VictorJuiz/thesis huggingface dataset:
The Colloidal Stabilization of Quantum Dots: Towards Manufacturable, Efficient Solution-Processed Solar Cells
Keywords: cleavable ligands
colloidal chemistry
hemiketal
ligand design
nanoparticles
solar cells

Understanding colloidal stabilization can influence the design of optoelectronic devices and enable improvements to their performance and stability. For photovoltaics, important characteristics of the active layer material are high conductivity along with a minimum of recombination centers. In order to capitalize on the benefits of solution-processed materials, it is important to minimize the number of processing steps: ideally, to achieve a low-cost solution, materials would be deposited using a single process step compatible with roll-to-roll manufacturing. Prior to this work, the highest-performing colloidal quantum dots (CQD) solar cells have relied on several deposition steps that are repeated in a layer-by-layer (LBL) fashion. The purpose of these process steps has been to remove the long insulating ligands used in synthesis and replace them with short ligands that allow electrical conduction. The large number of steps combined, typically implemented via spin coating, leads to inefficient materials utilization and fails to show a path to a manufacturable solution. In this work, the first CQD solar cells were designed, built, and characterized combining state-of-art performance with scalable manufacture. Firstly, I report the first automated CQD synthesis to result in CQDs that form high-performance CQD solar cells. I analyze the CQD synthesis and by separating it into two phases - nucleation and growth phase - my insights are used to create higher-quality CQDs exhibiting enhanced monodispersity. I then proceed to develop a CQD ink: a CQD solution ready for direct deposition to form a semiconducting film exhibiting low trap state density. In early trials the CQD ink showed only limited power conversion efficiencies of 2%. I designed a new ink strategy, which I term cleavable hemiketal ligands. This novel two-component ligand strategy enables the combination of colloidal stabilization (via this longer two-component ligand) and cleavability (enabling excellent packing in film and, ultimately, excellent electronic properties). As capstone, I report CQD solar cells exhibiting 7.9% solar power conversion efficiencies. This is, by a wide margin, the most efficient class of CQD solar cells to be reported based on a manufacturable fabrication method. The advances in this work - from automated synthesis to synchrotron studies of CQD packing to novel cleavable ligands - pave the way for new sustainable energy harvesting strategies based on solution-processed nanomaterials.
A Mouse Model of Adynamic Bone Disease (ABD) and its Consequences on Bone Quality with Age
Keywords: adynamic bone disease
ageing
biomechanics
bone quality
mouse model
osteogenic progenitors

Adyanmic bone disease (ABD) is a bone condition that is characterized by absent or very low bone turnover, which can lead to bone fragility and increased risk for fracture. The focus of this dissertation was to develop a mouse model of ABD that directly targeted osteoblasts and osteoclasts to generate the cellular hallmark of this disease. This mouse model was then used to investigate the independent and interactive effects of age and ABD on bone quality, and possible mechanisms of age-related decline in bone formation. The Col2.3∆tk (DTK) transgenic mouse was used for all aims in this study. The DTK mouse expresses a truncated version of the HSV-tk gene (∆tk) driven under a 2.3kb fragment of the rat type I collagen α1 (Col1a1) promoter, in which concomitant treatment with ganciclovir (GCV) and pamidronate induces a loss of bone turnover. GCV depletes differentiated osteoblasts to prevent bone formation while pamidronate inhibits bone resorption by osteoclasts. This mouse model of ABD showed a profound suppression in bone formation and resorption, and it has the histological hallmarks of the human condition. Aged ABD mice revealed that bisphosphonate treatment had a protective effect on trabecular bone volume and microarchitecture. However, it did not protect against age-related deterioration of bone mechanical properties and this deterioration may be due to changes beyond the mineral phase. Lastly, GCV-induced osteoblast depletion caused bone marrow stress that aged the DTK mouse skeleton by decreasing the number and osteogenic potential of progenitor cells. Our findings suggest that bone mineral density testing and even trabecular structure may not be sufficient indices for bone health in ABD. Understanding how bone cells age and their involvement in bone homeostasis may provide novel targets and paradigms for the intervention of age-related bone loss.
Synthetic and Computational Studies of Metal-ligand Cooperation with Iron Group Complexes for Water Splitting and Ketone Hydrogenation
Keywords: catalysis
density functional theory
hydrogenation
synthesis
water splitting

