584 research outputs found
Toward Supergravity Spectral Action
A spectral action of Euclidean supergravity is proposed. We calculate up to
, the Seeley-Dewitt coefficients in the expansion of the spectral action
associated to the supergravity Dirac operator. This is possible because in
simple supergravity, as in pure gravity, a well defined and mathematically
consistent Dirac operator can be constructed.Comment: 10pages, no figures, matches published versio
Supersymmetric features of the Maxwell fish-eye lens
We provide a supersymmetric analysis of the Maxwell fisheye (MF) wave problem
at zero energy. Working in the so-called sector, we obtain the
corresponding superpartner (fermionic) MF effective potential within Witten's
one-dimensional (radial) supersymmetric procedure.Comment: 5 pages in Latex, one figure not included has been published as Fig.
2 in Phys. Lett. A 208 (1995) 33-3
Bistability for asymmetric discrete random walks
We show that asymmetric time-continuous discrete random walks can display
bistability for equal values of Jauslin's shifting parameters. The bistability
becomes more pronounced at increased asymmetry parameterComment: Follow-up note to hep-th/9411026[PRE 51, 5112 (May 95)], one fig.
include
quantum cosmological solutions for Class A Bianchi Models
We find solutions for quantum Class A Bianchi models of the form generalizing the results obtained by Moncrief and Ryan in
standard quantum cosmology. For the II and IX Bianchi models there are other
solutions , to the Hamilton-Jacobi
equation for which is necessarely zero, in contrast with solutions
found in supersymmetric quantum cosmology.Comment: 15 pages, Late
Presence and regulation of D1 and D2 deiodinases in rat white adipose tissue
Thyroid hormones regulate adipogenic differentiation, lipogenic and lipolytic metabolism, and mitochondrial activity in adipose tissue. Triiodothyronine (T3) levels in tissues are regulated by the deiodinase enzymes. The objective was to study the activity and messenger RNA (mRNA) expression of the 5′ outer-ring deiodinases (type 1 [D1] and type 2 [D2] deiodinase) and thyroid hormone concentrations in rat white adipose tissue (WAT), where only D1 activity had been described. Control, thyroidectomized, and thyroid hormone–treated rats were used. Type 1 and type 2 deiodinase mRNAs were determined in WAT by quantitative real-time polymerase chain reaction using Taqman probes; D1 and D2 activities were determined using reverse T3 and thyroxine (T4) as substrates. Thyroxine and T3 were measured by radioimmunoassay in plasma, liver, and adipose tissue. Type 1 and type 2 deiodinase mRNAs are present in epididymal rat WAT with similar abundance, which is 7% of the D2 mRNA levels in brown adipose tissue and 1% of D1 in liver. The Michaelis-Menten constants in WAT are 40 nmol/L T4 for D2 and 0.35 μmol/L reverse T3 for D1. Both D1 and D2 are regulated in rat epididymal WAT by thyroidal status. Thyroxine and T3 concentrations in plasma, liver, and WAT decreased after thyroidectomy and recovered after treatment with T4 + T3. Both D1 and D2 mRNAs increased in WAT from thyroidectomy rats; and T4 + T3 treatment inhibited them, especially D2 mRNA. Type 1 deiodinase activity did not change with thyroidal status, whereas D2 activity was inhibited by T4 + T3. The presence of both deiodinases in WAT suggests important roles in regulating T3 bioavailability for adipose tissue function and regulation of lipid metabolism and thermogenesis.Supported by SAF2006-01319 and SAF2009-2243 from MICINN and Fundacion Mutua Madrileña 2006.Peer Reviewe
- …