VictorJuiz/thesis huggingface dataset:
Testing the Normative Hypothesis of Relational Aggression and Psychopathology through Gender and Age Moderation
Keywords: relational aggression
psychopathology
adolescence
gender differences

The gender normative hypothesis of relational aggression and psychopathology states that relational aggression is more detrimental to boys than it is to girls because relational aggression is more normative in girls. In the present study, this hypothesis was tested in a large sample of 6-to-18-year-old children and this hypothesis was also extended to the domain of age norms. Specifically, it was tested whether relational aggression would also be most detrimental outside of the age in which it is most normative. The results showed some evidence supporting the gender normative hypothesis. Specifically, it was found that relationally aggressive boys suffered more internalizing and externalizing problems than non-relationally aggressive boys did. Relationally aggressive girls, however, suffered only more externalizing problems than non-relationally aggressive girls did. Results did not support the age normative hypothesis. Implications of these findings and future directions are discussed.
Experimental Verification of a Three Dimensional Photonic Crystal Bandgap
Keywords: Photonic Crystal
Bandgap

Photonic crystals (PC) are periodic structures that dictate the behavior of electromagnetic radiation and can be one-dimensional, two-dimensional or three-dimensional (3D). A 3DPC was modeled and fabricated based on a three-layer design resulting in a face centered cubic structure. Different simulation methods were used to show the existence of a complete 3D bandgap, and were verified experimentally by obtaining transmission measurements in several directions. A prototype of the structure was fabricated using ECCOSTOCK HiK high dielectric sheets (dielectric of 12) and machined using a computer and numerical controlled mill. Experiments to test this structure were performed in an anechoic chamber making use of a network analyzer, a pair of horn antennas, collimating lenses, and a track for alignment. Free-space Thru-Reflect-Line measurements were taken between 10GHz and 15GHz to obtain the transmission through the prototype. Finally, a defect layer was added to the structure at different locations and localized modes observed.
Nutrient and Biomass Contributions of Downed Woody Debris in Boreal Mixedwood Forests of Northeastern Ontario
Keywords: Biomass and nutrient pools
Downed woody debris
Doreal mixedwoods
Wood decay patterns

Harvest-related decreases of downed woody debris (DWD) in forests may have important ecological implications; however, patterns of nutrient release from decaying DWD are poorly understood. The importance of DWD was investigated relative to biomass and nutrient pools in six, second-growth boreal mixedwood forest stands, differing by harvest regime near Kapuskasing, Ontario. Nutrient concentrations and mineralization trends using ion exchange resins at three proximities during the decay of Abies balsamea and Populus tremuloides were also examined. Concentrations of N, P, Ca, and Mg increased with decay, whereas K decreased. DWD was a minor contributor to biomass and nutrient pools. Inorganic N, P, Ca, and Mn were significant between harvest types with decay class interaction for N, Ca, and Mn. Species and proximity effects were found for Al, Fe, and K. These results suggest DWD may be a minor contributor to biomass and nutrient pools, but highlights its dynamic nature.
Modeling Hydrogen Sulfide Adsorption by Activated Carbon made from Anaerobic Digestion By-product
Keywords: hydrogen sulfide
adsorption
activated carbon
modeling

Biogas, produced from anaerobic digestion of cattle manure, is an attractive alternative energy source as it is rich in methane. However, it is necessary to remove hydrogen sulfide from the biogas before it can be used in engines for electricity generation. Currently, large scale biogas systems employ physical adsorbing solvents to upgrade and purify biogas which is not economically feasible for small scale biogas systems. Activated carbon made from anaerobic digestate proves to be an effective adsorbent of hydrogen sulfide because it has minimal operating costs and essentially zero raw material cost. A model is developed to predict the adsorption capacity, carbon bed life span, and breakthrough time for this carbon material. By analyzing the reaction constant, adsorption constant, and degradation constant, adsorption behavior under different operating conditions were studied. The model can be scaled-up to model adsorption for biogas loading rates for small to large scale cattle farms.
Factors Influencing Ecological Metrics of Thermal Response in North American Freshwater Fish
Keywords: Thermal Ecology
Freshwater fish

