VictorJuiz/thesis huggingface dataset:
Fabrication of a 3-dimensional Cardiac Tissue using a Modular Tissue Engineering Approach
Keywords: Tissue engineering
cardiac muscle

Implantation of engineered cardiac tissue may restore lost cardiac function to damaged myocardium. We propose that functional cardiac tissue can be fabricated using a modular, vascularized tissue engineering approach developed in our laboratory. In this study, rat aortic endothelial cells (RAEC) were coated onto sub-millimetre size modules embedded with cardiomyocyte-enriched neonatal rat heart cells (CM) and assembled into a contractile, macroporous sheet-like construct. Cell morphologies, contractility and responsiveness to electrical stimulus were examined to evaluate the function of the resulting modular construct. CM embedded modules contracted spontaneously at day 7 post-fabrication and remained viable in vitro at day 14. Modules cultured in 10% bovine serum were more contractile and responsive to external stimulus compared to 10% FBS medium cultured modules. VE-cadherin staining showed a confluent layer of RAEC on CM embedded co-culture modules at day 7. Co-culture modules were also contractilie, but when compared to CM only modules their electrical responsiveness was slightly diminished. Modules assembled into macroporous sheets retained their characteristics at day 10 post-assembly. Micrographs from histological sections revealed the existence of muscle bundles near the perimeter of modules and at inter-module junctions. The fate of modular cardiac tissues in vivo was examined using two implantation strategies based on a syngeneic animal model. Co-culture modules (CM and EC) were either injected into the peri-infarct zone of the heart, or fabricated into a patch form and implanted over a right ventricular free wall defect. In both models, donor EC were involved in the formation of blood vessels-like structures, which appeared to have connected with the host vasculature. Co-culture implants had a higher overall vessel density compared to CM-only implants, but only in the absence of MatrigelTM. Moreover, donor CM organized into striated muscle-like structures, at least when MatrigelTM was removed from the matrix. Together these results suggest that modular cardiac tissue can survive and develop into native-like structures when implanted in vivo and the potential of the modular approach as a platform for building 3-D vascularised cardiac tissue should be explored in greater depth.
Multiple-antenna Communications with Limited Channel State Information
Keywords: multiple-antenna communications
channel state information
limited feedback systems
relay channel
single-user point-to-point channel
multiuser broadcast channel
Grassmannian codebooks
beamforming
power control
quantization codebook
multiuser interference
quantization resolution
quality-of-service
MIMO
CSI

Due to its significant advantage in spectral efficiency, multiple-antenna communication technology will undoubtedly be a major component in future wireless system implementations. However, the full exploitation of this technology also requires perfect feedback of channel state information (CSI) to the transmitter-- something that is not practically feasible. This motivates the study of limited feedback systems, where CSI feedback is rate limited. This thesis focuses on the optimal design of limited feedback systems for three types of communication channels: the relay channel, the single-user point-to-point channel, and the multiuser broadcast channel. For the relay channel, we prove the efficiency of the Grassmannian codebooks as the source and relay beamforming codebooks, and propose a method for CSI exchange between the relay and the destination when global CSI is not available at destination. For the single-user point-to-point channel, we study the joint power control and beamforming problem and address the channel magnitude and direction quantization codebook design problem. It is shown that uniform quantization of the channel magnitude (in dB scale) is asymptotically optimal regardless of the channel distribution. The analysis further derives the optimal split of feedback bandwidth between the magnitude and direction quantization codebooks. For the multiuser broadcast channel, we first prove the sufficiency of a product magnitude-direction quantization codebook for managing the multiuser interference. We then derive the optimal split of feedback bandwidth across the users and their magnitude and direction codebooks. The optimization results reveal an inherent structural difference between the single-user and multiuser quantization codebooks: a multiuser codebook should have a finer direction quantization resolution as compared to a single-user codebook. It is further shown that the users expecting higher rates and requiring more reliable communication should provide a finer quantization of their CSI. Finally, we determine the minimum required total feedback rate based on users' quality-of-service constraints and derive the scaling of the system performance with the total feedback rate.
Adaptation of the Capacity Evaluation Process to Make Admission Decisions: Increasing Access for People with Aphasia and other Communication Barriers
Keywords: Capacity evaluation
Communication barriers

