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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the 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.
311

Defining markers and mechanisms of human somatic cell reprogramming

Ratanasirintrawoot, Sutheera January 2013 (has links)
Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by over expression of the transcription factors OCT4, SOX2, KLF4 and c-MYC. Using serial live cell immunofluorescence imaging of human fibroblasts undergoing reprogramming, we traced the emergence of nascent iPS cell colonies among heterogeneous cell populations and defined the kinetics of marker expression. We identified distinct colony types that morphologically resemble embryonic stem (ES) cells yet differ in molecular phenotype and differentiation potential. By analyzing expression of pluripotency markers, methylation at the OCT4 and NANOG promoters, and differentiation into teratomas, we determined that only one colony type represented bona fide iPS cells, whereas the others represented reprogramming intermediates. Proviral silencing and expression of TRA-1-60, DNMT3B, and REX1 distinguished the fully reprogrammed state, whereas Alkaline Phosphatase, SSEA-4, GDF3, hTERT and NANOG proved insufficient as markers. Reprogramming in chemically defined medium favored formation of bona fide iPS cell colonies relative to partially reprogrammed colonies. These data highlight the need for rigorous characterization and standardization of putative iPS cells.
312

A sound divided : the battles of musical space in Austin, Texas

Thompson, Todd M. 21 February 2011 (has links)
Austin is the self-proclaimed “Live Music Capital of the World,” and its commitment to the practice of musical performance has created a unique environment for musicians and audiences. In particular, this paper focuses on the history of music in public places in Austin. This creative identity has helped encourage growth that creates stress on cultural and social relations. The conflict over amplified music is one front where this opposition plays out. Currently, the Austin noise ordinance is a decibel-based, quantifiable measurement, but everyone involved must make a greater effort to communicate and compromise in the social sphere. To cultivate a thriving live music scene, a strong commitment from venues, musicians, residents, and city hall is necessary. / text
313

Spanning the Continuum: From Single Cell to Collective Migration

Vig, Dhruv Kumar January 2015 (has links)
A cell's ability to sense and respond to mechanical signals highlights the significance of physical forces in biology; however, to date most biomedical research has focused on genetics and biochemical signaling. We sought to further understand the physical mechanisms that guide the cellular migrations that occur in a number of biological processes, such as tissue development and regeneration, bacterial infections and cancer metastasis. We investigated the migration of single cells and determined whether the biomechanics of these cells could be used to elucidate multi-cellular mechanisms. We first studied Borrelia burgdorferi (Bb), the bacterium that causes Lyme disease. We created a mathematical model based on the mechanical interactions between the flagella and cell body that explained the rotation and undulation of the cell body that occurs as the bacterium swims. This model further predicts how the swimming dynamics could be affected by alterations in flagellar or cell wall stiffnesses. Fitting the model to experimental data allowed us to calculate the flagellar torque and drag for Bb, and showed that Treponema pallidum (Tp), the syphilis pathogen, is biomechanically similar to Bb. Next, we used experimentally-determined parameters of Bb's motility to develop a population-level model that accounts for the morphology and spreading of the "bulls-eye" rash that is typically the first indicator of Lyme disease. This work supported clinical findings on the efficacy of antibiotic treatment regimes. Finally, we investigated the dynamics of epithelial monolayers. We found that intracellular contractile stress is the primary driving force behind collective dynamics in epithelial layers, a result previously predicted from a biophysical model. Taken together, these findings identify the relevance of physics in cellular migration and a role of mechanical signaling in biomedical science.
314

