In support of educational equity, the White Paper 6 (Department of Education, 2001) states that every learner in South Africa has the right to pursue their learning potential to the best of their ability. The South African Schools Act of 1996 states that a school’s language policy may not exclude learners from different backgrounds. As a result, many English second language (L2) learners struggle to understand the learning material and perform poorly academically. Poor literacy and reading skills have been identified in the literature (for example Pretorius, 2005) as a significant cause for poor academic performance. In an endeavour to work within the Outcomes Based Education (OBE) system, teachers are increasingly seeking ways to improve group learning. These factors motivated the present study and a paired reading intervention was selected and administered to Grade 9 English second language learners. Volunteer participants consisted of an Experimental Group (n 53) and a Comparison Group (n 53). Each group was divided into strong (mentor) and weak (mentee) readers. Pre-tests and post-tests were conducted regarding the Experimental and Comparison Group’s scores on the Vocabulary and Comprehension subtests of the Stanford Reading Diagnostic Test (SDRT): Brown Level and the Academic Performance of both groups were recorded at pre and post-test phases. After an 11 week intervention programme a statistical analysis of the results was conducted. The overall means for the groups were analysed using t-tests to establish any significant differences between the pre-test and post-test results. An Analysis of Covariance (ANCOVA) was also conducted to determine whether any significant differences existed between the Experimental and Comparison Group. A null hypothesis was supported. It would appear that the whole-hearted commitment and participation of all role-players is essential for the effective implementation of a peer reading intervention at a school.

Thesis advisor: Stefan Hoderlein / This dissertation is divided into two parts. Part I - Dynamic Kidney Exchange In recent years, kidney paired donation (KPD) has an emerged as an attractive alternative for end-stage renal disease patients with incompatible living donors. However, we argue that the matching algorithm currently used by organ clearinghouses is inefficient, in the sense that a larger number of patients may be reached if kidney transplant centers take into consideration how their pool of patients and donors will evolve over time. In our work Two Novel Algorithms for Dynamic Kidney Exchange, we explore this claim and propose new computational algorithms to increase the cardinality of matchings in a discrete-time dynamic kidney exchange model with Poisson entries and Geometric deaths. Our algorithms are classified into direct prediction methods and multi-armed bandit methods. In the direct prediction method, we use machine learning estimator to produce a probability that each patient-donor pair should be matched today, as op- posed to being left for a future matching. The estimators are trained on offline optimal solutions. In contrast, in multi-armed bandit methods, we use simulations to evaluate the desirability of different matchings. Since the amount of different matchings is enormous, multi-armed bandits (MAB) are employed to decrease order to decrease the computational burden. Our methods are evaluated using simulations in a variety of simulation configurations. We find that the performance of at least one of our methods, based on multi-armed bandit algorithms, is able to uniformly dominate the myopic method that is used by kidney transplants in practice. We restrict our experiments to pairwise kidney exchange, but the methods described here are easily extensible, computational constraints permitting. Part II - Econometrics In our econometric paper Heterogenous Production Functions, Panel Data, and Productivity, we present methods for identification of moments and nonparametric marginal distributions of endogenous random coefficient models in fixed-T linear panel data models. Our identification strategy is constructive, immediately leading to relatively simple estimators that can be shown to be consistent and asymptotically normal. Because our strategy makes use of special properties of “small” (measure-zero) subpopulations, our estimators are irregularly identified: they can be shown to be consistent and asymptotically Normal, but converge at rates slower than root-n. We provide an illustration of our methods by estimating first and second moments of random Cobb-Douglas coefficients in production functions, using Indian plant-level microdata. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

The Queen’s domination problem has a long and rich history. The problem can be simply stated as: What is the minimum number of queens that can be placed on a chessboard so that all squares are attacked or occupied by a queen? The problem has been expanded to include not only the standard 8x8 board, but any rectangular m×n sized board. In this thesis, we consider both paired and total domination versions of this renowned problem.