Habitat temperature is a major determinant of performance and activity in fish. I examined the relationships between thermal response metrics describing growth (optimal growth temperature [OGT] and final temperature preferendum [FTP]), survival (upper incipient lethal temperature [UILT] and critical thermal maximum [CTMax]), and reproduction (optimum spawning [OS] and optimum egg development temperature [OE]) for 173 North American freshwater fish species. All metrics were highly correlated and associated with thermal preference class, reproductive guild and spawning season. Controlling for phylogeny resulted in an overall decrease in correlation strength, varying with metric pair relationship. ANCOVA and Bayesian hierarchical models were utilized to assess the influence of phylogeny on metric pair relationships. For both methods, FTP based metric pairs were weakly correlated within taxonomic family. Strong within family associations were found for reproduction metrics OS-OE. These results suggest that evolutionary history plays an important role in determining species thermal response to their environment.
Embodiment, Pain, and Circumcision in Somali-Canadian Women
Keywords: pain
women's health
female genital cutting
immigration and health
biocultural

Female genital cutting/circumcision/mutilation (FGC) is found predominantly in the Sahel, Northern Africa, removing parts/all of the clitoris, labia minora and majora in girls. Cutting the highly innervated external genitalia may change sensory processing leading to chronic pain. Fourteen Somali women in the Greater Toronto Area (21-46, Type III FGC) completed qualitative, quantitative and psychophysical methods to evaluate pain. Interviews analyzed by interpretive phenomenology form the core method, examining circumcision stories and present, embodied life. The second Short Form McGill Pain Questionnaire and quantitative sensory testing with a vulvalgesiometer form secondary components. Somali women with FGC have pain-filled stories about circumcision and daily life. Socio-cultural considerations are central for women to comprehend how their own bodies feel. SF-MPQ-2 indicates low intensity or no pain symptoms; however, many body regions were indicated. QST reveals low vulvar pressure-pain thresholds. Reports from three measures suggest that FGC may cause sensory changes including chronic pain.
The Role of Colony-stimulating Factor 1 and its Receptor on Acute Myeloid Leukemia
Keywords: Leukemia
AML
Cancer stem cells
Leukemia stem cells
CSF-1
M-CSF

Colony-stimulating factor 1 receptor (CSF1R, Fms) is an integral transmembrane glycoprotein with tyrosine specific protein kinase activity that it is found on the mononuclear phagocytes to promote their survival, proliferation and differentiation. Colony-stimulating factor 1 (CSF-1), also known as M-CSF, is a protein ligand that acts on the CSF1R. There is a variable association of Fms with the stem cell marker CD34 on acute myeloid leukemia (AML) cells and this suggests different structures of the AML hierarchy in different patients. Mouse stromal cells (MS-5) were transduced with a plasmid containing human CSF-1 because mouse CSF-1 is inactive on human CSF1R. Results show that AML cells cultured with CSF-1-expressing stroma had a much better growth and survival than the control stroma, suggesting that CSF-1 might be a stimulating factor for the growth of leukemic stem cells.
The Catalytic Aspartic Acid Shows a Role in Substrate Positioning in 5-methylthioribose Kinase
Keywords: kinase
5-methylthioribose
methionine recycling
enzyme mechanism

Methionine is involved in many cellular processes, several of which produce a feedback inhibitor. 5-methylthioribose (MTR) kinase, one protein involved in the removal of this inhibitor, has a protein kinase fold with conserved kinase motifs and several unique MTR binding motifs. Site-directed mutagenesis and characterization of the Bacillus subtilis enzyme was performed to probe the role of one motif. Active site D233 mutants show an activity profile similar to other protein kinase-like enzymes, suggesting a common mechanism that does not require a catalytic acid. An ordered sequential binding mechanism, with nucleotide binding first, was seen in wild type MTR kinase. Binding studies of the mutant proteins suggest that hydrogen bonding is important for MTR binding. The structures of the mutant proteins also show more differences in MTR binding than nucleotide binding. Overall, D233 is important for increasing the nucleophilicity of MTR, and ensuring its correct position in the active site.
Investigating the Role of Fwd and Potential Role of the Rab11-interacting Protein dRip11 in Drosophila Spermatocyte Cytokinesis
Keywords: cytokinesis
phosphoinositides
membrane trafficking

