Thesis (PhD)--Stellenbosch University, 2012. / Includes bibliography / ENGLISH ABSTRACT: Mycobacterium tuberculosis, the causative organism of tuberculosis (TB), is a major cause for mortality and morbidity world-wide with a death toll only second to HIV among infectious diseases. Drug resistance is widespread and cases of multiple drug resistant TB (MDR-TB) and extensively drug resistant TB (XDR-TB) have emerged in several countries. Drug treatment is problematic and new drugs are not developed rapidly enough to offset the rapid drug resistance mutation rate of M. tuberculosis. Simple and effective diagnostics are required to contain the spread of the disease as current routine diagnostics are not fulfilling this role. Additionally, current rapid TB diagnostics are out of reach to resource poor settings due to infrastructure, cost and skill requirements. Novel TB diagnostics are thus required that meet these requirements. Mycobacteriophages are phages that infect mycobacteria and could offer a viable and cost effective alternative rapid TB diagnostics. In this study, an affinity-tagged fluorescent reporter mycobacteriophage is described, which was engineered to act as a TB diagnostic. Its performance proved favourable and superior to current existing mycobacteriophage-based TB diagnostics. / AFRIKAANSE OPSOMMING: Mycobacterium tuberculosis, die organisme verantwoordelik vir tuberkulose (TB), is `n groot bron van mortaliteit en morbiditeit wêreldwyd en slegs HIV is verantwoordelik vir groter getalle sterftes as gevolg van n aansteeklike siekte. Middelweerstandigheid is algemeen en gevalle van meervoudigemiddelweerstandige tuberkulose (MDR-TB) en uiters weerstandige tuberkulose (XDR-TB) kom in verskeie lande voor. Antibiotika behandeling is problematies en nuwe anti-TB middels word nie vinnig genoeg ontwikkel om die antibiotika weerstandigheid mutasie spoed van M. tuberculosis te bekamp nie. Doeltreffende diagnostiese toetse word benodig om die verspreiding van die siekte te beheer en bestaande roetine diagnostiese toetse voldoen tans nie aan hierdie vereiste nie. Behalwe hiervoor, is huidige vinnige TB diagnostiese toetse buite bereik van arm instansies weens vereistes aan infrastruktuur, meegaande kostes en werknemervaardigheid. Nuwe TB diagnostiese toetse is dus nodig om aan hierdie vereistes te voldoen. Mikobacteriofaage is fage wat mikobacteria infekteer en kan moontlik 'n lewensvatbare en koste-effektiewe alternatief bied vir vinnige TB diagnostiese toetse. In hierdie studie word 'n affiniteitgekoppelde fluoreserende rapporteringsmikobakteriofaag beskryf wat ontwerp is om op te tree as `n nuwe vinnige TB diagnostiese toets. Die werking hiervan vertoon gunstige en beter resultate as die huidige, mikobacteriofaaggebaseerde TB-diagnostiese toetse.

