VictorJuiz/thesis huggingface dataset:
Greening the City: Exploring Health, Well-being, Green Roofs, and the Perception of Nature in the Workplace

This five-paper thesis explores office workers perceptions of green roofs and how this influences their health/well-being in Toronto and Chicago. Paper 1 examines the underlying paradigms and world-views of major research programs that look at the human relationship to nature and health/well-being, showing that despite some convergence between their methods and integration of different paradigms, continued differences and lack of clarity on the normative assumptions underlying each approach leads to confusion in the specification of ‘nature’ in health/well-being and place research. Paper 2 is a comparative analysis of the implementation of green roof policies in Toronto and Chicago. Paper 2 demonstrates the importance of ‘selling’ green roofs by linking them to larger environmental programs and of the municipal power structure that influences how and if environmental programs are implemented. Paper 3 examines the awareness, attitudes, and feelings towards green roofs by office workers with access to them (visual or physical) from their workplace in Toronto and Chicago. Using a phenomenological analysis of semi-structured interviews (n=55), Paper 3 shows that the hinterland, expectations of different kinds of ‘nature’ and aesthetics in the city, and access all influence perceptions of green roofs and sense of place. Paper 4 explores office workers awareness of and attitudes towards green roofs and the possible influence on their well-being in Toronto and Chicago from a large survey (n = 903). Participants showed a high literacy on the environmental benefits of green roofs. Chi-square analysis showed mixed results for health, but a significant association between visual access to a green roof and improved concentration. Paper 5 tests whether the relationship found in Paper 4, improved concentration with visual access, was still significant when other confounding variables were added to the model. Using a logistic regression on the same survey population (subset n =505), results found that concentration was no longer significant but that there was a trend towards improved concentration.

Keywords: Green roofs, health, nature, workplace, sense of place, Toronto, Chicago, Urban nature, green building, well-being, phenomenology, logistic regression
Advisor: Relph, Ted
Wakefield, Sarah
Functional Development of Amygdalae and Anterior Cingulate Cortex in Emotion Processing

Emotion processing involves specialised brain regions allowing for effective evaluation of the social environment and for the acquisition of social skills that emerge over childhood. In humans, an important aspect of normal development is the ability to understand the facial expressions of others that signal the nature and safety of the environment. Existing functional data, however, have not characterised the developmental trajectories associated with the differing neural and cognitive-behavioural development. The current thesis investigates the functional specialisation and development of the spatial and temporal patterns in neural activities during implicit processing of facial emotions from early childhood through adulthood. The first study identified brain regions engaged in implicit processing of emotional expressions using a simple emotion-processing paradigm (target detection task) with fourteen healthy adults using magnetoencephalography (MEG) recordings. Participants responded to a non-face target (a scrambled pattern) while ignoring the emotional face presented in a different hemifield. Results showed ACC and right-lateralised amygdala activations in early latencies in response to the unattended emotional faces related to rapid and implicit attention to the task-irrelevant facial emotions, specifically during the processing of the fearful emotion. Based on the findings in the first study, the second study investigated the developmental patterns and age-related differences in brain activities associated with the rapid and automatic processing of the emotional expressions in MEG with twelve children 7 – 10 years old, twelve adolescents 12 – 15 years old and twelve young adults (mean age 24.4 years) using the same paradigm. The results showed that emotion processing developed early in childhood in the amygdalae, whereas the processing of fear had later maturation engaging the ACC. The results further demonstrated an age-correlated increase in development in ACC activity and an age-related laterality shift in the amygdalae related to fear processing. The present thesis provides new evidence contributing to the understanding of the protracted but differing normal development in the emotional brain over the childhood into adulthood, and offers critical insights into understanding possible dysfunctions of these brain regions during development.

