Contribution to the genus Chrysoesthia Hübner, 1825 (Lepidoptera: Gelechiidae) from East Africa, with description of three new species and new country records
Contribution to the genus Chrysoesthia Hübner, 1825 (Lepidoptera: Gelechiidae) from East Africa, with description of three new species and new country records
- Research Article
23
- 10.1111/padr.12011
- Dec 6, 2016
- Population and Development Review
Our aim in this chapter is to provide an updated and concise description of the diversity of fertility decline patterns among countries1 in sub- Saharan Africa drawing on the latest series of fertility estimates that take into account many different data sources and that are harmonized with other demographic components (United Nations 2015d). We focus on the level of fertility prior to the start of fertility decline the time period of the fertility transition and the estimated pace of decline. We also explore the implications of different fertility decline patterns for future fertility and population projections in the region. We draw on the distinct patterns of fertility decline among countries worldwide that are advanced in (or have completed) their first fertility transition to construct probabilistic fertility and population projections for sub-Saharan African countries. The illustrative comparisons of projections highlight the demographic impact if future fertility decline in sub-Saharan countries were to accelerate and follow the rapid pace of decline already experienced by a diverse group of countries. (excerpt)
- Research Article
54
- 10.1016/0034-6667(88)90083-8
- Jun 1, 1988
- Review of Palaeobotany and Palynology
A review of late quaternary pollen studies in East, Central and Southern Africa
- Research Article
50
- 10.1111/padr.12030
- Feb 8, 2017
- Population and Development Review
This research has two main goals: (i) to examine fertility desires (number of children) in sub-Saharan Africa: levels as compared to other major regions and recent trends; and (ii) to assess the extent to which fertility decline in sub-Saharan Africa is contingent on decline in fertility desires (singly and in combination with other reproductive changes).
- Research Article
3
- 10.1186/s12977-021-00554-4
- May 5, 2021
- Retrovirology
BackgroundThe HIV-1 epidemic in sub-Saharan Africa is heterogeneous with diverse unevenly distributed subtypes and regional differences in prevalence. Subtype-specific differences in disease progression rate and transmission efficiency have been reported, but the underlying biological mechanisms have not been fully characterized. Here, we tested the hypothesis that the subtypes prevalent in the East Africa, where adult prevalence rate is higher, have lower viral replication capacity (VRC) than their West African counterparts where adult prevalence rates are lower.ResultsGag-protease sequencing was performed on 213 and 160 antiretroviral-naïve chronically infected participants from West and East Africa respectively and bioinformatic tools were used to infer subtypes and recombination patterns. VRC of patient-derived gag-protease chimeric viruses from West (n = 178) and East (n = 114) Africa were determined using a green fluorescent protein reporter-based cell assay. Subtype and regional differences in VRC and amino acid variants impacting VRC were identified by statistical methods. CRF02_AG (65%, n = 139), other recombinants (14%, n = 30) and pure subtypes (21%, n = 44) were identified in West Africa. Subtypes A1 (64%, n = 103), D (22%, n = 35), or recombinants (14%, n = 22) were identified in East Africa. Viruses from West Africa had significantly higher VRC compared to those from East Africa (p < 0.0001), with subtype-specific differences found among strains within West and East Africa (p < 0.0001). Recombination patterns showed a preference for subtypes D, G or J rather than subtype A in the p6 region of gag, with evidence that subtype-specific differences in this region impact VRC. Furthermore, the Gag A83V polymorphism was associated with reduced VRC in CRF02_AG. HLA-A*23:01 (p = 0.0014) and HLA-C*07:01 (p = 0.002) were associated with lower VRC in subtype A infected individuals from East Africa.ConclusionsAlthough prevalent viruses from West Africa displayed higher VRC than those from East Africa consistent with the hypothesis that lower VRC is associated with higher population prevalence, the predominant CRF02_AG strain in West Africa displayed higher VRC than other prevalent strains suggesting that VRC alone does not explain population prevalence. The study identified viral and host genetic determinants of virus replication capacity for HIV-1 CRF02_AG and subtype A respectively, which may have relevance for vaccine strategies.
