Homologous recombination is the primary DNA repair pathway in bacteria and it is immensely important in repairing DNA double strand breaks. Components of the homologous recombination pathway have been well conserved throughout evolution as an essential part of cell survival. Homologous recombination plays an important role in cellular processes like DNA repair as well as exchange of genetic information through chromosomal crossover. During homologous recombination, DNA strand exchange leads to formation of a heteroduplex joint between the invading and displaced DNA strands. This hetereoduplex joint is called a Holliday Junction. Resolution of the Holliday Junction proceeds via one of two pathways. In the presence of RuvC and/or RecG, Holliday Junction resolution proceeds via a cut and paste pathway where the invading DNA strand replaces a region of homologous DNA on the target DNA. In the absence of RuvC and RecG, Holliday Junction resolution takes place via a copy and paste pathway during which DNA synthesis needs to be primed at Holliday Junction intermediates formed during strand invasion. In an effort to separate this myriad of different requirements, I have attempted to develop a novel ends-in recombination assay system using E. coli as a model organism. This ends-in system would allow recombinant molecule formation by DNA synthesis of approximately 200 to 2000 bp size interval between the two converging ends of an invading linear dsDNA substrate oriented just like the greek letter Ù, but with the arms pointing inwards. In this study, a number of linear dsDNA assay templates were constructed and analyzed. All the constructs had two arms of homology to the chromosome pointing inwards i.e. in the ends-in orientation. Using this ends-in system, it was demonstrated that the presence of chi (Crossover Hotspot Initiator) sites was an important requirement for ends-in recombination in wild type E. coli cells. Our studies also showed that ends-in homologous recombination did not occur if chi sites were placed at or very near to the ends of the incoming linear dsDNA molecule, suggesting that the chi site recognition is efficient only if the incoming dsDNA has chi sites internal to the ends. Moreover, it was shown that neither RuvC nor RecG were required for successful recombinant product formation using the ends-in assay. This finding reinforces previous observations that suggest the idea that Holliday Junctions can be resolved independent of both RuvC and RecG.

Arousal-biased competition (ABC; Mather & Sutherland, 2011) theory predicts that emotional arousal increases both the activation of relevant items and the suppression of irrelevant items in working memory. Study 1 tested ABC theory’s prediction in young and older adults. Suppression was measured with the Healey et al. (2010) paradigm and arousal was manipulated during interference resolution. Item accessibility was measured by comparing naming times of target and competitor words to baseline naming times. Young adults showed suppression of competitors while older adults did not. Arousal did not affect young adults’ naming times, but a mild suppression effect was seen in older adults whose arousal increased after the manipulation. A follow-up study showed that older and younger adults generally agreed on the arousing quality of the stimuli in Study 1. These studies partially support ABC theory and suggest that older adults may retain the ability to suppress irrelevant information when aroused.

<p>State practice and literature suggest that devolution of power can address the main challenges of underdevelopment, internal conflict and abuse of centralised power in developing states. However, this thesis advances the argument that the design features of devolved government for these purposes are not always compatible. Accordingly, while there are complementary and neutral design features in the three designs, trade-offs have to be made between the unique design features in order to ensure the effective pursuit of the three purposes through a single system of devolved government. Kenya, the case study for this inquiry, confirms the international trend as its major challenges over the last 50 years have been underdevelopment, internal conflict and abuse of central power. As such, development, ethnic harmony, and the limiting of central power featured prominently throughout the entire constitutional review process as purposes to be pursued by means of devolution of power. To this end, the devolution of state power is one of the central elements of the current constitutional dispensation in Kenya. There are trade-offs made in Kenya‟s devolution design in order to accommodate the three purposes of devolution. However, the overall result has been that the emphasis falls on development at the expense of conflict resolution and limiting central power. Nevertheless, regardless of the trade-offs and nature of the final design, the design‟s effectiveness or lack thereof may depend very much on factors external to the design. Lack of political will to make devolution work can negate the effectiveness of even the most perfect design / by same token, political will could make an apparently bad design effective. In practice, therefore, effectiveness depends on an array of other context-specific factors.</p>

Despite wide acceptance of the stereotype that women apologize more readily than men, there is little systematic evidence to support this stereotype or its supposed bases. In the present research, I explored whether gender differences in apology behaviour occur and, if so, why they occur. In Study 1, I used daily diaries to assess everyday apologies and found that women indeed apologized more frequently than men did. I found no difference in the proportion of offenses for which men and women apologized, however, suggesting that women may apologize more often than men do because they have a lower threshold for what constitutes offensive behaviour. In Studies 2 and 5, I replicated a gender difference in apology behaviour using hypothetical offenses and obtained evidence that this difference is mediated by different judgments of offense severity. In Study 3, I adapted a signal detection paradigm and demonstrated that women exhibit a more liberal response bias in the direction of remembering an apology. In Study 4, I found that women and men similarly associate apologies with positive outcomes, and that only women endorse the stereotype that women apologize more often than men do. Finally, in Study 6, I conducted a daily diary study with romantic couples and found that, as in Study 1, women and men apologized for a similar proportion of the offenses they reported. Together, these studies suggest that a gender difference in apology frequency is caused by different judgments of severity rather than by a difference in willingness to apologize.

