10,068 research outputs found
Statistical Mechanics of Phase-Space Curves
We study the classical statistical mechanics of a phase-space curve. This
unveils a mechanism that, via the associated entropic force, provides us with a
simple realization of effects such as confinement, hard core, and asymptotic
freedom. Additionally, we obtain negative specific heats, a distinctive feature
of self-gravitating systems and negative pressures, typical of dark energy.Comment: 24 pages, 15 figure
3D Effects Of The Entropic Force
This work analyzes the classical statistical mechanics associated to
phase-space curves in three dimensions. Special attention is paid to the
entropic force. Strange effects like confinement, hard core, and asymptotic
freedom are uncovered. Negative specific heats, that were previously seen to
emerge in a one-dimensional setting, disappear in 3D, and with them,
gravitational effects of the entropic force.Comment: arXiv admin note: substantial text overlap with arXiv:1306.203
Physical peculiarities of divergences emerging in q-deformed statistics
It was found in [Europhysics Letters {\bf 104}, (2013), 60003] that classical
Tsallis theory exhibits poles in the partition function and the mean
energy . These occur at a countably set of the q-line. We give
here, via a simple procedure, a mathematical account of them. Further, by
focusing attention upon the pole-physics, we encounter interesting effects. In
particular, for the specific heat, we uncover hidden gravitational effects.Comment: 21 pages, 3 figures. Title has changed. Text has change
VGF changes during the estrous cycle: a novel endocrine role for TLQP peptides?
Although the VGF derived peptide TLQP-21 stimulates gonadotropin-releasing hormone (GnRH) and gonadotropin secretion, available data on VGF peptides and reproduction are limited. We used antibodies specific for the two ends of the VGF precursor, and for two VGF derived peptides namely TLQP and PGH, to be used in immunohistochemistry and enzyme-linked immunosorbent assay complemented with gel chromatography. In cycling female rats, VGF C-/N-terminus and PGH peptide antibodies selectively labelled neurones containing either GnRH, or kisspeptin (VGF N-terminus only), pituitary gonadotrophs and lactotrophs, or oocytes (PGH peptides only). Conversely, TLQP peptides were restricted to somatostatin neurones, gonadotrophs, and ovarian granulosa, interstitial and theca cells. TLQP levels were highest, especially in plasma and ovary, with several molecular forms shown in chromatography including one compatible with TLQP-21. Among the cycle phases, TLQP levels were higher during metestrus-diestrus in median eminence and pituitary, while increased in the ovary and decreased in plasma during proestrus. VGF N- and C-terminus peptides also showed modulations over the estrous cycle, in median eminence, pituitary and plasma, while PGH peptides did not. In ovariectomised rats, plasmatic TLQP peptide levels showed distinct reduction suggestive of a major origin from the ovary, while the estrogen-progesterone treatment modulated VGF C-terminus and TLQP peptides in the hypothalamus-pituitary complex. In in vitro hypothalamus, TLQP-21 stimulated release of growth hormone releasing hormone but not of somatostatin. In conclusion, various VGF peptides may regulate the hypothalamus-pituitary complex via specific neuroendocrine mechanisms while TLQP peptides may act at further, multiple levels via endocrine mechanisms involving the ovary
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