95,549 research outputs found
Solving QCD evolution equations in rapidity space with Markovian Monte Carlo
This work covers methodology of solving QCD evolution equation of the parton
distribution using Markovian Monte Carlo (MMC) algorithms in a class of models
ranging from DGLAP to CCFM. One of the purposes of the above MMCs is to test
the other more sophisticated Monte Carlo programs, the so-called Constrained
Monte Carlo (CMC) programs, which will be used as a building block in the
parton shower MC. This is why the mapping of the evolution variables (eikonal
variable and evolution time) into four-momenta is also defined and tested. The
evolution time is identified with the rapidity variable of the emitted parton.
The presented MMCs are tested independently, with ~0.1% precision, against the
non-MC program APCheb especially devised for this purpose.Comment: version compatible with with the erratum in Acta Physica Polonic
MODULATION OF CALCIUM CHANNELS IN ARTERIAL SMOOTH-MUSCLE CELLS BY DIHYDROPYRIDINE ENANTIOMERS
The actions of the optical enantiomers of BAY K 8644 and Sandoz 202,791 were studied on barium inward currents recorded using the whole-cell configuration of the patch clamp technique from enzymatically isolated smooth muscle cells from the rabbit ear artery. The enantiomers were applied by bath perfusion or rapidly by a concentration jump technique, which enabled the study of drug action under equilibrium and nonequilibrium conditions. A larger effect of agonists was seen on peak inward current in 110 mM Ba when small rather than large depolarizations were applied. The midpoint voltage of the steady-state inactivation curve of IBa was -12.8 +/- 1.9 mV (n = 4) in the absence of drug, -16.4 +/- 2.5 mV (n = 4) in 1 microM (+)202,791, and -31.4 +/- 0.4 mV (n = 4) in 1 microM (-)202,791. The rate of onset of action of the agonist and antagonist enantiomers of BAY K 8644 and Sandoz 202,791 was studied by rapid application during 20-ms depolarizing steps from different holding potentials to +30 mV at 1 or 0.2 Hz. The drugs were applied as concentration jumps between two single pulses of a pulse train. The rates of onset of drug action on peak IBa during a 1-Hz pulse train were concentration dependent over the range of 100 nM-3 microM for both (+) and (-)202,791. The rate of onset of inhibition of peak current by antagonist enantiomers was not significantly influenced by the test pulse frequency. At a holding potential of -60 mV, the onset rate of the increase in peak IBa on application of 1 microM of agonist enantiomers (+)202,791 or (-)BAY K 8644 during a train of pulses occurred with mean time constants of 2.1 +/- 0.7 s (n = 7) and 2.3 +/- 0.2 s (n = 4), respectively. The onset of current increase on application of 1 microM (+)202,791 during a single voltage clamp step to 20 mV was faster, with a mean time constant of 380 +/- 80 ms (n = 3)
Quantum thermodynamics at critical points during melting and solidification processes
We systematically explore and show the existence of finite-temperature
continuous quantum phase transition (CTQPT) at a critical point, namely, during
solidification or melting such that the first-order thermal phase transition is
a special case within CTQPT. Infact, CTQPT is related to chemical reaction
where quantum fluctuation (due to wavefunction transformation) is caused by
thermal energy and it can occur maximally for temperatures much higher than
zero Kelvin. To extract the quantity related to CTQPT, we use the ionization
energy theory and the energy-level spacing renormalization group method to
derive the energy-level spacing entropy, renormalized Bose-Einstein
distribution and the time-dependent specific heat capacity. This work
unambiguously shows that the quantum phase transition applies for any finite
temperatures.Comment: To be published in Indian Journal of Physics (Kolkata
Reply to a Commentary "Asking photons where they have been without telling them what to say"
Interesting objections to conclusions of our experiment with nested
interferometers raised by Salih in a recent Commentary are analysed and
refuted.Comment: Published version (Frontiers in Physics) to revised version of the
Commentar
Update of MRST parton distributions.
We discuss the latest update of the MRST parton distributions in response
to the most recent data. We discuss the areas where there are hints
of difficulties in the global fit, and compare to some other updated sets of
parton distributions, particularly CTEQ6. We briefly discuss the issue of
uncertainties associated with partons
MRST global fit update.
We discuss the impact of the most recent data on the MRST global analysis -
in particular the new high-ET jet data and their implications for the gluon and
the new small x structure function data. In the light of these new data we also
consider the uncertainty in predictions for physical quantities depending on parton
distributions, concentrating on the W cross-section at hadron colliders
Optimal design of single-tuned passive filters using response surface methodology
This paper presents an approach based on Response Surface Methodology (RSM) to find the optimal parameters of the single-tuned passive filters for harmonic mitigation. The main advantages of RSM can be underlined as easy implementation and effective computation. Using RSM, the single-tuned harmonic filter is designed to minimize voltage total harmonic distortion (THDV) and current total harmonic distortion (THDI). Power factor (PF) is also incorporated in the design procedure as a constraint. To show the validity of the proposed approach, RSM and Classical Direct Search (Grid Search) methods are evaluated for a typical industrial power system
3D spatially-resolved optical energy density enhanced by wavefront shaping
We study the three-dimensional (3D) spatially-resolved distribution of the
energy density of light in a 3D scattering medium upon the excitation of open
transmission channels. The open transmission channels are excited by spatially
shaping the incident optical wavefronts. To probe the local energy density, we
excite isolated fluorescent nanospheres distributed inside the medium. From the
spatial fluorescent intensity pattern we obtain the position of each
nanosphere, while the total fluorescent intensity gauges the energy density.
Our 3D spatially-resolved measurements reveal that the local energy density
versus depth (z) is enhanced up to 26X at the back surface of the medium, while
it strongly depends on the transverse (x; y) position. We successfully
interpret our results with a newly developed 3D model that considers the
time-reversed diffusion starting from a point source at the back surface. Our
results are relevant for white LEDs, random lasers, solar cells, and biomedical
optics
Ranking Significant Discrepancies in Clinical Reports
Medical errors are a major public health concern and a leading cause of death
worldwide. Many healthcare centers and hospitals use reporting systems where
medical practitioners write a preliminary medical report and the report is
later reviewed, revised, and finalized by a more experienced physician. The
revisions range from stylistic to corrections of critical errors or
misinterpretations of the case. Due to the large quantity of reports written
daily, it is often difficult to manually and thoroughly review all the
finalized reports to find such errors and learn from them. To address this
challenge, we propose a novel ranking approach, consisting of textual and
ontological overlaps between the preliminary and final versions of reports. The
approach learns to rank the reports based on the degree of discrepancy between
the versions. This allows medical practitioners to easily identify and learn
from the reports in which their interpretation most substantially differed from
that of the attending physician (who finalized the report). This is a crucial
step towards uncovering potential errors and helping medical practitioners to
learn from such errors, thus improving patient-care in the long run. We
evaluate our model on a dataset of radiology reports and show that our approach
outperforms both previously-proposed approaches and more recent language models
by 4.5% to 15.4%.Comment: ECIR 2020 (short
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