6,747 research outputs found
Recommended from our members
The effects of flavonoids on cardiovascular health: a review of human intervention trials and implications for cerebrovascular function
Research has suggested a number of beneficial effects arising from the consumption of
dietary flavonoids, found in foods such as cocoa, apples, tea, citrus fruits and berries on cardiovascular
risk factors such as high blood pressure and endothelial dysfunction. These effects are thought to have
a significant impact upon both vascular and cerebrovascular health, ultimately with the potential to
prevent cardiovascular and potentially neurodegenerative disease with a vascular component, for
example vascular dementia. This review explores the current evidence for the effects of flavonoid
supplementation on human endothelial function and both peripheral and cerebral blood flow (CBF).
Evidence presented includes their potential to reduce blood pressure in hypertensive individuals,
as well as increasing peripheral blood perfusion and promoting CBF in both healthy and at-risk
populations. However, there is great variation in the literature due to the heterogeneous nature of
the randomised controlled trials conducted. As such, there is a clear need for further research and
understanding within this area in order to maximise potential health benefits
Long-range sound-mediated dark soliton interactions in trapped atomic condensates
A long-range soliton interaction is discussed whereby two or more dark
solitons interact in an inhomogeneous atomic condensate, modifying their
respective dynamics via the exchange of sound waves without ever coming into
direct contact. An idealized double well geometry is shown to yield perfect
energy transfer and complete periodic identity reversal of the two solitons.
Two experimentally relevant geometries are analyzed which should enable the
observation of this long-range interaction
Slow Quenches Produce Fuzzy, Transient Vortices
We examine the Zurek scenario for the production of vortices in quenches of
liquid in the light of recent experiments. Extending our previous
results to later times, we argue that short wavelength thermal fluctuations
make vortices poorly defined until after the transition has occurred. Further,
if and when vortices appear, it is plausible that that they will decay faster
than anticipated from turbulence experiments, irrespective of quench rates.Comment: 4 pages, Revtex file, no figures Apart from a more appropriate title,
this paper differs from its predecessor by including temperature, as well as
pressure, quenche
Heavy hydrocarbon main injector technology program
The Heavy Hydrocarbon Main Injector Program was an analytical, design, and test program to demonstrate an injection concept applicable to an Isolated Combustion Compartment of a full-scale, high pressure, LOX/RP-1 engine. Several injector patterns were tested in a 3.4-in. combustor. Based on these results, features of the most promising injector design were incorporated into a 5.7-in. injector which was then hot-fire tested. In turn, a preliminary design of a 5-compartment 2D combustor was based on this pattern. Also the additional subscale injector testing and analysis was performed with an emphasis on improving analytical techniques and acoustic cavity design methodology. Several of the existing 3.5-in. diameter injectors were hot-fire tested with and without acoustic cavities for spontaneous and dynamic stability characteristics
The asymptotic quasi-stationary states of the two-dimensional magnetically confined plasma and of the planetary atmosphere
We derive the differential equation governing the asymptotic quasi-stationary
states of the two dimensional plasma immersed in a strong confining magnetic
field and of the planetary atmosphere. These two systems are related by the
property that there is an intrinsic constant length: the Larmor radius and
respectively the Rossby radius and a condensate of the vorticity field in the
unperturbed state related to the cyclotronic gyration and respectively to the
Coriolis frequency. Although the closest physical model is the
Charney-Hasegawa-Mima (CHM) equation, our model is more general and is related
to the system consisting of a discrete set of point-like vortices interacting
in plane by a short range potential. A field-theoretical formalism is developed
for describing the continuous version of this system. The action functional can
be written in the Bogomolnyi form (emphasizing the role of Self-Duality of the
asymptotic states) but the minimum energy is no more topological and the
asymptotic structures appear to be non-stationary, which is a major difference
with respect to traditional topological vortex solutions. Versions of this
field theory are discussed and we find arguments in favor of a particular form
of the equation. We comment upon the significant difference between the CHM
fluid/plasma and the Euler fluid and respectively the Abelian-Higgs vortex
models.Comment: Latex 126 pages, 7 eps figures included. Discussion on various forms
of the equatio
Mydriatics: Drop the dose
This study investigated the difference in pupillary dilation between a normal dose and a substandard dose of a topical ophthalmic mydriatic agent, the combination of hydroxyamphetamine hydrobromide 1% and tropicamide 0.25% (Paremydâ„¢ solution). The manufacturer\u27s recommended dosage is 1-2 drops per eye. A typical opthalmic drop ranges in volume from 30 - 75. We hypothesized that a small, substandard dose of 10 will create a pupillary dilation clinically and statistically equivalent to that of the larger, standard dose of 30 in part due to the reflex tear response and increased lacrimal drainage. Our research found that the smaller dose of the mydriatic does indeed provide a clinically and statistically equivalent pupillary dilation to the larger dose. Clinically, the use of a reduced dose of a topical mydriatic will reduce the inherent risks and side effects to the patient (especially to the high-risk patient), while still allowing the eye care practitioner ample pupillary dilation to provide a quality dilated fundus examination
Phase diagram of quantized vortices in a trapped Bose-Einstein condensed gas
We investigate the thermodynamic stability of quantized vortices in a dilute
Bose gas confined by a rotating harmonic trap at finite temperature.
Interatomic forces play a crucial role in characterizing the resulting phase
diagram, especially in the large Thomas-Fermi regime. We show that the
critical temperature for the creation of stable vortices exhibits a maximum as
a function of the frequency of the rotating trap and that the corresponding
transition is associated with a discontinuity in the number of atoms in the
condensate. Possible strategies for approaching the vortical region are
discussed.Comment: Revtex, 4 pages, 2 figure
- …