5,970 research outputs found
Nature vs. Nurture: Dynamical Evolution in Disordered Ising Ferromagnets
We study the predictability of zero-temperature Glauber dynamics in various
models of disordered ferromagnets. This is analyzed using two independent
dynamical realizations with the same random initialization (called twins). We
derive, theoretically and numerically, trajectories for the evolution of the
normalized magnetization and twin overlap as the system size tends to infinity.
The systems we treat include mean-field ferromagnets with light-tailed and
heavy-tailed coupling distributions, as well as highly-disordered models with a
variety of other geometries. In the mean-field setting with light-tailed
couplings, the disorder averages out and the limiting trajectories of the
magnetization and twin overlap match those of the homogenous Curie--Weiss
model. On the other hand, when the coupling distribution has heavy tails, or
the geometry changes, the effect of the disorder persists in the thermodynamic
limit. Nonetheless, qualitatively all such random ferromagnets share a similar
time evolution for their twin overlap, wherein the two twins initially
decorrelate, before either partially or fully converging back together due to
the ferromagnetic drift.Comment: 16 pages, 7 figure
Circulating fibroblast growth factor 21 Is a sensitive biomarker for severe ischemia/reperfusion injury in patients with liver transplantation
published_or_final_versio
Influence of interleukin-2 on Ca2+ handling in rat ventricular myocytes
In the present study, we examined the effect of interleukin-2 (IL-2) on cardiomyocyte Ca2+ handling. The effects of steady-state and transient changes in stimulation frequency on the intracellular Ca2+ transient were investigated in isolated ventricular myocytes by spectrofluorometry. In the steady state (0.2 Hz) IL-2 (200 U/ml) decreased the amplitude of Ca2+ transients induced by electrical stimulation and caffeine. At 1.25 mM extracellular Ca2+ concentration ([Ca 2+]o), when the stimulation frequency increased from 0.2 to 1.0 Hz, diastolic Ca2+ level and peak intracellular Ca 2+ concentration ([Ca2+]i), as well as the amplitude of the transient, increased. The positive frequency relationships of the peak and amplitude of [Ca2+]i transients were blunted in the IL-2-treated myocytes. The effect of IL-2 on the electrically induced [Ca2+]i transient was not normalized by increasing [Ca2+]o to 2.5 mM. IL-2 inhibited the frequency relationship of caffeine-induced Ca2+ release. Blockade of sarcoplasmic reticulum (SR) Ca2+-ATPase with thapsigargin resulted in a significant reduction of the amplitude-frequency relationship of the transient similar to that induced by IL-2. The restitutions were not different between control and IL-2 groups at 1.25 mM [Ca2+]o, which was slowed in IL-2-treated myocytes when [Ca2+]o was increased to 2.5 mM. There was no difference in the recirculation fraction (RF) between control and IL-2-treated myocytes at both 1.25 and 2.5 mM [Ca 2+]o. The effects of IL-2 on frequency relationship, restitution, and RF may be due to depressed SR functions and an increased Na+-Ca2+ exchange activity, but not to any change in L-type Ca2+ channels. © 2003 Elsevier Ltd. All rights reserved.postprin
Zigzag-shaped nickel nanowires via organometallic template-free route
In this manuscript, the formation of nickel nanowires (average size: several tens to hundreds of ÎŒm long
and 1.0-1.5 ÎŒm wide) at low temperature is found to be driven by dewetting of liquid organometallic
precursors during spin coating process and by self-assembly of Ni clusters. Elaboration of metallic thin
films by low temperature deposition technique makes the preparation process compatible with most of the
substrates. The use of iron and cobalt precursor shows that the process could be extended to other metallic
systems. In this work, AFM and SEM are used to follow the assembly of Ni clusters into straight or
zigzag lines. The formation of zigzag structure is specific to the Ni precursor at appropriate preparation
parameters. This template free process allows a control of anisotropic structures with homogeneous sizes
and angles on standard Si/SiO2 surface
Factors related to childrenâs caries: a structural equation modeling approach
BACKGROUND: Dental caries among preschool children is highly prevalent in many less-developed countries. METHODS: A model which explored the factors related to childrenâs dental caries was tested in this study using structural equation modeling. Caregivers of children aged 5Â years were surveyed on their socioeconomic status, and their oral health knowledge, attitudes and practices. In addition, information on their childrenâs oral health practices, dental insurance and dental service utilization were collected. Examination of caries was conducted on all children who returned fully completed questionnaires. RESULTS: The results showed that socioeconomic factors influenced childrenâs oral health practices through the impact of caregiversâ oral health knowledge and practices; that caregiversâ oral health knowledge affected childrenâs oral health practices through the influence of caregiversâ oral health attitudes and practices; and finally, that childrenâs oral health practices were linked directly to their caries. CONCLUSION: The findings have important applications for promoting policies aimed at advancing childrenâs oral health
Bioinformatics advances in saliva diagnostics
There is a need recognized by the National Institute of Dental & Craniofacial Research and the National Cancer Institute to advance
basic, translational and clinical saliva research. The goal of the Salivaomics Knowledge Base (SKB) is to create a data management system and web resource constructed to support human salivaomics research. To maximize the utility of the SKB for retrieval,
integration and analysis of data, we have developed the Saliva Ontology and SDxMart. This article reviews the informatics advances in saliva diagnostics made possible by the Saliva Ontology and SDxMart
Flow noise from spoilers in ducts
2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Nature versus Nurture in Complex and Not-So-Complex Systems
Understanding the dynamical behavior of many-particle systems both in and out
of equilibrium is a central issue in both statistical mechanics and complex
systems theory. One question involves "nature versus nurture": given a system
with a random initial state evolving through a well-defined stochastic
dynamics, how much of the information contained in the state at future times
depends on the initial condition ("nature") and how much on the dynamical
realization ("nurture")? We discuss this question and present both old and new
results for low-dimensional Ising spin systems.Comment: 7 page
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