Note and Comment

The Rule of Certainty in Damages and the Value of a Chance; Is a Bank Check an Assignment Pro Tanto of the Fund on Deposit?; The Finger-Print Case; Right of Husband to Recover Alimony Independent of an Action for Divorce

Kinetic Enhancement of Raman Backscatter, and Electron Acoustic Thomson Scatter

1-D Eulerian Vlasov-Maxwell simulations are presented which show kinetic enhancement of stimulated Raman backscatter (SRBS) due to electron trapping in regimes of heavy linear Landau damping. The conventional Raman Langmuir wave is transformed into a set of beam acoustic modes [L. Yin et al., Phys. Rev. E 73, 025401 (2006)]. For the first time, a low phase velocity electron acoustic wave (EAW) is seen developing from the self-consistent Raman physics. Backscatter of the pump laser off the EAW fluctuations is reported and referred to as electron acoustic Thomson scatter. This light is similar in wavelength to, although much lower in amplitude than, the reflected light between the pump and SRBS wavelengths observed in single hot spot experiments, and previously interpreted as stimulated electron acoustic scatter [D. S. Montgomery et al., Phys. Rev. Lett. 87, 155001 (2001)]. The EAW is strongest well below the phase-matched frequency for electron acoustic scatter, and therefore the EAW is not produced by it. The beating of different beam acoustic modes is proposed as the EAW excitation mechanism, and is called beam acoustic decay. Supporting evidence for this process, including bispectral analysis, is presented. The linear electrostatic modes, found by projecting the numerical distribution function onto a Gauss-Hermite basis, include beam acoustic modes (some of which are unstable even without parametric coupling to light waves) and a strongly-damped EAW similar to the observed one. This linear EAW results from non-Maxwellian features in the electron distribution, rather than nonlinearity due to electron trapping.Comment: 15 pages, 16 figures, accepted in Physics of Plasmas (2006

Threshold for Electron Trapping Nonlinearity in Langmuir Waves

We assess when electron trapping nonlinearity is expected to be important in Langmuir waves. The basic criterion is that the inverse of the detrapping rate nu_d of electrons in the trapping region of velocity space must exceed the bounce period of deeply-trapped electrons, tau_B = (n_e/delta n)^{1/2} 2pi/omega_pe. A unitless figure of merit, the "bounce number" N_B = 1/(nu_d tau_B), encapsulates this condition and defines a trapping threshold amplitude for which N_B=1. The detrapping rate is found for convective loss (transverse and longitudinal) out of a spatially finite Langmuir wave. Simulations of driven waves with a finite transverse profile, using the 2D-2V Vlasov code Loki, show trapping nonlinearity increases continuously with N_B for transverse loss, and is significant for N_B ~ 1. The detrapping rate due to Coulomb collisions (both electron-electron and electron-ion) is also found, with pitch-angle scattering and parallel drag and diffusion treated in a unified manner. A simple way to combine convective and collisional detrapping is given. Application to underdense plasma conditions in inertial confinement fusion targets is presented. The results show that convective transverse loss is usually the most potent detrapping process in a single f/8 laser speckle. For typical plasma and laser conditions on the inner laser cones of the National Ignition Facility, local reflectivities ~3% are estimated to produce significant trapping effects.Comment: 16 pages, 15 figures, accepted for publication in Phys. Plasma

Methylation status of oestrogen receptor-α gene promoter sequences in human ovarian epithelial cell lines

We have determined the methylation status of the CpG island of the oestrogen receptor α gene in seven human ovarian cell lines. Cell lines expressing oestrogen receptor α showed no evidence of hypermethylation. In three of four cell lines that produced no detectable oestrogen receptor α protein, hypermethylation was observed at the NotI site of the CpG island. These results indicate that aberrant hypermethylation may be responsible for a significant proportion of epithelial ovarian tumours in which oestrogen receptor α expression is lost

Which Software Faults Are Tests Not Detecting?

Context: Software testing plays an important role in assuring the reliability of systems. Assessing the efficacy of testing remains challenging with few established test effectiveness metrics. Those metrics that have been used (e.g. coverage and mutation analysis) have been criticised for insufficiently differentiating between the faults detected by tests. Objective: We investigate how effective tests are at detecting different types of faults and whether some types of fault evade tests more than others. Our aim is to suggest to developers specific ways in which their tests need to be improved to increase fault detection. Method: We investigate seven fault types and analyse how often each goes undetected in 10 open source systems. We statistically look for any relationship between the test set and faults. Results: Our results suggest that the fault detection rates of unit tests are relatively low, typically finding only about a half of all faults. In addition, conditional boundary and method call removals are less well detected by tests than other fault types. Conclusions: We conclude that the testing of these open source systems needs to be improved across the board. In addition, despite boundary cases being long known to attract faults, tests covering boundaries need particular improvement. Overall, we recommend that developers do not rely only on code coverage and mutation score to measure the effectiveness of their tests

Loved Ones Near and Far: Feinberg's Personal Significance Theory

This paper examines Todd Feinberg's theory of the misidentification syndromes

FISH in analysis of gamma ray-induced micronuclei formation in barley

A micronucleus test in combination with fluorescent in situ hybridization (FISH) using telomere-, centromere-specific probes and 5S and 25S rDNA was used for a detailed analysis of the effects of gamma ray irradiation on the root tip meristem cells of barley, Hordeum vulgare (2n = 14). FISH with four DNA probes was used to examine the involvement of specific chromosomes or chromosome fragments in gamma ray-induced micronuclei formation and then to explain their origin. Additionally, a comparison of the possible origin of the micronuclei induced by physical and chemical treatment: maleic hydrazide (MH) and N-nitroso-N-methylurea (MNU) was done. The micronuclei induced by gamma ray could originate from acentric fragments after chromosome breakage or from whole lagging chromosomes as a result of a dysfunction of the mitotic apparatus. No micronuclei containing only centromeric signals were found. An application of rDNA as probes allowed it to be stated that 5S rDNA–bearing chromosomes are involved in micronuclei formation more often than NOR chromosomes. This work allowed the origin of physically- and chemically-induced micronuclei in barley cells to be compared: the origin of micronuclei was most often from terminal fragments. FISH confirmed its usefulness in the characterization of micronuclei content, as well as in understanding and comparing the mechanisms of the actions of mutagens applied in plant genotoxicity

Forward Neutral Pion Transverse Single Spin Asymmetries in p+p Collisions at \sqrt{s}=200 GeV

We report precision measurements of the Feynman-x dependence, and first measurements of the transverse momentum dependence, of transverse single spin asymmetries for the production of \pi^0 mesons from polarized proton collisions at \sqrt{s}=200 GeV. The x_F dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p_T dependence at fixed x_F are not consistent with pQCD-based calculations.Comment: 6 pages, 4 figure