Electrostatic Waves in Magnetized Electron-Positron Plasmas

The behavior of arbitrary amplitude linear and nonlinear electrostatic waves that propagate in a magnetized four component, two-temperature, electron-positron plasma is presented. The characteristics of the dispersive properties of the associated linear modes using both fluid and kinetic theory are examined. The fluid theory analysis of the electrostatic linear waves shows the existence of electron acoustic, upper hybrid, electron plasma and electron cyclotron branches. A kinetic theory analysis is then used to study the acoustic mode, in particular the effect of Landau damping, which for the parameter regime considered is due to the cooler species. Consequently, it is found that a large enough drift velocity is required to produce wave growth. Nonlinear electrostatic solitary waves (ESWs), similar to those found in the broadband electrostatic noise observed in various regions of the earth’s magnetosphere is further investigated. A set of nonlinear differential equations for the ESWs, which propagate obliquely to an external magnetic field is derived and numerically solved. The effect of various plasma parameters on the waves is explored and shows that as the electric driving force is increased, the electric field structure evolves from a sinusoidal wave to a spiky bipolar form. The results are relevant to both astrophysical environments and related laser-induced laboratory experiments

Assuring the Quality of Teaching at Makerere University in Uganda: Practices and Experiences of Academics and Students

Quality is an ethos in academia and assuring it is top of the agenda at many universities. Since the 1990s, substantial research has been conducted on the quality assurance systems of developed countries with advanced higher education systems. However, literature on quality assurance systems in the context of Sub-Saharan Africa is limited. The study examined the practices and experiences of stakeholders at the student-academic interface in assuring the quality of teaching at Makerere University. A case study design was employed and respondents included academics and final-year students. Data was collected through documents review, interviews and focus group discussions. Thematic analysis and content analysis were used to analyse the data. The findings demonstrate that the university employs five practices to assure the quality of teaching, namely, recognition of teaching, student evaluation of teaching, pedagogical training, monitoring and supervision of teaching, competence-based deployment and interfacing. The findings further show that stakeholders had varying experiences of teaching quality assurance practices

Good Teaching: Aligning Student and Administrator Perceptions and Expectations

Literature attests to limited systematic inquiry into students’ conceptions of good teaching in higher education. Resultantly, there have been calls for engaging students in construing what makes good university teaching and in developing a richer conception of teaching excellence. This interpretivist study that is based on views of final year university students from six academic disciplines investigated students’ conceptions of good teaching at Makerere University in Uganda. Students conceived good teaching as being student-centred, demonstrating strong subject and pedagogical knowledge, being approachable, being responsive, being organised, and being able to communicate well. Most of the conceptions of good teaching hinge on what the teacher does (the means) rather than affording high quality student learning (an end). It can therefore been concluded that good teaching is a multi-dimensional construct that defies a single definition and cannot be assured and assessed using a single indicator

Making Sense of an Elusive Concept: Academics’ Perspectives of Quality in Higher Education

Objective: Since the 1990s studies on how stakeholders in higher education perceive quality have burgeoned. Nevertheless, the majority of studies on perception of quality in higher education focus on students and employers. The few studies on academics’ perceptions of quality in higher education treat academics as a homogeneous group and, therefore, do not point out cross-disciplinary perspectives in perceptions of quality. This article explores how academics across six disciplines perceive quality in higher education. Method: The article is anchored in the interpretivist paradigm. Data was collected from 14 purposely selected academics at Makerere University in Uganda and analyzed using thematic analysis. Results: The findings show that academics perceive quality in higher education as transformation, fitness for purpose, and exceptional. The findings further demonstrate that a stakeholder group or an individual stakeholder can subscribe to a notion of quality in higher education but voice divergent views on its variants. Similarly, the academic discipline, the perceived purpose of higher education, and the problems within a higher education system have an influence on stakeholders’ conception of quality in higher education. Conclusions: From the findings it can be inferred that quality in higher education defies a single definition and that stakeholders’ perceptions of quality do not take place in a vacuum. Implication for Theory and/or Practice: The multidimensional nature of quality and the contestations around it necessitate a multidimensional approach to assuring and assessing it

Understanding the basis of specificity of Bacillus thuringiensis Cry2A toxins towards Aedes aegypti

