167,484 research outputs found
Reply to "Unrealistic nonphysiological amounts of reagents and a disregard for published literature"
Peer reviewedPublisher PD
Results of FM-TV threshold reduction investigation for the ATS F trust experiment
An investigation of threshold effects in FM TV was initiated to determine if any simple, low cost techniques were available which can reduce the subjective video threshold, applicable to low cost community TV reception via satellite. Two methods of eliminating these effects were examined: the use of standard video pre-emphasis, and the use of an additional circuit to blank the picture tube during the retrace period
Indometh acin-antihistamine combination for gastric ulceration control
An anti-inflammatory and analgesic composition containing indomethacin and an H2 histamine receptor antagonist in an amount sufficient to reduce gastric distress caused by the indomethacin was developed. Usable antagonists are metiamide and cimetidine
Polarimetric variations of binary stars. II. Numerical simulations for circular and eccentric binaries in Mie scattering envelopes
We present numerical simulations of the periodic polarimetric variations
produced by a binary star placed at the center of an empty spherical cavity
inside a circumbinary ellipsoidal and optically thin envelope made of dust
grains. Mie single-scattering is considered along with pre- and post-scattering
extinction factors which produce a time-varying optical depth and affect the
morphology of the periodic variations. We are interested in the effects that
various parameters will have on the average polarization, the amplitude of the
polarimetric variations, and the morphology of the variability. We show that
the absolute amplitudes of the variations are smaller for Mie scattering than
for Thomson scattering. Among the four grain types that we have studied, the
highest polarizations are produced by grains with sizes in the range 0.1-0.2
micron. In general, the variations are seen twice per orbit. In some cases,
because spherical dust grains have an asymmetric scattering function, the
polarimetric curves produced also show variations seen once per orbit.
Circumstellar disks produce polarimetric variations of greater amplitude than
circumbinary envelopes.
Another goal of these simulations is to see if the 1978 BME (Brown, McLean, &
Emslie, ApJ, 68, 415) formalism, which uses a Fourier analysis of the
polarimetric variations to find the orbital inclination for Thomson-scattering
envelopes, can still be used for Mie scattering. We find that this is the case,
if the amplitude of the variations is sufficient and the true inclinations is
i_true > 45 deg. For eccentric orbits, the first-order coefficients of the
Fourier fit, instead of second-order ones, can be used to find almost all
inclinations.Comment: 23 pages, 5 figures, to be published in Astronomical Journa
Indomethacin-antihistamine combination for gastric ulceration control
An anti-inflammatory and analgesic composition containing indomethacin and an H sub 1 or an H sub 2 histamine receptor antagonist in an amount sufficient to reduce gastric distress caused by the indomethacin is described. Usable antagonists include pyrilamine, promethazine, metiamide and cimetidine
The Effects of Surface Disturbances on the Leaching of Heavy Metals
The harmful effects of heavy metal contamination of
surface waters impacted by gold mining activity are well
documented. An examination was conducted on the effects of
surface disturbances in Wade Creek on the concentrations
of heavy metals in solution, and whether Thiobacillus
ferrooxidans, a bacteria found in heavy metal contaminated
drainages from placer mines, is found in the drainage.
Thiobacillus ferrooxidans was not detected in this
particular setting. The effects of mining activity and relandscaping
of stockpiled tailings showed in a short
distance, a net increase of dissolved arsenic, copper,
zinc, and iron. However, the long distance impact of
dissolved metals was minimal. Generally, it seems that the
dampening of the total suspended solids had a direct
effect on the removal of metals dissolved in solution.The research on which the report is based was financed in part by the
United States Department of the Interior, Geological Survey, through
grant number 14-08-0001-61313 to the Water Research Center
The local extragalactic velocity field, the local mean mass density, and biased galaxy formation
The biased galaxy formation picture accounts for the low apparent mass density derived from clustering dynamics by the assumption that the mass per galaxy is unusually low in the regions of high density where clustering has been studied. It would follow that the mass per galaxy is unusually high where the mass density is low, and, by continuity, that the mass per galaxy is close to the global mean in regions where the ambient mass density, p_t, is close to the global mean, P_b. That is, we would expect that the best chance for an unbiased estimate of the mean mass per galaxy, and hence of P_b, would be from the dynamics of regions with p_t ≈ P_b. The local density at redshifts 200 ≾ cz ≾ 400 km s^(-l) must be close to P_b because, as Sandage has emphasized, the local Hubble flow is so little perturbed. In this paper we derive a relationship between the local mass density and the perturbation of the local Hubble flow. The local mass density is estimated by the method used in the Virgocentric flow. We use the infrared Tully-Fisher distances of Aaronson et al. to find limits on the gravitational perturbation to the local Hubble flow, and we use bright galaxy counts, N, to estimate the local galaxy concentration. The statistics on the latter are weak because N is small. We can conclude, however, that
if mass were proportional to N, with no fluctuations, and the local mass per galaxy were a fair sample, then
the density parameter (Ω = P_b/Einstein-de Sitter density) would be Ω ≈ 0.1, consistent with the other dynamical
estimates and inconsistent with the above naive interpretation of biasing
Inside the brain of an elite athlete: The neural processes that support high achievement in sports
Events like the World Championships in athletics and the Olympic Games raise the public profile of competitive sports. They may also leave us wondering what sets the competitors in these events apart from those of us who simply watch. Here we attempt to link neural and cognitive processes that have been found to be important for elite performance with computational and physiological theories inspired by much simpler laboratory tasks. In this way we hope to inspire neuroscientists to consider how their basic research might help to explain sporting skill at the highest levels of performance
- …