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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.
941

Exploring Impulsive Activation During Spoken Language Comprehension

Tsang, Cara Kar Lee 07 January 2013 (has links)
A language comprehension mechanism that immediately starts processing language as it is encountered is typically thought of as one that speeds and facilitates spoken language comprehension. However, there exist cases where the earliest parts of a word or phrase encode information that is somewhat at odds with the remainder of the word or phrase in full. Examples of these "potentially misleading" cases include compound words where the initial subpart of the compound belongs to a different syntactic category than the entire compound (e.g., "popcorn", "greyhound"), or noun phrases where the initial element of the phrase signals perceptual properties possessed by the referent of the noun phrase (e.g., some Chinese Cantonese classifier-noun phrases). Using a visual-world methodology, this dissertation explores the kinds of unintended or "impulsive" activation that are triggered when listeners encounter such cases, as well as how syntactic and contextual cues can constraining this impulsive activation. Experiment 1 examines whether hearing compound subparts (e.g., "pop-" in "popcorn") activates conceptual associates across syntactic categories, and Experiment 2 examines whether this activation is moderated by listeners' expectations about the syntactic structure of the sentences they encounter. Experiments 3 and 4 investigate the processing of compounds whose initial subparts correspond to colour terms (e.g., "greyhound"). Experiment 3 explores whether these colour subparts trigger the activation of phrasal-level descriptions of non-target objects in the visual display, and whether this activation is influenced by the presence/absence of motivation to use colour descriptions when naming screen objects. Experiment 4 further explores whether a perceptual mismatch between a target object and the colour term in its name increases this impulsive activation. Finally, Experiment 5 investigates whether listeners use the perceptual information encoded in pre-nominal classifiers in Cantonese Chinese to guide their consideration of referential candidates whose perceptual properties do or do not match the classifier semantics. The findings from this dissertation point to the highly interactive nature of spoken language comprehension, suggesting that the kinds of impulsive activation under current discussion are rampant and automatic, but can also be suppressed to varying degrees by the syntactic, semantic, and contextual cues available to the listener.
942

Understanding Treatment Effectiveness for Aggressive Youth: The Importance of Regulation in Parent-child Interactions

De Rubeis, Sera 11 December 2009 (has links)
Reviews summarizing hundreds of studies cite Parent Management Training (PMT) and Cognitive-Behaviour Therapy (CBT) as some of the most effective interventions for aggressive youth (e.g., Brestan and Eyberg, 1998). However, variability in outcomes persists, and we have yet to understand why certain interventions only produce behaviour change in some children. Using a clinical sample of 57 children (53 boys, 4 girls) and their mothers enrolled in a combined PMT/CBT program, the current study examined the relation between changes in real-time parent-child interactions, and children’s externalizing outcomes from pre- to post-treatment. Results showed that dyads who were regulated in their interactions over time reported greater reductions in externalizing symptoms from pre- to post-treatment compared to dysregulated dyads. Changes in mean levels of affective content (e.g., negativity) were not associated with aggressive outcomes. Findings suggest that dyadic regulation may be an important process associated with treatment success for aggressive youth.
943

Evaluation of a genomic work flow for the detection of Bacillus subtilis in animal feed and food samples

Lindberg, Stina January 2005 (has links)
Bacillus anthracis is one of the most feared agents of biological warfare and causes the deadly disease called anthrax. SVA (statens veterinärmedicinska anstalt) is working on a project together with SLV (statens livsmedelsverk) where the target is to find rapid and effective detection methods for Bacillus anthracis in animal feed and food samples. Bacillus subtilis, which is harmless, was used in this study as a model organism to Bacillus anthracis. A known concentration of vegetative Bacillus subtilis was spiked in animal feed and food samples. The genomic work flow was based on automated DNA isolation and real time PCR. The aim of the study was to screen for inhibitory components in the animal feed and food samples using two different DNA isolation robots; Magnatrix 8000 and Biorobot EZ1. The results showed that DNA of high quality was extracted from the samples with both robots. However, the CT-value generated by the real time PCR showed considerable variation depending on the sample matrix. Some samples, for instance egg and liver, were problematic and gave low concentrations and high CT-values probably due to inhibitory components in the samples. Further studies will be needed to solve these problems and optimize the methods that were used in this study.
944

