scholarly journals Within-infection diversity ofPlasmodium falciparumantigens reflects host-mediated selection

2017 ◽  
Author(s):  
Angela M. Early ◽  
Marc Lievens ◽  
Bronwyn MacInnis ◽  
Christian F. Ockenhouse ◽  
Sarah K. Volkman ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sub Saharan Africa ◽  
Pathogen Diversity ◽  
Allele Specific ◽  
Targeted Deep Sequencing ◽  
Sub Saharan ◽  
Uniform Manner ◽  
Amino Acid Diversity ◽  
The Impact ◽  
First Time

AbstractHost immunity exerts strong selection on pathogens, but it does not act in a uniform manner across individual hosts. By providing a direct approach for understanding host-specific selection pressures, patterns of intra-host pathogen diversity complement population genetic analyses performed on broad geographic scales. Here, we perform a combined analysis of inter- and intra-host diversity for the malaria parasitePlasmodium falciparumwith haplotype sequences of three antigens sampled from over 4,500 natural infections in sub-Saharan Africa using targeted deep sequencing. We find that multi-strain infections in young children contain non-random combinations of parasite genotypes, and identify individual amino acid positions that may contribute to strain-specific blocking of infections. These results demonstrate for the first time that natural host defenses toPlasmodiumdetectably impact which infections proceed to the blood stage within a given host. This selection partially explains the extreme amino acid diversity observed at many parasite antigens and suggests that vaccines targeting such proteins should account for the impact of allele-specific immunity.

What Should be the Focus of Agricultural Policy Reforms in Sub-Saharan Africa? A CGE Analysis

2019 ◽  
Vol 13 (4) ◽  
pp. 401-435
Author(s):  
Jean Balié ◽  
Badri Narayanan
Keyword(s):  
Developing Countries ◽  
Import Substitution ◽  
Jel Classification ◽  
Sub Saharan Africa ◽  
Market Development ◽  
Policy Reforms ◽  
Sub Saharan ◽  
The Impact ◽  
First Time ◽  
Data Constraints

While a lot of research has been conducted on agricultural subsidies and other forms of policy transfers in developed and developing countries alike, substantial data constraints have characterised those conducted in developing countries. For this study, we employ a novel and uniquely developed dataset on these policies in Sub-Saharan Africa (SSA), to analyse the impact of policy reforms, using the latest available GTAP 9.1 Data Base, in the widely employed GTAP framework, for the first time. We simulate the scenarios of removal of output subsidies, removal of ‘market development gaps’ within and outside the country. Our results indicate that removing market development gaps is likely to increase the agricultural output without affecting trade much, while removing the subsidies could harm output a lot by import-substitution of the costly domestic output. We conclude that governments in SSA may do well to focus on developing their markets better rather than cutting the assistance to their farmers, which could in fact be counter-productive instead of raising the efficiency of domestic farmers through competition. JEL Classification: C68, Q11, Q13, Q17, Q18

The African Rinderpest Panzootic, 1888–1897

2018 ◽  
Author(s):  
Thaddeus Sunseri
Keyword(s):  
Sub Saharan Africa ◽  
Power Dynamics ◽  
Horn Of Africa ◽  
Trade Patterns ◽  
Senegal River ◽  
African Cattle ◽  
Almost Everywhere ◽  
Sub Saharan ◽  
The Impact ◽  
First Time

Between 1888 and 1897, rinderpest virus (cattle plague) spread throughout sub-Saharan Africa, presumably for the first time, killing over 90 percent of African cattle and countless wildlife, expedited by European colonial conquest. Beginning in the Eritrean port of Massawa, the virus was transmitted across the Sahel, reaching the Senegal River by 1891. The epizootic spread south out of the Horn of Africa, into the western and eastern Rift valleys, and likely by sea with coastal commerce, infecting East Africa after 1891. Although slowed by the Zambezi River, in 1896 rinderpest reached the regions of modern Zimbabwe, Mozambique, Botswana, South Africa, Namibia, and southern Angola before it burned out or was arrested by breakthroughs in vaccine therapy by 1900. South of the Zambezi, early European methods of stanching rinderpest by destroying all cattle exposed to the virus often elicited protest, resistance, and sometimes rebellion. Rinderpest was eliminated from southern Africa shortly after the turn of the 20th century but became enzootic in other parts of the continent, often in wildlife, until eradicated globally in 2011. In each region of infection, local ecologies, trade patterns, agricultural bases, social structures, and power dynamics shaped the impact of rinderpest. Almost everywhere, rinderpest was preceded by drought and locust plagues, and followed by human diseases, especially smallpox and malnutrition.

