VictorJuiz/thesis huggingface dataset:
Design of High Performance Organic Light Emitting Diodes
Keywords: organic light emitting diodes
organic electronics

Organic light emitting diodes (OLEDs) are being commercialized in display applications, and will be potentially in lighting applications in the near future. This thesis is about the design of high performance OLEDs, which includes both the electrical and optical design of OLEDs. In particular, the following work is included in this thesis: i) Energy level alignment and charge injection at metal/organic interfaces have been systematically studied. ii) Transition metal oxide anodes have been developed to inject sufficient holes into the OLEDs due to their high work function. The oxide anodes have also been used to systematically study the transport properties in organic semiconductors. iii) Highly simplified OLED devices with unprecedentedly high efficiency have been realized using both fluorescent and phosphorescent emitters. The high performance was enabled by using a high work function metal oxide anode and a hole transport material with very a deep highest occupied molecular orbital (HOMO). iv) An optical model has been developed to describe the optical electric field across the OLED device. By using the model, a high performance flexible OLED using metal anode was designed and realized.
Improving Posing and Ranking of Molecular Docking
Keywords: Docking
Molecular Modeling
Pharmacophore

Molecular docking is a computational tool commonly applied in drug discovery projects and fundamental biological studies of protein-ligand interactions. Traditionally, molecular docking is used to address one of three following questions: (i) given a ligand molecule and a protein receptor, predict the binding mode (pose) of the ligand within the context of a receptor, (ii) screen a collection of small-molecules against a receptor and rank ligands by their likelihood of being active, and (iii) given a ligand molecule and a target receptor, predict the binding affinity of the two. Here, we focus on the first two questions, namely ranking and pose prediction. Currently, state-of-the-art docking algorithms predict poses within 2A of the native pose in a rate lower than ∼60% and in many cases, below 40%. In ranking, their ability to identify active ligands is inconsistent and generally suffers from high false-positive rate. In this thesis we present novel algorithms to enhance the ability of molecular docking to address these two questions. These algorithms do not substitute traditional docking but rather being applied on top of them to provide synergistic effect. Our algorithms improve pose predictions by 0.5-1.0A and ranking order for 23% of the targets in gold-standard benchmarks. As importantly, the algorithms improve the consistence of the posing and ranking predictions over diverse sets of targets and screening libraries. In addition to the posing and ranking, we present the pharmacophore concept. A pharmacophore is an ensemble of physiochemical descriptors associated with a biological target that elucidates common interaction patterns of ligands with that target. We introduce a novel pharmacophore inference algorithm and demonstrate its utilization in molecular docking. This thesis is outlined as follow. First we introduce the molecular docking approach for pose prediction and ranking. Second, we discuss the pharmacophore concept and present algorithms for pharmacophore inference. Third, we demonstrate the utilization of pharmacophores for pose prediction by re-scoring candidate poses generated by docking algorithms. Finally, we present algorithms to improve ranking by reducing bias in scoring functions employed by docking algorithms.
The Statistical Learning Of Musical Expectancy
Keywords: music cognition
statistical learning
priming
expectancy
memory

This project investigated the statistical learning of musical expectancy. As a secondary goal, the effects of the perceptual properties of tone set familiarity (Western vs. Bohlen-Pierce) and textural complexity (melody vs. harmony) on the robustness of that learning process were assessed. A series of five experiments was conducted, varying in terms of these perceptual properties, the grammatical structure used to generate musical sequences, and the methods used to measure musical expectancy. Results indicated that expectancies can indeed be developed following statistical learning, particularly for materials composed from familiar tone sets. Moreover, some expectancy effects were observed in the absence of the ability to successfully discriminate between grammatical and ungrammatical items. The effect of these results on our current understanding of expectancy formation is discussed, as is the appropriateness of the behavioural methods used in this research.
Biology Inspired Nano-materials: Superhydrophobic Surfaces
Keywords: Nano-materials
Superhydrophobic
Polymer Structuring
Electrodeposition

