The North-West University is a newly merged institution from 1 January 2004 onwards with three campuses at Potchefstroom, Mahikeng and Vanderbijlpark, South Africa. The Potchefstroom Campus is the largest, and the head office of the University is situated at this location. With its merged status, the North-West University became one of the largest universities in South Africa and has 64 081 students .The universities that merged to form this institution are the Potchefstroom University for Christian Higher Education and the University of North-West . These two campuses form the main hubs of the university, with the Potchefstroom campus catering to Afrikaans speakers and the Mahikeng campus being broader in orientation. Wikipedia.
North West University South Africa | Date: 2016-09-23
This invention relates to a method of producing a recombinant enzyme, more particularly, this invention relates to a method of producing water soluble enzymatically active recombinant glycine N-acyltransferase (GLYAT (E.G. 18.104.22.168)), including the steps of providing a suitable expression host; preparing a vector including a gene for expressing GLYAT in the expression host to form an expression plasmid; transforming the host with the expression plasmid to form an expression system; expressing the GLYAT gene in the expression system; and separating the expressed GLYAT from the expression system.
Loots D.T.,North West University South Africa
Antimicrobial Agents and Chemotherapy | Year: 2014
The most common form of drug resistance found in tuberculosis (TB)-positive clinical samples is monoresistance to isoniazid. Various genomics and proteomics studies to date have investigated this phenomenon; however, the exact mechanisms relating to how this occurs, as well as the implications of this on the TB-causing organisms function and structure, are only partly understood. Considering this, we followed a metabolomics research approach to identify potential new metabolic pathways and metabolite markers, which when interpreted in context would give a holistic explanation for many of the phenotypic characteristics associated with a katG mutation and the resulting isoniazid resistance in Mycobacterium tuberculosis. In order to achieve these objectives, gas chromatography-time of flight mass spectrometry (GCxGC-TOFMS)-generated metabolite profiles from two iso-niazid- resistant strains were compared to a wild-type parent strain. Principal component analyses showed clear differentiation between the groups, and the metabolites best describing the separation between these groups were identified. It is clear from the data that due to a mutation in the katG gene encoding catalase, the isoniazid-resistant strains experience increased susceptibility to oxidative stress and have consequently adapted to this by upregulating the synthesis of a number of compounds involved in (i) increased uptake and use of alkanes and fatty acids as a source of carbon and energy and (ii) the synthesis of a number of compounds directly involved in reducing oxidative stress, including an ascorbic acid degradation pathway, which to date hasn't been proposed to exist in these organisms. Copyright © 2014 American Society for Microbiology. All Rights Reserved.
Potgieter M.S.,North West University South Africa
Space Science Reviews | Year: 2013
The global modulation of galactic cosmic rays in the inner heliosphere is determined by four major mechanisms: convection, diffusion, particle drifts (gradient, curvature and current sheet drifts), and adiabatic energy losses. When these processes combine to produce modulation, the complexity increases significantly especially when one wants to describe how they evolve spatially in all three dimensions throughout the heliosphere, and with time, as a function of solar activity over at least 22 years. In this context also the global structure and features of the solar wind, the heliospheric magnetic field, the wavy current sheet, and of the heliosphere and its interface with the interstellar medium, play important roles. Space missions have contributed significantly to our knowledge during the past decade. In the inner heliosphere, Ulysses and several other missions have contributed to establish the relative importance of these major mechanisms, leading to renewed interest in developing more sophisticated theories and numerical models to explain these observations, and to understand the underlying physics that determines galactic cosmic ray modulation at Earth. An overview is given of some of the observational and modeling highlights over the past decade. © 2011 Springer Science+Business Media B.V.
Moraal H.,North West University South Africa
Space Science Reviews | Year: 2013
The temporal variation of the cosmic-ray intensity in the heliosphere is called cosmic-ray modulation. The main periodicity is the response to the 11-year solar activity cycle. Other variations include a 27-day solar rotation variation, a diurnal variation, and irregular variations such as Forbush decreases. General awareness of the importance of this cosmic-ray modulation has greatly increased in the last two decades, mainly in communities studying cosmogenic nuclides, upper atmospheric physics and climate, helio-climatology, and space weather, where corrections need to be made for these modulation effects. Parameterized descriptions of the modulation are even used in archeology and in planning the flight paths of commercial passenger jets. The qualitative, physical part of the modulation is generally well-understood in these communities. The mathematical formalism that is most often used to quantify it is the so-called Force-Field approach, but the origins of this approach are somewhat obscure and it is not always used correct. This is mainly because the theory was developed over more than 40 years, and all its aspects are not collated in a single document. This paper contains a formal mathematical description intended for these wider communities. It consists of four parts: (1) a description of the relations between four indicators of "energy", namely energy, speed, momentum and rigidity, (2) the various ways of how to count particles, (3) the description of particle motion with transport equations, and (4) the solution of such equations, and what these solutions mean. Part (4) was previously described in Caballero-Lopez and Moraal (J. Geophys. Res, 109: A05105, doi: 10.1029/2003JA010358 2004). Therefore, the details are not all repeated here. The style of this paper is not to be rigorous. It rather tries to capture the relevant tools to do modulation studies, to show how seemingly unrelated results are, in fact, related to one another, and to point out the historical context of some of the results. The paper adds no new knowledge. The summary contains advice on how to use the theory most effectively. © 2011 Springer Science+Business Media B.V.
