The Commelinaceae of West Africa: A biosystematic survey

All the known West African taxa are surveyed and their variation and distribution is discussed. Chromosome numbers for most of the taxa are given, in many cases for the first time, and published cytological data for those genera occurring in West Africa is reviewed. Many of the taxa have been studied under cultivation and most under living conditions in the field. The results of these observations are considered in relation to the evolution of new variations and to the taxonomy of the groups concerned. The following new taxa are described: Aneilema beniniense subsp. leonense, C'ommelina diffusa subsp. montana, Floscopa africana subsp. petrophila and Slanfieldiella axillaris. Several nomenclatural changes have been made, the most important being the recognition that the African species Commelina gerrardi C. B. Clarke and C. vogelii C. B. Clarke are conspecific with the American C. erecta Linn, which thus becomes a pantropie species complex. Several species are recorded from West Africa for the first time including: Coleolrype kiurentii K. Schum. Commelina carsonii C. B. Clarke, C. zambesiaca C. B. Clarke, Cyanotis arachnoidea C. B. Clarke, and Palisota lagopus Mildbr. The pattern of variation in the larger species complexes in the genera Aneilema, Commelina, Cyanotis and Floscopa is considered in detail. These and other groups in the family are considered to be in an active state of evolutionary change. The factors which have stimulated these changes and the biological processes by means of which they are brought about are discussed. Attention is drawn to the suitability of this family for evolutionary studies and its value in the teaching of experimental taxonomy in the tropics.     

The genusDaphnia in Cameroon,West Africa

Three species of the genusDaphnia are recorded from Cameroon.Daphnia obtusa was found in a single lake out of 37 sampled.Daphnia laevis was found in the same lake asD. obtusa and in two other lakes, whileD. rosea was found in three other lakes. All the lakes were at altitudes over 1 000 m. The records can be interpreted either as altitudinal survivals of continually dispersing species, or as relicts in an area whereDaphnia is usually very rare or absent.     

The Lion in West Africa Is Critically Endangered

The African lion has declined to <35,000 individuals occupying 25% of its historic range. The situation is most critical for the geographically isolated populations in West Africa, where the species is considered regionally endangered. Elevating their conservation significance, recent molecular studies establish the genetic distinctiveness of West and Central African lions from other extant African populations. Interventions to save West African lions are urgently required. However formulating effective conservation strategies has been hampered by a lack of data on the species'' current distribution, status, and potential management deficiencies of protected areas (PAs) harboring lions. Our study synthesized available expert opinion and field data to close this knowledge gap, and formulate recommendations for the conservation of West African lions. We undertook lion surveys in 13 large (>500 km²) PAs and compiled evidence of lion presence/absence for a further eight PAs. All PAs were situated within Lion Conservation Units, geographical units designated as priority lion areas by wildlife experts at a regional lion conservation workshop in 2005. Lions were confirmed in only 4 PAs, and our results suggest that only 406 (273–605) lions remain in West Africa, representing <250 mature individuals. Confirmed lion range is estimated at 49,000 km², or 1.1% of historical range in West Africa. PAs retaining lions were larger than PAs without lions and had significantly higher management budgets. We encourage revision of lion taxonomy, to recognize the genetic distinctiveness of West African lions and highlight their potentially unique conservation value. Further, we call for listing of the lion as critically endangered in West Africa, under criterion C2a(ii) for populations with <250 mature individuals. Finally, considering the relative poverty of lion range states in West Africa, we call for urgent mobilization of investment from the international community to assist range states to increase management effectiveness of PAs retaining lions.     

The Cashew Frontier in Guinea-Bissau,West Africa: Changing Landscapes and Livelihoods

Guinea-Bissau farmers are replacing shifting cultivation with cashew (Anacardium occidentale) orchards in response to international and national economic and conservation policies, local social changes and perceived increasing climate instability. However, changes from relative food self-provisioning to full dependence on one cash crop and from a complex mosaic of agricultural fields, fallows and forest patches to a homogenous landscape of cashew agroforests impacts both the natural environment and livelihoods. This article on the demise of shifting cultivation in the tropics contributes to the growing body of scholarship on land use-cover change (LUCC) and its multiplex global, national and local drivers, varying across time and space. Further, we argue that instead of adopting an approach exclusively focused on parks, conservation-oriented external interventions should engage with farmers in the development of innovations that both preserve forest ecosystems and enhance food security.     

The Spectrum of Cancers in West Africa: Associations with Human Immunodeficiency Virus

Background

Cancer is a growing co-morbidity among HIV-infected patients worldwide. With the scale-up of antiretroviral therapy (ART) in developing countries, cancer will contribute more and more to the HIV/AIDS disease burden. Our objective was to estimate the association between HIV infection and selected types of cancers among patients hospitalized for diagnosis or treatment of cancer in West Africa.

Methods

A case-referent study was conducted in referral hospitals in Côte d’Ivoire and Benin. Each participating clinical ward enrolled all adult patients seeking care for a confirmed diagnosis of cancer and clinicians systematically proposed an HIV test. HIV prevalence was compared between AIDS-defining cancers and a subset of selected non-AIDS defining cancers to a referent group of non-AIDS defining cancers not reported in the literature to be positively or inversely associated with HIV. An unconditional logistic model was used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of the risk of being HIV-infected for selected cancers sites compared to a referent group of other cancers.

Results

The HIV overall prevalence was 12.3% (CI 10.3–14.4) among the 1,017 cancer cases included. A total of 442 patients constituted the referent group with an HIV prevalence of 4.7% (CI 2.8–6.7). In multivariate analysis, Kaposi sarcoma (OR 62.2 [CI 22.1–175.5]), non-Hodgkin lymphoma (4.0 [CI 2.0–8.0]), cervical cancer (OR 7.9 [CI 3.8–16.7]), anogenital cancer (OR 11.6 [CI 2.9–46.3]) and liver cancer (OR 2.7 [CI 1.1–7.7]) were all associated with HIV infection.

Conclusions

In a time of expanding access to ART, AIDS-defining cancers remain highly associated with HIV infection. This is to our knowledge, the first study reporting a significant association between HIV infection and liver cancer in sub-Saharan Africa.     

Museums and Archaeology in West Africa.

Museums and Archaeology in West Africa. Claude Daniel Ardouin. ed. Washington, DC: Smithsonian Institution Press, 1998.178 pp.