Cytokinesis is the final separation of daughter cells after division. Membrane trafficking increases the surface area of dividing cells and may deliver cargo needed for division. The Drosophila PI4-kinase Fwd is required for spermatocyte cytokinesis and likely acts, in part, by mediating Rab11-dependent trafficking to the furrow. To further understand the mechanism of action of Fwd, I attempted to place fwd in a pathway with other cytokinesis genes encoding Rab11, phosphatidylinositol transfer protein and a subunit of the exocyst. I also investigated a potential role for the Rab11 interacting protein dRip11 in cytokinesis. My results suggest that Rab11, like Fwd, is required for cell integrity during cytokinesis and that the Rab11 interacting protein Nuf is an important candidate to investigate along with dRip11 as a relevant Fwd/Rab11 effector during this highly conserved process.
Maternal Dietary Restriction and the Effects of Postweaning Nutrition on Fetal Development, Insulin Signalling, Glucose Metabolism and Body Composition In C57BL/6J Mice
Keywords: metabolic syndrome
maternal undernutrition
omega-3 fatty acids
intervention

Mice (C57BL/6J: B6) exposed to maternal dietary restriction (DR) exhibited fetal growth- restriction and as adults develop symptoms of the metabolic syndrome. We aimed to determine the impact of DR on fetal hepatic gluconeogenic pathway and insulin sensitivity in late gestation. Second, we aimed to determine whether a postweaning diet rich in omega-3 fatty acids would alter the development of glucose intolerance, insulin resistance and obesity in DR male offspring. The reduced rate of fetal glycogen synthesis by DR male offspring and altered hepatic gene expression of enzymes involved in insulin signalling and glucose metabolism suggest abnormal fetal development in response to DR that may contribute to the later development of the metabolic syndrome. The postweaning omega-3 diet improved obesity, glucose intolerance and insulin resistance in both DR and control males. These data suggest that nutrition in pregnancy and postnatal life play important roles in determining life-long metabolic health.
Investigating Type I Collagen Self-assembly Processes and End Products
Keywords: collagen
atomic force microscopy
self-assembly
nanoindentation
segmental long spacing
fibrous long spacing
elastic modulus
mica
in vitro assembly

Segmental long spacing (SLS) collagen self-assembly was studied by analyzing aggregates formed from different nucleoside triphosphates at various protonation stages. Triple-negatively charged triphosphate groups were determined to be critical for SLS assembly, electrostatically bridging basic residues between collagen monomers. In the second part of this thesis, the nominal elastic modulus for each of the three forms of Type I collagen aggregate was measured and compared. Fibrous long spacing collagen, often associated with diseased tissues, exhibited lower stiffness in comparison to the other forms, native and SLS, suggesting decreased structural stability in diseased tissues. In the last section, a unidirectional pattern of native fibrils was assembled using mica as a template; the ability to customize and change the surface morphology was also demonstrated. For the first time, collagen monomers deposited on the mica were demonstrated to gain lateral mobility.
Reusable OpenCL FPGA Infrastructure
Keywords: FPGA
OpenCL
SDRAM

OpenCL has emerged as a standard programming model for heterogeneous systems. Recent work combining OpenCL and FPGAs has focused on high-level synthesis. Building a complete OpenCL FPGA system requires more than just high-level synthesis. This work introduces a reusable OpenCL infrastructure for FPGAs that complements previous work and specifically targets a key architectural element - the memory interface. An Aggregating Memory Controller that aims to maximize bandwidth to external, large, high-latency, high-bandwidth memories and a template Processing Array with soft-processor and hand-coded hardware elements are designed, simulated, and implemented on an FPGA. Two micro-benchmarks were run on both the soft-processor elements and the hand-coded hardware elements to exercise the Aggregating Memory Controller. The micro-benchmarks were simulated as well as implemented in a hardware prototype. Memory bandwidth results for the system show that the external memory interface can be saturated and the high-latency can be effectively hidden using the Aggregating Memory Controller.
Assembly, Integration, and Test of the Instrument for Space Astronomy Used On-board the Bright Target Explorer Constellation of Nanosatellites
Keywords: Charge Coupled Device
Space Telescope
Instrument Characterization
BRITE
Bright Target Explorer
Spacecraft assembly, integration and testing
CCD gain
Dark current
Readout noise
bias level
saturation level
full well saturation

