Longitudinal Designs, Associated Theories, and Communication Research in Africa

This paper is an effort to promote the adoption of longitudinal designs and mainstream them in communication research in Africa, especially Nigeria. The concept and types of longitudinal research are explained. The reasons why longitudinal approaches are indispensable to communication research are discussed. This task is crucial since the trend among African and Nigerian researchers is to consign longitudinal approaches to the sidelines while overly emphasizing cross-sectional designs. The paper takes a cursory journey down the road of media effects theory, among others, to show that the cumulative effects of the media can better be researched with longitudinal systems than with crosssectional ones. Three empirical works are reviewed to show the weaknesses of using only cross-sectional methodologies to study every kind of communication problem while strengthening the case for longitudinal systems. The recommendations expose researchers to the threat of extinction that longitudinal designs face as well as motivate the longitudinal habit

OpenFlow Communications and TLS Security in Software-Defined Networks

The adoption of Software-Defined Networking (SDN), a networking approach where data traffic control and execution are made independent of each other, is an ongoing process that some companies are considering as an option but have not embraced yet due to different factors. Incorporating this new paradigm into an existing network defines a shift in networking technology with different benefits expected to derive from this implementation. These benefits include (1) the ability to use customised business specific applications, (2) reduce overhead costs on legacy network infrastructure, taking full control of network, (3) reduce network application update time, increase productivity, and (4) apply increased security among others. However, the security of SDN itself has been a subject of debate. This is mainly because, the communication standard used by SDN, known as OpenFlow, and developed by the Open Network Foundation, does not enforce the implementation of the Transport Layer Security (TLS) but defines it only as optional. This could then make the network infrastructure vulnerable and therefore affect the overall security of a company. Security plays a significant part in an organisation and it is one of the determinants of the success of SDN. OpenFlow security relies on the implementation of TLS, which has been proven vulnerable, and therefore bringing to mind the question on how secure organisation's data is when the implementation of secure data transfer is treated with laxity. This paper focuses on securing OpenFlow communication in SDN by summarising TLS security flaws and recommending ways of improving TLS security thereby securing OpenFlow communication

Endo-Helminth Fauna of the Rainbow Lizard (Agama Agama)

This parasitological study was carried out between February and May 2019 to determine the prevalence and intensity of helminthiasis in the rainbow lizard (Agama agama) in Okrika, Rivers State, Nigeria. A total of one hundred and fifty-one (151) specimens made up of 93 males and 75 females were caught by a local netting system during the day and anaesthesized with chloroform. Samples were collected from two stations (Ogoloma-Ama and Oba-Ama). After dissection, the esophagus, stomach, small intestine, rectum, liver, lungs, urinary bladder, heart and body cavity were searched for helminths using conventional methods. Five species of helminths belonging to Nematoda - Strongyluris brevicaudata, Parapharyngodon awokoyai, encysted Ascaridida larva, Cestoda - Oochoristica sp. and Trematoda - Mesocoelium spp -  were recovered from infected lizards. Helminths infected one hundred and twenty-three (123) (82%) of the lizards. In Oba-Ama, forty-five (45) (76.3%) out of 59 and in Ogoloma-Ama, seventy-eight (78) (84.8%) out of 92 were infected with helminths. By abundance, in both locations, the males were more infected than their female counterparts with a prevalence of 51(93%) and 72(75%) (P<0.05), respectively. This study has revealed the helminth parasites infecting the agamid lizard of Rivers State, Nigeria. It has also shown some unidentified species of Mesocoelium and  Oochoristica sp. Additionally the trapping system used was also found to be effective and efficient

The politics and administration of community development in the Rivers State of Nigeria

This thesis is about the politics and administration of community development in the Rivers State of Nigeria, Prior to the creation of the Rivers State in 1967, efforts had been made by the people to improve their local communities; and the people's attainment of political autonomy presented enormous challenge in the task of local development. Today, both at the local and state government levels, resources are mobilised so as to improve living conditions in the state. There are new expectations in a new state. At the local level, there are different participants in community development, namely, planning committees, chiefs, elders, youths and communal patrons. However, neither are all participants in community development united, nor is there a widespread consensus about political interests and values among the people. In some communities, there are political disputes and power struggles among the different participants, thus affecting the pace of local development. Nevertheless, all the participants appreciate the need for development. At the official level, there are planning bodies. Rural Development Officers, Sole Authorities, Permanent Secretaries and Commissioners who make or influence decisions in respect of community development. Of the different participants in community development, this work shows that those of the patron class are the most eminent, not only in the locality but also in the public service. Hence the patron is in a position to play a 'linkage role' between the locality and Port Harcourt, the seat of administration. The linkage role of the patron largely explains the fact that rural polyethnic politics is projected into Port Harcourt, Hence this thesis casts light on: the politics of communalism, the activities of the. different participants in community development and the emergence of community influentials. One of the main themes of the thesis is that, given the general pattern of expectations in a new state, even as an administrator, the community influential (the patron) will always protect the interest (whether they be real or imagined) of his people. In short, the main argument is that administration has no purpose other than to serve the political goals of the different communities in the State

Hybrid Approach for Detecting and Classifying Power Quality Disturbances Based on the Variational Mode Decomposition and Deep Stochastic Configuration Network

This paper proposes a novel, two-stage and hybrid approach based on variational mode decomposition (VMD) and the deep stochastic configuration network (DSCN) for power quality (PQ) disturbances detection and classification in power systems. Firstly, a VMD technique is applied to discriminate between stationary and non-stationary PQ events. Secondly, the key parameters of VMD are determined as per different types of disturbance. Three statistical features (mean, variance, and kurtosis) are extracted from the instantaneous amplitude (IA) of the decomposed modes. The DSCN model is then developed to classify PQ disturbances based on these features. The proposed approach is validated by analytical results and actual measurements. Moreover, it is also compared with existing methods including wavelet network, fuzzy and S-transform (ST), adaptive linear neuron (ADALINE) and feedforward neural network (FFNN). Test results have proved that the proposed method is capable of providing necessary and accurate information for PQ disturbances in order to plan PQ remedy actions accordingly

