5,235 research outputs found
Quantum Gravitational Effects and Grand Unification
In grand unified theories with large numbers of fields, renormalization
effects significantly modify the scale at which quantum gravity becomes strong.
This in turn can modify the boundary conditions for coupling constant
unification, if higher dimensional operators induced by gravity are taken into
consideration. We show that the generic size of, and the uncertainty in, these
effects from gravity can be larger than the two-loop corrections typically
considered in renormalization group analyses of unification. In some cases,
gravitational effects of modest size can render unification impossible.Comment: 3 pages, to appear in the proceedings of 16th International
Conference on Supersymmetry and Unification of Fundamental Interactions
(SUSY08), Seoul, Korea, June 16-21 200
Demo: An Interoperability Development and Performance Diagnosis Environment
Interoperability is key to widespread adoption of sensor network technology, but interoperable systems have traditionally been difficult to develop and test. We demonstrate an interoperable system development and performance diagnosis environment in which different systems, different software, and different hardware can be simulated in a single network configuration. This allows both development, verification, and performance diagnosis of interoperable systems. Estimating the performance is important since even when systems interoperate, the performance can be sub-optimal, as shown in our companion paper that has been conditionally accepted for SenSys 2011
BU10038 as a safe opioid analgesic with fewer side-effects after systemic and intrathecal administration in primates
© 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Background: The marked increase in mis-use of prescription opioids has greatly affected our society. One potential solution is to develop improved analgesics which have agonist action at both mu opioid peptide (MOP) and nociceptin/orphanin FQ peptide (NOP) receptors. BU10038 is a recently identified bifunctional MOP/NOP partial agonist. The aim of this study was to determine the functional profile of systemic or spinal delivery of BU10038 in primates after acute and chronic administration. Methods: A series of behavioural and physiological assays have been established specifically to reflect the therapeutic (analgesia) and side-effects (abuse potential, respiratory depression, itch, physical dependence, and tolerance) of opioid analgesics in rhesus monkeys. Results: After systemic administration, BU10038 (0.001–0.01 mg kg −1 ) dose-dependently produced long-lasting antinociceptive and antihypersensitive effects. Unlike the MOP agonist oxycodone, BU10038 lacked reinforcing effects (i.e. little or no abuse liability), and BU10038 did not compromise the physiological functions of primates including respiration, cardiovascular activities, and body temperature at antinociceptive doses and a 10–30-fold higher dose (0.01–0.1 mg kg −1 ). After intrathecal administration, BU10038 (3 μg) exerted morphine-comparable antinociception and antihypersensitivity without itch scratching responses. Unlike morphine, BU10038 did not cause the development of physical dependence and tolerance after repeated and chronic administration. Conclusions: These in vivo findings demonstrate the translational potential of bifunctional MOP/NOP receptor agonists such as BU10038 as a safe, non-addictive analgesic with fewer side-effects in primates. This study strongly supports that bifunctional MOP/NOP agonists may provide improved analgesics and an alternative solution for the ongoing prescription opioid crisis.Peer reviewedFinal Published versio
Over-represented sequences located on UTRs are potentially involved in regulatory functions
Eukaryotic gene expression must be coordinated for the proper functioning of biological processes. This coordination can be achieved both at the transcriptional and post-transcriptional levels. In both cases, regulatory sequences placed at either promoter regions or on UTRs function as markers recognized by regulators that can then activate or repress different groups of genes according to necessity. While regulatory sequences involved in transcription are quite well documented, there is a lack of information on sequence elements involved in post-transcriptional regulation. We used a statistical over-representation method to identify novel regulatory elements located on UTRs. An exhaustive search approach was used to calculate the frequency of all possible n-mers (short nucleotide sequences) in 16,160 human genes of NCBI RefSeq sequences and to identify any peculiar usage of n-mers on UTRs. After a stringent filtering process, we identified circa 4,000 highly over-represented n-mers on UTRs. We provide evidence that these n-mers are potentially involved in regulatory functions. Identified n-mers overlap with previously identified binding sites for HuR and Tia1 and, AU-rich and GU-rich sequences. We determined also that over-represented n-mers are particularly enriched in a group of 159 genes directly involved in tumor formation. Finally, a method to cluster n-mer groups allowed the identification of putative gene networks.Over-represented sequences, UTRs, regulatory functions
