The objective of this study was to determine if the presence of two ALS inhibiting herbicide residues in three Saskatchewan soils would result in an additive, synergistic, or antagonistic interaction. This was determined through field trials where herbicides were applied sequentially over the course of two years and through dose-response modelling. The herbicides examined in these experiments were imazamethabenz, flucarbazone-sodium, sulfosulfuron, and florasulam, each in combination with imazamox/imazethapyr. The phytotoxicity and persistence of the herbicides in soil was assessed using an Oriental mustard root inhibition bioassay. The determination of herbicide interaction was made through the comparison of the experimentally observed values to theoretically expected values derived from a mathematical equation.<p>The dose response curves created by placing incremental concentrations of these herbicides in soil were compared using the I50 parameter, which is the concentration resulting in a 50% reduction in root length. It appeared that soil organic matter followed by soil pH had the greatest effect in reducing herbicide residue phytotoxicity in the tested soils. Based on the bioassay analysis of sequentially applied ALS inhibiting herbicides, it is proposed that the phytotoxic effect of herbicide residues in soil result in additive injury effects rather than synergistic or antagonistic interactions.

<p>In this thesis, we explore techniques in statistics and persistent homology, which detect features among data sets such as graphs, triangulations and point cloud. We accompany our theorems with algorithms and experiments, to demonstrate their effectiveness in practice.</p><p></p><p>We start with the derivation of graph scan statistics, a measure useful to assess the statistical significance of a subgraph in terms of edge density. We cluster graphs into densely-connected subgraphs based on this measure. We give algorithms for finding such clusterings and experiment on real-world data.</p><p></p><p>We next study statistics on persistence, for piecewise-linear functions defined on the triangulations of topological spaces. We derive persistence pairing probabilities among vertices in the triangulation. We also provide upper bounds for total persistence in expectation. </p><p></p><p>We continue by examining the elevation function defined on the triangulation of a surface. Its local maxima obtained by persistence pairing are useful in describing features of the triangulations of protein surfaces. We describe an algorithm to compute these local maxima, with a run-time ten-thousand times faster in practice than previous method. We connect such improvement with the total Gaussian curvature of the surfaces.</p><p></p><p>Finally, we study a stratification learning problem: given a point cloud sampled from a stratified space, which points belong to the same strata, at a given scale level? We assess the local structure of a point in relation to its neighbors using kernel and cokernel persistent homology. We prove the effectiveness of such assessment through several inference theorems, under the assumption of dense sample. The topological inference theorem relates the sample density with the homological feature size. The probabilistic inference theorem provides sample estimates to assess the local structure with confidence. We describe an algorithm that computes the kernel and cokernel persistence diagrams and prove its correctness. We further experiment on simple synthetic data.</p> / Dissertation

Recent studies have reported that open-end fund has its performance persistence. However, those studies didn¡¦t mention the factors of performance persistence. Therefore, investors knows the character of the types of fund, but unable to determine which individual fund have the character given the type of fund. The main purpose of this study is to provide investors a new way to select funds. First, investors can select high performance funds in the past period and aim to pick the individual funds which fit the character of high performance persistence. This study is divided into two parts. In first part, the researcher use Spearman's Rank Correlation Coefficient Test to examine the existence of performance persistence. In second part, the study aims to use Panel Data Analysis to examine the impact of 10 factors on the performance persistence in different type of funds, and periods. Samples in the study are chosen from 160 Taiwan open-end equity funds during 2004-2011. The return rate data is rolling data. In order to remove the difference of the risks of the funds, simple return rates were transferred into Jensen¡¦s Alpha. The conclusions are shown as below¡G 1. In short term, Time of Establishment often has a positive effect on fund performance persistence. 2. In short term, Net Asset Value often has a negative effect on fund performance persistence. In long term, net asset value often has a positive effect on fund performance persistence. 3. In short and middle term, Average Investment Amount always has a positive effect on fund performance persistence. 4. Almost in all type of funds and all periods, Stock Holding Rate has a negative effect on fund performance persistence. 5. Almost in all type of funds and all periods, The Score of Monitoring indicator has a negative effect on fund performance persistence.

