1,396 research outputs found
Drug Points: Apparent interaction between warfarin and levonorgestrel used for emergency contraception
No abstract available
Automated real time detection of solar wind shocks and consequences for the identification of SSC and SI events
Algorithms have been developed to automatically detect Earth bound shocks in the solar wind as measured by the ACE satellite. These involve simple threshold techniques and wavelet analysis.
One practical application of this shock detection is that it can provide power companies with advanced warning of the potential for geomagnetically induced currents. The automatically detected shocks have been tested against published lists of known shocks and accuracy statistics are presented. Another use for automated shock detection is an aid to the preparation of lists of rapid variations: SSC and SI events.
To contribute to the IAGA published list of rapid variations, as prepared by Ebro Observatory, BGS staff
routinely identify, scale and classify the events recorded at the three UK magnetic observatories. This is carried out using the criteria from the Atlas of Rapid Variations (1959) and subsequent IAGA instructions.
The usefulness of automated detection of solar wind shocks for this task is examined by testing these against lists of identified SSC and SI events
Vortex Reconnection as the Dissipative Scattering of Dipoles
We propose a phenomenological model of vortex tube reconnection at high
Reynolds numbers. The basic picture is that squeezed vortex lines, formed by
stretching in the region of closest approach between filaments, interact like
dipoles (monopole-antimonopole pairs) of a confining electrostatic theory. The
probability of dipole creation is found from a canonical ensemble spanned by
foldings of the vortex tubes, with temperature parameter estimated from the
typical energy variation taking place in the reconnection process. Vortex line
reshuffling by viscous diffusion is described in terms of directional
transitions of the dipoles. The model is used to fit with reasonable accuracy
experimental data established long ago on the symmetric collision of vortex
rings. We also study along similar lines the asymmetric case, related to the
reconnection of non-parallel vortex tubes.Comment: 8 pages, 3 postscript figure
Comparative efficacy of two Ivermectin Pour-on anthelmintics in beef steers in a commercial feedyard
Generic products generally have a cost advantage for beef producers over brand-name products. Recently, many beef producers have debated whether to utilize generic anthelmintics in cow/calf herds and feeder cattle. If generics are to be justified, the products must be proven to have efficacy similar to the brand-name product. Previous studies have indicated that generic macrocyclic lactones are less effective in controlling gastrointestinal parasites of cattle than the original brand-name products. The objective of this study was to compare the efficacy of Vetrimec (Norbrook Laboratories Limited, Newry, Co. Down, Northern Ireland) pour-on and Ivomec (Merial Animal Health, Duluth, GA) pour-on by utilizing the fecal egg reduction test in newly arrived feedlot steers
VLA imaging of 12CO J = 1-0 and free-free emission in lensed submillimetre galaxies
We present a study using the Karl G. Jansky Very Large Array (VLA) of 12CO J = 1-0 emission in three strongly lensed submillimetre-selected galaxies (SMM J16359, SMM J14009 and SMM J02399) at z = 2.5-2.9. These galaxies span LIR = 1011-1013 L⊙, offering an opportunity to compare the interstellar medium of luminous infrared galaxies and ultraluminous infrared galaxies at high redshift. We estimate molecular gas masses in the range of 2-40 × 109 M⊙ using a method that assumes canonical underlying brightness temperature (Tb) ratios for star-forming and non-star-forming gas phases and a maximal star formation efficiency. A more simplistic method - using XCO = 0.8 and the measured Tb ratios - yields gas masses twice as high. In SMM J14009 we find L CO 3-2'/L CO 1-0'=0.95±0.12, indicative of warm, star-forming gas, possibly influenced by the central active galactic nucleus (AGN). We set a gas mass limit of 3σ < 6 × 108 M⊙ for the Lyman break galaxy, A2218 #384, located in the same field as SMM J16359 at z = 2.515. Finally, we use the rest-frame ˜115 GHz free-free flux densities for SMM J14009 and SMM J02399 - measurements tied directly to the photoionization rate of massive stars, and made possible by VLA's bandwidth - to estimate star formation rates (SFRs) of 400-600 M⊙ yr-1 and to estimate the fraction of LIR due to AGN
Serum- and bone-mineral status of ostriches with tibiotarsal rotation
