VictorJuiz/thesis huggingface dataset:
Human aryl hydrocarbon (AH) receptor, molecular cloning and genetic variations

Aromatic hydrocarbon toxicities are mediated by the AH receptor, a transcriptional regulator of growth and proliferation genes as well as enzymes such as CYP1A1 and CYP1A2 that activate chemical procarcinogens such as benzo['a']pyrene. In mice an AHR polymorphism, based on a single nucleotide difference in the ligand-binding domain is sufficient to reduce affinity for ligand (2,3,7,8 tetrachlorodibenzo-'p'-dioxin, TCDD) by more than 10-fold. In humans, relatively little is known about genetic variation in the AHR. Our goal was to determine if the human 'AHR' gene is polymorphic. With an 'in-vitro' radioligand binding assay, our laboratory found a bimodal distribution of binding affinities for TCDD in placental tissues from two human populations (n = 75 and n = 40). The Kd varied over about a 10-fold range within each population from normal, full-term pregnancies from subjects of mixed ethnic background. After cDNA and genomic cloning of human AHR, I performed single strand conformation polymorphism (SSCP) analysis and detected three mutations in the transactivation domain of the human AHR. The first is the same as reported by Kawajiri 'et al'. ('Pharmacogenetics' 5:151, 1995a) with an arginine to lysine substitution at codon 554 in Japanese subjects. I discovered ethnically-dependent variations in the allelic frequency of the codon 554 mutant allele; the highest frequency was found in African subjects, followed by Asians and Caucasians. The second mutation at codon 570 results in the replacement of valine by isoleucine; this mutation was found in African subjects but not in any other ethnic group. I identified a novel human AHR point mutation at codon 517 resulting in the replacement of proline by serine. Genetic linkage analysis showed that the codon 517 variant is linked to the variants at codon 554 and codon 570. Direct sequencing experiments of the AHR coding region of three subjects with a wide range of TCDD-binding affinities did not reveal any additional mutations. I developed a transient expression system and found that the codon 554 lysine substitution did not affect AHR function. AHR harboring both codon 554 lysine and codon 570 isoleucine showed a time-dependent decrease in CYP1A1 induction by TCDD. The functional alteration of codon 517 serine in AHR could not be deduced from these studies.
Moth diversity in young jack pine-deciduous forests after disturbance by wildfire or clear-cutting

Moth diversity was compared between four to eight year-old jack pine-deciduous forests that had been burned by wildfire or clear-cut. Field work took place north of Sudbury, Ontario between June and August 1997. Diversity under the two disturbance types was not significantly different based on comparisons of the number of individuals and species, rank abundance curves, diversity indices, DCA ordinations and species rankings. Exceptions to this were: 'Nemoria rubrifrontaria' and four other geometrids which were found significantly more frequently in burned sites, and ' Acronicta innotata' and 'Euxoa' species which were found more frequently in cut sites. Plant composition appeared to be influential in determining moth composition. Additionally, increasing numbers of moths were caught as night temperature increased. In terms of the response by nocturnal macrolepidopterans, clear-cutting appears to be emulating the natural disturbance, fire, in these young jack pine-birch-poplar-spruce forests.
Organic coating removal by single particle impact

Organic coatings are often removed using solvents that create waste which is difficult and expensive to dispose of. For this reason, mechanical coating removal techniques such as blast cleaning are of increasing interest. The impact of single particles with two typical coating/substrate systems was examined in detail as an important first step to understanding the fundamental mechanisms which govern the removal of organic coatings by blast cleaning. A gas gun capable of launching single particles at speeds of up to 120 m/s and a high-speed photographic setup capable of measuring inbound and rebound particle velocities were constructed in order to characterise impact behaviour with respect to energy loss. The impact sites were photographed and the amount of coating removal was determined using image analysis. Coating removal for a typical alkyd enamel on a pretreated steel substrate was found to be due to impact-induced buckling delamination of the coating. An analytical technique based on the coupling of a novel post-buckling analysis with an existing strain energy release rate analysis was developed with the purpose of predicting the amount of coating removed when a single particle was launched, at a given velocity, against a coated substrate. Predictions of delamination size using this model were obtained for a wide variety of incident velocities, particle sizes, and coating thicknesses, and comparison with measured delamination size revealed good agreement. A second coating system, consisting of a typical aerospace urethane coating with an epoxy primer applied to an aluminum substrate, was found to be eroded, and an existing rigid-plastic erosion theory developed for semi-infinite targets and spherical particles was modified to include elastic effects and shown to predict crater size well. A general rigid-plastic analysis was then developed in which the size of an impact crater, particle rebound velocity and energy loss could be predicted for an incident particle of any size, shape, and density, impacting at any angle of attack and in any orientation. Finally, a parametric study in the case of symmetric particles of arbitrary angularity revealed interesting trends with respect to coating removal.
Complexity and markedness in optimality theory

