VictorJuiz/thesis huggingface dataset:
Supervised and Active Learning for Recommender Systems
Keywords: Active Learning
Machine Learning
Paper Matching
Recommender Systems
Reviewer Matching
Supervised Learning

Traditional approaches to recommender systems have often focused on the collaborative filtering problem: using users' past preferences in order to predict their future preferences. Although essential, rating prediction is only one of the components of a successful recommender system. One important problem is how to translate predicted ratings into actual recommendations. Furthermore, considering additional information either about users or items may offer substantial gains in performance while allowing the system to provide good recommendations to new users.We develop machine learning methods in response to some of the limitations of current recommender-systems' research. Specifically, we propose a three-stage framework to model recommender systems.We first propose an elicitation step which serves as a way to collect user information beneficial to the recommendation task. In this thesis we framed the elicitation process as one of active learning. We developed several active elicitation methods which, unlike previous approaches which exclusively focus improving the learning model, directly aim at improving the recommendation objective.The second stage of our framework uses the elicited user information to inform models that predict user-item preferences. We focus user-preference prediction for a document recommendation problem for which we introduce a novel graphical model over the space of user side-information, item (document) contents, and user-item preferences. Our model is able to smoothly tradeoff its usage of side information and of user-item preferences to make good document recommendations in both cold-start and non-cold-start data regimes.The final step of our framework consists of the recommendation procedure. In particular, we focus on a matching instantiation and explore different natural matching objectives and constraints for the paper- to-reviewer matching problem. Further, we explore and analyze the synergy between the recommendation objective and the learning objective.In all stages of our work we experimentally validate our models on a variety of datasets from different domains. Of particular interest are several datasets containing reviewer preferences about papers submitted to conferences. These datasets were collected using the Toronto Paper Matching System, a system we built to help conference organizers in the task of matching reviewers to submitted papers.
Regulating GLUT4 Sorting into the Insulin-Responsive Compartment in Muscle Cells
Keywords: GLUT4
insulin
insulin resistance
intracellular sorting
Syntaxin-6

Skeletal muscle and adipose tissue serve as the major storage sites for glucose, and insulin is the major signal for glucose uptake into these tissues. Glucose transporter 4 (GLUT4) is responsible for the uptake of glucose into muscle and adipose tissues. This protein constitutively recycles between the plasma membrane and intracellular depots. Under resting conditions, most GLUT4 molecules are maintained in intracellular compartments. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting a fraction of GLUT4 to the plasma membrane from insulin responsive vesicles. However, steady-state measurements of GLUT4 localization have failed to reveal the subcellular localization of these vesicles or how GLUT4 is sorted to them.By analyzing the sorting of GLUT4 as it internalizes from the cell surface, advances may be made in revealing how GLUT4 acquires insulin-responsiveness and the intracellular location in which this occurs. In L6 myoblasts stably expressing
The Fossil Fueled Metropolis: Los Angeles and the Emergence of Oil-based Energy in North America, 1865-1930
Keywords: Energy systems
Fossil fuels
Historical geography
Los Angeles
Oil
Spatial Fix

Beginning with coal in the nineteenth century, the mass production and intensive consumption of fossil fuel energy fundamentally changed patterns of urban and industrial development in North America. Focusing on the metropolitan development of Los Angeles, this dissertation examines how the emergence of oil-based capitalism in the first three decades of the twentieth century was sustained and made increasingly resilient through the production of urban and industrial space. In a region where coal was scarce, the development of oil-based energy was predicated on long-term investments into conversion technologies, storage systems and distribution networks that facilitated the efficient and economical flow of liquefied fossil fuel. In this dissertation, I argue that the historical and geographical significance of the Southern California petroleum industry is derived from how its distinctive market expansion in the first three decades of the twentieth century helped establish the dominance of oil-based energy as the primary fuel for transportation in capitalist society. In North America, the origins of oil-based capitalism can be traced to the turn of the twentieth century when California was the largest oil-producing economy in the United States and Los Angeles was the fastest growing metropolitan region. This dissertation traces how Los Angeles became the first city in North America where oil became a formative element of urban and industrial development: not only as fuel for transportation, but also in the infrastructures, landscapes and networks that sustain a critical dependence on oil-based energy. With a distinctive metropolitan geography, decentralized and automobile-dependent, Los Angeles became the first oil-based city in North America and thus provides an ideal case study for examining the regional dynamics of energy transition, establishment and dependence. Interwoven with the production of urban and industrial space, oil remains the primary fuel that sustains the capitalist mode of production.
Multiple Institutional Logics within the (Trans)National Welfare Diamond: Child Welfare Transformation in Post-Soviet Kazakhstan
Keywords: post-Soviet transformation
social policy
transnationalism
welfare institutions

