VictorJuiz/thesis huggingface dataset:
Adolescent Maturation: Identification, Estimation, and Implications

Adolescents engage in risky behaviors due to a lack of self-control; many among them stop after they mature. This behavioral theory, supported by neuroscientific evidence on late brain maturation, implies that an age-participation rate plot of any risky behavior should be hump-shaped. In this thesis, I introduce maturation to a standard panel model describing risky behaviors to serve two purposes: First, doing so corroborates the neuroscientific findings on maturation timing. Second, it allows the study of maturation's effects on adolescent risky behaviors. The key difficulty of introducing maturation in to a behavioral model is that in a behavioral data set, maturation is a latent time-varying characteristic, and also it correlates with the observables (age in particular); therefore, a standard panel data model cannot capture it. To solve this problem, I define maturation as one or more unobserved treatments, with both the treatment effect and timing being unknown and heterogeneous. Chapter 1 reports the empirical findings of an analysis using the basic specification of this augmented econometric model with one unobservable treatment. Specifically, the estimated maturation age distribution has a median of age 21 and is right-skewed. Maturation effects are much stronger than environmental effects, evidenced by the observation that adolescents mostly stop engaging in risky behaviors due to maturation rather than environmental changes. The estimated maturation effect for binge drinking can serve as a benchmark for the evaluation of existing adolescent policies. Chapter 2 develops the formal theory in a treatment effect framework with multiple unobserved treatments. The theoretical development starts from a simple single treatment effect model. I then extract one unobserved treatment --- maturation --- which is neither a common age effect nor an individual fixed effect, and prove its identification conditions. Then I consider the general case with multiple unobserved treatments. Chapter 3 studies the gender gap in risky behaviors. While the maturation timings of the males and females are close to each other, their maturation effects differ. The environmental differences between the two genders also diverge as adolescents age. Together, these two findings explain a diverging gender gap related to risky behaviors.

Keywords: Adolescence
Maturation
Structural Break
Advisor: Siow, Aloysius
McMillan, Robert
Neuromuscular Control of the Trunk during Sitting Balance

Sitting stability is maintained by continuous and intermittent activation of trunk and lower limb muscles. However, spinal cord injury (SCI) can result in paralysis of the trunk muscles and affects sitting balance. Currently, chest straps and trunk braces are used to correct sitting after SCI. In addition to these passive devices, functional electrical stimulation (FES) could be used to artificially contract trunk muscles and regulate sitting balance. The objectives of this research project were to: (1) investigate neuromuscular synergies of the trunk during perturbed sitting; (2) investigate the effects of anticipation of the perturbation on trunk muscle responses; (3) compare sitting balance between able-bodied individuals and people with SCI; and (4) examine the effects of electrical stimulation of trunk muscles on sitting balance. The first deliverable (Chapter 2) of this project was the development of neural network models that encode trunk muscle responses during perturbed quiet sitting. These models describe complex neuromuscular synergies of the trunk and allow us to understand which muscles are used to stabilize sitting balance. The second deliverable (Chapter 3) was a study which showed that anticipation of direction and time of perturbation resulted in approximately 15 ms faster trunk muscle activations. These results indicate that the reflexive and patterned neuromuscular responses of the trunk can be modulated by the central nervous system using anticipatory information. The third deliverable (Chapter 4) was a study that investigated differences in sitting balance between able-bodied individuals and individuals with SCI. This study has shown that trunk control is significantly compromised in individuals with SCI, which is the main cause of their reduced balance control during quiet sitting. The fourth deliverable (Chapter 5) was a study that investigated the effects of FES of trunk muscle on sitting balance control. The results showed that co-contractions of trunk muscles with FES could increase trunk stiffness. These findings combined advanced our understanding of the neuromuscular control of the trunk during sitting balance. Moreover, they helped us develop a neuroprosthesis, which could improve sitting balance in individuals with SCI, and consequently contribute to improving their mobility, independence and, ultimately, quality of life.