This thesis explores the issue of segmental representations in Optimality Theory. I make two claims relating to this issue. First, I argue that input segmental representations may vary from language to language, and that these differences influence the patterning of different segment types in the phonology. Second, I argue that segmental markedness is evaluated in terms of representational complexity: the more complex a representation is, the more marked it is. Markedness relations are thus encoded in the segmental representations, so that marked segments involve more structure than unmarked segments. The variation that is found in segmental markedness across languages is expected under the proposed theory, since representations are constructed in response to contrasts in the inventory. Since segmental representations are influenced by contrast, variation in inventories entails variation in segmental representations. The representations that I propose are built in response to the competing considerations of structure minimization and the need to make contrasting specifications representationally distinct. Structure is only added to a specification under the pressure of contrast. Since additional structure means a more complex representation, and markedness is linked to complexity, the markedness status of a particular segment may vary depending on the number and type of contrasts in an inventory. My proposal entails that input representations play a more central role in the phonology than is currently assumed in the Optimality Theory literature. I argue that, despite claims to the contrary, all cross-linguistic variation cannot be made to fall out from output constraint ranking alone. Instead, phonemic inventories are necessarily defined in the input, and therefore there is no universal set of inputs.
The removal of phenolic compounds for the production of high-quality canola protein isolates

A membrane-based protein isolation process was originally developed to produce two protein isolates from defatted canola meal. Both products had high protein content while low in phytates and essentially free of glucosinolates, thus representing a potential source of food-grade protein. As phenolic compounds present in canola bind to the proteins, and cause the dark colour and undesirable taste of these protein products or their aqueous solutions, the interactions between phenolic compounds and canola proteins were investigated using a series of chemical treatments in combination with membrane processing to break phenolic-protein complexes and separate the phenolics from the proteins. Approximately 50% of the phenolic compounds extractable in aqueous media was thus identified to be bound to canola protein by different mechanisms: ionic bonding, hydrophobic interactions, hydrogen bonding, and covalent bonding. Based on the study of phenolic-protein interactions, a variety of treatments was tested for the removal of phenolic compounds from canola protein. The combined use of these treatments was able to reduce the phenolic contents in the products by 80-90%. The original protein isolation process was then modified with the treatments to remove phenolics. The modified process produced two high-quality canola protein isolates, both of high protein content (>85%), low in phenolic acids (~200 mg/100 g), and essentially free of tannins, and the removal of phenolic compounds improved the colour and taste of canola protein isolates. Also, as a necessary tool in this study, a new analytical method was developed for the determination of total phenolic acid content in canola protein products, giving accurate quantification in a reasonable time.
The Acquisition of the Landed Estates of the Hospitallers in the Latin East, 1099-1291

During the period of the Crusades (1099-1291), the Knights of the Order of the Hospital of St. John of Jerusalem, or Hospitallers, developed into one of the largest institutional landholders in the Latin East and Europe. This thesis examines the acquisition policy of the Order and documents the chronological and geographical distribution of its rural properties in the Latin East. In addition to land, the Hospital also acquired fortresses, houses, and other edifices, as well as rights to people, animals, water, and vines. This thesis profiles the individuals and families who transferred property to the Order and discusses the relationship between benefactor and recipient. An additional area of exploration is the administration of these lands and the people who inhabited them. As a monastic order, the Hospital largely acquired its landed estates through pious donations made by benefactors in return for spiritual rewards. These donations were augmented by strategic purchases, which demonstrate clearly that the Order actively pursued properties with the intention to consolidate land and to develop contiguous estates. The charters also suggest that rural settlement was more extensive than has previously been assumed. As settlers, the Hospitallers came into contact with the native population. The evidence presented in this thesis indicates that the Order developed strong ties with many Syrian Christians, but maintained a distance from most Muslims. It is also suggested that the Franks employed a system of land tenure which had many parallels with that practiced in parts of Europe. The primary sources used in this thesis are the charters of the archive of the Hospitallers, of which nearly 600 related to the Latin East have been transcribed and edited by Delaville le Roulx in 'Cartulaire général de l'ordre des Hospitaliers de Saint-Jean de Jérusalem' (' 1100'- '1310'). For ease of recall and reference, the charters have been coded and entered into a relational database according to person, property, and type of transfer. These documents have been supplemented by the charters of other property-holding institutions in the Latin East, as well as various Latin and Arabic chronicles of the Crusading period.
Applications of reflection to topology

This work looks at reflection properties for topological spaces both in the large cardinal/forcing context and in the elementary submodel context. We present a general technique valid for an interesting class of spaces (e.g. locally compact, <math> <f> <a><ac><rm>C</rm></ac><ac>&d9;</ac></a></f> </math>ech-Complete, first-countable) in both contexts and which allows us to reproduce results, present new results and also to obtain interesting upwards and downwards reflection results and examples.
Iconographic windows to Ezekiel's world

