VictorJuiz/thesis huggingface dataset:
Investigating the Mechanisms of Forgetting in Aging Using Eyetracking

Recent studies in rodents (McTighe et al, 2010; Burke et al, 2010) have suggested that forgetting is caused by the misidentification of novel stimuli as being familiar, matching the predictions of the representational-hierarchical model of Saksida & Bussey (2010). Here, we tested this idea in humans. Three groups of participants (young, healthy elders, elders at-risk for MCI) viewed novel and repeated stimuli in a continuous viewing task while their eye movements were recorded. According to the eye-movement based memory effect (Ryan et al, 2000) individuals make fewer fixations on items which are perceived as familiar. As interference increased, eye-movements directed to the novel stimuli declined, indicating these novel items were perceived as familiar. This effect was stronger in groups more vulnerable to interference (eg. at-risk elders). These results suggest that forgetting in humans, like rats, is driven by the misidentification of novel items as being familiar.

Keywords: forgetting
interference
aging
eyetracking
representational-hierachical model
Advisor: Barense, Morgan
The Neural Correlates of Implicit Theory Violation

Implicit theories play an important role in the structure and maintenance of people’s sense of meaning, and violations to one’s theory can create significant distress. Using electroencephalography (EEG), this study examined the neural correlates of implicit theory violation. Participants were primed with one of two implicit theories of success attainment and were then shown a series of words that either confirmed or violated that theory. Analyses revealed that compared to implicit theory confirmations, implicit theory violations produced greater N400 amplitudes, which is a brain wave associated with “semantic violations,” or violations of meaning. Current literature on the N400 has been limited to language-specific semantic violations. Therefore, these results represent a novel extension of the N400 to include violations of complex lay theories of human behavior. Furthermore, these data suggest that implicit theories represent a fundamental type of semantic knowledge that helps perceivers to generate predictions about the social world.

Keywords: implicit theory
N400
theory violation
Advisor: Plaks, Jason
Nonlinear Fault-tolerant Guidance and Control for Damaged Aircraft

This research work presents a fault-tolerant flight guidance and control framework to deal with damaged aircraft. Damaged scenarios include the loss of thrust, actuator malfunction and airframe damage. The developed framework objective is to ensure that damaged aircraft can be stabilized and controlled at all times. The guidance system is responsible for providing the airspeed, vertical and horizontal flight path angle commands while considering aircraft dynamics. The control system, designed by the nonlinear state-dependent Riccati equation (SDRE) control method, is used to track the guidance commands and to stabilize the damaged aircraft. The versatility of SDRE allows it to passively adapt to the aircraft parameter variations due to damage. A novel nonlinear adaptive control law is proposed to improve the controller performance. The new control law demonstrated improved tracking ability. The framework is implemented on the nonlinear Boeing 747 and NASA Generic Transport Model (GTM) to investigate the simulation results.

Keywords: fault-tolerant guidance and control
damaged aircraft
Advisor: Liu, Hugh H. T.
Quantifying Multi-directional Trunk Stiffness During Sitting with and without Functional Electrical Stimulation: Able-bodied Subjects

To build an Functional Electrical Stimulation (FES) system that assists individuals with spinal cord injury (SCI) to improve sitting balance, one needs to determine multidirectional stiffness of the trunk during sitting and demonstrates that this stiffness can be influenced by FES. Therefore, the purposes of this study were: (1) to develop a novel protocol to quantify and identify the multidirectional stiffness of the trunk during sitting; and (2) to test the effect of FES on the multidirectional stiffness of the trunk. 15 able-bodied subjects were recruited. Each subject was perturbed in 8 different directions using 8 linear motors during quiet sitting with and without FES applied to his front/back trunk muscles. Stiffness in the lateral directions was the highest and FES increased stiffness of the trunk in the anterior/posterior direction. These results can be used to develop an FES protocol for individuals with SCI to improve their sitting balance.