Keywords: electromyography
functional electrical stimulation
neuroprosthesis
sitting balance
trunk
Advisor: Popovic, Milos R.
McConville, Kristiina M.V.
A Pilot Randomized Controlled Trial of the Effects of Continuous Glucose Monitoring on Metabolic Control in Children with Type 1 Diabetes

Type 1 diabetes (T1D) is one of the most common chronic illnesses affecting children. Rigorous metabolic control helps delay longterm health complications in children with T1D. Continuous subcutaneous insulin infusion (CSII) with continuous glucose monitoring (CGM) provides information not available with self-monitoring of blood glucose (SMBG) alone. Few studies have evaluated the effectiveness of CGM on metabolic control in children using CSII. A 12-week multi-site pilot randomized controlled trial (RCT) was carried out in order to provide preliminary indicators of the effects of CGM compared to SMBG on metabolic control and fear of hypoglycemia, as well as provide an estimate of recruitment rates, assess compliance with allocated treatment, and determine participants’ satisfaction with allocated treatment. Children in the intervention group were asked to wear CGM for up to five days per week and perform three SMBG calibration checks per day. Children in the usual care group were asked to perform three SMBG checks per day. Forty children and adolescents participated, 24 in the intervention group and 16 receiving usual care. After 12 weeks of CGM use, there was no statistically significant difference between groups in changes in mean HbA1c (CGM, -0.32 + 0.89; SMBG, -0.05 + 0.70; -0.27 [-0.83, -0.28], t=-0.99, p=0.33). There was a statistically significant difference between groups, favouring the intervention group, in changes in mean fear of hypoglycemia scores (CGM, -5.00 + 6.89; SMBG, 3.13 + 10.49; 8.13 [-13.92, -2.34], t=-2.85, p=0.007). The findings from the pilot trial addressed several feasibility questions. Enrollment rate (48% of those eligible) and percentage of children who would participate again in a larger trial (n = 27; 71%) approached pre-set acceptability parameters, but compliance was low (only 9 participants met pre-set parameters; 39%). Currently, a larger RCT is not warranted until further studies evaluate methods to improve compliance with CGM.

Keywords: Children
Continuous Glucose Monitoring
Metabolic Control
Type 1 Diabetes
Advisor: Hodnett, Ellen
Proteomic Identification of Mediators Implicated in the Metastatic Progression of Ovarian Cancer

Ovarian cancer (OvCa) is the leading cause of death among gynecological malignancies, and is characterized by peritoneal metastasis and increased resistance to chemotherapy. Acquired drug resistance is often attributed to the formation of multicellular aggregates (MCAs) in the peritoneal cavity, which seed abdominal surfaces, particularly, the mesothelial lining of the peritoneum. Given that the presence of metastatic implants is a predictor of poor survival, a better understanding of the underlying biology surrounding OvCa metastasis may lead to the identification of key molecules that are integral to the progression of the disease, which therefore, may serve as practicable therapeutic targets. To that end, in vitro cell line models of cancer-peritoneal interaction and aggregate formation were used to identify proteins that are differentially expressed during cancer progression, using mass spectrometry-based approaches. First, we performed a proteomics analysis of a co-culture model of ovarian cancer and mesothelial cells, in which we identified numerous proteins that were differentially regulated during cancer-peritoneal interaction. We further validated one protein, MUC5AC, and confirmed its expression at the cancer-peritoneal interface. Next, we conducted a quantitative proteomics analysis of a cell line grown as a monolayer and as MCAs. After identifying a subset of overexpressed proteins, we determined that CLCA1 plays a role in MCA formation. Additional studies using a CLCA1 blocker, as well as siRNA knockdown of CLCA1 in OvCa cells, resulted in a decreased ability of cancer cells to aggregate, a reduced ability to adhere to extracellular matrix components, and decreased cell viability. Moreover, we demonstrated that CLCA1 is able to regulate MUC5AC expression, as CLCA1-knockdown cells exhibited reduced expression of MUC5AC. In summary, the research presented in this thesis adds to our current understanding about ovarian cancer progression, and identifies two proteins that play a role in OvCa progression, which may serve as novel therapeutic targets.

