VictorJuiz/thesis huggingface dataset:
Molecular interactions, contact angles and solid-fluid interfacial tensions

Contact angle hysteresis experiments show that amorphous polymers show the largest hysteresis and the more closely packed semi-crystalline surfaces yield the smallest hysteresis. The effect of geometry of liquid molecules as well as the three-phase line velocity on hysteresis is also identified. Advancing contact angles of different liquids measured on the same solid surface fall very close to a smooth curve, when plotted as a function of liquid surface tension, i.e. gamma1vcostheta vs. gamma1v. Changing the solid surface (and hence gammasv) shifts the curve in a regular manner, suggesting that gamma1vcostheta depends only on gamma1v and gammasv. These patterns led to the development of an equation of state for the determination of solid surface tensions. A close examination of the smooth curves showed that contact angles typically show a scatter of 1-3 degrees around the curves. Accurate reproducibility of the contact angle measurements show that the deviations are not experimental errors and must have physical causes. The contact angles of a large number of liquids on the surfaces of four different fluoropolymers have been studied to determine the causes of the deviations. Specific molecular interactions at solid-vapor and/or solid-liquid interfaces are not directly taken into account in the equation of state and it is shown that these interactions account for the minor contact angle deviations. Specific criteria are proposed to identify probe liquids which eliminate specific interactions. Octamethylcyclotetrasiloxane (OMCTS) and decamethylcyclopentasiloxane (DMCPS) are proposed as two liquids that meet those criteria. Thus, solid surface tensions are obtained with an accuracy of +/-0.2 mJ/m2. Stick-slip of the three-phase line during contact angle measurements has also been investigated. A non-uniform vapor adsorption onto the heterogeneous solid surface is suggested as the cause of stick-slip.
Preliminary model of corrosion and iron release in a pipeline system

The model is able to predict the correct trend of the substances' concentration and provide an order of magnitude estimate of the time-varying concentration of various substances. The work done in this research marks a preliminary step towards a more thorough iron corrosion modelling effort, one which eventually simulates relevant parameters and their interactions, as opposed to the individual parameter approach largely adopted to date. This research focuses on water quality degradation arising from internal pipe corrosion processes. The model is a simplified multi-component model that includes several important water chemistry parameters: pH, dissolved oxygen (DO), and interactions from the carbonate system. The model simulates the iron concentration fluctuation as a function of the concentration variation of other related substances, using a numerical integration approach.
Fab fragments of monoclonal antibodies directed against HER2/neu or tumor-associated glycoprotein-72 for radioimmunodetection of breast cancer

