VictorJuiz/thesis huggingface dataset:
Dynamic analysis of a rotor shaft system with viscoelastically supported bearings

This thesis investigates the dynamic problem of a single-rotor shaft system with elastic bearings at the ends mounted on viscoelastic suspensions. Timoshenko shaft model is utilized to incorporate the flexibility of the shaft; the rotor is considered to be rigid and located at the mid-span of the shaft. Two models of the viscoelastic supports are considered, namely: Kelvin-Voigt model, and the four-element viscoelastic model. Two types of bearing are also considered: the linear bearings with linear spring and linear damping characteristics, and nonlinear bearings with nonlinear spring characteristics and linear damping characteristics. In the analysis of the system with linear bearings, equations of motion are derived, and both free and forced vibration analysis are performed. Comparisons of the natural frequencies are made between the Jeffcott model and the Timoshenko model. The effects of stiffness and loss coefficients of the viscoelastic supports on the complex natural frequencies are investigated. Stability analysis is performed adopting the Routh Hurwitz criterion for polynomials with complex coefficients. The system dynamic behavior due to nonlinearity of the bearings is investigated. A nonlinear bearing pedestal model is assumed which has a cubic nonlinear spring and linear damping characteristics. Free and forced vibration is investigated based on the direct multiple scales method of one-to-one frequency-to-amplitude relationship of the nonlinear system using the third order perturbation expansion. The direct multiple scales method yields better results than the discretized one for finite mode truncations and for systems having quadratic and cubic nonlinearities. Also, this approach does not require the selection of an orthogonal basis; however, it requires additional eigenfunction solutions at every level of approximation. The results of nonlinear analysis show that a limiting value of the internal viscous damping coefficient of the shaft exists where the trend of the frequency-amplitude curve switches. Also, the primary resonance peak shifts to higher frequencies with the increase of the bearing nonlinear elastic characteristics, but with a flattened curve and hence lower peak values. Jump phenomenon takes place for high values of the bearing nonlinear elastic characteristics. Experimental investigations were carried out for the system and were compared to the predicted theoretical results. Theoretical results show that optimum values of the viscoelastic stiffness and loss coefficient can be achieved for a specific rotating shaft system to reduce vibrations and increase the operating regions.
Improving classification models when a class hierarchy is available

We introduce a new method for modeling hierarchical classes, when we have prior knowledge of how these classes can be arranged in a hierarchy. The application of this approach is discussed for linear models, as well as nonlinear models based on Dirichlet process mixtures. Our method uses a Bayesian form of the multinomial logit (MNL) model, with a prior that introduces correlations between the parameters for classes that are nearby in the hierarchy. Using simulated data, we compare the performance of the new method with the results from the ordinary MNL model, and a hierarchical model based on a set of nested MNL models. We find that when classes have a hierarchical structure, models that, acknowledge such existing structure in data can perform better than a model that ignores such information (i.e., MNL). We also show that our model is more robust against miss-specification of class structure compared to the alternative hierarchical model. Moreover, we test the new method on page layout analysis and document classification problems, and find that it performs better than the other methods. Our original motivation for conducting this research was classification of gene functions. Here, we investigate whether functional annotation of genies can be improved using the hierarchical structure of functional classes. We also introduce a new nonlinear model for classification, in which we model the joint distribution of response variable, y, and covariates, x, non-parametrically using Dirichlet process mixtures. In this approach, we keep the relationship between y and x linear within each component of the mixture. The overall relationship becomes nonlinear if the mixture contains more than one component. We extend this method to classification problems where a class hierarchy is available. We use our model to predict protein folding classes, which can be arranged in a hierarchy. We find that our model provides substantial improvement over previous methods, which were based on Neural Networks (NN) and Support Vector Machines (SVM). Together, the results presented in this thesis show that higher predictive accuracy can be obtained using Bayesian models that incorporate suitable prior information.
Optimality and asymptotics for some Bayesian inferences

In this thesis, we study the optimality of relative surprise inferences in the class of Bayesian inferences and we develop the asymptotic theory of these inferences. We develop optimal Bayesian repeated sampling inferences using a generalized idea of what it means for a credible region to contain a false value and discuss the practical use of this idea for error assessment and experimental design. Moreover, we present results that connect Bayes factors with optimal inferences and develop a generalized concept of unbiasedness for credible regions. Furthermore we show that relative surprise inferences arise naturally when considering reparametrizations. We consider asymptotic results for relative surprise inferences under regularity conditions. We show that under these conditions the LRSE is consistent and asymptotically normal for the full and coordinate parameter case. We apply these methods to Poisson regression and Normal-location problems. Further we discuss the asymptotics for an example where such conditions do not hold and that has proven difficult for many approaches to inference. We carry out a rigorous analysis that shows that relative surprise corrects for these deficiencies.