This dissertation centers on the under-researched construct of interactional competence, which refers to features of jointly constructed discourse. When applied to the testing of speaking skills in a second language, interactional competence refers to features of the discourse that the two students produce together; rather than the speaking ability or performance of each person individually. This dissertation describes the construct of interactional competence in a low-stakes, paired speaking test setting targeted at students in their second year of German instruction at the college level. The purpose of this study is two-fold. First, the study analyzes the conversational resources that are co-constructed in the test discourse to maintain mutual understanding, which is considered the basis for interactional competence. Second, the study examines the impact of task (jigsaw task and discussion task) and speaking ability-level combination (same and different ability) in the test-taker pair on the co-constructed test discourse and thus on the deployment of the conversational resources to maintain intersubjectivity. In that respect, this study also seeks to analyze how the identified conversational resources are involved in establishing and negotiating language ability identities that are displayed in the test discourse. Conversation analytic conventions were used to investigate the interactional resources that test takers deploy to maintain mutual understanding. The procedures of repair (self-repair in response to other-initiated repair, inter-turn delays, and misunderstandings as well as other-repair in conjunction with word search activities) that emerged from the inductive analysis of the test discourse have broadened the conceptualization of interactional competence in the context of paired speaking assessments. Frequency distributions of the interactional resources were created to provide a better understanding of the impact of task and ability-level combination on the co-constructed repair procedures. The rationale behind this analysis is the general understanding of language testers that both resources and context influence test performance. The findings from the quantitative analysis suggest that there are more similarities than differences in repair use across the jigsaw task and the discussion task. In addition, even though some trends in the co-construction of repair procedures may be attributed to the higher or lower speaking ability of the test takers, the relationship between the ability-level combination in the pair and the use of repair seems to be rather variable. Finally, to learn more about the interrelationship between test takers’ speaking ability and interactional competence, this dissertation also approached speaking ability in terms of test takers’ co-constructed language ability identities that are displayed in the test discourse. By means of single case analyses, the study provided a detailed picture of the relationship between language ability identities and the procedures of repair, both of which are co-constructed at the discourse level. The findings from the conversation analysis show that the speaker who provides the repair is usually able to position himself or herself as the more competent or proficient speaker in the test discourse.

Having acquired some degree of oral proficiency but low (or non-existent) literacy, the learning of Chinese heritage learners' (CHLs) learning needs are different from those of Chinese foreign language learners (CFLs), who have learned Chinese only in the classroom setting. Although researchers have advocated for a separate curriculum for CHLs, creating a heritage track may not be an option for many Chinese programs due to insufficient enrollment and limited resources. Huge proficiency variations among CHLs also make it difficult to provide a language curriculum that fits the needs of all learners. Therefore, CHLs are assigned to classes with CFLs in most Chinese language programs. From a pedagogical point of view, uneven proficiency levels are a great concern for instructors who teach a language class with students of different language backgrounds and with varying abilities, especially when assigning students to work in pairs or small groups. Although CHL-CFL paired interaction has become a common phenomenon in Chinese language classes, it has not been fully explored. Grounded in sociocultural theory, this research explores the nature of dyadic interaction between Chinese heritage learners (CHLs) and Chinese foreign language learners (CFLs) in a classroom setting. It investigates the roles that Chinese heritage learners and their foreign language peers play in paired discussions, how learners' proficiency gaps influence the dynamics of paired interaction, and whether peer-peer collaboration affects learners' individual oral performance. In this study, data were collected in three intermediate-level Chinese classes. Participants first filled out a language background survey to lead to a better understanding of the environments in which they use Chinese. Next, they took two proficiency tests to assess their comprehensive Chinese skills. Over the course of a semester, ten CHL-CFL pairs engaged in paired discussions on six different occasions. Before and after each pair work session, each participant was required to give an individual verbal report assessing the influence of paired interaction on his or her oral performance. After data from the six sessions were collected, participants took an end-of-study survey, which provides their perceptions about paired discussion and their roles in paired interaction over the research period. According to the findings, three interaction patterns (passive collaboration pattern, active collaboration pattern, and peer-tutoring pattern) were identified. The results of this study show that CHLs' language background and the amount of Chinese language exposure determined the CHL-CFL proficiency gaps in each pair, and further influenced the pattern of paired interaction. Learners generated more LREs (Language-related episodes) and were more likely to acquire knowledge from pair work when the degree of interaction mutuality was high. Even when the proficiency gaps were large, the less proficient learners still could transfer new knowledge to their independent work. To conclude, this study may be of importance in presenting the dynamics of CHL-CFL paired interaction in a mixed Chinese language class, as well as in providing instructors with a better understanding of how different factors such as interlocutors' proficiency gaps, individual participants' beliefs and attitudes relate to their interaction behaviors and subsequent independent performance.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Psychology, 2006. / Includes bibliographical references.

