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This paper presents a sequence-stratigraphic interpretation from the lithologic data and palynological and palynofacies analyses of four shallow boreholes (Badore-1, Epe-1, Ikoyi-1, and Olokonla-1) within the upper Eocene-lower Oligocene interval of the Dahomey Basin. Three lithofacies, namely sandstones, shaly sands, and sandy shales were delineated. Sandstones and shaly sands could probably serve as reservoir rocks, while sandy shales could probably serve as source and seal rocks. Two major broad palynological zones were identified, i.e., the Verrucatosporites usmensis and Magnastriatites howardi Pan-tropical, which correlated to P500 and P400 zones. These zones were further subdivided into the P470 and P480, and P520 and P540 subzones. First occurrences (FOs) of Achomosphaera alcicornu, Homotryblium plectilum, and Adnatosphaeridium multispinosum and last appearance datum (LAD) of Homotryblium tenuispinosum were palynostratigraphic events that defined upper Eocene and lower Oligocene boundary in the four boreholes. Two and four depositional sequences were delineated in Epe-1 and Badore-1 boreholes, respectively, and three each were recorded in Olokonla-1 and Ikoyi-1 boreholes. Seven maximum flooding surfaces (38.8Ma, 37.5Ma, 36.5Ma, 35.0Ma, 32.0Ma, 29.0Ma, and 27.5Ma) and sequence boundaries (39.5Ma, 38.0Ma, 37.0Ma, 36.0Ma, 33.0Ma, 30.0Ma, and 28.4Ma) were identified in the four boreholes. The findings in this present study will be useful in understanding the significance of strata horizons and their respective ages, and system tracts sediment packages in the petroleum system.

IntroductionThe emerging role of non-albicans Candida species (NACS) as causal agents of mild to life-threatening mycoses is increasingly being appreciated. Some NACS are known for intrinsic resistance or reduced susceptibility to some antifungal drugs. To inform on therapeutic options and management of candidiasis, we embarked on Candida species surveillance in South west Nigeria.MethodWe obtained retrospective yeast isolates from urogenital samples of patients in a tertiary hospital in South west Nigeria. Among 47 isolates identified phenotypically, we encountered a yeast which failed to produce pseudohyphae in human serum but was morphologically similar to Candida albicans. We characterized this yeast by sequencing the internal transcribed spacer (ITS1-5.8S-ITS2) region of the ribosomal DNA.ResultsA BLAST search and sequence homology identified the yeast as Candida (Diutina)mesorugosa, with a strong bootstrap.ConclusionCandida mesorugosa, a rarely isolated yeast from clinical samples worldwide, should be considered among potentially relevant NACS in Nigerian clinics. To the best our knowledge, this is the first report of Candida mesorugosa from a clinical sample in Nigeria. This finding confirms the need for more specific methods, such as DNA sequencing, for extensive surveillance of NACS.

The graphic correlation method provides better and higher resolution to the stratigraphic problems than zonation biostratigraphy. The measured total stratigraphic ranges of 44 palynomorphs present in five wells from the Niger Delta Basin have been assembled by graphic correlation method into a chronostratigraphic framework. The analysis by graphic correlation reveals that for a meter of sediment accumulation in Well E, correspondingly amounted to only 0.8794 m, 0.7586 m, 0.8677 m and 0.8686 m of sediments that were deposited in wells A, B, C and D, respectively. These relative rates of sediment accumulation indicate that either there was less erosion taking place and/or more accommodation space in Well E than Wells A, B, C and D. A graphic correlation horizontal terrace was recorded in each of the Wells A, C and D, which are interpreted as condensation of sediments that had truncated the sediments accumulation profile in these wells. These condensed sections are interpreted as sediment starvation and very slow rates of sedimentation during the Early Pliocene, Late Pliocene and Late Pleistocene due to marine transgression(s) at these stages in the Niger Delta Basin. The generated correlation equations, slopes and intercept values from graphic correlation plots allow the correlation of six biostratigraphic and sedimentological events in Wells A, B, C, D and E. The resulting chronostratigraphic framework in this study is essential for sequence stratigraphic interpretations and basin analysis, and in particular, to correlate widely separated wells.

The concentration and biodiversity of airborne fungi of the Redemption City, an immense campground for Christian faithful and the temporary site of the Redeemer’s University in south-western Nigeria, was studied between February and May 2011 using the culture plate method. The study was undertaken to assess the concentrations of fungal spores and their health implication in this ever-busy environment. Fifteen different sites classified as closed or open were selected. During the experiment, a total of 228 colonies were counted, and 29 fungal species belonging to 26 genera were isolated which include the following: Aspergillus flavus, Aspergillus niger, Bipolaris spp., Chrysosporium spp., Cladosporium spp., Coniothyrium corda, Curvularia spp., Diplodia spp., Fusarium spp., Gliocladium spp., Monilia spp., Mucor spp., Mucor plumbeus, Penicillium spp., Phycomyces spp., Phytophthora spp., Pilobolus spp., Pyrenochaeta spp., Rhizopus stolonifer, Torula spp., Trichoderma spp. and Trichophyton spp. The most frequently occurring fungi were A. niger, C. corda and M. plumbeus, while the least recorded were Torula and Trichophyton species. Majority of the fungi isolated are known allergens; they could also be opportunistic causing various diseases in man. There is therefore a dire need for good sanitation practices within the studied areas of the camp.