486 research outputs found
Interannual variability of Alexandrium fundyense abundance and shellfish toxicity in the Gulf of Maine
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 52 (2005): 2843-2855, doi:10.1016/j.dsr2.2005.06.020.Six years of oceanographic surveys of Alexandrium fundyense concentrations in the Gulf of Maine are combined with shellfish toxicity records from coastal monitoring stations to assess covariations of these quantities on seasonal to interannual time scales. Annual mean gulf-wide cell abundance varies by less than one order of magnitude during the time interval examined (1993-2002). Fluctuations in gulf-wide annual mean cell abundance and shellfish toxicity are not related in a consistent manner. This suggests that interannual variations in toxicity may be regulated by transport and delivery of offshore cell populations, rather than the absolute abundance of the source populations themselves.We gratefully acknowledge the support of the US ECOHAB Program, sponsored by NOAA, NSF, EPA, NASA, and ONR
Non-invasive determination of port wine stain anatomy and physiology for optimal laser treatment strategies
Non-invasive determination of port wine stain anatomy and physiology for optimal laser treatment strategies
Nuclear effects in at small in deep inelastic scattering on Li and He
We suggest to use polarized nuclear targets of Li and He to study
nuclear effects in the spin dependent structure functions .
These effects are expected to be enhanced by a factor of two as compared to the
unpolarized targets.
We predict a significant dependence at of due to nuclear shadowing and nuclear
enhancement. The effect of nuclear shadowing at is of an
order of 16% for and 10% for
. By imposing the requirement that
the Bjorken sum rule is satisfied we model the effect of enhancement.
We find the effect of enhancement at to be of an
order of for and
for , if enhancement
occupies the region (). We predict
a 2% effect in the difference of the scattering cross sections of deep
inelastic scattering of an unpolarized projectile off Li with =3/2
and =1/2. We also show explicitly that the many-nucleon description of
deep inelastic scattering off Li becomes invalid in the enhancement region
.Comment: 29 pages, 5 figures, RevTe
Search for the Proton Decay Mode proton to neutrino K+ in Soudan 2
We have searched for the proton decay mode proton to neutrino K+ using the
one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained
from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for
occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0.
We found one candidate event consistent with background, yielding a limit,
tau/B > 4.3 10^{31} years at 90% CL with no background subtraction.Comment: 13 pages, Latex, 3 tables and 3 figures, Accepted by Physics Letters
Superdeformed rotational bands in the Mercury region; A Cranked Skyrme-Hartree-Fock-Bogoliubov study
A study of rotational properties of the ground superdeformed bands in \Hg{0},
\Hg{2}, \Hg{4}, and \Pb{4} is presented. We use the cranked
Hartree-Fock-Bogoliubov method with the {\skm} parametrization of the Skyrme
force in the particle-hole channel and a seniority interaction in the pairing
channel. An approximate particle number projection is performed by means of the
Lipkin-Nogami prescription. We analyze the proton and neutron quasiparticle
routhians in connection with the present information on about thirty presently
observed superdeformed bands in nuclei close neighbours of \Hg{2}.Comment: 26 LaTeX pages, 14 uuencoded postscript figures included, Preprint
IPN-TH 93-6
Magnetic Reconnection in Extreme Astrophysical Environments
Magnetic reconnection is a basic plasma process of dramatic rearrangement of
magnetic topology, often leading to a violent release of magnetic energy. It is
important in magnetic fusion and in space and solar physics --- areas that have
so far provided the context for most of reconnection research. Importantly,
these environments consist just of electrons and ions and the dissipated energy
always stays with the plasma. In contrast, in this paper I introduce a new
direction of research, motivated by several important problems in high-energy
astrophysics --- reconnection in high energy density (HED) radiative plasmas,
where radiation pressure and radiative cooling become dominant factors in the
pressure and energy balance. I identify the key processes distinguishing HED
reconnection: special-relativistic effects; radiative effects (radiative
cooling, radiation pressure, and Compton resistivity); and, at the most extreme
end, QED effects, including pair creation. I then discuss the main
astrophysical applications --- situations with magnetar-strength fields
(exceeding the quantum critical field of about 4 x 10^13 G): giant SGR flares
and magnetically-powered central engines and jets of GRBs. Here, magnetic
energy density is so high that its dissipation heats the plasma to MeV
temperatures. Electron-positron pairs are then copiously produced, making the
reconnection layer highly collisional and dressing it in a thick pair coat that
traps radiation. The pressure is dominated by radiation and pairs. Yet,
radiation diffusion across the layer may be faster than the global Alfv\'en
transit time; then, radiative cooling governs the thermodynamics and
reconnection becomes a radiative transfer problem, greatly affected by the
ultra-strong magnetic field. This overall picture is very different from our
traditional picture of reconnection and thus represents a new frontier in
reconnection research.Comment: Accepted to Space Science Reviews (special issue on magnetic
reconnection). Article is based on an invited review talk at the
Yosemite-2010 Workshop on Magnetic Reconnection (Yosemite NP, CA, USA;
February 8-12, 2010). 30 pages, no figure
Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj
Nuclear shadowing is observed in the per-nucleon cross-sections of positive
muons on carbon, calcium and lead as compared to deuterium. The data were taken
by Fermilab experiment E665 using inelastically scattered muons of mean
incident momentum 470 GeV/c. Cross-section ratios are presented in the
kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are
consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj
decreases, the size of the shadowing effect, as well as its A dependence, are
found to approach the corresponding measurements in photoproduction.Comment: 22 pages, incl. 6 figures, to be published in Z. Phys.
Narrative inquiry into (re)imagining alternative schools: a case study of Kevin Gonzales.
Although there are many alternative schools that strive for the successful education for their students, negative images of alternative schools persist. While some alternative schools are viewed as âidealistic havens,â many are viewed as âdumping grounds,â or âjuvenile detention centers.â Employing narrative inquiry, this article interrogates how a student, Kevin Gonzales, experiences his alternative education and raises questions about the role of alternative schools. Kevin Gonzalesâs story is presented in a literary form of biographical journal to provide a âmetaphoric loftâ that helps us imagine other students like Kevin. This, in turn, provokes us to examine our current educational practice, and to (re)imagine ways in which alternative education can provide the best possible educational experiences for disenfranchised students who are increasingly underserved by the public education system
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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