4,263 research outputs found

    Experimental Observation of Modulation Instability and Optical Spatial Soliton Arrays in Soft Condensed Matter

    Get PDF
    In this Letter we report observations of optically induced self-organization of colloidal arrays in the presence of un-patterned counter-propagating evanescent waves. The colloidal arrays formed along the laser propagation-axis are shown to be linked to the break-up of the incident field into optical spatial solitons, the lateral spacing of the arrays being related to modulation instability of the soft condensed matter system.Comment: 16 pages, 3 figure

    Superconducting Surface Impedance under Radiofrequency Field

    Full text link
    Based on BCS theory with moving Cooper pairs, the electron states distribution at 0K and the probability of electron occupation with finite temperature have been derived and applied to anomalous skin effect theory to obtain the surface impedance of a superconductor under radiofrequency (RF) field. We present the numerical results for Nb and compare these with representative RF field-dependent effective surface resistance measurements from a 1.5 GHz resonant structure

    EC85-198 Nebraska Poisonous Range Plants

    Get PDF
    Extension Circular 85-198: Nebraska Poisonous Range Plants. This circular helps people identify plants that grow in Nebraska that may be poisonous

    EC85-198 Nebraska Poisonous Range Plants

    Get PDF
    Extension Circular 85-198: Nebraska Poisonous Range Plants. This circular helps people identify plants that grow in Nebraska that may be poisonous

    Performance and Potential of Intergeneric Wheatgrass Hybrids in the Central Great Plains

    Get PDF
    Three studies were conducted to evaluate intergeneric wheatgrass hybrids for their potential as range and pasture grasses in the Central Great Plains. Quackgrass [Elytriga-repens (L.) Nevski] X bluebunch wheatgrass [Psueodoroegneria spicata (Pursh) A. LoveJ F5 hybrid lines (RS lines) developed by D.R. Dewey were grown in a space transplanted nursery at Lincoln, NE, to estimate genetic variability for forage yield and quality as measured by in vitro dry matter digestibility (IVDMD) and protein in the RS population. There was significant variability among the RS lines for all traits (broad-sense heritability H \u3e 0.5) except for first harvest IVDMD (H = 0.26). The highest yielding RS lines yielded only about half as much forage as \u27Slate\u27 intermediate wheatgrass [Thinopyron intermedium (Host) Barkworth and D.R. Dewey subsp. intermedium], which was included as a check. Slate intermediate wheatgrass, \u27Ruff crested wheatgrass [Agropyron cristatum (L.) Gaertner], \u27Nordan\u27 crested wheatgrass [A. desertorum (Fisch.) SchultesJ, RS-1 and RS-2 (quackgrass X bluebunch wheatgrass germplasm), and a quackgrass X A. desertorum hybrid designated as RD were then evaluated in sward nurseries in two environments (Mead and Alliance, NE) that differ widely in climate. Intermediate wheatgrass was clearly superior in forage yield and quality as measured by IVDMD in the eastern part (Mead) of the Central Great Plains. In the western part of this area (Alliance) intermediate and the crested wheatgrasses were equal or superior to the RS hybrids in forage yield and intermediate wheatgrass had higher IVDMD. The RD hybrid had lower yields than the other strains at both locations. Yields of the intergeneric wheatgrass hybrids could be improved by breeding to make them more competitive with intermediate and crested wheatgrasses. The same breeding effort could be used to improve these pure species for which substantial genetic variability for both yield and IVDMD has been previously documented and would probably result in greater overall progress. Forages from grasses grown at Mead in swards were analyzed using the detergent system of analyses and there was considerable variation among the grasses in fiber composition and digestibility of the fiber components even though the grasses were very similar in physiological maturity when harvested. The results suggest that there are genetic differences among these wheatgrasses in forage fiber composition and the digestibility of the fiber components

    Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

    Get PDF
    Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

    Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

    Get PDF
    Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

    Evaluation of Crested Wheatgrass Introductions for Forage Yield and Quality

    Get PDF
    Crested wheatgrass, Agropyron cristatum and A. desertorum, are among the most important cool-season forage grasses in the United States and Canada, particularly for reseeding arid range sites. Further improvement in this grass by breeding depends on identifying sources of genetic variability for forage yield and quality. Foreign introductions are an obvious source of genetic variation since crested wheatgrasses are introduced species. In this study 38 accessions (PI lines) and 8 Nebraska experimental lines were evaluated for forage quality as measured by in vitro dry matter digestibility (IVDMD) and protein content and for forage yield. The cultivars \u27Ruff\u27 and \u27Nordan\u27 and two clonal lines were included as checks. The strains were evaluated at Lincoln and Alliance, NE., which differ markedly in climate. There were large differences among strains evaluated for all traits including first- and second-cut forage yield, IVDMD, protein content, heading date, height and first year basal spread. Utilization of PI 369167, PI 369170, Ruff, and Nordan in a breeding program could result in crested wheatgrasses with improved forage yield and quality

    Genotype and Genotype x Environment Interaction Effects on Forage Yield and Quality of Intermediate Wheatgrass in Swards

    Get PDF
    Genetic differences among cultivars or strains for specific traits can be significantly reduced or increased by differential genotypic responses to environments. The objective of this study was to determine the relative magnitude of genotype and genotype x environment interaction effects, which are due to differential responses, on forage yield and quality of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] when grown in seeded swards in the central Great Plains. Thirty-four strains (genotypes), which included cultivars, experimental strains, and PI lines, were grown in replicated trials at Mead, North Platte, and Alliance, NE. The three sites differed markedly in precipitation and length of growing season. There were significant differences among strains for all evaluated traits. Genotype x location and genotype x year interaction effects were not significant for in vitro dry matter digestibility (IVDMD), indicating that this trait is quite stable across environments. Genotype x location interaction effects were significant for forage yield and protein concentration; genotype x year effects were significant for forage yield. Spearman rank correlations, used to test for consistency of ranking of the strains across environments, were high and significant for IVDMD, but were low and usually not significant for forage yield. Improving IVDMD should be emphasized in intermediate wheatgrass breeding programs, since there is substantial genetic variation for IVDMD, it is stable across environments, and it can improve livestock production per hectare

    Characterizing the Aerobic and Anaerobic Energy Costs of Polynesian Dances

    Get PDF
    International Journal of Exercise Science 11(4): 1156-1172, 2018. This study characterized both aerobic and anaerobic energy expenditure (EE) for several Polynesian dances in a group of experienced professional Polynesian dancers. Thirteen men and 17 women were tested using indirect calorimetry to assess aerobic EE (and converted to METs), and fingertip blood lactate to estimate anaerobic EE, during both resting and dancing activities. Total EE was then computed as the sum of both aerobic and anaerobic activity energy expenditure (AEE, or EE above resting). One sample t-tests compared mean MET values for each type of dance to the 3-MET and 6-MET thresholds for moderate and vigorous physical activity (MVPA), respectively. Mean MET values for all dances, except the Maori poi balls dance (Mean±SD: 3.7±1.1 METs; P=0.340), were significantly \u3e3.0 METs (5.9±3.1 METS; P=0.005 for Maori haka; 6.5±2.4 METs for Hawaiian hula; 6.6±1.2 METs for Samoan sasa; 9.6±1.5 METs for Samoan slap; 8.3±1.8 METs for Tahitian; 6.0±2.3 METs for Tongan; 7.0±2.6 METs for Fijian; P\u3c0.001). Mean METs for Samoan slap and Tahitian were also significantly \u3e6.0 METs (P=0.002 and P\u3c0.001, respectively). Aerobic and anaerobic AEE contributed an average of 83.4% and 16.6%, respectively, across all Polynesian dances, with Hawaiian hula being the most aerobic (88.7%) and Samoan slap being the least aerobic (74.2%). Thus, the Polynesian dances tested not only met the current MVPA intensity guidelines (i.e., ≥3.0 METs), each dance also had a large anaerobic EE. These data suggest that Polynesian dancing is an appropriate mode of aerobic exercise for health promotion and disease prevention
    • …
    corecore