Search

The purpose of this dissertation was to understand and compare the effect of training non-native English Speaking (NNES) learners (N = 480) in two distinct learning environments, (i) traditional face-to-face and (ii) online synchronous hybrid learning (SHL). In the traditional training mode, NNES learners (n = 360) were trained by NNES voice and accent (VANC) trainers in a physical, face-to-face setting. In the second, CAPT+SHL training mode, the NNES learners were trained by NNES VANC trainers with the help of a native-English computer-assisted pronunciation training (CAPT) tool in an online SHL environment. Factor analysis, higher-order factor analysis, hierarchical cluster analysis, and multidimensional scaling yielded a reliable scale, Eddie's Voice Test (EVT). Multiple regression yielded a predictive model between NNES pronunciation and their performance. In addition, the CAPT+SHL training mode produced higher scores on pronunciation and performance than the traditional training mode, suggesting a combination of NES and NNES VANC instructors are more effective in training NNES learners than NNES instructors by themselves. The case study (n = 3) on VANC trainers' perception of CAPT and SHL yielded three themes: (1) challenges with synchronous hybrid learning (sub-themes include physical challenges, social challenges, and cognitive challenges); (2) computer-assisted pronunciation training (CAPT) impact on non-native-English-speaking (NNES) learner pronunciation (sub-themes include self-paced pronunciation learning and pronunciation benchmarking; and (3). SHL as an equitable learning environment. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Bovine viral diarrhea viruse (BVDV) causes immunosuppression and persistent infection that are great threats to the health of cattle. Antigen presenting cells (APC), like dendritic cells (DC), provide active surveillance and present antigens to the immune system. Monocyte-derived dendrite cells (MDDC) were used as an in vitro model to evaluate the effect of BVDV on DC cell surface markers expression and the role of DC in BVDV dissemination. The study used 4 different strains of BVDV: severe acute noncytopathic (ncp) BVDV2a-1373, mild acute ncpBVDV2a-28508-5, and type1b mucosal disease virus pair, cytopathic (cp) TGAC or ncp TGAN strains. MDDC did not produce infectious virus. However viral RNA was replicated and translated into the NS5a viral protein. The MDDC precursor, monocytes were infected and produced infectious BVDV. The infectious BVDV production was reduced over time as the monocyte differentiated to MDDC and virus production was completely lost by 120 hr of differentiation. The cp-BVDV1b-TGAC up regulated the MHCI, MHCII and CD86 expression while the three ncp BVDV strains reduced the MHCI, MHCII and CD86 expression in MDDC. The role of BVDV infection in autophagy induction and effect of autophagy in BVDV replication was examined. BVDV infection induced autophagy in MDBK cells and Bt cells. There was no significant difference between cp or ncp strains of BVDV in autophagosome formation. The autophagy inducing drug, rapamycin, enhanced the viral replication while the autophagy inhibiting drug, 3MA (3-Methyladenine), suppressed viral replication. The co-localization study, using BVDV NS5A or E1 with GFP-LC3 revealed that BVDV did not replicate in autophagosomes. The effect of cp or ncp BVDV infection in vivo on immune polarization to T helper-2 (TH2) or T helper-1 (TH1) by measuring serum IgG1 and IgG2 concentrations was done using the TGAC-TGAN virus pair. Ncp TGAN directed the immune response toward a TH1 or cellular immune response while the TGAC cytopathic strain of BVDV directed the immune response toward TH2 or humoral immune response. The cumulative findings of these studies contributed to the general body of knowledge regarding immunosuppression associated with BVDV infections.

The current designs of color video projectors suffer from color errors commonly referred to as rainbow artifact. In this thesis, we propose new projector hardware and processing technique that reduce these artifacts signicantly. The hardware and preprocessing designs are tested in simulation by generating a video sequence that can be viewed on a 120 Hz monitor.Our contributions are in three parts. We first propose the notion of rendering error, or an error in the projected image perceived by the human visual system. We then propose spatial-temporal color wheel design incorporated the requirements for the zero rendering error condition and amplitude demodulation. The output was satisfactory, although it required a modied color wheel. Finally, we proposepreprocessing scheme that reduce rendering error by introducing a correction term to cancel the predicted rendering error. This technique can be applied to traditional color wheels, and it was veried on RGB and RGBWW color wheels.

Aseptic processing of low-acid foods containing large particles is an emerging technology. Most multiphase process validation methods employ simulated particles to contain residence time tags, thermo-sensitive implants and/or bio-loads for temperature detection, time-temperature integration, and bactericidal efficacy confirmation. Such particles need to have conservative (fast-moving and slow-heating) characteristics to compare them with real food particles for thermal treatment. This study was conducted to fabricate and test (by heat penetration studies) conservative simulated particles which serve as carriers for thermo-sensitive implants and bio-loads in the validation procedure required for aseptic processing of shelf stable low-acid multiphase foods. A custom developed CPD (Conservative Particle Design) software was used to determine the minimum wall thickness (~ 2 mm) and cavity dimensions of half inch cubic particles for validation of aseptic processing of foods containing half inch cubic potato, carrot and other vegetable pieces. These particles were fabricated from PP (polypropylene) and PMP (polymethylpentene) polymers and they exhibited conservative heat penetration characteristics when compared with various real food particles. Duplicate samples of simulated and real food particles were fitted with thermocouples and heated (< 127 degree C) under pressurized (autoclave, 24 psi) conditions. The method developed in this study can be used for experimental validation of the safety of aseptic processing of multiphase foods and would reduce the cost and complexity of process documentation and filing with regulatory agencies and bring aseptic multiphase foods closer to commercial reality.