VictorJuiz/thesis huggingface dataset:
Measurement of Hair Cortisol Concentration in Pregnant Women and Children with Asthma to Assess Its Potential as a Biomarker of the Hypothalamic-pituitary-adrenal Axis

The recommended long-term treatment for asthma is inhaled corticosteroid (ICS) therapy, but research has shown that ICS use is associated with adrenal suppression. Cortisol is important physiologically and involved in fetal maturation and epigenetic programming. Hair cortisol has been used as a biomarker of the long-term effects on the hypothalamic-pituitary- adrenal (HPA) axis for a variety of psychiatric and medical conditions. This research hypothesizes that hair cortisol may be able to detect lower cortisol concentrations in pregnant women and children on ICS therapy and, therefore, have potential as a useful biomarker for possible adrenal suppression due to ICS use. This retrospective cohort study collected hair samples from children and pregnant women with asthma, treated and not treated with ICS, and those without asthma. Hair samples were segmented, based on an average growth of 1 cm/month, and analyzed using a validated ELISA method. A children's pilot study analyzed the hair prior to and during ICS therapy for the same children. The proximal 3 cm hair segment was analyzed for the large cohort of children. Hair segments for preconception, trimesters 1-3, and postpartum were analyzed for the pregnant women. The results were compared within and among the groups, as appropriate. The children's pilot study showed hair cortisol concentrations were twofold lower during ICS therapy (median 89.8 ng/g vs. 198.2 ng/g, p=0.0015, n=18). For pregnant women (n=118), asthma was a significant factor associated with lower hair cortisol. Women with asthma and consistent ICS use had significantly lower third trimester hair cortisol (47%, p=0.029) compared to Controls. The comparison of median hair cortisol concentrations among the three groups in the large cohort of children (n=460) was not significant. However, 5.3% of children on ICS therapy had hair cortisol below 2 ng/g compared to none in the control groups, which may indicate children with or at risk of adrenal suppression. The significant factors associated with hair cortisol in children were age, female sex, intranasal corticosteroid use, and BMI. Hair cortisol analysis successfully detected significantly lower hair cortisol concentrations suggesting it is a useful biomarker of the HPA axis in pregnant women and children. The correlation of hair cortisol concentrations with a diagnosis of adrenal suppression or insufficiency and the potential impact of decreased maternal cortisol in women with asthma on perinatal outcomes remain to be determined.

Keywords: asthma
biomarker
children
hair cortisol
inhaled corticosteroids
pregnancy
Advisor: Ito, Shinya
Koren, Gideon
Engineering The Scattering, Refraction and Polarization Of Microwaves Using Huygens Surfaces

An electric and a magnetic dipole that are superimposed and orthogonal to each other have interesting properties where the dipoles can be designed to radiate into one half of space only. Such a configuration is referred to as a Huygens source. Both active and passive configurations of Huygens sources exist. Active configurations consist of antennas while passive configurations consist of scatterers engineered to have induced electric and magnetic dipole moments. Here, the properties of arrays of passive and active Huygens sources are investigated. These arrays are referred to as Huygens surfaces. These surfaces are interesting because they can be designed to implement, thin, low-profile devices which is desirable for current RF/microwave hardware. The design of active and passive Huygens surfaces is investigated for three specific applications in the microwave frequency range; scattering, refraction and polarization. For the problem of scattering, active Huygens surfaces are investigated to implement a cloak which suppresses scattering from an object in all directions. Both theoretical and experimental aspects are examined and limitations and possible workarounds of active cloaking are briefly discussed. On the problem of refraction, the synthesis and analysis of a passive Huygens surface to refract a plane wave is discussed for the application of thin microwave lenses. Equivalent circuit models and the implementation of these Huygens surfaces are also discussed. Finally for polarization control, the design of passive Huygens surfaces is examined from theoretical, numerical and measurement perspectives to demonstrate polarization manipulation. Passive Huygens surfaces are constructed to perform polarization conversion and chiral polarization effects (circular birefringence). This idea of implementing chiral surfaces is further examined by looking at the design and measurement of surfaces consisting of an electric response only.

