VictorJuiz/thesis huggingface dataset:
First measurement of (gg -> tt)/o(pp̄ -> tt)

The work presented here is the first measurement of the fraction of top quark pair production through gluon-gluon fusion. We use an integrated luminosity of 0.96 +/- 0.06 fb-1 of pp collisions at s of 1.96 TeV collected by the CDF II detector. We select t t candidates by identifying a high-pT lepton candidate, a large missing ET as evidence for a neutrino candidate and at least four high ET jets, one of which has to be identified as originating from a b quark. The challenge is to discriminate between the two production processes with the identical final state, gg rarr; t t and qq rarr; tt. We take advantage of the fact that compared to a quark, a gluon is more likely to radiate a low momentum gluon and therefore, one expects a larger number of charged particles with low pT in a process involving more gluons. Given the large uncertainties associated with the modeling of the low pT charged particle multiplicity, a data-driven technique was employed. Using calibration data samples, we show there exists a clear correlation between the observed average number of low pT charged particles and the average number of gluons involved in the production process predicted by Monte Carlo calculations. Given the correlation, one can identify low pT charged particle multiplicity distributions associated with specific average number of gluons. The W+0 jet sample and dijets sample with leading jet ET in the range of 80--100 GeV are used to find no-gluon and gluon-rich low pT charged particle multiplicity distributions, respectively. Using these no-gluon and gluon-rich distributions in a likelihood fit, we find the fraction of gluon-rich events in tt candidates. This fraction has contributions from the signal and background events. Taking into account these contributions and the gg rarr; tt and qq rarr; tt production channel acceptances, we find sigma(gg rarr; tt)/sigma(pp rarr; tt) = 0.07 +/- 0.14(stat) +/- 0.07(syst) in agreement with the theoretical predictions of 0.15 +/- 0.05. This measurement is a stepping stone towards a better understanding of the production mechanism of top quark pairs and implies that at least 67% of the tt events are consistent with q q production at 95% C.L, leaving little room for non SM processes which are not similar to the qq rarr; tt in their gluon radiation. The result confirms our current understanding of the SM high pT production mechanism and the relative gluon PDFs at relatively high Q 2 and x.
Synthesis and optical characterization of dielectric and hybrid spherical multilayer microspheres

In this project, three sets of spherical multilayer microspheres with radial modulation in the refractive index were synthesized: microspheres made of (1) alternating high-and low-refractive index polymers, (2) gold nanoparticles and polymers, and (3) polymeric layers containing semiconductor quantum dots in the core. In each case, a set of homogeneous particles with the same size and average refractive index were synthesized in order to extract the effect of the multilayered structure. In (1), it was found that the size and index of refraction more strongly influenced the extinction cross-section than did the multilayer character. In (2), the extinction characteristics of the hybrid structures were characterized, and the refractive index due to the addition of gold nanoparticles increased from 1.5 to 1.8. In (3), the photoluminescence changed between the homogeneous and multilayered structures, according to variation in the internal electric field caused by the radius and index of refraction.
Ascending auctions for markets with externalities and applications to routing in wireless networks

We encode a model of a wireless network with the general allocation model and develop an auction with a compact bidding space. Optimality results are supported by empirical results showing the mechanism finds good allocations and, relative to a VCG auction, generates higher auction revenues. This thesis addresses the problem of finding socially optimal routing allocations in wireless networks with selfish users. We model the problem as a resource allocation problem in a market with externalities. Finding an optimal solution to the underlying resource allocation problem requires solving a mathematical program with non-convex constraints which is difficult to approach using traditional distributed price-mediated allocation mechanisms. We consider centralized ascending auction mechanisms as robust allocation techniques. A general allocation model is developed which can be used to encode a wide variety of markets including markets with externalities. We show that an ascending auction over this model is approximately optimal given myopic bidding.
Synchronization to disturbed AC utility network signals in power electronics applications

This thesis presents a digital signal processing system for synchronization to AC utility network signals in power electronics applications. The proposed system is suitable in applications where the signal to which synchronization must be accomplished contains severe disturbances and where the signal frequency and the signal amplitude are variable. The system is based on a multirate phase-locked loop (PLL). The main advantages of the multirate approach are that it relaxes the implementation of the antialiasing filter and it enables one to accommodate the varying amplitude of the input signals. The antialiasing filter, which is in this case a high order bandpass filter, is implemented in the digital part of the system. This feature is achieved by applying the oversampling technique to the input signal. The antialiasing filter automatically adapts to the input signal frequency through the system's variable sample rate operation. The thesis deals with modeling, analysis, control and implementation issues of the proposed system. Nonlinear and linear state-space models and a transfer function model of the system are derived. The system's control aspects are discussed using the derived transfer function model. The system is implemented on a platform based on the Texas Instruments TMS320C31 floating point digital signal processor. Tracking properties of the implemented system are verified with realistic signals such as a sinusoidal signal containing notch type disturbance and noise and an arc furnace voltage signal.
Energy-containing nutritional supplements can affect usual energy intake postsupplementation in institutionalized seniors with probable Alzheimer's disease

