11,499 research outputs found
The generation of oxygen radicals during host plant responses to infection
Recent evidence points to significant oxygen radical production by some plant tissues in response to pathogenic challenge. These findings have proved quite controversial, in part because of an inadequate appreciation of the behaviour of oxygen radicals in biological systems. This review critically discusses the evidence to date and outlines several potential roles for oxygen species in host-pathogen interactions. The production of oxygen radicals during plant defence responses is compared to the respiratory burst of mammalian phagocytic cells
Relative annoyance and loudness judgements of various simulated sonic boom waveforms
Effects of various simulated sonic boom waveforms on human subjective respons
The APM Galaxy Survey III: An Analysis of Systematic Errors in the Angular Correlation Function and Cosmological Implications
We present measurements of the angular two-point galaxy correlation function,
, from the APM Galaxy Survey. The performance of various estimators
of is assessed using simulated galaxy catalogues and analytic arguments.
Several error analyses show that residual plate-to-plate errors do not bias our
estimates of by more than . Direct comparison between our
photometry and external CCD photometry of over 13,000 galaxies from the Las
Campanas Deep Redshift Survey shows that the rms error in the APM plate zero
points lies in the range 0.04-0.05 magnitudes, in agreement with our previous
estimates. We estimate the effects on of atmospheric extinction and
obscuration by dust in our Galaxy and conclude that these are negligible. We
use our best estimates of the systematic errors in the survey to calculate
corrected estimates of . Deep redshift surveys are used to determine the
selection function of the APM Galaxy Survey, and this is applied in Limber's
equation to compute how scales as a function of limiting magnitude. Our
estimates of are in excellent agreement with the scaling relation,
providing further evidence that systematic errors in the APM survey are small.
We explicitly remove large-scale structure by applying filters to the APM
galaxy maps and conclude that there is still strong evidence for more
clustering at large scales than predicted by the standard scale-invariant cold
dark matter (CDM) model. We compare the APM and the three dimensional power
spectrum derived by inverting , with the predictions of scale-invariant CDM
models. We show that the observations require in the range
0.2-0.3 and are incompatible with the value of the standard CDM
model.Comment: 102 pages, plain TeX plus 41 postscript figures. Submitted to MNRA
OBSERVATIONS OF PROPERTIES OF SINTERED WROUGHT TUNGSTEN SHEET AT VERY HIGH TEMPERATURES
Examination of mechanical properties of tungsten sheet at very high temperature
One-pot multi-reaction processes: synthesis of natural products and drug-like scaffolds
One-pot multi-reaction processes involving Overman rearrangements, metathesis cyclizations, and Diels–Alder reactions have been developed for the rapid and efficient synthesis of amino-substituted carbocyclic and heterocyclic compounds. This account describes the development and optimization of these processes, as well as their applications in the synthesis of natural products and drug-like scaffolds
Test for a large amount of entanglement, using few measurements
Bell-inequality violations establish that two systems share some quantum
entanglement. We give a simple test to certify that two systems share an
asymptotically large amount of entanglement, n EPR states. The test is
efficient: unlike earlier tests that play many games, in sequence or in
parallel, our test requires only one or two CHSH games. One system is directed
to play a CHSH game on a random specified qubit i, and the other is told to
play games on qubits {i,j}, without knowing which index is i.
The test is robust: a success probability within delta of optimal guarantees
distance O(n^{5/2} sqrt{delta}) from n EPR states. However, the test does not
tolerate constant delta; it breaks down for delta = Omega~(1/sqrt{n}). We give
an adversarial strategy that succeeds within delta of the optimum probability
using only O~(delta^{-2}) EPR states.Comment: 17 pages, 2 figures. Journal versio
Design of strapdown gyroscopes for a dynamic environment Semiannual report, 1 Dec. 1968 - 31 May 1969
Strapdown gyros which employ time modulation torquing techniqu
Bostonia. Volume 2
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
Generalized Thermalization in an Integrable Lattice System
After a quench, observables in an integrable system may not relax to the
standard thermal values, but can relax to the ones predicted by the generalized
Gibbs ensemble (GGE) [M. Rigol et al., Phys. Rev. Lett. 98, 050405 (2007)]. The
GGE has been shown to accurately describe observables in various
one-dimensional integrable systems, but the origin of its success is not fully
understood. Here we introduce a microcanonical version of the GGE and provide a
justification of the GGE based on a generalized interpretation of the
eigenstate thermalization hypothesis, which was previously introduced to
explain thermalization of nonintegrable systems. We study relaxation after a
quench of one-dimensional hard-core bosons in an optical lattice. Exact
numerical calculations for up to 10 particles on 50 lattice sites (~10^10
eigenstates) validate our approach.Comment: 8 pages, 9 figures, as publishe
Genomic regions associated with common root rot resistance in the barley variety Delta
Common root rot (CRR) caused by Bipolaris sorokiniana is a serious disease constraint in the dry temperate cereal growing regions of the world. Currently little is known about the genetic control of resistance to CRR in cereals. In this study based on a Delta/Lindwall barley population we have undertaken a bulked segregant analysis (BSA) and whole genome mapping approach utilising Diversity Arrays Technology (DArT) to identified quantitative trait loci (QTL) associated with CRR expression. One QTL each was identified on chromosomes 4HL and 5HL explaining 12 and 11% of the phenotypic variance, respectively
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