8,482 research outputs found
Modification of serum adiponectin and CINC-1 levels by intermittent hypoxia and/or hyperlipidemia in vivo
published_or_final_versionThe 15th Medical Research Conference, Department of Medicine, The University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16, suppl. 1, p. 22, abstract no. 2
Cellular mechanisms involved in intermittent hypoxia-induced heart damage in rat
Poster PresentationBACKGROUND: Obstructive sleep apnoea (OSA), characterised by intermittent hypoxia (IH) during sleep, is increasingly recognised as an independent risk factor of cardiovascular diseases (CVD). OSA has been reported to be associated with changes in the levels of circulating oxidative stress and inflammatory markers as well as dyslipidemia, supporting their mediating roles in cardiovascular pathogenesis. This study aimed to investigate the ...published_or_final_versionThe 17th Medical Research Conference, Department of Medicine, The University of Hong Kong, Hong Kong, 14 January 2012. In Hong Kong Medical Journal, 2012, v. 18 n. 1, suppl. 1, p. 23, abstract no. 2
Large Extra Dimension effects through Light-by-Light Scattering at the CERN LHC
Observing light-by-light scattering at the Large Hadron Collider (LHC) has
received quite some attention and it is believed to be a clean and sensitive
channel to possible new physics. In this paper, we study the diphoton
production at the LHC via the process through graviton exchange in the Large Extra
Dimension (LED) model. Typically, when we do the background analysis, we also
study the Double Pomeron Exchange (DPE) of production. We
compare its production in the quark-quark collision mode to the gluon-gluon
collision mode and find that contributions from the gluon-gluon collision mode
are comparable to the quark-quark one. Our result shows, for extra dimension
, with an integrated luminosity at the
14 TeV LHC, that diphoton production through graviton exchange can probe the
LED effects up to the scale for the forward
detector acceptance , respectively, where
, and .Comment: 25 pages. 7 figs. Change some grammatical error
Role of heme oxygenase-1 in intermittent hypoxia-induced inflammation and oxidative stress in eAhy 926 endothelial cell line
published_or_final_versionThe 16th Medical Research Conference (MRC), Department of Medicine, The University of Hong Kong, Hong Kong, China, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17 n. 1, suppl. 1, p. 29, abstract no. 4
Effects of intermittent hypoxia on A-/E-FABP expression in human aortic endothelial cells
postprin
Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout
The enormous stiffness and low density of graphene make it an ideal material
for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and
electrical readout of monolayer graphene resonators, and test their response to
changes in mass and temperature. The devices show resonances in the MHz range.
The strong dependence of the resonant frequency on applied gate voltage can be
fit to a membrane model, which yields the mass density and built-in strain.
Upon removal and addition of mass, we observe changes in both the density and
the strain, indicating that adsorbates impart tension to the graphene. Upon
cooling, the frequency increases; the shift rate can be used to measure the
unusual negative thermal expansion coefficient of graphene. The quality factor
increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing
many of the basic attributes of monolayer graphene resonators, these studies
lay the groundwork for applications, including high-sensitivity mass detectors
Band-gap expansion in the surface-localized electronic structure of MoS2(0002)
The electronic band structure of MoS2 single crystals has been investigated using angle-resolved photoelectron spectroscopy and first-principles calculations. The orbital symmetry and k dispersion of these electronic states responsible for the direct and the indirect electronic band gaps have been unambiguously determined. By experimentally probing an increase of the electronic band gap, we conclude that a MoS2 (0002) surface localized state exists just below the valence band maximum at the Gamma point. This electronic state originates from the sulfur planes within the topmost layer. Our comprehensive study addresses the surface electronic structure of MoS2 and the role of van der Waals interlayer interactions.open112625Nsciescopu
Dual HLA B*42 and B*81-reactive T cell receptors recognize more diverse HIV-1 Gag escape variants
Closely related HLA alleles presenting similar HIV-1 epitopes can be associated with variable clinical outcome. Here the authors report their findings on CD8+ T cell responses to the HIV-1 Gag-p24 TL9 immunodominant epitope in the context of closely related protective and less protective HLA alleles, and their differential effect on viral contro
N-player quantum games in an EPR setting
The -player quantum game is analyzed in the context of an
Einstein-Podolsky-Rosen (EPR) experiment. In this setting, a player's
strategies are not unitary transformations as in alternate quantum
game-theoretic frameworks, but a classical choice between two directions along
which spin or polarization measurements are made. The players' strategies thus
remain identical to their strategies in the mixed-strategy version of the
classical game. In the EPR setting the quantum game reduces itself to the
corresponding classical game when the shared quantum state reaches zero
entanglement. We find the relations for the probability distribution for
-qubit GHZ and W-type states, subject to general measurement directions,
from which the expressions for the mixed Nash equilibrium and the payoffs are
determined. Players' payoffs are then defined with linear functions so that
common two-player games can be easily extended to the -player case and
permit analytic expressions for the Nash equilibrium. As a specific example, we
solve the Prisoners' Dilemma game for general . We find a new
property for the game that for an even number of players the payoffs at the
Nash equilibrium are equal, whereas for an odd number of players the
cooperating players receive higher payoffs.Comment: 26 pages, 2 figure
Sex-biased parental care and sexual size dimorphism in a provisioning arthropod
The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests.
To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest.
We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight.
Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species
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