Minimizing Risks and Morbidity in Live Kidney Donors

Biglarnia, Ali-Reza January 2010 (has links)
Live kidney donors are healthy volunteers who are exposed to major surgical procedure and physical harms with no direct therapeutic benefits. Efforts to minimize their risks and morbidity are therefore of utmost importance. The current thesis describes studies on donor evaluation, surgical procedure and postoperative management of live kidney donors. The overall purpose is to evaluate and possibly improve routines and treatments in order to reduce risks and the overall morbidity of live kidney donors. In Study I, we evaluated the assessment of kidney function during donor evaluation and found that the accuracy of iohexol glomerular filtration rate (GFR) is compromised by large variations in repeated measurements in presumably healthy donors. We proposed that there is a need for improvement of GFR measurements and that the assessment of predonation kidney function should be more comprehensive, involving GFR, laboratory investigations, functional and morphological examinations and sound clinical judgment. In Study II, we addressed the risk of perioperative venous thromboembolism (VTE) and concluded that expanding the standard screening protocol for VTE to include perioperative venous duplex can potentially decrease the VTE-related morbidity. In studies III and IV, we investigated the impact of hand-assisted retroperitoneoscopic (HARS) nephrectomy on donor safety and perioperative morbidity. The HARS nephrectomy uses the hand-assisted approach, which enables immediate manual compression for hemostasis in case of sudden and severe bleeding. Additionally, the pure retroperitoneal access further increases the safety margin of laparoscopic donor nephrectomy by 1) minimizing the risk of intestinal injury, and 2) exposure of the retroperitoneal nerves, making HARS suitable for continuous infusion of local anesthetics (CILA). CILA effectively reduces the need for opioid consumption and has the potential to totally obviate opiate analgesics postoperatively. Consequently, CILA in combination with HARS reduces morphine-related morbidity and promotes postoperative recovery. In accordance with these data, we recommend improvement and modification of the donor evaluation process as well as a broad introduction of HARS nephrectomy in combination with CILA to increase the safety margin for live kidney donors.
315

The stress of moving out : physiological and behavioural effects of commercial transport on Atlantic salmon (Salmo salar) smolts

Nomura, Miki 05 1900 (has links)
Despite the controversy over environmental sustainability, salmon aquaculture in British Columbia is economically important for many coastal communities and is reported as being the largest agricultural export product for the province. This thesis examined the welfare status of commercially produced Atlantic salmon smolts during transport from freshwater farms to the saltwater net pens using physiology and behaviour to assess transport stress. Smolts were transported first by truck from the freshwater farm to the dock, and then in the flow-through cargo holds of a live-haul vessel to the saltwater net pens. Fish and water were sampled before and after truck transport, and several times aboard the vessel. Assessment of stress was based on measurement of plasma cortisol, glucose, lactate, potassium, sodium and chloride concentrations, as well as behavioural observations made on underwater video footage. Seven transports of fish originating from two different hatcheries were sampled; one was a land-based tank hatchery that required a 30-min drive to the dock, and the other a lake net pen facility that was 90 min to the dock. Analysis of plasma constituents supported previous studies that recovery from the stress accumulated during loading and truck transport can be quite rapid in a live-haul vessel. Underwater video footage, recorded at the freshwater farms and in the cargo holds of the Sterling Carrier, also suggested recovery onboard in that for the most part, behaviour onboard was similar to behaviour at the freshwater farms. There were some significant differences between fish from the two types of hatcheries, particularly in the original hatchery conditions and in their behavioural responses to transport conditions; however, post-transport growth and mortality rates reported by the saltwater farms showed no significant difference. Although fish were subjected to moderately stressful conditions during part of the process, smolt transport as currently carried out by our industry partners reflects good husbandry practices and fish welfare.
316

Namuose slaugomų sunkiai sergančių asmenų ir jų artimųjų gyvenimo kokybės ypatybės / The specific features of quqlity life of persons with poor health state nursing at home and theys family members

Sapiegienė, Gražina 14 January 2009 (has links)
Gauti rezultatai parodė, kad slaugomų sunkai sergančių asmenų ir jų artimųjų gyvenimo kokybė pasižymi tam tikromis ypatybėmis, tačiau slaugymo procesas, kaip veikla, nėra pagrindinis veiksnys, keičiantis gyvenimo kokybę. / Quality of live is individual evaluation of the status of very persons based on the ground of system of culture influenced by physical, psychological health, level of its independence and by communication between the persons and environment.
317

MAIDS, MEDIA, AND MIGRATION: FILIPINO NEWS MEDIA IN MONTRÉAL AND THE TRANSNATIONAL LIVES OF LIVE-IN CAREGIVERS

Kiely, Shannon 29 April 2011 (has links)
This thesis explores the role of media in the lives of live-in caregivers in Montréal by looking at two Filipino newspapers and mainstream news coverage on Filipinas and the Philippines. While Filipino newspapers elaborate Filipino identity and speak back to stereotypes in mainstream news, their impact is curtailed by limited distribution and content range. Live-in caregivers in Montréal were selected as a special audience group through which to examine media representations of Filipinos because they are ‘othered’ through interlocking processes of gender and race. The live-in caregiver program (LCP), through which they migrate to Canada, lays bare the price that third world women immigrants are asked to pay for citizenship rights in Canada. LCP work is often underpaid, demeaning, and exploitative. Examining the lives and media habits of LCP workers ethnographically breaks new ground in studies of both domestic work and minorities and media in Canada.
318

