41,034 research outputs found

    Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV

    No full text
    The prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region

    The multitasking framework: the effects of increasing workload on acute psychobiological stress reactivity

    No full text
    A variety of techniques exist for eliciting acute psychological stress in the laboratory; however, they vary in terms of their ease of use, reliability to elicit consistent responses and the extent to which they represent the stressors encountered in everyday life. There is, therefore, a need to develop simple laboratory techniques that reliably elicit psychobiological stress reactivity that are representative of the types of stressors encountered in everyday life. The multitasking framework is a performance-based, cognitively demanding stressor, representative of environments where individuals are required to attend and respond to several different stimuli simultaneously with varying levels of workload. Psychological (mood and perceived workload) and physiological (heart rate and blood pressure) stress reactivity was observed in response to a 15-min period of multitasking at different levels of workload intensity in a sample of 20 healthy participants. Multitasking stress elicited increases in heart rate and blood pressure, and increased workload intensity elicited dose–response increases in levels of perceived workload and mood. As individuals rarely attend to single tasks in real life, the multitasking framework provides an alternative technique for modelling acute stress and workload in the laboratory

    Letter from Carl T. Hayden to C. H. Gensler, Havasupai Reservation

    No full text
    Letter from Carl T. Hayden to C. H. Gensler, Havasupai Indian Reservation, regarding Hualapai and Cataract Canyons geography

    Aesop in Verse

    No full text
    The introduction finds verse appealing for children and even adults and offers the combined authority of Socrates, Phaedrus, and La Fontaine in favor of fables in poetry. At any rate, among the countless current editions of the Fables one edition in verse will not be regarded as quite out of place (ix). The morals are given in pentameter couplets, while the stories themselves are in couplets apparently of four feet and then three. The T of C on xiii-xvi numbers the one hundred fables here, and there is an AI at the back. A fable and its illustration take up either one or two pages. I read the first ten fables and enjoyed them and their illustrations. Wetherell is faithful to the tradition. The wolf's final retort to the lamb is nicely done: All your excuses but vex me the more,/And there's yet one way to treat you:/If I'm always wrong and you're always right,/I still can manage to eat you (3). Does it help MM to have the maid walking home rather than to market (4)? Poetry is a cruel mistress, and WC may show the compromises Wetherell needs to make to keep his rhyme and rhythm going (7). I am surprised that I have never heard or read of this book. May it not have been distributed outside Canada? Not in Bodemann. Page 105 of the extra copy is damaged, and its front cover is growing loose.This is a hardbound book (hard cover)By J.E. Wetherel

    A possible mechanism of superconductivity in high-T-c cuprates

    No full text
    This paper derives a generic T-c formula by using the long-range phase coherence condition in quantum phase fluctuation of the order parameter. Taking the two-local-spin-mediated interaction (TLSMI) proposed by Liu and Chen [Phys. Rev. B 58 (1998) 8812] as a Cooper pair potential, and the T-c formula, this paper explains five basic experimental facts in high-T-c cuprates. The aim of this paper is to show that TLSMI is a possible pairing mechanism of superconductivity in high-T-c cuprates. (C) 2000 Elsevier Science B.V. All rights reserved.Physics, AppliedSCI(E)EI0ARTICLE4276-28434

    Memorandum from A. E. Demaray to E. C. Finney

    No full text
    Four letters of correspondence about the purchase of Bright Angel Trail between A. E. Demaray, Acting Director of the Grand Canyon National Park; E. C. Finney, Department of the Interior First Assistant Secretary; Carl T. Hayden, Representative (AZ); and Stephen T. Mather, Director of the National Park Service

    Letter from C. T. Woolfolk, Coconino County Board of Supervisors, to Carl Hayden

    No full text
    Letter from C. T. Woolfolk to Carl Hayden expressing his support for the national park bill

    DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire

    No full text
    The majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
    corecore