VictorJuiz/thesis huggingface dataset:
Normal Aging and Interacting Attentional Processes
Keywords: aging
attention

To examine whether executive attention is affected by perceptual attention, we manipulated executive load in a single experiment. Moreover, we assessed the influence of normal aging on knowledge-driven and attentional sensory-driven processes. Healthy young and older adult participants viewed visual streams of superimposed face/place images at low and high perceptual loads while making sex judgments on each face component and then completing a low or high executive load working memory task. Younger adults exhibited independent behavioural patterns for the executive and perceptual load manipulations due to intact selective attention mechanisms, whereas older adults exhibited interacting processes. This is evidenced by the performance of older adults on concurrent executive and perceptual tasks, which was associated with working memory capacity; whereas younger adults did not exhibit this dependency. Selective attention processes that are independent in younger populations seem to converge in older populations due to decrements in executive and perceptual attention domains.
Programmer-assisted Automatic Parallelization
Keywords: compiler
automatic parallelization
programmer guarantees

Parallel software is now required to exploit the abundance of threads and processors in modern multicore computers. Unfortunately, manual parallelization is too time-consuming and error-prone for all but the most advanced programmers. While automatic parallelization promises threaded software with little programmer effort, current auto-parallelizers are easily thwarted by pointers and other forms of ambiguity in the code. In this dissertation we profile the loops in SPEC CPU2006, categorize the loops in terms of available parallelism, and focus on promising loops that are not parallelized by IBM's XL C/C++ V10 auto-parallelizer. For those loops we propose methods of improved interaction between the programmer and compiler that can facilitate their parallelization. In particular, we (i) suggest methods for the compiler to better identify to the programmer the parallelization-blockers; (ii) suggest methods for the programmer to provide guarantees to the compiler that overcome these parallelization-blockers; and (iii) evaluate the resulting impact on performance.
A Knowledge Structuring Framework to Support the Design of Social Media for Online Deliberation
Keywords: knowledge management
requirements engineering
online deliberation
design
information systems

Although online social media have achieved spectacular success in some instances, the design of such systems remains an art. In some specialized areas, such as online deliberation systems for participatory democracy, experiences from many projects have been reported in the research literature. Designers can benefit from knowledge accumulated from these experiences. However, the knowledge is dispersed and not organized for ready access by practicing professionals. This thesis proposes a framework for structuring and codifying design knowledge from published studies to help designers make design choices that will attain design objectives.
The Construct Validity of Openness to Experience in Middle Childhood: Contributions from Personality and Temperament
Keywords: Openness to Experience
child personality
temperament
psychopathology
behavioral competencies

Controversy exists over the validity of child Openness to Experience (OE), which is typically considered a major trait in adult personality models. In an effort to establish construct validity for child OE, data were collected for 346 children (51% girls) approximately 9–10 years of age (M = 9.92, SD = 0.83). Parents completed questionnaires about their children’s personality, temperament, and behavioral problems and competencies. Factor analyses of relevant personality and temperament facets revealed a robust and measurable OE factor made up of three facets: Intellect, Imagination, and Sensitivity. Evidence for convergent and discriminant validity was established via associations with other higher-order personality traits, behavioral problems, and behavioral competencies. The results underscore the importance of drawing from both temperament and personality literatures in attempts to establish construct validity for child trait domains as well as of moving beyond the higher-order domain and examining facet-level associations between OE and child behavior.
Real-Time Spatial Object Tracking on iPhone
Keywords: Visual Object Tracking
Spatial Updating
iPhone Programming

In this thesis, a novel Object Tracking Algorithm is proposed which tracks objects on Apple iPhone 4 platform in real-time. The system utilizes the colorspace of the frames provided by iPhone camera, in parallel with the motion data provided by iPhone motion sensors, to cancel the effect of iPhone rotations during tracking and matching different candidate tracks. The proposed system also adapts to changes in target appearance and size, thus leading to an object tracking robust to such changes. Several experiments conducted on actual video sequences are used to illustrate the functionality of the proposed approach.
Stroke Services in Ontario- based Long- Term Care Homes
Keywords: stroke services
long term care
health services research
rehabilitation