Advisor: Eleftheriades, George V
FMRFamide-like Peptides and their Role in Reproduction in the Chagas Vector, Rhodnius prolixus

Insect reproductive systems are tightly modulated by neurotransmitters via direct innervation, by neurohormones circulating in the haemolymph and by neuromodulators that can be released either locally or more widespread in the periphery. FMRFamide-like peptides (FLPs) are large families of neuropeptides with conserved RFamide C-termini and have been implicated in vertebrate and invertebrate neuroendocrinology. This thesis examines the differing roles that members of the FLP superfamily have in the adult female reproductive system of Rhodnius prolixus. The entire female reproductive tract is composed of different arrangements of striated muscles. Two members of the N-terminally extended FM/L/IRFamides have been shown to stimulate ovariole, ovary, oviduct and bursal muscle contraction in a dose-dependent manner; whereas the myosuppressin, RhoprMS, does not have any myogenic effect on the reproductive tract. The RhoprNPF (neuropeptide F) and RhoprNPF receptor (RhoprNPFR) genes have been cloned from the R. prolixus central nervous system (CNS) and phylogenetic analysis implies possible receptor-ligand co-evolution. RhoprNPFR has been classified as a G-protein coupled receptor (GPCR) containing 7 transmembrane domains and a conserved 8th Îą-helix that are classic characteristics of rhodopsin-type GPCRs. FMRFamide-like immunoreactivity (FLI) was observed in cells and processes in the adult CNS and processes on the reproductive tract. Moreover a specific subset of median neurosecretory cells (MNSCs) in the brain as well as small cell bodies along the muscle fibers of the lateral oviduct express the RhoprNPF transcript. The RhoprNPFR transcript is also expressed in putative pre-follicular cells of the R. prolixus telotrophic ovariole. RhoprNPFR transcript appears to be supplied to the developing oocyte during vitellogenesis and the receptor most likely aids in the differentiation of pre-follicular cells into mature follicle cells surrounding the growing oocyte and helps regulate the supply of nutrients. Screening members of the FLP family in an egg-laying assay showed that N-terminally extended FM/L/IRFamides and short NPF stimulate oogenesis, whereas MS inhibits it. Although RhoprNPF does not have a myogenic effect on lateral oviduct muscle, I have shown that it potentially aids in ovulation. Sulfakinins exhibit no effect on egg-laying. In summary, this thesis demonstrates the importance of FLPs in the control and regulation of the female R. prolixus reproductive system.

Keywords: contraction
immunohistochemistry
insect
neuropeptide
oogenesis
reproduction
Advisor: Lange, Angela B
Eating-out: A Study of the Nutritional Quality of Canadian Chain Restaurant Foods and Interventions to Promote Healthy Eating

Canadians are increasingly eating outside-the-home. At the outset of this thesis there were no data on the nutritional quality of Canadian chain restaurant foods, the Sodium Working Groupâ s plan to monitor sodium reductions in the food supply was abandoned, and despite interest and numerous bills, there was no existing menu-labelling legislation in Canada. The specific objectives of this thesis were to 1) investigate the nutritional quality of the Canadian chain restaurant food supply; 2) explore consumersâ use of menu-labelling; and 3) test the potential of alternative forms of labelling in non-chain restaurant settings. Objective 1 was investigated by developing and analyzing a national database of over 9000 menu-items from Canadian fast-food and sit-down chain restaurants which was created in 2010. There was wide variation in calorie levels within each restaurant and food category; furthermore, portion size, as opposed to calorie density, was the most important driver of this variation. Sodium levels in menu items often exceed daily recommendations and despite reported efforts by the restaurant sector to improve, as of 2013, reductions were minimal. Objective 2 used an online, national consumer survey to test three menu-labelling treatments (calories; calories and sodium; and calories, sodium and serving size labelling). The effect of labelling on consumer choice varied depending on the restaurant setting, however, overall, labelling sodium in addition to calories led consumers to choose meals with significantly less sodium. There was no additional benefit from adding serving size information. Objective 3 was examined in a quasi-experimental, population-level nutrition labelling/education intervention study in a campus cafeteria. Results showed that this intervention could modestly increase fruit and vegetable consumption, and decrease sugar-sweetened beverage consumption among University students. Overall, this thesis provides food supply and consumer data to inform public health policy debates around issues concerning food consumed outside-the-home.