The BRIght Target Explorer (BRITE) constellation is revolutionary in the sense that the same scientiﬁc objectives can be achieved smaller (cm3 versus m3 ) and lighter (< 10kg versus 1, 000kg). It is a space astronomy mission, observing the variations in the apparent brightness of stars. The work presented herein focuses on the assembly, integration and test of the instrument used on-board six nanosatellites that form the constellation. The instrument is composed of an optical telescope equipped with a Charge Coupled Device (CCD) imager and a dedicated computer. This thesis provides a particular in-depth look into the inner workings of CCD. Methods used to characterize the instrument CCD in terms of its bias level stability, gain factor determination, saturation, dark current and readout noise level evaluation are provided. These methodologies are not limited to CCDs and they provide the basis for anyone who wishes to characterize any type of imager for scientic applications.
ED-A Fibronectin: A Storage Site for Latent TGFB-1 in the Myofibroblast Matrix?
Keywords: biology

Fibrosis, a major cause of organ failure, has no effective therapy available. Responsible for fibrosis are myofibroblasts. Mechanical stress, TGF myofibroblast differentiation, however the exact link remains elusive. I hypothesize that ED-A FN stores the latent TGF -1 in the ECM by interacting with the latent TGF -1 binding protein (LTBP-1), and that matrix stiffness is a regulator of ED-A FN and LTBP-1. Using co-IP and ED-A domain antagonists, ED-A FN and LTBP-1 associated in the ECM of human dermal fibroblasts (HDFs). The effects of the 11th_ED-A_12th recombinant FN peptide was most prominent in blocking LTBP-1 incorporation in the ECM. HDFs seeded on collagen- coated substrates, showed an increase in expression and organization for both proteins with matrix stiffness. In conclusion, the ED-A domain may require the aid of heparin linkages flanking the 12th domain of FN to bind to LTBP-1 in the ECM.
Biophysical Drivers of Tree Crop Performance in Shade Agroforestry Systems: The Case of Coffee in Costa Rica
Keywords: Agroecology
Resource management
Agroforestry
Coffee
Tropical agriculture
Soil management
Shade management

Agroforestry production methods present one option for addressing growing concerns about the long term sustainability of intensive coffee production techniques. A study was designed to compare the effects of fertilization and shading from two leguminous species, Erythrina poeppigiana and Chloroleucon eurycyclum, on coffee grown at a Costa Rican research site. Coffee below biannually pruned, conventionally fertilized Erythrina exhibited the highest photosynthetic performance under both low and high light levels as well as greater biomass and higher N concentration. Soil P did not affect coffee performance, although shade trees on sites with higher soil P fixed more N compared to trees grown on low P sites, most of which were not found to be fixing. Results suggest shade mechanisms are the most important drivers of coffee adaptation in coffee agroforestry systems, though proper soil nutrient management and legume species pairing also appear to augment coffee response to microclimate conditions.
Construction and Characterization of Microbial Fuel Cells Using a Defined Co-culture of G. sulfurreducens and E. coli
Keywords: Microbial fuel cell
geobacter sulfurreducens
E. coli

An air cathode, membrane-less microbial fuel cell (MFC) containing a co-culture of Geobacter sulfurreducens and Escherichia coli was constructed and compared to pure culture MFCs of both organisms. The E. coli containing MFCs were unsparged and relied on E. coli for oxygen removal. The pure G. sulfurreducens MFC had a power output of 128 mW/m2, compared to 63 mW/m2 for the co-culture at an early stage and 56 mW/m2 for the late stage co-culture. The limiting current density is 404 mA/m2 for the pure G. sulfurreducens culture, 184 mA/m2 for the early co-culture, and 282 mA/m2 for the late co-culture, despite an increase in internal resistance between the early and late co-culture cells. Analysis of metabolites has shown that succinate production is likely to have negatively affected current production by G. sulfurreducens, and the removal of succinate is responsible for the increased current density in the late co-culture cell.
Identifying and Phenotyping an ENU Derived Mouse Model of MYH9 Related Disease
Keywords: ENU
MYH9-RD
Next Generation Sequencing