In this research, a low-cost template-based process has been developed to structure the surfaces of polymeric materials rendering them superhydrophobic. This biology-inspired approach was developed using results from the first part of this thesis: the first known detailed study of superhydrophobic aspen leaf surfaces. Aspen leaves, similar to lotus leaves, possess a dual-scale hierarchical surface structure consisting of micro-scale papillae covered by nano-scale wax crystals, and this surface structure was used as a blueprint in the structuring of templates. These distinctive surface features coupled with a hydrophobic surface chemistry is responsible for these leaves’ extreme non-wetting property. Non-wetting is further augmented by the unique high aspect ratio aspen leafstalk geometry. The slender leafstalks offer very little resistance to twisting and bending, which results in significant leaf movement in the slightest breeze, facilitating water droplet roll-off. The structured template surfaces, produced by sand blasting and chemical etching of electrodeposited nanocrystalline nickel sheets, resemble the negative of the superhydrophobic aspen leaf surfaces. Re-usable templates were subsequently employed in a hot embossing technique where they were pressed against softened polymers (polyethylene, polypropylene and polytetrafluoroethylene) thereby transferring their surface structures. The resulting pressed polymer surfaces exhibited features very similar to aspen leaf surfaces. This process increased the water contact angle for all pressed polymers to values above 150 degrees. Additionally, after pressing the water roll-off angle for all polymer surfaces dropped below 5 degrees. The effects of water surfactant concentration, water drop size and temperature on the wetting characteristics of the structured polymers were studied to indicate in which applications these functional surfaces could be most beneficial. Coupling this attractive superhydrophobic surface property with mechanical motion (shaking, bending, or vibrating) could result in superhydrophobic surfaces with superior non-wetting properties suitable for a wide range of applications.
MRI in the Prediction and Diagnosis of Pediatric-onset Multiple Sclerosis: Insights from Children with Incident CNS Demyelination
Keywords: multiple sclerosis
pediatric
magnetic resonance imaging
diagnosis
prediction
demyelination
central nervous system

An acute demyelinating syndrome (ADS) in a child may be a monophasic illness or may represent the incident attack of multiple sclerosis (MS) – an inflammatory demyelinating neurodegenerative disorder affecting the brain, spinal cord and optic nerves. The central objective of this dissertation was to identify MRI parameters present at ADS that predict MS diagnosis. A scoring tool was first created containing 14 parameters identified from the literature and demonstrating substantial inter-rater agreement (Cohen’s kappa values ≥0.6). Children aged <16 years were enrolled at incident ADS and are currently followed for five years at 23 Canadian centers. Standardized MRI scans were acquired at onset and serially. MS was defined based on the occurrence of a second demyelinating attack or MRI evidence of new lesions in accordance with McDonald criteria for dissemination in time. Multivariable Cox proportional hazards regression models were used to identify MRI parameters that predicted MS diagnosis. Over 1100 MRI scans in 284 children with ADS were evaluated. To date, 57(20%) children have been diagnosed with MS. For those that developed MS, the median (IQR) time from incident attack to diagnosis was 6.2 (4.7-11.1) months. The presence of ≥1 T1-hypointense lesion (HR 20.6, 95% CI 5.5-78.0) and ≥1 T2 periventricular lesion (3.3, 1.3-8.8) were associated with an increased likelihood for MS diagnosis (sensitivity 84%, specificity 93%, PPV 76%, NPV 96%). The predictive parameters were validated in an independent Dutch cohort of 45 children with ADS (n=15, 33% MS): sensitivity 93%, specificity 87%, PPV 78%, NPV 96%. Finally, it was determined that the 2010 McDonald criteria are applicable for diagnosis of pediatric-onset MS diagnosis in older children with non-ADEM presentations. The work embodied herein emphasizes the value of MRI in predicting MS diagnosis in children with incident ADS. Early identification of children with MS is important for planning clinical care and will be valuable in future pediatric MS treatment trials.
Mms1 & Mms22 Mediate Genome Stability in Saccharomyces cerevisiae
Keywords: Saccharomyces cerevisiae
DNA
Replication
Repair
Mms1
Mms22
Genome stability

