No description available.

No description available.

Mapping images – when words don’t work. My master essay is a walking contradiction. It is an explanation of how a non-wordly thought process emerged – but explained in words. Words have never been my strong suit and in my essay I try to illustrate how I use images instead of words, mapping instead of structure, to escape the dictatorship of the written explanation. Where words have a certain linear structure from A to B my thought process is instead a juxtaposed jumble of heterogeneous elements that together create different associations in a rhizomatic and non-structured way. When I begin a project it is always the images that guide my idea instead of the idea guiding my images. In this way I let myself be seduced by the non-explainable atmosphere of the images. Instead of explanations I collect the images in big maps that have no clear beginning, middle or end. I let the images speak to each other, compliment or contrast one another. For me this is a way of keeping my work open as long as possible. As I work with video and narrative structure in the final product, the juxtaposing of images is a way of postponing and contrasting the more closed process of editing on a linear timeline.  I have a strong belief in the power of images. The old cliché ‘a picture says more than a thousand words’ still works for me, specifically because they don’t have to explain themselves or be ‘literal’ (in the literal sense of the word). They allow me to dwell in atmospheres, non-logic connections and open questions. Together, the mapping of images doesn’t create one clear design for my work, but a heterogeneous multiplicity of potential works to come. Sooner or later I have to take control of the process and be the dictator of the images. But my experience have taught me, that the more I allow the images to speak for themselves in all their ambivalence, the more I can infuse my final work with the same ambivalence and open-endedness. My works are not answers, but questions. And the collection of images that guide my work process let me keep asking the questions that words cannot formulate. The essay grabbles with these themes of words, images and process. As an illustration of my process, the essay is accompanied by a visual map, where I have tried to explain the associations that the images create for the theme of my work. I haven’t escaped the dictatorship of words yet, but maybe given the images their proper place within my work process. / A 4 channel video installation. Size on screens: 136 x 76 cm. Duration on video: 17 min. In a defenceless condition we enter a room. And they in us. All of the rooms. Sure, there are differences. Though it is not important here, not anymore anyway. It is not important, when you will not remember why you walked into the room to begin with. What got you to enter, and why do you stay. Moments that extends infinitely in time, expands and pushes away the oxygen in the room, like the last to experience before death is this strange, anaerobe environment. Two people are sitting in a room that changes looks six times. They are waiting, but no one knows what they are waiting for. While waiting they start to confess to each other, but never directly. In stead they try to explain and apologize their action without ever mentioning what the actions were.

