http://dspace.library.cornell.edu The eCommons@Cornell digital repository system captures, stores, indexes, preserves, and distributes digital research material. Search the Channel search http://dspace.library.cornell.edu/simple-search http://hdl.handle.net/1813/11096 Title: 2006/2007 Annual statistics (printed, summary version) <br/> <br/>Authors: Cornell University Library <br/> <br/>Abstract: CUL 5-year longitudinal input and output statistics on collections, services, expenditures, staffing and facilities. Includes unit and library-wide data. http://hdl.handle.net/1813/11095 Title: 2006/2007 Annual Statistics (full version) <br/> <br/>Authors: Cornell University Library <br/> <br/>Abstract: CUL fiscal year input and output statistics on collections, services, expenditures, staffing and facilities. Includes current and 5-year, and unit and library-wide data. http://hdl.handle.net/1813/11094 Title: Lead and Cadmium Bioavailability: Cysteine- and Glutathione-mediated Soil Desorption and Plant Uptake <br/> <br/>Authors: Vadas, Timothy <br/> <br/>Abstract: The use of plants in phytoremediation is limited by incomplete knowledge of transport mechanisms and low solubility of metals in soil. I have investigated the use of biogenic thiols cysteine and glutathione to chelate Pb and Cd in soils and to create a soluble metal-thiol species that may be actively transported into plants. Short-term hydroponic experiments revealed that both cysteine and glutathione mediate uptake of Pb and Cd into roots of Zea mays and Brassica napus. Uptake rates were enhanced after pre-exposure to cysteine or glutathione and inhibited in the presence of vanadate, suggesting a biological mechanism of uptake. Increasing concentrations of glutathione resulted in decreasing Pb uptake rates, which indicates competition for transport between the free glutathione and Pb-glutathione species. Pb uptake in the presence of increasing cysteine concentrations resulted in decreased uptake initially but linearly increasing uptake at higher thiol concentrations. Uptake is possibly mediated by a peptide or amino acid transporter. While cysteine and glutathione mediate uptake of Pb into roots, shoot translocation was not significant in wildtype B. napus, Z. mays or Arabidopsis thaliana. Experiments with A. thaliana tDNA insertion mutants deficient in OPT, PTR, or PDR transporters showed changes in root Pb accumulation as well as increased shoot translocation in the OPT5 knockout. Root vacuolar sequestration may be occurring and will be verified in future experiments using TEM and x-ray spectroscopy. Cysteine and glutathione are both effective at solubilizing Pb and Cd from several contaminated soils at pH 7 and 8. While glutathione is relatively stable in solution and maintains metal solubility, cysteine is rapidly oxidized resulting in short-lived solubility of metals. Sequential extractions showed that cysteine and glutathione removed from 20 to 100 % of the soil metal contaminant after 4 cycles depending on the soil. In intact soil systems, Pb and Cd solubility ranged from 20 to 200 ppm due to thiol treatment, while Cd solubility was less than 10 ppm. Root and shoot uptake of Pb and Cd from soil into Zea mays did not result in significantly higher uptake than the control, but these initial experimental methods were inconclusive. http://hdl.handle.net/1813/11093 Title: Investigating Prosodic Boundaries <br/> <br/>Authors: Crivellaro, Serena <br/> <br/>Abstract: This thesis relates the results of a series of experiments testing speakers' interpretation of ambiguous sentences in which prosodic cues at two relevant locations have been systematically manipulated. The goal was to develop a model to predict sentence's interpretations based on information about the relative strength of the two boundaries. The model we present builds on Carlson, Clifton and Frazier's (2001) Informative Boundary Hypothesis, which proposes that attachments are derived based on the relative strength of the two phonetic boundaries, and introduces room for variability based on the effects of Overall Bias and Conditional Bias on the distribution of results. Overall Bias is a bias introduced into the distribution of responses that affects all tokens, shifting the probabilities of each interpretation for every token by the same amount. Conditional Bias is instead defined as a processing-related bias, that reduces the probability of one or the other interpretations only for boundaries larger than a certain amount at a specific location in the sentence. Extra time at this boundary allows the speaker to process the sentence, which makes one or the other readings unlikely. To test the model, we generated a set of sentences with equally spaced boundaries at each of two locations in the sentence that would be consistent with high or low attachment interpretations, thus generating a grid-like structure that can be used as the base for a map of the sentences' interpretations. The tokens were generated using an automated script from a single base file which in turn had been produced by a speech synthesizer, to minimize the amount of variability across tokens. Subjects were then asked to select an interpretation and a confidence rating for each token, which were then combined to result in a weighted response variable. The distribution of the responses, and the point at which interpretations change, can be plotted for each of the items. The predictions about Conditional Bias made on the grounds of sentence processing were borne out for almost all the structures. Some items also showed the effects of Overall Bias, and the remaining part of the cases can be explained by introducing the effects of the experimental task, which can trigger earlier processing points under very specific circumstances. Furthermore, it appears that the amount of boundary which triggers a Conditional Bias effect is consistent across items and structures, suggesting that a systematic threshold is necessary for processing to take place, which should be investigated further in future research.