1,659 research outputs found
Dietary strategies for remission of type 2 diabetes: A narrative review
Type 2 diabetes (T2DM) is a growing health issue globally, which, until recently, was considered to be both chronic and progressive. Although having lifestyle and dietary changes as core components, treatments have focused on optimising glycaemic control using pharmaceutical agents. With data from bariatric surgery and, more recently, total diet replacement (TDR) studies that have set out to achieve remission, remission of T2DM has emerged as a treatment goal. A group of specialist dietitians and medical practitioners was convened, supported by the British Dietetic Association and Diabetes UK, to discuss dietary approaches to T2DM and consequently undertook a review of the available clinical trial and practice audit data regarding dietary approaches to remission of T2DM. Current available evidence suggests that a range of dietary approaches, including low energy diets (mostly using TDR) and low carbohydrate diets, can be used to support the achievement of euglycaemia and potentially remission. The most significant predictor of remission is weight loss and, although euglycaemia may occur on a low carbohydrate diet without weight loss, which does not meet some definitions of remission, it may rather constitute a âstate of mitigationâ of T2DM. This technical point may not be considered as important for people living with T2DM, aside from that it may only last as long as the carbohydrate restriction is maintained. The possibility of actively treating T2DM along with the possibility of achieving remission should be discussed by healthcare professionals with people living with T2DM, along with a range of different dietary approaches that can help to achieve this
Zero modes, entropy bounds and partition functions
Some recent finite temperature calculations arising in the investigation of
the Verlinde-Cardy relation are re-analysed. Some remarks are also made about
temperature inversion symmetry.Comment: 12 pages, JyTe
How does the entropy/information bound work ?
According to the universal entropy bound, the entropy (and hence information
capacity) of a complete weakly self-gravitating physical system can be bounded
exclusively in terms of its circumscribing radius and total gravitating energy.
The bound's correctness is supported by explicit statistical calculations of
entropy, gedanken experiments involving the generalized second law, and
Bousso's covariant holographic bound. On the other hand, it is not always
obvious in a particular example how the system avoids having too many states
for given energy, and hence violating the bound. We analyze in detail several
purported counterexamples of this type (involving systems made of massive
particles, systems at low temperature, systems with high degeneracy of the
lowest excited states, systems with degenerate ground states, or involving a
particle spectrum with proliferation of nearly massless species), and exhibit
in each case the mechanism behind the bound's efficacy.Comment: LaTeX, 10 pages. Contribution to the special issue of Foundation of
Physics in honor of Asher Peres; C. Fuchs and A. van der Merwe, ed
A Hydrophobic Gate in an Ion Channel: The Closed State of the Nicotinic Acetylcholine Receptor
The nicotinic acetylcholine receptor (nAChR) is the prototypic member of the
`Cys-loop' superfamily of ligand-gated ion channels which mediate synaptic
neurotransmission, and whose other members include receptors for glycine,
gamma-aminobutyric acid, and serotonin. Cryo-electron microscopy has yielded a
three dimensional structure of the nAChR in its closed state. However, the
exact nature and location of the channel gate remains uncertain. Although the
transmembrane pore is constricted close to its center, it is not completely
occluded. Rather, the pore has a central hydrophobic zone of radius about 3 A.
Model calculations suggest that such a constriction may form a hydrophobic
gate, preventing movement of ions through a channel. We present a detailed and
quantitative simulation study of the hydrophobic gating model of the nicotinic
receptor, in order to fully evaluate this hypothesis. We demonstrate that the
hydrophobic constriction of the nAChR pore indeed forms a closed gate.
