179,252 research outputs found
The influence of shc proteins and aging on whole body energy expenditure and substrate utilization in mice.
While it has been proposed that Shc family of adaptor proteins may influence aging by regulating insulin signaling and energy metabolism, the overall impact of Shc proteins on whole body energy metabolism has yet to be elucidated. Thus, the purpose of this study was to determine the influence of Shc proteins and aging on whole body energy metabolism in a mouse model under ambient conditions (22°C) and acute cold exposure (12°C for 24 hours). Using indirect respiration calorimetry, we investigated the impact of Shc proteins and aging on EE and substrate utilization (RQ) in p66 Shc-/- (ShcKO) and wild-type (WT) mice. Calorimetry measurements were completed in 3, 15, and 27 mo mice at 22°C and 12°C. At both temperatures and when analyzed across all age groups, ShcKO mice demonstrated lower 24 h total EE values than that of WT mice when EE data was expressed as either kJ per mouse, or adjusted by body weight or crude organ mass (ORGAN) (P≤0.01 for all). The ShcKO mice also had higher (P<0.05) fed state RQ values than WT animals at 22°C, consistent with an increase in glucose utilization. However, Shc proteins did not influence age-related changes in energy expenditure or RQ. Age had a significant impact on EE at 22°C, regardless of how EE data was expressed (P<0.05), demonstrating a pattern of increase in EE from age 3 to 15 mo, followed by a decrease in EE at 27 mo. These results indicate a decline in whole body EE with advanced age in mice, independent of changes in body weight (BW) or fat free mass (FFM). The results of this study indicate that both Shc proteins and aging should be considered as factors that influence energy expenditure in mice
On Einstein equations on manifolds and supermanifolds
The Einstein equations (EE) are certain conditions on the Riemann tensor on
the real Minkowski space M. In the twistor picture, after complexification and
compactification M becomes the Grassmannian of 2-dimensional
subspaces in the 4-dimensional complex one. Here we answer for which of the
classical domains considered as manifolds with G-structure it is possible to
impose conditions similar in some sense to EE. The above investigation has its
counterpart on superdomains: an analog of the Riemann tensor is defined for any
supermanifold with G-structure with any Lie supergroup G. We also derive
similar analogues of EE on supermanifolds. Our analogs of EE are not what
physicists consider as SUGRA (supergravity), for SUGRA see \cite{GL4,LP2}.Comment: arxiv version is already officia
Neutrino oscillations and signals in beta and 0nu2beta experiments
Assuming Majorana neutrinos, we infer from oscillation data the expected
values of the parameters m_{nu_e} and m_{ee} probed by beta and 0nu2beta-decay
experiments. If neutrinos have a `normal hierarchy' we get the 90% CL ranges
|m_{ee}| = (0.7 - 4.6) meV, and discuss in which cases future experiments can
test this possibility. For `inverse hierarchy', we get |m_{ee}| = (12 - 57) meV
and m_{\nu_e} = (40 - 57) meV. The 0nu2beta data imply that almost degenerate
neutrinos are lighter than 1.05 h eV at 90% CL, competitive with the beta-decay
bound. We critically reanalyse the data that were recently used to claim an
evidence for 0nu2beta, and discuss their implications. Finally, we review the
predictions of flavour models for m_{ee} and theta_{13}.Comment: 30 pages, 12 figures. Version 2: footnote at page 21 added. Version
3: updated including SNO NC data. Version 4: addendum about KamLAND data at
pages 25,26,27. Version 5: addendum about SNO salt data at pages 28,29,3
Flexible resource allocation for joint optimization of energy and spectral efficiency in OFDMA multi-cell networks
The radio resource allocation problem is studied, aiming to jointly optimize the energy efficiency (EE) and spectral efficiency (SE) of downlink OFDMA multi-cell networks. Different from existing works on either EE or SE optimization, a novel EE-SE tradeoff (EST) metric, which can capture both the EST relation and the individual cells’ preferences for EE or SE performance, is introduced as the utility function for each base station (BS). Then the joint EE-SE optimization problem is formulated, and an iterative subchannel allocation and power allocation algorithm is proposed. Numerical results show that the proposed algorithm can exploit the EST relation flexibly and optimize the EE and SE simultaneously to meet diverse EE and SE preferences of individual cells.<br/
Violation of the Wiedemann-Franz law in clean graphene layers
The Wiedemann-Franz law, connecting the electronic thermal conductivity to
the electrical conductivity of a disordered metal, is generally found to be
well satisfied even when electron-electron (e-e) interactions are strong. In
ultra-clean conductors, however, large deviations from the standard form of the
law are expected, due to the fact that e-e interactions affect the two
conductivities in radically different ways. Thus, the standard Wiedemann-Franz
ratio between the thermal and the electric conductivity is reduced by a factor
, where is the momentum relaxation
rate, and is the relaxation time of the thermal
current due to e-e collisions. Here we study the density and temperature
dependence of in the important case of doped, clean
single layers of graphene, which exhibit record-high thermal conductivities. We
show that at low temperature is of the
quasiparticle decay rate. We also show that the many-body renormalization of
the thermal Drude weight coincides with that of the Fermi velocity.Comment: 6 pages, 5 appendices (13 pages
Acne resolution rates: Results of a single-blind, randomized, controlled, parallel phase III trial with EE/CMA (Belara (R)) and EE/LNG (Microgynon (R))
Background and Objective: Acne in women can often be successfully treated by the intake of oral contraceptives containing gestagens with anti-androgenic properties. This study aimed to evaluate the efficacy of the monophasic oral contraceptive ethinylestradiol/chlormadinone acetate (EE/CMA; Belara (R)) for the treatment of mild to moderate papulopustular acne of the face and acne-related disorders in comparison to EE/levonorgestrel (LNG; Microgynon (R)). Methods: 199 female acne patients were enrolled in a single-blind, randomized, multicentre phase III study and divided into two groups who received either EE/CMA or EE/LNG. The primary end point was fulfilled if the number of papules/pustules per half of the face present on admission had decreased by at least 50% in the 12th medication cycle. Results: 59.4% of the women under EE/CMA and 45.9% under EE/LNG were responders. The relative frequency of women with complete resolution was 16.5% under EE/CMA and 4.3% under EE/LNG at cycle 12. Conclusion: EE/CMA is an efficient treatment for women with mild and moderate papulopustular acne of the face and related disorders, reflecting the well-known anti-androgenic properties of the progestogen CMA. Copyright (C) 2001 S, Karger AG, Basel
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