Development of An Antibiotic Marker-Free Gene Delivery System in Streptococcus gordonii

Hulbah, Maram 11 April 2013 (has links)
Streptococcus gordonii, a commensal oral bacterium, is considered a good candidate to function as a live oral vaccine vector. The introduction of vaccine antigen genes into S. gordonii relies on the use of antibiotic resistance genes as selectable markers, which is undesirable. In this study, we used auxotrophic complementation (deletion of an essential gene from the chromosome and insertion into a plasmid) as a means to create an antibiotic marker-free gene delivery system in S. gordonii. S. gordonii ?thyA was created and complemented by an antibiotic marker-free expression plasmid containing the intact thyA gene, pDL276/thyAdelkan. Transformation of pDL276/thyAdelkan into the mutant gave an unexpected 100-fold increase in transformation efficiency as compared to pDL276. The transformants arose from both single and double crossing over. The increase in transformation efficiency suggests that a highly efficient antibiotic marker-free system to deliver genes to the chromosome has been created using thyA complementation.
319

Investigations of Myelin Basic Protein, SH3 Proteins and the Oligodendrocyte Cytoskeleton during Maturation and Development

Smith, Graham 29 August 2012 (has links)
The myelin basic protein (MBP) family arises from different transcription start sites of the Golli (gene of oligodendrocyte lineage) gene, with further variety generated by differential splicing. The “classic” MBP isoforms are peripheral membrane proteins that facilitate compaction of the mature myelin sheath, but also have multiple protein interactions. As an intrinsically disordered protein, MBP has proven to have complex structural and functional relationships with proteins in vitro including actin, tubulin, Ca2+-calmodulin, and multiple protein kinases. The investigations reported in this thesis were to further examine the multifunctionality, and protein:protein interactions of MBP with cytoskeletal and SRC homology 3 domain (SH3) proteins in cells using an oligodendrocyte (OLG) model system to better understand MBP’s contributions to membrane structure, formation, and elaboration in the developing OLG. A new function of MBP has been described showing that classic MBPs can modulate voltage operated calcium channels (VOCCs) by direct or indirect protein-protein interactions at the OLG cytoplasmic leaflet. These interactions contribute to global calcium homeostasis, and may play a complex developmental and spatiotemporal role in the regulation of oligodendrocyte precursor cell (OPC) migration and OLG differentiation. The importance of MBPs SH3 ligand binding domain within its central amino acid region was investigated with the protein-tyrosine kinase Fyn. Co-expression of MBP with a constitutively-active form of Fyn in OLGs resulted in membrane process elaboration, a phenomenon that was abolished by amino acid substitutions within MBP’s SH3-ligand domain. These results suggest that MBP’s SH3-ligand domain plays a key role, and may be required for proper membrane elaboration of developing OLGs. Lastly, interactions of MBP with the OLG cytoskeleton were investigated in OLGs transfected with fluorescently-tagged MBP, actin, tubulin, and zonula occludens 1 (ZO-1). MBP redistributes to distinct ‘membrane-ruffled’ regions of the plasma membrane where it had increased co-localization with actin and tubulin, and with the SH3-domain-containing proteins cortactin and ZO-1, when stimulated with PMA, a potent activator of the protein kinase C pathway. The results presented here advance our understanding regarding protein:protein interactions of MBP, and its multifunctionality in OLGs with regards to membrane formation and elaboration. / This work was supported by the Canadian Institutes of Health Research (MOP #86483, J.M.B. and G.H.), and Discovery Grants from the Natural Sciences and Engineering Research Council of Canada (NSERC, G.H., RG121541). G.S.T.S. was a recipient of a Doctoral Studentship from the Multiple Sclerosis Society of Canada
320

A narrative inquiry into three Korean teachers' experiences of teaching returnee children

Hong, Young-Suk Unknown Date
No description available.

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