Overexpressed surface receptors/antigens on cancer cells can be targeted specifically by antibodies for radioimmunoimaging or intraoperative radioimmunodetection of cancer. In breast cancer, HER2/neu and tumor-associated glycoprotein-72 (TAG-72) are overexpressed in 30% and 80% of patients, respectively. Their overexpression has been associated with a poor prognosis and more aggressive form of disease. The goal of this research was to construct Fab fragments of monoclonal antibodies directed against HER2/neu or TAG-72 for radioimmunoimaging and intraoperative radioimmunodetection of breast cancer. Fab fragments of the anti-HER2/neu monoclonal antibody trastuzumab (Herceptin RTM) were prepared by proteolysis of intact trastuzumab IgG and subsequently radiolabeled with 99mTc or 111In for tumor localization studies in athymic mice bearing subcutaneous HER2/neu-positive BT-474 breast cancer xenografts. Trastuzumab Fab was immunoreactive toward HER2/neu with a 2-4 fold higher Kd compared with intact trastuzumab IgG (1.4-3.6 x 10-8 M vs. 4.7-14 x 10-9 M, respectively). Both 99mTc- and 111In-trastuzumab Fab localized avidly and specifically in BT-474 xenografts. 99mTc-trastuzumab Fab was useful for imaging HER2/neu overexpression at early time points, i.e. up to 24 hours post-injection. Small BT-474 tumor xenografts (approximately 3-5 mm) were clearly visualized by gamma-scintigraphy as early as 2-6 hours after injection of 99mTc-trastuzumab Fab. 111In-trastuzumab Fab was useful for visualizing the BT-474 xenografts at later times, i.e. up to 72 hours post-injection. At this point, tumor uptake and the tumor-to-blood (T/B) ratio reached 7.8% ID/g and 25:1, respectively. Immunoreactive recombinant Fab (rFab) of anti-TAG-72 monoclonal antibody CC49 was produced by cloning the genes of Fab from CC49 hybridoma cells and subsequent expression in Pichia pastoris. rFab was purified by affinity chromatography to homogeneity. 123I-rFab accumulated specifically in TAG-72-positive LS 174T colon cancer xenografts in athymic mice, evidenced by its 18-fold greater tumor uptake of 123I-rFab in LS 174T xenografts than in TAG-72-negative A375 tumors (6.0 vs. 0.3% ID/g at 24 hours post-injection). 123I-rFab was rapidly cleared from the blood and normal tissues, allowing LS 174T xenografts to be visualized by gamma-scintigraphy as early as 2 hours post-injection. These promising results suggest that trastuzumab Fab and CC49 rFab may be useful for radioimmunoimaging or intraoperative radio immunodetection of breast cancer.
Effects of acid concentration on hybrid layer thickness: a SEM study

Sixty extracted human third molars were randomly divided into 12 groups. Dentin was exposed and etched with the respective etchants (35% aqueous phosphoric acid and gel, 10 and 5% aqueous phosphoric and maleic acids). A water- and an acetone-based adhesive were applied to moist dentin and sealed with resin composite. Four longitudinal 1-mm sections were obtained; two sections were first deproteinized in 5.25% NaOCl and all four were critical point dried. Hybrid layer thickness and the degree of resin penetration were determined under the SEM and statistically analyzed. 5 and 10% acids produced a significantly thinner HL with both adhesives and a significantly greater degree of resin penetration with SBMP (p<0.05). Under the SEM, well-defined hybrid layers were seen with resin tag formation. Deproteinized sections demonstrated an uninfiltrated layer between the adhesive and the underlying dentin for both adhesive resins in all etchant groups.
The use of electronic ceramics and magnetic treatment to prevent fouling on UV lamp sleeves

In this research, two scale mitigation technologies are evaluated for minimizing or preventing inorganic UV lamp fouling. The devices are Electronic Ceramics (ELCE) and ScaleFreeRTM, a conventional magnetic treatment. Both devices were tested under accelerated scaling conditions by adjusting tap water for pH, calcium, iron, and alkalinity concentrations which are conducive to scale formation; and passing the water through a customized medium pressure lamp reactor. The fouling material, which accumulated on the surface of the quartz, was analyzed for the decrease in quartz UV transmittance and by digesting the minerals and determining the calcium and iron concentrations using atomic absorption spectrophotometry. Results show the incapability of the ScaleFreeRTM to alter pH and alkalinity or fouling behaviour, while the ELCE has shown otherwise. Also, the ELCE device has demonstrated many effects that are observed for magnetically treated water. The fouling of quartz sleeves induced by the heat of ultraviolet (UV) lamps remains as an operational barrier for UV disinfection technology although cleaning mechanisms exist, but they are unsuccessful or add to the operational complexity.
An application of the CBM design analysis tool to network assets

Highly reliable operation of a telephone network system is of great importance for maintaining customer satisfaction. It is noted that the bad weather conditions are responsible for as much as 70% of the signal interruptions. In this research, we apply Condition-based Maintenance (CBM) methodology to analyze the telephone line system, in which both the interruptions and various weather conditions are considered to make decisions. We analyze the system by applying optimization modeling software, EXAKT, which is being developed at the University of Toronto's CBM Laboratory. Proportional Hazard Model (PHM) was utilized incorporating the complex weather conditions of the network system. A case study is proposed and the key factors relating to the reliability are identified. A new methodology for data pre-processing is developed in data preparation phase, which lays the groundwork for further investigations. The research also presents an extension of the classical long-term optimal decision policy.
Computer modeling of enzyme catalysis and inhibition