Bacillus thuringiensis is a gram-positive spore forming soil bacterium and one of the most successful, environmentally friendly, intensively used and studied microbial insecticides. The major characteristic of Bt is the production of proteinaceous crystals containing toxins with specific activity against many insects including diptera, lepidoptera and coleoptera. Understanding the basis of specificity of Cry2A toxins of Bacillus thuringiensis is important for the risk assessment of novel insecticidal toxins from this bacterium to ensure that they are not detrimental to non-target organisms within the environment. Cry2A toxins are a group of three-domain proteins with highly similar sequences, and this project sought to understand the basis of the specificity of Cry2A toxins against the mosquito Aedes aegypti. This was investigated through finding out which domain(s) and /or amino acid motif(s) were crucial for activity. Cry2A toxins in our lab were characterised and expressed, after which bioassays were conducted against Aedes aegypti, and several hybrid toxins and mutants were created based on the bioassay results and were used to determine the relationship between amino acid sequence and toxicity through bioassay and bioinformatic analyses. Domain I was found to be responsible for the specificity of Cry2A toxins against Aedes aegypti, specifically the 49-amino acids comprising the N-terminal region, which folds back onto domain II. The specificity-determining region was further found to consist of four amino acids (E/RTD) within this N-terminal region. Finally, the mechanism of proteolytic activation of Cry2A by Aedes aegypti was studied in vitro, leading to a proposed model of proteolytic activation, which was contrary to previously published reports

Hierarchical Neural Networks (HNN): Using TensorFlow to build HNN

This research demonstrates the use of TensorFlow to build a Hierarchical Neural Network (HNN). Constructing and engineering neural networks to maximize accuracy and efficiency is an active field of research in machine learning. HNN, along with several other applications of split networks have been developed as recently as 2017. However, implementations thus far have required custom-built and coded HNNs. The research conducted here uses TensorFlow to validate this structure by building entirely separate neural nets with logical relations between the output of one net and the inputs of the nets that are downstream. Research has shown that Hierarchical Neural Networks can increase training speed and reduce compute resources. The validation results of HNN using the Fashion-MNIST dataset demonstrate a prediction accuracy of 99.49%, 95.96%, and 88.84% for coarse, medium, and fine level classification, respectively, in which the fine level classification accuracy is greater than the baseline model

Linear and nonlinear fluctuations in electron-positron plasmas.

Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2009.The behaviour of both small amplitude and arbitrary amplitude nonlinear electrostatic fluctuations are studied in electron-positron plasmas. The propagation characteristics of associated linear modes are also examined for selected plasma models. In the case of the four component, two-temperature, electron-positron plasma, three particular features are investigated. The first investigates existence conditions of the range of possible electrostatic linear waves that can propagate in a two-temperature electron-positron plasma, the study being particularly relevant to both astrophysical situations and laser induced fusion experiments. The second includes the development and investigation of the mKdV-ZK equation governing the three dimensional propagation of solitary waves in a magnetized plasma. The third application is the investigation of nonlinear electrostatic solitary waves structures, similar to those found in the broadband electrostatic noise observed in various regions of the earth’s magnetosphere. The study ends by considering relativistic effects on solitary waves in an electron-positron plasma

A simulation to minimize traffic violation in Nigeria through the use of smart spike strip

Traffic light violations always have negative effects on lives and environment and to quantify these negative effects is complex. For traffic light violation to be mitigated or eliminated, gathering of information on traffic incidents such as nature of the road, congestion spots, and volume of traffic on each road cannot be overemphasized. The elimination of traffic light violation particularly in developing countries like Nigeria may not be a realistic goal, but controlling or managing it to reduce the intensity of violation may be achievable. The unbearable traffic congestion is the highest cause of traffic light violation, most especially within the rush hours of the morning when individuals go to work (between 7.00am – 8.00am) and coming back in the evenings (4.00 – 5.00pm and 6.00 – 7.00pm) at most cross roads in Kaduna metropolis. In this research work, an algorithm is developed to control the traffic light violation on one lane of a traffic junction by introducing the smart spike strip which is synchronized with the traffic light control system. The implementation of the algorithm to simulate the control of the traffic light violation on a traffic junction is achieved using Visual Studio 2012 IDE as a platform for the simulation. Screenshots to illustrate the different of the vehicles and lanes which are states static, ready and motion states shown

The relationship between Counseling Psychology and Positive Psychology

The aim of this chapter is to explore the relation between the professional specialty of counseling psychology and positive psychology. Following a brief historical overview of counseling psychology, we explore its theoretical convergence with positive psychology and examine how the ideas from positive psychology have been received by counseling psychologists. We argue that although counseling psychology has its roots in ideas that are consistent with positive psychology, the profession has developed a broad practice range in recent decades accommodating a diversity of ways of working, many of which prioritize working with distress and its origins over seeking to enhance and build on existing strengths. As such, the positive psychology movement can offer a new impetus for the profession of counseling psychology to reexamine its fundamental assumptions and reflect on its training curriculum. Based on this overview, we conclude that further bridges need to be built between positive psychology and counseling psychology. Our goal is to encourage counseling psychologists to engage more fully with the ideas and research of positive psychology