2,684 research outputs found
Constraints on models for the initial collision geometry in ultra relativistic heavy ion collisions
Monte Carlo (MC) simulations are used to compute the centrality dependence of
the collision zone eccentricities (), for both spherical and
deformed ground state nuclei, for different model scenarios. Sizable model
dependent differences are observed. They indicate that measurements of the
and order Fourier flow coefficients ,
expressed as the ratio , can provide robust constraints
for distinguishing between different theoretical models for the initial-state
eccentricity. Such constraints could remove one of the largest impediments to a
more precise determination of the specific viscosity from precision
measurements at the Relativistic Heavy Ion Collider (RHIC).Comment: 4 pages, 3 figs - version accepted for publicatio
Azimuthal anisotropy: transition from hydrodynamic flow to jet suppression
Measured 2nd and 4th azimuthal anisotropy coefficients v_{2,4}(N_{part}),
p_T) are scaled with the initial eccentricity \varepsilon_{2,4}(N_{part}) of
the collision zone and studied as a function of the number of participants
N_{part} and the transverse momenta p_T. Scaling violations are observed for
p_T \alt 3 GeV/c, consistent with a dependence of viscous corrections
and a linear increase of the relaxation time with . These empirical
viscous corrections to flow and the thermal distribution function at freeze-out
constrain estimates of the specific viscosity and the freeze-out temperature
for two different models for the initial collision geometry. The apparent
viscous corrections exhibit a sharp maximum for p_T \agt 3 GeV/c, suggesting
a breakdown of the hydrodynamic ansatz and the onset of a change from
flow-driven to suppression-driven anisotropy.Comment: 5 pages, 4 figs; submitted for publicatio
Recommended from our members
Immature HIV-1 assembles from Gag dimers leaving partial hexamers at lattice edges as potential substrates for proteolytic maturation
The CA (capsid) domain of immature HIV-1 Gag and the adjacent spacer peptide 1 (SP1) play a key role in viral assembly by forming a lattice of CA hexamers, which adapts to viral envelope curvature by incorporating small lattice defects and a large gap at the site of budding. This lattice is stabilized by intrahexameric and interhexameric CA-CA interactions, which are important in regulating viral assembly and maturation. We applied subtomogram averaging and classification to determine the oligomerization state of CA at lattice edges and found that CA forms partial hexamers. These structures reveal the network of interactions formed by CA-SP1 at the lattice edge. We also performed atomistic molecular dynamics simulations of CA-CA interactions stabilizing the immature lattice and partial CA-SP1 helical bundles. Free energy calculations reveal increased propensity for helix-to-coil transitions in partial hexamers compared to complete six-helix bundles. Taken together, these results suggest that the CA dimer is the basic unit of lattice assembly, partial hexamers exist at lattice edges, these are in a helix-coil dynamic equilibrium, and partial helical bundles are more likely to unfold, representing potential sites for HIV-1 maturation initiation
A Large-scale Synthesis and Characterization of Quaternary CuInâGaâââSâ Chalcopyrite Nanoparticles via Microwave Batch Reactions
Various quaternary CuInxGa1-xS2 (0â€xâ€1) chalcopyrite nanoparticles have been prepared from molecular single-source precursors via microwave decomposition. We were able to control the nanoparticle size, phase, stoichiometry, and solubility. Depending on the choice of surface modifiers used, we were able to tune the solubility of the resulting nanoparticles. This method has been used to generate up to 5g of nanoparticles and up to 150g from multiple batch reactions with excellent reproducibility. Data from UV-Vis, photoluminescence, X-ray diffraction, TEM, DSC/TGA-MS, and ICP-OES analyses have shown high reproducibility in nanoparticle size, composition, and bandgap
OpenMSCG: A Software Tool for Bottom-Up Coarse-Graining