Bartonella Henselae Inhibits Cellular Apoptotic Regulators to Ensure Survival

Parker, Jeffery Todd 01 December 2009 (has links)
Human pathogens survive anti-pathogen host immune assault by either circumventing or evading the host immune response. Bartonella henselae, an intracellular pathogen previously shown to disrupt intrinsic apoptotic messengers to enhance its survival, exploits multiple facets of the cellular apoptotic mechanisms. Cellular pathways affected by apoptotic processes were assessed using real-time reverse-transcriptase-polymerase-chain-reaction (rRT-PCR) to measure the effect of B. henselae on cell regulator gene expression (TRADD, FADD, caspase-8 and caspase-3), caspase activity, DNA cell cycle analysis, cell regulator protein expression and overall cell viability and morphology. The presence of B. henselae suppresses overall gene expression for TRADD and FADD and it dramatically suppresses ceramide-induced TRADD and FADD gene expression. The presence of B. henselae has a noticeable effect on ceramide-induced caspase-8 and caspase-3 gene expression. Only caspase-3 enzymatic activity was ceramide-induced and likewise supressed by the presence of B. henselae, whereas caspase-6 and caspase-8 were unaffected and equivalent to controls. The presence of B. henselae inhibits ceramide-induced DNA fragmentation, maintains overall cell morphology and enhances host cell viability. Lastly, B. henselae inhibits the time-dependant ceramide-induction of TRADD protein and suppresses ubiquitous FADD protein expression. We demonstrated that B. henselae inhibits apoptotic induction in a systematic manner following exogenous apoptotic induction. B. henselae protection of microvascular endothelial cells from apoptosis induction begins at the modulation of cell surface receptor-dependent signaling. B. henselae minimizes, but does not completely abrogate, the cytotoxic effect of the apoptogenic shingolipid ceramide on human microvascular endothelial cells (CDC.EU.HMEC-1). Broadening our understanding of the sequence of cell regulator suppression events by intracellular pathogens will provide insight into disease manifestation. Further, understanding how infected cells initiate and conclude apoptosis will open new avenues into the study of disease treatment.
945

Experimental study of a two-DOF five bar closed-loop mechanism

Moazed, Reza 28 August 2006
This research is to carry out an experimental study to examine and verify the effectiveness of the control algorithms and strategies developed at the Advanced Engineering Design Laboratory (AEDL). For this purpose, two objectives are set to be achieved in this research. The first objective is to develop a generic experiment environment (test bed) such that different control approaches and algorithms can be implemented on it. The second objective is to conduct an experimental study on the examined control algorithms, as applied to the above test bed. <p>To achieve the first objective, two main test beds, namely, the real-time controllable (RTC) mechanism and the hybrid machine, have been developed based on a two degree of freedom (DOF) closed-loop five-bar linkage. The 2-DOF closed-loop mechanism is employed in this study as it is the simplest of multi-DOF closed-loop mechanisms, and control approaches and conclusions based on a 2-DOF mechanism are generic and can be applied to a closed-loop mechanism with a higher number of degrees of freedom. The RTC mechanism test bed is driven by two servomotors and the hybrid machine is driven by one servomotor and a traditional CV motor. To achieve the second objective, an experimental study on different control algorithms has been conducted. The Proportional Derivative (PD) based control laws, i.e., traditional iii PD control, Nonlinear-PD (NPD) control, Evolutionary PD (EPD) control, non-linear PD learning control (NPD-LC) and Adaptive Evolutionary Switching-PD (AES-PD) are applied to the RTC mechanism; and as applied to the Hybrid Actuation System (HAS), the traditional PD control and the SMC control techniques are examined and compared. <p> In the case of the RTC mechanism, the experiments on the five PD-based control algorithms, i.e., PD control, NPD control, EPD, NPD-LC, and AES-PD, show that the NPD controller has better performance than the PD controller in terms of the reduction in position tracking errors. It is also illustrated by the experiments that iteration learning control (ILC) techniques can be used to improve the trajectory tracking performance. <p>However, AES-PD showed to have a faster convergence rate than the other ILC control laws. Experimental results also show that feedback ILC is more effective than the feedforward ILC and has a faster convergence rate. In addition, the results of the comparative study of the traditional PD and the Computed Torque Control (CTC) technique at both low and high speeds show that at lower speeds, both of these controllers provide similar results. However, with an increase in speed, the position tracking errors using the CTC control approach become larger than that of the traditional PD control. In the case of the hybrid machine, PD control and SMC control are applied to the mechanism. The results show that for the control of the hybrid machine and the range of speed used in this experimental study, PD control can result in satisfactory performance. However, SMC proved to be more effective than PD control.
946