Keywords: Cancer Progression
Mass Spectrometry
Metastasis
Ovarian Cancer
Proteomics
Advisor: Diamandis, Eleftherios P
Lusztig Slices in the Affine Grassmannian and Nilpotent Matrices

The focus of this dissertation is to present some new results related to an isomorphism of Mirkovic-Vybornov between Lusztig slices in the affine Grassmannian and varieties of nilpotent matrices. We give an explicit alternate Mirkovic-Vybornov isomorphism in the GLn-affine Grassmannian and an explicit isomorphism in the GL2-affine Grassmannian. We also transport an additive action on the Lusztig slice through the Mirkovic-Vybornov isomorphism and show that it corresponds to a residual conjugation action. We go on to verify that this additive action matches a previously discovered action on the Slodowy slice.

Keywords: affine
Grassmannian
Langlands
lattices
Lusztig
Representation Theory
Advisor: Kamnitzer, Joel
Hair as a Matrix for Assessing Polybrominated Diphenyl Ether (PBDE) Exposure in Animals and Humans

Polybrominated diphenyl ethers (PBDEs) are synthetic chemicals added to various consumer products as flame retardants. They persist in the environment and their potential endocrine disrupting properties are a growing concern. The efficacy of using hair as a matrix for assessing exposure to PBDEs was evaluated in humans and an animal model. Paired human hair and serum samples were obtained (n=50). In parallel, hair, serum, liver and fat were collected from adult male Sprague-Dawley rats exposed to increasing doses of the PBDE mixture found in house dust for 70 days via diet. All samples were analyzed by gas chromatography and mass spectrometry (GC/MS) for eight common PBDEs: BDE-28, 47, 99, 100, 153, 154, 183 and 209. Paired human hair and serum samples had five congeners (BDE-28, 47, 99, 100 and 154) with significant individual correlations (0.345 – 0.566). Significant correlations (0.803-0.988) were observed for six congeners in rat hair, serum, liver and fat across doses. Thus, the use of hair as a matrix for assessing PBDE exposure is validated. To determine if hair needs washing prior to analysis for PBDEs, individual hair samples from ten adults were subjected to wash protocols: (i) no wash; (ii) water; (iii) 10% sodium dodecyl sulfate (SDS); and (iv) hexane. Hair and wash effluent were analyzed for PBDEs by GC/MS. Washing with water, 10% SDS and hexane decreased hair PBDE levels by 1.9%, 7%, and 11.4%, respectively, compared with unwashed hair (p

Keywords: Flame retardant
GCMS
Hair
Hypospadias
PBDE
Advisor: Koren, Gideon
Interactive Effects of Flaxseed and Flaxseed Oil and Trastuzumab on the Growth of Breast Tumors Overexpressing HER2

Trastuzumab (TRAS), a first line therapy for human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer, is limited by innate and acquired resistance. Approaches to enhance TRAS effectiveness and prevent resistance are needed. Flaxseed (FS) contains high levels of lignans and oil (FSO) rich in the n-3 polyunsaturated fatty acid α-linolenic acid (ALA). FS is commonly consumed by breast cancer patients and has demonstrated anticancer effects. This thesis determined whether FS, FSO and ALA, alone and combined with TRAS, could reduce the growth of HER2-overexpressing breast cancer and explored potential mechanisms with focus on HER2 signaling. Dietary FS and FSO alone did not affect growth of HER2-overexpressing, estrogen receptor (ER) positive breast tumors (BT-474) in athymic mice; however, FSO enhanced TRAS effectiveness in reducing tumor growth and cell proliferation and increasing apoptosis. Dietary FSO reduced biomarkers of HER2 signaling (pHER2, pAkt/Akt, pMAPK/MAPK). Tumor levels of ALA and its metabolites eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were elevated in FS and FSO-fed mice while conversion of ALA to EPA and DHA did not occur in BT-474 cells in vitro. Using concentrations derived from in vivo studies, ALA and DHA, alone and combined with TRAS, reduced BT-474 cell growth in vitro but only DHA reduced biomarkers of HER2 signaling (pAkt/Akt and pMAPK/MAPK). To further understand ALA mechanisms, it was tested in MCF-7 cells (ER+, low HER2) and was shown to affect the expression of ER-related signaling biomarkers. ALA did not prevent the development of TRAS resistance but reduced the growth of TRAS-resistant BT-474 derivatives and the TRAS-resistant UACC-732 cells. Together, these findings improve the understanding of the effects and mechanisms of FS and its components, particularly ALA in breast cancer and suggest that ALA-rich FSO may be a cost-effective complementary treatment for women with breast cancer being treated with TRAS.

