A Comparative Study Of Antibody Responses In Tst+ And Tst- Groups With Long Term Exposure To Mycobacterium Tuberculosis

Tuberkulosis (TB) merupakan penyakit yang disebar oleh Mycobacterium tuberculosis (MTB) melalui udara. Secara tradisinya T-sel diberikan penekanan yang utama dalam pengantaraan jangkitan MTB dengan sedikit penekanan diberikan kepada B-sel dan antibody Tuberculosis (TB) is an air-borne disease caused by Mycobacterium tuberculosis (MTB). MTB infection is traditionally conceived as entirely T-cell mediated with little emphasis given to B-cell and antibod

Supramolecular Devices and Materials

This thesis describes work towards the development of a range of supramolecular devices and materials based on cyclodextrin host-guest interactions, and/or short peptide structures. The first such device targeted was a photoswitchable molecular lariat composed of a [c2] (cyclic, two-component) asymmetric daisy chain. Upon combining the two hetero monomer units it was found that a [c2]-dimer was not formed. The next phase of research involved the design of a second type of supramolecular device, also based on cyclodextrin host-guest inclusion complexes, this time serving to produce a change in peptide secondary structure. A range of devices were synthesised giving several modifications; increasing the stability of hexavaline beta sheets, reducing the PPII (polyproline type II) helicity in pentaalanine and introducing beta sheet character to pentaalanine. Furthermore, an azobenzene moiety was introduced as a photo-switchable cyclodextrin guest, enabling PPII helicity to be switched between states of increased and decreased structure via photoirraditation. This principle was then developed to give a device which not only produced a change in peptide structure but also brought about a change in function, in this case metal-binding ability. Upon cyclodextrin host-guest [c2]-dimer formation, beta sheet structure was induced in a short peptide strand which facilitated the arrangement of histidine residues in order to bind to a metal ion in a pseudo-chelating arrangement. The unmodified peptide, with no cyclodextrin or guest attached did not bind to zinc ions, whereas the cyclodextrin dimer was found to bind to Zn2+ with a Ka of 2,223 M-1. The system was then investigated in the solid-phase and a crystal was grown wherein [c1]-complexes were bound to Zn2+ in tetrameric assemblies. In addition, the same crystal structure was observed in the absence of Zn2+ showing that the system pre-assembles to form a crystal lattice with vacant metal binding sites. A number of smaller studies were also performed to explore the possibility of the application of peptide chemistry techniques and principles to supramolecular concepts. The solid-phase synthesis technique used to make peptide sequences was investigated as a method for the preparation of rotaxanes. Despite several attempts no interlocked structures were synthesised, however a method was established for the mobilisation of a cyclodextrin onto a stationary phase. -Sheet peptide-peptide interactions, in conjunction with cyclodextrin host-guest interactions were then explored as a method for the generation of self-assembling polymers. A range of polymeric structures were considered, however within all the systems examined it was found that none formed. Finally, it was observed that a peptide amphiphile (PA), synthesized during the preparation of a metal-binding cyclodextrin dimer, formed a gel in acetonitrile/water mixtures, DMF and acetone at just 0.06 wt.%. The compound did not form a gel in water, despite its structural similarity to previously reported PAs, but did obey the structure-property relationships determined for these hydrogels. This suggests that despite the difference in solvents, assembly of these organo and hydrogels is the same and indicates a new strategy for the modification of PAs in order to gel target solvents

The characterisation of actinomycetes isolated from diverse South African sources, with emphasis on the genus Kribbella

Includes abstract.Includes bibliographical references (p. 169-171).Actinomycetes were isolated from the leaves of indigenous plants, aquatic sediment and soil samples, using alternative isolation methods to select for actinomycetes belonging to the rarer genera. Thirty actinomycete strains belonging to the genera Gordonia, Kineococcus, Kribbella, Micromonospora, Nocardia and Streptomyces were selected for full characterisation. A polyphasic approach combining physiology, chemotaxonomy and phylogenetic analysis was used to characterise these isolates. A number of potentially novel strains belonging to the rarer genera were identified, including two Kineococcus and three Micromonospora strains. Two novel Kribbella species were isolated from soil samples and the species descriptions of Kribbella karoonensis Q41T and Kribbella swartbergensis HMC25T were published in 2006

Study of prompt dimuon and charm production with proton and heavy ion beams at the CERN SPS

NA6

Reactive inkjet printing and functional inks : a versatile route to new programmed materials

