Data gathered by Mathematica Policy Research, Inc., contractor for the Department of Education were used to analyze successful project level characteristics of the Upward Bound program. Mathematica Policy Research, Inc. provided two data files for this study: a student data file and a grantees data file. The first data file includes information from a nationally representative sample of students who applied to the Upward Bound program between 1992 and 1994 and were assigned to either the Upward Bound group or a control group. The second data file included information from a random sample of Upward Bound project grantees. Both the student and grantees data files were used to create a design to determine Upward Bound project level characteristics that highly correlated to student success. The project level characteristics that were examined included project setting (location, size and host institution), academic characteristics (student-staff ratio, course offerings during the summer and academic year, and the number of years a project has been in operation) and student characteristics (gender, race/ethnicity and employment). The student success measures used in this study included grade point average, total high school credits earned, Advanced Placement credits earned, high school dropout status and graduation status. Findings from this study suggest that Upward Bound projects with lower student to staff ratios and fewer academic year course offerings have students earning more high school credits and more student graduating from high school. In addition to academic characteristics, ethnicity seem to be related to the success of projects. When compared across project settings, projects from two-year rural colleges and four-year public suburban colleges have the most successful students. / Ph. D.

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The fate of tritium in the environment is a target of interest in many studies. However reported concentrations of organically bound tritium (OBT) in soil are not well understood. In this study, a supplementary non-biological process of soil OBT activation in the environment was explored. The vicinity of SRB Technologies (Pembroke, Ontario) was chosen as the sampling location because of a significant airborne tritium release prior to 2001 which resulted in groundwater contamination. Soil cores were extracted from the ground near the tritium-releasing facility stack in 2017 and split into 10 cm subsamples for HTO/OBT, total carbon and hydrogen, particle size, thermogravimetric, radiocarbon and 3He mass spectrometry analyses. Observed HTO profiles revealed elevated tritium concentrations still retained in the soil. The results indicated that clay bound tritium masks the OBT signal and cannot be easily distinguished. Multiple short-term sample rinses with tritium-free water have little effect on clay bound water removal. Therefore, clay bound tritium should to be addressed in any future research related to soil OBT.

This research introduces a new value elicitation method for non-market valuation, referred to as the “quasi-double-bound (QDB)” method, applied to the case of barrierisland restoration in Mississippi. The objective of this thesis is to implement the QDB method in an actual stated-preference survey instrument and to test empirically whether the method elicits consistent responses and yields more efficient welfare estimates relative to the more-commonly used single-bound (SB) method. To test the QDB method, several models were estimated to derive a variety of welfare estimates for comparison to the estimates derived from the SB method. The QDB method introduced here results in a median willingness to pay (WTP) that was higher than the estimate of median WTP using the SB method in three of the five models estimated. The variances (i.e., confidence interval) of the QDB models were generally lower than those of the SB models.

Many of the immune effector functions of T-lymphocytes are mediated through cell-cell interactions involving membrane glycoproteins. During normal T-lymphocyte differentiation, many of these glycoproteins undergo changes in expression and structural modifications. To date, very little is known regarding altertions in the oligosaccharide groups of T-lymphocyte surface glycoproteins that accompany differentiation and maturation of these cells. For this purpose, a method for isolating glycoconjugates from the surface of intact cells was developed. This was achieved by treating acute lymphoblastic leukaemia cells of the AKR mouse with biotinylated concanavalin A (different degrees of biotinylation and a variety of biotinyl derivatives were examined), and retrieving the detergent solubilised biotinylated-Con A/glycoprotein complexes on immobilised stretavidin. From [<SUP>35</SUP>S]-methionine labelled cells, surface glycoproteins isolated by this procedure were analysed by two dimensional gel electrophoresis. This technique of 'indirect affinity chromatography' developed here with intact cells provides significant improvements for studying cell surface components compared to other methods which use isolated plasma membrane preparations. The indirect affinity chromatography procedure was also used to analyse the carbohydrate groups of the isolated Con A-binding glycoproteins labelled with [2-<SUP>3</SUP>H]-mannose, and resulted in the identification of a high mannose, endoglycosidase H sensitive oligosaccharide at the surface of the acute lymphoblastic leukaemia cells. The indirect affinity chromatography procedure was then applied in a comparative investigation of the difference between surface Con A-binding glycoproteins of quiescent and mitogen stimulated T-lymphpcytes. Using the two dimensional gel electrophoretic technique, changes in the expression of [<SUP>35</SUP>S]-methionine labelled Con A-binding glycoproteins were analysed. This sensitive technique allowed the detection of at least five major radiolabelled glycoproteins from stimulated T-lymphocytes that could not be detected in the profile of glycoproteins isolated from quiescent T-lymphocytes. The oligosaccharide groups of the Con A-binding, [2-<SUP>3</SUP>H]-mannose labelled glycoproteins isolated from quiescent and Con A-stimulated T-lymphocytes were compared. The predominant glycopeptide isolated from activated T-lymphocytes, using indirect affinity chromatography, was analysed by gel filtration following treatment with endo- and exoglycosidases and was shown to have a Man<SUB>5</SUB>G1cNAc<SUB>2</SUB>-structure. Since this oligosaccharide could not be isolated from the surface of quiescent T-lymphocytes the significance of its surface location in stimulated T-lymphocytes is discussed. This project shows that protein bound glycan patterns change with mitogenic activation of T-lymphocytes and strengthens the view that particular glycoproteins are differently glycosylated during stages of cellular development and these altered carbohydrate chains have different, specific functions. In an attempt to explain why Man<SUB>5</SUB>G1cNAc<SUB>2</SUB>- was synthesised by stimulated T-lymphocytes but not by quiescent T-lymphocytes, the enzyme G1cNAc-transferase I, for which this oligosaccharide is a substrate, was assayed in both types of cell. No conclusive answer was provided by this investigation, however, the hypothesis proposed in this dissertation, that changes in the activity of G1cNAc-transferase I with mitogenic stimulation result in the appearance of the Man<SUB>5</SUB>G1cNAc<SUB>2</SUB> oligosaccharide at the surface of Con A-stimulated T-lymphocytes, is discussed.