Background – Every competent person in Ontario has the right to decide whether or not he or she will be admitted to long-term care. If your capacity to make such a decision is in doubt, then it is evaluated. The current evaluation process is inaccessible to people with aphasia or other communication barriers, and social work evaluators report significant problems in communicating with this population. Competent individuals have been found lacking in capacity because of communication barriers. Aims – To create a communicatively accessible capacity evaluation process with training in specialized communication techniques. Also, to test the validity and effectiveness of the Communication Aid to Capacity Evaluation (CACE) to reveal the inherent capacity of participants with aphasia using social work evaluators. Methods – 32 social workers were partnered with 32 competent participants with aphasia. They were randomly divided into an experimental and control group. Both groups administered the current ‘Capacity to Make Admissions Decisions’ questionnaire to establish a baseline measurement of capacity. The social workers in the experimental group were introduced to CACE and received communication training. Following a two-week interval they administered CACE and the control group re-administered the current capacity questionnaire. The 64 capacity evaluations were video recorded and 3 independent speech-language pathologists administered standardized assessment measures on the recordings. Finally, the participants completed surveys measuring confidence and communication abilities. Outcomes - Using the current capacity questionnaire, one social worker found a competent participant lacking in capacity and one third of social workers were unable to determine capacity. Following the introduction of CACE with communication training, analyses of the standardized measures and survey results showed a statistically significant difference between the participants in the experimental group and the control group. The social workers in the experimental group had significantly better communication skills, (‘Revealing Competence’ f (2, 29) = 12.03, p = 0.002), the participants with aphasia’ abilities to ‘Transfer Information’ increased, (f (2, 29) = 10.51, p < 0.003), and the evaluators’ confidence in their determinations of capacity improved (f (2, 29) = 13.511, p = .001). The use of CACE with communication training resulted in accurate determinations of capacity in competent participants with aphasia. Conclusions - CACE was an effective tool to evaluate the capacity to make a decision regarding admission to long-term care. It was communicatively accessible for this research population with aphasia, enhancing comprehension of the capacity process and enabling the person to communicate a response. Improved communication skills, transfer of information and confidence allowed the evaluators to accurately determine capacity.
Overcoming Barriers and Finding Strengths: The Lives of Single Mother Students in University
Keywords: single mothers
university
inclusive schooling
barriers
strengths

The impetus for this study came from my own history of being a single mother while completing my undergraduate degree and the struggles that entailed. The research uncovers both the barriers and facilitators experienced by single mothers in undergraduate programs in a Canadian context and utilizes a framework of access and equity in education. The co-participants belonged to diverse social and political identities in terms of age, race and ethnicity, sexuality, (dis)ability, and countries of birth. All the women attended universities in Southern Ontario. Twenty-five women agreed to be interviewed in either a group or individual interview. Co-participants were encouraged to contribute to the design and analysis of the study wherever possible. Previous research based in the United States conceptualized single mother students as social assistance recipients and explored their difficulties within this context. This study suggests using a wider lens to include other experiences identified by co-participants and the literature review. The study locates barriers both within the university as well as in the larger society such as interpersonal violence, stress, financial insecurity, racism and other forms of discrimination. However, it also identifies supports and strengths single mothers encountered such as family, friends, children as motivation, professors, on-campus supports, and critical pedagogy, all of which were largely missing from previous research. Many women challenged the often pathologizing dominant discourse and instead described single motherhood as empowering, independent, and liberating as compared to being a part of a traditional nuclear family. Co-participants also identified feeling isolated, discussions around which engendered a social group outside of the research project. By creating awareness of the needs of diverse single mother students, this project aims to disrupt the still-prevalent notion of the “traditional student” and accompanying policies and practices in institutions of education and the wider community. While much has been documented in Canada about the need for access, equity, and inclusive schooling, single mothers in particular have not been a main focus and included among other intersections of identity. The findings from this study address this gap and contribute to the literature.
Signaling during Mechanical Strain Injury of the Urinary Bladder: ERK, STAT3 and mTOR Pathways
Keywords: bladder obstruction
mechanotransduction

Bladder obstruction (neurogenic or anatomic) induces strain injury in detrusor smooth muscle cells. Signaling via strain injury in other systems has been highly studied, while in bladder obstruction, it has been quite limited to a small number of pathways. In our study we have examined the effects of strain injury using a combination of in vivo, ex vivo and in vitro models, with the aim of understanding disease pathogenesis in the bladder. Using a combination of literature searches, phospho-protein screens and pathway analysis, we uncovered three pathways activated by mechanical strain, ERK, STAT3 and mTOR, with potential for changing not only the way we understand but also the way we treat obstructive myopathies of the bladder. We found that not only were these pathways activated in response to strain and distension injury of BSMC, but they were also responsible for proliferation and sometimes de-differentiation. Included herein are three chapters, published in 2006 and 2010, on the role of ERK, STAT3 and mTOR pathways in bladder smooth muscle cell proliferation and differentiation, 8 Appendices containing the first pages of other papers and reviews published during the course of my studies.
On Emotion’s Ability to Modulate Action Output
Keywords: Emotion
Attention
Motor control
Evolution

