3,268 research outputs found
Prevalence of the metabolic syndrome in Chinese adolescents
Since national figures on the occurrence of metabolic syndrome among Chinese adolescents are lacking, this study aims to estimate its prevalence and distribution among Chinese youngsters. The 2002 China National Nutrition and Health Survey is a nationally representative cross-sectional study. Applying the criteria for US adolescents, we estimated the prevalence of metabolic syndrome among 2761 adolescents aged 15 to 19 years. The prevalence of metabolic syndrome among Chinese adolescents overall was 3·7% (10% in US adolescents). It was 35·2 %, 23·4% and 2·3% among adolescents who were overweight (BMI 85th percentile and one or two parent(s) with metabolic syndrome, the prevalence was 46·4 %. A total of 96% of overweight adolescents had at least one and 74·1% overweight adolescents had at least two abnormalities of metabolic syndrome. Based on these figures, it is estimated that more than three million Chinese adolescents have metabolic syndrome. Both overweight and metabolic syndrome prevalence among adolescents are still relatively low in China, but the prevalence of metabolic syndrome among Chinese overweight adolescents is similar to those living in the USA
A Drosophila Perspective
The so-called active zones at pre-synaptic terminals are the ultimate filtering devices, which couple between action potential frequency and shape, and the information transferred to the post-synaptic neurons, finally tuning behaviors. Within active zones, the release of the synaptic vesicle operates from specialized “release sites.” The (M)Unc13 class of proteins is meant to define release sites topologically and biochemically, and diversity between Unc13-type release factor isoforms is suspected to steer diversity at active zones. The two major Unc13-type isoforms, namely, Unc13A and Unc13B, have recently been described from the molecular to the behavioral level, exploiting Drosophila being uniquely suited to causally link between these levels. The exact nanoscale distribution of voltage-gated Ca2+ channels relative to release sites (“coupling”) at pre-synaptic active zones fundamentally steers the release of the synaptic vesicle. Unc13A and B were found to be either tightly or loosely coupled across Drosophila synapses. In this review, we reported recent findings on diverse aspects of Drosophila Unc13A and B, importantly, their nano-topological distribution at active zones and their roles in release site generation, active zone assembly, and pre-synaptic homeostatic plasticity. We compared their stoichiometric composition at different synapse types, reviewing the correlation between nanoscale distribution of these two isoforms and release physiology and, finally, discuss how isoform-specific release components might drive the functional heterogeneity of synapses and encode discrete behavior
Brane Inflation from Rotation of D4 Brane
In this paper, a inflationary model from the rotation of D4-brane is
constructed. We show that for a very wide rage of parameter, this model
satisfies the observation and find that regarded as inflaton, the rotation of
branes may be more nature than the distance between branes. Our model offers a
new avenue for brane inflation.Comment: 6 pages, no figure
Acoustic interferometry for sediment geoacoustic characterization using broadband ship noise in the Yellow Shark environment
Constraints on Oscillating Quintom from Supernova, Microwave Background and Galaxy Clustering
We consider in this paper a simple oscillating Quintom model of dark energy
which has two free parameters and an equation of state oscillating and crossing
-1. For low redshifts the equation of state of this model resembles itself
similar to the linearly parameterized dark energy, however differ substantially
at large redshifts. We fit our model to the observational data separately from
the new high redshift supernova observations from the HST/GOODS program and
previous supernova, CMB and galaxy clustering. Our results show that because of
the oscillating feature of our model the constraints from observations at large
redshifts such as CMB become less stringent.Comment: 4 pages, 6 figures Revtex
Scalar Perturbations Through Cycles
We analytically and numerically investigate the evolutions of the scalar
perturbations through the cycles with nonsingular bounce. It is found that the
amplitude of the curvature perturbation on large scale will be amplified cycle
by cycle, and the isocurvature perturbations also obtain an amplification, but
the rate of its amplification is slower than that of curvature perturbation,
unless its coupling to the metric perturbation is not negligible.Comment: 7 pages, 10 figure
Partially Observable Markov Decision Process Modelling for Assessing Hierarchies
Hierarchical clustering has been shown to be valuable in many scenarios.
Despite its usefulness to many situations, there is no agreed methodology on
how to properly evaluate the hierarchies produced from different techniques,
particularly in the case where ground-truth labels are unavailable. This
motivates us to propose a framework for assessing the quality of hierarchical
clustering allocations which covers the case of no ground-truth information.
This measurement is useful, e.g., to assess the hierarchical structures used by
online retailer websites to display their product catalogues. Our framework is
one of the few attempts for the hierarchy evaluation from a decision-theoretic
perspective. We model the process as a bot searching stochastically for items
in the hierarchy and establish a measure representing the degree to which the
hierarchy supports this search. We employ Partially Observable Markov Decision
Processes (POMDP) to model the uncertainty, the decision making, and the
cognitive return for searchers in such a scenario
Assisted Tachyonic Inflation
The model of inflation with a single tachyon field generates larger
anisotropy and has difficulties in describing the formation of the Universe .
In this paper we consider a model with multi tachyon fields and study the
assisted inflationary solution. Our results show that this model satisfies the
observation.Comment: 5 pages, no figures, a revised version and reference adde
Spectrum of Curvature Perturbation of Multi-field Inflation with Small-Field Potential
In this paper, we have studied the spectrum of curvature perturbation of
multi-field inflation with general small-field potential. We assume that the
isocurvature perturbation may be neglected, and by using the Sasaki-Stewart
formalism, we found that the spectrum may be redder or bluer than of its
corresponding single field. The result depends upon the values of fields and
their effective masses at the horizon-crossing time. We discuss the relevant
cases.Comment: 8 pages, no figure, to publish in JCA
The Bouncing Jet: A Newtonian Liquid Rebounding off a Free Surface
We find that a liquid jet can bounce off a bath of the same liquid if the
bath is moving horizontally with respect to the jet. Previous observations of
jets rebounding off a bath (e.g. Kaye effect) have been reported only for
non-Newtonian fluids, while we observe bouncing jets in a variety of Newtonian
fluids, including mineral oil poured by hand. A thin layer of air separates the
bouncing jet from the bath, and the relative motion replenishes the film of
air. Jets with one or two bounces are stable for a range of viscosity, jet flow
rate and velocity, and bath velocity. The bouncing phenomenon exhibits
hysteresis and multiple steady states.Comment: 9 pages, 7 figures. submitted to Physical Review
- …