Keywords: Statistics
Transgenic analysis of the Alzheimer's disease amyloid precursor protein (APP)

In Alzheimer's Disease (AD), the Amyloid Precursor Protein (APP) is endoproteolytically cleaved by beta-secretase to liberate beta-stub and subsequently processed by beta-secretase to produce Amyloid-beta (AP). Considering these endoproteolytic products have been implicated in AD pathogenesis, we have modified APP such that the cytoplasmic domain is absent and unable to support full-length beta-stub synthesis, yet able to produce full-length Abeta. By engineering mice with this transgene, we can assess whether Abeta or beta-stub cause cognitive deficits as compared to TgCRND8 mice that support synthesis of full length APP, beta-stub and Abeta. Moreover, transgenes with an altered APP copper binding domain (CuBD) have been made to prevent the post-natal lethality seen in TgCRND8 mice, while still exhibiting AD pathology. Through genetic, biochemical, and behavioural analyses of our transgenic mouse models, we will be able to define the contributions of the cytoplasmic tail and the CuBD of APP in AD pathogenesis.
A clinical comparison of the effect of powered and manual toothbrushes on dentin hypersensitivity

The effects of Philips Sonicare Elite® powered toothbrushes and Oral-B CrossAction® Vitalizer™ (soft) manual toothbrushes on dentin hypersensitivity (DS) when used in conjunction with Sensodyne F® Ultrafresh toothpaste were examined. Methods. An eight-week, parallel-group, randomized controlled trial involving 42 subjects with sensitivity on at least one canine/premolar tooth was conducted. Tactile and thermal stimulation were used to elicit DS, which was measured using a 100mm visual analogue scale (VAS) and the Short-Form McGill Pain Questionnaire (SF-MPQ). Results. There was no difference between the two groups in terms of relevant socio-demographic variables. On average, 25% to 31% reduction in DS was observed using the powered toothbrush compared to 16% to 19% using the manual toothbrush after 8 weeks. Group differences were borderline statistically significant using thermal stimulation (p = 0.08). Conclusion. Powered toothbrushes may be effective in reducing dentin hypersensitivity when used in conjunction with desensitizing toothpaste.
Diplomatic assurances against torture: Impermissible inter se modifications of erga omnes obligations?

This thesis examines the legal status of diplomatic assurances against torture, and its implications. As bilateral agreements between individual States, they may conflict with non-refoulement obligations owed to the entire international community. Only if DAs against torture are legally binding are they subject to international norms to determine their permissibility. It is argued that canons for interpreting legal status lead to contradictory conclusions. Moreover, the discretion of States to conclude non-legally binding agreements because they are more convenient and confidential than legally binding ones is not justifiable where it could affect multilateral treaties prohibiting refoulement and evade international norms to protect other parties' rights. Finally, in order to override the non-refoulement prohibition, DAs against torture must be legally binding by necessary implication. Therefore, parties who intend to conclude one must notify the international community in advance to allow its members to express their views on its permissibility.

Keywords: Torture
Treatise
Mammalian brain development: the role of distinct neural stem and progenitor cells from embryonic neural induction to adult neurogenesis

One of the most intriguing mysteries of mammalian development is how the pluripotent cells of the inner cell mass become restricted in potential and generate the many differentiated cell types of complex tissues, such as the brain. In this thesis, I explore the early cell types involved at the outset of this process, and present evidence suggesting that primitive and definitive neural stem cells can be successively derived from pluripotent ES cells, and further that these neural stem cells differ in terms of their gene expression patterns and ability to generate non-neural tissues. I posit that these characteristics vary as a function of exposure to LIF and level of Oct4 expression. In harmony with the early neural lineage model that has evolved from in vitro studies, I also report the clonal isolation of primitive neural stem cells directly from the early murine epiblast. As development proceeds, neural stem cells become restricted to specific brain regions. In the early postnatal period, I demonstrate that neural precursor cells that are transiently neuronogenic can be isolated from many brain regions, including those in which neurogenesis has been completed (such as the striatum and cortex) as well as from one region that is never a site of neurogenesis (optic nerve). However, these cells do not exhibit self-renewal in vivo nor maintenance of multipotentiality in vitro or in vivo, and thus are more aptly termed restricted neural progenitors. I argue that fundamental biological differences exist between neural stem and progenitor cells, and that both cell types persist into adulthood and are responsible for the continued generation of new neurons in the adult brain. Specifically, I provide evidence that neural stem cells and restricted neuronal progenitors underlie olfactory bulb and dentate gyrus neurogenesis, respectively. Finally, I suggest that the definitions of stem and progenitor cell are applicable to other tissue systems, and describe a novel adult pancreatic progenitor cell that is capable of generating multiple differentiated cell types of both pancreatic and neural lineages.
Gastrointestinal peptides across a continuum of energy-related menstrual cycle disturbances in exercising women

