VictorJuiz/thesis huggingface dataset:
Porosity and structure of alum coagulation and activated sludge flocs

Knowledge of floc porosity and structure is the basis for the study of floc permeability. This study determined the porosity and structure of alum coagulation and activated sludge flocs. The porosity of these flocs can be expressed in geometric and mass terms. Yet mass porosity can be 10 times higher than geometric porosity due to an underestimation of floc density in the settling test. Given the more reliable data expressed by geometric porosity, an experimental method for studying the geometric porosity of aggregates was developed. The average geometric porosity was 9% for alum flocs and 8% for activated sludge flocs. Similar average geometric porosity and size of the primary particles in these two aggregates suggested similar permeability of these flocs, while the settling behaviour of these flocs suggested that activated sludge flocs were more permeable than alum flocs. This suggested that the floc permeability couldn't be estimated based on the average porosity of the floc. Interpretation of the geometric porosity data using the concepts of fractal geometry enabled three pore populations--small, medium and large--to be identified within alum and activated sludge flocs. Small pores had a cross-sectional area smaller than 3 [mu]m2. The medium pores of alum flocs were smaller than 10 [mu]m2, and the medium pores of activated sludge flocs were smaller than 20 [mu]m2. Activated sludge flocs are more permeable than alum flocs because the pores forming flow channels--medium and large--are bigger in activated sludge flocs than the corresponding pores in alum flocs. Based on the size of pores, permeability and structural models were proposed for the flocs studied. In the activated sludge floc model flocculi were two times larger than the flocculi in alum flocs. The size of the flocculi determines the size of pores facilitating the internal flow; therefore, it should be incorporated in the floc permeability models. This study makes two recommendations: (1) developing floc permeability models that do not require floc porosity estimate; (2) re-calculation of floc mass transfer and drag force predictions using an improved estimate of floc permeability.
Random effects and AR(1) models in longitudinal data analysis

In longitudinal studies repeated measurements of exposures and response are made on individuals to assess the relationship between them. These repeated measurements of response collected from individuals often exhibit more similarity within individuals than among individuals. Such clustering can be accounted for in the statistical model by incorporating within subject correlation or by allowing the fixed effect parameters to have probability distributions. In this thesis the effect of ignoring such clustering on the estimation of the fixed effects in a linear model are explored. The fixed effects (slopes) can be estimated without bias, but the variance of estimated slopes may be over- or under-estimated if the within subject correlation is ignored. This may lead to a biased conclusion about the fixed effects. The direction of the bias may depend on the relative sizes of the correlation in the exposure and response variables. This thesis also explores the factors related to the identification of random effects or AR(1) correlation. The factors studied include the number of individuals, the number of repeated observations, the variance of the predictor variable and the variance of the error term. The results from this study will be useful in the evaluation of fixed effects, and in the design of a study, which identifies clustering phenomena.
Discovery of novel G protein-coupled receptor genes including human GALR3 receptor gene

The G protein-coupled receptors (GPCRs) form a large superfamily of integral membrane proteins. GPCRs have been implicated in a large number of system functions including behaviour, cognition, drug addiction, and various neuropsychiatric diseases. The research work presented in this thesis describes the discovery of six novel putative GPCR genes and a new human galanin receptor subtype GALR3. The genes encoding GPR40, GPR41, GPR42 and GPR43 were identified using a degenerate PCR strategy together with database searches. The aim in that particular project was to search for novel human galanin receptor subtypes. GPR40, GPR41, GPR42 and GPR43 encoded intronless genes that shared little homology with galanin receptors and occurred downstream from the CD22 gene localized previously to chromosome 19q13.1. Use of a customized search procedure of high throughput genomic sequence (HTGS) GenBank database yielded a DNA sequence encoding a human GALR3 receptor gene. In addition a rat orthologue of GALR3 was isolated. The mRNA distribution of GALR3 in rat and human tissues indicated expression in distinct brain regions and peripheral tissues. The human GALR3 was localized to chromosome 22q12.2-13.1 using fluorescence ' in situ' hybridization (FISH). The same database strategy was successful in identification of GPR52 gene and a pseudogene TGPR53 localized to chromosomes 1q24 and 6p21, respectively.
Human novelty assessment systems, positron emission tomographic evidence