High-speed coordination in groupware

Barjawi, Mutasem 18 November 2009
Coordination is important in groupware because it helps users collaborate efficiently. However, groupware systems in which activities occur at a faster pace need faster coordination in order to keep up with the speed of the activity. Faster coordination is especially needed when actions are dependent on one another (i.e., they are tightly-coupled) and when each user can see and interact with other users actions as they occur (i.e., real time). There is little information available about this type of fast coordination (also named high-speed coordination or HSC) in groupware. In this thesis, I addressed this problem by providing a body of principles and information about high-speed coordination. This solution was achieved by creating a groupware game called RTChess and then conducting an exploratory evaluation in which high-speed coordination was investigated. The results of this evaluation show that there were small amounts of high-speed coordination in the game and that high-speed coordination was difficult to achieve. In addition, HSC was affected by five main characteristics of the groupware environment: user experience, level of awareness of the partners interactions, communication between partners, number of dependencies that affect the users interactions, and pace of activities in the system.
947

Changes in proteoglycans in endothelial cells under hyperglycemic conditions

Han, Juying 02 December 2009
Heparan sulfate proteoglycan (HSPG) or heparan sulfate (HS) degradation may contribute to endothelial cell (EC) dysfunction in diabetes. HSPGs, syndecan and perlecan, contain a protein core with mainly HS glycosaminoglycans (GAGs) attached. HSPGs modulate growth factors and function in membrane filtering. Heparanase induction is likely responsible for diabetic HS degradation. Heparin protects endothelium and insulin regulates glucose metabolism. Our objectives were to observe HSPG changes by studying EC GAG content and gene expression of syndecan, perlecan and heparanase under hyperglycemic conditions with insulin and/or heparin treatment.<p> GAGs, including HS, were determined by the carbazole assay and visualized by agarose gel electrophoresis in porcine aortic EC cultures treated with high glucose (30 mM) and/or insulin (0.01 U/ml) for 24, 48 and 72 hours and/or heparin (0.5 µg/ml) for 72 hours. High glucose decreased cell GAGs and increased medium GAGs. GAGs increased with time in control cultures and in high glucose plus insulin treated medium. GAGs were decreased with insulin but increased with insulin or heparin plus high glucose.<p> Confluent cultured human aortic ECs were incubated with control medium, high glucose and/or insulin and/or heparin for 24 hours. Real time PCR determination showed that: high glucose increased heparanase, decreased syndecan and had no effect on perlecan mRNA; insulin or heparin with/without high glucose decreased and insulin and heparin with high glucose increased heparanase mRNA; heparin and insulin with high glucose increased but insulin decreased syndecan mRNA. Actinomycin D (10 µg/ml) inhibited heparanase and syndecan mRNA with high glucose plus insulin plus heparin and inhibited heparanase mRNA with high glucose compared to time 0 but not â-actin after addition for 0, 2, 4, 8 and 24 hours. Bioinformatic studies revealed that transcription factor Sp1 activates heparanase promoter by high glucose and may play a role in regulation of perlecan and syndecan promoters.<p> Insulin or heparin inhibited the reduction in EC GAGs and syndecan mRNA and induction in heparanase by high glucose, indicating their protective effect. Decreased GAGs by insulin may relate to the pathology of hyperinsulinemia. Transcriptional regulation by heparin and/or insulin may cause variation in gene expression of heparanase, syndecan and perlecan.
948

