34,761 research outputs found
Dimeric procyanidins as modulators of airway inflammation in the context of allergic asthma : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (PhD) in Human Physiology at Massey University, Manawatū, Palmerston North, New Zealand
Procyanidins are polyphenolic compounds that have come to be known as
biologically active in the context of promoting human health. Epidemiological evidence
suggests that populations that consume diets rich in procyanidins are less susceptible to
inflammatory diseases. Allergic asthma is an inflammatory lung disease with an
estimated 100 million affected individuals worldwide, with New Zealand having the
world’s second highest rate. Inflammation at the airway epithelium and infiltration of
immune cells, specifically eosinophils, into the lung tissue are two central
characteristics of allergic asthma. Thymic stromal lymphopoietin (TSLP) and eotaxin
isoforms, eotaxin-1 (CCL11) and eotaxin-3 (CCL26), are three biomarkers of airway
inflammation produced by the epithelium. Cell culture models were successfully
optimized for CCL11 and CCL26 production in A549 cells. Investigation of
procyanidins effect on epithelial TSLP production was not possible because TSLP
production in A549 cells was undetectable. Data suggests that dimeric A-type linked
procyanidin A2, but not B-type linked procyanidin B1 or B2, is capable of inhibiting
IL-4-induced CCL11 production when incubated on A549 cells prior to an
inflammatory insult. Co-incubation of A549 cells with procyanidin A2 and procyanidin
B2 demonstrated no evidence of a synergistic relationship for inhibiting cytokine-
induced CCL11 production. Similarly, A549 cells exposed to procyanidin A2, and to a
lesser extent procyanidin B2, had reduced production of cytokine-induced CCL26
production. An inhibition time course demonstrated procyanidin A2 had greatest
inhibition efficacy on cytokine-induced CCL26 production when incubated for 2 h prior
to an inflammatory insult. Comparison of procyanidin A2 inhibition to the known
CCL26 inhibitor, IFN , demonstrated that procyanidin A2 and IFN did not share the
same temporal inhibition patterns. Furthermore, experiments investigating concomitant
incubation of procyanidin A2 and IFN demonstrated that procyanidin A2 could
interfere with IFN –mediated CCL26 inhibition. Two possible mechanisms responsible
for the procyanidin A–mediated inhibition of cytokine-induced CCL11 and CCL26
were investigated: the modulation of cytokine receptor expression, and modulation of
plasma membrane fluidity. However, there was no evidence to support either of these
modes of action. The data presented in this thesis collectively demonstrate the ability of
procyanidin A2 to inhibit cytokine-induced eotaxin production from the lung epithelium
in vitro and support further investigation of procyanidin A2 as a preventative approach
for managing airway inflammation
Portable automatic blood analyzer
Analyzer employs chemical-sensing electrodes for determination of blood, gas, and ion concentrations. It is rugged, easily serviced, and comparatively simple to operate. System can analyze up to eight parameters and can be modified to measure other blood constituents including nonionic species, such as urea, glucose, and oxygen
Measuring attendance: issues and implications for estimating the impact of free-to-view sports events
A feature of many non-elite sports events, especially those conducted in public places is that they are free-to-view. The article focuses on the methodological issue of estimating spectator attendance at free-to-view events and the consequences of this for impact evaluation. Using empirical data from three case studies, the article outlines various approaches to measuring attendance and discusses the key issues and implications for evaluating free-to-view sports events in the future
Two-fluid behavior of the Kondo lattice in the 1/N slave boson approach
It has been recently shown by Nakatsuji, Pines, and Fisk [S. Nakatsuji, D.
Pines, and Z. Fisk, Phys. Rev. Lett. 92, 016401 (2004)] from the
phenomenological analysis of experiments in Ce1-xLaxCoIn5 and CeIrIn5 that
thermodynamic and transport properties of Kondo lattices below coherence
temperature can be very successfully described in terms of a two-fluid model,
with Kondo impurity and heavy electron Fermi liquid contributions. We analyze
thermodynamic properties of Kondo lattices using 1/N slave boson treatment of
the periodic Anderson model and show that these two contributions indeed arise
below the coherence temperature. We find that the Kondo impurity contribution
to thermodynamics corresponds to thermal excitations into the flat portion of
the energy spectrum.Comment: 7 pages, 2 figure
League-Table Incentives and Price Bubbles in Experimental Asset Markets
We study experimental markets in which participants face incentives modeled upon those prevailing in markets for managed funds. Each participant's portfolio is periodically evaluated at market value and ranked in a league table according to short-term paper returns. Those who rank highly attract a larger share of new fund inflows. Under conditions in which prices are close to intrinsic value, the effect of incentives is mild. However under conditions in which markets are prone to bubble, mispricing is greatly exacerbated by incentives. Even in experienced markets, prices climb to levels clearly indicative of speculation and do not always crash back.league tables, price bubbles, managed funds markets, tournament incentives, asset market experiments
Inversion of polarimetric data from eclipsing binaries
We describe a method for determining the limb polarization and limb darkening
of stars in eclipsing binary systems, by inverting photometric and polarimetric
light curves.
Because of the ill-conditioning of the problem, we use the Backus-Gilbert
method to control the resolution and stability of the recovered solution, and
to make quantitative estimates of the maximum accuracy possible. Using this
method we confirm that the limb polarization can indeed be recovered, and
demonstrate this with simulated data, thus determining the level of
observational accuracy required to achieve a given accuracy of reconstruction.
This allows us to set out an optimal observational strategy, and to critcally
assess the claimed detection of limb polarization in the Algol system.
The use of polarization in stars has been proposed as a diagnostic tool in
microlensing surveys by Simmons et al. (1995), and we discuss the extension of
this work to the case of microlensing of extended sources.Comment: 10pp, 5 figures. To appear in A&
Commutating brushes tested in dc motors in dry argon atmospheres
Test apparatus, procedures, and results are given for dc-motor brushes operating in dry argon. Minimum concentrations of argon impurities are also determined
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