2,471 research outputs found
Shot noise in the chaotic-to-regular crossover regime
We investigate the shot noise for phase-coherent quantum transport in the
chaotic-to-regular crossover regime. Employing the Modular Recursive Green's
Function Method for both ballistic and disordered two-dimensional cavities we
find the Fano factor and the transmission eigenvalue distribution for regular
systems to be surprisingly similar to those for chaotic systems. We argue that
in the case of regular dynamics in the cavity, diffraction at the lead openings
is the dominant source of shot noise. We also explore the onset of the
crossover from quantum to classical transport and develop a quasi-classical
transport model for shot noise suppression which agrees with the numerical
quantum data.Comment: 4 pages, 3 figures, submitted to Phys.Rev.Let
Designing potentials by sculpturing wires
Magnetic trapping potentials for atoms on atom chips are determined by the
current flow in the chip wires. By modifying the shape of the conductor we can
realize specialized current flow patterns and therefore micro-design the
trapping potentials. We have demonstrated this by nano-machining an atom chip
using the focused ion beam technique. We built a trap, a barrier and using a
BEC as a probe we showed that by polishing the conductor edge the potential
roughness on the selected wire can be reduced. Furthermore we give different
other designs and discuss the creation of a 1D magnetic lattice on an atom
chip.Comment: 6 pages, 8 figure
Uniform generation in trace monoids
We consider the problem of random uniform generation of traces (the elements
of a free partially commutative monoid) in light of the uniform measure on the
boundary at infinity of the associated monoid. We obtain a product
decomposition of the uniform measure at infinity if the trace monoid has
several irreducible components-a case where other notions such as Parry
measures, are not defined. Random generation algorithms are then examined.Comment: Full version of the paper in MFCS 2015 with the same titl
Befragung zum Status-Quo der Tierhaltung bei 287 sĂĽddeutschen Bio-Betrieben (Demeter- und Bioland)[Inquiry to the status quo of livestock husbandry in organic farms in southern germany]
Fazit:
Die gegenüber früheren Untersuchungen gestiegenen Bestandsgrößen weisen darauf hin, daß sich im ökologischen Landbau ein ähnlicher Strukturwandel wie in der konventionellen Landwirtschaft vollzieht (Wachstum und Spezialisierung). Die Auswertung zeigt ferner, daß die Betriebe zunehmend bemüht sind, bereits jetzt den zukünftigen Haltungsvorschriften der EU-Verordnung zu entsprechen. Fast alle Betriebe führen Weidegang durch und trotz der relativ geringen Bestandsgröße haben die meisten Betriebe bereits Laufställe; Auslaufmöglichkeiten fallen demgegenüber allerdings noch ab
Relations between M\"obius and coboundary polynomial
It is known that, in general, the coboundary polynomial and the M\"obius
polynomial of a matroid do not determine each other. Less is known about more
specific cases. In this paper, we will try to answer if it is possible that the
M\"obius polynomial of a matroid, together with the M\"obius polynomial of the
dual matroid, define the coboundary polynomial of the matroid. In some cases,
the answer is affirmative, and we will give two constructions to determine the
coboundary polynomial in these cases.Comment: 12 page
RNA-binding protein CPEB1 remodels host and viral RNA landscapes.
Host and virus interactions occurring at the post-transcriptional level are critical for infection but remain poorly understood. Here, we performed comprehensive transcriptome-wide analyses revealing that human cytomegalovirus (HCMV) infection results in widespread alternative splicing (AS), shortening of 3' untranslated regions (3' UTRs) and lengthening of poly(A)-tails in host gene transcripts. We found that the host RNA-binding protein CPEB1 was highly induced after infection, and ectopic expression of CPEB1 in noninfected cells recapitulated infection-related post-transcriptional changes. CPEB1 was also required for poly(A)-tail lengthening of viral RNAs important for productive infection. Strikingly, depletion of CPEB1 reversed infection-related cytopathology and post-transcriptional changes, and decreased productive HCMV titers. Host RNA processing was also altered in herpes simplex virus-2 (HSV-2)-infected cells, thereby indicating that this phenomenon might be a common occurrence during herpesvirus infections. We anticipate that our work may serve as a starting point for therapeutic targeting of host RNA-binding proteins in herpesvirus infections
Calculation of some determinants using the s-shifted factorial
Several determinants with gamma functions as elements are evaluated. This
kind of determinants are encountered in the computation of the probability
density of the determinant of random matrices. The s-shifted factorial is
defined as a generalization for non-negative integers of the power function,
the rising factorial (or Pochammer's symbol) and the falling factorial. It is a
special case of polynomial sequence of the binomial type studied in
combinatorics theory. In terms of the gamma function, an extension is defined
for negative integers and even complex values. Properties, mainly composition
laws and binomial formulae, are given. They are used to evaluate families of
generalized Vandermonde determinants with s-shifted factorials as elements,
instead of power functions.Comment: 25 pages; added section 5 for some examples of application
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