1,351 research outputs found
Multivariate medians and measure-symmetrization
We discuss two research areas dealing respectively with (1) a class of
multivariate medians and (2) a symmetrization algorithm for probability
measures.Comment: Published at http://dx.doi.org/10.1214/074921707000000201 in the IMS
Lecture Notes Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Remarks and Open Problems in the Area of the FKG Inequality
The FKG inequality is an effective device when the requisite assumptions can be verified. Sometimes these have to be approached circuitously. This is discussed with reference to past uses and suggestions for work on the range of applicability. New areas of potential application are also presented
Wideband dual sphere detector of gravitational waves
We present the concept of a sensitive AND broadband resonant mass
gravitational wave detector. A massive sphere is suspended inside a second
hollow one. Short, high-finesse Fabry-Perot optical cavities read out the
differential displacements of the two spheres as their quadrupole modes are
excited. At cryogenic temperatures one approaches the Standard Quantum Limit
for broadband operation with reasonable choices for the cavity finesses and the
intracavity light power. A molybdenum detector of overall size of 2 m, would
reach spectral strain sensitivities of 2x10^-23/Sqrt{Hz} between 1000 Hz and
3000 Hz.Comment: 4 pages, 3 figures. Changed content. To appear in Phys. Rev. Let
The role of CDC48 in the retro-translocation of non-ubiquitinated toxin substrates in plant cells
When the catalytic A subunits of the castor
bean toxins ricin and Ricinus communis
agglutinin (denoted as RTA and RCA A,
respectively) are delivered into the
endoplasmic reticulum (ER) of tobacco
protoplasts, they become substrates for ER-associated
protein degradation (ERAD). As
such, these orphan polypeptides are retro-translocated
to the cytosol, where a significant
proportion of each protein is degraded by
proteasomes. Here we begin to characterise
the ERAD pathway in plant cells, showing
that retro-translocation of these lysine-deficient
glycoproteins requires the ATPase
activity of cytosolic CDC48. Lysine
polyubiquitination is not obligatory for this
step. We also show that while RCA A is found
in a mannose-untrimmed form prior to its
retro-translocation, a significant proportion of
newly synthesised RTA cycles via the Golgi
and becomes modified by downstream
glycosylation enzymes. Despite these
differences, both proteins are similarly retro-translocated
Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance
This paper presents DELPHI measurements and interpretations of
cross-sections, forward-backward asymmetries, and angular distributions, for
the e+e- -> ffbar process for centre-of-mass energies above the Z resonance,
from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are
consistent with the predictions of the Standard Model and are used to study a
variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering
and several models which include physics beyond the Standard Model: the
exchange of Z' bosons, contact interactions between fermions, the exchange of
gravitons in large extra dimensions and the exchange of sneutrino in R-parity
violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.
A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events
Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the
Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy
and momentum constraint methods. The results are expressed as deviations from
the nominal LEP centre-of-mass energy, measured using other techniques. The
results are found to be compatible with the LEP Energy Working Group estimates
for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.
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