Keywords: Biomedical
Advisor: Popovic, Milos R.
Development of a Novel Measure of Three-dimensional Bone Connectivity in a Mouse Tibia Fracture Model: Characterizing Torsional Strength and Stiffness Through Failure Surface Analysis

The high incidence of long bone fractures and appreciable rate of delayed and non-union (5-10%) necessitates the development of non-invasive tools to monitor healing progression. The objective of this study was to develop a novel µCT-based measure of three-dimensional bone connectivity and to compare its ability to assess fracture callus mechanical stability to previously described measures. Bone connectivity parameters local to the failure surface were found to significantly correlate with mechanical stability, and proved superior to previously developed measures of torsional rigidity. Visualization of the failure surfaces demonstrated a consistent failure pattern indicative of the applied torsional loading, however the locations of the failure surfaces showed varying levels of fracture callus involvement. The results of this proof of concept work indicate the potential utility of bone connectivity analysis in non-invasive assessment of fracture callus stability.

Keywords: fracture healing
strength
Advisor: Whyne, Cari
Nam, Diane
Catalytic Gasification of Pretreated Activated Sludge Supernatant in Near-critical Water

Pretreatment of waste activated sludge (WAS) and the subsequent near-critical water gasification (NCWG) is a potential avenue to convert WAS into value added products. Part one of the research investigated thermal and thermochemical pretreatments. No difference was observed in the percentage of sludge liquefied beyond 10min between 200°C to 300°C. It was found that pretreated activated sludge supernatant (PASS) doubled the gas yield compared to untreated sludge when gasified. The order of effectiveness for sludge treatment was thermo-alkali > thermal > thermo-acid for hydrogen production in NCWG. Part two investigated NCWG parameters to identify optimal conditions. High gasification yields were obtained using a commercial catalyst (Raney nickel), with hydrogen content of 65-75% of the gas phase products. Thermo-alkali treated PASS was found to perform well at subcritical temperatures with 25% higher yields than thermally treated PASS. Increased catalyst loading had little additional effect on gas yields above 0.075g.

Keywords: Pretreatment, Activated Sludge, supercritical water gasification
Advisor: Farnood, Ramin
Assessing the Combined Effect of Targeting ILK Signaling and Chemotherapy in Rhabdomyosarcoma

The pediatric sarcoma alveolar rhabdomyosarcoma (ARMS) is highly aggressive with a poor prognosis for diagnosed patients. Here, we demonstrate that targeting the unique oncogene integrin-linked kinase (ILK) in ARMS cells in conjunction with the common chemotherapy agent vincristine, a synergistic effect is found in the reduction of cell viability in vitro. This result was achieved by both RNAi-mediated depletion of ILK and using a small molecule kinase inhibitor specific for ILK. Both techniques were found to disrupt important protein interactions at the site of the centrosome. Combination ILK disruption and vincristine treatment of cells induced the expression of apoptotic markers and arrested cells in the G2/M stage of the cell cycle. Interestingly, protein levels of JNK and its target c-Jun were regulated with combined treatment. Altogether, these findings indicate that the use of molecular targets like ILK may further improve the clinical treatment of ARMS.

Advisor: Malkin, David
Development of a Hybrid Linear Actuator

This thesis focuses on the development of a novel hybrid linear actuator (HLA). The research includes the optimal design, the particular fabrication, and the experimental validation. The principle of the HLA is based on the integration of the mechanisms of the solenoid actuator and the voice coil actuator. Such integration is achieved by a magnetic circuit consisting of a magnetic flux orientator, a permanent magnet, a composite shell, and a special coil. The HLA is capable of having a high repelling force at one end and a high attractive force at another end. A step-optimization technique is developed and used to determine the key parameters of the HLA, with the aid of sweeping functions in finite element analysis. Moreover, a single-pulse power supply is specially designed and prototyped for driving the HLA. The performance of the HLA is systematically characterized by simulations and experiments.