Keywords: Calories
Fast-food
Menu-labelling
Nutrition
Restaurants
Sodium
Advisor: L'Abbe, Mary R
The Influence of Selection Silviculture Biomass Harvesting on Soil Carbon, Nutrients, and Respiration in a Northern Mixed-Deciduous Forest

Concerns have been raised about soil fertility following increased recovery of biomass in northern mixed deciduous forests. Several studies suggest that biomass extraction and enhanced decomposer activity can lead to losses of soil C and nutrients, increased nitrification, and reduced soil CO2 efflux (FCO2) from compaction and root senescence. However, results are inconsistent; differences may be linked to insufficient investigation and characterisation of variability in forest structure, silvicultural methods, and intensity and heterogeneity of disturbances. Without a comprehensive understanding of how soil biogeochemical processes respond to different types and intensities of harvesting disturbances, we cannot accurately predict losses and ecological sustainability of harvesting. My thesis tests this by evaluating changes to forest structure and various soil edaphic and physical properties following tree-length (TL) and more intensive biomass selection-harvests for 3 years and on primary and tertiary skid trails. Several metrics of forest harvesting intensity were correlated to higher post-harvest FCO2 rates and losses of soil and dissolved soil organic C (SOC/DOC), K+, and NH4+. Increased canopy openness and soil temperatures accounted for 34-41% of elevated FCO2. Woody debris inputs and SOC/DOC losses correlated to higher autumn FCO2 rates and NH4+ losses, while harvested tree biomass correlated to lower summer rates and higher nitrate concentrations. Primary skid trails had low SOC/nutrient concentrations and FCO2 from compaction and inhibited regrowth, potentially functioning as C sources. Biomass harvesting halved woody debris inputs relative to TL harvesting; otherwise, short-term treatment differences were nominal. However, estimated base cation losses through additional biomass recovery may produce net long-term soil depletion not observed in conventional harvesting. These results support my hypotheses that harvesting increased decomposer and nitrification activity, losses of C and nutrients, and that harvesting and trail use intensity can potentially predict these changes. Ecosystem-scale projections of forest C and nutrient storage that do not distinguish between spatiotemporally variable source/sink components (e.g. skid trails, harvested forest) may not effectively estimate changes. Combined with a detailed mensuration of pre/post-harvest forest structure and environmental covariates, future studies that representatively sample these different areas may improve our ability to predict system responses to disturbances.

Keywords: Bioenergy
Carbon loss
Decomposition
Harvest intensity
Soil biogeochemistry
Soil compaction
Advisor: Basiliko, Nathan
Transformation and Standstill: Iranian Experiences of Splintering Urbanism in Dubai

This dissertation focuses on Dubai’s recent urban transformation, and its descent into crisis. Conducted between 2010 and 2012, it examines how the city splintered into a series of upscale “mega-projects” in the periphery known as “New Dubai”, while inner city neighborhoods grew congested with “unskilled” labor and targeted for policing. Through political economic analysis, I argue that New Dubai was not just a geographic category but a techno-political regime working to conflate local real estate with global capital through strategies of flexible sovereignty. Through ethnographic analysis focusing on middle and working class Iranian immigrants I show how immigrants in Dubai variously engaged with or were marginalized by this urban transformation as they inhabited new relations of debt and property in pursuit of “the good life,” or found themselves at risk of eviction, debtor’s jail, and deportation.

Keywords: Dubai
Ethics
Financialization
Infrastrcutre
Speculation
Splintering Urbanism
Advisor: Barker, Joshua
patial Control of the Conductivity of Poly(3,4-ethylenedioxythiopehe): Poly(styrenesulfonate) Thin Films

Poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin films have undergone treatment from rapid thermal processing and direct ultraviolet irradiation at a wavelength of 254 nm. Through various characterization methods, the underlying physical changes as a result of rapid thermal annealing indicate a shift of morphology that correlates to an increase in material conductivity. Through fitting the electrical transport theory of space charge limited current carrier transportation through polymeric materials to experimental results, this shift of morphology can be linked to an increase in the effective mobility of carriers in PEDOT:PSS. Characterization subsequent to various doses of ultraviolet irradiation exhibits up to a 4 order of magnitude loss in conductivity as a result of exposure. This reduction in conductivity has been determined to arise from a scission process induced by the high energy photons. By applying this previously unexplored direct write patterning technique using ultraviolet exposure, novel device demonstrations of patterned organic light emitting diodes as well as an all PEDOT:PSS capacitive sensing array were implemented. The key feature of such device demonstration being that no physical patterning or structuring of the device was required to obtain proper functionality. Both the rapid thermal annealing and the ultraviolet irradiation are suitable for implementation into a roll-to-roll fabrication process which is critical for taking full advantage of the benefits of polymeric electronic materials such as flexibility and low cost fabrication.

Keywords: Organic Electronics
PEDOT:PSS
Rapid Thermal Annealing
Advisor: Helmy, Amr
Thermally Sprayed High Temperature Sandwich Structures: Physical Properties and Mechanical Performance

Metallic foam core sandwich structures have been of particular interest for engineering applications in recent decades due to their unique physical and mechanical properties. One of the potential applications of open pore metallic foam core sandwich structures is in heat exchangers. An investigation of sandwich structures fabricated from materials suitable for application at high temperatures and in corrosive environments was undertaken in this project. A novel method for fabrication of metallic foam core sandwich structures is thermal spray deposition of the faces on the prepared surfaces of the metallic foam substrate. The objective of the current study was to optimize the twin wire arc spray process parameters for the deposition of alloy 625 faces with controllable porosity content on the nickel foam substrate, and to characterize the physical and mechanical properties of the sandwich structure. The experimental investigations consisted of microstructural evaluation of the skin material and the foam substrate, investigation of the effect of alloying on the mechanical and thermal properties of the nickel foam, optimization of the grit-blasting and arc spray processes, observation of mechanical properties of the alloy 625 deposit by tensile testing and evaluation of the overall mechanical properties of the sandwich structure under flexural loading condition. The optimization of arc spraying process parameters allowed deposition of alloy 625 faces with a porosity of less than 4% for heat exchanger applications. Modification of the arc spraying process by co-deposition of polyester powder enabled 20% porosity to be obtained in the deposited faces for heat shield applications with film cooling. The effects of nickel foam alloying and heat treatment on the flexural rigidity of the sandwich structures were investigated and compared with as-received foam and as-fabricated sandwich structures. Available analytical models were employed to describe the effect of constituentsâ mechanical properties on the overall mechanical performance of the sandwich structures. Finite element modeling using ANSYS Structural was used to simulate the behaviour of the sandwich structures in four-point bending. The analytical and simulation results were compared with the experimental results obtained from the flexural tests.

Keywords: Arc Spray
coating
materials selection
Metallic foam core
Sandwich Structure
thermal spray
Advisor: Mostaghimi, Javad
Coyle, Thomas W
Scaling of Hybrid Wing-body-type Aircraft: Exploration Through High-fidelity Aerodynamic Shape Optimization

Unconventional aircraft configurations have the potential to reduce aviationâ s contribution to climate change through substantial reductions in fuel burn. One promising configuration which has received much attention is the hybrid wing-body (HWB). Due to the lack of design experience for unconventional configurations, high-fidelity design and optimization methods will be critical in their development. This thesis presents the application of a gradient-based aerodynamic shape optimization algorithm based on the Reynolds-averaged Navier-Stokes equations to the aerodynamic design of conventional tube-and-wing (CTW) and HWB aircraft. The optimal aerodynamic shapes and performance for a range of aircraft sizes including regional, narrow-body, midsize, and wide-body classes are found so as to characterize the aerodynamic efficiency benefits of the HWB configuration with respect to equivalent CTW designs. Trim-constrained drag minimization is performed at cruise, with a large design space of over 400 design variables. The smaller optimized HWBs, including the regional and narrow-body classes, while more aerodynamically efficient, burn at least as much fuel as to the equivalently optimized CTWs due to their increased weight, while the larger wide-body-class HWB has almost 11% lower cruise fuel burn. To investigate alternative configurations which may yield improved efficiency, exploratory optimizations with significant geometric freedom are then performed, resulting in a set of novel shapes with a more slender lifting fuselage and distinct wings. Based on these exploratory results, new lifting-fuselage configurations (LFCs) are designed. The slenderness of the LFC fuselage decreases with aircraft size, such that, for the largest class, the LFC reverts to a classical HWB shape. This new configuration offers higher aerodynamic efficiency than the HWBs, with the smaller classes seeing the largest benefit from the new configuration. This new lifting-fuselage concept offers 6% lower cruise fuel burn than the CTW in the regional class, and a marginal benefit in the narrow-body class. The effects of cruise altitude, stability requirements, and weight sensitivity are also examined.

