Maintaining cotton fiber quality is crucial for the survival of the U.S. cotton industry. Previous studies have indicated that spatial variability of fiber quality parameters exists in cotton fields. If site-specific measurement and prediction of quality is possible, then fiber could be segregated during the harvesting process, thus increasing the overall price a producer would receive for his crop. Because of the importance of fiber micronaire to the textile industry, the fact that micronaire exhibits moderate variation in the field, and the fact that it has been shown to be related to optical properties of cotton fibers, micronaire measurement was considered for quality segregation. Two years? cotton and soil data from two fields in Brooksville, Mississippi were used to investigate how much spatial variation in cotton quality factors could be explained by soil parameters. It was found that spatial variability exists in soil and cotton quality parameters, and micronaire (maturity and fineness) was found to have relatively large variability compared to other quality parameters. About 22 to 35% of the variation in micronaire could be explained by soil parameter variability. Site-specific prediction of micronaire based on only soil seems to be not practical according to the results of this study. Another objective was to develop a methodology for measuring important parameters of cotton crop quality in the field. USDA Micronaire Standard Calibration samples were used in infrared spectral measurements in order to relate their micronaire values to near-infrared and mid-infrared wavelength spectra. Near-infrared reflectance measurements in certain wavelengths ranging from 800 to 2500 nm were found to be closely correlated to micronaire values. Mid-infrared transmittance measurements (ratios) in certain wavelengths ranging from 2.5 to 25 µm were also related to micronaire values. The R2 value of the optimal prediction model was 0.92. This model was validated with HVI measurement of cotton samples from Mississippi and Arizona. Optical sensors based on spectral reflectance and transmittance measurements seem to be a reasonable choice for site-specific harvesting. A practical sensor mounted on cotton picker for measuring cotton micronaire appears to be feasible and a draft design was proposed.

No description available.

No description available.

No description available.

No description available.

Little attention has been given to studying the important nuances and contributions of individual works by the artist Maurizio Cattelan. Since beginning his career as an "art world outsider," the artist has consistently resisted categorization of his work, be it stylistic, nationalistic or ideological. This has made an approach based on examining his social and political context in relation to individual works rather difficult. Instead, the scholarship surrounding his art has most frequently been in the form of a survey, using his earlier conceptual pieces to contextualize later installations and sculptures, an approach that limits a fuller understanding of Cattelan's art. Rather than reading specific works in the context of their individual exhibition history, critics place them in the trajectory of Cattelan's overall practice. Furthermore, much of the existing scholarship has relied on the artist's own discussions of his oeuvre, providing a superficial understanding of both his work and words. Thus, Cattelan has been generally understood and labeled the art-world "joker," and his artwork is seen as a series of "one-liners," limiting the reading of his work. I propose, instead, an in-depth study of specific sculptures, which will lead to a richer understanding of the artist's overall practice within a historical and contextual period. In my opinion, Cattelan's work has been overlooked in relation to notions of site specificity. Through a close reading of Cattelan's most pivotal work, La Nona Ora, I will argue that this artistic paradigm will prove a much more effective lens through which to view his practice. / Art History

Purpose: Administration of a mechanical bowel preparation (MBP) has long been standard before colorectal surgery with the aim of preventing complications such as surgical site infection (SSI). Newer evidence suggests that MBP does not reduce the risk of infection and that oral antibiotic (OA) use may be important in reducing post-operative infectious complications, however, there is little evidence comparing MBP, OA, and combination preparations. Our goal was to determine the relationship between type of bowel preparation and SSI in patients undergoing elective colorectal resections Methods: All patients within the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database undergoing elective colorectal resections from 2012 to 2013 were identified. The primary outcomes of interest were: any post-operative SSI, wound SSI, and organ/space SSI. Secondary outcomes were anastomotic leak, post-operative ileus, cardiac complications, renal complications, death, unplanned readmission, and length of stay (LOS). Univariate models were used to compare frequencies of patient and surgical characteristics across types of bowel preparation, and propensity adjustment was used to study the relationship between type of bowel preparation and all outcomes of interest. Results: Among the study sample, 25.5% received no bowel preparation, 40.8% received MBP, 3.3% received OA, and 30.4% received OA+MBP. A total of 1,844 patients (9.5%) developed any type of post-operative SSI. 1,231 (6.4%) developed a wound SSI and 672 (3.5%) developed an organ/space SSI. MBP was not associated with a reduced risk of any type of SSI compared to no bowel preparation. Both OA and OA+MBP were significantly associated with a decreased risk of any SSI and wound SSI compared to both no preparation and compared to MBP. No differences were observed for any SSI or wound SSI between OA and OA+MBP. Compared to no preparation, OA+MBP was associated with a decreased risk of anastomotic leak and post-operative ileus. No differences were observed between MBP and OA, or between these preparation methods and no preparation, for these secondary outcomes. There were no significant associations between type of bowel preparation and cardiac or renal complications, mortality, or readmissions. Both OA and OA+MBP were associated with a reduction in LOS. Conclusion: These results suggest that a combination oral and mechanical bowel preparation may be most effective at preventing SSI after elective colorectal resection and that OA alone may also be effective. Future prospective studies comparing combination and OA preparations may be warranted to explore this relationship further. / Clinical Research and Translational Medicine