民國七十七年，可說是台灣報界的起飛年，實施近四十年的「報禁」，元月一日起正 式解除，台灣新聞界進入一個嶄新的里程。 長久以來，新聞記者與消息來源之間便存在一種曖昧、模糊不清的關係，一方面新聞 記者必需依賴消息來源提供新聞，進而加以求證、報導、引述；另一方面消息來源必 需依賴記者將想要讓社會知曉的事物加以披露、報導、宣傳，兩方各有各的立場及出 發點，時而兩造間立場一致、相互合作，時而兩造間立場相左，便會發生衝突。 根據相當多的研究顯示，政府官員是新聞記者報導新聞時的主要消息來源，研究政府 官員與記者間的關係，便成為新聞學研究中一項基本的課題，本研究目的地就是在探 究官員和員記者間的互動關係，看看那些因素會影響兩造間的互動關係。 本研究選擇甫成立不滿兩年的行政院環境保護署為對象，調查三十七位採訪環保署新 聞的記者，瞭解他們如何進行採訪工作？如何選擇採訪對象？又調查一百九十四位環 保署官員，瞭解他們在工作之餘，何以要接受記者訪問？他們如何看待記者？如何接 受記者訪問？進而描繪出兩者之間的互動關係。 本研究再以重點訪談（FOCUSED INTERVIEW） 的方法，訪問部分的官員及記者，希望 能更進一步瞭解兩者間的互動關係。 本研究係屬初探性研究，研究發現不論政府官員或新聞記者都認為「報導大眾應知道 的事務」為新聞媒介的主要功能，但政府官員和新聞記者卻對彼此關係在認知上有極 大的不同，大多數受訪的官員認為和記者間不必刻意建立起特殊的關係，只要各自扮 演好自己的角色即可；大多數受訪的記者則認為和官員間除扮演好自己的角色外，為 了雙方便利，應視情況需要，發展出互信、互賴的關係。 整個研究所得資料豐碩，但囿於人力、物力，除做一般總體資料描述及若干相關變項 的檢定外，並未做更進一步的分析解釋，又由於本研究只是針對環保署官員及採訪環 保署的記者進行調查，推論上有其限制。建議未來對所有路線的記者進行調查，同時 也針對不同身分、背景的消息來源進行週查，以求能窺出記者與消息來源互動關係的 全貌。

本文共分緒論、文獻探討、研究方法、資料分析、結論與建議等五章。 第一章緒論：包括研究動機、目的、與問題。旨在探求環保記者的專業意理取向為何 ？並尋找影響記者專業意理取向的因素有那些？ 第二章文獻探討：包括新聞專業意理、職業社會學、媒介組織、大眾媒介與環保運動 之關係等相關理論及研究文獻的探討。 第三章研究方法：本文採問卷調查法，以台北、台中、高雄六縣市的報社環保記者為 研究對象，並採用百分比、因素分析、迴歸分析、卡方考驗等統計方法。 第四章資料分析：因素分析的結果發現環保記者有傳佈者（DISSEMINATOR）、解釋者 （INTERPRETER）、對立者（ADVERSARY）三種專業意理的取向。人口變項、職業經驗 等因素對專業意理取向有不同的影響程度。 第五章結論與建議：將資料分析中的主要結果，進一步的檢討，並提出本研究受限之 處，作為未來研究者的參考。

Transmissible spongiform encephalopathies (TSEs) or prion diseases are a class of fatal brain disorders better known as Creutzfeldt-Jacob Disease (CJD) in humans, bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep, and chronic wasting disease (CWD) in deer and elk. The infectious agent responsible for these diseases is a misfolded prion protein capable of catalyzing a conformational change in normal cellular prion proteins (PrPC) into aberrant disease-causing structural isoforms (PrPSc). Although the etiological agent for TSEs has clearly been defined as PrPSc, there are important gaps in our understanding of how these proteins target and invade brain tissue. It remains to be established how ingested PrPSc ultimately reach the brain and also to understand why these tissues are particularly targeted, notwithstanding that several other tissues highly express prion proteins. Certain viruses, retroviruses in particular, efficiently hijack host proteins and can carry these proteins with them when they are released from a cell. Several lines of evidence have shown that prions and retroviruses can interact and associate at various stages of the retroviral replication cycle. Of special interest is that most retroviruses can cross the blood-brain barrier and could therefore deliver host-derived proteins to neuronal cells. In view of these observations, this thesis investigates whether retroviruses can act as vectors to capture prions from an infected cell and deliver them to a susceptible target cell. In this work, I have cloned human and mouse prion cDNAs from PBMCs and the murine cell line NIH 3T3. Either a FLAG epitope tag or the eGFP reporter protein cDNA was inserted into a region of the prion cDNA that is predicted to be amenable to such genetic insertions without affecting protein folding or expression. I then confirmed using both fluorescent and confocal microscopy and that the recombinant proteins had a similar cell distribution to the endogenous prion protein. Using Western blot analysis, I then showed that endogenous and overexpressed prion proteins can be detected in co-transfected cells producing HIV and murine leukemia virus (MLV) retroviral particles. Finally, I went on to show that prions are also present at high levels in HIV and MLV retroviral particles released from these cells. This work constitutes the first step in determining whether retroviruses can act as vectors for prion dissemination. Establishing a strong and clear association between retroviruses, pathogenic prions and prion disease would provide the rationale for preventive measures to be taken directly against retroviruses in order to protect humans and animals that have been newly exposed to PrPSc-infected products or those who are genetically predisposed to develop prion diseases. Anti-retroviral drugs could also be potentially used to delay disease progression and reduce prion transmission in human and animal tissues. The availability of such a treatment would constitute a significant advancement because there is currently no cure or treatment for prion diseases.

