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The Global ETD Search service is a free service for researchers
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 31 to 35 of 35 (0.018 seconds)| 31 |
Risk factors associated with positive quantiFERON-TB gold in-tube and tuberculin skin tests results in Zambia and South AfricaShanaube, Kwame, Hargreaves, James, Fielding, Katherine, Schaap, Ab, Lawrence, Katherine-Anne, Hensen, Bernadette, Sismanidis, Charalambos, Menezes, Angela, Beyers, Nulda, Ayles, Helen, Godfrey-Faussett, Peter 04 1900 (has links)
The original publication is available at http:/www.plosone.org / Introduction: The utility of T-cell based interferon-gamma release assays for the diagnosis of latent tuberculosis infection remains unclear in settings with a high burden of tuberculosis. Objectives: To determine risk factors associated with positive QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) results and the level of agreement between the tests; to explore the hypotheses that positivity in QFT-GIT is more related to recent infection and less affected by HIV than the TST. Methods: Adult household contacts of tuberculosis patients were invited to participate in a cross-sectional study across 24 communities in Zambia and South Africa. HIV, QFT-GIT and TST tests were done. A questionnaire was used to assess risk factors. Results: A total of 2,220 contacts were seen. 1,803 individuals had interpretable results for both tests, 1,147 (63.6%) were QFT-GIT positive while 725 (40.2%) were TST positive. Agreement between the tests was low (kappa = 0.24). QFT-GIT and TST results were associated with increasing age (adjusted OR [aOR] for each 10 year increase for QFT-GIT 1.15; 95% CI: 1.06-1.25, and for TST aOR: 1.10; 95% CI 1.01-1.20). HIV positivity was less common among those with positive results on QFT-GIT (aOR: 0.51; 95% CI: 0.39-0.67) and TST (aOR: 0.61; 95% CI: 0.46-0.82). Smear positivity of the index case was associated with QFT-GIT (aOR: 1.25; 95% CI: 0.90-1.74) and TST (aOR: 1.39; 95% CI: 0.98-1.98) results. We found little evidence in our data to support our hypotheses. Conclusion: QFT-GIT may not be more sensitive than the TST to detect risk factors associated with tuberculous infection. We found little evidence to support the hypotheses that positivity in QFT-GIT is more related to recent infection and less affected by HIV than the TST. © 2011 Shanaube et al. / Publishers' Version
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Anomalous Dimensions in the WF O(N) Model with a Monodromy Line DefectSöderberg, Alexander January 2017 (has links)
General ideas in the conformal bootstrap program are covered. Both numerical and analytical approaches to the bootstrap equation are reviewed to show how it can be manipulated in different ways. Further analytical approaches are studied for theories with defects. We consider the three-dimensional CFT at the corresponding WF fixed point in the O(N) \phi^4 model with a co-dimension two, monodromy defect. Anomalous dimensions for bulk- and defect-local fields as well as one of the OPE coefficients are found to the first loop order. Implications of inserting this defect and constraints that arises from symmetries of the theory are investigated.
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The evaluation of whole blood cytokine assay for diagnosis of M.tuberculosis infection in South African children with household tuberculosis contact.Masilo, J. M. 04 1900 (has links)
M. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Background: There are critical unmet needs for improved strategies in the detection
and diagnosis of M.tuberculosis infection in children, and for prevention of
tuberculosis disease in children. Bacillus Calmette-Guérin (BCG) vaccination has
limited the utility of tuberculin skin testing (TST) in areas with high vaccine coverage.
Objectives: The aim of this study was to estimate the prevalence of M.tuberculosis
infection in children with household tuberculosis contacts, using QFT-GIT testing in
comparison with TST.
Methods: This study was a cross-sectional design to assess the performance of a
new T-cell based blood test, namely QuantiFERON-TB Gold In Tube (QFT-GIT), for
diagnosis of tuberculosis infection in the children (n=182) of adults (n=124) with
pulmonary tuberculosis, additionally to determine the prevalence of M.tuberculosis
infection in children with household tuberculosis contacts, using QFT-GIT testing in
comparison with TST. The study was carried out at Chris Hani Hospital. For children
involved in the study, tuberculosis exposure information was obtained, together with
TST, QFT-GIT, and HIV testing.
Data obtained from both experiments was statistically analysed using SPSS version
24 to determine whether there was a significant agreement between QFT-GIT and
TST on the detection of M.tuberculosis prevalence in children with house hold
contacts with confirmed M.tuberculosis infection.
Results: This study examined the sensitivity and specificity of the QFT-GIT tests
compared with the standard TST for diagnosing latent tuberculosis disease in
paediatric contacts. Because of the lack of a latent tuberculosis “gold standard”, the
specificity and sensitivity of QFT-GIT was calculated with a two-by-two table method.
The specificity of the QFT-GIT was 84% and the sensitivity was 85%. There was a
good correlation between QFT-GIT and TST (Cohen’s kappa of 0.705). Seventeen
percent (17%) of the 182 children tested by QFT-GIT yielded indeterminate results.
Age was associated with indeterminate QFT-GIT results in paediatric tuberculosis
contacts. Point prevalence for QFT-GIT was recorded as 31% at baseline and 39.5%
after six months indicating variability between QFT-GIT results at baseline and after
six months.
Conclusion: It was concluded that the prevalence of tuberculosis infection was
common among South African children who live with an adult with active
tuberculosis. The agreement between QFT-GIT assay and TST for the diagnosis of
latent tuberculosis in children was high. Although TST and QFT-GIT assays
appeared comparable, QFT-GIT showed higher positivity rate amongst those
contacts with reported household tuberculosis exposure compared to TST. The QFTGIT
assay was a better indicator of the risk of M.tuberculosis infection than TST in a
BCG-vaccinated population.
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Quantum structure of holographic black holes / Kvantstruktur hos holografiska svarta hålRiedel Gårding, Elias January 2020 (has links)
We study a free quantum scalar field in the BTZ spacetime as a model of the AdS/CFT correspondence for black holes, and show the essential steps in computing Bogolyubov coefficients between modes on either side of the wormhole. As background, we review the BTZ geometry in standard, Kruskal and Poincaré coordinates, holographic renormalisation of the dual field theory and canonical quantisation in curved spacetime. / Vi studerar ett fritt skalärt kvantfält i BTZ-rumtiden som en modell av AdS/CFT-dualiteten för svarta hål och visar huvudstegen i beräkningen av Bogolyubov-koefficienter mellan moder på olika sidor av maskhålet. Som bakgrund redogör vi för BTZ-geometrin i standard-, Kruskal- och Poincarékoordinater, holografisk renormering av den duala fältteorin och kanonisk kvantisering i krökt rumtid.
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Exotic Decays of a Vector-liketop Partner at the LHCSkwarcan-Bidakowski, Alexander January 2019 (has links)
An evaluation of how sensitive some ATLAS searches for new physics are to a new beyond standard model (BSM) vector-like quark (VLQ) and a pseudo Nambu-Goldstone boson (pNGB) scalar. This was done by simulating a signal containing these new particles and making a recast of it onto existing verified ATLAS searches for new physics at center-of-mass (CM) energy of 13 TeV (Run 2) at the Large Hadron Collider (LHC). Signals for recasting were tailored such that their final states would be appropriate in relation to each respective ATLAS search in order to use the same selection criteria as applied in the existing searches. The results are summarized in the form of significances (Z) for each masspoint of the new top-partner and S particle. Significances did not show any expectiation of excluding any masspoint in the examined mass range for the recasts at 95% CL. This suggests that a dedicated search for these particles in the considered masspoints would be required.
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