Starting as an ink dispensing tool for documents and images, inkjet printing has emerged as an important instrument for delivering reactive fluids, into a means for creating new, programmed materials. Inkjet is a processing technology with some very unique capabilities, which allows the handling of materials in the picoliter range, and the creation of functionality in new, previously unexplored ways. In particular, drop-on-demand technology provides the chance to dispense liquids in picoliter/nanoliter quantities to very specific locations, with minimal material loss, and in a contact-free manner. This dramatic scale-down of production, not just miniaturization but "nanonization", affords materials that would be either too costly or otherwise inaccessible by other manners. As this is still an emerging technology, there remain a lot of opportunities to pioneer new applications. The underlying, unifying concept behind the chapters of this thesis has been an interest in investigating how inkjet printing, combined with reactive inks, can lead to new applications, new devices, and new materials, wherein unique functionality is imparted as a direct result of the confluence between microfluidic processing, chemistry, and life science. The ability to deliver uniform, sub-nanoliter droplets to specific locations opens up new possibilities that did not exist before. Inherent in the geometry of such droplets, the volume of liquid dispensed also offers some special utility. Based on the aforementioned diameters, drop-on-demand inkjet printing can deliver volumes in the range of approximately 0.5 to 1,000 pL; the direct writing attributes of inkjet ensure that these droplets are not only precise, but can be delivered to a specific location, giving them a "home address". This combination of precise, reproducible, small aliquots and precision deposition is especially important for preparing high-density analytical arrays, as discussed in Chapter 1 on inkjet printing of proteins. In the case of highly specialized proteins such as reactive enzymes or antibodies, where available materials are often limited, the ability to dispense precise quantities in a reproducible fashion means that small amounts of precious material can be used parsimoniously to perform thousands of experiments without compromising the quality of the data. For drop-on-demand printing, droplets normally produced by inkjet printing are commonly in the range of 10 to 125 µm in diameter, depending on the physical characteristics of the fluid, the nozzle used, and the printing conditions; taking advantage of the this aliquot size has some unique attributes that make dispensing highly suitable to materials science challenges that have gone unmet. In the second chapter of this thesis, this size domain is taken advantage of for use in tissue engineering, where it is used to create soft, cell-scale porogenic structures by the use of a reversible, rapid alginate gelation reaction to freeze droplet structures in place. By switching to a continuous inkjet device, larger volumes of beads in the size domain of 100 to 500 µm can be achieved, opening up prospects for pore sizes matching those needed for hosting capillaries. By incorporating reversible hydrogels as a motif in these applications, these controlled cell-scale dimensions can be retained during key processing steps, and then removed (or eroded) later after they have served their function. Extending the concept to the task of dispensing living cells, in Chapter 3, printed alginate structures are used for cell encapsulation. By adjusting the printing conditions to prevent jet break-up before alginate hardening, continuous, one-dimensional "living threads" can be created, which allow for cell cultures to be handled and woven into desired complex patterns. In addition to their role as basic building materials for tissue engineering scaffolds, the alginate threads provide a stable, bio-friendly environment for culturing different cell types, with cells exhibiting a high post-processing viability rate. In Chapter 4, the lower limits of single cell printing are explored, in the concept of "one cell-one well", where the attributes of inkjet printing are used to dispense individual cells. By careful selection of droplet size and accounting of cell concentrations, the statistical probability of single cell printing can be optimized, yielding spatially addressable arrays of isolated living cell cultures on a surface. Additional steps necessary to prevent cells from dehydration are also outlined, offering access to high density arrays of isolated living single cells on glass slides, where each individual droplet acts as independent nanoincubator, hosting intrinsically monoseptic cell cultures in parallel. In addition to describing the theoretical limits of single-pass cell printing experiment designs, an outline is given for experimental designs for tuning single particulate dispensing probability to any value desired between 0 and 1. The focus of Chapter 5 relates to reactive inkjet printing of ultrathin films on surfaces. For systems with moderately good surface wetting, such as polar solvents on glass or metal oxides, inkjet printed droplets result in features ranging approximately from 20 to 300 µm in diameter per droplet. By first printing a thiol-functionalized heterochelic linker and covalently bonding it to the print surface, the surface will accommodate subsequent thiol-ene click reactions only with original monolayer, and only where the first and second deposition features overlap. This combination of spatial selectivity as well as chemoselectivity allows for the preparation of a wide range of monolayers on a printed surface, in a format well-suited to automated surface characterization techniques, as was illustrated using XPS. In Chapters 6, two different categories of irreversible polymerization reactions are described, where print features are reacted in a specific pattern that is process unique. Printable ionogels are developed, which impart conductivity to printed patterns, and consequently, functionality to only those locations where the material has been deposited. Also in Chapter 6, the first example of a moisture-sensitive reactive printing is outlined, where a diisocyanate is combined with different polyols within seconds to create highly crosslinked, ultra-stiff surfaces, which can be built up into three dimensions by successive layering. The topics outlined in this thesis are intended to illustrate the breadth of how inkjet technology can be utilized to support a diverse field of materials science applications — particularly when coupled with modular, off-the-shelf synthetic transformations. The incorporation of synthetic chemistry into inkjet extends the application of inkjet from dispensing static materials merely from a cartridge onto a target, into a dynamic tool for transforming these materials into something new. At the same time, inkjet printing and other allied microfluidics tools enable chemistry experiments (and by extension, life science experiments) on a scale that would otherwise be challenging to realize by other means. The two driving forces of high-throughput experiment design, miniaturization and automation, are both embodied in this dispensing technique, and consequently inkjet printing is a rapidly evolving discipline; it is the intent of this work and the examples given to underscore the diversity offered by this technology

