The dynamics of managing people in the diverse cultural and institutional context of Africa

Purpose The purpose of this article is to introduce the special issue which considers some of the contemporary debates in managing people in Africa. Design/methodology/approach The papers that constitute this special issue were selected from submissions to various events hosted by the Africa Research Group, a community of scholars committed to researching Africa, and from a more general call for submissions. Findings The papers highlight the changing picture of the African organisational landscape and provide both theoretical and empirical insights about the opportunities and challenges of managing people in a culturally complex continent. Originality/value Taken together, the papers make an important contribution by engaging current debates and demonstrating potential new areas for further research

Effects of heating temperature and time on some mechanical properties of Balanites Aegyptiaca nut

Balanites aegyptiaca nuts were pretreated by heating at different temperatures in the range of 30 – 90oC for time durations in the range of 30 – 120 mins. Moisture content of the nuts prior to pretreatment was 4.7 % (d.b.). Some strength properties of the pretreated nuts namely, bioyield, yield and rupture points; bioyield, compressive and rupture strengths; and moduli of elasticity, resilience, stiffness and toughness were determined at lateral and longitudinal axial loading, using a Universal Testing Machine (UTM). Results showed that all the strength properties of the nut decreased with increase in temperature and varied significantly with heating time at different loading orientations. Temperature and heating time range existed within which the nuts exhibited the typical behavior of biomaterials when heated and subjected to compression. After these ranges were exceeded, the nuts’ behavior deviated.         The study suggests that in addition to conditioning balanites aegyptiaca nuts to a moisture level at which they could easily be cracked, further treatment by exposure to heat at a level and for a duration that would not compromise product quality, could be used to enhance energy efficiency. Loading along the longitudinal axis should be applied if the cracking of nut is to be carried out using uniaxial compression

The Sero-Prevalence of Parvovirus Antibodies among Children with Sickle Cell Anaemia in Zaria

Parvovirus is an erythrovirus that infects red cell precursors in individuals with conditions characterised by a high red cell turnover like sickle cell anaemia and thalassaemia. Arthritis, vasculitis, carditis, bone marrow failure, and the slapped cheek appearance have been associated with Parvovirus B19 infection. Recurrent blood transfusion is a risk factor for the B19 serotype of Parvovirus infection, with the P antigen as the mediator for erythroid invasion presenting as transient erythroblastopaenia (TEB). Although TEB is self-limiting a few cases may progress to aplastic anaemia. Previous studies report seroprevalence rates of between 44 and 71%, but the dearth of data on the seroprevalence of B19 parvovirus strain in our region prompted this study. Venous blood samples from 239 children aged 1to 15 years of consenting parents and guardians were screened for Parvovirus B19 IgG antibodies using the ELISA technique and antibody titer assessed spectrophotometrically. All the participants have sickle cell anaemia, but were in the steady state. Of this serum samples from 204 (85.4%) participants were positive for IgG antibodies against Parvovirus B19 while 35 (14.6%) were negative for the IgG antibodies.). The age-group with the highest prevalence is 10-12year group with seroprevalence rate of 88.9%. The overall seroprevalence of Parvovirus B19 antibodies is 85.4 %. The seroprevalence of Parvovirus B19 antibodies is high in all socio-economic groups. Antibody prevalence is higher in thenon-transfused group suggesting that other factors than transfusion play a role in the spread of the B19 strain of Parvovirus B19

Energy and Spectral Efficiency Balancing Algorithm for Energy Saving in LTE Downlinks

In wireless network communication environments, Spectral Efficiency (SE) and Energy Efficiency (EE) are among the major indicators used for evaluating network performance. However, given the high demand for data rate services and the exponential growth of energy consumption, SE and EE continue to elicit increasing attention in academia and industries. Consequently, a study of the trade-off between these metrics is imperative. In contrast with existing works, this study proposes an efficient SE and EE trade-off algorithm for saving energy in downlink Long Term Evolution (LTE) networks to concurrently optimize SE and EE while considering battery life at the Base Station (BS). The scheme is formulated as a Multi-objective Optimization Problem (MOP) and its Pareto optimal solution is examined. In contrast with other algorithms that prolong battery life by considering the idle state of a BS, thereby increasing average delay and energy consumption, the proposed algorithm prolongs battery life by adjusting the initial and final states of a BS to minimize the average delay and the energy consumption. Similarly, the use of an omni-directional antenna to spread radio signals to the user equipment in all directions causes high interference and low spatial reuse. We propose using a directional antenna instead of an omni-directional antenna by transmitting signals in one direction which results in no or low interference and high spatial reuse. The proposed scheme has been extensively evaluated through simulation, where simulation results prove that the proposed scheme is efficiently able to decrease the average response delay, improve SE, and minimize energy consumption.Comment: 19 page

