1,163 research outputs found
A burst storm from the repeating FRB 20200120E in an M81 globular cluster Dataset
No full textThe dataset to reproduce the results in Nimmo et al. 2023 (https://ui.adsabs.harvard.edu/abs/2022arXiv220603759N/abstract).
The dataset provided contains 5.12us Stokes I filterbank files containing all 60 bursts in Nimmo et al. 2023. These filterbank files were created from the raw voltage data using PSRCHIVE (Hotan et al. 2004; http://psrchive.sourceforge.net) and are coherently dedispersed to the best-known dispersion measure 87.7527 (Nimmo et al. 2022, https://ui.adsabs.harvard.edu/abs/2022NatAs...6..393N/abstract). Some exceptions to this is B15 on January 14 2022 which is provided at 1.28us resolution, since this burst was found in the microsecond-search of the data and is incredibly narrow in time (~14us), and also B2 on Jan 14, and B1&2 on Feb 21 2022 where the only data we have available is the EDD pulsar backend data with a time resolution of 40.96us (and no coherent dedispersion is applied).
Requests for other materials should be addressed to the lead author
Dispersion of material by wind and tide in shallow seas
No full textMixing processes in shallow seas are of particular importance in the dispersion of pollution (e.g. oil slicks) as well as in the distribution of sediment and biological material (e.g. phytoplankton and fish larvae). This study aims to further investigate the processes of wind-driven Langmuir circulation and bottom-generated turbulence and to quantify the effects they have on the dispersion of buoyant material. A numerical and analytical study is made of the dispersion of a plume of floating particles under the combined action of Langmuir circulation and a mean current. The numerical simulations show the general patterns the plume will form, with initial meanders leading to the formation of distinct windrows. The analytical model shows that the lateral diffusivity, the rate of across-current dispersion of the particles, is greatest when the angle between the direction of the wind and current is between 30° and 120°, and when the wind speed is large in comparison to the current speed. Further, it is found that the effects of Langmuir circulation will dominate the dispersion process when the wind speed is greater than about 10 times the current speed. Acoustic and visual observations of the surface effects of bottom-generated turbulence in a tidally-influenced and well-mixed region of the North Sea are presented. Although the sea bed in the area is flat, it is found that at any one time 20-30% of the water surface is affected by boils - circular regions of local upwelling - of diameter 0.9±0.2 times the water depth. The signature of individual boils persists for at least 7 minutes and, in accordance with laboratory and numerical studies, shows the appearance of eddies. Again, analytical and numerical models are constructed to estimate the effects of the boils on the dispersion of floating particles. The numerical simulations provide good qualitative agreement with the patterns observed in visual images of the dispersion of oil. Further, the horizontal diffusivities calculated by both them and the analytical methods show that the presence of boils can account for the dispersion measured by experimental methods in shallow tidal seas. In summarising and discussing the main findings of this work, particular emphasisis placed on the need for further observations of these two processes, in particular the boils and eddies and their interaction with the Langmuir circulation, to further improve the estimates of dispersion
Electromyogram changes during sustained contraction after resistance training in women in their 3rd and 8th decades
No full textThe present study aimed at investigating the neuromuscular adaptations to 6 weeks of resistance training in women in their third (6 experimental, 8 controls) and eighth decades (8 experimental, 8 controls). The surface electromyogram (sEMG) was measured from the biceps brachii muscle during constant-force isometric contractions lasting 12 s at 80% of maximal voluntary contraction (MVC). All the signals were analysed adopting in the time domain the root mean square (RMS) as a measure of amplitude and in the frequency domain the median frequency (MDF) of the power spectrum. Quantitative analysis was performed from the 3rd to the 6th second, to describe the early phase of the contraction ("Early"), starting from point at which 80% of the MVC was reached, and from the 9th to the 12th second, to describe the last part of the constant-force sustained contraction ("Late"). After training, the MVC increased by 22.4% in the young (P < 0.0001) and by 13.4% in the older (P < 0.05) women. The "Early" RMS increased by 60.4% with respect to the pre-training condition in the young (P < 0.01) but not in the older women. In contrast, the "Late" RMS increased by 46.7% in the older (P < 0.05) but not in the young women. The MDF remained unchanged in both groups. These results indicate that young and older women showed different training-induced adaptation of the motor unit (MU) activation pattern, in order to keep a constant level of force during a sustained isometric contraction at 80% of MVC.</p
Brain, spinal and nerve injury treatment.