Thesis (PhD)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Given the organisation of the maize genome as well as demands placed on the saturation of molecular linkage maps it would be desirable to identify informative molecular markers that is located or linked to genic rich areas. Sequences of gene products from different gene classes were investigated. Proteins containing a nucleotide binding site (NBS) and leucine-rich repeat (LRR) region comprise the largest class of disease resistance proteins. Resistant gene analogue (RGA) primers belonging to this specific class were derived from previous published literature studies. By means of similarity studies of short stretches of conserved amino acid and DNA sequences, primers were developed that belonged to the peroxidase and reductase gene classes. A novel class of transposable element was identified, that occurred in the gene rich areas of a diverse range of grass genomes. Of all the MITE families described so far, the Heartbreaker (Hbr) and Hb2 family elements were of particular interest. The unique properties of MITEs, especially their high copy number, polymorphism, stability and preference for genic areas together with the RGA primers, were exploited to develop a new marker technique for the isolation of a class of molecular marker with a strong preference for genic areas. Using the publicly available recombinant inbred population, Tx303 x C0159, 196 MITE/RGA markers were added to the existing recombinant inbred linkage map consisting of ±1033 already established markers. It became apparent that just like loci for disease resistance, the 196 MITE/RGA fragments were not randomly distributed across the maize genome but occurred in clusters spread across the ten maize chromosomes. Ninety-two (92) of the MITE/RGA fragments showed significant correlation to previously mapped maize resistance genes. To establish the conservation and specificity of both the Hbr and Hb2 elements, sequences of 19 MITE/RGA fragments were ascertained. When comparing the partial MITE element sequences from these fragments, a high degree of element conservation was observed. One fragment showed good sequence correlation to a NADPH He Toxin reductase protein product and mapped to the same chromosomal location as the hm1 gene locus in maize. This fragment can be considered a candidate gene for resistance against the pathogen, Helminthosporium carbonum. The Hbr primer used proved to be very specific for the Heartbreaker MITE element, this was in contrast to the non-specificity of the Hb2 primer. The applicability of this technique was tested on two maize diseases that cause immense damage in the maize production industries in South Africa. Fourteen MITE/RGA markers were used to fine map the putative chromosomal locations for the HtN1, Ht1, Ht2 and Ht3 genes that confer resistance. against Setosphaeria turcica, the northern corn leaf blight (NelS) pathogen in maize. Three MITE/RGA fragments were identified that aided in the saturation of the linkage map for quantitative trait resistance (QTl) against gray leaf spot (GlS) in maize. This novel MITE/RGA technique presented a unique opportunity to search for additional candidate genes by using polymerase chain reaction (peR) analysis. When compared to the conventional amplified fragment length polymorphism (AFLP) technique, the MITE/RGA technique proved to be just as efficient but was more cost effective and less time consuming. / AFRIKAANSE OPSOMMING: Die organisasie van die mielie genoom as ook die vereistes wat daar geplaas word op die versadiging van koppelingskaarte, vereis dat daar meer klem geplaas word op die ontwikkeling van molekulêre tegnieke wat merkers in geenryke areas identifiseer. Die volgordes van geenprodukte, wat behoort tot verskillende geenklasse, is deeglik bestudeer. Proteïenprodukte wat bestaan uit 'n nukleotiedbindingsarea (NBA) en 'n leusienryke herhalende (LRH) area is een van die grootste klasse waaronder siekteweerstandsproteïene sorteer. Polimerase kettingreaksie (PKR) inleiers wat behoort tot hierdie spesifieke klas, is verkry vanuit vorige publikasies. Deur kort gekonserveerde aminosuur en DNS volgordes te vergelyk is inleiers ontwikkel wat behoort tot die peroksidase en reduktase gene klasse. 'n Nuwe klas transponeerbare elemente wat voorkom in die geenryke areas van diverse gras genome, is geïdentifiseer. Van al die miniatuur inversie herhalende transponeerbare elemente (MITE) wat al geïdentifiseer is, is die twee elemente, Heartbreaker (Hbr) en Hb2, van groot belang. Unieke eienskappe van die MITEs, veral hul hoë kopie aantal, polimorfiese-indeks, stabiliteit asook voorkeur vir geenryke areas, tesame met die weerstandsgeen analoë (WGA) inleiers, is gebruik om 'n nuwe merker tegniek te ontwikkel. Hierdie nuwe tegniek identifiseer 'n klas merker wat 'n sterk voorkeur het vir geenryke areas. Deur gebruik te maak van die openbare beskikbare rekombinante ingeteelde (RI) populasie, Tx303 x C0159, is 196 MITE/WGA-merkers gekarteer op die bestaande RIL koppelingskaart, wat alreeds bestaan uit ±1033 gevestigde merkers. Net soos die lokusse vir siekteweerstand het dit geblyk dat hierdie 196 merkers in groepe voorkom wat verspreid is oor die tien mielie chromosome. Twee-en-negentig (92) van die 196 gekarteerde MITE/WGA-merkers het betekenisvolle korrelasie gewys met reeds gekarteerde mielie weerstandsgene. Die volgordes van 19 MITE/WGAfragmente is bepaal om sodoende die spesifisiteit en mate van konservering van die Hbr and Hb2 elemente te bereken. 'n Hoë mate van element konservering is waargeneem. Een fragment het In baie goeie volgorde korrelasie gewys met In NADPH HG toksien reduktase proteïen produk en karteer op dieselfde chromosomale posisie as die hm1 geen lokus. Hierdie fragment kan gesien word as In kandidaatgeen vir weerstand teen die mielie patogeen, Helminthosporium carbonum. Die toepasbaarheid van hierdie tegniek is getoets op twee siekte toestande, wat lei tot groot verliese in die mielie industrie, in Suid-Afrika. Veertien van die MITE/WGAmerkers is gebruik om die waarskynlike chromosomale posisies van die HtN1, Ht1, Ht2 en Ht3 gene, wat weerstand bied teen Setosphaeria turcica, die noordelike mielie blaarvlek (NMBV) patogeen, fyner te karteer. Drie MITE/WGA fragmente is geïdentifiseer wat gehelp het in die versadiging van die koppelingskaart vir die kwantitatiewe kenmerk weerstandbiedenheid (KKW) teen grys blaarvlek (GBV) in mielies. Deur gebruik te maak van polimerase kettingreaksie (PKR) analise, verskaf hierdie tegniek die moontlikheid om te soek vir addisionele kandidaatgene. Hierdie tegniek is ook vergelyk met die konvensionele geamplifiseerde fragment lengte polimorfisme (AFLP) tegniek. Daar is gevind dat die nuwe tegniek net so informatief is, maar wel meer koste effektief en tyd besparend.

