8,778 research outputs found
Microsatellite loci among Alaskan rabies hosts: Arctic and red fox
Little is known about the population dynamics between Arctic and red foxes in Alaska and consequences for rabies ecology. Both species carry different variants of rabies and inhabit different environments. As the global warming trends progress, the Arctic and red fox will have increased habitat overlap due to northward range expansion of the red fox into the historic habitat of the Arctic fox.
Hypothesis: global warming trends will significantly influence the disease dynamics between red and Arctic foxes as well as their roles in disease dynamics in the far North. In order to better survey the movement of the variants of rabies among Arctic and red fox, microsatellites will be used to assess population structure of these host species
Research and Development for a Gadolinium Doped Water Cherenkov Detector
The proposed introduction of a soluble gadolinium (Gd) compound into water
Cherenkov detectors can result in a high efficiency for the detection of free
neutrons capturing on the Gd. The delayed 8 MeV gamma cascades produced by
these captures, in coincidence with a prompt positron signal, serve to uniquely
identify electron antineutrinos interacting via inverse beta decay. Such
coincidence detection can reduce backgrounds, allowing a large Gd-enhanced
water Cherenkov detector to make the first observation of supernova relic
neutrinos and high precision measurements of Japan's reactor antineutrino flux,
while still allowing for all current physics studies to be continued. Now, a
dedicated Gd test facility is operating in the Kamioka Mine. This new facility
houses everything needed to successfully operate a Gd doped water Cherenkov
detector. Successful running of this facility will demonstrate that adding Gd
salt to SK is both safe for the detector and is capable of delivering the
expected physics benefits.Comment: Proceedings from the Technology and Instrumentation for Particle
Physics 2011 (TIPP 2011) conferenc
Solar Neutrino Results from Super-Kamiokande
Super-Kamiokande-IV (SK-IV) data taking began in September of 2008, after
upgrading the electronics and data acquisition system. Due to these upgrades
and improvements to water system dynamics, calibration and analysis techniques,
a solar neutrino signal could be extracted at recoil electron kinetic energies
as low as 3.5 MeV. When the SK-IV data is combined with the previous three SK
phases, the SK extracted solar neutrino flux is found to be
[2.37\pm0.015\mbox{(stat.)}\pm0.04\mbox{(syst.)}]\times10^6/(cmsec).
The combination of the SK recoil electron energy spectra slightly favors
distortions due to a changing electron flavor content. Such distortions are
predicted when assuming standard solar neutrino oscillation solutions. An
extended maximum likelihood fit to the amplitude of the expected solar zenith
angle variation of the neutrino-electron elastic scattering rate results in a
day-night asymmetry of (stat.)(syst.)]. A solar
neutrino global oscillation analysis including all current solar neutrino data,
as well as KamLAND reactor antineutrino data, measures the solar mixing angle
as , the solar neutrino mass squared splitting
as eV and
System level comparison of FDMA vs. CDMA (under conference guideline constraint)
The margin that is required to mitigate the near-far problem in a Code Division Multiple Access (CDMA) mobile satellite system is determined by the radio-propagation model selected, the distribution of the users in clear and shadowed environments, and implementation techniques. The use of revenue potential as a means of evaluating the relative merits of CDMA and Frequency Division Multiple Access (FDMA) systems is a convenient way to rationalize the performance of systems using high-gain and low-gain antennas. The revenue potential of CDMA is much greater than the revenue potential for FDMA for a particular satellite design considered
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