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The impact of fruit flavonoids on memory and cognition
There is intense interest in the studies related to the potential of phytochemical-rich foods to prevent age-related neurodegeneration and cognitive decline. Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. This review will highlight the evidence for the actions of such flavonoids, found most commonly in fruits, such as apples, berries and citrus, on cognitive behaviour and the underlying cellular architecture. Although the precise mechanisms by which these flavonoids act within the brain remain unresolved, the present review focuses on their ability to protect vulnerable neurons and enhance the function of existing neuronal structures, two processes known to be influenced by flavonoids and also known to underpin neuro-cognitive function. Most notably, we discuss their selective interactions with protein kinase and lipid kinase signalling cascades (i.e. phosphoinositide-3 kinase/Akt and mitogen-activated protein kinase pathways), which regulate transcription factors and gene expression involved in both synaptic plasticity and cerebrovascular blood flow. Overall, the review attempts to provide an initial insight into the potential impact of regular flavonoid-rich fruit consumption on normal or abnormal deteriorations in cognitive performance
Electronic structure and thermoelectric properties of CuRh(1-x)MgxO2
Electronic structure calculations using the augmented spherical wave method
have been performed for CuRhO2. For this semiconductor crystallizing in the
delafossite structure, it is found that the valence band maximum is mainly due
to the 4d t2g orbitals of Rh^{3+}. The structural characterizations of
CuRh(1-x)MgxO2 show a broad range of Mg^{2+} substitution for Rh^{3+} in this
series, up to about 12%. Measurements of the resistivity and thermopower of the
doped systems show a Fermi liquid-like behavior for temperatures up to about
1000K, resulting in a large weakly temperature dependent power factor. The
thermopower is discussed both within the Boltzmann equation approach as based
on the electronic structure calculations and the temperature independent
correlation functions ratio approximation as based on the Kubo formalism.Comment: 9 pages, 12 figures, more information at
http://www.physik.uni-augsburg.de/~eyert
Some remarks on the coherent-state variational approach to nonlinear boson models
The mean-field pictures based on the standard time-dependent variational
approach have widely been used in the study of nonlinear many-boson systems
such as the Bose-Hubbard model. The mean-field schemes relevant to
Gutzwiller-like trial states , number-preserving states and
Glauber-like trial states are compared to evidence the specific
properties of such schemes. After deriving the Hamiltonian picture relevant to
from that based on , the latter is shown to exhibit a Poisson
algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the
-based picture. Then states are shown to be a superposition of -boson states and the similarities/differences of the -based and
-based pictures are discussed. Finally, after proving that the simple,
symmetric state indeed corresponds to a SU(M) coherent state, a dual
version of states and in terms of momentum-mode operators is
discussed together with some applications.Comment: 16 page
A schematic model for QCD at finite temperature
The simplest version of a class of toy models for QCD is presented. It is a
Lipkin-type model, for the quark-antiquark sector, and, for the gluon sector,
gluon pairs with spin zero are treated as elementary bosons. The model
restricts to mesons with spin zero and to few baryonic states. The
corresponding energy spectrum is discussed. We show that ground state
correlations are essential to describe physical properties of the spectrum at
low energies. Phase transitions are described in an effective manner, by using
coherent states. The appearance of a Goldstone boson for large values of the
interaction strength is discussed, as related to a collective state. The
formalism is extended to consider finite temperatures. The partition function
is calculated, in an approximate way, showing the convenience of the use of
coherent states. The energy density, heat capacity and transitions from the
hadronic phase to the quark-gluon plasma are calculated.Comment: 33 pages, 11 figure
r.hu-Erythropoietin (EPO) treatment of pre-ESRD patients slows the rate of progression of renal decline