One of the most fundamental and adaptive mental faculties any organism can possess is the ability to differentiate novel things from familiar things. Novelty assessment is the name given to the collection of neural processes which supports this ability. The goal of this thesis was to examine the workings of novelty assessment using positron emission tomography (PET). This was done in two parts--a multi-study analysis which examined recognition of novel and familiar words and pictures across five PET studies and an original study which examined encoding of novel and familiar words under semantic and non-semantic encoding instructions. The multi-study analysis examined novelty assessment across five PET studies of recognition memory. The objective was to determine whether a common novelty assessment system operates within the brain. The results revealed a common pattern of brain activation across four of the five studies. This common pattern distinguished between regions whose activity was greatest when subjects recognized novel items (novelty activations) and regions whose activity was greatest when subjects recognized familiar items (familiarity activations). Novelty activations were observed within the right hippocampus, bilateral middle and superior temporal gyri, and left prefrontal cortex. The findings of the multi-study analysis suggested that a task-, modality-, and stimulus-independent novelty assessment network may operate within the brain. Next, an original PET study was carded out to examine semantic and non-semantic encoding of visually and auditorily presented novel and familiar words. The objective of this experiment was to examine implicit novelty assessment. The main findings from this study suggested that implicit novelty assessment modulated the activity of task-specific (semantic and non-semantic encoding) brain networks rather than relying on a dedicated brain network. These findings suggest that explicit and implicit novelty assessment may rely on different underlying neural mechanisms. In the former case, the results of the multi-study analysis suggested that novelty assessment may be implemented as a dedicated brain network, whereas in the latter case, the results of the novelty-encoding experiment suggested that novelty assessment may modulate task-specific activations. These results are discussed in relation to current views about the neural mechanisms underlying novelty assessment.
Molecular cytogenetic analysis and gene amplification in rhabdomyosarcoma and neuroblastoma

An understanding of the genetic changes that lead to malignancy is of fundamental importance in the study of carcinogenesis. As tumors progress, multiple genetic aberrations are accumulated which often correlate with biological and clinical behavior. Recent advances in cancer cytogenetics can provide a greater depth of information regarding chromosomal changes in tumors. This thesis addresses the molecular genetic consequences of chromosomal and DNA copy number alterations in two pediatric neoplasms: rhabdomyosarcoma and neuroblastoma. Rhabdomyosarcoma predominantly presents as two major subtypes: embryonal RMS (RMS-E) and alveolar RMS (RMS-A). Comparative genomic hybridization performed on 21 RMSs identified distinct differences between the two subtypes. Whole chromosomal gains of 2, 5, 7, 8, 11 and 12 were observed in RMS-E, and high copy number amplification, involving the 2p24 region (6/12 tumors) and less frequently the 12q13-21, 9p22 and 17q22-25 regions was detected in RMS-A. Patients with amplification had a shorter disease free interval and a higher mortality. Spectral karyotype analysis of a RMS cell line of each subtype identified a surprisingly high level of structural change. Gene expression studies using the Atlas Human Cancer Array (588 genes) showed that 45 genes showed differential expression. Currently, very little information is available on the evolution of ' MYCN' amplicon as either double minute chromosomes (dmins) or homogeneously staining regions (hsrs). Free chromatin fluorescence in situ hybridization was therefore performed to provide relational mapping of 'MYCN' and 'DDX1' within band 2p24 and to analyze the configuration of the two genes in dmin and hsr. 'DDX1' was found to be telomeric to 'MYCN' and no regular reiterated amplicon repeat unit was present in hsrs. A more detailed analysis of the configurations of ' DDX1' and 'MYCN' within each array detected a complex pattern of amplicons within hsrs suggesting that multiple rearrangements must have taken place. Analysis of dmins showed a simpler pattern of amplicon structure suggesting that deletions and/or duplications of 'MYCN' and ' DDX1' may have occurred. These data are consistent with a molecular mechanism for amplification involving many rearrangements as it develops resulting in complex amplicon structures leading to changes in both relative gene copy number and in the intragenic distances between co-amplified genes.
Dimensions of ethnicity as predictors of adolescent cigarette smoking