Keywords: Aerodynamic shape optimization
Exploratory optimization
Hybrid wing-body aircraft
Lifting fuselage aircraft
Advisor: Zingg, David W
Transport Phenomena in Drying Paint Films

Paint films with uniform thicknesses ranging from 150 to 820 µm were applied on stainless steel substrates using a model paint consisting of a resin dissolved in butanol. Test samples were cured in a natural convection oven at a temperature of 140°C. Photographs of the paint surface were taken during drying and the weight loss was measured. Cellular structures appeared on the paint surface, induced by surface tension-driven flows due to solvent concentration variations. For thin films (

Keywords: Diffusion Growth
Mass Transfer and Drying
Paint Defects
Particle Self-assembly
Surface-tension-driven instability
Two-phase Flow
Advisor: Chandra, Sanjeev
Adaptation Mechanisms of Streptococcus mutans to Stresses Induced by Resin Composite Biodegradation By-products

Resin composites are currently the most popular dental restorative materials. While providing several beneficial properties such as superior esthetics and excellent adhesive strength to dentin and enamel, resin composites undergo biological breakdown in the oral cavity that results in secondary/recurrent caries and reduced restoration longevity compared to amalgam. The breakdown of the resin-dentin interface by salivary and bacterial esterases generates biodegradation by-products (BBPs) including triethylene glycol (TEG) and bis-hydroxy-propoxy-phenyl-propane (BisHPPP). This chemical degradation contributes to gap formation between the restoration and the tooth, providing a path for microleakage of cariogenic microorganisms such as Streptococcus mutans, potentially resulting in recurrent/secondary caries, which is a major cause for resin composite restorations replacement. To test the hypothesis that BBPs activate signaling pathways that are involved in Streptococcus mutans pathogenicity and understand the molecular pathways that regulate the BBPsâ effects on cariogenic bacteria, this thesis quantitatively and mechanistically studied the effect of TEG or BisHPPP at clinically-relevant concentrations on the virulence properties of S. mutans UA159 in a relevant in vitro model. Quantitative real-time polymerase chain reaction showed up-regulation of seven dominant virulence-associated genes i.e. gtfB, gtfC, gbpB, comCDE and atpH, more significantly in biofilm vs. planktonic cells, only at cariogenic pH (5.5). Exposure of the constructed knock-out and complemented strains of S. mutans for the key regulatory genes, vicK and comC, to BBPs suggested these signalling pathways as potential mechanisms for up-regulation of the virulence-associated genes. S. mutans biofilm proteome analysis after exposure to TEG/BisHPPP confirmed activation of specific bacterial adaptation mechanisms such as biofilm formation and adhesion, acid tolerance, optimization of phosphotransferase system and stress-response pathways in response to BBPs. Microarray data were consistent with the proteomics findings for BisHPPP. Furthermore, both BBPs increased glucosyltransferases enzyme activity, involved in synthesizing exopolysaccharide glucan associated with the formation of cariogenic biofilms. This thesis provides significant insight into the adaptive response of S. mutans to the dental biomaterial-derived degradation products and elucidates the potential molecular mechanisms that could contribute in pathogenesis of secondary caries in resin composite restorations. It also provides a rationale for development of dental restorative materials that are more biostable and biocompatible.

Keywords: Biodegradation
BisHPPP
Dental composites
Secondary caries
Streptococcus mutans
Triethylene glycol
Advisor: Finer, Yoav
Cvitkovitch, Dennis