The âbottom-upâ approach to coarse-graining, for building accurate and efficient computational models to simulate large-scale and complex phenomena and processes, is an important approach in computational chemistry, biophysics, and materials science. As one example, the Multiscale Coarse-Graining (MS-CG) approach to developing CG models can be rigorously derived using statistical mechanics applied to fine-grained, i.e., all-atom simulation data for a given system. Under a number of circumstances, a systematic procedure, such as MS-CG modeling, is particularly valuable. Here, we present the development of the OpenMSCG software, a modularized open-source software that provides a collection of successful and widely applied bottom-up CG methods, including Boltzmann Inversion (BI), Force-Matching (FM), Ultra-Coarse-Graining (UCG), Relative Entropy Minimization (REM), Essential Dynamics Coarse-Graining (EDCG), and Heterogeneous Elastic Network Modeling (HeteroENM). OpenMSCG is a high-performance and comprehensive toolset that can be used to derive CG models from large-scale fine-grained simulation data in file formats from common molecular dynamics (MD) software packages, such as GROMACS, LAMMPS, and NAMD. OpenMSCG is modularized in the Python programming framework, which allows users to create and customize modeling ârecipesâ for reproducible results, thus greatly improving the reliability, reproducibility, and sharing of bottom-up CG models and their applications
The Student Movement Volume 107 Issue 22: Fulfilled: AU Presents a Story of Redemption
HUMANS
Speaking Up With Women, Interviewed by: Grace No
What is it Like to Work at the Athletics Department?, Interviewed by: Grace No
What is Title IX?. Interviewed by: Caryn Cruz
ARTS & ENTERTAINMENT
Currently: Foreign Film, Solana Campbell
Fulfilled: A Musical of Redemption, Aiko J. Ayala Rios
NEWS
KASA Banquet, Interviewed by: Anna Pak
Watchmen A Capella Concert: Unstoppable: A Journey Through Self-Discovery , Gloria Oh
IDEAS
Charge It!, Alexander Navarro
Feminism is for Everybody. Yes-Even You, Dude!, Reagan McCain
Tick Tock... for TikTok?, Abby Shim
PULSE
Dorm Delicacies, Melissa Moore
How Have We Grown?, Abraham Bravo
What Do We Wish We Did?, Abraham Bravo
LAST WORD
Take It From Me , SM Section Editorshttps://digitalcommons.andrews.edu/sm-107/1021/thumbnail.jp
Estimated incidence of previously undetected atrial fibrillation on a 14-day continuous electrocardiographic monitor and associated risk of stroke
Aims There is uncertainty about whether and how to perform screening for atrial fibrillation (AF). To estimate the incidence of previously undetected AF that would be captured using a continuous 14-day ECG monitor and the associated risk of stroke. Methods and results We analysed data from a cohort of patients >65 years old with hypertension and a pacemaker, but without known AF. For each participant, we simulated 1000 ECG monitors by randomly selecting 14-day windows in the 6 months following enrolment and calculated the average AF burden (total time in AF). We used Cox proportional hazards models adjusted for CHA(2)DS(2)-VASc score to estimate the risk of subsequent ischaemic stroke or systemic embolism (SSE) associated with burdens of AF > and 6 min was 3.10% (95% CI 2.53-3.72). This was consistent across strata of age and CHA(2)DS(2)-VASc scores. Over a mean follow-up of 2.4 years, the rate of SSE among patients with 6 min of AF. Conclusions Approximately 3% of individuals aged >65 years with hypertension may have more than 6 min of AF detected by a 14-day ECG monitor. This is associated with a stroke risk of over 2% per year. Whether oral anticoagulation will reduce stroke in these patients is unknown
On positivity of Ehrhart polynomials
Ehrhart discovered that the function that counts the number of lattice points
in dilations of an integral polytope is a polynomial. We call the coefficients
of this polynomial Ehrhart coefficients, and say a polytope is Ehrhart positive
if all Ehrhart coefficients are positive (which is not true for all integral
polytopes). The main purpose of this article is to survey interesting families
of polytopes that are known to be Ehrhart positive and discuss the reasons from
which their Ehrhart positivity follows. We also include examples of polytopes
that have negative Ehrhart coefficients and polytopes that are conjectured to
be Ehrhart positive, as well as pose a few relevant questions.Comment: 40 pages, 7 figures. To appear in in Recent Trends in Algebraic
Combinatorics, a volume of the Association for Women in Mathematics Series,
Springer International Publishin
- âŠ