Keywords: hybrid
actuator
Advisor: Zu, Jean W.
Effect of G-Jitter on Liquid Bridge Vibrations with & without Marangoni Convection

Effects of external vibrations (called g-jitter) on Marangoni convection in a liquid bridge were investigated on the International Space Station (ISS) and in ground-based experiments. In ISS, most dominant g-jitter frequency was noted to be ~110 Hz. ISS experiments suggested that the surface vibrations were mainly affected by the aspect ratio (length/diameter ratio), but not the imposed temperature gradient. Liquid bridge surface vibrations agreed well with Ichikawa et al.’s model. Ground-based experiments confirmed that increasing the volume ratio would cause the resonance frequency to increase. When a temperature difference was imposed between the upper and lower disks, for constant aspect and volume ratios, the resonance frequency tended to increase with the decreasing temperature difference. Furthermore, the shift in the resonance frequency due to a temperature difference, was found to be due to Marangoni convection and not due to reduced viscosity or surface tension of the fluid.

Keywords: Marangoni
convection
g-jitter
Advisor: Kawaji, Masahiro
Borinic Acid-catalyzed Regioselective Functionalization of Polyols

The selective manipulation of hydroxyl groups in di- and polyols is a frequently encountered problem in organic synthesis. Such processes are often tedious and/or moderate yielding, and often necessitate multistep protection / deprotection sequences. Applying boron–diol interactions previously exploited in molecular recognition and based on methods previously developed in our research group, we have developed two classes of chemical transformations: 1. Regioselective sulfonylations of carbohydrate derivatives catalyzed by a borinic ester, providing access to the corresponding mono-tosylates in high yields; 2. Selective monoalkylations and monosulfonylations of structurally diverse 1,2- and 1,3-diol substrates.

Keywords: borinic acid catalysis
diol
carbohydrate
Advisor: Taylor, Mark S.
The Role of Alternatively spliced Fibroblast Growth Factor Receptor 2 Isoforms in Breast Cancer

Recent genome-wide association studies identified FGFR2 as one of breast cancer susceptibility genes. FGFR2 expression was down-regulated in breast carcinomas when compared with paired normal epithelium. Stable retroviral transduction of FGFR2-IIIb and its alternatively spliced FGFR2-IIIc variants was achieved in breast cancer MDA-MB-231, T47D and near normal MCF-10A cells. Our findings revealed a direct reduction of breast cancer cell growth and motility, a significant arrest of transformed morphogenetic changes including the Epithelial to Mesenchymal transition (EMT), anchorage independent growth, and the formation of growth-arrested 3D acinar architectures, and suppressive actions on orthotopically xenografted epithelial neoplasms and surrounding tumor stroma. These tumor protective effects were concordant with physical interactions between the two FGFR2 isoforms and IKKβ. Consistent with these interactions we noted FGFR2 to inhibit NF-κB signaling, including decreased nuclear RelA/p65 NF-κB localization, down-regulation of a transfected NF-κB luciferase reporter, reduced production of NF-κB-dependent transcripts, Interleukin-6 and p-STAT3.

Keywords: Fibroblast Growth Factor Receptor 2
Breast Cancer
NF-κB
Advisor: Ezzat, Shereen
Establishing the Functional Links between Stowaway-like MITEs and Transposases Belonging to the Tc1/Mariner Superfamily in the Yellow Fever Mosquito, Aedes aegypti

Miniature Inverted-repeat Transposable Elements (MITEs) are a type of transposable element (TE) that lacks coding capacity. It has been established that in rice that certain Stowaway MITEs are mobilized by transposases from the Tc1/Mariner superfamily of TEs. To retrieve all Tc1/Mariner TEs from the genome, bioinformatic approaches were performed. A total of 295 Tc1/Mariner TEs that encoded a full or partial transposase were recorded which 100 were newly described. Sequence alignment, and identification of the catalytic motif placed these transposases into eight groups. A functional link was established by comparing the terminal sequences of the Stowaway-like MITEs to the termini of the terminal sequences of Tc1/Mariner TEs. A yeast excision assay was used to experimentally test these functional links. Majority of the Stowaway-like MITE and transposase combinations tested did not indicate a functional link. However, a possible functional link was observed between the AATp3-13 transposase and AAStow-5 Stowaway-like MITEs.