Potential of mean force (PMF) calculations reveal that the constriction
presents a barrier of height ca. 10 kT to the permeation of sodium ions,
placing an upper bound on the closed channel conductance of 0.3 pS. Thus, a 3 A
radius hydrophobic pore can form a functional barrier to the permeation of a 1
A radius Na+ ion. Using a united atom force field for the protein instead of an
all atom one retains the qualitative features but results in differing
conductances, showing that the PMF is sensitive to the detailed molecular
interactions.Comment: Accepted by Physical Biology; includes a supplement and a
supplementary mpeg movie can be found at
http://sbcb.bioch.ox.ac.uk/oliver/download/Movies/watergate.mp
Substantial and sustained improvements in blood pressure, weight and lipid profiles from a carbohydrate restricted diet: an observational study of insulin resistant patients in primary care
Hypertension is the second biggest known global risk factor for disease after poor diet; perhaps lifestyle interventions are underutilized? In a previous small pilot study, it was found that a low carbohydrate diet was associated with significant improvements in blood pressure, weight, âdeprescribingâ of medications and lipid profiles. We were interested to investigate if these results would be replicated in a larger study based in âreal worldâ GP practice. 154 patients with type 2 diabetes or impaired glucose tolerance were recruited into an observational cohort study in primary care. The effects of a low carbohydrate diet sustained for an average of two years (interquartile range 10â32 months) on cardiovascular risk factors were examined. Results demonstrate significant and substantial reductions in blood pressure (mean reduction of systolic BP 10.9 mmHg (interquartile range 0â22 mmHg) (p < 0.0001), mean reduction in diastolic BP 6.3 mmHg (interquartile range 0â12.8 mmHg) (p < 0.0001) and mean weight reduction of 9.5 Kg (interquartile range 5â13 Kg) (p < 0.0001) together with marked improvement in lipid profiles. This occurred despite a 20% reduction in anti-hypertensive medications. This novel and potentially highly effective dietary modification, done very cheaply alongside routine care, offers hope that should be tested in a large prospective trial
Entropy Bounds and Black Hole Remnants
We rederive the universal bound on entropy with the help of black holes while
allowing for Unruh--Wald buoyancy. We consider a box full of entropy lowered
towards and then dropped into a Reissner--Nordstr\"om black hole in equilibrium
with thermal radiation. We avoid the approximation that the buoyant pressure
varies slowly across the box, and compute the buoyant force exactly. We find,
in agreement with independent investigations, that the neutral point
generically lies very near the horizon. A consequence is that in the generic
case, the Unruh--Wald entropy restriction is neither necessary nor sufficient
for enforcement of the generalized second law. Another consequence is that
generically the buoyancy makes only a negligible contribution to the energy
bookeeping, so that the original entropy bound is recovered if the generalized
second law is assumed to hold. The number of particle species does not figure
in the entropy bound, a point that has caused some perplexity. We demonstrate
by explicit calculation that, for arbitrarily large number of particle species,
the bound is indeed satisfied by cavity thermal radiation in the thermodynamic
regime, provided vacuum energies are included. We also show directly that
thermal radiation in a cavity in dimensional space also respects the bound
regardless of the value of . As an application of the bound we show that it
strongly restricts the information capacity of the posited black hole remnants,
so that they cannot serve to resolve the information paradox.Comment: 12 pages, UCSBTH-93-2
On the Nature of Andromeda IV
Lying at a projected distance of 40' or 9 kpc from the centre of M31,
Andromeda IV is an enigmatic object first discovered during van den Bergh's
search for dwarf spheroidal companions to M31. Being bluer, more compact and
higher surface brightness than other known dwarf spheroidals, it has been
suggested that And IV is either a relatively old `star cloud' in the outer disk
of M31 or a background dwarf galaxy. We present deep HST WFPC2 observations of
And IV and the surrounding field which, along with ground-based long-slit
spectroscopy and Halpha imagery, are used to decipher the true nature of this
puzzling object. We find compelling evidence that And IV is a background galaxy
seen through the disk of M31. The moderate surface brightness (SB(V)~24), very
blue colour (V-I<~0.6), low current star formation rate (~0.001 solar mass/yr)
and low metallicity (~10% solar) reported here are consistent with And IV being
a small dwarf irregular galaxy, perhaps similar to Local Group dwarfs such as
IC 1613 and Sextans A. Although the distance to And IV is not tightly
constrained with the current dataset, various arguments suggest it lies in the
range 5<~D<~8 Mpc, placing it well outside the confines of the Local Group. It
may be associated with a loose group of galaxies, containing major members UGC
64, IC 1727 and NGC 784. We report an updated position and radial velocity for
And IV.Comment: 26 pages, LaTex with 9 figures (including 6 jpg plates). Accepted for
publication in A
Vacuum stability and the Cholesky decomposition
We discuss how the Cholesky decomposition may be used to ascertain whether a
critical point of the field theory scalar potential provides a stable vacuum
configuration. We then use this method to derive the stability conditions in a
specific example.Comment: 7 page
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