Fusion Peptides Promote Formation of Bilayer Cubic Phases in Lipid Dispersions. An X-Ray Diffraction Study

AbstractSmall angle x-ray diffraction revealed a strong influence of the N-terminal influenza hemagglutinin fusion peptide on the formation of nonlamellar lipid phases. Comparative measurements were made on a series of three peptides, a 20-residue wild-type X-31 influenza virus fusion peptide, GLFGAIAGFIENGWEGMIDG, and its two point-mutant, fusion-incompetent peptides G1E and G13L, in mixtures with hydrated phospholipids, either dipalmitoleoylphosphatidylethanolamine (DPoPE), or monomethylated dioleoyl phosphatidylethanolamine (DOPE-Me), at lipid/peptide molar ratios of 200:1 and 50:1. All three peptides suppressed the HII phase and shifted the Lα–HII transition to higher temperatures, simultaneously promoting formation of inverted bicontinuous cubic phases, QII, which becomes inserted between the Lα and HII phases on the temperature scale. Peptide-induced QII had strongly reduced lattice constants in comparison to the QII phases that form in pure lipids. QII formation was favored at the expense of both Lα and HII phases. The wild-type fusion peptide, WT-20, was distinguished from G1E and G13L by the markedly greater magnitude of its effect. WT-20 disordered the Lα phase and completely abolished the HII phase in DOPE-Me/WT-20 50:1 dispersions, converted the QII phase type from Im3m to Pn3m and reduced the unit cell size from ∼38 nm for the Im3m phase of DOPE-Me dispersions to ∼15 nm for the Pn3m phase in DOPE-Me/WT-20 peptide mixtures. The strong reduction of the cubic phase lattice parameter suggests that the fusion-promoting WT-20 peptide may function by favoring bilayer states of more negative Gaussian curvature and promoting fusion along pathways involving Pn3m phase-like fusion pore intermediates rather than pathways involving HII phase-like intermediates

State of the Art of Technology for Rural Water System Development

The objective of this study was to review the current state of the art in rural water system technology. This was to be accomplished by a literature review of the Water Resources Scientific Information Center (WRSIC), National Technical Information Service (NTIS), and Smithsonian Science Information Exchange (SSIE). This literature search was to be augmented by interviews with consulting engineers, operating system managers and industrial literature. Both groundwater and surface water technology was to be reviewed. The technology was then to be grouped into four classes: (1) current technology, (2) technology which has been developed, but not currently being used, (3) technology under development which looks promising, and (4) research needed. After the searches were conducted, it became feasible to combine group (2) and (3) into one group entitled technology under development but not fully utilized

Effect of Crude Glycerin Concentration on Growing Steer Performance in Forage Diets

The effect of increasing crude glycerin concentration was evaluated in a 91- d growing trial utilizing 60 steers. Crude glycerin was included at 0, 4, 8, and 12% of dietary DM in diets consisting of 50% wheat straw; 22.9- 37.0% wet corn bran, and 8.0- 10.1% soybean meal. Crude glycerin replaced wet corn bran and soybean meal was added to maintain dietary CP. Steer ending BW was not different among treatments. Th ere was a quadratic increase in DMI from 0 to 8% crude glycerin and subsequent decrease at 12%. Th ere was no difference in ADG or feed efficiency among crude glycerin concentrations. Therefore, crude glycerin appears to have an energy value slightly less than wet corn bran in a forage- based diet

Steer Performance Grazing Corn Residue and Supplemented with Modified Distillers Grains plus Solubles with or without Urea

A growing study was conducted to evaluate the effects of supplementing growing calves grazing corn residue with modified distillers grains plus solubles (MDGS; 3 or 5 lb/d) and with or without urea on growth performance. There were no significant MDGS × urea inclusion interactions observed. Urea inclusion level (0 and 0.12 lb/d) did not affect supplemental intake, ADG, or ending BW. Steers fed 5 lb of MDGS had an increased ADG and a heavier ending BW compared to steers fed 3 lb MDGS daily. Supplemental urea is not necessary when supplementing at least 3 lb MDGS to steers grazing corn residue

The Effect of Harvest Method and Ammoniation of Corn Residue on Growing Calf Performance

A growing trial was conducted to determine the effect of feeding baled corn residue harvested using three different methods, with and without ammoniation of the residue. Residue harvested with the New Holland Cornrower™ with two rows of chopped stem added to the windrow resulted in a 9% increase in ADG compared to conventional rake and bale harvest or turning off the combine spreader and baling tailing. Ammoniation of residue increased ADG 67% (increase of 1.1 lb/d) over non-ammoniated residue. Feed efficiency was not affected by harvest method, but ammoniation decreased F:G by 13% compared to cattle fed non-ammoniated residue. Although alternative harvest technologies can improve ADG, ammoniation of corn residue has a considerably greater impact on cattle performance

Evaluation of Corn Distillers Solubles on Growing Steer Performance

A growing study evaluated increasing inclusions of corn distillers solubles (CDS) at 10, 20, 30, and 40%, or increasing wet distillers grains plus solubles (WDGS) at 10, 20, 30, and 40% compared to a corn control. Corn was replaced by CDS or WDGS in each forage-based diet. Increasing CDS resulted in a quadratic increase for both DMI and F:G. Increasing WDGS linearly increased both DMI and ADG with no effect on F:G. The energy value of CDS is less than that of corn, whereas WDGS had an energy value similar to corn in growing diets with 50% brome hay. A 73.7% TDN value was determined for CDS at 40% inclusion in forage-based diets

Evaluation of Revalor-XH for beef heifers fed different days on feed

Heifers were treated with either no implant, an initial implant of Revalor-200 and re-implanted with Revalor-200, or Revalor-XH and assigned to one of four serial slaughter harvests at 151, 165, 179, and 193 days on feed to determine the effects on feedlot performance and carcass characteristics. Implanting heifers increased final BW, ADG and HCW while decreasing marbling score and improving feed efficiency compared to non-implanted heifers. Increasing days on feed decreased ADG while increasing feed efficiency, HCW, fat thickness, marbling score, and calculated yield grade. By increasing HCW sold, implanting revenue can be maximized, assuming added risk for YG discounts