South Africa ratified the Stockholm Convention (SC), which became legally binding on 17 May 2004. This Convention targets 12 particularly toxic persistent organic pollutants (POPs) for virtual elimination. The Convention also requires parties to reduce the release of organochlorine pesticides and the intentionally- and unintentionally-produced POPs such as dioxins, furans and polychlorinated biphenyls (PCBs) (referred to as dioxin-like chemicals). Dioxins are a heterogeneous mixture of chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) congeners. These substances were never intentionally produced but are produced as by-products of industrial processes (such as metallurgical processes and bleaching of paper pulp). They can also be formed during natural processes such as volcanic eruptions and forest fires. The largest contributor to releases of PCDD/Fs in the environment is incomplete combustion from waste incinerators leading to the unintentional production of these compounds. Polychlorinated biphenyls (PCBs) are used in transformers and capacitors, but can also be formed unintentionally during industrial and thermal processes. Dioxin-like chemicals (PCDD/Fs and/or PCBs) are classified as persistent because of the following characteristics: lipophilicity and hydrophobicity; resistance to photolytic, chemical and biological degradation and they are able to travel long distances. As South Africa is a semiarid region, POPs will be less prone to travel here because these substances favour colder regions with high soil organic matter. Fish, predatory birds, mammals (including humans) absorb high concentrations of POPs through the process of bio-concentration, leading to bio-accumulation of these substances in the fatty tissue. PCDD/Fs occur as unwanted trace contaminants in air, water, land, in residues and products (such as consumer goods e.g. paper and textiles). The distribution of these chemicals into various matrices is problematic since they cause damage to the environment and human health. These chemicals pose a threat to human health when found in high concentrations that may lead to acute hepatoxicity and dermal toxicity (chloracne). Long-term exposure to low concentrations of these substances might lead to chronic effects such as reproductive problems and carcinogenicity. Since ferrous and non-ferrous metal production is a source of dioxin-like chemicals, a platinum mine in the Limpopo Province, South Africa, was selected for this investigation. The aim of the study was to determine if there are dioxin-like chemicals associated with platinum mining and processing, and if the H4IIE reporter gene bio-assay could be used to semi-quantify and assess the potencies of the complex environmental and process samples by determining their Toxic Equivalency Quotients (TEQ). The implications of the sources to the formation of dioxin-like chemicals regarding the SC were investigated and recommendations were made to improve this study. Samples were collected from tailings dams, woodchips, a dumpsite and slag from the smelter at Union Section. Samples were extracted with the Soxhlet apparatus using hexane as solvent. The percentage total organic carbon (%TOC) was determined for each sample to normalise the data. The method used was the Walkley-Black method. In determining the TEQ of each sample, the H4IIE luc cell line was used. The cells of the H4IIE luc line are genetically modified rat hepatoma cells stably transfected with a luciferase firefly gene. The luciferase gene is activated by the presence of dioxin-like compounds and the concentration of the enzyme is measured as relative light units (RLUs). The amount of RLUs is directly proportional to the dioxin load in the extract. This method is rapid, cost and time-effective in determining the TEQ when compared to chemical analysis. The TEQ2o-valuesin the various samples, as determined with the H4IIE luc cell line, ranged from 0.007 ngTEQ/kg to 54.06 ngTEQ/kg. Thermal processes at the smelter, sorption of hydrophobic organic compounds (HOCs) to soil and tailings, and external sources such as anthropogenic activities contributed to high TEQ2o-values. Climatic conditions, wind, precipitation, and solubility of HOCs into surfactants lead to low TEQ20. The smelter at Union Section had a very high TEQ20of 44.62 ngTEQ/kg compared to Impala Platinum mine (5.15 ngTEQ/kg). This implies that workers at Union Section are possibly