Keywords: Transposable element
Miniature inverted repeat transposable elements
Tc1/Mariner
Aedes aegypti
Stowaway
Advisor: Yang, Guojun
Dissecting The Role Of TNFα In Kawasaki Disease: Alteration Of Cell Fate By TNFα After Superantigen Activation

Kawasaki disease (KD) is an acute inflammatory disease characterized by persistent inflammation of the coronary arteries. KD is characterized by the release of cytokines such as tumor necrosis factor alpha (TNFα) and is thought to be initiated by a superantigen (SAg). The Lactobacillus casei cell wall extract model of KD demonstrates a critical requirement for TNFα and its receptor during pathogenesis, although the precise effect of TNFα is unknown. A persistent T cell infiltrate in the coronary artery disagrees with established fates of SAg activated cells, which undergo apoptosis. In this work, TNFα was found to promote the survival of SAg-reactive T cells. The results demonstrate that TNFα regulates B7.2 molecule expression on antigen presenting cells, and that TNFα indirectly promotes the survival of SEB-stimulated T cells by driving costimulation. These observations demonstrate how TNFα prevents T cell apoptosis and lend support to KD therapies which target TNFα and B7.

Keywords: Kawasaki Disease
TNF
Superantigen
apoptosis
Advisor: Yeung, Rae S. M.
Determining the Constitutionality of the National Securities Regulator Proposal and Beyond: The Federal Trade and Commerce Power, the General Motors test and the Choice Between ‘Categorization’ and ‘Balancing’

In addition to demonstrating the judiciary’s role in constitutional adjudication and an application of the federal trade and commerce power, judicial determination of Parliament’s constitutional jurisdiction to enact securities legislation is noteworthy also due to the vast policy debates that are involved. Though such determinations routinely invite a process removed from the contemplation of desirable policy, the ‘General Motors test’ used to define and apply the relevant constitutional power here seems to implicitly allow it. The choice between ‘categorization’ and ‘balancing’ in constitutional analysis is therefore significant, in terms of its juxtaposed tolerance for policy considerations. With these analytical options in mind, this thesis considers Parliament’s proposal, so to identify a reasonable process for determining its constitutionality. It argues that balancing relevant policy concerns is necessary and justifiable in the application of the legal norms in question. Crucial, however, is lending the process structure, so that its shortcomings are mitigated.

Keywords: constitutional law
securities
federalism
supreme court
general motors
trade and commerce power
division of powers
categorization
balancing
Advisor: Lee, Ian B.
Assessing the Determinants of Quality in Ontario's Long-term Care Homes: Relationships Between Staff and Resident Satisfaction

This thesis aimed to test the relationship between resident satisfaction and staff satisfaction. Using a cross-sectional design, administrators, staff and residents from 24 LTC homes were surveyed. Logistic regression models predicting high resident satisfaction were developed with a primary focus on the relationship to direct care staff satisfaction, while controlling for facility, staff and resident characteristics (and facility-level clustering). Regression models were developed for overall staff satisfaction and three other domains of job satisfaction. The odds of high overall resident satisfaction decreased by 27% and 31% for each 1-unit increase in overall job satisfaction and satisfaction with workload, respectively. In contrast, the odds of high overall resident satisfaction increased by 5.56 times for each 1-unit increase in mean staff satisfaction with work content. LTC homes may be able to improve staff and resident experiences concurrently by encouraging direct care staff to enter into meaningful relationships with residents.

Keywords: Long-Term Care
Staff Satisfaction
Resident Satisfaction
Advisor: Wodchis, Walter
DC-DC Converter with Improved Dynamic Response and Efficiency Using a Calibrated Auxiliary Phase

A digital adaptive slope control (DASC) technique is presented to improve the dynamic response and efficiency of a current programmed mode (CPM) buck converter employing a low-cost auxiliary phase. Compared to the existing nonlinear control techniques, the advantages of the proposed control scheme include superior voltage droop and settling time, and on-line calibration to compensate for tolerance in the inductance. The proposed technique is experimentally verified on a 500 kHz, 10 V to 2.5 V CPM buck converter prototype. Charge balancing and optimal transient response are achieved for a range of positive and negative load steps. In addition, compared to a representative single phase converter, the proposed system not only has better dynamic response but also achieves 2 % heavy-load and 10 % light-load steady-state efficiency improvement. The impact of the auxiliary phase operation on the converter’s dynamic efficiency is also evaluated at different load step amplitudes and frequencies.