There is limited information regarding the provision of rehabilitation services in long-term care (LTC) to meet the needs of residents living with stroke. This project assessed service availability within Ontario-based homes and examined the relationship between service comprehensiveness and functional outcome for residents with rehabilitation potential. The first phase involved survey development and distribution to a sample of homes to assess comprehensiveness. The second phase linked survey findings and administrative data to determine whether comprehensiveness (measured using an index score derived from survey responses) was correlated with change in functional status using linear regression modeling. There was marked variability in service comprehensiveness across responding homes (n=32 of 154 homes; 21%). No significant linear correlation was shown between comprehensiveness and change in ADL function (n=178). Although our study failed to show an association, rehabilitation should be considered an important aspect of LTC programming and should adhere to practice standards where possible.
Elliptical Hollow Section T and X Connections
Keywords: steel structures
hollow structural sections
elliptical hollow section
connection

Elliptical hollow sections (EHS) are the newest steel shape to emerge in the industry, but appropriate design guidance is lacking, being completely absent from Canadian codes and guidelines. Geometric property and compressive resistance tables were established to be potentially added to the Canadian guides. The equivalent RHS method, originally proposed by Zhao and Packer in 2009, was simplified and modified to validate its use for the design of EHS columns and beams. An experimental programme was developed to investigate the behaviour of EHS-to-EHS welded connections. Twelve T and X connection tests were performed to study the effect of connection angle, orientation type and loading. Two methods were developed to predict connection capacities and failure modes: the equivalent CHS and the equivalent RHS approaches. Both methods proved to be conservative on average, but the equivalent RHS approach proved to be more successful at capturing the actual failure mode of EHS-to-EHS connections.
An Evolutonary Parametrization for Aerodyanmic Shape Optimization
Keywords: aerodynamic shape optimization
evolutionary parametrization
B-spline
knot insertion

An evolutionary geometry parametrization is established to represent aerodynamic configurations. This geometry parametrization technique is constructed by integrating the classical B-spline formulation with the knot insertion algorithm. It is capable of inserting control points to a given parametrization without modifying its geometry. Taking advantage of this technique, a shape design problem can be solved as a sequence of optimizations from the basic parametrization to more refined parametrizations. Owing to the nature of the B-spline formulation, feasible parametrization refinements are not unique; guidelines based on sensitivity analysis and geometry constraints are developed to assist the automation of the proposed optimization sequence. Test cases involving airfoil optimization and induced drag minimization are solved adopting this method. Its effectiveness is demonstrated through comparisons with optimizations using uniform refined parametrizations.
Detecting Anxiety through Song: Mapping Physiological Indicators to Music
Keywords: Emotion
Anxiety

This research aimed to help caregivers easily recognize physiological indicators of pediatric anxiety. To this purpose, we first elucidated the physiological indicators of anxiety in children by presenting an anxiety-inducing task while recording biosignals. We discovered patterns suggestive of cardiac reciprocal inhibition, increased respiration rate, and increased electrodermal activity. These patterns informed the optimization of an existing auditory prototype for presenting biosignals to caregivers (biosongs), which maps physiological features to musical elements. The effectiveness of the optimized biosongs for conveying anxiety was evaluated by quantifying the accuracy with which adults could distinguish anxious and calm states by listening to music translated from children's physiological signals. High overall sensitivity (90%), specificity (78%), and accuracy (84%) were achieved, suggesting the promise of biosongs as an effective anxiety screening tool. This technology could lead to profound improvements in caregiving contexts, including anxiety management during medical procedures, and home-based monitoring for chronic conditions.
Lecithin:Cholesterol Acyltransferase Deficiency Protects against Cholesterol-induced Hepatic Endoplasmic Reticulum Stress in Mice
Keywords: cholesterol
ER stress

