3,271 research outputs found
Revising the age for the Baptistina asteroid family using WISE/NEOWISE data
We have used numerical routines to model the evolution of a simulated
Baptistina family to constrain its age in light of new measurements of the
diameters and albedos of family members from the Wide-field Infrared Survey
Explorer. We also investigate the effect of varying the assumed physical and
orbital parameters on the best-fitting age. We find that the physically allowed
range of assumed values for the density and thermal conductivity induces a
large uncertainty in the rate of evolution. When realistic uncertainties in the
family members' physical parameters are taken into account we find the
best-fitting age can fall anywhere in the range of 140-320 Myr. Without more
information on the physical properties of the family members it is difficult to
place a more firm constraint on Baptistina's age.Comment: 27 pages, 16 figures, accepted to Ap
Statistical Mechanics of Nonuniform Magnetization Reversal
The magnetization reversal rate via thermal creation of soliton pairs in
quasi-1D ferromagnetic systems is calculated. Such a model describes e.g. the
time dependent coercivity of elongated particles as used in magnetic recording
media. The energy barrier that has to be overcome by thermal fluctuations
corresponds to a soliton-antisoliton pair whose size depends on the external
field. In contrast to other models of first order phase transitions such as the
phi^4 model, an analytical expression for this energy barrier is found for all
values of the external field. The magnetization reversal rate is calculated
using a functional Fokker-Planck description of the stochastic magnetization
dynamics. Analytical results are obtained in the limits of small fields and
fields close to the anisotropy field. In the former case the hard-axis
anisotropy becomes effectively strong and the magnetization reversal rate is
shown to reduce to the nucleation rate of soliton-antisoliton pairs in the
overdamped double sine-Gordon model. The present theory therefore includes the
nucleation rate of soliton-antisoliton pairs in the double sine-Gordon chain as
a special case. These results demonstrate that for elongated particles, the
experimentally observed coercivity is significantly lower than the value
predicted by the standard theories of N\'eel and Brown.Comment: 21 pages RevTex 3.0 (twocolumn), 6 figures available on request, to
appear in Phys Rev B, Dec (1994
AIM2 inflammasome is activated by pharmacological disruption of nuclear envelope integrity.
Inflammasomes are critical sensors that convey cellular stress and pathogen presence to the immune system by activating inflammatory caspases and cytokines such as IL-1ÎČ. The nature of endogenous stress signals that activate inflammasomes remains unclear. Here we show that an inhibitor of the HIV aspartyl protease, Nelfinavir, triggers inflammasome formation and elicits an IL-1R-dependent inflammation in mice. We found that Nelfinavir impaired the maturation of lamin A, a structural component of the nuclear envelope, thereby promoting the release of DNA in the cytosol. Moreover, deficiency of the cytosolic DNA-sensor AIM2 impaired Nelfinavir-mediated inflammasome activation. These findings identify a pharmacologic activator of inflammasome and demonstrate the role of AIM2 in detecting endogenous DNA release upon perturbation of nuclear envelope integrity
Exome sequencing improves the molecular diagnostics of paediatric unexplained neurodevelopmental disorders
\ua9 The Author(s) 2024. Background: Neurodevelopmental disorders (NDDs) and/or associated multiple congenital abnormalities (MCAs) represent a genetically heterogeneous group of conditions with an adverse prognosis for the quality of intellectual and social abilities and common daily functioning. The rapid development of exome sequencing (ES) techniques, together with trio-based analysis, nowadays leads to up to 50% diagnostic yield. Therefore, it is considered as the state-of-the-art approach in these diagnoses. Results: In our study, we present the results of ES in a cohort of 85 families with 90 children with severe NDDs and MCAs. The interconnection of the in-house bioinformatic pipeline and a unique algorithm for variant prioritization resulted in a diagnostic yield of up to 48.9% (44/90), including rare and novel causative variants (41/90) and intragenic copy-number variations (CNVs) (3/90). Of the total number of 47 causative variants, 53.2% (25/47) were novel, highlighting the clinical benefit of ES for unexplained NDDs. Moreover, trio-based ES was verified as a reliable tool for the detection of rare CNVs, ranging from intragenic exon deletions (GRIN2A, ZC4H2 genes) to a 6-Mb duplication. The functional analysis using PANTHER Gene Ontology confirmed the involvement of genes with causative variants in a wide spectrum of developmental processes and molecular pathways, which form essential structural and functional components of the central nervous system. Conclusion: Taken together, we present one of the first ES studies of this scale from the central European region. Based on the high diagnostic yield for paediatric NDDs in this study, 48.9%, we confirm trio-based ES as an effective and reliable first-tier diagnostic test in the genetic evaluation of children with NDDs
Nucleon-nucleon elastic scattering analysis to 2.5 GeV
A partial-wave analysis of NN elastic scattering data has been completed.
This analysis covers an expanded energy range, from threshold to a laboratory
kinetic energy of 2.5 GeV, in order to include recent elastic pp scattering
data from the EDDA collaboration. The results of both single-energy and
energy-dependent analyses are described.Comment: 23 pages of text. Postscript files for the figures are available from
ftp://clsaid.phys.vt.edu/pub/said/n
Credibility and adjustment: gold standards versus currency boards
It is often maintained that currency boards (CBs) and gold standards (GSs) are alike in that they are stringent monetary rules, the two basic features of which are high credibility of monetary authorities and the existence of automatic adjustment (non discretionary) mechanism. This article includes a comparative analysis of these two types of regimes both from the perspective of the sources and mechanisms of generating confidence and credibility, and the elements of operation of the automatic adjustment mechanism. Confidence under the GS is endogenously driven, whereas it is exogenously determined under the CB. CB is a much more asymmetric regime than GS (the adjustment is much to the detriment of peripheral countries) although asymmetry is a typical feature of any monetary regime. The lack of credibility is typical for peripheral countries and cannot be overcome completely even by âhardâ monetary regimes.http://deepblue.lib.umich.edu/bitstream/2027.42/40078/3/wp692.pd
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
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