44 research outputs found
Synergy Between Adiposity, Insulin Resistance, Metabolic Risk Factors, and Inflammation in Adolescents
The purpose of this study was to investigate relationships between inflammatory markers and components of a metabolic syndrome cluster in adolescents. This was a cross-sectional analysis of an Australian childhood cohort (n = 1,377) aged 14 years. Cluster analysis defined a "high-risk" group similar to adults with metabolic syndrome. Relevant measures were anthropometry, fasting insulin, glucose, lipids, inflammatory markers, liver function, and blood pressure. Of the children, 29% fell into a high-risk metabolic cluster group compared with 2% by a pediatric metabolic syndrome definition. Relative to the "low-risk" cluster, they had higher BMI (95% CI 19.5-19.8 vs. 24.5-25.4), waist circumference (centimeters) (95% CI 71.0-71.8 vs. 83.4-85.8), insulin (units per liter) (95% CI 1.7-1.8 vs. 3.5-3.9), homeostasis model assessment (95% CI 1.7-1.8 vs. 3.5-3.9), systolic blood pressure (millimeters of mercury) (95% CI 110.8-112.1 vs. 116.7-118.9), and triglycerides (millimoles per liter) (95% CI 0.78-0.80 vs. 1.25-1.35) and lower HDL cholesterol (millimoles per liter) (95% CI 1.44-1.48 vs. 1.20-1.26). Inflammatory and liver function markers were higher in the high-risk group: C-reactive protein (CRP) (P < 0.001), uric acid (P < 0.001), alanine aminotransferase (ALT) (P < 0.001), and γ-glutamyl transferase (GGT) (P < 0.001). The highest CRP, GGT, and ALT levels were restricted to overweight children in the high-risk group. Cluster analysis revealed a strikingly high proportion of 14 year olds at risk of cardiovascular disease-related metabolic disorders. Adiposity and the metabolic syndrome cluster are synergistic in the pathogenesis of inflammation. Systemic and liver inflammation in the high-risk cluster is likely to predict diabetes, cardiovascular disease, and nonalcoholic fatty liver disease
Hydrodynamic bubble coarsening in off-critical vapour-liquid phase separation
Late-stage coarsening in off-critical vapour-liquid phase separation is
re-examined. In the limit of bubbles of vapour distributed throughout a
continuous liquid phase, it is argued that coarsening proceeds via inertial
hydrodynamic bubble collapse. This replaces the Lifshitz-Slyozov-Wagner
mechanism seen in binary liquid mixtures. The arguments are strongly supported
by simulations in two dimensions using a novel single-component soft sphere
fluid.Comment: 5 pages, 3 figures, revtex3.
A relativistic action-at-a-distance description of gravitational interactions?
It is shown that certain aspects of gravitation may be described using a
relativistic action-at-a-distance formulation. The equations of motion of the
model presented are invariant under Lorentz transformations and agree with the
equations of Einstein's theory of General Relativity, at the first
Post-Newtonian approximation, for any number of interacting point masses
A derivation of the Breit equation from Barut's covariant formulation of electrodynamics in terms of direct interactions
We study Barut's covariant equations describing the electromagnetic
interactions between N spin-1/2 particles. In the covariant formulation each
particle is described by a Dirac spinor. It is assumed that the interactions
between the particles are not mediated by a bosonic field (direct
interactions). Within this formulation, using the Lagrangian formalism, we
derive the approximate (semirelativistic) Breit equation for two interacting
spin-1/2 particles
Dark solitons in atomic Bose-Einstein condensates: from theory to experiments
This review paper presents an overview of the theoretical and experimental
progress on the study of matter-wave dark solitons in atomic Bose-Einstein
condensates. Upon introducing the general framework, we discuss the statics and
dynamics of single and multiple matter-wave dark solitons in the quasi
one-dimensional setting, in higher-dimensional settings, as well as in the
dimensionality crossover regime. Special attention is paid to the connection
between theoretical results, obtained by various analytical approaches, and
relevant experimental observations.Comment: 82 pages, 13 figures. To appear in J. Phys. A: Math. Theor
Dynamics of Barred Galaxies
Some 30% of disc galaxies have a pronounced central bar feature in the disc
plane and many more have weaker features of a similar kind. Kinematic data
indicate that the bar constitutes a major non-axisymmetric component of the
mass distribution and that the bar pattern tumbles rapidly about the axis
normal to the disc plane. The observed motions are consistent with material
within the bar streaming along highly elongated orbits aligned with the
rotating major axis. A barred galaxy may also contain a spheroidal bulge at its
centre, spirals in the outer disc and, less commonly, other features such as a
ring or lens. Mild asymmetries in both the light and kinematics are quite
common. We review the main problems presented by these complicated dynamical
systems and summarize the effort so far made towards their solution,
emphasizing results which appear secure. (Truncated)Comment: This old review appeared in 1993. Plain tex with macro file. 82 pages
18 figures. A pdf version with figures at full resolution (3.24MB) is
available at http://www.physics.rutgers.edu/~sellwood/bar_review.pd
The genetic architecture of the human cerebral cortex
The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
Bronchodilator response during acute viral bronchiolitis in infancy
Bronchodilator responsiveness was assessed by measuring specific respiratory conductance before and after inhalation of aerosolized bronchodilator in 50 infants who had acute bronchiolitis due to respiratory syncytial virus infection. Thirty per cent of the infants showed an improvement in specific conductance. Responders could not be differentiated from nonresponders by family histories of atopy, eosinophil counts, or immunoglobulin levels in blood and nasal secretions. Eighty‐three per cent of the families and 54% of the mothers of the infants were smokers. Babies of smoking mothers had lower specific conductances than did those of nonsmoking mothers but showed no differences in bronchodilator response. The clinical significance of this bronchodilator‐responsive subgroup has yet to be defined