Conflicts in Biafra, Katanga and Cabinda as a result of the geopolitical legacy of colonialism

2020 ◽  
Vol 2020 (10-3) ◽  
pp. 238-246
Author(s):  
Olga Dzhenchakova
Keyword(s):  
Democratic Republic ◽  
Economic Factor ◽  
Colonial Period ◽  
Sub Saharan Africa ◽  
Negative Consequences ◽  
Post Colonial ◽  
Republic Of The Congo ◽  
Sub Saharan ◽  
The Republic ◽  
The Impact

The article considers the impact of the colonial past of some countries in sub-Saharan Africa and its effect on their development during the post-colonial period. The negative consequences of the geopolitical legacy of colonialism are shown on the example of three countries: Nigeria, the Democratic Republic of the Congo and the Republic of Angola, expressed in the emergence of conflicts in these countries based on ethno-cultural, religious and socio-economic contradictions. At the same time, the focus is made on the economic factor and the consequences of the consumer policy of the former metropolises pursuing their mercantile interests were mixed.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

scholarly journals The impact and cost‐effectiveness of community‐basedHIVself‐testing in sub‐Saharan Africa: a health economic and modelling analysis

2019 ◽  
Vol 22 (S1) ◽  
pp. e25243 ◽  
Author(s):  
Valentina Cambiano ◽  
Cheryl C Johnson ◽  
Karin Hatzold ◽  
Fern Terris‐Prestholt ◽  
Hendy Maheswaran ◽  
...  
Keyword(s):  
Health Economic ◽  
Cost Effectiveness ◽  
Sub Saharan Africa ◽  
Modelling Analysis ◽  
Sub Saharan ◽  
The Impact

scholarly journals Labellum and gynostemium micromorphology in Polystachya (Orchidaceae)

2020 ◽  
Vol 307 (1) ◽  
Author(s):  
Mytnik Joanna ◽  
Davies L. Kevin ◽  
Narajczyk Magdalena ◽  
Łuszczek Dorota ◽  
Kubiak Joanna ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sub Saharan Africa ◽  
Capitate Trichomes ◽  
Sub Saharan ◽  
First Time ◽  
Scanning Electron

AbstractPolystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy (SEM). Our results show the scale of infrageneric diversity of trichomes and papillae relative to the sampled sections. They also demonstrate the taxonomic value of labellar micromorphology at the sectional level. The study revealed seven types of papillae and five types of trichomes (uni- and multi-cellular) in Polystachya, some of which, are described here for the first time. Clavate trichomes are the most common and are present in 60% of the species studied. Moniliform trichomes mainly occur in sect. Polystachya and are strongly characteristic of the section. Pseudopollen is formed by fragmentation of moniliform trichomes or the detachment of other trichomes as bicellular units. We provide, for the first time, evidence for the detachment of the terminal cells of capitate trichomes.

scholarly journals Schistosoma mansoni eggs induce Wnt/β-catenin signaling and activate the protooncogene c-Jun in human and hamster colon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jakob Weglage ◽  
Friederike Wolters ◽  
Laura Hehr ◽  
Jakob Lichtenberger ◽  
Celina Wulz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Colorectal Carcinogenesis ◽  
Sub Saharan Africa ◽  
Interleukin 4 ◽  
Health Burden ◽  
Sub Saharan ◽  
Considerable Morbidity ◽  
First Time

AbstractSchistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia, in sub-Saharan Africa, and particularly also in Europe. The WHO describes an increasing global health burden with more than 290 million people threatened by the disease and a potential to spread into regions with temperate climates like Corsica, France. The aim of our study was to investigate the influence of S. mansoni infection on colorectal carcinogenic signaling pathways in vivo and in vitro. S. mansoni infection, soluble egg antigens (SEA) and the Interleukin-4-inducing principle from S. mansoni eggs induce Wnt/β-catenin signaling and the protooncogene c-Jun as well as downstream factor Cyclin D1 and markers for DNA-damage, such as Parp1 and γH2a.x in enterocytes. The presence of these characteristic hallmarks of colorectal carcinogenesis was confirmed in colon biopsies from S. mansoni-infected patients demonstrating the clinical relevance of our findings. For the first time it was shown that S. mansoni SEA may be involved in the induction of colorectal carcinoma-associated signaling pathways.

scholarly journals Financial Inclusion, Income Inequality and Sustainable Economic Growth in Sub-Saharan African Countries

2021 ◽  
Vol 13 (4) ◽  
pp. 1780
Author(s):  
Chima M. Menyelim ◽  
Abiola A. Babajide ◽  
Alexander E. Omankhanlen ◽  
Benjamin I. Ehikioya
Keyword(s):  
Economic Growth ◽  
Income Inequality ◽  
Financial Services ◽  
Sub Saharan Africa ◽  
Kuznets Curve ◽  
African Countries ◽  
Financial Access ◽  
Sub Saharan ◽  
Sustainable Economic Growth ◽  
The Impact

This study evaluates the relevance of inclusive financial access in moderating the effect of income inequality on economic growth in 48 countries in Sub-Saharan Africa (SSA) for the period 1995 to 2017. The findings using the Generalised Method of Moments (sys-GMM) technique show that inclusive financial access contributes to reducing inequality in the short run, contrary to the Kuznets curve. The result reveals a negative effect of financial access on the relationship between income inequality and economic growth. There is a positive net effect of inclusive financial access in moderating the impact of income inequality on economic growth. Given the need to achieve the Sustainable Development Targets in the sub-region, policymakers and other stakeholders of the economy must design policies and programmes that would enhance access to financial services as an essential mechanism to reduce income disparity and enhance sustainable economic growth.

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