The ubiquitin proteasome system (UPS) depends on three enzymes called E1, E2, and E3 to ubiquitinate proteins and several isopeptidases to de-ubiquitinate them. Ubiquitination serves as a post-translational modification that either tags proteins for degradation by the proteasome or serves to modulate their function. This dynamic system plays a role in synaptic plasticity and dysfunction of the UPS is associated a variety of neurodegenerative diseases. In this study, three inhibitors the UPS, ziram, clasto-lactacystin β-lactone (lactacystin) and G5 were employed to illuminate involvement of the UPS in long-term and short term plasticity in area CA1 of rat hippocampal slices. Ziram, lactacystin and G5 inhibits the E1 ubiquitin-activating enzyme, the proteasome and isopeptidases, respectively. It was found that UPS inhibition enhanced long-term plasticity, by specifically increasing the magnitude of long-term depression (LTD) and altered short term plasticity, measured with paired pulse facilitation (PPF), to varying degrees. These findings establish that the UPS may play a regulatory role in LTD and PPF, and the changes in PPF further indicate that the UPS may be acting presynaptically. Overall, the results suggest ubiquitination and proteasome-mediated proteolysis are important in both long-term and short-term plasticity.

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast neutrons with the alloy. It is possible, therefore, by changing the alloy thickness, to produce distinctly different dose weighted neutron spectra inside the exposure cave of the FNIS. The calculated neutron spectra showed close agreement with the results of activation foil measurements, unfolded by SAND-II close to the cell window. However, there was a considerable less agreement for locations far away from the cell window. Even though the magnitude of values such as neutron flux and tissue kerma rates in air differed, the weighted average neutron energies showed close agreement between the MCNP and SAND-II since the normalized neutron spectra were in a good agreement each other. A paired ion chamber system was constructed, one with a tissue equivalent plastic (A-150) and propane gas for total dose monitoring, and another with graphite and argon for photon dose monitoring. Using the pair of detectors, the neutron to gamma ratio can be inferred. With the 20 cm-thick FNIS, the absorbed dose rates of neutrons measured with the paired ion chamber method and calculated with the SAND-II results were 13.7 ?? 0.02 Gy/min and 15.5 Gy/min, respectively. The absorbed dose rate of photons and the gamma contribution to total dose were 6.7??10-1 ?? 1.3??10-1 Gy/min and 4.7%, respectively. However, the estimated gamma contribution to total dose varied between 3.6 % to 6.6 % as the assumed neutron sensitivity to the graphite detector was changed from 0.01 to 0.03.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 97 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Alcohol expectancy theory suggests that genetically influenced personality characteristics may lead to differential acquisition of expectancy information, and that this information then may serve as one mediational pathway for alcoholism risk. Research has already shown that expectancy information can predict and even mediate risk, but it has yet to be shown that personality traits can influence the acquisition of alcohol expectancy information. To that end, personality characteristics known to be risk factors for the development of excessive alcohol use were assessed in 83 male undergraduates. In addition, each participant studied, in a paired-associate learning/cued-recall test paradigm, a list of word pairs matching alcohol content words (keg, beer), positive/arousing alcohol expectancy words (happy, fun), and neutral words (backpack, desk). / ABSTRACT: Their rate of learning the second word from each pair after being cued with the first word was then assessed across three trials of this task, and overall learning of the pairs was then assessed using free-recall. To determine whether learning rates for each type of word pair was a function of participants' status on the personality risk measures, hierarchical regression analyses were conducted for cued- and free-recall data. Results indicated that higher sensation seeking, more drinking-related problems, and a lesser degree of a family history of alcohol problems were predictive of greater recall for word pairs containing alcohol and expectancy information. Consistent with predictions, these risk indicators were also associated with a higher rate of learning for the alcohol and expectancy pairs. / ABSTRACT: These findings suggest that significant differences exist in the ability to learn alcohol to expectancy word associations, and lend support to recent theories that implicate individual difference factors as a predisposition for the development of problematic alcohol to expectancy associations in memory. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Sensation seeking is a personality characteristic associated with problematic alcohol use and positive alcohol expectancies, but little research has examined the relationship between sensation seeking and the acquisition of alcohol expectancy information. In a recent study (Steinberg, 2003), sensation seeking was associated with how quickly and accurately college-aged students were able to learn alcohol-expectancy word pairs in a paired associate learning task. In this age group, however, the individuals had fully developed alcohol expectancies that may have influenced their rates of learning. The current study sought to minimize the influence of previously held alcohol expectancies by exploring this relationship in children when the development of alcohol expectancies is just beginning. The participants in this study were fifth grade students. A series of regressions examined the relationship between sensation seeking, alcohol expectancies, current and predicted future drinking with the acquisition of alcohol and expectancy word pairs in a paired associate learning task. Although no statistically significant relationships were found, children with higher drinking frequency and males with higher Thrill and Adventure Seeking (TAS) demonstrated a minor advantage in their ability to match alcohol and expectancy words in cued-recall trials. Although the results of this study are inconclusive, they suggest that sensation seeking may play a role in the acquisition of alcohol expectancies. Future research with refined word pairs and a larger sample size is necessary to further clarify these trends.