3,029 research outputs found
Alterations in thoracolumbosacral movement when pain causing lameness has been improved by diagnostic analgesia
Lameness, thoracolumbosacral pain and reduced range of motion (ROM) often coexist; better understanding of their relationship is needed. The objectives were to determine if thoracolumbosacral movement of horses changes when pain causing lameness is improved by diagnostic analgesia. We hypothesised that reduction of lameness will increase ROM of the thoracolumbosacral region. Thirteen horses with different types of hind limb lameness were trotted in straight lines and lunged on a 10 m diameter circle on left and right reins before and after lameness was subjectively substantially improved by diagnostic analgesia. Inertial sensor data were collected from the withers, thirteenth (T13) and eighteenth thoracic (T18) vertebrae, third lumbar (13) vertebra, tubera sacrale (TS), left and right tubera coxae. ROM of flexion-extension, axial rotation, lateral bending, dorsoventral, lateral-lateral motion and vertical movement symmetry were quantified at each thoracolumbar site. Hiphike difference (HHD), maximum difference (MaxDiff) and minimum difference (MinDiff) for the pelvic sensors were measured. Percentage changes for before and after diagnostic analgesia were calculated; mean standard deviation (SD) or median [interquartile range] were determined.
Associations between the change in pelvic versus thoracolumbar movement symmetry after each local analgesic technique were tested. After resolution of lameness, HHD decreased by 7% [68%] (P = 0.006). The MinDiff decreased significantly by 33%[61%] (P = 0.01), 45 +/- 13% (P = 0.005) and 52 +/- 23% (P = 0.04), for TS, L3 and T18, respectively. There was significantly increased ROM in flexion-extension at T13, in axial rotation at T13, T18, 13 and in lateral-lateral ROM at 13. Thoracolumbosacral asymmetry and reduced ROM associated with lameness were both altered immediately by improvement in lameness using diagnostic analgesia. (C) 2017 Elsevier Ltd. All rights reserved
350 Micron Observations of Ultraluminous Infrared Galaxies at Intermediate Redshifts
We present 350micron observations of 36 ultraluminous infrared galaxies
(ULIRGs) at intermediate redshifts (0.089 <= z <= 0.926) using the
Submillimeter High Angular Resolution Camera II (SHARC-II) on the Caltech
Submillimeter Observatory (CSO). In total, 28 sources are detected at S/N >= 3,
providing the first flux measurements longward of 100micron for a statistically
significant sample of ULIRGs in the redshift range of 0.1 < z < 1.0. Combining
our 350micron flux measurements with the existing IRAS 60 and 100micron data,
we fit a single-temperature model to the spectral energy distribution (SED),
and thereby estimate dust temperatures and far-IR luminosities. Assuming an
emissivity index of beta = 1.5, we find a median dust temperature and far-IR
luminosity of Td = 42.8+-7.1K and log(Lfir/Lsolar) = 12.2+-0.5, respectively.
The far-IR/radio correlation observed in local star-forming galaxies is found
to hold for ULIRGs in the redshift range 0.1 < z < 0.5, suggesting that the
dust in these sources is predominantly heated by starbursts. We compare the
far-IR luminosities and dust temperatures derived for dusty galaxy samples at
low and high redshifts with our sample of ULIRGs at intermediate redshift. A
general Lfir-Td relation is observed, albeit with significant scatter, due to
differing selection effects and variations in dust mass and grain properties.
The relatively high dust temperatures observed for our sample compared to that
of high-z submillimeter-selected starbursts with similar far-IR luminosities
suggest that the dominant star formation in ULIRGs at moderate redshifts takes
place on smaller spatial scales than at higher redshifts.Comment: (24 pages in preprint format, 1 table, 7 figures, accepted for
publication in ApJ
Quantum-Assisted Telescope Arrays
Quantum networks provide a platform for astronomical interferometers capable
of imaging faint stellar objects. In a recent work [arXiv:1809.01659], we
presented a protocol that circumvents transmission losses with efficient use of
quantum resources and modest quantum memories. Here we analyze a number of
extensions to that scheme. We show that it can be operated as a truly broadband
interferometer and generalized to multiple sites in the array. We also analyze
how imaging based on the quantum Fourier transform provides improved
signal-to-noise ratio compared to classical processing. Finally, we discuss
physical realizations including photon-detection-based quantum state transfer.Comment: 10 pages, 8 figures; v2 - clarifications and references; v3 - close
to published versio
Molecular gas in extreme star-forming environments: the starbursts Arp220 and NGC6240 as case studies
We report single-dish multi-transition measurements of the 12^CO, HCN, and
HCO^+ molecular line emission as well as HNC J=1-0 and HNCO in the two
ultraluminous infra-red galaxies Arp220 and NGC6240. Using this new molecular
line inventory, in conjunction with existing data in the literature, we
compiled the most extensive molecular line data sets to date for such galaxies.
The many rotational transitions, with their different excitation requirements,
allow the study of the molecular gas over a wide range of different densities
and temperatures with significant redundancy, and thus allow good constraints
on the properties of the dense gas in these two systems. The mass (~(1-2) x
10^10 Msun) of dense gas (>10^5-6 cm^-3) found accounts for the bulk of their
molecular gas mass, and is consistent with most of their IR luminosities
powered by intense star bursts while self-regulated by O,B star cluster
radiative pressure onto the star-forming dense molecular gas. The highly
excited HCN transitions trace a gas phase ~(10-100)x denser than that of the
sub-thermally excited HCO^+ lines (for both galaxies). These two phases are
consistent with an underlying density-size power law found for Galactic GMCs
(but with a steeper exponent), with HCN lines tracing denser and more compact
regions than HCO^+. Whether this is true in IR-luminous, star forming galaxies
in general remains to be seen, and underlines the need for observations of
molecular transitions with high critical densities for a sample of bright
(U)LIRGs in the local Universe -- a task for which the HI-FI instrument on
board Herschel is ideally suited to do.Comment: 38 pages (preprint ApJ style), 3 figures, accepted for Ap
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Determining the optimal length of regulatory guarantee: A Length-of-Contract Auction
One of the biggest challenges in the area of infrastructure investment is the provision of funding to finance activities. This paper presents an auction design which can reduce the financing cost of infrastructure investments by allowing the length of the regulatory funding period to be determined via an auction. The auction allows bidders to submit bids against a payment for periods of varying length. Thus instead of, for example, a fixed 20-year contract period, some bidders might want to bid for financing over a longer period, say 25 or 30 years. This can be desirable in terms of securing more favourable terms in the financial markets. Our auction design can secure efficiency and lower financing costs. Our auction is motivated by the auctions currently being undertaken by the UK energy regulator (Ofgem) for financing offshore transmission assets. Although the auction was designed with electricity transmission in mind, the auction could be used in other areas of infrastructure investment
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The Strategic Robustness of Mark-up Equilibria
This paper is an extension of the paper 'The Robustness of Agent-Based Models of Electricity Wholesale Markets', EPRG1213 which was motivated by the problem of analysing market power in liberalised electricity markets. That paper examined two particular forms of agent-based models commonly used in electricity market modelling, and showed that while these mark-up equilibria are robust against Nash deviations. This paper extends the earlier results to explain why these equilibria are robust to single firm Nash Cournot deviations but shows they are vulnerable to more sophisticated deviations
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