Mms1 and Mms22 are important mediators of genome stability in Saccharomyces cerevisiae. Deletion mutants of both genes display decreased viability in the presence of a number of known DNA damaging agents as well as agents that perturb DNA replication. Here I present a detailed analysis of Mms1 and Mms22 function in stabilizing DNA replication forks. I find that mms1∆ and mms22∆ strains accumulate spontaneous DNA damage and have an increased rate of mutation during a normal cell cycle. Additionally, treatment with genotoxic agents causes defects in induced recombination as well as inhibiting the ability of cells to efficiently recover from DNA damage. Genetic interaction data support a model where Mms1 and Mms22 function with components of the replication fork. Accordingly I observed that the enrichment of key replication fork proteins at regions proximal to replication origins is decreased in mms1∆ and mms22∆ cells during replication stress. Furthermore, I monitored DNA replication in wild-type and mms1∆ strains and found that mms1∆ strains exhibit irregular fork progression under conditions of replication stress. I therefore concluded that Mms1 and Mms22 function at replication forks. Lastly, I uncovered that Mms1 is regulated by Rtt101-dependent ubiquitin-mediated proteolysis. Mms1 degradation is likely necessary for its function as overexpression of Mms1 results in decreased cell viability both during a normal cell cycle, and during treatment with DNA damaging agents. I found that Mms1 and Mms22 operate at sites of DNA replication to promote the stability of the genome, especially under conditions of DNA damage and replication fork stress.
Reconfiguring Canadian Penality: Gender, Diversity, and Parole
Keywords: parole
gender
diversity
punishment

This research provides a local case study of responses to ‘gender’ and ‘diversity’ within Canada’s federal parole system. I examine the following questions: How are certain ‘differences’ and categories of offenders constituted as targets for ‘accommodation’ or as having ‘special needs’? How do penal institutions frame ‘culturally relevant’ or ‘gender responsive’ policy and, in doing so, use normative ideals and selective knowledge of gender, race, culture, ethnicity, and other social relations to constitute the identities of particular groups of offenders? I explore these questions by tracing the history of policy discussions about gender and facets of diversity within legislation and penal and parole policies and practices, as well as the current approaches to managing difference used by the National Parole Board (NPB). Specific focus is given to the organizational responses and approaches developed for Aboriginal, female, and ‘ethnocultural’ offenders. In this study, I show that the incorporation of diversity into the federal parole system works to address a variety of organizational objectives and interests, including fulfilling the legislative mandate to recognize and respond to diversity; appealing to human rights ideals and notions of fairness; managing reputational risk and conforming to managerial logics; instituting ‘effective’ correctional practice; and addressing issues of representation. At the same time, the recognition of gender and diversity produces new penal subjectivities, discourses, and sites upon which to govern. I argue that the accommodation of gender and diversity provides a narrative of conditional release and an institutional framework that positions the NPB as responsive to the diverse needs and/or experiences of non-white and non-male offenders. In the Canadian context, the penal system strives to deliver ‘fair’ punishment through the selective inclusion of difference, and without altering or reconsidering fundamental structures, practices, and power arrangements. Diversity and difference are instead added onto and/or incorporated into preexisting penal policy and logics, including risk management and managerialism.
Withdrawal Motivation and Empathy: Do Empathic Reactions Reflect the Motivation to "Reach Out" or the Motivation to "Get Out"?
Keywords: Empathy
Emotion
Motivation
Electroencephalography
Electromyography

Evolutionary accounts of empathy often focus on the ways in which empathy-motivated helping can give rise to indirect fitness benefits. These accounts posit that empathy is adaptive insofar as it motivates strategic helping behavior, but they neglect a key feature of the empathic process – it can prepare one to act effectively within a shared environment. In particular, adopting the affective and motivational states of others provides a rapid and automatic way to avoid danger and threat, which play a disproportionately large role in shaping behavior. Based on the idea that empathic processes facilitate adaptive reactions to threat, I conducted four experiments to test the hypothesis that empathic reactions reflect withdrawal motivation. In the first experiment I used electroencephalography (EEG) to measure baseline right-frontal cortical asymmetry, a reliable neural correlate of withdrawal motivation. I then assessed empathic reactions to images of children ostensibly taken from a charity campaign. Participants who showed greater right-frontal cortical asymmetry also showed stronger empathic reactions to the images. In the second study I used self-report measures fear and anger to assess dispositional withdrawal- and approach-motivation, respectively. This time, participants indicated their empathic reactions to targets experiencing happiness and targets experiencing sadness. Empathy for both types of targets was positively related to fear and negatively related to physical aggression, again supporting a link between empathy and withdrawal motivation. In the third study I measured state withdrawal motivation by using facial electromyography (EMG) to assess disgust expressions towards charity images. These expressions were positively correlated with empathic reactions, demonstrating that state withdrawal motivation is also positively related to empathy. In the final study I manipulated approach and withdrawal emotions by having participants make emotional facial expressions. Focusing on fear and anger, I found that participants were more empathic when making fearful faces than when making angry faces, although these results must be interpreted with caution, as the manipulation may not have had the intended effects on emotional state. Taken together, these four studies provide converging evidence of an association between withdrawal motivation and empathy, supporting the idea that empathy plays a role in the adaptive response to threat.
Clinician Mandatory Reporting and Maintenance of the Therapeutic Alliance
Keywords: mandatory reporting
therapeutic alliance

