2,544 research outputs found

    Research Notes : United States : Allelism tests of T218H and T225H

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    Genetic type T218M was found in \u27Illini\u27 in 1952 at Urbana, IL. T218H was derived from T218M by crossing a yellow branch as male parent with Illini. The F1 plants were green. Segregation in the F2 gave 3 green: 1 yellow lethal plants. F2 green plants gave ratios of 1 nonsegregating: 2 segregating prog-enies in the F3 generation, confirming monogenic inheritance (Palmer, 1978, unpublished). The recessive allele is carried as the heterozygote in T218H

    The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

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    Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over $\sim 2 \ \mathrm{deg}^2oftheCOSMOSfield.WesplittheradiosourcepopulationintoStarFormingGalaxies(SFGs)andActiveGalacticNuclei(AGN),andfurtherseparatetheAGNintoradiativelyefficientandinefficientaccreters.Restrictingouranalysisto of the COSMOS field. We split the radio source population into Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to z<1,wefindSFGshaveabias,, we find SFGs have a bias, b = 1.5 ^{+0.1}_{-0.2},atamedianredshiftof, at a median redshift of z=0.62.Ontheotherhand,AGNaresignificantlymorestronglyclusteredwith. On the other hand, AGN are significantly more strongly clustered with b = 2.1\pm 0.2atamedianredshiftof0.7.ThissupportstheideathatAGNarehostedbymoremassivehaloesthanSFGs.WealsofindlowaccretionrateAGNaremoreclustered( at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low-accretion rate AGN are more clustered (b = 2.9 \pm 0.3)thanhighaccretionrateAGN() than high-accretion rate AGN (b = 1.8^{+0.4}_{-0.5})atthesameredshift() at the same redshift (z \sim 0.7),suggestingthatlowaccretionrateAGNresideinhighermasshaloes.ThissupportspreviousevidencethattherelativelyhotgasthatinhabitsthemostmassivehaloesisunabletobeeasilyaccretedbythecentralAGN,causingthemtobeinefficient.WealsofindevidencethatlowaccretionrateAGNappeartoresideinhalomassesof), suggesting that low-accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low-accretion rate AGN appear to reside in halo masses of M_{h} \sim 3-4 \times 10^{13}h^{-1}MM_{\odot}atallredshifts.Ontheotherhand,theefficientaccretersresideinhaloesof at all redshifts. On the other hand, the efficient accreters reside in haloes of M_{h} \sim 1-2 \times 10^{13}h^{-1}MM_{\odot}atlowredshiftbutcanresideinrelativelylowermasshaloesathigherredshifts.Thiscouldbeduetotheincreasedprevalenceofcoldgasinlowermasshaloesat at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at z \ge 1comparedto compared to z<1$.Comment: 20 pages, 10 figures, 1 table, accepted by MNRA

    Polyphenol Oxidase Activity and \u3ci\u3ein vitro\u3c/i\u3e Proteolytic Inhibition in Grasses

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    Harvesting and storing high quality forage in the cool humid regions remains a challenge due to the potential for protein degradation during ensiling. Red clover is an exception as high protein levels are maintained during ensiling. Decreased proteolytic activity in red clover is due to polyphenol oxidase (PPO) activity and appropriate o-diphenol substrates (Jones et al., 1995, Sullivan et al., 2004). This project was undertaken to determine if PPO activity is present in a range of grasses and the potential role in proteolytic inhibition in the presence of the o-diphenol caffeic acid

    Polyphenol Oxidase Activity and \u3cem\u3ein Vitro\u3c/em\u3e Proteolytic Inhibition in Grasses

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    Harvesting and storing high quality forage in the cool humid regions remains a challenge due to the potential for protein degradation during ensiling. Red clover is an exception as high protein levels are maintained during ensiling. Decreased proteolytic activity in red clover is due to polyphenol oxidase (PPO) activity and appropriate o-diphenol substrates (Jones et al., 1995, Sullivan et al., 2004). This project was undertaken to determine if PPO activity is present in a range of grasses and the potential role in proteolytic inhibition in the presence of the o-diphenol caffeic acid

