East Carolina University : Research and Creative Achievement Week 2012
Does egg shell coloration influence parental care in the Eastern bluebird?, William Davis, East Carolina University, Greenville, NC 27858 Biliverdin is an antioxidant that has been linked to blue-green coloration in the shells of avian eggs. Previous studies have shown a negative correlation between plasma antioxidant levels and pigment levels in egg shells. We thus expect there to be an adaptational advantage to allocating an antioxidant into egg shells, and it has been proposed that the blue-green coloring produced by biliverdin in egg shells may act as a signal to mates of female quality. One prediction from this hypothesis is that males mated to females who produce brightly colored eggs should invest more in parental care. We have investigated parental feeding rates and egg shell coloration in Eastern bluebirds (Sialia sialis) over one breeding season. The Eastern bluebird lays blue eggs. Yet this species nests in cavities, where we would not expect crypsis to be a strong factor in shell color evolution. Of our 32 nests 26 were occupied by bluebirds and each pair raised an average of 2 broods. Broods that were laid within 2 days of each other and differed noticeably in egg color were swapped between nests. Newly hatched nestlings were swapped back after hatching to control for the possible confounding factor of signaling by different quality chicks hatched from experimental eggs. Because we seek to only measure difference in feeding rate due to egg color, allowing the parents to raise their own chicks in both control and experimental nest assures that the only difference is egg color during incubation. Through both visual and camera observations we obtained the feeding rates of both male and female bluebirds. Preliminary results do not suggest any association between egg brightness and total male feeding rate, nor an association between egg brightness and male feeding rate per chick.
UO11
Investigation of the Formation and Degradation of Urea Linkages Formed Between Aromatic Isocyanates and Aromatic Amines using Model Compounds and in-situ Kinetic NMR Spectroscopy, Jason Atkinson, East Carolina University, Greenville, NC 27858 Polyurethanes, a relatively broad class of technologically and commercially important materials are based primarily on isocyanate chemistry. Aliphatic and aromatic isocyanates readily react with alcohols and amines to form urethane and urea linkages (respectively). This chemistry forms the basis for vast majority of polyurethane synthesis. While some urethane and urea connective groups can be subject to hydrolysis or oxidative degradation under some conditions, many years of research and experience has shown that they are generally very stable. During elevated temperature degradation studies of poly (urea-urethane) copolymers conducted in our laboratories, some questions emerged regarding the stability, potential reversibility or possible exchange reactions of urea linkages formed between aromatic isocyanates and aromatic amines. In order to further understand these results and potentially exploit this finding to our advantage, we have designed and synthesized model compounds to allow direct observation of the groups in question using in situ kinetic 1H NMR spectroscopy. Model compounds have been synthesized and characterized using Electrospray Ionization Mass Spectrometry and 1H NMR spectroscopy and preliminary kinetic experiments have been carried out. Initial studies have been conducted using commercially available carbodiimide modified 4, 4methylenediphenyldiisocyanate and 4,4-Methylenebis(N-Sec-Butylaniline). Further kinetic experiments involving these and related compounds coupled with the synthesis of selected new secondary aromatic amines are currently underway.
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