The objectives of this study are two-fold: (a) to delineate the factors that guide Ontario social workers’ decision-making when rendering judgments on the mandatory reporting of child maltreatment and (b) to understand how social workers maintain the therapeutic alliance with children and families following the decision to report suspected child maltreatment. The study is informed by two distinct bodies of literature: the decision-making theoretical literature within the fields of medicine, psychology, social work, and marriage and family therapy and the therapeutic alliance theoretical literature. Harnessing the advantages of online survey technology, the study surveyed registered members (n = 480) of the Ontario Association of Social Workers who provide direct service to children and families. Participants responded to prepared vignettes of suspected child maltreatment followed by Likert-scale questions (strongly agree to strongly disagree) and open-ended questions on strategies to maintain the alliance. Open-ended questions allowed respondents to offer further commentary regarding their opinions on mandatory reporting and on maintaining the therapeutic alliance. These comments added a rich source of information to the quantitative data. Multiple logistic regression analyses showed that social workers’ ethical responsibility to the College of Social Workers and Social Service Workers, their legal responsibility to the provincial mandatory reporting laws of Ontario, and consultation with peers or eliciting direction from a supervisor comprised the main factors in their decision-making around reporting suspected child maltreatment to the Children’s Aid Society. Qualitative analyses showed that social workers employ a plethora of strategies to repair the alliance following a disclosure of child maltreatment including reporting strategies, information strategies, affect regulation strategies, advocacy strategies, and resource strategies. The major limitation of the research design was the use of vignette research, which in proscribed circumstances may not reflect what the social worker does in actual practice. Design features that compensate for this limitation include (1) use of a 5-point Likert-item response of strongly agree to strongly disagree to allow respondents a range of responses; and (2) use of open-ended questions to allow respondents the opportunity to express their opinions on the issues.
Exploring Impulsive Activation During Spoken Language Comprehension
Keywords: psycholinguistics
impulsive processing
sentence processing
real-time language comprehension
bottom-up activation
interaction

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.
Modulation of N-methyl-D-aspartate receptors by Gαs- and Gαi/o-coupled receptors
Keywords: N-methyl-D-aspartate receptors
synaptic plasticity
metaplasticity
G-protein-coupled receptor
schizophrenia
dopamine D1-like receptor
metabotropic glutamate receptors 2 and 3

The induction of synaptic plasticity at CA1 synapses requires NMDAR activation. Modulation of NMDAR function by various GPCRs can shift the thresholds for LTP and LTD induction and contribute to metaplasticity. Here we showed that the activity of GluN2A- and GluN2B-containing NMDARs is differentially regulated by Gαi/o-coupled, Gαq- and Gαs-coupled receptors. Furthermore, enhancing the relative function of GluN2A-to-GluNB NMDAR activity by GPCRs can alter the balance of LTP and LTD induction and contribute to metaplasticity. In CA1 neurons, activation of the Gαs-coupled D1/D5R selectively recruited Fyn kinase and enhanced GluN2B-mediated NMDAR currents. Biochemical experiments confirmed that D1/D5R stimulation activates Fyn kinase and enhances the tyrosine phosphorylation of GluN2B subunits. In contrast, activation of the Gαq-coupled PAC1R selectively recruited Src kinase to enhance the function of GluN2A-containing NMDARs. Enhancing the functional ratio of GluN2A-to-GluN2B subunits by PAC1R activation lowered the threshold for LTP induction whereas enhancing the functional ratio of GluN2B-to-GluN2A subunits by D1/D5R activation increased the threshold for LTP induction. Unexpectedly, activation of the Gαi/o-coupled mGluR2/3 enhanced NMDAR-mediated function via a previously unidentified mechanism. Inhibition of the cAMP-PKA pathway via mGluR2/3 activation resulted in activation of Src via decreased phosphorylation of its C-terminal Tyr527 by Csk. Stimulation of mGluR2/3 selectively potentiated the function of GluN2A-containing NMDARs but whether it shifted the modification threshold θm to the left requires further investigation.