http://hdl.handle.net/123456789/1379 Tue, 14 Apr 2026 23:08:12 GMT 2026-04-14T23:08:12Z http://hdl.handle.net/123456789/3764 Sexual differentiation of Crassostrea tulipa in two contrasting brackishwater environments Yankson, K Article Fri, 01 Nov 1996 00:00:00 GMT http://hdl.handle.net/123456789/3764 1996-11-01T00:00:00Z http://hdl.handle.net/123456789/3763 Natural selection for rare and mimetic colour pattern combinations in wild populations of the diadem butterfly, Hypolimnas misippus L. Gordon, I.J Mark recapture and morph frequency data, gathered during a population irruption of Hypolimnas misippus in southern Ghana, provide evidence for apostatic and mimetic selection. During a period of low adult survival, both the recapture rate and the frequency of the commonest morph (misippus) were significantly reduced. Selection against this form increased phenotypic diversity and generated significant disequilibrium in the combinations of unlinked fore- and hindwing phenotypes. There was also evidence for selection against those forms (weak akippoides) which most closely resemble misippus. Other morphs, including both good mimics of Danaus chrysippus and rare non-mimics, showed no reductions in recapture rate during the period of low survival, but only the good mimics increased significantly in frequency. The results provide a predictive ecological model for densitydependent selection by predators which is consistent with field data from previous studies of H. misippus in Ghana and Tanzania. Their evolutionary implications are discussed, and it is suggested. that anomalies in the mimicry of this species may be partly due to lack of predation when it is scarce. Article Mon, 01 Sep 1986 00:00:00 GMT http://hdl.handle.net/123456789/3763 1986-09-01T00:00:00Z http://hdl.handle.net/123456789/3762 The genetics of the butterfly hypolimnas misippus (L.): The classification of phenotypes and the inheritance of forms misippus and inaria Smith, D.A.S; Gordon, I.J Hypolimnas misippus is a polymorphic and mimetic butterfly with a pantropicaP distribution. The polymorphism is autosomal and female-limited, the several female forms being generally regarded as Batesian mimics of the distasteful, toxic and polymorphic danaine butterfly Danaus chrysippus. The female phenotypes of H. misippus are described and classified. New data, from the rearing of 140 broods of H. misippus in Ghana and Sierra Leone, are analysed together with older material (21 broods) from other parts of Africa. Form misippus (genotype M-) is found to be genetically dominant to form maria (genotype mm). However, a large proportion of mm butterflies has an intermediate phenotype, especially in association with white on the hiudwing. Evidence is adduced to show that the genes giving hindwing white are variably epistatic over the 'maria' pattern in the mm genotype, producing a phenotype transitional to or even identical to misippus. The various intermediate phenotypes are poor mimics of D. chrysippus: their abundance, geographical range and, hence, significance have been much underestimated. Article Sun, 01 Mar 1987 00:00:00 GMT http://hdl.handle.net/123456789/3762 1987-03-01T00:00:00Z http://hdl.handle.net/123456789/3476 Oncogenic human papillomavirus infection and genotypes characterization among sexually active women in Tenkodogo at Burkina Faso, West Africa Ouedraogo, R.A; Zohoncon, T.M; Guigma, S.P; Angèle Traore, I.M; Ouattara, A.K; Ouedraogo, M.; Djigma, F.W Objective: This study was conducted to determine the prevalence and distribution of high-risk human papillomavirus (HR-HPV) genotypes among sexually active women in Tenkodogo, Burkina Faso. Methods: Among 131 sexually active women attending the Tenkodogo Urban Medical Center, endocervical samples were collected prior to screening for precancerous lesions. After viral DNA extraction, fourteen HR-HPV genotypes were characterized by real-time multiplex PCR in these cervical samples. Results: The mean age was 35.5 ± 9.5 years. Of the 131 women, 45 were infected with at least one HR-HPV genotype. The prevalence of HR-HPV infection among these women was 34.4%. Among the 45 oncogenic HPVinfected women, single HR-HPV genotype was found in 55.6% while 44.4% were infected with more than one HR-HPV genotype. The most frequent genotypes were HPV56 (36.5%), HPV66 (36.5%). Conclusion: Tenkodogo women included in this study had a higher prevalence of HPV 56, HPV 66. A larger study with a more representative sample would therefore be needed to determine predominant oncogenic genotypes in the subregion and especially in cancer cases. Article Sat, 01 Sep 2018 00:00:00 GMT http://hdl.handle.net/123456789/3476 2018-09-01T00:00:00Z