Our laboratory has recently reported that lecithin:cholesterol acyltransferase (LCAT) deficient mice are hypersensitive to insulin and resistant to diet-induced obesity, particularly in the LDL receptor (LDLR) knockout background. These phenotypes are linked to hepatic endoplasmic reticulum (ER) stress, which we showed is elevated basally and highly inducible in LDLR deficient mice. While in LCAT/LDLR deficient mice, ER stress is normalized basally and its diet-induction is attenuated. Mechanistically, we show here that excess free cholesterol (FC), in part from the bile, accumulates in the ER membrane of LDLR deficient mice. In contrast, LCAT/LDLR deficient mice have reduced levels of ER membrane FC and are resistant to cholesterol diet-induced elevations, in part from increased INSIG-1 expression and cholesterol esterification by ACAT2. Our analysis has led to the first report of cholesterol-induced hepatic ER stress in vivo and the identification of ER FC levels as a critical indicator of ER stress susceptibility.
Automatic 3D Segmentation of the Breast in MRI
Keywords: Image Segmentation
Breast MRI

Breast cancer is currently the most common diagnosed cancer among women and a significant cause of death. Breast density is considered a significant risk factor and an important biomarker influencing the later risk of breast cancer. Therefore, ongoing epidemiological studies using MRI are evaluating quantitatively breast density in young women. One of the challenges is segmenting the breast in order to calculate total breast volume and exclude non-breast surrounding tissues. This thesis describes an automatic 3D breast volume segmentation based on 3D local edge detection using phase congruency and Poisson surface reconstruction to extract the total breast volume in 3D. The boundary localization framework is integrated on a subsequent atlas-based segmentation using a Laplacian framework. The 3D segmentation achieves breast-air and breast-chest wall boundary localization errors with a median of 1.36 mm and 2.68 mm respectively when tested on 409 MRI datasets.
Anaerobic Oxidation of Methane in Northern Peatlands
Keywords: Anaerobic
Methane
Oxidation
Peatlands

Anaerobic oxidation of methane (AOM) in peatlands was investigated using 13carbon isotope tracers. Existence of AOM in marine and freshwater ecosystems is well known, but only recently has solid evidence for this process been demonstrated in northern peat accumulating wetland ecosystems. The primary objective of this thesis research was to characterize rates of AOM in peatlands across site types (bogs and fens with varying physicochemical properties) and latitudinal gradients. It was found that AOM was ubiquitous process across North American sites and dominant in fens over bogs, however carbon derived from methane was similar in both types of peatlands. Though, none of the proposed electron acceptors hypothesized stimulated AOM. AOM had a combined, average rate of 2.9 nmol methane kg-1s-1, which would translate to an approximate global consumption of 24 Tg methane annually. This mass of methane is equivalent to almost 7% of all annual anthropogenic carbon dioxide emissions.
Characterization of NP22 and its Potential Role in NMDA Receptor-mediated Transmission
Keywords: NMDA
neuroscience
protein interactions
NP22
synaptic plasticity
affinity purification

N-methyl D-aspartate (NMDA) receptors represent integral signal transducers for excitatory glutamate neurotransmission. While NMDA receptors are critical for synaptic plasticity, the molecular events underlying this process are not fully elucidated. The potential role of NP22, a novel neuronal protein, as a downstream mediator of NMDA receptor function is explored. NP22 protein expression in genetic and pharmacological models of NMDA receptor hypofunction is examined and no significant changes are reported. Characterization of the NP22 protein complex via tandem-affinity and FLAG-purification coupled with mass spectrometry was used and no novel protein interactions are reported. GFP-tagged NP22 colocalization with F-actin decreases in cell processes of transiently transfected HEK293 cells in response to elevated intracellular calcium, while similar colocalization reductions are not seen in stably transfected HEK293 under a comparable treatment regiment. Changes in intracellular calcium affecting NP22 biology can be useful in the ongoing characterization of this novel protein.
Evaluation of the Expression of LIN28A and LIN28B within the Hypothalamic-pituitary-gonadal Axis
Keywords: Pubertal Timing
HPO Axis
LIN28B
Ovary
qRT-PCR
IHC
RT-PCR
LIN28A
GnRH Neuron
Single Nucleotide Polymorphisms
Genome Wide Association Studies
Let-7
Follicle
Oocyte

