78 research outputs found
Hysteresis, Avalanches, and Disorder Induced Critical Scaling: A Renormalization Group Approach
We study the zero temperature random field Ising model as a model for noise
and avalanches in hysteretic systems. Tuning the amount of disorder in the
system, we find an ordinary critical point with avalanches on all length
scales. Using a mapping to the pure Ising model, we Borel sum the
expansion to for the correlation length exponent. We sketch a
new method for directly calculating avalanche exponents, which we perform to
. Numerical exponents in 3, 4, and 5 dimensions are in good
agreement with the analytical predictions.Comment: 134 pages in REVTEX, plus 21 figures. The first two figures can be
obtained from the references quoted in their respective figure captions, the
remaining 19 figures are supplied separately in uuencoded forma
Melatonin treatment in old mice enables a more youthful response to LPS in the brain
Melatonin modulates the expression of a number of genes related to inflammation and immunity. Declining levels of melatonin with age may thus relate to some of the changes in immune function that occur with age. mRNA expression levels in murine CNS were measured using oligonucleotide microarrays in order to determine whether a dietary melatonin supplement may modify age-related changes in the response to an inflammatory challenge. CB6F1 male mice were fed 40ppm melatonin for 9 weeks prior to sacrifice at 26.5 months of age, and compared with age-matched untreated controls and 4.5-month-old controls. A subset of both young and old animals was injected i.p. with lipopolysaccharide (LPS). After 3 hours, total RNA was extracted from whole brain (excluding brain stem and cerebellum), and individual samples were hybridized to Affymetrix Mouse 430-2.0 arrays. Data were analyzed in Dchip and GeneSpring. Melatonin treatment markedly altered the response in gene expression of older animals subjected to an LPS challenge. These changes in general, caused the response to more closely resemble that of young animals subjected to the same LPS challenge. Thus melatonin treatment effects a major shift in the response of the CNS to an inflammatory challenge, causing a transition to a more youthful mRNA expression profile
Microelectrode Sensing of Adenosine/Adenosine-5′-triphosphate with Fast-Scan Cyclic Voltammetry
Some biochemical properties of melatonin and the characterization of a relevant metabolite arising from its interaction with H 2
Chronic second-by-second measures of l-glutamate in the central nervous system of freely moving rats
Ammonia-induced heme oxygenase-1 expression in cultured rat astrocytes and rat brain in vivo
Comparison of cerebral Open Flow Microperfusion and Microdialysis when sampling small lipophilic and small hydrophilic substances
Activation of anterior thalamic reticular nucleus GABAergic neurons promotes arousal from propofol anesthesia in mice
Tonic glutamate in CA1 of aging rats correlates with phasic glutamate dysregulation during seizure
Melatonin potentiates flavone-induced apoptosis in human colon cancer cells by increasing the level of glycolytic end products
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