The objective of this thesis was to assess the impact of a three-week, mid-morning nutritional supplement intervention on energy intake as assessed by investigator-weighed food intake in the week following supplement termination and to investigate the impact of body mass index (BMI), as well as, cognitive and behavioural assessments on this response by performing a secondary analysis of a randomized, crossover, nonblinded clinical trial. Thirty institutionalized seniors with probable Alzheimer's disease who ate independently underwent analysis. Individuals who responded very successfully to supplementation (n = 16) as shown by increases in daily energy intake were likely to maintain 58.8% of that increase post-supplementation. However, removal of the supplement was associated with decreased self-selected energy intake in low-BMI individuals who reduced their daily intakes during supplementation. Cognitive/behavioral tests were not significant predictors of postsupplement intake. Disease-specific disturbances to the cognitive and physiological control of feeding may be involved.
Protection of famous trade-marks in Canada

While the recent Supreme Court of Canada decision in Veuve Clicquot Ponsardin v. Boutiques Cliquot Ltée. purports to extend special protection to famous marks in appropriate circumstances, a closer analysis shows that the Court's reasoning merely confirms the general tendency to interpret s.22 of the Canadian Trade-marks Act to offer no more protection than is already available under a traditional, consumer-confusion analysis. However, much as is true in decisions concerning the U.S. famous marks legislation, courts have often found in favour of plaintiffs under s.22 claims where courts have perceived defendants to have committed free-riding with respect to the plaintiffs' marks. This impulse to sanction free-riding, even despite the absence of consumer confusion as to the source of the good or service at issue, does not fall within the traditional ambit of trade-mark protection, but the desire to censure dishonest commercial practices should be followed in a duly limited manner.
Tagfilter :a power-aware tag hierarchy for high-level caches

This thesis proposes and evaluates Tagfilter, a novel power-aware cache hierarchy, coupled with an alternate cache indexing scheme, as a means for reducing power dissipation in high-level caches by filtering out unnecessary accesses. As high-level caches get larger and increase in associativity, they will inevitably consume sizable amounts of power. Interposed between the L1 and the L2 tag arrays, Tagfilter is a small, cache-like structure that caches a small number of recently accessed L2 tag sets, and filters out unnecessary tag array accesses that would otherwise waste considerable power in the L2 tag array. The Tagfilter exploits the tag-set locality existing in typical L2 access patterns. We also propose an alternate cache indexing scheme, which increases Tagfilter's efficiency (filter rate) by increasing tag-set locality. The Tagfilter results in reduced power because it reduces accesses to the much more power-demanding L2 tag array. Power savings by the Tagfilter are evaluated using the SPEC CPU2000 benchmarks running on SimpleScalar V3.0, a software processor model. The modified Wattch power models are used. On average, the Tagfilter reduces the power dissipation in the L2 tag array by 43% for the writeback L1 data cache and by 85% for the writethrough L1 data cache.
Natural regeneration and stand dynamics in a managed pine-oak forest in the Sierra Madre Occidental, Mexico

The pine-oak forests of Mexico's Sierra Madre Occidental have been subjected to industrial logging for less than 50 years. They retain many pre-European settlement characteristics, including uneven-aged stand structures and surface fires. However, logging is increasingly intensive, and the forests may be on the cusp of permanent change. The goals of this thesis were to (1) explore environmental and logging effects on regeneration dynamics and stand structures in a managed Madrean forest, and (2) assess these effects in relationship to Forest Stewardship Council (FSC) certification principles for the management of natural forests. Natural regeneration dynamics were explored in relationship to logging and environmental influences. Microsite affinities of seedlings and spatial relationships between mature oak and pine trees were investigated under different fire regimes. Finally, the effects of logging on stand structure trajectories was modelled under a variety of fire regimes. Environmental factors, particularly evidence of fire, accounted for four times more variation in species composition and abundance than year of harvest. Steep topography, mineral soil exposure, the occurrence of surface stones and widespread evidence of fire were associated with regeneration of fire-adapted pine species. Oaks and shade tolerant pines were associated with fine-textured soils, deep litter layers and extensive crown cover. Patches of fire-resistant pine seedlings were associated with spatially heterogeneous mineral soil and surface stone microsites in frequent fire stands. In contrast, oaks had weaker associations with deep litter and shade, and tended to be distributed randomly. Different diameter classes of adult pines were spatially dissociated in frequent fire stands, but clustered or distributed at random in stands with longer fire-free intervals. Longer fire-free intervals may also foster the formation of near-monospecific tree neighbourhoods. Many larger diameter trees are cut during logging. Residual diameter distributions are therefore skewed towards smaller diameter classes. However, models suggested that trees would grow into the larger diameter classes and forest productivity would be maintained under an intermediate (15 year) fire regime. Overall, while natural processes continue and natural regeneration was abundant on most sites, high grading and plans for fire suppression may impede any attempt to certify this community owned forest.
The effectiveness of chlorhexidine gluconate as an intracanal medication in endodontics: an in vivo microbiological study

