476 research outputs found

    Nodulation of leguminous plants as affected by root secretions and red light

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    Nodulation of bean plants, Phaseolus vulgaris L., in water culture was poor during hot sunny weather in the greenhouse. It did not improve when indoleacetic acid, kinetin, gibberellic acid, purines and pyrimidines, yeast and soil extract were added. Nodulation was enhanced by adding used culture solution of nodulated pea or bean plants or an extract of root nodules. The active substance was soluble in water and ether and was inactivated by heating at 80°C. During purification it was observed that the active fractions strongly absorbed ultraviolet light at about 260 mμ.Light quality also influenced nodulation of plants grown in light cabinets: nodulation was good in red and poor in blue light. If the shoot was radiated with far- red light (about 730 mμ) for a few minutes at the end of the photoperiod, there were fewer nodules and this effect could be counteracted by subsequent radiation with red light (about 660 mμ). These results suggested that nodulation was controlled by the phytochrome system.The hypothesis was put forward that a kinetin-like substance was involved in the formation of root-nodules

    Rocket measurements of positive ions during polar mesosphere winter echo conditions

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    On 18 January 2005, two small, instrumented rockets were launched from Andøya Rocket Range (69.3° N, 16° E) during conditions with Polar Mesosphere Winter Echoes (PMWE). Each of the rockets was equipped with a Positive Ion Probe (PIP) and a Faraday rotation/differential absorption experiment, and was launched as part of a salvo of meteorological rockets measuring temperature and wind using falling spheres and chaff. Layers of PMWE were detected between 55 and 77 km by the 53.5 MHz ALWIN radar. The rockets were launched during a solar proton event, and measured extremely high ion densities, of order 1010 m−3, in the region where PMWE were observed. The density measurements were analyzed with the wavelet transform technique. At large length scales, ~103 m, the power spectral density can be fitted with a k−3 wave number dependence, consistent with saturated gravity waves. Outside the PMWE layers the k−3 spectrum extends down to approximately 102 m where the fluctuations are quickly damped and disappear into the instrumental noise. Inside the PMWE layers the spectrum at smaller length scales is well fitted with a k−5/3 dependence over two decades of scales. The PMWE are therefore clearly indicative of turbulence, and the data are consistent with the turbulent dissipation of breaking gravity waves. We estimate a lower limit for the turbulent energy dissipation rate of about 10−2 W/kg in the upper (72 km) layer

    An examination of therapists’ professional characteristics as moderators of the effect of feedback on psychological treatment outcomes

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    Objective Feedback-informed treatment (FIT) has been shown to reduce the gap between more and less effective therapists. This study aimed to examine therapists’ professional characteristics as potential moderators of the effect of feedback on treatment outcomes. Methods The IAPT-FIT Trial was a clinical trial where therapists were randomly assigned to a FIT group or a usual care control group. Treatment response was monitored using measures of depression (PHQ-9), anxiety (GAD-7) and functional impairment (WSAS). In a secondary analysis of this trial (n = 1,835 patients; t = 67 therapists), we used multilevel modelling to examine interactions between therapists’ professional characteristics (e.g., attitude towards and self-efficacy regarding feedback utilization, decision-making style, job satisfaction, burnout, difficulties in practice, coping styles, caseload size) with random allocation (FIT vs. controls) to identify moderators of the effects of feedback. Results Between 9.6% and 10.8% of variability in treatment outcomes was attributable to therapist effects. Therapist-level caseload sizes and external feedback propensity (EFP) moderated the effect of feedback on depression outcomes. No statistically significant main effects were found for any of the included therapist characteristics. Conclusion FIT reduced variability in outcomes between therapists and was particularly effective for therapists with high EFP and larger caseloads

    Isgur-Wise Functions from the Mit Bag Model

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    The Isgur-Wise functions for the ground state to ground state semileptonic decays involving bcb \rightarrow c transitions are calculated from the (modified) MIT bag model. It is checked that the results for the decays BDlν\overline{B} \rightarrow D l \overline\nu and BDlν\overline{B} \rightarrow D^* l \overline\nu agree well with experiment. Predictions for the decays ΛbΛclν\Lambda_b \rightarrow \Lambda_c l \overline\nu, BsDslν\overline{B}_s \rightarrow D_s l \overline\nu and BsDslν\overline{B}_s \rightarrow D^*_s l \overline\nu are given and discussed.Comment: 12 pages (3 figures available upon request), LaTeX, TPJU - 9/9

    Orbital anastomoses of the anterior deep temporal artery

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    The anterior deep temporal artery may provide a major collateral pathway to the intracranial circulation through anastomoses with branches of the ophthalmic artery. Review of carotid angiograms in 26 patients with internal carotid artery occlusive disease revealed anterior deep temporal to ophthalmic artery anastomoses in 16 cases. This route of collateral blood flow was associated in most instances with total occlusion of the cervical portion of the internal carotid artery. Three cases demonstrating the angiographic anatomy of the anterior deep temporal artery and its potential anastomoses with branches of the ophthalmic artery are presented. L'artère temporale profonde antérieure peut être à l'origine de circulation colatérale grâce à ses anastomoses avec l'artère ophtalmique. Une telle anastomose a été constatée 16 fois sur 26 cas de thrombose de l'artère carotide interne. Über die A. temporalis anterior ist über Anastomosen zu den Ästen der A. ophthalmica ein Kollateral-Kreislauf zu den intracraniellen Gefäßabschnitten möglich. Bei 26 Patienten mit einem A. carotis interna-Verschluß zeigte sich dieser Kreislauf in 16 Fällen. Es wird über 3 Fälle ausführlich berichtet, bei denen die angiographische Anatomie der A. temporalis anterior und die möglichen Anastomosen mit Ästen der A. ophthalmica besprochen wird.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46672/1/234_2004_Article_BF00335020.pd

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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