Keywords: Breast cancer
Drug-diet interaction
Flaxseed
Omega 3 fatty acids
Trastuzumab
Advisor: Thompon, Lilian U
Amenability and Unique Ergodicity of the Automorphism Groups of all Countable Homogeneous Directed Graphs

We establish the amenability, unique ergodicity and nonamenability of various automorphism groups from Cherlin's list of countable homogeneous directed graphs. This marks a complete understanding of the amenability of the automorphism groups from this list, and except for the Semigeneric graph case, marks a complete understanding of the unique ergodicity of these groups. Along the way we establish that a certain product of Fraïssé classes preserves amenability, unique ergodicity and the Hrushovski property. We also establish the unique ergodicity of various other automorphism groups of Fraïssé structures that do not appear on Cherlin's list.

Keywords: Amenability
Automorphism Groups
Directed Graphs
Unique Ergodicity
Advisor: Todorcevic, Stevo
Pestov, Vladimr
We Are Witnesses, Not Victims. The Affective Politics of Representation in the Struggle against ‘femicide’ in Italy

In this dissertation I focus on the political mobilization of Italian—especially Salentine— feminists around gendered violence and ‘femicide’ (femminicidio). I explore their modes of representation, giving special emphasis to those modes that are inspired by performances and practices of dignity, understood as a privileged ‘battlefield’ in their struggle particularly against ordinary forms of gendered violence. My work contributes to the anthropological debates on the relations between politics and the senses, and to the ones in the Anthropology of Ethics. First, by engaging with the work of Rancière, I read the feminist representational struggle as a form of dissensus —i.e. of sensing and making sense differently. I read it as a political enterprise that aims at widening the available sensorium by changing the practices and performances of seeing and sensing around gendered violence and ‘femicide’ in Italy. Second, since this political activity of the reconfiguration of the sensible has not just aesthetic but also ethical implications, my ethnographic material adds to the current anthropological debates in the Anthropology of Ethics. I show some possible consequences of the quite explicit links between the practice of autopoiesis, the work of art, and political activism that emerged during my fieldwork in the Salento area of Italy. The performative dimensions of performance (Lowell Lewis 2013) are at the center of my ethnographic and anthropological analyses, and these concentrate not only on the illocutionary, but also on the perlocutionary aspects of representations in political activism. My analyses of their role in constructing audiences by affecting the latter’s practices and performances of seeing and sensing, in Rancièrian terms, are elements that could offer a contribution to the current debates in Performance Studies.

Keywords: Anthropology
Gender Studies
Italy
Politics and the Senses
Violence against Women
Advisor: Muehlebach, Andrea
Solid-phase Extraction and Detection Techniques for Digital Microfluidics

Digital microfluidics (DMF) is a microscale fluid handling technology in which discrete liquid droplets are individually actuated in two dimensions over an array of dielectric-coated electrodes. DMF is gaining popularity as a platform for the development of micro-total analysis systems because of its ease of automation, portability, and ability to perform multiple processes simultaneously. A key step for the analysis of complex samples is extraction for clean-up, fractionation and preconcentration. Previously, the only extraction methods available for DMF were sample drying and re-dissolution, and liquid-liquid extraction. In this thesis, the first methods for performing solid-phase extraction (SPE) on DMF are introduced, along with a complementary optical detection system for on-chip absorbance and fluorescence interrogation of droplets. In Chapters 2 and 3, the formation of porous polymer monoliths with reverse-phase and strong cation exchange functionalities are demonstrated. Using these solid phases, small molecules, peptides and proteins are purified and enriched on DMF chips via SPE. In Chapter 4, an optical fibre-based absorbance and fluorescence detection system is presented, using a custom manifold to allow easy adjustment of absorbance pathlength with droplet stretching for sensitivity enhancement. Liquid lensing further enhances measurements, resulting in significant increases in sensitivity and limits of detection. In Chapter 5, an automated DMF elution solvent optimization protocol using design of experiments is developed, and applied to perform on-chip SPE with C18 beads. This method enables clean-up and fractionation of small molecule and peptide samples, with on-the-fly adjustment of solid phase volume. The advancements presented herein represent the first techniques allowing SPE to be performed with DMF. These methods promise to support the development of micro-total analysis systems for complex samples, including analyses for proteomics and clinical applications.