Cigarette smoking is the major source of preventable disease and death in Canada (Ashley, 1995) and the United States (U.S.D.H.H.S., 1994). Although there is some evidence that the prevalence and patterns of cigarette use may vary among different ethnic groups, the influence of ethnicity on adolescent smoking has not been studied. In light of the recent increase in rates of youth smoking and the diverse ethnic and cultural makeup of Canada's population, the issue of ethnicity and adolescent smoking requires further investigation. The purpose of the present study is the examine the relationship between ethnicity and adolescent smoking. Objectives. The objectives of the present study were: (1) to identify differences in smoking status among adolescents from various ethnic backgrounds, and (2) to determine whether dimensions of ethnicity, namely level of acculturation, strength of ethnic identity and immigration status, were significant predictors of adolescent smoking. (Abstract shortened by UMI.)
The role of Src family kinases in the pathogenesis of fulminant viral hepatitis due to murine hepatitis virus strain-3

Murine Hepatitis Strain-3 (MHV-3) infection of susceptible mice induces fulminant hepatitis and liver necrosis by stimulating macrophage/Kupffer cell expression of the prothrombinase, fgl-2, within hepatic sinusoids. MHV-3 induced fgl-2 activity requires activation of ERK1/2 and p38 MAPKs. To define the upstream steps of MHV-3 signaling, we examined the role of Src family tyrosine kinases in fgl-2 expression. In peritoneal exudative macrophages challenged with MHV-3, the activity of the Src kinases Hck and Lyn was increased, whereas the activity of the Src kinase Fgr was unaffected. Src inhibition prevented MHV-3 induced ERK1/2 and p38 MAPK phosphorylation, as well as fgl-2 mRNA and procoagulant activity (PCA). 'Thus': Src kinases are activated by MHV-3 and contribute to the expression of fgl-2 mRNA and PCA through the activation of ERK1/2 and p38 kinases. These studies demonstrate the crucial link of proximal protein tyrosine kinases in the signal pathways contributing to virally mediated liver disease.
A predicative model for probabilistic specifications and programs

The incorporation of probability into several theories of programming has been formalized by Morgan et al. (17, 18). He et al. (3) present two different semantic models for extending Dijkstra's guarded command language with an additional operator, namely probabilistic choice. The aim of this thesis is in the same line as the work mentioned above--to extend Hehner's theory of programming (5) (referred to as the standard model) to incorporate probabilistic behavior. The extended theory (referred to as the probabilistic model) makes it possible for the development of probabilistic programs from probabilistic specifications. In the probabilistic model, a probabilistic specification is a boolean expression as in the standard model, but the variables of the boolean expression are no longer the prestate and the poststate. Instead, they are the prestate, and a function: the probability distribution over all possible poststates. Refinement is implication, as in the standard model. Probabilistic programs are probabilistic specifications. The probabilistic programming language is an extension of the standard programming language, and contains a construct for probabilistic choice. Various issues of interest, such as nondeterminism and timing, are discussed. The work in this thesis is consistent with the framework proposed by Hoare and He (9) for unifying theories of programming.
Alzheimer's disease, filling in pieces of the big puzzle