Computer modeling techniques have been extensively used to aid drug design via enzymatic reactions studies. Here we present the investigations of catalysis by orotidine monophosphate decarboxylase (ODCase) and the inhibition of protein kinase C (PKC) isozymes. Decarboxylation, pseudohydrolysis and covalent inhibition reactions were studied using QM and QM/MM methods to understand the mechanistic details of ODCase catalysis. We found that the proposed mechanisms are not feasible energetically. The catalytic site architecture and binding interactions of PKC isozymes alpha, beta and zeta were investigated, in the context of PKC-beta inhibitor, ruboxistaurin. Homology modeling and docking were used to model the three-dimensional structures of the kinase domains of PKC isozymes and the PKC-ruboxistaurin complexes, respectively. For the first time, specific interactions for ruboxistaurin that favor binding to PKC-beta were uncovered. A second binding site was discovered for PKC-zeta, which provides opportunity to design isozyme-specific inhibitors.
Neural correlates of short-term somatosensory skill learning in healthy controls

The specific neural substrates that underpin sensorimotor recovery following stroke remain poorly understood. Since the foundation of long-term sensorimotor recovery is believed to be rooted within short-term neural changes accumulated over time, it is therefore essential to acquire an initial understanding of the short-term cortical influences of skill learning. To provide a framework for future studies in stroke, the present studies examined the neural correlates of short-term skill learning in healthy subjects. A novel vibrotactile discrimination task appropriate for use with functional magnetic resonance imaging (fMRI) was developed. Experimental results revealed that as skill improved there were significant changes in the spatial extent and intensity of cortical activation over a widely-distributed somatosensory-related neural network. Interestingly, contrasting cortical effects were revealed during periods of skill 'training' and 'testing', which may suggest important differences in the underlying neural processes subserving the acquisition and performance of skill, respectively.
Impact of life events and difficulties on the mental health of Chinese immigrant women

Over the last decade Chinese migrants have constituted the largest ethno-cultural group to arrive in Canada, with the highest concentration among business people and skilled workers. Research, both theoretical and policy-driven, has not kept pace with this rapidly expanding population. Moreover, the experiences of women are often obscured by broad-stroke statistics reflective of the principal migrants only, the majority of whom tend to be men. Therefore, the purpose of this study was to examine the life events and difficulties in Chinese women's lives inhere to the immigration process and the sources of social support which contribute to mental health and well-being. To this end a six-month follow-up study, utilizing a semi-structured interview protocol and standardized questionnaires, was conducted with a group of Chinese women who had migrated with their romantic partners in the past decade. Analyses are based on a sample of 43 middle-class women from mainland China, Hong Kong, and Taiwan over two time points within a half year interval. All of the women and all of their partners experienced major downward mobility in Canada. Correspondingly, the most frequent negative life event was employment-related and the most frequent difficulty was the financial strain of living below the poverty line, factors which significantly predicted symptoms of psychological distress and negative affect among these women. Social support in the form of dyadic functioning between the women and their partners and relationship harmony within the women's broader interpersonal network had neither a main effect on psychological distress and affect nor a buffer effect on the relationship between life events and difficulties and the mental health outcome measures. A construct, "belief in common fate" was developed from interviews with the women and refers to an unfailing devotion to the traditional Confucian ideal of the marital union without regard for external contingencies or individual needs. Analyses revealed that women who did not believe in common fate reported more positive affect and fewer symptoms of psychological distress, particularly in the face of adverse life circumstances. Results are discussed in light of a social-cognitive model of psychological distress. The findings of this study have implications for immigration and settlement policy and directions for future research are suggested.