exposed to low and high concentrations of dioxin-like chemicals. Long-term exposure to these compounds could lead to bio-accumulation in the fatty tissue of the mine workers, leading to chronic effects such as reproductive problems and cancer. The air emission of the furnace at the smelter was 0.03 gTEQ/annum and the release of the PCDD/Fs into the slag was 0.60 gTEQ/annum. By effectively managing the smelter it is possible to reduce the TEQ. The TEQ of each sample increased due to normalising the data. The normalised TEQ20 ranged from 0.94 ng TEQ/kg to 42497.48 ngTEQ/kg. Dioxin-like chemicals are present on a platinum mine, but at varying quantities and the effects of these compounds might be detrimental to the environment and the workers at the platinum mine. Further analyses of the health impacts associated with the platinum mine are needed. The H4IIE reporter gene bio-assay could be used to effectively determine the TEQ of each sample. Although this investigation has identified the formation and presence of dioxin-like chemicals at certain stages of mining and processing, not all of the processes were investigated. Some of these processes have the potential to add, and even destroy, these chemicals, affecting potential human exposure and amounts released to the environment. This, however, requires further investigation. The financial assistance of the National Research Foundation (NRF) towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the author and are not necessarily to be attributed to the NRF. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

La symbiose mycorhizienne entre les champignons du sol et les racines de la plupart des plantes constitue une relation à bénéfice réciproque et joue un rôle majeur dans la productivité des écosystèmes. Les récentes avancées dans le domaine ont abouties à l'identification et à la caractérisation fonctionnelle de nombreux systèmes de transport du partenaire fongique. Le travail présenté s'inscrit dans le cadre de développement d'outils permettant la localisation de gènes d'intérêts du champignon ectomycorhizien Hebeloma cylindrosporum et de leur caractérisation fonctionnelle. Les systèmes de transport candidats ont été identifiés au sein d'une banque EST du champignon et semblent impliqués dans les échanges de phosphate (Pi) et de potassium (K+) entre Hebeloma et la plante hôte Pinus pinaster. Une stratégie de fusion transcriptionnelle utilisant l'EGFP comme gène rapporteur a été développée pour permettre la localisation de deux transporteurs de phosphate, HcPT1 et HcPT2, d'un transporteur de potassium, HcTrk1, et d'un canal potassique de type Shaker, HcSKC1, dans les hyphes en culture pure et au sein de l'ectomycorhize. Les Agrotransformations de la souche h7 d'Hebeloma avec des vecteurs de fusion transcriptionnelle ont montré une expression mycélienne de l'EGFP sous contrôle des promoteurs de nos gènes d'intérêts. Sous contrôle des différents promoteurs, l'expression de l'EGFP apparait comme étant site-spécifique dans les hyphes différenciés des ectomycorhizes. Le promoteur du transporteur de Pi HcPT1 induit l'expression du gène rapporteur au niveau des hyphes extramatriciels et du manteau mycélien entourant la racine. De plus, son expression est stimulée en cas de carence en Pi, indiquant ainsi l'implication de ce transporteur dans la récupération du Pi du sol lorsque celui-ci devient limitant. Pour ce qui est du promoteur de HcTrk1, il permet l'expression de l'EGFP dans les hyphes extraracinaires et dans le manteau, tandis que celui de HcSKC1 permet son expression au niveau du réseau de Hartig et du manteau. Ceci indique, qu'ils semblent respectivement participer à la récupération du K+ du sol et à son excrétion vers la plante. Pour poursuivre la caractérisation fonctionnelle de nos systèmes de transport candidats, un second canal potassique, HcSKC2, a été isolé à partir de la souche h1 et exprimé dans des ovocytes de xénope. Tout comme HcSKC1, HcSKC2 n'a pas été actif en système d'expression hétérologue. Cependant, des fusions traductionnelles avec l'EGFP ont montré que la protéine HcSKC2 est bien dirigée à la membrane. En perspective, la caractérisation fonctionnelle de ce canal issue de la souche h7 récemment séquencée sera tentée. / The mycorrhizal symbiosis made it possible the first plants to conquest emerged lands and is a major biological phenomenon of terrestrial ecosystems. The fungal partner efficiently