2,173 research outputs found
Cereal and nonfat milk support muscle recovery following exercise
All authors are with the Exercise Physiology and Metabolism Laboratory Department of Kinesiology and Health Education The University of Texas at Austin Austin, TX, USABackground: This study compared the effects of ingesting cereal and nonfat milk (Cereal) and a carbohydrate-electrolyte sports drink (Drink) immediately following endurance exercise on muscle glycogen synthesis and the phosphorylation state of proteins controlling protein synthesis: Akt, mTOR, rpS6 and eIF4E. -- Methods: Trained cyclists or triathletes (8 male: 28.0 ± 1.6 yrs, 1.8 ± 0.0 m, 75.4 ± 3.2 kg, 61.0 ± 1.6 ml O2•kg-1•min-1; 4 female: 25.3 ± 1.7 yrs, 1.7 ± 0.0 m, 66.9 ± 4.6 kg, 46.4 ± 1.2 mlO2•kg-1•min-1) completed two randomly-ordered trials serving as their own controls. After 2 hours of cycling at 60–65% VO2MAX, a biopsy from the vastus lateralis was obtained (Post0), then subjects consumed either Drink (78.5 g carbohydrate) or Cereal (77 g carbohydrate, 19.5 g protein and 2.7 g fat). Blood was drawn before and at the end of exercise, and at 15, 30 and 60 minutes after treatment. A second biopsy was taken 60 minutes after supplementation (Post60). Differences within and between treatments were tested using repeated measures ANOVA.
-- Results: At Post60, blood glucose was similar between treatments (Drink 6.1 ± 0.3, Cereal 5.6 ± 0.2 mmol/L, p < .05), but after Cereal, plasma insulin was significantly higher (Drink 123.1 ± 11.8, Cereal 191.0 ± 12.3 pmol/L, p < .05), and plasma lactate significantly lower (Drink 1.4 ± 0.1, Cereal 1.00 ± 0.1 mmol/L, p < .05). Except for higher phosphorylation of mTOR after Cereal, glycogen and muscle proteins were not statistically different between treatments. Significant Post0 to Post60 changes occurred in glycogen (Drink 52.4 ± 7.0 to 58.6 ± 6.9, Cereal 58.7 ± 9.6 to 66.0 ± 10.0 μmol/g, p < .05) and rpS6 (Drink 17.9 ± 2.5 to 35.2 ± 4.9, Cereal 18.6 ± 2.2 to 35.4 ± 4.4 %Std, p < .05) for each treatment, but only Cereal significantly affected glycogen synthase (Drink 66.6 ± 6.9 to 64.9 ± 6.9, Cereal 61.1 ± 8.0 to 54.2 ± 7.2%Std, p < .05), Akt (Drink 57.9 ± 3.2 to 55.7 ± 3.1, Cereal 53.2 ± 4.1 to 60.5 ± 3.7 %Std, p < .05) and mTOR (Drink 28.7 ± 4.4 to 35.4 ± 4.5, Cereal 23.0 ± 3.1 to 42.2 ± 2.5 %Std, p < .05). eIF4E was unchanged after both treatments.
-- Conclusion: These results suggest that Cereal is as good as a commercially-available sports drink in initiating post-exercise muscle recovery.Kinesiology and Health [email protected]
Tensor product representation of topological ordered phase: necessary symmetry conditions
The tensor product representation of quantum states leads to a promising
variational approach to study quantum phase and quantum phase transitions,
especially topological ordered phases which are impossible to handle with
conventional methods due to their long range entanglement. However, an
important issue arises when we use tensor product states (TPS) as variational
states to find the ground state of a Hamiltonian: can arbitrary variations in
the tensors that represent ground state of a Hamiltonian be induced by local
perturbations to the Hamiltonian? Starting from a tensor product state which is
the exact ground state of a Hamiltonian with topological order,
we show that, surprisingly, not all variations of the tensors correspond to the
variation of the ground state caused by local perturbations of the Hamiltonian.
Even in the absence of any symmetry requirement of the perturbed Hamiltonian,
one necessary condition for the variations of the tensors to be physical is
that they respect certain symmetry. We support this claim by
calculating explicitly the change in topological entanglement entropy with
different variations in the tensors. This finding will provide important
guidance to numerical variational study of topological phase and phase
transitions. It is also a crucial step in using TPS to study universal
properties of a quantum phase and its topological order.Comment: 10 pages, 6 figure
From Ground States to Local Hamiltonians
Traditional quantum physics solves ground states for a given Hamiltonian,
while quantum information science asks for the existence and construction of
certain Hamiltonians for given ground states. In practical situations, one
would be mainly interested in local Hamiltonians with certain interaction
patterns, such as nearest neighbour interactions on some type of lattices. A
necessary condition for a space to be the ground-state space of some local
Hamiltonian with a given interaction pattern, is that the maximally mixed state
supported on is uniquely determined by its reduced density matrices
associated with the given pattern, based on the principle of maximum entropy.
