This thesis examines leaders‘ behaviours differential effects on the work/home balance of their followers through a leader/follower fit perspective. The study explores perceived effects of leader‘s actions on followers‘ work/home balance in a Lebanese context. At the individual/dyad level, this research attempts to integrate these two areas of study. It aims to better understand, Lebanese employees‘ perspectives on the Lebanese leaders‘ practice of leadership in the banking industry and the perceived effect of this practice on the followers‘ work and home boundary management. Based on the adoption of a qualitative exploratory approach, the author conducts thirty semi-structured interviews with five leaders and twenty-five followers in different regions and divisions of the XYZ bank. The dissertation makes several theoretical and empirical contributions. First, boundary theory is empirically extended through the identification of one of the antecedents, i.e., polychronicity, of an individual‘s work/home segmentation/integration preference. Second, boundary theory is developed through the exploration of the Lebanese leaders‘ actions‘ impact on the followers‘ management of their work/home boundaries. Third, the literature on fit between the leader and the follower along different dimensions of interest to them is extended and developed. Fourth, the literature on the Middle East and in Lebanon on specific is enhanced. The implications of the Lebanese context, subject of this study, on the leadership and work/home literature are meaningful. In addition to these contributions, this study helps to surface ―actionable knowledge‖ on how to facilitate an employee‘s struggle to reach a harmony between his work and home life. This search for balance is increasingly sought nowadays as a result of the increase in work-related pressures especially for dual-earners.

We have engineered a mutant of HIV Reverse Transcriptase that can be fluorescently labeled by covalent attachment of the environmentally sensitive fluorophore 7-diethylamino-3-((((2-maleimidyl)ethyl)amino)carbonyl)coumarin (MDCC). The result is a polymerase that is kinetically indistinguishable from the wild-type enzyme, but provides a signal to monitor changes in enzyme structure that result from conformational changes induced by substrate binding. Using this system, we have expanded the kinetic model governing nucleotide binding to include an enzymatic isomerization following initial nucleotide binding. In doing so, we define the role of induced-fit in nucleotide specificity and mismatch discrimination. Additionally, we have characterized the kinetics governing the specificity and discrimination of several widely administered Nucleotide Reverse Transcriptase Inhibitors (NRTI’s) used to combat HIV infection including 3TC (Lamivudine), FTC (Emtricitabine), and AZT (Zidovudine) for the wild-type polymerase and mutants with clinical resistance to these compounds. Our findings resolve the apparent tighter binding of these inhibitor compounds compared to the correct nucleotide by showing that the affinity for the correct nucleotide is stronger than the inhibitors. The apparent weaker binding of the correct nucleotide is a result of a incomplete interpretation of binding data that fails to account for the importance of the reverse rate of the conformational change. The apparent Kd (Kd,app) measurements for correct nucleotide estimates Km rather than Kd because nucleotide binding does not reach equilibrium. The conformationally sensitive enzyme has also been used to characterize the kinetics governing DNA association. We show that DNA binding is governed by a two-step process where a fast initial association is followed by a second, slow isomerization that is off the pathway for nucleotide binding and incorporation. Finally, we have implemented single molecule techniques using fluorophore labeled nucleotides to study the effects of AZT incorporation on the DNA translocation dynamics of the polymerase. We find that primer termination with AZT results in DNA that fails to translocate, therefore occluding the next nucleotide from binding. This shift in translocation equilibrium exposes the newly formed phosphodiester bond to ATP- or pyrophosphate-mediated AZT excision; thereby rescuing productive polymerization. This finding represents the first kinetic measurement of DNA translocation by a polymerase. / text

