21,725 research outputs found
A Rate-Splitting Based Bound-Approaching Transmission Scheme for the Two-User Symmetric Gaussian Interference Channel with Common Messages
This paper is concerned with a rate-splitting based transmission strategy for the two-user symmetric Gaussian interference channel that contains common messages only. Each transmitter encodes its common message into multiple layers by multiple codebooks that drawn from one separate code book, and transmits the superposition of the messages corresponding to these layers; each receiver decodes the messages from all layers of the two users successively. Two schemes are proposed for decoding order and optimal power allocation among layers respectively. With the proposed decoding order scheme, the sum-rate can be increased by rate-splitting, especially at the optimal number of rate-splitting, using average power allocation in moderate and weak interference regime. With the two proposed schemes at the receiver and the transmitter respectively, the sum-rate achieves the inner bound of HK without time-sharing. Numerical results show that the proposed optimal power allocation scheme with the proposed decoding order can achieve significant improvement of the performance over equal power allocation, and achieve the sum-rate within two bits per channel use (bits/channel use) of the sum capacity
On the Quantum Chromodynamics of a Massive Vector Field in the Adjoint Representation
In this paper, we explore the possibility of constructing the quantum
chromodynamics of a massive color-octet vector field without introducing higher
structures like extended gauge symmetries, extra dimensions or scalar fields.
We show that gauge invariance is not enough to constraint the couplings.
Nevertheless the requirement of unitarity fixes the values of the coupling
constants, which otherwise would be arbitrary. Additionally, it opens a new
discrete symmetry which makes the coloron stable and avoid its resonant
production at a collider. On the other hand, a judicious definition of the
gauge fixing terms modifies the propagator of the massive field making it
well-behaved in the ultra-violet limit. The relation between our model and the
more general approach based on extended gauge symmetries is also discussed.Comment: Subsection 2.1 rewritten in order to make it more pedagogical. This
version match the text accepted in IJMP
Heterodimerization of apelin receptor and neurotensin receptor 1 induces phosphorylation of ERK1/2 and cell proliferation via Gαq-mediated mechanism
Dimerization of G protein-coupled receptors (GPCRs) is crucial for receptor function including agonist affinity, efficacy, trafficking and specificity of signal transduction, including G protein coupling. Emerging data suggest that the cardiovascular system is the main target of apelin, which exerts an overall neuroprotective role, and is a positive regulator of angiotensin-converting enzyme 2 (ACE2) in heart failure. Moreover, ACE2 cleaves off C-terminal residues of vasoactive peptides including apelin-13, and neurotensin that activate the apelin receptor (APJ) and neurotensin receptor 1 (NTSR1) respectively, that belong to the A class of GPCRs. Therefore, based on the similar mode of modification by ACE2 at peptide level, the homology at amino acid level and the capability of forming dimers with other GPCRs, we have been suggested that APJ and NTSR1 can form a functional heterodimer. Using co-immunoprecipitation, BRET and FRET, we provided conclusive evidence of heterodimerization between APJ and NTSR1 in a constitutive and induced form. Upon agonist stimulation, hetrodimerization enhanced ERK1/2 activation and increased proliferation via activation of Gq α-subunits. These novel data provide evidence for a physiological role of APJ/NTSR1 heterodimers in terms of ERK1/2 activation and increased intracellular calcium and induced cell proliferation and provide potential new pharmaceutical targets for cardiovascular disease. © 2014 The Authors
Fiber Based Multiple-Access Optical Frequency Dissemination
We demonstrate a fiber based multiple-access optical frequency dissemination
scheme. Without using any additional laser sources, we reproduce the stable
disseminated frequency at an arbitrary point of fiber link. Relative frequency
stability of 3E10^{-16}/s and 4E10^{-18}/10^4s is obtained. A branching fiber
network for highly-precision synchronization of optical frequency is made
possible by this method and its applications are discussed.Comment: 5 pages, 3 figure
The Performance of CRTNT Fluorescence Light Detector for Sub-EeV Cosmic Ray Observation
Cosmic Ray Tau Neutrino Telescopes (CRTNT) using for sub-EeV cosmic ray
measurement is discussed. Performances of a stereoscope configuration with a
tower of those telescopes plus two side-triggers are studied. This is done by
using a detailed detector simulation driven by Corsika. Detector aperture as a
function of shower energy above 10^17 eV is calculated. Event rate of about 20k
per year for the second knee measurement is estimated. Event rate for cross
calibration with detectors working on higher energy range is also estimated.
Different configurations of the detectors are tried for optimization.Comment: 5 pages, 4 figures, submitted to HEP & N
CDK5-mediated phosphorylation of SIRT1 at serine 47 contributes to the development of endothelial senescence
ISA 2012 Monday AbstractsPoster Session 1 – Vascular Biology of Atherosclerosis: Poster no. 98: Monday abstract no. 206BACKGROUND: Senescence of endothelial cells precedes the occurrence of vascular dysfunction and promotes the development of atherosclerosis. SIRT1 is a NAD-dependent deacetylase possessing anti-aging activities. In senescent endothelial cells, both the activity and expression level of SIRT1 are decreased. However, mechanisms underlying this down-regulation of SIRT1 are largely uncharacterized. The present study evaluated the regulation and role of ...postprintThe 16th International Symposium on Atherosclerosis (ISA2012), Sydney, Australia, 25-29 March 2012. In ISA2012 Monday Abstract
A comparison study of alfalfa (Medicago sativa) populations with long-term grazing history
Non-Peer ReviewedUnderstanding the effect of long-term grazing on alfalfa populations is important for identifying superior alfalfa genotypes adapted to animal grazing. The objective of this study was to compare alfalfa populations collected from 14 ranch sites across four soil zones of Saskatchewan for dry matter at first and second cuts, stem number) plant height forage nutritive value (protein, fibers), and verticillium wilt resistance. Crude protein concentration was significantly different (P<0.001) among the populations, but fiber concentrations (acid detergent and neutral detergent fiber) were similar. Resistance (%) to verticillium wilt varied (P=0.0028) among the alfalfa populations. The initial results indicated that DM at first cut was significantly different (P<0.0001) among 14 alfalfa populations, with alfalfa population from MacDowell had the highest first cut DM (287.8g) and regrowth DM (121.7g). Among the four soil zones, alfalfa populations from Black Soil Zone had the highest DM (P<0.0001) at first cut than alfalfa populations from Brown, Dark Brown and Grey wooded soil zones. During regrowth, alfalfa populations from Black (99.7g) and Grey wooded soil zones (99g) had significantly (P<0.001) higher DM than those from Dark Brown (82.6g) and Brown (81.9g) zones. Also, plant height (PH) among 14 alfalfa populations was significantly different (P<0.0001), with plants in MacDowell being tallest (90.4 cm), and in Val Marie population being the shortest (67.3 cm). Furthermore, stem number at first cut was significantly different (P<0.0163), with MacDowell had the highest stem number (98 stem plant-1), and Val Marie had the lowest (68 stem plant-1). There were positive correlations between DM yield with plant height at first cut (R=0.68, P<0.0001) regrowth DM with stem number (R=0.76, P<0.0001). In conclusion, alfalfa populations from these long-term grazing sites had diverse for the measured traits in this study, which may be useful for further selection for grazing tolerance and regional adaptation
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