Alzheimer's disease (AD) has been proposed to result from interactions between susceptibility genes and environmental factors. This thesis examines such potential interactions between aluminum exposure, presenilin (PS) mutations and amyloid deposition. Differences in uptake and toxicity between various aluminum salts were examined. Aluminum toxicity did not always correlate with uptake in neurons and astrocytes. I hypothesised that amyloid precursor protein (APP) secretion may be altered following aluminum insults. In response to aluminum exposure, both neurons and astrocytes increased APP secretion. These data were the first evidence for an interaction between aluminum and APP. I tested the hypothesis that the effect of PS mutations on APP may derive from the mislocation of mutated PS. The distribution of mutant PS1 was examined in dissociated cultures of hippocampal neurons and in fibroblasts derived from AD. Confocal microscopy revealed that PS was localised to the endoplasmic-reticulum-Golgi intermediate compartment of both cell lines but that the distribution of mutant presenilin was identical to that of wild-type PS1 (wtPS1). Cells expressing PS1 mutations have been shown to have an increased susceptibility to excitotoxic insults. In addition, the possibility that fibroblasts derived from AD patients would have a decreased viability when exposed to aluminum compared to those expressing wtPS1 was examined. No difference in toxicity was obtained between fibroblasts bearing wtPS1 or mutants presenilin in response to aluminum exposure. However, cells expressing PS1 mutants had the greatest levels of aluminum uptake which is the first evidence for a link between aluminum and the presenilins. Artificial "plaques" were created from aggregated synthetic Aß peptides to test the hypothesis that senile amyloid plaques are toxic to neurons. These plaques inhibited neuronal adhesion and neurite extension without affecting cell viability. No effects were obtained in astrocytes growing under these same conditions. Taken together these results provide a compelling link for the interaction between aluminum exposure and PS. The increasing prevalence of AD associated with our aging population places a heavy burden on our society. Further insights into the role played by APP, aluminum, and PS on the AD neurodegenerative process will facilitate the development of new treatments for this debilitating disease.
Hitler's clean slate, everyday life in the Reichskommissariat Ukraine, 1941-1944

This is the first detailed study of the impact of Nazi rule on the largest colony of Germany's Third Reich, the Reichskommissariat Ukraine. It should be of interest to students of the Soviet Union, eastern Europe, Nazi Germany, and the Holocaust. Although the majority population--Ukrainians--receive the most attention, this is intended as a territorial history and, therefore, takes into account the experiences and perceptions of non-Ukrainians as well. The focus is on three aspects of everyday life under civilian Nazi rule: (1) socio-economic conditions--work, housing, food, and famine; (2) spiritual life--religious and popular culture, ethnic identity, and political loyalties; and (3) special targets of the Nazis--prisoners of war, Jews, Roma/Gypsies, ethnic Germans, and candidates for forced labor in the Reich--as well as the relation of these people with the rest of the population. This work is based on many published materials and in particular on a wide range of primary sources that were previously not available to researchers. German-language sources include documents produced by the Nazi authorities, dealing with the Reichskommissariat Ukraine, the Ministry for the Occupied Eastern Territories, and the SS. Other sources are the records of the auxiliary native administrations in the Kiev region; records of Communist underground activists and partisans; contemporary newspapers, magazines, brochures, leaflets, and posters; folkloric materials, diaries, and memoirs; and interviews conducted by Soviet historians during the 1940s as well as by the author during the 1990s. One of the contentions of the study is that Nazi rule, besides being mortally dangerous for the inhabitants, was a tremendous disappointment for the vast majority of the population. Nonetheless, throughout this period prewar mentalities continued to have a tremendous hold over the native population. In particular, it is very doubtful whether the Nazi experience prompted more than a limited nostalgia for Soviet rule, and it is also unlikely that Ukrainians became more conscious of their ethnicity. In the final analysis, the Nazi regime did little more than kill people. It hardly had any impact on the Weltanschauung of those who survived.
Age Dependent Pupillary and Cognitive Responses to Cholinergic Drugs as a Model for Identificaton of Future Biological Markers for Alzheimer's Disease

