4,747 research outputs found
Bremsstrahlung from relativistic heavy ions in a fixed target experiment at the LHC
We calculate the emission of bremsstrahlung from lead and argon ions in A
Fixed Target ExpeRiment (AFTER) that uses the LHC beams. With nuclear charges
of equal and respectively, these ions are accelerated to
energies of TeV. The bremsstrahlung peaks around
GeV and the spectrum exposes the nuclear structure of the incoming ion. The
peak structure is significantly different from the flat power spectrum
pertaining to a point charge. Photons are predominantly emitted within an angle
of to the direction of ion propagation. Our calculations are based
on the Weizs\"{a}cker-Williams method of virtual quanta with application of
existing experimental data on photonuclear interactions.Comment: 9 pages, 3 figures. Submitted to Advances in High Energy Physic
Automatic sleep staging of EEG signals: recent development, challenges, and future directions.
Modern deep learning holds a great potential to transform clinical studies of human sleep. Teaching a machine to carry out routine tasks would be a tremendous reduction in workload for clinicians. Sleep staging, a fundamental step in sleep practice, is a suitable task for this and will be the focus in this article. Recently, automatic sleep-staging systems have been trained to mimic manual scoring, leading to similar performance to human sleep experts, at least on scoring of healthy subjects. Despite tremendous progress, we have not seen automatic sleep scoring adopted widely in clinical environments. This review aims to provide the shared view of the authors on the most recent state-of-the-art developments in automatic sleep staging, the challenges that still need to be addressed, and the future directions needed for automatic sleep scoring to achieve clinical value
Optical alignment and polarization conversion of neutral exciton spin in individual InAs/GaAs quantum dots
We investigate exciton spin memory in individual InAs/GaAs self-assembled
quantum dots via optical alignment and conversion of exciton polarization in a
magnetic field. Quasiresonant phonon-assisted excitation is successfully
employed to define the initial spin polarization of neutral excitons. The
conservation of the linear polarization generated along the bright exciton
eigenaxes of up to 90% and the conversion from circular- to linear polarization
of up to 47% both demonstrate a very long spin relaxation time with respect to
the radiative lifetime. Results are quantitatively compared with a model of
pseudo-spin 1/2 including heavy-to-light hole mixing.Comment: 5 pages, 3 figure
Production of antibiotic-free pigs – tools and results
The present paper describes preliminary results from a Danish project with production of antibiotic-free pigs. The project herd is a traditional Danish 500 sow herd with weaned pigs on the same site. 1/3 of the pigs are kept until slaughter on an adjacent farm and remaining pigs are sold to local finishing producers. Before initiation of the project, the herd had a consumption of antibiotics around 50% of the threshold given by the Danish authorities. However, the farmer took the challenge to produce pigs without any antibiotics at all, with the initial goal to deliver 50% antibiotic-free pigs for slaughter. The measures implemented were a stronger focus on management and vaccination against Lawsonia intracellularis on top of Mycoplasma hyopneumoniae and PCV2 vaccination. The results are promising: In the first 6 months of the project, the herd has not only experienced reduced use of antibiotics, but also an increased productivity. The monthly prescriptions of antibiotics were lowered from 2.15 to 1.86 Animal Daily Doses (ADD) per 100 pigs per day in the sow herd and from 8.30 to 4.19 ADD/100 pigs/day in the weaners. Compared to the previous year, the piglet mortality in the farrowing unit dropped by 2.5 %, the average daily weight gain in weaners increased by 34 g/day and the feed conversion rate dropped by 0.15 FE/kg. Data from finishers are not yet available
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