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The Anambra Basin is a Cretaceous intracratonic basin, trending NE–SW in the southern part of Nigeria. The basin is believed to have been formed during the Santonian tectonic episode, which affected the entire Benue Trough. Inorganic geochemical data of the Nanka Sandstone was applied in studying its tectonic setting and provenance. The sandstones have fractionated chondrite-normalised rare earth element (REE) patterns, enriched light rare earth elements (LREE) and nearly horizontal REE with negative europium (Eu) anomalies. These patterns as well as a wide range of LREE/HREE (heavy rare earth elements) ratios and negative Eu anomalies suggest a felsic and/or mixed rock type source. A provenance discriminant function diagram utilising major oxides indicates a quartzose recycled sedimentary source. A plot of La/Th vs. Hf suggests a mixed felsic/basic source; a plot of Cr/Th and Th/Sc indicates contributions from felsic and basic end members, suggesting a mixed-source provenance. A Th/Co vs. La/Sc diagram, V-Ni-Th*10 ternary plot and Th/Co vs. La/Co suggest mixed source rock. Provenance investigations allude to sediment derivation from felsic, intermediate and mafic components and probably inputs from recycled older sediments. Tectonic discrimination based on major and trace elements indicates a passive margin setting. [ABSTRACT FROM AUTHOR]

The paleoweathering, paleoclimate and paleoenvironment of the Nanka sandstone of the Anambra basin have been evaluated based on geochemical data. The Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), Plagioclase Index of Alteration (PIA), Mineralogical Index of Alteration (MIA) and the A-CN-K ternary plot indicates intense weathering. Also, Rb/Sr, Al/K, Rb/K ratios are high while Sr/Ba is low indicating that the sediments were derived during intense chemical weathering of the source area. The Th/U-Th plot suggests that weathering conditions were not constant during sedimentation. The K2O/Al2O3 ratio reveal that Nanka sandstone has minimal K-feldspar. There is negative correlation between CIA with K and Na+Ca; as weathering intensity increases, these elements are depleted, while there is a linear negative correlation between CIA and Al which implies high intensity of chemical weathering and subsequent formation of clay minerals. The paleoenviromental indices (U/Th, Ni/Co, Cu/Zn, (Cu+Mo)/Zn, V/Sc, V/Ni, V/Cr ratios, Mn*, Fe/Al, plot of Ni versus V, plot of V/Cr against Ni/Co, Mo concentrations and Ce/Ce*) and paleoclimate results suggest that the Nanka sandstone was deposited under oxic conditions with a humid climate on low relief in a non-marine deltaic environment and the paleosalinity based on low Sr/Ba ratio indicates low saline water during deposition in a continental environment. [ABSTRACT FROM AUTHOR]

Benue Trough basin is geologically subdivided into three segments. It consists of marine and continental sediments that are affected by folding movements. In the upper section, the continental coal-bearing Campano-Maastrichtian-age is found within Gombe Sandstone and the Cenozoic Kerri-Kerri Formation of the Tertiary. In the middle segment, the late Turonian/early Santonian coal-bearing Awgu Formation lies conformably on the Ezeaku Formation. In the lower part, shales at Nkporo mark marine incursion and deposition of the Maastrichtian Mamu Formation coal measures. Cretaceous coal samples taken from the three segments of Benue Trough basin were examined using ultimate and proximate, organic petrographic, x-ray fluorescence (XRF) and laser ablation-induced coupled plasma spectroscopy (LA-ICPMS) analytical techniques. Results of trace element ratios, Ce/Ce* values ("where Ce* is the theoretical Ce value derived from a chondrite-normalized rare earth element (REE) pattern"), authigenic uranium values, and low hydrogen content indicate deposition under oxic to suboxic conditions. However, the V/Ni and V/Sc ratios indicate under oxic, suboxic to reducing conditions. The Y/Ho values for selected coals are lower than the range for seawater, indicating terrigenous influence. The Sr/Ba values indicate low influence of saline water during deposition and a strong continental rather than marine influence. High value of vitrinite and low proportion of liptinite/intertinite suggest that peat in the study areas were situated on the irregular basin floor where sediment thicknesses vary from place to place thus the depositional environments shifted causing mineral matter filling in coal. Based on the tissue preservation index (TPI) and gelification index (GI), LFB, CHK, OKB, LMZ, IMG; and ENG (high GI and high TPI) were deposited in telmatic facies; wet-forest swamps with rapid organic matter accumulation. This trend indicates mild humification and strong gelification of plant tissues which ascribed to high rate of subsidence with wood- and bark-derived telovitrinite. The MGA peats were deposited in terrestrial facies in a dry-forest swamp with wood-derived telo-inertinite. The coal samples code-named IMG and ENG were deposited in planar margin mires. However, coal samples code-named LFB, CHK and LMZ were deposited in planar central mires. Lastly, OKB and MGA were deposited in transitional-wet and transitional-dry mire. The low V and Ni concentrations, low H/C, high O/C, high C/N, and very low N/C ratios <0.05 implies Type III land-plant organic matter that is not oil-prone. The depositional environments interpretations of investigated coal seams indicate that the coals were deposited within a telmatic, limnic, limno-telmatic and open march zone. Generally, a combination of results from inorganic geochemistry and organic petrology is required for precise and all-inclusive determination of coal depositional environments. [Display omitted] • Paleoredox parameters, Ce/Ce* values, authigenic U values, and low H 2 content suggest oxic to suboxic depositional conditions. • Sr/Ba values indicate low influence of saline water during deposition and a strong continental rather than marine influence. • The Y/Ho values for selected coals are lower than the range for seawater, indicating terrigenous influence. • The studied coals contain Type III land-plant organic matter that is not oil-prone. [ABSTRACT FROM AUTHOR]