The paradigm of metal-ligand cooperation pervades the fields of organometallic chemistry and catalysis. In its simplest form, metal-ligand cooperation can be viewed as a strategic partnership between the metal and its surrounding ligand system to achieve new modes of chemical reactivity. Classic cases of metal-ligand cooperation involve elaborate chiral catalysts containing noble metals for enantioselective hydrogenation reactions, which are able to generate chiral compounds of great value to the pharmaceutical, agrochemical, and flavour industries. In recent years, creative design innovations have allowed chemists to create new molecules that use inexpensive iron-based catalysts for the same enantioselective transformations. Furthermore, metal-ligand cooperation has been recently employed in catalyst design pertaining to renewable/green energy applications. In particular, the activation of benign small molecules such as water, carbon dioxide, and methanol can be performed with well-defined molecular catalysts exhibiting metal-ligand cooperativity. This thesis encompasses two areas in which metal-ligand cooperation plays a vital role in the overall reactivity. First, new ruthenium complexes containing bidentate, tridentate, and tetradentate ligand systems are synthesized and investigated for applications in water splitting (2 H2O --> 2 H2 + O2). Second, computational investigations are performed to elucidate the mechanism of ketone hydrogenation using three generations of iron hydrogenation catalysts containing tetradentate PNNP ligand frameworks.
The Development and Pilot Test of a Shortened Systematic Review Format For Use By Physicians
Keywords: Decision Making
Evidence Based Medicine
Primary Care Physicians
Primary Health Care
Systematic Reviews as Topic

There have been great advances in refining the methods of conducting and reporting systematic reviews, however they are used infrequently by practitioners in making clinical decisions. Contextualization, format, and presentation of systematic reviews have been given little attention in the literature thus leaving a gap in what is known about these attributes. Graham's Knowledge to Action process for knowledge translation was used as a theoretical framework in the development of two shortened formats for the presentation of research evidence from systematic reviews for use in decision making by clinicians. Within the Knowledge to Action process, the tailoring of knowledge is represented as a Knowledge Funnel which includes Knowledge Synthesis and the creation of Knowledge Products and Tools. This PhD project was composed of three phases. In Phase One, a systematic review was conducted to examine the evidence on the impact of interventions for seeking, appraising, and applying evidence from systematic reviews in decision-making by clinicians. There was insufficient evidence identified from this systematic review to identify key aspects of strategies that encouraged clinicians to use systematic reviews in decision making. Similarly, no alternate formats for systematic reviews that had been rigorously developed and evaluated were identified in this systematic review. Phase Two involved a multi-component process that began with creating a prototype that employed user-centered design principles, which focus on making tools that are usable, useful, and accessible. This component was followed by a mapping exercise to identify obstacles described by clinicians in using clinical evidence in decision-making, a heuristic evaluation by an expert in human factors engineering (a usability inspection method), and a review of the clinical content in the prototypes. Iterative focus groups were then conducted with physicians who provided input on the refinement of the two prototypes. Their feedback guided changes to the format, presentation, and layout of the prototypes in order to increase uptake for end-users. Phase Three was composed of usability testing of the two prototypes by clinicians and a pilot randomized trial. Iterative usability testing offered essential insight into aspects that required modifications, and alterations were made in order to create finalized versions of the two shortened systematic review formats. A pilot randomized trial was then conducted to test methods and procedures in order to refine the processes for a larger scale randomized controlled trial, which will determine the impact of the two distinct shortened systematic review formats compared with a traditional full-length systematic review on generalist physicians' understanding of evidence and ability to apply it to a patient in a clinical scenario.
Language Teaching as Foreign Policy: Japanese Language Teachers in Japan's International Cooperation Volunteer Program
Keywords: Bilingualism
Foreign policy
Globalization
Japan
Language teaching
Neoliberalism