Keywords: Amygdala
Anterior Cingulate Cortex (ACC)
Emotion processing
Neuroimaging
Advisor: Taylor, Margot
Smith, Mary Lou
Reaction Dynamics of Alkyl Bromides at Silicon; Experiment and Theory

Physisorption and reaction at silicon surfaces of a series of brominated organic molecules: bromoethane, 1,2-dibromoethane, 1-bromopropane, 1-bromobutane and 1-bromopentane were examined by Scanning Tunneling Microscopy (STM). On Si(111)-7×7, a widely-spaced “one-per-corner-hole” pattern was observed, formed by the physisorption and reaction of several alkyl bromides. This “one-per-corner-hole” pattern suggested long-range repulsion between the adsorbates. Density Functional Theory (DFT) calculations, performed by others in parallel with these experiments, showed that this long-range repulsion was due to lateral charge transfer in the Si(111)-7×7 surface consequent on the physisorption of an alkyl bromide or chemisorption of a Br atom. The reaction rate of bromine ‘abstraction’ (transfer of a Br-atom from the adsorbate to the silicon) was examined for two physisorbed states of 1 bromopentane on Si(111)-7×7, one vertical and one horizontal, each distinguishable by STM. The energy barrier was found to be significantly lower for abstraction of Br-atom from the vertical than for the horizontal 1 bromopentane, both for thermal and electron-induced reaction. This finding accords with previous DFT calculations for methyl bromide, for which theory exhibited a clear preference for a vertical transition state in the bromination of Si(111)-7×7. The effect of alkyl chain-length on the rate of thermally-induced dissociative attachment reactions was investigated for a series of primary bromo-alkanes (bromoethane, 1-bromopropane and 1-bromobutane) on a different face of silicon; Si(100)-c(4×2). These three bromo-alkanes all physisorbed exclusively ‘inter-row’, bridging the gap between Si dimer-rows of Si(100)-c(4×2). Thermal reaction was highly ‘localized’, i.e. the chemisorbed Br-atom was formed directly below the parent bromo-alkane. The thermal barrier heights were found experimentally to increase systematically with chain length. This trend was interpreted, on the basis of DFT calculations performed by the author, as being due to the extra energy required to lift the alkyl group in going from the initial physisorbed state to the more-nearly vertical transition state.

Keywords: Reaction dynamics
Silicon
Alkyl bromides
Scanning tuneling miscroscopy
Density funcitional theory
Advisor: Polanyi, John
Vitamin D Status and its Contribution to Multiple Sclerosis Risk: Insights Gained through the Study of Children with Central Nervous System Demyelination

Acute demyelination in children may be a monophasic illness or the sentinel attack of multiple sclerosis (MS) – a chronic inflammatory neurodegenerative demyelinating disease. MS risk is largely determined during childhood and vitamin D may protect against MS. The primary objective of this thesis was to evaluate vitamin D status in children presenting with acute demyelinating syndromes (ADS) as a potential contributor to MS outcome. The LIAISON “25 OH Vitamin D TOTAL” assay was validated to assess the biomarker of vitamin D status – serum 25-hydroxyvitamin D (25(OH)D) concentrations. Consecutive patients (<16 y) were enrolled at presentation with ADS and prospectively evaluated at 23 Canadian centres. MS was defined by a second clinical demyelinating event or by MRI evidence of new lesions over time. Cox proportional hazards regression models assessed risk of MS outcome as a function of serum 25(OH)D tertiles, accounting for factors associated with either MS risk or vitamin D status – age, sex, season, and HLA-DRB1*15 status. Of 211 children with 25(OH)D measured in sera obtained a median of 9 days from onset (interquartile range, 5 – 17 d; maximum 36 days), 20% (n = 41) were diagnosed with MS after 3.7 mos. (3.1 – 7.3 mos.). Risk of MS was lower in children with 25(OH)D levels in the highest tertile (≥ 74 nmol/L) at ADS versus those in the lowest tertile (<50 nmol/L) (HR 0.41; 95% CI 0.18 to 0.97, adjusted model). Children with higher circulating 25(OH)D concentrations at ADS have a lower risk of MS. Further evidence for a role of vitamin D insufficiency during childhood and adolescence contributing to MS risk comes from three MS patients with suboptimally managed pseudo-vitamin D deficiency rickets. Finally, a sun exposure questionnaire was validated in the latter part of this thesis for use in future research into determinants of vitamin D status and their association with risk of MS.

