25 research outputs found
Chemoenzymatic Preparation of Sugar-Based Hydrogels
We have prepared sugar-based hydrogels using a chemoenzymatic synthetic approach. Specifically, the regioselectivity of enzymes was used to prepare sugar acrylate monomers. These monomers were polymerized with a crosslinker in a standard free radical polymerization. The polymers consist of a polyacrylate backbone with sucrose, (α-methyl glucoside, or β-methyl galactoside pendant groups. These materials are highly water absorbent swelling to more than 100 times their initial weight when placed in water. The degree of swelling for poly(β-methyl galactoside 6-acrylate) hydrogel was relatively insensitive to pH (from pH 4.5-9) and ionic strength (0.15-3 M NaCl). Potential applications of these materials include waterabsorbents and drug delivery systems
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Effects of Messenger® Treatments on Upland Cotton in the Palo Verde Valley, 2001
Messenger® was applied ar various growth stages of cotton to ascertain effects upon yield and quality. Plant mapping data indicated that treated cotton aborted lowest developing fruits when temperatures caused stress during experiment, untreated cotton did not. Lack of Messenger® after first bloom resulted in lower lint quality. Untreated cotton had highest yields and value/ acre from the Nov. 9 harvest date, although Messenger® applied at both first bloom and three weeks after first bloom had highest yields and value/acre when harvested on October 15
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Evaluation of Twin-Line Cotton Production in Arizona - 2002
Twin-line (two seed lines 7.25 in apart per bed) and conventional single seed line per bed cotton production systems were compared at 16 sites across Arizona and Blythe, Ca. in 2002. The twin-line system produced more lint than the conventional single-line system at 4 of 16 locations; the yields of the twinline and single-line systems were 1273 and 1186 lb/acre, 1572 and 1461 lb/acre, 1478 and 1290 lb/acre, and 1309 and 1210 lb/acre, respectively, at the Grasty, Ramona, Rovey, and Wells sites, respectively. There were no significant differences in yield or fiber micronaire in 7 of the 16 experiments. The twin-line system produced less lint than the conventional system at 5 of 16 locations; yields of the twin-line and single-line systems were 2019 and 2189 lb/acre, 1400 and 1489 lb/acre, 1537 and 1845 lb/acre, 1065 and 1200 lb/acre, and 1271 and 1431 lb/acre, respectively, at the Chaffin (75K), Cooley, Hull, Papago, and Wakimoto sites, respectively. Fiber micronaire was reduced in five experiments; the micronaire values were 4.25 and 4.73, 4.46 and 4.78, 4.60 and 4.85, 4.76 and 4.98, and 4.93 and 5.15, in the twin-line and single-line systems, respectively, at the Rogers, Papago, Grasty, Hull, and Perry sites, respectively. Research will continue in 2003 in order to develop system comparison data for multiple years and to elucidate the reasons for the variable results measured in the 2002 cotton season
Global genetic diversity, lineage distribution, and Wolbachia infection of the alfalfa weevil Hypera postica (Coleoptera: Curculionidae)
The alfalfa weevil (Hypera postica) is a well‐known example of a worldwide‐distributed pest with high genetic variation. Based on the mitochondrial genes, the alfalfa weevil clusters into two main mitochondrial lineages. However, there is no clear picture of the global diversity and distribution of these lineages; neither the drivers of its diversification are known. However, it appears likely that historic demographic events including founder effects played a role. In addition, Wolbachia, a widespread intracellular parasite/symbiont, likely played an important role in the evolution of the species. Wolbachia infection so far was only detected in the Western lineage of H. postica with no information on the infecting strain, its frequency, and its consequences on the genetic diversity of the host. We here used a combination of mitochondrial and nuclear sequences of the host and sequence information on Wolbachia to document the distribution of strains and the degree of infection. The Eastern lineage has a higher genetic diversity and is found in the Mediterranean, the Middle East, Eastern Europe, and eastern America, whereas the less diverse Western lineage is found in Central Europe and the western America. Both lineages are infected with the same common strain of Wolbachia belonging to Supergroup B. Based on neutrality tests, selection tests, and the current distribution and diversification of Wolbachia in H. postica, we suggested the Wolbachia infection did not shape genetic diversity of the host. The introduced populations in the United States are generally genetically less diverse, which is in line with founder effects