Tibiotarsal rotation in ostrich chicks is a serious problem that accounts for considerable financial loss to ostrich farmers. Serum- and bone-mineral analyses of 20 ostrich chicks with tibiotarsal rotation were compared with serum- and bone-mineral analyses of eight normal ostrich chicks of comparable age, sex and body mass, and raised under identical conditions. The serum-zinc values were significantly higher and the bone-calcium and phosphorus values significantly lower in the affected group than in the group of normal ostrich chicks. The results indicated poor mineralization of bone with subsequent reactive osteoid formation.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
On generation-integrated energy storage
Generation-integrated energy storage (GIES) systems store energy at some point along the transformation between the primary energy form and electricity. Instances exist already in natural hydro power, biomass generation, wave power, and concentrated solar power. GIES systems have been proposed for wind, nuclear power and they arise naturally in photocatalysis systems that are in development. GIES systems can compare very favourably in both performance and total cost against equivalent non-integrated systems comprising both generation and storage. Despite this, they have not hitherto been recognised as a discrete class of systems. Consequently policy decisions affecting development or demonstration projects and policy approaches concerning low-carbon generation are not fully informed. This paper highlights that policy structures exist militating against the development and introduction of GIES systems-probably to the detriment of overall system good
Sperm-storage tubules in the vagina of the ostrich (Struthio camelus)
Sperm-storage tubules have been described in a number of species of birds. The presence of these
tubules in the Rhea has been mentioned, but no description of these structures in ratites is available.
The purpose of this study was to determine the presence and morphology of sperm-storage tubules in
the vagina of the ostrich. The study was performed with the use of conventional light- and electron-microscopic
techniques. Sperm-storage tubules were located in a 200-mm-wide band of the vagina adjacent
to the utero-vaginal junction. The tubules were mostly branched and slightly coiled and lined by
columnar epithelial cells. The cells contained a basal nucleus and displayed extensive apical junctional
complexes. TEM revealed sperm in all the tubules examined.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Relative stereociliary motion in a hair bundle opposes amplification at distortion frequencies
Direct gating of mechanoelectrical-transduction channels by mechanical force
is a basic feature of hair cells that assures fast transduction and underpins
the mechanical amplification of acoustic inputs. But the associated
nonlinearity - the gating compliance - inevitably distorts signals. Because
reducing distortion would make the ear a better detector, we sought mechanisms
with that effect. Mimicking in vivo stimulation, we used stiff probes to
displace individual hair bundles at physiological amplitudes and measured the
coherence and phase of the relative stereociliary motions with a dual-beam
differential interferometer. Although stereocilia moved coherently and in phase
at the stimulus frequencies, large phase lags at the frequencies of the
internally generated distortion products indicated dissipative relative
motions. Tip links engaged these relative modes and decreased the coherence in
both stimulated and free hair bundles. These results show that a hair bundle
breaks into a highly dissipative serial arrangement of stereocilia at
distortion frequencies, precluding their amplification.Comment: 33 pages in total, including the main article with one table and
three figures, as well as the supplemental information that itself contains
two figure
The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources
The production and analysis of distributed sources of 24Na and 222Rn in the
Sudbury Neutrino Observatory (SNO) are described. These unique sources provided
accurate calibrations of the response to neutrons, produced through
photodisintegration of the deuterons in the heavy water target, and to low
energy betas and gammas. The application of these sources in determining the
neutron detection efficiency and response of the 3He proportional counter
array, and the characteristics of background Cherenkov light from trace amounts
of natural radioactivity is described.Comment: 24 pages, 13 figure
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