Model Predictive Control for Active Magnetic Bearings

Lundh, Joachim January 2012 (has links)
This thesis discuss the possibility to position control a rotor levitated with active magnetic bearings. The controller type considered is model predictive control which is an online strategy that solves an optimization problem in every sample, making the model predictive controller computation-intense. Since the sampling time must be short to capture the dynamics of the rotor, very little time is left for the controller to perform the optimization. Different quadratic programming strategies are investigated to see if the problem can be solved in realtime. Additionally, the impact of the choices of prediction horizon, control horizon and terminal cost is discussed. Simulations showing the characteristics of these choises are made and the result is shown. / Det här examensarbetet diskuterar möjligheten att positionsreglera en rotor som leviteras på aktiva magnetlager. Reglerstrategin som används är modellbaserad prediktionsreglering vilket är en online-metod där ett optimeringsproblem löses i varje sampel. Detta gör att regulatorn blir mycket beräkningskrävande. Samplingstiden för systemet är mycket kort för att fånga dynamiken hos rotorn. Det betyder att regulatorn inte ges mycket tid att lösa optimeringsproblemet. Olika metoder för att lösa QP-problem betraktas för att se om det är möjligt att köra regulatorn i realtid. Dessutom diskuteras hur valet av prediktionshorisont, reglerhorisont och straff på sluttillståndet påverkar regleringen. Simuleringar som visar karakteristiken av dessa val har utförts.
949

A PC-based data acquisition system for sub-atomic physics measurements

Chabot, Daron 23 July 2008
Modern particle physics measurements are heavily dependent upon automated data acquisition systems (DAQ) to collect and process experiment-generated information. One research group from the University of Saskatchewan utilizes a DAQ known as the Lucid data acquisition and analysis system. This thesis examines the project undertaken to upgrade the hardware and software components of Lucid. To establish the effectiveness of the system upgrades, several performance metrics were obtained including the system's dead time and input/output bandwidth.<p>Hardware upgrades to Lucid consisted of replacing its aging digitization equipment with modern, faster-converting Versa-Module Eurobus (VME) technology and replacing the instrumentation processing platform with common, PC hardware. The new processor platform is coupled to the instrumentation modules via a fiber-optic bridging-device, the sis1100/3100 from Struck Innovative Systems.<p>The software systems of Lucid were also modified to follow suit with the new hardware. Originally constructed to utilize a proprietary real-time operating system, the data acquisition application was ported to run under the freely available Real-Time Executive for Multiprocessor Systems (RTEMS). The device driver software provided with sis1100/3100 interface also had to be ported for use under the RTEMS-based system. <p>Performance measurements of the upgraded DAQ indicate that the dead time has been reduced from being on the order of milliseconds to being on the order of several tens of microseconds. This increased capability means that Lucid's users may acquire significantly more data in a shorter period of time, thereby decreasing both the statistical uncertainties and data collection duration associated with a given experiment.
950

Understanding Treatment Effectiveness for Aggressive Youth: The Importance of Regulation in Parent-child Interactions

De Rubeis, Sera 11 December 2009 (has links)
Reviews summarizing hundreds of studies cite Parent Management Training (PMT) and Cognitive-Behaviour Therapy (CBT) as some of the most effective interventions for aggressive youth (e.g., Brestan and Eyberg, 1998). However, variability in outcomes persists, and we have yet to understand why certain interventions only produce behaviour change in some children. Using a clinical sample of 57 children (53 boys, 4 girls) and their mothers enrolled in a combined PMT/CBT program, the current study examined the relation between changes in real-time parent-child interactions, and children’s externalizing outcomes from pre- to post-treatment. Results showed that dyads who were regulated in their interactions over time reported greater reductions in externalizing symptoms from pre- to post-treatment compared to dysregulated dyads. Changes in mean levels of affective content (e.g., negativity) were not associated with aggressive outcomes. Findings suggest that dyadic regulation may be an important process associated with treatment success for aggressive youth.

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