Keywords: Vitamin D
Multiple Sclerosis
Nutrition
Pediatric
Autoimmune
Cholecalciferol
Calciferol
Bradford Hill
Sun exposure
Questionnaire
UVB
Advisor: Vieth, Reinhold
Banwell, Brenda
Establishing Relations between BOLD Variability, Age, and Cognitive Performance

Neuroscientists have long known that brain function is inherently variable. Functional magnetic resonance imaging (fMRI) research often attributes blood oxygen level-dependent (BOLD) signal variance to measurement-related confounds. However, what is typically considered “noise” variance in data may be a vital feature of brain function that reflects development, cognitive adaptability, flexibility, and performance. In the present thesis, we examine how brain signal variability (measured with a modified BOLD time series standard deviation (SDBOLD)) relates to human aging and cognitive performance in a series of studies. In Study 1, we examined brain variability during fixation baseline periods. We found that not only was the SDBOLD pattern robust, its unique age-predictive power was more than five times that of meanBOLD (a common measure of BOLD activity), yet revealed a spatial pattern virtually orthogonal to meanBOLD. Contrary to typical conceptions of age-related neural noise, young adults exhibited greater brain variability overall. In Study 2, we found that younger, faster, and more consistent performers exhibited significantly higher brain variability across three cognitive tasks, and showed greater variability-based regional differentiation compared to older, poorer performing adults. SDBOLD and meanBOLD spatial patterns were again orthogonal across brain measures. Study 3 demonstrated experimental condition-based modulations in SDBOLD. SDBOLD was an effective discriminator between internal (lower variability) and external (higher variability) cognitive demands, particularly in younger, high performing adults. Finally, to gauge the extent that brain variability can be incrementally manipulated within a single cognitive domain, Study 4 examined parametric modulations in SDBOLD on a face processing task in a young-only sample. Results indicated that SDBOLD can be robustly manipulated through experimental control, and that this manipulation linearly follows performance trends across conditions. These studies help establish the age- and performance-relevance of BOLD variability. We thus argue that the precise nature of relations between aging, cognition, and brain function is incompletely characterized by using mean-based brain measures exclusively.

Keywords: Brain variability
aging
cognition
fMRI
Advisor: Grady, Cheryl L.
Integrating Patients into Integrated Healthcare: Perspectives from Individuals Coinfected with Tuberculosis and HIV

Background: Tuberculosis (TB) and human-immunodeficiency virus (HIV) infections are intertwined through complex biological and social pathways that affect over one million people worldwide. Mitigation of the co-epidemic is undermined by a failure to integrate TB and HIV healthcare services as a result of critical clinical, operational and social challenges. The social challenges of TB/HIV coinfection and integrated care are least understood. Objectives: This research examines the social contexts of TB/HIV illness and related healthcare from the perspective of patients coinfected with TB and HIV. Methods: The study was set within a constructivist-interpretivist theoretical framework. Non-participant field observations and semi-structured in-depth interviews were held with 40 coinfected adults (24 women, 16 men) and 8 healthcare workers at 3 ambulatory clinics in KwaZulu-Natal, South Africa, providing varying models of TB and HIV care. Subjective meanings of illness and healthcare were analyzed in relation to patients’ social contexts. Findings and Interpretations: Coinfection exposes patients to a double and unequal form of social stigma around TB and HIV. Affected individuals construct dual identities and negotiate selective disclosure of TB over HIV in order to manage this double stigma. Their experiences with stigma are bound by social, structural and gendered inequalities, and mediate their decisions to disclose, access and adhere to medical care. Coinfection also exposes patients to pluralistic, disparate and fragmented forms of healthcare delivery. Experiences with stigma and with distinct cultures of TB and HIV care affect their decisions for integrated healthcare. While integration may allow for some technical and clinical efficiency, it may also heighten some patients’ social burden of illness as a result of HIV disclosure and stigmatization. Conclusion: Integration efforts should consider the social contexts of TB/HIV coinfection, social consequences of patients’ health decisions, and paradigms within which such efforts are set in the design and execution of successful interventions.