The Simulium damnosum Theobald complex transmits Onchocerca volvulus Leuckart (Spirurida: Onchocercidae), the causative agent of onchocerciasis. Recent evidence suggests that control efforts have strongly suppressed parasite populations, but vector surveillance is needed in parts of Africa where the disease remains endemic. Here, studies on biting rates and infectivity status of suspected vector species were conducted in three onchocerciasis-endemic areas, namely Iwo, Ede, and Obokun, in Osun State, Nigeria. A total of 3,035 black flies were collected between October 2014 and September 2016, and examined for parity and parasites using standard methods. A separate collection of 2,000 black flies was pool-screened for infectivity using polymerase chain reaction (PCR) amplification of the O-150 marker. Results showed that parous flies were significantly less common than nulliparous flies with overall parous rates of 8.02% in Iwo and 35.38% in Ede at the end of the study period. Obokun had a parous rate of 22.22% obtained in the first year only. None of the dissected parous flies were infected with O. volvulus and PCR assays showed no amplification of O-150 O. volvulus-specific repeats in head and body pools. However, annual biting rates exceeded the World Health Organization threshold of 1,000 bites/person/yr. Thus it appears that, with such high rates of biting, even low levels of vector infection can sustain onchocerciasis in African communities., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: It is believed that intensive care greatly improves the prognosis for critically ill children and that critically ill children admitted to a dedicated Paediatric Intensive Care Unit (PICU) do better than those admitted to a general intensive care unit (ICU)., Methods: A retrospective study of all paediatric (< 16 years) admissions to our general ICU from January 1994 to December 2007., Results: Out of a total of 1364 admissions, 302 (22.1%) were in the paediatric age group. Their age ranged from a few hours old to 15 years with a mean of 4.9 ± 2.5 years. The male: female ratio was 1.5:1. Postoperative admissions made up 51.7% of the admissions while trauma and burn made up 31.6% of admissions. Medical cases on the other hand constituted 11.6% of admissions. Of the 302 children admitted to the ICU, 193 were transferred from the ICU to other wards or in some cases other hospitals while 109 patients died giving a mortality rate of 36.1%. Mortality was significantly high in post-surgical paediatric patients and in patients with burn and tetanus. The length of stay (LOS) in the ICU ranged from less than one day to 56 days with a mean of 5.5 days., Conclusion: We found an increasing rate of paediatric admissions to our general ICU over the years. We also found a high mortality rate among paediatric patients admitted to our ICU. The poor outcome in paediatric patients managed in our ICU appears to be a reflection of the inadequacy of facilities. Better equipping our ICUs and improved man-power development would improve the outcome for our critically ill children. Hospitals in our region should also begin to look into the feasibility of establishing PICUs in order to further improve the standard of critical care for our children.