Successful disabling of the 5' UTR of HCV using adeno-associated viral vectors to deliver artificial primary microrna mimics

dissertation submitted to the Faculty of Health Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine. Johannesburg, 2015Chronic hepatitis C virus (HCV) infection is a major health concern and is strongly associated with cirrhosis, hepatocellular carcinoma and liver related mortality. The current standard treatment for HCV is a combination of interferon-based therapies and ribavirin, which only produces sustained viral suppression in 40-50% of patients. Thus, the development of new treatments for HCV infection is critical. The HCV genome is the template for both protein translation and viral replication and, being RNA, is amenable to direct genetic silencing by RNA interference (RNAi). HCV is a highly mutable virus with error prone RNA replication and it has been previously reported that the virus can escape RNAi-mediated treatments through various point mutations. This has highlighted the importance of developing RNAi-based therapy that simultaneously targets multiple regions of the HCV genome. Thus, five artificial primary miRNA (pri-miRNA) were designed to mimic the naturally occurring monomeric pri-miRNA-31. The natural guide sequence on the 5’ arm of the pri-miRNA-31 was replaced with sequences complementary to different regions of the 5’ UTR of HCV. Potent knockdown of an HCV reporter was seen with four of the five constructs, and these were used to generate polycistronic cassettes, which showed impressive silencing of an HCV target. To further their application as a gene therapy recombinant adeno-associated viral (rAAV) vectors that express the polycistronic pri-miRNA mimics were generated. Two different promoter sequences were used to direct the expression of the polycistronic constructs. Ubiquitously expressed CMV and liver-specific mTTR promoters were used to generate rAAVs. All of the vectors enter liver- derived cells efficiently and significantly knock down the expression of an HCV target and showed dramatic inhibition of HCV replicon replication. The expressed polycistronic pri-miRNA mimics did not induce any off-target effects, such as stimulation of the immune response and saturation of the RNAi pathway. All the pri-miRNA mimics within the polycistronic cassettes were processed according to their intended design. The anti-HCV rAAVs developed have the potential to be an effective therapy that may contribute to the eradication of HCV

Vicarious Learning through Informational Interviews: A New Experiential Learning Tool

Many students find it difficult to transition into the workforce successfully. They often accept unsuitable positions through happenstance rather than actively planning their career trajectories. This is due to their unawareness of career exploration and mapping. We use informational interviewing as an in class experiential learning assignment to solve this problem. The assignment gives students the opportunity to source information from industry experts and expand their professional network. It helps students develop their professional presence, find careers of interest, and ultimately succeed in their transition into the workforce

The smoking of dagga (Indian hemp) among the native races of South Africa, and the resultant evils

PART I, Deals with the Smoking of Dagga ameng the various Dative races of South Africa. This has been gone into fully as the literature on the subject is scanty. Further the description is a general one and does not apply to any tribe in particular. Although somewhat of a digression the question of "Black Peril" cases has been included, because many people believe Dagga to be one of' the causal factors.PART II. Deals with the Insanity resulting from Dagga smoking. The subject has been treated in the manner usually adopted in text books. Any figures quoted are entirely original and are in all instances vouched for by statistics compiled from case sheets

Characterisation of Cryogenic Material Properties of 3D-Printed Superconducting Niobium using a 3D Lumped Element Microwave Cavity

We present an experimental characterisation of the electrical properties of 3D-printed Niobium. The study was performed by inserting a 3D-printed Nb post inside an Aluminium cylindrical cavity, forming a 3D lumped element re-entrant microwave cavity resonator. The resonator was cooled to temperatures below the critical temperature of Niobium (9.25K) and then Aluminium (1.2K), while measuring the quality factors of the electromagnetic resonances. This was then compared with finite element analysis of the cavity and a measurement of the same cavity with an Aluminium post of similar dimensions and frequency, to extract the surface resistance of the Niobium post. The 3D-printed Niobium exhibited a transition to the superconducting state at a similar temperature to the regular Niobium, as well as a surface resistance of $3.1\times10^{-4}$ $\Omega$. This value was comparable to many samples of traditionally machined Niobium previously studied without specialised surface treatment. Furthermore, this study demonstrates a simple new method for characterizing the material properties of a relatively small and geometrically simple sample of superconductor, which could be easily applied to other materials, particularly 3D-printed materials. Further research and development in additive manufacturing may see the application of 3D-printed Niobium in not only superconducting cavity designs, but in the innovative technology of the future.Comment: 5 pages, 4 figure

The ORGAN Experiment: An axion haloscope above 15 GHz

We present first results and future plans for the Oscillating Resonant Group AxioN (ORGAN) experiment, a microwave cavity axion haloscope situated in Perth, Western Australia designed to probe for high mass axions motivated by several theoretical models. The first stage focuses around 26.6 GHz in order to directly test a claimed result, which suggests axions exist at the corresponding mass of $110~\mu$eV. Later stages will move to a wider scan range of 15-50 GHz ($60-210~\mu$eV). We present the results of the pathfinding run, which sets a limit on $g_{a\gamma\gamma}$ of $2.02\times 10^{-12}$eV$^{-1}$ at 26.531 GHz, or 110~$\mu$eV, in a span of 2.5 neV (shaped by the Lorentzian resonance) with $90 \%$ confidence. Furthermore, we outline the current design and future strategies to eventually attain the sensitivity to search for well known axion models over the wider mass range.Comment: 15 pages, 5 figures. V2: As published in Physics of Dark Univers