A dominant ENU screen produced mouse line 7238 with large platelets. Sequence capture and Next Generation sequencing identified a mutation in Myh9 at Q1443L [1]. Mice were tested for aspects of MYH9-Related Disease (MYH9RD), a rare human condition caused by mutations within MYH9; macrothrombocytopenia and neutrophil inclusions are found in almost all cases, while deafness, cataracts and renal disease have variable penetrance and severity. Myh9Q1443L/+ and Myh9Q1443L/Q1443L animals have neutrophil inclusions [1] and increased cataracts at 2, 6 and 12 months; Myh9Q1443L/Q1443L animals at 12 months have changes in kidney output [2]. Immunofluoresence showed changes in protein expression in glomeruli at two months. This is the first ENU mouse model identified by a sequence capture mechanism, and the first mouse line to produce a point mutation within the Myh9 gene [1,2]. This mouse models MYH9RD, and is an invaluable tool to understand the role of this protein, and to determine mechanisms underlying this disease.
Effectiveness of Prequalification Practices in Public Procurement
Keywords: Construction Management
Prequalification

Due to legally restrictive nature of public work, contracts are often awarded solely based on the price of the bid. This has often resulted in contracts being awarded to less qualified contractors. Between the practices developed to deal with this issue, prequalification has proven to be one of the most effective practices in dealing with this problem. As it was investigated in this research, practice of prequalification is widespread amongst the public owners in the region. However, an in-depth look at the practices has revealed that these owners are not currently using this process to its fullest potential and integration of some of the best practices suggested in this paper has the potential to make this process more effective. This research also contains a specially fabricated model which encumbers all of the suggested practices and aims at creating a simple, practical and transparent model for the public owners in the Southern Ontario region.
Design of a Catalytic Combustor for Pure Methanol and HTPEM Fuel Cell Anode Waste Gas
Keywords: Catalytic Combustion
Methanol
HTPEM
Anode Waste Gas

Transportation sector CO2 emissions contribute to global warming. Methanol generated from clean energy sources has been proposed as a transportation fuel as an alternative to gasoline or diesel to reduce emissions. Catalytic methanol-steam reformers can be combined with high temperature polymer electrolyte membrane (HTPEM) fuel cell systems to create compact electrical power modules which run on liquid methanol. These modules combine the efficiency of a fuel cell system with the convenience of using a traditional, liquid hydrocarbon fuel. Catalytic methanol-steam reformers require a heat source as the methanol-steam reforming process is endothermic. The heat source for this system will initially be from the catalytic combustion of either pure methanol, during startup, or from HTPEM fuel cell anode waste gas during system operation. Efficient use of catalyst requires effective premixing of the fuel and air. This study will investigate parameters affecting premixing and their effect on temperature distributions and emissions.
A Platform for High-throughput Mechanobiological Stimulation of Engineered Microtissues
Keywords: bioreactor
high-throughput
mechanobiology
microtissues

While tissue-engineering approaches of heart valves have made great strides towards creating functional tissues in vitro, the instruments used, named bioreactors, cannot efficiently integrate multiple stimuli to accurately emulate the physiological microenvironment. To address this, we conceptually designed and built a bioreactor system that applied a range of mechanical tension conditions, modulated matrix stiffness, and introduced biochemical signals in a combinatorial and high-throughput manner. Proof-of-concept experiments on PAVIC-seeded hydrogels were performed to assess the independent and combined effects of tensile strain, matrix stiffness and TGF-β1 on myofibroblast differentiation by measuring α-SMA expression, a marker that indicates a disease-associated phenotype. We found that matrix stiffness and TGF-β1 significantly increased α-SMA levels (p < 0.001), while the effect of mechanical strain was only significant on soft gels (~12 kPa) without TGF-β1. This study therefore demonstrated independent and integrated effects of multiple stimuli in regulating key cellular events in the aortic valve.