The genes that regulate pubertal timing in the general population are not well understood. Recently, genome-wide association studies have demonstrated that genetic variants near LIN28B associate with variation in pubertal timing in humans. To investigate where within the hypothalamic-pituitary-ovarian (HPO) axis Lin28b, and its homologue Lin28a, regulate pubertal timing, expression of these genes was assessed across the pubertal transition. The finding that Lin28a/b expression decreases only in the ovary suggests that the Lin28 pathway may exert its regulatory effects with respect to puberty in the ovary. Another aim of this thesis was to examine the effect of estrogen on Lin28b expression in immortalized GnRH neuronal cells, but the data remains equivocal and detailed future studies are needed to make definitive conclusions. The ovarian expression data lay the foundation for further studies using conditional knockout mice to verify the importance of the tissue and age specific developmental pattern that was identified.
Structural and Functional Characteristics of a Soluble Form of Endoglin in the Context of Preeclampsia
Keywords: preeclampsia
endoglin

Endoglin is an auxiliary receptor for ligands of TGF-β receptor superfamily, present in endothelial cells and the placental syncytiotrophoblast. The expression of placental membrane endoglin (mEng) is further increased during preeclampsia, a pregnancy-specific hypertensive syndrome. We hypothesize that the soluble form of endoglin (sEng) released from the placenta leads to endothelial dysfunction and hypertension by disrupting normal BMP-9 signaling. We show that cell surface mEng inhibits TGF-β1, BMP-2, and BMP-7 induced Smad1,5,8 phosphorylation while potentiating BMP-9 induced signaling. sEng has been shown to be elevated in the sera of preeclamptic women and is postulated to interfere with endothelial cell function. We show that sEng binds to BMP-9 with a 2 nM affinity and can compete for its binding to endothelial cells, inhibiting downstream Smad1,5,8 phosphorylation. Our results suggest that sEng is contributing to endothelial dysfunction by dysregulating BMP-9 signaling.
The Mismatch Repair Pathway Functions Normally at a non-AID Target in Germinal Center B cells
Keywords: mismatch repair
somatic hypermutation
germinal center
activation induced cytidine deaminase
B cells
mutations

Deficiency in Msh2, a component of the mismatch repair (MMR) system, leads to a ~10-fold increase in the mutation frequency in most tissues. By contrast, Msh2-deficiency in germinal center (GC) B cells decreases the mutation frequency at the IgH V-region, as a dU:dG mismatch produced by AID initiates modifications by MMR resulting in mutations at nearby A:T basepairs. This raises the possibility that GC B cells express a factor that converts MMR into a globally mutagenic pathway. To test this notion, we investigated whether MMR corrects mutations in GC B cells at a gene not mutated by AID. We found that GC B cells accumulate 5-times more mutations than follicular B cells. Notably, the mutation frequency was ~10 times higher in Msh2-/- compared to wildtype GC B cells. These results show that in GC B cells MMR functions normally at an AID-insensitive gene.
Regioselective Activation Of Glycosyl Acceptors By a Diarylborinic Acid Catalyst
Keywords: Synthesis
Glycosylation
Methodology

The realization that oligosaccharides play a central role in many biological processes has led to increasing interest in the preparation of synthetic targets for use in medical or biochemical research and drug discovery. The preparation of oligosaccharides from simple carbohydrate derivatives requires efficient methods for the construction of O-glycosidic bonds. Much effort has been made towards the development of selective methods for the preparation of oligosaccharide targets. The most common method to overcome the challenge of regioselectivity is the use of protecting group manipulations to suppress glycosylation at undesired positions. This is highly inefficient in terms of atom and step economy. Organoboron catalysis is a recent strategy that imparts regioselective activation of the equatorial hydroxy group of cis-vicinal diols towards functionalization. Following the initial findings that diarylborinic acid catalyzes the regioselective acylation of carbohydrate derivatives, an analogous method for regioselective glycosylation under Koenigs-Knorr conditions has been developed.
Changes in Gap Junction Expression and Function Following Ischemic Injury of Spinal Cord White Matter
Keywords: Spinal Cord Injury
Electrophysiology
Gap Junction
Oxygen-Glucose Deprivation

