Radiation-induced changes in the export of photoassimilated carbon /|nBarry Jess Shelp. -- 260 0 St. Catharines, [Ont. : s. n.],

Low levels of ionizing radiation induce two translocation responses in soybean: a reduction in photoassimilate export from leaves and a change in the distribution pattern of exported photoassimilate within the plant. In this investigation these responses have been further studied specifically to ascertain the site of radiation damage and to better understand the physiological responses observed. Experimentally the primary data was obtained from studies in which a mature trifoliate leaf of a young soybean plant (Glycine ~ L. cultivar Harosoy '63) is isolated in a closed transparent chamber and allowed to photoassimilate 14C02 for 15 minutes. This is followed by an additional 45 ~_il'1;ute period before the plant is sectl.o ne d an d 14 C-ra dl' oactl.v.l ty d eterml. ne d'l n a 11 parts. Such 14c data provides one with the magnitude and distribution pattern of translocation. Further analyses were conducted to determine the relative levels of the major photosynthetic products using the techniques of paper chromatography and autoradiography. Since differences between control and irradiated P 1 ants were not 0 b serve d l' n t h e par tl't"lo nlng 0 f 14 C between the 80% ethanol-soluble and -insoluble fractions 14 or in the relative amounts of C-products of photosynthesis, the reduction in export in irradiated plants is not likely due to reduced availability of translocatable materials. Data presented in this thesis shows that photoassimilate export was not affected by gamma radiation until a threshold dose between 2.0 and 3.0 krads was reached. It was also observed that radiation-induced damage to the export process was capable of recovery in a period of 1 to 2 hours provided high light intensity was supplied. In contrast, the distribution pattern was shown to be extremely radiosensitive with a low threshold dose between .25 and .49 krads. Although this process was also capable of recovery,lt" occurred much earlier and was followed by a secondary effect which lasted at least for the duration of the experiments. The data presented in this thesis is interpreted to suggest that the sites of radiation action for the two translocation responses are different. In regards to photoassimilate export, the site of action of ionizing radiation is the leaf, quite possibly the process of photophosphorylation which may provide energy directly for phloem loading and for membrane integrity of the phloem tissue* In regards to the pattern of distribution of exported photoassimilate, the site is likely the apical sink, possibly the result of changes of levels of endogenous hormones. By the selection of radiation exposure dose and time post-irradiation, it is possible to affect independently these two processes suggesting that each may be regulated independent of the other and involves a distinct site.

The Informational Value of Corporate Credit Ratings

This thesis examines the quality of credit ratings issued by the three major credit rating agencies - Moody’s, Standard and Poor’s and Fitch. If credit ratings are informative, then prices of underlying credit instruments such as fixed-income securities and credit default insurance should change to reflect the new credit risk information. Using data on 246 different major fixed income securities issuers and spanning January 2000 to December 2011, we find that credit default swaps (CDS) spreads do not react to changes in credit ratings. Hence credit ratings for all three agencies are not price informative. CDS prices are mostly determined by historical CDS prices while ratings are mostly determined by historical ratings. We find that credit ratings are marginally more sensitive to CDS than CDS are sensitive to ratings.

Letter from the Chairman of the Committee of Ways and Means to the Secretary of the Treasurer on the subject of a system of revenue to revive and maintain unimpaired the public credit, with the answer of the Secretary thereto. (1814)

October 18, 1814. Read, and committed to the Committee of the whole House on the report of the Committee of Ways and Means on so much of the President's message as relates to the finances of the United States.

Effects of credit rating change on risk-taking

This thesis investigates whether there are changes in risk-taking behavior following an upgrade or downgrade in credit ratings. Research on effects of rating changes on capital markets is well-documented but the literature on how rating changes may affect firm behavior is sparse. Following, a downgrade in credit rating, managers may increase risk-taking to improve their overall performance or reduce risk-taking following upgrades to ensure that their performance is assessed more on the basis of what they may deem success in the form of an upgrade. Using a sample of firms trading in the U.S from 1994-2013, we find evidence of change in risk-taking behavior. We use cross-sectional regressions and matching using propensity scores and Barber and Lyon (1997) methodology to measure changes in risk-taking and we do find evidence of changes in managerial risk-taking behavior. Furthermore, we find that the direction of change (increase or decrease) in some cases is dependent on the type of measure rather than the type of rating change.

Credit to S.D. Woodruff from Pratt and Company for $150.00

Credit to S.D. Woodruff from Pratt and Company for $150.00, Sept. 7, 1876.

Credit to S.D. Woodruff from Pratt and Company for $62.00

Credit to S.D. Woodruff from Pratt and Company for $62.00, Nov. 6, 1876.