A nano-patterned photonic crystal laser with a dye-doped liquid crystal
Covering a nano-patterned titanium dioxide photonic crystal (PC) within a well-oriented film of dye-doped liquid crystal (LC), a distributed feedback laser is constructed whereby the emission characteristics can be manipulated in-situ using an electric field. This hybrid organic-inorganic structure permits simultaneous selectivity of both the beam pattern and laser wavelength by electrical addressing of the LC director. In addition, laser emission is obtained both in the plane and normal to the PC. Along with experimental data, a theoretical model is presented that is based upon an approximate calculation of the band structure of this birefringent, tuneable laser device
The mid-infrared view of red sequence galaxies in Abell 2218 with <i>AKARI</i>
We present the AKARI Infrared Camera (IRC) imaging observation of early-type galaxies (ETGs) in A2218 at z ~ 0.175. Mid-infrared (MIR) emission from ETGs traces circumstellar dust emission from asymptotic giant branch (AGB) stars or/and residual star formation. Including the unique imaging capability at 11 and 15 μm, our AKARI data provide an effective way to investigate MIR properties of ETGs in the cluster environment. Among our flux-limited sample of 22 red sequence ETGs with precise dynamical and line strength measurements (less than 18 mag at 3 μm), we find that at least 41% have MIR-excess emission. The N3 – S11 versus N3 (3 and 11 μm) color-magnitude relation shows the expected blue sequence, but the MIR-excess galaxies add a red wing to the relation especially at the fainter end. A spectral energy distribution analysis reveals that the dust emission from AGB stars is the most likely cause of the MIR excess, with a low level of star formation being the next possible explanation. The MIR-excess galaxies show a wide spread of N3 – S11 colors, implying a significant spread (2-11 Gyr) in the estimated mean ages of stellar populations. We study the environmental dependence of MIR-excess ETGs over an area out to a half virial radius (~1 Mpc). We find that the MIR-excess ETGs are preferentially located in the outer region. From this evidence, we suggest that the fainter, MIR-excess ETGs have just joined the red sequence, possibly due to the infall and subsequent morphological/spectral transformation induced by the cluster environment
Quantifying the legacy of the Chinese Neolithic on the maternal genetic heritage of Taiwan and Island Southeast Asia
There has been a long-standing debate concerning the extent to which the spread of Neolithic ceramics and Malay-Polynesian languages in Island Southeast Asia (ISEA) were coupled to an agriculturally driven demic dispersal out of Taiwan 4000 years ago (4 ka). We previously addressed this question using founder analysis of mitochondrial DNA (mtDNA) control-region sequences to identify major lineage clusters most likely to have dispersed from Taiwan into ISEA, proposing that the dispersal had a relatively minor impact on the extant genetic structure of ISEA, and that the role of agriculture in the expansion of the Austronesian languages was therefore likely to have been correspondingly minor. Here we test these conclusions by sequencing whole mtDNAs from across Taiwan and ISEA, using their higher chronological precision to resolve the overall proportion that participated in the “out-of-Taiwan” mid-Holocene dispersal as opposed to earlier, postglacial expansions in the Early Holocene. We show that, in total, about 20 % of mtDNA lineages in the modern ISEA pool result from the “out-of-Taiwan” dispersal, with most of the remainder signifying earlier processes, mainly due to sea-level rises after the Last Glacial Maximum. Notably, we show that every one of these founder clusters previously entered Taiwan from China, 6–7 ka, where rice-farming originated, and remained distinct from the indigenous Taiwanese population until after the subsequent dispersal into ISEA
CHY representations for gauge theory and gravity amplitudes with up to three massive particles
We show that a wide class of tree-level scattering amplitudes involving
scalars, gauge bosons, and gravitons, up to three of which may be massive, can
be expressed in terms of a Cachazo-He-Yuan representation as a sum over
solutions of the scattering equations. These amplitudes, when expressed in
terms of the appropriate kinematic invariants, are independent of the masses
and therefore identical to the corresponding massless amplitudes.Comment: 20 pages, 1 figure; v2: minor typos corrected, published versio
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