10,766 research outputs found
Angular Distribution Of Decay Electrons From The 6P Resonance Excitations In Xenon
Angular distributions for the electrons produced by the decay of the 4d--\u3e6p excitations in xenon have been measured using an undulator radiation source. The resolution employed in the experiment has allowed us to derive separate beta values for features which had not been isolated previously, as well as to determine beta values for previously unreported lines. Comparison is made between existing experimental and theoretical results
Overcoming cognitive set bias requires more than seeing an alternative strategy
Determining when to switch from one strategy to another is at the heart of adaptive decision-making. Previous research shows that humans exhibit a ‘cognitive set’ bias, which occurs when a familiar strategy occludes—even much better—alternatives. Here we examined the mechanisms underlying cognitive set by investigating whether better solutions are visually overlooked, or fixated on but disregarded. We analyzed gaze data from 67 American undergraduates (91% female) while they completed the learned strategy-direct strategy (LS-DS) task, which measures their ability to switch from a learned strategy (LS) to a more efficient direct strategy (DS or shortcut). We found that, in the first trial block, participants fixated on the location of the shortcut more when it was available but most (89.6%) did not adopt it. Next, participants watched a video demonstrating either the DS (N = 34 Informed participants) or the familiar LS (N = 33 Controls). In post-video trials, Informed participants used the DS more than pre-video trials and compared to Controls. Notably, 29.4% of Informed participants continued to use the LS despite watching the DS video. We suggest that cognitive set in the LS-DS task does not stem from an inability to see the shortcut but rather a failure to try it
Anisotropy of the Cosmic Neutrino Background
The cosmic neutrino background (CNB) consists of low-energy relic neutrinos
which decoupled from the cosmological fluid at a redshift z ~ 10^{10}. Despite
being the second-most abundant particles in the universe, direct observation
remains a distant challenge. Based on the measured neutrino mass differences,
one species of neutrinos may still be relativistic with a thermal distribution
characterized by the temperature T ~ 1.9K. We show that the temperature
distribution on the sky is anisotropic, much like the photon background,
experiencing Sachs-Wolfe and integrated Sachs-Wolfe effects.Comment: 5 pages, 2 figures / updated references, discussion of earlier wor
Avoiding BBN Constraints on Mirror Models for Sterile Neutrinos
We point out that in models that explain the LSND result for neutrino
oscillation using the mirror neutrinos, the big bang nucleosynthesis constraint
can be avoided by using the late time phase transition that only helps to mix
the active and the sterile neutrinos. We discuss the astrophysical as well as
cosmological implications of this proposal.Comment: 5 pages, latex; more discussion added; results unchange
A fluorescent mutant of the phosphorus-solubilizing fungus Penicillium bilaiae to image rhizosphere growth
Non-Peer ReviewedNovozymes manufactures and markets a phosphate inoculant, JumpStart®, based on the
phosphorus-solubilizing fungus Penicillium bilaiae. We are developing a mutant of this fungus
that expresses the DsRed-Express fluorescent protein, which will be used as a research tool to
allow us to see where and how P. bilaiae interacts with plant roots
Large Extra Dimensions, Sterile neutrinos and Solar Neutrino Data
Solar, atmospheric and LSND neutrino oscillation results require a light
sterile neutrino, , which can exist in the bulk of extra dimensions.
Solar , confined to the brane, can oscillate in the vacuum to the zero
mode of and via successive MSW transitions to Kaluza-Klein states of
. This new way to fit solar data is provided by both low and
intermediate string scale models. From average rates seen in the three types of
solar experiments, the Super-Kamiokande spectrum is predicted with 73%
probability, but dips characteristic of the 0.06 mm extra dimension should be
seen in the SNO spectrum.Comment: 4 pages, 2 figure
Some model experiments on continental shelf waves
This paper describes some model experiments that verify the theoretical form of continental shelf waves. Both the dispersion relationship and the positions of the orbital gyres are confirmed. The existence of a maximum frequency for each mode, with a corresponding zero group velocity, may be of significance for field observations
Large Angular Scale CMB Anisotropy Induced by Cosmic Strings
We simulate the anisotropy in the cosmic microwave background (CMB) induced
by cosmic strings. By numerically evolving a network of cosmic strings we
generate full-sky CMB temperature anisotropy maps. Based on maps, we
compute the anisotropy power spectrum for multipole moments . By
comparing with the observed temperature anisotropy, we set the normalization
for the cosmic string mass-per-unit-length , obtaining , which is consistent with all other
observational constraints on cosmic strings. We demonstrate that the anisotropy
pattern is consistent with a Gaussian random field on large angular scales.Comment: 4 pages, RevTeX, two postscript files, also available at
http://www.damtp.cam.ac.uk/user/defects/ to appear in Physical Review
Letters, 23 September 199
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