takes up nutritive ions from the soil solution and transfers them to the host plants in exchange for photosynthetates. However, despite the importance of this symbiosis on ecosystem productivity, our knowledge about molecular processes controlling this symbiotic interaction and solute transports at the membrane level is very scarce. The objective of the project aims at dissecting part of the molecular mechanisms required for a functional ectomycorrhizal symbiosis associated with most of the woody species from boreal and temperate forests, by focusing on K+ exchanges occurring through the continuum soil-hyphae-plant. The general aim of the project is to gain new insights into the molecular mechanisms responsible for the polarization and differentiation of the plasma membrane between the site of nutrient uptake and the site of efflux into the apoplastic space in the ectomycorrhizal root. The team "Canaux Ioniques – Ion channels" has obtained an EST library of the fungus Hebeloma cylindrosporum (1) and has identified and characterized a potassium transporter of the Trk family (2). Also a Shaker-type potassium cannel was identified within the EST library but it is not yet functionally characterized. A second transcript was found from this channel with a longer N-terminus compared to the first transcript isolated in the beginning. Also, a sugar transporter was identified among the ESTs that could participate in the absorption of sugars, coming from the host plant, by the fungus. The objective of the PhD thesis is the functional characterization of these fungal transport systems as well as their localization. The functional characterization of these candidate genes will be accomplished using heterologous expression systems (Xenopus oocytes, COS cells, complementation of yeast mutants) and by the means of electrophysiology. Localization of genes within the fungus being in symbiotic interaction with the host plant, the tree Pinus pinaster, will help to better understand the role of the transport systems. The differentiation of the fungus, when establishing symbiosis, into the specialized interfaces soil-fungus and fungal cell- host plant cell within the ectomycorrhiza (Hartig net) is probably accompanied by a specific expression of transport proteins and ion channels

The objective of this thesis, The Image of a Journalist in Hollywood Film, is to interpret the images of journalists created in Hollywood films in the period from 1997 to 2007 by means of qualitative and comparative analyses. The analysis is carried out based on journalist characters appearing as protagonists in thirteen motion pictures from the given period. The comparison of the characters is executed within three groups, classified according to the type of journalist - investigative journalists, celebrity and lifestyle journalists and television anchormen and reporters. The characters are compared to each other from the point of view of physical appearance, character traits, family and social relations, their attitude towards authorities, the most common stereotypes and other character's perception of them. The summarization and data evaluation of the analysis confirms that journalist stereotypes do not often occur in this period, the protagonists are predominantly portrayed as heroes and that the differences outweigh the similarities.

The Representation of Journalists in Videogames aims to find out how do videogame developers represent journalists in the mainstream videogames. The analysis is based on five case studies of various videogames but it also includes sequels and prequels of the selected games. The author of this thesis analyzes nine videogame journalists which can be differentiated into several categories: investigative reporters, photojournalists, paparazzis, radio and TV reporters and hosts of various television shows. Their behavior is not the only aspect this thesis analyzes because their visual appearance is also fully in the hands of the game developers. This thesis proves that the videogame journalists are sometimes depicted stereotypically but if so, it is always for a reason. Videogame developers do not always use this sort of depictions and can even accurately describe journalistic practice and behavior. Journalism is always better described if the journalist is a heroic protagonist of their videogame. If they are villains, it is often described using various negative stereotypes.

