1,195 research outputs found
A note on a result of Liptser-Shiryaev
Given two stochastic equations with different drift terms, under very weak
assumptions Liptser and Shiryaev provide the equivalence of the laws of the
solutions to these equations by means of Girsanov transform. Their assumptions
involve both the drift terms. We are interested in the same result but with the
main assumption involving only the difference of the drift terms. Applications
of our result will be presented in the finite as well as in the infinite
dimensional setting.Comment: 22 pages; revised and enlarged versio
PIN24 The Impact Of Renal Impairment, Inflammatory Bowel Disease And Advanced Age On Mortality Among Hospitalized Patients With Clostridium Difficile-Associated Diarrhea
A posteriori inclusion of parton density functions in NLO QCD final-state calculations at hadron colliders: The APPLGRID Project
A method to facilitate the consistent inclusion of cross-section measurements
based on complex final-states from HERA, TEVATRON and the LHC in proton parton
density function (PDF) fits has been developed. This can be used to increase
the sensitivity of LHC data to deviations from Standard Model predictions. The
method stores perturbative coefficients of NLO QCD calculations of final-state
observables measured in hadron colliders in look-up tables. This allows the
posteriori inclusion of parton density functions (PDFs), and of the strong
coupling, as well as the a posteriori variation of the renormalisation and
factorisation scales in cross-section calculations.
The main novelties in comparison to original work on the subject are the use
of higher-order interpolation, which substantially improves the trade-off
between accuracy and memory use, and a CPU and computer memory optimised way to
construct and store the look-up table using modern software tools.
It is demonstrated that a sufficient accuracy on the cross-section
calculation can be achieved with reasonably small look-up table size by using
the examples of jet production and electro-weak boson (Z, W) production in
proton-proton collisions at a center-of-mass energy of 14 TeV at the LHC.
The use of this technique in PDF fitting is demonstrated in a PDF-fit to HERA
data and simulated LHC jet cross-sections as well as in a study of the jet
cross-section uncertainties at various centre-of-mass energies
Heavy-quark mass dependence in global PDF analyses and 3- and 4-flavour parton distributions
We study the sensitivity of our recent MSTW 2008 NLO and NNLO PDF analyses to
the values of the charm- and bottom-quark masses, and we provide additional
public PDF sets for a wide range of these heavy-quark masses. We quantify the
impact of varying m_c and m_b on the cross sections for W, Z and Higgs
production at the Tevatron and the LHC. We generate 3- and 4-flavour versions
of the (5-flavour) MSTW 2008 PDFs by evolving the input PDFs and alpha_S
determined from fits in the 5-flavour scheme, including the eigenvector PDF
sets necessary for calculation of PDF uncertainties. As an example of their
use, we study the difference in the Z total cross sections at the Tevatron and
LHC in the 4- and 5-flavour schemes. Significant differences are found,
illustrating the need to resum large logarithms in Q^2/m_b^2 by using the
5-flavour scheme. The 4-flavour scheme is still necessary, however, if cuts are
imposed on associated (massive) b-quarks, as is the case for the experimental
measurement of Z b bbar production and similar processes.Comment: 40 pages, 11 figures. Grids can be found at
http://projects.hepforge.org/mstwpdf/ and in LHAPDF V5.8.4. v2: version
published in EPJ
Health behavior correlates among colon cancer survivors: NC STRIDES baseline results
Objective: To examine health behaviors (fruit/vegetable intake and physical activity) and their association with social cognitive theory (SCT) constructs among colorectal cancer (CRC) survivors (n=304) and comparable non-CRC-affected participants (n=521). Methods: Baseline data were analyzed bivariately and modeled with linear regression. Participants were 48% female, 36% African American (mean age = 67). Results: Behaviors were comparable between groups, but survivors perceived more social support for behaviors (P<.05). Lack of employment was associated with greater frequency of healthy behaviors (P<.05) as were more modifiable factors including higher self-efficacy and lower barriers. Conclusions: SCT constructs were associated with behavior and may be targets for future interventions, but other variables may be important as well
Organic film thickness influence on the bias stress instability in Sexithiophene Field Effect Transistors
In this paper, the dynamics of bias stress phenomenon in Sexithiophene (T6)
Field Effect Transistors (FETs) has been investigated. T6 FETs have been
fabricated by vacuum depositing films with thickness from 10 nm to 130 nm on
Si/SiO2 substrates. After the T6 film structural analysis by X-Ray diffraction
and the FET electrical investigation focused on carrier mobility evaluation,
bias stress instability parameters have been estimated and discussed in the
context of existing models. By increasing the film thickness, a clear
correlation between the stress parameters and the structural properties of the
organic layer has been highlighted. Conversely, the mobility values result
almost thickness independent
Summary of the HERA-LHC workshop
I present a summary of the last in the series of HERA-LHC workshops, CERN,
26-30th May 2008.Comment: To appear in the proceedings of the Ringberg Workshop on New Trends
in HERA Physics, October 2008. 12 pages, 14 figures included as .ps or .eps
file
Magnetic relaxation phenomena and cluster glass properties of La{0.7-x}Y{x}Ca{0.3}MnO{3} manganites
The dynamic magnetic properties of the distorted perovskite system
La{0.7-x}Y{x}Ca{0.3}MnO{3} (0 <= x <= 0.15) have been investigated by
ac-susceptibility and dc magnetization measurements, with emphasis on
relaxation and aging studies. They evidence for x >= 0.10 the appearance of a
metallic cluster glass phase, that develops just below the ferromagnetic
transition temperature. The clusters grow with decreasing temperature down to a
temperature T(f0) at which they freeze due to severe intercluster frustration.
The formation of these clusters is explained by the presence of yttrium induced
local structural distortions that create localized spin disorder in a magnetic
lattice where double-exchange ferromagnetism is dominant.Comment: Accepted for publication in Phys. Rev.
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