However, it is unclear whether this condition is in general also sufficient. We
examine the situations for the existence of such a local Hamiltonian to have
satisfying the necessary condition mentioned above as its ground-state
space, by linking to faces of the convex body of the local reduced states. We
further discuss some methods for constructing the corresponding local
Hamiltonians with given interaction patterns, mainly from physical points of
view, including constructions related to perturbation methods, local
frustration-free Hamiltonians, as well as thermodynamical ensembles.Comment: 11 pages, 2 figures, to be published in PR
Ozone predictabilities due to meteorological uncertainties in the Mexico City basin using ensemble forecasts
The purpose of the present study is to investigate the sensitivity of ozone (O<sub>3</sub>) predictions in the Mexico City Metropolitan Area (MCMA) to meteorological initial uncertainties and planetary boundary layer (PBL) parameterization schemes using state-of-the-art meteorological and photochemical prediction models through ensemble forecasts. The simulated periods (3, 9, 15 and 29 March 2006) represent four typical meteorological episodes ("South-Venting", "O<sub>3</sub>-North", "O<sub>3</sub>-South" and "Convection-North", respectively) in the Mexico City basin during the MCMA-2006/MILAGRO campaign. Our results demonstrate that the uncertainties in meteorological initial conditions have significant impacts on O<sub>3</sub> predictions, including peak time O<sub>3</sub> concentrations ([O<sub>3</sub>]), horizontal and vertical O<sub>3</sub> distributions, and temporal variations. The ensemble spread of the simulated peak [O<sub>3</sub>] averaged over the city's ambient monitoring sites can reach up to 10 ppb. The increasing uncertainties in meteorological fields during peak O<sub>3</sub> period contribute to the largest unpredictability in O<sub>3</sub> simulations, while the impacts of wind speeds and PBL height on [O<sub>3</sub>] are more straightforward and important. The magnitude of the ensemble spreads varies with different PBL schemes and meteorological episodes. The uncertainties in O<sub>3</sub> predictions caused by PBL schemes mainly come from their ability to represent the mixing layer height; but overall, these uncertainties are smaller than those from the uncertainties in meteorological initial conditions
Chloroquine supplementation increases the cytotoxic effect of curcumin against Her2/neu overexpressing breast cancer cells in vitro and in vivo in nude mice while counteracts it in immune competent mice
Autophagy is usually a pro-survival mechanism in cancer cells, especially in the course of chemotherapy, thus autophagy inhibition may enhance the chemotherapy-mediated anti-cancer effect. However, since autophagy is strongly involved in the immunogenicity of cell death by promoting ATP release, its inhibition may reduce the immune response against tumors, negatively influencing the overall outcome of chemotherapy. In this study, we evaluated the in vitro and in vivo anti-cancer effect of curcumin (CUR) against Her2/neu overexpressing breast cancer cells (TUBO) in the presence or in the absence of the autophagy inhibitor chloroquine (CQ). We found that TUBO cell death induced by CUR was increased in vitro by CQ and slightly in vivo in nude mice. Conversely, CQ counteracted the Cur cytotoxic effect in immune competent mice, as demonstrated by the lack of in vivo tumor regression and the reduction of overall mice survival as compared with CUR-treated mice. Immunohistochemistry analysis revealed the presence of a remarkable FoxP3 T cell infiltrate within the tumors in CUR/CQ treated mice and a reduction of T cytotoxic cells, as compared with single CUR treatment. These findings suggest that autophagy is important to elicit anti-tumor immune response and that autophagy inhibition by CQ reduces such response also by recruiting T regulatory (Treg) cells in the tumor microenvironment that may be pro-tumorigenic and might counteract CUR-mediated anti-cancer effects
Local unitary versus local Clifford equivalence of stabilizer and graph states
The equivalence of stabilizer states under local transformations is of
fundamental interest in understanding properties and uses of entanglement. Two
stabilizer states are equivalent under the usual stochastic local operations
and classical communication criterion if and only if they are equivalent under
local unitary (LU) operations. More surprisingly, under certain conditions, two
LU equivalent stabilizer states are also equivalent under local Clifford (LC)
operations, as was shown by Van den Nest et al. [Phys. Rev. \textbf{A71},
062323]. Here, we broaden the class of stabilizer states for which LU
equivalence implies LC equivalence () to include all
stabilizer states represented by graphs with neither cycles of length 3 nor 4.
To compare our result with Van den Nest et al.'s, we show that any stabilizer
state of distance is beyond their criterion. We then further prove
that holds for a more general class of stabilizer states
of . We also explicitly construct graphs representing
stabilizer states which are beyond their criterion: we identify all 58 graphs
with up to 11 vertices and construct graphs with () vertices
using quantum error correcting codes which have non-Clifford transversal gates.Comment: Revised version according to referee's comments. To appear in
Physical Review
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