The biblical book Ezekiel, often castigated by its critics, has in recent years found those who draw comparisons between the literary descriptions in the book and the art of the ancient Near East. But while drawing such parallels is helpful, it does not illuminate the intense programmatic nature of a writing which claims to be both historical and prophetic. Clearly something more is needed. The use of iconography to interpret biblical writings is in its infancy, in part because ancient Near Eastern iconographic systems are only beginning to be understood. And while efforts have advanced studies of poetic texts and isolated views of "historical moments," no adequate model for the interpretation of a writing like Ezekiel had been undertaken. An adequate tool to apply the iconographic record from the ancient Near East was needed, a significant methodological advance necessary. Understanding unifying principles behind the art, in order to correctly apply them to the type of text under consideration, led to the development of an "iconography of empire." Examining art from the ancient Near East (including Egypt), with particular attention to the first half of the first millennium BC, allowed ideological motifs connected with the great empires to be understood in a systematic manner. While the analysis could hardly be exhaustive, sufficient evidence was found to demonstrate that the value systems presented in the art were understood and shared across social and political boundaries, as well as cultural and chronological borders. The book of Ezekiel provided a test case. Could an iconographic reading using the ideology of empire enable the interpretation of a literary work? A thoroughgoing reading of Ezekiel is undertaken, with clear results. Ezekiel worked with readily recognizable images and patterns and used this material to facilitate communication with the reader. This fresh reading of Ezekiel indicates the value of the model to texts of a similar genre. Such an opportunity for new insights to an ancient text is not to be minimized. By enabling us to read the text as sensible and programmatic, an iconographic analysis of the text represents a major advance in the study of Ezekiel.
Temperature dependence of crack wake bridging stresses in silicon carbide-reinforced alumina composites

R-curves for a SiC-platelet-reinforeed alumina and a SiC-whisker-reinforced alumina were obtained between room temperature and 1400°C from chevron-notched flexure specimens. In response to evidence that R-curves alone provide inadequate characterization of the crack wake bridging processes due to their strong geometry dependence, a procedure based on a fracture mechanics weight function was developed to characterize the bridging stresses imposed on the crack surfaces by the bridging elements as a function of crack surface displacement. Finite element analysis was used to obtain the required weight function for crack surface tractions in specific chevron-notched flexure specimen geometries, and to find the crack opening displacement due to the applied load. An iterative scheme was devised to extract the bridging relation from the measured R-curves. The temperature dependence of the bridging stresses could then be studied through analysis of the R-curves measured for the composites. Similar levels of bridging stresses were found in both of the composites. The bridging stresses in the SiCpl-Al2O3 were found to be limited to a smaller crack surface displacement range, almost half of the value for the SiCw-Al2O3 material. These stresses were found to decay linearly with temperature in the whisker-reinforced material, while the limited non-linearity observed in the case of the platelet-reinforcement was attributed to the presence of an interfacial amorphous phase found in this composite. The unexpected similarity in the magnitude of the bridging stresses in the two composites is discussed in terms of the micromechanics of pullout bridging. The crack tip toughness is found to increase with temperature in the whisker-reinforced material. In agreement with some previous studies of the composite, this toughening effect is associated with a microcrack zone formed ahead of the crack tip by the coalescence of diffusional cavities at the SiC w/Al2O3 interface. However, the results do not indicate any crack length dependence in this behavior or any influence from the microcrack zone on the bridging stresses.
Molecular mechanisms of ventilator-induced lung injury, Biotrauma

Ventilator-induced lung injury is recognized as a source of significant morbidity and mortality in intensive care units. Until recently, studies examining the pathophysiology of this disorder focused almost exclusively on the physiological effects and structural sequelae of different ventilatory strategies. These studies demonstrated that ventilation at either extreme of lung volume is injurious, and can produce injury comparable to that observed with the acute respiratory distress syndrome. In this thesis we explored the hypothesis that there is an active cellular and molecular mediated component involved in the pathogenesis of ventilator-induced lung injury. Using an isolated rat lung model to assess the effect of ventilation on the lung independent of confounding hemodynamic or systemic effects, we demonstrated that ventilation with strategies that produced high end-inspiratory or low end-expiratory lung volume increased inflammatory cytokine production by the lung. The time course of production of TNFÃ at the protein and steady state mRNA levels was found to be dependent on both time and the particular ventilator strategy used. Increased TNFÃ appeared to precede signs of histologic injury, and was associated with evidence of surfactant dysfunction. In situ hybridization for TNFÃ and IL-6 revealed that injurious ventilation produced an increase in expression of these inflammatory cytokines by the vast airway and alveolar epithelium. In contrast, epithelial expression of these cytokines in lungs subjected to non-injurious ventilation was significantly less, and comparable to that seen in lungs freshly harvested. As the epithelium of the lung is exposed directly to the mechanical stresses of ventilation, further studies were performed 'in vitro' to assess whether cell stretch was responsible, in part, for inducing the changes in alveolar epithelial cytokine expression we observed. We conclude that mechanical ventilation can have a significant effect on the inflammatory response of the lung and that this may be important in the initiation and propagation of lung injury, as well as potentially the development of a persistent systemic inflammatory response. We speculate that the use of interventions that target the inflammatory sequelae of ventilation combined with manipulation of ventilatory parameters may reduce the morbidity and mortality of patients with acute respiratory failure.
Dietary patterns and the risk of renal cell carcinoma