Potgieter M.S.,North West University South Africa
Living Reviews in Solar Physics | Year: 2013
This is an overview of the solar modulation of cosmic rays in the heliosphere. It is a broad topic with numerous intriguing aspects so that a research framework has to be chosen to concentrate on. The review focuses on the basic paradigms and departure points without presenting advanced theoretical or observational details for which there exists a large number of comprehensive reviews. Instead, emphasis is placed on numerical modeling which has played an increasingly significant role as computational resources have become more abundant. A main theme is the progress that has been made over the years. The emphasis is on the global features of CR modulation and on the causes of the observed 11-year and 22-year cycles and charge-sign dependent modulation. Illustrative examples of some of the theoretical and observational milestones are presented, without attempting to review all details or every contribution made in this field of research. Controversial aspects are discussed where appropriate, with accompanying challenges and future prospects. The year 2012 was the centennial celebration of the discovery of cosmic rays so that several general reviews were dedicated to historical aspects so that such developments are briefly presented only in a few cases.
Pieters M.,North West University South Africa
Blood | Year: 2013
Fibrinogen γ' is known to influence fibrin clot structure in purified experimental models, but little is known regarding its influence on clot structure in plasma. Furthermore, the environmental and biological factors that affect its concentration are poorly described. We analyzed fibrinogen γ', total fibrinogen concentration, and fibrin clot structure in 2010 apparently healthy black South Africans and related them to traditional cardiovascular disease (CVD) risk factors. Fibrinogen γ' generally increased with increasing fibrinogen concentration, but a decreased γ'/total fibrinogen ratio was found at the highest total fibrinogen concentrations. Clot maximum absorbance increased with total fibrinogen and fibrinogen γ', but decreased with γ'/total fibrinogen ratio. Clot lysis time showed a stronger relationship with fibrinogen γ' than with total fibrinogen, whereby increased fibrinogen γ' delayed clot lysis. CVD risk factors (excluding fibrinogen) explained 20% and 3%, respectively, of the variance in fibrinogen γ' and the γ'/total fibrinogen ratio, with C-reactive protein making the biggest contribution. More than 50% of the variance in fibrinogen γ' and γ'/total fibrinogen ratio is explained by factors other than total fibrinogen or other traditional CVD risk factors. Our data show that fibrinogen γ' modulates plasma clot structure and fibrinolysis and is also influenced by factors other than fibrinogen.
North West University South Africa | Date: 2014-03-12
A plant supporting formulation which is also suitable for use as a delivery vehicle, or a component of a delivery vehicle, for the delivery of one or more phytologically beneficial substances to a plant, and for enhancing the translocation of such delivered substance(s) in or on the plant, the formulation comprising a micro-emulsion constituted by a dispersion of vesicles or microsponges of a fatty acid based component in an aqueous carrier, the fatty acid based component comprising at least one long chain fatty acid based substance selected from the group consisting of free fatty acids and derivatives of free fatty acids. The dispersion is preferably characterized in that at least 50% of the vesicles or microsponges are of a diametrical size of between 50 nm and 5 micrometer. The dispersion is further also characterized in that the micro-emulsion has a zeta potential of between 25 mV and 60 mV.
North West University South Africa | Date: 2016-11-23
A circuit and a method of using a circuit to drive an insulated gate semiconductor device (12) comprising as a first terminal a gate (20) and at least second and third terminals (22, 24). The circuit comprises a charge storage device (14) and switching means (16, 116) connected in a series circuit to the gate of the semiconductor device to transfer charge from the charge storage device to the gate of the semiconductor device so as to switch the semiconductor device between one of an on state and an off state and the other of the on state and the off state. Sufficient charge to switch the device on is transferred from the charge storage device to the gate during a charge transfer stage which is complete prior to a change in the current flow between the second and third terminals (22, 24) of the semiconductor device and during which a voltage on the gate exceeds and then remains above a threshold voltage between the gate and the third terminal of the device.
South African Nuclear Energy Corporation and North West University South Africa | Date: 2014-11-04
This invention relates to a pharmaceutical composition for parenteral or oral administration containing a radioactive compound which can be used diagnostically or therapeutically. The composition comprises a micro-emulsion constituted by a dispersion of vesicles or microsponges of a fatty acid based component in an aqueous or other pharmacologically acceptable carrier in which nitrous oxide is dissolved, the fatty acid based component comprising at least one long chain fatty acid based substance selected from the group consisting of free fatty acids and derivatives of free fatty acids, and the radioactive compound.
North West University South Africa | Date: 2014-05-20
A formulation for administration of at least one therapeutic mammalian protein to a mammal or a protein selected from the group, and for enhancing the absorption, distribution and release of the at least one therapeutic mammalian protein in or on the mammal, comprising at least one therapeutic mammalian protein in a micro-emulsion comprising a dispersion of vesicles or microsponges of a fatty acid based component in an aqueous or other pharmacologically acceptable carrier in which nitrous oxide is dissolved, the fatty acid based component comprising at least one long chain fatty acid based substance selected from the group consisting of free fatty acids and derivatives of free fatty acids. A method for effective delivery of at least one therapeutic mammalian protein to a mammal and for enhancing the therapeutic efficacy of such at least one therapeutic mammalian protein, comprising the step of administering the at least one therapeutic mammalian protein to the mammal in such a formulation.