For over two post-Soviet decades, Kazakhstan has experienced multiple transformations, big and small, visible and invisible, recognized and unnoticed. Focusing on child welfare transformation in post-Soviet Kazakhstan, this thesis pursues two research questions: (1) How have child welfare institutions changed in Kazakhstan in the post-Soviet period? (2) What was the role of (trans)national institutional factors (i.e., legal and regulatory environments, organizational policies and practices, and interorganizational relationships) and Soviet institutional legacies in shaping institutions of child welfare provision in Kazakhstan?Using an integrated multidimensional theoretical framework built upon the welfare diamond, a transnational approach, and historical institutionalism, I examine a mix of national and transnational organizations involved in child welfare reform, conceptualizing them as interconnected policy actors embedded in the historically contingent (trans)national institutional (legal and regulatory) environment. Using qualitative case study methodology for social policy analysis, this thesis draws upon data collected through interviews with key informants, conducted between June and September 2012, and textual documents (policy and legal documents, organizational and program documents, research reports, and media reports). The thesis develops two main arguments. The first argument concerns institutional factors that shape child welfare institutions. The transformation of the child welfare system was a function of relations among (trans)national organizational actors whose behaviors were constrained and enabled by the wider (trans)national legal/regulatory environment. The institutional environment and the child welfare diamond were characterized by multiple, competing, and shifting institutional logics. My second argument concerns the effects of the institutional and organizational environment on child welfare institutions. Multiple institutional logics, I argue, have accounted for the development of hybrid child welfare institutions, which encompass core Soviet-type child welfare institutions, maintained and reproduced, along with multiple layers of new institutions introduced over the past twenty years. This analysis indicates that the post-Soviet change in welfare provision consisted of numerous incremental and multidirectional institutional adjustments.
Highly Efficient Organic Light-Emitting Diodes by Exciton Harvesting
Keywords: energy transfer
exciton harvest
iridium complex
organic synthesis
phosphorescent organic light-emitting diodes
triplet exciton

Tremendous progress has been made on organic light emitting diodes (OLEDs) over the past two decades. This has enabled the commercialization of active-matrix OLED displays for mobile phones and even large-area flat panels recently. However, in terms of solid-state lighting, further reduction in electrical energy consumption at high brightness levels is urgently needed to make the technology viable to the lighting industry and to compete with its inorganic LED counterpart as well as compact fluorescent light bulbs. In this respect, considerable effort has been focused on the use of a variety of complex device architectures including insertion of exciton confining or carrier blocking layers, doping of the transport layers, as well as implementing gradient or mixed emissive zone structures in a single OLED device. While effective, these designs are generally overly cumbersome for large-scale commercial applications.In this thesis, two effective ways to significantly enhance the efficiency of OLEDs without compromising device simplicity are presented. These techniques involve firstly effective exciton harvesting followed by intrazone and interzone energy transfers, respectively. High external quantum efficiencies (EQEs) of > 20% were achieved at a high brightness of 1,000 cd/m2 for red and greenish-yellow OLEDs, which are among the best performances reported to date with respect to each emissive color. Furthermore, white OLEDs with a superior combination of EQE (> 20%) and color rendering index (~85) were achieved for the first time at a lighting-suitable brightness of 5,000 cd/m2, which represents a significant step toward OLEDs in solid-state lighting. Detailed investigations on the working mechanism of these two techniques as well as future work related to these strategies will be discussed.
iPS Cell Based Models of Silent Chromatin and of Gene Expression in Rett Syndrome Neurons
Keywords: Chromatin
Epigenetics
Reprogramming
Rett syndrome

Induced pluripotent stem (iPS) cell technology is an attractive new avenue for studying the reorganization of chromatin during development and for modeling human disease. I demonstrate that the completion of the gradual reprogramming process in murine somatic cells is temporally associated with epigenetic silencing of reprogramming retroviral vectors and acquisition of decondensed constitutive heterochromatin fibres. By specifically investigating H3K9me3-enriched heterochromatin, we provide structural evidence that compact heterochromatin domains are organized as densely packed 10 nm chromatin fibres. To model the effect of mutations in the methyl CpG-binding protein 2 (MECP2) in human neurons, we established iPS cells from a Rett syndrome patient with an exon 1 MECP2 frameshift mutation. Neuronal differentiation specification was unaffected in MECP2 mutant neurons when evaluated by single-cell Fluidigm analyses. Subtle changes in a subset of MECP2 target genes were found implicating MECP2e1 as a transcriptional modulator rather than a master regulator of gene transcription in neurons. Finally, MECP2e1 deficiency is sufficient to reduce neuronal soma-size even in presence of the alternate MECP2e2 isoform demonstrating that MECP2e1 is the dominant endogenous isoform that is essential for healthy neuron function.
FRESH -- A Phenomenological Enquiry
Keywords: Anapana Meditation
Educational holistic attitudes and theory
Holistic educational approach at Maher (NGO)
Mindful education
Phenomenology of practise oriented towards pedagogy
The lived experiences of children in India who practise a secular meditation