Peer-to-peer Approach for Distributed Privacy-preserving Deep Learning

The revolutionary advances in machine learning and Artificial Intelligence have enables people to rethink how we integrate information, analyze data, and use the resulting insights to improve decision making. Deep learning is the most effective, supervised, time and cost efficient machine learning approach which is becoming popular in building today’s applications such as self-driving cars, medical diagnosis systems, automatic speech recognition, machine translation, text-to-speech conversion and many others. On the other hand the success of deep learning among others depends on large volume of data available for training the model. Depending on the domain of application, the data needed for training the model may contain sensitive and private information whose privacy needs to be preserved. One of the challenges that need to be address in deep learning is how to ensure that the privacy of training data is preserved without sacrificing the accuracy of the model. In this work, we propose, design and implement a decentralized deep learning system using peer-to-peer architecture that enables multiple data owners to jointly train deep learning models without disclosing their training data to one another and at the same time benefit from each other’s dataset through exchanging model parameters during the training. We implemented our approach using two popular deep learning frameworks namely Keras and TensorFlow. We evaluated our approach on two popular datasets in deep learning community namely MNIST and Fashion-MNIST datasets. Using our approach, we were able to train models whose accuracy is relatively close to models trained under privacy-violating setting, while at the same time preserving the privacy of the training data

Roles of various virulence and resistance genes associated with Salmonella and methods of their identification

Salmonellosis is an infectious disease affecting human and animals. The virulence of Salmonella is a function of chromosomal and plasmid factors, many genes code for these factors. Salmonella genes can be classified as core (housekeeping) genes and accessory genes. The core genes of a species are those genes found in (nearly) all known members of the species and they include mostly genes that are necessary for the cell to survive and grow, these include gene encoding enzymes which function in biosynthetic pathways. Genes in the accessory genome are those unique to particular strains and are mainly in the following groups: genomic islands including Salmonella Pathogenicity islands (SPls), prophages, insertion sequences.Keywords: Genes, Pathogenicity, Resistance, Salmonella, Virulenc

Seroprevalence of hepatitis C virus antibodies amongst blood donors in Ahmadu Bello University Teaching Hospital (ABUTH) Kaduna

Background: Hepatitis C virus (HCV) is one of the most common transfusion transmissible infections hence the introduction of routine screening for its antibodies in blood donors in most blood banks. Methods: This was a retrospective study in which the blood donor screening register for all intending donors were reviewed and analyzed. Results: There were 4,731 potential donors with age range 20-41years. Eighty six (1.8%) were sero-positive to HCV antibodies with a decreasing incidence over the period under review. The highest incidence was recorded the age group 31-40 years. Aim: To determine the sero-prevalence of HCV among blood donors in ABUTH Kaduna. Conclusion: HCV infection is not uncommon in our environment hence the need to emphasize it’s routine screening among all potential donors.

Effects of softwood biochar on the status of nitrogen species and elements of potential toxicity in soils

The effects of softwood-derived biochar materials on the chemical behaviour of environmental contaminants in soils were examined in two microcosm scenarios. Addition of the biochar materials into an alkaline sandy soil significantly reduced NH3 volatilization and made it available for conversion into NO3- via nitrification. This process could be enhanced by an increased application rate of biochar produced at a higher pyrolysis temperature. Under the alkaline conditions encountered in the experiment, the biochar surfaces tended to be negatively charged which disfavours the adsorption of NO3-. Therefore, in a fully open system, the addition of biochar materials was likely to contribute to nitrate leaching from the fertilized alkaline sandy soil. The effects of the biochar materials on the immobilization of Fe2+ generated via anaerobic iron reduction in the inundated contaminated soil were not observed, except for the treatment with a higher dose of biochar material produced under pyrolysis temperature at 700°C after the 240th h of incubation. Arsenic showed similar behaviour to Fe. Zn tended to have a higher affinity to the biochar, as compared to Mn. Immobilization of Pb occurred regardless of whether or not the biochar is present

Depositional environment of the Gombe Formation in the Gongola sub-basin of the northern Benue trough: Using grain size parameters

The depositional environment of the Gombe Formation was determined using grain size parameters in which sixteen sandstone samples and ninety nine pebbles were subjected to granulometric and pebbles morphometric analysis respectively. The granulometric analysis for the sixteen (16) samples of the Gombe Formation show an average graphic mean of 2.51ϕ (fine grained sandstone), mean standard deviation of 0.58ϕ (moderately well sorted sandstone), mean skewness value of 0.09ϕ (nearly symmetrical) and mean kurtosis value of 0.89ϕ (platykurtic). The Bivariate plot of standard deviation vs. skewness indicated dominance of fluvial environment. While the probability curves plots showed a dominance of three sand populations  indicating influence of marine processes. Environmental discrimination formulae for Y1, Y2 and Y3 indicated dominance of Aeolian, shallow agitated marine environment and shallow marine environment respectively. The plots of Y2 vs.Y1 and Y3 vs. Y2 showed a dominance shallow marine environment. The morphometric analysis indicates both fluvial and beach environment with dominance of fluvial environment.Keywords: Gombe Formation, Gongola Sub-Basin, Pebbles Morphology,  Granulometric analysis, grain siz