Keywords: Life change events, Psychological aspects
Chinese, Mental health
Chinese, Ontario
Depression in women, Ontario
Women immigrants, Mental health
Women immigrants, Ontario
A fault current limiter for minimizing impacts of distributed generation on coordinated relay protection in radial systems

To determine the effectiveness of the FCL for the proposed application, test systems are introduced, the effects of DG on the relay protection system are examined, and the effectiveness of FCL to mitigate these effects are determined. Radial power distribution systems, common in North America, typically use coordinated relay protection for fault protection. However, the rising interest in distributed generation (DG) poses a problem, as DG causes such systems to lose their radial nature, disrupting the coordinated relay protection. The use of a fault current limiter (FCL) is proposed to limit the effect of the DG on the coordinated relay protection scheme in a radial system during a fault. Additionally, this thesis shows that the FCL enhances the stability of and limits the transient stresses on the DG. Such a device is only recently more plausible with the ongoing developments of a new hybrid mechanical/electrical fault current limiter.
NHEJ-deficient DT40 cells have increased levels of immunoglobulin gene conversion: Evidence for a double strand break intermediate

Activation-induced cytidine deaminase (AID) likely initiates Immunoglobulin (Ig) gene-conversion (GC) by deaminating cytidine within the V-region genes of chicken B-cells. However, the intervening DNA lesion required to initiate GC remains elusive. GC could be initiated by a single strand break or a double strand break (dsB). To distinguish between these possibilities, we examined GC in the chicken DT40 B cell line deficient in non-homologous end joining (NHEJ). It is known that the NHEJ and homologous recombination DNA repair pathways compete for dsBs. In light of this, if a dsB is the major intermediate, deficiency in NHEJ should result in increased levels of GC. Here we show that DNA-PKcs-/-/- and Ku70-/- DT40 cells had 5- to 10-fold higher levels of GC relative to wild type DT40 as measured by surface IgM reversion and sequencing of the V-region. These data suggest that a dsB is the major DNA lesion that initiates GC, and, that processing of AID induced lesions generates dsBs in the V-region of B-cells undergoing secondary Ig diversification.
Installation behaviour of ASTM F1852 twist-off type tension control bolts

In current RCSC Specification, ASTM F1852 twist-off tension-control bolt assemblies are directly recognized and twist-off-type tension-control bolt pretensioning is considered as one of the four bolt pretensioning methods. Twist-off tension-control bolt is characterized by the splined end which will be sheared off at a circular notch (torque control groove) when the required pretension is reached. Twist-off tension-control pretensioning is in fact based on torque control. Factors that affect the pretension of twist-of bolts are the bolt material strength, geometric properties of the bolts, thread conditions, lubrication conditions at the bolt and nut threads as well as the washer. A series of test programmes were performed to examine the influence of lubricants on installation, including time delays, weather conditions at time of installation, as well as the effects of other parameters on the bolt pretension. In addition, reinstallations of removed twist-off tension-control bolts with turn-of-nut pretensioning method were also investigated.
Fringe proteins enhance competition for limiting niches during lymphoid lineage commitment, differentiation, and homeostasis

Notch signaling regulates various stages of T and B lymphocyte development. Fringe proteins are evolutionarily conserved glycosyltransferases that alter Notch sensitivity for Delta versus Serrate/Jagged Notch ligands. To assess the roles of Lunatic Fringe (Lfng) and Manic Fringe (Mfng) in regulating Notch1 (N1) or Notch2 (N2)-dependent phases of T and B cell development and homeostasis, I established single and mixed chimeras using constitutive or conditional Fringe knock-out mice and transgenic Lfng mice. Using this method, I identified a novel function for Lfng in maintaining thymic organ size by regulating competition for limiting niches at the cortico-medullary junction (CMJ) and sub-capsullary zone (SCZ). In addition, I also showed that Fringe proteins regulate peripheral T cell homeostasis, although my data suggest that different Notch ligand families mediate Notch activation in the thymus and the periphery. Finally, I showed that Lfng and Mfng synergistically enhance N2-dependent marginal zone (MZ) B cell development and homeostasis, by enhancing precursor competition for limiting Delta-like I (Dill) in red pulp endothelial niches. Collectively, these findings advance our understanding of how Fringe-mediated regulation of Notch signaling contributes to the development and maintenance of mammalian adaptive immunity by regulating competition for limiting Notch ligands in various developmental niches.
Culture, hidden curriculum and political economy: exploring a college general arts program