This study assessed the effectiveness of 2% chlorhexidine (CHX) liquid as an intracanal medication in teeth with apical periodontitis. Culture method (CM) and epifluorescence microscopy (EM) were used. Twenty-two teeth were treated. At the conclusion of the first appointment, canals were medicated with CHX. Bacteriological samples were obtained before (1A) and after (1B) instrumentation at the first appointment, and at the beginning (2A) and at the end (2B; n = 11) of the second appointment. Bacteria were abundant in all 1A samples. A highly significant decrease in bacterial counts was shown with CM and EM between 1A and 1B samples (Paired t-tests, p
Re-evaluating the proposed lectin properties of IL-2 for high mannose ligands, and crystallographic studies of IL-2 molecules

IL-2 has been previously proposed to possess lectin properties. The proposed carbohydrate binding specificity is for high mannose sugars. This lectin property has been postulated to play a role in several critical functions. Using various assays, the work in this thesis has unequivocally shown that IL-2 does not possess a lectin specificity for these sugars. Several possibilities for the discrepancy between the results in this thesis and other studies are discussed. The work in this thesis also includes the determination of two crystal structures. One crystal structure is of human IL-2 and represents the highest resolution structure of this molecule to date. A crystal structure of more modest resolution is also presented of a human-mouse chimera of IL-2. Interestingly, Asp 20 (human numbering), known to be critical in receptor binding, is involved in co-coordinating zinc in both these structures. Several possible roles for the binding of zinc are discussed.
Building bridges: the nature and implications of student-teacher relations in a Canadian urban high school

In this thesis Evelyn Paris poses the question: what are the nature and implications of student-teacher relations in a Canadian urban high school where students are predominantly from low income, cultural minority backgrounds, and teachers are predominantly white and middle class? She seeks to answer this question by using a narrative inquiry approach, beginning with her own experiences of student-teacher connections in a relatively homogenous high school setting in the late 1980s, and juxtaposing this reality with the experiences of eight current students who attend the same Canadian high school. Paris suggests that positive, pro-social student-teacher relations are a key element to urban students' academic success, and that there are salient teacher traits that distinguish teachers who are able to "connect" with their students making them effective urban school educators. She concludes by suggesting that a more holistic approach to teacher-training be adopted in order to better prepare new teachers for the unique and often challenging experiences involved in teaching in Canadian urban high schools today.

Keywords: Urban high schools, Ontario
Teenagers with social disabilities, Education
Teenagers with social disabilities, Ontario
Teacher-student relationships, Ontario
High school students, Attitudes
High school students, Ontario
Maintenance and repair contracts: Modeling and optimization

Maintenance and Repair Contracts (MARCs) on equipment have become standard practice in the mining industry. This work suggests a method of optimizing maintenance decisions in the framework of non-trivial interrelations between parties negotiating terms of a contract. A Game-Theoretic modeling approach is suggested to describe relations between companies involved in negotiation of a MARC. Approaches to analyses necessary for rational cooperative and non-cooperative decision making from points of view of both players (mining company and contractor) are proposed. Solutions to bargaining problems in cases of Transferable and Non-Transferable Utilities are considered for cooperative opponents. The theoretical setting proposed in this thesis has been applied to a real MARC provided by a senior gold mining corporation. Modeling steps and solution concepts are included and explained. Possibilities of improvement of current values of terms of the contract are discussed.
The isolation, fractionation, and purification of soyasaponins and the evaluation of their colon anti-carcinogenic activity

