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An investigation of the inorganic chemistry of peat systemsHao, Jicheng January 1996 (has links)
No description available.
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Wetland characteristics and abundance of breeding ducks in prairie CanadaBartzen, Blake 23 December 2008
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.
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Wetland characteristics and abundance of breeding ducks in prairie CanadaBartzen, Blake 23 December 2008 (has links)
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.
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Cash auction bankruptcy and corporate restructuringThorburn, Karin S. January 1998 (has links)
In Sweden, firms that file for bankruptcy are all auctioned off either piecemeal or as going concerns. Upon filing, managers lose control of the firm. In contrast, in the U.S. managers retain control by selecting to renegotiate the financial claims on the firm under court-supervision (Chapter 11). This thesis addresses the ongoing debate as to whether a Chapter 11-style renegotiation option is valuable to the firm’s securityholders. The optimal bankruptcy system depends on how well the auction system itself functions as well as on the extent to which managers misuse the renegotiation option to their own benefit (the agency problem). While there is substantial evidence on Chapter 11 cases, the thesis provides some first evidence on the workings of a pure auction system using Swedish data. The first essay examines direct costs, creditor recovery rates and auction premiums in Sweden, and compares the results to extant evidence on U.S. Chapter 11 cases. Overall, the results suggest that mandatory auctions provide a relatively cost-efficient bankruptcy procedure, producing recovery rates that are similar to those reported for much larger firms in Chapter 11. Moreover, auction premiums are significant and tend to increase with industry distress, which contradicts arguments that financially distressed firms sell assets below their true value. The second essay provides some first evidence on managerial compensation, turnover and corporate performance following Swedish bankruptcy auctions. The evidence indicates that mandatory auctions act as a substantial managerial disciplinary force: CEOs typically incur significant compensation losses and a majority of CEOs lose their job through the auction. Nevertheless, the operating profitability of the auctioned firms is typically at par with industry norms. Thus, although CEO wealth effects and turnover rates are dramatic, there is little support for the argument that managers in an auction bankruptcy system tend to delay filing at the detriment of the firm's going concern value. Essays three and four take a broader perspective on corporate restructurings. The third essay examines alternative econometric explanations for the lack of stock market gains to bidder firms reported in the literature. The analysis, which uses a large sample of Canadian targets, provides new evidence consistent with the proposition that the measured gains to relatively large, frequent acquirors reflect an attenuation bias produced by event-study econometrics. Moreover, the results suggest that mergers between relatively equal-sized firms, and which have not generated anticipation of future acquisition activity, tend to produce significantly positive bidder gains. This supports the use of mergers also as an alternative to bankruptcy. / <p>Diss. Stockholm : Handelshögskolan, 1998</p>
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The pricing of corporate bonds and determinants of financial structureThorsell, Håkan January 2008 (has links)
This thesis contain three chapters. Default Risk in Corporate Bond Pricing. This chapter provides a model for how the corporate bond default risk influences the systematic risk and an empirical analysis of the systematic and idiosyncratic parts of U.S. corporate bond returns during 2001-2005. The average corporate bond beta is low and positive (0.06). Investment grade bonds have negative betas (between - 0.01 and -0.13) and non-investment grade bonds have positive betas (between 0.11 and 1.48), but both groups have similar within groups systematic risks. When controls for interest rate and liquidity risks are introduced there are still remaining default probabilities, implying that the default risk is in part systematic and in part idiosyncratic. Returns to Defaulted Corporate Bonds. In the second chapter short term excess returns in a sample of 279 defaulted US corporate bonds are tested for using multiple regression analysis. There are robust excess returns after controlling for market and liquidity risk. The expected recovery rate during 2001-2006 is estimated to be, on average, four percentage points lower the first month after default than the present value of the recovery rate after nine months. Capital Structure Choices. The trade-off and pecking order theories are tested using both established tests from the literature and new tests. The main contributions of this chapter are the new tests of financing of operating net assets (for the pecking order theory), the mean reversion tests (for the trade-off theory) and the test of mean reversion and trends. These tests allow for extended conclusions on the validity of the pecking order versus the tradeoff theory. / <p>Diss. Stockholm : Handelshögskolan, 2008 Sammanfattning jämte 3 uppsatser</p>
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