Vocal-Affective Weaning and its role in musical enculturation: children’s interest in music beyond the Infant-Directed Register

Well-established theoretical approaches to the Infant-directed Register (IDReg) draw a more or less tacit causal relation between it and all future musical engagement: the former establishes a basis for the latter. However, a mechanistic, observable chain of events linking these two phenomena has only been assumed, remaining for the most part unproblematized and undescribed. This thesis represents a first systematic attempt to fill this theoretical and empirical gap by concretely linking early musicality and the first manifestations of the most characteristic and widespread Western form of musical engagement: listening to recorded music. It does so by introducing a new construct as a mediating motivational factor— Vocal- Affective Weaning (VAW) —which mainly concerns the variation of caregivers’ use of the IDReg across developmental time. The thesis is grounded and tested in three literature reviews, two theoretical chapters, and three empirical ones. In terms of main findings, little evidence is found to support the existence of VAW as depicted in the main thesis. Consequently, any direct relationship between VAW and toddlers' attention to recorded music seems doubtful. Instead, data evidences a progressive use of Infant-Directed Speech (IDSp) as an ostensive cue used in the context of Natural Pedagogy, which allows for a better understanding of the relative importance of affectivity and cognition as parallel, coexisting governing principles that exert an influence on developmental changes concerning parental use of IDSp. If anything, data highlights interaction as a much more promising element in an explanatory chain linking the IDReg and Western forms of music engagement. The mentioned mismatch between the main thesis and results is interpreted in terms of the former’s unjustified stress on ‘centripetal’ over ‘centrifugal’ attachment dynamics. Resulting data also allows to delineate more nuanced factorial and developmental accounts of toddlers’ sustained attention to musical stimuli than has been previously advanced.Becas-Chile Scholarship, CONICYT Chile CONICYT- Chile Cambridge Scholarship, Cambridge Commonwealth, European & International Trus

Tělo, mysl a ztracená generace v dílech Hemingwaye a Fitzgeralda

Diplomová práce zkoumá koncept tělesnosti ve vybraných románech Ernesta Hemingwaye a Francise Scotta Fitzgeralda, přičemž jako teoretický základ využívá dílo francouzského filozofa Jeana Baudrillarda. Práce se snaží rozklíčovat významovost lidského těla skrze podrobnou analýzu vyobrazených postav, přičemž se zaměřuje zejména na roli těla jako znaku, který odráží nejen strasti svého majitele, ale i zásadní společenské změny. Autoři ztracené generace ve svých dílech zachycují postupný rozpuk kapitalismu a konzumerismu a reflektují tak vznik konzumní společnosti, která se pro Jeana Baudrillarda stala hlavním předmětem zkoumání. Základním cílem diplomové práce je tedy probádat, jak lidské tělo ve vybraných románech reflektuje společenské změny a jakými způsoby individuální postavy využívají své tělo v rámci definice vlastní pozice ve společnosti. Po uvedení teoretického rámce se analýza nejprve zabývá módou. Na konkrétních příkladech je demonstrována její schopnost sjednotit členy konzumní společnosti prostřednictvím společné touhy sledovat konkrétní trendy, nebo naopak hierarchicky rozdělit spotřebitele na základě odlišných přístupů ke konzumaci. Druhou oblastí výzkumu je sport. Zatímco Fitzgerald většinou zobrazuje esteticky štíhlé atletické tělo a sport jako prostředek k dosažení sociálního statusu,...The thesis explores the notion of physicality in selected novels of Ernest Hemingway and Francis Scott Fitzgerald, using the works of Jean Baudrillard as its theoretical base. The text seeks to uncover the significance of a human body in the novels through a detailed observation of the depicted characters, focusing mainly on the role of the body as an emblem that reflects not only its owner's individual battles, but also the transgressive processes taking place in the society. The study assumes that the works written by the authors of the Lost Generation capture the gradual onset of capitalism and consumerism, and thus they reflect the emergence of the consumer society, a social order that became Baudrillard's main subject of study. The main aim of the thesis is thence to explore the human body as a reflection of major societal changes and uncover the methods in which the characters use their bodies to define their own position in the newly arising system. Following the theoretical introduction, the analysis firstly examines fashion and demonstrates its capability to either unify the members of the consumer society through their shared desire to follow specific trends, or alternatively hierarchically divide the consumers based on their dissimilar approaches to consumption. Secondly, the thesis...Department of Anglophone Literatures and CulturesÚstav anglofonních literatur a kulturFaculty of ArtsFilozofická fakult