This thesis is an ethnographic exploration of the role of Japanese as heritage language (JHL) education in the overseas communities of Japanese descent (Nikkei communities) in the contemporary diaspora strategy of the Japanese government. Through the case of a state-sponsored international volunteer program designed to serve Nikkei communities in South America (Nikkei volunteer program), this thesis illustrates how individual subjectivity formed part of a state strategy, mediated through discourses on language. This thesis discusses these processes in which the volunteers became state-sponsored JHL teachers from the perspective of governmentality with a focus on the state. The first section of the thesis illustrates historical shifts in Japan's diaspora strategies. Historically, the Nikkei population has been understood primarily as a population with Japanese ancestry, and thus Japan's support for their linguistic and cultural heritage was emphasized for the sake of community maintenance. Since the 1990s, Japan began to reframe them also as "diplomatic assets" who could "bridge" Japan and their countries of residence. South American Nikkei population's hybrid cultural identity and bilingual language skills in Portuguese or Spanish and Japanese are valued especially in Japan's development cooperation projects in countries in and outside of South America which share those languages. Situated in this context, the official promotion of JHL to the Nikkei population is seen as an effective means of maintaining a "bonding tie" between Japan and the Nikkei "assets" in South America. The second section provides a close examination of one of the key components of the above mentioned process: the training of Japanese language teaching volunteers in the Nikkei volunteer program. Using data collected from in-depth life history interviews and fieldwork, this section illustrates the volunteers' subjectivity shifts in relation to multiple discourses on language, such as English, nihongo-Japanese as a foreign language (JFL), and JHL. The discourses of English and then JFL had an impact on the volunteers' trajectories before they applied for the Nikkei volunteer program. Further transformation occurred in the volunteer training sessions, when they encountered the institutional discourse of JHL and gradually conceptualized their roles and responsibilities as teachers of Japanese as Nikkei's heritage language.
Understanding and Improving Online Social Interactions and Processes: Methods, Algorithms Applications
Keywords: algorithms
data mining
graph mining
information network mining
knowledge discovery
online social media

Over the last years, the web witnesses a prolific growth largely due to the changing trends in the use of web technology that aims to enhance interconnectivity, self-expression and information sharing. These trends have led to the development and evolution of online social systems, but also to the creation of voluminous user-generated data. Even as these new online social media change the way we communicate, the social processes occurring remain governed by long-standing principles of human behavior and social interaction. In this thesis, we focus on the algorithmic and computational issues involved in the study of online social interactions and processes, such as, behavior, influence and diffusion. We first present an analysis of user-generated content published online by non-technical users. Our analysis reveals cascading patterns of online communication and establishes evidence of a cascading effect occurring in online communities. Then, we design an analytical method for detecting social influence, the cause of cascading effects, in social systems. Our method suggests a strategy for studying the causality between changes of individual behavior and the social influence that individuals exert in their network. The ability of a network to carry on social processes is a characteristic that depends, to a great extent, on its topology. Therefore, slight modifications in the network topology, might have a dramatic effect on how efficiently social processes evolve. We approach network modification as a graph augmentation problem and come up with methods that can optimize connectivity properties of the network that can boost social processes. Finally, we present efficient methods that utilize information available in a user's social network in order to improve the quality of results they get back when they search the web. The main goal and premise is to re-order the list of retrieved results in a way that favors items that are more relevant to a user's interest towards a more personalized search experience. Overall, formal understanding of principles and models of social interaction and processes that are persistent in online social media provides an opportunity to design and develop methods, algorithms and applications that can positively impact the way we interact with, search and access information online.
Aspects of Orientalism in Dante
Keywords: Dante Studies
Divine Comedy
Islam
Orientalism
Reception Theory

Dante Alighieri's references to the Islamic world are analyzed in order to determine how he perceived the Muslim Other through his medieval Christian lens, and how this shaped both his religious conception of salvation, as well as his political dream for a universal monarchy. Edward Said's Orientalism acts as a foundational theory guiding this study, in conjunction with Hans-Robert Jauss' Reception Theory, serving to determine how Dante's perception of the Islamic world was shaped through the subjective study of the Orient which preceded him, as well as his own politically and religiously divided milieu. While Dante's depictions of the Islamic prophets, Mohammad and Ali, give the initial impression that the poet was vehemently anti-Islam, the analysis of his other references to the Muslims and later, to other non-Christians, reveal that his views on the Other are far more complex and not necessarily negative. Although Dante does denigrate those individuals whose actions initiated schism, the poet's condemnation is not limited by religious or political ascriptions, nor does he condemn those who followed the teachings of schismatic leaders, marking him as a unique figure amongst many of his contemporaries. Dante's views on the Crusades and the conflict between Church and State are also highlighted for the significant impact that these aspects had on Dante's desire for a universal monarchy. Through his inclusion of many references - both subtle and overt - primarily to the Islamic world, while also to the Jews and other non-Christians, Dante raises complex questions about the possibility of salvation beyond Christianity and religious supersessionism, applying these questions to his political vision of a stable and united universal monarchy and the threat that otherness poses to this ideal.
A Peptide Modified Hydrogel Therapy for Acute Myocardial Infarction
Keywords: biomaterial
cardiac tissue engineering
chitosan
collagen
hydrogel
peptide

