtained during the colonial era. It is based on the Hugh Tracey Collection preserved at the International Library of African Music (ILAM). A summary of Tracey’s early life and his work throughout sub-Saharan Africa from 1929 to 1972 is followed by the reasons why, with digital conversion and online access to the Collection accomplished, digital return and restudy of Tracey’s field recordings became the ethically responsible thing for ILAM to do. Description of the return of his Kipsigis recordings of “Chemirocha” to their source community in Kenya is followed by consideration of how Tracey’s embrace of the colonial worldview—with its inherent paternalism, racism, and white privilege—mandates digital return as an act of reciprocity and archival ethics. It suggests this gesture toward decolonization of ILAM serves as a model for decolonization of ethnomusicology at large.

scholarly journals An Economic Rationale for the West African Scramble? The Commercial Transition and the Commodity Price Boom of 1835–1885

2018 ◽  
Vol 78 (1) ◽  
pp. 231-267 ◽  
Author(s):  
Ewout Frankema ◽  
Jeffrey Williamson ◽  
Pieter Woltjer
Keyword(s):  
West Africa ◽  
Commodity Price ◽  
West African ◽  
Sub Saharan Africa ◽  
Export Markets ◽  
Colonial Era ◽  
Export Prices ◽  
Economic Rationale ◽  
Price Boom ◽  
Sub Saharan

We use a new trade dataset showing that nineteenth century sub-Saharan Africa experienced a terms of trade boom comparable to other parts of the “global periphery.” A sharp rise in export prices in the five decades before the scramble (1835–1885) was followed by an equally impressive decline during the colonial era. This study revises the view that the scramble for West Africa occurred when its major export markets were in decline and argues that the larger weight of West Africa in French imperial trade strengthened the rationale for French instead of British initiative in the conquest of the interior.

scholarly journals Efficacy of Three-Week Oxytetracycline or Rifampin Monotherapy Compared with a Combination Regimen against the Filarial Nematode Onchocerca ochengi

2013 ◽  
Vol 58 (2) ◽  
pp. 801-810 ◽  
Author(s):  
Germanus S. Bah ◽  
Emma L. Ward ◽  
Abhishek Srivastava ◽  
Alexander J. Trees ◽  
Vincent N. Tanya ◽  
...  
Keyword(s):  
Adult Worm ◽  
Sub Saharan Africa ◽  
Filarial Nematode ◽  
Close Relative ◽  
Combination Regimen ◽  
River Blindness ◽  
Level Control ◽  
Content Type ◽  
Onchocerca Ochengi ◽  
Sub Saharan

ABSTRACTOnchocerciasis (river blindness), caused by the filarial nematodeOnchocerca volvulus, is a major cause of visual impairment and dermatitis in sub-Saharan Africa. AsO. volvuluscontains an obligatory bacterial symbiont (Wolbachia), it is susceptible to antibiotic chemotherapy, although current regimens are considered too prolonged for community-level control programs. The aim of this study was to compare the efficacies of oxytetracycline and rifampin, administered separately or in combination, against a close relative ofO. volvulus(Onchocerca ochengi) in cattle. Six animals per group were treated with continuous or intermittent oxytetracycline regimens, and effects on adult worm viability, dermal microfilarial loads, andWolbachiadensity in worm tissues were assessed. Subsequently, the efficacies of 3-week regimens of oxytetracycline and rifampin alone and a combination regimen were compared, and rifampin levels in plasma and skin were quantified. A 6-month regimen of oxytetracycline with monthly dosing was strongly adulticidal, while 3-week and 6-week regimens exhibited weaker adulticidal effects. However, all three regimens achieved >2-log reductions in microfilarial load. In contrast, rifampin monotherapy and oxytetracycline-rifampin duotherapy failed to induce substantive reductions in either adult worm burden or microfilarial load, although a borderline effect onWolbachiadensity was observed following duotherapy. Dermal rifampin levels were maintained above the MIC for >24 h after a single intravenous dose. We conclude that oxytetracycline-rifampin duotherapy is less efficacious againstO. ochengithan oxytetracycline alone. Further studies will be required to determine whether rifampin reduces oxytetracycline bioavailability in this system, as suggested by human studies using other tetracycline-rifampin combinations.

Social Class and Consumer Behaviour in Sub-Saharan Africa

2020 ◽  
pp. 147-168
Author(s):  
Ayodele Oniku
Keyword(s):  
Social Class ◽  
Formal Education ◽  
Land Ownership ◽  
Sub Saharan Africa ◽  
Colonial Era ◽  
Western Religion ◽  
Sub Saharan ◽  
White Settlers ◽  
And Migration ◽  
African Institution

The development around social class evolvement in sub-Saharan African market dated back to pre-colonial era when traditional African institution operated on the basis of royalty, land ownership, subjugation of weak tribe and superiority of strong and powerful tribes. The advent of slavery and migration of white settlers and traders (slaves and goods) further entrenched social class structure in the system. The advent of colonial rule greatly impacted social class system whereby new strata were created based on the new administrative system that colonial system introduced into sub-Saharan Africa. Largely, acquisition of formal education, salary and wage-collection jobs, business opportunities, western religion, clothing styles and new roles to the traditional chiefs opened doors for new social class strata. Social class has witnessed development and improvement that has further improved marketing system and consumer understanding in the society through design of products and services for the market.

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