- Research Article
13
- 10.1016/0040-1951(93)90177-l
- Mar 1, 1993
- Tectonophysics
Can differences in heat flow between east and southern Africa be easily interpreted?: Implications for understanding regional variability in continental heat flow
- Research Article
27
- 10.1111/j.1365-3156.2006.01593.x
- Mar 23, 2006
- Tropical Medicine & International Health
Despite a broadening consensus about the effectiveness of intermittent preventive treatment (IPTp) in preventing the adverse outcomes of malaria during pregnancy, policy change to IPTp was initially limited to East Africa. In West Africa, where the policy change process for the prevention of malaria during pregnancy started much later, IPTp has been taken up swiftly. To describe the factors that contributed to the rapid adoption of policies to prevent malaria during pregnancy in West Africa. Several factors appear to have accelerated the process: (1) recognition of the extent of the problem of malaria during pregnancy and its adverse consequences; (2) a clear, evidence-based program strategy strongly articulated by an important multilateral organization (World Health Organization); (3) subregionally generated evidence to support the proposed strategy; (4) a subregional forum for dissemination of data and discussion regarding the proposed policy changes; (5) widespread availability of the proposed intervention drug (sulfadoxine-pyrimethamine); (6) technical support from reputable and respected institutions in drafting new policies and planning for implementation; (7) donor support for pilot experiences in integrating proposed policy change into a package of preventive services; and (8) financial support for scaling up the proposed interventions.
- Research Article
22
- 10.1016/j.cliser.2022.100319
- Aug 1, 2022
- Climate Services
Application of real time S2S forecasts over Eastern Africa in the co-production of climate services
- Book Chapter
1
- 10.1093/oso/9780199260317.003.0016
- Oct 11, 2007
Disease, we have argued, influenced patterns of colonization, especially in West Africa, the Americas, and Australia (Chapter 2). In turn, imperial transport routes facilitated the spread of certain diseases, such as bubonic plague. This chapter expands our discussion of environmentally related diseases by focusing on trypanosomiasis, carried by tsetse fly, in East and Central Africa. Unlike plague, this disease of humans and livestock was endemic and restricted to particular ecological zones in Africa. But as in the case of plague, the changing incidence of trypanosomiasis was at least in part related to imperialism and colonial intrusion in Africa. Coastal East Africa presented some of the same barriers to colonization as West Africa. Portugal maintained a foothold in South-East Africa for centuries, and its agents expanded briefly onto the Zimbabwean plateau in the seventeenth century, but could not command the interior. Had these early incursions been more successful, southern Africa may have been colonized from the north, rather than by the Dutch and British from the south. Parts of East Africa were a source of slaves and ivory in the eighteenth and early nineteenth centuries. The trading routes, commanded by Arab and Swahili African networks, as well as Afro-Portuguese further south, were linked with the Middle East and the Indian Ocean. In the early decades of the nineteenth century, slave-holding expanded within enclaves of East Africa, such as the clove plantations of Zanzibar. When Britain attempted to abolish the slave trade in the early nineteenth century, and policed the West African coast, East and Central African sources briefly became more important for the Atlantic slave trade. African slaves from these areas were taken to Latin America and the Spanish Caribbean. Britain did not have the same intensity of contact with East Africa as with West and southern Africa until the late nineteenth century. There was no major natural resource that commanded a market in Europe and British traders had limited involvement in these slave markets. But between the 1880s and 1910s, most of East and Central Africa was taken under colonial rule, sometimes initially as protectorates: by Britain in Kenya and Uganda; Germany in Tanzania; Rhodes’s British South Africa Company in Zimbabwe, Zambia, and Malawi; and by King Leopold of Belgium in the Congo.
- Research Article
12
- 10.1186/s12936-024-04925-y
- Apr 8, 2024
- Malaria journal
BackgroundIn sub-Saharan Africa (SSA), Plasmodium falciparum causes most of the malaria cases. Despite its crucial roles in disease severity and drug resistance, comprehensive data on Plasmodium falciparum genetic diversity and multiplicity of infection (MOI) are sparse in SSA. This study summarizes available information on genetic diversity and MOI, focusing on key markers (msp-1, msp-2, glurp, and microsatellites). The systematic review aimed to evaluate their influence on malaria transmission dynamics and offer insights for enhancing malaria control measures in SSA.MethodsThe review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Two reviewers conducted article screening, assessed the risk of bias (RoB), and performed data abstraction. Meta-analysis was performed using the random-effects model in STATA version 17.ResultsThe review included 52 articles: 39 cross-sectional studies and 13 Randomized Controlled Trial (RCT)/cohort studies, involving 11,640 genotyped parasite isolates from 23 SSA countries. The overall pooled mean expected heterozygosity was 0.65 (95% CI: 0.51–0.78). Regionally, values varied: East (0.58), Central (0.84), Southern (0.74), and West Africa (0.69). Overall pooled allele frequencies of msp-1 alleles K1, MAD20, and RO33 were 61%, 44%, and 40%, respectively, while msp-2 I/C 3D7 and FC27 alleles were 61% and 55%. Central Africa reported higher frequencies (K1: 74%, MAD20: 51%, RO33: 48%) than East Africa (K1: 46%, MAD20: 42%, RO33: 31%). For msp-2, East Africa had 60% and 55% for I/C 3D7 and FC27 alleles, while West Africa had 62% and 50%, respectively. The pooled allele frequency for glurp was 66%. The overall pooled mean MOI was 2.09 (95% CI: 1.88–2.30), with regional variations: East (2.05), Central (2.37), Southern (2.16), and West Africa (1.96). The overall prevalence of polyclonal Plasmodium falciparum infections was 63% (95% CI: 56–70), with regional prevalences as follows: East (62%), West (61%), Central (65%), and South Africa (71%).ConclusionThe study shows substantial regional variation in Plasmodium falciparum parasite genetic diversity and MOI in SSA. These findings suggest a need for malaria control strategies and surveillance efforts considering regional-specific factors underlying Plasmodium falciparum infection.
