3,291 research outputs found
Lookahead Strategies for Sequential Monte Carlo
Based on the principles of importance sampling and resampling, sequential
Monte Carlo (SMC) encompasses a large set of powerful techniques dealing with
complex stochastic dynamic systems. Many of these systems possess strong
memory, with which future information can help sharpen the inference about the
current state. By providing theoretical justification of several existing
algorithms and introducing several new ones, we study systematically how to
construct efficient SMC algorithms to take advantage of the "future"
information without creating a substantially high computational burden. The
main idea is to allow for lookahead in the Monte Carlo process so that future
information can be utilized in weighting and generating Monte Carlo samples, or
resampling from samples of the current state.Comment: Published in at http://dx.doi.org/10.1214/12-STS401 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Test of conformal gravity with astrophysical observations
Since it can describe the rotation curves of galaxies without dark matter and
can give rise to accelerated expansion, conformal gravity attracts much
attention recently. As a theory of modified gravity, it is important to test
conformal gravity with astrophysical observations. Here we constrain conformal
gravity with SNIa and Hubble parameter data and investigate whether it suffers
from an age problem with the age of APM~08279+5255. We find conformal gravity
can accommodate the age of APM~08279+5255 at 3 deviation, unlike most
of dark energy models which suffer from an age problem.Comment: 6 pages, 2 figure
THE ADJUSTMENT OF LEG STIFFNESS DURING DYNAMIC EXERCISE AND DOWNWARD STEPPING FOR ELDERLY
The purpose of the present study was to evaluate the ability of leg stiffness regulation during downward stepping and maximal Counter-Movement-Jump (CMJ) for the elderly. Ten healthy aged people (age: 68.6Β±5 years; height: 165.3Β±4.4cm; mass: 61.7Β±9.3kg) and 10 students (age: 24.3Β±2years; height: 171.5Β±4.6cm; mass: 65.9Β±8kg) volunteered as subjects. Kistler force platform (1200Hz) and Peak high-speed camera (120Hz) were used synchronously to record the ground reaction force and the kinematic parameters of the subjects performing CMJ and stepping down from different heights. The results revealed that the elderly group has a smaller joint range of motion and greater leg stiffness than the young group during stepping down. The force and the leg stiffness during CMJ were significantly smaller for the elderly. The leg stiffness during downward stepping is independent of dynamic leg stiffness during CMJ. With aging, the adjustment ability of leg stiffness for maximal dynamic voluntary contraction was decreased
An extended WASPAS approach for teaching quality evaluation based on pythagorean fuzzy reducible weighted Maclaurin symmetric mean
Global analysis of the eukaryotic pathways and networks regulated by Salmonella typhimurium in mouse intestinal infection in vivo
<p>Abstract</p> <p>Background</p> <p>Acute enteritis caused by <it>Salmonella </it>is a public health concern. <it>Salmonella </it>infection is also known to increase the risk of inflammatory bowel diseases and cancer. Therefore, it is important to understand how <it>Salmonella </it>works in targeting eukaryotic pathways in intestinal infection. However, the global physiological function of <it>Salmonella </it>typhimurium in intestinal mucosa <it>in vivo </it>is unclear. In this study, a whole genome approach combined with bioinformatics assays was used to investigate the <it>in vivo </it>genetic responses of the mouse colon to <it>Salmonella</it>. We focused on the intestinal responses in the early stage (8 hours) and late stage (4 days) after <it>Salmonella </it>infection.</p> <p>Results</p> <p>Of the 28,000 genes represented on the array, our analysis of mRNA expression in mouse colon mucosa showed that a total of 856 genes were expressed differentially at 8 hours post-infection. At 4 days post-infection, a total of 7558 genes were expressed differentially. 23 differentially expressed genes from the microarray data was further examined by real-time PCR. Ingenuity Pathways Analysis identified that the most significant pathway associated with the differentially expressed genes in 8 hours post-infection is oxidative phosphorylation, which targets the mitochondria. At the late stage of infection, a series of pathways associated with immune and inflammatory response, proliferation, and apoptosis were identified, whereas the oxidative phosphorylation was shut off. Histology analysis confirmed the biological role of <it>Salmonella</it>, which induced a physiological state of inflammation and proliferation in the colon mucosa through the regulation of multiple signaling pathways. Most of the metabolism-related pathways were targeted by down-regulated genes, and a general repression process of metabolic pathways was observed. Network analysis supported IFN-Ξ³ and TNF-Ξ± function as mediators of the immune/inflammatory response for host defense against pathogen.</p> <p>Conclusion</p> <p>Our study provides novel genome-wide transcriptional profiling data on the mouse colon mucosa's response to the <it>Salmonella typhimurium </it>infection. Building the pathways and networks of interactions between these genes help us to understand the complex interplay in the mice colon during <it>Salmonella </it>infection, and further provide new insights into the molecular cascade, which is mobilized to combat <it>Salmonella</it>-associated colon infection <it>in vivo</it>.</p
Small intestinal vascular malformation bleeding: diagnosis by double-balloon enteroscopy combined with abdominal contrast-enhanced CT examination
Non-Abelian Chiral Spin Liquid on the Kagome Lattice
We study spin liquid states on the kagome lattice constructed by
Gutzwiller-projected superconductors. We show that the obtained spin
liquids are either non-Abelian or Abelian topological phases, depending on the
topology of the fermionic mean-field state. By calculating the modular matrices
and , we confirm that projected topological superconductors are
non-Abelian chiral spin liquid (NACSL). The chiral central charge and the spin
Hall conductance we obtained agree very well with the (or,
equivalently, ) field theory predictions. We propose a local
Hamiltonian which may stabilize the NACSL. From a variational study we observe
a topological phase transition from the NACSL to the Abelian spin liquid.Comment: 12 pages, 7 figures, 1 tabl
Sequential Wnt Agonist then Antagonist Treatment Accelerates Tissue Repair and Minimizes Fibrosis
Tissue fibrosis compromises organ function and occurs as a potential
long-term outcome in response to acute tissue injuries. Currently, lack of
mechanistic understanding prevents effective prevention and treatment of the
progression from acute injury to fibrosis. Here, we combined quantitative
experimental studies with a mouse kidney injury model and a computational
approach to determine how the physiological consequences are determined by the
severity of ischemia injury, and to identify how to manipulate Wnt signaling to
accelerate repair of ischemic tissue damage while minimizing fibrosis. The
study reveals that Wnt-mediated memory of prior injury contributes to fibrosis
progression, and ischemic preconditioning reduces the risk of death but
increases the risk of fibrosis. Furthermore, we validated the prediction that
sequential combination therapy of initial treatment with a Wnt agonist followed
by treatment with a Wnt antagonist can reduce both the risk of death and
fibrosis in response to acute injuries
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