The role of gap junctions in modulating the dynamics of axonal dysfunction in spinal cord white matter injury remains uncertain; hence, I examined the functional role and changes in expression of gap junctions following CNS injury. I hypothesized that inhibition of gap junctions improves axonal conduction during oxygen and glucose deprivation (OGD) in vitro. Carbenoxolone and octanol, gap junction blockers, did not change CAP amplitude in non-injured tissue, yet they significantly reduced the extent of its decline during OGD. No difference in mRNA expression of connexins 32, 36 was found. However, during OGD in the presence of gap junction blockers, expression of connexins 30, 43 was downregulated. Immunohistochemistry confirmed the presence of connexins in spinal cord slices: connexins 30, 43 overlapping with GFAP, connexin 32 with MBP and connexin 36 with CC1. Thus, blocking gap junctions enhances axonal conduction during OGD and promotes dynamic changes in connexin mRNA expression.
Potassium Acetate Deicer and Concrete Durability
Keywords: Potassium Acetate Deicer
ASR

An investigation on the damaging effects of potassium acetate deicer (KAc) on concrete durability was conducted. Different SCM replacement levels were used. ASTM C 1293 and ASTM C 1260 test methods results indicated that KAc is capable of inducing alkali-silica reaction (ASR) expansion in specimens containing reactive aggregate. Class C fly ash was ineffective even at a replacement level of 45%. Class F fly ash and slag were effective in mitigating ASR expansion for specimens exposed to diluted (25% by weight) KAc. KAc showed an increase in pH value upon exposure to concrete specimens. Concrete specimen without SCM and exposed to deicers had higher [K]/[Na] molar ratio near the surface but ions penetrated less compared to specimens containing SCM. ASTM C 666 and MTO LS-412 test methods results showed that air-entrained concrete slabs and prisms without SCM and exposed to KAc are resistant to scaling and freezing and thawing damage.
The Patterns of Sleep Disorders and Circadian Rhythm Disruptions in Children and Adolescents with Fetal Alcohol Spectrum Disorders
Keywords: fetal alcohol spectrum disorders (FASD)
sleep disorders
circadian rhythms

Background: Sleep disorders have been poorly described in children and adolescents diagnosed with FASD. The objective of this study is to describe the sleep and circadian rhythm characteristics of children with FASD using overnight polysomnography, sleep questionnaires, and the Dim Light Melatonin Onset (DLMO) test. To our knowledge, no comprehensive studies of this nature have been conducted. Methods: Children ages 6-18 years diagnosed with Fetal Alcohol Spectrum Disorder (FASD) were recruited from various FASD clinics to the Youthdale Child and Adolescent Sleep Centre in Toronto. After medical consultation, each participant had one night of overnight polysomnography, as well as an additional night of DLMO. Participants completed various sleep and FASD questionnaires. Results: Significant differences were found when comparing the sleep architecture of FASD participants to normative data. There was a high prevalence of sleep disorders in this sample. Most of the melatonin profiles of the FASD participants were found to be abnormal.
Reducing ‘Failure-to-Rescue’ Events through Enhanced Critical Care Response Teams
Keywords: Electronic Patient Monitoring
Medical Emergency Teams

Failure to recognize and respond to changes in a patient’s condition is a limitation in the effective utilization of Medical Emergency Teams (METs). A system that uses smartphone technology to facilitate vital signs collection at bedside has been developed. The alerts engine, based upon Mount Sinai Hospital’s (MSH) MET calling criteria, can automatically alert the MET of patients exhibiting abnormal vital signs. The system, without automated alerting, was piloted at MSH. Sensitivity and specificity calculations revealed that the MSH algorithm had a lower sensitivity and specificity than the Cuthbertson or the Modified Early Warning Score algorithms. This suggests that the MSH algorithm, compared to the others, was poor at identifying patients that did and did not require a MET consultation. Furthermore, the low positive predictive value suggests that the majority of alerts were not associated with a MET call. Therefore, the MSH algorithm is not recommended for the automated system.