The primary purpose of this study was to examine ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1) in exercising women with menstrual cycle disturbances. Volunteers were retrospectively characterized by exercise level and menstrual status: Sedentary Ovulatory (SedOv), Exercising Ovulatory (ExOv), Exercising Anovulatory (ExAnov), and Exercising Amenorrheic (ExAmen). Menstrual status was assessed by daily urinary ovarian steroids for 2-3 menstrual cycles. Serum samples were analysed for ghrelin, PYY, and GLP-1. Ovarian steroids were lower in the ExAmen group compared to all other groups. Serum ghrelin levels were higher in the ExAmen compared to the SedOv and the ExOv groups. LogPYY concentrations were higher in the ExAmen compared to all groups. GLP-1 concentrations were similar among groups. This study provides evidence that fasting PYY and ghrelin concentrations are elevated in association with menstrual cycle disturbances in exercising women.
Significance of nutrient and carbon storage on drought sensitivity of black spruce (Picea mariana (Mill.) B.S.P.) seedlings

Reforestation of northern Canadian forests involves the outplanting of container grown nursery seedlings. Seedling establishment following outplanting is often hampered by high mortality due to drought stress. Increasing reserves of nutrients and carbohydrates during the nursery phase could improve seedling establishment after transplanting to the field, because stored nutrients and carbon may be used to construct new root tissues, promote osmotic adjustment and repair damaged tissue. To address this hypothesis I investigated the effect of nutrient and carbon loading regimes on the drought sensitivity of Picea mariana. Nursery grown seedlings were subjected to drought preconditioning treatments, exponential nutrient loading or conventional fertilization; and carbon loading or ambient air conditions. Seedling growth following nutrient and carbon loading was enhanced in both drought and non-drought conditions. Moreover, loading resulted in an increased root: shoot ratio and osmotic adjustment in response to drought, both of which may enhance water and nutrient uptake. The results indicate that nutrient and carbon loading improve early outplanting performance of seedlings, and may benefit future reforestation programs.
"The sweetest of all charities": the Toronto Hospital for Sick Children's medical and public appeal, 1875-1905

The powerful image of the female nurse providing domestic care and moral instruction to a poor sick child was essential to the Toronto Hospital for Sick Children's (HSC's) early marketing efforts. The gender issues evident in HSC's initial thirty years studied in this paper reveal a covert, subconscious power struggle between the men and women at HSC as they attempted to accommodate the general public's expectations of pediatric hospital care. HSC's early history demonstrates that public expectations, female agency, and male intervention into hospital politics ultimately align under a common cause of specialized pediatric care. However a struggle to define pediatric medicine did ensue, influenced by gender roles, scientific paradigm-shifts, and public desire infused with their expectations of sex-role stereotypes of the times. This struggle has left its mark on HSC's history in the form of an uncommon collaboration, evident in the hospital's built form, marketing campaigns, philanthropic management, and medical outlook. Even today, HSC's appeal encourages public support by promoting its paternalistic social welfare efforts. For the public caring, in addition to curing, remains a defining feature of pediatric medicine. Dubbing itself ‘The Sweetest of All Charities’, HSC continues to advocate a need for good nursing care as a way of administering scientific medical cures to children. The combination of money and mercy, medical-science and hygienic ideals, and caring and curing were established in HSC's first thirty years of hospital work, from 1875 to 1905. This project investigates why and how this combination emerged as defining features of pediatric medicine.
The impact of acute vigorous physical activity on cravings, affect, and cortisol concentration among abstinent smokers experiencing withdrawal

Background. Acute, moderate-intensity bouts of physical activity reduce cravings in temporarily abstinent smokers. However, the mechanisms underpinning this reduction are unclear, and impact of vigorous exercise on cravings is unknown. Objectives. To determine the impact of acute vigorous activity on cravings to smoke, and assess if either post-exercise changes in salivary cortisol or affect may underlie this reduction in cravings. Methods. Using a repeated measures crossover design, participants (N=18) sat, walked (45-50% HRR) and ran (80-85% HRR) on separate days. Cravings, mood, and affect scores were collected at baseline, mid-condition, and 0-, 10-, 20-, and 30-min post-condition. Saliva samples were collected at baseline, 0- and 30-min post-condition. Results/discussion. Vigorous activity neither further reduced, nor increased cravings, relative to walking, thus proving to be neither more beneficial than walking, nor detrimental to a quit attempt. Both affect and cortisol concentration were discounted as primary mechanisms underpinning post-exercise reductions in cravings.
Thermodynamic electron equivalent models for Geobacter species