A predicted loss of agricultural rice-wetlands and increasing urbanization and development threatens the remaining freshwater wetlands along the upper Texas coast. To avoid, minimize, and mitigate wetland loss, the U.S. Army Corps of Engineers (Corps) is directed to enforce Section 404 of the Clean Water Act (1975 amendment) by administering permits for development. Furthermore, a 1990 Memorandum of Agreement (MOA) between the Corps and the U.S. Environmental Protection Agency (EPA) proposed a national goal of no net wetland loss (NNL). My goals were to identify the frequency of occurrence of freshwater wetland loss due to dredge or fill, assess final plans to mitigate wetland loss, and verify the persistence of the created compensatory wetlands. I created a database of 96 individual, Section 404 permits issued from 1981 to 2001 in the counties of Chambers, Hardin, Jefferson, Liberty, Montgomery, Orange, and San Jacinto (Galveston District Office, U.S. Army Corps of Engineers). Descriptive statistics were calculated for permit characteristics in relation to issue date (pre- or post-NNL). Public comments received from national and state agencies were rank ordered against mitigation plan type to determine Spearman's Rank Order Correlation Coefficient. Visual identification (via site visits and 1996 aerial photos) was used to validate compensatory wetland persistence. Shoreline protection of private property and oil and gas drilling (64% of permit applicants and 59% of impacts) had the greatest effect on wetland loss in the region, particularly Chambers, Jefferson, and Montgomery counties. Overall, 79.3 ha of freshwater wetlands were gained; however, gain was overestimated due to large projects for habitat enhancement. Permits issued post-NNL were more likely to have formal mitigation plans (58% vs. 13% pre-NNL) and allowed no net wetland loss. Although agency comments recommending more formal mitigation plans increased after NNL, only a weak positive correlation was detected (Spearman's r less than or equal to 0.4). Six of seven created wetlands remained in existence through 2006 though they are freshwater ponds replacing more diverse aquatic systems. I recommend the development of a comprehensive method to track wetland loss, mitigation, and changes in watersheds over time.

This thesis compares the variability of commissioning savings and the persistence of savings from the Normalized Annual Consumption (NAC) and standard International Performance Measurement and Verification Protocol (IPMVP) weather normalization approaches and from Option C and Option D of the IPMVP. Twenty-nine different weather years were used to obtain a set of savings results under each method. Variability of savings was quantified by the average standard deviation of the 29 percent savings results across all post-commissioning periods for each method. For the combined chilled and hot water savings, the average standard deviation is 0.39% savings for Option D using the NAC weather normalization approach, 0.57% savings for Option D using the standard IPMVP weather normalization approach, 0.71% savings for Option C with regression models using the NAC weather normalization approach, and 0.98% savings for Option C with regression models using the standard IPMVP weather normalization approach. The variability of savings persistence results deviate a little from variability of savings results. For the combined chilled and hot water persistence of savings, the average standard deviation across all post-commissioning periods is 0.48% persistence for Option D using the NAC weather normalization approach, 0.55% persistence for Option D using the standard IPMVP weather normalization approach, 0.52% persistence for Option C with regression models using the NAC weather normalization approach, and 1.26% persistence for Option C with regression models using the standard IPMVP weather normalization approach. Overall, the NAC weather normalization approach shows less variability in savings and persistence than the standard IPMVP weather normalization approach. Additionally, Option D of the IPMVP generally shows less variability in savings and persistence of savings than Option C with regression models. This thesis also determines the savings and persistence of savings from commissioning for three Texas A&M University buildings. Aggregate site savings averaged 11.4%, 16.5%, and 19.0% for the three buildings over differing periods of available data. Persistence results for the three buildings are quite favorable, as each building shows an increase in aggregate site savings between the first and last post-commissioning periods. Follow-up commissioning restored and prevented degradation of savings in two of the buildings.

