6,135 research outputs found
Comparison of thread-cutting behaviour in three specialist predatory mites to cope with complex webs of Tetranychus spider mites
Anti-predator defenses provided by complex webs of Tetranychus mites can severely impede the performance of generalist predatory mites, whereas this may not be true for specialist predatory mites. Although some specialist predatory mites have developed morphological protection to reduce the adverse effects of complex webs, little is known about their behavioral abilities to cope with the webs. In this study, we compared thread-cutting behavior of three specialist predatory mites, Phytoseiulus persimilis, Neoseiulus womersleyi and N. californicus, exhibited inside the complex web of T. urticae. No major difference was observed among them in the basic pattern of this behavior, using chelicerae and palps, and in the number of silken threads severed while moving inside the web. These results and observations suggest that each predator species cut many sticky silken threads to move inside the complex web without suffering from serious obstructio
Computationally efficient algorithms for the two-dimensional Kolmogorov-Smirnov test
Goodness-of-fit statistics measure the compatibility of random samples against some theoretical or reference probability distribution function. The classical one-dimensional Kolmogorov-Smirnov test is a non-parametric statistic for comparing two empirical distributions which defines the largest absolute difference between the two cumulative distribution functions as a measure of disagreement. Adapting this test to more than one dimension is a challenge because there are 2^d-1 independent ways of ordering a cumulative distribution function in d dimensions. We discuss Peacock's version of the Kolmogorov-Smirnov test for two-dimensional data sets which computes the differences between cumulative distribution functions in 4n^2 quadrants. We also examine Fasano and Franceschini's variation of Peacock's test, Cooke's algorithm for Peacock's test, and ROOT's version of the two-dimensional Kolmogorov-Smirnov test. We establish a lower-bound limit on the work for computing Peacock's test of
Omega(n^2.lg(n)), introducing optimal algorithms for both this and Fasano and Franceschini's test, and show that Cooke's algorithm is not a faithful implementation of Peacock's test. We also discuss and evaluate parallel algorithms for Peacock's test
Statistical description of turbulent transport for flux driven toroidal plasmas
A novel methodology to analyze non-Gaussian probability distribution
functions (PDFs) of intermittent turbulent transport in global full-f
gyrokinetic simulations is presented. In this work, the Auto-Regressive
Integrated Moving Average (ARIMA) model is applied to time series data of
intermittent turbulent heat transport to separate noise and oscillatory trends,
allowing for the extraction of non-Gaussian features of the PDFs. It was shown
that non-Gaussian tails of the PDFs from first principles based gyrokinetic
simulations agree with an analytical estimation based on a two fluid model.Comment: arXiv admin note: text overlap with arXiv:1008.321
In--Flight () Reactions for the Formation of Kaonic Atoms and Kaonic Nuclei in Green function method
We study theoretically the kaonic atom and kaonic nucleus formations in the
in--flight () reactions using the Green function method, which is suited
to evaluate formation rates both of stable and unstable bound systems. We
consider C and O as the targets and calculate the spectra of the
() reactions. We conclude that a no peak structure due to kaonic nucleus
formation is expected in the reaction spectra calculated with the chiral
unitary kaon--nucleus optical potential. In the spectra with the
phenomenological deep kaon--nucleus potential, we may have possibilities to
observe some structures due to kaonic nucleus states. For all cases, we have
peaks due to the kaonic atom formations in the reaction spectra.Comment: 10 pages, 9 figures, newly calculated results added, revisions and
updated references, to appear in Physical Review
Electrodynamic trapping of spinless neutral atoms with an atom chip
Three dimensional electrodynamic trapping of neutral atoms has been
demonstrated. By applying time-varying inhomogeneous electric fields with
micron-sized electrodes, nearly strontium atoms in the state
have been trapped with a lifetime of 80 ms. In order to design the electrodes,
we numerically analyzed the electric field and simulated atomic trajectories in
the trap, which showed reasonable agreement with the experiment.Comment: 4pages, 4figures, to appear in Phys. Rev. Let
Spin observables in the reaction
The T matrix of the LambdaN-> NN reaction, which is a strangeness changing
weak process, is derived. The explicit formulas of the spin observables are
given for s-wave p-Lambda final states which kinematically corresponds to
inverse reaction of the weak nonmesonic decay of Lambda hypernuclei. One can
study interferences between amplitudes of parity- conserving and violating,
spin- singlet and triplet and isospin- singlet and triplet. Most of them are
not available in the study of the nonmesonic decay. They clarify structure of
the reaction and constrain strongly theoretical models for weak hyperon nucleon
interaction.Comment: 7pages,ReVTeX,no figure
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