This thesis examines the lived experiences of children in Maharashtra, India who practise a secular meditation. Worldwide children are now encouraged to develop awareness through practicing similar although distinctive forms of secular mindful methods, such as contemplation, social and emotional learning and meditation. The children in this study have for several years practised a breath awareness and loving kindness meditation at the non-governmental organisation where they reside and/or at the school they attend. This study points to the children's experiences around the theme of their mindful practise by asking three guiding questions: 1) How does the child experience meditation? 2) How does the child build morality through meditation practise? 3) How does the child's meditation practise offer certain "protective" benefits? To approach these questions this thesis engages a phenomenological practice orientated towards pedagogy and relies on educational holistic attitudes and theory. Overall research on meditation and children is uncommon, but in the last few years that has begun to change as internationally people across the disciplines investigate this subject area. The research that has been done on the subject of children and meditation is more survey oriented and clinical based. This study is distinct in its focus on listening to and learning from the lived experiences of children who are born, raised and educated in environments that encourage meditation as integral to the development of emotional, mental, physical, social and spiritual well-being. Eight children ages 11 to 16 are this study's key informants. To help inform the children's stories, four adults familiar with the participant children and/or their environments contributed their lived experiences around the theme of mindful practise. I worked with the participant children as a meditation group facilitator in India for over 2.5 consecutive years. This study reveals an ongoing development of friendship, trust and participation with and research on Indian cultures; an ongoing engagement with the children and their families, friends and communities; and an ongoing effort around meditation through group work, observation and volunteer work. This involvement was integral to understanding the children and their cultures, faiths, traditions, beliefs, politics, histories, practices, geographical locations and more.
Adoption and Use of High Technology Medical Imaging in Ontario Hospitals: The Determinants of Adoption and the Relationship between Use and In-patient Mortality and Length of Stay
Keywords: Adoption of Technologies
Computed Tomography
Imaging Use
Magnetic Resonance Imaging
Quality and Efficiency
Value of Imaging

There is broad agreement that a substantial fraction of imaging examinations are unnecessary and do not positively contribute to patient care. The negative implications for health care quality and costs, including unnecessary exposure to radiation, resulting from unnecessary use of medical imaging have been extensively recognized in the scholarly and policy literature. Not surprisingly, the need for evidence documenting the value of medical imaging is increasingly gaining more interest. This thesis aims to address this need by investigating the value of adoption and use of CT scanners and MRI machines in hospitals operating in a universal, single-payer system. Adoption was hypothesized to be a central element of quality and efficiency, linking hospital structural characteristics and market factors with hospital outcomes. Empirical investigations focused on the determinants of adoption, and the relationship between adoption (and use) and hospital mortality and length of stay in medical in-patients. Hospital size, specialization, and financial condition emerged as consistent determinants of hospital adoption of CT and MRI technologies. Market factors, however, showed inconsistent relationships with adoption. The results also suggest that adoption reduces mortality and length of stay, and that imaging use reduces mortality and increases length of stay. The relationship between imaging use and outcome was conditional to the hospital adoption pattern or behaviour. That is, the use of imaging saves lives, but only in hospitals with at least one technology available. This was not the case in hospitals without CT and MRI technologies, where imaging scans are contracted out to other hospitals or independent health facilities. The imaging use-outcome relationships examined also suggest the existence of diminishing returns and flat-of-the-curve medicine. These results may have important implications for policy development aimed at improving the value of imaging. Some potential changes to the current funding models are discussed and delineated, including the use of financial incentive systems specific to CT and MRI services. This thesis has demonstrated the potential to inform empirical investigations of the value of high technology medical imaging, and has contributed to the literature by advancing the understanding of the mechanisms that produce quality and efficiency in hospitals.
Job Developers in Transition: A Study of Informal and Nonformal Job Skills Training of Job Developers in Nonprofit Organizations in Ontario
Keywords: Education
Informal Learning
Nonformal Learning
Sociology
Workplace Learning