It is widely thought that emotional stimuli receive privileged neural status compared to their non-affective counterparts. This prioritization, however, comes at a cost, as the neural capacity of the human brain is finite; the prioritization of any one object comes at the expense of other concurrent objects in the visual array competing for awareness (Desimone & Duncan, 1995). Despite this reality, little work has examined the functional benefit derived from the perceptual prioritization of affective information. Why do we preferentially attend to emotional faces? According to evolutionary accounts, emotions originated as adaptations towards action, helping to prepare the organism for movement (Darwin, 1872; Frijda, 1986). The current dissertation examines this from the perceptive of visual neuroscience and motor cognition. Chapters 1 and 2 examine the mechanisms involved during the perceptual prioritization of emotional content in the context of action system modulation. Chapters 3 and 4 then directly examine emotions effect on oculomotor action output. Results across the studies are discussed in the context of evolutionary theories related to biological origins of emotional expression.
Atmospheric Chemistry of Polyfluorinated Compounds: Long-lived Greenhouse Gases and Sources of Perfluorinated Acids
Keywords: polyfluorinated compound
long-lived greenhouse gas
perfluorinated acid
long-range transport
radiative efficiency

Fluorinated compounds are environmentally persistent and have been demonstrated to bioaccumulate and contribute to climate change. The focus of this work was to better understand the atmospheric chemistry of poly- and per-fluorinated compounds in order to appreciate their impacts on the environment. Several fluorinated compounds exist for which data on climate impacts do not exist. Radiative efficiencies (REs) and atmospheric lifetimes of two new long-lived greenhouse gases (LLGHGs) were determined using smog chamber techniques: perfluoropolyethers and perfluoroalkyl amines. Through this, it was observed that RE was not directly related to the number of carbon-fluorine bonds. A structure-activity relationship was created to allow the determination of RE solely from the chemical structure of the compound. Also, a novel method was developed to detect polyfluorinated LLGHGs in the atmosphere. Using carbotrap, thermal desorption and cryogenic extraction coupled to GC-MS, atmospheric measurements can be made for a number of previously undetected compounds. A perfluoroalkyl amine was detected in the atmosphere using this technique, which is the compound with the highest RE ever detected in the atmosphere. Perfluorocarboxylic acids (PFCAs) are water soluble and non-volatile, suggesting they are not susceptible to long-range transport. A hypothesis was derived to explain the ubiquitous distribution of these compounds involving atmospheric formation of PFCAs from volatile precursors. Using smog chamber techniques with offline analysis, perfluorobutenes and fluorotelomer iodides were shown to yield PFCAs from atmospheric oxidation. Dehydrofluorination of perfluorinated alcohols (PFOHs) is poorly understood in the mechanism of PFCA atmospheric formation. Using density functional techniques, overtone-induced photolysis was shown to lead to dehydrofluorination of PFOHs. In the presence of water, this mechanism could be a sink of PFOHs in the atmosphere. Confirmation of the importance of volatile precursors was derived from examination of snow from High Arctic ice caps. This provided the first empirical evidence of atmospheric deposition. Through the analytes observed, fluxes and temporal trends, it was concluded that atmospheric oxidation of volatile precursors is an important source of PFCAs to the Arctic.
Towards a Microfluidic Toolbox for Proteomics: Novel Sample Pre-processing and Separation Techniques
Keywords: Microfluidics
Hybrid

Microfluidics was introduced in the early 1990’s and was posited to usher in a new age of integrated analysis systems in the form of labs-on-a-chip. To date, numerous embodiments of microfluidic technologies including fully integrated analysis systems have been described for various applications. Microfluidics can be sub-divided into two paradigms based on fluid manipulation in streams or droplets. In the former, streams of fluids flow through micron-dimension channels, and typical volumes manipulated are in the pico-liter to nano-litre range. These devices are mainly employed for rapid, high efficiency chemical separations, among other applications. In the latter, droplets are manipulated on a dielectric-coated array of microelectrodes in a process called digital microfluidics (DMF). In DMF each droplet is individually addressable, giving superior spatial control over fluid droplets with volumes in the pico-liter to micro-litre range. Independently addressable droplets make DMF amenable to carrying out sequential reactions. This thesis presents methods towards the integration of these two microfluidic paradigms into “hybrid microfluidic” platforms. Hybrid devices contain a DMF array for sample preparation and a microfluidic channel network for on-line analysis by chemical separation. Sample transfer between the platforms is made by way of a digital-channel interface, which has been fabricated in two geometries: side-on and vertical. Chemical separations on hybrid devices are performed in various open-channel and chromatographic modes. In open-channel methods analytes are separated by microchannel zone electrophoresis (MZE) or micellar electrokinetic chromatography (MEKC). In chromatographic separations porous polymer monolithic (PPM) columns were created in situ by UV-initiated polymerization of acrylate monomers. Prior to integration into hybrid microfluidic devices PPMs were optimized for use in gradient elution microchannel electrochromatography (MEC) of peptides. It is anticipated that hybrid microfluidic devices will bridge a large bottleneck for myriad analyses by combining sample preparation with on-line analysis by chemical separation.
Crisis and Hermeneutics: Wang Fuzhi’s Interpretation of Confucian Classics in a Time of Radical Change from Ming to Qing Dynasty
Keywords: 0318
0332