We consider the problem of enabling a robot to efficiently obtain a dense haptic map of its visible surroundings Using the complementary properties of vision and tactile sensing. Our approach assumes that visible surfaces that look similar to one another are likely to have similar haptic properties. In our previous work, we introduced an iterative algorithm that enabled a robot to infer dense haptic labels across visible surfaces in an RGB-D image when given a sequence of sparse haptic labels. In this work, we describe how dense conditional random fields (CRFs) can be applied to this same problem and present results from evaluating a dense CRF’s performance in simulated trials with idealized haptic labels. We evaluated our method using several publicly available RGB-D image datasets with indoor cluttered scenes pertinent to robot manipulation. In these simulated trials, the dense CRF substantially outperformed our previous algorithm by correctly assigning haptic labels to an average of 93% (versus 76% in our previous work) of all object pixels in an image given the highest number of contact points per object. Likewise, the dense CRF correctly assigned haptic labels to an average of 81% (versus 63% in our previous work) of all object pixels in an image given a low number of contact points per object. We compared the performance of dense CRF using uniform prior with a dense CRF using prior obtained from the visible scene using a Fully Convolutional Network trained for visual material recognition. The use of the convolutional network further improves the performance of the algorithm. We also performed experiments with the humanoid robot DARCI reaching in a cluttered foliage environment while using our algorithm to create a haptic map. The algorithm correctly assigned the label to 82.52% of the scenes with trunks and leaves after 10 reaches into the environment.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Mycobacterium tuberculosis (M. tuberculosis) is the causative agent of tuberculosis (TB), a disease that affects millions of people world-wide. The species M. tuberculosis consists of a large number of different strains that can be grouped into at least 40 different known strain families. Many of the strains present with different pathogenic characteristics and host adaptations. The F11 LAM strains and Beijing strains currently have a nearly equal representation in the population of Cape Town, making up a total of 45% of all strains in this setting. The Latin-American Mediterranean (LAM) family of M. tuberculosis is proved to be the cause of a large percentage of TB cases worldwide and it is the predominant strain in high-prevalence regions such as the Western Cape and KwaZulu-Natal regions of South Africa, Zambia, Zimbabwe, and South America. This project aimed to investigate the evolution and biological characteristics of the members of the principle genetic group (PGG) 2 Latin-American Mediterranean (LAM) genotype of M. tuberculosis using a combination of whole genomic and proteomic analyses, coupled to mycobacterial molecular epidemiological techniques. The evolution of M. tuberculosis strain families from the Western Cape Province of South Africa proved to be consistent with previous evolutionary scenarios for M. tuberculosis isolated from other parts of the world. This genome-wide SNP-based phylogeny for the evolution of M. tuberculosis offers novel insight into the unique global representation of the M. tuberculosis isolates from the Western Cape, South Africa. The evolutionary scenario presented confirms six LAM sub-lineages, namely IS6110 RFLP families F9, F11, F13, F14, F15, and F26. A subset of sub-lineage defining SNPs was determined for each of the six LAM sub-lineages. The genomic changes in the LAM genotype strains observed through the SNP analysis presented here mostly occur in the genes involved in the cell wall, cell processes, intermediary metabolism and respiration. The same phenomenon was observed when the non-redundant SNPs of the non-LAM isolates were functionally annotated. The functional classification of the regulated proteins in the representative of the LAM RDRio lineage of M. tuberculosis suggests that proteins involved in the lipid metabolism, intermediary