35,412 research outputs found
Higher-order compatible finite element schemes for the nonlinear rotating shallow water equations on the sphere
We describe a compatible finite element discretisation for the shallow water
equations on the rotating sphere, concentrating on integrating consistent
upwind stabilisation into the framework. Although the prognostic variables are
velocity and layer depth, the discretisation has a diagnostic potential
vorticity that satisfies a stable upwinded advection equation through a
Taylor-Galerkin scheme; this provides a mechanism for dissipating enstrophy at
the gridscale whilst retaining optimal order consistency. We also use upwind
discontinuous Galerkin schemes for the transport of layer depth. These
transport schemes are incorporated into a semi-implicit formulation that is
facilitated by a hybridisation method for solving the resulting mixed Helmholtz
equation. We illustrate our discretisation with some standard rotating sphere
test problems.Comment: accepted versio
Effect of neck cut position on time to collapse in halal slaughtered cattle without stunning
This study examined the effect of neck cut position on the time to physical collapse in upright restrained halal slaughtered cattle (n = 644). Time to collapse was used as an indirect indicator of the early stages of onset of unconsciousness. Cattle were slaughtered with either a conventional low (LNC) (n = 561) or a high neck cut (HNC) (n = 83). Mean time to final collapse was higher in the LNC compared to HNC group (18.9 ± 1.1 s and 13.5 ± 1.3 s respectively (P 20 s to final collapse had larger false aneurysms. In summary, the HNC reduced the mean time to final collapse and the frequency of animals that took longer than 20 s to collapse
International consensus (ICON) on treatment of Ménière's disease
Objective: To present the international consensus for recommendations for Ménière's disease (MD) treatment. Methods: Based on a literature review and report of 4 experts from 4 continents, the recommendations have been presented during the 21st IFOS congress in Paris, in June 2017 and are presented in this work. Results: The recommendation is to change the lifestyle, to use the vestibular rehabilitation in the intercritic period and to propose psychotherapy. As a conservative medical treatment of first line, the authors recommend to use diuretics and Betahistine or local pressure therapy. When medical treatment fails, the recommendation is to use a second line treatment, which consists in the intratympanic injection of steroids. Then as a third line treatment, depending on the hearing function, could be either the endolymphatic sac surgery (when hearing is worth being preserved) or the intratympanic injection of gentamicin (with higher risks of hearing loss). The very last option is the destructive surgical treatment labyrinthectomy, associated or not to cochlear implantation or vestibular nerve section (when hearing is worth being preserved), which is the most frequent option
Anomalous isotopic predissociation in the F³Πu(v=1) state of O₂
Using a tunable, narrow-bandwidth vacuum-ultraviolet source based on third-harmonic generation from excimer-pumped dye-laser radiation, the F³Πu←X³Σg-(1,0)photoabsorption cross sections of ¹⁶O₂ and ¹⁸O₂ have been recorded in high resolution. Rotational analyses have been performed and the resultant F(v=1) term values fitted to the ³Π Hamiltonian of Brown and Merer [J. Mol. Spectrosc. 74, 488 (1979)]. A large rotationless isotope effect is observed in the F(v=1)predissociation, wherein the Lorentzian linewidth component for ¹⁸O₂ is a factor of ∼50 smaller than the corresponding ¹⁶O₂linewidth. This effect, a consequence of the nonadiabatic rotationless predissociation mechanism, is described using a coupled-channel treatment of the strongly Rydberg-valence-mixed 3Πu states. Significant J, e/f-parity, and sublevel dependencies observed in the isotopic F(v=1) rotational widths are found to derive from an indirect predissociation mechanism involving an accidental degeneracy with the E³Σ−u(v=3) level, itself strongly predissociated by ³Σ−u Rydberg-valence interactions, together with L-uncoupling (rotational) interactions between the Rydberg components of the F and E states. Transitions into the E(v=3) level are observed directly for the first time, specifically in the ¹⁸O₂ spectrumPartial support
was provided by an NSF International Opportunities for Scientists
and Engineers Program Grant No. INT-9513350, and
Visiting Fellowships for G.S. and J.B.W. at the Australian
National University
Trunk muscle activity during drop jump performance in adolescent athletes with back pain
It was with great interest we read the recently published article “Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain.” Investigating back pain (BP) in adolescents is commendable as there is growing evidence that for many, an experience of BP as early as 14 years of age may relate to ongoing pain in adulthood (Coenen et al., 2017). Indeed, the conventional narrative is changing as individual physical factors such as posture, use of schoolbags, and hypermobility are only weakly associated with adolescent BP. Rather, factors which predict BP at a young age are considered to be multi-dimensional and include gender, negative BP beliefs and poor mental health (O\u27Sullivan et al., 2017; Smith et al., 2017). Mueller et al. (2017) have focused on a single physical factor (trunk muscle activation patterns) drawing inferences regarding BP prevention and treatment. This article prompts consideration of three essential aspects regarding research design and interpretation of findings:
1. Interpreting results from cross-sectional designs
2. Interpreting pain-related differences in motor behavior
3. Translating and conveying scientific results to the end-user (patients, healthcare professionals and policy makers)
Hierarchical formation of bulgeless galaxies II: Redistribution of angular momentum via galactic fountains
Within a fully cosmological hydrodynamical simulation, we form a galaxy which
rotates at 140 km/s, and is characterised by two loose spiral arms and a bar,
indicative of a Hubble Type SBc/d galaxy. We show that our simulated galaxy has
no classical bulge, with a pure disc profile at z=1, well after the major
merging activity has ended. A long-lived bar subsequently forms, resulting in
the formation of a secularly-formed "pseudo" bulge, with the final
bulge-to-total light ratio B/T=0.21. We show that the majority of gas which
loses angular momentum and falls to the central region of the galaxy during the
merging epoch is blown back into the hot halo, with much of it returning later
to form stars in the disc. We propose that this mechanism of redistribution of
angular momentum via a galactic fountain, when coupled with the results from
our previous study which showed why gas outflows are biased to have low angular
momentum, can solve the angular momentum/bulgeless disc problem of the cold
dark matter paradigm.Comment: 9 Pages, 10 Figures, accepted MNRAS version. Comments welcom
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