Environmental quality and emissions guidelines are implemented due to their expected benefit for human and environmental health. However, implementation of such legislation requires knowledge of the behaviour and fate of the contaminants to be controlled. This thesis contributed to the overall understanding of atmospheric PAH deposition to remote lakes and the role atmospherically deposited contaminants play in site assessments which account for environmental pollution due to industry. In chapter 2, atmospheric PAH deposition derived from regional energy generation or industrial sources was found to be decreasing in recent sediments from Siskiwit Lake, Michigan, U.S.A. Considering that Siskiwit Lake is isolated from traffic and development, this supports recent theories which suggest that regional PAH deposition is being overprinting by local traffic sources in sub-urban or urban areas. This study also contributed to the understanding of perylene production in sediments by conclusively demonstrating increases in sedimentary perylene concentrations over a 20 year period. Moreover, kinetic modeling using 1st and 2nd order rate laws failed to accurately predict the concentration changes observed despite rate constants that were similar. This strongly suggested that perylene does not follow a simple concentration dependant kinetic reaction and is more likely controlled by complex kinetics perhaps involving biology. In chapter 3, the superiority of contaminant profiles in sediment cores over current dredge or grab sampling techniques was demonstrated. This was shown by successfully apportioning the source of contaminants to a northern lake as atmospheric deposition rather than point source release from the adjacent industrial facility. Contaminant profiles are able to constrain concentration changes with time and thus atmospheric deposition and point source contributions can be recognized. This is essential as chapter 3 also demonstrated that atmospheric deposition has the potential to produce sediment concentrations at or above current federal guidelines using standard dredge sampling techniques. Without the use of contaminant profiles these exceedences may be attributed incorrectly to industry which may face remediation costs or other fines associated with environmental contamination. This has implications for redefining sediment quality guidelines or currently accepted sampling methods. Moreover, remediation efforts for atmospherically deposited contaminants must differ from a point source release. Site remediation would be effective for a single release of contaminants however with a continuous source, as is the case with atmospheric deposition, remediation efforts must be focussed on the atmospheric contaminant emissions which can be a large distance from the site. / Thesis / Master of Science (MSc)

The active site of porcine kidney microsomal aminopeptidase was investigated using single, multiple and EDTA inactivation kinetic studies. Good inhibitors invariably contained a zinc-coordinating group such as the mercapto moiety, which proved to be the best ligand for aminopeptidase. Due to the potency of β -mercaptoethylamine, derivatives of this compound were examined for aminopeptidase inhibition. (S)-2-amino-4-methyl-l-pentanethiol (L-leucinthiol) exhibited the largest potency and specificity towards aminopeptidase when compared against carboxypeptidase A and thermolysin, two similar zinc-peptidases. The presence of a zinc-coordination subsite, two hydrophobic pocket subsites and a second amine-binding subsite (distinct from that responsible for substrate recognition) were discerned and the binding modes of amino acid hydroxamates and mercaptoamines compared using Yonetani-Theorell inhibition kinetics. Aminopeptidase does not show virtually any stereoselectivity between L-and D-leucine hydroxamate while greater than a 1,000-fold preference is seen for L-leucinthiol over the D isomer. Also, the amino group of mercaptoamines is crucial to the binding of these inhibitors whereas that of the hydroxamate compounds does not seen to contribute much to their binding. The differences in binding between hydroxamates and mercaptoamines are postulated to be a consequence of the product analogue nature of the former and transition state analogue character of the latter. L-leucine hydroxamate is proposed to bind in a backwards orientation while the D isomer binds in the normal substrate-like position. Similarly, L-leucinthiol is proposed to bind in the same fashion as substrate. Design of future inhibitors should endeavour to: (1) lower the pᵏₐ of the α-amino group, (2) include an extended chain structure capable of binding to additional hydrophobic pockets, (3) incorporate a second amine moiety into the structure to interact with the second amine-binding subsite and (4) replace the mercapto group with a more potent zinc ligand such as the selenol group. / Thesis / Master of Science (MSc)

No description available.