Keywords: tuberculosis
HIV
coinfection
qualitative methods
service integration
patient perspectives
Advisor: Calzavara, Liviana
Destabilization of IL-8 mRNA by Anthrax Lethal Toxin: Demonstration of the Requirement for TTP and Examination of its Cellular Interactions

Control of mRNA stability is an important aspect in the regulation of gene expression. A well studied signal for rapid transcript decay in mammalian cells is the AU-rich element (ARE), which is found in the 3’ untranslated region (UTR) of many labile transcripts. These sequence elements confer destabilization of transcripts by binding to AU-binding proteins (AUBPs) that can recruit cellular decay enzymes. The stability of ARE-containing mRNAs can be regulated by extracellular stimuli, which allows for cells to adapt to the changing environment. AREs are found in many transcripts that encode for inflammatory genes, including TNF, GM-CSF, and IL-8. Pathogens evolve and devise mechanisms to subvert the immune response of the host to aid in its infection. Bacillus anthracis is one such infectious agent that can disable numerous arms of the host immune response. Its secreted toxin, anthrax lethal toxin (LeTx), causes the accelerated decay of the IL-8 mRNA. IL-8 is a dual function cytokine and chemokine that can recruit and activate neutrophils at the site of infection. Through the inactivation of MAPK pathways, LeTx activity causes the destabilization of IL-8 transcripts through its ARE. In this thesis, I show that an AUBP, TTP, is dephosphorylated by LeTx and MAPK inhibitors, and knock-down of its expression stabilized IL-8 transcripts. LeTx activity also increased the colocalization of TTP to P-bodies, cytoplasmic sites concentrated with RNA decay enzymes. This suggests that the post-translational modification of TTP induced by LeTx led to its enhanced destabilization function. Identified TTP-associated proteins, non-muscle myosin heavy chain 9 (myosin-9) and HSC-70, were examined for their role in IL-8 transcript decay. Knock-down of each protein led to a slower rate of IL-8 mRNA destabilization. However, treatment of LeTx continued to mediate accelerated destabilization of IL-8 in these siRNA-transfected cells. This suggests that LeTx, myosin-9, and HSC-70 modulate the destabilization function of TTP independently.

Keywords: Anthrax lethal toxin
mRNA destabilization
Tristetraprolin
Advisor: Mogridge, Jeremy
Things Rank and Gross in Nature: Psychological, Physiological and Neuroimaging Investigations of Sociomoral Disgust

Much like unpalatable foods, filthy restrooms and bloody wounds, sociomoral transgressions are often described as “disgusting”. This linguistic similarity suggests that there is a link between sociomoral disgust and more rudimentary forms of disgust associated with toxicity and disease. Critics have argued, however, that such references are purely metaphorical, or that sociomoral disgust may be limited to transgressions that remind us of more basic disgust stimuli. My aim was to provide more direct evidence that sociomoral transgressions do genuinely evoke disgust, and to explore factors that may influence how much disgust is evoked. I first searched for similarity in the facial expressions evoked by gustatory distaste (elicited by unpleasant tastes), physical disgust (elicited by photographs of contaminants), and moral disgust (elicited by unfair treatment in an economic game). I found that all three states evoked activation of the levator labii muscle region of the face, characteristic of an oral-nasal rejection response and consistent with an origin of sociomoral disgust in oral disgust. I next investigated whether individual differences in the tendency to experience physical disgust are related to variability in sociomoral judgement and emotion. In two different populations, heightened sensitivity toward physical disgust was related to more severe sociomoral judgements. A complementary neuroimaging study showed overlap between the neural correlates of physical disgust and sociomoral judgement, as well as highlighting brain regions that may underlie sociomoral hypersensitivity. Finally, I tested the idea that perceived differences in the causal stability of sociomoral transgressions may specifically affect levels of disgust. Although it was not possible to dissociate disgust from anger, the transgressions that were presented did evoke reliable self-reports of disgust. Taken together, these findings converge to support the conclusion that sociomoral transgressions can in fact elicit disgust, and accordingly that references to the disgusting nature of wrongdoing reflect biological reality rather than metaphor.