No full textPATENT: R. Vink, A.J.Nimmo. US 2005/0107380 A1 (PCT/AU01/00046) filed Jan 18, 2001; published Jan 11, 2005.A treatment for brain, spinal and nerve injury comprising use of a substance P receptor antagonist optionally in combination with a magnesium compound. There is also provided a formulation for use in this treatment comprising a substance P receptor antagonist and a magnesium compound.Invented by R. Vink, A.J.Nimmo; Hoffmann La-Roche agents for inventors
A rigid and weathered ice shell on Titan
No full textSeveral lines of evidence suggest that Saturn's largest moon, Titan, has a global subsurface ocean beneath an outer ice shell 50 to 200 kilometres thick. If convection is occurring, the rigid portion of the shell is expected to be thin; similarly, a weak, isostatically compensated shell has been proposed to explain the observed topography. Here we report a strong inverse correlation between gravity and topography at long wavelengths that are not dominated by tides and rotation. We argue that negative gravity anomalies (mass deficits) produced by crustal thickening at the base of the ice shell overwhelm positive gravity anomalies (mass excesses) produced by the small surface topography, giving rise to this inverse correlation. We show that this situation requires a substantially rigid ice shell with an elastic thickness exceeding 40 kilometres, and hundreds of metres of surface erosion and deposition, consistent with recent estimates from local features. Our results are therefore not compatible with a geologically active, low-rigidity ice shell. After extrapolating to wavelengths that are controlled by tides and rotation, we suggest that Titan's moment of inertia may be even higher (that is, Titan may be even less centrally condensed) than is currently thought
Conservation of leathercraft and related objects tensioning gilded and painted leather
No full textEdinburgh (UK
The effect of exercise on plasma soluble IL-6 receptor concentration: a dichotomous response
No full textThe aim of this article is to review current literature on the response of soluble interleukin-6 receptor to exercise and identify a potential role for sIL-6R in skeletal muscle function. We also provide novel data on the impact of eccentric exercise on circulating levels. The aim of the research study was to investigate changes in plasma concentration of soluble interleukin-6 receptor (sIL-6R) and soluble glycoprotein 130 (sgp130) during recovery from exercise-induced muscle damage (EIMD) up to 72 h and their relationship with delayed onset muscle soreness (DOMS) and muscle function. 18 participants attended the laboratory on 4 consecutive days. On the first day, participants completed 6 sets of 10 repetitions of unilateral eccentric-concentric knee flexions at a test speed of 1.05 rad.s(-1) using a Cybex Isokentic dynamometer to induce muscle damage of the hamstrings. Prior to the eccentric exercise bout and each subsequent morning, following an overnight fast, participants had a venous blood sample taken which was centrifuged immediately and plasma frozen at -80 degrees C until later analysis. Plasma IL-6 and sgp130 were unchanged at any time point during recovery but sIL-6R was significantly reduced at 48 h and 72 h post-exercise (p < 0.05). Plasma sIL-6R was correlated with DOMS at 48 h post EIMD (r = 0.45, p < 0.05) and peak muscle torque at 24 h and 48 h following EIMD (r = -.42; p < 0.05; r = -.57; p < 0.01 respectively). Our novel finding that sIL-6R concentrations are decreased 2-3 days following a single bout of EIMD may reflect a regulatory mechanism controlling the influx of different leukocyte subpopulations into damaged tissue, although this needs to be confirmed by future studies. Our data suggests an association between sIL-6R, perception of pain and reduced peak muscle performance post-EIMD but further investigation is warranted to explore this relationship and implications for exercise performance
Tidal dissipation of binaries in asteroid pairs
No full textTidal dissipation in a celestial body can be used to probe its internal
structure. Tides govern the orbital evolution of binary systems and therefore
constraints on the interior of binary system members can be derived by knowing
the age and tidal state of the binary system. For asteroids, age estimates are
challenging due to a lack of direct observation of their surface. However, the
age of asteroid pairs formed by rotational fission of a parent body can be
derived from dynamical modeling, and as such can be used to constrain the age
of binary systems existing within asteroid pairs.We study 13 binary asteroid
systems existing in asteroid pairs by modeling their tidal locking and
eccentricity damping timescales from tidal dissipation in the primaries and
secondaries. We consider the impact of thermal torques on these timescales from
the YORP and BYORP effects. The resulting constraints on the tidal dissipation
ratio Q/k2 are compared to monolithic and rubble pile asteroid theories,
showing that all secondaries are consistent with rubble piles with regolith
layers greater than 3m and suggest that Q/k2 for rubble piles increases with
radius. A particular case is the first bound secondary of asteroid (3749)
Balam, whose Q/k2 is constrained to be between 2.7x10^4 and 1.4x10^6,
consistent with a rubble-pile with a regolith thickness between 30m and 100m.Comment: 24 pages, 5 figures, 1 appendix Published in Icarus: Pou L, Nimmo F.
Tidal dissipation of binaries in asteroid pairs. Icarus. 2024 Mar
15;411:115919. https://doi.org/10.1016/j.icarus.2023.11591
GRAIL Crustal Thickness Archive
No full text<p>This archive contains crustal thickness models of the Moon derived from GRAIL (Gravity Recovery And Interior Laboratory) gravity. The original crustal thickness data were published in map form in <em>Wieczorek et al. </em>(2013).</p>
<p>Wieczorek, M. A., G. A. Neumann, F. Nimmo, W. S. Kiefer, G. J. Taylor, H. J. Melosh, R. J. Phillips, S. C. Solomon, J. C. Andrews-Hanna, S. W. Asmar, A. S. Konopliv, F. G. Lemoine, D. E. Smith, M. M. Watkins, J. G. Williams, M. T. Zuber, The crust of the Moon as seen by GRAIL, <em>Science</em>, <strong>339</strong>, 671-675, doi:10.1126/science.1231530, 2013.</p>
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