Poultry Nutrition and Feeding Poultry Production in Ohio

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Effects of Macromolecular Crowding on Amyloid Beta (16-22) Aggregation Using Coarse-Grained Simulations

To examine the effect of crowding on protein aggregation, discontinuous molecular dynamics (DMD) simulations combined with an intermediate resolution protein model, PRIME20, were applied to a peptide/crowder system. The systems contained 192 Aβ(16-22) peptides and crowders of diameters 5, 20, and 40 Å, represented here by simple hard spheres, at crowder volume fractions of 0.00, 0.10, and 0.20. Results show that both crowder volume fraction and crowder diameter have a large impact on fibril and oligomer formation. The addition of crowders to a system of peptides increases the rate of oligomer formation, shifting from a slow ordered formation of oligomers in the absence of crowders, similar to nucleated polymerization, to a fast collapse of peptides and subsequent rearrangement characteristic of nucleated conformational conversion with a high maximum in the number of peptides in oligomers as the total crowder surface area increases. The rate of conversion from oligomers to fibrils also increases with increasing total crowder surface area, giving rise to an increased rate of fibril growth. In all cases, larger volume fractions and smaller crowders provide the greatest aggregation enhancement effects. We also show that the size of the crowders influences the formation of specific oligomer sizes. In our simulations, the 40 Å crowders enhance the number of dimers relative to the numbers of trimers, hexamers, pentamers, and hexamers, while the 5 Å crowders enhance the number of hexamers relative to the numbers of dimers, trimers, tetramers, and pentamers. These results are in qualitative agreement with previous experimental and theoretical work. © 2014 American Chemical Society.

Gelation and cross-linking in multifunctional thiol and multifunctional acrylate systems involving an in situ comonomer catalyst

Dynamic rheology in combination with Fourier transform infrared spectroscopy (FTIR) is used to examine the gelation kinetics, mechanism, and gel point of novel thiol-acrylate systems containing varying concentrations of an in situ catalyst. Gelation, as evidenced from the gel time determined using the Winter-Chambon criterion, is found to occur more quickly with increasing catalyst concentration up until a critical catalyst concentration of 22 mol %, whereupon the gel time lengthens. Such a minimum in gel time may be attributed to changes in the number of available reaction sites and percentage conversion required for gelation. Chemical conversions at the gel point measured for representative samples are consistent with theoretical values calculated using Flory-Stockmayer\u27s statistical approach, confirming our hypothesis. Relaxation exponents of 0.97 and fractal dimensions of 1.3 are calculated for all samples, consistent with coarse-grained discontinuous molecular dynamics (DMD) simulations. The elevated value of n may be due to the low molecular weight prepolymer. The relaxation exponent and fractal dimensions are invariable over all systems studied, suggesting the cross-linking mechanism remains unaffected by changes in catalyst concentration, allowing the gel time to be tailored by simply modulating the catalyst concentration. © 2014 American Chemical Society

Department of Animal Sciences research and reviews: poultry and swine

Skeletal muscle collagen organization may be associated with proteoglycan expression / Sandra G. Velleman -- Influence of adult body weight and egg weight on hatching time in selected and random bred control lines of turkeys / K. E. Nestor and D. O. Noble -- Effect of crossing a line selected for increased shank width with two commercial sire lines on performance and walking ability of turkeys / Karl E. Nestor and John W. Anderson -- The energy used for maintenance each day by broiler chickens / David Latshaw and Matthew Toussant -- Variation at microsatellite loci in the large white, Yorkshire, and Hampshire breeds of swine / S. L. Kacirek, K. M. Irvin, P. I. Dimsoski, M. E. Davis, and H. C. Hines -- The estimation of maternal and individual heterosis in Yorkshire, large white, and Hampshire swine and their crosses / M. J. Barhorst, K. M. Irvin, S. J. Moeller, and S. M. Neal -- Investigation of the estrogen receptor gene and its association with reproductive tract traits in swine / B. Isler, K. M. Irvin, and S. M. Neal -- Effects of exogenous testosterone on follicular responsiveness to gonadotrophins during the luteal phase of the estrous cycle in gilts / M. B. Cunningham and W. F. Pope -- Evaluation of the further-processing quality of ham muscles from Hampshire hogs / C. L. Knipe, D. L. Meeker, B. D. Paxton, S. J. Moeller, K. M. Irvin, D. M. Wulf, and R. C. Emnett -- Frequency and effects of the napole gene in the U.S. pork industry / D. L. Meeker, S. J. Moeller, K. M. Irvin, D. M. Wulf, C. L. Knipe, and R. C. Emnet

Sequence-indexed mutations in maize using the UniformMu transposon-tagging population

<p>Abstract</p> <p>Background</p> <p>Gene knockouts are a critical resource for functional genomics. In Arabidopsis, comprehensive knockout collections were generated by amplifying and sequencing genomic DNA flanking insertion mutants. These Flanking Sequence Tags (FSTs) map each mutant to a specific locus within the genome. In maize, FSTs have been generated using DNA transposons. Transposable elements can generate unstable insertions that are difficult to analyze for simple knockout phenotypes. Transposons can also generate somatic insertions that fail to segregate in subsequent generations.</p> <p>Results</p> <p>Transposon insertion sites from 106 UniformMu FSTs were tested for inheritance by locus-specific PCR. We confirmed 89% of the FSTs to be germinal transposon insertions. We found no evidence for somatic insertions within the 11% of insertion sites that were not confirmed. Instead, this subset of insertion sites had errors in locus-specific primer design due to incomplete or low-quality genomic sequences. The locus-specific PCR assays identified a knockout of a 6-phosphogluconate dehydrogenase gene that co-segregates with a seed mutant phenotype. The mutant phenotype linked to this knockout generates novel hypotheses about the role for the plastid-localized oxidative pentose phosphate pathway during grain-fill.</p> <p>Conclusion</p> <p>We show that FSTs from the UniformMu population identify stable, germinal insertion sites in maize. Moreover, we show that these sequence-indexed mutations can be readily used for reverse genetic analysis. We conclude from these data that the current collection of 1,882 non-redundant insertion sites from UniformMu provide a genome-wide resource for reverse genetics.</p