Homologous recombination is the primary DNA repair pathway in bacteria and it is immensely important in repairing DNA double strand breaks. Components of the homologous recombination pathway have been well conserved throughout evolution as an essential part of cell survival. Homologous recombination plays an important role in cellular processes like DNA repair as well as exchange of genetic information through chromosomal crossover. During homologous recombination, DNA strand exchange leads to formation of a heteroduplex joint between the invading and displaced DNA strands. This hetereoduplex joint is called a Holliday Junction. Resolution of the Holliday Junction proceeds via one of two pathways. In the presence of RuvC and/or RecG, Holliday Junction resolution proceeds via a cut and paste pathway where the invading DNA strand replaces a region of homologous DNA on the target DNA. In the absence of RuvC and RecG, Holliday Junction resolution takes place via a copy and paste pathway during which DNA synthesis needs to be primed at Holliday Junction intermediates formed during strand invasion. In an effort to separate this myriad of different requirements, I have attempted to develop a novel ends-in recombination assay system using E. coli as a model organism. This ends-in system would allow recombinant molecule formation by DNA synthesis of approximately 200 to 2000 bp size interval between the two converging ends of an invading linear dsDNA substrate oriented just like the greek letter Ù, but with the arms pointing inwards. In this study, a number of linear dsDNA assay templates were constructed and analyzed. All the constructs had two arms of homology to the chromosome pointing inwards i.e. in the ends-in orientation. Using this ends-in system, it was demonstrated that the presence of chi (Crossover Hotspot Initiator) sites was an important requirement for ends-in recombination in wild type E. coli cells. Our studies also showed that ends-in homologous recombination did not occur if chi sites were placed at or very near to the ends of the incoming linear dsDNA molecule, suggesting that the chi site recognition is efficient only if the incoming dsDNA has chi sites internal to the ends. Moreover, it was shown that neither RuvC nor RecG were required for successful recombinant product formation using the ends-in assay. This finding reinforces previous observations that suggest the idea that Holliday Junctions can be resolved independent of both RuvC and RecG.

Synthetic aperture sonar (SAS) is the underwater acoustic counterpart to stripmap-mode synthetic aperture radar (SAR). Current seagoing SAS systems are deployed on unmanned robotic vechicles, commonly referred to as autonomous underwater vehicles (AUVs). As with SAR, SAS imaging is ideally done with a straight-line collection trajectory. However, SAS is far more susceptible to image degradation caused by the actual sensor trajectory deviating from a pefectly straight line. Unwanted motion is virtually unavoidable in the sea due to the influence of currents and wave action. In order to construct a perfectly-focused SAS image the motion must either be constrained to within one-eighth of a wavelength over the synthetic aperture, or it must be measured with the same degree of accuracy and then accounted for in the processing software. Since the former is not possible, the latter approach must be taken. The technique known as redundant phase centers (RPC) has proven to be insrumental in solving the problem of SAS motion compensation. In essence, RPC simply refers to the practice of overlapping a portion of the receiver array from one ping (transmission and reception) to the next. The signals observed by this overlapping portion will be identical except for a time shift proportional to the relative motion between pings. The time shifts observed by the RPC channels of the receiver array are scalars representing the projection of the array receiver locations onto the image slant plane, and these time shifts can be used to compensate for the unwanted platform motion. This thesis presents several extensions to the standard RPC technique in which the RPC time delays are combined with the AUV's on-board navigation data. The scalar time delays are decomposed into the components induced by the six degrees of freedom of the motion: i.e., the linear and angular velocities. Thus, the time delays observed in the image slant plane can be used to refine the motion estimate in an absolute frame of reference external to the AUV. Creating a high-resolution SAS image of the sea floor in an automatic fashion demands accurate and robust motion estimation. The performance of the motion estimation schemes presented is demonstrated using actual field data collected from an assortment of current research SAS systems.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 166-167). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 110-113). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of California, San Diego, 2001. / Vita. Includes bibliographical references (leaves 443-454).

Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 182-188).