Geobacter species have been shown to be important agents in the bioremediation of subsurface environments contaminated with organic and/or metal contaminants. In order to optimize the design of bioremediation strategies, accurately predicting the growth yield of Geobacter species on various substrates is critical. Thermodynamic electron equivalent modeling (TEEM) is a method that was previously developed to predict the maximum bacterial yield with a variety of electron acceptors. Application of the TEEM method failed to accurately predict growth yields of Geobacter species. Therefore, a process to modify the TEEM to allow accurate prediction for Geobacter species is developed. This modification of the TEEM approach provides a more accurate prediction of biomass yield than the basic model and it is speculated that it will significantly improve attempts to model the growth of Geobacter species in the subsurface during in situ bioremediation.
Using logic duplication to improve performance in FPGAs

The purpose of this thesis is to introduce a modified packing and placement algorithm for FPGAs that utilizes logic duplication to improve performance. The modified logic-packing algorithm was designed to leave unused basic logic elements (BLEs) in timing critical clusters, to allow potential targets for logic duplication. The modified placement algorithm consists of a new stage in which logic duplication is performed to shorten the length of the critical path. In this paper, we show that in a representative FPGA architecture using .18 μm technology, the length of the final critical path can be reduced by an average of 14.2%. Approximately half of this gain comes directly from the changes to the logic-packing algorithm while the other half is a result of logic duplication performed.
Optimization of a vinyl-lysine-urethane scaffold for use in oral mucosa regeneration

This work focused on using a biodegradable vinyl-lysine-urethane (VLU) scaffold and rendering it more biocompatible by replacing methacrylate components, with a cross-linker (hydroxyethylmethacrylate---lysine diisocyanate---hydroxyethylmethacrylate). The cross-linker was observed to influence the wet-state mechanical properties of the scaffolds, in a linear manner (R2 = 0.84). Also an optimized VLU scaffold, formulated to contain the least amount of catalyst (dibutyl-tin-dilaurate 0.01 mL/mmol Polycarbonate diol), was used to generate an in vitro model of oral mucosa. The in vitro biodegradation (using human salivary derived esterase), degradation product cytotoxicity, and ability of the scaffold to support in-growth of epithelial and fibroblast cell lines was assessed. The scaffold degraded at a rate of 9.2wt%/month, biodegradation products were non-toxic towards SCC-15 cells, and both cell types adhered and proliferated into the scaffold. This study is the first use of such a synthetic, biodegradable, mechanically strong scaffold to help create a full-thickness oral mucosa model.
Air-sea interaction in the North Atlantic

The air-sea interaction in the North Atlantic Ocean is studied in three parts. In the first part, we use the historical dataset from Ocean Weather Station (OWS) Bravo to characterize the air-sea fluxes occurring in the Labrador Sea. The Labrador Sea is one of a handful of locations where deep ocean convection is known to occur. We find that there is significant high frequency variability (which would get masked with monthly mean analyses) in the buoyancy flux attributable to the passage of synoptic weather systems. We also highlight the importance of precipitation as it is an important source of positive buoyancy flux at high latitudes. The buoyancy flux temporarily becomes positive during the passage of a cyclone. The timescale for this change in buoyancy flux is similar to the timescale for the convective plumes in the ocean, suggesting that the variability of the high frequency variability in the atmosphere could modify deep ocean convection. In the second part, we introduce a novel way to quantify the variance of a time series and apply it to the OWS Bravo dataset. The method involves first filtering the time series using filters with different temporal characteristics, and then using a moving window to calculate the variances in each filtered time series. The use of a moving window allows the original temporal resolution to be retained, as well as allowing one to study how the variance changes with time. We find that the variance during the winter months is strongly influenced by weather systems in the bandpass and the lowpass frequency range. The variance during the summer months, on the other hand, is dominated by the shortwave radiation in the highpass frequency range. Finally, in the third part, using a global meteorological dataset, we examine basin scale signals in the North Atlantic. Using a trigger point in the Greenland, Iceland and Norwegian Sea, we identify a basin scale regime shift that resembles the North Atlantic Oscillation (NAO) spatial pattern. Unlike the NAO signal which occurs on an annual timescale, this regime shift occurs on intra-month time scales. Composites of the “before” and “after” regimes illustrate the respective flow patterns and the associated changes in the heat fluxes.