Keywords: digital microfluidics
magnetic beads
microfluidics
optical fibres
porous polymer monoliths
solid phase extraction
Advisor: Wheeler, Aaron R
Magnetic and Structural Properties of Iridates and Cuprates in Reduced Dimensions

Physics at reduced dimensionality has seen an increased interest in the last decade, due to the novel properties that arise in low-dimensional materials. In this dissertation, we have employed scattering and absorption x-ray techniques to investigate the magnetic and structural properties of two classes of transition metal-oxides with reduced dimensionality: Sr2IrO4 (a 5d layered perovskite iridate) and Bi2Sr2CaCuO8+δ (a 3d cuprate). X-ray Resonant Magnetic Scattering (XRMS) was used to study the magnetic properties of epitaxially-strained Sr2IrO4 thin films grown via pulsed laser deposition. Epitaxial strain proves to be a great way of tuning the magnetic transition temperature TN of Sr2IrO4, a system in which the interplay between the strong spin-orbit coupling and crystal field renders the magnetic properties very sensitive to small structural distortion. The strong magneto-elastic coupling in Sr2IrO4 is also illustrated by the observation of a spontaneous magnetostriction effect in a 20-nm thin film sample, which increases significantly at the onset of magnetic ordering, and could be attributed to the strong spin-orbit interactions in the 5d oxide. The 20-nm film also exhibits a smoothly evolving field-driven phase transition, which is irreversible at 5 K. Finally, the XRMS study of a Sr2IrO4 single-crystal under an applied magnetic field displays a rich field-driven phase diagram, characterized by magnetic domain re-population, a hysteresis behaviour, and a change in magnetic domain size with temperature. A combination of Micro-Fluorescence (μXRF) and Micro-Diffraction (μXRD) was developed to study the structural properties of nanocrystals obtained via mechanical exfoliation. The structural studies have focused on the thickness dependence of the “4.7 b” structural modulation in Bi2Sr2CaCuO8+δ nanocrystals, exfoliated on Si/SiO2 and mica substrates. The structural modulation is present even at a thickness of 6 nm for Bi2Sr2CaCuO8+δ nanocrystals on Si/SiO2, and maintains the same periodicity of “4.7 b”. A twofold suppression of the modulation intensity was observed upon reducing the sample thickness from 200 to 6 nm. All the experimental techniques mentioned above offer insights into the study of thin films and reveal the importance of the substrate-thin film interaction, which can occur both in thin films made by deposition and in exfoliated nanocrystals.

Keywords: cuprates
exfoliation
iridates
magnetic properties
thin films
x-ray scattering
Advisor: Kim, Young-June
Experimental Wars: Learning and Complexity in Counterinsurgency

How do policymakers learn to solve complex policy problems? I offer an explanation based on a plurality of policy learning processes. Policymakers learn in multiple ways, thereby grappling with the complexity of their environment. I identify three methods of learning. Learning by paradigm deploys systematic assumptions. Learning by doing employs ad-hoc experiments. Learning by simulation replicates others thoughts and intentions. The three vary in their aptitude to dealing with complexity: learning by doing is most so, and by paradigm least, with simulation falling in between. The most effective approach to complexity will involve combining methods. I apply these to learning in counterinsurgency. I take as cases manuals: documents reflecting what their authors learned. I focus on three such cases. The Hessian officer Johann Ewald served the British for eight years, in the American Revolutionary War. He subsequently wrote of the earliest manuals of irregular war in the European tradition. C. E. Callwell, a prominent Victorian military officer, was the author of the most influential British small wars manual of his generation. He served in the Boer war, among many others. David Galula, a French officer who served in East Asia and in Algeria, is perhaps the most influential counterinsurgency theorist-practitioner on record. I trace their learning processes, as documented in their autobiographical writings, explaining the learning outcomes documented in their manuals. I find those who learn in multiple ways are most adaptive to complexity. Galula was most effective at doing so, and Callwell least so, with Ewald falling in between.

Keywords: Complexity
Counterinsurgency
Insurgency
Learning
Pragmatism
Advisor: Stein, Janice