Condition Monitoring and Fault Detection for Electrical Machines Using Advanced Sensing Techniques Based on Fibre Bragg Gratings

Emerging techniques are being researched to expand the suite of condition monitoring solutions available for electric machines to adapt to a world of net zero carbon emissions. This research investigates the use of fibre bragg gratings (FBG) for condition monitoring and fault detection in three 2.2kW induction motors (IMs) using stray flux in a non-invasive manner. Optical fibre is immune to electromagnetic interference (EMI) which is an advantage but limits its direct use for magnetic field sensing. A magnetostrictive transducer, terfenol-D was bonded to FBG to form a composite sensor - FBG-T. The FBG-T was inserted into an acrylic tube - which is unaffected by magnetic field - and then positioned both axially and transversely relative to the machine’s rotor shaft at the drive end (DE). The transverse position showed better repeatability and sensitivity over different operating frequencies. Temperature and magnetic flux calibrations of the FBG-T sensor gave sensitivities of 20.77 picometre per degree Celsius (pm/°C) and 19.38 picometre per micro-tesla (pm/μT) respectively. Various investigations were carried out at different operating frequencies and under three motor conditions viz: healthy, broken rotor and inter-turn short circuit conditions. Experimental results confirm that the FBG-T sensor reliably distinguished each of the three machine conditions using different orders of magnitudes of braggshifts. The FBG-T sensor accurately detected faults with the short circuit condition reaching braggshifts of hundreds of pm. Healthy and broken rotor conditions reached braggshifts in the low–to-mid-hundred and high-hundred pm range respectively. Fast Fourier Transform (FFT) analysis performed on the measured stray flux showed that not only its amplitude but also the harmonic component of its spectrum, affected the magnetostrictive behaviour of the magnetic dipoles of the terfenol-D transducer. This effect was translated into strain on the FBG. The investigation proved that FBG technology can reliably and accurately monitor the condition of the motors as well as detect faults in a non-intrusive manner

Case report of bullous pemphigoid in a 65 year old woman

The unique thing about this case is that it is the first reported case of bullous pemphigoid in the elderly that has been clinically diagnosed with histologic findings highly suggestive of this blistering disorder although an immunofluorescence could not be done due to unavailability in the centre. Patient was managed successfully and discharged home with improvement on subsequent hospital visits. This case report shows how diagnosis of an immunobullous disease was made and managed in a resource poor setting. A descriptive summary of 65-year old black Nigerian woman with bullous pemphigoid covering history, physical examination and management. The main diagnosis was bullous pemphigoid in a recently diagnosed type 2 diabetic. Patient was placed on corticosteroids as well as immunosuppressive agents and diabetes was managed with subcutaneous insulin and oral hypoglycemics with appropriate wound care. Patient showed remarkable improvement after management and was discharged home with subsequent follow up in the clinics. Bullous Pemphigoid (BP) can be diagnosed clinically with a high index of suspicion with the aid of skin biopsy and histology, and can be managed successfully even in a resource poor centre where immunofluorescence facilities are lacking

La economía popular y solidaria en la crianza de la Pachamama: caso de estudio, localidades de la Junta parroquial rural San José, Ecuador

El presente trabajo tiene su fundamento en los resultados de una investigación realizada con el propósito de velar por la crianza de la Pachamama o naturaleza dentro de la Economía Popular y Solidaria. Se realizó un análisis conceptual de esta economía y se determinó que sus organizaciones tienen la responsabilidad de cuidar la Pachamama al momento de ejecutar procesos de producción, distribución, intercambio y consumo de bienes y servicios, ya que la Pachamama es la generadora del SumakKawsay (el Buen Vivir). Se emplearon en forma interrelacionada, métodos teóricos, empíricos y estadísticos.El trabajo presentado demuestra que laactividad económica principal que ejecutan los pobladores de las localidades de la Junta parroquial rural San José constituye la agrícolacon el 72,7 % lo que está ocasionado el deterioro de la Pachamama. Ante lo cual se necesita proponer soluciones sostenibles

Optical FBG-T Based Fault Detection Technique for EV Induction Machines

Abstract: Electric vehicles (EV) represent a key technology to achieve a low-carbon transportation objective, whist induction motors are one of the promising topologies. The reliability of these machines is crucial to minimize the downtime, cost and unwanted human lives. Although several techniques are utilized in the condition monitoring and fault detection of electrical machines, there is still no single technique that provides an all-round solution to fault detection in these machines and thus hybrid techniques are used widely. This paper presents a novel non-invasive optical fiber technique in condition monitoring of induction machines and in the process detecting inter-turn short circuit faults. Owing to optical fiber’s immunity to magnetic flux, a composite FBG-T sensor formed by bonding a giant magnetostrictive transducer, Terfenol-D, onto a fiber Bragg grating is utilized to sense machines’ stray flux as a signature to determine the internal winding condition of the machines. A tri-axial auto datalogging flux meter was used to obtain the stray magnetic flux and test results obtained via LabView were analyzed in MatLab. Experimental and numerical results agree with each other and how that the FBG-T sensor accurately and reliably detected the short-circuit faults. Bragg shifts observed under short-circuit faults were in 100s of picometre range under various operating frequencies compared to the mid-10s of picometre obtained under healthy machine condition. These provide much promise for future EVs