Wetlands of the Prairie Pothole Region of North America provide habitat for over 50% of the continent's breeding waterfowl, but most of the region's wetlands have been lost or degraded through intensive agricultural development. Despite widespread wetland losses in much of the Canadian prairies, there is little information about trends in degradation of remaining wetlands. Using habitat data collected for ~10,500 wetlands across the Canadian prairies during annual waterfowl surveys, 1985-2005, I employed multistate models in Program MARK to estimate rates of impact and recovery of wetlands resulting from agricultural activities. Then, I characterized the incidence of agricultural degradation to these wetlands. Rates of impact to wetland margins (natural vegetation around flooded basins) declined over time, likely due to a decreasing percentage of unaffected wetlands; recovery rates for margins were always lower than impact rates, suggesting increased cumulative degradation of wetlands over time. Unlike margins, impact and recovery rates for basins fluctuated with spring pond densities. Shallow ephemeral wetlands located in agricultural fields had the highest impact and lowest recovery rates. Multistate modeling could also be used to estimate rates associated with other landscape processes.<p><p> My second objective was to determine whether physical characteristics of prairie Canada wetlands could be used to predict breeding duck abundance. First, I sought to determine how pre-existing models developed in the Dakotas (USA) performed when predicting breeding duck abundances on Canadian prairie wetlands. I related duck pair abundance to pond area, and then compared observed to predicted duck abundance. The Dakota models performed reasonably well in predicting numbers of blue-winged teal (<i>Anas discors</i>), gadwall (<i>A. strepera</i>), and northern pintail (<i>A. acuta</i>), but predicted fewer mallards (<i>A. platyrhynchos</i>) and northern shovelers (<i>A. clypeata</i>) than were observed on wetlands. Pond area was an important predictor of duck abundance in all models, but results were less biased and more consistent in models developed specifically for Canadian wetlands. Spatiotemporal variation in the relationship of breeding duck abundance and wetland characteristics was also affected by regional duck and pond densities. Overall, the new applications and models developed and validated in this study will be useful for wetland and waterfowl management in the Canadian prairies.

The essence of the interest rate modeling by using Heath-Jarrow-Morton framework is to find the drift condition of the instantaneous forward rate dynamics so that the entire term structure is arbitrage free. In this study, instantaneous forward interest rates are modeled using random fields and Markov Jump processes and the drift conditions of the forward rate dynamics are given. Moreover, the methodology presented in this study is extended to certain financial settings and instruments such as multi-country interest rate models, term structure of defaultable bond prices and forward measures. Also a general framework for bond prices via nuclear space valued semi-martingales is introduced.

This thesis conducts a comprehensive examination on the random walk behavior of 29 foreign exchange rates over the period of floating exchange regime, using variance-ratio tests. The cross-country and time-series test show that random walk model cannot be rejected on majority, and the random walk behavior is quite volatile across the whole floating exchange regime period. It then goes further to explore possible factors that can explain the probability of rejection/ non-rejections on random walk model using linear as well as nonlinear probability models, and find that the factors such as capital openness and investment-to-trade ratio significantly increases the chance of its exchange rate exhibiting random walk behavior.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (doctoral)--Freie Universität, Berlin, 2004. / EAN: 9786610701315 (electronic bk.). Title from e-book title screen (viewed Oct. 15, 2007). Description based on print version record. Includes bibliographical references (p. [143]-155).

We first describe the methodology for a two-dimensional, elastic deformable microplate modeling approach for continental plate boundaries. Deformable microplate models combine discrete slip on microplate boundaries (faults) with continuous deformation in block interiors. Two idealized models simulating continental collision are presented, one with two microplates and one with four microplates. / Earth and Planetary Sciences

Immigrant women are frequently found to have higher fertility relative to women in the majority population. This is often attributed to their socioeconomic characteristics, cultural preferences and patterns of childbearing, and adaptation to the destination context. However, several limitations in the research to date may mask the associations and processes which shape women’s fertility: 1) frequently used indicators are not sensitive to the way in which fertility is shaped by the migration process 2) key proximate determinants of fertility are often not integrated into analyses and 3) non‐migrant women in sending countries are often excluded as a reference for immigrant women’s childbearing behavior. In order to assess how women’s migratory moves and social context affect fertility, I compare the risk of first birth and patterns of contraceptive use at higher‐order parities for non‐migrant, immigrant and native‐born women. For these analyses, I use data from nationally‐representative surveys of reproductive health and family formation from Mexico, the United States, Turkey and Germany. The results from these analyses demonstrate that both foreign‐born Mexican‐ and Turkish‐origin immigrant women experience first birth earlier than non-migrants, second generation immigrants, and native-born women at destination. However the underlying determinants of earlier birth are different for these two groups. There are also differences for second generation women; US-born Mexicans experience first birth at significantly younger ages than whites, whereas age at first birth is very similar for German-born Turkish women and ethnic Germans. Furthermore, patterns of contraceptive use among immigrant women who have at least one child are notably different than patterns observed for non-migrants. US-born women have similar contraceptive use compared to whites, but Mexican-born women are less likely to use permanent and highly effective methods, even after controlling for fertility intentions. Turkish-origin women in Germany exhibit large differences in contraceptive use relative to non-migrant women, particularly the very low reported use of withdrawal. These findings indicate that fertility determinants vary across origin and destination context. The observed differences between Mexican- and Turkish-origin women suggest that distinct processes of migration, socialization, and access to contraception lead to variation in the fertility outcomes for these two groups. / text

published_or_final_version / Public Administration / Master / Master of Social Sciences

Escherichia coli is a bacterial species that lives in the gut of all warm-blooded animals, fish, birds as well as reptiles and is commonly used as an indicator of fecal contamination in water. This project assessed currently used culture based media for the detection of E. coli in irrigation waters used in Arizona and California, and will present recommendations towards the most reliable media for the evaluation of irrigation waters used for produce. Currently, no microbial indicator standards exist for irrigation waters used for produce production in the United States. The produce industry suggests that the recreational water standard guideline (126 E. coli/100 ml) established by the United States Environmental Protection Agency (USEPA) be used. There is concern that the false positive rate of E. coli detection may be high in these waters giving false indications of the level of risk from enteric pathogens. This project evaluated three commercially available media for E. coli detection to test irrigation waters from three agricultural areas (Yuma and Maricopa, AZ and Imperial Valley, CA) and then assessed false positive rates by utilizing Polymerase Chain Reaction (PCR) and DNA sequencing of the bacterial isolates. The media that were chosen for evaluation were (1) MI Agar, (2) IDEXX Colilert Quanti-Tray® and (3) m-ColiBlue24® broth, all evaluation media accepted by the USEPA and widely used in the monitoring of irrigation water quality by the produce industry. Four hundred and fifty 1-L irrigation water grab samples were collected between March 2012 and November 2012. The samples were analyzed for both cultural counts and water quality parameters including temperature, salinity and pH. Isolates positive and negative for E. coli were then selected and assessed utilizing PCR and DNA sequencing. The false positive rate of each method was found to be high, with MI Agar, m-ColiBlue24® broth and the IDEXX Colilert Quanti-Tray® at an accuracy of 67%, 72%, and 51% respectively. A false positive result is reported when presumptive E. coli sub cultured from the media is found to be non-E. coli through molecular analysis. Overall the IDEXX Colilert Quanti-Tray® performed at a greater rate of accuracy than the other two media evaluated, however, high false positive rates may lead to inaccurate assessment of water quality.

No description available.