We investigated the role of diet in the etiology of renal cell carcinoma using a population-based case-control study conducted in Ontario between 1995 and 1996. A total of 461 histopathologically confirmed cases (210 females, 251 males) were frequency-matched to controls on (1) age (422 females, 250 males) and (2) age and smoking (217 females, 241 males). For each analysis, diet patterns were created using a factor analysis of 69 food items consumed weekly. These patterns were entered in a stepwise logistic regression analysis to identify patterns most significantly associated with the risk of renal cell carcinoma. For the age-matched analyses, a 'dessert' diet pattern was significantly associated with disease, with the strongest associations observed among men (males, odds ratio estimate (OR) = 3.8, 95% confidence interval (CI) 2.1-7.1; females OR = 1.4, 95% CI 0.8-2.2 for the highest vs. lowest quartile). In the age/smoking-matched analysis, a 'high protein and fat' diet pattern was significantly associated with risk of disease, again with higher risks confined to males (males, OR = 2.7, 95% CI 1.5-4.9; females OR = 1.5, 95% CI 0.8-2.6). With the exception of the age-matched female analysis, the remaining analyses showed a significant increased risk associated with higher consumption levels of a 'fruit juice' pattern (age/smoking-matched males OR = 2.2, 95% CI 1.3-3.8; females OR = 1.4, 95% CI 0.7-2.6). A subsequent analysis of supplementary vitamin C did not reveal any association with renal cell carcinoma. Our findings confirm that high fat and protein diet patterns may be risk factors for renal cell carcinoma. These data also suggest an increased risk is associated with a juice pattern, a finding not previously reported.
Serotonin-7 receptor pseudogene cloned from human genomic DNA

The discovery of multiple types of dopamine receptor has accelerated the search for the function of these proteins in the brain. Specifically, the brain dopamine D4 receptor, which is blocked by atypical neuroleptics such as clozapine, is under investigation for its possible linkage to schizophrenia. There is indirect evidence from binding studies suggesting that D4-like receptors may be elevated in schizophrenia. In addition, an increased binding of [ 3H]benzquinoline (a D4-specific antagonist) has recently been found in schizophrenia striatum. This increased binding site indicated the possible existence of a novel dopamine D4-like receptor. The objective of this present project was to detect this new receptor. Molecular techniques such as homology library screening and PCR amplification were carried out. A serotonin-7 receptor-like gene (PG6-D1), together with a partial genomic sequence (PCR15) which is also serotonin-7 receptor-like, were isolated. The in-frame partial clone (PCR15) shared significant homology with the serotonin-7 receptor gene among the TM6-TM7 region, and named as the serotonin-7B receptor. Characterization of clone PG6-D1 sequence indicated it to be a pseudogene of the newly proposed serotonin-7 receptor gene. Because the new serotonin-7B pseudogene has 40% nucleotide identity to the D2 receptor gene within the TM region, the sequence of this new gene may be useful in the continued search for a new D2-like receptor.
Gypsum scale formation in continuous hydrometallurgical neutralization reactors

An experimental study was carried out to determine the rate and extent of scale formation of gypsum (calcium sulphate dihydrate) on stainless steel surfaces in two types of continuous hydrometallurgical sulphuric acid neutralization reactors: a calcium carbonate partial neutralization reactor, and a calcium oxide total neutralization reactor. The purpose of the study was to determine the effects of pH, temperature, residence time, presence of metal sulphates (Fe, Al, Ni, and Mg), addition of surfactants, and addition of gypsum seed on scale growth. The rate of scale formation was found to be reduced by lower temperatures, longer residence times, and the presence of nickel and magnesium. pH had no significant effect. The effect of these variables on the rate of scale formation was related to the degree of gypsum supersaturation. Scale reduction through the addition of sulphonated anionic surfactants was found to only be effective under certain conditions. However, gypsum seeding was found to be an effective method of scale reduction. Scale was reduced by 50% or more at a seed concentration of 10g/L.