Laotian American students attending universities across the U.S. are first-, second-, and third-generation American. This generation status, along with their families' unique immigration experiences, likely impacts their adjustment to college. Data from the 2000 U.S. Census indicates a very low representation of Laotian Americans (7.6%) in the cluster of Asian Americans who have attained at least a Bachelor?s degree (42.7%). This low representation calls for further research on the Laotian American population to discover ways to increase these numbers. This study examines the mediating effect of campus connectedness on ethnic identity and college persistence attitudes and on other-group orientation and college persistence attitudes. It also examines mean group differences on campus connectedness by cultural orientation, among 82 low-land Laotian American college students. Results reveal that campus connectedness does not mediate the relationship between ethnic identity and college persistence attitudes. A mediation effect exists for campus connectedness on: 1) ethnic identity cognitive clarity (EI-clarity) and persistence and 2) other-group orientation and persistence. Mean group differences on campus connectedness by cultural orientation appear in the results.

The Hispanic population continues to rapidly increase within the state of Texas as well as the nation. However, the Hispanic population educational attainment level lags behind that of the general population. Hispanic males are the lowest educated segment of society averaging less than a high school diploma. The negative long-term economic impact of such low educational attainment levels coupled with the rapid increase of the Hispanic population has been documented by Texas state demographers as well as the U.S. Census Bureau. The researcher conducted a qualitative study to inform a deeper understanding of the experiences that facilitated the persistence of 18 Hispanic male first-time-in-college students through the official reporting date of their fall first termat a community college in South Texas. An asset model and related conceptual framework, which recognized students as experts, were utilized. Focus group interviews, semi-structured interviews, and existing data were analyzed utilizing qualitative research methods. The researcher identified six overarching themes that significantly influenced the students? ability to persist. In addition, analysis of the data produced five barrier themes that these students overcame via the utilization of corresponding knowledge and actions themes. Finally, students provided recommended college changes for mitigating the barriers faced by future Hispanic male students. The researcher provided conclusions regarding Hispanic male students, recommendations for students, recommendations for colleges and universities serving Hispanic male students, recommendations for the focal community college, and implications for the theoretical model utilized. The researcher recommended expanding this research to other institutions of higher education and notes the national implications for increasing the educational attainment level of Hispanic male students.

As the United States and Texas become increasingly dependent on the success of Hispanics in higher education based on degree attainment, decision-makers and policy-makers are looking for strategies for addressing the education attainment needs of the Hispanic population. The purpose of this naturalistic inquiry was to understand 1) the barriers experienced by successful first year (fall to fall) first-time-in-college Hispanic students at a predominately Hispanic student community college on the South Texas/Mexico Border Region, 2) the expertise/knowledge required to successfully overcome these barriers during the first year (fall to fall) in college, and 3) based on these findings, offer suggestions and recommendations for addressing the barriers experienced by Hispanic students enrolled in such community colleges. More specifically, the researcher examined the barriers experienced by students during the first year of college, and based on their experiences, the expertise required to overcome those barriers. The study utilized Padilla‘s (1991) Student Success Model as the primary theoretical framework for the study. The data analysis led to the identification of six barrier categories, which included: 1) transition from high school to college; 2) personal and family commitments; 3) institutional support; 4) student accountability; 5) instructor issues; and 6) developmental studies/college readiness. In the findings, I include the role of general college knowledge and academic college readiness in students successfully completing the first year (fall to fall) of college. The researcher utilized the results of the study to develop the Community College Student Success Model for First-Time-in-College Students, which was adapted from Padilla (1991, 2001) and Padilla, Treviño, Gonzalez, and Treviño (1996). The researcher recommends utilizing Lynham‘s (2002) General Method of Theory-Building to move towards the development of a theory for Hispanic student success in predominately Hispanic community colleges. The researcher also recommended the development and implementation of collaborative programs and services between the public school districts and the community college for facilitating the acquisition of general college knowledge by high school students before they graduate from high school.

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Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 207-214). Also available on the World Wide Web.