This thesis explores the hidden curriculum of a community college general arts program. The literature review component of this research establishes a conceptual framework rooted in Marxian Conflict oriented sociological analysis. I review a number US based ethnographies of community colleges to establish a theoretical framework to be employed throughout the thesis. The qualitative findings of the ethnographies are coupled with US data. This US data is compared with recent Ontario statistics to establish a background for my interview research results. I conducted a series of interviews with a number of faculty and students from a general arts program in Ontario. The results of these interviews find a number of distinct similarities with the US ethnographies. There is evidence to suggest a correspondence between the curriculum of the program, and the social relations of the lower sectors of the workplace.

Keywords: Community college students, Social conditions
Community colleges, Curricula
Postsecondary education, Political aspects
Evolution of integron-borne multidrug resistance in clinical and environmental Pseudomonas aeruginosa

Pseudomonas aeruginosa is a commonly isolated gram-negative bacterium, and a leading opportunistic human pathogen responsible for life threatening nosocomial infections in cystic fibrosis (CF) and immunocompromised patients. Since the early 1990s, P. aeruginosa outbreaks were associated with the emergence of class 1 integron-borne metallo beta-lactamases (MBLs). However, the relationship between integron structures and the bacterium's clonal structure retrained to be investigated. Using 136 clinical and environmental P. aeruginosa strains isolation from 13 countries and between years 1925-2006, we determined their antibiotic resistance phenotypes, class 1 integron sequences and MBL production. In general, our data suggested that the dissemination of MBLs is largely the result of horizontal transferring at the intergron level. This is further supported by the lack of correlation between antibiotic resistance phenotypes and MBL production to the P. aeruginosa clonal structure.
QDo: a quiescent state callback facility

In systems that only have short-lived threads, it is possible to define a Quiescent Point (QP(t)), relative to time t, as the earliest time after t where no thread exists that was alive at time t. Quiescent points have a number of uses, such as memory reclamation for lock free objects. QDo is a facility that allows clients to register their interest for QP(t). QDo then monitors and notifies interested parties when a quiescent point is established. We have designed, implemented and analyzed the performance of the QDo facility. QDo works by checking the number of active threads in the previous epoch per processor. When that number reaches zero, a local quiescent point is established. QDo then communicates with other processors to establish a global quiescent point. Our experiment shows that callback latency and overhead is highly dependent on how frequently the QDo facility monitors for quiescent point. Checking frequency of 10ms results in 2% overhead for SDET benchmark.
Optimization of RF HBTs in 0.35[mu]n silicon-germanium BiCMOS technology

Motivated by the fast-growing demand for analog RF ICs, SiGe-HBT has received wide attention due to its compatibility with existing Si BiCMOS processes. The objective of this thesis is to develop a systematic optimization strategy for the design of RF HBTs in 0.35μm SiGe BiCMOS process. The proposed strategy first targets the SiGe-epitaxy base design for high-speed performance. This is followed by the tailoring of collector profile to achieve a well-balanced DC/AC performance. The optimization of Asahi Kasei Microsystems' (AKM) SiGe-HBT in 0.35μm BiCMOS process is used as a case study to validate this optimization strategy. The combined DC/AC performance is comparable to previously published results for SiGe BiCMOS process. Nonetheless, this work is based on a conventional 0.35μm BiCMOS photolithography without advanced structural designs. Guided by this work, it is expected that the performance of a SiGe-HBT of any generic structure can be optimized to its maximum efficiency.