3,384 research outputs found
One-dimensional lattice of oscillators coupled through power-law interactions: Continuum limit and dynamics of spatial Fourier modes
We study synchronization in a system of phase-only oscillators residing on
the sites of a one-dimensional periodic lattice. The oscillators interact with
a strength that decays as a power law of the separation along the lattice
length and is normalized by a size-dependent constant. The exponent of
the power law is taken in the range . The oscillator frequency
distribution is symmetric about its mean (taken to be zero), and is
non-increasing on . In the continuum limit, the local density of
oscillators evolves in time following the continuity equation that expresses
the conservation of the number of oscillators of each frequency under the
dynamics. This equation admits as a stationary solution the unsynchronized
state uniform both in phase and over the space of the lattice. We perform a
linear stability analysis of this state to show that when it is unstable,
different spatial Fourier modes of fluctuations have different stability
thresholds beyond which they grow exponentially in time with rates that depend
on the Fourier modes. However, numerical simulations show that at long times,
all the non-zero Fourier modes decay in time, while only the zero Fourier mode
(i.e., the "mean-field" mode) grows in time, thereby dominating the instability
process and driving the system to a synchronized state. Our theoretical
analysis is supported by extensive numerical simulations.Comment: 7 pages, 4 figures. v2: new simulation results added, close to the
published versio
Synthetic Mudscapes: Human Interventions in Deltaic Land Building
In order to defend infrastructure, economy, and settlement in Southeast Louisiana, we must construct new land to
mitigate increasing risk. Links between urban environments and economic drivers have constrained the dynamic delta
landscape for generations, now threatening to undermine the ecological fitness of the entire region. Static methods of
measuring, controlling, and valuing land fail in an environment that is constantly in flux; change and indeterminacy are
denied by traditional inhabitation.
Multiple land building practices reintroduce deltaic fluctuation and strategic deposition of fertile material to form the
foundations of a multi-layered defence strategy. Manufactured marshlands reduce exposure to storm surge further
inland. Virtual monitoring and communication networks inform design decisions and land use becomes determined
by its ecological health. Mudscapes at the threshold of land and water place new value on former wastelands. The
social, economic, and ecological evolution of the region are defended by an expanded web of growing land
Thrombosis And Hemostasis Centers Pilot Sites Registry: Thrombophilia Screening In Children
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106147/1/jth03026.pd
Weak charge form factor and radius of 208Pb through parity violation in electron scattering
We use distorted wave electron scattering calculations to extract the weak
charge form factor F_W(q), the weak charge radius R_W, and the point neutron
radius R_n, of 208Pb from the PREX parity violating asymmetry measurement. The
form factor is the Fourier transform of the weak charge density at the average
momentum transfer q=0.475 fm. We find F_W(q) =0.204 \pm 0.028 (exp) \pm
0.001 (model). We use the Helm model to infer the weak radius from F_W(q). We
find R_W= 5.826 \pm 0.181 (exp) \pm 0.027 (model) fm. Here the exp error
includes PREX statistical and systematic errors, while the model error
describes the uncertainty in R_W from uncertainties in the surface thickness
\sigma of the weak charge density. The weak radius is larger than the charge
radius, implying a "weak charge skin" where the surface region is relatively
enriched in weak charges compared to (electromagnetic) charges. We extract the
point neutron radius R_n=5.751 \pm 0.175 (exp) \pm 0.026 (model) \pm 0.005
(strange) fm$, from R_W. Here there is only a very small error (strange) from
possible strange quark contributions. We find R_n to be slightly smaller than
R_W because of the nucleon's size. Finally, we find a neutron skin thickness of
R_n-R_p=0.302\pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm, where
R_p is the point proton radius.Comment: 5 pages, 1 figure, published in Phys Rev. C. Only one change in this
version: we have added one author, also to metadat
Harnessing Natureâs Diversity: Discovering organophosphate bioscavenger characteristics among low molecular weight proteins
Organophosphate poisoning can occur from exposure to agricultural pesticides or chemical weapons. This exposure inhibits acetylcholinesterase resulting in increased acetylcholine levels within the synaptic cleft causing loss of muscle control, seizures, and death. Mitigating the effects of organophosphates in our bodies is critical and yet an unsolved challenge. Here, we present a computational strategy that integrates structure mining and modeling approaches, using which we identify novel candidates capable of interacting with a serine hydrolase probe (with equilibrium binding constants ranging from 4 to 120 ÎŒM). One candidate Smu. 1393c catalyzes the hydrolysis of the organophosphate omethoate (kcat/Km of (2.0 ± 1.3) Ă 10â1 Mâ1sâ1) and paraoxon (kcat/Km of (4.6 ± 0.8) Ă 103 Mâ1sâ1), V- and G-agent analogs respectively. In addition, Smu. 1393c protects acetylcholinesterase activity from being inhibited by two organophosphate simulants. We demonstrate that the utilized approach is an efficient and highly-extendable framework for the development of prophylactic therapeutics against organophosphate poisoning and other important targets. Our findings further suggest currently unknown molecular evolutionary rules governing natural diversity of the protein universe, which make it capable of recognizing previously unseen ligands
Evaluation of the Relevance of a Web-Based Ask an Expert Feature: StratSoy and Soy and Human Health Queries
StratSoy, a state-of-the-art Web-based information system, has an Ask an Expert (AE) feature that allows Web site browsers to question experts in 13 areas including Soy and Human Health (SHH). The objectives of this research were to: a) assess the use of the SHH AE feature; b) examine respondent attitudes about soy-related topics to help guide development of a Frequently Asked Questions (FAQ) section; and c) improve the information dissemination process on the Web site based on the results of this research. Study participants were 50 Web site users and 48 people who were unfamiliar with the site. The results of the study indicated topic areas of interest and additional Web site features desired by the respondents. The findings identified specific areas that may be targeted to improve the Web site
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