This thesis used FIT Science (Fletcher & Stead, 2000) as a framework to study different aspects of family functioning. FIT variables measure the cognitive and behavioural characteristics of a person that mediate interpretations of events and attempts at coping with constraints. The research sought to examine whether scores on FIT variables explain differences in perceptions of family functioning and outcomes such as individual stress levels. In the first questionnaire study, members of the general population (N=235) completed The FIT Profiler (Fletcher, 1999), which measures scores on FIT variables, and the Family Assessment Device (Epstein, Baldwin & Bishop, 1983), which measures family functioning across six dimensions. The study found that higher scores on FIT variables were associated with more positive experiences of the family. A similar pattern of results was observed in study two involving participants (N=52) with Autistic Spectrum Conditions (ASCs). The results of the studies suggested that FIT Science is a useful framework to study family functioning in diverse contexts. Study three compared the stress and perceptions of family functioning of mothers of typically developing children (n=55), and children with ASCs (n=33). Mothers scoring high on FIT variables had better perceptions of family functioning, were less anxious and depressed, and also coped better with the demands of parenting. Studies four and five explored whether FIT Science also offers a useful framework for promoting changes in family functioning and individual well being. Study four reported a randomized control trial of a FIT-­‐Do Something Different (FIT-­‐DSD) intervention, which was administered to mothers (n=13) of children with ASCs. The FIT-­‐DSD intervention aimed at expanding behavioural flexibility and disrupting constraining habits. Study five reported a qualitative follow-­‐up of the intervention group in study four. 17 The results of studies four and five suggested that the FIT-­‐DSD intervention was a useful and novel tool to help mothers across a number of domains of family life. Relative to a wait-­‐list control group (n=11), the intervention group reported moderate to large improvements in their levels of parenting stress, depression, relationship satisfaction and scores on the cognitive FIT variable Self-­‐responsibility. Qualitative investigation also suggested that the intervention helped mothers develop feelings of control, self-­‐esteem and self-­‐efficacy. The thesis suggests that FIT Science offers a fruitful framework with which to study and intervene with family functioning. Further research seeking to explore the use of FIT Science as a vehicle for family change is recommended. This may help promote better physical and psychological health for individuals struggling with their environmental and self-­‐generated constraints.

Recent work has shown that the regulatory fit between global approach/avoidance goals and the local approach/avoidance mechanisms of goal pursuit influence cognition and behavior in predictable ways. A regulatory fit leads to an increase in motivation and engagement relative to a regulatory mismatch. The increase in engagement can lead to an increase in cognitive flexibility on cognitively demanding tasks. This work is composed of three inter-related studies that examine how the fit between global performance incentives and local mechanisms of goal pursuit influence decision-making and categorization. In Study 1 I examine how the interaction between global performance incentives and local goal pursuit mechanisms influences decision-making strategies in an experience-based decision-making paradigm. In this paradigm decision-making strategies can be classified as more exploratory or more exploitative. I find that participants in a regulatory fit would exhibit more exploratory decision-making patterns than participants in a regulatory mismatch. In Study 2 I examine how social pressure is related to approach and avoidance-based performance incentives using two types of category-learning tasks. I test the hypothesis that increasing performance pressure will induce an avoidance-based prevention focus which then interacts with the local mechanism of goal pursuit employed in the task (maximizing points gained or minimizing points lost). Participants either perform an explicit, rule-based category-learning task, or an implicit information-integration category-learning task. Behavioral and model-based analyses support the hypothesis that social pressure induces a prevention focus. When the pressure-induced prevention focus aligns with the local goal-pursuit mechanism participants perform better on the rule-based task, but worse on the information-integration task. Study 3 examines the effects of social pressure on categorization in highly-trained participants. Participants performed over 2500 training trials of either a rule-based or an information-integration category-learning task, and then performed another 640 trials after half received a manipulation designed to raise social pressure. Performance was worse on both the rule-based and information-integration task for participants who were under high social pressure compared to participants under low social pressure. The results from all three projects suggest that motivational incentives have a large effect on cognitively demanding tasks. / text

published_or_final_version / Statistics and Actuarial Science / Master / Master of Philosophy

The purpose of this study was to examine the effectiveness of combining implementation intentions (II) and regulatory fit in the context of two important health goals: increasing leisure time physical activity and decreasing leisure time sedentary behaviour. Implementation intentions specify exactly how, when, and where a behaviour will occur and can be an effective method of increasing goal enactment. Regulatory fit occurs when a goal or strategy used to achieve the goal matches an individual’s regulatory orientation. University students (N = 180) were randomly assigned to a goal (increase activity/decrease screen time) and an experimental condition (II/non-II). Participants formed a goal to increase their physical activity or decrease their screen time over the following four weeks according to their random assignment. Participants’ commitment to their goal was monitored over the course of the study. The II group also formed a detailed plan regarding how they would accomplish their goal. Regulatory fit was determined based on group assignment and score on the regulatory focus questionnaire. Physical activity and screen time were assessed with self-report questionnaires. Follow-up occurred online four weeks after baseline. Data were analyzed separately by goal type using linear regressions to examine the effects of regulatory fit, experimental condition, and goal commitment on the behaviour variables. The regulatory fit manipulation was not successful. Among those with the physical activity goal, no significant effects emerged for the experimental variables. Among those with the screen time goal and in the fit, II group, stronger goal commitment tended to be associated with increased participation in moderate physical activity, β = .17, t(22) = .94, p = .36. Also, participants who set II for the screen time goal and were committed to this goal tended to report less screen time than participants with lower goal commitment (β = -.40, t(69) = -2.05, p = .05). Findings provide preliminary insight into the effectiveness of II and the importance of goal commitment in interventions aiming to reduce sedentary behaviour. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2010-07-02 11:32:18.716