    Edges and Diffractive Effects in Casimir Energies

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    The prototypical Casimir effect arises when a scalar field is confined between parallel Dirichlet boundaries. We study corrections to this when the boundaries themselves have apertures and edges. We consider several geometries: a single plate with a slit in it, perpendicular plates separated by a gap, and two parallel plates, one of which has a long slit of large width, related to the case of one plate being semi-infinite. We develop a general formalism for studying such problems, based on the wavefunctional for the field in the gap between the plates. This formalism leads to a lower dimensional theory defined on the open regions of the plates or boundaries. The Casimir energy is then given in terms of the determinant of the nonlocal differential operator which defines the lower dimensional theory. We develop perturbative methods for computing these determinants. Our results are in good agreement with known results based on Monte Carlo simulations. The method is well suited to isolating the diffractive contributions to the Casimir energy.Comment: 32 pages, LaTeX, 9 figures. v2: additional discussion of renormalization procedure, version to appear in PRD. v3: corrected a sign error in (70

    Implications of invariance of the Hamiltonian under canonical transformations in phase space

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    We observe that, within the effective generating function formalism for the implementation of canonical transformations within wave mechanics, non-trivial canonical transformations which leave invariant the form of the Hamilton function of the classical analogue of a quantum system manifest themselves in an integral equation for its stationary state eigenfunctions. We restrict ourselves to that subclass of these dynamical symmetries for which the corresponding effective generating functions are necessaarily free of quantum corrections. We demonstrate that infinite families of such transformations exist for a variety of familiar conservative systems of one degree of freedom. We show how the geometry of the canonical transformations and the symmetry of the effective generating function can be exploited to pin down the precise form of the integral equations for stationary state eigenfunctions. We recover several integral equations found in the literature on standard special functions of mathematical physics. We end with a brief discussion (relevant to string theory) of the generalization to scalar field theories in 1+1 dimensions.Comment: REVTeX v3.1, 13 page

    Effect of metoprolol on myocardial function and energetics in patients with nonischemic dilated cardiomyopathy: A randomized, double-blind, placebo-controlled study

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    AbstractObjectives. This study examined the of metoprolol on left ventricular performance, efficiency, neurohormonal activation and myocardial respiratory quotient in patients with dilated cardiomyopathy.Background.The mechanism by which beta-adrenergie blockade improves ejection fraction in patients with dilated cardiomyopathy remains an enigma. Thus, we undertook an extensive hemodynamic evaluation of this mechanism. In addition, because animal models have shown that catecholamine exposure may increase relative fatty acid utilization, we hypothesized that antagonism of sympathetic stimulation may result in increased carbohydrate utilization.Methods. This was a randomized, double-blind, prospective trial in which 24 men with nonischemic dilated cardiomyopathy underwent cardiac catheterization before and after 3 months of therapy with metoprolol (n = 15) or placebo (n = 9) in addition to standard therapy. Pressure-volume relations were examined using a micromanometer catheter and digital ventriculography.Results. At baseline, the placebo-treated patients had somewhat more advanced left ventricular dysfunction. Ejection fraction and left ventricular performance improved only in the metoprolol-treated patients. Stroke and minute work increased without an increase in myocardial oxgen consumption, suggesting increased myocardial efficiency. Further increases in ejection fraction were seen between 3 and 6 months in the metoprolol group. The placebo group had a significant increase in ejection fraction only after crossover to metoprolol. A significant relation the change in coronary sinus norepinephrine and myocardial respiratory quotient was seen, suggesting a possible effect of adrenergic deactivation on substrate utilization.Conclusions. These data demonstrate that in patients with cardiomyopthy, metoprolol treatment improves myocardial performance and energetics, and favorably alters substrate utilization. Beta-adrenergic blocking agents, such as metoprolol, are hemodynamically and energetically beneficial in the treatment of myocardial failure
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