University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

The Dominant white, Dun and Smoky Color Variants in Chicken Are Associated With Insertion/Deletion Polymorphisms in the PMEL17 Gene

Abstract: Dominant white, Dun, and Smoky are alleles at the Dominant white locus, which is one of the major loci affecting plumage color in the domestic chicken. Both Dominant white and Dun inhibit the expression of black eumelanin. Smoky arose in a White Leghorn homozygous for Dominant white and partially restores pigmentation. PMEL17 encodes a melanocyte-specific protein and was identified as a positional candidate gene due to its role in the development of eumelanosomes. Linkage analysis of PMEL17 and Dominant white using a red jungle fowl/White Leghorn intercross revealed no recombination between these loci. Sequence analysis showed that the Dominant white allele was exclusively associated with a 9-bp insertion in exon 10, leading to an insertion of three amino acids in the PMEL17 transmembrane region. Similarly, a deletion of five amino acids in the transmembrane region occurs in the protein encoded by Dun. The Smoky allele shared the 9-bp insertion in exon 10 with Dominant white, as expected from its origin, but also had a deletion of 12 nucleotides in exon 6, eliminating four amino acids from the mature protein. These mutations are, together with the recessive silver mutation in the mouse, the only PMEL17 mutations with phenotypic effects that have been described so far in any species.

Oblique collision in the northeastern Caribbean from GPS measurements and geological observations

Abstract: [1] Previous Caribbean GPS studies have shown that the rigid interior of the Caribbean plate is moving east-northeastward (070°) at a rate of 18–20 ± 3 mm/yr relative to North America. This direction implies maximum oblique convergence between the island of Hispaniola on the Caribbean plate and the 22–27-km-thick crust of the Bahama carbonate platform on the adjacent North America plate. We present a tectonic interpretation of a 15-site GPS network which spans the Hispaniola-Bahama oblique collision zone and includes stable plate interior sites on both the North America and Caribbean plates. Measurements span the time period of 1994–1999. In a North America reference frame, GPS velocities in Puerto Rico, St. Croix, and the Lesser Antilles indicate that these areas move as a single block in an east-northeast direction (070°) at a rate of 19–20 mm/yr consistent with the movement of the rigid interior of the Caribbean plate. GPS velocities at six sites in central and eastern Hispaniola (Dominican Republic) show drastically different behavior with more eastwardly strikes (080°) and much slower rates (4–17 mm/yr) than areas of the stable Caribbean plate. The boundary between the relatively slower-moving Hispaniola collisional zone and the relatively faster-moving, uncollided Puerto Rico-Virgin Islands area is the Mona Passage where late Neogene rifting occurs in a broad zone. Elastic modeling favors strain partitioning with oblique slip on the outer, low-angle submarine thrust faults (North Hispaniola, Muertos) and strike slip on the inner, subvertical subaerial, strike-slip faults (Septentrional, Enriquillo).

Sudden Death Syndrome of Soybean

Abstract:  Sudden death syndrome (SDS) is one of the most important diseases of soybean in North and South America.  Soybeans are at greater risk for SDS when planted into cool, wet soils, when soybean cyst nematode (SCN) is present, and when summer rains cause saturated soils.  Managing SDS can involve several practices such as relieving soil compaction, delaying planting, and selecting soybean products with a good disease tolerance package.