Studien handlar om hur tittare och producenter upplever intervjusekvenser i 360°-video i en VR-miljö och syftet är att synliggöra tittares upplevelser av produktion för att skapa bättre förutsättningar för journalistiska 360°- produktioner. Studien fokuserar på tittarens upplevelser av 360°-video i olikheter i gestaltningsval, utifrån gestaltningskomponenterna: point-of-view, distans till intervjupersonen, intervjupersonens blickriktning och hur reporter används i 360°-video, samt på vilka olika sätt man som producent kan gestalta intervjusekvenser i journalistisk 360°-video och hur det skiljer sig cinematografiskt och berättartekniskt från traditionell videoproduktion. Studien har utgått från ett egenproducerat testmaterial bestående av sex olika 360°-videor. Detta material har använts i en tittarstudie där testpersonerna har tittat på materialet i VR-headset, tänkt högt enligt thinking aloud-metoden och medverkat i en simulated recall-intervju med kortsortering. För att få ett producentperspektiv har även yrkesverksamma 360°-producenter intervjuats. Testpersonernas upplevelser har analyserats utifrån hur vi traditionellt gestaltar intervjuer i rörliga medier. Studien visar hur individuellt tittare upplever grundläggande parametrar i gestaltningsval i intervjusekvenserna, att tittarna vill känna sig delaktiga och uppleva ett förstahandsperspektiv med stabilitet och kameran placerad i ett för dem normalt perspektiv i höjdled, vara nära intervjusituationen men inte för nära och känna sig bekräftade av blickar från samtliga medverkande. Samtidigt påverkar närhet till intervjuperson och dennes blickriktning hur villig tittaren är att utforska miljön. En synlig reporter kan upplevas som en konkurrent om uppmärksamheten eller fungera som en bra guide. Studien visar också hur all 360°-produktion i möjligaste mån bör efterlikna verkligheten och hur en intervjusituation också bör efterlikna en verklig situation där tittaren upplever illusionen av att vara delaktig. Intervjusituationen i 360°- video konkurrerar många gånger om tittarens uppmärksamhet med den rena miljöupplevelsen och intervjupersoner blir väldigt utlämnade i 360°-formatet. Det är därför av stor vikt att man har en överenskommelse om produktionens stil innan inspelningen.

Avec de nombreuses qualités exceptionnelles (biocompatible et ostéogénique), la nacre représente un biomatériau naturel comme substitut osseux. Mais les composés ostéogéniques dans la nacre ne sont pas encore connus. Nos travaux visent à l’identification des composés ostéogéniques de la nacre. L’ESM (éthanol soluble matrix) est un extrait de la nacre qui est démontré ostéogénique. A partir d’ESM, nous avons essayé plusieurs approches pour cibler et identifier ces composés. Grâce au couplage des cellules MC3T3-E1 et d’ostéoblastes humains arthrosiques, nous avons démontré que la partie cationique d’ESM est ostéogénique, sans interaction avec la partie anionique. Le calcium joue un rôle dans l’activité ostéogénique d’ESM. Ensuite, nous avons créé une lignée cellulaire exprimant de manière stable un plasmide contenant un gène rapporteur ostéogénique (ATDC5 pMetLuc2 ColX promoteur). Grâce à cette lignée, nous avons découvert que les lipides et les sucres présents dans l’ESM ont un effet ostéogénique. Les peptides précipités par TCA sont aussi démontrés ostéogéniques, et ont conduit à leur identification partielle par LC-MS. Ces résultats nous permettent d’avancer plus loin et plus rapidement vers l’identification des composés ostéogéniques de la nacre et vers les applications de la nacre en orthopédie clinique / With many exceptional qualities (biocompatible and osteogenic), nacre represents a natural biomaterial as a bone substitute. However, the osteogenic compounds in nacre are not yet known. Our work aims at the identification of the osteogenic compounds in nacre. The ESM (soluble ethanol matrix) is an extract of nacre that is shown to be osteogenic. From the ESM, we have tried several approaches to target and identify these compounds. Thanks to the coupling of MC3T3-E1 cells and the human osteoarthritis osteoblasts, we demonstrated that the cationic part of the ESM is osteogenic, without interaction with the anionic part. Calcium plays a role in the osteogenic activity of the ESM. Then, we created a cell line stably expressing a plasmid containing an osteogenic reporter gene (ATDC5 pMetLuc2 ColX promoter). Thanks to this cell line, we found out that the lipids and sugars in the ESM have an osteogenic effect. The peptides precipitated by TCA are also demonstrated to be osteogenic, which have led to their partial identification by LC-MS. These results allow us to move farther and faster towards the identification of osteogenic compounds in nacre and the applications of nacre in clinical orthopaedics