Background. An increased pharmacological response to cholinergic drugs has been proposed as a predictor of deficits in cholinergic neurotransmission in Alzheimer's disease. This thesis assessed the effect of normal aging on (a) pupillary response to tropicamide and pilocarpine (b) scopolamine effect on memory in healthy elderly and young volunteers. Methods. Elderly (n = 10, age: 70 $\pm$ 2) (mean $\pm$ SD) and young (n = 9, age: 33 $\pm$ 2) volunteers were tested over four sessions following a randomized double-blind design. In one session, tropicamide (20$\mu$l, 0.01%) was administered to one eye, and placebo to the other. In another session, tropicamide (20$\mu$l, 0.01%) was administered to both eyes followed at 25 minutes post-tropicamide by application of pilocarpine (20$\mu$l, 0.1%) to one eye and placebo to the other. In both sessions, pupil diameter was assessed using a computerized infrared pupillometer over a period of 4 hours. On two separate sessions, a single dose of scopolamine (0.5 mg, iv) or placebo was administered and effects on word-recall were measured for 2 hours. Results. Aging did not significantly affect pupillary response to tropicamide. The placebo-corrected pilocarpine effect on pupil size was greater in the elderly at 85, 125, 165 and 215 minute time points compared to the young. Scopolamine effect on word-recall was greater in the elderly at 60 (41.7%, % of baseline), 90 (43.1%) and 120 (47.l%) minute time points compared to young subjects (58.7%, 60.6%, 103.0%, respectively). Conclusions. Scopolamine effect on cognitive function is increased during normal aging. There is an age-related increase in pupil response to pilocarpine whereas the effect of tropicamide on pupil size is not changed with aging. (Abstract shortened by UMI.)
Prolactin response with typical and atypical antipsychotics

'Introduction'. Evidence suggests that, unlike typical antipsychotics, 'atypicals' spare the prolactin (PRL) secreting system. Most of the evidence, however, is based on studies of single-point PRL levels, usually done 12-24 hours post drug dose. The kinetics of PRL response over the course of a single dose cycle with atypical antipsychotics has not been heretofore examined. 'Hypothesis'. All antipsychotic medications studied will give rise to some degree of prolactin elevation over the course of a single dose cycle. 'Methods'. PRL levels in 18 male patients with schizophrenia maintained on their current antipsychotic for >=4 weeks were monitored via an indwelling intravenous catheter over 24 hours following an oral dose of their daily medication. 'Results '. Patients in each drug group demonstrated an increase in PRL levels above their baseline values. 'Conclusions'. These data demonstrate that all tested atypical antipsychotics give rise to PRL elevation after each dose, even after chronic dosing previously.
An analysis of visual perception and visual attention skills in school-aged children with spina bifida and shunted hydrocephalus, an initial investigation

Visual perception and visual attention difficulties are consistently reported cognitive deficits in school-aged children with spina bifida and shunted hydrocephalus. An understanding of their pattern of strengths and weaknesses is incomplete. Seventeen 8-to-12 year old children were assessed using the Componential Assessment of Visual Perception$\sp\copyright$. Accuracy and speed data were collected and linked to medical risk factors. The application of a motor-reduced assessment helped to illustrate patterns of visual perception and attention performance. The results showed these children retain the ability to perform simple visual discrimination tasks, encode stimuli and shift attention. Difficulty ignoring irrelevant stimuli was found for complex tasks. Children with a greater number of risk factors demonstrated poorer performance. The implications of these results and suggestions for future research are discussed.
Application of static transfer switch for induction motor load transfer

The most cost-effective way to provide a large power user with uninterruptible power is to supply the consumer's facility with two feeders and to install automatic transfer equipment to switch over to an alternate feeder if the primary supply fails. The given work is concerned with such a type of load transfer. For the purpose of a transfer process study, a laboratory prototype of an automatic transfer switch was built. The control algorithm of the switch operation was developed and implemented on the controller board utilizing a TMS320C40 digital signal processor. Transfer tests were performed on various types of common industrial loads under different disturbances, although the study of an induction motor transfer was of primary importance. Likewise digital time-domain simulations using PSCAD/EMTDC software was made and comparison with laboratory tests provided. Results and observations found in the studies are presented in this thesis.