Keywords: disgust
emotion
moral
Advisor: Anderson, Adam K.
Essays on the Allocation of Talent, Skills and Inequality, and Life-cycle Effects of Health Risk

This dissertation consists of three essays. The first essay studies how health risk affects individuals' economic decisions due to changes in productivity, required medical expenditures, available time and survival probabilities implied by changes in health status. It assesses the role of these four channels in determining labour supply, asset accumulation and welfare using a life-cycle model calibrated to the U.S. economy. I find that all channels and the interactions between them have large implications for the macroeconomic variables studied. Health has larger effects for the non-college than college educated, explaining a significant fraction of the difference in labour supply, degree of reliance on government transfers and asset accumulation across education groups. Improving non-college health outcomes to approach those of college graduates results in large welfare gains, higher labour supply, and significantly lower reliance on government welfare programs. The second essay studies the evolution of wage inequality in the United States between 1980 and 2002 in a framework that accounts for changes in the employment of physical and cognitive skills and their returns. I find that within education-gender groups, average employed cognitive skills have remained constant, while average physical skills have declined. The returns to high levels of cognitive skills have increased dramatically, while returns to low levels of cognitive skills and physical skills have remained approximately constant. Skills account for approximately half of the increase in the college wage premium, and for a small but growing fraction of residual wage inequality. The final essay studies the sorting decisions of students with different levels of analytical and verbal skills into college fields of study. I build a model where each field tests and perfectly reveals to potential future employers only the students' skill that is intensively required in that field. Students' expected wages after graduation are a function of their revealed skill levels and firms' expectations of the unrevealed skills given the chosen field. I show how the size of each field and the average talent it attracts depend on the average skill levels, on skill dispersion and on the degree of correlation between skills in the student population.

Keywords: Health Risk
Earnings Inequality
Life-cycle Model
Cognitive Skills
Physical Skills
College Field Choice
Advisor: Kambourov, Gueorgui
Are There Age Differences in Shallow Processing of Text?

There is growing evidence that young adult readers frequently fail to create exhaustive textbased representations as they read. Although there has been a significant amount of research devoted to age-related effects on text processing, there has been little research concerning this so-called shallow processing by older readers. This dissertation uses eye tracking to explore age-related effects in shallow processing across different levels of text representations. Experiment 1 investigated shallow processing by older readers at the textbase level by inserting semantic anomalies into passages read by participants. Older readers frequently failed to report the anomalies, but no more frequently than did younger readers. The eye-fixation behaviour revealed that older readers detected some of the anomalies sooner than did younger readers, but had to allocate disproportionately more processing resources to looking back to the anomalies to achieve comparable levels of detection success as their younger counterparts. Experiment 2 examined age-related effects of shallow processing at the surface form by inserting syntactic anomalies into passages read by older and younger adults. Older readers were less likely to detect syntactic anomalies when first encountering them relative to younger readers and engaged in increased regressive fixations to the anomalies. However, older readers with high iii reading comprehension skill were able to use their familiarity with text content to increase their likelihood of syntactic anomaly detection. Experiment 3 investigated the role of aging on shallow processing of the temporal dimension of the situation model. No age-related differences reporting the anomalies were found. The eye-fixation behaviour revealed that older readers with high working memory capacity detected some anomalies sooner than did younger readers; however, they had to allocate increased processing resources looking back to the anomalies to achieve comparable levels of detection as younger readers. Together, the results demonstrate that older readers are susceptible to shallow processing, but no more so than younger readers when they can rely on their linguistic skill or their existing knowledge to help reduce processing demands. However, older readers appear to require additional processing time to achieve comparable levels of anomaly detection as younger readers.

Keywords: aging
reading comprehension
eye movements
error detection
shallow processing
Advisor: Daneman, Meredyth