15,677 research outputs found
Probing Contact Interactions at High Energy Lepton Colliders
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
and contact interactions using the
reactions: at future
linear colliders with TeV and colliders
with 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
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
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
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
We use an exact transfer-matrix approach to compute the equilibrium
properties of a system of hard disks of diameter confined to a
two-dimensional channel of width 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
that is less than the maximum possible , 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
. 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 as our equivalent of the
penetration length for amorphous order: In the channel system, it reaches a
maximum value of around at , which is larger than the
penetration lengths that have been reported for three dimensional systems. It
is argued that the -relaxation time would appear on extrapolation to
diverge in a Vogel-Fulcher manner as the packing fraction approaches .Comment: 17 pages, 16 figure
Absence of hyperuniformity in amorphous hard-sphere packings of nonvanishing complexity
We relate the structure factor in a system of
jammed hard spheres of number density to its complexity per particle
by the formula . We have verified this formula for
the case of jammed disks in a narrow channel, for which it is possible to find
and analytically. Hyperuniformity, which is the
vanishing of , 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
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
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