15,677 research outputs found

    Probing Contact Interactions at High Energy Lepton Colliders

    Full text link
    Fermion compositeness and other new physics can be signalled by the presence of a strong four-fermion contact interaction. Here we present a study of qq\ell\ell qq and \ell\ell\ell'\ell' contact interactions using the reactions: ++,bbˉ,ccˉ\ell^+ \ell^- \to \ell'^+\ell'^-,b\bar b, c\bar c at future e+ee^+e^- linear colliders with s=0.55\sqrt s=0.5-5 TeV and μ+μ\mu^+\mu^- colliders with s=0.5,4\sqrt s=0.5,4 TeV. We find that very large compositeness scales can be probed at these machines and that the use of polarized beams can unravel their underlying helicity structure.Comment: 12 pg, to appear in the {\it Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics - Snowmass96}, Snowmass, CO, 25 June - 12 July, 199

    An unusual case of intertrigo in an adult caused by purely cutaneous Langerhans cell histiocytosis

    Get PDF
    We report a case of persistent intertrigo in an adult, eventually diagnosed as cutaneous Langerhans cell histiocytosis (LCH). It is known that LCH has a predilection for intertriginous areas, however purely cutaneous disease as in our case, is uncommon and usually other systems are affected. Following the report, literature of similar cases is reviewed to determine possible outcomes and to decide on the best possible treatment options.peer-reviewe

    The Aphids (Homoptera: Aphididae) Associated With Bell Peppers and Surrounding Vegetation in Southern Illinois

    Get PDF
    Outbreaks of cucumber mosaic virus (CMV) disease, caused by an aphid- transmitted pathogen, greatly reduced yields of bell pepper in southern Illinois in the mid-1990s. To provide the basis for further studies of the roles of individual apbid species in virus transmission, we surveyed aphid flights in and around pepper fields in 1996 and 1997 by using suction traps, interception nets, landing traps, sweep nets, and hand-picking. We collected 78 species of aphids, 15 of which have been reported to transmit CMV to peppers. The most abundant species taken from suction traps and interception nets in combination were Lipaphis erysimi, Rhopalosiphum padi, Rhopalosiphum maidis, Schizaphis graminum, and Aphis craccivora. All of these species are known to transmit CMV to peppers, but the phenology of R. maidis in Illinois suggests it is not the vector that brings CMV to pepper fields to initiate disease outbreaks. Brachycaudus helichrysi was relatively abundant in 1996 in May and June when a CMV outbreak may have been initiated; it was absent in 1997, and CMV infections were rare that season. Two species, Carolinaia carolinensis and Myzus hemerocallis were recorded for the first time in Illinois

    Compact 85 fs frequency doubled 810 nm fiber system with 60 mW of average power

    No full text
    We demonstrate a sub-100 fs frequency doubled fiber laser operating at 810 nm. The laser produces 60 mW of average power at a repetition rate of 50 MHz. Extremely low amplitude noise (below 0.1%) and compact size makes this source ideal replacement for low power ultrafast Ti:Spphire lasers

    Understanding the ideal glass transition: Lessons from an equilibrium study of hard disks in a channel

    Full text link
    We use an exact transfer-matrix approach to compute the equilibrium properties of a system of hard disks of diameter σ\sigma confined to a two-dimensional channel of width 1.95σ1.95\,\sigma at constant longitudinal applied force. At this channel width, which is sufficient for next-nearest-neighbor disks to interact, the system is known to have a great many jammed states. Our calculations show that the longitudinal force (pressure) extrapolates to infinity at a well-defined packing fraction ϕK\phi_K that is less than the maximum possible ϕmax\phi_{\rm max}, the latter corresponding to a buckled crystal. In this quasi-one-dimensional problem there is no question of there being any \emph{real} divergence of the pressure at ϕK\phi_K. We give arguments that this avoided phase transition is a structural feature -- the remnant in our narrow channel system of the hexatic to crystal transition -- but that it has the phenomenology of the (avoided) ideal glass transition. We identify a length scale ξ~3\tilde{\xi}_3 as our equivalent of the penetration length for amorphous order: In the channel system, it reaches a maximum value of around 15σ15\,\sigma at ϕK\phi_K, which is larger than the penetration lengths that have been reported for three dimensional systems. It is argued that the α\alpha-relaxation time would appear on extrapolation to diverge in a Vogel-Fulcher manner as the packing fraction approaches ϕK\phi_K.Comment: 17 pages, 16 figure

    Absence of hyperuniformity in amorphous hard-sphere packings of nonvanishing complexity

    Get PDF
    We relate the structure factor S(k0)S(\mathbf{k} \to \mathbf{0}) in a system of jammed hard spheres of number density ρ\rho to its complexity per particle Σ(ρ)\Sigma(\rho) by the formula S(k0)=1/[ρ2Σ(ρ)+2ρΣ(ρ)]S(\mathbf{k} \to \mathbf{0})=-1/ [\rho^2\Sigma''(\rho)+2\rho\Sigma'(\rho)]. We have verified this formula for the case of jammed disks in a narrow channel, for which it is possible to find Σ(ρ)\Sigma(\rho) and S(k)S(\mathbf{k}) analytically. Hyperuniformity, which is the vanishing of S(k0)S(\mathbf{k} \to \mathbf{0}), will therefore not occur if the complexity is nonzero. An example is given of a jammed state of hard disks in a narrow channel which is hyperuniform when generated by dynamical rules that produce a non-extensive complexity.Comment: 5 pages, 3 figure

    The validity of capillary blood sampling in the determination of human growth hormone concentration during exercise in men

    Get PDF
    This is an open access article - Copyright © 2004 BMJ Publishing Group LtdBACKGROUND: Studies measuring human growth hormone (hGH) in blood during exercise have mainly used venous sampling. The invasive nature of this procedure makes evaluation of hGH impossible in various exercise environments. OBJECTIVE: To determine whether capillary sampling could offer an alternative sampling method. METHODS: Capillary and venous blood samples were collected for determination of hGH at the end of each exercise stage during an incremental exercise test in 16 male club level competitive cyclists (mean (SD) age 30.8 (8.0) years, body mass 72.2 (7.1) kg, body fat 12.9 (3.5)%, peak oxygen consumption 4.18 (0.46) l⋅min−1). Linear regression, from a plot of venous v capillary blood hGH concentration, showed a correlation coefficient of r = 0.986 (p<0.001). When geometric means and log transformations were used, a coefficient of variation of 14.2% was demonstrated between venous and capillary flow for hGH concentration. The mean ratio limits of agreement were 0.62 (1.72)—that is, 95% of the ratios were contained between 0.36 and 1.07, with a mean of 0.62. CONCLUSIONS: Capillary blood sampling is an acceptable alternative to venous sampling for determining hGH concentration during rest and exercise. Sample sites should not be used interchangeably: one site should be chosen and its use standardised
    corecore