Job Developers have complex and demanding jobs that require balancing the needs of organizations, employers, and job seekers. Job Developers must meet new employers and potential employees every day, earn their trust, and learn their needs. A common role Job Developers play is helping people find jobs and helping employers find employees. Job Developers attempt to learn what employers and job seekers need and what each can offer to match the right applicants to the right employers.Competent Job Developers must have organization, research, marketing, selling, communication, and negotiation skills. Job development has become a high growth occupation. Because the nature of their jobs changes constantly, Job Developers must also stays updated on employment trends and labor market information. While these changes provide opportunities for practitioners to expand their roles, they also impose increased demands and challenges to build their skills and capacity to perform their jobs. The job developer profession (also known as employment specialist) is a recently new concept in the nonprofit sector. Job Developers' potential as advocates for the unemployed, those with disabilities, and new immigrants is fundamental in today's competitive job market and in the context of equitable opportunity for employment. Informal and nonformal learning are well-recognized and well-used in the job development field. Job Developers rely on informal and nonformal learning for professional development and occupational autonomy.
Formation, Characteristics and Electrocatalytic Properties of Nanoporous Metals Formed by Dealloying of Ternary-noble Alloys
Keywords: Dealloying
Electrocatalysis
Platinum
Surface segregation
Ternary-noble precursors

Nanoporous metals formed by electrochemical dealloying of silver from Ag-Au-Pt alloys, with 77 at.% silver and platinum contents of 1, 2 and 3 at.%, have been studied. The presence of platinum, which is immobile relative to gold, refine the ligament size and stabilized the nanostructure against coarsening, even under experimental conditions that would be expected to promote coarsening (e.g., exposure to high temperature, longer dealloying times). By adding only 1 at.% Pt to the alloy precursor, the ligament/pore size was reduced by 50% with respect to that in nanoporous gold (NPG), which was formed on a Ag-Au alloy with the same silver content as ternary alloys. A further decrease in the ligament size was observed by increasing the platinum content of the precursor; however, most of the improvement occurred with 1 at.% Pt. The adsorbate-induced surface segregation of platinum was also investigated for these nanoporous metals. By exposing freshly-dealloyed nanostructures to moderate temperatures in the presence of air, platinum segregated to the ligament surface; in contrast, in an inert atmosphere (Ar-H2), platinum mostly reverted to the bulk of the ligaments. This thermally activated process was thermodynamically driven by the interaction between platinum and oxygen; however, at the desorption temperature of oxygen, platinum de-segregated from the surface. Moreover, the co-segregation of platinum and oxygen hindered the thermal coarsening of the ligaments. Finally, the electrocatalytic abilities of these nanostructures were studied towards methanol and ethanol electro-oxidation, in alkaline and acidic media, showing significantly improved response in comparison to that observed in NPG. The synergistic effect between gold and platinum atoms and the smaller feature size of the nanostructures were directly associated with this behaviour. In alkaline electrolyte, the nanostructure formed on the alloy with 1 at.% Pt showed higher catalytic response than the other two ternary nanostructures, which could be associated with the platinum/gold ratio on the surface of the structure. In acidic electrolyte, the nanostructure with the highest platinum content displayed the highest electrocatalytic response. Furthermore, the presence of platinum changed the selectivity of both reactions: the concentrations of carbonate produced increased by increasing the platinum content in the alloy precursor.
Fabrication and Optimization of Ni Superalloy Inconel 600 Microtruss Materials
Keywords: Cellular materials
End constraint rigidity
Increasing formability
Optimization of properties of cellular materials
Pin design for increased formability
Plastic strain distribution

Microtruss materials are multifunctional cellular hybrids composed of an interconnected arrangement of internal struts that can offer enhanced strength and stiffness at low densities. This study looks at the potential of Ni-based superalloys as microtruss materials. The potential of using the in-situ plastic strain imparted during stretch forming to grain boundary engineer the internal struts of Inconel 600 (IN600) cellular hybrids was also explored. In order to examine this question, a combination of experimental and finite element (FE) methods were employed. The non-uniform plastic deformation imparted to the microtruss struts during fabrication was modeled by FE and the local changes in grain boundary character in the fabricated trusses were mapped by electron backscattered diffraction.This study also examined the distribution of plastic strain over the microtruss architecture. A mechanical press with various pin geometries was employed to experimentally validate the FE models. Standard pin geometry results in substantially non-uniform plastic strain, which limits the maximum formability of the starting sheet material. Importantly, pins designed with tapers and spheres were shown to impart plastic strain along the entire length of the microtruss. This opened up possibility of new design strategies for facilitating grain boundary engineering over the entire truss. It may also present opportunities for enhancing the energy absorption performance of microtruss materials.Finally, this study examined the mechanical properties of IN600 microtrusses, in particular focusing on the significance of strut end constraints in determining the overall mechanical performance. While it is straightforward to analytically determine the inelastic buckling resistance of plastically deformed struts, there is no simple way to determine the rotational end constraint of the struts deformed to varying truss angles. It was seen that end constraint rigidity k could be determined using a FE-based bifurcation analysis and the value of k was architecture dependent.