Le Problème de la Somme Coloration Minimum (MSCP) d'un graphe est un problème d'optimisation combinatoire dont l'objectif est de déterminer une coloration valide minimisant la somme des poids associés aux couleurs utilisées. Le nombre minimum de couleurs dans une solution optimale de MSCP est appelé la force du graphe, et la somme des poids des couleurs utilisées est appelée la somme chromatique du graphe. L'objectif de cette thèse a été d'étudier MSCP afin de proposer de nouvelles approches permettant sa résolution. La contribution de cette thèse est double. Premièrement, nous avons introduit deux nouvelles bornes supérieures de la force d'un graphe et une nouvelle borne inférieure de la somme chromatique, basées sur la notion de motif que nous avons adapté de la littérature. L'intérêt majeur de ces travaux est la réduction de l'espace des solutions de MSCP. Deuxièmement, nous avons proposé plusieurs approches de résolution exacte de MSCP. La première méthode consiste en une modélisation de MSCP en un formalisme MaxSAT partiel pondéré ou MinSAT partiel pondéré afin d'utiliser les solveurs MaxSAT/MinSAT de l'état de l'art pour résoudre MSCP. Nous avons montré que notre borne de la force du graphe permet de réduire grandement la taille des instances MaxSAT/MinSAT obtenues et de rendre les solveurs MaxSAT compétitifs pour résoudre MSCP. Les deux autres méthodes de résolution proposées sont des approches de type Branch-and-Bound appelées BBMSCP et 3LMSCP. La différence entre BBMSCP et 3LMSCP est que 3LMSCP exploite la partition du graphe en stables afin de ne pas considérer les colorations symétriques / The Minimum Sum Coloring Problem (MSCP) of a graph is an optimization problem whose the aim is to find a valid coloring such that the sum of weights associated to the used color is minimum. The minimum number of colors needed in an optimal solution is called the strength of the graph, and the sum of weights of the colors used in an optimal solution is called the chromatic sum of the graph. The aim of this thesis was to study the MSCP in order to propose new approaches for its resolution. The contribution of the thesis is twofold. First, we have introduced two upper bounds of the strength and one lower bound of the chromatic sum of a graph, based on a notion called motif adapted from the literature. These bounds allow to reduce significantly the search space of the MSCP. Second, we have proposed several exact resolution methods for the MSCP. The first method consists in modelling the MSCP to a weighted partial MaxSAT or a weighted partial MinSAT and solves the MSCP using state-of-the-art MaxSAT/MinSAT solvers. We have showed that our upper bound of the strength allows to improve substantially the MaxSAT/MinSAT encodings, and consequently, the MaxSAT solvers are competitive to solve the MSCP. The two other resolution methods are based on the Branch-and-Bound scheme and are called BBMSCP and 3LMSCP respectively. The difference between BBMSCP and 3LMSCP is that BBMSCP explores many symmetric colorings but 3LMSCP exploits the partitions of the graph into stables to avoid symmetric colorings

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 51-52). Also available in electronic version. Access restricted to campus users.

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