In an effort to explore how hermeneutic reason functions in cultural crises, and more specifically, how a Ming loyalist Wang Fuzhi dealt with the political and cultural crises at the Ming-Qing dynastic transition, this dissertation critically examines his commentaries on Confucian classics and historical writings as well as his criticism toward other Confucian scholars and heretical schools. My conclusion is that, unlike his peers’ iconoclastic criticism of Neo-Confucianism, Wang’s uniqueness consists in that he attempted to reconstruct it through such criticism. Through this reconstruction, he tried to provide a solution to the political and cultural crises of his time by promoting universal harmony/he and humanity/ren. In his opinion, humanity originated from the harmonious qi in the universe, was identical with human nature, and demonstrated in the humane governance. Thus, he established a comprehensive system that incorporated cosmology, human nature, and political governance. Wang insisted that human beings’ destruction of the universal harmony caused the rise of perverse qi that gave rise to natural disasters and social conflicts. In order to decrease the amount of perverse qi and in turn the number of bad people and conflicts generated, Wang thought that man could cultivate his own harmonious qi or humanity and thus increase the universal harmonious qi through self-cultivation. Individually, the measures were dependent upon complying with ritual propriety and awakening one’s innate knowledge. Politically, it depended upon the ruler’s humane governance—the cultivation and extension of humanity to the people. Wang’s motivation of reconstruction was also powered by his arrogance. From his slogan, “the Six Classics require me to start a new phase”, he tacitly assumed himself to be on par with Confucius, justifying his criticism of others. Regrettably, his criticism of other non-Confucian schools was often impertinent and biased although his criticism of Neo-Confucianism was to the point.
Development of Rhodium-catalyzed Reactions for the Enantioselective Desymmetrization and Carbonylation of meso Alkenes
Keywords: organometallic catalysis
synthesis
rhodium
asymmetric catalysis
chirality

This thesis describes the discovery of catalytic reactions that create carbon-carbon bonds stereoselectively between substrates bearing an alkene and organoboronic acids reagents. Chiral rhodium(I) catalysts were found to react with various meso-symmetrical substrates, thereby resulting in enantioselective desymmetrization reactions. The methodologies presented herein allow the rapid synthesis of several chiral functionalized molecules; including branched homoallylic alcohols, cyclopentenyl hydrazines, and ketohydrazines. The thesis is divided according to three main transformations: asymmetric allylic substitution of allylic carbonates, asymmetric ring-opening of [2.2.1]-diazabicyles, and carbonylation of alkenes or alkynes. Chapter 2 details the investigations of a ligand-controlled catalytic process to prepare either trans-2-arylcyclopent-3-enols (up to 94% ee), or trans-4-arylcyclopent-2-enols (up to 99% ee) as the major products starting from cyclic meso allylic dicarbonates. This rhodium-catalyzed methodology was extended to include linear allylic dicarbonates, thereby yielding chiral 2-arylbut-3-enols with up to 95% ee. An enantioselective desymmetrization of strained alkenes by ring-opening of meso bicyclic hydrazines is described in Chapter 3. The reaction allows one to prepare trans-2-arylcyclopent-3-enyl hydrazides with up to 99% ee. In addition, an enantioselective hydroarylation process was identified to yield 5-aryl-2,3-diazabicyclo[2.2.1]heptanes. Mechanistic investigations showed that the reaction proceeds via an unusual C-H activation/1,4-migration of the rhodium catalyst. Finally, Chapter 4 outlines the development of a mild catalytic acylation of pi systems. This mode of reactivity was optimized to promote the desymmetrization of [2.2.1]-diazabicycles via a formal allylic substitution with acyl anions as nucleophiles. The method yields densely functionalized trans-2-ketocyclopent-3-enyl hydrazides. In addition, preliminary studies demonstrate that the rhodium(I)-catalyzed acyl anion addition is also possible with other pi electrophiles. For example, with alkyne, it provided a synthesis of cyclopentenones that complements the Pauson-Khand reaction. Overall, the catalytic transformations reported herein give access to seven classes of products stereoselectively; starting from simple reagents.