Keywords: DC-DC Converter
Dynamic Response
Digital Control
Non-Linear Control
Advisor: Trescases, Olivier
Coagulation Optimization to Minimize and Predict the Formation of Disinfection By-products

The formation of disinfection by-products (DBPs) in drinking water has become an issue of greater concern in recent years. Bench-scale jar tests were conducted on a surface water to evaluate the impact of enhanced coagulation on the removal of organic DBP precursors and the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). The results of this testing indicate that enhanced coagulation practices can improve treated water quality without increasing coagulant dosage. The data generated were also used to develop artificial neural networks (ANNs) to predict THM and HAA formation. Testing of these models showed high correlations between the actual and predicted data. In addition, an experimental plan was developed to use ANNs for treatment optimization at the Peterborough pilot plant.

Keywords: water treatment
drinking water
coagulation
disinfection by-products
process optimization
artificial neural network
Advisor: Andrews, Robert C.
The Role of RELA (p65) in Regulation of NF-kappaB Homeostasis: Implications for Atherosclerosis

The NF-κB/Rel family of transcription factors and IκB inhibitors play a key role in regulation of gene expression in inflammation and immunity. Previous studies from our laboratory suggested that steady-state levels of p65 and other NF-κB components in the normal mouse aorta determine the magnitude of NF-κB target gene expression in response to pro-inflammatory stimuli, however, the mechanism(s) by which steady-state levels of NF-κB components are set is not clear. This study aims at elucidating the mechanisms behind NF-κB homeostasis and how that affects atherosclerosis susceptibility. In HeLa cells and HUVEC, siRNA silencing of p65 correlated with reduced steady-state expression of a subset of NF-κB/Rel and IκB genes at the transcriptional and post-transcriptional levels, respectively, in addition to reducing TNFα-induced NF-κB/Rel and IκB gene expression. This correlation was also observed in atherosclerosis-susceptible mouse aortic endothelium suggesting the role of p65 in modulating NF-κB homeostasis and affecting atherosclerosis susceptibility.

Keywords: Inflammation
Nuclear factor-kappaB
Gene expression
endothelial cells
Advisor: Jongstra-Bilen, Jenny
Cybulsky, Myron
Thermal Conductivity of Nanocrystalline Nickel

The grain-size dependences of thermal conductivity and electrical resistivity of polycrystalline and nanocrystalline nickel were measured by the flash method and four-point probe method, respectively. Nanocrystalline nickel was made by the pulsed-current electrodeposition process, while polycrystalline nickel was commercially available Ni 200 in annealed condition. The grain sizes of the materials examined ranged from 28 nanometers to 57 micrometers. Noticeable changes in thermal conductivity and electrical resistivity with grain size were observed in particular for samples with grain sizes less than 100 nm. These results can be explained on the basis of the rapid increase in the intercrystalline grain boundary and triple junction volume fractions at very small grain sizes. The relationship between thermal conductivity and electrical resistivity of nanocrystalline nickel follows the classic Wiedemann-Franz law.

Keywords: Thermal Conductivity
Nanocrystalline
Wiedemann-Franz law
Electrical Resistivity
Advisor: Erb, Uwe
Attention Capture by Animate Motion is Modulated by Physical and Subjectively-perceived Animacy

Previous research on animate motion perception indicates that animacy detection may be an evolutionarily developed mechanism of the visual system, responsible for adaptive alerting to other organisms in the environment. The present study further examined previously described attention capture by animate motion, and explored whether capture may be modulated by type of animacy (e.g., human motion vs. other animacy). The link between subjective animacy experience and perceptual processing was also examined. Results suggested that attention capture by animacy extends to situations in which animate motion is self-relevant. Animate motion entering the observer’s visual field captured attention relative to motion leaving out of the visual field. Subjective ratings of animacy experience also reliably predict reaction time in perceptual/attention tasks. Implications for theories of social cognition and higher order processing of agency are discussed.

Keywords: animacy
attention
perception
motion processing
Advisor: Anderson, Adam K.
Pratt, Jay