Myocardial infarction (MI) results in the death of cardiomyocytes (CM) followed by scar formation and pathological remodeling of the heart. We postulate that immobilization of the pro-survival angiopoietin-1-derived peptide, QHREDGS, to a chitosan-collagen hydrogel could produce a clinically translatable thermo-responsive hydrogel to attenuate post-MI cardiac remodeling. Conjugation of QHREDGS peptide to chitosan does not interfere with gelation, structure, or mechanical properties of chitosan-collagen hydrogel blends. The storage modulus of 2.5mg/mL 1:1 mass:mass chitosan:collagen was measured to be 54.9±9.1 Pa and loss modulus of 6.1±0.9 Pa. Dose response of the QHREDGS peptide was assessed and it was found that CMs encapsulated in High peptide gel (651±8 nmol peptide/mL-gel) showed improved morphology, viability, and metabolic activity in comparison to the Low peptide (100±30 nmol peptide/mL-gel) and Control (No Peptide) groups. Construct (CMs in hydrogel) functional properties were not significantly different between the groups, however success rate of obtaining a beating construct was improved in the hydrogel with the High amount of QHREDGS peptide immobilized compared to the Low and Control groups. An adult Lewis rat left anterior descending coronary artery ligation procedure to mimic acute MI model was used to assess in vivo hydrogel performance. QHREDGS-conjugated hydrogel (QHG213H), Control gel, or PBS was injected into 3 locations in the MI zone. By in vivo tracking and chitosan staining, the hydrogel was demonstrated to remain in situ for 2 weeks and cleared in about 3 weeks. By echocardiography and pressure-volume analysis, the QHG213H hydrogel significantly improved cardiac function compared to the controls. Scar thickness and scar area fraction were also significantly improved with QHG213H gel injection compared to the controls. Mechanistically, there were significantly more cardiomyocytes, determined by cardiac troponin-T staining, in the MI zone of the QHG213H hydrogel group. No significant difference in inflammatory response between groups was observed as determined by gene regulation and cytokine analysis of excised heart sections 24 hours after treatment. The interaction of CMs with QHREDGS was found to be mediated by β1-integrins and to increase expression of the pro-survival effector MAPK.
Learning Design: Aesthetic Models for Color, Layout and Typography
Keywords: Aesthetics
Colour
Computer Graphics
Graphic Design
Typography

This thesis presents aesthetic models for three key components of graphic design: color compatibility, layout creation, and font selection. We develop these models using a variety of techniques, including machine learning and data mining, crowdsourcing, and optimization, and demonstrate their use in practical design applications. We first model color compatibility from large datasets, including analysis of existing color theories, a learned model for predicting compatibility, and several applications using this model. We then use a collaborative filtering approach to model color preferences for individual users. Secondly, we present an energy-based model for single-page design layouts derived from design principles, using novel analysis algorithms. We show how this model can be trained using existing layouts, and demonstrate its use on various tasks including style-based synthesis and retargeting. We then extend this model to enable an interactive, suggestion-based layout tool. Finally, we model fonts using attributes and similarity data from crowdsourced studies, then use these models to develop exploratory font selection interfaces.
Functional and Mechanistic Analyses of Neural-regulated Alternative Splicing
Keywords: Alternative Splicing
Neurogenesis
RNA biology
RNA-Seq

Recent applications of genome-wide approaches to profile the transcriptomes of cells and tissues have provided novel insights into the regulatory principles governing the dynamic control of gene expression. Such global analyses have revealed that alternative splicing (AS) of precursor messenger RNAs, a fundamental process by which cells can expand their transcriptomic diversity from a limited number of genes, occurs in ~95% of human multi-exon genes with the highest frequency observed in the brain. A current goal in the field is to determine how these alternative exon networks are coordinated and contribute to neural functions. Previously, we identified the vertebrate and neural-specific Ser/Arg-related protein of 100 kDa (nSR100/SRRM4) as a novel splicing factor that promotes the inclusion of a subset of brain-specific exons with critical functions in nervous system development. In this thesis, I describe an in-depth investigation of the roles of individual nSR100-dependent splice variants, and the mechanisms by which nSR100 activates its target exon network during neurogenesis. My results uncover an important nSR100-dependent neural AS event in the transcription factor REST/NRSF that modulates its activity and influences the expression of REST targets. I further discuss how the coordination of the AS and transcriptional regulatory layers impact neuronal differentiation. Finally, I describe how I combined multiple experimental and bioinformatic analyses to elucidate important mechanistic features underlying positive and negative regulation of the nSR100-dependent exon network. At the heart of this regulation is an intronic cis-element that can contribute to exon skipping and inclusion depending on the cellular context. Collectively, these studies have advanced our understanding of the functions of nSR100 and its target exons in neural development.