metabolism and respiration may be the key to the pathogenic effectiveness of the RDRio LAM lineage. A combination of the LAM SNP analysis and the LAM RDRio/non-RDRio comparison showed that the overall genomic- and proteomic features involved in the cell wall and cell processes of the LAM genotype differ to a large extent from what is seen in the reference strain, M. tuberculosis H37Rv. This genome wide phylogenetic study is the first of its kind in a South African context, and not only presents a robust phylogeny of the M. tuberculosis strain families, and specifically the LAM lineage, but also gives the first ever insight into the protein differences which distinguishes RDRio and non-RDRio M. tuberculosis strains from each other. / AFRIKAANSE OPSOMMING: Mycobacterium tuberculosis (M. tuberculosis) is die mikrobiese agent wat tuberkulose (TB), 'n siekte wat miljoene mense wêreldwyd affekteer, veroorsaak. Die spesie M. tuberculosis bestaan uit 'n groot aantal verskillende stamme wat in ten minste 40 verskillende bekende stam-families gegroepeer word. Baie van die stamme toon verskillende patogeniese eienskappe en gasheer aanpassings. Die F11 LAM stam en Beijing stam het tans 'n byna gelyke verteenwoordiging in die bevolking van Kaapstad, wat 'n totaal opmaak van 45% van stamme wat in hierdie gebied gevind word. Die Latyns-Amerikaanse Meditereense (LAM) familie van M. tuberculosis is bewys om die oorsaak van 'n groot persentasie van TB-gevalle wêreldwyd te wees, en dit is die oorheersende stam in hoë voorkoms streke soos die Wes-Kaap en KwaZulu-Natal streke van Suid-Afrika, Zambië, Zimbabwe en Suid-Amerika. Hierdie projek het ten doel gehad om die evolusie en biologiese eienskappe van die lede van die basiese genetiese groep (BGG) 2 Latyns-Amerikaanse Meditereense (LAM) genotipe van M. tuberculosis te ondersoek deur gebruik te maak van 'n kombinasie van heel genoom en proteoom analise, gekoppel aan mikobakteriële molekulêre epidemiologiese tegnieke. Die evolusie van M. tuberculosis stam families van die Wes-Kaap Provinsie van Suid-Afrika blyk om in ooreenstemming te wees met vorige evolusionêre scenario's vir M. tuberculosis wat in ander dele van die wêreld geïsoleer is. Die genoom-wye enkelnukleotied polimorfisme-gebaseerde filogenetiese hipotese vir die evolusie van M. tuberculosis bied nuwe insig in die unieke wêreldwye verteenwoordiging van die M. tuberculosis isolate van die Wes-Kaap, Suid-Afrika. Die evolusionêre scenario wat hier aangetoon word bevestig ses LAM sub-lyne, naamlik IS6110 RFLP families F9, F11, F13, F14, F15, en F26. 'n Versameling sub-lyn definiërende enkelnukleotied polimorfismes was bepaal vir elk van die ses LAM sub-afstammelinge. Die genomiese veranderinge wat waargeneem is in die LAM-genotipe isolate deur die enkelnukleotied polimorfisme analise wat hier aangebied word, is meestal in die gene wat betrokke is in die selwand, selprosesse, intermediêre metabolisme en respirasie. Dieselfde verskynsel is waargeneem wanneer die nie-oorbodige enkelnukleotied polimorfismes van die nie-LAM isolate funksioneel geannoteer is. Die funksionele klassifikasie van die gereguleerde proteïene in die verteenwoordiger van die LAM RDRio-lyn van M. tuberculosis dui daarop dat die proteïene wat betrokke is in die lipiedmetabolisme, intermediêre metabolisme en respirasie die sleutel tot die patogene doeltreffendheid van die RDRio-LAM-lyn kan wees. 'n Kombinasie van die LAM enkelnukleotied polimorfisme analise en die LAM-RDRio/nie-RDRio vergelyking het getoon dat die totale genomiese- en proteomiese kenmerke wat verwant is aan selwand en selprosesse van die LAM genotipe tot ʼn groot mate verskil van wat gesien word in die verwysing stam, M. tuberculosis H37Rv. Hierdie genoom-wye filogenetiese studie is die eerste van sy soort in 'n Suid-Afrikaanse konteks, en bied nie net ‗n robuuste filogenie van die M. tuberculosis stam families, en spesifiek die LAM genotipe van M. tuberculosis nie, maar gee ook die eerste keer ooit insig in die proteïen verskille wat RDRio en nie-RDRio M. tuberculosis stamme van mekaar onderskei.

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Biological Sciences / Master / Master of Philosophy

No description available.

No description available.