GPS Modeling of the Ionosphere Using Computer Neural Networks

This chapter presents a detailed description to modeling the ionosphere using the method of computer neural networks and data from the GPS (Global Positioning System). The chapter essentially motivates the use of artificial neural networks for ionospheric modeling, and it presents a detailed description of the processes and considerations involved in using artificial neural networks to model the ionosphere. Specific illustration was done using vertical total electron content (VTEC) data from 14 GPS stations in Nigeria that cover the period from years 2011 to 2016, to develop a neural network model of the GPS-TEC over Nigeria in space and in time. Sample simulations from the developed model shows that the model was accurate in predicting the VTEC variation patterns in terms of diurnal, seasonal, annual, longitudinal and latitudinal variations. A comparative analysis between the neural network predictions and those of other models like the IRI-Plas and NeQuick showed that predictions from the neural network model were predominantly more accurate

Developing an ionospheric map for South Africa

This thesis describes the development of an ionospheric map for the South African region using the current available resources. The International Reference Ionosphere (IRI) model, the South African Bottomside Ionospheric Model (SABIM), and measurements from ionosondes in the South African Ionosonde Network, were incorporated into the map. An accurate ionospheric map depicting the foF2 and hmF2 parameters as well as electron density profiles at any location within South Africa is a useful tool for, amongst others, High Frequency (HF) communicators and space weather centers. A major product of the work is software, written in MATLAB, which produces spatial and temporal representations of the South African ionosphere. The map was validated and demonstrated for practical application, since a significant aim of the project was to make the map as applicable as possible. It is hoped that the map will find immense application in HF radio communication industries, research industries, aviation industries, and other industries that make use of Earth-Space systems. A potential user of the map is GrinTek Ewation (GEW) who is currently evaluating it for their purpose

The relation of H2CO, 12CO, and 13CO in molecular clouds

Aims. We seek to understand how the 4.8 GHz formaldehyde absorption line is distributed in the MON R2, S156, DR17/L906, and M17/M18 regions. More specifically, we look for the relationship among the H2CO, 12CO, and 13CO spectral lines. Methods. The four regions of MON R2 (60'x90'), S156 (5'0x70'), DR17/L906 (40'x60'), and M17 /M18 (70'x80')were observed for H2CO (beam 10'), H110a recombination (beam 10'), 6 cm continuum (beam 10'), 12CO (beam 1'), and 13CO (beam 1'). We compared the H2CO,12CO,13CO, and continuum distributions, and also the spectra line parameters of H2CO,12CO, and 13CO. Column densities of H2CO,13CO, and H2 were also estimated. Results. We found out that the H2CO distribution is similar to the 12CO and the 13CO distributions on a large scale. The correlation between the 13 CO and the H2CO distributions is better than between the 12CO and H2CO distributions. The H2CO and the 13CO tracers systematically provide consistent views of the dense regions. T heir maps have similar shapes, sizes, peak positions, and molecular spectra and present similar centr al velocities and line widths. Such good agreement indicates that the H2CO and the 13CO arise from similar regions.Comment: 21 pages, 12 figures published, 201

Addressing operational complexities through re-inventing leadership style:A systemic leadership intervention

This research investigates leadership practice in private organisations in Nigeria. It focuses on learning about theapplication of leadership styles to address operational complexities in organisations. The research is based on acase study of a commercial livestock farm in Nigeria using systemic intervention as the methodology. Datacollection tools, such as a workshop, semi-structured interviews, boundary setting and participant observation,were applied. Key leadership issues identified in the case study were addressed via the creation of an effectiveapproach from different leadership underpinnings. Part of thefindings is the difficulty in sustaining the imple-mentation of a particular leadership style(s) due to unstructured nature of complexities involved in the deter-mination of suitable leadership style at different stages of the research. The research wrapped up with thesuggestion for further research on systemic leadership intervention to consider exploring the public sector, as wellas the need to further review on the use of CATWOE in the research process, to avoid the occurrence of mar-ginalisation in its apllication

SMEs Succession Education and Family Business Succession: A Conceptual Review

This research focused on investigating the effect of succession education on family-owned business succession in small and medium-scale enterprises in Nigeria. The study adopted a conceptual review of extant literature and theories. Findings from extant literature revealed that level of education, on-the-job training, mentorship and willingness to learn have a strong impact on family-owned business succession in small and medium-scale enterprises. Succession education can form effective resilience to address the challenge of family business succession. The study highlighted the necessity for family-owned SMEs to promote succession education for their potential successors since the higher the level of education of the incumbent and successors are, the more likely the success of the succession process. It is also recommended for the potential successors to be exposed to learning the business early to enable them to acquire adequate on-the-job training for a smooth transfer of ownership and entrepreneurship which is intended to enhance sustainability among Nigerian family-owned businesses

A transcriptomics-based drug repositioning approach to identify drugs with similar activities for the treatment of muscle pathologies in spinal muscular atrophy (SMA) models

© 2023 The Author(s). Published by Oxford University Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by the reduction of survival of motor neuron (SMN) protein levels. Although three SMN-augmentation therapies are clinically approved that significantly slow down disease progression, they are unfortunately not cures. Thus, complementary SMN-independent therapies that can target key SMA pathologies and that can support the clinically approved SMN-dependent drugs are the forefront of therapeutic development. We have previously demonstrated that prednisolone, a synthetic glucocorticoid (GC) improved muscle health and survival in severe Smn-/-;SMN2 and intermediate Smn2B/- SMA mice. However, long-term administration of prednisolone can promote myopathy. We thus wanted to identify genes and pathways targeted by prednisolone in skeletal muscle to discover clinically approved drugs that are predicted to emulate prednisolone's activities. Using an RNA-sequencing, bioinformatics, and drug repositioning pipeline on skeletal muscle from symptomatic prednisolone-treated and untreated Smn-/-; SMN2 SMA and Smn+/-; SMN2 healthy mice, we identified molecular targets linked to prednisolone's ameliorative effects and a list of 580 drug candidates with similar predicted activities. Two of these candidates, metformin and oxandrolone, were further investigated in SMA cellular and animal models, which highlighted that these compounds do not have the same ameliorative effects on SMA phenotypes as prednisolone; however, a number of other important drug targets remain. Overall, our work further supports the usefulness of prednisolone's potential as a second-generation therapy for SMA, identifies a list of potential SMA drug treatments and highlights improvements for future transcriptomic-based drug repositioning studies in SMA.Peer reviewe