Saponins are bioactive compounds found in many plant materials, including legumes. The objectives of the present work were to isolate, fractionate, and purify saponins from soybeans, known as soyasaponins; to determine their potential in vitro colon anti-carcinogenic activity; and to establish a structure-activity relationship. The purified soyasaponins were tested for their ability to suppress the growth of HT-29 colon cancer cells. The most potent compounds were the aglycones, soyasapogenol A and B, which demonstrated a dose dependent and statistically significant suppression of cell growth. The glycosides, soyasaponin A 1, soyasaponin A2, soyasaponin I, soyasaponin III, soyasapogenol B monoglucuronide, group B soyasaponins and deacetylated and acetylated group A fractions, on the other hand were largely inactive. These results suggest a structure-activity relationship: the polar glycosides are inactive while the lipophilic sapogenins are bioactive. Furthermore, in vitro fermentation experiments indicated that colonic microflora readily converted the soyasaponins to the aglycone form. These observations, taken together, suggest that the soyasaponins, after alteration by microflora, may be potential chemopreventive agents against colon cancer. To investigate the role of colonic microflora, soyasaponins were incubated under anaerobic conditions with human microflora. The soyasaponins were converted to soyasapogenol A and soyasapogenol B. Because of the absence of commercially available purified soyasaponins, researchers have always had to isolate the soyasaponins themselves, limiting research on their bioactivity. The methods developed here exploited simple and inexpensive technologies, hopefully encouraging more research interest. Isolation of soyasaponins was achieved using precipitation with ammonium sulphate, solid phase extraction and reverse phase low pressure liquid chromatography. Toxic solvents typically used in saponin chemistry, chloroform, acetonitrile and butanol, were avoided and instead ethanol, methanol and acetone were used. An analytical method named direct densitometry was developed, validated, and used, along with thin layer chromatography to routinely quantitate and evaluate the purity of isolated soyasaponins. Four soyasaponin mixtures, free of non-saponin contaminants were isolated: acetylated and deacetylated group A soyasaponins, group B soyasaponins, and a soyasaponin A2-rich fraction. Six soyasaponins, purified to greater than 80% one compound, were isolated: soyasaponin A 1, soyasaponin I, soyasaponin III, soyasapogenol B monoglucuronide, soyasapogenol A and soyasapogenol B. The identity of each of these fractions was confirmed by NMR spectroscopy.
A novel developmental arrest in Caenorhabditis elegans induced by the volatile chemical diacetyl

Some organisms are able to arrest their development in response to adverse environmental factors. C. elegans has two known types of developmental arrest, the larval 1 (L1) arrest and dauer formation. We discovered that C. elegans, in the L1 stage, stop moving and stop growing for a period of time after being exposed to undiluted diacetyl. Here we investigate the neuronal and molecular mechanisms involved in this novel developmental arrest. Exposure to 4 mul of diacetyl revealed that the arrest is mediated by the AWA neurons and by neuron(s) affected by the osm-3 mutation. Entry into the arrest is inhibited by signaling from the guanylyl cyclase ODR-1 and the TRPV-channel subunit OCR-2. The AWC neurons and OCR-2 signaling are involved in inducing recovery from the arrest. The ASE and AWB neurons and signaling from the OSM-9 TRPV-related channel subunit contribute to the recovery at higher volumes of diacetyl. Studying the diacetyl-induced L1 developmental arrest displays how chemosensory genes are recruited by a variety of signaling pathways.
The problem of therapeutic action in child psychoanalysis: what to do, how to be, why it works

In child psychoanalysis there are at least three persuasive theories of therapeutic intervention, but because there is no consensus on what theory is most trustworthy, the therapist is confronted with a problem. The problem of how to intervene with a child dovetails with the puzzle of how children learn and change in psychotherapy. If therapists knew precisely how children change this could potentially indicate what intervention to use. But, as there is no consensus on how children change in the therapeutic process, confusion remains about what interventions should be used and those that should be discarded. In the psychoanalytic literature, this dilemma is known as the problem of therapeutic action. This study considers therapeutic action the principal problem therapists face as they learn to practice. Three theories of therapeutic action—interpretation, the therapeutic relationship, and play—have been forged by other workers in this field to create boundary and shape to the problem, making it more approachable for the learner. The problem with the existing literature is that it limits its method of investigation to theoretical constructions and clinical examples. What is missing from this field of literature is a comparison of personal accounts of how one learns this profession, given the problem I have introduced. Few psychoanalytic researchers have considered the interview a method that can potentially reveal new findings about old problems. The personally revealing narration of one's experience of learning how to practice child psychotherapy can potentially expose more about the development of understanding that is often hidden in the well-organized theory and accompanying, cleanly edited example. Therefore, I have gathered accounts from three child therapists that will narrate the course of their personal and professional development in this context. Therapists' stories of learning to practice can potentially contribute much to the existing body of literature on the educational problem of learning to be a therapist. Additionally, developmental stories can serve as reflective mirrors for beginning and experienced therapists to observe themselves in, encouraging self-reflective practice that has the potential to enrich this practice.