University of Nigeria, Nsukka

About: University of Nigeria, Nsukka is a education organization based out in Nsukka, Nigeria. It is known for research contribution in the topics: Population & Health care. The organization has 10211 authors who have published 13685 publications receiving 138922 citations.

The 2014 alma long baseline campaign: an overview*

Abstract: A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from 2014 September to late November, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C 138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.

Bagasse filled recycled polyethylene bio-composites: Morphological and mechanical properties study

Abstract: Bagasse filled recycled polyethylene bio-composites were produced by the compounding and compressive molding method. Two sets of composites were produced using uncarbonized (UBp) and carbonized (CBp) bagasse particles by varying the bagasse particles from 10 to 50 wt%. The surface morphology and the mechanical properties of the composites were examined. The results showed that the uniform distribution of the bagasse particles in the microstructure of the polymer composites is the major factor responsible for the improvement of the mechanical properties. The bagasse particles added to the RLDPE polymer improved its rigidity and the hardness values of the composites. The tensile and bending strengths of the composite increased with increasing percentage of the bagasse to a maximum of 20 wt%UBp and 30 wt%CBp. The impact energy and fracture toughness decreases with wt% bagasse particles. The developed composites have the best properties in the ranges of 30 wt% bagasse particle additions and for optimum service condition, carbonized bagasse particles addition should not exceed 30 wt%.

Onchocerciasis: the clinical and epidemiological burden of skin disease in Africa

Abstract: An attempt was made to assess the true public-health importance of onchocercal skin disease throughout the African region and hence provide an objective basis for the rational planning of onchocerciasis control in the area. The seven collaborative centres that participated in the study (three in Nigeria and one each in Ghana, Cameroon, Tanzania and Uganda) were all in areas of rainforest or savannah-forest mosaic where onchocercal blindness is not common. A cross-sectional dermatological survey was undertaken at each site following a standard protocol. At each site, the aim was to examine at least 750 individuals aged 5 years and living in highly endemic communities and 220-250 individuals aged 5 years and living in a hypo-endemic (control) community. Overall, there were 5459 and 1451 subjects from hyper-and hypo-endemic communities, respectively. In the highly endemic communities, the prevalence of itching increased with age until 20 years and then plateaued, affecting 42% of the population aged 20 years. There was a strong correlation between the prevalence of itching and the level of endemicity (as measured by the prevalence of nodules; r=0.75; P<0.001). The results of a multivariate logistic regression analysis showed that, at the individual level, the presence of onchocercal reactive skin lesions (acute papular onchodermatitis, chronic papular onchodermatitis and/or lichenified onchodermatitis) was the most important risk factor for pruritus, with an odds ratio (OR) of 18.3 and 95% confidence interval (CI) of 15.19-22.04, followed by the presence of palpable onchocercal nodules (OR=4.63; CI=4.05-5.29). In contrast, non-onchocercal skin disease contributed very little to pruritus in the study communities (OR=1.29; CI=1.1-1.51). Onchocercal skin lesions affected 28% of the population in the endemic villages. The commonest type was chronic papular onchodermatitis (13%), followed by depigmentation (10%) and acute papular onchodermatitis (7%). The highest correlation with endemicity was seen for the prevalence of any onchocercal skin lesion and/or pruritus combined (r=0.8; P<0.001). Cutaneous onchocerciasis was found to be a common problem in many endemic areas in Africa which do not have high levels of onchocercal blindness. These findings, together with recent observations that onchocercal skin disease can have major, adverse, psycho-social and socio-economic effects, justify the inclusion of regions with onchocercal skin disease in control programmes based on ivermectin distribution. On the basis of these findings, the World Health Organization launched a control programme for onchocerciasis, the African Programme for Onchocerciasis Control (APOC), that covers 17 endemic countries in Africa.