BACKGROUND: As EPO treatment of chronic anemia of advanced renal disease is now the standard of care we examined if such treatment may slow the progression of renal function decline. METHODS: Data of 18 pre-ESRD patients were analyzed retrospectively 12 months prior and prospectively 12 months after the initiation of EPO. Mean creatinine was 5.0 ± 1.8 mg/dL (Mean ± SEM) when starting EPO at a weekly dose of 5000 ± 500 units once the hematocrit was below 30 %. EPO dose was titrated monthly for a hematocrit between 33.0% and 37.0%. Metabolic complications and hypertension were controlled. RESULTS: At month_0 the average blood pressure was 148/76 ± 5/4 mmHg and at month_12 it was 145/73 ± 6/3 mmHg (p = 0.75 by 2 tailed paired Student's t test). 12/18 patients were on an ACE-i or ARB before month_0 and 14/18 were on it after (p = 0.71 by Fisher's 2 tailed exact test). The average hematocrit rose from 26.9% ± 0.6 to 33.1 % ± 0.1. When linear regression analysis was applied to pre- and post-EPO 1/creatinine data the mean rate of decline was -0.0140 ± 0.0119 (mean ± SD) and -0.0017 ± 0.0090 (non-parametric Wilcoxon matched pairs signed rank sum test: Z value: -2.91; P = 0.004) respectively. 5/18 patients did not require dialysis 12 months after starting EPO (month_0). CONCLUSION: Treatment of the anemia of chronic renal failure with erythropoietin, when instituted together with vigorous metabolic control may slow the rate of renal function decline
Fermion-Boson Interactions and Quantum Algebras
Quantum Algebras (q-algebras) are used to describe interactions between
fermions and bosons. Particularly, the concept of a su_q(2) dynamical symmetry
is invoked in order to reproduce the ground state properties of systems of
fermions and bosons interacting via schematic forces. The structure of the
proposed su_q(2) Hamiltonians, and the meaning of the corresponding deformation
parameters, are discussed.Comment: 20 pages, 10 figures. Physical Review C (in press
Transport properties of the layered Rh oxide K_0.49RhO_2
We report measurements and analyses of resistivity, thermopower and Hall
coefficient of single-crystalline samples of the layered Rh oxide K_0.49RhO_2.
The resistivity is proportional to the square of temperature up to 300 K, and
the thermopower is proportional to temperature up to 140 K. The Hall
coefficient increases linearly with temperature above 100 K, which is ascribed
to the triangular network of Rh in this compound. The different transport
properties between Na_xCoO_2 and K_0.49RhO_2 are discussed on the basis of the
different band width between Co and Rh evaluated from the magnetotransport.Comment: 3 figures, submitted to PR
Pair Fluctuations in Ultra-small Fermi Systems within Self-Consistent RPA at Finite Temperature
A self-consistent version of the Thermal Random Phase Approximation (TSCRPA)
is developed within the Matsubara Green's Function (GF) formalism. The TSCRPA
is applied to the many level pairing model. The normal phase of the system is
considered. The TSCRPA results are compared with the exact ones calculated for
the Grand Canonical Ensemble. Advantages of the TSCRPA over the Thermal Mean
Field Approximation (TMFA) and the standard Thermal Random Phase Approximation
(TRPA) are demonstrated. Results for correlation functions, excitation
energies, single particle level densities, etc., as a function of temperature
are presented.Comment: 22 pages, 13 figers and 3 table
Tea drinking and cognitive function in oldest-old Chinese
10.1007/s12603-012-0077-1The Journal of Nutrition, Health & Aging169754-75
Yukawa Textures From Heterotic Stability Walls
A holomorphic vector bundle on a Calabi-Yau threefold, X, with h^{1,1}(X)>1
can have regions of its Kahler cone where it is slope-stable, that is, where
the four-dimensional theory is N=1 supersymmetric, bounded by "walls of
stability". On these walls the bundle becomes poly-stable, decomposing into a
direct sum, and the low energy gauge group is enhanced by at least one
anomalous U(1) gauge factor. In this paper, we show that these additional
symmetries can strongly constrain the superpotential in the stable region,
leading to non-trivial textures of Yukawa interactions and restrictions on
allowed masses for vector-like pairs of matter multiplets. The Yukawa textures
exhibit a hierarchy; large couplings arise on the stability wall and some
suppressed interactions "grow back" off the wall, where the extended U(1)
symmetries are spontaneously broken. A number of explicit examples are
presented involving both one and two stability walls, with different
decompositions of the bundle structure group. A three family standard-like
model with no vector-like pairs is given as an example of a class of SU(4)
bundles that has a naturally heavy third quark/lepton family. Finally, we
present the complete set of Yukawa textures that can arise for any holomorphic
bundle with one stability wall where the structure group breaks into two
factors.Comment: 53 pages, 4 figures and 13 table
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