- Research Article
1
- 10.1016/j.jafrearsci.2023.105071
- Oct 4, 2023
- Journal of African Earth Sciences
This paper explores a variety of different attempts to reconstruct Quaternary environments in East and North Africa during the last century or so and shows how the research on African Quaternary environments has also had an impact on Quaternary research worldwide. One important lesson is that the uncritical acceptance of a single climatic model developed in one continent, such as the glacial pluvial model from North America, and its wholesale application to another continent, such as Africa, can prove highly misleading and can (and did) retard progress in reconstructing Quaternary environments in Africa by many years. The most recent wet climatic interval in East Africa and the Sahara occurred between 15,000 and 5,000 years ago, following a cold, dry and windy climatic interval during the late Pleistocene, when lakes dried out across East Africa, desert dunes were active in the Sahara, and huge plumes of desert dust were blown into the Atlantic. The repeated changes in Quaternary environments in East and North Africa exerted a powerful influence upon early human adaptations and migrations, culminating in the emergence of Neolithic plant and animal domestication in the Nile valley and the Sahara and the flowering of early Egyptian urban civilization.
- Research Article
55
- 10.1111/padr.12043
- Mar 15, 2017
- Population and Development Review
In this chapter the author adopts a comparative approach to examining longterm trends in female age at marriage and fertility in sub-Saharan Africa with a focus on continental countries having at least 1 million inhabitants. The author’s database on nuptiality includes over 360 censuses and national surveys conducted in these 39 countries since the 1960s. The author analyzes the association between changes in age at first union and the onset of fertility transition examining whether there is a typical pattern of association followed by most countries in the region.
- Abstract
12
- 10.1016/s0140-6736(17)31119-4
- Apr 1, 2017
- The Lancet
Impact of climate change on malaria in Africa: a combined modelling and observational study
- Research Article
6
- 10.11648/j.ajrs.20150302.11
- Jan 1, 2015
- American Journal of Remote Sensing
The spatial and temporal cloud coverage derived by CloudSat, CERES, ISCCP satellite observations and their relationship with GPCP and TRMM precipitation in West, East and South of Africa were analyzed in this study. CloudSat, CERES and ISCCP show that the high spatial cloud coverage is more frequent in equatorial regions mainly due to more strong convection than other regions. CloudSat shows a low temporal cloud coverage than CERES and ISCCP which are close. Only ISCCP was used to investigate seasonal and temporal variability of different cloud types. The stratocumulus, altostratus, and cirrus clouds are the low, middle and high cloud types with high cloud coverage during JJA, JJA, MAM in West of Africa, during SON, JJA, MAM in East of Africa, and during SON, DJF, DJF in South of Africa respectively . The correlation between cloud coverage and precipitation dataset generally shows a low positive correlation in East of Africa probably due to GPCP and TRMM observations biases whereas a high positive correlation in West and South of Africa. Only middle clouds level in East of Africa, both low and middle in West of Africa show negative correlation with precipitation, whereas all cloud types level in South of Africa show a positive correlation with precipitation.
- Research Article
8
- 10.1016/j.oneear.2021.02.012
- Mar 1, 2021
- One Earth
Co-development of East African regional water scenarios for 2050
- Book Chapter
13
- 10.1016/b978-0-12-821450-3.00008-1
- Jan 1, 2021
- The Beans and the Peas
Chapter 6 - Faba bean
- Ask R Discovery
- Chat PDF
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