No description available.

In a meta-analysis of articles employing clustering methods, we find that little attention is paid to remaining within-cluster heterogeneity and that average values are relatively high. We suggest addressing this potentially problematic "dark side" of cluster analysis by providing two coefficients as standard information in any cluster analysis findings: a goodness-of-fit measure and a measure which relates explained variation of analysed empirical data to explained variation of simulated random data. The second coefficient is referred to as the Index of Clustering Appropriateness (ICA). Finally, we develop a classification scheme depicting acceptable levels of remaining within-cluster heterogeneity. (authors' abstract)

RNase P is a ubiquitous ribonuclease responsible for removing the 5’ leader of tRNA precursor. Bacterial RNase P contains one RNA (RPR) and one protein (RPP) subunit. However, the number of protein variants depends on the origin. The RNA subunit is the catalytic subunit that in vitro cleaves its substrate with and without the protein subunit. Therefore RNase P is a ribozyme. However, the protein subunit is indispensable in vivo. The objective of this thesis was to understand the mechanism of and substrate interaction in RPR-mediated cleavage, in particular the contributions of the two domains of RPR and the roles of the base at the -1 residue in the substrate. As model systems I have used bacterial (Eco) and archaeal (Pfu) RPRs. The TSL (T-stem-loop) region of a tRNA precursor and the TBS (TSL-binding site) in the RPR S-domain interact upon RPR-substrate complex conformation. A productive TSL/TBS-interaction affects events at the cleavage site by influencing the positioning of chemical groups and/ or Mg2+ such that efficient and correct cleavage occurs consistent with an induced fit mechanism. With respect to events at the cleavage site, my data show that the identity of the residue immediately upstream the 5’ of the cleavage site (at -1) plays a significant role for efficient and accurate cleavage although its presence is not essential. My data also show that the RPR C-domain can cleave without the S-domain. However, the presence of the S-domain increases the efficiency of cleavage but lowers the accuracy. The structure of the S-domain of Pfu RPR differs from that of Eco RPR and my data suggest that the Pfu S-domain does not affect the accuracy in the same way as for Eco RPR. It also appears that the proteins that bind to the Pfu S-domain play a role in formation of a productive TSL/TBS-interaction. It is therefore possible that the proteins of Pfu RNase P have evolved to take over the role of the S-domain with respect to the interaction with the TSL-region of the substrate.

abstract: Graph coloring is about allocating resources that can be shared except where there are certain pairwise conflicts between recipients. The simplest coloring algorithm that attempts to conserve resources is called first fit. Interval graphs are used in models for scheduling (in computer science and operations research) and in biochemistry for one-dimensional molecules such as genetic material. It is not known precisely how much waste in the worst case is due to the first-fit algorithm for coloring interval graphs. However, after decades of research the range is narrow. Kierstead proved that the performance ratio R is at most 40. Pemmaraju, Raman, and Varadarajan proved that R is at most 10. This can be improved to 8. Witsenhausen, and independently Chrobak and Slusarek, proved that R is at least 4. Slusarek improved this to 4.45. Kierstead and Trotter extended the method of Chrobak and Slusarek to one good for a lower bound of 4.99999 or so. The method relies on number sequences with a certain property of order. It is shown here that each sequence considered in the construction satisfies a linear recurrence; that R is at least 5; that the Fibonacci sequence is in some sense minimally useless for the construction; and that the Fibonacci sequence is a point of accumulation in some space for the useful sequences of the construction. Limitations of all earlier constructions are revealed. / Dissertation/Thesis / Ph.D. Mathematics 2010